announcer: today on "21st century," cuba's musical legacy from slaves, running for peace in congo, new york's recyclers doing what they can to save the planet, and a young woman scientist who's already changed the world. in cuba, the musicalal legacy oa million slaves. [speaking spanish] announcncer: as mucuch as 60% of cucuba's current populatition is

descended from african slaves. [speaking spanish] announcer: blending african and latin in cuba. [woman speaking spanish]

narrator: magali rolando is a piano teacher who lives in havana, the capital city of cuba. she eagerly teachches the younger generation about the roots of cuba's music. >> ♪ yo soy un hombre sincero... ♪ narrator: music lies at the heart and soul of every cuban. it originated mostly from africa by those who were brought and enslaved centuries ago on this caribbean island. >> [singing in spanish] narrator: magali's ancestors originated in southern africa, which connects her to the african beat. besides teaching, magali plays in a musical band led by 45-year-old ramon garcia, who creates his own music.

[speaking spanish] garcia: ha ha ha! narrator: now songs and tunes are mixed with spanish and pre-colonial indigenous originss as thehe enslaved d embraced t e tetempo they f found in cucuba n theey first arriveved. it is estimated that more than one million africans were brought to the island through the port of matanzas, some 100 kilometers from havana, as part of the transatlantic slave trade from the 16th century until slslavery was s abolished inin n 1886. [speaking spanish]

narrator: communication was difficult, forcing many to create ways to send messages to their people. [speaking spanish] narrator: today people of african descent treasure the legacy of music and song brought to cuba by their ancestors, and the younger generation is keeping that flame alive. but that isn't the only contribution by people of african descent to the development and culture of cuba. in recognition of their

african heritage, cuba participates in a global slave route project initiated by unesco in 1994. [speaking spanish] narrator: situated at the docks of matanzas, the enslaved would carve symbols on slabs of stone depicting their religious and cultural background. [speaking spanish] narrator: now a cultural heritage site, san severino castle documents the history of slavery through memorabilia and

photos dating back to the 16th century. by the time slavery was formally abolished, the enslaved had constructed forts and iconic buildings that still stand today, attracting thousands of visitors to the island. there are around 200 million people of african descent living in the americas. many millions more live in other parts of the world outside of the african continent. across the globe, africans and the african diaspora continue to suffer inequality and disadvantage because of the legacy of slavery and colonialism. the united nations has also set aside an international decade for people of african descent, which began in january 2015 to acknowledge their contribution to human history. the decade also recognizes injustices they endured while promoting and

protecting their human rights. >> [singing in spanish] announcer: running in the united states, running baback home i ie congo. [speaking accented english] announcer: one man's rarace for peace. [speaking accented english]

announcer: in new york city, the group that's doing what they can to save the planet. [speaking accented english]

announcer: recycling bottles and cans bthe million. [speaking accented english] announcer: changing the world can by can. woman: a lot? ha ha ha! [speaking accented english]

gadsen: uh, we, um... [speaking accented english]

man: the waste that we generate very often ends up as pollutioin unless we make an effort, first, to reduce the waste and secondly, to recycle the waste products that result of our consumption. recycling is really important, particularly recycling of plastics. no act o of recycling is too small. if you recycle one plastic bottle, that is one plastic bottle less that winds up in a landfill or that ends up as marine debris out at sea. [speaking accented english]

[cans rattling]

martinez de luca: so... [speaking accented english] harris: we need to get people aware of the consequencnces and the impact of our consumption, and as we become aware of that, then we will find that by changing the way we consume,

changing the amount of waste that we generate, we will certainly make a difference. [people speaking various languages] jin: i don't think until high school i really realized gender equality was a problem. by now, i had assumed, the problem had been solved and d that i was fuy equal and that i'm part of this new generation where women, we could say we're fully equal to men. and as i've grown, gone through college, started my career, i've realized that we're not.

in high school when i wanted to takke computer scicience class,i was told, "the boys will probably be better, so you ould focusus on thin that you'd be gogood at." and it wasn't until i got to college where i really starteted to actualally challengege those assumptions and then discovered how much i like math and sciences s and realized that i have the capacity to not only do well in these classes, but use this education to invent and create things myself, so in my junior year, me along with my other two co-founders started this company to help health care workers around the world battle infectious diseases. the project was started in 2014 in response to the ebola crisis in west africa, so right now, thehe health care woworkers, they are wearing g ts big, yellow suit called a ppe suit. once you're done treating a patient, you are supposed to take off the suit, but before

you do that, they spray you down with bleach to make sure there's no more bacteria or virus left on your suit. one of the biggest problems with the ebola crisis is there was such a high rate of infection for health care workers, and a lot of that was from ineffective decontamination. man: so one bottle... jin: so our idea was initially to colorize the solution so you could see where you're spraying the transparent disinfectant bleach and, therefore, have a good idea of what surfaces you've covered and what surfaces you haven't. we also learned that bleach needs to remain on the surface for 10 minunutes for the pathogn to be kikilled, so we also addea color marker that would tell you when you can take off the suit. so the cool thing about the color is that once it's completely faded to clear, you'll know that you don't-- you can touch the surface, and it'll be safe to touch, and while it's still blue, you'll know that it still has active pathogens on it. it's really amazing to be able

to improve the confidence of these people that are already sacrificing so much. right now, the technology is limited to bleach sprays, which is usually used in the ngo epidemic context. we're expanding it to wipes and hand sanitizers so it can be used for daily decontamination also in hospitals. so we can make a big impact on reducing infection rates as a whole. when i wake up in the morning, i have goals where i want to have another implementation in the field, or i wantnt to develop an additional proroduct in this pipeline so we can help or impact more people. right now, we have some units deployed in haiti to help treat their choholera outbreak with international memedical corps.

as a scientist, i do think we have a responsibility to make a larger impact in society beyond the research that we're doing, you know, really taking part actively in discussions. hi. i'm katherine jin... not only about science-related issues, but everytything ranging from education to women's rights. we should have a much bigger footprint, and we should be there to uplift each other, and not bring each other down. yes. there are a lot of still-implicit powers that are holding women back, whether it be the snide comments like, "women aren't good in math or science," or actual things where you see women earn less than men or women are less likely to get certain jobs. and i think it's really sad d that we've already lost the potential on so many women who have come before me. i want to make sure that my potential and the potentials of my peers and other women of my generation will be fully

realizeded.

[atmospheric music] ♪ - because i saw that my country was running instead of, you know-- instead of developing, we are undeveloping. we are j just going backwas. - there are some who will be president, who desire to be president. there are some who desire to be journalists, like me. there are some who desire to be doctors. - because we are very young, we can do nothing. but maybe if we had the power... - and that's's why i know, in jesus' name, that my generation will change that,