Scientists at the University of Basel report first ever successful nose reconstruction surgery using cartilage grown in the laboratory. Cartilage cells were extracted from the patient’s nasal septum, multiplied and expanded onto a collagen membrane. The so-called engineered cartilage was then shaped according to the defect and implanted. The results will be published in the current edition of the academic journal The Lancet.A research team from the University of Basel in Switzerland has reported that nasal reconstruction using engineered cartilage is possible. They used a method called tissue engineering where cartilage is grown from patients’ own cells. This new technique was applied on five patients, aged 76 to 88 years, with severe defects on their nose after skin cancer surgery. One year after the reconstruction, all five patients were satisfied with their ability to breathe as well as with the cosmetic appearance of their nose. None of them reported any side effects.Cells from the nasal septumThe type of non-melanoma skin cancer investigated in this study is most common on the nose, specifically the alar wing of the nose, because of its cumulative exposure to sunlight. To remove the tumor completely, surgeons often have to cut away parts of cartilage as well. Usually, grafts for reconstruction are taken from the nasal septum, the ear or the ribs and used to functionally reconstruct the nose. …Read more
The Baryon Oscillation Spectroscopic Survey (BOSS), the largest component of the third Sloan Digital Sky Survey (SDSS-III), pioneered the use of quasars to map density variations in intergalactic gas at high redshifts, tracing the structure of the young universe. BOSS charts the history of the universe’s expansion in order to illuminate the nature of dark energy, and new measures of large-scale structure have yielded the most precise measurement of expansion since galaxies first formed.The latest quasar results combine two separate analytical techniques. A new kind of analysis, led by physicist Andreu Font-Ribera of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and his team, was published late last year. Analysis using a tested approach, but with far more data than before, has just been published by Timothe Delubac, of EPFL Switzerland and France’s Centre de Saclay, and his team. The two analyses together establish the expansion rate at 68 kilometers per second per million light years at redshift 2.34, with an unprecedented accuracy of 2.2 percent.”This means if we look back to the universe when it was less than a quarter of its present age, we’d see that a pair of galaxies separated by a million light years would be drifting apart at a velocity of 68 kilometers a second as the universe expands,” says Font-Ribera, a postdoctoral fellow in Berkeley Lab’s Physics Division. “The uncertainty is plus or minus only a kilometer and a half per second.” Font-Ribera presented the findings at the April 2014 meeting of the American Physical Society in Savannah, GA.BOSS employs both galaxies and distant quasars to measure baryon acoustic oscillations (BAO), a signature imprint in the way matter is distributed, resulting from conditions in the early universe. While also present in the distribution of invisible dark matter, the imprint is evident in the distribution of ordinary matter, including galaxies, quasars, and intergalactic hydrogen.”Three years ago BOSS used 14,000 quasars to demonstrate we could make the biggest 3D maps of the universe,” says Berkeley Lab’s David Schlegel, principal investigator of BOSS. “Two years ago, with 48,000 quasars, we first detected baryon acoustic oscillations in these maps. Now, with more than 150,000 quasars, we’ve made extremely precise measures of BAO.”The BAO imprint corresponds to an excess of about five percent in the clustering of matter at a separation known as the BAO scale. …Read more
Why does a mouse’s heart beat about the same number of times in its lifetime as an elephant’s, although the mouse lives about a year, while an elephant sees 70 winters come and go? Why do small plants and animals mature faster than large ones? Why has nature chosen such radically different forms as the loose-limbed beauty of a flowering tree and the fearful symmetry of a tiger?These questions have puzzled life scientists since ancient times. Now an interdisciplinary team of researchers from the University of Maryland and the University of Padua in Italy propose a thought-provoking answer based on a famous mathematical formula that has been accepted as true for generations, but never fully understood. In a paper published the week of Feb. 17, 2014 in the Proceedings of the National Academy of Sciences, the team offers a re-thinking of the formula known as Kleiber’s Law. Seeing this formula as a mathematical expression of an evolutionary fact, the team suggests that plants’ and animals’ widely different forms evolved in parallel, as ideal ways to solve the problem of how to use energy efficiently.If you studied biology in high school or college, odds are you memorized Kleiber’s Law: metabolism equals mass to the three-quarter power. This formula, one of the few widely held tenets in biology, shows that as living things get larger, their metabolisms and their life spans increase at predictable rates. Named after the Swiss biologist Max Kleiber who formulated it in the 1930s, the law fits observations on everything from animals’ energy intake to the number of young they bear. It’s used to calculate the correct human dosage of a medicine tested on mice, among many other things.But why does Kleiber’s Law hold true? …Read more
Understanding the human brain is one of the greatest challenges facing 21st century science. If we can rise to this challenge, we will gain profound insights into what makes us human, develop new treatments for brain diseases, and build revolutionary new computing technologies that will have far reaching effects, not only in neuroscience.Scientists at the European Human Brain Project — set to announce more than a dozen new research partnerships worth Eur 8.3 million in funding later this month — the Allen Institute for Brain Science, and the US BRAIN Initiative are developing new paradigms for understanding how the human brain works in health and disease. Today, their international and collaborative projects are defined, explored, and compared during “Inventing New Ways to Understand the Human Brain,” at the 2014 AAAS Annual Meeting in Chicago.Brain Simulation, Big Data, and a New Computing ParadigmHenry Markram from the Ecole Polytechnique Fdrale de Lausanne (EPFL), in Switzerland, where the Human Brain Project is based, describes how the project will leverage available experimental data and basic principles of brain organization to reconstruct the detailed structure of the brain in computer models. The models will allow the HBP to run super-computer based simulations of the inner working of the brain.”Brain simulation allows measurements and manipulations impossible in the lab, opening the road to a new kind of in silico experimentation,” Markram says.The data deluge in neuroscience is resulting in a revolutionary amount of brain data with new initiatives planning to acquire even more. But searching, accessing, and analyzing this data remains a key challenge.Sean Hill, also of EPFL and a speaker at AAAS, leads The Neuroinformatics Platform of the Human Brain Project (HBP). In this scientific panel, he explains how the platform will provide tools to manage, navigate, and annotate spatially referenced brain atlases, which will form the basis for the HBP’s modeling effort — turning Big Data into deep knowledge.The Neuroinformatics Platform will bring together many different kinds of data. University of Edinburgh’s Seth Grant, a key member of the HBP, describes how he is deriving new methods to decode the molecular principles underlying the brain’s organization, such as how individual proteins assemble into larger complexes. As Grant explains in Chicago, this has important practical applications as many mutations in schizophrenia and autism converge on these so-called supercomplexes in the brain.As we understand more and more about the way the brain computes we can apply this knowledge to technology. Karlheinz Meier, of Heidelberg University in Germany and a speaker at AAAS, outlines how he is working to create entirely new computing systems as part of the HBP. These Neuromorphic Computing Systems will merge realistic brain models with new hardware for a completely new paradigm of computing — one that more closely resembles how the brain itself processes information.”The brain has the ability to efficiently perform computations that are impossible even for the most powerful computers while consuming only 30 Watts of power,” Meier says.Brain: Get Ready For Your Close-upAt AAAS, Christof Koch lays out another ambitious, 10-year plan from the Allen Institute for Brain Science: to understand the structure and function of the brain by mapping cell types from mice and humans with computer simulations and figuring out how the cells connect, and how they encode, relay, and process information. …Read more
New research from Case Western Reserve University and University of Toronto neuroscientists finds that the brains of autistic children generate more information at rest — a 42% increase on average. The study offers a scientific explanation for the most typical characteristic of autism — withdrawal into one’s own inner world. The excess production of information may explain a child’s detachment from their environment.Published at the end of December in Frontiers in Neuroinformatics, this study is a follow-up to the authors’ prior finding that brain connections are different in autistic children. This paper determined that the differences account for the increased complexity within their brains.”Our results suggest that autistic children are not interested in social interactions because their brains generate more information at rest, which we interpret as more introspection in line with early descriptions of the disorder,” said Roberto Fernndez Galn, PhD, senior author and associate professor of neurosciences at Case Western Reserve School of Medicine.The authors quantified information as engineers normally do but instead of applying it to signals in electronic devices, they applied it to brain activity recorded with magnetoencephalography (MEG). They showed that autistic children’s brains at rest generate more information than non-autistic children. This may explain their lack of interest in external stimuli, including interactions with other people.The researchers also quantified interactions between brain regions, i.e., the brain’s functional connectivity, and determined the inputs to the brain in the resting state allowing them to interpret the children’s introspection level.”This is a novel interpretation because it is a different attempt to understand the children’s cognition by analyzing their brain activity,” said Jos L. Prez Velzquez, PhD, first author and professor of neuroscience at University of Toronto Institute of Medical Science and Department of Pediatrics, Brain and Behavior Center. “Measuring cognitive processes is not trivial; yet, our findings indicate that this can be done to some extent with well-established mathematical tools from physics and engineering.”This study provides quantitative support for the relatively new “Intense World Theory” of autism proposed by neuroscientists Henry and Kamila Markram of the Brain Mind Institute in Switzerland, which describes the disorder as the result of hyper-functioning neural circuitry, leading to a state of over-arousal. More generally, the work of Galn and Prez Velzquez is an initial step in the investigation of how information generation in the brain relates to cognitive/psychological traits and will begin to frame neurophysiological data into psychological aspects. The team now aims to apply a similar approach to patients with schizophrenia.Story Source:The above story is based on materials provided by Case Western Reserve University. …Read more
Seven nations won out against 143 others in the debate over whether chrysotile asbestos should be added to the United Nation’s Prior Informed Consent (PIC) list of hazardous substances in the Rotterdam Convention. India, Kazakhstan, Kyrgyzstan, Russia, Ukraine, Vietnam, and Zimbabwe all objected to the addition at the sixth meeting of the Rotterdam Convention which took place April 28 – May 10,2013, in Geneva Switzerland. It comes as no surprise that the countries which objected to the listing are home to a booming asbestos industry. Russia alone mines an estimated 1,000,000 tons of asbestos annually and is the supplier for half of the world’s chrysotile production.In September of 2012, Canada, which was the sole objector to the addition at the 2011 conference, announced it would no longer object to the listing. Russia, …Read more
Sep. 3, 2013 — Sleep increases the reproduction of the cells that go on to form the insulating material on nerve cell projections in the brain and spinal cord known as myelin, according to an animal study published in the September 4 issue of The Journal of Neuroscience. The findings could one day lead scientists to new insights about sleep’s role in brain repair and growth.Scientists have known for years that many genes are turned on during sleep and off during periods of wakefulness. However, it was unclear how sleep affects specific cells types, such as oligodendrocytes, which make myelin in the healthy brain and in response to injury. Much like the insulation around an electrical wire, myelin allows electrical impulses to move rapidly from one cell to the next.In the current study, Chiara Cirelli, MD, PhD, and colleagues at the University of Wisconsin, Madison, measured gene activity in oligodendrocytes from mice that slept or were forced to stay awake. The group found that genes promoting myelin formation were turned on during sleep. In contrast, the genes implicated in cell death and the cellular stress response were turned on when the animals stayed awake.”These findings hint at how sleep or lack of sleep might repair or damage the brain,” said Mehdi Tafti, PhD, who studies sleep at the University of Lausanne in Switzerland and was not involved with this study.Additional analysis revealed that the reproduction of oligodendrocyte precursor cells (OPCs) — cells that become oligodendrocytes — doubles during sleep, particularly during rapid eye movement (REM), which is associated with dreaming.”For a long time, sleep researchers focused on how the activity of nerve cells differs when animals are awake versus when they are asleep,” Cirelli said. “Now it is clear that the way other supporting cells in the nervous system operate also changes significantly depending on whether the animal is asleep or awake.”Additionally, Cirelli speculated the findings suggest that extreme and/or chronic sleep loss could possibly aggravate some symptoms of multiple sclerosis (MS), a disease that damages myelin. Cirelli noted that future experiments may examine whether or not an association between sleep patterns and severity of MS symptoms exists.This research was funded by the University of Wisconsin-Madison Department of Psychiatry.Read more
Aug. 31, 2013 — STEMI incidence fell in southern Switzerland after implementation of the smoking ban in public places, reveals research presented at the ESC Congress today by Dr. Alessandra Pia Porretta from Switzerland.Second-hand smoke increases the risk of coronary artery disease and acute myocardial infarction. For this reason, health policies aimed at reducing tobacco consumption and public smoke exposure are strongly recommended.Dr Porretta said: “Canton Ticino (CT), which is one of the 26 cantons of the Swiss Federation, was the first Swiss canton to introduce a smoking ban in April 2007. We had the opportunity to assess the long-term impact of the smoking ban on the incidence of ST-segment elevation myocardial infarction (STEMI) and to compare STEMI epidemiology with Canton Basel City (CBC), where the law was not yet implemented.”The principal investigator of the study (Dr Marcello Di Valentino) collected data retrospectively from the codified hospital discharge registry (ICD-10 codes) on STEMI hospitalisations in CT and CBC during the 3 years before (2004-2007) and after (2007-2010) the ban was implemented in CT.In CT, data were acquired from the four cantonal public hospitals and from Cardiocentro Ticino, an exclusive institution for invasive coronary interventions. In CBC, data were obtained from the public University Hospital of Basel. For each considered year, STEMI incidence per 100,000 inhabitants was calculated for both CT and CBC using demographic data from the Swiss Federal Statistical Office.The study found a significant and long-lasting reduction in the incidence of STEMI hospitalisations in the overall population of Canton Ticino after the smoking ban was implemented. Incidence reduced by an average of 21.1% between 2004-07 and 2007-2010. Compared to 2004-2007, incidence reduced by 23% in 2007-2008, 15% in 2008-2009, and 24% in 2009-2010.When population subsets were analysed, the researchers found that the significant and long-lasting reduction in STEMI admissions was observed only among older people, with a 27.4% post-ban decrease in women ≥65 years and a 27.3% reduction in men ≥65 years. Younger people (<65 years) of both sexes showed a reduction (statistically significant in men, near to significance in women) in STEMI admissions only in the first year after the ban was enforced, with no significant decrease in the second and third years.</p>Dr Porretta said: “The varying impact of smoke-free legislation between age groups may be explained in part by the different role played by passive and active smoking in younger and older people.”In CBC there was no change in the overall population incidence of STEMI between 2004-2007 and 2007-2010. …Read more
Aug. 26, 2013 — The brain’s tactile and motor neurons, which perceive touch and control movement, may also respond to visual cues, according to researchers at Duke Medicine.The study in monkeys, which appears online Aug. 26, 2013, in the journal Proceedings of the National Academy of Sciences, provides new information on how different areas of the brain may work together in continuously shaping the brain’s internal image of the body, also known as the body schema.The findings have implications for paralyzed individuals using neuroprosthetic limbs, since they suggest that the brain may assimilate neuroprostheses as part of the patient’s own body image.”The study shows for the first time that the somatosensory or touch cortex may be influenced by vision, which goes against everything written in neuroscience textbooks,” said senior author Miguel Nicolelis, M.D., PhD, professor of neurobiology at Duke University School of Medicine. “The findings support our theory that the cortex isn’t strictly segregated into areas dealing with one function alone, like touch or vision.”Earlier research has shown that the brain has an internal spatial image of the body, which is continuously updated based on touch, pain, temperature and pressure — known as the somatosensory system — received from skin, joints and muscles, as well as from visual and auditory signals.An example of this dynamic process is the “rubber hand illusion,” a phenomenon in which people develop a sense of ownership of a fake hand when they view it being touched at the same time that something touches their own hand.In an effort to find a physiological explanation for the “rubber hand illusion,” Duke researchers focused on brain activity in the somatosensory and motor cortices of monkeys. These two areas of the brain do not directly receive visual input, but previous work in rats, conducted at the Edmond and Lily Safra International Institute of Neuroscience of Natal in Brazil, theorized that the somatosensory cortex could respond to visual cues.In the Duke experiment, the two monkeys observed a realistic, computer-generated image of a monkey arm on a screen being touched by a virtual ball. At the same time, the monkeys’ arms were touched, triggering a response in their somatosensory and motor cortical areas.The monkeys then observed the ball touching the virtual arm without anything physically touching their own arms. Within a matter of minutes, the researchers saw the neurons located in the somatosensory and motor cortical areas begin to respond to the virtual arm alone being touched.The responses to virtual touch occurred 50 to 70 milliseconds later than physical touch, which is consistent with the timing involved in the pathways linking the areas of the brain responsible for processing visual input to the somatosensory and motor cortices. Demonstrating that somatosensory and motor cortical neurons can respond to visual stimuli suggests that cross-functional processing occurs throughout the primate cortex through a highly distributed and dynamic process.”These findings support our notion that the brain works like a grid or network that is continuously interacting,” Nicolelis said. “The cortical areas of the brain are processing multiple streams of information at the same time instead of being segregated as we previously thought.”The research has implications for the future design of neuroprosthetic devices controlled by brain-machine interfaces, which hold promise for restoring motor and somatosensory function to millions of people who suffer from severe levels of body paralysis. Creating neuroprostheses that become fully incorporated in the brain’s sensory and motor circuitry could allow the devices to be integrated into the brain’s internal image of the body. …Read more
Aug. 21, 2013 — Every year, 15 to 20 people in Switzerland lose a hand in an accident. Provided suitable preconditions are met, a hand transplant is the best treatment method, particularly for patients who have lost both hands. The main problem with this treatment is that patients have to be immunosuppressed, i.e. their total immune system has to be brought down with drugs to prevent their organism rejecting the foreign tissue. This treatment is associated with undesirable side effects and impairments to the quality of life. Until now though, patients have had no other option.Share This:In laboratory experiments on rats, it has now been possible to replace systemic (total) immunosuppression with a local treatment of the transplanted limb. This has been successfully achieved by a research team from the Department of Plastic and Hand Surgery, Inselspital, and the Department of Clinical Research (DKF) of the University of Bern under the direction of scientist Dr Thusitha Gajanayake from Sri Lanka. Professor Robert Rieben from the DKF, Head of Research in hand transplantation: “The results are very promising. Just a single treatment results in the complete prevention of a rejection reaction.” Professor Esther Vögelin, Senior Consultant and Co-Director of the Department of Plastic and Hand Surgery: “This laboratory success means that in future hand transplant patients can hope for a significant improvement in quality of life, because systemic immunosuppression could be reduced or omitted altogether.The Bern research team is now working with great zeal towards its long-term goal of performing a hand transplant in Switzerland. …Read more
Aug. 12, 2013 — Researchers at the University of Rochester have measured for the first time light emitted by photoluminescence from a nanodiamond levitating in free space. In a paper published this week in Optics Letters, they describe how they used a laser to trap nanodiamonds in space, and — using another laser — caused the diamonds to emit light at given frequencies.The experiment, led by Nick Vamivakas, an assistant professor of optics, demonstrates that it is possible to levitate diamonds as small as 100 nanometers (approximately one-thousandth the diameter of a human hair) in free space, by using a technique known as laser trapping.”Now that we have shown we can levitate nanodiamonds and measure photoluminescence from defects inside the diamonds, we can start considering systems that could have applications in the field of quantum information and computing,” said Vamivakas. He said an example of such a system would be an optomechanical resonator.Vamivakas explained that optomechanical resonators are structures in which the vibrations of the system, in this case the trapped nanodiamond, can be controlled by light. “We are yet to explore this, but in theory we could encode information in the vibrations of the diamonds and extract it using the light they emit.”Possible avenues of interest in the long-term with these nano-optomechanical resonators include the creation of what are known as Schrödinger Cat states (macroscopic, or large-scale, systems that are in two quantum states at once). These resonators could also be used as extremely sensitive sensors of forces — for example, to measure tiny displacements in the positions of metal plates or mirrors in configurations used in microchips and understand friction better on the nanoscale.”Levitating particles such as these could have advantages over other optomechanical oscillators that exist, as they are not attached to any large structures,” Vamivakas explained. “This would mean they are easier to keep cool and it is expected that fragile quantum coherence, essential for these systems to work, will last sufficiently long for experiments to be performed.”The future experiments that Vamivakas and his team are planning build on previous work at Rochester by Lukas Novotny, a co-author of the paper and now at ETH in Zurich, Switzerland. Novotny and his group showed previously that by tweaking the trapping laser’s properties, a particle can be pushed towards its quantum ground state. By linking the laser cooling of the crystal resonator with the spin of the internal defect it should be possible to monitor the changes in spin configuration of the internal defect — these changes are called Bohr spin quantum jumps — via the mechanical resonator’s vibrations. Vamivakas explained that experiments like this would expand what we know about the classical-quantum boundary and address fundamental physics questions.The light emitted by the nanodiamonds is due to photoluminescence. …Read more
July 30, 2013 — Researchers from the Center for Neuroprosthetics at the Swiss Federal Institute of Technology (EPFL), Switzerland, show that people can be “tricked” into feeling that an image of a human figure — an “avatar” — is their own body. The study is published in the open-access journal Frontiers in Behavioral Neuroscience.Twenty-two volunteers underwent a Full Body Illusion when they were stroked with a robotic device system while they watched an avatar being stroked in the same spot. The study is the first to demonstrate that Full Body Illusions can be accompanied by changes in body temperature.Participants wore a 3D high-resolution head-mounted display to view the avatar from behind. They were then subjected to 40 seconds of stroking by a robot, on either their left or right back or on their left or right leg. Meanwhile, they were shown a red dot that moved synchronously on the same regions of the avatar (see image).After the stroking, the participants were prompted to imagine dropping a ball and to signal the moment when they felt that the ball would hit the floor. This allowed the researchers to objectively measure where the participants perceived their body to be.The volunteers were asked questions about how much they identified with the avatar and where they felt the stroking originated from. Furthermore, to test for physiological changes during the illusion, the participants’ skin temperature was measured on four locations on the back and legs across 20 time points.Results showed that stroking the same body part simultaneously on the real body and the avatar induced a Full Body Illusion. The volunteers were confused as to where their body was and they partly identified with the avatar. More than 70% of participants felt that the touch they had felt on their body was derived from the stroking seen on the avatar.Data revealed a continuous widespread decrease in skin temperature that was not specific to the site of measurement and showed similar effects in all locations. The changes in body temperature “were highly significant, but very small,” write the authors in the study, adding that the decrease was in the range of 0.006-0.014 degrees Celsius.The recorded temperature change was smaller than an earlier study found (0.24 degrees Celsius) that looked at fluctuations during rubber hand illusion, probably because the latter used a hand-held thermometer over longer periods and different regions of the body, the authors explain.”When the brain is confronted with a multisensory conflict, such as that produced by the Full Body Illusion, the way we perceive our real body changes. …Read more
July 26, 2013 — A 30 million year-old fossil has revealed how remoras — also called sharksuckers — evolved the sucker that enables them to stick to other fishes and ‘hitch a ride’.Previous evidence, such as the segmented structure of the sucker and how it develops in a similar way to fins in normal fish, led scientists to believe that it must be a modified dorsal fin — the fin located on the back of normal fishes. But the evolutionary steps that led from fin to sucker were a mystery.Now a team led by scientists from Oxford University and London’s Natural History Museum has studied an early fossil remora and found that it evolved a fully-functioning sucker — ‘adhesion disc’ — on its back. It was only later in the evolutionary history of remoras that the sucker migrated to the top of the head where it is found in all remoras alive today.A report of the research is published in the journal Proceedings of the Royal Society B.’The remora sucker is a truly amazing anatomical specialisation but, strange as it may seem, it evolved from a spiny fin,’ said Dr Matt Friedman of Oxford University’s Department of Earth Sciences, lead author of the report. ‘In this fossil the fin is clearly modified as a disc but is found on the back of the fish. It enables us to say that first fin spines on the back broadened to form wide segments of a suction disc. After the disc evolved, it migrated to the skull, and it was there that individual segments became divided in two, the number of segments increased, and a row of spines were developed on the back of individual segments.’Modern remoras use their sucker to fasten themselves to hosts including whales, turtles, and sharks. The researchers have shown that the fossil remora (†Opisthomyzon), dating from the Oligocene period and unearthed in Switzerland, falls outside the branch on the evolutionary tree occupied by all living remoras. As such it preserves primitive aspects of the shape and construction of the adhesion disc not found in modern remoras, all of which share discs that are broadly similar in construction.’It’s exciting that fossil fish from the Natural History Museum were so crucial to this study, and shows the important value of our collections for scientific research,’ said Dr Zerina Johanson, palaeontologist at London’s Natural History Museum. ‘Following painstaking preparation by our fossil preparator, Mark Graham, we were able to clearly see several important features of the disc in the fossil, for example that it’s much shorter than the disc in living remoras, with fewer segments.”One of the remarkable things we’ve learned about modern fishes is that some creatures that look very different, for example pufferfishes and anglerfishes, are actually very closely related,’ said Dr Friedman. ‘It’s through fossils like this one, which preserve body plans and structures that have been pruned from the evolutionary tree by extinction, that we can unravel how they diverged from one another to assume the very different forms we see today.’Read more
July 19, 2013 — A discovery facilitated by Rice University’s contribution to the Large Hadron Collider (LHC) will impact scientists’ search for dark matter in the universe.CERN, the European Organization for Nuclear Research, announced in Switzerland this morning that researchers on two separate LHC experiments have succeeded in measuring “one of the rarest measurable processes in physics,” the decay of B-subscript-s mesons into two muons. The evidence, which scientists have been seeking for 25 years, matches predictions made using the Standard Model of Particle Physics.That match, with only a 1-in-100,000 chance of being caused by a statistical error, virtually eliminates any possibility that B-sub-s meson decay is related to interaction with particles predicted by dark matter theories, as some physicists have suspected.Papers with the results have been posted online and have been submitted to the journal Physical Review Letters.The Compact Muon Solenoid (CMS), an LHC component that played a role in last year’s discovery of the Higgs boson, is one of the two experiments that captured the new data. (The other is the LHCb experiment.) Rice scientists have spent decades designing components for the CMS and are now enjoying the chance to help analyze the results.”The particle itself was discovered quite some time ago, and that isn’t news,” said Rice physicist Paul Padley, a co-investigator on the CMS experiment and a co-author of the new paper along with nine of his Rice colleagues. “The news is that the Standard Model has predicted that this B-sub-s meson will decay to two muons very, very rarely, and that is what we’ve seen.”The CMS finds rare needles in very large haystacks of data when protons are smashed together at near-light speed in the world’s largest collider. Electronics invented at Rice help sort useful data about subparticles produced by the collisions from background noise.According to a statement by CERN, for every billion B-sub-smesons produced, only three or so are expected to decay into two muons, heavier cousins of the electron. That expectation is confirmed by the new data. Physicists look for results inconsistent with those predicted by the Standard Model to expand knowledge of the physical world — but that didn’t happen here.”It’s extremely rare that it should decay this way,” Padley said of the B-sub-s meson. “But there has been the possibility it could decay through new particles predicted by dark matter theories, such as supersymmetry. If it were decaying through supersymmetric or other new particles, then the prediction of how often this decay should happen would be wrong. And we’d get a different answer.”So the theoretical particle physics community has been extremely interested to see what the two-muon decay rate is for this type of meson,” Padley said. …Read more
July 12, 2013 — Scientists have created a virtual model of the brain that daydreams like humans do.Researchers created the computer model based on the dynamics of brain cells and the many connections those cells make with their neighbors and with cells in other brain regions. They hope the model will help them understand why certain portions of the brain work together when a person daydreams or is mentally idle. This, in turn, may one day help doctors better diagnose and treat brain injuries.”We can give our model lesions like those we see in stroke or brain cancer, disabling groups of virtual cells to see how brain function is affected,” said senior author Maurizio Corbetta, MD, the Norman J. Stupp Professor of Neurology at Washington University School of Medicine in St. Louis. “We can also test ways to push the patterns of activity back to normal.”The study is now available online in The Journal of Neuroscience.The model was developed and tested by scientists at Washington University School of Medicine in St. Louis, Universitat Pompeu Fabra in Barcelona, Spain, and several other European universities including ETH Zurich, Switzerland; University of Oxford, United Kingdom; Institute of Advanced Biomedical Technologies, Chieti, Italy; and University of Lausanne, Switzerland.Scientists first recognized in the late 1990s and early 2000s that the brain stays busy even when it’s not engaged in mental tasks. Researchers have identified several “resting state” brain networks, which are groups of different brain regions that have activity levels that rise and fall in sync when the brain is at rest. They have also linked disruptions in networks associated with brain injury and disease to cognitive problems in memory, attention, movement and speech.The new model was developed to help scientists learn how the brain’s anatomical structure contributes to the creation and maintenance of resting state networks. The researchers began with a process for simulating small groups of neurons, including factors that decrease or increase the likelihood that a group of cells will send a signal.”In a way, we treated small regions of the brain like cognitive units: not as individual cells but as groups of cells,” said Gustavo Deco, PhD, professor and head of the Computational Neuroscience Group in Barcelona. …Read more
May 14, 2013 — Microscopic algae that live within reef-forming corals scoop up available nitrogen, store the excess in crystal form, and slowly feed it to the coral as needed, according to a study published in mBio®, the online open-access journal of the American Society for Microbiology. Scientists have known for years that these symbiotic microorganisms serve up nitrogen to their coral hosts, but this new study sheds light on the dynamics of the process and reveals that the algae have the ability to store excess nitrogen, a capability that could help corals cope in their chronically low-nitrogen environment.
“It was a great surprise to find the nitrogen-rich crystals inside the algae,” says corresponding author Anders Meibom of the École Polytechnique Fédérale de Lausanne, Switzerland. “It all makes perfect sense now. The algae suck up the ammonium and nitrate like a sponge when the concentration of these molecules increases, then store this nitrogen as uric acid crystals for later use.”
Like all reef-forming corals, the species they studied, Pocillopora damicornis, is actually a symbiosis of two different organisms: the coral provides protection to a species of photosynthetic algae called dinoflagellates, which, in turn, provide sugars and nitrogen to the coral host. The symbiosis allows the coral to thrive in clear, tropical waters that are naturally nutrient-poor. In many places, however, coral reefs are suffering from an excess of nutrients – pollution from sewage and fertilizers that impacts the symbiotic relationship and the health of coral in unknown ways.
To better understand these exchanges of materials and to determine how an excess of nutrients might affect the balance, the researchers exposed pieces of coral to varying concentrations of isotopically-labeled nitrogen-rich compounds. Using the facilities at the Aquarium Tropicale Porte Dorée in Paris, France, the scientists applied a relatively new analytic technique called nano-scale secondary ion mass-spectrometry (NanoSIMS) to follow the path of the nitrogen. NanoSIMS enabled them to visualize and quantify the uptake, movement, and accumulation of this labeled nitrogen within the coral.
When supplied with nitrogen in the form of ammonium, nitrate or aspartic acid the dinoflagellates responded by rapidly storing the nitrogen as crystals of uric acid within its cells. But the dinoflagellates don’t hang onto the nitrogen for long. Starting at about six hours after exposure, the microbes begin translocating nitrogen-rich compounds to the coral host, where the nitrogen is used in specific cellular compartments all over the surface layers of the coral.
This storage and release process helps explain how these corals get through the ups and downs of nitrogen concentrations, says Meibom. “This gives the coral-algae symbiosis a very efficient way to deal with strong fluctuations in nitrogen availability,” writes Meibom. “When the nitrogen availability suddenly becomes high, the algae can take-up large amounts of nitrogen on a timescale of a few hours, store it into crystals inside the algae cells and then release this stored nitrogen for metabolic processes and growth when the nitrogen levels become normal again.”
To follow up on this work, Meibom says he and his colleagues are now studying how carbon-based nutrients are taken up and distributed in the same coral-algae symbiosis.Read more
May 29, 2013 — EPFL researchers have detected microplastic pollution in one of Western Europe’s largest lakes, Lake Geneva, in large enough quantities to raise concern. While studies in the ocean have shown that these small bits of plastic can be harmful to fish and birds that feed on plankton or other small waterborne organisms, the full extent of their consequences in lakes and rivers is only now being investigated.
The study, which is being extending under a mandate by the Swiss Federal Office for the Environment, was published in the latest issue of the journal Archives des Sciences.
“We were surprised to find such high concentrations of microplastics, especially in an environmentally aware country like Switzerland,” says first author Florian Faure from EPFL. Faure’s study focused on Lake Geneva, where both beaches and lake water were shown to contain significant amounts of microplastic contamination — pieces of plastic waste up to 5 mm in diameter. The study is one of the first of its kind to focus on a continental freshwater lake. And according to Faure, given the massive efforts put into protecting the lakes shores over the past decades, both on its French and the Swiss shores, the situation is likely to be representative of fresh water bodies around the world.
Microplastics in continental waters may be the main source of microplastic pollution in oceans, where huge hotspots containing high concentrations of these pollutants have formed. Scientists estimate that only around 20 percent of oceanic microplastics are dumped straight into the sea. The remaining 80 percent are estimated to originate from terrestrial sources, such as waste dumps, street litter, and sewage.
Microplastic pollution is also a strain to lake and river ecosystems, threatening the animals that inhabit these aquatic ecosystems both physically and chemically. When inadvertently swallowed by aquatic birds and fish, the tiny bits of plastic can wind up stuck in the animals’ intestines, where they obstruct their digestive tracts, or cause them to suffocate by blocking their airways. Ingested plastics may also leach toxic additives and other pollutants stuck to their surface into the animals that swallow them, such as bisphenol A (BPA) and phthalates, two carcinogenic agents used in transparent plastics, or other hydrophobic water pollutants, such as PCBs.
Like counting needles in a haystack
Florian Faure and his collaborators used a variety of approaches to quantify plastic and microplastic pollution in and around the lake, from combing beaches along Lake Geneva for plastic litter to dissecting animals, fishes (pikes, roaches and breams) and birds from the aquatic environment, and observing bird droppings around the lake.
To measure the concentration of microplastics in the water, Faure worked in collaboration with Oceaneye, a Geneva-based non-profit organization. Using an approach developed to study plastic pollution in the Mediterranean Sea, they pulled a manta trawl — a floating thin-meshed net — behind a boat in Lake Geneva to pick up any solid matter in the top layer of the water. The samples were then sorted out, dried and the solid compounds were analyzed for their composition.
“We found plastic in every sample we took from the beaches,” says Faure. Polystyrene beads were the most common culprits, but hard plastics, plastic membranes, and bits of fishing line were also widespread. In this preliminary study, the amount of debris caught in Lake Geneva using the manta trawl was comparable to measurements made in the Mediterranean Sea.
The scientists are now extending their focus to lakes and rivers across the country, backed by a mandate from the Swiss Federal Office for the Environment. According to the lab’s director, Luiz Felippe de Alencastro, this will involve studying microplastic pollution in lakes, rivers, and biota across the country, as well as the associated micropollutants, such as PCBs, which have already been found stuck on microplastics from Lake Geneva in significant concentrations.Read more