321 research outputs found
Dissipative quantum theory: Implications for quantum entanglement
Three inter-related topics are discussed here. One, the Lindblad dynamics of
quantum dissipative systems; two, quantum entanglement in composite systems and
its quantification based on the Tsallis entropy; and three, robustness of
entanglement under dissipation. After a brief review of the Lindblad theory of
quantum dissipative systems and the idea of quantum entanglement in composite
quantum systems illustrated by describing the three particle systems, the
behavior of entanglement under the influence of dissipative processes is
discussed. These issues are of importance in the discussion of quantum
nanometric systems of current research.Comment: 12 pages, 1 Tabl
Combined Recording of Mechanically Stimulated Afferent Output and Nerve Terminal Labelling in Mouse Hair Follicle Lanceolate Endings
A novel dissection and recording technique is described for monitoring afferent firing evoked by mechanical displacement of hairs in the mouse pinna. The technique is very cost-effective and easily undertaken with materials commonly found in most electrophysiology laboratories, or easily purchased. The dissection is simple and fast, with the mechanical displacement provided by a generic electroceramic wafer controlled by proprietary software. The same software also records and analyses the electroneurogram output. The recording of the evoked nerve activity is through a commercial differential amplifier connected to fire-polished standard glass microelectrodes. Helpful tips are given for improving the quality of the preparation, the stimulation and the recording conditions to optimize recording quality. The system is suitable for assaying the electrophysiological and optical properties of lanceolate terminals of palisade endings of hair follicles, as well as the outcomes from their pharmacological and/or genetic manipulation. An example of combining electrical recording with mechanical stimulation and labeling with a styryl pyridinium vital dye is given
Nanofabrication technologies: high-throughput for tomorrow's metadevices
Fabrication fundamentals1. Serial versus parallel? Most are currently fabricated by serial writing….2. Additive or subtractive?3. Feature size required.4. One-off demonstration (journal paper) or volume production (in the shops by next Christmas…)5. What material?6. Cost….(+ normalise to 150mm diameter wafer)7. Time to fabricat
Molecular characterization of the intact mouse muscle spindle using a multi-omics approach
The proprioceptive system is essential for the control of coordinated movement, posture and skeletal integrity. The sense of proprioception is produced in the brain using peripheral sensory input from receptors such as the muscle spindle, which detects changes in the length of skeletal muscles. Despite its importance, the molecular composition of the muscle spindle is largely unknown. In this study, we generated comprehensive transcriptomic and proteomic datasets of the entire muscle spindle isolated from the murine deep masseter muscle. We then associated differentially expressed genes with the various tissues composing the spindle using bioinformatic analysis. Immunostaining verified these predictions, thus establishing new markers for the different spindle tissues. Utilizing these markers, we identified the differentiation stages the spindle capsule cells undergo during development. Together, these findings provide comprehensive molecular characterization of the intact spindle as well as new tools to study its development and function in health and disease
Confinement and Chiral Symmetry Breaking via Domain-Like Structures in the QCD Vacuum
A qualitative mechanism for the emergence of domain structured background
gluon fields due to singularities in gauge field configurations is considered,
and a model displaying a type of mean field approximation to the QCD partition
function based on this mechanism is formulated. Estimation of the vacuum
parameters (gluon condensate, topological susceptibility, string constant and
quark condensate) indicates that domain-like structures lead to an area law for
the Wilson loop, nonzero topological susceptibility and spontaneous breakdown
of chiral symmetry. Gluon and ghost propagators in the presence of domains are
calculated explicitly and their analytical properties are discussed. The
Fourier transforms of the propagators are entire functions and thus describe
confined dynamical fields.Comment: RevTeX, 48 pages (32 pages + Appendices A-E), new references added
[1,2,4,5] and minor formulae corrected for typographical error
Large-scale pathways-based association study in amyotrophic lateral sclerosis
Sporadic amyotrophic lateral sclerosis (ALS), a devastating neurodegenerative disease, most likely results from complex genetic and environmental interactions. Although a number of association studies have been performed in an effort to find genetic components of sporadic ALS, most of them resulted in inconsistent findings due to a small number of genes investigated in relatively small sample sizes, while the replication of results was rarely attempted. Defects in retrograde axonal transport, vesicle trafficking and xenobiotic metabolism have been implicated in neurodegeneration and motor neuron death both in human disease and animal models. To assess the role of common genetic variation in these pathways in susceptibility to sporadic ALS, we performed a pathway-based candidate gene case-control association study with replication. Furthermore, we determined reliability of whole genome amplified DNA in a large-scale association study. In the first stage of the study, 1277 putative functional and tagging SNPs in 134 genes spanning 8.7 Mb were genotyped in 822 British sporadic ALS patients and 872 controls using whole genome amplified DNA. To detect variants with modest effect size and discriminate among false positive findings 19 SNPs showing a trend of association in the initial screen were genotyped in a replication sample of 580 German sporadic ALS patients and 361 controls. We did not detect strong evidence of association with any of the genes investigated in the discovery sample (lowest uncorrected P-value 0.00037, lowest permutation corrected P-value 0.353). None of the suggestive associations was replicated in a second sample, further excluding variants with moderate effect size. We conclude that common variation in the investigated pathways is unlikely to have a major effect on susceptibility to sporadic ALS. The genotyping efficiency was only slightly decreased (∼1%) and genotyping quality was not affected using whole genome amplified DNA. It is reliable for large scale genotyping studies of diseases such as ALS, where DNA sample collections are limited because of low disease prevalence and short survival time. © 2007 The Author(s)
Hepatitis E Virus in Pork Liver Sausage, France
We investigated viability of hepatitis E virus (HEV) identified in contaminated pork liver sausages obtained from France. HEV replication was demonstrated in 1 of 4 samples by using a 3-dimensional cell culture system. The risk for human infection with HEV by consumption of these sausages should be considered to be high
Unit bar architecture in a highly‐variable fluvial discharge regime: Examples from the Burdekin River, Australia
Unit bars are relatively large bedforms that develop in rivers over a wide range of climatic regimes. Unit bars formed within the highly-variable discharge Burdekin River in Queensland, Australia, were examined over three field campaigns between 2015 and 2017. These bars had complex internal structures, dominated by co-sets of cross-stratified and planar-stratified sets. The cross-stratified sets tended to down-climb. The development of complex internal structures was primarily a result of three processes: (i) superimposed bedforms reworking the unit bar avalanche face; (ii) variable discharge triggering reactivation surfaces; and (iii) changes in bar growth direction induced by stage change. Internal structures varied along the length and across the width of unit bars. For the former, down-climbing cross-stratified sets tended to pass into single planar cross-stratified deposits at the downstream end of emergent bars; such variation related to changes in fluvial conditions whilst bars were active. A hierarchy of six categories of fluvial unsteadiness is proposed, with these discussed in relation to their effects on unit bar (and dune) internal structure. Across-deposit variation was caused by changes in superimposed bedform and bar character along bar crests; such changes related to the three-dimensionality of the channel and bar geometry when bars were active. Variation in internal structure is likely to be more pronounced in unit bar deposits than in smaller bedform (for example, dune) deposits formed in the same river. This is because smaller bedforms are more easily washed out or modified by changing discharge conditions and their smaller dimensions restrict the variation in flow conditions that occur over their width. In regimes where unit bar deposits are well-preserved, their architectural variability is a potential aid to their identification. This complex architecture also allows greater resolution in interpreting the conditions before and during bar initiation and development
Flexible Near-Field Wireless Optoelectronics as Subdermal Implants for Broad Applications in Optogenetics
In vivo optogenetics provides unique, powerful capabilities in the dissection of neural circuits implicated in neuropsychiatric disorders. Conventional hardware for such studies, however, physically tethers the experimental animal to an external light source, limiting the range of possible experiments. Emerging wireless options offer important capabilities that avoid some of these limitations, but the current size, bulk, weight, and wireless area of coverage is often disadvantageous. Here, we present a simple but powerful setup based on wireless, near-field power transfer and miniaturized, thin, flexible optoelectronic implants, for complete optical control in a variety of behavioral paradigms. The devices combine subdermal magnetic coil antennas connected to microscale, injectable light-emitting diodes (LEDs), with the ability to operate at wavelengths ranging from UV to blue, green-yellow, and red. An external loop antenna allows robust, straightforward application in a multitude of behavioral apparatuses. The result is a readily mass-producible, user-friendly technology with broad potential for optogenetics applications.114419Ysciescopu
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