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Intricate, Curving 3D Nanostructures Created Using Capillary Action Forces

By Guest PostOctober 20, 2010Science3d, 3d nanotube structures, a john hart, acetone condense, aircraft, bending petals, capillary action, capillary forming, carbon nanotubes, concentric rings, drinking straw, evaporate, gravity, john hart, liquids, microdevices, miniature, phenomenon, spacecraft, three-dimensional, twisting spires, university of michigan

Twisting spires are one of the 3D shapes researchers at the University of Michigan were able to develop using a new manufacturing process. Image credit: A. John Hart

ANN ARBOR, Mich

.— Twisting spires, concentric rings, and gracefully bending petals are a few of the new three-dimensional shapes that University of Michigan engineers can make from carbon nanotubes using a new manufacturing process.

The process is called “capillary forming,” and it takes advantage of capillary action, the phenomenon at work when liquids seem to defy gravity and spontaneously travel up a drinking straw.

The new miniature shapes have the potential to harness the exceptional mechanical, thermal, electrical, and chemical properties of carbon nanotubes in a scalable fashion, said A. John Hart, an assistant professor in the Department of Mechanical Engineering and in the School of Art & Design.

The 3D nanotube structures could enable countless new materials and microdevices, including probes that can interface with individual cells, novel microfluidic devices, and lightweight materials for aircraft and spacecraft. (more…)

What Did T. Rex Eat? Each Other.

By Guest PostOctober 20, 2010Sciencecanada, cannibalism, carnivore, dinosaurs, fossil, gregory erickson, john horner, largest terrestrial carnivores, majungatholus, mammal tooth, marks, museum, nick longrich, North America, paleontologists, philip currie, scavengers, t rex, tyrannosaurus rex, united states, yale researcher

T. rex was the only big carnivore in western North America 65 million years ago that was capable of making such large gouges. Image credit: Nicholas Longrich

It turns out that the undisputed king of the dinosaurs, Tyrannosaurus rex, didn’t just eat other dinosaurs but also each other. Paleontologists from the United States and Canada have found bite marks on the giants’ bones that were made by other T. rex, according to a new study published online Oct. 15 in the journal PLoS ONE.

While searching through dinosaur fossil collections for another study on dinosaur bones with mammal tooth marks, Yale researcher Nick Longrich discovered a bone with especially large gouges in them. Given the age and location of the fossil, the marks had to be made by T. rex, Longrich said. “They’re the kind of marks that any big carnivore could have made, but T. rex was the only big carnivore in western North America 65 million years ago.” (more…)

Tackling Cognitive Deficits in Alzheimer’s Disease: One STEP at a Time

By Guest PostOctober 19, 2010Health, Sciencealzheimer’s disease, american health assistance foundation, national academy of sciences, paul greengard, paul lombroso, rockefeller university, yale university

Lowering levels of a key protein involved in regulating learning and memory—STtriatal-Enriched tyrosine Phosphatase (STEP)—reversed cognitive deficits in mice with Alzheimer’s disease, Yale School of Medicine researchers report in the October 18 issue of Proceedings of the National Academy of Sciences. (more…)

Breakthrough in Nanocrystals Growth

By Guest PostOctober 19, 2010Scienceevolution of nanoparticles, nanocrystals growth, nanoparticles, synchrotron radiation techniques

Nanoparticles. Image credit: Wenge Yang

Argonne, ILL — For the first time scientists have been able to watch nanoparticles grow from the earliest stages of their formation. Nanoparticles are the foundation of nanotechnology and their performance depends on their structure, composition, and size. Researchers will now be able to develop ways to control conditions under which they are grown. The breakthrough will affect a wide range of applications including solar-cell technology and chemical and biological sensors. The research is published in NANOLetters.

As coauthor Wenge Yang of the Carnegie Institution’s Geophysical Laboratory explained: “It’s been very difficult to watch these tiny particles be born and grow in the past because traditional techniques require that the sample be in a vacuum and many nanoparticles are grown in a metal-conducting liquid. So we have not been able to see how different conditions affect the particles, much less understand how we can tweak the conditions to get a desired effect.” (more…)

Haiti Earthquake Shaking Amplified by Local Landforms

By Guest PostOctober 19, 2010Scienceaftershock recordings, earthquake in haiti, geological conditions, haiti earthquake

PORT-AU-PRINCE, Haiti — The severe damage and loss-of-life caused by the devastating January 2010 M7.0 earthquake in Haiti was exacerbated by amplification of shaking due to local geological conditions and landforms in Port-au-Prince, according to a study published online today in Nature Geoscience. (more…)

U of T Biologists Identify Influence of Environment on Sexual vs. Asexual Reproduction

By Guest PostOctober 18, 2010Scienceasexual reproduction, evolutionary biologist, homogenous environment, sexual reproduction, tree of life

Evolutionary biologists at U of T have found that environment plays a key role in determining whether a species opts for sexual over asexual reproduction. (more…)

A River Ran Through It

By Guest PostOctober 17, 2010Nature, Sciencealan tessier, arizona state university, climate change, colorado, colorado river delta, downstream, ecosystems, food chain, grand canyon, humans, irrigation, jacques finlay, john sabo, las vegas, los angeles, minneapolis, Mississippi, new york city, Phoenix, river flows, rivers, sea of cortez, small tributaries, storm floods, streams

About the image: A now dry Colorado River delta branches into the Baja/Sonoran Desert near the Sea of Cortez. Image credit: Pete McBride

Rivers and streams supply the lifeblood to ecosystems across the globe, providing water for drinking and irrigation for humans as well as a wide array of life forms from single-celled organisms up to the fish humans eat.

But humans and nature itself are making it tough on rivers to continue in their central role to support fish species, according to new research by a team of scientists including John Sabo, a biologist at Arizona State University.

Globally, rivers and streams are being drained due to human use and climate change. These and other human impacts alter the natural variability of river flows.

Some affected rivers have dried and no longer run, while others have seen increases in the variability of flows due to storm floods. (more…)

Giant Star Goes Supernova — and is Smothered by Its Own Dust

By Guest PostOctober 16, 20105 commentsScience10-meter keck telescope, active galactic nuclei, agn, astronomers, christopher kochanek, deep wide field survey, eta carinae, Galaxy, giant star, hawaii, homunculus nebula, hypernova, krzysztof stanek, light years, Milky Way, milky way galaxy, NASA, ohio state university, spitzer space telescope, star system, super-massive black holes, supernovae, szymon kozlowski, wide field infrared explorer, wise

COLUMBUS, Ohio — A giant star in a faraway galaxy recently ended its life with a dust-shrouded whimper instead of the more typical bang.

Ohio State University researchers suspect that this odd event — the first one of its kind ever viewed by astronomers – was more common early in the universe. (more…)

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