Tag Archives: university of arizona

Hunter-Gatherers Expend Same Calories as Average Americans

By Guest PostAugust 3, 2012Scienceafrica, audax mabulla, brian wood, caloric intake, calories, cause, david raichlen, energetic expenditure, evolutionary science, frank w marlowe, gym membership, hazda, herman pontzer, hunter college, hunter gatherer, obesity, obesity pandemic, physical exercise, susan b racette, Tanzania, Technology, university of arizona, western population, yale anthropologist

Taking in too many calories far outweighs getting too little exercise as a cause of obesity, according to a study of a hunter-gatherer society co- authored by Yale anthropologist Brian Wood and recently published in the July issue of the journal PLoS One.

Using state-of-the-art technology to measure the daily energetic expenditure of the Hazda, a foraging people of Tanzania, Wood and co-authors Herman Pontzer (Hunter College) and David Raichlen (University of Arizona) discovered that even though these last remaining hunter-gatherers in Africa are quite physically active, they expend on average no more calories in a day than the adult population of the industrialized world. Given the total lack of obesity among the Hadza, whose average daily calorie consumption is far lower than that found in the developed world, the researchers concluded that increased caloric intake is the main source of rising obesity in Western populations. (more…)

Today in the Milky Way: Cloudy Skies

By Guest PostJune 30, 2012Scienceadam block, aquila dark cloud, aquila rift arcs, astronomy picture, cloudy skies, dust lanes, Galaxy, gas and dust, herbig haro object, hh32, infrared, ldn 673, light years, Milky Way, mount lemmon skycenter, radiation, radio wave, rno 109, schulmann telescope, stellar winds, summer triangle, university of arizona

Adam Block of the UA’s Mount Lemmon SkyCenter brings us a rare view of the clouds wafting through our Milky Way in this Astronomy Picture of the Day.

In silhouette against the Milky Way’s faint starlight, its dusty molecular clouds likely contain raw material to form hundreds of thousands of stars, prompting astronomers to eagerly search the clouds for telltale signs of star birth.

This telescopic close-up looks toward the region at a fragmented Aquila dark cloud complex identified as LDN 673, stretching across a field of view slightly wider than the full moon.

For this image selected by NASA as the June 29 Astronomy Picture of the Day, astrophotographer Adam Block of the University of Arizona’s Mount Lemmon SkyCenter remotely operated the 32-inch Schulmann Telescope to peer into the vast chasms of gas and dust wafting through the Milky Way, exposing for about 15 minutes at a time during several nights in April and May. (more…)

Evolution of Religious Patriarchy as a Mate-Guarding Strategy?

By Guest PostJune 15, 2012Culture, Scienceadultery, african population, african society, beverly strassmann, Bible, biological anthropologist, brenda gillespie, brendan hugg, christianity, contraception, cuckoldry, dogon belief, dogon people, dogon practice, eneticist, erin burke, evolution, female sexuality, fertility status, fidelity, genetic data, ideology, indigenous, islam, Mali, menstrual huts, menstrual taboos, michael hammer, monotheistic religion, nikhil kurapati, pollution, quran, rates of cuckoldry, religious patriarchy, religious practices, sacred texts, tatiana karafet, traditional, united states, university of arizona, university of michigan, village, virginity, west africa, word of god, y dna mismatch

One of the largest and longest studies in a traditional African society sheds light on religious practices and cuckoldry. Genetic data suggest religious patriarchy is directly analogous to the mate-guarding tactics used by animals to ensure paternity.

Religious practices that strongly control female sexuality are more successful at promoting certainty about paternity, according to a study published in the June 4, 2012 issue of the Proceedings of the National Academy of Sciences.

In an interdisciplinary collaboration, a group of researchers around biological anthropologist Beverly Strassmann from the University of Michigan and University of Arizona geneticist Michael Hammer analyzed genetic data on 1,706 father-son pairs in a traditional African population – the Dogon people of Mali, West Africa – in which Islam, two types of Christianity and an indigenous, monotheistic religion are practiced in the same families and villages. (more…)

Largest Meteorite Hunt in History Yields Treasure for UA

By Guest PostMay 16, 2012Sciencean ounce, california, carbonaceous chondrites, daniel stolte, dante lauretta, dolores hill, ed beshore, greg hupe, hiroshima bom, meteorite, meteorite hunt, michael farmer, NASA, nevada, nuclear explosion, osiris rex mission, planetary science, robert ward, scientists, sierra nevada, sky, solar system, spacecraft, sutters mill, university of arizona

Thanks to the generosity of three professional meteorite hunters, the UA Lunar and Planetary Laboratory will own three samples of a rare kind of meteorite leftover from the earliest beginnings of the solar system.

To the untrained eye, the black, smooth-edged lump that is sitting under a glass cover looks similar to a piece of charcoal. But to scientists Dante Lauretta and Ed Beshore from the University of Arizona Lunar and Planetary Laboratory, it is one of the most intriguing stones they have ever seen.

“This meteorite is the oldest rock you’ll ever find on Earth. In fact, it formed 50 to 60 million years before the Earth even existed,” said Lauretta, who is a professor of planetary science and principal investigator of NASA’s OSIRIS-REx mission, which will send a spacecraft to return a sample from an asteroid in 2023. (more…)

UA Researchers Hunt Bomb-Eating Bugs

By Guest PostApril 29, 2012Environment, Weaponsarmy, aromatic amines, bacteria, bacterial eating habits, bio augmentation, bomb eating bugs, cancer, carcinogenic compound, conventional explosive, cytotoxic, degradation pathway, department of defense, ed stiles, environmental effect, environmental fate, environmental impact, fate and toxicity, food source, groundwater, humic polymer, humus, imcs, insensitive munitions compounds, james a field, jon chorover, molecular ecology technique, munition, mutagenic, nitro aromatic compound, organic matter, polymerization, reyes sierra, site selection, surface water, threat, tnt, university of arizona

UA researchers are investigating bacterial eating habits as part of a $1 million study to determine the environmental fate of newly developed munitions.

University of Arizona researchers are studying the environmental effects of insensitive munitions compounds, or IMCs, which are new, more stable explosives that won’t detonate in response to heat or shock.

Not much is known about the environmental impact of IMCs, which the U.S. Department of Defense hopes will reduce injuries and fatalities among troops who handle explosives. (more…)

Playing the Odds to Your Favor

By Guest PostApril 25, 2012Educationamerica, applied stochastic processes, area, average, China, chinese native, energy, evaluation, flinn scholarship, galileo circle, ireland, jason xu, kevin lin, knowledge, mathematical statistics, mathematics, ming xu, monte carlo method, physics, population, probability distribution, queen's university belfast, random sample, research, tucson, ua student, university of arizona, Wuhan

UA student Jason Xu has been recognized by the College of Science for his undergraduate research.

Wuhan, China and Tucson, Ariz.: These cities are thousands of miles apart, but they have one commonality – University of Arizona student Jason Xu.

A Chinese native and mathematics senior in the Honors College, Xu was selected as the recipient of this year’s Excellence in Undergraduate Research award by the UA College of Science at its Galileo Circle reception event.

The award “is a huge honor and means a lot to me. I feel really good to be representing the math department,” Xu said. (more…)

12-Mile-High Martian Dust Devil Caught in Act

By Guest PostApril 6, 2012Scienceamazonis planitia, dust devil, earth, hirise camera, mars reconnaissance orbiter, martian dust devil, martian surface, meteorite impact, NASA, northern mars, northern summer solstice, plume, red planet, tucson, university of arizona

A Martian dust devil roughly 12 miles high (20 kilometers) was captured whirling its way along the Amazonis Planitia region of Northern Mars on March 14. It was imaged by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. Despite its height, the plume is little more than three-quarters of a football field wide (70 yards, or 70 meters).

Dust devils occur on Earth as well as on Mars. They are spinning columns of air, made visible by the dust they pull off the ground. Unlike a tornado, a dust devil typically forms on a clear day when the ground is heated by the sun, warming the air just above the ground. As heated air near the surface rises quickly through a small pocket of cooler air above it, the air may begin to rotate, if conditions are just right. (more…)

Mesquite Trees Displacing Southwestern Grasslands

By Guest PostMarch 21, 2012Environment, Natureatmosphere, biochemical pathway, bouteloua eriopoda, carbon dioxide, catalina mountains, changing climate, climate, climate data, desert, ecohydrology, ecosystems, eddy covariance tower, grama grass, grassland, greg barron gafford, groundwater, groundwater pool, mesquite tree, muhlenbergia porter, muhly, photosynthesis, predictions, prosopis velutina, rainfall, root system, san pedro river riparian area, santa rita mountains, seasonal precipitation, southeastern arizona, southwest, southwestern climate, sugars, temperature, university of arizona, warming climate, water resource, woody shrub

Mesquite trees and woody shrubs are better adapted than grasslands to a Southwestern climate predicted to shift toward higher temperatures and greater variability in rainfall, UA ecologists have discovered.

As the desert Southwest becomes hotter and drier, semi-arid grasslands are slowly being replaced by a landscape dominated by mesquite trees, such as Prosopis velutina, and other woody shrubs, a team of University of Arizona researchers has found.

In a “leaf-to-landscape” approach, the team combined physiological experiments on individual plants and measurements across entire ecosystems to quantify how well grasslands, compared to mesquite trees and woody shrubs, cope with heat and water stress across seasonal precipitation periods. (more…)