on this edition for saturday, march 29th, russian troops amass at the ukrainian border. in our signature segment, a landmark lawsuit over teacher tenure. >> students' rights to be in front of a highly effective teacher, to blow up the entire system really misses the boat. and this young man's unlikely journey. next, on pbs news hour weekend.

from lincoln center in new york. good evening. thanks for joining us. russian foreign minister sergei lavrov and secretary of state john kerry will meet tomorrow in paris to discuss the crisis in ukraine. lavrov said his country has no interest in invading eastern ukraine. this despite a large buildup of russian troops near the border between the two countries.

nato secretary-general said the alliance is worried about russia's attentions and called the troop buildup a concrete threat to ukraine. it is now three weeks since malaysia airlines flight 370 went missing, and today the hunt for the 777 tripled 700 miles from where the serb was going on. one of the aircraft found three brightly colored objects in the new search area. wrapping up his week-long trip in europe and saudi arabia this morning, president obama bestowed a human rights award on a woman who promotes stopping violence in that country. the president reportedly did not raise the issue of human rights or women's rights in saudi arabia during his conversations with saudi king abdullah. at the stroke of midnight, gay marriage became legal in england and wales, and gave

couples across that country to tie the knot. last july parliament passed legislation legalizing same-sex marriage with david cameron. civil partnerships had been legal since 2005. britain is now the 15th country to allow gay marriage. a promising treatment to help millions of americans with high blood pressure has been shown to be ineffective. the treatment called renal denervation failed to reduce hypertension. the treatment was considered a break-through for high blood pressure that couldn't be lowered with drugs. an earthquake struck the downtown area, but the quake broke water mains. objects were also tossed from stoor shelves. tlr with dozens of after-shocks overnight. in washington state, a moment of silence. to mark the moment a week ago todayhen a huge landslide

buried a cluster of homes north of seattle. 27 people are presumed dead and 90 more are still believed missing. the revelation late yesterday afternoon that russian president vladimir putin called president obama with hopes that the situation in ukraine might be solved through diplomacy. tens of thousands of russian soldiers show no sign of pulling back. for more about that, we're joined now from washington by anthony from the center for strategic and international stud sis. so, there are some estimates by ukrainians there might be up to 85,000 russian troops along the border. whatever the number is, do we know about the composition of those forces? and what can russia do with that kind of an army? >> well, first, we don't really

know the exact structure. we have been told on background, there are between 48,000 and 50,000 at least troops. they haven't identified which units they belong to. but russia announced there were going to be exercises, and there haven't been any exercises, they just kept building up a presence, one that could be going into eastern ukraine. troops aren't the only problem. there are very large numbers of ministry of interior units russia also has. these are almost ideal troops for occupying cities and urban areas. there are certainly pro-russian elements in some of the cities in the eastern ukraine. so at almost any time you could have a russian thrust into the eastern ukraine, and one that could at least take some cities, probably in a matter of days, if not hours. >> we've been focused on crimea. are there other regions we need

to be concerned about? last week we mentioned the area between moldova and ukraine. >> russia has a limited presence in the area already. it is not a marriage combat presence, but there is no major combat presence in that area, in the ukraine to the east or to the west. it's certainly an area russia could suddenly put pressure on the ukraine. there is an airborne guard division, basically, which could be moved in, at least in part, fairly quickly. because the ukraine, frankly, is not capable of effective air defense. so russia certainly has the ability to put pressure on the ukraine in two different directions. and i think what's of great concern to the ukraine is when putin called obama, he didn't talk about negotiations alone, he talked about the fact that russia had no intention of

invading if the ukraine did not have hard line elements in its government, if there are no protests against the russians. so it really was not in any sense a quick initiative towards peace. >> so countries like astonia, lithuania, latvia, they've been asked for increased nato presence. do they have reason to be concerned? >> we have not seen any element of russian invasion, but the baltic states are near major russian forces. they really don't have to do anything. they're already there. to put pressure on them. and we have moved u.s. aircraft into one of those states, as we have into poland. but i think certainly in today's climate, the problem is, if the ukraine becomes a major source of confrontation between east and west, if russia goes beyond the crimea, and thrusts into the

ukraine, then nato's response would have to be largely in other areas, and that could trigger a process of confrontation, that none of these states can predict. >> anthony, joining us from washington, thanks so much. >> thank you. and now to our signature segment. our original in-depth reports from around the nation and the world. for years a debate has raged across the united states about tenure for teachers. that battle is now playing out in a california courtroom where a number of students have joined forces with a multimillionaire to try to strike down that state's tenure laws. an effort being resisted by the teachers union. final arguments in the case were thursday. megan thompson reports. >> sisters beatrice and

elizabeth attend public high school in a low-income mostly hispanic section of northern los angeles. the girls are aiming for college, and would be the first in the family with higher degrees. but the sisters say in middle school, they face obstacles in pursuing their education. chaotic classrooms and little to no instruction. elizabeth, now a junior, and beatrice, a sophomore, say back in 7th grade they both had a particularly bad history teacher. >> he would just be at his desk. use his computer, or sleeping. >> i didn't learn anything. >> he wouldn let students smoke marijuana in class. >> reporter: beatrice also says a science teacher was offensive. >> he would call this girl a -- and go over there. >> what went through your mind when you heard that? >> i didn't want to -- i didn't

want him to offend me. >> reporter: they were really being traumatized by these teachers. beatrice and elizabeth's mother, who emigrated from mexico, said she complained to a school administrator about the two teachers, and two others. but she says nothing happened. >> he didn't do anything to address the situation. they didn't take me seriously. >> so in 2012 she volunteered her daughters to join a lawsuit against the state and teachers unions that went to trial in january. >> i felt i was wasting my time. not learning anything. >> reporter: the nine student plaintiffs in the case are challenging two main areas of state law. permanent employment and dismissal statutes, the plaintiffs say make it difficult to get rid of bad teachers. and the seniority based layoff system, which they say makes it hard to keep good, less senior

teachers during difficult times. >> there were certain teachers that you knew, if you got stuck in their class, you wouldn't learn a thing. >> instead of learning a subject, he sat in the class coloring and watching videos. >> reporter: the plaintiffs say the laws deny students their right to a quality education, guaranteed by the california constitution. and affect minority students. experts say the legal strategy could be used to challenge education laws in other states. >> our education system delivers a constitutional right. so there's a certain responsibility of our society to deliver. >> i believe every child everywhere -- >> reporter: david welsh is a wealthy silicon valley entrepreneur who largely finances students matter, an education reform group that spearheaded the lawsuit. as of 2012, welsh had donated or loaned nearly $2 million to the group, which is footings the bill for a high-powered legal time that includes ted olson,

former solicitor general of the united states. he went to public schools for most of his education. >> most of these teachers have had a successful career. >> reporter: welsh also has three young kids, and has supported other education and environmental causes over the years. what motivated you? >> i'm a father, i'm an employer, and when i look at the system, i realize the system actually inhibits one of the most important things for an education, for a child, and that's access -- uniform access for every child to have a passion al and effective teacher. >> reporter: some people say kids were recruited. maybe they're just being used for the personal mission of a wealthy businessman. >> when you sat there and watch the children get on the stand, there's no one that put them up to that other than themselves. >> and made me not want to try. or show up to school. >> reporter: one law he's fighting is the statute that

governs teacher layoffs. california is one of ten states that requires seniority be considered to determine who stays or goes during budget cuts. john is the superintendent of the unified school district, and he testified against the so-called in, first out law. >> i can't find a more destructive statute for the students, staff or system. we've had to lay off very effective teachers in the same school that we are documenting the teacher for dismissal. >> their contributions to the school, their relationships with students, how they're supporting and helping parents, none of the factors other than the hiring date is used. now, is seniority an important contribution? i would argue it is. it shouldn't be the only factor, however. >> reporter: the lawsuit also challenges laws governing teacher tenure. california's two-year probationary period for new teachers is one of the shortest in the nation. after two years, most teachers get permanent employment status.

superintendent gacy said that permanent status means the l.a. school district can end up spending hundreds of thousands to fire a single underperforming teacher, a process he says could take up to a decade. >> the overwhelming majority of teachers are amazing people. phenomenal people. we're talking about a small subset who should and must leave employment. >> it came out in the trial that only about 3% of teachers who were evaluated last year were below standard. should we overhaul the entire system to take care of what might be a few bad apples? >> when you've identified chronic low performers, you can't exit them quick enough so the students are not being harmed. that's what we're talking about. >> are there teachers who shouldn't in the classroom? absolutely. but to blow up the entire system for evaluating and protecting teacher rights based on a couple of students' perspective, i think really misses the boat.

>> reporter: joshua is president of the california federation of teachers, one of the unions fighting the lawsuit. he says the union supports efforts to streamline the dismissal process. >> i think the process could be more effective and efficient. >> reporter: he said many ineffective teachers are weeded out during the two-year probation period. and he says granting permanent status to the rest encourages them to stay op the job, despite often difficult class roomd conditions. >> the bigger problem we have in california, and i think nationally, is that we can't keep teachers in the profession. classes are overcrowded. that really is a bigger issue in public education. that's creating conditions that make it attractive for people to make this a life-long profession. >> reporter: this 4th grade teacher in englewood, california, says she knows

firsthand how precarious her job can be. she's been laid off three times in the last three years because she doesn't have enough seniority, then brought back. even though, she supports the seniority based layoff system. she said it's objective and clear. >> it's fair. it's fair, and i support it. >> reporter: she al says she supports the other part of the law that's being challenged. permanent status for teachers after two years. she says that provision actually add vocates for students withou fear of being fired. >> i speak out very frequently about resources being brought to our district, for lowering class sizes. if i'm local, someone doesn't like what i'm saying, then i can be let go for that. and i don't think that's fair. >> reporter: and they also say a teacher's effectiveness is difficult to measure. and they say students don't necessarily connect with every teacher. during the trial, elizabeth testified that she learned nothing in english class, and wasn't assigned an entire book

to read all year. but the teacher testified that her reading scores actually west up. >> we read and wrote every day. >> did you ever receive any negative marks on your evaluations or observations? >> i did not. >> reporter: the defense also argued many superintendents, including daisy, had the rule to get rid of ineffective teachers. >> to increase the dismissals from ten in 2009, to 99 in the 2011 to 2012 school year, correct? >> i believe that's accurate. >> people on the other side of this issue said this isn't about the statute, it's about the management. the school is well run, they can get rid of ineffective teachers. >> that is not the point. the point is, students' rights to be in front of a highly effective teacher. a teacher who is not harming

them every single day of the year. >> reporter: the sisters say that's all they want for their old middle school. as it turns out the first two teachers they complained about are still teaching there. >> it's horrible. there are students who actually want to learn. >> i want to have good teachers that motivate me. not only me, but everyone. >> reporter: the judge will deliver a verdict in the case in the coming weeks. any decision he makes is expected to be appealed. >> find out which states have teacher tenure laws. some of the world's best young opera singers hail from a place that might surprise you. the impoverished black townships of south africa. they're performing at the documentary film festival, for a documentary about their lives.

the film's director, julie cohen, tells the story of one of the singers. >> i grew up in difficulty. i grew up in poverty. there was a time where my mom and dad both didn't work, but they tried to make sure there was something on the table for us to eat. >> he grew up in a township in central south africa. with the same challenges confronting many of the country's black communities. crime, poor access to health care, and an unemployment rate of up to 70%. >> my dad was a messenger in a bank before he was retrenched. >> in his early childhood, before apartheid ended and nelson mandela was elected president in 1994, the family had to contend with racist laws

that restricted travel and education. >> that is why i always tell all my children that since we are in new environment, please devote yourself to status. >> his vision of a better life was filled with music. in his church choir he discovered a talent for singing. he was chosen for a community chorus where he first learned opera, which he wanted to pursue as a career. his parents, who hoped he would support them in old age, were skeptical. did your father make those concerns clear to you? >> yes, he made them quite clear. i mean, the dream was mine. >> he was accepted to the opera school at the university of capetown, which had been white only for most of its 100-year

history. >> our culture is a thing to go to university. >> the family was able to scrape together bus fare to send him to capetown. he was awarded a scholarship including room and board. >> the right to music. i feel it's a fundamental human right. we all have a right to have a chance to make music. >> but with a first-grade education, it opened doors to opportunities unthinkable a generation ago. shortly after completing his undergraduate degree, he was selected as an apprentice in upstate new york, and invited to sing before the united nations general assembly. >> it was an auspicious occasion. a very elegant different posture.

>> but as thrilled as he was by accolades from around the world, he had another audience in mind, his mom and dad had never seen an opera. >> i would like to see a theater. >> the makers of "i live to sing" paid for plane tickets so his parents could come to capetown to see him perform. the city's main opera hall once closed to both black performers and black audiences is now a launching pad for a new generation of black opera stars. as his parents listened intently, he took center stage. this is pbs news hour

weekend saturday. and now to viewers like you, your chance to tell us what you think. tonight, some of the comments you judged most popular. we heard from many of you about our report last week from the netherlands about the pot laws there. something we thought was especially timely as tuesday's colorado and washington had legalized recreational marijuana. jillian echoed comments by a dutch researcher who said marijuana is less damaging than other legal sub sdastances and we could prevent a lot of harm alcohol causes by choosing cannabis instead of alcohol. august responded by saying, i agree. tolerance, flexibility, pragmatism is key indeed. i'm against drugs, i always discourage cannabis consumption, but believe in regulation

because it results in a less harmful society. a viewer called candid 1 was critical of our report saying, comparing two modest size western u.s. states with a modest size sovereign old world nation is a stretch. pierre chimed in on facebook. he wrote, as with all things, americans will do things our own way, and we don't need lessons in capitalism from anyone. stronger forces will overcome weaker ones, advantages will be exploited, whatever negative health implications there are will be absorbed in the name of the money generated. some of the toughest language came from douglas, who wanted us to come down forcefully in favor of legalization. would it kill you to develop just a little bit of an edge, something bold rather than meandering pieces like this? let us know what you think. our website is newshour.pbs.org. there you'll also see a timeline documenting the dramatic changes to american and dutch drug laws.

join us on air and online tomorrow. we'll take you to east africa where some countries are devising plans to try to profit from e-weight, discarded computers coming from the united states and other western countries. >> looking at income generating. >> that's this edition of pbs news hour weekend. thank you for watching.

-- captions by vitac -- www.vitac.com

[applause] >> did you know it's possible to make your heart ten years younger, regardless of your body composition, genetics, or age? and as you follow this plan, you'll feel healthier, trimmer, fitter, sexier, mentally sharper, and better than you have in a decade. >> narrator: dr. steven masley is board-certified physician, nutritionist, longevity researcher, and award-winning educator, honored as a fellow by the american heart association. >> your food choices, they make a huge difference, not just on your cholesterol profile; they impact the function of your arteries themselves. >> narrator: he is a chef trained at the four seasons and has created delicious, healthy recipes as part of his program to transform his patients' lives