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BOSS Quasars Unveil a New Era in the Expansion History of the Universe

By Guest PostNovember 21, 2012Scienceacceleration, analytic techniques, ancient universe, andreu font ribera, apache point observatory, bao, baryon, baryon acoustic oscillations, berkeley lab, bigboss, bill carithers, BOSS, clouds, cosmology, dark energy, dark matter, data sets, david schlegel, deceleration, density variation, digital sky survey, early universe, evolution, expanse of sky, expansion, gas clouds, gas density, gravity, hydrogen absorption lines, intergalactic gas, lyman alpha forest, mocks, new mexico, nicholas ross, oscillation, patrick mcdonald, quasars, riemann linux cluster, sdss, sloan, Space, spectra, spectroscopic, survey, universe, volume

Berkeley Lab scientists and their Sloan Digital Sky Survey colleagues use quasars to probe dark energy over 10 billion years in the past

BOSS, the Baryon Oscillation Spectroscopic Survey, is mapping a huge volume of space to measure the role of dark energy in the evolution of the universe. BOSS is the largest program of the third Sloan Digital Sky Survey (SDSS-III) and has just announced the first major result of a new mapping technique, based on the spectra of over 48,000 quasars with redshifts up to 3.5, meaning that light left these active galaxies up to 11.5 billion years in the past.

“No technique for dark energy research has been able to probe this ancient era before, a time when matter was still dense enough for gravity to slow the expansion of the universe, and the influence of dark energy hadn’t yet been felt,” says BOSS principal investigator David Schlegel, an astrophysicist in the Physics Division of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). “In our own time, expansion is accelerating because the universe is dominated by dark energy. How dark energy effected the transition from deceleration to acceleration is one of the most challenging questions in cosmology.” (more…)

How Do Cells Tell Time? Scientists Develop Single-Cell Imaging to Watch the Cell Clock

By Guest PostNovember 18, 2012Science24 hour, activity, biological noise, cell, cell division, circadian clock, cyclic gene, cyclic protein, cyclical behavior, embryonic segmentation, embryonic segments, emilie delaune, gene, gene activation, life, lifespan, mesoderm, mitosis, molecular clock, muscle, nathan shih, nervous system, notch signaling pathway, oscillating pattern, oscillation, paul françois, phase, protein, sharon amacher, signal, signal reception, single cell, somites, synchronization, tissue segments, vasculature, vertebrae, visualization, visualize, zebrafish embryos

COLUMBUS, Ohio – A new way to visualize single-cell activity in living zebrafish embryos has allowed scientists to clarify how cells line up in the right place at the right time to receive signals about the next phase of their life.

Scientists developed the imaging tool in single living cells by fusing a protein defining the cells’ cyclical behavior to a yellow fluorescent protein that allows for visualization. Zebrafish embryos are already transparent, but with this closer microscopic look at the earliest stages of life, the researchers have answered two long-standing questions about how cells cooperate to form embryonic segments that later become muscle and vertebrae. (more…)

Breakthrough Technique Images Breast Tumors in 3-D with Great Clarity, Reduced Radiation

By Guest PostOctober 23, 2012Health, Science3d picture, alberto mittone, aniko sztrokay, blind evaluation, bone, breakthrough, breast cancer, breast tissue, computing algorithm, ct scanner, digital, dual view, equally sloped tomography, est, european, european colleague, france, Germany, image, jianwei miao, ludwig maximilians university, mammogram, mammography, maximilian reiser, oscillation, paola coan, patient, paul claude diemoz, radiation, radiation facility, researcher, scientist, screening, sergei gasilov, susanne liebhardt, synchrotron, technique, three-dimensional, tomography, tumor, ucla, united states, xray, yunzhe zhao, zhifeng huang

Like cleaning the lenses of a foggy pair of glasses, scientists are now able to use a technique developed by UCLA researchers and their European colleagues to produce three-dimensional images of breast tissue that are two to three times sharper than those made using current CT scanners at hospitals. The technique also uses a lower dose of X-ray radiation than a mammogram.

These higher-quality images could allow breast tumors to be detected earlier and with much greater accuracy. One in eight women in the United States will be diagnosed with breast cancer during her lifetime.

The research is published the week of Oct. 22 in the early edition of the journal Proceedings of the National Academy of Sciences. (more…)

Study Sheds Light on How Heat is Transported to Greenland Glaciers

By Guest PostMarch 29, 2011Environmentarctic water, bath tub, claudia cenedese, fiamma straneo, fjords, floating ice tongue, freshwater runoff, glacier ice, greenland, gulf stream, heat, heat transport, helheim glacier, ice sheet, kjetil våge, melting the glaciers, ocean circulation, oscillation, predictions, ruth curry, sea-level rise, sermilik fjord, subtropical waters

Warmer air is only part of the story when it comes to Greenland’s rapidly melting ice sheet. New research by scientists at Woods Hole Oceanographic Institution (WHOI) highlights the role ocean circulation plays in transporting heat to glaciers.

Greenland’s ice sheet has lost mass at an accelerated rate over the last decade, dumping more ice and fresh water into the ocean. Between 2001 and 2005, Helheim Glacier, a large glacier on Greenland’s southeast coast, retreated 5 miles (8 kilometers) and its flow speed nearly doubled. (more…)

Tag Archives: oscillation

BOSS Quasars Unveil a New Era in the Expansion History of the Universe

How Do Cells Tell Time? Scientists Develop Single-Cell Imaging to Watch the Cell Clock

Breakthrough Technique Images Breast Tumors in 3-D with Great Clarity, Reduced Radiation

Study Sheds Light on How Heat is Transported to Greenland Glaciers