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X-Ray Telescope Finds New Voracious Black Holes in Early Universe

By Guest PostJune 17, 2011Sciencebig bang, black holes, cdfs, chandra, chandra deep field south, chandra x ray observatory, cosmic dawn, cosmic fog, early universe, eric gawiser, ezequiel treister, galaxies, giant black holes, Hubble Space Telescope, kevin schawinski, marta volonteri, massive black holes, NASA, neutral hydrogen, new jersey, optical and infrared images, photons, physics, priya natarajan, quasars, reionization, Rutgers University, supermassive black holes, university of hawaii, university of michigan, x ray image, yale university, young black holes

ANN ARBOR, Mich.— Using the deepest X-ray image ever taken, a University of Michigan astronomer and her colleagues have found the first direct evidence that massive black holes were common in the early universe. This discovery from NASA’s Chandra X-ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies.

By pointing Chandra at a patch of sky for over six weeks, astronomers obtained what is known as the Chandra Deep Field South (CDFS). When combined with very deep optical and infrared images from NASA’s Hubble Space Telescope, the new Chandra data allowed astronomers to search for black holes in 200 distant galaxies, from when the universe was between about 800 million and 950 million years old. (more…)

Study Reveals Important Aspects of Signalling Across Cell Membranes in Plants

By Guest PostJune 17, 2011Scienceanimal cell, cellular membranes, communication process, joanne chory laboratory, membrane, membrane bound receptor, michael hothorn, national science foundation, plant cell, receptor molecules, salk institute, signal, transmembrane signalling, yellow steroid

*Plant receptors use different signalling method than do animal receptors*

Every living plant cell and animal cell is surrounded by a membrane. These cellular membranes contain receptor molecules that serve as the cell’s eyes and ears, and help it communicate with other cells and with the outside world.

The receptor molecules accomplish three basic things in the communication process: 1) recognize an outside signal, 2) transport that signal across the cell’s membrane and 3) initiate the reading of the signal inside the cell and then initiate the cell’s response to that signal. These steps are collectively known as transmembrane signaling. (more…)

Gulf of Mexico Dead Zone Severely Impairs Reproduction in Atlantic Croaker, Researchers Find

By Guest PostJune 16, 2011Environment, Scienceandrogens, aromatase, atlantic croaker, coast of louisiana, coastal regions, dead zone, enzyme, estrogens, female sex hormones, fish population, gulf of mexico, hypoxic area, hypoxic coastal zone, hypoxic dead zone, impairment of reproductive output, low oxygen waters, male sex hormones, marine animals, marine science, marine scientist, masculinized, neuroendocrine function, ovarian masculinization, oxygen levels, peter thomas, reproductive impairment, saydur rahman, second largest seasonal hypoxic zone, sperm and eggs, the university of texas at austin, thomas and rahman, world

AUSTIN, Texas — Atlantic croaker living in the large Gulf of Mexico “Dead Zone” exhibit severe reproductive impairment with potential long-term impacts on the fish’s population abundance, researchers from The University of Texas at Austin’s Marine Science Institute have found.

Males and females were found to produce dramatically fewer sperm and eggs. In addition, females in the hypoxic Dead Zone waters were masculinized — some 20 percent actually produced sperm in their ovaries. The sex ratio was also heavily skewed toward males in the hypoxic area. (more…)

GPS Stations Can Detect Clandestine Nuclear Tests

By Guest PostJune 15, 2011Environment, Scienceair molecules, airborne radioactive gas, bubble of disturbed particles, chemical sensors, comprehensive nuclear-test-ban treaty organization, computer algorithms, ctbto, dorota grejner brzezinska, earth, eastern asia, evidence of a nuclear explosion, fluctuation in atmospheric electron density, gangwon province, geodetic science, global positioning system, gps, hamyong province, igs, illegal nuclear explosions, inje county, international gnss service, ionosphere, ionospheric electron density, jihye park, luis gaya pique, north korea, north korean nuclear test in 2009, ohio state university, punggye, ralph von frese, seismic detectors, shockwave, south korea, south korean gps network, underground nuclear tests, upper atmosphere, yu morton

VIENNNA, Austria – At the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) meeting, American researchers are unveiling a new tool for detecting illegal nuclear explosions: the Earth’s global positioning system (GPS).

Even underground nuclear tests leave their mark on the part of the upper atmosphere known as the ionosphere, the researchers discovered, when they examined GPS data recorded the same day as a North Korean nuclear test in 2009. Within minutes on that day, GPS stations in nearby countries registered a change in ionospheric electron density, as a bubble of disturbed particles spread out from the test site and across the planet. (more…)

Telecommunications Wavelength Quantum Dot Laser Grown on Silicon Substrate

By Guest PostJune 15, 2011Science, Technologydemonstration of an electrically driven, department of electronic and electrical engineering at ucl, epsrc national centre, fabrication of active devices in electronics silicon photonics, growth of compound semiconductor laser material, Nanotechnology, nature photonics journal, photonics with silicon electronics, quantum dot laser grown directly, royal society university, semiconductors, silicon based information technology, silicon substrate (si), university college london, wafer bonding, wavelength (1300-nm)

A new generation of high speed, silicon-based information technology has been brought a step closer by researchers in the Department of Electronic and Electrical Engineering at UCL and the London Centre for Nanotechnology. The team’s research, published in Nature Photonics journal, provides the first demonstration of an electrically driven, quantum dot laser grown directly on a silicon substrate (Si) with a wavelength (1300-nm) suitable for use in telecommunications. (more…)

Probes Suggest Magnetic Bubbles at Solar System Edge

By Guest PostJune 13, 2011Sciencemagnetic bubbles, magnetic field, solar magnetic field, solar system, solar system edge

PASADENA, Calif. –– Observations from NASA’s Voyager spacecraft, humanity’s farthest deep space sentinels, suggest the edge of our solar system may not be smooth, but filled with a turbulent sea of magnetic bubbles. (more…)

ALPHA Stores Antimatter Atoms Over a Quarter of an Hour – and Still Counting

By Guest PostJune 8, 2011Sciencealpha collaboration, anti atoms, antihydrogen atoms, antimatter atoms, atoms, atoms of antihydrogen, berkeley lab, CERN, geneva, joel fajans, jonathan wurtele, lasers, magnetic trap, matter antimatter asymmetry, properties of antihydrogen, switzerland, time to go for coffee

*Berkeley Lab physicists join with their international colleagues in reaching a new frontier in antimatter science*

The ALPHA Collaboration, an international team of scientists working at CERN in Geneva, Switzerland, has reported storing a total of 309 atoms of antihydrogen, some for up to 1,000 seconds (almost 17 minutes), with an indication of much longer storage time as well.

ALPHA announced in November, 2010, that they had succeeded in storing antimatter atoms for the first time ever, having captured 38 atoms of antihydrogen and storing each for a sixth of a second. In the weeks following, ALPHA continued to collect anti-atoms and hold them for longer and longer times. (more…)

‘Ancient Hominid Males Stayed Home While Females Roamed’

By Guest PostJune 7, 2011Scienceantelope, australopithecus africanus, baboons, basalt, bipedal hominid species, bipedalism, darryl de ruiter, early hominids, ethiopian fossil, female teeth, fossilized teeth, gadabout gals, geological substrates, Germany, granite, high tech analysis, hominid family tree, hyraxes, julia lee thorp, laser ablation, leipzig, local geology, lucy, male hominid teeth, mammal teeth, matt sponheimer, max plank institute for evolutionary anthropology, paranthropus boisei, paranthropus robustus, quartzite, sandi copeland, sandstone, South Africa, south african savannah, sterkfontein and swartkans cave systems, strontium isotope, strontium isotope signatures, university of colorado boulder

The males of two bipedal hominid species that roamed the South African savannah more than a million years ago were stay-at-home kind of guys when compared to the gadabout gals, says a new high-tech study led by the University of Colorado Boulder.

The team, which studied teeth from a group of extinct Australopithecus africanus and Paranthropus robustus individuals from two adjacent cave systems in South Africa, found more than half of the female teeth were from outside the local area, said CU-Boulder adjunct professor and lead study author Sandi Copeland. In contrast, only about 10 percent of the male hominid teeth were from elsewhere, suggesting they likely grew up and died in the same area. (more…)

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