Smaller and more energy-efficient electronic chips could be made using molybdenite. In an article appearing online January 30 in the journal Nature Nanotechnology, EPFL’s Laboratory of Nanoscale Electronics and Structures (LANES) publishes a study showing that this material has distinct advantages over traditional silicon or graphene for use in electronics applications.

A discovery made at EPFL could play an important role in electronics, allowing us to make transistors that are smaller and more energy efficient. Research carried out in the Laboratory of Nanoscale Electronics and Structures (LANES) has revealed that molybdenite, or MoS2, is a very effective semiconductor. This mineral, which is abundant in nature, is often used as an element in steel alloys or as an additive in lubricants. But it had not yet been extensively studied for use in electronics.

100,000 times less energy

“It’s a two-dimensional material, very thin and easy to use in nanotechnology. It has real potential in the fabrication of very small transistors, light-emitting diodes (LEDs) and solar cells,” says EPFL Professor Andras Kis, whose LANES colleagues M. Radisavljevic, Prof. Radenovic et M. Brivio worked with him on the study. He compares its advantages with two other materials: silicon, currently the primary component used in electronic and computer chips, and graphene, whose discovery in 2004 earned University of Manchester physicists André Geim and Konstantin Novoselov the 2010 Nobel Prize in Physics.

One of molybdenite’s advantages is that it is less voluminous that silicon, which is a three-dimensional material. “In a 0.65-nanometer-thick sheet of MoS2, the electrons can move around as easily as in a 2-nanometer-thick sheet of silicon,” explains Kis. “But it’s not currently possible to fabricate a sheet of silicon as thin as a monolayer sheet of MoS2.” Another advantage of molybdenite is that it can be used to make transistors that consume 100,000 times less energy in standby state than traditional silicon transistors. A semi-conductor with a “gap” must be used to turn a transistor on and off, and molybdenite’s 1.8 electron-volt gap is ideal for this purpose.

Better than graphene

In solid-state physics, band theory is a way of representing the energy of electrons in a given material. In semi-conductors, electron-free spaces exist between these bands, the so-called “band gaps.” If the gap is not too small or too large, certain electrons can hop across the gap. It thus offers a greater level of control over the electrical behavior of the material, which can be turned on and off easily.

The existence of this gap in molybdenite also gives it an advantage over graphene. Considered today by many scientists as the electronics material of the future, the “semi-metal” graphene doesn’t have a gap, and it is very difficult to artificially reproduce one in the material.

Source: EPFL’s Laboratory of Nanoscale Electronics and Structures (LANES)

NASA will host a news briefing at 1 p.m. EST, Wednesday, Feb. 2, to announce the Kepler mission’s latest findings about planets outside our solar system. The briefing will be held in the NASA Headquarters auditorium at 300 E St S.W. in Washington and carried live on NASA Television and the agency’s website at http://www.nasa.gov/ntv.

Kepler is the first NASA mission capable of finding Earth-size planets in or near the “habitable zone,” the region in a planetary system where liquid water can exist on the surface of the orbiting planet. Although additional observations will be needed over time to achieve that milestone, Kepler is detecting planets and planet candidates with a wide range of sizes and orbital distances to help us better understand our place in the galaxy.

The news conference will follow the scheduled release of Kepler mission science data on Feb. 1. The data release will update the number of planet candidates and is based on observations conducted between May 2 and Sept. 17, 2009.

Participants are:
– Douglas Hudgins, Kepler program scientist, NASA Headquarters, Washington
– William Borucki, Kepler Science principal investigator, NASA’s Ames Research Center, Moffett Field, Calif.
– Jack Lissauer, Kepler co-investigator and planetary scientist, Ames
– Debra Fischer, professor of Astronomy, Yale University, New Haven, Conn.

Reporters also may ask questions from participating NASA field centers or by phone. To obtain dial-in information, journalists must send their name, affiliation and telephone number to Steve Cole by e-mail at stephen.e.cole@nasa.gov by noon EST on Feb. 1.

For more information about the Kepler mission and to view the Feb. 1 data release, visit:

http://www.nasa.gov/kepler

The tiger reserves of Asia could support more than 10,000 wild tigers – three times the current number – if they are managed as large-scale landscapes that allow for connectivity between core breeding sites, a new study from some of the world’s leading conservation scientists finds. The study, published in Conservation Letters, is the first assessment of the political commitment made by all 13 tiger range countries last November to double the tiger population across Asia by 2022.

“A Landscape-Based Conservation Strategy to Double the Wild Tiger Population” finds that the commitment made by tiger range states in November’s historic tiger summit to double the wild tiger population is not only possible, but can be exceeded. However, it will take a global effort to ensure that core breeding reserves are maintained and connected via habitat corridors. The paper also notes that tiger landscapes can potentially “pay their way” through payment schemes for carbon storage and sequestration and other ecosystem services.

“In the midst of a crisis, it’s tempting to circle the wagons and only protect a limited number of core protected areas, but we can and should do better,” said Dr. Eric Dinerstein, Chief Scientist at WWF-US. “We absolutely need to stop the bleeding, the poaching of tigers and their prey in core breeding areas, but we need to go much further and secure larger tiger landscapes before it is too late.”

Wild tiger numbers have declined from about 100,000 in the early 1900s to as few as 3,200 today due to poaching of tigers and their prey, habitat destruction and human/tiger conflict. Most of the remaining tigers are scattered in small, isolated pockets across their range in 13 Asian countries.

“Tiger conservation is the face of biodiversity conservation and competent sustainable land-use management at the landscape level,” said Dr. John Seidensticker of the Smithsonian Conservation Research Institute. “By saving the tiger we save all the plants and animals that live under the tiger’s umbrella.”

The authors found that the 20 priority tiger conservation landscapes with the highest probability of long-term tiger survival could support more than 10,500 tigers, including about 3,400 breeding females. They also looked at historical examples to prove that a doubling or tripling is possible using large landscapes:

• In the jungles of lowland Nepal, tiger numbers crashed during civil conflict from 2002 to 2006. However, tigers did not disappear because Nepal and India’s tiger reserves are linked by forest corridors, which likely allowed for replenishment from India.

• In the Russian Far East tigers almost disappeared in the 1940s, but the region was re-populated by tigers moving in from northeastern China.

• Recently designated habitat corridors across the Sino-Russia border are helping tigers re-establish themselves in China’s Changbaishan mountains, where they had disappeared in the 1990s

• In India’s Nagarahole National Park, tiger numbers are “healthy and resilient” because the park is connected to other reserves in the region. Tigers number almost 300 in this large landscape of connected parks and reserves.

In contrast, the authors point to two of India’s premier tiger reserves to show how lack of connectivity can preclude tiger population recovery. Tigers disappeared from Sariska and Panna tiger reserves in 2005 and 2009 due to poaching and were not able to re-colonize because these reserves are not connected to other reserves through habitat corridors. Consequently, wild tigers had to be translocated into these reserves to attempt to re-establish populations.

Besides poaching and habitat loss, the $7.5 trillion in infrastructure projects like roads, dams and mines that will be invested in Asia over the next decade threatens tiger landscapes. A focus only on core sites and protected areas like reserves, instead of larger landscapes, could be seen by developers and politicians as a green light to move forward with infrastructure projects outside of core sites.

The authors insist that conservationists and governments must be involved in helping design infrastructure projects to mitigate their impacts on tigers both inside core sites and in current and potential forest corridors. A recently built oil depot in India’s Terai Arc, for example, severed a vital elephant and tiger corridor. Conservationists are now in litigation to remove the depot. Early intervention could have avoided this.

“Following the St. Petersburg Declaration, Nepal has committed to the goal of doubling wild tiger numbers across our country by 2022,” said Deepak Bohara, Nepal’s Minister for Forests and Soil Conservation. “This analysis shows that it can be done, not just in Nepal, but, if done right with careful study and planning, across the entire tiger range. It is also worth noting that tiger conservation provides carbon credits, protects water resources, and complements community development efforts. Thus, it is important to promote regional cooperation to maintain a healthy tiger corridor between different reserves.”

Source: Wiley.com

Neutron science provides first experimental data showing how DNA structure changes as it ‘melts’. This knowledge is a step towards technological applications of DNA, such as computer components.

An experiment led at ILL just released in PRL.

Neutron scattering has been used to investigate the structure of fibre DNA during the melting transition. This is the range of temperatures over which the bonds between base pairs break, or denature, causing the two strands of DNA to separate.

Neutron scattering gives information about the correlation between base pairs during denaturation, which is not possible using other techniques. This is used to measure the characteristic size of the denatured regions as the temperature is changed, and these sizes can be compared with those predicted by the theoretical model.

The Peyrard-Bishop-Dauxois (PBD) model predicted that fibre DNA denaturation due to temperature would happen in patches along the molecule, rather than ‘unzipping’ from one end to another.  This experiment, the first to investigate the model, strongly supported the model’s predications for the first part of the transition, as the molecule is heated. The experiment could only measure the first stage because when the strands become 50% denatured they are too floppy to remain ordered and the fibre structure is no longer stable – the DNA sample literally falls to pieces.

“This is an important verification of the validity of model and the associated theory, so it can be applied with more confidence to predict the behaviour and properties of DNA,” says Andrew Wildes, an instrument scientist at ILL. “This will help to understand biological processes such as gene transcription and cell reproduction, and is also a step toward technological applications such as using DNA as nanoscale tweezers or as computer components.”
“There’s been a lot of research producing good data – eg nice melting curves – about the transition point, but these couldn’t tell us how it was happening. For example at 50% melted are half the DNA molecules totally denatured and the other half still firmly joined? Or are the strands of each molecule partially separated? Neutron scattering has enabled us to get structural information on the melting process to answer this kind of question,” says Michel Peyrard Professor of Physics at Ecole Normale Supérieure de Lyon, and co-developer of the PBD model. “As well as implications for technological development it could also help biological applications, such as predicting where genes might be located on long stretches of DNA sequences.”
The experiment follows from the pioneering work of Rosalind Franklin, who showed that x-ray scattering from DNA fibres would give structural information.  Based on her work, James Watson and Francis Crick deduced the well-known double helix structure of DNA in 1953. DNA is a dynamic molecule that undergoes large structural changes during normal biological processes. For example, DNA inside the cell nucleus is usually ‘bundled up’ into chromosomes, but when the genetic information is being copied it must be unravelled and the strands separated to allow the code to be read.

DNA computing – a form of computing that uses DNA, biochemistry and molecular biology, instead of the traditional silicon-based computer technologies. DNA computer components (logic gates and biochips) may take years to develop into a practical, workable DNA computer, but such computers would be more compact, accurate and efficient than conventional computers. There is also interest in using DNA as computer memory because it is a very long lived and stable molecule, and has four different base pair combinations rather than the binary system currently used.

Source: Institut Laue-Langevin

Larry Heaman

(Edmonton) University of Alberta researchers have determined that a fossilized dinosaur bone found in New Mexico confounds the long-established paradigm that the age of dinosaurs ended between 65.5 and 66 million years ago.

The U of A team, led by Larry Heaman from the Department of Earth and Atmospheric Sciences, put the femur bone of a sauropod through an elaborate testing procedure and found it’s only 64.8 million years old.

Heaman says that means this particular sauropod was alive about 700,000 years after the mass extinction event, which many paleontologists believe wiped all non-avian dinosaurs off the face of Earth forever. It’s commonly believed debris from a giant meteorite impact blocked out the sun, causing extreme climate conditions and killing vegetation worldwide.

“If our uranium-lead dating technique bears out on more fossils, than the whole end of the age of dinosaurs paradigm will have to be revised,” said Heaman.

Heaman and colleagues used a method called uranium-lead dating to target the age of the fossilized femur of the sauropod. A laser beam unseated minute particles of the bone, which then underwent isotopic analysis.

“This new technique not only allows the age of fossil bone to be determined,” said Heaman, “but also potentially distinguishes the type of food a dinosaur ate.”

Heaman explains that living bone contains very low levels of uranium, but during fossilization (typically less than 1,000 years after death) bone is enriched in elements like uranium. The uranium atoms in the bone then decay to lead and, once fossilization is complete, the uranium-lead clock starts ticking. Heaman says the isotopic composition of lead determined in the sauropod’s femur bone is, therefore, a measure of its absolute age.

Currently, paleontologists date dinosaur fossils using a technique called relative chronology. Where possible, a fossil’s age is estimated relative to the known depositional age of a layer of sediment in which it was found. Heaman says this method is limited because researchers have to be certain of the age of the rock layers surrounding the fossil.

Another potential weakness in the relative chronology approach cited by Heaman is that, over millions of years, geologic and environmental forces may cause erosion of a fossil-bearing layer of rock, and cause the fossil to drift or migrate from its original layer in the strata. Heaman says his direct-dating technique eliminates that kind of false age reading.

Heaman and his research colleagues say there could be several reasons why the New Mexico sauropod came from a line of dinosaurs that survived the great mass extinction events of the late Cretaceous period or, as it’s also known, the KT extinction event. Heaman says it’s possible that in some areas the vegetation wasn’t wiped out and a number of the sauropod species survived. The researchers also say the potential survival of dinosaur eggs during extreme climatic conditions needs to be explored.

Heaman says uranium lead testing could open new doors in dinosaur research.

“Our technique could eliminate old dating errors,” said Heaman. “Current theories, that dinosaurs on opposite sides of the world lived at the same time because their bones are similar, can now be proven or disproven by direct aging of the fossils”

The research was published online Jan. 26 in the journal Geology.

Source: University of Alberta

Researchers at Charité – University Medicine Berlin were the first to show that a specific food supplement made from fruit and vegetable juice concentrates significantly reduced the number of days with severe cold symptoms. The report appears in the British Journal of Nutrition*, published on behalf of the Nutrition Society by Cambridge University Press, and it sees the potential benefits of the product in a reduced number of sick days and correspondingly lower expenditure on cold medicines.

Researchers from the Institute of Social Medicine, Epidemiology and Health Economics, in cooperation with more than 500 employees of the Charité, as test participants, carried out an 8-month study on the effects of the preparation “Juice Plus+” ®, from the US-American supplier NSA from Collierville, Tennessee. In a randomised double-blind study, half the subjects took the drug daily, while the other half received a placebo. After just two months the results showed: The number of colds in both groups was equal. However, in the group that received the drug, the colds were much milder. As a result, there was a decrease of moderate and severe cold symptoms of about 20 per cent.

The question of whether the product is suitable for prolonged use, to reduce the severity of symptoms and the incidence of colds further, could be the subject of future studies of “Juice Plus+” ® according to the authors. Also unclear is the specific mode of action of the preparation. “The results of the study are certainly encouraging because they show that certain dietary supplements may mitigate the burdens and consequences of the common cold,” said Prof. Stefan Willich, Director of the Institute for Social Medicine, Epidemiology and Health Economics of Charité and head of the study.

The neutrality of the study was ensured by the fact that as a sponsor of the study, no study data were transmitted to the manufacturer of the preparation and they were also not involved in the interpretation of the study results.

To read the full text please visit http://journals.cambridge.org/charite

This short animation is a creative collaboration between BYU animation professor Ryan Woodward and Dance Dept. instructor Kori Wakamatsu.

Woodward, who has done storyboards for Hollywood blockbusters (Iron Man 2, Spider Man 3 and Where the Wild Things Are), approached Wakamatsu with the concept this summer.

Thought of You from Ryan J Woodward on Vimeo.

Video has more than 1 million views between Vimeo and YouTube

Animated short was created by filming dancers, then drawing 24-frames per second of the dancing

“Thought of You” in HD, behind-the-scenes documentary and flip charts of film animations featured in HFAC Gallery 303 Jan. 20-29

Read more in the Deseret News

Professor Richard Watt

Professor Richard Watt and his chemistry students suspected that a common protein could potentially react with sunlight and harvest its energy – similar to what chlorophyll does during photosynthesis.

The story of how they proved it sounds as colorful as the legend of the leprechaun who hid his pot of gold at the end of the rainbow.

They started with citric acid from oranges and mixed it with the protein. Next they dissolved gold powder into the solution. Then they put vials of the yellow-colored mixture in direct sunlight and crossed their fingers in the hope that it would turn purple.

Here’s the reason why: If it turned purple, that would signal that the gold atoms had received electrons and used the donated energy to bunch together as small, purple-colored nanoparticles. And that would mean that the protein used the sunlight to excite the citric acid and trigger a transfer of energy.

While direct sunlight did the trick in about 20 minutes, a high-powered tungsten mercury lamp worked much faster.

“We set the system up, turned on the light, and the solution turned purple,” Watt said. “We knew that we’d proved the concept.”

The beauty of this experiment lies not in its colors – unless, of course, you’re thinking of it as a potential “green” energy source that keeps the environment clean.

The BYU researchers published their experiments in the Journal of Nanoparticle Research. The final step of this project will involve connecting the protein to an electrode to channel the energy into a battery or fuel cell. The BYU chemists will partner with Jae-Woo Kim of the National Institute of Aerospace for this next stage of the work.

Professor Watt’s pedigree includes a post-doc at Princeton, a father who developed a fuel cell that runs on sugar and weed-killer and a more distant ancestor credited with inventing the first practical steam engine. That ancestor is also the Scottish engineer for whom the unit of power “watt” is named.

Co-authors on the new study include BYU graduate Jeremiah Keyes, grad student Robert Hilton and Jeff Farrer, who runs an electron microscope lab at BYU.

A new species of parrot-sized dinosaur, the first discovered with only one finger, has been unearthed in Inner Mongolia, China.

Scientists named the new dinosaur Linhenykus monodactylus, after the nearby city of Linhe. The work is published online today in Proceedings of the National Academy of Sciences (PNAS).

The new dinosaur belongs to the Alvarezsauroidea, a branch of the carnivorous dinosaur group Theropoda. Theropods gave rise to modern birds and include such famous dinosaurs as Tyrannosaurus and Velociraptor.

An international team of palaeontologists, led by Prof. Xing Xu of the Chinese Academy of Sciences, found the fossil preserved in rocks of the Upper Cretaceous Wulansuhai Formation, which is located near the border between Mongolia and China. The formation dates to 84-75 million years ago and has yielded a rich trove of vertebrate fossils including the recently discovered theropod Linheraptor exquisitus. The authors uncovered a partial skeleton from the site, which included bones of the vertebral column, the forelimb, a partial pelvis and nearly complete hind limbs.

Linhenykus most likely grew to a couple of feet tall and weighed only as much as a large parrot. The new theropod is unusual in having just one large claw, which may have been used to dig into insect nests, on each of its hands. This feature makes the specimen the only known dinosaur with one finger, and highlights the wide variety of evolutionary modifications of the hand that existed in different theropods.

Michael Pittman of the Department of Earth Sciences at University College London, co-author and discoverer of the specimen said: “Non-avian theropods start with five fingers but evolved to have only three fingers in later forms. Tyrannosaurs were unusual in having just two fingers but the one-fingered Linhenykus shows how extensive and complex theropod hand modifications really were.”

Most theropod dinosaurs have three fingers on each hand, but in most alvarezsauroids other than Linhenykus the two outer fingers are reduced to tiny, apparently useless structures. The presence of only one finger in Linhenykus, which is hypothesized to be a relatively primitive alvarezsauroid, shows that these vestigial fingers were not present in all members of the group. The reasons for the loss of the two outer fingers in Linhenykus are unclear, and their disappearance may simply reflect the fact that they were no longer being actively maintained by natural selection

Jonah Choiniere, co-author and co-discoverer of the specimen from the Division of Paleontology at the American Museum of Natural History said: “Vestigial structures, like legs in whales and snakes, may appear and disappear seemingly randomly in the course of evolution. Linhenykus highlights the vestigiality of the outer fingers of advanced alvarezsauroids and underscores the complexity in evolution of these vestigial fingers.”

Linhenykus lived with closely-related and similarly-sized theropod dinosaurs, but the specializations of its skeleton may reflect differences in behaviour or foraging strategy. Linhenykus also lived alongside small mammals, lizards, clubbed dinosaurs (ankylosaurs) and horned dinosaurs (ceratopsians).

Image: Artist’s impression of Linhenykus monodactylus, © Julius T. Csotonyi

• Links:
• UCL Earth Sciences
• Coverage in The Guardian
• Coverage in Metro
• Coverage on BBC Radio 4 ‘Today’

The digital revolution has triggered a wild proliferation of video games, but what of the revolution in biotechnology? Does it have the potential to spawn its own brood of games?  Stanford physicist Ingmar Riedel-Kruse has begun developing “biotic games” involving paramecia and other living organisms. He hopes the games lead to advances in education and crowd-sourcing of laboratory research while helping to raise the level of public discourse on bio-related issues.

Source: http://news.stanford.edu/news/2011/january/biotic-video-games-011211.html