323 research outputs found

    Performance of a repetitive task by aged rats leads to median neuropathy and spinal cord inflammation with associated sensorimotor declines

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    Epidemiological studies have demonstrated a relationship between advancing age and susceptibility to risk factors for median neuropathies and musculoskeletal disorders. In this study, we determined if performance of a voluntary reaching task by aged rats induced sensorimotor declines, median nerve dysfunction and increased inflammatory cytokines in peripheral nerves, muscle and spinal cord neurons. Aged (14 mon) rats were trained for 15 min/day for 4 weeks to learn a high repetition, low force (HRLF) task (19 reaches/min; 15% maximum pulling force). Aged task rats performed the task for 2 h/day, 3 days/wk, for 12 weeks (until they were 18 mon of age). No behavioral changes were detected in normal controls (NC) or food-restricted controls (FR C) as they aged. However, grip strength declined in HRLF rats in weeks 6-12 (P\u3c0.01 each) and 12-week trained-only rats (TR; P\u3c0.05), compared to NC. Mechanical hypersensitivity was present in weeks 9 and 12 HRLF reach limb forepaws (P\u3c0.01 and P\u3c0.05, respectively), and 12-week HRLF support limb forepaws (P\u3c0.01) and hindpaws (P=0.03), compared to NC. By week 12, median nerve conduction velocity declined 23%, bilaterally, in HRLF (P\u3c0.001 each), and 13% in TR (P\u3c0.05), compared to NC. Tumor necrosis factor alpha (TNFα) increased in 12-week HRLF muscle (P=0.005), median nerve (P\u3c0.01), and neurons in superficial lamina of HRLF cervical spinal cords (P\u3c0.01), compared to NC. interleukin 1 beta (IL1β) also increased in superficial lamina neurons (P\u3c0.01). Loss of grip strength was correlated with median nerve conduction slowing (r=0.70) as well as increased nerve and muscle TNFα (r=-0.38 and r=-0.41, respectively); decrease in forepaw withdrawal thresholds was correlated with median nerve conduction slowing (r=0.81), increased nerve TNFα (r=-0.59), and increased TNFα and IL1β in neurons in spinal cord dorsal horns (r=-0.52 and r=-0.47, respectively). Thus, aged rats performing a repetitive task exhibited sensorimotor declines that were associated with decreased median nerve conduction, and increased pro-inflammatory cytokines in the median nerve and cervical spinal cord neurons

    Ecosystem carbon 7 dioxide fluxes after disturbance in forests of North America

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    Disturbances are important for renewal of North American forests. Here we summarize more than 180 site years of eddy covariance measurements of carbon dioxide flux made at forest chronosequences in North America. The disturbances included stand-replacing fire (Alaska, Arizona, Manitoba, and Saskatchewan) and harvest (British Columbia, Florida, New Brunswick, Oregon, Quebec, Saskatchewan, and Wisconsin) events, insect infestations (gypsy moth, forest tent caterpillar, and mountain pine beetle), Hurricane Wilma, and silvicultural thinning (Arizona, California, and New Brunswick). Net ecosystem production (NEP) showed a carbon loss from all ecosystems following a stand-replacing disturbance, becoming a carbon sink by 20 years for all ecosystems and by 10 years for most. Maximum carbon losses following disturbance (g C m−2y−1) ranged from 1270 in Florida to 200 in boreal ecosystems. Similarly, for forests less than 100 years old, maximum uptake (g C m−2y−1) was 1180 in Florida mangroves and 210 in boreal ecosystems. More temperate forests had intermediate fluxes. Boreal ecosystems were relatively time invariant after 20 years, whereas western ecosystems tended to increase in carbon gain over time. This was driven mostly by gross photosynthetic production (GPP) because total ecosystem respiration (ER) and heterotrophic respiration were relatively invariant with age. GPP/ER was as low as 0.2 immediately following stand-replacing disturbance reaching a constant value of 1.2 after 20 years. NEP following insect defoliations and silvicultural thinning showed lesser changes than stand-replacing events, with decreases in the year of disturbance followed by rapid recovery. NEP decreased in a mangrove ecosystem following Hurricane Wilma because of a decrease in GPP and an increase in ER

    Understanding the treatment benefit of hyperimmune anti-influenza intravenous immunoglobulin (Flu-IVIG) for severe human influenza

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    Background: Antibody-based therapies for respiratory viruses are of increasing importance. The INSIGHT 006 trial administered anti-influenza hyperimmune intravenous immunoglobulin (Flu-IVIG) to patients hospitalized with influenza. Flu-IVIG treatment improved outcomes in patients with influenza B but showed no benefit for influenza A. Methods: To probe potential mechanisms of Flu-IVIG utility, sera collected from patients hospitalized with influenza A or B viruses (IAV or IBV) were analyzed for antibody isotype/subclass and Fcγ receptor (FcγR) binding by ELISA, bead-based multiplex, and NK cell activation assays. Results: Influenza-specific FcγR-binding antibodies were elevated in Flu-IVIG–infused IBV- and IAV-infected patients. In IBV-infected participants (n = 62), increased IgG3 and FcγR binding were associated with more favorable outcomes. Flu-IVIG therapy also improved the odds of a more favorable outcome in patients with low levels of anti-IBV Fc-functional antibody. Higher FcγR-binding antibody was associated with less favorable outcomes in IAV-infected patients (n = 50), and Flu-IVIG worsened the odds of a favorable outcome in participants with low levels of anti-IAV Fc-functional antibody. Conclusion: These detailed serological analyses provide insights into antibody features and mechanisms required for a successful humoral response against influenza, suggesting that IBV-specific, but not IAV-specific, antibodies with Fc-mediated functions may assist in improving influenza outcome. This work will inform development of improved influenza immunotherapies

    The role of the chemokine receptor CXCR4 in infection with feline immunodeficiency virus

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    Infection with feline immunodeficiency virus (FIV) leads to the development of a disease state similar to AIDS in man. Recent studies have identified the chemokine receptor CXCR4 as the major receptor for cell culture-adapted strains of FIV, suggesting that FIV and human immunodeficiency virus (HIV) share a common mechanism of infection involving an interaction between the virus and a member of the seven transmembrane domain superfamily of molecules. This article reviews the evidence for the involvement of chemokine receptors in FIV infection and contrasts these findings with similar studies on the primate lentiviruses HIV and SIV (simian immunodeficiency virus)

    A Solution to the Strong CP Problem with Gauge-Mediated Supersymmetry Breaking

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    We demonstrate that a certain class of low scale supersymmetric ``Nelson-Barr'' type models can solve the strong and supersymmetric CP problems while at the same time generating sufficient weak CP violation in the K0−Kˉ0K^{0}-\bar{K}^{0} system. In order to prevent one-loop corrections to θˉ\bar{\theta} which violate bounds coming from the neutron electric dipole moment (EDM), one needs a scheme for the soft supersymmetry breaking parameters which can naturally give sufficient squark degeneracies and proportionality of trilinear soft supersymmetry-breaking parameters to Yukawa couplings. We show that a gauge-mediated supersymmetry breaking sector can provide the needed degeneracy and proportionality, though that proves to be a problem for generic Nelson-Barr models. The workable model we consider here has the Nelson-Barr mass texture enforced by a gauge symmetry; one also expects a new U(1) gauge superfield with mass in the TeV range. The resulting model is predictive. We predict a measureable neutron EDM and the existence of extra vector-like quark superfields which can be discovered at the LHC. Because the 3×33\times 3 Cabbibo-Kobayashi-Maskawa matrix is approximately real, the model also predicts a flat unitarity triangle and the absence of substantial CP violation in the BB system at future BB factories. We discuss the general issues pertaining to the construction of such a workable model and how they lead to the successful strategy. A detailed renormalization group study is then used to establish the feasibility of the model considered.Comment: Proof-read version to appear in Phys. Rev.

    Late quaternary biotic homogenization of North American mammalian faunas

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    Biotic homogenization-increasing similarity of species composition among ecological communities-has been linked to anthropogenic processes operating over the last century. Fossil evidence, however, suggests that humans have had impacts on ecosystems for millennia. We quantify biotic homogenization of North American mammalian assemblages during the late Pleistocene through Holocene (similar to 30,000 ybp to recent), a timespan encompassing increased evidence of humans on the landscape (similar to 20,000-14,000 ybp). From similar to 10,000 ybp to recent, assemblages became significantly more homogenous (>100% increase in Jaccard similarity), a pattern that cannot be explained by changes in fossil record sampling. Homogenization was most pronounced among mammals larger than 1 kg and occurred in two phases. The first followed the megafaunal extinction at similar to 10,000 ybp. The second, more rapid phase began during human population growth and early agricultural intensification (similar to 2,000-1,000 ybp). We show that North American ecosystems were homogenizing for millennia, extending human impacts back similar to 10,000 years.Peer reviewe

    Late quaternary biotic homogenization of North American mammalian faunas

    Get PDF
    Biotic homogenization-increasing similarity of species composition among ecological communities-has been linked to anthropogenic processes operating over the last century. Fossil evidence, however, suggests that humans have had impacts on ecosystems for millennia. We quantify biotic homogenization of North American mammalian assemblages during the late Pleistocene through Holocene (similar to 30,000 ybp to recent), a timespan encompassing increased evidence of humans on the landscape (similar to 20,000-14,000 ybp). From similar to 10,000 ybp to recent, assemblages became significantly more homogenous (>100% increase in Jaccard similarity), a pattern that cannot be explained by changes in fossil record sampling. Homogenization was most pronounced among mammals larger than 1 kg and occurred in two phases. The first followed the megafaunal extinction at similar to 10,000 ybp. The second, more rapid phase began during human population growth and early agricultural intensification (similar to 2,000-1,000 ybp). We show that North American ecosystems were homogenizing for millennia, extending human impacts back similar to 10,000 years.Peer reviewe

    Estimating the Population Size of Female Sex Workers in Zimbabwe: Comparison of Estimates Obtained Using Different Methods in Twenty Sites and Development of a National-Level Estimate.

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    BACKGROUND: National-level population size estimates (PSEs) for hidden populations are required for HIV programming and modelling. Various estimation methods are available at the site-level, but it remains unclear which are optimal and how best to obtain national-level estimates. SETTING: Zimbabwe. METHODS: Using 2015-2017 data from respondent-driven sampling (RDS) surveys among female sex workers (FSW) aged 18+ years, mappings, and program records, we calculated PSEs for each of the 20 sites across Zimbabwe, using up to 3 methods per site (service and unique object multipliers, census, and capture-recapture). We compared estimates from different methods, and calculated site medians. We estimated prevalence of sex work at each site using census data available on the number of 15-49-year-old women, generated a list of all "hotspot" sites for sex work nationally, and matched sites into strata in which the prevalence of sex work from sites with PSEs was applied to those without. Directly and indirectly estimated PSEs for all hotspot sites were summed to provide a national-level PSE, incorporating an adjustment accounting for sex work outside hotspots. RESULTS: Median site PSEs ranged from 12,863 in Harare to 247 in a rural growth-point. Multiplier methods produced the highest PSEs. We identified 55 hotspots estimated to include 95% of all FSW. FSW nationally were estimated to number 40,491, 1.23% of women aged 15-49 years, (plausibility bounds 28,177-58,797, 0.86-1.79%, those under 18 considered sexually exploited minors). CONCLUSION: There are large numbers of FSW estimated in Zimbabwe. Uncertainty in population size estimation should be reflected in policy-making

    Crop Updates 2005 - Katanning

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    This session covers twenty five papers from different authors KEYNOTE How Farmers Can Work Together for a More Sustainable and Profitable Business, Brian McAlpine Farmer, Nuffield Scholar GENERAL 2005 Seasonal Outlook, David Stephens and Nicola Telcik, Department of Agriculture Essentials for cereal leaf disease management, K. Jayasena, R. Loughman, G. Thomas, C. Beard, and B. Paynter, Department of Agriculture Benefits to the grower of grain licensing, Colin Mann, Grain Licensing Authority SOIL & NUTRIENTS The effect of higher nitrogen fertiliser prices on rotation and fertiliser strategies in cropping systems, Ross Kingwell, Department of Agriculture Effect of stubble burning and seasonality on microbial processes and nutrient cycling, Francis Hoyle, University of Western Australia Soil Biology and Crop Production in Western Australian Farming Systems, D.V. Murphy, N. Milton, M. Osman, F.C. Hoyle, L.K Abbott, W.R. Cookson and S. Darmawanto, University of Western Australia Nutrient Management to get optimal production, Bill Bowden, Department of Agriculture OTHER CROPS Which malting barley variety and why? Blakely Paynter, Department of Agriculture KASPA AND OTHER NEW PULSE VARIETIES, 1. New Pulse varieties and where they fit in, K. Regan, P. White, Department of Agriculture & CLIMA, K. Siddique, CLIMA, K. Adhikari, Department of Agriculture & CLIMA, M. Harries, CLIMA Kaspa in the WA Grain Belt 2003-2004, Ian Pritchard, Department of Agriculture New annual pastures for Mediterranean farming systems, Angelo Loi, Phil Nichols, Clinton Revell & David Ferris, Department of Agriculture Challenging herbicide resistant ryegrass, Bill Roy, Agricultural Consulting & Research Services Pty.Ltd WEED MANAGEMENT Ingest, incinerate or invert? The pro’s and con’s of 3 weed seed removal tactics, Sally Peltzer1, Dave Minkey1 and Michael Walsh2 Department of Agriculture 1 and Western Australian Herbicide Resistance lnitiative2 A good use guide for pre-emergent herbicides, Alexandra Douglas, Department of Agriculture OTHER USEFUL INFORMATION 17.Growing season outlook, Meredith Fairbanks, Ian Foster, Geraldine Pasqual, David Stephens, Nicola Telcik, David Tennant, Department of Agriculture 18. Status Of Department Of Agriculture Western Australia Crop Varieties 19. Seed Licensee Details 20. Gene technology for growers. What is it? How does it Work? Belinda Barr, Australian Centre for Plant Functional Genomics, Dr Heather Bray, Molecular Plant Breeding Cooperative Research Centre. 21. Agronomic package for EGA Eagle Rock, Steve Penny, Department of Agriculture 22. Nutrient timing and requirements for increased crop yields in the high rainfall cropping zone, Narelle Hill, Ron McTaggart, Dr. Wal Anderson and Ray Tugwell Department of Agriculture 23. Insect contamination of cereal grain at harvest, Svetlana Micic and Phil Michael, Department of Agriculture 24. Crop leftovers: what’s in stubble for sheep? Roy Butler and Keith Croker, Department of Agriculture 25. Mandelup – Narrow-leafed lupi
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