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The latest news reports about salt are enough to make a parent ponder a household ban on pizza and cold cuts. A study published last week in Pediatrics found that children eat, on average, 3.4 grams of sodium daily—more than twice the amount recommended for adults by the Institute of Medicine (IOM). News outlets, including the Associated Press and USA Today, explained that, according to the study, the quarter of American kids who eat the most sodium are twice to three times as likely to develop high blood pressure as the quarter who eat the least....

A few years ago researchers using the radio-based Event Horizon Telescope (EHT) performed an extraordinary observation, the likes of which remains a dream for most other astronomers. The EHT team announced in April 2019 that it had successfully imaged the shadow of a supermassive black hole in a nearby galaxy by combining observations from eight different radio telescopes spread across our planet. This technique, called interferometry, effectively gave the EHT the resolution, or the ability to distinguish sources in the sky, of an Earth-sized telescope....

Perfectly secure cryptography requires no technology more exotic than pencil and paper: Choose a random string of letters and numbers to serve as the key for an enciphered message. Write the key down on a piece of paper, use it once and then burn the paper. The trick is to make sure no one intercepts or tampers with the key—and on the Internet, keys are stolen or tampered with all the time....

LAGUNA NIGUEL, Calif. – Researchers working on a technology they say could stop global warming want the government to keep it out of private hands, a lead investigator said this week. David Keith, a Harvard University professor and an adviser on energy to Microsoft founder Bill Gates, said he and his colleagues are researching whether the federal government could ban patents in the field of solar radiation. The technology, also known as geoengineering, involves a kind of manipulation of the climate....

By Angelina Davydova ST PETERSBURG, Russia, Jan 15 (Thomson Reuters Foundation) - R ussia’s forests may lose their power to help curb global warming without stronger domestic protection and a place in a new global climate change deal, scientists have warned. Russia has 19 percent of world forest reserves by surface area. But experts say the U.N. process drafting the climate change pact, due to be agreed at the end of 2015, has concentrated mainly on tropical forests....

When the kidney does not properly eliminate salts and minerals, those waste products can grow into the small, agonizing pellets known as kidney stones. Roughly one in 11 Americans develops them—a rate that has doubled over the past two decades as a result, in part, of our obesity epidemic. About the size of a grape seed, this stone passed through the ureter of its owner naturally. The false-colored scanning electron microscope image (magnified 50×) depicts the stone in grisly detail, with smooth calcium oxalate monohydrate crystals overgrown with jagged dehydrate crystals....

Space may be incomprehensibly vast, but Earth’s environs are crowded with junk. Spent rockets, derelict spacecraft, satellite fragments and loose hardware now form a cloud of debris that poses a threat to orbiting satellites and astronauts. Sky watchers have catalogued more than 16,000 objects larger than about 10 centimeters, most of them in low Earth orbit, at altitudes of 200 to 2,000 kilometers. And the junk is self-sustaining. If humankind were to cease all spacefaring activities, the hardware we have already cast off would continue to collide and fragment into bits for centuries....

For the first time, astronomers have observed the final stages of galactic mergers, peering through thick walls of gas and dust to see pairs of supermassive black holes drawing closer together and the black holes’ rapid growth. At the centers of most, if not all, galaxies are supermassive black holes with masses that are millions to billions of times that of Earth’s sun. For instance, at the heart of our Milky Way galaxy lies Sagittarius A*, which is about 4....

DAR ES SALAAM, Dec 23 (Reuters) - Tanzania has arrested a Kenyan businessman suspected of trafficking ivory and other big-game trophies, the police said on Tuesday. Feisal Mohamed Ali, 47, was arrested in Dar es Salaam on Monday on a warrant issued by Interpol which is trying to track down armed gangs that kill elephants for tusks and rhinos for horns to be shipped to Asia for use in ornaments and medicines....

From Nature News Blog Today the US Centers for Disease Control and Prevention (CDC) announced that the number of reported cases in an ongoing outbreak of a strain of the H3N2 animal influenza virus (H3N2v) that transmits between pigs and humans has jumped to 145 in the past week. On 3 August, CDC officials reported 16 total cases of H3N2v infection. In all cases, patients interacted with pigs either in their occupation or at local agricultural fairs, suggesting that the virus has not yet evolved the ability to efficiently transmit between humans....

In a painstaking experiment that may help revise our view of depression, a team at the Johns Hopkins University School of Medicine found that rats given Prozac did not merely experience a change in their brain chemistry but also grew new nerve fibers in mood-critical areas. This finding, which suggests that depression reflects problems of fine neural structure and not just chemistry (the prevailing model), should bolster the emerging “network hypothesis” of mood....

The 2014 annual meeting of the Society for the Study of Reproduction began, somewhat incongruously, with a discussion of contraception. With the global population set to top 8 billion in a little more than a decade, clinicians, public-health researchers and some private funders see a pressing need to support work on new contraceptive methods — and to get existing methods into the hands of those who want them. Contraception is unique among medical interventions for the wide variety of benefits it offers, says Anna Glasier, a researcher in contraception and public health at the University of Edinburgh, UK....

The brain’s reward system learns the actions that produce positive outcomes, such as obtaining food or sex. It then reinforces the desire to initiate those behaviors by inducing pleasure in anticipation of the relevant action. But in some circumstances this system can become oversensitized to pleasurable but harmful behaviors, producing pathological impulses like drug addiction, binge eating and compulsive gambling. But what if we could spot impulsive urges in the brain and intervene to prevent the act?...

ALTHOUGH OUR PERCEPTION of the world seems effortless and instantaneous, it actually involves considerable image processing, as we have noted in many of our previous columns. Curiously enough, much of the current scientific understanding of that process is based on the study of visual illusions. Analysis and resolution of an image into distinct features begin at the earliest stages of visual processing. This was discovered in cats and monkeys by a number of techniques, the most straightforward of which was to use tiny needles—microelectrodes—to pick up electrical signals from cells in the retina and the areas of the brain associated with vision (of which there are nearly 30)....

New Shepard consists of a rocket and a capsule, both of which are reusable. Blue Origin is developing the duo to fly people and scientific experiments to and from suborbital space. (The system is named after Alan Shepard, who became the first American in space during a suborbital jaunt in May 1961.) [In Photos: Blue Origin’s In-Flight Abort Launch & Landing] New Shepard blasted off from Blue Origin’s test range in west Texas at 11:36 a....

In a long-awaited move designed to protect people from cancer, California on Thursday proposed a new health goal for chromium 6 in drinking water that is thousands of times lower than the amount contaminating some water supplies. The recommendation culminates a decade of debate among scientists trying to decide what concentration is safe to drink. The controversial water contaminant was made famous by Erin Brockovich and a small Mojave Desert town that won the largest tort injury settlement in U....

Dr. Nick Nelson walks through busy Highland Hospital to a sixth-floor exam room, where he sees patients from around the world who say they have fled torture and violence. Nelson, who practices internal medicine, is the medical director of the Highland Human Rights Clinic, part of the Alameda Health System. A few times each week, he and his team conduct medical evaluations of people who are seeking asylum in the United States....

Climactic changes might currently be threatening the survival of polar bears (Ursus maritimus), but similar shifts appear to have played an important part in bringing the species into existence in the not too distant past. Researchers announced today that they have sequenced the mitochondrial genome of an ancient polar bear. The genetic traces they found in the bear’s 110,000- to 130,000-year-old jawbone reveal that the species likely split from brown bears (U....

Climate change’s impacts on crop yields may force as many as seven million Mexicans to emigrate to the U.S. over the next 70 years, according to research published July 26 in the Proceedings of the National Academy of Sciences. The study is among the first to attempt to put hard numbers on questions about “environmental refugees” that may be caused by climate change. “There is a significant response of emigration from Mexico to past climate variations,” says atmospheric scientist Michael Oppenheimer of Princeton University, an author of the study....

Sports are being played in empty stadiums. The Olympics have been postponed. Professional athletics teams are being isolated and their seasons reduced—to varying levels of success. But athletics organizations are not the only ones trying to determine what competition looks like in the time of COVID-19. Youth STEM competitions may have a smaller footprint and grab fewer headlines, but they are just as important—and the loss of them just as crushing—to the students who take part....