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Rising temperatures are affecting organisms in all of Earth's biomes, but the complexity of ecological responses to climate change has hampered the development of a conceptually unified treatment of them. In a remarkably comprehensive synthesis, this book presents past, ongoing, and future ecological responses to climate change in the context of two simplifying hypotheses, facilitation and interference, arguing that biotic interactions may be the primary driver of ecological responses to climate change across all levels of biological organization. Eric Post's synthesis and analyses of ecological consequences of climate change extend from the Late Pleistocene to the present, and through the next century of projected warming. His investigation is grounded in classic themes of enduring interest in ecology, but developed around novel conceptual and mathematical models of observed and predicted dynamics. Using stability theory as a recurring theme, Post argues that the magnitude of climatic variability may be just as important as the magnitude and direction of change in determining whether populations, communities, and species persist. He urges a more refined consideration of species interactions, emphasizing important distinctions between lateral and vertical interactions and their disparate roles in shaping responses of populations, communities, and ecosystems to climate change.

Human-induced climate change is emerging as one of the gravest threats to biodiversity in history, and while a vast amount of literature on the ecological impact of climate change exists, very little has been dedicated to the management of wildlife populations and communities in the wake of unprecedented habitat changes. This book brings together leaders in the fields of climate change ecology, wildlife population dynamics, and environmental policy to examine the impacts of climate change on populations of terrestrial vertebrates.

Human-induced climate change is emerging as one of the gravest threats to biodiversity in history, and while a vast amount of literature on the ecological impact of climate change exists, very little has been dedicated to the management of wildlife populations and communities in the wake of unprecedented habitat changes. Wildlife Conservation in a Changing Climate is an essential resource, bringing together leaders in the fields of climate change ecology, wildlife population dynamics, and environmental policy to examine the impacts of climate change on populations of terrestrial vertebrates. Chapters assess the details of climate change ecology, including demographic implications for individual populations, evolutionary responses, impacts on movement patterns, alterations of species interactions, and predicting impacts across regions. The contributors also present a number of strategies by which conservationists and wildlife managers can counter or mitigate the impacts of climate change as well as increase the resilience of wildlife populations to such changes. A seminal contribution to the fields of ecology and conservation biology, Wildlife Conservation in a Changing Climate will serve as the spark that ignites a new direction of discussions about and action on the ecology and conservation of wildlife in a changing climate.

The Southern Alaska Peninsula Caribou (Rangifer tarandus) Herd (SAPCH) and its two sub-groups were the focus of a study addressing the hypotheses: (1) food limitation during winter caused a decline in the herd; and, (2) higher calf productivity within the Caribou River group than within the Black Hill group was related to greater forage availability on the seasonal ranges of the Caribou River group. Intense, systematic range and calving surveys in 1991 and 1992 supported the hypothesis of food limitation during winter, and indicated that greater calf production in the Caribou River group was related to earlier commencement of the season of plant growth and greater forage availability on the summer range of that group, coupled with earlier parturition among females of the Caribou River herd. In a comparative study involving the two SAPCH groups and the West Greenland Caribou Herd, daily variation in sizes of foraging groups, densities of caribou within feeding sites, distances between individuals within feeding sites, distances moved by foraging groups, and frequency of group movement was modeled using the following ecological parameters: predation risk, insect harassment (by mosquitos), range patchiness, feeding-site patchiness, feeding-site area, and range-wide density of caribou. Models revealed that intraseasonal social dynamics of foraging caribou were governed in most instances by patterns of forage availability and distribution across landscapes and within feeding sites, in some instances by insect harassment and social pressures, but in no instance by levels of predation risk inherent to the ranges on which they foraged. In a study of the interrelationships between characteristics of graminoids and intensity of grazing by caribou, vegetation on each of the Black Hill and Caribou River ranges was sampled and tested for responses to clipping. Biomass density (g/m$\\sp3$) of forage, shoot density (#/m$\\sp2$), and nutrient and mineral densities (g/m$\\sp3$) and concentrations (g/100g tissue) correlated positively with use of sites by caribou. Productivity and responses to clipping were independent of previous use, but consistent within ranges. These results indicate that caribou are sensitive to local variation in forage quantity and quality, and preferentially use sites with higher returns of nutrients and minerals.

BackgroundTreatment and preventative advances for chronic obstructive pulmonary disease (COPD) have been slow due, in part, to limited subphenotypes. We tested if unsupervised machine learning on CT images would discover CT emphysema subtypes with distinct characteristics, prognoses and genetic associations.MethodsNew CT emphysema subtypes were identified by unsupervised machine learning on only the texture and location of emphysematous regions on CT scans from 2853 participants in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS), a COPD case–control study, followed by data reduction. Subtypes were compared with symptoms and physiology among 2949 participants in the population-based Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study and with prognosis among 6658 MESA participants. Associations with genome-wide single-nucleotide-polymorphisms were examined.ResultsThe algorithm discovered six reproducible (interlearner intraclass correlation coefficient, 0.91–1.00) CT emphysema subtypes. The most common subtype in SPIROMICS, the combined bronchitis-apical subtype, was associated with chronic bronchitis, accelerated lung function decline, hospitalisations, deaths, incident airflow limitation and a gene variant near DRD1, which is implicated in mucin hypersecretion (p=1.1 ×10−8). The second, the diffuse subtype was associated with lower weight, respiratory hospitalisations and deaths, and incident airflow limitation. The third was associated with age only. The fourth and fifth visually resembled combined pulmonary fibrosis emphysema and had distinct symptoms, physiology, prognosis and genetic associations. The sixth visually resembled vanishing lung syndrome.ConclusionLarge-scale unsupervised machine learning on CT scans defined six reproducible, familiar CT emphysema subtypes that suggest paths to specific diagnosis and personalised therapies in COPD and pre-COPD.

Structural variants (SVs) rearrange large segments of DNA 1 and can have profound consequences in evolution and human disease 2 , 3 . As national biobanks, disease-association studies, and clinical genetic testing have grown increasingly reliant on genome sequencing, population references such as the Genome Aggregation Database (gnomAD) 4 have become integral in the interpretation of single-nucleotide variants (SNVs) 5 . However, there are no reference maps of SVs from high-coverage genome sequencing comparable to those for SNVs. Here we present a reference of sequence-resolved SVs constructed from 14,891 genomes across diverse global populations (54% non-European) in gnomAD. We discovered a rich and complex landscape of 433,371 SVs, from which we estimate that SVs are responsible for 25–29% of all rare protein-truncating events per genome. We found strong correlations between natural selection against damaging SNVs and rare SVs that disrupt or duplicate protein-coding sequence, which suggests that genes that are highly intolerant to loss-of-function are also sensitive to increased dosage 6 . We also uncovered modest selection against noncoding SVs in cis -regulatory elements, although selection against protein-truncating SVs was stronger than all noncoding effects. Finally, we identified very large (over one megabase), rare SVs in 3.9% of samples, and estimate that 0.13% of individuals may carry an SV that meets the existing criteria for clinically important incidental findings 7 . This SV resource is freely distributed via the gnomAD browser 8 and will have broad utility in population genetics, disease-association studies, and diagnostic screening. A large empirical assessment of sequence-resolved structural variants from 14,891 genomes across diverse global populations in the Genome Aggregation Database (gnomAD) provides a reference map for disease-association studies, population genetics, and diagnostic screening.

California is currently the only state that does not regulate who can and cannot call themselves athletic trainers (ATs). Therefore, previous national or state-specific investigations may not have provided an accurate representation of AT availability at the secondary school level in California. Similarly, it is unknown whether the factors that influence AT availability in California, such as socioeconomic status, are similar to or different from those identified in previous studies. To describe the availability of ATs certified by the Board of Certification in California secondary schools and to examine potential factors influencing access to AT services in California secondary schools. Cross-sectional study. Online survey. Representatives of 1270 California high schools. Officials from member schools completed the 2017-2018 California Interscholastic Federation Participation Census. Respondents provided information regarding school type, student and student-athlete enrollment, whether the school had ATs on staff, and whether the ATs were certified by the Board of Certification. The socioeconomic status of public and charter schools was determined using the percentage of students eligible for free or reduced-price lunch. More than half (54.6%) of schools reported that they either did not employ ATs (47.6%) or employed unqualified health personnel (UHP) in the role of AT (7.0%). Nearly 30% of student-athletes in California participated in athletics at a school that did not employ ATs (n = 191 626, 28.9%) and 8% of student-athletes participated at a school that employed UHP in the role of AT (n = 54 361, 8.2%). Schools that reported employing ATs had a lower proportion of students eligible for free or reduced-price lunch than schools that did not employ ATs and schools that employed UHP (both values < .001). With ongoing legislative efforts to obtain regulation of ATs in California, secondary school administrators are encouraged to hire ATs with the proper certification to enhance the patient care provided to student-athletes and improve health outcomes.

The global emergence of many severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants jeopardizes the protective antiviral immunity induced after infection or vaccination. To address the public health threat caused by the increasing SARS-CoV-2 genomic diversity, the National Institute of Allergy and Infectious Diseases within the National Institutes of Health established the SARS-CoV-2 Assessment of Viral Evolution (SAVE) programme. This effort was designed to provide a real-time risk assessment of SARS-CoV-2 variants that could potentially affect the transmission, virulence, and resistance to infection- and vaccine-induced immunity. The SAVE programme is a critical data-generating component of the US Government SARS-CoV-2 Interagency Group to assess implications of SARS-CoV-2 variants on diagnostics, vaccines and therapeutics, and for communicating public health risk. Here we describe the coordinated approach used to identify and curate data about emerging variants, their impact on immunity and effects on vaccine protection using animal models. We report the development of reagents, methodologies, models and notable findings facilitated by this collaborative approach and identify future challenges. This programme is a template for the response to rapidly evolving pathogens with pandemic potential by monitoring viral evolution in the human population to identify variants that could reduce the effectiveness of countermeasures. The SARS-CoV-2 Assessment of Viral Evolution (SAVE) programme provides a real-time risk assessment of SARS-CoV-2 variants with the potential to affect transmission, virulence and resistance to infection- and vaccine-induced immunity.

Prediction of high latitude response to climate change is hampered by poor understanding of the role of nonlinear changes in ecosystem forcing and response. While the effects of nonlinear climate change are often delayed or dampened by internal ecosystem dynamics, recent warming events in the Arctic have driven rapid environmental response, raising questions of how terrestrial and freshwater systems in this region may shift in response to abrupt climate change. We quantified environmental responses to recent abrupt climate change in West Greenland using long-term monitoring and paleoecological reconstructions. Using >40 years of weather data, we found that after 1994, mean June air temperatures shifted 2.2 °C higher and mean winter precipitation doubled from 21 to 40 mm; since 2006, mean July air temperatures shifted 1.1 °C higher. Nonlinear environmental responses occurred with or shortly after these abrupt climate shifts, including increasing ice sheet discharge, increasing dust, advancing plant phenology, and in lakes, earlier ice out and greater diversity of algal functional traits. Our analyses reveal rapid environmental responses to nonlinear climate shifts, underscoring the highly responsive nature of Arctic ecosystems to abrupt transitions.

A Correction to this paper has been published: https://doi.org/10.1038/s41586-020-03176-6.