19 research outputs found
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Alterations in sperm long RNA contribute to the epigenetic inheritance of the effects of postnatal trauma
Abstract: Psychiatric diseases have a strong heritable component known to not be restricted to DNA sequence-based genetic inheritance alone but to also involve epigenetic factors in germ cells. Initial evidence suggested that sperm RNA is causally linked to the transmission of symptoms induced by traumatic experiences. Here, we show that alterations in long RNA in sperm contribute to the inheritance of specific trauma symptoms. Injection of long RNA fraction from sperm of males exposed to postnatal trauma recapitulates the effects on food intake, glucose response to insulin and risk-taking in adulthood whereas the small RNA fraction alters body weight and behavioural despair. Alterations in long RNA are maintained after fertilization, suggesting a direct link between sperm and embryo RNA
Spin Injection and Detection in Magnetic Nanostructures
We study theoretically the spin transport in a nonmagnetic metal connected to
ferromagnetic injector and detector electrodes. We derive a general expression
for the spin accumulation signal which covers from the metallic to the
tunneling regime. This enables us to discuss recent controversy on spin
injection and detection experiments. Extending the result to a superconducting
device, we find that the spin accumulation signal is strongly enhanced by
opening of the superconducting gap since a gapped superconductor is a low
carrier system for spin transport but not for charge. The enhancement is also
expected in semiconductor devices.Comment: 4 pages, 3 figure
Spin injection and spin accumulation in all-metal mesoscopic spin valves
We study the electrical injection and detection of spin accumulation in
lateral ferromagnetic metal-nonmagnetic metal-ferromagnetic metal (F/N/F) spin
valve devices with transparent interfaces. Different ferromagnetic metals,
permalloy (Py), cobalt (Co) and nickel (Ni), are used as electrical spin
injectors and detectors. For the nonmagnetic metal both aluminium (Al) and
copper (Cu) are used. Our multi-terminal geometry allows us to experimentally
separate the spin valve effect from other magneto resistance signals such as
the anomalous magneto resistance (AMR) and Hall effects. We find that the AMR
contribution of the ferromagnetic contacts can dominate the amplitude of the
spin valve effect, making it impossible to observe the spin valve effect in a
'conventional' measurement geometry. In a 'non local' spin valve measurement we
are able to completely isolate the spin valve signal and observe clear spin
accumulation signals at T=4.2 K as well as at room temperature (RT). For
aluminum we obtain spin relaxation lengths (lambda_{sf}) of 1.2 mu m and 600 nm
at T=4.2 K and RT respectively, whereas for copper we obtain 1.0 mu m and 350
nm. The spin relaxation times tau_{sf} in Al and Cu are compared with theory
and results obtained from giant magneto resistance (GMR), conduction electron
spin resonance (CESR), anti-weak localization and superconducting tunneling
experiments. The spin valve signals generated by the Py electrodes (alpha_F
lambda_F=0.5 [1.2] nm at RT [T=4.2 K]) are larger than the Co electrodes
(alpha_F lambda_F=0.3 [0.7] nm at RT [T=4.2 K]), whereas for Ni (alpha_F
lambda_F<0.3 nm at RT and T=4.2 K) no spin signal is observed. These values are
compared to the results obtained from GMR experiments.Comment: 16 pages, 12 figures, submitted to PR
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Food Quality Protection Act launches search for pest management alternatives
Insecticides have long been important tools for California farmers to combat agricultural pests. By 1995, organophosphate (OP) insecticides such as chlorpyrifos, azinphos-methyl, methamidophos, phosmet and diazinon accounted for an estimated 34% of worldwide insecticide sales, and they are widely credited with allowing large yield increases in commercial agriculture. The U.S. Food Quality Protection Act (FQPA), signed into law in 1996, established a new human health–based standard that “reasonable certainty of no harm will result from aggregate exposure to the pesticide chemical residue.” When the FQPA was passed, 49 OP pesticides were registered for use in pest control in the United States; since then, many uses have been canceled and others are expected to be lost, with particular significance for California growers. A number of alternative pest-control products and strategies are available, with varying degrees of effectiveness and cost. Research and development of control measures to replace OP insecticides must be pursued to maintain an economically viable state agricultural industry
Can static foot posture measurements predict regional plantar surface area?
Background: The intent of this study was to determine if the use of a single or combination of static foot posture measurements can be used to predict rearfoot, midfoot, and forefoot plantar surface area in individuals with pronated or normal foot types. Methods: Twelve foot measurements were collected on 52 individuals (mean age 25.8 years) with the change in midfoot width used to place subjects in a pronated or normal foot mobility group. Dynamic plantar contact area was collected during walking with a pressure sensor platform. The 12 measures were entered into a stepwise regression analysis to determine the optimal set of measures associated with regional plantar surface area. Results: A two variable model was found to describe the relationship between the foot measurements and forefoot plantar contact area (r2=0.79, p\u3c0.0001). A four variable model was found to describe the relationship between the foot measurements and midfoot plantar contact area (r2=0.85, p\u3c0.0001) in those individuals with a 1.26cm or greater change in midfoot width. Conclusions: The results indicate that clinicians can use a combination of simple, reliable and time efficient foot measures to explain 79% and 85% of the plantar surface area in the forefoot and midfoot, respectively
Alterations in sperm long RNA contribute to the epigenetic inheritance of the effects of postnatal trauma
Psychiatric diseases have a strong heritable component known to not be restricted to DNA sequence-based genetic inheritance alone but to also involve epigenetic factors in germ cells. Initial evidence suggested that sperm RNA is causally linked to the transmission of symptoms induced by traumatic experiences. Here, we show that alterations in long RNA in sperm contribute to the inheritance of specific trauma symptoms. Injection of long RNA fraction from sperm of males exposed to postnatal trauma recapitulates the effects on food intake, glucose response to insulin and risk-taking in adulthood whereas the small RNA fraction alters body weight and behavioural despair. Alterations in long RNA are maintained after fertilization, suggesting a direct link between sperm and embryo RNA