179 research outputs found
Projected climate-induced faunal change in the western hemisphere
Climate change is predicted to be one of the greatest drivers of ecological change in the coming century. Increases in temperature over the last century have clearly been linked to shifts in species distributions. Given the magnitude of projected future climatic changes, we can expect even larger range shifts in the coming century. These changes will, in turn, alter ecological communities and the functioning of ecosystems. Despite the seriousness of predicted climate change, the uncertainty in climate-change projections makes it difficult for conservation managers and planners to proactively respond to climate stresses. To address one aspect of this uncertainty, we identified predictions of faunal change for which a high level of consensus was exhibited by different climate models. Specifically, we assessed the potential effects of 30 coupled atmosphereâocean general circulation model (AOGCM) future-climate simulations on the geographic ranges of 2954 species of birds, mammals, and amphibians in the Western Hemisphere. Eighty percent of the climate projections based on a relatively low greenhouse-gas emissions scenario result in the local loss of at least 10% of the vertebrate fauna over much of North and South America. The largest changes in fauna are predicted for the tundra, Central America, and the Andes Mountains where, assuming no dispersal constraints, specific areas are likely to experience over 90% turnover, so that faunal distributions in the future will bear little resemblance to those of today
ATHEROGENIC LIPOPROTEIN PARTICLE SUBCLASSES AND RESIDUAL CARDIOVASCULAR RISK: AN ANALYSIS OF THE JUPITER TRIAL
A NOVEL BIOMARKER OF CIRCULATING GLYCOPROTEINS AND CARDIOVASCULAR AND ALL-CAUSE MORTALITY AMONG 39,521 INITIALLY HEALTHY ADULTS
Clinical Camel: An Open Expert-Level Medical Language Model with Dialogue-Based Knowledge Encoding
We present Clinical Camel, an open large language model (LLM) explicitly
tailored for clinical research. Fine-tuned from LLaMA-2 using QLoRA, Clinical
Camel achieves state-of-the-art performance across medical benchmarks among
openly available medical LLMs. Leveraging efficient single-GPU training,
Clinical Camel surpasses GPT-3.5 in five-shot evaluations on all assessed
benchmarks, including 64.3% on the USMLE Sample Exam (compared to 58.5% for
GPT-3.5), 77.9% on PubMedQA (compared to 60.2%), 60.7% on MedQA (compared to
53.6%), and 54.2% on MedMCQA (compared to 51.0%). In addition to these
benchmarks, Clinical Camel demonstrates its broader capabilities, such as
synthesizing plausible clinical notes. This work introduces dialogue-based
knowledge encoding, a novel method to synthesize conversational data from dense
medical texts. While benchmark results are encouraging, extensive and rigorous
human evaluation across diverse clinical scenarios is imperative to ascertain
safety before implementation. By openly sharing Clinical Camel, we hope to
foster transparent and collaborative research, working towards the safe
integration of LLMs within the healthcare domain. Significant challenges
concerning reliability, bias, and the potential for outdated knowledge persist.
Nonetheless, the transparency provided by an open approach reinforces the
scientific rigor essential for future clinical applications.Comment: for model weights, see https://huggingface.co/wanglab
Relations of Change in Plasma Levels of LDLâC, NonâHDLâC and apoB With Risk Reduction From Statin Therapy: A MetaâAnalysis of Randomized Trials
Background: Identifying the best markers to judge the adequacy of lipidâlowering treatment is increasingly important for coronary heart disease (CHD) prevention given that several novel, potent lipidâlowering therapies are in development. Reductions in LDLâC, nonâHDLâC, or apoB can all be used but which most closely relates to benefit, as defined by the reduction in events on statin treatment, is not established. Methods and Results: We performed a randomâeffects frequentist and Bayesian metaâanalysis of 7 placeboâcontrolled statin trials in which LDLâC, nonâHDLâC, and apoB values were available at baseline and at 1âyear followâup. Summary level data for change in LDLâC, nonâHDLâC, and apoB were related to the relative risk reduction from statin therapy in each trial. In frequentist metaâanalyses, the mean CHD risk reduction (95% CI) per standard deviation decrease in each marker across these 7 trials were 20.1% (15.6%, 24.3%) for LDLâC; 20.0% (15.2%, 24.7%) for nonâHDLâC; and 24.4% (19.2%, 29.2%) for apoB. Compared within each trial, risk reduction per change in apoB averaged 21.6% (12.0%, 31.2%) greater than changes in LDLâC (P<0.001) and 24.3% (22.4%, 26.2%) greater than changes in nonâHDLâC (P<0.001). Similarly, in Bayesian metaâanalyses using various prior distributions, Bayes factors (BFs) favored reduction in apoB as more closely related to risk reduction from statins compared with LDLâC or nonâHDLâC (BFs ranging from 484 to 2380). Conclusions: Using both a frequentist and Bayesian approach, relative risk reduction across 7 major placeboâcontrolled statin trials was more closely related to reductions in apoB than to reductions in either nonâHDLâC or LDLâC
Aerosol and Surface Contamination of SARS-CoV-2 Observed in Quarantine and Isolation Care
The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in Wuhan, China in late 2019, and its resulting coronavirus disease, COVID-19, was declared a pandemic by the World Health Organization on March 11, 2020. The rapid global spread of COVID-19 represents perhaps the most significant public health emergency in a century. As the pandemic progressed, a continued paucity of evidence on routes of SARS-CoV-2 transmission has resulted in shifting infection prevention and control guidelines between classically-defined airborne and droplet precautions. During the initial isolation of 13 individuals with COVID-19 at the University of Nebraska Medical Center, we collected air and surface samples to examine viral shedding from isolated individuals. We detected viral contamination among all samples, supporting the use of airborne isolation precautions when caring for COVID-19 patients
The causal exposure model of vascular disease
Primary prevention of cardiovascular disease is governed at present by the risk factor model for cardiovascular events, a model which is widely accepted by physicians and professional associations, but which has important limitations: most critically, that effective treatment to reduce arterial damage is often delayed until the age at which cardiovascular events become common. This delay means that many of the early victims of vascular disease will not be identified in time. This delay also allows atherosclerosis to develop and progress unchecked within the arterial tree with the result that the absolute effectiveness of preventive therapy is limited by the time it is eventually initiated. The causal exposure model of vascular disease is an alternative to the risk factor model for cardiovascular events. Whereas the risk factor model aims to identify and treat those at markedly increased risk of vascular events within the next decade, the causal exposure model of vascular disease aims to prevent events by treating the causes of the disease when they are identified. In the risk factor model, age is an independent non-modifiable risk factor and the predictive power of age far outweighs that of the other risk factors. In the causal exposure model, age is the duration of time the arterial wall is exposed to the causes of atherosclerosis: apoB (apolipoprotein B) lipoproteins, hypertension, diabetes and smoking. Preventing the development of advanced atherosclerotic lesions by treating the causes of vascular disease is the simplest, surest and most effective way to prevent clinical events
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Atherogenic Lipoprotein Determinants of Cardiovascular Disease and Residual Risk Among Individuals With Low LowâDensity Lipoprotein Cholesterol
Background: Levels of LDL (lowâdensity lipoprotein) cholesterol in the population are declining, and increasing attention is being focused on residual lipidârelated pathways of atherosclerotic cardiovascular disease risk beyond LDL cholesterol. Among individuals with low (<130 mg/dL) LDL cholesterol, we undertook detailed profiling of circulating atherogenic lipoproteins in relation to incident cardiovascular disease in 2 populations. Methods and Results: We performed proton nuclear magnetic resonance spectroscopy to quantify concentrations of LDL and VLDL (very lowâdensity lipoprotein) particle subclasses in 11 984 JUPITER trial participants (NCT00239681). Adjusted Cox models examined cardiovascular disease risk associated with lipoprotein measures according to treatment allocation. Risk (adjusted hazard ratio [95%CI] per SD increment) among placeboâallocated participants was associated with total LDL particles (1.19 [1.02, 1.38]) and total VLDL particles (1.21 [1.04, 1.41]), as well as apolipoprotein B, nonâhighâdensity lipoprotein cholesterol, and triglycerides, but not LDLâc. Rosuvastatin reduced LDL measures but had variable effects on triglyceride and VLDL measures. Onâstatin levels of the smallest VLDL particle subclass were associated with a 68% perâSD (adjusted hazard ratio 1.68 [1.28, 2.22]) increase in residual riskâthis risk was related to VLDL cholesterol and not triglyceride or larger VLDL particles. There was evidence that residual risk prediction during statin therapy could be significantly improved through the inclusion of key VLDL measures (Harrell Câindex 0.780 versus 0.712; P<0.0001). In an independent, prospective cohort of 4721 individuals referred for cardiac catheterization (CATHGEN), similar patterns of lipoproteinârelated risk were observed. Conclusions: Atherogenic lipoprotein particle concentrations were associated with cardiovascular disease risk when LDL cholesterol was low. VLDL lipoproteins, particularly the smallest remnant subclass, may represent unused targets for risk prediction and potential therapeutic intervention for reducing residual risk. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00239681
The effectiveness of modern cardiac rehabilitation : A systematic review of recent observational studies in non-attenders versus attenders
BACKGROUND: The beneficial effects of cardiac rehabilitation (CR) have been challenged in recent years and there is now a need to investigate whether current CR programmes, delivered in the context of modern cardiology, still benefit patients. METHODS: A systematic review of non-randomised controlled studies was conducted. Electronic searches of Medline, Embase, CINAHL, science citation index (web of science), CIRRIE and Open Grey were undertaken. Non-randomised studies investigating the effects of CR were included when recruitment occurred from the year 2000 onwards in accordance with significant CR guidance changes from the late 1990's. Adult patients diagnosed with acute myocardial infarction (AMI) were included. Non-English articles were considered. Two reviewers independently screened articles according to pre-defined selection criteria as reported in the PROSPERO database (CRD42015024021). RESULTS: Out of 2,656 articles, 8 studies involving 9,836 AMI patients were included. Studies were conducted in 6 countries. CR was found to reduce the risk of all-cause and cardiac-related mortality and improve Health-Related Quality of Life (HRQOL) significantly in at least one domain. The benefits of CR in terms of recurrent MI were inconsistent and no significant effects were found regarding re-vascularisation or re-hospitalisation following AMI. CONCLUSION: Recent observational evidence draws different conclusions to the most current reviews of trial data with respect to total mortality and re-hospitalisation, questioning the representativeness of historic data in the modern cardiological era. Future work should seek to clarify which patient and service level factors determine the likelihood of achieving improved all-cause and cardiac mortality and reduced hospital re-admissions
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