6,095 research outputs found

    Beneath the Baselines: Detecting Molecular Emission from Submillimeter Galaxies with the GBT

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    We report the first detection of a submillimeter galaxy (SMG) in CO(1 →0) emission using the GBT. We identify a line with Δv_(FWHM) ~1000 kms^(−1) in the 1 cm spectrum of SMM J13120+4242 at z = 3.408, which is significantly greater than the width of the previously detected CO(4→3) line. If the observed CO(1→0) line profile arises from a single object and not several merging objects, the CO(4 →3)/CO(1→0) brightness temperature ratio of ~0.26 suggests n(H_2) > 10^3 cm^(−3) and the presence of sub-thermally excited gas. The 10σ integrated line flux implies a cold molecular gas mass M(H2) ~10^(11)M_⊙, comparable to the dynamical mass estimate and four times larger than the H_2 mass found from the CO(4 →3) line. While our observations confirm that this SMG is massive and highly gas-rich, they also suggest that J_(upper) > 3 transitions of CO may not accurately trace cold, diffuse molecular gas in SMGs

    Spatiotemporal dynamics of lianas during 50 years of succession to temperate forest

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    Although they are important components of forest communities, the general ecology and spatiotemporal patterns of temperate lianas during forest regeneration are largely unknown. The dependence of lianas on other plants for physical support makes them a potentially important driver of community dynamics. We examined 50 years of vegetation data from an old-field succession study to determine the dynamics and community controls on liana expansion within the Piedmont region of New Jersey, USA. Four lianas, Lonicera japonica, Parthenocissus quinquefolia, Toxicodendron radicans, and Vitis spp., occurred in enough abundance for detailed analyses. In general, liana cover peaked during mid-succession (20–30 years post-abandonment) when community composition was mostly herbaceous with scattered trees and shrubs. Liana cover began to decrease as trees became dominant and the canopy closed. Temporal patterns of cover dynamics of abundant species indicated three early- and one late-successional liana species within the community. In contrast to cover, frequency of lianas increased throughout succession, indicating that liana populations persisted despite dramatic declines in cover for the three early-successional species. Temporal dynamics between native and nonnative lianas were similar but spatially distinct as cover of native species dispersed and expanded near the forest edge while the nonnative species preferentially grew far from the forest. These dynamics indicate that successional processes may ultimately lead to the decline of most lianas. However, the persistence of lianas as high numbers of suppressed individuals suggests that they may rebound quickly following canopy disturbance

    Assessment of the cross-protective capability of recombinant capsid proteins derived from pig, rat, and avian hepatitis E viruses (HEV) against challenge with a genotype 3 HEV in pigs

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    Hepatitis E virus (HEV), the causative agent of hepatitis E, is primarily transmitted via the fecal-oral route through contaminated water supplies, although many sporadic cases of hepatitis E are transmitted zoonotically via direct contact with infected animals or consumption of contaminated animal meats. Genotypes 3 and 4 HEV are zoonotic and infect humans and other animal species, whereas genotypes 1 and 2 HEV are restricted to humans. There exists a single serotype of HEV, although the cross-protective ability among the animal HEV strains is unknown. Thus, in this study we expressed and characterized N-terminal truncated ORF2 capsid antigens derived from swine, rat, and avian HEV strains and evaluated their cross-protective ability in a pig challenge model. Thirty, specific-pathogen-free, pigs were divided into 5 groups of 6 pigs each, and each group of pigs were vaccinated with 200 µg of swine HEV, rat HEV, or avian HEV ORF2 antigen or PBS buffer (2 groups) as positive and negative control groups. After a booster dose immunization at 2 weeks post-vaccination, the vaccinated animals all seroconverted to IgG anti-HEV. At 4 weeks post-vaccination, the animals were intravenously challenged with a genotype 3 mammalian HEV, and necropsied at 4 weeks post-challenge. Viremia, fecal virus shedding, and liver histological lesions were compared to assess the protective and cross-protective abilities of these antigens against HEV challenge in pigs. The results indicated that pigs vaccinated with truncated recombinant capsid antigens derived from three animal strains of HEV induced a strong IgG anti-HEV response in vaccinated pigs, but these antigens confer only partial cross-protection against a genotype 3 mammalian HEV. The results have important implications for the efficacy of current vaccines and for future vaccine development, especially against the novel zoonotic animal strains of HEV

    Recommended Joint and Meta‐Analysis Strategies for Case‐Control Association Testing of Single Low‐Count Variants

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    In genome‐wide association studies of binary traits, investigators typically use logistic regression to test common variants for disease association within studies, and combine association results across studies using meta‐analysis. For common variants, logistic regression tests are well calibrated, and meta‐analysis of study‐specific association results is only slightly less powerful than joint analysis of the combined individual‐level data. In recent sequencing and dense chip based association studies, investigators increasingly test low‐frequency variants for disease association. In this paper, we seek to (1) identify the association test with maximal power among tests with well controlled type I error rate and (2) compare the relative power of joint and meta‐analysis tests. We use analytic calculation and simulation to compare the empirical type I error rate and power of four logistic regression based tests: Wald, score, likelihood ratio, and Firth bias‐corrected. We demonstrate for low‐count variants (roughly minor allele count [MAC] < 400) that: (1) for joint analysis, the Firth test has the best combination of type I error and power; (2) for meta‐analysis of balanced studies (equal numbers of cases and controls), the score test is best, but is less powerful than Firth test based joint analysis; and (3) for meta‐analysis of sufficiently unbalanced studies, all four tests can be anti‐conservative, particularly the score test. We also establish MAC as the key parameter determining test calibration for joint and meta‐analysis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99692/1/gepi21742.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99692/2/gepi21742-sup-0010-figureS1.pd

    The Development of Speech-Language Pathologists’ Counseling Self-Efficacy

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    The purpose of this investigation was to understand, from the perspective of speech-language pathologists (SLPs), what factors contribute to the essential structure of the experience of SLPs with low perceived counseling self-efficacy (CSE), the factors that contribute to the essential structure of the experience of SLPs with high perceived CSE, and how SLPs can transition from lower to higher perceived CSE. Ten female speech-language pathologists participated in interviews to discuss their counseling experiences and the development of their personal SLP CSE. The interviews were divided into 982 meaning units. The meaning units were categorized to determine the recurring themes contributing to the essential structure of low and high SLP CSE and to determine how the transition from low to high CSE occurs. Four recurring themes associated with low CSE were identified, including: (a) lack of knowledge, (b) lack of experience, (c) lack of feedback from others, and (d) personal attributes. Seven recurring themes associated with high CSE were identified, including: (a) experience, (b) situation-specific confidence, (c) experiences of success, (d) life experiences, (e) observation of others, (f) feedback from others, and (g) personal attributes. Four themes associated with perceived needs and resources for continued CSE growth were identified, including: (a) further counseling training, (b) feedback from others, (c) experience, and (d) self-reflection. Further, it was found that internal locus of control was associated with higher levels of CSE

    Investigating the susceptibility of laboratory-generated bacterial aerosols to antimicrobial 405 nm light

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    Airborne transmission of infectious organisms is a major concern within the healthcare environment. A number of methods for 'whole room' decontamination, such as antimicrobial 405nm light, are being developed, and it is important that efficacy against airborne, as well as surface-deposited contamination is established. This study demonstrates evidence of the dose-response kinetics of airborne bacterial contamination when exposed to 405nm light. Aerosols of Staphylococcus epidermids, generated using a 6-Jet Collison nebuliser, were introduced into an aerosol chamber designed to maintain prolonged airborne suspension and circulation. Aerosolized bacteria were exposed to increasing doses of 405nm light, and air samples were extracted from the chamber using a BioSampler liquid impinger, with viability analysed using pour plate culture. Initial results have demonstrated successful aerosol inactivation, with a 98.4% reduction (1.8 log10 reduction) achieved with 1-hour exposure to low irradiance 405nm light (P=<0.001). Natural decay of the suspended aerosol was observed, however this was significantly less than achieved with light treatment (P=0.004). Inactivation using ultraviolet (UV) light was also investigated in order to quantify the comparative efficacy of these antimicrobial light regions.Overall, results have provided early evidence of the susceptibility of bacterial aerosols to antimicrobial 405 nm light. Although less germicidally efficient than UV-light, the benefits of 405 nm light in terms of increased safety for human exposure, provide advantages for a number of applications, including continuous 'whole room' environmental decontamination, where reducing levels of airborne bacteria should contribute to reducing infections arising from airborne contamination

    Effects of building orientation on the residential property

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    Thesis (B.Sc)--University of Hong Kong, 2010.Includes bibliographical references (p. 72-75).published_or_final_versio

    Application of a multibeam echosounder to document changes in animal movement and behaviour around a tidal turbine structure

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    Acknowledgements We acknowledge the support of Shaun Fraser, Vladimir Nikora, James Waggitt, Paul Bell, Ian Davies, Eric Armstrong, and staff at Marine Scotland Science and the European Marine Energy Centre. Hydrodynamic model data were provided by Pierre Cazenave and Ricardo Torres (Plymouth Marine Laboratory). The constructive and extensive comments from three reviewers of an earlier version of this manuscript are gratefully acknowledged. Funding This work was funded by NERC and Defra (NE/J004308/1, NE/J004200/1, NE/J004332/1, NE/N01765X/1), a NERC MREKEP Internship, Innovate UK KTP (KTP009812), and the UK Department for Business, Energy and Industrial Strategy’s offshore energy Strategic Environmental Assessment programme.Peer reviewedPublisher PD
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