A decade ago cosmologists began to suspect that the universe might be bizarrely lopsided. Hints of a universal imbalance emerged from the afterglow of the big bang, known as the cosmic microwave background, or CMB, which is dotted with hot and cold spots signifying fluctuations in the density of matter. Starting in 2003, data from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) suggested that one side of the cosmos is hotter than the other....
Nine out of every 10 cancer deaths occur because the disease has spread. Yet metastasis is the most poorly understood process in cancer biology. “Its complexity has scared away many cancer scientists,” notes Robert Weinberg, a researcher at the Massachusetts Institute of Technology’s Whitehead Institute for Biomedical Research. How does a cancer cell suddenly acquire the ability to jump to distant organs? Then how does the itinerant cell learn to invade the brain or liver?...
Excerpted from My Search for Ramanujan: How I Learned to Count by Ken Ono and Amir Aczel. Copyright © 2016 by Ken Ono and Amir Aczel. With permission of the publisher, Springer. All rights reserved. In the spring of 1991, I took an algebraic number theory course from Professor Basil Gordon. Gordon loved the material, and the students in the class could sense his deep devotion to the subject. Gordon’s lectures were inspirational sermons....
How does a microbe know how to share electrons with an inanimate object? A wide variety of microbes can send electrons into, or accept electrons from, conducting materials. Witness the fuel cells that rely on different types of bacteria to exchange electrons with graphite electrodes. But investigators have wondered how that ability arose. Most organisms internally generate energy by coupling the addition of electrons to one molecule with their removal from another....
Knocking out a single gene can switch on a worm’s ability to regenerate parts of its body, even enabling it to grow a new head. The fact that such a simple manipulation can restore healing abilities provides new insight into how the stem cells involved in this process are marshaled in animals. Some animals, such as salamanders and newts, can regenerate entire body parts, and mice can regrow toes if left with enough nail (see ‘How nails regenerate lost fingertips’)....
DENVER — Gardeners and farmers may love earthworms for their rich castings and composting help, but in forests near the Great Lakes, the creatures are alien invaders. No earthworms are native to North America’s northern forests (massive ice age glaciers kept the land worm-free). But in the years since settlers arrived, 15 earthworm species have appeared in Minnesota, from Europe and Asia. Some of the invasive species are changing local forests, scientists have discovered....
The leading hypothesis for the moon’s formation contends that a massive impact billions of years ago knocked a wealth of planetary material off of Earth, which coalesced into our lunar companion. But that coalescence was not a serene process—the heat of formation left the nascent moon coated with an ocean of magma, researchers studying samples returned by Apollo 11 theorized in 1970. As that ocean cooled, its most buoyant components floated to the top, forming an outer shell over denser layers of rock....
By Julie Gordon KITIMAT, British Columbia (Reuters) - Just a few miles from the spot where Enbridge Inc plans to build a massive marine terminal for its Northern Gateway oil pipeline, Gerald Amos checks crab traps and explains why no concession from the company could win his support for the project. Amos, the former chief of the Haisla Nation on the northern coast of British Columbia and a community leader, has argued for years that the risk - no matter how small - of an oil spill in these waters outweighs any reward the controversial project might offer....
The Better Angels of Our Nature: Why Violence Has Declined by Steven Pinker. Viking Adult, 2011 ($40) According to the Stockholm International Peace Research Institute (SIPRI), worldwide military expenditures have been growing annually for the past 15 years, and between 15 and 20 major armed conflicts—yes, wars—are in progress as you read this. All told, upward of 175 million people died in war-related violence during the 20th century, plus another eight million because of conflicts among individuals....
When physicists at CERN’s Large Hadron Collider announced the discovery of a new particle on July 4, they did not call it “the Higgs boson.” This was not just the typical caution of scientists. It also signified that the announcement comes at a profound moment. We are at the end of a decades-long theoretical, experimental and technological odyssey, as well as at the beginning of a new era in physics....
Climate science tells us the world’s coastal zones are in trouble from storm surges and sea-level rise. Food-producing regions are at risk of drought, disease and climate-hardy pests. But what about the roughly 25 percent of the Earth’s land area defined as “mountain regions”? A new U.N. report finds that mountains and the societies that call them home face their own suite of climate challenges. They include temperature and precipitation extremes, which in turn can trigger avalanches, flooding, drought and wildfire....
Biology is now in the early stages of an historic transition to an information science, while also gaining the tools to reprogram the ancient information systems of life. Few of us go more than a few months without changing the software programs we use in our electronic devices, yet the 23,000 software programs inside our cells called genes have not changed appreciably in thousands of years (although recent research suggests that a few have changed as recently as a few hundred years ago)....
Unlike the traditional power grid, a “smart” grid is designed to accommodate a two-way flow of both electricity and data. This creates great promise, including lower energy prices, increased use of renewable resources and, it is hoped, fewer brownouts and blackouts. But a smart grid also poses several potential security problems—networked meter data, power companies’ computers and those of customers could all be vulnerable to tampering. A smart grid adds a layer of cybersecurity complexity to challenges that already existed with the traditional grid....
SAN FRANCISCO – When Dr. Darragh Flynn sits down with her pregnant patients, she preaches healthy habits: Don’t smoke or drink, eat nutritious foods and take vitamins. She also advises them to avoid gasoline fumes, pesticides, certain types of fish and some household cleaners and cosmetics. “It’s only for nine months,” she tells them. “Let someone else put gas in the car.” But Flynn is in the minority. A new nationwide survey of 2,600 obstetricians and gynecologists found that most do not warn their pregnant patients about chemicals in food, consumer products or the environment that could endanger their fetuses....
President Trump, as he so often does, dominated the coal headlines in 2017. But America’s bombastic leader had less to do with the major developments in the coal sector than the headlines would suggest. After a dismal 2016, which saw U.S. coal production fall to the lowest level since 1978, America’s miners had a lot to be happy about in 2017. Mine output was 719 million tons through the first 11 months of the year, an increase of 8 percent over last year....
People who have been exposed to pesticides are 70 percent more likely to develop Parkinson’s disease than those who haven’t, according to a new study. The results suggest that any pesticide exposure, whether occupationally related or not, will increase a person’s risk of the disease. This means that using pesticides in the home or garden may have similarly harmful effects as working with the chemicals on a farm or as a pest controller....
In her new book Maia Szalavitz recalls her behavior as a child in school and at home. Anxious, bright and slightly obsessive, she didn’t seem to fit the stereotype of the “addictive personality”. Nevertheless, in college she would become addicted to heroin and cocaine, forcing her to reexamine her assumptions about addiction and its treatment. The following is an excerpt from Unbroken Brain: A Revolutionary New Way of Understanding Addiction, by Maia Szalavitz....
People cry when reunited with loved ones, scream on getting good news and pinch cute babies’ cheeks. Yet why do such positive experiences elicit these “negative” reactions? New research suggests we may do it to calm ourselves down so we can handle situations better. Oriana Aragón, a psychologist at Yale University, and her colleagues surveyed 143 adults about how they tend to react to good and bad experiences. Then they showed the subjects pictures of babies that varied in terms of their “cuteness,” based on earlier research that suggests that babies are considered cuter if they have bigger cheeks and eyes and smaller chins and noses....
BALTIMORE—The generic line on dark matter is that nobody really knows what it is because nobody has seen it. The former claim remains basically unassailable—there are many forms dark matter could take. But one research group would dispute the latter assertion. Over the past several years, the Italian DAMA (for DArk MAtter) collaboration has been making the claim that their subterranean detector has registered the signature of dark matter as Earth passes through a sea of the stuff....
Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. Ancient India in the Vedic Period (c. 1500-1000 BCE) did not have social stratification based on socio-economic indicators; rather, citizens were classified according to their Varna or castes. ‘Varna’ defines the hereditary roots of a newborn, it indicates the colour, type, order or class of people. Four principal categories are defined: Brahmins (priests, gurus, etc....
