It’s been four and a half months since 46-year-old man called George Floyd died after pleading he couldn’t breathe as a Minneapolis officer knelt on his neck. The four officers involved were fired and Derek Chauvin, who pressed his knee on the man’s neck, was charged with third-degree murder and second-degree manslaughter. In the days since Floyd’s death, thousands poured onto the country’s streets to protest the killing and those who died before Floyd as a result of police brutality.

The demonstrations began in Minneapolis and spread like wildfire across the U.S.Los Angeles, Atlanta, Washington, DC, Miami, New York City and Chicago all saw crowds demonstrating. Many protests were peaceful, with people holding “Black Lives Matter” and “I can’t breathe” signs, shouting loudly and armed with face masks for protection against coronavirus. But some groups turned violent over the weekend, setting fires to buildings and police cars, breaking through windows of businesses, looting and fighting with police forces. Police responded forcefully, shooting tear gas and rubber bullets at the crowds and arresting hundreds throughout the countries. In New York City, a police vehicle was seen driving through a crowd of protesters. In Atlanta, two officers were fired after their violent arrest of two college students was caught on video. It’s still unclear what the coming days will look like.

To help control the violence, at least 40 cities lawfully established curfews and more than a dozen governors organized National Guard army. In the nation’s capital, a similar scene. Just before 8 p.m. Sunday night, armed officers and protesters remained in a standoff in downtown Washington as crowds threw water bottles at police and police responded with flash bangs and pepper spray. In New York, a group of protesters remained in Manhattan as night fell, facing off with police after several fires were set and some stores were looted. Officials in several cities have warned that those who are looting stores and creating scenes of chaos are not there to protest Floyd’s death.

Pioneers of the research that led to one of the first COVID-19 vaccines (疫苗) say breakthroughs made in their studies could point the way toward developing a potential vaccine against cancer before the end of the decade. In a BBC interview, husband and wife team Ugur Sahin and Ozlem Tureci, co-founders of BioNTech, said technology they had developed could be repurposed to help the immune system respond to cancer cells.

The mRNA COVID-19 vaccine causes cells to create spike proteins (刺突蛋白), which warn the body’s immune system about things to look out for and to attack. It is hoped that this could be reworked using proteins found in cancer tumor (肿瘤) cells, causing a similar bodily defensive action.

BioNTech was founded in 2008 specifically to work on cancer treatments. “From the very beginning, our focus has always been on exploiting the full potential of the body’s immune system to successfully help address cancer and infectious diseases,” says the company website.

“As scientists we are always hesitant to say we will have a cure for cancer,” said Tureci. “We have a number of breakthroughs and we will continue to work on them. This will also definitely accelerate our cancer vaccine.”

She added that “the dream” was for a way to be found to enable the body to recognize a cancer tumor as a foreign element, in the same way it had dealt with COVID-19, and to respond accordingly, so that the immune system could be trained to hunt down the rogue presence. “You’re training the immune system like a smart bomb, in a way, to see those differences and kill that tumor cell,” she continued.

“What made the potential breakthrough even more exciting,” she said, “was that any treatment could be personalized to work on an individual cancer patient’s specific circumstances.” “You can take someone who’s got cancer, take their own tumor and make an RNA vaccine out of that and strengthen their own immune system specifically against their own tumor. That’s a really wonderful thing to see,” she added.

Want a book? Head to a Rocket Ship in Boulder, Colorado, United States, a cottage (小屋) near Ghen, Belgium, or a tree in Coeurd’ Alene, Idaho, United States. These are just three of the more than 80,000 Little Free Libraries in more than 90 countries. Unlike traditional libraries, these small structures aren't buildings where people check out books from a librarian.

“A Little Free Library is a box full of books from which, when you find one, you can take a book home with you,” explains Margret Aldrich, Little Free Library spokes-woman. “Or if you have a book to share, you can leave it for someone else to read.”

Little Free Libraries are everywhere: outside homes or beside coffee shops.

The first was set on a post in front of Todd Bol’s home in Hudson, Wisconsin, United States, 10 years ago. The little schoolhouse Bol built held free books anyone could enjoy.

It became a local hit.

A year after setting up his library, Bol and Rick Brooks, a friend and business partner, launched Little Free Library as a nonprofit organization in 2012. Their goal was to make books more widely available while building connections within communities.

They inspired a book-sharing revolution.

Little Free Libraries began to spread all over the place-from Salvador, Brazil, to Grand Marais, Minnesota, United States.

Today, those who want to build one can get free instructions from the Little Free Library website.

“There weren't many public places like libraries where I live” says 10-year-old Umayr Ansari, who put a Little Free Library outside his home in Doha, Qatar. “I had a lot of extra books, and I wanted to share them so people who didn't have their own books could have a chance to read.”

“I liked to build the libraries and get the feeling of, ‘Wow I helped make that,’” says 11-year-old Ava Jelliek, “That gave me confidence.”