2,246 research outputs found

    Infrared Lightcurves of Near Earth Objects

    Get PDF
    We present lightcurves and derive periods and amplitudes for a subset of 38 near earth objects (NEOs) observed at 4.5 microns with the IRAC camera on the the Spitzer Space Telescope, many of them having no previously reported rotation periods. This subset was chosen from about 1800 IRAC NEO observations as having obvious periodicity and significant amplitude. For objects where the period observed did not sample the full rotational period, we derived lower limits to these parameters based on sinusoidal fits. Lightcurve durations ranged from 42 to 544 minutes, with derived periods from 16 to 400 minutes. We discuss the effects of lightcurve variations on the thermal modeling used to derive diameters and albedos from Spitzer photometry. We find that both diameters and albedos derived from the lightcurve maxima and minima agree with our previously published results, even for extreme objects, showing the conservative nature of the thermal model uncertainties. We also evaluate the NEO rotation rates, sizes, and their cohesive strengths.Comment: 16 pages, 4 figures, 3 tables, to appear in the Astrophysical Journal Supplement Serie

    The Discovery of Cometary Activity in Near-Earth Asteroid (3552) Don Quixote

    Get PDF
    The near-Earth object (NEO) population, which mainly consists of fragments from collisions between asteroids in the main asteroid belt, is thought to include contributions from short-period comets as well. One of the most promising NEO candidates for a cometary origin is near-Earth asteroid (3552) Don Quixote, which has never been reported to show activity. Here we present the discovery of cometary activity in Don Quixote based on thermal-infrared observations made with the Spitzer Space Telescope in its 3.6 and 4.5 {\mu}m bands. Our observations clearly show the presence of a coma and a tail in the 4.5 {\mu}m but not in the 3.6 {\mu}m band, which is consistent with molecular band emission from CO2. Thermal modeling of the combined photometric data on Don Quixote reveals a diameter of 18.4 (-0.4/+0.3) km and an albedo of 0.03 (-0.01/+0.02), which confirms Don Quixote to be the third-largest known NEO. We derive an upper limit on the dust production rate of 1.9 kg s^-1 and derive a CO2 gas production rate of (1.1+-0.1)10^26 molecules s^-1. Spitzer IRS spectroscopic observations indicate the presence of fine-grained silicates, perhaps pyroxene rich, on the surface of Don Quixote. Our discovery suggests that CO2 can be present in near-Earth space over a long time. The presence of CO2 might also explain that Don Quixote's cometary nature remained hidden for nearly three decades.Comment: 40 pages, 8 figures, accepted by Ap

    Views of new internal medicine faculty of their preparedness and competence in physician-patient communication

    Get PDF
    BACKGROUND: We sought to assess self-rated importance of the medical interview to clinical practice and competence in physician-patient communication among new internal medicine faculty at an academic medical center. METHODS: Since 2001, new internal medicine faculty at the Mayo Clinic College of Medicine (Rochester, Minnesota) have completed a survey on physician-patient communication. The survey asks the new faculty to rate their overall competence in medical interviewing, the importance of the medical interview to their practice, their confidence and adequacy of previous training in handling eight frequently encountered challenging communication scenarios, and whether they would benefit from additional communication training. RESULTS: Between 2001 and 2004, 75 general internists and internal medicine subspecialists were appointed to the faculty, and of these, 58 (77%) completed the survey. The faculty rated (on a 10-point scale) the importance of the medical interview higher than their competence in interviewing; this difference was significant (average ± SD, 9.4 ± 1.0 vs 7.7 ± 1.2, P < .001). Similar results were obtained by sex, age, specialty, years since residency or fellowship training, and perceived benefit of training. Experienced faculty rated their competence in medical interviewing and the importance of the medical interview higher than recent graduates (ie, less than one year since training). For each challenging communication scenario, the new faculty rated the adequacy of their previous training in handling the scenario relatively low. A majority (57%) said they would benefit from additional communication training. CONCLUSION: Although new internal medicine faculty rate high the importance of the medical interview, they rate their competence and adequacy of previous training in medical interviewing relatively low, and many indicate that they would benefit from additional communication training. These results should encourage academic medical centers to make curricula in physician-patient communication available to their faculty members because many of them not only care for patients, but also teach clinical skills, including communication skills, to trainees

    Circulating heart failure biomarkers beyond natriuretic peptides:review from the Biomarker Study Group of the Heart Failure Association (HFA), European Society of Cardiology (ESC)

    Get PDF
    New biomarkers are being evaluated for their ability to advance the management of patients with heart failure. Despite a large pool of interesting candidate biomarkers, besides natriuretic peptides virtually none have succeeded in being applied into the clinical setting. In this review, we examine the most promising emerging candidates for clinical assessment and management of patients with heart failure. We discuss high-sensitivity cardiac troponins (Tn), procalcitonin, novel kidney markers, soluble suppression of tumorigenicity 2 (sST2), galectin-3, growth differentiation factor-15 (GDF-15), cluster of differentiation 146 (CD146), neprilysin, adrenomedullin (ADM), and also discuss proteomics and genetic-based risk scores. We focused on guidance and assistance with daily clinical care decision-making. For each biomarker, analytical considerations are discussed, as well as performance regarding diagnosis and prognosis. Furthermore, we discuss potential implementation in clinical algorithms and in ongoing clinical trials.</p

    Shifts in Plant Functional Composition Following Long-term Drought in Grasslands

    Get PDF
    1. Plant traits can provide unique insights into plant performance at the community scale. Functional composition, defined by both functional diversity and community-weighted trait means (CWMs), can affect the stability of above-ground net primary production (ANPP) in response to climate extremes. Further complexity arises, however, when functional composition itself responds to environmental change. The duration of climate extremes, such as drought, is expected to increase with rising global temperatures; thus, understanding the impacts of long-term drought on functional composition and the corresponding effect that has on ecosystem function could improve predictions of ecosystem sensitivity to climate change. 2. We experimentally reduced growing season precipitation by 66% across six temperate grasslands for 4 years and measured changes in three indices of functional diversity (functional dispersion, richness and evenness), community-weighted trait means and phylogenetic diversity (PD). Specific leaf area (SLA), leaf nitrogen content (LNC) and (at most sites) leaf turgor loss point (pi(TLP)) were measured for species cumulatively representing similar to 90% plant cover at each site. 3. Long-term drought led to increased community functional dispersion in three sites, with negligible effects on the remaining sites. Species re-ordering following the mortality/senescence of dominant species was the main driver of increased functional dispersion. The response of functional diversity was not consistently matched by changes in phylogenetic diversity. Community-level drought strategies (assessed as CWMs) largely shifted from drought tolerance to drought avoidance and/or escape strategies, as evidenced by higher community-weighted pi(TLP), SLA and LNC. Lastly, ecosystem drought sensitivity (i.e. relative reduction in ANPP in drought plots) was positively correlated with community-weighted SLA and negatively correlated with functional diversity. 4. Synthesis. Increased functional diversity following long-term drought may stabilize ecosystem functioning in response to future drought. However, shifts in community-scale drought strategies may increase ecosystem drought sensitivity, depending on the nature and timing of drought. Thus, our results highlight the importance of considering both functional diversity and abundance-weighted traits means of plant communities as their collective effect may either stabilize or enhance ecosystem sensitivity to drought

    Use of procalcitonin for the diagnosis of pneumonia in patients presenting with a chief complaint of dyspnoea: results from the BACH (Biomarkers in Acute Heart Failure) trial

    Get PDF
    Biomarkers have proven their ability in the evaluation of cardiopulmonary diseases.We investigated the utility of concentrations of the biomarker procalcitonin (PCT) alone and with clinical variables for the diagnosis of pneumonia in patients presenting to emergency departments (EDs) with a chief complaint of shortness of breath. The BACH trial was a prospective, international, study of 1641 patients presenting to EDs with dyspnoea. Blood samples were analysed for PCT and other biomarkers. Relevant clinical data were also captured. Patient outcomes were assessed at 90 days. The diagnosis of pneumonia was made using strictly validated guidelines. A model using PCT was more accurate [area under the curve (AUC) 72.3%] than any other individual clinical variable for the diagnosis of pneumonia in all patients, in those with obstructive lung disease, and in those with acute heart failure (AHF). Combining physician estimates of the probability of pneumonia with PCT values increased the accuracy to .86% for the diagnosis of pneumonia in all patients. Patients with a diagnosis of AHF and an elevated PCT concentration (.0.21 ng/mL) had a worse outcome if not treated with antibiotics (P ¼ 0.046), while patients with low PCT values (,0.05 ng/mL) had a better outcome if they did not receive antibiotic therapy (P ¼ 0.049). Procalcitonin may aid in the diagnosis of pneumonia, particularly in cases with high diagnostic uncertainty. Importantly, PCT may aid in the decision to administer antibiotic therapy to patients presenting with AHF in which clinical uncertainty exists regarding a superimposed bacterial infection

    Association between patient activation, self-management behaviours and clinical outcomes in adults with diabetes or related metabolic disorders: a systematic review and meta-analysis protocol.

    Get PDF
    INTRODUCTION: Diabetes and related metabolic disorders such as obesity and cardiovascular diseases (CVD) are a growing global issue. Equipping individuals with the necessary 'knowledge, skills and confidence to self-manage their health' (ie, patient activation (PAct)) may lead to improvements in health outcomes. It is unclear whether existing evidence allows us to assume a causal relationship. We aim to synthesise and critically appraise evidence on the relationship between PAct and self-management behaviours and clinical outcomes of people living with diabetes and related metabolic disorders. METHODS AND ANALYSIS: The protocol is based on guidance on Preferred Reporting Items for Systematic Review and Meta-analysis Protocols. We will search Medline, Embase, CENTRAL, PsycInfo, Web of Science and CINAHL using search terms related to PAct, diabetes, pre-diabetes, obesity and CVD. Any quantitative study design is eligible provided studies assess the association between PAct and clinical outcomes and/or self-management behaviours of diabetes and related metabolic disorders. Outcomes include behavioural (eg, diet) and clinical (eg, blood pressure) outcomes. Two reviewers will independently screen titles/abstracts and full texts and assess risk of bias using the revised Cochrane risk-of-bias tool for randomised trials or the Risk of Bias Assessment Tool for Nonrandomised Studies (RoBANS).One reviewer will extract data, with independent checking by a second reviewer. We will critically assess the level of evidence available for assuming a causal association between PAct and outcomes. Data permitting, we will use the Hunter-Schmidt random-effects method to meta-analyse correlations across studies. ETHICS AND DISSEMINATION: Ethical approval is not required. The review will be disseminated in the form of a peer-reviewed journal article, at conferences and other presentations. The findings of the review will be of interest to clinical commissioning groups, policymakers and intervention deliverers/developers. PROSPERO REGISTRATION NUMBER: CRD42021230727

    Expert Panel Recommendations on Lower Urinary Tract Health of Women Across Their Life Span

    Full text link
    Urologic and kidney problems are common in women across their life span and affect their daily life, including physical activity, sexual relations, social life, and future health. Urological health in women is still understudied and the underlying mechanisms of female urological dysfunctions are not fully understood. The Society for Women's Health Research (SWHR?) recognized the need to have a roundtable discussion where researchers and clinicians would define the current state of knowledge, gaps, and recommendations for future research directions to transform women's urological health. This report summarizes the discussions, which focused on epidemiology, clinical presentation, basic science, prevention strategies, and efficacy of current therapies. Experts around the table agreed on a set of research, education, and policy recommendations that have the potential to dramatically increase awareness and improve women's urological health at all stages of life.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140146/1/jwh.2016.5895.pd

    The ‘Tommy Atkins’ mango genome reveals candidate genes for fruit quality

    Get PDF
    Mango, Mangifera indica L., an important tropical fruit crop, is grown for its sweet and aromatic fruits. Past improvement of this species has predominantly relied on chance seedlings derived from over 1000 cultivars in the Indian sub-continent with a large variation for fruit size, yield, biotic and abiotic stress resistance, and fruit quality among other traits. Historically, mango has been an orphan crop with very limited molecular information. Only recently have molecular and genomics-based analyses enabled the creation of linkage maps, transcriptomes, and diversity analysis of large collections. Additionally, the combined analysis of genomic and phenotypic information is poised to improve mango breeding efficiency

    The Science Case for an Extended Spitzer Mission

    Full text link
    Although the final observations of the Spitzer Warm Mission are currently scheduled for March 2019, it can continue operations through the end of the decade with no loss of photometric precision. As we will show, there is a strong science case for extending the current Warm Mission to December 2020. Spitzer has already made major impacts in the fields of exoplanets (including microlensing events), characterizing near Earth objects, enhancing our knowledge of nearby stars and brown dwarfs, understanding the properties and structure of our Milky Way galaxy, and deep wide-field extragalactic surveys to study galaxy birth and evolution. By extending Spitzer through 2020, it can continue to make ground-breaking discoveries in those fields, and provide crucial support to the NASA flagship missions JWST and WFIRST, as well as the upcoming TESS mission, and it will complement ground-based observations by LSST and the new large telescopes of the next decade. This scientific program addresses NASA's Science Mission Directive's objectives in astrophysics, which include discovering how the universe works, exploring how it began and evolved, and searching for life on planets around other stars.Comment: 75 pages. See page 3 for Table of Contents and page 4 for Executive Summar
    corecore