May 4, 2014

Two studies published on Sunday show that blood from young mice reversed aging in old mice, rejuvenating both their muscles and their brains, The New York Times reports.

Dr. Saul Villeda at the University of California, San Francisco, and his colleagues discovered that after young mice and old mice were stitched together at their flanks and their blood was flowing through each other, the old mice formed several new neurons in the hippocampus region of the brain, an important area for imprinting memories. The scientists also removed cells and platelets from the blood of young mice and injected the remaining plasma into old mice, which helped the older rodents perform better on memory tests.

Over at Harvard University, Dr. Amy J. Wagers and her team found that when old mice were joined together with young mice, more blood vessels grew in the brain of the old mice, leading to the creation of more neurons that gave the old mice a better sense of smell. During an earlier study, Wagers and her colleagues had discovered that GDF11, a protein, was plentiful in young mice and scarce in old mice, and could rejuvenate heart tissue when injected into older mice.

This time around, Wagers and her colleagues injected GDF11 into the old mice (not joined to younger mice) and found that it also spurred the growth of blood vessels and neurons in the brain, as well as — in a separate new study — stem cells in the aging muscles, increasing the strength and endurance of older mice.

Taken together, the separate research could eventually lead to treatments for human heart disease and degenerative brain disorders like Alzheimer's, among other Fountain of Youth remedies. "There's no conflict between the groups, which is heartening," Dr. Richard M. Ransohoff, director of the Neuroinflammation Research Center at the Cleveland Clinic, told The New York Times.

The idea of being able to rejuvenate body parts this way is exciting, but scientists also warn that stem cells could multiply uncontrollably, leading to cancer. Villeda's team published its findings in the journal Nature Medicine, while Wagers' studies came out in Science. Catherine Garcia

it's getting hot in here
1:47 p.m. ET

Without waiting for the end of the year, the World Meteorological Organization announced Wednesday that 2015 was the hottest year on record. "I would call it certain. Something game-changing massive would have to happen for it not to be a record," Deke Arndt, the National Oceanic and Atmospheric Administration's chief climate officer, told The Associated Press. 2015 saw temperatures soar worldwide as a result of a strong El Nino and man-made global warming, with the planet likely having warmed by 1 degree Celsius, an alarming climate change milestone.

Here's a look back at some of the extreme weather across the globe, from heat waves in Pakistan and India to Hurricane Patricia to droughts, floods, and fires across the United States. Jeva Lange

Kunduz hospital bombing
12:41 p.m. ET

A U.S.-led airstrike on a Doctors Without Borders hospital in Kunduz, Afghanistan in October was the result of "human error," according to findings released today. The military had accidently aimed at the hospital instead of at the intended target, a Taliban command center 450 yards away. Technical errors were also at fault.

At least 30 staff members and patients were killed in the attack, which continued even after the humanitarian organization made repeated distress calls to U.S. and Afghan officials during the strike. "U.S. forces would never intentionally [strike] a hospital," Gen. John Campbell, the top NATO and U.S. commander in Afghanistan, said. Jeva Lange

pies for the people
12:15 p.m. ET

President Obama is a man who likes his pies. He's even joked that his former pastry chef, Bill Yosses, is so good at what he does that it's like the pies have crack in them (Obama and Michelle fondly called Yosses "the Crustmaster").

The Obama Thanksgiving dinners famously have all kinds of pies as a result of the president's tastes; last year there were at least half a dozen varieties including huckleberry, pecan, peach, apple, chocolate cream, sweet potato, pumpkin, cherry, and coconut and banana cream.

But why stop at six? Here's how you can make all of the famous White House pies from over the years. Jeva Lange

Obama's pumpkin pie

Mamie Eisenhower's pumpkin pie

Obama's apple pie

Obama's huckleberry pie

Obama's sweet potato pie

Obama's flaky nectarine pie

Michelle Obama's spinach pie

Laura Bush's Texas buttermilk coconut pie with whipped cream

Lady Bird Johnson's Pecan Pie

White House fruit pocket pies

happy thanksgiving
11:40 a.m. ET

An estimated 1 percent of the U.S. population is catching a flight for Thanksgiving — although if their destinations are any indication, quite a few of those 3.6 million travelers aren't going home for the holiday. According to numbers crunched by The New York Times, places like Nevada and Hawaii have a large influx of incoming travelers this Thanksgiving, indicating that perhaps plenty of people across the U.S. have been pining for a little sun or slots. More than anywhere else, however, flights to Miami and Orlando have seen the biggest swell of travelers, once adjusted for populations.

To be fair, that doesn't necessarily mean everyone is racing to the beach rather than home to their families; "home to family," the Times points out, could mean visiting parents who have moved elsewhere and retired. Although that's not to say you can't kill two birds with one stone — both Orlando and Miami are expecting 80-degree Thanksgivings.

Take a look at where everyone's flying today, below. Jeva Lange

see something, say something
11:39 a.m. ET
Ty Wright/Getty Images

Speaking at a campaign event in South Carolina on Tuesday, Donald Trump suggested that Americans should call the police on new people in their neighborhoods who look suspicious while moving in.

"People move into a house a block down the road, you know who's going in," Trump said. "You can see and you report them to the local police." He noted that "most likely" reports will be wrong, "but that's OK." In this manner, Trump added, everyone can be "their own cop in a way."

The same evening, Trump redoubled his calls for surveillance of "mosques and other places" and asked why President Obama is "so empathetic [sic] on not solving the problem." Bonnie Kristian

11:21 a.m. ET

Thanksgiving with family often features an unwanted serving of political debate, and this year the Democratic National Committee wants to ensure millennial Democrats can give as good as they get. To this end, the DNC has published a 2015 version of, which offers comeback flashcards — with overtones of snark and undertones of rage — pertaining to five hot-button issues and five GOP presidential candidates.

While the issue selection seems pretty straightforward, the logic of which candidates were included isn't so clear: For instance, why does John Kasich, polling below 3 percent nationally, make the cut, while Ben Carson, who nears 20 percent support in recent polls, is nowhere to be found? Also unclear is what users can do if their uncle fails to be persuaded by the handful of responses offered for each category — or, in the site's parlance, if he's "still talking."

The DNC released a similar site in 2013 and 2014, announcing the flashcards in the latter year with a tweet suggesting the offending uncles in question sound like this. Bonnie Kristian

out to get you
10:54 a.m. ET

It's no secret that campaigns want to know who you know. President Obama's campaign, for example, developed "Targeted Sharing" back in 2012, a tactic which encouraged users who opted in to share specific content with particular groups of friends in order to get them to register to vote, donate to the campaign, or watch a persuasive video.

"People don't trust campaigns. They don't even trust media organizations," Teddy Goff, the Obama campaign's digital director, told Time in 2012. "Who do they trust? Their friends."

Ohio Gov. John Kasich gets that — or, at the very least, his super-PAC New Day for America does. They're working with a New York data company, Applecart, to construct "webs" of influencers in order to target potential voters, Bloomberg reports. But instead of limiting themselves to who is active on Facebook, Applecart is taking an old-school approach, combing high school yearbooks, local newspapers, community sports rosters, and published staff lists to discover who might be receptive to who:

When volunteers arrive at New Day phone banks either in New Hampshire or Kasich's political base of Columbus, Ohio, they are given call sheets prioritized by who the voters know. The targets are prospective "anchors," those whom statistical models have identified as open to Kasich (even as a second or third choice) and also whose connection scores showed them as likely to be interacting with others. The idea is to convert these anchors into de facto campaign surrogates. "It doesn't take too many people who are connected to a persuadable target to say nice things to them about John Kasich," to start to close the deal, says Matt Kalmans, a 22-year-old co-founder of Applecart. [Bloomberg]

Applecart uses social graphs, where each voter is webbed to their known contacts — Bloomberg notes that a dozen such voters in New Hampshire were deemed "hermits," with no significant interpersonal links. Although to be fair, anyone being bombarded by old high school friends who have suddenly got nothing to talk about but John Kasich might be wishing they were a hermit, too. Jeva Lange

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