diana t. vagelos vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america-- designing customized individuai and group ment products. that's why we're your retirement company. additional supportas been provided by: and by the corporation for public broadcasting, a by contributions to your pbs station from viewers like you. thank you. from the tisch wnet studios at lincoln center in new york, megan thompson. >> thompson: good evening and g us. you for join investigators in virginia beach are still searching for a motive for the mass murder of 12 people in a municipal office building on friday. at a news conference today police and city officials said government offrees there will in closed tomorrow. and they gave a detailed description of the 36-minutes from the time police were dispatched until the suspect was shot and captured. he later died at the hngpital. >> calll units. he's on the >> i can tell you that in the police world-- anything longer an 3-5 shots is a long battle. that's what was happening. i ca

diana t. vagelos vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg.orporate funding is provided by mutual of america--

vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america-- designing customized individual and group retirement products. that's why we're your retirement company. additional support has been provided by: and by the corporation for publicroadcasting, and by contributions to your pbs statio fthank you.s like you. from the tisch wnet ncudios at n center in new york, hari sreenivasan. >> sreenivasan: good evening and thanks for joining us. president trump began his day today disping a "new york times" report that details of friday's u.s.-mexico agreement were "already promised" in discussions between officials that took place months ago. the "times" reported unnamed officials from both countries said the mexican government hadlready pledged to send troops to its southern border in march. president ump tweeted that the report was "false" and "we have been trying to get se of these border actions for a long time..." but didn't get them," ...until our signed agreement with mexico." the president also tweeted this weekend that mexico has agreed to buy "large quantities of agricultural product" from u.s" farmers "mediately," although he did not say that was part of the new agreement. at a rally last night in tijuana, mexican president andres m supporters that prior to friday's agreement he was prepared to impose retaliatory tariffs on the u.s. >> ( translated ): we celebrate the important agreement of yesterday because it was a very difficult situation, very awkward doing the same and applying tariffs to some products of the united states. >> sreenivasan: foreign minister marcelebrard, who helped negotiate the agreement, told the crowd that mexico has" emerged with our dignity intact." hundreds of thousands of demonstrators marched in hong kong today to prott government-sponsored extradition legislation.l the proposed buld allow residents of hong kong to be extradited to mainland china to face criminal charges. opponents argue thatsthina's legal will not offer the same rights as those in semi- aunomous hong kong and tha the bill threatens hong kong's legal independence. the demonstrators marched for hours-- ending up afr dark outside governmentffices. police lined the area and reportedly used pepper spray on some protestors. hong kong's government issued a statement sunday night saying the bill would preventong kong from becoming a haven for fugitives and said the government wants to engage with protestors "through calm and rational discussion." the extradition bill is scheduled to be presented to hong kong's legislature on wednesday. shops were closed and streets were empty in sudan today. leaders of the protest movement against the ruling military-led government called for a general strike beginning today-- the first day of the work week there. in khartoum, people lined at up at the few open bakeries and at gas stations.ti the opposion movement is demanding civilian control of sudan's government. last week, security forces killed dozens of protestors who were holding a sit-in. venezuela reopened its border tewith colombia yesterday four months of blockades and closures of main crossing points. thousands crowded onto roads and bridges to cross into colombian towns where they could purchase food, medicine and goods not available in venezuela. g the venezuelernment of nicolas maduro closed the busy border crossings in february when opposition leader jn guaidÓ called for international humanitarian aid to be trucked in. the u.s. and dozens er countries are supporting guaidÓ and ntinue to call for madur to step down. for more on the situation in venzuela, john otis reports venezuela and colombia for n.p.r. and joi us now via skype from bogota colombia. i know you're working on a story now. e border crossing, we've seen or heard of hundreds if not thousands of peoplwanting to get across that border to just get basic goods. >> well, yes, it is quite significant news for desperate venezuelans, bouause when y have the border bridges blocked, they're actually blocked withpi sh containers, so people couldn't get across the bridge, but they could still get into colombia, and that wou have to use these clandestine food -- footpaths used by drug smugglers. there are rial gangs, and there are quite oftenhootouts, so it's dangerous. they would also have to cross the river that forms the boarder. i was up there recent limp they would wade across the river up to their chest in water. i met won woman bringinher son across the border across the river, and she was bringing himo the boarder to go to a daycare center on the colombian side. she had to cross the river once to drop her son off, then go back to the venezuelan side to work. she'd cross again in the afternoon to pick up her son and go home. that was four timrossing the river. you can see how tough it can get to get intoolombia with those borders officially closed. but now they're opening up again. >> sreenivasan: now, these are venezuelans that have opted to stay there. but there have been an otplow of venezuelans leaving the country over the past couple years. >> that's correct. the latest figures from the u.n. show that four million venezuelans have left the country. most of those just in the last y fors. the u.n. is calling it the biggest exodus in recent latin american history. these are venezuelans of all stripes from professnals to as station attendants to students looking fetter life, and they've actually become another major lifeline for vends lands who are back in venezuela becaople back in venezuela really depend on u.s. dollars coming back into the country to deal with hyperinflation and 2t high cost of living there. >> gen that situation, i know you had a chance to speak to ortinguaidoÓ on your rep ip, what does he think is possible? >> well, when i spoke to guaido, pposition forces he represents were involved in neg shitions in --otiations in norway with the government ou nicolaÁs . there wasn't much progress being made, and guaido sounded down and out on the whole process. neither side wants to back down. the opposition isaying nicolaÁs maduro must leave off, and maduro is saying, i'm notgoing anywhere. the military is still supporting maduro. r so it's l stalemate right now. guaidoÓ is callin more street protests. he keeps calling on maduro the leave office. he's trying to connce military leaders to turn against maduro, but even if they did, if there was some kind of a military coup in venezuela, there is no guarantee that would result in a democratic government. you might have a situation say as in egypt where the military takes over and maintainsro co >> sreenivasan: what happens in the interim? he has his supporters. it doesn't seem to be forcing change. it's been nths now. how long does he think he can continue? >> the maduro government doesn' seem particularly interested in arresting godid guÓ, because they could have if they wanted to already. and guaidoÓ has been barnstormig the country since january when he claimed that nicolaÁs maduro an an illegitimate president because of fraudlast year's presidential election. he's getting a lot of support a he goes around the country, a lot of people have been comingto ouee him. he does provide a kind of ray of ho for most venezuelans who don't like their current government and they want madtouo eave, but still he's not really showing the way out. he has not been able to -- he wasn't able tou getmanitarian aid in this country. he hasn't been able to turn the litary to turn against maduro. at this stalemate goes on, he's likely l theose some of that popular sport he enjoys. >> sreenivasan: john otis joining us from bogota, colombia. thank you so much. >> thank you. >> sreenivasan: pacific gas and electric shut off power to more than 20,000 residents in northern california today. the blackouts, the first of the 2019 fire season, are fire safety precautions during a hot, dry, and windyeekend. northwest of sacramento residents were ordered to evacuate yesterday afternoon as the fast-moving "sand fire" spread across nearly 2,000 acres. by sunday afternoon the sand fire was 0% strong winds that fueled the blaze were expected to die down. pg&e was found responsible for the "camp fire" in 2018 that killed 85 people and destroyed 19,000 homes, businesses, and other structures in the area around the norther ocalifornia toparadise. the utility filed for bankruptcy protection in january and is facing at least $30-billion in liability charges from two years of wildfire-caused damages. we'll have more on fire prevention techniques later in the program. reports of gunfire at washinon, d.c.'s annual pride parade late yesterday afternoon caused panic and sent severale people to thspital with minor injuries. people ran through the streets, knocked over barricades and hid in nearby buildings as word spread. a spokesman for the police department said no shots were fired, but that they did arrestp a man who was session of a gun. for more on california's wildfires and the controversial pohir blackout implemented t weekend visit pbs.org/newshour. 2018 was onef the worst wildfire seasons in u.s. history. tastrophic blazes like t camp fire in northern california destroyed entire cities and killed nearly 100 people. as this years' wildfire season ramps up, a new report from climate central shows how a key prevention strategy has not been used as widely as it could be in fire prone aas in the western u.s. i spoke yesterday via skype with crystal kolden. she's an associate professor of fire sciences at the university of idaho, and the author of a new paper in the journal "fire" on the use of prescribed fire or controlled burns across the u.s. crystal, just so everyone has kind of an understanding, what's a prescribed burn? how do we have a controlled burn? >> a prescribed buris one that is set intentionally by fire management, and it's very different from the wildfire, whicis unintentional. it's also very different from what some people see on the new during wildfires, which are the burnout operatis or back burns. those are set to try to stop a scfire. a prbed fire is done well ahead of time, trying to remove fuels from an area that cold burn to either prevent or minimize fir. >> sreenivasan: this is something that's been happening for hundreds of years? >> even lger than thatch indigenous people globally and particularly in rth america actually did a lot of prescribed burning, controlled burning lono europeans settled this country. so there's a long history of using fire intentionally in the landscapes and in parts of the u.s. we've been using it in a managev context for al decades. >> sreenivasan: part of your research, you have maps thatp show a big n how th prescribed burns are used in differntt parts of the cou. in the lower right southeast corner in the united states, they're being used a lot more than in the west, where we rely think of big fires being. >> that's true. the southeastern u.s. states have been using prescribed fire for over eight deades. and they really got going using it because they recognized that it was good for improving their timb production. it was good for industry. it was also really good for game habitat. prescribed fire was one of the way to improve the habitat. they have seen the bener ts of that oe decades since. so they use a lot of prescribed fire in the southeast, millions of acres every single year. in the wt we're not even close to that. >> sreenivasan: why is that? what's the west scared of? whis the policy different in the west than it is in the east? >> there's a lot of reasons. it's really hard to pinpoint one. in some places it has to do with the air quality concerns. people are not big fans of smoke, of course, and prescribed fire always produces smoke, although there's a fair amount of science that shows that smoke is much less dangerous than wildfire smoke and is much easier to control in terms of length of time that it's imcting people than wildfire smoke. there are other concerns just if termear of fires. there have been instances where prescribed fires have escaped control and become wildfires. and people in the west are not used to seeing a lot of fire on the landscape except forfi wis. it's really different in the southeast. people that have lived in theca southeast for s are sort of used to it. limated tory much acc seeing prescribed fire being used widely in their become yards andirhe communities. the outcome of that is that they sea lot less wild fire. >> sreenivasan: tell me about the correlation. if you have less fuel, i'm assuming you have less wildfires. so in the southeast, if you can see the correlation between a lot more prescribed burnsa lot less fuel, a lot less out-of-control wifires, is the inverse the case in the west? >> that's what we had 'sprophesized. eally hard to point to a single wildfire or a single prescribed fire and oh, that prescribed fire prevented the wildfire from spreading and becoming a disaster, vice versa, adf wile as bad as it was because there was no spriebed fire. it's really had to they ve that on an individual fire level. what we do with that is across the west and across the southeast and the rest of the country, where d have a lot of prescribed fire reducing fuel and notn evecessarily preventing fire, because fires are always going tot start, bu what's important to recognize is that prescribed fire really just reduces the fuel availkele to hat fire hotter, burn more out of conrtrol, andoduce the types of negative impacts that we don't want to see, thikengs ousing burning down or worst-case scenari fatalities. so prescribed fire really reduces the chances of a hetastrophe. >> is a kind of national conversation on the policy level about this? if something needs to change, what has to happen o create that change? >> there's a lot of things that have to change. fire agencies at the national level, also at the state and local levels, they all recogniz this. and where they are challenged is that they're stuck very much in a cycle of having to spend all of t bhedget on suppressing wide first in the wes yt. an know, the other challenge is that they really need a lot of support from the public. and that's a key cultural difference between the southeast and the west. tural's enormous cul support for prescribed fire in the southeast, and in the west there's not that support. we have prescribed fire councils all over the country, and there's just not as much involvement in those prescribed fire councils in th west by the general public. if the public wants to bepr supportive oscribed fire and having it reduce the risk of wildfire, that's one avenue that they can get involved in. they can help try and change some of those policies and to help try and improve the amount of prescribed fire on the landscape. >> sreenivasan: all right. crystal kolden joining us live .ia skype, thank you >> you're welcome. >> sreenivasan: 's a year of anniversaries for famed guitarist carlos santana, and the band that bears his name. later this summer he'll be celebrating 50 years since both the release of the group a first album their legendary performance at woodstock. m but this monks the 20th anniversary of his biggest hit record of all, and he's on the road with a brand-new album released just two days ago. newshour weekend's tom casciato recently sat down with carlos santana at the musician's home base in las vegas, and has our story. ♪ ♪ >> reporter: it wath20 years ago month that carlos santana released what would become one of the biggest hit albums in music history, the grammy-winning classic, "supernatural." this record was a worldwide phenomenon. >> so they tell me, it's like i'm right there with, we got right there with michael jackson "thriller" and the eagles "greatest hits." >> reporter: that's the top of the top in sales. >> that's good company to be with. >> reporter: "supernatural" was a superstar-filled affair. one song was written by and featured lauryn hill. ♪ yo watch the master plan the pastures span ♪ through the streets move the sheep ♪ flipped the beat like the shepherd ♪ >> reporter: dave matthews co-wrote and guested on anothere ♪ you are, that's where i want to be ♪ >> reporter: and, of course, the co-writer and singer of the smash hit "smooth" was rob t omas. ♪ or else forgeout it ♪ ♪o >> reportecelebrate the 20th anniversary of "supernatural," carlos santana company have embarked on what they're calling the "supernatural now" tour. ♪ ♪r but with o albums to his name, carlos santana has never rested on his laurels. and the new tour is accompanied by a new album. produced by the prolific rick rubin, it's called "africa speaks and carlos santana seessi his new muc as the logical extension of a rhythmic tradition he'sssong been obseed with. eell me about "africa speaks." >> we requested torick rubin. and i presented to him with the weconcept because he said,, what do you want to do?" you know just straight up. i says, "i want to play ythms that they don't play in coachella." rick rubin called me back says, "i'm in, i heard t songs," and we recorded, again, 49 songs in ten days. and these are just like or 14 songs from that batch. ♪ ♪ >> reporter: wow. that's a lot of work. m >> well, see fit wasn't work. i feel like a fire hydrant that it was gushing. not little twinkles of water, we were gushing a lot. ♪ ♪ >> reporter: santana has always been known for infusing his work with sounds that go beyond the fusion of rock and latin music he's known for. in fact he's written that the group "was never a purebred when it came to music. we were always a mutt." ♪ ♪hm and african rhhave always been part of the band's repertoire. in fact the song "jing composed by the famed nigerian percussionist babatunde olatunji, was among the earliest they performed. ♪ ♪ it's a song the band still play ♪ ♪ >> somebody asked me, "if africa speaks what does it say toou?" to me it ss invite people to hope and courage. give them encouragement. because african music has this naked awareness of pure joy. you don't want to cure yourself if you're happy. you only want to hurt yourself when you're unhappy. thto's, you know, nobody goe see a therapist, analyst, psychiatrist when you're happy. >> reporter: where "supernatural" featured a ra of lead vocalists, "africa speaks" has just one: the spanish singer of equatorial-guinean descent: buika. ♪ tina was no deceiver ♪ few were inclined to believe her ♪ aba tina oh who you have there ♪ breakin' down the door it is the first time we ever had a female spirit solely on every song. her singing is a combination of everything that slove about nione, etta james and tinarn and more. yet she doesn't sound like them♪ ♪ >> reporter: the music has an tarthy sound. but for carlos s, buika's vocals and the rest of the band's performance put his new work on a plane he preo speak of in philosophical terms. >> you know, this music, you get eto this trance. this outside of boerience where you-- you're dancing with absoluteness. it has that... it starts off as a ceremy, but it enters a vortex outside of time and outside of gravity. ♪ ♪ because that's what people go to church or they go to rituals in haiti or africa. musicians do it really, really,o really you know, a musician can make you feel your absoluteness and then they make you cry and laug when a musician really plays it's like you remember your innocence again. ♪ ♪ >> sreenivasan: on tomorrow's newshour, stone by stone, w rebuilding thington national cathedral following a devastating earthquake. are there lessons for paris' notre dame?at all for this edition of" pbs newshour weekend." i'm hari sreenivasan. thanks for watching. have good night. captioning sponsored by wnet captioned by media access group a.wwgbh acceh.org >> pbs newshour weekend is made: possible bernard and irene schwartz. sue and edgar wachenheim iii. seton melvin. the cheryl and philip milstein family. dr. p. roy vagelosope zuckerberg. corporate funding is provided by mutual of america-- designing customized individual and group retirement products. that's why we're your retirement company. additional support has been provided by: for by the corporati public broadcasting, and by contributions to your pbs ation from viewers like you. thank you. be more. pbs. (dramatic music) kennnnedy: we choose to go to te moon. vo: it was a monumental challenge in a divided nation, and an incredible triumph. armstrong: that's one small step for man. vo: on the 50th anniversary, explore unknown stories. man: i was really convinced i was in the c b. vo: with never exbefore seen footage.s. man: the fire shattered my wife's confidence in nasa. vo: go behind the scenes with the production team, and get a sneak peak at this major television event, when pbs and american experiencereview chasing the moon. vo: pbs previews: chasg the moon was made possible by contributions to your pbs station from viewers like you, thank you.

vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. g. barbara hope zuckerb corporate funding is providedua by mof america-- designing customized individual tirement products. that's why we're your retirement company. additional suppo been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. thank you. from the tisch wnet studios at lincoln center in new york, hari sreenivasan. >> sreenivasan: good evening and thank you for joining us. the u.s. milary confirmed today that a modified iranian surface-to-air missile was launched at an amecan drone-- in an attempt to disrupt surveillance of thursday's attack on two oil tankers in the gulf of oman. in a statement, u.s. central command also said a houthi surface-to-air missile shot down a u.s. drone earlier this month in yemen, "enabled by iranian assistance." on the sunday talk shows, secretary of state mike pompeo isain blamed iran for the attacks and said heaching out to allies for support. >> china gets over 80% of its crude oil transiting through the strait of hormuz. south korea, japan, thes nations are incredibly dependent on these resources. we're prepared to do our part. we always defend freedom ofna gation. we are going to work to build out a set of countries that have deep vested intest in keeping that strait open to help us do that. udi arabia's crown princ mohammed bin salman was quoted in a saudi-owned newspaper, saying the country does not seek war but "will not hesitate to deal with any threat to our people, sovereignty and vital interests.no great britaiplans to deploy 100 marines to the persian gulf to protect british ships and the country's foreign minister said today it believes that iran is responsible for the recent attacks. en well, we have done our own intelligence asses and the phrase we use is "almost certain."ow you we've got videos of what happened, we've seen evidence, we don't believe anyone ee could have done this. hundreds of thousands of protesters fled hong kong's streets again today-- one day after the semi-autonomous territory's chief executive suspended consideration of a proposed extradition law. the demonstrations stretched across parks and streets throughout the downtown area... continuing into the night. hours after the protest began, the government, led by chief executive carrie lam, issued ano apolog"causing disappointment and grief." budemonstrators were not satisfied. >> only when carrie lam apologizes, withdraws the bill, and steps down, will hong kong people end all of our protests. >> sreenivasan: many of the w protesters tode black and visited a memorial to a man who fell to ath late yesterday while standing on scaffolding and unfurling a protest banner. a massive power failure in an interconnected power grichleft f argentina, uruguay and paraguay, as well asnsmaller portiof chile and brazil, without electricity this morning. cars traveled through darkness and subways were out of service as power companies scrambled to restore power to tens of millions sf people. intement released this morning, an argentinian official called the outage" precedented." the cause of the power collapse is unknown, but an investigation is undery. trade tensions between the united states d india rose today as delhi began imposing tariffs on $1.4 billn of u.s. goods, including almonds, walnuts, apples and finished metal items. the new taxes-- some as high as 70%-- come after washington refused to exempindia from tariffs on aluminum and steel twports. the trade dispute n the two countries accelerated earlier this month when the white house anunced that the u.s. is rescinding a preferential trade agreement with india. president trump and india's recently reelected prime minister narendra modi are a expected to methe g-20 summit in japan later this month. >> sreenivasan: hurricane season officially begins again this month, but for people in the panhandle of florida, it's almost as if it never ended. edhurricane michael devasthe region last october, leaving residents homeless, jobless, and in search of goverent aid and services. but now, children, inul part, are feeling another kind of after-effect-- mental health issues.d" "miami hereporter elizabeth koh is reporting on rois. she joins us now tallahassee. >> sreenivasan: toll me, what are some of the things that teachers are seeing in their students? >> they are tell me, what are some of the things that teachers are seedeg in their ss? >> they're seeing a lot of symptoms of depression and anxiety and p.t.s.d. bay coty, which was directly hit by the storm, has put together a list of mental health needs that ty've been seeing in their students, and it's taken a lot of forms. we've seen students who start crying just when they start hearing the rain, because it reminds them of what the storm sounded like. we've had some extreme cases, like a couple of girls coming to school with razor blades and a icide pact, cutting their wrists open in front of their classmates. we've had children as as six, telling teachers and people at school that they want to kill themselves. it's a pretty serious situation that's starting to develop in the panhandle. >> sreenivasan: and do they have any kind of mental health ifrastructure to deal with this at the school level, or wider? >> the school has some mental health resources, but what we're oseing in the panhandle after the storm is that resources aren't enough. so, you'll remember the parkland shooting that happened last year in florida spurred lawmakers to actually dedicditional funding for mental health resources in school. and some of at funding has actually been helpful, particularly for bay county. but in terms of funding directly related to hurricaneichael and the mental health after-effects, bay county and other school districts haven't gottenyt ng for that. >> sreenivasan: and so when yous look athe entire community, are adults as well as children suffering some of these long-tm effects? >> it's everybody. ste panhandle was particularly devastated by thm. hurricane michael was one of the strongest hurricanes to ever hit the country. so this is something, a real disaster, that they were never really anticipating, and you can see it when you just walk around this region. there are still trees down. there's still debris in so places. and some of that debris may never even be picked up, just because there's so mh of it. what i've heard from providers in the area is that, eight months after the storm, was, people are starting to adjust to the fact that this is their new normal. this is when some of these symptoms are starting to set in. >> sreenivasan: you know, from the school board report, basic needs are still not being met for many residents, including shelter, food, water and security. how is that possible?e' >> well, looking at a situation where the panhandle is still waiting on a lot of staten and federal fu keep in mind that a lot of the communities that were hit were already communities ere pretty low in terms of their socioeconomic status. 've seen communities, fo example, like mexico beach, where their annual budget is completely overwhelmed by the cost of just debris removal, let alone addressing all of these other needs. and given the delays and getting federal funding even passed in congress, let alone passed down to people at the local level, these are people who are still waiting on contractors thelp fix their homes, get some of their debris hauled out from their homes' back yards. they're people who are dealingua with sons where, even if their housing is all right, maybe their jobs were not all right. and so, there is a lot of after- effects that just have continued to snowball since the storm hit. >> sreenivasan: so i'm assuming that even if a teacher or a school district are able to recruimental health counselors to be able to come to the area, that housing is excansive, just e the stock is down. >> exactly. well, in panama citylone, we've seen more than 70%-- about 70% of housing be damaged destroyed. the rents on places that are still remaining have gone up almost four-fold. so for someone who is thinking about coming to this area to help fill these huge gaps ong mental health providers, the pay's not that high, and where u going to live? >> sreenivasan: all right. elizabeth koh from the "miami herald," joining us fromto tallahasseght. thanks so much. >> thanks very much for your time. >> sreenivasan: in 2017, president trump signed the bideest overhaul to the tax in 30 years. tucked inside the bill's 186ge was a tax incentive its proponents claim was designed to help low-income mmunities. they're called "opportunity zones."bu as i learned on a recent trip to arizona, whether or not these areas with special tax breaks for investors will truly help distressed communities is still uncertain. this former plant nursery in tempe, arizona, just outside phoenix, has been vacant for more than six years. but this week, a developer broke ground on something new. so what's this place going to look like? >> this is going to be a four-story, modern-style, contemporary apartment building; 90 units. >> sreenivasan: quinn palomino is the co-founder and c.e.o. of virtua partners, a private equity and real tate developer based in scottsdale, arizona. she says the first resents will be moving into this $20 million complex next yea >> here you have an opportunity to build entry level housing, and you have investors who are looking at an opportunity to invest their... their funds. sreenivasan: for virtua and its investors, this isn't just any ordinary residential development.mo it's the first projects in the country to use a federal tax incentivcreated in the 2017 tax overhaul. >> with opportunity zones, we are drawing investment into neglected and under-served communities of americahat all americans, regardless of zip code, have access to the american dream. to>> sreenivasan: accordints supporters, the influx of private investment will spur economic development, including job creation, in disadvantaged communities around the country. last june, the u.s. treasury department certified me than 8,700 census tracts as opportunity zones. r the most part, the tracts are low-income. to qualify, the poverty rate has to be above 20%, or the median family income has to be below 80% of the state's median , come. in temere are five opportunity zones including the 320 acres within which virtua's aparent complex will be buil the poverty rate here is nearly 40%. >> there weren't enough dollars in the community to redevelop these areas. so it's a solution where vestors could put money into this. without the opportunity zones, a lot of investors wouldn't know about this project, or wouldn't invest a dollar here. >> sreenivasan: by investing in an opportunity zone, either by funding or expanding a business or developing re estate, investors receive a significant incentive. for example, let's say you have $10,000 profit from selling stock. depending on your income, you might pay 20% in federal taxes. instead, you can defer those taxes and invest that money in an opportunity zone. depending on how lonhold the investment, the taxable total of your $10,000 decreases by up to 15%. on top of that, after ten years, any new profit that comes from that oppornity zone investment is totally ax-free. in tempe, virtua's planned apartment complex is mting a real need, according to maria laughner, an economic development manager for the city.p to hplain why, she took me six stories up to the roof of an office building under construction. i can see, in downtown tempe, it's a lot of dense residential as well. >> yes. there's a great need for housing so we're having more... more multi-family going up. >> sreenivasan: tempe, a city of nearly 200,000, estimates that it will need 21,000 units of affordable housing by 2040 to meet demand. >> we don't nt to be just an area where everyone is building luxury homes. we have other issues that are very important for our community, and housing ia big one. so what we're trying to do is work with partners to make tha happen. so far, so good. >> sreenivasan: virtua's apartment complex will be priced at market rate. but the company says it will voluntarily set aside at least st nine of the 90 units for those earning around the median income, aategory known as workforce housing. but there is no requirement within the legislation for a plal estate developer to provide a benefit beyond screating a "substantial improvement;" meaning an increase in the value of the property over a 30-month period. that means cities like tempe can't force developers to build projects in opportunity zones that deliver specific benefits, like affordable housing. >> they're not really getting anything from us, it's hard for us, you know... on private property, it's hard fo to impose itself. >> sreenivasan: right. >> so i think, more than anything, it's come out of... i hate to say, it sounds so cheesy, but the goodness of their heart. that they want to do somethings thatigned with the vision of the city. >> sreenivasan: but, short of the goodness of their heart, how do you make sure that somebody thdoesn't take advantage o and leave tempe a little bit worse f? >> well, we also do have zoning codes in place. if someone wted to build something that wasn't in the zoning code, they would have to go through a relatively lengthy process. >> sreenivasan: but existing tools like zoning codes don't alleviate the fears of some critics, that opportunity zonent investmecould push out the very communities they are designed to help. >> when you're bringing that size of capital into low-income communities, it could rapidly increase that timeline of gentrification, displacement of people in this community. >> sreenivasan: victor vidalesde is the lof a community group in neighboring south phoenix. he also lives and works in portunity zones. the tools are there for municipalities to combat some of those potential fears that low income communities have. but do they have the when they understand those developments bring jobs, they bring dollars, they bring tax base that helps the cities? >> sreenivasan: how do you make sure that social impact is almost a requirent in this? because right now the legislation doesn't require an investor to make those kinds of commitments. >> many of us in business have a heart. we have wanted to give back to the community. here is an opportunity for us to work togetheo that. and we need to develop metrics. we need to require those in this industry to identify, how many mjobs are you creating, hy units are you providing that are entry level? >> sreenivasan: palomino is not alone in calling for more regulatory guidance on measuring the impact of opportunity zone investments.>> 've been on a national opportunity tour... >> sreenivasan: republican senator tim scott of south carolina is one of the itchitects of the opportun zone incentive. in february, he attended the groundbreaking for virtua's first project to use the tax break, a hotel being built just west of phoenix. in may, he co-sponsored a bill requiring that data on opportunity zone investments be collected and reported to congress. in a statement to newshour weekend, he said, in part, "i'm pleased to see initiatives being taken across the administration and in congress to ensure that folks in distressed mom opportunity zones." meanwhile, virtua ing ahead. it has raised $100 million to invest in opportunity zones, and has a pipeline of nearly 100 projects. >> youe now seeing a huge population of investors that, t have soldwould the stock, and they would have kept those dollars on the sidelines.ok now they're g at investing here. >> sreenivasan: but incentivizing these investments is not free. congress's joint committee on etaxation estimates that opportunity zone incentive willl cost $1.6 n in lost federal tax revenue over ten years. >> this is a public cost. these are public dollars. n's a public investment. there should be sous with public benefit, and eere's no way ure that there is. >> sreenivasan: mark stapp is the director of the real estate developmt program at arizona state university, and a long- time developerimself. he says the influx of capital could distort the market, and points to exisng incentives as being more targeted to deliver benefits like affordable housing. >> where is the definable, measurable public outcome that should go with making th public investment, which is the tax incentive? will there be a lot of money p thrs into it? absolutely. will all of that capit be properly deployed and provide the public benefit that equals the public cost? i don't think so. en sreenivasan: some opportunity zones have also riticized for not being economically distressed. almost 200 of the zones qualified simply by being next to low-income areas. in tempe, the future site of virtua's apartment complex also has a lot of positives for a veloper, in addition to its location in an opportunity zone. it's close to public transportation, it's about two anles from arizona state's sprawling campustempe is a fast-growing city with a housing shortage. fact, quinn palomino concedes that virtua would have built this project even if it was not in an opportunity zone.ld if you wave invested in this place anyway, that's the market at work. why should a tax payer in kansas subsidize an investmat's happening here that might have happened anyway? >> might have happened anyway, this project, and i-- we would haveone this one. but how do you scale thaho hari? i mean how can you take what's happening here and take it across the couny? this is 90 units, and i understand that's a small project. that's not going to solve the country's problems. but if we could take this model and take it across the country, then we can. >> sreenivasan: invests like virtua and residents of opportunity zones across the country will have until 2027 to see how this model takes hold. >> sreenivasan: next week, we will kick off our special series, "the future of food," where we'll explore global problems and solutions involving food supply and nutrition. for some early perspective on a few of the challenges and possibilities, i recently sat down with amanda little, professor ofnvestigative journalism and science writing at vanderbilt university, and the author of thbook, "the fate of food: what we'll eat in a bigger, hotter, smarter world." let's put this in perspectiv kind of the big picture here. what kind of a food crisis is the planet facing?el >> we're pretty, kind of close to a crisis, but we're not probably in one. it's hard to say, you know, you know, in very definitive terms. there are a lot of-- there's a lot of evidence of clima change in the way it's affecting food systems all over the place. and, you know, in the midwest, for example, we've seen the impacts on corn and soy farmers right now because of all the storms that are really saturating the soil and making it hard tolant-- >> sreenivasan: and that's going to move markets. less food in the field means the price is going to go up. >> yes, and i mean, itu know, in italy we're hearing about the devastation to olive groves. and in georgia and florida, we hear about the impacts on peach and citrus production. we hear about, you know, cacao and coffee damage to farms in equatori i mean, it's just sort of endless. you can look almost anywhere in any food system and see the impacts of heat, drought, flooding, invasive insects. and, you know, there's just trauma t in different ways.elf it's hard for consers to relate to, right, because we're so displaced from the source of our food. so, as farmers begin to experience this in different ways, consumers are maybe experiencing it as, you know, fluctuations in cost. but the real, you know, sort of crisis iterms of food security, and, you know, and disruption food supply, you know, will happen regionally. you know, in one region hit by floods or blizzards or droughts, there might be a temporaryti disr. certainly in parts of india and you know, subsaharan africa,er ase serious famines going on in the middle so, you know, in one region, it might be, you know, a to, you know, chardonnay and strawberries. innother region, it might serious food security issues. which is why that question, you know, "is this a criw?" it's hard to answer. certainly the beginning-- this sort of early stages of isis are becoming evident. 10, 20 years from now, will we ,see serious food, you kn disruptions and supply? very, very possibly. >> sreenivasan: and you're saying that those general trendlines are heading in, sort of the wrong direction. >> i came out of this really often, i became really optimistic this is sort of a narrative as old as civilization, right? , you know, we have been wondering are we going to run out of 0 food? will we have enough to food humanity for, you know, agin millennia. and, you know, we have always found a way to, you know, adapt and to survive. and a what is interesting is this is, you know, sort of engaging and motivating ourin incts for survival, so some of what i encountered was, you know, capable of not only 0 sort of beginning to preempt andar pr for these precious six pressures that are coming on 0d line but to ss the problems that existed -- you know, that have to come have iustrial, from industrial agriculture. we have this system to begin with that is, you know, very chemically inten receive, that is eroding the soil that is unhealthy in a lot ofdways an have all of this new pressure coming online. utions some of these sol do both? what i found out was that, in fact, a lot of what emerging, the really, really, great interesting, you know, approaches to solutions are doing both.dd they canss the problems of the past, and sort to prepare to for what is coming. so the answer in short is yes, i think we are going to do it. >> sreenivasan: seen more of my conversation with amanda little >> sreenivasan: see more of my conversation with amanda little here, or online, ats. www.g/newshour. imes we paint technology 0 as the ultimate savior to all of these problems that we have. how do we mind kind of mix between where leading edge technology is and maybe things that we have learned from farming for a few thousand years? >> the thing thahit i reallt on, two key things, one is the main way we are going experience climate change is through its impact on the food system, most people o planet earth there will be regional disturbances but across the board we are all goncg to experthis in some way or another. the second thing is that the food debate is very polarized, it is vey, you know, politicized and even, you know, it is very elitist and accessible to a lotf people. there needs to be a third way that we really draw on the wisdom of sustainable and traditional food systems and we leverage ande, usake use of the best technologies that are available today. lying are ways of ap technology that can support and sustain sustainable food systems, o approaches to food production. there is one side nventis saying, let's rei food, i think that's a quote bill gates said, the food is ripe for reinvention a coue of years ago, and then the sustainable food books are saying i want my food deinvented thank you very much, i want to return to prindustrial agriculture. and we need to move beyond at sort of binary approach and a think about how do we do technology 0 right? and so i looked at, you know, crisper and vertical farms and drones and artificial intelligence and robotics and also at insects and as you plant, and, you know, perma culture and there are ways we can sort of do thte best of boh approaches. >> amanda little, vanderbilt university, the back into is fate of od thanks so much for joining us. >> thanks so much. >> sreenivasan: >> sreenivasan: also on our newshour facebook page: a recent investigation by reveal from the center for investigative reporting uncovered hundreds of law enforcement officers whowe members of facebook groups sharing extremist, racist, misogynist and homophobic messag. see my conversation with reveal reporter will carless at facebook.com/newshour. that's all for this edition of pbs newshour weekend. i'm hari sreenivasan. happy father's day. have a good night. captioning sponsored by wnet captioned by media access group at wgbh access.wgbh.org >> pbs newshour weekend is made possible by: bernard and irene schwartz. sue and edgar wachenheim iii.me setoin. the cheryl and philip milstein family. dr. p. roy vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mual of america-- designing customized individual and group retirement products. that's why we're your retirement company. ditional support has been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like yo thank you. be more. pbs. - [narrator] expxplore new worlds and new ideas throu programs like this, made available for everyone through contributions to your pbs soution from viewers like. thank you. - hello i'm paula kerger, presidt of pbs. our goal in public television is to bring you a wide array of perspectives and voices in history, science and the arts. today we are so pleased to psent henry louis gates jr. uncovering america which celebrates one of our most pactful historians. professor gates is an award winning filmmaker, literary scholar, journalist and cultural critic who helps us discove

roy vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg.

vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america-- designing customized individual and group retirement products. that's why we're your retirement company. additional support haseen provided by: and by the corporation for public broadcasting, and by contributions to your pbs u.ation from viewers like thank you. from the tisch wnet studios at lincoln center in new york, hari sreenivasan. >> sreenivasan: good evening and thank you for joining us. president trump said late yesterday that the u.s. will n"" indefinitely suspend" the ooreat of tariffs on billions of dollars of mexican, after three days of negotiations over the increasing number of migrants crossing the u.s.- mexico border. the news came in a tweet from the president last night that said mexico "agreed to takes strong measu stem the tide of migration through mexico, and to our southern border." formally, the two cos issued a joint statement which outlined mexico's enforcement actions without giving specific numbers or benchmarks. >> mexico will take unprecedented steps to increase deforcement to curb irregular migration to inche deployment of his national guard throughout mexico, giving priority to its southe border. >> sreenasan: on thursday, mexico's foreign minister said 6,000 troops from its newly formed national guard would bee deployed to thuthern border with guatemala. the agreement also includes an expansion of a six-month-old u.s. policknown as "remain in mexico" which returns asylum seekers to mexico while they wait for processing of theircl ms. that policy is being challenged in u.s. courts. house speaker nancy pelosi called it a "failed" policy which "violates the rights of asylum seekers under u.s. law and fails to address the root causes of central american migration." last week mr. trump suddenly announced a plan to impose tariffs on nearl$350 billion worth of mexican imports, starting at five percent on monday june 10, and growing to 25% by october, unless mexico did more to stop migrants from coming to the u.s. u.s. treasury secretary steve mnuchin said today that he plans to speak with the governor of china's central bank one-on-one about the ongoing trade dispute between the two countries. mnuchin is attending the groupon of 20 major ies meeting in japan with financial leaders. the treasury secretary said that he expects progress to come later this month when president trump meetwith chinese president xi jinping in osaka at the g-20 summit. mnuchin said there are no plans for official trade talks befate eeting. pacific gas & electric announced day that it's turning of power temporarily to 1600 s in northern california in an effort to prevent wildfires. the company ripes to reduce s during what forecasters predict will be a hot, dry, and windy weekend. the company said it may also cut off power to about 30,000 customers in the sierra foothills region that includes the city of paradise, california. a wildfire there last year destroyed nearly 15,000 homes. downed power lines and p.g. & e. equipment are blamed for previous fires and sta regulators recently approved allowing utilities to cut off electricity when fire risk is extremely high. protest leaders in sudan are calling for w demonstrations tomorrow after government security forces arrested two of their leaders this weekend-- that's after they met with ethiopian prime minister abiy ahmed. ahmed had traveled to khartoum to try to revive talks between sudan's ruling generals and leaders of the pro-democracy protest movement. dozens of protesters were killed during the past week while demanding that sudan have civilian rule, the worst bloodshed since the overthrow of president omar abashir in ap ahmed proposed creating a transitional council comprised evof eight civilians and s military officers with a rotating presidency.n the ethiopiaader said envoys from ethiopia and the african union will continue thens negotiat in the democratic republic of congo, officials say there are now more than 2,000 re cases of ebola, mostly in the o eastern regithe country. fighting between rebel and government forces have limited health workers' access to the ea and slowed efforts to contain the spread of the disease. the world health organization also warned this week that the number of cases may be much higher, saying it is only detecting about 75% of all ebola cases. nearly 1400 people have died of the disease since the outbreak began last august. for more on the g-20 summit and alled trade negotiations between the u.s. and china visit pbs.org/newshour. >> sreenivasan: after a disqualification in the kentuckd derby, aless horse in the preakness and different winners in both races, there will be no triple crown winner after this evening's belmont stakes. but in horse racing this year the focus is not on the winners, but on a tragic statistic: nearly 10 horses a week, on average, died at american racetracks in 2018, a fatality rate that is 2.5 to five timesgr ter than in the rest of the horse racing world. joining me now is new yorkor times' rr joe drape who is covering the sport and the response to the deaths and injuries to these equine athletes. f sadly, we are only awareis because of the news around big races, or big racetracks, that that number adds up to, what, 0 horses a year in the united states? >> well, it's actually aer cotive estimate. we did a series in 2012 where where we freedommed of information everything and we found 25 horaise week. and that's because we counted training accidents and things that happened off trhack. so has been out there. i've looked at congressional testimony about this going back to the 1980s. this is not a secret. i think what happened is society has evolved. the fact that it happened in california, which is a progressive state, and, especially, during triple crown season because now this is when the casual fan tues in. they want to see the big hats at the derby and dhiend of ting. >> sreenivasan: right. is it-- we've heard, for example, some of the tracks and the bad weather. i mean, horses have run in mud before. i mean, what's so different about it this year? >>of think a coupl things happened. california got cold and rainy, more so than it had in 2 years. but there's also a horse hashortage. yo less horses. when i started doing this 20 years ago, a full crop of 35,000. now we're down to 19,000. but at the same timple, peoare racing year-round at various traction. i mean, right nowday, within 200 miles, there's nine tracks running. not enough horses to go on. and then there's the drug culture and that's what we have focused on. the drg culture is kind of two-fold. there are the people who cheat, who try to take edges everywhere from viagra to human growth hormonto put them in the horses to make them faster, and then there are people who try to get them to the track, much like football players, cortisone shots to play that game, just to t them out on the track and run its race and hopefully make some money. >> sreenivan: you know, in bicycle racing, for example, there have been-- drugs have been abused, so right afterwards the athlete ts to go and ge tested. is that the case with horses? >> there is testing. it'sot terribly effective. and there's 38 different s risdictions. so ther uniform drug laws or punishments. so it's kind of a patchwork of state by state. and, you know, just like the human sports and the olympics and cycling, people are just way ahead of things. i mean, tny have their ow labs. but, you know, overall, there's never been a big effort to catch people and to make sure that these horses are safe and soud d ed properly. that's, obviously, got to change. >> sreenivas: but when you art talking about labs, it remind me, this is a very expensive sport to be in, aner s a lot of money at stake. >> there is. i mean, there's millions purses, billions in purses. $15 billion ae bet on the horses throughout the year. you know, it was the sport of kings for the rean. they did it as sportsmen. they're not trying to live off their purse money. but that dynamic has changed. you know, 90% you have syndicates now, where you have 20, 40, 60t people puting in a little bit there. and, you know, they need to pay their way through thert spo and that's where i believe the abuses start. you know, you look the other way. you're like, "get them out of the stall. let's race them." >> sreenivasan: islihis moment ly to change the future of horse racing? >> this moment is going toe change the fut horse racing. and it is either going to change it to were it doesn't exist anymore-- out in california you only need 600,000 signatures on a ballot initiative to vote if s uld even exist. polls say that would be a close vote, and it would probably end the sport california. if california falls, it keeps going on across the untry. what need to happen is real reform, and a "sles more" sort of model here. i mean, tre's too much racing with too few horses, and they need to be rested. they need to be treated like athletes, like they once were in the 50s, 60s, , of their heyday. and when that happens-- and, you know, that's going to cause a lot of pain. a lot of people are gointo lose jobs. whenever there's disruption, jobs get lost and, you know, weo see ier and over in society. so, you know, people are going to lose their job and they're going to throw people out. or it's not going to exist. so that'where we are right now. >> sreenivasan: all right, "new york times" joe drape, thanks so much. >> thank you. >> sreenivasan: yesterday, nasa wnounced that it would al tourists to visit the international space station, possibly starting as early as next year. nasa's effort to find new commercial opportunities comes at a time when there's a new t'space race underway, and not countries competing, it's private companies. space-x recently launched doze of satellites designed to provide global intomnet coverage pace, and nasa granted contracts to three private companies to devel robotic landers for missions to the moon. but with all that competition, is even a place like space vast enough? newshour weekend's megan thompson recently sat down with loren grush, senior reporter for the verge to discuss. >> thompson: so, first, just tell us what is t space-x up there? i understand they recently launched 60 satellite's whhis all about? >> an ever green question. space-x's star link initiative is to provide global internet coveragey using thousands of satellites that beam internet coverage noun downfrom space. now, we haelve sattes that provide internet coverage from space right now. they're very high up, you know, fthousands and thousandsmiles above the surface. but what space-x and other companies want to do is launch them into low orbits so that they can beam internet and you don't really exwrve anyalatancy ht signal so the roundtrip lig time takes less time to get to you. but when you have satellites in a lower orbit, in order to provide that global coverage, you need a lot more satellites because they have to be able to see the entire planet. and so that's why space-x has proposed sending nearly 12,00 satellites into space to provide this coverage. >> thompson: and i understand they're t the only private company look to get into this. who else is involved? >> there's another company called one web that launched its own satellites. and amazon recently said it wants to launch thousands of satellites. there are other companies looking into this, too. so it's definitely a very coveted goal among the sp industry. >> thompson: so space-x could launch at some point up to 12,000e atellites. the all these other companies looking to launch thousand more. what are the implications of having that may satellites up in space? >> so the biggest thing that people are concerned witis, obviously, this orbital debris problem. we already have many thousandsli of sats in space right now, which this could triple o quadruple that number with the star link initiative alone. so the problem is the satellites are movofing at thousandiles per hour in space. they're not just floating up there. so if one of them ruons int another one, then that could create a very, you know, catastrophic debris field. and in those pieces of debrisov are g at thousands of miles per hour as well. the good news sspace is big. and so these collisions really don't happen very often, if at all. but there is a concern the more that we put up there, the higher the risk of thlese colisions happening. the good news, though, is that space-x has thought about this. they have orbital debris-mitigation plan for one thing, they have this kind of like a g.p.s. trackerten their ites -- at least they say-- where they use track information that the air forcee has and they at to kind of maneuver out of the way if they happen to be, you know, on path to collide with something. and, also, the orbits that they've gone to, eventuallyte these satelwill decay over time because of gravity, ourmo here will pull them down. but it is still a concern. and it's not-- no one reya quite knows what's going to happen. but we are ting to think of ways to mitigate this problem before we launch into sp >> thompson: if there was a massive collision of these satellites, i mean, what would the feedged of effects of that be? >> well, we've already seen that happen. two satellites collided a couple of years ago, and like i sai they created hundreds to thousands of piece of debris, and that debris goes into various orbits. it doesn't really have any kind of uniform path. and so once that happens, then the air force has to track that as well, and so then you have to catalog all those piece of debris. an bthen thcomes-- that becomes a hazard. and so you'll have to-- now other satellite operators would have to know where that piece of debris is, and if it's heading in your satellite's way, then you're going to have move or you might get hit. >> thompson: could it knock out global communications if something like that happens? >> it could knock out a very functioning satelofte, and some these satellites that are up there had hundreds of thousands of dollars, millions of dollars to make. e , yeah, it is a very real problem if you hese pieces of debris. for now, space-x ha only launched 60 satellites, so it's not that many. but givag thenitude that they want to launch, it could become a concern. at least sk of collision could go up significantly. >> thompson: and i undstd that astronomers have an issue with all these satellites up there. tell me out tha >> right. so orbital debris was, obviously, on everybody's minds before space-x launched, but then over the weekend, you know, astronomers saw them in space, they were quite brigh because the shiny and they have solar panels that reflect the sunlight. ed you can still se them at night, even though the earth is shrouded in darkness, these satellites are very high up, so they can still catch the sun's r light anflect that back on to the earth. and that's a problem for astronomers who already have to deal with satellites now. they take loimng-exposureges with their telescopes so whenever you have a bright object zooming through your image, it creates this long, bright-white streak, and thatn caeally muck up mur observationing of the universe because you need to take in a lot of light, but if you have a long streak through it you can't real rale see a galaxy or asteroid or however many light-years away from earth. >> thompson: for so many years space was a place only national governments went, and now we're seeing all these private companies, all these launchings happening. i mean, are we looking at essentially the privatization of space? what are the potentialpl ations of that? >> it is a very real transition that is happening in the spacest in right now. more and more companies are launching than governments. and i think, you know, with every neevolution there are positives and there are negatives, right? now we have a whole new way for new players to get into space, people that probably never thought they could operate in the space indtry, now th prices are coming down, the more that we launch, more people cane send satelnd research into space, which is great. but at the same time, we're seeing the implications of having more-frequent launches and, you know, there's concern wiwe the more that ut into space, the more debris there could be, and then, eventually, we might not be able to use space if it gets too crowded and if we don't think about these and like we were saying ttook the astronomers seeing these i satellitorbit and being so bright to really understand the implications of what mi happen. so i think there's a lot of things that we're going to seeay ut as they launch more, but, like i said, there's positives and there's negatives to any kind of new emerging trend, and i think that will play out in the years ahead. >> thompson: great. loren grush of "ththverge" k you so much for being here. >> thank you for having me. >> sreenivasan: despite efforts to curb illegal immigration to the u.s., the number of migrants risking their lives crossing remote and treacherous terrain continues, often at a deadly cost. in southern arizona, more than 3000 human remains have been found over the past two decades, many of them are unidentified. but one local artist has made it his mission to honor the lives of the migrants who have died in the sonoran desert. arizona public media brings us the story of artist alvaro enciso, who marks those deadly crossings with crosses. >> when i moved here, i immediately wanted to connect with the people who were putting the word out in the desert. and i saw the mass of red dots almost covering the geographical detail of the map. i knew right then and there i oceded to take that red dot to where the tragedrred. every time they collect a body, they put a g.p.s. marking where the person was found. so, the night before, i look at how am i going to get there? how far we're going to have to walk? and we prepare for it.te the ultimaoal is to get to the location one way or another. we try to put four crosses every time we go. so, red dot mark a locn. and we operate in an area that is 40,000 square miles. i got an email from a woman whose brother died he. and she says, "could youut a cross for my brother?" >> when did he die, i wonder? >> 2013. i have a friend who's my g.p.s. person, who's able to guide us to the exact location. >> well, it looks like there might be a couple of ways to connect to it.th but the one ink is... >> sometimes you have to find... >> ...three miles.ad >> ...that the map doesn't even show. most of the migrants who died out in the desert were off the trail. they were left behind. they got lost, disoriented, and they ended up walking in circles until they ran out of water and died. it's a tragedy that has a lot of ramifications. there's a void in thaty. i'm walking along with them. i'm walking the same ground.th i'm feele same heat. three beeps, it's okay wh me. do we have a name? >> unidentified. undetermined skeletal remains. apl 13, 2018. >> half of the time, we don't have the names of the person. and those cases affect me the most. okay. because there's no closure for the family. that family still hoping that one day this pern is going to make a phone call and say, "hey, i'm here." we know that that's not going to happen, and that breaks my heart. this is like a little oasis here. so, he probably got here, looking for shade and a little cool, and just couldn't get up. i knew that these crosses weren't going to be seen byy. anyb the families of those people never get to see them. but every now and then, something magical happens. the family came all the way from new jersey, her two daughters anher husband, and we went together and put a cross with them >> she was trying to help as much as possible.ir and she in so many people, like family members anyone that needed help. >> i don't have enoughin me to finish it, so it's going to be an incomplete project. but i'm okay with that because, little by little, the truth is coming out. >> sreenivasan: finally tonigh >> i want to play a rhythm. >> sreen >> sreenivasan: join us again tomorrow for a special look at the career of guitar great carlos santana. 50 years after his appearance at woodstock, he's still making music, touring and this weekend, he just released his latest album, "africa speaks."th at's all for this edition of pbs newshour weekend. i'm hari sreenivasan. thanks for watching. a haood night. ni capt sponsored by wnet captioned by media access group at wgbh access.wgbh.org >> pbs newshour weekend is made possible by: bernard and irene schwartz. im sue and edgar wachenii. seton melvin. the cheryl and philip milstein family.oy dr. p.agelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america--gn deg customized individual and group retirement products. that's why we're your retirement company. additional support has been provided by: and by the corporation for puic broadcasting, and by contributions to your pbs station from viewers like you. thank you. ♪ (birds calling) ♪ (people talking in background) (people talking in background) martin boyce: for me, heere was no bar like ttonewall, because the onewall was ke the watering hole on the savannah.

vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america-- designing customized individua and group retirement products. that's why we're your retirement company. additional support has been provided by: anby the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. thank you. from the tisch wnet studios at lincoln center in new york, hari sreenivas. >> sreenivasan: good evening and thank you for joining us. multiple news reports cited a senior u.s. official claiming that iran fired a surface-to-air missile at an american drone today. this, as the united states continues to blame iran forrs attacks on tann the gulf of oman thursday. the two tankers were hit after passing through the strait of hormuz. iran has denied being involved in the attack. the 23 crew members from the norwegn tanker were flown to dubai today after being held for two days in iran. a dutch ship and the u.s. navy srescued the 21 crew memb aboard the japanese tanker. the u.s.ilitary central command released video on thursday which they say shows iranians removg evidence from one of the tankers. and they released this photo, which shs the damage to the japanese-owned tanker on the left side and what the u.s military says is "likely" an unexploded limpet mine on the right. at a conference in tajikistan today, iranian president hassan rouhani did not mention the attacks but said iran would scale back its comiance with the 2015 nuclear agreement, unless other signatories show" positive signals." >> ( translated ): obviously, iran cannot stick to this agreement unilaterally. it is necessary that all the sides of this agreement contribute to restoring it.: >> sreenivas will have more on this story coming up after the news summary.rn hong kong's gont is suspending-- but not withdrawing-- legislation that would allow extritions to inland china. the territory's chief executive, carrie lam, announced the decision this morning after roys of massivests against the bill. >> ( translated ): as a sponsible government, we have to maintain law and order on the one hand and evaluate a sin for the greatest interests of hong kong, including restoring calmness in society, as soon as possible an avoiding any mjuries to w enforcement officers a citizens. >> no evil law! carrie lamtep down! >> sreenivasan: opposion legislators reject s the indefinipension and demanded lam step down. inaders of the massive street protests that coued throughout the past week said they will go ahead with another march tomorrow to demand the bill be withdrawn. they called toy's announcement" too little, too late." the united states'op diplomat to africa is calling for a" independent and credible" investigation into a violent government attack on protestors in sudan earlier this month. on a two-day visit to khartoum, tibor nagy, the u.s. assistantof secretary tate for african affairs, met with sudan's military leaders and with protestors who are demandi a civilian government. s sudan's governays it is conducting its own investigation of the security forces' dispersal of a protest camp where dozens were killed. slovakia inaugurated its new president today-- zuzana caputova became the oluntry's fifth president and the first woman tothe largely ceremonial job. in her inaugural address, caputova-- formerly an environmental activist and a lawyer said "i'm not here to rule, i'm here to serve" and said she will continue to be a firm sporter of slovakia's membership in the european union and nato. slovakia became an independent country in 1993 after the break up of the former czechoslovakia. the notre dame cathedral held itfirst mass today since a fire in april seriously damaged the legeary building. ♪ ♪ attendance at today's service was limid and only included the archbishop of paris, priests, canons, and a few chur employees, all of whom were required to wear hard hats. the cathedraremains closed to the public and according to officials it is in a "fragile state." french president emmanuel macron has set an ambitious goal to rebuild the cathedral in five years. auto workers at a volkswagen plant in chattanooga, tennessee voted against unionizing their factory last night. preliminy results showed 833 votes against unionizing and 776 in favor. the vote is a setback to the united auto workers' efforts to organize in foreign auto facilities in the south. the u.a.w. also narrowly lost a 2014 vote at the chattanooga plant. final results will not be official until certification by the national labor relations board. we asked educators for a summer- break student reading listir in by the novel "to kill a mockingbird." read their picks at pbs.org/newshour. her more on the confrontation between iran andnited states we turn to barbara slavin, director of the future of iran inatiative at the ntic council in washington d.c. thanks so much for joini m us. >> sure pleasure. >> sreenivasan: so, first, let me start out with there's kind of two levels here. there's rhetoric and there's action, and thesy both m to be esk laict. >> yindeed. i think the aion is th part that concerns me the most. we've had 40 years of exchanging insults between iran and the united states. but this action is particularly worrisome. the events in the persianulf seem to be heating up. fortunately there's been no loss of life. but, of course, something like this could always spiral out of control. >> sreenivasan: you know, the tankers thawe saw that were in the news in the past couple of days, that overshadowed the news that prime minister abe of japan was there trying to have kind of a diplomatic solution to this, trying to be a bridge between the united states and ira >> well, you know, one can still hope that some messages were passed. i think the iranians probably told prime minister abe that if the united states really wants new negotiations it's going to have to make some conssns to iran. it cannot continue an embargo on all sales, all eports of iranian oil. it's going to have to promiseso concession, i think, and i'm not sure the truadmp nistration is prepared to do that, especially not after these incidents in the persian gulf gl. >> sreenivasan: now we see the irans are saying we're ramping up our ability to make nuclear weapons. >> first of all, the iranians t deny that heir intention. >> sreenivasan: right. >> what they are doing is they are slowly beginning to increase the aims of low-enriched yoorm, which they have. and at some int, yes, they may go above the limits that were set by the 2015 clear deal. but let's remember that the united states pulled out of that deal a yea ir ago whian was in full exwiens and has now put st stringent sanctions on iran in the history of the islamic republic of iran. w sould say what iran is doing, least in terms of itsam nuclear prois much more calibrated in a way than what we're seeing in the persian gulf. >> sreenivasan: after the u.s. withdrawal from the agreement with iran, what have its other signatories been doing in the past year? >> the others that participated in the negotiaons have been trying to encourage iran to stay in the agreement. but, unfortunately-- particularly in the case of the europeans -- they have not been able to find a way to connue to trade with iran, even on non-sanctioned goods, like food and medicine, that has not been threatened by u.s. sanctions. so the iranians are very frustr understandably so that they at least, up until now, had been observing this agreement and they're getting no economican benefitsi think we're going to beginning to seehis frustration boil over and unfortunately in ways that are rather wreckles wreckless and d. >> sreenivasan: how does the iranian public see all of this? >> i think the iian public is just miserable. there were great hopes aftgr thiseement was reached that iran's economy would really revive. they were exeriencing economic growth. businessmen were coming from all over the world looking into various ventures in iran. people had great hopes. and then,pr firstident trump was elected with all the things he had to say about this agreement-- he didn't like ic very m and then after, you know, threats and more threats, finally, he pulled out and reimposed sanctions. so in some ways, people are mor unhappy nan they've ever been because their expectations had been raised for a better life and she those expectivation now been taken away. >> sreenivasan: barbara slavin, director of the future of in initiative at the atlantic council in washington, d.c., thanks so much for joining . >> thanks for having me. >> sreenivasan: in 2017, a u.s. postage stamp was dedicated to father theodore hesburgh, the longtime president of the university of notre dame. the postal service citation called him one of the mostpo ant civic and educational leaders of the 20th century. in our century, his story is somewhat less well-known, but a new documentary film has set out to change that. newshour weekend's christopher booker has more. >> reporter: it was b father ted hesburgh didn't take erhaps best illustrates the reverence in which he was held. >> there was a point in time where he was actually asked to run nasa. he turned it down. t didn't think that that was maybe a great fifor him. >> he advises presidents. >> he was a mythic fige. >> he confers with the pope. s >> we heard these storieaboutl this, thend. >> he is chairman of the rockafeller foundation. >> my god, how many lives did this man live? >> he is father theore martin hesburgh, president of the university of notre dame. >> reporter: in the late 20th century, very few people held as much behind the scenes power and exercised as much influence as father ted hesburgh. he served on 16 different presidential commissions, helping author and champion some of the most transformative legislation in amecan history. >> we call him the "forrest gump of... of america in the... in the later half of the 20th century." >> reporter: patrick creadon is the director of the doary "hesburgh." >> he was this person who sort of somehow popped up all over the place in our society. and everywhere he... everywhere he showed up, he was able to nert of get the tough jobs done that needed to be he was never a president. he was never a u.s. senator. w never a prominent news figure or anchorman or anchorwoman. he was the guy behind the guy. >> reporter: now, you, attended notre dame... >> yeah, we actually kind of crossed paths for about a year there. i never met him,onut i'd see him ampus. and i... i certainly knew his t reputation, and i knew t was a major figure on the american landscape but being a documentary slmmaker, i... i... i alw have a little bit of a skeptical eye, and i really wanted to sort of see for myselif his work really lived up to his reputation. and it did. >> reporter: hesburgh's urney started as a young college president hoping to transform his university, an ethat required money, which father hesburgh was particularly adept at securing through donations. throughout the early '50s, his network grew ever larger, and soon the president of notre dame would meet the president of the united stes. what would start with an appointment to the national science board in 195d lead to an appointment to one of the most consequential commissions in u.s. history: the u.s. commission on civil rights, a group tasked by the president to research civil and racial inequality in the segregated south. >> we are trying to create one nation.y it could vssibly be that we are verging through our institutions towards two societies-- one black and one white. and that wouldn't be america, i don't think. h>> reporter: while hesbu championed civil rights, he was also an advocate for free speech and the exchange of ideas, even those ideas clashed with his own. in 1963, a campus group invited alabama governor and segregationist george wallace to speak at notre dame, the very same george wallace who in 1958 had threatened to throw hesburgh and the other members of the commission on civil rights in majail if they visited ala >> reporter: despite student protes against wallace's visit to notre dame, hesburgh allowed the speech ttake place. but just one year later, the work of the commission on civil rights would be part of a majorr sformation of america. >> my fellow americans, i am about to sign into law the civil rights act of 1964. >> reporter: on july 2, 1964, president lyndon johnson signed the landmark civil rights act, outlawing discrimination based on race, color, religion, sex or national origin. father hesburgh was called the architect of the law. but the coming years would be challenging for father hesburgh as student protests against the vietnam war expanded throughout the country. >> he wore a lot of different hats, and those... those... those bs that he held were oftentimes in conflict with each other. >> the most natural thing i could do here today is talk about student unrest. but i suspect most of you had it about up to here, and i have to admit that i have had it up to here also. >> reverend theodore hesburgh today announced a "get tough" policy. father hesburgh said demonstrators will be given 15 minutes to halt their protest. if they don't,enhey'll be sud on the spot. if they do not halt within ilother five minutes, they be expelled. t reporter: your film paints a portrait of fath being on the right side of history for nearly everything... >> uh-huh. >> reporter: ...except student protest. >> yeah, there's a real nuance to that. father ted believed that... that a campus was supposed to be a crossroads of differenideas. he wasn't against protesting; he was against violent protesting or the kind of protesting that would impede someone else's education. and so, back in 1970, he ended up... they ended up expelling five students who had blocked the entrance to job interviews that were taking place. >> reporter: with the c.i.a. and dow chemicals. >> it was the c.i.a. and it was dow chemical, two very unpopular groups during the midd of the vietnam war. >> reporter: but just over a year later, hesburgh would come a very public critic of the war in vietnam after four students were shot and killed by the national guard at kent state university in ohio duringin protests agast president nixon's expansion of the war into cambodia. >> there comes a time in life, in personal life and in national life, when moral righteousness more important than emp victory. ( sirens )>> eporter: his speech became known as the "hesbergh declaration" and was signed by00 15tudents and residents of south bend. ergh sent it to presiden nixon in may of 1970. hesburgh's relationship with nixon was frayin a few months later, he and the esvil rights commission, against the president's wi published a report that detailed the governments slow implementation of civil rights legislation. >> here is a... the first comple study ever made of the whole federal establishment as regards at least civil rights complice and how we're delivering and what the law says we should do. this says the performance is pretty poor. it always has been. >> they were concerned about the timing, and we didn't share their concern as to the political importance of the report. >> reporter: nixon fired hesburgh from the civil rights commission in 1972. >> i think president nixon had no idea that father ted was going to become one of his... one of his most hard-hitting adversaries. and i think, as history went on, i think father ted actually kiat of wore s a badge of honor. he lost his job, but he kept his, you know... he... he kept his conscience. >> reporter: as a viewer, i did find myself waiting for, are we going to get to ththolic church sex scandal? >> yeah. no, that's a great question. it's worth noting that father ted retired in 1987. so, in some ways, the story of the... of the scandal within the church really kind of missed father ted. he just simply wasn't a part of that conversation. teat's one of the great regrets i have for fathes story, is that i wish that he wast engaged in tnversation and in that problem. >> reporter: but father shesburgh's retirement ye weren't silent. he was still consulted and called upon by presidents. president bill clinton awarded him the congreional gold medal, one of the highest civilian honors in the country. and in 2009, when otest otupted before president barack obama's visit to n dame, it was father hesburgh who reassured the school's administration that hosting a pro-choice presidentt catholic university was the right thing to do. >> differences of cultur and religion, and conviction can coexist with friendship, civility, hospitality, and especially love. >> reporter: father hesburgh died in 2015 at the age of 82. >> sreenivasan: we've been working with former "new york times" food writer and lling author mark bittma on a new series of reports about a world he knows well and all of us need to understand. rewe're calling it "the fuf food." mark will be hosting the series, and is going to tell you more about it. reporting for this series is supported by the pulitzer center reporter: i'm mark bittman and this is pbs newshour weekend's "future of food" series. w by 2050, tld's population will reach nearly ten billion. c and although orent food system can produce enough food, it will difficult to do so sustainably and ethically. the issues are complicated, but they include an industrial food system that pruces food that can lead to chronic illness, barriers to small-scale farming, pollution and the mistreatment of animals. industrial agriculture is also a major contributor to climate change. take meat production. globally, more people are eating more meat than ever before and demand is projected to double in the next 30 years. but there are serious concerns about the conditions manyar animalraised in. and there isn't enough land or water to increase producon using current methods. with meat consuming two, three, even- in the case of beef- ten times as many resources as pnt foods, we need more creative solutions. fish are a promising protein alternative.n but more t% of fish are caught at or beyond their sustainable limits. d with many fish farms struggling with issues of pollut alternative is far from ideal.th way we raise crops carry risks to human health and the. environment, t modern farming practices like indiscriminate tilling, heavy fertilizer use, and pesticides-- used on more than 90 america's main crops-- are damaging soil, contaminating water and ultimately drainingob our resources. and while the world's farmers already producmore than enough food to feed everyone on earth, morehan 800 million people don't have enough to eat. a that's largely function of poverty. but we also waste a tremendous amount of food. around one third of the food w produce is damaged in transit, spoiled or just plain toed in the trash. how do we eate a food system that can provide us all with nutritious and affordable food while doing so in a way that's both green and fair? over the coming months, the pbs newshour weekend "future of food" series will report on work being done around the world by people who believe they have solutions. some of it sounds too good to be true. we take you to california, where scientists are growing real meat in laboratories. no slaughtering of animals involved. you didn't tell me this was raised in a lab, i would have no idea.e >> s it is controversial. we will take you to canada, to see the first genetically dified animal approved for human consumption: a faster-. growing salm >> same age, twice the size. >> same age,tienetically idl except for one single gene. so this opens up a whole new opportunity for globmon production. >> but not everyone is happy about it. >> when you mess with mother nature, so to speak, i have concerns with that >> some of it is about returning to time-tested techniques. we'll travel to wa and india, where farmers are using a combination of old and new methods that are better for the soil and water,we use resources, support small scale farms and may even improve the quality of the crops. and as for h food gets to those who need it most, we'll take you to lebanon and jordan, where aid workers are using new technologies to better provide food to hundreds of thousands of syrian refugees. >> insad of paying with cash or with a card, everyone pays with their eyes. and you can never forget your card. it's biometrics, it is the future. we see it more and more. lastly, we'll travel to franceto ook at a one-of-a-kind , tional program that's cracking down on food wasile also helping feed people in need. >> reporter: so this is stuff that is no longer proper to sell? >> yes, but proper to eat. f it's shocking to think that this is the kinding that otherwise would have been thrown away. >> reporter: tune into your local pbs station and online for the pbs newshour weekend series "the future of food."th >> is "pbs newshour weekend," sunday. >> sreenivasan: new five-part online docu-series examines an onn'oing crisis in the natios largest public housing authority." a dream deferred: the broken promise of new york city public housing" premieres this week, it's part of the continuing series "chasing the dream: poverty and oprtunity in america." >> the conditions that i've seen here at n.y.c.h.a. are some of the worst i have seen ywhere. and the shame is n.y.c.h.a. at one time was the model of pb housin it was the best. it's gone from the best to the worst! you have children living with asthma in units with mold. this is new york city! it's not ah tird-world country! you are 400,000 people.t you want to e attention of the politicians? you say 400,000. you want toet people to support you? expose the nditions and the truth. there is no one who will se what saw and allow it to continue >> my name is sylvia harrington. i'veoeen cmplaining for years. it fas on def ears. so we decided to work together, a few other people in the community, and bring the place back to the wayt was when i move here. i spent money buyingse trees and every kind of flower out there. i've had people tell me, "the reason we come this way to go to rk is to admire your flowers." it's just my idea of the w i want to live. >> sreenivasan: italian director franco zeffirelli, whose productions included films, operas, stage plays and even live broadcasts from the vatican, died today in rome. in the u.s., zeffirelli is best known for his films includg a 1968 veron of romeo and juliet and for the made-for-television mini series "jesus of nazareth" released in 1977. franco zefirelli was 96-years- old. that's all for this edition of" pbs newshour weekend." i'm hari sreenivasan. thanks for watching. have a good night. captioning sponsored by wnet captioned by media access group at wgbhss acgbh.org >> pbs newshour weekend is made possible by: bernard and irene schwartz. suand edgar wachenheim iii seton melvin. the cheryl and philip milstein family. dr. p. roy vagel diana t. vagelose j.p.b. foundation. rosalind pwalter. barbara hope zuckerberg. corporate funding is provid by mutual of america-- designing customized individp l and grtirement products. that's why we're your retirement company. additional support has been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. thank you. be more. be more. pbs.ou [s of the door opening] [sound of turning on the power button] [sound of albums being pushed in and out] [sound of the needle being placed on threcord] "in the flesh" ♪♪

vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america-- designing customized individual and group retirement products. that's why we're your retirement company. h additional suppo been provided by: and by the corporation for public broadcasting, and by contributions to your pbs n from viewers like you. thank you. from the tisch wnet studios at lincoln center in new york, hari sreenivasa >> sreenivasan: good evening and thank you for joining us. trusmp administration offici in washington and in the middle east are holding talks with allies in the region, as the u.s. reprepares to add sanctions against iran tomorrow. before leaving for saudi arabia and the united arab emirates this afternoon, secretary of state mike pompeo said the u.s. is preared to negotiate directly with iran with no precondatitions, but sanctions will continue. >> on monday, there will be a signifint set of new sanctions, and the world should know that we will continue to make sure it's understood that this effort that we've engaged in, to deny iran the resources to foment terror, to build out their nuclear weapons system, to build t their missile program, we are going to deny them the resources they need to do that, thereby keeping american interests and american people safe, all around the world. >> senivasan: in jerusalem today, national secu brity advir olton met with israel's prime minister benjamin netanyahuan to discuss shooting down of a u.s. drone last thursday, and the u.s. decision lnot nch a military strike. >> neither iran nor any other hostile actor should mistake u.s. prudcend discretion for weakness. no one has granted them a hunting licse in the middle east. >> iran is facing unprecedented economic pressure as a result of its aggression. so i was pleased to hear president trump make erear yey that pressure will continue and that pressure will increa >> sreenivasan: in an interview with an iranian news agency, president the united states for "new tensions in the region" and called on "international bodies to show proper reaction to this u.s. aggressive move." and, in an interview taped on friday, president trump said he is willing to talk. >> i'm not l and if there is, it'll be obliteration like you've never seen before. but i'm not looking to do that. but you can't have a nuclear weapon. you want to talk? od. otherwise, you can have a bad economy over the next three years. >> no preconditions? >> not as far as i'm concerned, no preconditions. >> and you'll talknyway? >> here it is, look, you can't have nuclear weapons, and if you want to talk about it, good. otherwise, you can live in a shattered economy for a long time to come. >> sreenivasan: ethiopia's prime minister said today that a coup attempt against a regional government north of the capital of addis ababa failed late yesterday, and that a high- ranking military chief and several others were shot and killed. prime minister abiy ahmed appeard on state-run television late at night wearing fatigues and calling for calm. n he told tion the military leader was killed by his own bodyguard.s as n of the coup attempt emerged saturday night, all access to the internet was shut down, and army and police checkpoiwent set up around the capital. turkey's president recep tayyip erdogan's ruling party narrowly lost a re-run election in the race for istanbul's mayor today. in the first election, the opposition candidate defeated erdogan's justice andty development pandidate. but turkey's electoraouboard threw t the results and ordered a new vote, claiming that some of the officials e erseeing te were not civil servants. the winner's successful campaign focused on urban poverty and turkey's economic recession. erdogan's ruling party has been in control of turkey since 2002. >> sreenivasan: former house speaker paul ryan will sit down with judy woodruff tonight to discuss life after congress. watch the interview live beginning at 10:30 eastern time at www.pbsrg/newshour. >> sreenivasan: this week, the top 20 democratic presidential candidates are facing off over two nights in miami. it's the first official debate of the 2020 primaries. special correspondent jeff greenfield talked with a bipartisan pair of strategists to learn what the candidates can do in a such a big field, and whetbaher a more than seven months before the first votes are cast will make any difference at all.he >> candidates need no introduction. >> reporter: if you think this was thfirst broadcast presidential debate, think again. back in 1948, republican governors harold stassen and thomas dewey sounded off on radio before the critical oregon primary. >> for the past few weeks, oregonians have been rticipating in a red hot political campaign. >> reporter: and in 1960, before edhe spaith richard nixon, john f. kennedy debated texas tor lyndon johnson at th democratic convention. >> i appreciate what senator johnson had to say. he made some genel references to perhaps the shortcomings of oretherdential candidates, but as he was not specific, i assume he was talking about some of the other candidates and not about me. ( laught ) >> reporter: but over the decades, primary debates have radically changed: there are more of them, they begin earlier and earlier, and the number of contenders has exploded. this coming week, 20-- count them, 20-- democratic hopefuls will meet over two nights in miami. but as candidates from new york to california, from texas to wahington state, as an army of journalists descend on miami for these debates, a question arises: with ten candidates on the same stage at the same time, is that a debate? >> not a classic debate. you have a, basically a joint appearance. >> reporter: mike murphy has been a significant player in republican politics going back more than 30 years. >> there's still some of the same risk, but it's not a classic one- or two- or three- way debate, with real candidate- on-candidate conflicts. it's just not the nature of the beleast, with that many pe >> reporter: that's a view with bipartisan support. robert shrum's work with democrats goes back nearly half a century. along with murphy, he runs a think tank at the university of southern california, and agrees witmurphy that a huge debat field means a specific strategy for each contender. >> so, what's really important for everybody, they're going to look for a moment. they're going to look for a line, an opening, something that can capture people's attention, get out, and really work. >> reporter: these "moments" have become ingrained in political lore. there was ronald reagan's response when threatened with a microphone shutoff, after his campaign had funded a 1980 g.o.p. debate: >> i am paying for this microphone, mr. green! >> reporter: or ex-vice president walter mondale's jibe at senator gary hart in 1984 about his substance: >> when i hear your new ideas, i'm reminded of that ad: "where's the beef?" ( laughter ) >> reporter: and sometimes, that need for a moment can turn bizarre. in 1972, when anti-poverty organizer ned coll ran for the democratic nomination, he tried to dramatize urban poverty by brandishing a rubber rat. a "momo ent" can a highly unwelcome, as when texas governor rick perry t 2011 forgotremember what federal agencies he wanted to abolish. >> the education... uh, the, uh... ( laughs ) >> commerce. >> coms merce... and, lee. i can't, the third one, i can't. sorry. oops. >ck> reporter: or when ba obama flippantly "complimented" his rival. >> t i donnk i'm that bad. >> you're likable enough, hillary. >> thank you so much. ( laughter ) >> reporter: so as these 20 candid and into the debate hall, they and their advisors will be dealing with a raft of questions about strategy and tactics: when orf to critihoze a rival, w to stand out in the crowd. i asked our two war-room veterans to put on their "advisor" hats and offer some insigh into how these ndidates might approach these questions. i'm jenoe babout to go into this debate. give me the one thing i most have to remember, and to do, and not to. >> if you're joe biden, the thing you most want to do in this debate is demonstrate vigor and command of the issu, because people assume that, but given his age, they want to make sure. >> reporter: okay. next call's coming to you from bernie sanders. what's my goal? >> i'd say your goal would be to look like a happy warrior, instead of an angry warrior. and i would advise you not to attack elizabeth warren or joe biden, at which point he would hang uphe phone. >> they've all got their own agenda, beyond getting noticed and "doing well." mayor pete has to show a little ghness does he take a generational poke at bernie, who's a much easier target than the belov joe biden? so, they all have a reason maybe to have a conflictinute with sobody, because that's also the best way to make the media tape. mediaan conflict. >> reporter: but suppose one of these candidates does stand out from the crowd with a powerful argument, a powerful impression. will nythat really make difference to voters here in california? or for that matter, in most other states, who n't actually be voting for eight months or more? >> probably not, although i think people are shopping, and so, if you make a good impression, that can stay with you. >> reporter: and mike murphy has one more piece of advice, borrowed from baseball: don't go for the home run. you want to swing for the fences, or you want to be a contact hitter? >> contact hitter. swinging for the feines is ruafter risk. and there are a lot of debates. this isn't the only super bowl. so i think the best thing to do is get your moment, ere you can look at the camera, connect wih people with something thate is tabout you, so you say it with confidence and strength, and rele >> sreenivasan: and joining me now is jeff greenfield, who will be watching the debates this week. jeff, a crowd of 20. how they separate themselves out from the pack, as you just laid out here, they're all going to be looking for these "moments." how are they sure that they can get one? well, that's one of the interesting questions about so large a field. one t thing i'm confid predicting is, somewhere in these debates, the lesser-known candidates will complain that nobody'asking them any questions, because there's no guarantee of equal time. and tr he other dan, if you rehearse a clever line too much, and it sounds like something your atsdvisors or consult have come up with, it actually doesn't help you. and so a, itery, very difficult icallenge, partarly for the ones who are at one-half of 1% in the polls. >> sreenivasan: anthat cut-off line, that's been decided by the d.n.c., on the number of supporters you have, the amount of money you've been able to raise, to get you through-- are those hurdles going to change over time, to try to whitt? the field do >> yes, they've already-- the democrat in the later debates, they're going to ratchet up the conditions, toake it not just one of three, but allhree. but, look, i have to say that, you put more than four or five people on the same stage, you're asnot having a debate, as mentioned in the piece. you're having a-- i don't know what, a cattle show, and the idea of any kind of exchange of views is difficult. instead, you have, you have the candidates looking at the strai tegy, "who a with?" sanders and warren are not going to be able to face off on who's the m they're on two different nights. and so, it creates a whole bunch of difcult questions for any candidate, and any candidates they have to try to figurout. >> sreenivasan: given that we're living in this time where everything is kind of stagrammed, or chopped down into social bits, how do we get to a point where we can say, okay, this is what this candidate's substance is about, this is that, kind of, that somethg, that, in the body language, something that, non- verbal cu te that makes me wa trust this human being? >> to me, part of the onsibility is on moderatorsto ask questions at actually push a candidate to say something substantive abouthi herself oelf. i would, for instance, be very intereabsted in hearing elh warren answer the question, "if you think the wealth tax that you propose is such a dea, how come almost every country that's tried it, has abandoned it, because it's too difficult?" i think the biden questions, instead of the obvious ones, "what dayid you mean byg that you can work with james eastland?" is to ask a broader question. so many of the people that he cites, in workg with, have literally not been in the senate for 30 years. isn't this an indication that you may be past your prime. it's up to the moderators in this very wide field the try to zero in particularly on a more credible candidate and ask some tough questions about where they stand. >> sreenivasan: and finally, it matters more perhaps in our industry but the idea that msnbc was given the right to this and cspan and other networks were denied, does that end up reflecting our polarized society and fox gets debates inm6 future and with certain debates only go to one channel william. >> it is an outrage to me that a political party has ceded a preliminary debate to one network. nichnip this in theud. not going on fox debate to try e. persuade people who may be persuada i think we have already seen the polarizati, if you aren for trump you're going to watch fox, if you are not for trump you are going to watch nbc cnn. i hope some kind ever reversal and say, we'll did on fox and say a lot o what you have said about us is wrong. >> sreenivasan: jeff greenfield, thanks so much. >> thank you. >> sreenivasan: if you think back to high school, you may remember some of the laws of classical physics, like newton's third law of motion: fry action, there is an equal and opposite reaction. intuitive laws like these form the basis of classical physics, and they're all true. except when you get to the smallest units in the universe. this is the domain of what's known as quantum mechanics. it's how particles smaller than atoms interact with each other, and at this miniscule scale, entirely different laws of physics apply. in fact, it may be possible for one particle to be in two different places at the same time. it's aifficult concept for anyone to understand, but understanding how subatomic ould lead toteract major technological leaps. in fact, researchersudre already ng how quantum mechanics could lead to breakthroughs in super ing, encryption, and even medical treatment. but, i quantum technology, the u.s. may be falling behind. christopher bookorts. >> reporter: in 1957, a russian ertellite called sputnik u in the space age when it orbited the earth for the firstime. few may realize it, but a chinese satellite launched in 2016 may have a similar scientific significance. it's the wor's first satellite containing quantum communication technology. it's been called quant's sputnik moment. why is that? >> well, i think it was an awakening in many areas of the government to note that it was technologically possible. >> reporter: university of chicago professor david awschalom has spent a great deal of time thinking about that awakening. not about the satellite itself, but how, after decades of investment in quantum research, american capabilities have been surpassed. >> to put a satellite in orbit that could send entangled particles of light to ground stations 1,000 kilometers apart... it's an extraordinary technological achievement. >> reporter: the launch is a giant leap forward in a global race to develop technology that exploits the principles of quantcsum mecha those are the governing behaviors of the smallest parti.cles in the univer >> the fact that we can control the quantum properties of individual oms, electrons, clei, even photons, will lead to lots and lots of new applicfrations new types of medical diagnostics, to new types of seors, to encrypted and safe communication, to advanced tes of computing. reporter: and this is what the chinese satellite did. beaminlight particles called photons back to earth, it demonstrated that impenetrable, encrypted communicbeion might no possible. >> one of the odd things about these quantum states, is, the act of looking changes them. so you might think that's a liability, but for secure communication, that's an asset. if you send me a quantum ate, and somebody attempts to eavesdrop, you'll change the message. you'll actually destroy the .essage >> reporter: so, as an outside viewer, if we were to try to look aton that transmisthe state would change? we wouldn't be able to interpret what it was saying? >> correct. this is one of the unusual, weird properties of quantum mechanics that make it very difficult to grasp, for any of us. reporter: difficult to grasp, or even harder than that. after all, the words of the most famon-us americaborn physicist of the 20th century, richard feynman, still resonate more than 50 years after he said them: >> ...i think i can safely say that nobody understands quantum mechics. ( laughter ) >> it's complicated in the sense that it's extremely non-intuitive. it's counter-intuitive. we d won't see this in old today, right? we don't see the properties of matter that could allow you to walk through a wall. >it> reporter: minute, properties that would allow us to walk through a wall? >> in the quantum world, that's lowed, with a certain probability. in our world, in the classical d, that doesn't happen. that can't happen to you. this type of interactions has bee tn happening atomic world forever. it's how matter is put together. it's how matter ieracts. it's the-- potentially the puzzle pieces that keep our wor together. ths clean room is one of the best in the country. >> reporter: for decades, the u.s. has been working on this puzzle, spenng around $200 million a year in research and development grants. that sounds le a lot. but in recent years, many other developed nations have launched s,tional quantum initiati pumping billions into programs of their own. most notably, china. while the exact number is not known, some estimates put their ent at tens of billions of dollars. >> china has launched a major program; europe, japan, australia, canada. so, i don't believe the united states is behind, but i think the united states will have formidable competition. >> reporter: last december,co ress approved a slight expansion of u.s. efforts, establishing the national quantum initiative act committing nearly $1.3 billion of federal money to the research of quantum information science over the next five years. the act also establishes a federal strategy to coordinatedy research alraking place in universities and private industry. but if tuihe u.s. hopes to b and patent those quantum products of the future, awschalom says funonng is not th issue; the country will need to dramatically increase the numbnter q scientists. >> well, without a workforce, it won't happen. we need torain students that are both comfortable with these new experimental techniques; develonew microscopes, n ways to look at matter; and essentially bring industry up t speed, translate these ideas into a larger setting. so, they're absolutely critic. >> reporter: there is also a fairly long turnaround time, because the students that we train today, we are talking essentially almost a ten-year development period? >> it is important to appreciate that. so, a graduate ph.d program is five to six years. then there are couple of years of engagement. so if we drton't sow, we will be a decade behind. it is very important to launch this now. so, the yellow light is designed so they can make smaller circuits. >> reporter: in 2013, when the university of chicago convinced awschalom to move his qubotum tory from the university of california at santa barbara to its new institute for molecular engineering housed in a $300 million state-of-the-art building, he brought 12 graduate students with him, and was one of only four professors. but today, with university, federal, d corporate, and nor funding, the institute has expanded exponentially, just hiring iets 31st full-t professor, and teaching 128 graduate students. in may, after receiving a $100 million gift, the institute became the nation's first school dedicated entirely to molecular engineering. but awschalom says the u.s. will need thousands of quantum engineers if it hopes to outpace the efforts of foreign competitors. and it will need the help of private industry, which the universittny of chicago ps with. >> some major american companies, like google, and ibm, and microsoft, and intel, all now have msquantum prog so, it's beginning to move. people are seeing real systems being built >> reporter: in addition to advanced encryption, awschalom says applications of quantum technology will include dramatic increases in computing speed, as well as the development of precise medical diagnostic tools. >> so imagine putting a sensor in a living cell, watching information moving through the membrane, measuring the temperature of the cell precisely. look at the effect of a pharmaceutical in a biological system. it would revoluonize areas of medicine and healthcare. >> reporter: but awschalom says that the biggest advances from qutum technology will likely be beyond what we can imagine today. >> you know, we're just at the beginning. and, you know, a nice parallel is when yothink about the electronics technology. we're at the stage of the first transistoreing developed. that's the way a lot of us like to think about it. and i thinit's hard to imagine, when people built the first transistor that was about the size of your thumb, that there'd be hundreds of millions of them in an iphone. it's very hard tpredict where these things will go, and i think many of us will not be the users of quantum technology. it will be the next generation. >> reporter: with the space race, it was identifiable to everyone. we're going to send a rocket to space. we're going to put a person on the moon this isn't like that. .> well, in a way, it is; in a way, it isn aat i found extraordinary about the space race iecision was made to go to the moon, not really kt,nowing how to dout with the confidence that, when problems would appear, they would be solved.t so, quum technology, i view a little bit of that. there are challenges, but i'm very confident the community willvercome them. and i think in the end, it will end up being more exciting than we envision today. >> this is "pbs newshour weekend," sunday. in the czech rndublic today, reds of thousands of people gathered to call for the ouer of theri country's minister. it was one of the largest demonstrations since the 1989 "velvet revolution," which ended communism in what was then czechoslovakia. protests against the billionaire businessman prime minister andrej babis have grown in recent weeks, as he faces vestigations over alleged fraud and conflicts of interest. babis denies the charges. thousands marched through georgia's capital city of tbilisi last night to the headquarters of the country's ruling party. it was the third straight day of demonstrations against what the protesters say is too close a relatiobenshieen the georgian government and russia. on friday, russian president vladimir putin canceled all flights from russia to georgia, starting on july 8, an econothc blow to country's tourism industry. putin's decision followed violent protests on thursday, when a russian ltor was being allod to speak inside the parliament building. climate activists in germany called off demonstrations today inside of one of the country's largest open-pit coal mines. the protesters were attempting to save a forest that a utility company is planning to ra in orer to expand the mine. they left the mine after arrests and repeated warnings that they faced life-threatening danger. mining activity was halted during the three days of protests. one year after being trapped in a cave in northern thailanfor nearly three weeks, some of the rescued boys, their soccer coach, and members of the rescue teamran and biked in a marathon today. thousands participated in the event to raise funds to improve conditions in the cave complex where the boys and their coach were trapped during flooding last year. several of the rescued boys and their coach posed for photos and ran in the marathon. government officials also honored the thai diver who died during the rescue mission. >> sreenivasan: on tomorrow's >> sreenivasan: on tomorrow's newshour, a look at stonewall at 50. personal reflections on the movement toward gay rights. that's all for this edition of pbs newshour weekend. i'm hari sreenivasan. thanh for watching. e a good night. captioning sponsored by wnet captioned by media access group at wgbh h. access.wg >> pbs newshour weekend imade possible by: sc bernard and irenartz. sue and edgar wachenheim iii. seton melvin. the cheryl and philip milstein family. nadr. p. roy vagelos and d. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america-- designing customized individual and group retirement products. at why we're your retirement company. additional support has been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. thank you. an ed: the e hawaiiowboys were considered some of the best cowboys in the world who made a tender air-dried beef jerky called pipi kaula. come with me, ed kenney; and musician kuana torres kahele to a california adobe and discover how these traditionsf music and food are still enjoyed today. er thare so many reasons why i became a chef. er dish has a story. food brings people together and has the power to conjure up cherished memories. i was born and raised in the hawaiian islands, one of the most diverse communities in the world. in t s show, we'll meeta guest f, learn about their favote d

vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america-- designing customized individual and group retirement products. that's why we're your retirement company. additional support has been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. thank you. from the tisch wnet studios at lincoln center in new york, hari sreenivasan. >> sreenivasan: good evening and thanks for joining us. the united stateand china put their tariff war on hold after president trump and president x jinping the g-20 summit in osaka, japan today. the agreement does not endal tariffady in place, but the president said the u.s. will not impose new 25% tariffs on $300 billion in chinese imports that he had threatened, and that we will lift some restrictions on the chinese technology company huawei. in return china will reportedly buy mo american agricultural products and trade talks will resume. >> we're going to work with china on where we left off to see if we can make a deal. china is going to start, they're going to be consulting wh us and they're going to start spending money even during the negotiation to our farmers, our great farmers in thest. >>reenivasan: before the multinational talks wrapped up and bere heading to south korea, the president tweeted an invitation to north korea's leader, kim jong un, to meet him at the dilitarized zone between north and south korea. "if chairman kim of korea sees this, i would meet him at the border/d.m.z. just to shake his hand and say hello." a north korean official called the trump twitter invite "a very interesting suggestion." questioned about t possible meeting at his news conference today in osaka, the president said north korea was" receptive," but did not confirm that the meeting would happen. for more on the g-20 and president trump's wide-ranging news conference, scott horsley-- chief economics correspondent for npr-- joins us now from seoul, south korea. first off, the big news is the china trade riffs, any kind of negotiations that might restart again. >> china has a kind of longa history of ying rope-a-dope with the united states, nodding, saying we're going to make changes and then maybe not actually changing their behavior. so if the measure is going to b actual verifiable changes in china's behavior, this could be really tough negotiation, and certainlye trump administration will continue to hold out the threat of even mory tariffs if ton't get what they want. at the same time, you know, don't forget welready have 25% tariffs on some $250 billion worth of chinese imports. a lot of those are not thing that are quite so visible to annsumers but they are having effect on the u.s. economy. >>eah, i was down in wisconsin this week, a lot of farmers are feeling it. let's talk also about what's happening in terms of this possible visit in north korea to the d.m.z. and the president seems to suggest an impromptu possibility of chatting with kim jong un. >> so the president tweeted that he was inviting kim jong un to come and have a hand shake with him at the d.m.z., the heavily anrtified border between north south korea. they say they've got an positive responserom the north koreans but aren't saying definitively kim will show up. >> you have one dayon lefhe trip. what are the expectations, what will happen in korea? >> this will be a compelling ldoto onif kim jong un shows up. trump said he wave no problems about stepping into north korea. so i think there certainly will be apectacle. but is there going to be meaningful movement on thnd effort to north korea's outlawed nuclear program q that's anothestion. remember the last time kim and trump met, it didn't go so well. president trump was sort of downplaying expectations for a substantive movement on the denuclearization puzzle. it's probably going to be a couple ofments at most if he and kim do meet up. >> also press available to ofs? so a press conference? a very wide ranging one? y new news from that? >> the president had news toan unce, news that would rally the markets that the economy would feel good about with this trade truce with chi. he buried the lead, gave a lengthy opening statement and barely spelled out what the trade truce wowfnlt reporters asked can you explain what was doing on, mr. pre adent? but o touched on the potential meeting with kim, the democratic debate. he was joking with reporters saying, do you want me to stop, keep gng? says i'm in no hurry, my plane will wait fore. a lot of reporters who had commercial plane tickets were nervously lookg at their watches and saying we don't want to stop the questionsut we have to make our way from japan to korea soon. >> scott horsley joining me from seoul, south korea, thank you so much. >> my pleasure. >> sreenivasan: in a pair of iflings late yesterday, a u.s. federal judge in cnia blocked the trump administration from using defense department f nding for construction oa wall on the border with mexico. u.s. district court judge haywood gilliam ruled that $2.5-billion allocated for anti- drug programs could not be used for the wall. two cases-- one filed by california on behalf of 20 states, and other led by the a.c.l.u.-- challenged president trump's order to divermore than $6-billion in federal funding after declaring a national emergency last february. the rulings clear the way for the u.s. ninth circuit court of appeals to take up the issue as soon as next week. florida govern ron desantis signed a bill late yesterday that puts limits on a planned voting rights expansion for convicted felons. the state's voters passed an amendment in november to restore voting rights to as many as 1.5-million people with felony records. but the republican-controlled state legislature voted in mayui to r felons to pay court- ordered fines, fees, and restitution to victims before they can register. the american civil liberties cunion of florida and othil rights groups have already filed block the law. on the italian island of lampedusa in the mediteranean sea, a german captain of a humanitarian rescue ship was arrested todayfter ramming an italian police motorboat. the captain said she decided th 40 migraon board could no longer wait toock after 17 days at sea. the migrants were scued from a boat launched by libya-based human traffickers. italian officials were refusing to let the migrants dik until other european union member states agreed to help. the nations of finland, france, germany, luxembourg, and portugal have now offered asylum to the migrants. ptlawyer for the ship's can said she was arrested for resisting a warship after she hit a customs and border police force motorboat blocking access to the dock. no one was injured. for more on the fate of the migrants and the captain of the rescue ship, visit pbs.org/newshour. >> sreenivasan: the stonewall riots in new york city were a flashpoint in civil rights history. 50 years ago, gay, lesbian, trans and other gender non-conforming people ried at a bar called the stonewall inn, liter police raided the club. the new york publiary has one of the largest collections of artifacts from that tumultuo being displayed in a major exhibit. newshour weekend's ivettee feliciano spth the exhibit's curator about what is widely seen as the birth of thef modern dht for l.g.b.t.q. rights. r: in its exhibit titled "love & resistance: stonewall 50," the new york public library is marking the momentous anniversary with never before seen photos and artifacts from an era that defined one of america's great fights for human rights. >> these are really t me of the fimonstrations in the united states for l.g.b.t.q. rights. >> reporter: jas baumann curated the exhibit and is coordinator of the library's l.g.b.t.q. initiativ he says the events at new york city's s changed the face of gay and trans culture and activism. the weeklong uprising that began on june 28, 1969 brought to light systemic crackdowns on a culture that was not seen as socially acceptable. >> these kinds of raids were fairly routine at these clubs the village in the 1960s. many of the bars that catered to gay and lesbian and also transgender patrons were illegal clubs. because a bar could be shut down or lose its liquor license, in eye 1960s in new york, if had gay or transgender patrons. demonstrations in '65. >> reporter: the exhibition begins during the period before the historic rebellion, in 1965. >> you'd had this almost a decade of this political activism. ere were also a number of riots before stonewall around the country-- at compton's cafeteria, at the black cat and other establishments that leads up to it. e reporter: one of the main attractions of tibit, rare photos by noted photographers kay tobin lahusen and diana yvies, who captured every life. >> so often, multiracial,i- muhnic couples. often also older couples to shot that l.grelationships aren't these fleeting illegalgs clandestine thbut really that you can make a life together. eporter: another section shows photos of pioneering demonstrations like this one from a 1965 march in front of the white house. >> so you have these activists from the 1950s and 's who had a very kind of conservative appearance, who were often trying to find ways to slowly work within the system. >> reporter: but the exhibit demonstrates a change in the tone of l.g.b.t.q. activists after stonewall, particularly in san francisco and new york city's greenwich village. >> you have this new generation that joins. and these younger people who were on the streets of the village really have a much more confrontational politics. >> reporter: featured in the exhibit are activists marsha p. johnson and sylvia rivera, two transgender women color who, in 1970, co-founded "star" or the "street transvestite action revolutionaries." e organization addressed the concerns of low-income and homeless queer and trans ethnic-minorities. >> people debate about this, but it seems fairly clear from people's memies of stonewall, that it was actually transgender women of color who were really he front lines of the conflict with the police those first three dama of stonewall. ha p. johnson and sylvia rivera were on the frontlines of all the demonstrations in 70e ivfore them you didn't have this kind of street am. they really had a very broad intersection political agenda. >> reporter: this new wave of activism emboldened thousands across the country to express themselves. dozens of organizations formed, including the gay liberation front and radical lesbians. the exhibit also features gazines that existed before stonewall that boldly brought people out of the shadows. >> they start puing real happy lesbians on the cover. before that, lesbians would be depied as killers as mentall ill as criminal, right? or suicidal. so to have this happy, out, well-adjusted human being, full human being on the cover of a magazine as a lesbian is totally revolutionary. >> reporter: another section titled "bars" features invitations to dances, bars, and discos that blossomed after stonewall. >> so you see in the activism part of it is creating alternative nightlife, of creating these dances in all of these kinds of different alternatives to police entrapment in the bars. so it is about creating these spaces for freedom. (cheers and applause) >> reporter: to recreate this era, the library hosted at cabaret ni april with a performance by the iconic singer hed comedian justin vivian bond. >> i called my mup. i said, "mom, we're going to bei in ' fair.'" she said, "is that a gay magazine?"au ter) >> reporter: also featured were a younger generation of tivists and entertainers >> my sisters are literally dying. ♪ (cheers and applause) >> my sisters are literally dying. ♪ ♪ ♪ dying >> l.g.b.t.q. history really isn't taught in schools. they aren't being brought up getting this history. we're often given this kind of narrative where stonewall's sord of like this geginning of gay liberation that starts, and then all of a sudden, then there's gay marriage, and we're not given all of the steps in between. and i think the real lessons from all of that is that our society changed beuse people became active politically. and it can inspire people today to really realize that our society changed because people got out of their houses, and into the streets. >> reenivasan: the landmark 1954 supreme court decision brown v. brd of education declared school-based racial segregation to be al.onstituti it was intended to desegregate schools-- but that isn't exactly what happened, at least in new yorktate. researchers have found that new york city has some of america's most segregated schools. in the first of a two-part report exaning school diversity and equity in new york city, i met with a group of students protesting segregation, and visited a district in brooklyn with a plan to increase diversity. this is part of our ongoing series, "chasing the dream:an povertopportunity in america." >> we are integratenyc! ( cheers and applause ) >> sreenivasan: on the 65th anniversary of brown v. board of ucation last month, students from across new york city gathered in times square.ey anded out newspapers declaring "retire segregation" and called for the city's public schools to be integrated. >> it's been 65 years since segregatioin schools on the basis of race has been ruled unconstitutional. >> sreivasan: a u.c.l.a. study of public schools found in 2014, and again this year, that new york remains the most segregated state for african american students, with 65% of them in intensely segregated schools. the study found it was the second most segregated state for latino students. we sat down with three new york city high school students-- members of the group integratenyc-- who have been meeting with school district leadership, urging them to implement what they call a "reao integ" plan for the next generation of students. >> looking at how the city is segregated, we've e ticed that the five main ways thatgr the ation happens. >> sreenivasan: the students' plan addresses what they call the five r t. enrollment process, the resources that are distributed, the retionships in the schools and the curriculum. restorative juanice practices teacher representation. >> the mission is to have real inteation in schools. more resources for everybody. >> sreenivasan: how do you get there? >> by getting more young people into the movement because they're the ones that are affected by the system, and telling students that don't feel like leaders that they are leaders and th can make change in their own schools. >> sreenivasan: what does an integrated school look like to you? >> an integrated school would reflect that outwards community. if there's a certain percentage of white students, black, asian, latin, you know, the school should be able to reflect that. there's students who are english language learners, students with disabilities. there's different ways that students experience life and all of those different experiences put together in a school community are what make it so different and special and help the students learn from not only the content they're being taught but each oer. >> sreenivasan: new york city aps more than 400 high schools. when eighth gradery, they rank their top 12 choices. but"ny schools have so-calle screens," such as tests, attendance or g.p.a. requirements. >> you're a 12-year-old. and you have to choose out of a huge book and some of them with tests you have to take. but the problem withis that if i go to a school in the bronx, there's not-- there's not that many resources as some schools that have higher pay or higher resources than in manhattan or in brooklyn. like, there's different schools with differe resources. >> sreenivasan: so not all new york city public schools are created equal. >> no. >> no, they're not. >> the fact that we have any school system that is still segreged is really an indictment on all of us. so we want our schools to reflect the diversity of our city. >> sreenivasan: new york city schools chanllor richard carranza has led some of the country's biggest school districts. he says big changes to thece admissions p have begun, not for high schools, but for some middle schools.nt he poito progress for the admissions process at middle schools in two communityed ation districts. there are 32 of these districts across the city. brooklyn's district 15 is a racially and economically diverse district. it serves 6,000 students across 11 middle schools. a "working group" of community leaders, parents and educators looked at the district's data and found that the middle schools' use of screens, such as test scores, tardies and absences, disproportionatelyov "r black and latino students from the applicant pool. the group developed a diversity plan for the district over three public workshops, and proposed a plan, which the chancellor approved. dl district 15 removed all the screens of their mschools this year so students this year got to go to-- and choose to go to middle schools that in themi past where thet have been screened out. >> sreenivasan: in brooklyn, the district 15 diversity plan meath that while frade students still rank their middle school choices, previous as test scores, g.p.a., and attendance are no longer used. d w, seats are assigned ba a lottery. to reflect the district populaon, half of the seats at a school are prioritized for students eligible for free and reduced lunch, engliguage learners and those living in temporary housing. >> we heard from a lot of community members and engaging with families that really we ought to just create a school that serves students. any stent who wants to attend. >> sreenivasan: principal michael perlberg at m.s. 839 says that the district plan allows all students "equal access" to the school >> m.s. 839 was founded four years ago. it was the ly middle school in the district that used a lottery to admit students. and as part of a diversity pilot program, it began to set aside 40% of seats for low-income students. it's a random lottery for every single school. so there aren't any hoops for parents to jump through odi ons to make. >> sreenivasan: what are some of the challenges of rolling out a plan like this across an entirdi rict? >> i think buy-in. i know that a lot of families don't want their kid to be the first one for something to be tried out on. >> sreenivasan: do you think that it will scale? >> we've had a really positive experience with it. we've had to be really proactive and do a lot of work wit teachers and students and families arounanwhat does it o work in an integrated school? so from looking at our m curriculum aing sure it's not just a eurocentric curriculum but thawe are addressing the rich histories of all of our families, fro working with teachers and students about talking about race and having difficulter cotions, so i know that school leaders across the district have already been havinghose conversations about how to how to support their staff. >> sreenivasan: at m.s. 839, students are taught using a so- called "expeditionary learning" model. that means they have many outdoor and hands-on projects, but also have electives in the arts and music. in april, offers were sent out for next year's sixth graders in district 15. when will you kow at what you're trying is working and that you can institute it everywhere else in this city? we're monitoring very closely to make sure what are the consequences what are intended and unintended consequences? and being nimble to be able to address those issues as well. sreenivasan: given that you've worked in all these big school districts around the country, what have you learned about integration, equity, these kind of big ideas and how theynd translate downow can how they can work in new york? >> it's never an easy conversation. it always means looking in the mirror. and in the mirror i say "is what's reflected back truly what we believe in?"re and if t not an alignment with what we s we believe in and what the data is telling us the actual outcomes are, then why is that? so you have to work on systems and stctures. i've learned that in every community i've lived in. and i've lived on the west coast,ow in the east coast, and in between. and every community this issue has been an issue. i think the difference right now in new york city is that we are taking it on. >> sreenivasan: this month chancellor carranza, alongsi matthew diaz from integratenyc, announced that five additional districts would receiv$200,000 each to develop their own diversity plans. >> why not make a plan for youth, with the youth? >> sreenivasan: they include two more districts in brooklyn, and a district each in the bronx, queens and staten island. but the chancellor's most ntroversial proposal is to eliminate the admission test for the city's elite "specialized high schools."th story will air tuesday in part two of this series. >> this is "pbs newshour weekend," saturday. >> sreenivasan: little research has been done when it comes to understanding the early development of transgender children. psychologist and macarthur fellow kristina olson is using sciencto help change that. av ost recently ibeen study ago large cohort of hundredsof transgender and nongender children to understand what they're liefnlgt three to twelve when they start the study and we're following th for 20 years until they are young adults. two major findings from the transyouth project so far. these kids living as boys and girls who did not seem to be rhat gender when they were born have a gen that looks remarkably identical to the children born in their gender. a transgender girl looks like any other irls on our measures. if you could show me the data on a given child i could tell you whether they were gul girl or boy but not transgender. the second minder is the transyouth in our prject have good mental health. their ntal health seems to b as strong as any other child we have been studying in terms of having no higher rates of depression, for example having typical levels of high self-esteem, very young child. i think my interest inul part with transgender children came from a combination of just feeling like there's a group of people and in particular children ave really not been studied, and i found that to be unfortunateat given here's lots of decisions families and children have to mke, and thought this is an opportunity for science to play a role. i was quite surprised to learn that there was really not scientific research about the experiences of young were actually living as their gender and, so, that's when i decided that, you know, maybe that was aou way i make a contribution. >> sreenivasanfinally tonight, luis alvarez, died today. he is the former n york city police detective who pleaded with congress earlier this month to extend health benefits police officers, firefighters and others who responded to the september 11th terrorist attack alvarez died from complications of colorectal cancer, a disease heat was linked to the three months he spent inoxic rubble of the world trade center searching for survivors and then the remains of the tds of victims. he told lawmakers he was heading to his 69th round chemotherapy the day after his testimony. luis alvarez was 53-years-old. that's all for this edition of" pbs newshour weekend." m hari sreenivasan. thanks for watching. have a good night. captioning sponsored by wnet ptioned by media access group at wgbh access.wgbh.org >> pbs newshour weekend is made possible by: rnard and irene schwartz. sue and edgar wachenheim iii. seton melvin.e eryl and philip milstein family. dr. p. roy vagelosna t. valos. the j.p.b. foundation. rosand p. walter. barbara hope zuckerberg. corporate funding vided by mutual of america-- designing customized individual and group retirement products. that's why we're your retirement company. additional support has been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. thank you. be more. pbs. -our story beginsupportn mmore tha60 years ago.. inside an abandoned chicken coop, where our founder discovered a retired teacher living, no home, no healthcare. soand yes to transforming lives. it's this drive, this compassion that inspired aarp. today we empower people to choose how they live as they age. we provide health and financial resources. we strergthen communities evhere. we are aarp -- real possibilities. -additional support for "american masters" provided by the corporation for public broadcasting and by...

roy vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provideof by mutuaamerica-- designing customized individuan group retirement products. that's why we're your retirement company. additional support has been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. thank you. be more. be more. pbs.a mariver: perhaps the greatest mystery... is the human brain. cain only the past few s, scientists have made incredible leaps in our understanding. and we are just now raveling the secret of h the brain can change throughout our lives, leading to incredible transformation. hi merzenich: we have new understanding that the person that is within us is actually a product of change that occurs within our lifetime. this is new science. it's one of the great discoveries of our era, because it has the potential of giving everyone a better life.ve you'een given this gift. that's what brain plasticity is. seidler: the brain is adaptively c