9,235 research outputs found
Graphene Spin Transistor
Graphitic nanostructures, e.g. carbon nanotubes (CNT) and graphene, have been
proposed as ideal materials for spin conduction[1-7]; they have long electronic
mean free paths[8] and small spin-orbit coupling[9], hence are expected to have
very long spin-scattering times. In addition, spin injection and detection in
graphene opens new opportunities to study exotic electronic states such as the
quantum Hall[10,11] and quantum spin Hall[9] states, and spin-polarized edge
states[12] in graphene ribbons. Here we perform the first non-local four-probe
experiments[13] on graphene contacted by ferromagnetic Permalloy electrodes. We
observe sharp switching and often sign-reversal of the non-local resistance at
the coercive field of the electrodes, indicating definitively the presence of a
spin current between injector and detector. The non-local resistance changes
magnitude and sign quasi-periodically with back-gate voltage, and
Fabry-Perot-like oscillations[6,14,15] are observed, consistent with
quantum-coherent transport. The non-local resistance signal can be observed up
to at least T = 300 K
Stability of the Magnetic Monopole Condensate in three- and four-colour QCD
It is argued that the ground state of three- and four-colour QCD contains a
monopole condensate, necessary for the dual Meissner effect to be the mechanism
of confinement, and support its stability on the grounds that it gives the
off-diagonal gluons an effective mass sufficient to remove the unstable ground
state mode.Comment: jhep.cls, typos corrected, references added, some content delete
Measuring the Contribution of Water and Green Space Amenities to Housing Values: An Application and Comparison of Spatially-weighted Hedonic Models
This study estimates the influence of proximity to water bodies and park amenities on residential housing values in Knox County, Tennessee, using the hedonic price approach. Values for proximity to water bodies and parks are first estimated globally with a standard ordinary least square (OLS) model. A locally weighted regression model is then employed to investigate spatial non-stationarity and generate local estimates for individual sources of each amenity. The local model is able to capture the variability in the quality of water bodies and parks across the county, something a conventional hedonic model using OLS cannot do.Land Economics/Use,
Determinants of Demand for Participation in Wildlife Hunting: A County level Analysis
We developed an economic demand model of wildlife hunting and found that sociodemograpahic and ecological characteristics of county are its strong predictors. Result shows that the hunting is not popular among younger generation; and promoting hunting clubs and lease-hunting, recruiting young hunters could be effective policy considerations for retaining/promoting hunting.Wildlife hunting, License sales, Demand model, Resource /Energy Economics and Policy, Q21, Q26, L83,
TGFβ/BMP immune signaling affects abundance and function of C. elegans gut commensals.
The gut microbiota contributes to host health and fitness, and imbalances in its composition are associated with pathology. However, what shapes microbiota composition is not clear, in particular the role of genetic factors. Previous work in Caenorhabditis elegans defined a characteristic worm gut microbiota significantly influenced by host genetics. The current work explores the role of central regulators of host immunity and stress resistance, employing qPCR and CFU counts to measure abundance of core microbiota taxa in mutants raised on synthetic communities of previously-isolated worm gut commensals. This revealed a bloom, specifically of Enterobacter species, in immune-compromised TGFβ/BMP mutants. Imaging of fluorescently labeled Enterobacter showed that TGFβ/BMP-exerted control operated primarily in the anterior gut and depended on multi-tissue contributions. Enterobacter commensals are common in the worm gut, contributing to infection resistance. However, disruption of TGFβ/BMP signaling turned a normally beneficial Enterobacter commensal to pathogenic. These results demonstrate specificity in gene-microbe interactions underlying gut microbial homeostasis and highlight the pathogenic potential of their disruption
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