Using a single molecule to create a new magnetic field sensor

 

Fri, 01/30/2015 - 9:16am Univ. of Liverpool   Scanning tunneling microscope (STM) image of iron phtalocyanine.Researchers at the Univ. of Liverpool and Univ. College London (UCL) have shown a new way to use a single molecule as a magnetic field sensor. In a study, published in Nature Nanotechnology, the team shows how magnetism can manipulate the way electricity flows through a single molecule, a key step that could enable the development of magnetic field sensors for hard drives that are a tiny fraction of their present size. In hard drives, magnetized areas on spinning disks are used to store information. As the magnetized areas pass a magnetic sensor, they trigger fluctuations in electric current flowing through the sensor, allowing the data to be read. Making these areas smaller increases a hard drive's storage capacity without making it bigger, but also requires a smaller sensor. Fadi El Hallak, a researcher at UCL who conceived of the study and now works for Seagate Technology, said: "Making smaller sensors isn't trivial. It is difficult to use magnetism to control the current flowing through objects the size of single molecules because the response to changes in the magnetic field is often very weak." To get around this problem, the researchers developed a method of magnifying the effect of the magnetism on the flow of current in the detector. Mechanical tunneling First, they created a junction in which a single magnetic molecule was weakly coupled to two metallic leads. The barriers between the molecule and the nearby metals were high enough that electrical charge in the metals could not flow over the barriers. However, a small fraction of the electrons can effectively go through the barriers by undergoing quantum mechanical tunneling, which enables a tiny current to flow through the molecule when a voltage is applied across it. The scientists configured the junction so that the molecule was much more strongly connected to one metal lead than the other. The effect of the magnetic field on the tunneling current is then leveraged and greatly enhanced. Dr. Mats Persson, from the Univ. of Liverpool's Dept. of Chemistry, said: "This research demonstrates a new kind of single molecule sensor for magnetic fields, which is promising for creating new computer technologies." Source: Univ. of Liverpool

DNA nanoswitches reveal how life’s molecules connect

 

Fri, 01/30/2015 - 8:17am Kat J. McAlpine, Wyss Institute for Biologically Inspired Engineering Gel electrophoresis, a common laboratory process, sorts DNA or other small proteins by size and shape using electrical currents to move molecules through small pores in gel. The process can be combined with novel DNA nanoswitches, developed by Wyss Associate Faculty member Wesley Wong, to allow for the simple and inexpensive investigation of life's most powerful molecular interactions. Image: Wyss Institute at Harvard Univ. A complex interplay of molecular components governs almost all aspects of biological sciences—healthy organism development, disease progression and drug efficacy are all dependent on the way life's molecules interact in the body. Understanding these biomolecular interactions is critical for the discovery of new, more effective therapeutics and diagnostics to treat cancer and other diseases, but currently requires scientists to have access to expensive and elaborate laboratory equipment. Now, a new approach developed by researchers at the Wyss Institute for Biologically Inspired Engineering, Boston Children's Hospital and Harvard Medical School promises a much faster and more affordable way to examine biomolecular behavior, opening the door for scientists in virtually any laboratory world–wide to join the quest for creating better drugs. The findings are published in Nature Methods. "Biomolecular interaction analysis, a cornerstone of biomedical research, is traditionally accomplished using equipment that can cost hundreds of thousands of dollars," said Wyss Associate Faculty member Wesley P. Wong, PhD, senior author of study. "Rather than develop a new instrument, we've created a nanoscale tool made from strands of DNA that can detect and report how molecules behave, enabling biological measurements to be made by almost anyone, using only common and inexpensive laboratory reagents." Wong, who is also assistant professor at Harvard Medical School in the Depts. of Biological Chemistry & Molecular Pharmacology and Pediatrics and Investigator at the Program in Cellular and Molecular Medicine at Boston Children's Hospital, calls the new tools DNA "nanoswitches". Nanoswitches comprise strands of DNA onto which molecules of interest can be strategically attached at various locations along the strand. Interactions between these molecules, such as successful binding of a drug compound with its intended target, such as a protein receptor on a cancer cell, cause the shape of the DNA strand to change from an open and linear shape to a closed loop. Wong and his team can easily separate and measure the ratio of open DNA nanoswitches vs. their closed counterparts through gel electrophoresis, a simple lab procedure already in use in most laboratories, that uses electrical currents to push DNA strands through small pores in a gel, sorting them based on their shape. "Our DNA nanoswitches dramatically lower barriers to making traditionally complex measurements," said co–first author Ken Halvorsen, formerly of the Wyss Institute and currently a scientist at the RNA Institute at Univ. of Albany. "All of these supplies are commonly available and the experiments can be performed for pennies per sample, which is a staggering comparison to the cost of conventional equipment used to test biomolecular interactions." To encourage adoption of this method, Wong and his team are offering free materials to colleagues who would like to try using their DNA nanoswitches. "We've not only created starter kits but have outlined a step–by–step protocol to allow others to immediately implement this method for research in their own labs, or classrooms," said co–first author Mounir Koussa, a graduate candidate in neurobiology at Harvard Medical School. "Wesley and his team are committed to making an impact on the way bio–molecular research is done at a fundamental level, as is evidenced by their efforts to make this technology accessible to labs everywhere," said Wyss Institute Founding Director Donald Ingber, MD, PhD, who is also the Judah Folkman Professor of Vascular Biology at Boston Children's Hospital and Harvard Medical School and a Professor of Bioengineering at Harvard SEAS. "Biomedical researchers all over the world can start using this new method right away to investigate how biological compounds interact with their targets, using commonly available supplies at very low cost." Source: Wyss Institute for Biologically Inspired Engineering at Harvard Univ.

Objetos comuns fotografados em superzoom revelam um novo universo de detalhes

 

Objetos fotografados em Super-Zoom

 

Fonte : Gizmodo Brasil

OpenBiome will pay for poo

 

If you think your better half buys a lot of crap, then you might want to consider OpenBiome before starting on the criticism. The American non-profit is paying donors dollars for their doo-doo in an effort to gather more materials for fecal microbiota transplants (FMTs), a relatively new, but 90 percent effective, treatment for the debilitating Clostridium difficile infection (CDI). Clostridium difficile (C.difficile) are a bacteria found in the soil, air, water, and human and animal feces. Although many can carry the bacteria and suffer no ill effects, others will experience severe diarrhea, abdominal pain and fever. More extreme cases can require hospitalization and perhaps even lead to death. OpenBiome claims that between 14,000 and 30,000 deaths are estimated to be caused by CDI each year in the US alone. While healthy people are unlikely to develop CDI, those taking antibiotics are at higher risk of picking up cases of C.difficile from infected surfaces. This is because antibiotics kill good as well as bad bacteria in the gastrointestinal tract, providing a site for the bacteria to gain a foothold. According to the Mayo Clinic, the number of cases have increased rapidly over the past two decades, with the elderly who take antibiotics being particularly prone. Though ceasing the antibiotic used to treat the primary infection will generally be effective on treating mild CDI cases, more targeted antibiotic treatment is the standard procedure for more serious cases. However, the Centers for Disease Control now says that fecal transplants appear to be the most effective method for helping patients with repeat C. difficile infections. The US Food and Drug Administration has also classified FTM as an "investigational drug" and since the middle of 2013 it has allowed doctors to treat patients with C.difficile without their having to make the usual Investigational New Drug application. The problem, however, is that even as acceptance for fecal transplants grows – the Mayo Clinic began performing them in 2011 – the amount of fecal matter available does not. Typically it is close relations who provide the material. The OpenBiome team says they founded their non-profit, “after watching a friend and family member suffer through 18 months of C. difficile and 7 rounds of vancomycin before finally receiving a successful, life-changing Fecal Microbiota Transplantation (FMT)." After seeing the difficulty of securing the treatment first hand, they realized that expanded access was key. We have written about less-traditional uses of FMT before, though in the case of Dr Jeff Leach he was researching gut bacteria and the hunter-gatherer diet, rather than treating a stubborn case of C.difficile. But why does this work? The importance lies in gut flora and healthy gut bacteria. Scientists and medical professionals are beginning to understand that the key to many diseases and even allergies may lie in what lives in people’s guts. In fact, "hereditary gut bacteria" may play a role even in obesity, with researchers at Kings College London and Cornell University examining the potential of probiotic treatments for the obese. FMT involves introducing the stool containing microbes that include bacteria, fungi and viruses from a healthy donor into the gut of the person suffering a C. difficile infection. This is performed more or less in the way one would (or try not to) imagine: via colonoscopic or nasogastric administration – the latter refers to a tube inserted into the nose or mouth and down the throat. OpenBiome is seeking healthy donors who will be are financially remunerated at US$40 per sample, with those donating five times each week pocketing an extra $50. However, all donations must be done on-site at their Massachusetts suite and all donors go through a lengthy screening process and are rescreened each 60 days. Donors can also win prizes for the "biggest single donation of the month" or the most donations. According to the non-profit, less than 20 percent of people screened go on to become donors. For those on the receiving end, as a non-profit, the company charges $250 per treatment to cover its costs. Synthetic stool For those worried about what Scientific American termed the "ick factor" surrounding FMT, a synthetic stool sample, called "rePOOPulate," was developed last year for the treatment of C. difficile with the results published in the journal Microbiome in 2013. "Patient concerns" is the way both the rePOOPulate developers and those at OpenBiome describe said “ick” factor inherent in discussions of FMT. OpenBiome is also working to develop a synthetic alternative, partnering with Assembly Biosciences in researching and product supply. “[We] believe that supporting these research efforts will be critical to improving treatment options," says the company.   Source: OpenBiome

New Portable Vacuum Standard

 

January 23, 2015 Contact: Jacob Ricker (301) 975-4475 The PVS is housed within the white “igloo” enclosure at left. At right is an auxiliary vacuum system used for pressure calibrations. A novel Portable Vacuum Standard (PVS) has been added to the roster of NIST’s Standard Reference Instruments (SRI). It is now available for purchase as part of NIST’s ongoing commitment to disseminate measurement standards and thereby reduce the need for the expensive and time-consuming process of transporting customer instruments to NIST for calibration. The PVS is a compact, high-accuracy, low-pressure/vacuum laboratory standard that is calibrated directly against the primary standard at NIST. It enables high-precision calibrations, measurements, or inter-laboratory comparisons (ILC) at a customer’s facility. It can be used as a direct replacement for a commercial mercury manometer, while offering similar or better uncertainties and lower cost of ownership. The PVS package is also more rugged and does not contain mercury – a significant safety issue for the common high-accuracy manometers that it replaces. Many customers do not have the technical expertise to build their own standards or only need a standard for a short period of time, such as during an ILC. For about $100,000 per unit (depending on specifications and configuration), the PVS can meet those needs. NIST will provide the relevant calibration reports and method for analyzing the measurements. The latest version of the standard, which has been under development for more than a decade by scientists in NIST's Thermodynamic Metrology Group, enables pressure measurements from 1 Pa to 130,000 Pa. (Air pressure at sea level is about 101,325 Pa.) It is possible to extend the instrument’s range to 370,000 Pa as needed. The PVS combines two different kinds of low-pressure sensors enclosed in an insulated container the size of a suitcase that maintains a constant internal temperature to within 5 mK. The first is a resonance silicon gauge (RSG) that monitors two capacitance diaphragm gauges (CDGs). RSGs are microelectromechanical systems (MEMS) that measure the effect of pressure- induced strain on the resonant frequency of a silicon oscillator. CDGs measure pressure-induced changes in the position of an alloy diaphragm that serves as one plate of a capacitor, and are the workhorse sensors for most high-precision vacuum operations. Combining the two, says project scientist Jay Hendricks, brings unique benefits: "CDGs have extremely fine resolution at low pressure. RSGs have outstanding long-term drift stability—in the range of 0.01%, which is a factor of 10 better than the CDGs. So to get the best of both, we use an RSG to calibrate the CDGs.” Contact: Jacob Ricker, (301) 975-4475. Any mention or image of commercial products within NIST web pages is for information only; it does not imply recommendation or endorsement by NIST.

Potential new drug for lung cancer

 

Potential new drug target for lung cancer

Neutron beams reveal how two potential pieces of Parkinson’s puzzle fit

 

Thu, 01/29/2015 - 11:44am Chad Boutin, NIST The proteins GCase (in pink) and α-syn (blue) forms a complex in cellular membrane. Neutron reflectometry (suggested by the yellow beam) revealed the structure of the complex. α-Syn shifts GCase slightly away from membrane, possibly contributing to effects related to Parkinson’s disease. Image: Alan Hoofring/NIH Medical ArtsTo understand diseases like Parkinson’s, the tiniest of puzzles may hold big answers. That’s why a team including scientists from NIST have determined how two potentially key pieces of the Parkinson’s puzzle fit together, in an effort to reveal how the still poorly understood illness develops and affects its victims. This puzzle is a tough one because its pieces are not only microscopic but 3-D, and can even change shape. The pieces are protein molecules whose lengthy names are abbreviated as GCase and α-syn. The two proteins wrap around each other and take on a complicated shape before attaching themselves to the membrane surface inside a neural cell in a victim’s brain.  While much remains unknown about Parkinson’s, clues abound that the proteins’ behavior is somehow important. Parkinson’s victims have a buildup of α-syn in their cells, a possible factor in the dementia that the disease often brings. They also are far more likely to have a mutation in the gene that instructs cells to create GCase. Low levels of GCase cause another disease, Gaucher, and in some individuals suffering from both Parkinson’s and Gaucher simultaneously, Parkinson’s may appear at a younger age.  To get a better handle on how these proteins operate in the body, the team—which also included scientists from the National Institutes of Health (NIH) and Carnegie Mellon Univ.—came to the NIST Center for Neutron Research (NCNR) to get a picture of how the two proteins combine into a single unit called a complex that interacts with cell membranes. Using techniques including neutron reflectometry, the team teased out the first-ever structural picture of the GCase/α-syn complex, including their shape change, which NIH’s Jennifer Lee says would not have been detectable by any other methods.  “It gives us a potential interaction model of the two and structural insights in how α-syn may interfere with activity on a cell membrane,” Lee says. “An equally important contribution here is that this is the first, I believe, to look at complex formation at the membrane interface using neutron science.”  The study still leaves many mysteries about the complex—notably how it attaches to and interacts with the membrane inside a part of the cell called the lysosome where α-syn is broken-down. The team plans to follow up with additional investigations, especially once an improved reflectometer that could offer greater resolution arrives at the NCNR in about 2017. Meanwhile, the results of the current study—and the tools that provided them—will give the team other options to explore.  “It lays the groundwork for exploring the complex relationship between proteins that are involved in the causes of disease,” Lee says. “This will also offer a way for us to investigate other substances that would affect the interaction.” Source: NIST

10 cool Psychology Jobs

 

10 Psychology Jobs

Psychological disorders

 

List of psychological disorders

Extreme oxygen loss in oceans accompanied past global climate change

 

Thu, 01/29/2015 - 11:58am Kat Kerlin, UC Davis News Service Seafloor sediment cores reveal abrupt, extensive loss of oxygen in the ocean when ice sheets melted roughly 10,000 to 17,000 years ago, according to a study from the Univ. of California, Davis. The findings provide insight into similar changes observed in the ocean today. In the study, published in PLOS ONE, researchers analyzed marine sediment cores from different world regions to document the extent to which low oxygen zones in the ocean have expanded in the past, due to climate change. From the subarctic Pacific to the Chilean margins, they found evidence of extreme oxygen loss stretching from the upper ocean to about 3,000 m deep. In some oceanic regions, such loss took place over a time period of 100 years or less. “This is a global story that knits these regions together and shows that when you warm the planet rapidly, whole ocean basins can lose oxygen very abruptly and very extensively,” said lead author Sarah Moffitt, a postdoctoral scholar with the UC Davis Bodega Marine Laboratory and formerly a graduate student with the Graduate Group in Ecology.  Marine organisms, from salmon and sardines to crab and oysters, depend on oxygen to exist. Adapting to an ocean environment with rapidly dropping oxygen levels would require a major reorganization of living things and their habitats, much as today polar species on land are retreating to higher, cooler latitudes. The researchers chose the deglaciation period because it was a time of rising global temperatures, atmospheric carbon dioxide and sea levels—many of the global climate change signs the Earth is experiencing now. “Our modern ocean is moving into a state that has no precedent in human history,” Moffitt said. “The potential for our oceans to look very, very different in 100 to 150 years is real. How do you use the best available science to care for these critical resources in the future? Resource managers and conservationists can use science like this to guide a thoughtful, precautionary approach to environmental management.” Source: Univ. of California, Davis