21,207 research outputs found
Gene dynamics of toll-like receptor 4 through a population bottleneck in an insular population of water voles (Arvicola amphibius)
Acknowledgments We would like to thank all colleagues who have contributed to fieldwork and sampling during this study. We would especially like to thank Marius Wenzel and Sandra Telfer for collaboration with different aspects of the study, and Dave Jones and Nat Jones for Bartonella PCR assays. This work was supported by the BBSRC studentship to MKG (BB/J01446X/1) and a NERC studentship to MKO. The research was carried out under project license PPL 40/1813.Peer reviewedPublisher PD
The IRAS 1-Jy Survey of Ultraluminous Infrared Galaxies: I. The sample and Luminosity Function
A complete flux-limited sample of 118 ultraluminous infrared galaxies (ULIGs)
has been identified from the IRAS Faint Source Catalog (FSC). The selection
criteria were a 60 micron flux density greater than 1 Jy in a region of the sky
delta > -40 deg, |b| > 30 deg. All sources were subsequently reprocessed using
coadded IRAS maps in order to obtain the best available flux estimates in all
four IRAS wavelength bands. The maximum observed infrared luminosity is L_ir =
10^{12.90} L_{sun}, and the maximum redshift is z = 0.268. The luminosity
function for ULIGs over the decade luminosity range L_ir = 10^{12} - 10^{13}
L_{sun} can be approximated by a power law Phi (L) ~= L^{-2.35} Mpc^{-3}
mag^{-1}. In the local Universe z < 0.1, the space density of ULIGs appears to
be comparable to or slightly larger than that of optically selected QSOs at
comparable bolometric luminosities. A maximum likelihood test suggests strong
evolution for our sample; assuming density evolution proportional to
(1+z)^{alpha} we find alpha = 7.6+/-3.2. Examination of the two-point
correlation function shows a barely significant level of clustering, xi (r) =
1.6 +/- 1.2, on size scales r ~= 22 h^{-1} Mpc.Comment: 18 pages of text, 10 pages of figures 1 to 6, 6 pages of tables 1 to
3, ApJS accepte
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Controls on the spatial distribution of oceanic <i>Ī“</i><sup>13</sup>C<sub>DIC</sub>
We describe the design and evaluation of a large ensemble of coupled climateācarbon cycle simulations with the Earth system model of intermediate complexity GENIE. This ensemble has been designed for application to a range of carbon cycle questions, including the causes of late- Quaternary fluctuations in atmospheric CO2. Here we evaluate the ensemble by applying it to a transient experiment over the recent industrial era (1858 to 2008 AD). We employ singular vector decomposition and principal component emulation to investigate the spatial modes of ensemble variability of oceanic dissolved inorganic carbon (DIC) Ī“13C, considering both the spun-up pre-industrial state and the transient change. These analyses allow us to separate the natural (preindustrial) and anthropogenic controls on the Ī“13CDIC distribution. We apply the same dimensionally reduced emulation techniques to consider the drivers of the spatial uncertainty in anthropogenic DIC. We show that the sources of uncertainty related to the uptake of anthropogenic Ī“13CDIC and DIC are quite distinct. Uncertainty in anthropogenic Ī“13C uptake is controlled by airāsea gas exchange, which explains 63% of modelled variance. This mode of variability is largely absent from the ensemble variability in CO2 uptake, which is rather driven by uncertainties in thermocline ventilation rates. Although the need to account for airāsea gas exchange is well known, these results suggest that, to leading order, uncertainties in the ocean uptake of anthropogenic 13C and CO2 are governed by very different processes. This illustrates the difficulties in reconstructing one from the other, and furthermore highlights the need for careful targeting of both Ī“13CDIC and DIC observations to better constrain the ocean sink of anthropogenic CO2
Coastal water source of shortālived halocarbons in New England
Shortālived halocarbon tracers were used to investigate marine influences on air quality in a coastal region of New England. Atmospheric measurements made at the University of New Hampshire\u27s Observing Station at Thompson Farm (TF) in Durham, New Hampshire, indicate that relatively large amounts of halocarbons are emitted from local estuarine and coastal oceanic regions. Bromineācontaining halocarbons of interest in this work include bromoform (CHBr3) and dibromomethane (CH2Br2). The mean mixing ratios of CHBr3 and CH2Br2 from 11 January to 5 March 2002 were 2.6 pptv and 1.6 pptv, and from 1 June to 31 August 2002 mean mixing ratios were 5.9 pptv and 1.4 pptv, respectively. The mean mixing ratio of CHBr3 was not only highest during summer, but both CHBr3 and CH2Br2 exhibited large variability in their atmospheric mixing ratios during this season. We attribute the greater variability to increased production combined with faster atmospheric removal rates. Other seasonal characteristics of CHBr3 and CH2Br2 in the atmosphere, as well as the impact of local meteorology on their distributions at this coastal site, are discussed. Tetrachloroethene (C2Cl4) and trichloroethene (C2HCl3) were used to identify time periods influenced by urban emissions. Additionally, measurements of CHBr3, CH2Br2, C2Cl4, methyl iodide (CH3I), and ethyl iodide (C2H5I) were made at TF and five sites throughout the nearby Great Bay estuarine area between 18 and 19 August 2003. These measurements were used to elucidate the effect of the tidal cycle on the distributions of these gases. The mean mixing ratios of CHBr3, CH2Br2, CH3I, and C2H5I were ā¼82%, 46%, 14%, and 17% higher, respectively, near the coast compared to inland sites, providing evidence for a marine source of shortālived halocarbons at TF. Correlation between the tidal cycle and atmospheric concentrations of marine tracers on the night of 18 August 2003 showed that the highest values for the brominated species occurred ā¼2ā3 hours after high tide. Emission fluxes of CHBr3, CH2Br2, CH3I, and C2H5I on this night were estimated to be 26 Ā± 57, 4.7 Ā± 5.4, 5.9 Ā± 4.6, and 0.065 Ā± 0.20 nmol mā2 hā1, respectively. Finally, the anthropogenic source strength of CHBr3 was calculated to determine its impact on atmospheric levels observed in this region. Although our results indicate that anthropogenic contributions could potentially range from 15 to 60% of the total dissolved CHBr3 in the Great Bay, based on the observed ratio of CH2Br2/CHBr3 and surface seawater measurements in the Gulf of Maine, it appears unlikely that anthropogenic activities are a significant source of CHBr3 in the region
'It's a Form of Freedom': The experiences of people with disabilities within equestrian sport
This paper explores the embodied, gendered experiences of disabled horseāriders. Drawing on data from five inādepth interviews with paradressage riders, the ways in which their involvement in elite disability sport impacts upon their sense of identity and confidence are explored, as well as the considerable health and social benefits that this involvement brings. Social models of disability are employed and the shortcomings of such models, when applied to disability sport, are highlighted. The data presented here demonstrates the necessity of seeing disability sport as an embodied experience and acknowledging the importance of impairment to the experiences of disabled athletes. Living within an impaired body is also a gendered experience and the implications of this when applied to elite disability sport are considered
Simultaneous X-ray and Optical Observations of EX Hydrae
The intermediate polar, EX Hydrae, was the object of a large simultaneous
multiwavelength observational campaign during 2000 May - June. Here we present
the Rossi X-ray Timing Explorer photometry and optical photometry and
spectroscopy from ground-based observatories obtained as part of this campaign.
Balmer line radial velocities and Doppler maps provide evidence for an extended
bulge along the outer edge of the accretion disk and some form of
extended/overflowing material originating from the hot spot. In addition, the
optical binary eclipse possesses an extended egress shoulder, an indication
that an additional source (other than the white dwarf) is coming out of
eclipse. We also compare the X-ray and optical results with the results
obtained from the EUV and UV observations from the multiwavelength data set.Comment: to appear in the Astronomical Journal, April 200
Oscillatory Modes of a Prominence-PCTR-Corona Slab Model
Oscillations of magnetic structures in the solar corona have often been
interpreted in terms of magnetohydrodynamic waves. We study the adiabatic
magnetoacoustic modes of a prominence plasma slab with a uniform longitudinal
magnetic field, surrounded by a prominence-corona transition region (PCTR) and
a coronal medium. Considering linear small-amplitude oscillations, the
dispersion relation for the magnetoacoustic slow and fast modes is deduced
assuming evanescent-like perturbations in the coronal medium. In the system
without PCTR, a classification of the oscillatory modes according to the
polarisation of their eigenfunctions is made in order to distinguish modes with
fast-like or slow-like properties. Internal and external slow modes are
governed by the prominence and coronal properties respectively, and fast modes
are mostly dominated by prominence conditions for the observed wavelengths. In
addition, the inclusion of an isothermal PCTR does not substantially influence
the mode frequencies, but new solutions (PCTR slow modes) are present.Comment: Accepted for publication in Solar Physic
Identity development, attraction, and behaviour of heterosexually-identified men who have sex with men: A scoping review
Interventions for Indigenous Peoples making health decisions: a systematic review
Background: Shared decision-making facilitates collaboration between patients and health care providers for informed health decisions. Our review identified interventions to support Indigenous Peoples making health decisions. The objectives were to synthesize evidence and identify factors that impact the use of shared decision making interventions. Methods: An Inuit and non-Inuit team of service providers and academic researchers used an integrated knowledge translation approach with framework synthesis to coproduce a systematic review. We developed a conceptual framework to organize and describe the shared decision making processes and guide identification of studies that describe interventions to support Indigenous Peoples making health decisions. We conducted a comprehensive search of electronic databases from September 2012 to March 2022, with a grey literature search. Two independent team members screened and quality appraised included studies for strengths and relevance of studiesā contributions to shared decision making and Indigenous self-determination. Findings were analyzed descriptively in relation to the conceptual framework and reported using guidelines to ensure transparency and completeness in reporting and for equity-oriented systematic reviews. Results: Of 5068 citations screened, nine studies reported in ten publications were eligible for inclusion. We categorized the studies into clusters identified as: those inclusive of Indigenous knowledges and governance (āIndigenous-orientedā)(n = 6); and those based on Western academic knowledge and governance (āWestern-orientedā)(n = 3). The studies were found to be of variable quality for contributions to shared decision making and self-determination, with Indigenous-oriented studies of higher quality overall than Western-oriented studies. Four themes are reflected in an updated conceptual framework: 1) where shared decision making takes place impacts decision making opportunities, 2) little is known about the characteristics of health care providers who engage in shared decision making processes, 3) community is a partner in shared decision making, 4) the shared decision making process involves trust-building. Conclusions: There are few studies that report on and evaluate shared decision making interventions with Indigenous Peoples. Overall, Indigenous-oriented studies sought to make health care systems more amenable to shared decision making for Indigenous Peoples, while Western-oriented studies distanced shared decision making from the health care settings. Further studies that are solutions-focused and support Indigenous self-determination are needed
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