84 research outputs found

    Ecological strategies in California chaparral: Interacting effects of soils, climate, and fire on specific leaf area

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    Background: High values of specific leaf area (SLA) are generally associated with high maximal growth rates in resource-rich conditions, such as mesic climates and fertile soils. However, fire may complicate this relationship since its frequency varies with both climate and soil fertility, and fire frequency selects for regeneration strategies (resprouting versus seeding) that are not independent of resource-acquisition strategies. Shared ancestry is also expected to affect the distribution of resource-use and regeneration traits. Aims: We examined climate, soil, and fire as drivers of community-level variation in a key functional trait, SLA, in chaparral in California. Methods: We quantified the phylogenetic, functional, and environmental non-independence of key traits for 87 species in 115 plots. Results: Among species, SLA was higher in resprouters than seeders, although not after phylogeny correction. Among communities, mean SLA was lower in harsh interior climates, but in these climates it was higher on more fertile soils and on more recently burned sites; in mesic coastal climates, mean SLA was uniformly high despite variation in soil fertility and fire history. Conclusions: We conclude that because important correlations exist among both species traits and environmental filters, interpreting the functional and phylogenetic structure of communities may require an understanding of complex interactive effects

    Shockwave lithotripsy compared with ureteroscopic stone treatment for adults with ureteric stones : the TISU non-inferiority RCT

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    Acknowledgements The authors wish to thank the patients who participated in the TISU trial.We also thank Stanley Coutts (patient representative) and Charles Clark (patient representative and co-applicant) for their contribution to the design of the participant-facing documents (patient information sheet and questionnaires); Sharon Wren for her secretarial support and data management; previous data co-ordinators, Jessica Wood and Margery Heath, for their data and trial management support; the CHaRT programming team led by Gladys McPherson (to 2016) and Mark Forrest (2016–present); other staff within CHaRT and the HSRU for their assistance with the trial (Cynthia Fraser); members of the PMG for their ongoing advice and support of the trial, plus the independent members of the TSC and DMC; and the staff at the recruitment sites who facilitated the recruitment, treatment and follow-up of trial participants (all listed below); and, finally, we would like to thank the National Institute for Health Research and the Health Technology Assessment programme for funding the TISU trial. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 19. See the NIHR Journals Library website for further project information.Peer reviewedPublisher PD

    Robust Biomarkers: Methodologically Tracking Causal Processes in Alzheimer’s Measurement

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    In biomedical measurement, biomarkers are used to achieve reliable prediction of, and useful causal information about patient outcomes while minimizing complexity of measurement, resources, and invasiveness. A biomarker is an assayable metric that discloses the status of a biological process of interest, be it normative, pathophysiological, or in response to intervention. The greatest utility from biomarkers comes from their ability to help clinicians (and researchers) make and evaluate clinical decisions. In this paper we discuss a specific methodological use of clinical biomarkers in pharmacological measurement: Some biomarkers, called ‘surrogate markers’, are used to substitute for a clinically meaningful endpoint corresponding to events and their penultimate risk factors. We confront the reliability of clinical biomarkers that are used to gather information about clinically meaningful endpoints. Our aim is to present a systematic methodology for assessing the reliability of multiple surrogate markers (and biomarkers in general). To do this we draw upon the robustness analysis literature in the philosophy of science and the empirical use of clinical biomarkers. After introducing robustness analysis we present two problems with biomarkers in relation to reliability. Next, we propose an intervention-based robustness methodology for organizing the reliability of biomarkers in general. We propose three relevant conditions for a robust methodology for biomarkers: (R1) Intervention-based demonstration of partial independence of modes: In biomarkers partial independence can be demonstrated through exogenous interventions that modify a process some number of “steps” removed from each of the markers. (R2) Comparison of diverging and converging results across biomarkers: By systematically comparing partially-independent biomarkers we can track under what conditions markers fail to converge in results, and under which conditions they successfully converge. (R3) Information within the context of theory: Through a systematic cross-comparison of the markers we can make causal conclusions as well as eliminate competing theories. We apply our robust methodology to currently developing Alzheimer’s research to show its usefulness for making causal conclusions

    Assessment of acute myocardial infarction: current status and recommendations from the North American society for cardiovascular imaging and the European society of cardiac radiology

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    There are a number of imaging tests that are used in the setting of acute myocardial infarction and acute coronary syndrome. Each has their strengths and limitations. Experts from the European Society of Cardiac Radiology and the North American Society for Cardiovascular Imaging together with other prominent imagers reviewed the literature. It is clear that there is a definite role for imaging in these patients. While comparative accuracy, convenience and cost have largely guided test decisions in the past, the introduction of newer tests is being held to a higher standard which compares patient outcomes. Multicenter randomized comparative effectiveness trials with outcome measures are required

    Caracol, Belize, and Changing Perceptions of Ancient Maya Society

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    Surviving Sepsis Campaign: International guidelines for management of severe sepsis and septic shock: 2008

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    SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Strong Neurophilosophy and the Matter of Bat Consciousness: A case study

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    In “What is it like to be boring and myopic?” Kathleen Akins offers an interesting, empirically driven, argument for thinking that there is nothing that it is like to be a bat. She suggests that bats are “boring” in the sense that they are governed by behavioral scripts and simple, non-representational, control loops, and are best characterized as biological automatons. Her approach has been well received by philosophers sympathetic to empirically informed philosophy of mind. But, despite its influence, her work has not met with any critical appraisal. It is argued that a reconsideration of the empirical results shows that bats are not boring automatons, driven by short input-output loops, instincts, and reflexes. Grounds are provided for thinking that bats satisfy a range of philosophically and scientifically interesting elaborations of the general idea that consciousness is best understood in terms of representational functions. A more complete examination of bat sensory capabilities suggests there is something that it is like after all. The discussion of bats is also used to develop an objection to strongly neurophilosophical approaches to animal consciousness

    Thirty years of Biology & Philosophy: philosophy of which biology?

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    Which domains of biology do philosophers of biology primarily study? The fact that philosophy of biology has been dominated by an interest for evolutionary biology is widely admitted, but it has not been strictly demonstrated. Here I analyse the topics of all the papers published in Biology & Philosophy, just as the journal celebrates its thirtieth anniversary. I then compare the distribution of biological topics in Biology & Philosophy with that of the scientific journal Proceedings of the National Academy of Science of the USA, focusing on the recent period 2003-2015. This comparison reveals a significant mismatch between the distributions of these topics. I examine plausible explanations for that mismatch. Finally, I argue that many biological topics underrepresented in philosophy of biology raise important philosophical issues and should therefore play a more central role in future philosophy of biology
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