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Canadian researchers have identified a previously unknown type of stem cell in muscles that may one day be targeted to treat muscular dystrophy, a debilitating degenerative disease that affects some 250,000 Americans. “It basically is the discovery of a new type of stem cell—a satellite stem cell,” says Michael Rudnicki, director of the Sprott Center for Stem Cell Research at the Ottawa Health Research Institute (OHRI). So-called satellite cells were previously believed to be involved exclusively in helping injured muscles repair themselves....

People devote 30 to 40 percent of their total speaking time to describing their own opinions or experiences, according to much research. A new study suggests that self-expression is intrinsically rewarding, in the same way that sex or eating is. In fact, we find talking about ourselves so pleasurable that we will give up money to do so, as reported in the May 22 Proceedings of the National Academy of Sciences USA....

The orbits of Pluto’s four smallest moons are even more chaotic than scientists had expected, according to new results from the New Horizons mission, which made a close flyby of Pluto in July. “The way I would describe this system is not just chaos, but pandemonium,” Mark Showalter, a co-investigator on the New Horizons mission, said today (Nov. 9) during a news conference at the meeting of the Division for Planetary Sciences of the American Astronomical Society....

The upper slopes of Mount Everest are a punishing place for plant life: high levels of ultraviolet radiation scorch the mountain, temperatures regularly fall below freezing, and the icy, rocky terrain can hardly be called good soil. But now scientists have identified three new plant species capable of surviving this kind of place. Among the highest-elevation plants known to science, the specimens—collected decades ago but never studied until now—reveal unique adaptations to life on the roof of the world....

In Kiboko, Kenya, a barbed wire fence separates a field of hybrid corn from the surrounding lands. Inside the fence, food safety regulators are learning to grow the crop with little water. In recent years, droughts have hit the region between June and September, reducing yields. But two new varieties of corn, also known as maize, are coming to sub-Saharan Africa. One of them is conventionally bred; the other, better-yielding variety is genetically modified....

In the 1922 poem The Waste Land, T. S. Eliot writes, cryptically: Who is the third who always walks beside you?/When I count, there are only you and I together /But when I look ahead up the white road/There is always another one walking beside you. In his footnotes to this verse, Eliot explained that the lines “were stimulated by the account of one of the Antarctic expeditions [Ernest Shackleton’s] … that the party of explorers, at the extremity of their strength, had the constant delusion that there was one more member than could actually be counted....

California’s coastal redwoods, Sequoia sempervirens, are the tallest trees on earth. But measuring their precise dimensions—which is key to determining how much climate-altering carbon they store as biomass—is fraught with uncertainty. Widely used scaling equations between trunk diameter and volume are based on limited sampling of much smaller trees, given that few people are willing to don a climbing harness and take measurements 30 stories off the ground. Now, for the first time, researchers have surveyed S....

This story is a supplement to the feature “Using Causality to Solve the Puzzle of Quantum Spacetime” which was printed in the July 2008 issue of Scientific American. Simulation Results: By the authors’ calculations, the spectral dimension of spacetime shades from four (on large scales) to two (on small scales), and spacetime breaks up from a smooth continuum into a gnarled fractal. Physicists are still puzzling over whether this conclusion means that spacetime ultimately consists of localized “atoms” or is built up out of intricate patterns only very loosely related to our usual concepts of geometry....

Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. Christianity began as a sect of Judaism in Judea in the 1st century CE and spread to the cities of the Eastern Roman Empire and beyond. In these cities, non-Jews, Gentiles, wanted to join the movement, and these Gentile-Christians soon outnumbered the Jews. The evolution of Christian beliefs and concepts (what would become dogma) absorbed both Jewish ideas as well as those of the dominant culture, but Christianity created innovations that transformed traditional thinking in relation to society and gender roles....

Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. The Spanish explorer Hernando de Soto (c. 1500-1542) landed on the west coast of Florida on 30 May 1539, hoping to find wealthy kingdoms to conquer and plunder. His crew journeyed for over four years in southeastern North America, savaging the local peoples, but ultimately returned home empty-handed....

Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. Mesopotamian inventions include many items taken for granted today, most of which were created during the Early Dynastic Period (2900-2334 BCE) or developed from achievements of the Uruk Period (4100-2900 BCE). The Sumerians are credited with the earliest inventions, which were further developed in the Akkadian Period (2334-2218 BCE) and then by later Mesopotamian civilizations....

Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. Museums have been around much longer than one might think, but in the ancient world, they were principally institutions of research and learning rather than places to display artworks and artefacts, even if they were often located in grand buildings and decorated with examples of fine sculpture and painting....

Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. The Julio-Claudians were the first dynasty to rule the Roman Empire. After the death of the dictator-for-life Julius Caesar in 44 BCE, his adopted son Octavian - later to become known as Augustus (r. 27 BCE - 14 CE) - fought a civil war against his father’s enemies to eventually prevail and become the first Roman emperor....

For the first time, scientists have pinpointed an area of the brain involved in a woman’s menstrual cycle. The research, reported online this week by the Proceedings of the National Academy of Sciences, shows contrasts in activity over the course of a month and provides a baseline for understanding the emotional and behavioral changes that 75 percent of all women report experiencing before, during and after their period. For any woman who has found herself becoming inexplicably angry or sad during her menstrual cycle, the possibility that her “time of the month” may be responsible is not news....

Hillary Clinton raised objections to fracking for oil and natural gas during the Democratic debate last night, saying the process would be substantially limited if she’s elected. She would oppose hydraulic fracturing in states that do not want it and apply regulations to reduce methane emissions and protect water, Clinton said, emphasizing past statements. “I don’t support it when any locality or any state is against, No. 1. I don’t support it when the release of methane or contamination of water is present....

Dark matter may have turned spinning stars into black holes near the center of our galaxy, researchers say. There, scientists expected to see plenty of the dense, rotating stars called pulsars, which are fairly common throughout the Milky Way. Despite numerous searches, however, only one has been found, giving rise to the so-called “missing pulsar problem.” A possible explanation, according to a new study, is that dark matter has built up inside these stars, causing the pulsars to collapse into black holes....

Source: Food Environment Atlas, U.S. Department of Agriculture, Economic Research Service Even within the borders of one of the world’s top agricultural countries, healthy food can be hard to come by. Many Americans reside in food deserts—communities where retailers offering fresh food are scarce but fast-food restaurants and convenience stores selling prepared foods can abound. The top two maps at the right show the proximity of full-line grocers to two groups for whom healthy food is often difficult to procure: low-income households and those without access to a vehicle....

One evening 10 years ago 17-year-old Trayvon Martin was walking through a Florida neighborhood with candy and iced tea when a vigilante pursued him and ultimately shot him dead. The killing shocked me back to the summer of 1955, when as a six-year-old boy I heard that a teenager named Emmett Till had been lynched at Money, Miss., less than 30 miles from where I lived with my grandparents. I remember the nightmares, the trying to imagine how it might feel to be battered beyond recognition and dropped into a river....

The powerful thrust of ocean-spawned winds can zip a kite surfer across the sea’s surface at up to 55 miles per hour. Engineers are now trying to harvest the power in that wind to generate electricity. The Wing 7 airborne wind turbine pictured here is a prototype of a leading contender for the job. The autonomous, lightweight device is tethered to land or to a floating platform; when wind speeds pick up, four rotors fly it up above 820 feet in a circle perpendicular to the wind....

Our meat consumption habits take a serious toll on the environment. According to the Environmental Working Group (EWG), the production, processing and distribution of meat requires huge outlays of pesticides, fertilizer, fuel, feed and water while releasing greenhouse gases, manure and a range of toxic chemicals into our air and water. A lifecycle analysis conducted by EWG that took into account the production and distribution of 20 common agricultural products found that red meat such as beef and lamb is responsible for 10 to 40 times as many greenhouse gas emissions as common vegetables and grains....