Tag Archives: arizona

340 Krater fehlen noch

Forscher berechnen die Zahl der noch zu entdeckenden Einschlagstellen von Meteoriten auf der Erdoberfläche

Die Geologen Prof. Dr. Stefan Hergarten und Prof. Dr. Thomas Kenkmann vom Institut für Geo- und Umweltnaturwissenschaften der Universität Freiburg haben die weltweit erste Studie zu der Frage veröffentlicht, wie viele Meteoritenkrater auf der Erdoberfläche vorhanden sein müssten. 188 sind bislang nachgewiesen, 340 weitere gilt es zu entdecken – so das Ergebnis einer Wahrscheinlichkeitsrechnung, die die beiden Forscher im Fachjournal „Earth and Planetary Science Letters“ vorgestellt haben. (more…)

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Dwindling waterways challenge desert fish in warming world

One of Arizona’s largest watersheds – home to many native species of fish already threatened by extinction – is providing a grim snapshot of what could happen to watersheds and fish in arid areas around the world as climate warming occurs.

New research by University of Washington and Ohio State University scientists suggests that, by 2050, the Verde River Basin in Arizona will have up to one-fifth more streams dry up each season and at least a quarter more days with no water flow, a problem when fish are trying to reach spawning habitats and refuges where water still remains. (more…)

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Testing Water for Antibiotic-Resistant Bacteria

Antibiotic-resistant bacteria are an important concern for disease prevention in the future. UA doctoral candidate Victoria Obergh is testing Tucson-area wastewater systems to find out where these bacteria can be found.

In the lab, Victoria Obergh transfers bacterial DNA samples into a tray. A graduate student in the University of Arizona’s Department of Soil, Water and Environmental Science, part of the College of Agriculture and Life Sciences, Obergh works with the samples under a sterile hood sporting an ultraviolet light to kill any unwanted DNA. (more…)

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All for One: What Makes an Individual

Life as we know it has certain properties that are consistent regardless whether you’re looking at a bacterial colony in a petri dish or a primate colony in South America. Rick Michod, UA professor and department head of ecology and evolutionary biology, has received $1.3 million from NASA to investigate what properties of biology define an individual organism.

Many things in life are not fair. But some things are at least consistent.

For example, all life as we know it has certain universal properties, which presumably define how life would be organized anywhere it evolved in the universe, said Richard Michod, professor and head of the department of ecology and evolutionary biology at the University of Arizona.  (more…)

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Proximity to Coal-Tar-Sealed Pavement Raises Risk of Cancer, Study Finds

People living near asphalt pavement sealed with coal tar have an elevated risk of cancer, according to a study in the journal Environmental Science and Technology. Much of this calculated excess risk results from exposures in children, age six or younger, to polycyclic aromatic hydrocarbons (PAHs) from the sealant.

“The increased cancer risk associated with coal-tar-sealed asphalt (CSA) likely affects a large number of people in the U.S. Our results indicate that the presence of coal-tar-based pavement sealants is associated with significant increases in estimated excess lifetime cancer risk for nearby residents,” said E. Spencer Williams, Ph.D., principal author of the study and Baylor University assistant research scientist at the Center for Reservoir and Aquatic Systems Research in Baylor’s College of Arts & Sciences. (more…)

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UA Entomologists Partner with China to Thwart Bollworm Resistance to Bt Cotton

Researchers at the UA are studying resistance in pink bollworm in China and working to develop strategies against it.

University of Arizona entomologists are joining forces with scientists on the other side of the globe to protect cotton in China from potentially devastating insect pests.

Xianchun Li, associate professor of entomology in the UA College of Agriculture and Life Sciences, and Bruce Tabashnik, head of the department of entomology, both members of the UA BIO5 Institute, are partnering with Chinese scientists to combat insect resistance to genetically engineered cotton plants. (more…)

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Thawing ‘Dry Ice’ Drives Groovy Action on Mars

PASADENA, Calif. — Researchers using NASA’s Mars Reconnaissance Orbiter see seasonal changes on far-northern Martian sand dunes caused by warming of a winter blanket of frozen carbon dioxide.

Earth has no naturally frozen carbon dioxide, though pieces of manufactured carbon-dioxide ice, called “dry ice,” sublime directly from solid to gas on Earth, just as the vast blankets of dry ice do on Mars. A driving factor in the springtime changes where seasonal coverings of dry ice form on Mars is that thawing occurs at the underside of the ice sheet, where it is in contact with dark ground being warmed by early-spring sunshine through translucent ice. The trapped gas builds up pressure and breaks out in various ways. (more…)

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Moths Wired Two Ways to Take Advantage of Floral Potluck

Moths are able to enjoy a pollinator’s buffet of flowers – in spite of being among the insect world’s picky eaters – because of two distinct “channels” in their brains, scientists at the University of Washington and University of Arizona have discovered.

One olfactory channel governs innate preferences of the palm-sized hawk moths that were studied – insects capable of traveling miles in a single night in search of favored blossoms. The other allows them to learn about alternate sources of nectar when their first choices are not available.

For moths, the ability to seek and remember alternate sources of food helps them survive harsh, food-deprived conditions. Scientists knew bees could learn, but this is the first proof that moths can too. (more…)

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