11,906 research outputs found
Meta-Analysis of Cyathostomin Species-Specific Prevalence and Relative Abundance in Domestic Horses from 1975-2020: Emphasis on Geographical Region and Specimen Collection Method
BACKGROUND: Cyathostomins infect virtually all horses, and concomitant infections with 10 or more species per horse is standard. Species-specific knowledge is limited, despite potential species bias in development of disease and anthelmintic resistance. This is the first meta-analysis to examine effects of geographical region and cyathostomin collection method on reported composition of cyathostomin communities.
METHODS: Thirty-seven articles published in English in 1975 or later, in which adults of individual species were systematically enumerated, were included. Seven regions; North America, South America, eastern Europe, western Europe, northern Europe, southern Africa, and Oceania, and three cyathostomin collection methods; (i) standard necropsy recovery from the large intestine, (ii) critical test collection from post-treatment feces and necropsy, and (iii) diagnostic deworming recovery solely from post-treatment feces, were considered. Generalized mixed linear models analyzed the effects of region and collection method on species-specific prevalence and relative abundance. Species richness was analyzed by mixed linear models.
RESULTS: Definitively, the most prevalent and relatively abundant species were Cylicocyclus nassatus (prevalence = 93%, relative abundance = 20%), Cylicostephanus (Cys.) longibursatus (93%, 20%), and Cyathostomum catinatum (90%, 16%). A bias toward horses with high infection intensities and cyathostomin collection from feces resulted in North American critical tests and eastern European diagnostic deworming overestimating the species-specific prevalence and underestimating the relative abundance of rare/uncommon species compared to respective intra-regional standard necropsies. North American critical tests underestimated species richness due partially to identification key errors. Inter-regional standard necropsy comparisons yielded some species-specific regional differences, including a significantly higher Cys. longibursatus prevalence and relative abundance in North America (92%, 33%) than in eastern Europe (51%, 7%) (P \u3e 0.0001). Localization of critical tests to North America and diagnostic deworming to Eastern Europe precluded expansive ‘region by collection method’ interaction analyses.
CONCLUSION: We provide substantial data to inform study design, e.g. effect and study size, for cyathostomin research and highlight necessity for method standardization and raw data accessibility for optimal post-factum comparisons
Entanglement of two qubits mediated by one-dimensional plasmonic waveguides
We investigate qubit-qubit entanglement mediated by plasmons supported by
one-dimensional waveguides. We explore both the situation of spontaneous
formation of entanglement from an unentangled state and the emergence of driven
steady-state entanglement under continuous pumping. In both cases, we show that
large values for the concurrence are attainable for qubit-qubit distances
larger than the operating wavelength by using plasmonic waveguides that are
currently available.Comment: 4 pages, 4 figures. Minor Changes. Journal Reference added.
Highlighted in Physic
Geoacoustic Inversion of Ship Radiated Noise in Shallow Water Using Data From a Single Hydrophone
The Centre for Maritime Research and Experimentation conducted a geoacoustic inverse experiment in the Mediterranean Sea in the summer of 2012. Among the objectives was to employ an autono- mous underwater vehicle to collect acoustic data to invert for properties of the seafloor. Inversion results for the compression wave speed in the bottom and the source spectrum of the R/V Alliance during a close approach to the bottom moored vehicle are presented. The estimated wave speed was 1529 m/s (r ¼ 10). The source spectrum of the Alliance was estimated across more than six octaves of frequency
Holographic Noncommutativity
We examine noncommutative Yang-Mills and open string theories using
magnetically and electrically deformed supergravity duals. The duals are near
horizon regions of Dp-brane bound state solutions which are obtained by using
O(p+1,p+1) transformations of Dp-branes. The action of the T-duality group
implies that the noncommutativity parameter is constant along holographic
RG-flows. The moduli of the noncommutative theory, i.e., the open string metric
and coupling constant, as well as the zero-force condition are shown to be
invariant under the O(p+1,p+1) transformation, i.e., deformation independent.
We find sufficient conditions, including zero force and constant dilaton in the
ISO(3,1)-invariant D3 brane solution, for exact S-duality between
noncommutative Yang-Mills and open string theories. These results are used to
construct noncommutative field and string theories with N=1 supersymmetry from
the T^(1,1) and Pilch-Warner solutions. The latter has a non-trivial zero-force
condition due to the warping.Comment: latex, 40 pp. v2: minor changes, one ref. added. v3: corrections in
eqs. 27 and 7
Simulating Hamiltonians in Quantum Networks: Efficient Schemes and Complexity Bounds
We address the problem of simulating pair-interaction Hamiltonians in n node
quantum networks where the subsystems have arbitrary, possibly different,
dimensions. We show that any pair-interaction can be used to simulate any other
by applying sequences of appropriate local control sequences. Efficient schemes
for decoupling and time reversal can be constructed from orthogonal arrays.
Conditions on time optimal simulation are formulated in terms of spectral
majorization of matrices characterizing the coupling parameters. Moreover, we
consider a specific system of n harmonic oscillators with bilinear interaction.
In this case, decoupling can efficiently be achieved using the combinatorial
concept of difference schemes. For this type of interactions we present optimal
schemes for inversion.Comment: 19 pages, LaTeX2
Shift work and use of psychotropic medicine:A follow-up study with register linkage
OBJECTIVE: This study aimed to investigate a prospective association between shift work and use of psychotropic medicine. METHODS: Survey data from random samples of the general working population of Denmark (N=19 259) were linked to data from national registers. Poisson regression was used for analyses of prospective associations between shift work and redeemed prescriptions of psychotropic medicine. Prevalent cases were excluded at baseline. In secondary analyses, we tested differential effects on subsets of psychotropic medicine and, cross-sectionally, we studied correspondence between estimates based on psychotropic medicine and self-reported mental health. According to the protocol we interpret results from the secondary analyses following the principles for nested hypothesis testing, if the primary analyses reject the null-hypothesis, and otherwise we regard it as hypothesis generating exploratory analyses. RESULTS: In the primary analysis, the rate ratio for incidence of psychotropic medicine among shift workers was 1.09 (95% confidence interval 0.99–1.21). Results from the secondary analyses suggested increased incidence of use of hypnotics, sedatives and antidepressants and decreased incidence of use of anxiolytics. Cross-sectional analysis suggested increased risk for use of psychotropic medicine (all kinds), but not for poor self-rated mental health. CONCLUSIONS: Results did not support that working in shifts to the extent that is currently practiced in Denmark is associated with an increased incidence of overall psychotropic medicine use. Future studies should test, whether there is a differential incidence for different drugs among shift workers as suggested by the secondary analyses and how psychotropic medicine use and mental health are related
Decomposing generalized measurements into continuous stochastic processes
One of the broadest concepts of measurement in quantum theory is the
generalized measurement. Another paradigm of measurement--arising naturally in
quantum optics, among other fields--is that of continuous-time measurements,
which can be seen as the limit of a consecutive sequence of weak measurements.
They are naturally described in terms of stochastic processes, or
time-dependent random variables. We show that any generalized measurement can
be decomposed as a sequence of weak measurements with a mathematical limit as a
continuous stochastic process. We give an explicit construction for any
generalized measurement, and prove that the resulting continuous evolution, in
the long-time limit, collapses the state of the quantum system to one of the
final states generated by the generalized measurement, being decomposed, with
the correct probabilities. A prominent feature of the construction is the
presence of a feedback mechanism--the instantaneous choice weak measurement at
a given time depends on the outcomes of earlier measurements. For a generalized
measurement with outcomes, this information is captured by a real
-vector on an -simplex, which obeys a simple classical stochastic
evolution.Comment: 9 pages, LaTeX, name changed, typos correcte
Explanation and Elaboration Document for the STROBE-Vet Statement: Strengthening the Reporting of Observational Studies in Epidemiology—Veterinary Extension
The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement was first published in 2007 and again in 2014. The purpose of the original STROBE was to provide guidance for authors, reviewers and editors to improve the comprehensiveness of reporting; however, STROBE has a unique focus on observational studies. Although much of the guidance provided by the original STROBE document is directly applicable, it was deemed useful to map those statements to veterinary concepts, provide veterinary examples and highlight unique aspects of reporting in veterinary observational studies. Here, we present the examples and explanations for the checklist items included in the STROBE-Vet Statement. Thus, this is a companion document to the STROBE-Vet Statement Methods and process document, which describes the checklist and how it was developed
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