77 research outputs found

    The heat-stable cytosolic factor that promotes glucocorticoid receptor binding to DNA is neither thioredoxin nor ribonuclease

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    Treatment of rat liver cytosol containing temperature-transformed [3H]dexamethasone-bound receptors at 0[deg]C with the sulfhydryl modifying reagent methyl methanethiosulfonate (MMTS) inhibits the DNA-binding activity of the receptor, and DNA-binding activity is restored after addition of dithiothreitol (DTT). However, transformed receptors that are treated with MMTS and then separated from low Mr components of cytosol by passage through a column of Sephadex G-50 have very little DNA-binding activity when DTT is added to regenerate sulfhydryl moities. The receptors will bind to DNA if whole liver cytosol or boiled liver cytosol is added in addition to DTT. The effect of boiled cytosol is mimicked by purified rat thioredoxin or bovine RNase A in a manner that does not reflect the reducing activity of the former or the catalytic activity of the latter. This suggests that the reported ability of each of these heat-stable peptides to stimulate DNA binding by glucocorticoid receptors is not a biologically relevant action. We suggest that stimulation of DNA binding of partially purified receptors by boiled cytosol does not constitute a reconstitution of a complete cytosolic system in which the dissociated receptor must associate with a specific heat-stable accessory protein required for DNA binding, as has been suggested in the "two-step" model of receptor transformation recently proposed by Schmidt et al.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26525/1/0000064.pd

    Covariance of Antiproton Yield and Source Size in Nuclear Collisions

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    We confront for the first time the widely-held belief that combined event-by-event information from quark gluon plasma signals can reduce the ambiguity of the individual signals. We illustrate specifically how the measured antiproton yield combined with the information from pion-pion HBT correlations can be used to identify novel event classes.Comment: 8 pages, 5 figures, improved title, references and readability; results unchange

    Weak tradeoff between xylem safety and xylem-specific hydraulic efficiency across the world\u27s woody plant species.

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    The evolution of lignified xylem allowed for the efficient transport of water under tension, but also exposed the vascular network to the risk of gas emboli and the spread of gas between xylem conduits, thus impeding sap transport to the leaves. A well-known hypothesis proposes that the safety of xylem (its ability to resist embolism formation and spread) should trade off against xylem efficiency (its capacity to transport water). We tested this safety-efficiency hypothesis in branch xylem across 335 angiosperm and 89 gymnosperm species. Safety was considered at three levels: the xylem water potentials where 12%, 50% and 88% of maximal conductivity are lost. Although correlations between safety and efficiency were weak (r(2) \u3c 0.086), no species had high efficiency and high safety, supporting the idea for a safety-efficiency tradeoff. However, many species had low efficiency and low safety. Species with low efficiency and low safety were weakly associated (r(2) \u3c 0.02 in most cases) with higher wood density, lower leaf- to sapwood-area and shorter stature. There appears to be no persuasive explanation for the considerable number of species with both low efficiency and low safety. These species represent a real challenge for understanding the evolution of xylem

    BIOlogical Factors that Limit sustAined Remission in rhEumatoid arthritis (the BIO-FLARE study): protocol for a non-randomised longitudinal cohort study

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    Background Our knowledge of immune-mediated inflammatory disease (IMID) aetiology and pathogenesis has improved greatly over recent years, however, very little is known of the factors that trigger disease relapses (flares), converting diseases from inactive to active states. Focussing on rheumatoid arthritis (RA), the challenge that we will address is why IMIDs remit and relapse. Extrapolating from pathogenetic factors involved in disease initiation, new episodes of inflammation could be triggered by recurrent systemic immune dysregulation or locally by factors within the joint, either of which could be endorsed by overarching epigenetic factors or changes in systemic or localised metabolism. Methods The BIO-FLARE study is a non-randomised longitudinal cohort study that aims to enrol 150 patients with RA in remission on a stable dose of non-biologic disease-modifying anti-rheumatic drugs (DMARDs), who consent to discontinue treatment. Participants stop their DMARDs at time 0 and are offered an optional ultrasound-guided synovial biopsy. They are studied intensively, with blood sampling and clinical evaluation at weeks 0, 2, 5, 8, 12 and 24. It is anticipated that 50% of participants will have a disease flare, whilst 50% remain in drug-free remission for the study duration (24 weeks). Flaring participants undergo an ultrasound-guided synovial biopsy before reinstatement of previous treatment. Blood samples will be used to investigate immune cell subsets, their activation status and their cytokine profile, autoantibody profiles and epigenetic profiles. Synovial biopsies will be examined to profile cell lineages and subtypes present at flare. Blood, urine and synovium will be examined to determine metabolic profiles. Taking into account all generated data, multivariate statistical techniques will be employed to develop a model to predict impending flare in RA, highlighting therapeutic pathways and informative biomarkers. Despite initial recruitment to time and target, the SARS-CoV-2 pandemic has impacted significantly, and a decision was taken to close recruitment at 118 participants with complete data. Discussion This study aims to investigate the pathogenesis of flare in rheumatoid arthritis, which is a significant knowledge gap in our understanding, addressing a major unmet patient need

    Outlook for inverse design in nanophotonics

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    Recent advancements in computational inverse design have begun to reshape the landscape of structures and techniques available to nanophotonics. Here, we outline a cross section of key developments at the intersection of these two fields: moving from a recap of foundational results to motivation of emerging applications in nonlinear, topological, near-field and on-chip optics.Comment: 13 pages, 6 figure

    Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

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    Introduction: The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures. Methods: In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025. Findings: Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2–6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5–5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4–10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32–4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23–11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation. Interpretation: After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

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    Weak tradeoff between xylem safety and xylem-specific hydraulic efficiency across the world's woody plant species

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    * The evolution of lignified xylem allowed for the efficient transport of water under tension, but also exposed the vascular network to the risk of gas emboli and the spread of gas between xylem conduits, thus impeding sap transport to the leaves. A well-known hypothesis proposes that the safety of xylem (its ability to resist embolism formation and spread) should trade off against xylem efficiency (its capacity to transport water). * We tested this safety–efficiency hypothesis in branch xylem across 335 angiosperm and 89 gymnosperm species. Safety was considered at three levels: the xylem water potentials where 12%, 50% and 88% of maximal conductivity are lost. * Although correlations between safety and efficiency were weak (r2 < 0.086), no species had high efficiency and high safety, supporting the idea for a safety–efficiency tradeoff. However, many species had low efficiency and low safety. Species with low efficiency and low safety were weakly associated (r2 < 0.02 in most cases) with higher wood density, lower leaf- to sapwood-area and shorter stature. * There appears to be no persuasive explanation for the considerable number of species with both low efficiency and low safety. These species represent a real challenge for understanding the evolution of xylem.Fil: Gleason, Sean M.. Macquarie University. Department of Biological Sciences ; Australia. USDA-ARS. Water Management Research; Estados UnidosFil: Westoby, Mark. Macquarie University. Department of Biological Sciences; AustraliaFil: Jansen, Steven. Ulm University. Institute of Systematic Botany and Ecology; AlemaniaFil: Choat, Brendan. Western Sydney University. Hawkesbury Institute for the Environment; AustraliaFil: Hacke, Uwe G.. University of Alberta. Department of Renewable Resources; CanadáFil: Pratt, Robert B.. California State University. Department of Biology; Estados UnidosFil: Bhaskar, Radika. Haverford College. Department of Biology; Estados UnidosFil: Brodibb, Tim J.. University of Tasmania. School of Biological Sciences; AustraliaFil: Bucci, Sandra Janet. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia Golfo San Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia Golfo San Jorge. Universidad Nacional de la Patagonia "san Juan Bosco". Centro de Investigaciones y Transferencia Golfo San Jorge; ArgentinaFil: Cao, Kun-Fang. Guangxi University. College of Forestry. Utilization of Subtropical Agro-Bioresources ; ChinaFil: Cochard, Hervé. Clermont Université. Université Blaise Pascal. UMR547 PIAF; Francia. Institut National de la Recherche Agronomique; FranciaFil: Delzon, Sylvain. Institut National de la Recherche Agronomique; FranciaFil: Domec, Jean-Christophe. Duke University, Durham. Nicholas School of the Environment; Estados Unidos. Institut National de la Recherche Agronomique; FranciaFil: Fan, Ze-Xin. Chinese Academy of Sciences. Xishuangbanna Tropical Botanical Garden. Key Laboratory of Tropical Forest Ecology; ChinaFil: Feild, Taylor S.. James Cook University. School of Marine and Tropical Biology; AustraliaFil: Jacobsen, Anna L.. California State University. Department of Biology; Estados UnidosFil: Johnson, Daniel M.. University of Idaho. Rangeland and Fire Sciences. Department of Forest; Estados UnidosFil: Lens, Frederic. Leiden University. Naturalis Biodiversity Center; Países BajosFil: Maherali, Hafiz. University of Guelph. Department of Integrative Biology; CanadáFil: Martínez-Viralta, Jordi. CREAF; España. Institució Catalana de Recerca i Estudis Avancats; EspañaFil: Mayr, Stefan. University of Innsbruck. Department of Botany; AustriaFil: McCulloh, Katherine A.. University of Wisconsin-Madison. Department of Botany; Estados UnidosFil: Mencuccini, Maurizio. University of Edinburgh. School of GeoSciences; Reino Unido. Institució Catalana de Recerca i Estudis Avancats; EspañaFil: Mitchell, Patrick J.. CSIRO Land and Water Flagship; AustraliaFil: Morris, Hugh. Ulm University. Institute of Systematic Botany and Ecology ; AlemaniaFil: Nardini, Andrea. Università Trieste. Dipartimento Scienze della Vita ; ItaliaFil: Pittermann, Jarmila. University of California. Department of Ecology and Evolutionary Biology; Estados UnidosFil: Plavcová, Lenka. Ulm University. Institute of Systematic Botany and Ecology; Alemania. University of Alberta. Department of Renewable Resources; CanadáFil: Schreiber, Stefan G.. University of Alberta. Department of Renewable Resources; CanadáFil: Sperry, John S.. University of Utah. Department of Biology; Estados UnidosFil: Wright, Ian J.. Macquarie University. Department of Biological Sciences; AustraliaFil: Zanne, Ami E.. George Washington University. Department of Biological Sciences; Estados Unido
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