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. When it comes to the two basic types of cells, prokaryotes and eukaryotes, compartmentalization is everything. Prokaryotes are evolutionarily ancient cells that only have a membrane surrounding their outer boundary, while the more complex eukaryotes have an outer membrane and membrane bound compartments within the cell. Perhaps most notable is the double layered membrane that surrounds the nucleus, the cellular compartment which houses the cell's genetic material. http://www.physorg.com/news174050458.html Chemistry Tue, 06 Oct 2009 12:25:25 EST news174050458 (PhysOrg.com) -- The NPC is the only way in or out of a cell's nucleus. It plays a key role in cellular metabolism and signaling, and any malfunction in these pores can have lethal consequences. Now new research reveals further insights into the design of this evolutionarily ancient and little-understood transport machinery. The findings suggest that the nuclear pore complex takes on different formations to carry out its function. http://www.physorg.com/news173428123.html Biology Tue, 29 Sep 2009 08:20:01 EST news173428123 Using a powerful microscope, Karel Svoboda, a brain scientist at the Janelia Farm Research Campus in Ashburn, Va., peers through a plastic window in the top of a mouse's head to watch its brain's neurons sprout new connections -- a vivid display of a living brain in action. http://www.physorg.com/news173382165.html Medicine & Health Mon, 28 Sep 2009 18:43:27 EST news173382165 (PhysOrg.com) -- Life's ability to replicate itself is essential for evolution, yet even the simplest kind of replication requires a relatively complex system. So what kind of non-replicating system might have served as the predecessor of evolution, paving the way for life as we know it? The answer, according to a recent study, is a kind of "prelife" -- a chemical system that can lead to information and diversity, and that is capable of selection and mutation, but does not yet have the ability to self-replicate. http://www.physorg.com/news173351870.html Chemistry Mon, 28 Sep 2009 10:18:22 EST news173351870 Human activities have already pushed the Earth system beyond three of the planet's biophysical thresholds, with consequences that are detrimental or even catastrophic for large parts of the world; six others may well be crossed in the next decades, conclude 29 European, Australian and U.S. scientists in an article in the Sept. 24 issue of the scientific journal Nature. http://www.physorg.com/news172937155.html Space & Earth Wed, 23 Sep 2009 15:07:05 EST news172937155 Before it was learned that matter burns by taking up oxygen, most chemists sought to explain combustion as the release of a mysterious substance, which they named "phlogiston". Phlogiston theory was a conceptual breakthrough that helped chemists conduct experiments and share ideas. Only when it came to pinning down the distinctive physical properties of phlogiston did it become clear that no such thing exists. http://www.physorg.com/news172768776.html Biology Mon, 21 Sep 2009 17:10:47 EST news172768776 Cytokines are small proteins secreted by cells that serve as molecular messengers between cells. Pro-inflammatory cytokines - which function in the immune system - may be involved in alcohol dependence (AD). A study of three polymorphisms of the interleukin-1 gene complex (IL-1) and one of the tumor necrosis factor-alpha (TNFα) has found that IL-1 may directly contribute to AD among Spanish Caucasian males. http://www.physorg.com/news172513919.html Medicine & Health Fri, 18 Sep 2009 17:32:47 EST news172513919 (PhysOrg.com) -- To successfully compete in a global marketplace, manufacturers continually search for better materials: faster drying and less hazardous paint, longer-lasting sunscreen, and faster computers. Transition metal and complex oxide materials exhibit a range of properties unparalleled by any other class of materials. http://www.physorg.com/news172422021.html Chemistry Thu, 17 Sep 2009 16:03:32 EST news172422021 Using yeast genetics and a novel scheme to selectively remove a single protein from the cell division process called meiosis, a cell biologist at The Florida State University found that when a key molecular player known as Pds5 goes missing, chromosomes fail to segregate and pair up properly, and birth defects such as Down syndrome can result. http://www.physorg.com/news172334309.html Biology Wed, 16 Sep 2009 16:30:01 EST news172334309 Google's algorithm for ranking web-pages can be used to determine which species are critical for sustaining ecosystems. Drs. Stefano Allesina and Mercedes Pascual find that "PageRank" can be applied to the study of food webs, the complex networks describing who eats whom in an ecosystem. http://www.physorg.com/news171272789.html Biology Fri, 04 Sep 2009 08:47:09 EST news171272789 (PhysOrg.com) -- Computational biochemist Frank Alber compares determining the architecture of a macromolecular machine to solving a jigsaw puzzle. http://www.physorg.com/news169926693.html Chemistry Wed, 19 Aug 2009 19:30:01 EST news169926693 (PhysOrg.com) -- To protect their DNA, cells in higher organisms are very choosy about what they allow in and out of their nuclei, where the genes reside. Guarding access is the job of transport machines called nuclear pore complexes, which stud the nuclear membrane. Despite these gatekeepers` conspicuously large size (they are made of 30 different proteins), they have proved largely inscrutable to researchers over the years. But bit by bit, scientists are learning how these machines work. http://www.physorg.com/news169828329.html Biology Tue, 18 Aug 2009 16:20:01 EST news169828329 The findings, published in this week's issue of Science, conclude that food-web stability is enhanced when many diverse predator-prey links connect high and intermediate trophic levels. The computations also reveal that small ecosystems follow other rules than large ecosystems: differences in the strength of predator-prey links increase the stability of small webs, but destabilize larger webs. http://www.physorg.com/news168787660.html Biology Thu, 06 Aug 2009 15:20:01 EST news168787660 (PhysOrg.com) -- Here's a question. How many gumballs of different sizes can fit in one of those containers at the mall so as to reward a well-spent quarter? It's hard to believe that most people never consider it even when guessing the number of candies in a bowl at Halloween. http://www.physorg.com/news168534811.html Other Sciences Mon, 03 Aug 2009 16:14:18 EST news168534811 (PhysOrg.com) -- Rummaging through a biotechnology company`s chemical closet, Yale University researchers found two molecules that will allow scientists to better study how cells move. http://www.physorg.com/news168533622.html Chemistry Mon, 03 Aug 2009 16:10:01 EST news168533622 (PhysOrg.com) -- Creating error-free software remains time consuming and labour intensive. A major European research effort has developed a system that speeds software development from the drawing board to high-quality, platform-independent code. http://www.physorg.com/news168184708.html Technology Thu, 30 Jul 2009 14:59:20 EST news168184708 (PhysOrg.com) -- How many sweets fit into a jar? This question depends on the shapes and sizes of the sweets, the size of the jar, and how it is filled. Surprisingly, this ancient question remains unanswered because of the complex geometry of the packing of the sweets. Moreover, as any contestant knows, guessing the number of sweets in the jar is difficult because the sweets located at the center of the jar are hidden from view and can't be counted. Researchers at New York University have now determined how sweets pack from inside the jar, making it easier to more accurately count them. http://www.physorg.com/news168095052.html Physics Wed, 29 Jul 2009 14:04:49 EST news168095052 (PhysOrg.com) -- A new computer game prototype combines work and play to help solve a fundamental problem underlying many computer hardware design tasks. http://www.physorg.com/news167928385.html Technology Mon, 27 Jul 2009 15:46:56 EST news167928385 The often-used one-size-fits-all approach to policies aimed at achieving sustainable social-ecological systems needs to be updated with a diagnostic tool to help scholars from multiple disciplines better frame the question and think through the variables, asserts social scientist and political economist Elinor Ostrom. http://www.physorg.com/news167578673.html Other Sciences Thu, 23 Jul 2009 14:38:14 EST news167578673 (PhysOrg.com) -- The tremendous diversity of life continues to puzzle scientists, long after the 200 years since Charles Darwin's birth. However, in recent years, consistent patterns of biodiversity have been identified over space, time organism type and geographical region. http://www.physorg.com/news167057268.html Biology Fri, 17 Jul 2009 13:48:38 EST news167057268 (PhysOrg.com) -- For perhaps 1.8 billion years after life first emerged on Earth, a sort of evolutionary writer`s block stalled the development of organisms more complicated than single cells. Then, a burst of experimental creativity about 1.7 billion years ago brought the cell nucleus onto the scene, stashing the cell`s genetic material inside a protective inner membrane and setting the stage for the evolution of more sophisticated creatures from yeast, say, to plants and human beings. Now research shows that one of the most basic design principles of this new eukaryotic life-form - the gatekeeper to the cell nucleus known as the nuclear pore complex - is largely shared across the most distantly related eukaryotes. Its core components likely evolved once and for all and would be found in the nuclear pore complex of what is known as the last common eukaryotic ancestor. http://www.physorg.com/news166722019.html Chemistry Mon, 13 Jul 2009 17:00:02 EST news166722019 (PhysOrg.com) -- In the past 50 years it has become commonplace to think of Earth as a nurturing place, straining mightily to maintain equilibrium so that life might continue and flourish. http://www.physorg.com/news162045215.html Other Sciences Wed, 20 May 2009 13:34:10 EST news162045215 (PhysOrg.com) -- In the world of small things, shape, order and orientation are surprisingly important, according to findings from a new study by chemists at Washington University in St. Louis. http://www.physorg.com/news160669215.html Chemistry Mon, 04 May 2009 15:21:18 EST news160669215 (PhysOrg.com) -- Tough economic times call for tough measures to remain competitive. That goes for software modernisation as well. A European project has just released a prototype of a software engineering platform that could help companies save time, money and energy as they scramble to upgrade complex IT systems. The timing could not be better. http://www.physorg.com/news160664977.html Technology Mon, 04 May 2009 14:15:55 EST news160664977 Most cellular processes are carried out by molecular machines that consist of many interacting proteins. These protein complexes lie at the heart of life science research, but they are notoriously hard to study. Their abundance is often too low to extract them directly from cells and generating them with recombinant methods has been a daunting task. http://www.physorg.com/news160662977.html Chemistry Mon, 04 May 2009 13:36:51 EST news160662977 In an in vitro study, led by Grace Gill, PhD, Tufts University School of Medicine, researchers discovered how a protein called SUMO (Small Ubiquitin-related Modifier) guides an enzyme complex that alters the structure of chromatin to regulate expression of genes. Chromatin is a compacted mass of DNA and protein that make up chromosomes. The interaction between SUMO and the enzyme complex is of interest in the study of cancer and neurodegenerative diseases such as Alzheimer's, where aberrant gene expression and altered SUMO function are thought to be indicative of disease. http://www.physorg.com/news160048671.html Medicine & Health Mon, 27 Apr 2009 10:58:22 EST news160048671 Men and women who chewed Extra(R) sugar-free gum three times hourly in the afternoon chose and consumed less snacks and specifically, less sweet snacks than they did when they did not chew gum. They still reached for a variety of snacks provided but the decrease in overall snack intake was significant at 40 calories and sweet snack intake specifically was significantly lowered by 60 calories. http://www.physorg.com/news159372266.html Medicine & Health Sun, 19 Apr 2009 15:04:59 EST news159372266 Charles Darwin was fascinated by the colours of animals - he once wrote to his colleague Alfred Russell Wallace asking why certain animals were "sobeautifully and artistically coloured". http://www.physorg.com/news159108734.html Biology Thu, 16 Apr 2009 13:53:14 EST news159108734 (PhysOrg.com) -- The speed at which heat moves between two materials touching each other is a potent indicator of how strongly they are bonded to each other, according to a new study by researchers at Rensselaer Polytechnic Institute. http://www.physorg.com/news158859223.html Nanotechnology Mon, 13 Apr 2009 16:34:11 EST news158859223 Researchers at Eindhoven University of Technology (the Netherlands) have developed an entirely new method for starting chemical reactions. For the first time they used mechanical forces to control catalytic activity - one of the most fundamental concepts in chemistry. This allowed them to initiate chemical reactions with mechanical force. This discovery paves the way to developing materials capable of repairing themselves under the influence of mechanical tension. The results of their research will be published online on 6 April 2009 in the new international journal Nature Chemistry. http://www.physorg.com/news158245330.html Chemistry Mon, 06 Apr 2009 14:02:41 EST news158245330