429 research outputs found

    Anatomical correlates of cursoriality are compromised by body size and propensity to burrow in a group of small mammals (Lagomorpha)

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    Highly cursorial animals are specialised for fast, sustained running via specific morphological adaptations, notably including changes in limb segment length and mechanical advantage. Members of the order Lagomorpha (hares, rabbits and pikas) vary in cursorial ability; hares are generally highly cursorial, rabbits more frequently saltate, and pikas predominantly trot. Previous investigations of lagomorphs have identified anatomical trends correlated with this ‘cursoriality gradient’, however, the phylogenetic sampling of such investigations has been limited to three American species, namely the American pika (Ochotona princeps), brush rabbit (Sylvilagus bachmani), and black-tailed jackrabbit (Lepus californicus). Here, we expand the phylogenetic sample and body size range by including novel data from Australian samples of the European rabbit (Oryctolagus cuniculus) and European hare (L. europaeus), alongside unpublished data on the Eastern cottontail (S. floridanus). X-ray Computed Tomography and digital landmarking were used to capture proportions within the appendicular skeleton of ~ 40 specimens of each European species. In doubling the number of species studied, we find the previously-identified morphological gradients associated with cursorial behaviour are complicated when evaluated in the larger sample. The relative length and joint velocity of limbs was found to be lower than predicted in European rabbits and hares. Furthermore, we present a novel assessment of morphological integration in the lagomorph appendicular skeleton, finding between-limb covariation patterns that are generally similar to those of other mammals. Broadly, these results suggest cursoriality is only one of many selective forces driving lagomorph skeletal evolution, with variations in body size and fossoriality potentially having measurable impacts.Ellen M. Martin, Jesse W. Young, Connie D. Fellmann, Brian Kraatz, Emma Sherrat

    ACVIM consensus statement on the treatment of immune-mediated hemolytic anemia in dogs

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    Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases

    Linking high-frequency DOC dynamics to the age of connected water sources

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    Acknowledgments The authors would like to thank our NRI colleagues for all their help with field and laboratory work, especially Audrey Innes, Jonathan Dick, and Ann Porter. We would like to also thank Iain Malcolm (Marine Scotland Science) for providing AWS data and the European Research Council ERC (project GA 335910 VEWA) for funding the VeWa project. Please contact the authors for access to the data used in this paper. We would also like to thank the Natural Environment Research Council NERC (project NE/K000268/1) for funding.Peer reviewedPublisher PD

    Working memory training restores aberrant brain activity in adult attention-deficit hyperactivity disorder

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    The development of treatments for attention impairments is hampered by limited knowledge about the malleability of underlying neural functions. We conducted the first randomized controlled trial to determine the modulations of brain activity associated with working memory (WM) training in adults with attention-deficit hyperactivity disorder (ADHD). At baseline, we assessed the aberrant functional brain activity in the n-back WM task by comparing 44 adults with ADHD with 18 healthy controls using fMRI. Participants with ADHD were then randomized to train on an adaptive dual n-back task or an active control task. We tested whether WM training elicits redistribution of brain activity as observed in healthy controls, and whether it might further restore aberrant activity related to ADHD. As expected, activity in areas of the default-mode (DMN), salience (SN), sensory-motor (SMN), frontoparietal (FPN), and subcortical (SCN) networks was decreased in participants with ADHD at pretest as compared with healthy controls, especially when the cognitive load was high. WM training modulated widespread FPN and SN areas, restoring some of the aberrant activity. Training effects were mainly observed as decreased brain activity during the trained task and increased activity during the untrained task, suggesting different neural mechanisms for trained and transfer tasks.Peer reviewe

    The Interaction of Hypotaurine and Other Sulfinates with Reactive Oxygen and Nitrogen Species:A Survey of Reaction Mechanisms

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    Considerable strides have been made in understanding the oxidative mechanisms involved in the final steps of the cysteine pathway leading to taurine. The oxidation of sulfinates, hypotaurine and cysteine sulfinic acid, to the respective sulfonates, taurine and cysteic acid, has never been associated with any specific enzyme. Conversely, there is strong evidence that in vivo formation of taurine and cysteic acid is the result of sulfinate interaction with a variety of biologically relevant oxidants. In the last decade, many experiments have been performed to understand whether peroxynitrite, nitrogen dioxide and carbonate radical anion could be included in the biologically relevant reactive species capable of oxidizing sulfinates. Thanks to this work, it has been possible to highlight two possible reaction mechanisms (direct and indirect reaction) of sulfinates with reactive oxygen and nitrogen species.The sulfinates oxidation, mediated by peroxynitrite, is an example of both reaction mechanisms: through a two-electron-direct-reaction with peroxynitrite or through a one-electron-indirect-transfer reaction. In the indirect mechanism, the peroxynitrite homolysis releases hydroxyl and nitrogen dioxide radical and in addition the degradation of short-lived adduct formed by peroxynitrite and CO2 can generate carbonate radical anion. The reaction of hypotaurine and cysteine sulfinic acid with peroxynitrite-derived radicals is accompanied by extensive oxygen uptake with the generation of transient intermediates, which can begin a reaction by an oxygen-dependent mechanism with the sulfonates, taurine, and cysteic acid as final products. Due to pulse radiolysis studies, it has been shown that transient sulfonyl radicals (RSO2(‱)) have been produced during the oxidation of both sulfinates by one-electron transfer reaction.The purpose is to analyze all the aspects of the reactive mechanism in the sulfinic group oxidation of hypotaurine and cysteine sulfinic acid through the results obtained from our laboratory in recent years

    Accounting fraud, business failure and creative auditing: A microanalysis of the strange case of the Sunbeam Corporation

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    This article closely examines the Sunbeam Corporation’s path to failure and explores the reasons for its singularity. From the analysis of US fraud cases included in the UCLA-LoPucki Bankruptcy Research Database, this corporate case appears as an outlier. For Sunbeam, the time-lapse between fraud disclosure and its final bankruptcy is the longest of the entire sample; it is unique because of its length. This article uses a historical microanalysis to evaluate different hypotheses about the Sunbeam Corporation’s path to failure. The relationships between acquisitions and fraud, ‘scapegoat dynamics’ and ‘creative auditing’ are identified as the most relevant issues to be examined against a changing institutional context. The resulting reconstruction of the events provides unexpected insights and recommendations for future research on auditing and accounting fraud

    Precipitation control over inorganic nitrogen import-export budgets across watersheds: a synthesis of long-term ecological research

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    ABSTRACT We investigated long-term and seasonal patterns of N imports and exports, as well as patterns following climate perturbations, across biomes using data from 15 watersheds from nine Long-Term Ecological Research (LTER) sites in North America. Mean dissolved inorganic nitrogen (DIN) import-export budgets (N import via precipitation-N export via stream flow) for common years across all watersheds was highly variable, ranging from a net loss of 0Ð17 ƥ 0Ð09 kg N ha 1 mo 1 to net retention of 0Ð68 ƥ 0Ð08 kg N ha 1 mo 1 . The net retention of DIN decreased (smaller import-export budget) with increasing precipitation, as well as with increasing variation in precipitation during the winter, spring, and fall. Averaged across all seasons, net DIN retention decreased as the coefficient of variation (CV) in precipitation increased across all sites (r 2 D 0Ð48, p D 0Ð005). This trend was made stronger when the disturbed watersheds were withheld from the analysis (r 2 D 0Ð80, p < 0Ð001, n D 11). Thus, DIN exports were either similar to or exceeded imports in the tropical, boreal, and wet coniferous watersheds, whereas imports exceeded exports in temperate deciduous watersheds. In general, forest harvesting, hurricanes, or floods corresponded with periods of increased DIN exports relative to imports. Periods when water throughput within a watershed was likely to be lower (i.e. low snow pack or El Niño years) corresponded with decreased DIN exports relative to imports. These data provide a basis for ranking diverse sites in terms of their ability to retain DIN in the context of changing precipitation regimes likely to occur in the future
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