Education: States’ standardized tests have a negative impact on parents’ civic engagement

New research from a political scientist at the University of Massachusetts Amherst has found that parents of public school students in states with more extensive and stringent student assessment systems express lower trust in government, less confidence in government efficacy, and more negative views of their children’s schools, thereby threatening civic engagement and the potential for future education reform.In a study published by the journal Political Behavior, associate professor Jesse Rhodes merged data from an original survey of public school parents with quantitative measures of the scope and alignment of state standards, testing, and accountability policies, to determine whether and how education reforms influence the parents’ political attitudes and behaviors.He found that highly developed assessment policies alienate parents from government and discourage parental involvement in education, an effect he terms “demobilization.” Parental trust in government was 11 percent lower in states with the most extensive assessment policies, and parental assessments of government effectiveness were 15 percent lower, compared to states with less developed testing polices.Over the past decade, federal education policies such as No Child Left Behind and Race to the Top have led states to develop and adopt education reforms, including content standards specifying what children should know and be able to do, assessments measuring student progress toward those standards and systems of policies holding schools accountable for performance. As years have passed these policies have extended to a greater number of subjects and a wider range of education levels, but there is considerable state-by-state variation in the policies.While previous studies have examined how these policies affect student achievement, Rhodes’ research is the first to assess how they affect the citizenship practices of public school parents — a key education stakeholder.”Today, with trust in government near an all-time low, government’s authority to accomplish collective objectives is arguably at low ebb,” Rhodes writes in the study. “My findings indicate that standards-based reform policies may be further threatening the foundation of public support that government needs to function effectively.”In addition to their negative views of government, Rhodes also found that parents in states with more developed assessment systems were less likely to become engaged in some parental involvement behaviors, especially contacting teachers and participating in school fundraisers. The likelihood that parents would contact their children’s teachers was 17 percent lower in states with the most stringent testing policies, and the chance they would participate in school fundraisers was 28 percent lower. Parents residing in states with more developed assessment systems were more likely to attend their local school board meetings, but Rhodes argues that this involvement is stimulated by anger and dissatisfaction with the perceived negative consequences of state assessments.He argues that these policies tend to depress civic engagement among parents because they provide few opportunities for parental input and can introduce undesirable changes into schools.”My findings suggest that a major reassessment of standards, testing, and accountability policies is necessary,” Rhodes concludes. “At a minimum, standards-based reforms must be redesigned so that they engage parents more directly in the process of policy design and administration and allay parental concerns about counter-productive consequences. However, given the seriousness of the problems identified here, it is possible that an even more searching reevaluation of the standards-based agenda is necessary. Today, the question for policymakers and citizens is how to design education policies that advance the objective of high achievement for all students while strengthening the practice of citizenship for all adults.”Story Source:The above story is based on materials provided by University of Massachusetts Amherst. Note: Materials may be edited for content and length.

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A more potent greenhouse gas than carbon dioxide, methane emissions will leap as Earth warms

While carbon dioxide is typically painted as the bad boy of greenhouse gases, methane is roughly 30 times more potent as a heat-trapping gas. New research in the journal Nature indicates that for each degree that Earth’s temperature rises, the amount of methane entering the atmosphere from microorganisms dwelling in lake sediment and freshwater wetlands — the primary sources of the gas — will increase several times. As temperatures rise, the relative increase of methane emissions will outpace that of carbon dioxide from these sources, the researchers report.The findings condense the complex and varied process by which methane — currently the third most prevalent greenhouse gas after carbon dioxide and water vapor — enters the atmosphere into a measurement scientists can use, explained co-author Cristian Gudasz, a visiting postdoctoral research associate in Princeton’s Department of Ecology and Evolutionary Biology. In freshwater systems, methane is produced as microorganisms digest organic matter, a process known as “methanogenesis.” This process hinges on a slew of temperature, chemical, physical and ecological factors that can bedevil scientists working to model how Earth’s systems will contribute, and respond, to a hotter future.The researchers’ findings suggest that methane emissions from freshwater systems will likely rise with the global temperature, Gudasz said. But to not know the extent of methane contribution from such a widely dispersed ecosystem that includes lakes, swamps, marshes and rice paddies leaves a glaring hole in climate projections.”The freshwater systems we talk about in our paper are an important component to the climate system,” Gudasz said. “There is more and more evidence that they have a contribution to the methane emissions. Methane produced from natural or humanmade freshwater systems will increase with temperature.”To provide a simple and accurate way for climate modelers to account for methanogenesis, Gudasz and his co-authors analyzed nearly 1,600 measurements of temperature and methane emissions from 127 freshwater ecosystems across the globe.The researchers found that a common effect emerged from those studies: freshwater methane generation very much thrives on high temperatures. Methane emissions at 0 degrees Celsius would rise 57 times higher when the temperature reached 30 degrees Celsius, the researchers report. For those inclined to model it, the researchers’ results translated to a temperature dependence of 0.96 electron volts (eV), an indication of the temperature-sensitivity of the methane-emitting ecosystems.”We all want to make predictions about greenhouse gas emissions and their impact on global warming,” Gudasz said. “Looking across these scales and constraining them as we have in this paper will allow us to make better predictions.”Story Source:The above story is based on materials provided by Princeton University. …

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Zebrafish neurons may lead to understanding of birth defects like spina bifida

The zebrafish, a tropical freshwater fish similar to a minnow and native to the southeastern Himalayan region, is well established as a key tool for researchers studying human diseases, including brain disorders. Using zebrafish, scientists can determine how individual neurons develop, mature and support basic functions like breathing, swallowing and jaw movement. Researchers at the University of Missouri say that learning about neuronal development and maturation in zebrafish could lead to a better understanding of birth defects such as spina bifida in humans.”We are studying how neurons move to their final destinations,” said Anand Chandrasekhar, professor of biological sciences and a researcher in the Bond Life Sciences Center at MU. “It’s especially critical in the nervous system because these neurons are generating circuits similar to what you might see in computers. If those circuits don’t form properly, and if different types of neurons don’t end up in the right locations, the behavior and survival of the animal will be compromised.”The scientists studied zebrafish embryos, which are nearly transparent, making internal processes easy to observe. Using modified zebrafish expressing green fluorescent jellyfish protein, Chandrasekhar and his team were able to track neuronal migration.”This approach is used extensively to visualize a group of cells,” Chandrasekhar said. “In our study, clusters of green cells glowed and indicated where motor neurons were located in the brain. Some groupings are shaped like sausages while others are round, but each cluster of 50 to150 cells sends out signals to different groups of jaw muscles.”These motor neurons that Chandrasekhar studied are located in the hindbrain, which corresponds to the human brainstem and controls gill and jaw movement in these tiny fish. Genes controlling the development and organization of these neurons in zebrafish are functionally similar to genes in higher vertebrates including mammals.Chandrasekhar’s work contributes to a better understanding of how neuronal networks are organized and “wired” during development. These studies also may provide insight into birth defects like spina bifida, which affects 1 in every 2,000 births, according to the National Institutes of Health.”One of the hallmarks of spina bifida is an open neural tube in the spinal cord,” Chandrasekhar said. …

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Frequent school moves can increase the risk of psychotic symptoms in early adolescence

Researchers at Warwick Medical School have shown that frequently changing schools during childhood can increase the risk of psychotic symptoms in later years.The study, published in American Academy of Child and Adolescent Psychiatry, found that school mobility during childhood heightens the risk of developing psychotic-like symptoms in early adolescence by up to 60%.Suffering from psychotic-like symptoms at young age is strongly associated with mental health problems in adulthood, including psychotic disorders and suicide.Professor Swaran Singh, who led the study, explained, “Changing schools can be very stressful for students. Our study found that the process of moving schools may itself increase the risk of psychotic symptoms — independent of other factors. But additionally, being involved in bullying, sometimes as a consequence of repeated school moves, may exacerbate risk for the individual.”At the age of 12, participants in the study were interviewed to assess for the presence of psychotic-like symptoms including hallucinations, delusions and thought interference in the previous six months. Those that had moved school three or more times were found to be 60% more likely to display at least one definite psychotic symptom.The authors suggested that moving schools often may lead to feelings of low self-esteem and a sense of social defeat. This feeling of being excluded from the majority could also render physiological consequences leading to sensitisation of the mesolimbic dopamine system, heightening the risk of psychotic-like symptoms in vulnerable individuals.Dr Cath Winsper, Senior Research Fellow at Warwick Medical School and part of the study group said, “It’s clear that we need to keep school mobility in mind when clinically assessing young people with psychotic disorders. It should be explored as a matter of course as the impact can be both serious and potentially long lasting. Schools should develop strategies to help these students to establish themselves in their new environment.”Story Source:The above story is based on materials provided by University of Warwick. Note: Materials may be edited for content and length.

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Cosmic roadmap to galactic magnetic field revealed

Scientists on NASA’s Interstellar Boundary Explorer (IBEX) mission, including a team leader from the University of New Hampshire, report that recent, independent measurements have validated one of the mission’s signature findings — a mysterious “ribbon” of energy and particles at the edge of our solar system that appears to be a directional “roadmap in the sky” of the local interstellar magnetic field.Unknown until now, the direction of the galactic magnetic field may be a missing key to understanding how the heliosphere — the gigantic bubble that surrounds our solar system — is shaped by the interstellar magnetic field and how it thereby helps shield us from dangerous incoming galactic cosmic rays. “Using measurements of ultra-high energy cosmic rays on a global scale, we now have a completely different means of verifying that the field directions we derived from IBEX are consistent,” says Nathan Schwadron, lead scientist for the IBEX Science Operations Center at the UNH Institute for the Study of Earth, Oceans, and Space. Schwadron and IBEX colleagues published their findings online today in Science.Establishing a consistent local interstellar magnetic field direction using IBEX low-energy neutral atoms and galactic cosmic rays at ten orders of magnitude higher energy levels has wide-ranging implications for the structure of our heliosphere and is an important measurement to be making in tandem with the Voyager 1 spacecraft, which is in the process of passing beyond our heliosphere.”The cosmic ray data we used represent some of the highest energy radiation we can observe and are at the opposite end of the energy range compared to IBEX’s measurements,” says Schwadron. “That it’s revealing a consistent picture of our neighborhood in the galaxy with what IBEX has revealed gives us vastly more confidence that what we’re learning is correct.”How magnetic fields of galaxies order and direct galactic cosmic rays is a crucial component to understanding the environment of our galaxy, which in turn influences the environment of our entire solar system and our own environment here on Earth, including how that played into the evolution of life on our planet.Notes David McComas, principal investigator of the IBEX mission at Southwest Research Institute and coauthor on the Science Express paper, “We are discovering how the interstellar magnetic field shapes, deforms, and transforms our entire heliosphere.”To date, the only other direct information gathered from the heart of this complex boundary region is from NASA’s Voyager satellites. Voyager 1 entered the heliospheric boundary region in 2004, passing beyond what’s known as the termination shock where the solar wind abruptly slows. Voyager 1 is believed to have crossed into interstellar space in 2012.Interestingly, when scientists compared the IBEX and cosmic ray data with Voyager 1’s measurements, the Voyager 1 data provide a different direction for the magnetic fields just outside our heliosphere.That’s a puzzle but it doesn’t necessarily mean one set of data is wrong and one is right. Voyager 1 is taking measurements directly, gathering data at a specific time and place, while IBEX gathers information averaged over great distances — so there is room for discrepancy. Indeed, the very discrepancy can be used as a clue: understand why there’s a difference between the two measurements and gain new insight.”It’s a fascinating time,” says Schwadron. “Fifty years ago, we were making the first measurements of the solar wind and understanding the nature of what was just beyond near-Earth space. Now, a whole new realm of science is opening up as we try to understand the physics all the way outside the heliosphere.”Eberhard Mbius, UNH principal scientist for the IBEX-Lo instrument on board, is a coauthor on the Science paper along with colleagues from institutions around the country.Story Source:The above story is based on materials provided by University of New Hampshire. …

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Better broccoli, enhanced anti-cancer benefits with longer shelf life

While researching methods to increase the already well-recognized anti-cancer properties of broccoli, researchers at the University of Illinois also found a way to prolong the vegetable’s shelf life.And, according to the recently published study, the method is a natural and inexpensive way to produce broccoli that has even more health benefits and won’t spoil so quickly on your refrigerator shelf.Jack Juvik, a U of I crop sciences researcher, explained that the combined application of two compounds, both are natural products extracted from plants, increased the presence of cancer-fighting agents in broccoli while prolonging the post-harvest storage period.”We had figured out ways to increase the anti-cancer activity in broccoli, but the way we figured it out created a situation that would cause the product to deteriorate more rapidly after application,” Juvik said. “For fresh-market broccoli that you harvest, it’s not too big a deal, but many of these products have to be shipped, frozen, cut up, and put into other products. Usually the idea is to get it from the farm to at least the distributor (grocery store) within two to three days.”If we could figure out a way to prolong the appearance, taste, and flavor long after harvest and maintain the improved health-promoting properties, that’s always of great interest to growers,” he added.The researchers first used methyl jasmonate (MeJA), a non-toxic plant-signal compound (produced naturally in plants) to increase the broccoli’s anti-cancer potential, which they sprayed on the broccoli about four days before harvest. When applied, MeJA initiates a process of gene activity affiliated with the biosynthesis of glucosinolates (GS), which are compounds found in the tissue of broccoli and other brassica vegetables (such as cauliflower, cabbage, and kale).Glucosinolates have been identified as potent cancer-preventative agents because of their ability to induce detoxification enzymes, such as quinone reductase (QR), that detoxify and eliminate carcinogens from the human body.However, during this process, MeJA also signals a network of genes that lead to plant decay by inducing the release of ethylene, Juvik explained. “While we can use MeJA to turn on phytochemicals like the glucosinolates and dramatically increase the abundance of those helpful anti-cancer compounds, MeJA also reduces the shelf life after harvest,” he said.So the researchers tried using the recently developed compound 1-methylcyclopropene (1-MCP), which has been shown to interfere with receptor proteins in the plant that are receptor-sensitive to ethylene. They applied the compound after harvesting the same broccoli that had already been treated with MeJA before harvest.”Ethylene will move and bind to ethylene receptors and that binding process initiates decay. What this compound does is that it more competitively lands on the protein and binds to or pushes out ethylene,” Juvik explained. “It basically stops or dramatically slows down the decay associated with ethylene.”The combination is good,” he said.Like MeJA, 1-MCP is also a non-toxic compound naturally produced in plants, although Juvik said synthetic forms can be produced. He stressed that both the MeJA and 1-MCP treatments required very small amounts of the compounds.”It’s very cheap, and it’s about as toxic as salt. It takes very little to elevate all the desirable aspects. …

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Breast cancer survivors reap benefits of weight training, study finds

Tallahassee resident Jennie Simons couldn’t even reach over her head by the time she had finished her breast cancer treatment in 2008. She was a survivor, beating back a particularly aggressive case of breast cancer — first in 2000 and then again in 2008 when it recurred — but the chemotherapy left her body ravaged.She had 15 surgeries during the breast reconstruction process, plus additional surgeries on her spine and arms because the chemo had weakened her bones so much that they started chipping away.”I couldn’t reach over my head,” said Simons, 63. “I couldn’t reach my back to bathe it.”So, in 2010 when she heard about a new study at Florida State University that was working with postmenopausal breast cancer survivors by putting them on a weight training regime, she signed up.Said Simons: “At the end of six months, I was lifting a lot of weights. It helped me mentally and physically.”Through that study, researchers at Florida State University and other institutions found that if you put female breast cancer survivors on a weight training program and fed them prunes, they could at least maintain their current levels of muscle mass and bone density. The findings were published in Applied Physiology, Nutrition and Metabolism.”If we can prevent that decrease, that’s a step in the right direction, ” said Lynn Panton, associate professor of exercise science and a co-author of the study.Now, Panton and one of her doctoral students, Titch Madzima, are following up on that research, recruiting another group of women to participate in a study that involves personal training with Madzima and other graduate students twice per week, followed by consumption of a vanilla bean-flavored protein drink.Simons signed up again. So for the next three months, Madzima is taking her through leg presses, bicep curls, leg extensions and other exercises in a small laboratory on the FSU campus that is outfitted with a small gym. It’s a total body workout.Panton and Madzima are trying to find out if they tweak the approach from the first study if they can eventually reverse the effects of the chemotherapy and help women gain back some lost muscle mass and bone density.”If we can slow down that accelerated loss or reverse that process, hopefully we’ll improve the quality of life of the breast cancer survivor,” Madzima said.And while the ultimate goal is to find a solid program for breast cancer survivors to follow on a larger scale, the university researchers are also helping local women through the process of recovery.”Working with the ladies is amazing,” Panton said. “We almost become a family. We’ve done a number of parties, a potluck.”Study participant Nancy Van Wilder, who was diagnosed in 2009 right after her 50th birthday, said that cancer was a “kick in the butt” and having a support group from women who have gone through the same treatment and ultimate recovery is essential.Van Wilder said she participated in the original study in 2010 to get back into shape so she could run a 5K for breast cancer research. She wound up running nine races that year.Working out alongside the other women, plus Panton and her graduate students was key to that, she said. …

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Is an earthquake behind the Shroud of Turin image? Radiation from earthquake could have led to ‘wrong’ 1988 dating

Neutron radiation caused by 33 A.D. earthquake could have led to “wrong” 1988 radiocarbon dating of Shroud, suggest researchersAn earthquake in Old Jerusalem might be behind the famous image of the Shroud of Turin, says a group of researchers led by Alberto Carpinteri of the Politecnico di Torino in Italy in an article published in Springer’s journal Meccanica. They believe that neutron radiation caused by an earthquake could have induced the image of a crucified man — which many people believe to be that of Jesus — onto the length of linen cloth, and caused carbon-14 dating done on it in 1988 to be wrong.The Shroud has attracted widespread interest ever since Secondo Pia took the first photograph of it in 1898: about whether it is Jesus’ purported burial cloth, how old it might be, and how the image was created. According to radiocarbon dating done in 1988, the cloth was only 728 years old at the time. Other researchers have since suggested that the shroud is much older and that the dating process was incorrect because of neutron radiation — a process which is the result of nuclear fusion or nuclear fission during which free neutrons are released from atoms — and its interaction with the nuclei of other atoms to form new carbon isotopes.However, no plausible physical reason has yet been proposed to explain the origin of this neutron radiation. Now Carpinteri’s team, through mechanical and chemical experimentation, hypothesizes that high-frequency pressure waves generated in Earth’s crust during earthquakes are the source of such neutron emissions. This is based on their research into piezonuclear fission reactions, which are triggered when very brittle rock specimens are crushed under a press machine. In the process, neutrons are produced without gamma emissions. Analogously, the researchers theorize further that neutron flux increments, in correspondence to seismic activity, should be a result of the same reactions.The researchers therefore believe that neutron emission from a historical earthquake in 33 A.D. in Old Jerusalem, which measured 8.2 on the Richter Scale, could have been strong enough to cause neutron imaging through its interaction with nitrogen nuclei. …

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Ways to improve common furniture fire test

The bench-scale test widely used to evaluate whether a burning cigarette will ignite upholstered furniture may underestimate the tendency of component materials to smolder when these materials are used in sofas and chairs supported by springs or cloth, National Institute of Standards and Technology (NIST) and American University researchers report in a new study.The study comes as regulations and methods for evaluating the likelihood that soft-furniture materials will ignite are undergoing scrutiny. In November 2013, California removed an open-flame test from its furniture flammability testing law**-the de facto national standard since no national regulation currently exists-and now relies solely on the so-called cigarette-smoldering-ignition test.The new research identifies changes to this test that might make it more realistic-representative of a “near-worst-case scenario.” The modifications, the researchers write, would make the test more consistent and, therefore, more useful for identifying “upholstery materials most likely to prevent smoldering ignition.”In the same article, the research team reports guidelines for making a reproducible reference foam for furniture flammability testing-a challenging, longstanding priority of standards developers, regulators and fire researchers. Such a standardized foam would help in comparing flammability data from different laboratories.In the current setup for the test, two fabric-covered foam pieces are positioned like seat and back cushions on a small solid wood support structure. A lit standard reference cigarette (one certified by NIST to burn consistently***) is placed in the crevice formed by the two pieces. To pass, a fabric covering or barrier material under test must prevent the burning cigarette from igniting the underlying foam so that it does not smolder on its own, even after the cigarette self-extinguishes.The researchers found that directly placing the test samples on top of the wooden support impedes air flow and, as a consequence, inhibits smoldering. They point out that the arrangement is not representative of furniture with cushions that rest on air-permeable substrates such as springs or cloth, which allows air to circulate and promotes smoldering.The team introduced gaps between the foam samples and the underlying wood, permitting air flow. The adjustment increased-by up to threefold-the rate at which smoldering spread in the foam. It also generated significantly higher smoldering temperatures in the foam-as much as 400 degrees Celsius higher.”Because it inhibits air flow, the current test apparatus may diminish the propensity for smoldering ignition,” explains NIST’s Rick Davis. “Creating gaps to increase air flow, and the other modifications we are suggesting-especially adoption of a reference foam-will enable more consistent smoldering behavior and help to minimize other causes of inconsistent flammability test results.”Either overlooked or considered unavoidable, differences in foam samples can be a significant source of ambiguity in flammability test results. Whether a lit cigarette burning on, say, a fabric covering initiates self-sustained smoldering in the underlying foam depends on whether the heat produced exceeds the heat lost. …

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New microchip demonstrates how metastasis takes place

Nearly 70 percent of patients with advanced breast cancer experience skeletal metastasis, in which cancer cells migrate from a primary tumor into bone — a painful development that can cause fractures and spinal compression. While scientists are attempting to better understand metastasis in general, not much is known about how and why certain cancers spread to specific organs, such as bone, liver, and lungs.Now researchers from MIT, Italy, and South Korea have developed a three-dimensional microfluidic platform that mimics the spread of breast cancer cells into a bonelike environment.The microchip — slightly larger than a dime — contains several channels in which the researchers grew endothelial cells and bone cells to mimic a blood vessel and bone side-by-side. They then injected a highly metastatic line of breast cancer cells into the fabricated blood vessel.Twenty-four hours later, the team observed that twice as many cancer cells had made their way through the vessel wall and into the bonelike environment than had migrated into a simple collagen-gel matrix. Moreover, the cells that made it through the vessel lining and into the bonelike setting formed microclusters of up to 60 cancer cells by the experiment’s fifth day.”You can see how rapidly they are growing,” says Jessie Jeon, a graduate student in mechanical engineering. “We only waited until day five, but if we had gone longer, [the size of the clusters] would have been overwhelming.”The team also identified two molecules that appear to encourage cancer cells to metastasize: CXCL5, a protein ligand secreted by bone cells, and CXCR2, a receptor protein on cancer cells that binds to the ligand. The preliminary results suggest that these molecules may be potential targets to reduce the spread of cancer.Jeon says the experiments demonstrate that the microchip may be used in the future to test drugs that might stem metastasis, and also as a platform for studying cancer’s spread to other organs.She and her colleagues, including Roger Kamm, the Cecil and Ida Green Distinguished Professor of Mechanical and Biological Engineering at MIT, have outlined the results of their experiments in the journal Biomaterials.”Currently, we don’t understand why certain cancers preferentially metastasize to specific organs,” Kamm says. “An example is that breast cancer will form metastatic tumors in bone, but not, for example, muscle. Why is this, and what factors determine it? We can use our model system both to understand this selectivity, and also to screen for drugs that might prevent it.”Through a wall and into boneThe process by which cancer cells form secondary tumors requires the cells to first survive a journey through the circulatory system. These migrating cells attach to a blood vessel’s inner lining, and ultimately squeeze through to the surrounding tissue — a process called extravasation, which Kamm’s research group modeled last fall using a novel microfluidic platform.Now the group is looking to the next step in metastasis: the stage at which a cancer cell invades a specific organ. …

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False memories: The hidden side of our good memory

Justice blindly trusts human memory. Every year throughout the world hundreds of thousands of court cases are heard based solely on the testimony of somebody who swears that they are reproducing exactly an event that they witnessed in a more or less not too distant past. Nevertheless, various recent studies in cognitive neuroscience indicate both the strengths and weaknesses in this ability of recall of the human brain.Memory is a cognitive process which is intrinsically linked to language. One of the fundamental tasks that the brain carries out when undertaking a linguistic activity — holding a conversation, for example — is the semantic process.On carrying out this task, the brain compares the words it hears with those that it recalls from previous events, in order to recognise them and to unravel their meaning. This semantic process is a fundamental task for enabling the storing of memories in our brain, helping us to recognise words and to memorise names and episodes in our mind. However, as everyone knows, this is not a process that functions 100% perfectly at times; a lack of precision that, on occasions, gives rise to the creation of false memories.Two pieces of research, recently published by Kepa Paz-Alonso at the Basque Center on Cognition, Brain and Language (BCBL) in the Journal of International Neuropsychological Society and Schizophrenia Research scientific journals, have shown that this semantic process linked to the subsequent recognition of such words amongst children as well as amongst adult schizophrenics, is less efficient than that produced in a normal adult brain. Moreover, both studies have shown that children are less prone to producing this type of false memory in their brains, and something similar occurs in patients with schizophrenia.One of the reasons for this phenomenon is that children do not have this semantic process as automated and developed as adults. That is, the adult brain, after making the same connections over and over again between various zones of the brain concerned with memory, has mechanised the process of semantically linking new information for its storage. Nonetheless, according to the results of Mr. Paz-Alonso’s research, this process is more likely to generate false memories in the brain of an adult than in a child’s brain.According to the researcher, “in reality, the same processes that produce these “false memories” amongst healthy adults are also responsible for their having better memory. …

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New fruitfly sleep gene promotes the need to sleep

All creatures great and small, including fruitflies, need sleep. Researchers have surmised that sleep — in any species — is necessary for repairing proteins, consolidating memories, and removing wastes from cells. But, really, sleep is still a great mystery.The timing of when we sleep versus are awake is controlled by cells in tune with circadian rhythms of light and dark. Most of the molecular components of that internal clock have been worked out. On the other hand, how much we sleep is regulated by another process called sleep homeostasis, however little is known about its molecular basis.In a study published in eLIFE, Amita Sehgal, PhD, professor of Neuroscience at the Perelman School of Medicine, University of Pennsylvania, and colleagues, report a new protein involved in the homeostatic regulation of sleep in the fruitfly, Drosophila. Sehgal is also an investigator with the Howard Hughes Medical Institute (HHMI).The researchers conducted a screen of mutant flies to identify short-sleeping individuals and found one, which they dubbed redeye. These mutants show a severe reduction in the amount of time they slumber, sleeping only half as long as normal flies. While the redeye mutants were able to fall asleep, they would wake again in only a few minutes.The team found that the redeye gene encodes a subunit of the nicotinic acetylcholine receptor. This type of acetylcholine receptor consists of multiple protein subunits, which form an ion channel in the cell membrane, and, as the name implies, also binds to nicotine. Although acetylcholine signaling — and cigarette smoking — typically promote wakefulness, the particular subunit studied in the eLIFE paper is required for sleep in Drosophila.Levels of the redeye protein in the fly oscillate with the cycles of light and dark and peak at times of daily sleep. …

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Split decision: Stem cell signal linked with cancer growth

Researchers at the University of California, San Diego School of Medicine have identified a protein critical to hematopoietic stem cell function and blood formation. The finding has potential as a new target for treating leukemia because cancer stem cells rely upon the same protein to regulate and sustain their growth.Hematopoietic stem cells give rise to all other blood cells. Writing in the February 2, 2014 advance online issue of Nature Genetics, principal investigator Tannishtha Reya, PhD, professor in the Department of Pharmacology, and colleagues found that a protein called Lis1 fundamentally regulates asymmetric division of hematopoietic stem cells, assuring that the stem cells correctly differentiate to provide an adequate, sustained supply of new blood cells.Asymmetric division occurs when a stem cell divides into two daughter cells of unequal inheritance: One daughter differentiates into a permanently specialized cell type while the other remains undifferentiated and capable of further divisions.”This process is very important for the proper generation of all the cells needed for the development and function of many normal tissues,” said Reya. When cells divide, Lis1 controls orientation of the mitotic spindle, an apparatus of subcellular fibers that segregates chromosomes during cell division.”During division, the spindle is attached to a particular point on the cell membrane, which also determines the axis along which the cell will divide,” Reya said. “Because proteins are not evenly distributed throughout the cell, the axis of division, in turn, determines the types and amounts of proteins that get distributed to each daughter cell. By analogy, imagine the difference between cutting Earth along the equator versus halving it longitudinally. In each case, the countries that wind up in the two halves are different.”When researchers deleted Lis1 from mouse hematopoietic stem cells, differentiation was radically altered. Asymmetric division increased and accelerated differentiation, resulting in an oversupply of specialized cells and an ever-diminishing reserve of undifferentiated stem cells, which eventually resulted in a bloodless mouse.”What we found was that a large part of the defect in blood formation was due to a failure of stem cells to expand,” said Reya. “Instead of undergoing symmetric divisions to generate two stem cell daughters, they predominantly underwent asymmetric division to generate more specialized cells. As a result, the mice were unable to generate enough stem cells to sustain blood cell production.”The scientists next looked at how cancer stem cells in mice behaved when the Lis1 signaling pathway was blocked, discovering that they too lost the ability to renew and propagate. …

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Revealing how the brain recognizes speech sounds

UC San Francisco researchers are reporting a detailed account of how speech sounds are identified by the human brain, offering an unprecedented insight into the basis of human language. The finding, they said, may add to our understanding of language disorders, including dyslexia.Scientists have known for some time the location in the brain where speech sounds are interpreted, but little has been discovered about how this process works.Now, in Science Express (January 30th, 2014), the fast-tracked online version of the journal Science, the UCSF team reports that the brain does not respond to the individual sound segments known as phonemes — such as the b sound in “boy” — but is instead exquisitely tuned to detect simpler elements, which are known to linguists as “features.”This organization may give listeners an important advantage in interpreting speech, the researchers said, since the articulation of phonemes varies considerably across speakers, and even in individual speakers over time.The work may add to our understanding of reading disorders, in which printed words are imperfectly mapped onto speech sounds. But because speech and language are a defining human behavior, the findings are significant in their own right, said UCSF neurosurgeon and neuroscientist Edward F. Chang, MD, senior author of the new study.”This is a very intriguing glimpse into speech processing,” said Chang, associate professor of neurological surgery and physiology. “The brain regions where speech is processed in the brain had been identified, but no one has really known how that processing happens.”Although we usually find it effortless to understand other people when they speak, parsing the speech stream is an impressive perceptual feat. Speech is a highly complex and variable acoustic signal, and our ability to instantaneously break that signal down into individual phonemes and then build those segments back up into words, sentences and meaning is a remarkable capability.Because of this complexity, previous studies have analyzed brain responses to just a few natural or synthesized speech sounds, but the new research employed spoken natural sentences containing the complete inventory of phonemes in the English language.To capture the very rapid brain changes involved in processing speech, the UCSF scientists gathered their data from neural recording devices that were placed directly on the surface of the brains of six patients as part of their epilepsy surgery.The patients listened to a collection of 500 unique English sentences spoken by 400 different people while the researchers recorded from a brain area called the superior temporal gyrus (STG; also known as Wernicke’s area), which previous research has shown to be involved in speech perception. The utterances contained multiple instances of every English speech sound.Many researchers have presumed that brain cells in the STG would respond to phonemes. But the researchers found instead that regions of the STG are tuned to respond to even more elemental acoustic features that reference the particular way that speech sounds are generated from the vocal tract. “These regions are spread out over the STG,” said first author Nima Mesgarani, PhD, now an assistant professor of electrical engineering at Columbia University, who did the research as a postdoctoral fellow in Chang’s laboratory. “As a result, when we hear someone talk, different areas in the brain ‘light up’ as we hear the stream of different speech elements.””Features,” as linguists use the term, are distinctive acoustic signatures created when speakers move the lips, tongue or vocal cords. …

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Impaired cell division leads to neuronal disorder

Prof. Erich Nigg and his research group at the Biozentrum of the University of Basel have discovered an amino acid signal essential for error-free cell division. This signal regulates the number of centrosomes in the cell, and its absence results in the development of pathologically altered cells. Remarkably, such altered cells are found in people with a neurodevelopmental disorder, called autosomal recessive primary microcephaly. The results of these investigations have been published in the current issue of the US journal Current Biology.Normal separation of chromosomes (blue) with two centrosomes (red) in a bipolar spindel apparatus (green). Flawed separation of chromosomes (blue) with several centrosomes (red) in a multipolar spindel apparatus (green).Cell division is the basis of all life. Of central importance is the error-free segregation of genetic material, the chromosomes. A flawless division process is a prerequisite for the development of healthy, new cells, whilst errors in cell division can cause illnesses such as cancer. The centrosome, a tiny cell organelle, plays a decisive role in this process.Prof. Erich Nigg’s research group at the Biozentrum of the University of Basel has investigated an important step in cell division: the duplication of the centrosome and its role in the correct segregation of the chromosomes into two daughter cells. …

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Trick identified that aids viral infection

Scientists have identified a way some viruses protect themselves from the immune system’s efforts to stop infections, a finding that may make new approaches to treating viral infections possible.Viruses have well-known strategies for slipping past the immune system. These include faking or stealing a molecular identification badge that prevents a cell from recognizing a virus.Scientists at Washington University School of Medicine in St. Louis and elsewhere have found some viruses have another trick. They can block the immune system protein that checks for the identification badge.The blocking structure is called a stem-loop, found at the beginning of the virus’s genetic material. This is the first time scientists have found an immune-fighting mechanism built directly into the genetic material of a virus. They are looking for ways to disable it and searching for similar mechanisms that may be built into the genetic material of other disease-causing microorganisms.”When the stem-loop is in place and stable, it blocks a host cell immune protein that otherwise would bind to the virus and stop the infectious process,” said senior author Michael Diamond, MD, PhD, professor of medicine. “We found that changing a single letter of the virus’s genetic code can disable the stem-loop’s protective effects and allow the virus to be recognized by the host immune protein. We hope to find ways to weaken the stem-loop structure with drugs or other treatments, restoring the natural virus-fighting capabilities of the cell and stopping or slowing some viral infections.”Most life forms encode their genes in DNA. To use the instructions contained in DNA, though, cells have to translate them into a related genetic material, RNA, that can be read by a cell’s protein-making machinery.Some viruses encode their genes directly in RNA. Examples include West Nile virus and influenza virus, and the viruses that cause sudden acute respiratory syndrome (SARS), yellow fever and polio.When a virus infects a cell, it co-opts the cell’s protein-making machinery to make viral proteins. …

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How climate change affects microbial life below the seafloor

Oct. 22, 2013 — Traces of past microbial life in sediments off the coast of Peru document how the microbial ecosystem under the seafloor has responded to climate change over hundreds of thousands of years. For more than a decade scientists at the Max Planck Institute for Marine Microbiology and their colleagues at MARUM and the University of Aarhus have investigated microbial life from this habitat. This “Deep Biosphere,” reaching several hundred metres below the seafloor, is exclusively inhabited by microbes and is generally considered as stable.Nevertheless, only little is known about how this system developed over millennia and how this microbial life influences the cycling of carbon in the oceans. In a new study appearing in the Proceedings of the National Academy of Sciences (PNAS) Dr. Sergio Contreras, a palaeoceanographer, and his Bremen colleagues use a careful examination of drill-cores from the continental shelf of Peru to actually show how surprisingly dynamic this deeply buried ecosystem can be.Below the sea floor, consortia of two different domains of microorganisms (archaea and bacteria) tap the energy of methane, which they oxidize by using sulfate. This process is known as the anaerobic oxidation of methane (AOM) and has been intensively studied by Bremen researchers. Methane, also produced by archaea, emerges from deeper layers of the sediment, while sulfate diffuses slowly from the water column into the sediment. Both reactants meet at the so-called methane oxidation front. Only at this front are concentrations of sulfate and methane high enough for the microbial turnover to take place, and here the AOM process leaves behind mineral and biological fossil signatures. …

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‘Phenotype switching’ can make melanoma become metastatic, resistant to drugs

Oct. 18, 2013 — One of the challenges of understanding cancer is trying to determine the mechanisms that drive metastasis, or the process by which tumor cells are able to spread throughout the body. In order to investigate metastasis, researchers at The Wistar Institute focused on a process involving the phenotypes — the outward, physical appearance based on genetic coding — of tumor cells. According to the researchers, “phenotype switching” may be involved in changing appearance of melanoma tumors by altering the number and type of protein receptors that dot the surface of the individual melanoma cells within the tumor. Identifying the phenotype patients exhibit may help determine which patients are more likely to benefit from existing medications while also providing an opportunity to create new targeted therapies.The findings were published in the journal Cancer Discovery and are currently available online.”We were able to demonstrate for the first time that different receptors within a single signaling pathway — in this case, the Wnt signaling pathway — can guide the phenotypic plasticity of tumor cells, and increased signaling of Wnt5A in particular can result in an increase in highly invasive tumor cells that are less sensitive to existing treatments for metastatic melanoma,” said Ashani Weeraratna, Ph.D., assistant professor in the Tumor Microenvironment and Metastasis Program of Wistar’s NCI-designated Cancer Center, and senior corresponding author on the manuscript.While melanoma accounts for less than 5 percent of all cases of skin cancer, it is the deadliest form of the disease, resulting in a large majority of all the deaths related to skin cancer, according to the American Cancer Society. The five-year survival rate for patients with metastatic melanoma is between 15 and 20 percent, and while new, targeted therapies designed to combat the disease based on a person’s genetics have become available in recent years, some of these drugs are not particularly effective in many patients, and many who do respond well to the drugs often eventually become resistant to them. This makes understanding advanced stages of melanoma and what internal processes could be at work all the more important for developing new treatments.Weeraratna and her team focus on Wnt5A, a Wnt signaling molecule that has been found in increased levels in metastatic melanomas. In order for Wnt5A to promote the phenotype switch from early in the tumor’s formation to the time it becomes metastatic, the tyrosine kinase receptor ROR2 is required. When ROR2 is not present, Wnt5A is unable to promote tumor metastasis. The only other member of the family that has been identified is ROR1, and this research was done to determine what role ROR1 might play in the progression of melanoma.The researchers were able to determine that ROR1 inhibited the invasion of melanoma cells, and this receptor was targeted for degradation by Wnt5A and ROR2. …

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Seeking Legal Help, Part 2 of 2

On our blog last week, we looked at why mesothelioma victims sometimes turn to the legal system for help. But many mesothelioma victims are hesitant to take action, because they are unfamiliar with the legal process, and the prospect of dealing with a legal battle may seem insurmountable given their physical condition. In truth, the process is more simple than you may imagine.First, it is critical to select a lawyer carefully. Be sure that you understand who will actually be handling your case. Sometimes people hire a lawyer, not realizing that their case will be handed off to someone else. Finding this out after the contract is signed can be an unwelcome surprise at a difficult time.Be sure to inquire into the case history and …

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