http://www.physorg.com/ en-us Physorg.com internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. (PhysOrg.com) -- Engineers have built the first carbon nanotube (CNT) transistor with a channel length below 10 nm, a size that is considered a requirement for computing technology in the next decade. Not only can the tiny transistor sufficiently control current, it does so significantly better than predicted by theory. It even outperforms the best competing silicon transistors at this scale, demonstrating a superior current density at a very low operating voltage. http://www.physorg.com/news247290186.html Nanotechnology Wed, 01 Feb 2012 08:30:02 EST news247290186 (PhysOrg.com) -- Gene duplications are arguably the driving force of organismal evolution – and if they survive, such duplicate genes will diverge in both regulatory and coding genomic regions. Coding divergences, in turn, can be caused by nucleotide substitutions or exon-intron structural changes. (Exons are DNA bases that are transcribed into mRNA and eventually code for amino acids in proteins. Introns are DNA bases found between exons, but which are not transcribed.) Scientists have had limited knowledge in the latter case until recently, when researchers at the Institute of Botany of the Chinese Academy of Sciences investigated structural divergences during the evolution of duplicate and nonduplicate genes. They found that such structural divergences are very common in duplicate gene evolution, and have resulted from three primary causes – exon/intron gain/loss, exonization/pseudoexonization (where an intronic or intergenic sequence becomes exonic, or vice versa), and insertion/deletion – each contributing differently to structural divergence. The scientists concluded that structural divergences play a more important role in the evolution of duplicate genes than nonduplicate genes. http://www.physorg.com/news247218450.html Biology Tue, 31 Jan 2012 09:10:03 EST news247218450 (PhysOrg.com) -- A wide range of phenomena depend on ice – specifically, phase transitions during ice crystal surface melting. In this transition, which occurs near the melting point, the ice surface morphs into what is known as a quasi-liquid layer (QLL) – a thin layer of ice grains where the water molecules are not in rigid solid structure, yet not in the random order of liquid. While previous research showed that QLL thickness increased with temperature, the results varied by as much as two orders of magnitude. Recently, however, scientists at Hokkaido University, in conjunction with Olympus Engineering Co., Ltd., developed a technique – laser confocal microscopy combined with differential interference contrast microscopy – that increases spatiotemporal resolution to point needed to visualize transition process of the 0.37nm (the thickness of one water molecule) step-like crystal surface at 0.1 – 4 seconds per frame. Their findings provide molecular-level understanding of QLLs that has implications for many QLL-dependent applications, including skating rink slipperiness, regelation (pressure-induced change in freezing), ice column frost heave, recrystallization and coarsening of ice grains, morphological change of snow crystals, cryopreservation, and electrification of thunderclouds. http://www.physorg.com/news247122753.html Physics Mon, 30 Jan 2012 08:50:01 EST news247122753 (PhysOrg.com) -- The stock price of a company continuously changes, going up or down depending on the collective activity of a large number of investors. Although this process seems fairly straightforward, no one fully understands how this collective trading activity finds the "correct" price of a stock. Some theoretical models have been proposed to describe how different investment strategies affect price dynamics, but challenges such as investor confidentiality and complicated data mining make it difficult to gather empirical support for these models. http://www.physorg.com/news246883311.html Physics Fri, 27 Jan 2012 11:30:01 EST news246883311 (PhysOrg.com) -- Microfluidic chemistry is fast gaining popularity – and for good reason: In addition to allowing highly-precise reaction control, micro-reactions often exhibit higher yield and proceed faster than their macroscale cousins. They also readily scale to production environments, and are far safer when synthesizing hazardous compounds because of the very small volumes of materials inside the devices. Recently, scientists at the University of California, Los Angeles (UCLA) have advanced the field by developing and demonstrating an all-electronic digital microfluidic device for microscale chemical synthesis in organic solvents – and that is operated by electrowetting-on-dielectric, or EWOD. (Electrowetting modifies the wetting properties of a surface by applying an electric field; EWOD coats the electrode forming that surface with a dielectric insulating layer.) Their robust EWOD platform simultaneously resolves two limitations of previous technologies – namely, multistep reaction protocols and organic solvent compatibility. http://www.physorg.com/news246788753.html Chemistry Thu, 26 Jan 2012 09:40:01 EST news246788753 (PhysOrg.com) -- Until a few years ago, photosynthesis seemed to be a straightforward and well-understood process in which plants and other organisms use sunlight to convert carbon dioxide and water into sugars, with oxygen as a waste product. But recent research showing that the light energy entering these organisms’ light-absorbing chromophore molecules may exist in two places at once – as a quantum superposition – has raised a new question: what role, if any, do quantum effects play in the vastly important and widespread process of photosynthesis? http://www.physorg.com/news246702875.html Physics Wed, 25 Jan 2012 08:34:56 EST news246702875 (PhysOrg.com) -- One of the most promising methods for increasing the efficiency of solar cells consists of coating the cells’ surfaces with a thin layer of metal nanoparticles. The nanoparticles scatter incoming light in different directions, which allows the solar cells to absorb more light than they otherwise would. The scattering occurs when the incoming light stimulates the nanoparticles’ surface plasmons (SPs), which are coherent electron oscillations in the metal atoms that can reach a resonance mode when the electrons’ frequency matches the photons’ frequency. Under these conditions, the resulting “surface plasmon resonance” induces light scattering and enhances the light absorption of the surface. http://www.physorg.com/news246610361.html Nanotechnology Tue, 24 Jan 2012 07:50:01 EST news246610361 (PhysOrg.com) -- While most people know of DNA as the building blocks of life, these large molecules also have potential applications in areas such as biosensing, nanoparticle assembly, and building supramolecular structures. And now scientists have added another use to the list: invisible ink. http://www.physorg.com/news246548837.html Nanotechnology Mon, 23 Jan 2012 14:20:01 EST news246548837 (PhysOrg.com) -- The best performing solar cells are those that are thick enough to absorb light from the entire solar spectrum, while the cheapest solar cells are thin ones, since they require less, and potentially cheaper, material. In an attempt to combine the best of both worlds, a team of scientists has outlined designs for solar cells that can absorb light from the entire solar spectrum yet are as little as 10 nanometers thick. The new design approach, which could lead to improved low-cost solar cells, requires overcoming a thermodynamic light-trapping limit proposed in the 1980s. http://www.physorg.com/news246256250.html Nanotechnology Fri, 20 Jan 2012 08:30:01 EST news246256250 (PhysOrg.com) -- At the end of the Cretaceous period some 65 million years ago, an asteroid slammed into Mexico’s Yucatan Peninsula, causing severe but selective extinction. While that is widely accepted, it has remained unclear exactly what the mechanisms were that caused extinction of ocean-dwelling organisms. Proposed explanations include global darkness due to blocking of sunlight with resulting interruption of photosynthesis at the base of the food chain, deadly radiation due to ozone destruction, global cooling or warming, and ocean acidification). Various widely-accepted hypotheses focus on a collapse of the primary and export productivity in the oceans – such as the so-called Strangelove Ocean or Living Ocean hypotheses, respectively – but do not account for the finding that deep-sea floor dwelling phytoplankton-dependent benthic foraminifera did not undergo significant extinction. Recently, however, research conducted at Universidad Zaragoza in Spain compared benthic foraminiferal records with benthic and bulk stable carbon isotope records. The scientists concluded that decreased productivity was moderate, regional, and insufficient to explain marine mass extinction, suggesting instead that a temporary period of increased surface ocean acidity may have been the primary cause of extinction of calcifying plankton and ammonites, with recovery of primary productivity possibly being as fast in the oceans as on land. http://www.physorg.com/news246184252.html Space & Earth Thu, 19 Jan 2012 09:30:01 EST news246184252 (PhysOrg.com) -- Recently, researchers have been designing a wide variety of self-propelled micromotors, many of which operate using an oxygen-bubble propulsion mechanism that requires a high concentration of hydrogen peroxide fuel. Since hydrogen peroxide is hazardous at high concentrations, this requirement has hindered practical applications, especially biomedical uses. Now in a new study, scientists have designed and built a new type of micromotor that propels itself through acidic environments with hydrogen bubbles, and requires no additional fuels. At extremely low pH levels, the micromotors can travel at speeds of up to 100 body lengths per second, prompting the scientists to call them “microrockets.” http://www.physorg.com/news246090119.html Chemistry Wed, 18 Jan 2012 08:30:01 EST news246090119 (PhysOrg.com) -- Today’s most powerful telescopes collect huge amounts of data from the most distant locations of the universe – yet much of the information is simply discarded because it involves small length scales that are difficult to model. In an effort to waste less data from cosmological surveys, a team of scientists has developed a new technique that allows researchers to use otherwise unusable data by "clipping" some of the highest density peaks, which present the greatest challenge to models. This data could provide a way to address some unsolved problems in physics, including estimating the neutrino mass and investigating theories of modified gravity. http://www.physorg.com/news246005206.html Physics Tue, 17 Jan 2012 08:10:01 EST news246005206 (PhysOrg.com) -- Over the past several years, organic light-emitting diodes (OLEDs) have become a popular light source due to their advantages including bright displays, wide viewing angles, and the ability to be printed on flexible substrates. A lesser known alternative to OLEDs, which has these advantages plus some additional ones such as low turn-on voltage, is electrochemical light-emitting cells (LECs). In a recent study, scientists have merged LECs with transistors to create light-emitting electrochemical transistors (LECTs), and for the first time have demonstrated that the light-emitting zone of these devices can be spatially controlled. http://www.physorg.com/news245497980.html Physics Wed, 11 Jan 2012 09:53:46 EST news245497980 (PhysOrg.com) -- More than 500 years ago, Leonardo da Vinci observed a particular relationship between the size of a tree’s trunk and the size of its branches. Specifically, the combined cross-sectional areas of a tree’s daughter branches are equal to the cross-sectional area of the mother branch. However, da Vinci didn’t know why tree branching followed this rule, and few explanations have been proposed since then. But now in a new study, physicist Christophe Eloy from Aix-Marseille University in Aix-en-Provence, France, has shown that this tree structure may be optimal for enabling trees to resist wind-induced stresses. http://www.physorg.com/news244893735.html Physics Wed, 04 Jan 2012 10:40:01 EST news244893735 (PhysOrg.com) -- As a quantum theory of gravity, loop quantum gravity could potentially solve one of the biggest problems in physics: reconciling general relativity and quantum mechanics. But like all tentative theories of quantum gravity, loop quantum gravity has never been experimentally tested. Now in a new study, scientists have found that, when black holes evaporate, the radiation they emit could potentially reveal “footprints” of loop quantum gravity, distinct from the usual Hawking radiation that black holes are expected to emit. http://www.physorg.com/news244805864.html Physics Tue, 03 Jan 2012 09:38:04 EST news244805864 (PhysOrg.com) -- From science fiction and academia through assembly lines and telemedicine, robots have become both conceptually and physically ubiquitous. Technologically, robotics technology has advanced dramatically since the time of their namesake introduction in R.U.R. (Rossum's Universal Robots), a 1920 Czech-language science fiction (which nonetheless was conceptually quite visionary, since the robots it depicted were biological, and therefore essentially synthetic humans) in which robot was the English version of robota, meaning forced labor, in turn derived from rab, or slave. Today’s virtual and physical robots, however – imbued with artificial intelligence, artificial muscles, vision and pattern recognition, speech recognition and synthesis, sensors and actuators, and increasingly sophisticated interactivity – seem to be approaching those envisioned in Isaac Asimov’s seminal work I, Robot (but still from their human-level-and-beyond artificial intelligence, and certainly nowhere near the living robots envisioned in R.U.R.) That said, however, something’s still glaringly missing – namely, the ability to seamlessly interact with humans and other robots in a spontaneous, natural way that does not rely exclusively on specific preprogrammed behaviors. This is far more difficult than it seems, owing largely to the challenge of computationally emulating evolutionarily-determined perceptually-and emotionally-mediated contextual engagement. Enter Social Robotics: the effort to make robots more…well, sociable. http://www.physorg.com/news244370112.html Electronics Thu, 29 Dec 2011 10:00:04 EST news244370112 (Medical Xpress) -- Rather than being a passive state, perception is an active process fueled by predictions and expectations about our environment. In the latter case, memory must be a fundamental component in the way our brain generates these precursors to the perceptual experience – but how the brain integrates long-term memory with perception has not been determined. Recently, however, researchers in the Department of Experimental Psychology at the University of Oxford, by devising a method for integrating memory and attention, showed how LTM optimizes perception by varying brain states associated with anticipation of spatial localization in the visual field. The scientists also used fMRI to articulate a neural network involving a number of cortical areas likely to be active in the predictive use of memory in the visual cortex. http://www.physorg.com/news244276032.html Medicine & Health Wed, 28 Dec 2011 08:30:01 EST news244276032 (PhysOrg.com) -- Matter in the subatomic realm is, well, a different matter. In the case of strongly correlated phases of matter, one of the most surprising findings has to do with a phenomenon known as the Hall response – an important theoretical and experimental tool for describing emergent charge carriers in strongly correlated systems, examples of which include high temperature superconductors and the quantum Hall effect. At Weizmann Institute of Science and California Institute of Technology, recent theoretical physics research into bosons interacting in a magnetic field has shown that, among other surprising effects, Hall conductivity – and therefore flux flow – undergo reversal. The scientists have concluded that their findings are immediately applicable to a wide range of phenomena in the realm of condensed matter physics. http://www.physorg.com/news244194092.html Physics Tue, 27 Dec 2011 08:50:01 EST news244194092 (PhysOrg.com) -- Most of today’s electronics devices contain two different types of field-effect transistors (FETs): n-type (which use electrons as the charge carrier) and p-type (which use holes). Generally, a transistor can only be one type or the other, but not both. Now in a new study, researchers have designed a transistor that can reconfigure itself as either n-type or p-type when programmed by an electric signal. A set of these “universal transistors” can, in principle, perform any Boolean logic operation, meaning circuits could perform the same number of logic functions with fewer transistors. This advantage could lead to more compact hardware and novel circuit designs. http://www.physorg.com/news243599823.html Nanotechnology Tue, 20 Dec 2011 11:20:01 EST news243599823 (PhysOrg.com) -- In the 1960s, Dr. Lawrence J. Fogel introduced what would come to be known as evolutionary programming to the nascent field of Artificial Intelligence in an attempt to produce intelligent software without relying on neural networks modeled on the brain or human expert-based heuristic programming. Now, researchers in the Department of Ecology and Evolutionary Biology at Princeton University have shown the inverse – namely, that network theory, when applied to software systems, provides surprising insights into biology, ecology and evolution. Specifically, they explored evolutionary behavior in complex systems by analyzing how the Debian GNU/Linux operating system utilizes modular code. The researchers found that how the network becomes more modular over time in various OS installations often parallels that of ecological relationships between interacting species. http://www.physorg.com/news243510666.html Technology Mon, 19 Dec 2011 10:40:01 EST news243510666 (PhysOrg.com) -- It typically takes a day or two to prepare quantum dot solar cells in the conventional multifilm architecture. Now a team of researchers is reducing the preparation time of quantum dot solar cells to less than an hour by changing the form to a one-coat quantum dot solar paint. Although the paint form is currently about five times less efficient than the highest recorded efficiency for the multifilm form, the researchers predict that the efficiency can be improved, which could lead to a simple and economically viable way to prepare solar cells. http://www.physorg.com/news243240490.html Nanotechnology Fri, 16 Dec 2011 08:20:01 EST news243240490 (PhysOrg.com) -- The primary objective of NASA’s Kepler satellite, which was launched in March 2009 to orbit the Sun, is to search for Earth-like planets in a portion of the Milky Way galaxy. But now a team of physicists has proposed that Kepler could have a second appealing purpose: to either detect or rule out primordial black holes (PBHs) of a certain mass range as the primary constituent of dark matter. http://www.physorg.com/news242643434.html Physics Fri, 09 Dec 2011 09:50:01 EST news242643434 (PhysOrg.com) -- What does a proton look like? The common answer to this question is that protons are much too small to scatter light, and since light is necessary for us to see things, protons do not “look” like anything. But in a new study, physicists have gathered sufficient evidence to show that, at least at very high energies, the proton is a black disk – sort of an elongated hockey puck. This description fits only for protons at such ultrahigh energies that even the most advanced experiments will probably never be able to detect them. http://www.physorg.com/news242553117.html Physics Thu, 08 Dec 2011 09:00:01 EST news242553117 (PhysOrg.com) -- By applying extreme pressure to compress and flatten carbon nanotubes, scientists have discovered that they can create a new carbon polymer that simulations show is hard enough to crack diamond. The pressure-induced formation process of the new carbon allotrope, called Cco-C8, is similar to the 3D polymerization of the soccer-ball-like buckminsterfullerene, C60, at high pressure. When the carbon nanotube bundle is subjected to further compression, it becomes even more distorted and flattened to produce the Cco-C8 structure. http://www.physorg.com/news242467958.html Nanotechnology Wed, 07 Dec 2011 09:30:01 EST news242467958 (PhysOrg.com) -- While flexible OLED displays have begun appearing in some cell phones, the technology is still too expensive to be widely used in consumer electronics. In one of the latest attempts to enable low-cost mass-production of OLED displays, researchers have fabricated the first complete thin-film transistor circuits printed with a carbon nanotube (CNT) solution for use with display electronics. They found that these circuits are not only easy to fabricate, but they also work as excellent current switches when connected to OLEDs. http://www.physorg.com/news242379887.html Nanotechnology Tue, 06 Dec 2011 08:20:01 EST news242379887 (PhysOrg.com) -- As humans, we have a knack for estimating another person’s age quite accurately just by glancing at their face. Although age estimation may seem relatively simple to us, computers have a much more difficult time performing the task. In one of the latest attempts to build a computer that can accurately estimate a person’s age, researchers have taken a bottom-up approach to the challenge, collecting hundreds of thousands of images and videos from the Internet to train the system. Their goal is to build a universal human age estimator that is applicable to all ethnic groups and various image qualities. http://www.physorg.com/news242299374.html Technology Mon, 05 Dec 2011 09:23:19 EST news242299374 (PhysOrg.com) -- In its essence, technology can be seen as our perpetually evolving attempt to extend our sensorimotor cortex into physical reality: From the earliest spears and boomerangs augmenting our arms, horses and carts our legs, and fire our environment, we’re now investigating and manipulating the fabric of that reality – including the very components of life itself. Moreover, this progression has not been linear, but instead follows an iterative curve of inflection points demarcating disruptive changes in dominant societal paradigms. Suggested by mathematician Vernor Vinge in his acclaimed science fiction novel True Names (1981) and introduced explicitly in his essay The Coming Technological Singularity (1993), the term was popularized by inventor and futurist Ray Kurzweil in The Singularity is Near (2005). The two even had a Singularity Chat in 2002. http://www.physorg.com/news242019836.html Technology Fri, 02 Dec 2011 08:30:01 EST news242019836 (PhysOrg.com) -- In its essence, technology can be seen as our perpetually evolving attempt to extend our sensorimotor cortex into physical reality: From the earliest spears and boomerangs augmenting our arms, horses and carts our legs, and fire our environment, we’re now investigating and manipulating the fabric of that reality – including the very components of life itself. Moreover, this progression has not been linear, but instead follows an iterative curve of inflection points demarcating disruptive changes in dominant societal paradigms. Suggested by mathematician Vernor Vinge in his acclaimed science fiction novel True Names (1981) and introduced explicitly in his essay The Coming Technological Singularity (1993), the term was popularized by inventor and futurist Ray Kurzweil in The Singularity is Near (2005). The two even had a Singularity Chat in 2002. http://www.physorg.com/news241939341.html Technology Thu, 01 Dec 2011 08:30:01 EST news241939341 (PhysOrg.com) -- Physicists know that neutrinos (and antineutrinos) come in three flavors: electron, muon, and tau. In several experiments, researchers have detected each of the neutrino flavors and even watched them “oscillate” back and forth between flavors. But starting in the early ‘90s, some experiments have also revealed a nagging anomaly: muon antineutrinos oscillate into electron antineutrinos at a 3% higher rate than predicted. Physicists can reconcile this discrepancy by adding a fourth neutrino with a specific mass, although such a move would require modifying the Standard Model, the theory of subatomic particles that has taken decades to build. In a new study, a team of physicists thinks it’s time to put the question of the fourth neutrino’s existence to the test. http://www.physorg.com/news241767426.html Physics Tue, 29 Nov 2011 08:40:01 EST news241767426 (Medical Xpress) -- Neuroanatomy and neurophysiology are inherently three-dimensional domains. Neuronal cell body projections – axons and dendrites – can interconnect large numbers of neurons distributed over large cortical distances. Since the brain processes sensory, somatic, conceptual, and other classes of information in this 3D structural space, the need to (1) image neural structures and (2) stimulate and record neural signals are essential to understanding the relationship between brain structure and function. While 3D imaging and 3D photostimulation using scanning or parallel excitation methods have been used, they have not previously been combined into an optical system that can successfully decouple the corresponding optical planes when using a single lens – a shortcoming that has limited investigators to small neural areas. Recently, however, scientists at Université Paris Descartes have combined digital single photon holographic stimulation with remote-focusing-based epifluorescent functional imaging to overcome these limitations. http://www.physorg.com/news241716185.html Medicine & Health Mon, 28 Nov 2011 16:00:01 EST news241716185