special rrespondent fred de sam lazaro reports, part of our series "race matters," and fred's series,ts for change." >> reporter: it's been a heavy lift, that took years. but last month, tim luckett crossed the threshold into a new home-- a first step toward "happily ever after" with wife melva and six-month-old melani. >> feels great to finally become homeowners. >> reporter: why did you want to own a home? >> we wanted to be able to, you know, have her be able to play outside, have a yard, be able to take her out in the backyard, you know, play outside in the front, have a home for her. >> reporter: she wants to be on that yard right now. >> yes, she does! >> reporte the lucketts nabbed this modest north minneapolis duplex against tall odds. there's a severe shortage of homes, which has driven prices to record highs, and history has long stacked the deck against black homeownership across america, and in this market in particular. >> racial covenants did the work of jim crow in the north, all over the north. >> reporter: for much of the 20th century, it was common to see provisions

special correspondent fred de sam lazaro travelled to cambodia in 2019 where this danger is a daily partf life, and where an unlikely set of animals are making a difference. its a part of fred's series, agents for change. >> reporter: let's face it, rodents rarely trigger warm fuzzy feelings in most people. but, these african giant pouch rats, being gently awoken from their cages, are called hero rats by their halers. they have names like harry potter, godiva, and, er... frederick-- no relation. after getting sunscreened up, this "rat pack" of 11 animals is headed out before dawn to a former battlefield in rural cambodia. their task: sniff out landmines. >> everyone was surprised, even me. before i came to apopo, i hear that the rats were detecting landmines. it was like something unbelievable to me. >> reporter: mark shukuru is head rat trainer in cambodia for the belgian non-profit apopo. he is from tanzania, where this species is also native, and he learned early that they have some of the most sensitive noses in the animal kingdom. each comes out of a rigorous program in tanzania, sh

as special correspondent fred de sam lazaro reports from chicago, researchers are working on a novelh to aid in that recovery. the story is part of our breakthrough series. >> repter: this is, uh, one of the devices, is this the latest design? >> yeah. >> reporter: john rogers has no medical training, but his engineering laboratory at northwestern university is a pioneer in the emerging field he calls electronic medicine. >> very small, wireless and soft device. >> reporter: as hardware goes, it doesn't get any softer. it's a temporary, or transient, pacemaker that will be laminated, like a piece of scotch tape onto the heart after a patient has had surgery, and its controlled wirelessly from a small module attached to the chest. it would replace a far more invasive approach used today-- and is made from elements the human body actually needs. >> all of the materials that we're using for these pacemakers are recommended part of the daily diet. silicon. molybdenum, magnesium. >> reporter: and, like many nutrients, when the device's job is done over a few weeks it will disintegrate and

special correspondent fred de sam lazaro reports on schools coming together around water. part of this story was shot in uganda, just before the pandemic. it's part of his series: agents for change. >> reporter: across the developing world, many schools lack not only books or desks but something even more basic: water-- to drink, for sanitation >> irew up in a village in uganda. houses didn't have water, kitchens didn't have water. schools never had water. >> reporr: there's a lot less education going on fundamentally, is what you're saying. >> that's what i'm saying. >> reporter: twesigye jackson kaguri founded nyaka, a school tucked high in southern uganda's mountainous region. it provides free education to children who have lost a parent to h.i.v./aids. kaguri, who now lives in michigan, vividly remembers those early years, still the reality for millions of children around the world >> going to school at 7:00 a.m. in the morning, and finish school at 5:00 p.m. without drinking a sip of water. when i set out to build schools, one of the things i was determined to have is