53,786 research outputs found
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Atmospheric modelling for NOMAD-UVIS on board the ExoMars Trace Gas Orbiter mission
The Ultraviolet and Visible Spectrometer (UVIS) instrument development process requires the construction of an atmospheric model to provide synthetic UV transmission spectra. We discuss the requirements of the model to enable observational limits to be found, and the potential for certain atmospheric parameters to be further constrained
Spectrophotometry of Michigan-Tololo quasars
Emission-line quasar characteristics are confirmed for 80% of the objects observed, including at least four new quasars with spectral features indicative of supernova-like outflow. Approximately 73% of the redshifts predicted from the discovery plates are found accurate with a mean error in z of 0.03, and a large range of z (from about 0.1 to 3.16) is represented in the sample. The observed redshift distribution for quasars is marginally consistent with a constant co-moving quasar density above z approximately 2.0. The shape of the redshift distribution may be used as an isotropy probe with a cosmic time resolution of a few times one-hundred million years in the early universe; therefore, continued surveys of this sort are important even if accurate magnitudes are not determined
Evolved individual differences: Advancing a condition-dependent model of personality
Cataloged from PDF version of article.The field of personality psychology offers a wealth of robust empirical research and a successful descriptive
taxonomy, but neither explains the origins of the structure of human personality nor elaborates a
generative framework for predicting the specific conditions that evoke the development of distinct
personality traits. Exploration of traditional personality constructs within an evolutionary adaptive individual
differences framework may help fill this explanatory gap. Personality traits exhibit functional features
and patterns of variation expected from psychological adaptations designed to solve survival- and
reproduction-related challenges recurrently faced during our species’ evolutionary history. Conditiondependent
evolutionary models of personality have been proposed for decades, but only recently have
begun to see empirical investigation. These models posit that species-typical psychological mechanisms
take as input cues from the individual’s phenotype that would have been ancestrally linked to differential
cost–benefit tradeoffs of alternative personality strategies, and produce as output personality trait levels
with the greatest probabilistic net benefit for the individual. This paper elaborates a more nuanced conceptual
framework that builds on earlier conceptualizations of condition-dependent traits to yield new
and untested hypotheses about personality trait variation and covariation. It then describes clear future
research directions for empirically investigating these readily testable hypotheses. (C) 2014 Elsevier Ltd. All rights reserved
An affine generalization of evacuation
We establish the existence of an involution on tabloids that is analogous to
Schutzenberger's evacuation map on standard Young tableaux. We find that the
number of its fixed points is given by evaluating a certain Green's polynomial
at , and satisfies a "domino-like" recurrence relation.Comment: 32 pages, 7 figure
Performance of a transonic fan stage designed for a low meridional velocity ratio
The aerodynamic performance and design parameters of a transonic fan stage are presented. The fan stage was designed for a meridional velocity ratio of 0.8 across the tip of the stage, a pressure ratio of 1.57, a flow of 29.5 kilograms per second, and a tip speed of 426 meters per second. Radial surveys were obtained over the stable operating range from 50 to 100 percent of design speed. The measured, peak efficiency (0.81) of the stage occurred at a pressure ratio of 1.58 and a flow of 28.7 kilograms per second
Longevity and mortality in Kennel Club registered dog breeds in the UK in 2014
Abstract Background The domestic dog is one of the most diverse mammalian species, exhibiting wide variations in morphology, behaviour and morbidity across breeds. Therefore, it is not unexpected that breeds should also exhibit variation in mortality and longevity. While shorter longevity per se may not necessarily be a welfare issue, a generally foreshortened lifespan in a breed that is accompanied by a high prevalence of a particular cause of death may reveal potentially serious welfare concerns and highlight scope to improve breed welfare. Survey data gathered directly from owners offer useful insights into canine longevity and mortality that can support the overall evidence base for welfare reforms within breeds. Results Mortality data on 5663 deceased dogs registered with the UK Kennel Club were collected from an owner-based survey. The most commonly reported causes of death were old age (13.8%), unspecified cancer (8.7%) and heart failure (4.9%); with 5.1% of deaths reported as unknown cause. Overall median age at death was 10.33 years (interquartile range: 7.17–12.83 years). Breeds varied widely in median longevity overall from the West Highland Terrier (12.71 years) to the Dobermann Pinscher (7.67 years). There was also wide variation in the prevalence of some common causes of death among breeds, and in median longevity across the causes of death. Conclusion Substantial variation in the median lifespan and the prominent causes of death exists across breeds. This study has identified some breeds with both a low median lifespan and also a high proportional mortality for one or more specific causes of death that should be considered as both potential welfare concerns as well as opportunities for improvement
Large-scale survey to estimate the prevalence of disorders for 192 Kennel Club registered breeds
Abstract Background Pedigree or purebred dogs are often stated to have high prevalence of disorders which are commonly assumed to be a consequence of inbreeding and selection for exaggerated features. However, few studies empirically report and rank the prevalence of disorders across breeds although such data are of critical importance in the prioritisation of multiple health concerns, and to provide a baseline against which to explore changes over time. This paper reports an owner survey that gathered disorder information on Kennel Club registered pedigree dogs, regardless of whether these disorders received veterinary care. This study aimed to determine the prevalence of disorders among pedigree dogs overall and, where possible, determine any variation among breeds. Results This study included morbidity data on 43,005 live dogs registered with the Kennel Club. Just under two thirds of live dogs had no reported diseases/conditions. The most prevalent diseases/conditions overall were lipoma (4.3%; 95% confidence interval 4.13-4.52%), skin (cutaneous) cyst (3.1%; 2.94-3.27%) and hypersensitivity (allergic) skin disorder (2.7%; 2.52-2.82%). For the most common disorders in the most represented breeds, 90 significant differences between the within breed prevalence and the overall prevalence are reported. Conclusion The results from this study have added vital epidemiological data on disorders in UK dogs. It is anticipated that these results will contribute to the forthcoming Breed Health & Conservation Plans, a Kennel Club initiative aiming to assist in the identification and prioritisation of breeding selection objectives for health and provide advice to breeders/owners regarding steps that may be taken to minimise the risk of the disease/disorders. Future breed-specific studies are recommended to report more precise prevalence estimates within more breeds
Ion-ion dynamic structure factor, acoustic modes and equation of state of two-temperature warm dense aluminum
The ion-ion dynamical structure factor and the equation of state of warm
dense aluminum in a two-temperature quasi-equilibrium state, with the electron
temperature higher than the ion temperature, are investigated using
molecular-dynamics simulations based on ion-ion pair potentials constructed
from a neutral pseudoatom model. Such pair potentials based on density
functional theory are parameter-free and depend directly on the electron
temperature and indirectly on the ion temperature, enabling efficient
computation of two-temperature properties. Comparison with ab initio
simulations and with other average-atom calculations for equilibrium aluminum
shows good agreement, justifying a study of quasi-equilibrium situations.
Analyzing the van Hove function, we find that ion-ion correlations vanish in a
time significantly smaller than the electron-ion relaxation time so that
dynamical properties have a physical meaning for the quasi-equilibrium state. A
significant increase in the speed of sound is predicted from the modification
of the dispersion relation of the ion acoustic mode as the electron temperature
is increased. The two-temperature equation of state including the free energy,
internal energy and pressure is also presented
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Radiative transfer modelling for the NOMAD-UVIS instrument on the ExoMars Trace Gas Orbiter mission
The NOMAD (Nadir and Occultation for MArs Discovery) instrument is a 3-channel (2 IR, 1 UV/Vis) spectrometer due to fly on the 2016 ExoMars Trace Gas Orbiter mission. A radiative transfer model for Mars has been developed providing synthetic spectra to simulate observations of the UVIS channel in both solar occultation and nadir viewing geometries. This will allow for the characterization and mitigation of the influence of dust on retrievals of ozone abundance
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