captioning sponsored by wnet >> sreenivasan: on this edition for saturday may 16: u.s. commandos on the ground in syria kill a top isis leader; the united states loses one key weapon in the war on drugs; and, in our signature segment is it safe to control the spread of disease with genetically modified mosquitoes? >> the danger of this technology is exceptionally low. >> i don't want my kids to be laboratory rats. >> sreenivasan: next on pbs newshour weekend. >> pbs newshour weekend is made possible by:

corporate funding is provided by mutual of america-- designing customized individual and group retirement products. that's why we are your retirement company. additional support is 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 in lincoln center in new york, hari sreenivasan. >> sreenivasan: good evening. thanks for joining us. we begin tonight with news in the fight against isis. late last night, president obama authorized a rare and successful ground raid into eastern syria. the white house says u.s. commandos killed a senior islamic state leader, captured his wife and confiscated isis computer data in al-amr. officials say isis senior leader abu sayyaf was involved in military operations and oversaw illicit oil and gas operations funding terrorist attacks. his wife, umm sayyaf, is also

accused of playing an important role in terrorist attacks and may have helped enslave a woman who was rescued in last night's raid. sayyaf's wife is being detained in iraq. in a statement, u.s. defense secretary ashton carter called the raid a "significant blow to isil" and added: the ground raid comes just as the u.s. and its allies conducted six air strikes in syria and 15 more in iraq, all targeting islamic state fighters. but at the same time, iraqi government forces suffered a serious setback, losing control of ramadi. islamic state militants took over the city friday after a wave of suicide bombings. speaker of the house john boehner said that while he's encouraged by today's news, he remains "gravely concerned by isil's assault on ramadi that threatens the stability and sovereignty of iraq, which is vital to america's interests." for some perspective on the

raid, i'm joined by doug ollivant in washington d.c. he was the director for iraq in the national security council in the bush and obama administrations. he is a senior national security fellow at the new america foundation and a partner at mantid international. so, what do we know about this individual? why was he such a high-value target? >> there are many things we don't know about this individual. now, presumably, the u.s. intelligence knows the function that he is performing in the organization. he's evidently very tied into financing, oil sales, and the like. but exactly who he is we're not sure. abu sayyaf, his nickname meaning "father of sayyaf." we don't know who sayyaf is. presumably his son but we don't know how old or what he does. we seem confused where he comes from. the united states seems to think he's tunisian, but we have had reports out of the region saying he's from mosul and before that saudi arabia. >> sreenivasan: one of the interesting things i found is this is the first time i heard about u.s. troops on the ground in syria, and they were launched from iraq. >> that's right.

so this is the first time that we know of that u.s. special forces have gone into syria with the intent of killing or capturing enemy combatant. we know that there was the attempted raid to rescue hostages, such as james foley before. this is the first time they've gone forward to conduct combat and try to kill and capture people. and it was launched from. in the past iraq has been very circumspect about allowing attacks to be launched outside its borders into another country. evidently, the existence of the islamic state has changed their mind on that point. >> sreenivasan: criticking of the administration point out is this not a coincidence that this news is happening around the same time that ramadi, a city in iraq, is fallen into isis fighters? >> it's certainly convenient for the administration that the news is turning to this raid rather than the very real dangers in ramadi. on the other hand, the news this morning seems to be that ranadi is just a little bit better. some buildings have been recovered in the city. reinformats are flowing from

baghdad so there's a very real contest in ramaudey and we need to take it seriously, and the islamic state clearly had some good days the past day or two but we'll also see how this endsip. >> sreenivasan: there is another storied line on palmyra, another important site culturally that is threatened by isis' advance. >> a very beautiful set of roman ruins. i believe it is a unesco her ted site and it's being very much threatened by iselle as well. this is also important because we're seeing conflict between the syrian regime, the assad regime, and isil directly. many people have pointed out there are many place where's the two don't fight each other. well, there is a case where they are, and perhaps we're seeing the dynamics between the assad regime and isil changing as they're now in combat on this front. >> sreenivasan: in this larger narrative, how important is the killing of any single individual

in the leadership ranks? >> look the killing of any single individual never really matters in any organization. un we've-- we've heard him described as the chief financial officer of isil in syria. if you take out the "chief financial fer of any corporation in america, his junior, one of his underlingz will step up, take his place, step into that role. they doll something very, very similar. that said it never hurts to take out a senior leader and important let's intelligence that was gathered from this raid, the things that his wife knows, the data, the laptops, the thumb drives-- all this intelligence that's gathered in the raid may be very important. >> sreenivasan: all right, douglas ollivant, joining us from washington, thanks so much. >> thank you hari. >> sreenivasan: investigators in the deadly amtrak train derailment in philadelphia have called in f.b.i. experts to figure out whether something struck the left side of the train's windshield before the accident. investigators reportedly found

an unexplained, fist-sized indentation in the glass. the national transportation safety board says there's word another regional train might have been struck by some kind of projectile, too. investigators have also questioned the derailed train's engineer, but he told them he doesn't remember anything that happened after he left north philadelphia tuesday. the bodies of the eight victims have been recovered. more than 200 others are recuperating from injuries. in egypt, a court has sentenced ousted president mohammed morsi to death. morsi and more than 100 other defendants were convicted of escaping during a mass jailbreak in 2011. morsi supposedly colluded with foreigners to free islamic militants. he's currently serving a 20-year prison term for arresting and torturing protesters. just weeks before morsi took power in 2012, his predecessor, hosni mubarak, was sentenced to life in prison for allowing security forces to kill protesters during the "arab spring." it was later overturned. in northeastern nepal, crews

have recovered the bodies of all eight people on board the u.s. helicopter that crashed tuesday. the news comes just a day after search teams finally found the missing chopper in a remote and rugged area. six of the victims were u.s. marines. two were nepalise soldiers. they had been out on a relief mission. also today, a magnitude 5.7 struck nepal's capital city. at least 8,000 people have died since the first major quake and aftershocks since april 25. in southeast asia, myanmar's government says it is not responsible for the migrant boat crisis still stranding thousands of refugees. most of the refugees are muslims, fleeing ethnic persecution and poverty in myanmar and bangladesh. many have been stranded at sea for two months or more, with little food or water. crews did rescue almost 800 people yesterday after their boat capsized. indonesia, malaysia and thailand are turning away the boats, but thailand is hosting a summit at the end of this month to address the crisis. so far, myanmar is refusing to send any emissaries.

1,200 miles east of the andaman sea, chinese leaders are not backing down from claiming controversial territory in the south china sea, despite u.s. pressure. secretary of state john kerry met with china's foreign minister in beijing today, hoping to reduce tension between china and several other nations which border one of the world's busiest shipping routes. the u.s. is not taking an official position on the dispute. kerry called for a "diplomatic" resolution. >> sreenivasan: and now to our signature segment. a series of dengue fever outbreaks in florida in the last few years has raised concerns that the threat of the mosquito- borne disease may be outpacing mosquito control efforts. in the florida keys, officials are considering using a dramatic new approach-- releasing genetically-modified mosquitoes to kill off the species that carry dengue. the lab-grown mosquitoes have been tested in brazil and in the

cayman islands, but many keys residents worry that they will be living in the middle of an ongoing experiment. the newshour's stephen fee reports from florida. >> reporter: key west is a place where people generally come to relax, and the draw's pretty obvious-- white sand beaches, quaint architecture, the wildlife. but relaxing isn't on jessica brown's agenda today; she's a field inspector with the florida keys mosquito control district. and since it rained yesterday, she's got her work cut out for her. >> garbage cans, as long as they're turned over, they'll be good. >> reporter: there are 45 species of mosquito that thrive in the often-humid florida keys. brown's job: peck around peoples' backyards, clear out standing water and use tiny pellets and even larvae-gobbling fish to kill mosquitoes before they turn into adults. >> so, mosquitoes could depending on how long the water sits, lay their eggs, and have a

really big problem. >> reporter: her work's part of a $10 million a year effort by the keys mosquito control district, which covers all of monroe county in southern florida, to kill off as many of the flying bloodsuckers as possible because they're not just a nuisance. >> health officials find 39 cases of dengue fever in the keys. >> reporter: in 2009, an outbreak of a mosquito-borne disease called dengue fever struck the florida keys, the first local resurgence of the virus since the 1940s. >> dengue's really nasty when you get it. you know, you get a high fever. you get a rash all over. bone pain. they call it "break bone fever" because it hurts so bad. >> reporter: there were a few dozen cases and no fatalities, but the outbreak prompted mosquito control officials in the keys to consider an experiment that's never been tried in the u.s. before-- releasing potentially millions of genetically-modified mosquitoes to kill the species

that carries dengue and other dangerous diseases. but the idea of genetically- modified bugs flying around this traditionally fiercely independent community has many residents in the keys up in arms. >> we are humans, and we don't like being treated like guinea pigs. >> reporter: public meetings here in the keys have exposed a deep divide between mosquito control officials and some residents who worry that the genetically modified-- or g.m.-- mosquitoes could somehow make them sick. >> i am being told what to do, and i am being at risk for a >> reporter: is there any risk to my health if i get stung by a mosquito with a genetic modification like this? >> there's no evidence of any risk at all at this point. >> reporter: but "no evidence of risk" is different from the presence of risk, right? >> true, true. >> reporter: michael doyle is executive director of the keys mosquito control district and says the risk of dengue fever far outweighs any risks from genetically modified mosquitoes. >> the last thing we want people to do is to be concerned about coming down here and getting

something. and so, we're doing everything we can to make sure that never happens. >> reporter: the mosquitoes that carry dengue fever, called aedes aegypti, are tough to kill. they're immune to many insecticides and breed in sometimes hard to reach places, like underneath houses or in the leaves of plants like bromeliads. so, instead of sprays or pellets that don't reach those places, officials in the keys turned to a u.k. firm called oxitec. their scientists have developed a method to alter the mosquitoes' genetic code to kill them off, or at least kill lots of them. >> we've inserted two genes into this mosquito. one gene is a self limiting gene, and the other gene is a marker. now, the marker can identify where these genes are inserted, and the other one is the one that causes the offspring to die. >> reporter: scientist derric nimmo oversees oxitec's proposed keys trial. he and his colleagues are able

to tinker with the genes of male mosquitoes. >> those males have one job. they go and find a female, and they pass on their genes. and they pass on the oxitec gene along with their own genes. now, the offspring that inherit those genes, they die. and if you release enough of the oxitec males over a long enough period of time, you can get a crash of the mosquito population. >> reporter: oxitec says their method is both effective and safe. they've conducted small studies in the cayman islands, brazil and panama-- places where dengue is endemic-- and were able to reduce the population of mosquitoes that can carry dengue. and they say those experiments didn't harm anyone. with that in mind the five elected mosquito control officials in the keys decided to pursue their own g.m. mosquito experiment in the small island neighborhood of key haven. and oxitec agreed to conduct the trial for free a trial that has yet to begin. initially, florida keys businessperson mila de mier says

that all sounded great to her. >> i say, "wow, this is fantastic! this is a really, really great idea. be able to fight mosquitoes with another mosquitoes? what a great concept!" and, obviously, i don't like mosquitoes biting my kids or my dogs. >> reporter: but de mier says the more she considered it, she felt the science was too new and not enough was known for her to feel comfortable with g.m. mosquitoes in her community, despite oxitec's safety assurances. de mier started an online petition against the mosquito trial that's gathered 150,000 signatures from around the world. >> i do not want my kids to be laboratory rats. i don't want my kids to be guinea pigs. why? because this is a brand new technology. you get these mosquitoes you release once and for all, and then let's experiment to see what happens. >> reporter: university of florida professor phil lounibos has studied mosquitoes and the diseases they carry for over 40 years.

he's not involved with the proposed g.m. experiment in the keys. >> we believe, those of us who have worked with mosquitoes, that the probability of something going wrong is not very high. >> reporter: lounibos is convinced the trial would be safe, but he questions its effectiveness. he says other mosquito species can carry dengue, and the local bugs could evolve to outsmart the genetically modified males. >> in the absence of dengue, the absence of a really significant threat of dengue, i see the oxitec implementation in the keys in the context of strong public opposition to be inappropriate. >> reporter: globally, dengue has surged 30-fold in the past 50 years, and increased travel from endemic areas along with warmer temperatures means the threat is spreading. i asked de mier what might

happen if she blocks the trial and there's another, more serious dengue outbreak in the keys. do you worry that someone would call you up and say "mila you stood in the way. you did this"? do you... do you worry about that? >> no. >> reporter: why? >> no, because, to be honest with you, i think the... that people have to agree. and at this point, again, we are free of dengue for five years. we are, i think as a citizen as a mother and a taxpayer, i think these are my rights, and the whole community's right to choose. do we want to be part of these tests or no? >> reporter: did you ever think "maybe we should just go out and get everybody in key haven to just sign a piece of paper that says 'i'm okay with this'"? >> every person? no. because there's no way you can get 100 percent of people to agree to anything. that's, you know, putting in a road, putting a bridge. you've got someone who's going to disagree with it. >> reporter: the f.d.a.'s center

for veterinary medicine, which approves any genetic modifications to animals, will have the final say over whether or not the oxitec mosquito trial in the florida keys proceeds. an f.d.a. spokesperson told us there's no timeline for when that might happen. >> sreenivasan: for a closer look at how scientists are genetically modifying mosquitoes, watch the video on our facebook page at www.facebook/com/newshour. >> sreenivasan: for 15 years the united states' war on drugs in colombia has relied on crop dusting to kill the plants used to produce cocaine. but this week, columbia's government announced its phasing out the u.s.-led program. so, how will this shift in policy affect the relationship between the two countries? joining me via skype from bogota, colombia, is juan forero, the south american bureau chief for the "wall street journal." so give us a little bit of background for people just waking up to this story. what is the program we've been doing and why has it been so important?

>> it was 15 years ago what was called "plan colombia" which was a u.s. funded program began and it basically entoday used crop dusters to hit coca. this was a very controversial program when it began. there was a lot of criticism but this was approved in the bill clinton administration and it was 15 years ago, it was in december of 2000 when crop dusters hit industrialized fields of coca. >> sreenivasan: the chemical being used to keep the coca down could possibly cause cancer. is that right? >> exactly. there is a research arm of the world health organization which said it could possibly cause cancer in humans. so that caused quite a controversy here in colombia, although there had been criticism about fumigation for many, many years. i think part of the issue though, part of the reason, the big part of the reason why why this is finally coming to a

close is because of political reasons. in other words this thing just served its cycle. it did what it had to do in the minds of some, and now it's time to try something else and that's because of new political realities in colombia. >> sreenivasan: so what are the alternatives here to spraying? people who could manually eradicate all these crops. some of those soldiers have died because they stepped on land mines. >> look it's pretty horrific. you have had about 200 deaths over the last 10 years and most of those are soldiers. somesome of those are civilians paided to erad cat. and that's because of the land mines in the field. that's basically almost stopped manual eradication. but reasonable, the answer to resolving the coca issue is bringing the state into some of these regions. colombia say very large country. it's about twice the size of france. and you have all these far-flung regions that really aren't part of the state. the state needs to bring in

roads and hospitals and schools. there really are two colombias. you need to bring in the state and almost everybody actually pro fumigation, anti-fumigation, is in agreement with that. >> sreenivasan: and what happens to the farmers that seem to be caught in the middle here. on the one hand you've got government saying don't grow coca. on the other hand you have the rebels who sometimes make their money off of the cocaine industry. >> yeah, exactly. ithe other day i was talking to a lot of these farmers and i know them because i had been there a few months before in a particular area where i'm seeing more coca, and some of these farmers are saying, look the garil as are telling us to grow coca and when the guerrillas are telling to you grow coke athat's pressure tactics. they definitely are caught in the middle if they grow they have the spray planes come or eradicators come and if they don't grow they could be in the bind with the people who count on that money. >> sreenivasan: what is the

relationship between the ouz of expwriewts colombia and you said there are new political realities on the ground? >> i think over this they clashed because i think the counter-drug officials in the u.s. government are very much wholeheartedly supportive of fumigation, so they didn't want it it to end. but the political realities are different in colombia. when this program began, colombia was in a really, really tough state. certainly, the colombia that you have today 15 years later is a different country. it's very dynamic, a growing economy. there's a lot of good things that are happening here. and right now one of the big things that's happening is that the government is in the midst of peace talks with the guril as. that would end a very long conflict. and the government's point of view is fumigation is really a kind of militaristic approach in regions that are now peaceful. what they want to do is win hearts and minds and you don't do that pie fumigating them, by dropping defoliant on top of these people. >> sreenivasan: fernandez de juan

forero, joining us by skype from bogota, colombia, thank you so much. >> thank you, it was a pleasure. >> this is pbs newshour weekend saturday. >> sreenivasan: the u.s. is in the grip of the worst bird flu epidemic in the nation's history. the outbreak is creating a crisis for farmers: how to safely destroy infected birds and how to keep egg prices from skyrocketing in the process. associated press reporter david pitt has been covering the story and joins me now via skype from des moines, iowa. david just a couple of weeks ago we were talking about how bad this was, but it hasn't gotten any better. >> right, it does still seem to be spreading. the hardest hit states are minnesota where most-- you know, a lot of the turkeys in the united states are raised and iowa, the leading egg-producing state. so both states have seen increased cases in the last few days. so we are seeing it spread, still and the priority, i think, for those who study this problem is to try to figure out how to keep it from spreading and how it is spreading, and then stop it if possible.

>> sreenivasan: what are the the market effects now? this has just gone on long enough. are we seeing prices increase zoo we are. the last story i did a few days ago reflected carton egg prices going up about 17% or so in the midwest. the biggest impact so has been eggs used for ingredients in things like mayonnaise and cake mixes and that kind of thing. those markets have seen a little over 60% increase. >> sreenivasan: give me some perspective. when we say the largest of avian flu outbreak in the country's history, how bad is this? >> in iowa we are about 26 million birds. 23 of those are the type that lay eggs. the entire country has about 300 million chicken laying eggs. it's a small percentage of the total but it is getting to a point where we are seeing an impact on the market and availability of the product. >> sreenivasan: all right, david pitt of the associated press, thanks so much. >> thank you. >> sreenivasan: to see the full

interview, visit www.newshour.pbs.org. >> sreenivasan: before we leave you tonight, federal officials are now ordering amtrak to use computerized speed restrictions in more trains in the wake of tuesday's deadly derailment. the federal railroad administration issued the emergency order today requiring amtrak to automatically notify an engineer if they're speeding and apply the brakes if the engineer does not respond. amtrak is also being ordered to reevaluate the speed limit on every curve between boston and washington, d.c. that's it for this edition of pbs newshour weekend. i'm hari sreenivasan. thanks for watching. captioning sponsored by wnet captioned by media access group at wgbh access.wgbh.org

>> pbs newshour weekend is made possible by: corporate funding is provided by mutual of america-- designing customized individual and group retirement products. that's why we are your retirement company. additional support is provided by: and by the corporation for public broadcasting and by contributions to your pbs station from viewers like you. thank you.

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