5,201 research outputs found

    Spinally projecting preproglucagon axons preferentially innervate sympathetic preganglionic neurons

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    Glucagon-like peptide-1 (GLP-1) affects central autonomic neurons, including those controlling the cardiovascular system, thermogenesis, and energy balance. Preproglucagon (PPG) neurons, located mainly in the nucleus tractus solitarius (NTS) and medullary reticular formation, produce GLP-1. In transgenic mice expressing glucagon promoter-driven yellow fluorescent protein (YFP), these brainstem PPG neurons project to many central autonomic regions where GLP-1 receptors are expressed. The spinal cord also contains GLP-1 receptor mRNA but the distribution of spinal PPG axons is unknown. Here, we used two-color immunoperoxidase labeling to examine PPG innervation of spinal segments T1–S4 in YFP-PPG mice. Immunoreactivity for YFP identified spinal PPG axons and perikarya. We classified spinal neurons receiving PPG input by immunoreactivity for choline acetyltransferase (ChAT), nitric oxide synthase (NOS) and/or Fluorogold (FG) retrogradely transported from the peritoneal cavity. FG microinjected at T9 defined cell bodies that supplied spinal PPG innervation. The deep dorsal horn of lower lumbar cord contained YFP-immunoreactive neurons. Non-varicose, YFP-immunoreactive axons were prominent in the lateral funiculus, ventral white commissure and around the ventral median fissure. In T1–L2, varicose, YFP-containing axons closely apposed many ChAT-immunoreactive sympathetic preganglionic neurons (SPN) in the intermediolateral cell column (IML) and dorsal lamina X. In the sacral parasympathetic nucleus, about 10% of ChAT-immunoreactive preganglionic neurons received YFP appositions, as did occasional ChAT-positive motor neurons throughout the rostrocaudal extent of the ventral horn. YFP appositions also occurred on NOS-immunoreactive spinal interneurons and on spinal YFP-immunoreactive neurons. Injecting FG at T9 retrogradely labeled many YFP-PPG cell bodies in the medulla but none of the spinal YFP-immunoreactive neurons. These results show that brainstem PPG neurons innervate spinal autonomic and somatic motor neurons. The distributions of spinal PPG axons and spinal GLP-1 receptors correlate well. SPN receive the densest PPG innervation. Brainstem PPG neurons could directly modulate sympathetic outflow through their spinal inputs to SPN or interneurons

    Preference uncertainty as an explanation of anomalies in contingent valuation: coastal management in the UK

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    This is the final version. Available on open access from Springer via the DOI in this recordDirectly asking respondents in contingent valuation surveys their willingness-to-pay is one of the few quantitative methods available to assess full economic value (including both use and non-use values) of non-market environmental goods. It therefore remains vitally important to better understand the reasons for consistently observed violations of procedural invariance in such surveys. This paper describes an empirical experiment designed to examine whether uncertainty might provide an explanation for three commonly-observed violations of procedural invariance in contingent valuation. In each case we present a plausible explanation for each anomaly through decision heuristics brought about by respondents trying to answer the question truthfully when their underlying preferences are stable but uncertain. Using a novel semi-parametric estimator we find little evidence to support the idea that anomalies can be resolved through an uncertainty explanation but our experiment provides noteworthy insights into the ways uncertain preferences may be shaped by the nature of contingent valuation questions

    Probing Current Sheet Instabilities from Flare Ribbon Dynamics

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    The presence of current sheet instabilities, such as the tearing mode instability, are needed to account for the observed rate of energy release in solar flares. Insights into these current sheet dynamics can be revealed by the behavior of flare ribbon substructure, as magnetic reconnection accelerates particles down newly reconnected field lines into the chromosphere to mark the flare footpoints. Behavior in the ribbons can therefore be used to probe processes occurring in the current sheet. In this study, we use high-cadence (1.7 s) IRIS Slit Jaw Imager observations to probe for the growth and evolution of key spatial scales along the flare ribbons—resulting from dynamics across the current sheet of a small solar flare on 2016 December 6. Combining analyses of spatial scale growth with Si iv nonthermal velocities, we piece together a timeline of flare onset for this confined event, and provide evidence of the tearing mode instability triggering a cascade and inverse cascade toward a power spectrum consistent with plasma turbulence

    Phylogenetic relationships of Pestalotiopsis and allied genera inferred from ribosomal DNA sequences

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    Publication no. P-2001-0089-MSA,published_or_final_versio

    Statistical Characterization of the Dynamic Near‐Earth Plasma Sheet Relative to Ultra‐Low Frequency (ULF) Wave Growth at Substorm Onset

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    Magnetospheric substorms are a complex phenomenon. During the initial stages of a substorm a variety of important processes occur in near-Earth space within a span of several minutes. The relative timing and links between these processes are critical to understanding how, where and when substorms may occur. One of the first observed signatures at substorm onset is the exponential increase in ULF (Ultra-Low Frequency) wave power in the near-Earth magnetotail (e.g., −7.5 ≤ XGSM ≤ −12.5 RE). We use the Time History of Events and Macroscale Interactions during Substorms spacecraft to examine the conditions in the magnetotail plasma sheet before, during and after local ULF wave growth. Prior to the ULF wave growth, the magnetotail stretches with convectional flows dominating. We then find strong earthward and azimuthal flows that peak at a similar time to the peak ULF wave power. These flows are found to be faster in the mid-tail (−10 ≤ XGSM ≤ −12.5 RE) than the near-tail (−7.5 ≤ XGSM ≤ −10 RE). Examining the local plasma energy density (magnetic, thermal and kinetic), we find no statistical decrease that could explain the exponentially growing ULF waves, in fact the local energy density is found to increase. This suggests that there may be an injection of energy from elsewhere in the magnetotail. Following the peak ULF wave power the tail is seen to dipolarize, and the local energy density is enhanced

    Karyotypes versus Genomes: The Nymphalid Butterflies Melitaea cinxia, Danaus plexippus, and D. chrysippus

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    his is the author accepted manuscript. The final version is available from Karger via the DOI in this recordThe number of sequenced lepidopteran genomes is increasing rapidly. However, the corresponding assemblies rarely represent whole chromosomes and generally also lack the highly repetitive W sex chromosome. Knowledge of the karyotypes can facilitate genome assembly and further our understanding of sex chromosome evolution in Lepidoptera. Here, we describe the karyotypes of the Glanville fritillary Melitaea cinxia (n = 31), the monarch Danaus plexippus (n = 30), and the African queen D. chrysippus (2n = 60 or 59, depending on the source population). We show by FISH that the telomeres are of the (TTAGG) n type, as found in most insects. M. cinxia and D. plexippus have “conventional” W chromosomes which are heterochromatic in meiotic and somatic cells. In D. chrysippus, the W is inconspicuous. Neither telomeres nor W chromosomes are represented in the published genomes of M. cinxia and D. plexippus. Representation analysis in sequenced female and male D. chrysippus genomes detected an evolutionarily old autosome-Z chromosome fusion in Danaus. Conserved synteny of whole chromosomes, so called “macro synteny”, in Lepidoptera permitted us to identify the chromosomes involved in this fusion. An additional and more recent sex chromosome fusion was found in D. chrysippus by karyotype analysis and classical genetics. In a hybrid population between 2 subspecies, D. c. chrysippus and D. c. dorippus, the W chromosome was fused to an autosome that carries a wing colour locus. Thus, cytogenetics and the present state of genome data complement one another to reveal the evolutionary history of the species

    Valuing the social and environmental contribution of woodlands and trees in England, Scotland and Wales

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    Final published report. This publication is also available on the Foresty Commission website at: www.forestry.gov.uk/publicationsFirst published by the Forestry Commission in 2017.A second edition of this report is available in ORE: http://hdl.handle.net/10871/36539The diverse resources provided by trees and woodlands contribute to the production of a wide array of benefits ranging from timber to wildlife habitats and from carbon storage to water purification. This diversity is further complicated by the fact that, while some of the goods associated with forests are traded in markets and hence have associated prices, others arise outside markets and, while valuable, lack prices. The need to make evidencebased decisions regarding woodlands, including decisions such as how much public funding should be allocated to support the non-market benefits they generate, has necessitated the estimation of the value of those benefits. This scoping study provides a structured review of the state of knowledge regarding the economic valuation of social and environmental benefits derived from trees and woodlands in order to support policy and practice. Particular (although not exclusive) attention is paid to recent extensions to the literature since previous reviews (especially Eftec, 2011)

    Valuing the social and environmental contribution of woodlands and trees in England, Scotland and Wales. Second edition: to 2018

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    The first edition of this report is available in ORE: http://hdl.handle.net/10871/25958Woodlands and forests constitute arguably the most diverse environments on earth; diverse not only in terms of the plethora of characteristics and habitats they embrace, but also through the variety of benefits and values that they offer to people. While this diversity of benefits is now widely recognised, incorporating these values into decisions regarding the management and extension of woodland remains a challenge. While the value of some forest products, such as timber, is readily reflected within market prices, this is the exception rather than the rule. Most of the benefits provided by woodlands are not traded through markets and are therefore unpriced public goods. The UK Forestry Commission have for many years directly addressed the problem of incorporating the non-market benefits of woodland within conventional economic decision making through the application of techniques to estimate the economic value of these benefits (e.g. Willis, et al., 2003). As part of this initiative, in 2015 the Forestry Commission began working with the authors of the present report to provide a review of the research, policy and grey literature concerned with the economic valuation of the social and environmental benefits of woodlands and trees. This review, subsequently published as Binner et al., (2017) also included the development of a spreadsheet based decision support tool to facilitate the use of valuation estimates within decision making. The present report provides a second edition of that report, updating both the literature review and the accompanying spreadsheet decision support tool. In preparing this study, the research team at the University of Exeter undertook a structured reviewed of how technical and methodological developments are transforming the potential for robust valuation of non-market benefits and allied decision-making. The methods, data and modelling techniques, which underpin the existing evidence base on the value of woodlands and trees were critically evaluated, so as to provide a practical set of actionable options for enhancing that evidence base and improving decision making

    Managing clinical uncertainty in older people towards the end of life: a systematic review of person-centred tools.

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    BACKGROUND: Older people with multi-morbidities commonly experience an uncertain illness trajectory. Clinical uncertainty is challenging to manage, with risk of poor outcomes. Person-centred care is essential to align care and treatment with patient priorities and wishes. Use of evidence-based tools may support person-centred management of clinical uncertainty. We aimed to develop a logic model of person-centred evidence-based tools to manage clinical uncertainty in older people. METHODS: A systematic mixed-methods review with a results-based convergent synthesis design: a process-based iterative logic model was used, starting with a conceptual framework of clinical uncertainty in older people towards the end of life. This underpinned the methods. Medline, PsycINFO, CINAHL and ASSIA were searched from 2000 to December 2019, using a combination of terms: "uncertainty" AND "palliative care" AND "assessment" OR "care planning". Studies were included if they developed or evaluated a person-centred tool to manage clinical uncertainty in people aged ≥65 years approaching the end of life and quality appraised using QualSyst. Quantitative and qualitative data were narratively synthesised and thematically analysed respectively and integrated into the logic model. RESULTS: Of the 17,095 articles identified, 44 were included, involving 63 tools. There was strong evidence that tools used in clinical care could improve identification of patient priorities and needs (n = 14 studies); that tools support partnership working between patients and practitioners (n = 8) and that tools support integrated care within and across teams and with patients and families (n = 14), improving patient outcomes such as quality of death and dying and satisfaction with care. Communication of clinical uncertainty to patients and families had the least evidence and is challenging to do well. CONCLUSION: The identified logic model moves current knowledge from conceptualising clinical uncertainty to applying evidence-based tools to optimise person-centred management and improve patient outcomes. Key causal pathways are identification of individual priorities and needs, individual care and treatment and integrated care. Communication of clinical uncertainty to patients is challenging and requires training and skill and the use of tools to support practice

    Understanding the culture of antimicrobial prescribing in agriculture: a qualitative study of UK pig veterinary surgeons

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    Objectives The use of antimicrobials in food-producing animals has been linked with the emergence of antimicrobial resistance in bacterial populations, with consequences for animal and public health. This study explored the underpinning drivers, motivators and reasoning behind prescribing decisions made by veterinary surgeons working in the UK pig industry. Methods A qualitative interview study was conducted with 21 veterinary surgeons purposively selected from all UK pig veterinary surgeons. Thematic analysis was used to analyse transcripts. Results Ensuring optimum pig health and welfare was described as a driver for antimicrobial use by many veterinary surgeons and was considered a professional and moral obligation. Veterinary surgeons also exhibited a strong sense of social responsibility over the need to ensure that antimicrobial use was responsible. A close relationship between management practices, health and economics was evident, with improvements in management commonly identified as being potential routes to reduce antimicrobial usage; however, these were not always considered economically viable. The relationship with clients was identified as being a source of professional stress for practitioners due to pressure from farmers requesting antimicrobial prescriptions, and concern over poor compliance of antimicrobial administration by some farmers. Conclusions The drivers behind prescribing decisions by veterinary surgeons were complex and diverse. A combination of education, improving communication between veterinary surgeons and farmers, and changes in regulations, in farm management and in consumer/retailer demands may all be needed to ensure that antimicrobial prescribing is optimal and to achieve significant reductions in use
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