196 research outputs found

    Ultrahigh Bandwidth Spin Noise Spectroscopy: Detection of Large g-Factor Fluctuations in Highly n-Doped GaAs

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    We advance all optical spin noise spectroscopy (SNS) in semiconductors to detection bandwidths of several hundred gigahertz by employing an ingenious scheme of pulse trains from ultrafast laser oscillators as an optical probe. The ultrafast SNS technique avoids the need for optical pumping and enables nearly perturbation free measurements of extremely short spin dephasing times. We employ the technique to highly n-doped bulk GaAs where magnetic field dependent measurements show unexpected large g-factor fluctuations. Calculations suggest that such large g-factor fluctuations do not necessarily result from extrinsic sample variations but are intrinsically present in every doped semiconductor due to the stochastic nature of the dopant distribution.Comment: 5 pages, 3 figure

    Prevention of “Humanized” Diabetogenic CD8 T-Cell Responses in HLA-Transgenic NOD Mice by a Multipeptide Coupled-Cell Approach

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    OBJECTIVE: Type 1 diabetes can be inhibited in standard NOD mice by autoantigen-specific immunotherapy targeting pathogenic CD8+ T-cells. NOD.beta2m(null).HHD mice expressing human HLA-A2.1 but lacking murine major histocompatibility complex class I molecules develop diabetes characterized by CD8 T-cells recognizing certain autoantigenic peptides also targeted in human patients. These include peptides derived from the pancreatic beta-cell proteins insulin (INS1/2 A(2-10) and INS1 B(5-14)) and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP(265-273) and IGRP(228-236)). Hence, NOD.beta2m(null).HHD mice represent a model system for developing potentially clinically translatable interventions for suppressing diabetogenic HLA-A2.1-restricted T-cell responses. RESEARCH DESIGN AND METHODS: Starting at 4-6 weeks of age, NOD.beta2m(null).HHD female mice were injected intravenously with syngeneic splenocytes to which various admixtures of the four above-mentioned peptides were bound by the cross-linking agent ethylene carbodiimide (ECDI). RESULTS: Treatment with such cells bearing the complete cocktail of INS and IGRP epitopes (designated INS/IGRP-SPs) significantly inhibited diabetes development in NOD.beta2m(null).HHD recipients compared with controls receiving splenocytes coupled with an irrelevant HLA-A2.1-restricted Flu16 peptide. Subsequent analyses found syngeneic splenocytes bearing the combination of the two ECDI-coupled IGRPs but not INS peptides (IGRP-SPs or INS-SPs) effectively inhibited diabetes development in NOD.beta2m(null).HHD mice. This result was supported by enzyme-linked immunospot (ELISPOT) analyses indicating combined INS/IGRP-SPs diminished HLA-A2.1-restricted IGRP but not INS autoreactive CD8+ T-cell responses in NOD.beta2m(null).HHD mice. CONCLUSIONS: These data support the potential of a cell therapy approach targeting HLA-A2.1-restricted IGRP autoreactive CD8 T-cells as a diabetes intervention approach in appropriate human patients

    Sustainable intensification of livestock production on pastures

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    Growing human population and limited natural resources require a sustainable intensification of agricultural production systems. The ‘green revolution’ was successful in increasing world food production, but unintended consequences, including pollution of groundwater, soil erosion, climate change, and intensive use of agrochemicals, left a large footprint in the environment. Sustainable livestock intensification (SLI) implies greater productivity and more efficient use of natural resources, reducing the impact of livestock systems in the environment. Approaches to reach this goal include diversification of plant species and plant functional groups, multiple ruminant species, improvement in feeding techniques and grazing management, plant breeding for improved nutrient use efficiency, integrated crop-livestock systems, and silvopasture systems. Greater use of forage legumes appears to be an opportunity for SLI in extensive C4 grass-based pastureland commonly found in vast areas of Latin America. Grasslands in the 21st century will also be valued for multiple services they provide to humankind, and mechanisms of payment for these services are needed. A more ‘holistic’ approach will improve the social and economic sustainability of livestock systems. Achieving long-term sustainability must match short-term profits. Diversification of the products and services provided by grassland ecosystems is key to reach SLI in the near future

    Herbage Accumulation and Nutritive Value of Limpograss Breeding Lines Under Stockpiling Management.

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    Supplements or conserved forage are often used to overcome forage quantity deficits for beef cattle, but stockpiled forage can be more economical. Limpograss [Hemarthria altissima (Poir.) Stapf & C.E. Hubb.] is the best available species for stockpiling in Florida because it is productive in autumn and maintains greater digestibility than other grasses at advanced stages of maturity. New limpograss hybrid breeding lines have been developed, but they have not been tested under stockpiling. Three limpograss breeding lines (1, 4F, and 10) and the most-used cultivar, Floralta, received 50 or 100 kg N ha?1 at initiation of stockpiling and herbage accumulated for 8, 12, or 16 wk. Entry 4F had greater herbage accumulation (7.3 Mg ha?1) than Entries 10, 1, and Floralta (6.1, 6.0, and 5.4 Mg ha?1, respectively). Entry 4F also had greater in vitro digestible organic matter (IVDOM) concentration (530?594 g kg?1) than Entries 1 and Floralta, but 4F was not different from Entry 10 (519?531 g kg?1) after 12 and 16 wk of accumulation. As stockpiling period increased from 8 to 16 wk, herbage accumulation increased from 5.3 to 7.4 Mg ha?1, dead material proportion increased from 1 to 10%, and herbage crude protein (CP) decreased from 44 to 32 g kg?1. Limpograss hybrids 4F and 10 are superior to Floralta for stockpiling, stockpiling period should not be longer than 12 wk, and protein supplement will be required to achieve satisfactory animal performance on stockpiled limpograss

    T Cells Recognizing a Peptide Contaminant Undetectable by Mass Spectrometry

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    Synthetic peptides are widely used in immunological research as epitopes to stimulate their cognate T cells. These preparations are never completely pure, but trace contaminants are commonly revealed by mass spectrometry quality controls. In an effort to characterize novel major histocompatibility complex (MHC) Class I-restricted β-cell epitopes in non-obese diabetic (NOD) mice, we identified islet-infiltrating CD8+ T cells recognizing a contaminating peptide. The amount of this contaminant was so small to be undetectable by direct mass spectrometry. Only after concentration by liquid chromatography, we observed a mass peak corresponding to an immunodominant islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)206-214 epitope described in the literature. Generation of CD8+ T-cell clones recognizing IGRP206-214 using a novel method confirmed the identity of the contaminant, further underlining the immunodominance of IGRP206-214. If left undetected, minute impurities in synthetic peptide preparations may thus give spurious results

    Effectiveness of trigger point dry needling for plantar heel pain: study protocol for a randomised controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Plantar heel pain (plantar fasciitis) is a common and disabling condition, which has a detrimental impact on health-related quality of life. Despite the high prevalence of plantar heel pain, the optimal treatment for this disorder remains unclear. Consequently, an alternative therapy such as dry needling is increasingly being used as an adjunctive treatment by health practitioners. Only two trials have investigated the effectiveness of dry needling for plantar heel pain, however both trials were of a low methodological quality. This manuscript describes the design of a randomised controlled trial to evaluate the effectiveness of dry needling for plantar heel pain.</p> <p>Methods</p> <p>Eighty community-dwelling men and woman aged over 18 years with plantar heel pain (who satisfy the inclusion and exclusion criteria) will be recruited. Eligible participants with plantar heel pain will be randomised to receive either one of two interventions, (i) real dry needling or (ii) sham dry needling. The protocol (including needling details and treatment regimen) was formulated by general consensus (using the Delphi research method) using 30 experts worldwide that commonly use dry needling for plantar heel pain. Primary outcome measures will be the pain subscale of the Foot Health Status Questionnaire and "first step" pain as measured on a visual analogue scale. The secondary outcome measures will be health related quality of life (assessed using the Short Form-36 questionnaire - Version Two) and depression, anxiety and stress (assessed using the Depression, Anxiety and Stress Scale - short version). Primary outcome measures will be performed at baseline, 2, 4, 6 and 12 weeks and secondary outcome measures will be performed at baseline, 6 and 12 weeks. Data will be analysed using the intention to treat principle.</p> <p>Conclusion</p> <p>This study is the first randomised controlled trial to evaluate the effectiveness of dry needling for plantar heel pain. The trial will be reported in accordance with the Consolidated Standards of Reporting Trials and the Standards for Reporting Interventions in Clinical Trials of Acupuncture guidelines. The findings from this trial will provide evidence for the effectiveness of trigger point dry needling for plantar heel pain.</p> <p>Trial registration</p> <p>Australian New Zealand 'Clinical Trials Registry'. <a href="http://www.anzctr.org.au/ACTRN12610000611022.aspx">ACTRN12610000611022</a>.</p

    Absence of an association of human polyomavirus and papillomavirus infection with lung cancer in China: a nested case–control study

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    BACKGROUND: Studies of human polyomavirus (HPyV) infection and lung cancer are limited and those regarding the association of human papillomavirus (HPV) infection and lung cancer have produced inconsistent results. METHODS: We conducted a nested case–control study to assess the association between incident lung cancer of various histologies and evidence of prior infection with HPyVs and HPVs. We selected serum from 183 cases and 217 frequency matched controls from the Yunnan Tin Miner’s Cohort study, which was designed to identify biomarkers for early detection of lung cancer. Using multiplex liquid bead microarray (LBMA) antibody assays, we tested for antibodies to the VP1 structural protein and small T antigen (ST-Ag) of Merkel cell, KI, and WU HPyVs. We also tested for antibodies against HPV L1 structural proteins (high-risk types 16, 18, 31, 33, 52, and 58 and low-risk types 6 and 11) and E6 and E7 oncoproteins (high risk types 16 and 18). Measures of antibody reactivity were log transformed and analyzed using logistic regression. RESULTS: We found no association between KIV, WUV, and MCV antibody levels and incident lung cancer (P-corrected for multiple comparisons >0.10 for all trend tests). We also found no association with HPV-16, 18, 31, 33, 52, and 58 seropositivity (P-corrected for multiple comparisons >0.05 for all). CONCLUSIONS: Future studies of infectious etiologies of lung cancer should look beyond HPyVs and HPVs as candidate infectious agents. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12885-016-2381-3) contains supplementary material, which is available to authorized users
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