Science – Page 297 – Shamskm: A site to exchange knowledge and solutions

Amoeba May Offer Key Clue to Photosynthetic Evolution

By Guest PostMarch 3, 2012Scienceamoeba, animal cells, arthur grossman, bacterial cells, carbohydrates, cell wall, chemical energy, chloroplasts, chromatophores, cyanobacteria, endosymbiotic cyanobacterium, eva nowack, light energy, mitochondria, paulinella chromatophora, photosynthetic process, plant, silica scales, single celled bacteria, sugar breakdown, sugars

Stanford, CA— The major difference between plant and animal cells is the photosynthetic process, which converts light energy into chemical energy. When light isn’t available, energy is generated by breaking down carbohydrates and sugars, just as it is in animal and some bacterial cells. Two cellular organelles are responsible for these two processes: the chloroplasts for photosynthesis and the mitochondria for sugar breakdown. New research from Carnegie’s Eva Nowack and Arthur Grossman has opened a window into the early stages of chloroplast evolution. Their work is published online by the Proceedings of the National Academy of Sciences in the week of February 27-March 2. (more…)

Asteroid 2011 AG5 – A Reality Check

By Guest PostMarch 2, 2012Sciencearizona, asteroid 2011 ag5, cassegrain reflector telescope, catalina mountains, don yeomans, earth interception, gravitational influence, mars, mount lemmon, near earth object, orbit, space rock, spaceguard, torino impact hazard scale, tucson

Asteroid 2011 AG5 has been receiving a lot of attention lately because of a very unlikely scenario which would place it on an Earth-interception course 28 years from now. Here is a scientific reality check of this relatively nondescript space rock which is currently ranked a “1” on the 1 to 10 Torino Impact Hazard Scale

As of Feb. 26, 2012, asteroid 2011 AG5 is one of 8,744 near-Earth objects that have been discovered. It is approximately 460 feet (140 meters) in size and its orbit carries it as far out as beyond Mars’ orbit and as close to the sun as halfway between Earth and Venus. It was discovered on Jan. 8, 2011, by astronomers using a 60-inch Cassegrain reflector telescope located at the summit of Mount Lemmon in the Catalina Mountains north of Tucson, Arizona. (more…)

How Megakaryocytes Get so Big — and The Bad Things That Happen When They Don’t

By Guest PostMarch 2, 2012Scienceblood cells, cell division, diane krause, DNA, ect2, ee chun cheng, elenoe smith, endomitosis, gef h1, gene, giant blood cells, guanine exchange factors, krause lab, leukemia, lin wang, malfunction, malignant leukemias, megakaryoblastic leukemias, megakaryocyte maturation, megakaryocytes, mkl1, mutant, platelets, process, protein, sharon lin, siying zou, stephanie halene, supernova, yuan gao

Yale researchers have discovered how megakaryocytes — giant blood cells that produce wound-healing platelets — manage to grow 10 to 15 times larger than other blood cells.

The findings, to be published March 13 in the journal Developmental Cell, also hint at how a malfunction in this process may cause a form of leukemia. (more…)

It Takes Two to Tango: Pairs of Entwined Proteins Handle The Stress

By Guest PostMarch 2, 2012Sciencebacterial protein, bleach, cell paper, dana reichmann, dance floor, function, helper protein, hsp33, jim erickson, michael fitzgerald, molecular chaperone, oxidants, protein, protein folding process, stress specific, tango, university of michigan, ursula jakob, ying xu

ANN ARBOR, Mich.— Imagine two tango dancers sweeping across the dance floor and suddenly encountering a slick spot. To avoid a slip or even a nasty tumble, the pair must work together to support one another and glide safely through the stressful moment.

In a similar way, a certain type of helper protein called a stress-specific molecular chaperone prevents its client proteins from collapsing during stressful situations by uncoiling a long, supportive arm that wraps around them, a University of Michigan-led research team has shown. (more…)

UCLA Scientists ID Cell, Signaling Pathway That Regulate Blood Stem Cells in Placenta

By Guest PostMarch 2, 2012Scienceblood stem cells, placenta, placental niche, placental vasculature, signaling pathway

UCLA stem-cell researchers have identified a certain type of cell and a signaling pathway in the placental niche that play a key role in stopping blood stem cells from differentiating into mature blood cells in the placenta. Preventing this premature differentiation is critical to ensuring a proper blood supply for an individual’s lifetime. (more…)

Torosaurus is Not Triceratops, Yale Researchers Say

By Guest PostMarch 1, 2012Scienceanatomical difference, dinosaur research, horned dinosaurs, torosaurus, triceratops

A year-long study by Yale University paleontologists concludes that two related horned dinosaurs are different animals and not adult and juvenile versions of the same. (more…)

Russian Dolls of the Bug World

By Guest PostMarch 1, 2012Scienceacyrthosiphon pisum, aphid alarm pheromone, aphidius ervi, aphids, apse, bacteriophage, bacterium, battle for survival, environmental sciences, Europe, hamiltonella defense, hemolymph, insect, kerry oliver, martha molly hunter, North America, parasite and host, parasitic wasps, pea aphid, russian dolls, symbiont, trans b farnesene, university of arizona, virus, wasp larva

Parasitic wasps using tiny insects known as aphids as living nurseries for their brood can sniff out whether the host insect is protected by symbiotic bacteria, researchers have discovered.

A research team including Martha (Molly) Hunter from the department of entomology in the University of Arizona’s College of Agriculture of Life Sciences has disentangled relationships in an assembly of players that resemble Russian dolls: a bacterium that lives inside a tiny insect, a virus that infects those bacteria, and a parasitic wasp that lays its eggs in the insect.

In a war between parasite and host, the parasitic wasp, Aphidius ervi, and the pea aphid, Acyrthosiphon pisum, are locked in a battle for survival. (more…)

When Continents Collide: A New Twist To a 50 Million-Year-Old Tale

By Guest PostMarch 1, 2012Scienceearth, earthquakes, eurasia, fifty million years, geological activity, geological history, geology, geomorphologist, geophysicist, highest mountain, himalaya mountains, India, indian plate, indian sub continent, jim erickson, marin clark, mountain building episode, northern india, northern tibet, plate boundaries, plate tectonics, post collisional motion, the himalaya, theory, tibet, tibetan plateau, university of michigan, volcanoes

ANN ARBOR, Mich.— Fifty million years ago, India slammed into Eurasia, a collision that gave rise to the tallest landforms on the planet, the Himalaya Mountains and the Tibetan Plateau.

India and Eurasia continue to converge today, though at an ever-slowing pace. University of Michigan geomorphologist and geophysicist Marin Clark wanted to know when this motion will end and why. She conducted a study that led to surprising findings that could add a new wrinkle to the well-established theory of plate tectonics – the dominant, unifying theory of geology. (more…)

Category Archives: Science