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U-M Researchers Identify Protein Essential for Cell Division in Blood-forming Stem Cells

By Guest PostDecember 3, 2010Scienceampk, blood-forming stem cells, cell death, cell therapies, cellular metabolism, chromosomes, daisuke nakada, daughter cells, degenerative diseases, energy production, lkb1, normal cell division, protein, protein kinase, sean morrison, stem cell biology, stem cell function, stem cells, thomas saunders, tumor suppressor

ANN ARBOR, Mich.— University of Michigan researchers have discovered that a protein known to regulate cellular metabolism is also necessary for normal cell division in blood-forming stem cells. Loss of the protein results in an abnormal number of chromosomes and a high rate of cell death.

The finding demonstrates that stem cells are metabolically different from other blood-forming cells, which can divide without the protein, Lkb1. This metabolic difference could someday be used to better control the behavior of blood-forming stem cells used in disease treatments, said Sean Morrison, director of the U-M Center for Stem Cell Biology, which is based at the Life Sciences Institute. (more…)

Discovery Triples Number of Stars in the Universe

By Guest PostDecember 2, 2010Scienceastronomers, charlie conroy, dark matter, dim stars, earths, elliptical galaxies, evolution, galaxies, galaxy formation, gliese 581, hawaii, keck observatory, Milky Way, optical telescopes, pieter van dokkum, red dwarfs, sun, theoretical models, twin telescopes

Astronomers detected the faint signature of small, dim red dwarf stars in nearby galaxies (right), and found they are much more numerous than in our own Milky Way (left). Image credit: Patrick Lynch/Yale University

Astronomers have discovered that small, dim stars known as red dwarfs are much more prolific than previously thought — so much so that the total number of stars in the universe is likely three times bigger than previously believed.

Because red dwarfs are relatively small and dim compared to stars like our Sun, astronomers hadn’t been able to detect them in galaxies other than our own Milky Way and its nearest neighbors before now. Therefore, they did not know how much of the total stellar population of the universe is made up of red dwarfs.

Now astronomers have used powerful instruments on the Keck Observatory in Hawaii to detect the faint signature of red dwarfs in eight massive, relatively nearby galaxies called elliptical galaxies, which are located between about 50 million and 300 million light years away. They discovered that the red dwarfs, which are only between 10% and 20% as massive as the Sun, were much more bountiful than expected. (more…)

Contact With Dads Drops When Women Ovulate

By Guest PostNovember 30, 2010Scienceanimal behavior, behavior, biological forces, cell phone, cycle, debra lieberman, elizabeth pillsworth, evolutionary biologists, evolutionary inbreeding, high-fertility days, martie haselton, ovulating, period, sexual decisions, women

*Evidence of evolutionary protection against inbreeding in women?*

Through an innovative use of cell phone records, researchers at UCLA, the University of Miami and Cal State, Fullerton, have found that women appear to avoid contact with their fathers during ovulation.

“Women call their dads less frequently on these high-fertility days and they hang up with them sooner if their dads initiate a call,” said Martie Haselton, a UCLA associate professor of communication in whose lab the research was conducted. (more…)

MU Scientists Find Cinnamon Can Replace Harmful Chemicals Used to Create Nanoparticles

By Guest PostNovember 29, 2010Sciencecancer cells, cinnamon, electronics, fight cancer, gold nanoparticles, green process, kattesh katti, kitchen spice, nanoparticles, non-toxic, norman borlaug, toxic chemicals

*MU scientists make strides in green nanotechnology*

COLUMBIA, Mo. – Gold nanoparticles, tiny pieces of gold so small that they can’t be seen by the naked eye, are used in electronics, healthcare products and as pharmaceuticals to fight cancer. Despite their positive uses, the process to make the nanoparticles requires dangerous and extremely toxic chemicals. While the nanotechnology industry is expected to produce large quantities of nanoparticles in the near future, researchers have been worried about the environmental impact of the global nanotechnological revolution. (more…)

Will This Be The End of Hamburger Disease?

By Guest PostNovember 28, 2010Health, Sciencebacteria, blood vessels, cow, dairy products, e coli, e coli bacterium, e coli o157:h7, ethanolamine, food contamination, food poisoning, hamburger disease, human infections, intestine, josée harel, kidney failure, meat, nitrogen, projectsafebeef, raw milk, red blood cells, veterinary medicine

E. coli bacteria. Image credit: University of Montreal

Hamburger disease, a debilitating form of food poisoning, may be a thing of the past. New findings from an international research collaboration conducted by the French National Institute for Agronomic Research (INRA), involving the Université de Montréal are the first to show how the contaminating E.coli bacterium is able to survive in the competitive environment of a cow’s intestine by scavenging specific food sources. Published in this month’s Environmental Microbiology, and featured in Nature Reviews Microbiology, this study may lead to non-medicinal methods for eradicating this invasive bug.

“We studied E.coli O157:H7, which is the most prevalent species of bacteria associated with larger outbreaks,” says Josée Harel, co-author of the study and director of the Groupe de Recherche sur les Maladies Infectieuses du Porc at the Université de Montréal’s Faculty of Veterinary Medicine. “These outbreaks have been associated with direct contact with the farm environment and with the consumption of meat, raw milk and dairy products. Reduction or eradication of O157:H7 in cows will lead to a substantial decrease in food contamination and consequential human infections.” (more…)

Mammals Grew 1,000 Times Larger After the Demise of the Dinosaurs

By Guest PostNovember 27, 2010Scienceafrican elephant, body size patterns, deinotherium, dinosaurs, early pleistocene, eocene, Epoch, evolution of body size, extinction of dinosaurs, felisa smith, indricotherium, late-miocene, mammals, oligocene, saran twombly, united states, university of new mexico

*NSF enabled the assembly of an international, interdisciplinary team that was the first to quantitatively document body size patterns over the past 100 million years*

Researchers have demonstrated that the extinction of dinosaurs some 65 million years ago paved the way for mammals to get bigger, about a thousand times larger than they had been when dinosaurs roamed the earth. The study, released in the journal Science, is the first to quantitatively document the patterns of body size of mammals after the existence of dinosaurs.

About the Image: The largest land mammals that ever lived, Indricotherium and Deinotherium, would have towered over the living African Elephant. Indricotherium lived during the Eocene to the Oligocene Epoch (37 to 23 million years ago) and reached a mass of 15,000 kg, while Deinotherium was around from the late-Miocene until the early Pleistocene (8.5 to 2.7 million years ago) and weighed as much as 17,000 kg. Image credit: NSF RCN IMPPS (more…)

How Pathogens Hijack Host Plants

By Guest PostNovember 27, 20101 commentSciencearabidopsis, bacteria, cell membrane, cells, diabetes, fluorescence resonance energy transfer, frank white, fret, fungi, global crop, infestation, li-qing chen, mustard, mutation, novel transporters, organism, pathogen infection, pathogenic bacteria, pathogens, plant nutrients, pore proteins, protein genes, sensor-based technology, sugar efflux, sugar-pumping mechanism, sweets

Palo Alto, CA — Infestation by bacteria and other pathogens result in global crop losses of over $500 billion annually. A research team led by the Carnegie Institution’s Department of Plant Biology developed a novel trick for identifying how pathogens hijack plant nutrients to take over the organism. They discovered a novel family of pores that transport sugar out of the plant. Bacteria and fungi hijack the pores to access the plant sugar for food. The first goal of any pathogen is to access the host’s food supply to allow them to reproduce in large numbers. This is the first time scientists have a direct handle on controlling the food supply to pathogens and thus a new means to prevent a wide range of crop diseases and losses. (more…)

Getting a Tighter Grip on Cell Division

By Guest PostNovember 25, 2010Sciencebungo akiyoshi, cell, cell division, chinese handcuff, chromosomes, DNA, genetic information, kinetochore, microtubule, sue biggins

*Molecular “machine” responsible for pulling chromosome copies apart is isolated and seen in action outside the cell*

The dance of cell division is carefully choreographed and has little room for error. Paired genetic information is lined up in the middle of the cell in the form of chromosomes. The chromosomes must then be carefully pulled apart so that the resulting daughter cells each have an identical copy of the mother cell’s DNA. (more…)

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