1,884 research outputs found
Winter ecology of the Porcupine caribou herd, Yukon: Part III, Role of day length in determining activity pattern and estimating percent lying
Data on the activity pattern, proportion of time spent lying and the length of active and lying periods in winter are presented from a 3 year study on the Porcupine caribou herd. Animals were most active at sunrise and sunset resulting in from one (late fall, early and mid winter) to two (early fall and late winter) to three (spring) intervening lying periods. Mean active/lying cycle length decreased from late fall (298 mm) to early winter (238 min), increased to a peak in mid winter (340 min) then declined in late winter (305 min) and again in spring (240 min). Mean length of the lying period increased throughout the 3 winter months from 56 min m early winter to 114 min in mid winter and 153 min in late winter. The percent of the day animals spent lying decreased from fall to early winter, increased throughout the winter and declined in spring. This pattern was related, in part, to day length and was used to compare percent lying among herds. The relationship is suggested to be a means of comparing quality of winter ranges
CN Bimodality at Low Metallicity: The Globular Cluster M53
We present low resolution UV-blue spectroscopic observations of red giant
stars in the globular cluster M53 ([Fe/H]=-1.84), obtained to study primordial
abundance variations and deep mixing via the CN and CH absorption bands. The
metallicity of M53 makes it an attractive target: a bimodal distribution of
3883 angstrom CN bandstrength is common in moderate- and high-metallicity
globular clusters ([Fe/H] > -1.6) but unusual in those of lower metallicity
([Fe/H] < -2.0). We find that M53 is an intermediate case, and has a broad but
not strongly bimodal distribution of CN bandstrength, with CN and CH
bandstrengths anticorrelated in the less-evolved stars. Like many other
globular clusters, M53 also exhibits a general decline in CH bandstrength and
[C/Fe] abundance with rising luminosity on the red giant branch.Comment: 8 pages including 11 figures and 1 table, accepted by PAS
Comprehensive study of Leon-Queretaro area
There are no author-identified significant results in this report
Properties of the phi meson at high temperatures and densities
We calculate the spectral density of the phi meson in a hot bath of nucleons
and pions using a general formalism relating self-energy to the forward
scattering amplitude (FSA). In order to describe the low energy FSA, we use
experimental data along with a background term. For the high energy FSA, a
Regge parameterization is employed. We verify the resulting FSA using
dispersion techniques. We find that the position of the peak of the spectral
density is slightly shifted from its vacuum position and that its width is
considerably increased. The width of the spectral density at a temperature of
150 MeV and at normal nuclear density is more than 90 MeV.Comment: 4 pages, 5 figures, Poster presented at Quark Matter 200
âIt stays with youâ: multiple evocative representations of dance and future possibilities for studies in sport and physical cultures
This article considers the integration of arts-based representations via poetic narratives together with artistic representation on dancing embodiment so as to continue an engagement with debates regarding multiple forms/representations. Like poetry, visual images are unique and can evoke particular kinds of emotional and visceral responses, meaning that alternative representational forms can resonate in different and powerful ways. In the article, we draw on grandparent-grandchild interactions, narrative poetry, and artistic representations of dance in order to illustrate how arts-based methods might synergise to offer new ways of âknowingâ and âseeingâ. The expansion of the visual arts into interdisciplinary methodological innovations is a relatively new, and sometimes contentious approach, in studies of sport and exercise. We raise concerns regarding the future for more arts-based research in the light of an ever-changing landscape of a neoliberal university culture that demands high productivity in reductionist terms of what counts as âoutputâ, often within very restricted time-frames. Heeding feminist calls for âslow academiesâ that attempt to âchangeâ time collectively, and challenge the demands of a fast-paced audit culture, we consider why it is worth enabling creative and arts-based methods to continue to develop and flourish in studies of sport, exercise and health, despite the mounting pressures to âperformâ
Correction: Increasing ion yield circular dichroism in femtosecond photoionisation using optimal control theory
Correction for âIncreasing ion yield circular dichroism in femtosecond photoionisation using optimal control theoryâ by Manel Mondelo-Martell et al., Phys. Chem. Chem. Phys., 2022, 24, 9286â9297, https://doi.org/10.1039/D1CP05239J.
The authors have detected two issues in the numerical simulations reported in the originally published version of the article. First, the values of the electric and magnetic transition moments, obtained from quantum chemistry calculations were not sufficiently converged. Second, there was a mistake in the implementation of the rotational averaging in the model. After fixing these errors and choosing an improved optimisation functional, new simulations yield quantitatively different results. However, the physical mechanisms of the optimised pulses identified in the original paper remain valid. Here, the authors summarise the origin of the errors in the original publication and present newly converged energies, permanent and transition moments, as well as corrected figures and conclusions. Specifically, Tables 1 and 2 in the original article have been replaced with the corresponding tables in this correction, and Fig. 2â5 in the original article by Fig. 1â4 in this correction respectively. The authors also introduce and explain the new functional that has been used to optimise the pulse
Upgrading short read animal genome assemblies to chromosome level using comparative genomics and a universal probe set
Most recent initiatives to sequence and assemble new speciesâ genomes de-novo fail to achieve the ultimate endpoint to produce a series of contigs, each representing one whole chromosome. Even the best-assembled genomes (using contemporary technologies) consist of sub-chromosomal sized scaffolds. To circumvent this problem, we developed a novel approach that combines computational algorithms to merge scaffolds into chromosomal fragments, scaffold verification by PCR and physical mapping to chromosomes. Multi genome-alignment-guided probe selection led to the development of a set of universal avian BAC clones that permit rapid anchoring of multiple scaffold loci to chromosomes on all avian genomes. As proof of principle we assembled genomes of the pigeon (Columbia livia) and peregrine falcon (Falco peregrinus) to chromosome level comparable, in continuity, to avian reference genomes. Both species are of interest for breeding, cultural, food and/or environmental reasons. Pigeon has a typical avian karyotype (2n=80) while falcon (2n=50) is highly rearranged compared to the avian ancestor. Using chromosome breakpoint data, we established that avian interchromosomal breakpoints appear in the regions of low density of conserved non-coding elements (CNEs) and that the chromosomal fission sites are further limited to long CNE âdesertsâ. This corresponds with fission being the rarest type of rearrangement in avian genome evolution. High-throughput multiple hybridization and rapid capture strategies using the current BAC set provide the basis for assembling numerous avian (and possibly other reptilian) species while the overall strategy for scaffold assembly and mapping provides the basis for an approach that could be applied to any animal genome
Modeling broadband X-ray absorption of massive star winds
We present a method for computing the net transmission of X-rays emitted by
shock-heated plasma distributed throughout a partially optically thick stellar
wind from a massive star. We find the transmission by an exact integration of
the formal solution, assuming that the emitting plasma and absorbing plasma are
mixed at a constant mass ratio above some minimum radius, below which there is
assumed to be no emission. This model is more realistic than either the slab
absorption associated with a corona at the base of the wind or the exospheric
approximation that assumes that all observed X-rays are emitted without
attenuation from above the radius of optical depth unity. Our model is
implemented in XSPEC as a pre-calculated table that can be coupled to a
user-defined table of the wavelength dependent wind opacity. We provide a
default wind opacity model that is more representative of real wind opacities
than the commonly used neutral interstellar medium (ISM) tabulation.
Preliminary modeling of \textit{Chandra} grating data indicates that the X-ray
hardness trend of OB stars with spectral subtype can largely be understood as a
wind absorption effect.Comment: 9 pages, 9 figures. Includes minor corrections made in proof
Calibrations of Atmospheric Parameters Obtained from the First Year of SDSS-III APOGEE Observations
The SDSS-III Apache Point Observatory Galactic Evolution Experiment (APOGEE)
is a three year survey that is collecting 100,000 high-resolution spectra in
the near-IR across multiple Galactic populations. To derive stellar parameters
and chemical compositions from this massive data set, the APOGEE Stellar
Parameters and Chemical Abundances Pipeline (ASPCAP) has been developed. Here,
we describe empirical calibrations of stellar parameters presented in the first
SDSS-III APOGEE data release (DR10). These calibrations were enabled by
observations of 559 stars in 20 globular and open clusters. The cluster
observations were supplemented by observations of stars in NASA's Kepler field
that have well determined surface gravities from asteroseismic analysis. We
discuss the accuracy and precision of the derived stellar parameters,
considering especially effective temperature, surface gravity, and metallicity;
we also briefly discuss the derived results for the abundances of the
alpha-elements, carbon, and nitrogen. Overall, we find that ASPCAP achieves
reasonably accurate results for temperature and metallicity, but suffers from
systematic errors in surface gravity. We derive calibration relations that
bring the raw ASPCAP results into better agreement with independently
determined stellar parameters. The internal scatter of ASPCAP parameters within
clusters suggests that, metallicities are measured with a precision better than
0.1 dex, effective temperatures better than 150 K, and surface gravities better
than 0.2 dex. The understanding provided by the clusters and Kepler giants on
the current accuracy and precision will be invaluable for future improvements
of the pipeline.Comment: 40 pages, 15 figures, 4 tables, accepted to A
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