What do you get when you add a whole number like 1, 2, 3, or anything else to one of the good old-fashioned proper fractions that you’ve come to know-and-love such as 1/2 or 1/3? You get what’s called a mixed fraction. What exactly do mixed fractions look like? How can you convert them into normal everyday fractions? And when do you need to bother doing so? Stay tuned because those are exactly the questions we’ll be answering today....
Scientific American presents House Call Doctor by Quick & Dirty Tips. Scientific American and Quick & Dirty Tips are both Macmillan companies. I recently ran into a friend who shared his recent battles with recurrent diverticulitis. Devin was so distraught over the illness that he had started to limit his food choices significantly - to the point that his quality of life was truly diminished and he had lost quite a bit of weight as a result....
The idea of scientists trying to grow brain tissue in a dish conjures up all sorts of scary mental pictures (cue the horror-movie music). But the reality of the research is quite far from that sci-fi vision—and always will be, say researchers in the field. In fact, a leader in this area of research, Arnold Kriegstein of the University of California, San Francisco, says the reality does not measure up to what some scientists make it out to be....
After Richard Hodges pleaded guilty to cocaine possession and residential burglary, he appeared somewhat dazed and kept asking questions that had nothing to do with the plea process. That’s when the judge ordered that Hodges undergo a neuropsychological examination and magnetic resonance imaging (MRI) testing. Yet no irregularities turned up. Hodges, experts concluded, was faking it. His guilty plea would stand. But experts looking back at the 2007 case now say Hodges was part of a burgeoning trend: Criminal defense strategies are increasingly relying on neurological evidence—psychological evaluations, behavioral tests or brain scans—to potentially mitigate punishment....
The Arctic experienced its second-warmest year on record between October 2017 and September 2018, according to the annual Arctic Report Card. And average air temperatures in this frigid region have hit record or near-record levels every year since 2014. Temperatures in the Arctic are now increasing at roughly twice the rate of the global average, researchers say in the report released by the US National Oceanic and Atmospheric Administration (NOAA). Warming is causing changes across the entire Arctic, and those changes are building, said Emily Osborne, the programme manager at the NOAA Arctic Research Program in Silver Spring, Maryland....
Thanks to five mass extinctions, about 99 percent of all animal species have come and gone from the face of the earth. During many of these events, life took the greatest hit where it probably began: in the ocean, a sphere subdivided into layers where animals have specific ecological functions. One event—the Permian-Triassic, or End Permian, extinction of 252 million years ago—even wiped out about 96 percent of animal life in the sea....
Sometimes all it takes to break a bone is a step in the wrong direction or, more specifically, a force applied in the same direction as the line-up of the nano-size collagen fibers that give bone its strength. New research shows that bones react to forces from certain directions like reinforced plastics and from others like brittle ceramics. From an engineering standpoint, bones are riddled with structural flaws, from openings for blood vessels to microscopic canals for cells....
Our quirky minds thwart psychologists’ efforts to find durable theories. But terror-management theory has held up quite well since three psychologists proposed it more than 30 years ago. It holds that fear of death underpins many of our actions and convictions. We cling to our beliefs more tightly when reminded of our mortality, especially if those beliefs connect us to something transcending our puny mortal selves. Terror-management theory can account for puzzling political trends, such as our attraction to outlandish conspiracies and authoritarian leaders....
Scientists have found what may be the strongest evidence yet that a vaccine can prevent dengue, by deliberately infecting volunteers with a weakened form of the disease-causing virus. This method of testing vaccines, known as ‘human challenge’, fell out of favour during the last century, but could be crucial for combating certain diseases, including Zika. “This is a tremendous step forward, and something that has been desperately needed for 30 years,” says Duane Gubler, a disease researcher at the Duke NUS Medical School in Singapore who was not involved in the new study....
In response to the COVID-19 pandemic, members of the Rapid Deployment Vaccine Collaborative (or RaDVaC)—a group composed of scientists and their friends or colleagues—have been self-administering an untested vaccine for SARS-CoV-2 (the virus that causes COVID-19). The RaDVaC scientists describe their project as aiming “to reduce risk of harm from SARS-CoV-2, minimally until there is at least one effective commercial vaccine widely available.” Although the project’s white paper includes includes terms and conditions designed to shield the authors from liability, RaDVaC’s self-experimentation raises important legal and ethical questions....
Melissa writes: “I’ve heard that as you age the amount of digestive enzymes your body produces decreases making it more difficult to digest your food. So you end up with symptoms like excessive belching, bloating, gas. Some people recommend taking digestive enzyme supplements with each meal. Is this information correct? How and when should you use digestive enzyme supplements if at all?” Over-the-counter digestive enzymes supplements have grown increasingly popular and are marketed to help with digestive symptoms like indigestion, bloating, and gas....
BARCELONA—Once upon a time people in the trucking industry could fantasize about increasing efficiency by having the likes of Burt Reynold’s “Bandit” character—from the 1970s chase film Smokey and the Bandit—racing around in his classic black Trans Am to fend off the cops so his partner’s 18-wheeler could ignore speed limits. But with all due respect to the Bandit, the long-haul business has a much better idea these days: self-driving big rigs that improve logistics, cost savings and road safety....
His finalist year: 1974 His finalist project: Designing a wind tunnel that uses magnets to hold test models in place What led to the project: As a child growing up in rural Oregon in the 1960s, Ilan Kroo was obsessed with flying. Along with friends, he built a hang glider from bamboo poles, duct tape and plastic. They took the contraption to a nearby dairy farm, ran down a hill, and would actually get a few feet off the ground before crashing....
About a third of Americans live in areas where allergies could be made worse by a combination of high ozone levels and ragweed pollen, according to a new report. The top cities with this allergy-inducing combo — dubbed in the report as the “Sneeziest and Wheeziest” cities — include Richmond, Virginia; Memphis, Tennessee; Oklahoma City; Philadelphia; Chattanooga, Tennessee; and Chicago, according to the report, from the Natural Resources Defense Council (NRDC), an environmental advocacy group based in New York....
We all know that exercise improves our physical fitness, but staying in shape can also boost our brainpower. We are not entirely sure how, but evidence points to several explanations. First, to maintain normal cognitive function, the brain requires a constant supply of oxygen and other chemicals, delivered via its abundant blood vessels. Physical exercise—and even just simple activities such as washing dishes or vacuuming—helps to circulate nutrient-rich blood efficiently throughout the body and keeps the blood vessels healthy....
Dear EarthTalk: How can the new Obama administration and/or Congress undo the many antienvironmental actions the Bush administration undertook over the last eight years, including the obstruction of Bill Clinton’s landmark “roadless rule” legislation? – Ann Lyman, Lake Tahoe, CA The Bush administration has certainly been no friend to the environment. Besides working for eight years to overturn the Clinton administration’s “Roadless Rule” that prevented road building (and the logging that usually follows) on 58....
1966 Josephson Effect “Four years ago Brian D. Josephson, a young graduate student in physics at the University of Cambridge, made a startling prediction. On the basis of a purely theoretical analysis of the phenomenon of superconductivity (the abrupt disappearance of electrical resistance in certain substances at temperatures near absolute zero), Josephson came to the conclusion that in principle a ‘supercurrent’ consisting of correlated pairs of electrons could be made to flow across an insulating gap between two superconducting bodies, provided that the gap was small enough....
The sharpest look yet at Jupiter has revealed a number of surprises — including a surge of ammonia welling up from its gassy depths, a startlingly powerful magnetic field and what could be a large, but poorly defined, core. NASA’s Juno mission began to capture these insights on 27 August last year, during the first of a series of close swoops past the planet. Preliminary results appeared on 25 May in Science and Geophysical Research Letters....
Why is it so difficult to diagnose an infectious disease on the spot? We measure vital signs such as temperature or blood pressure routinely, yet we have no quick way to pinpoint the cause of most infection. Our inability to identify harmful bacteria and viruses costs patients dearly. During the several days or so that doctors usually take to identify bacteria and viruses, illnesses spread and may get harder to treat, and the most vulnerable patients—newborns, the elderly, anyone with a weak immune system—can die....
GREENSBURG, Kan.—On the north side of this Midwestern town, an enormous white grain silo—one of few structures that survived a 2007 tornado—stands watch over construction in the business district along U.S. Route 54. This commercial strip is still being rebuilt, along with the rest of Greensburg. New low-slung, ranch-style homes line some streets. Others are pocked by weedy open lots studded with “for sale” signs. Stumps dot the landscape, remnants of the once-stately trees that shaded the town....
