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The demography and dynamics of migratory bird populations depend on patterns of movement and habitat quality across the annual cycle. We leveraged archival GPS-tagging data, climate data, remote-sensed vegetation data, and bird-banding data to better understand the dynamics of black-headed grosbeak (Pheucticus melanocephalus) populations in two breeding regions, the coast and Central Valley of California (Coastal California) and the Sierra Nevada mountain range (Sierra Nevada), over 28 years (1992-2019). Drought conditions across the annual cycle and rainfall timing on the molting grounds influenced seasonal habitat characteristics, including vegetation greenness and phenology (maturity dates). We developed a novel integrated population model with population state informed by adult capture data, recruitment rates informed by age-specific capture data and climate covariates, and survival rates informed by adult capture-mark-recapture data and climate covariates. Population size was relatively variable among years for Coastal California, where numbers of recruits and survivors were positively correlated, and years of population increase were largely driven by recruitment. In the Sierra Nevada, population size was more consistent and showed stronger evidence of population regulation (numbers of recruits and survivors negatively correlated). Neither region showed evidence of long-term population trend. We found only weak support for most climate-demographic rate relationships. However, recruitment rates for the Coastal California region were higher when rainfall was relatively early on the molting grounds and when wintering grounds were relatively cool and wet. We suggest that our approach of integrating movement, climate, and demographic data within a novel modeling framework can provide a useful method for better understanding the dynamics of broadly distributed migratory species.
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Remote tropical oceanic islands are of high conservation priority, and they are exemplified by range-restricted species with small global populations. Spatial and temporal patterns in rainfall and plant productivity may be important in driving dynamics of these species. Yet, little is known about environmental influences on population dynamics for most islands and species. Here we leveraged avian capture-recapture, rainfall, and remote-sensed habitat data (enhanced vegetation index [EVI]) to assess relationships between rainfall, vegetation greenness, and demographic rates (productivity, adult apparent survival) of three native bird species on Saipan, Northern Mariana Islands: rufous fantail (Rhipidura rufifrons), bridled white-eye (Zosterops conspicillatus), and golden white-eye (Cleptornis marchei). Rainfall was positively related to vegetation greenness at all but the highest rainfall levels. Temporal variation in greenness affected the productivity of each bird species in unique ways. Predicted productivity of rufous fantail was highest when dry and wet season greenness values were high relative to site-specific 5-year seasonal mean values (i.e., relative greenness); while the white-eye species had highest predicted productivity when relative greenness contrasted between wet and dry seasons. Survival of rufous fantail and bridled white eye was positively related to relative dry-season greenness and negatively related to relative wet-season greenness. Bridled white-eye survival also showed evidence of a positive response to overall greenness. Our results highlight the potentially important role of rainfall regimes in affecting population dynamics of species on oceanic tropical islands. Understanding linkages between rainfall, vegetation, and animal population dynamics will be critical for developing effective conservation strategies in this and other regions where the seasonal timing, extent, and variability of rainfall is expected to change in the coming decades.
Asunto(s)
Modelos Biológicos , Passeriformes , Lluvia , Clima Tropical , Animales , Ecosistema , Especies en Peligro de Extinción , Abastecimiento de Alimentos , Micronesia , Passeriformes/fisiología , Desarrollo de la Planta , Dispersión de las Plantas , Dinámica Poblacional , Reproducción , Estaciones del Año , Análisis de SupervivenciaRESUMEN
Geologic carbon dioxide (CO2) sequestration drives physical and geochemical changes in deep subsurface environments that impact indigenous microbial activities. The combined effects of pressurized CO2 on a model sulfate-reducing microorganism, Desulfovibrio vulgaris, have been assessed using a suite of genomic and kinetic measurements. Novel high-pressure NMR time-series measurements using (13)C-lactate were used to track D. vulgaris metabolism. We identified cessation of respiration at CO2 pressures of 10 bar, 25 bar, 50 bar, and 80 bar. Concurrent experiments using N2 as the pressurizing phase had no negative effect on microbial respiration, as inferred from reduction of sulfate to sulfide. Complementary pressurized batch incubations and fluorescence microscopy measurements supported NMR observations, and indicated that non-respiring cells were mostly viable at 50 bar CO2 for at least 4 h, and at 80 bar CO2 for 2 h. The fraction of dead cells increased rapidly after 4 h at 80 bar CO2. Transcriptomic (RNA-Seq) measurements on mRNA transcripts from CO2-incubated biomass indicated that cells up-regulated the production of certain amino acids (leucine, isoleucine) following CO2 exposure at elevated pressures, likely as part of a general stress response. Evidence for other poorly understood stress responses were also identified within RNA-Seq data, suggesting that while pressurized CO2 severely limits the growth and respiration of D. vulgaris cells, biomass retains intact cell membranes at pressures up to 80 bar CO2. Together, these data show that geologic sequestration of CO2 may have significant impacts on rates of sulfate reduction in many deep subsurface environments where this metabolism is a key respiratory process.
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BACKGROUND: Pneumonia is the eighth leading cause of death in Canada. Use of guideline-concordant therapy tempers the development of resistance, decreases health care costs, and reduces morbidity and mortality. OBJECTIVES: The purpose of this study was to optimize the treatment of patients with pneumonia under hospitalist care by focusing on best practice and local antibiogram data. The objectives were to collaborate with a hospitalist representative to optimize in-hospital treatment of patients with community-acquired, hospital-acquired, and health care-associated pneumonia; to complete a baseline audit to determine the proportion of antibiotic orders adhering to the strategy; to present the strategy and baseline audit findings to the hospitalists; to perform a post-intervention audit, with comparison to baseline, and to present results to the hospitalists; to expedite de-escalation to a narrower-spectrum antibiotic; to expedite parenteral-to-oral step-down therapy and promote appropriate duration of therapy; and to determine if a pneumonia scoring system was used. METHODS: An audit and feedback intervention focusing on pre- and post-intervention retrospective chart audits was completed. Review of pneumonia guidelines and the local antibiogram assisted in identifying the study strategy. A presentation to the hospitalists outlined antimicrobial stewardship principles and described the findings of the baseline audit. Pre- and post-intervention audit results were compared. RESULTS: Local best-practice treatment algorithms were developed for community-acquired pneumonia and for hospital-acquired and health care-associated pneumonia. The pre-intervention audit covered the period December 2011 to January 2012, with subsequent education and audit results presented to the hospitalists in November 2012. The post-intervention audit covered the period December 2012 to January 2013. Adherence to the treatment algorithms increased from 10% (2/21) in the pre-intervention audit to 38% (5/13) in the post-intervention audit. There was a trend to reduced duration of therapy in the post-intervention group. CONCLUSION: An audit and feedback intervention related to hospitalists' prescribing for pneumonia increased adherence to local best practice.
CONTEXTE: La pneumonie est la huitième cause de mortalité au Canada. L'utilisation d'un traitement qui respecte les lignes directrices permet de freiner le développement de la résistance, de diminuer les coûts de soins de santé et de réduire la morbidité et la mortalité. OBJECTIFS: Le but de cette étude était d'optimiser le traitement des patients atteints de pneumonie qui sont suivis par des médecins hospitaliers en mettant l'accent sur les meilleures pratiques et les données locales d'antibiogrammes. Les objectifs étaient de collaborer avec un représentant des médecins hospitaliers afin d'optimiser les traitements à l'hôpital de patients atteints d'une pneumonie extra-hospitalière, nosocomiale ou associée aux soins de santé; d'effectuer une vérification initiale afin d'établir la proportion d'ordonnances d'antibiotiques qui respectent la stratégie; de présenter la stratégie et les conclusions de la vérification initiale aux médecins hospitaliers; d'effectuer une vérification post-intervention ainsi qu'une comparaison de cette dernière à la vérification initiale et de présenter les résultats aux médecins hospitaliers; d'accélérer le passage à un antibiotique à spectre plus étroit; de hâter le passage d'un traitement parentéral à un traitement oral et de favoriser le respect de la durée recommandée de la thérapie; et de déterminer si un système de notation pour la pneumonie a été utilisé. MÉTHODES: Une vérification et une intervention de rétroaction portant sur les vérifications rétrospectives de dossiers médicaux pré- et post-intervention ont été réalisées. Un examen des lignes directrices de traitement de la pneumonie et des données locales d'antibiogrammes a aidé à définir la stratégie d'étude. Une présentation destinée aux médecins hospitaliers exposait les principes de gestion responsable des antimicrobiens et décrivait les conclusions de la vérification initiale. Les résultats des vérifications pré- et post-intervention ont été comparés. RÉSULTATS: Des algorithmes de traitement stipulant les meilleures pratiques locales ont été élaborés pour la pneumonie extra-hospitalière et pour les pneumonies nosocomiale et associée aux soins de santé. La vérification pré-intervention a porté sur la période de décembre 2011 à janvier 2012 et elle a été suivie de la présentation des conclusions en découlant aux médecins hospitaliers ainsi que de la formation de ceux-ci en novembre 2012. La vérification post-intervention a porté sur la période de décembre 2012 à janvier 2013. L'observance des algorithmes de traitement est passée de 10 % (2/21) lors de la vérification pré-intervention à 38 % (5/13) lors de la vérification post-intervention. Une tendance à la réduction de la durée du traitement dans le groupe post-intervention a été observée. CONCLUSION: Une vérification et une intervention de rétroaction portant sur les habitudes de prescription des médecins hospitaliers traitant les personnes atteintes de pneumonie ont permis d'améliorer l'observance des meilleures pratiques locales.