Posts

Two decades ago biologists and natural historians around the world launched ambitious projects to create inventories of our planet’s biodiversity. After all, they said, you can’t work to save what you don’t know exists. Even the most optimistic estimates suggest only a quarter of Earth’s species are currently known to science, raising concerns about the big picture amid rising extinction rates. These projects have crept along because of the painstaking work of identifying and describing species—as well as, in many cases, collecting samples of the organisms for DNA sequencing....

To the list of wonders of the ancient world, perhaps another should be added: nanotechnology. It seems that a hair-dye formula dating to Greek and Roman days works by causing tiny nanocrystals to form deep inside strands of hair. Cosmetics were known thousands of years ago in ancient Egypt, where lead compounds were applied as foundation or eye makeup. A hair-dye recipe first described in Greco-Roman times involves applying a paste of lead oxide and calcium hydroxide, or lime, to graying and fair locks....

If you ask the scientists at the National Human Genome Research Institute (NHGRI) when the Human Genome Project wrapped up, they’ll tell you it was finished in 2003. However, a new study indicates that the composite reference genome cobbled together from parts of the genetic codes of multiple people, is definitely a work in progress. The completed genome was to serve as a model of the genetic makeup of a typical human that researchers could use as a reference to detect genetic flaws and defects in people with certain disorders....

Inspired by biotechnology executive John Crowley’s efforts to save his children, the movie Extraordinary Measures shows basic science and biotechnology teaming up to help researchers develop a treatment for a rare and fatal neuromuscular disorder. With a prevalence of one in 40,000, according to a 2007 review published in Pediatrics, Pompe disease results from a recessively inherited deficiency in the gene encoding acid alpha-glucosidase (GAA), an enzyme that converts glycogen to glucose....

Law-makers in Canada and the United States are making moves to restrict the use of rodent poisons based on blood thinners, as studies show that the toxins accumulate in birds of prey and other animals. The chemicals in question are anticoagulant rodenticides (ARs), which work like the human blood-thinning drug warfarin. Warfarin is itself used as a rat poison, but is what environmental toxicologists call a first-generation AR, less lethal and less prone to bioaccumulation than its second-generation successors....

Smart People Don’t Diet by Charlotte N. Markey Da Capo Press, 2014 ($16.99) Though not perfect, this is possibly the best book on weight loss ever written. Markey, a psychology professor who teaches a course called “The Psychology of Eating” at Rutgers University–Camden, is a true expert who has done what experts seldom do well. She has translated good science on eating and dieting into clear, friendly, informal language that virtually anyone with concerns about weight will find both interesting and helpful....

Key concepts Physics Aerodynamics Flight Stability Introduction Blast off! Have you ever played with a model or toy rocket, or seen a real rocket launch on TV? In this project you will make simple rockets out of paper and launch them by blowing into a drinking straw. Can you make the rocket that flies the farthest? Background All flying objects, from rockets to airplanes to birds, have something in common—they need to remain stable when they fly....

Energy efficiency seems to make rational economic sense—the less energy used, the more money saved. Yet, in the real world it’s actually competition with neighbors rather than cost savings that can drive people to turn down their thermostats, install insulation or simply switch off the lights when they leave a room. Such is the lesson of a host of efforts, ranging from a group called OPOWER’s comparative use utility billing to switching from miles per gallon to rate vehicle efficiency to gallons per mile....

It was a financial investment in a tobacco company that helped lead to the downfall of Brenda Fitzgerald, who until Wednesday was the director of the Centers for Disease Control and Prevention. For many in the public health community, the notion that the head of the CDC held shares of a company in an industry that has been so anathema to the agency’s mission was shocking. But Fitzgerald also purchased shares in pharma giants Merck and Bayer after taking over the CDC—an apparent conflict of interest that also confounded government ethics experts....

Bloom, who is based at the Fred Hutchinson Cancer Research Center in Seattle, Washington, saw these seasonal coronaviruses as potentially providing a roadmap for how SARS-CoV-2 might evolve and for the future of the pandemic. But little is known about how these other viruses continue to thrive. One of the best-studied examples—a seasonal coronavirus called 229E—infects people repeatedly throughout their lives. But it’s not clear whether these reinfections are the result of fading immune responses in their human hosts or whether changes in the virus help it to dodge immunity....

When the dark chill of winter gives way to the sunny warmth of spring, many people find themselves in the throes of spring fever: restless, energetic, romantic. Other symptoms, says Michael Terman—an expert on biorhythms at New York–Presbyterian Hospital—include increased heart rate, appetite loss and mood swings. Clearly, the condition is real, even if it is not, as Terman notes, “a definitive diagnostic category.” Researchers may lack an explanation of its biological underpinnings, but they do have a number of clues....

Even before they’ve hatched, red-eyed tree frogs have a nose for danger. The results of a new study suggest that the creatures can detect the vibrations from a predator and hatch early in order to escape. The eggs of red-eyed tree frogs usually hatch between six and eight days after fertilization but the animals can emerge up to 30 percent sooner if necessary. Karen M. Warkentin of Boston University and the Smithsonian Tropical Research Institute in Panama studied egg clutches located on the edge of Ocelot Pond in Panama to identify the circumstances under which embryos leave their clutch (the gelatinous mass deposited on a tree leaf) prematurely....

Odds are you carry DNA from a Neandertal, Denisovan or some other archaic human. Just a few years ago such a statement would have been virtually unthinkable. For decades evidence from genetics seemed to support the theory that anatomically modern humans arose as a new species in a single locale in Africa and subsequently spread out from there, replacing archaic humans throughout the Old World without mating with them. But in recent years geneticists have determined that, contrary to that conventional view, anatomically modern Homo sapiens did in fact interbreed with archaic humans, and that their DNA persists in people today....

It sounds like the stuff of science fiction, but scientists have discovered that a whiff of a certain hormone makes people more willing to trust others with their money. The hormone is oxytocin, which in nonhuman mammals is associated with social attachment, as well as a number of physiological functions related to reproduction. As such, it is believed to help animals overcome their natural tendency to avoid proximity and allow others to approach them....

Hannes Schroeder snaps on two pairs of blue latex gloves, then wipes his hands with a solution of bleach. In front of him is a large Tupperware box full of plastic bags that each contain sea water and a piece of red-stained bone. He lifts one out and inspects its contents as several archaeologists hover behind, waiting for his verdict. They’re hoping he can pull off a feat never attempted before—DNA analysis on someone who has been under the sea for 2,000 years....

Seven years ago, the global community of researchers, health-care workers and activists battling tuberculosis was euphoric. A landmark 2010 trial showed that a new genetic test was highly effective at diagnosing TB, prompting hopes that countries could soon finally control the disease, which killed 1.45 million that year. The World Health Organization (WHO), promptly endorsed the test, called GeneXpert, and promoted its roll-out around the globe to replace a microscope-based test that missed half of all cases....

About 200,000 years ago, ice age children squished their hands and feet into sticky mud thousands of feet above sea level on the Tibetan Plateau. These impressions, now preserved in limestone, provide some of the earliest evidence of human ancestors inhabiting the area and may represent the oldest art of their kind ever discovered. In a new report, published Sept. 10 in the journal Science Bulletin, the study authors argue that the hand and footprints should be considered “parietal” art, meaning prehistoric art that cannot be moved from place-to-place; this usually refers to petroglyphs and paintings on cave walls, for instance....

Vaccination against SARS-CoV-2 lowers the risk of long COVID after infection by only about 15%, according to a study of more than 13 million people1. That’s the largest cohort that has yet been used to examine how much vaccines protect against the condition, but it is unlikely to end the uncertainty. Long COVID — illness that persists for weeks or months after infection with SARS-CoV-2 — has proved difficult to study, not least because the array of symptoms makes it hard to define....

For years, medical researchers have hoped that a burgeoning class of cholesterol drugs targeting a protein called PCSK9 could be the next generation of blockbuster treatments. Now, a large clinical trial has demonstrated that this approach can lower the risk of heart disease. But it’s still unclear whether these drugs—which attempt to mimic a beneficial genetic mutation—will be the breakthrough that scientists and pharmaceutical companies had imagined. The results, published in the New England Journal of Medicine and presented at the American College of Cardiology conference in Washington DC on March 17, show that a drug called evolocumab (Repatha) reduced the risk of cardiovascular death, heart attack and stroke by about 20% in patients who were already taking other cholesterol-controlling drugs called statins....

Today’s scientists are scrambling to develop technology to cope with climate change; carbon capture technology, renewable energy and drought-resilient crops are just a few examples. But researchers recently learned that ours isn’t the first civilization to innovate as the Earth’s climate shifts. A new study suggests “pulses” in technological innovation that took place between 280,000 and 30,000 years ago in present-day South Africa could have been driven by dramatic shifts in the region’s weather conditions....