104 research outputs found

    Lassen Volcanic National Park Small Vertebrate Inventory Project: Preliminary Results 2000-2004

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    Biologists at Lassen Volcanic National Park in northern California conducted an inventory of non-flying small mammals, amphibians and reptiles from 2000 through 2004. The four primary habitat types in the park (brush, forest, riparian and subalpine) were each sampled at one high elevation and one mid-elevation site in the park. Each of the eight sites was sampled for four six-day periods between June and September each year using a combination of pitfall, Sherman and Tomahawk traps, coverboards and unbaited automatic camera stations. This effort yielded 12,150 captures and 776 photo detections. A total of 649 voucher specimens, representing 19 mammal, one amphibian and two reptile species, was collected and accessioned to the Museum of Vertebrate Zoology at the University of California, Berkeley

    Addressing biased occurrence data in predicting potential Sierra Nevada red fox habitat for survey prioritization

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    The Sierra Nevada red fox Vulpes vulpes necator is listed as a threatened species under the California Endangered Species Act. It originally occurred throughout California’s Cascade and Sierra Nevada mountain regions. Its current distribution is unknown but should be determined in order to guide management actions. We used occurrence data from the only known population, in the Lassen Peak region of northern California, combined with climatic and remotely sensed variables, to predict the species’ potential distribution throughout its historic range. These model predictions can guide future surveys to locate additional fox populations. Moreover, they allow us to compare the relative performances of presence-absence (logistic regression) and presence-only (maximum entropy, or Maxent) modeling approaches using occurrence data with potential false absences and geographical biases. We also evaluated the recently revised Maxent algorithm that reduces the effect of geographically biased occurrence data by subsetting background pixels to match biases in the occurrence data. Within the Lassen Peak region, all models had good fit to the test data, with high values for the true skill statistic (76–83%), percent correctly classified (86–92%), and area under the curve (0.94–0.96), with Maxent models yielding slightly higher values. Outside the Lassen Peak region, the logistic regression model yielded the highest predictive performance, providing the closest match to the fox’s historic range and also predicting a site where red foxes were subsequently detected in autumn 2010. Subsetting background pixels in Maxent reduced but did not eliminate the effect that geographically biased occurrence data had on prediction results relative to the Maxent model using full background pixels

    Sierra Nevada Red Fox (\u3ci\u3eVulpes vulpes necator\u3c/i\u3e): A Conservation Assessment

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    One goal of the Sierra Nevada Forest Plan Amendment (SNFPA) 2001 and 2004 Records of Decision was to protect and recover native Sierra Nevada red fox (Vulpes vulpes necator) populations in the Sierra Nevada (USDA Forest Service 2001 p. 14). To accomplish this goal, the ROD commits the U.S. Department of Agriculture (USDA) Forest Service to completing a conservation assessment for the Sierra Nevada red fox in cooperation with other federal, state, and local agencies, as well as Tribal governments. This conservation assessment synthesizes the best available scientific information and thought concerning habitat relationships, population status and trends, historical and current distributions, and key threats potentially affecting the distribution, abundance and persistence of the Sierra Nevada red fox. Biologists and resource managers from the Forest Service, US Department of the Interior (USDI) National Park Service, USDI Fish and Wildlife Service, US Geological Survey, University of California, and California Department of Fish and Game, along with private research scientists, worked cooperatively to develop this assessment. This conservation assessment provides a scientifically sound, comprehensive assessment of the status of the Sierra Nevada red fox population and its habitat. It identifies and evaluates key threats affecting viability and describes management considerations that could form the basis of a strategy to conserve and recover populations throughout the range of this species

    Niche Variation in Endemic Lilium pomponium on a Wide Altitudinal Gradient in the Maritime Alps

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    The relationship between altitudinal and ecological gradients has long been a dominant theme in plant ecology; moreover, how species respond to climate change has renewed this interest. Mediterranean mountains are often hotspots of endemism, and some endemic species have local distributions that span different climatic belts; hence, local variations in topography and fine-scaled niche conditions may play crucial roles in their persistence along such gradients. Studies of the fine-scaled niche are, however, very rare; most studies involve broad-scale variations in climatic parameters. The Turban lily, Lilium pomponium L. is endemic to the Maritime and Ligurian Alps, where it occurs across a wide altitudinal gradient. Previous work has shown no link between climatic marginality and geographic range limits on morphological traits and genetic variability; however, possible variations of local topographic and ecological parameters have not yet been examined. The objective of this paper is to characterise local ecological niche conditions of L. pomponium populations in the different bioclimatic zones it occupies along the altitudinal gradient. The species occurs in four main types of microecological niches. One of these niche types, with a high mineral cover, is the most abundant—type 2: it was detected in 39% of sampled quadrats and occurs across the whole bioclimatic gradient. Other niche types are more limited to subsections of the gradient: type 3 (in 19% of sampled quadrats) is restricted to high-altitude sites (>1070 m.a.s.l.) and is characterised by high vegetation and litter cover; type 4 (26%) corresponds to more forested habitats on substrates with low water retention capacities, in more inland zones close to the centre of L. pomponium distribution and across a range of altitudes; and type 1 (16% of quadrat) only occurs in the Mediterranean part of the gradient, close to distribution limits in pockets of soil among large blocks of rocks, mainly found at mid-altitudes. Despite heterogeneity in the spatial locations of niche types, there is no correspondence between ecological gradients and the distribution limits of this species. Knowledge of the fine-scaled ecological conditions that determine niche types is thus essential for conservation management of the habitats of this species and for the exploration of its possible response to ongoing climate change

    Hierarchization of priorities for an action plan for the protected flora in the Pyrénées National Park

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    In this paper we adapt a recently developed objective framework to assess which species may require monitoring, vigilance or enhanced prospection for the protected flora (124 taxa) present in the Pyrenees National Park (France). The method is based on three criteria : regional responsibility, local rarity and habitat vulnerability. The first two criteria were quantified by adapting classes according to previous work. The vulnerability criterion was quantified using three main parameters : the priority and conservation status of the habitat of each species combined with the proportion of known occurrences of the species in the « adhesion » area of the park which is not subject to regulatory control. Each species was ranked within a hierarchy developed in collaboration with the different park staff which allowed precise taxa to be selected for monitoring, vigilance and prospectionL'objectif de ce travail est de proposer une hiérarchisation des priorités pour la flore protégée du Parc national des Pyrénées (PNP). Une méthodologie objective basée sur trois critères, la responsabilité patrimoniale des taxons, leur rareté locale et la vulnérabilité de leur habitat, a donc été appliquée aux 124 taxons protégés présents sur ce territoire. Nous avons classé les taxons en adaptant les critères de responsabilité patrimoniale et de rareté au contexte biogéographique du PNP. Pour la vulnérabilité des habitats, nous avons mené un travail approfondi afin de quantifier ce critère en tenant compte de la priorité des habitats, de leur état de conservation et de la proportion de stations dans l'Aire Optimale d'Adhésion. Le renseignement de ces critères a permis d'élaborer une hiérarchisation qui, après avis des agents du PNP, met en évidence les taxons les plus pertinents en termes de suivis, de veille ou de prospection

    Quantifying Wildlife Use of Escape Ramps Along a Fenced Highway

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    Wildlife exclusion fencing can significantly reduce wildlife–vehicle collisions. However, some animals breach the fence and become trapped in the highway corridor, thereby increasing risk of a wildlife–vehicle collision. An emerging solution to this problem is the installation of earthen escape ramps (i.e., jumpouts), which allow trapped animals to escape the highway corridor. Few studies have quantified wildlife use of jumpouts, and none have investigated intraspecific differences in use. We used camera traps to document wildlife use of 4 2m-high jumpouts associated with wildlife exclusion fencing along Highway 101 near San Luis Obispo, California, USA, from 2012 to 2017. We surveyed for 7,361 nights across all 4 jumpouts, yielding 1,015 visitation events by 10 different species of large- and medium-sized mammals. Mule deer (Odocoileus hemionus) accounted for 895 (88%) detections; they jumped out 20% of the time when detected at the top of the ramp and were never detected using the jumpout to enter the highway corridor. We differentiated male and female deer using the presence of antlers and found that they jumped out at similar rates, but females were detected 6 times more often and were more likely to return to the same jumpout. Two groups of 2–3 deer accounted for ~41% of deer detections, which allowed us to investigate their behavior over time. These results indicate that individual variation could influence jumpout use, which should be considered when quantifying their use. To increase the overall jumpout rate, we recommend a jumpout height between 1.75 and 2 m

    The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

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    This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun’s centre, equal to half of Mercury’s perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Leveraging International Influenza Surveillance Systems and Programs during the COVID-19 Pandemic.

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    A network of global respiratory disease surveillance systems and partnerships has been built over decades as a direct response to the persistent threat of seasonal, zoonotic, and pandemic influenza. These efforts have been spearheaded by the World Health Organization, country ministries of health, the US Centers for Disease Control and Prevention, nongovernmental organizations, academic groups, and others. During the COVID-19 pandemic, the US Centers for Disease Control and Prevention worked closely with ministries of health in partner countries and the World Health Organization to leverage influenza surveillance systems and programs to respond to SARS-CoV-2 transmission. Countries used existing surveillance systems for severe acute respiratory infection and influenza-like illness, respiratory virus laboratory resources, pandemic influenza preparedness plans, and ongoing population-based influenza studies to track, study, and respond to SARS-CoV-2 infections. The incorporation of COVID-19 surveillance into existing influenza sentinel surveillance systems can support continued global surveillance for respiratory viruses with pandemic potential

    Association between convalescent plasma treatment and mortality in COVID-19: a collaborative systematic review and meta-analysis of randomized clinical trials.

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    Funder: laura and john arnold foundationBACKGROUND: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX ). METHODS: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. RESULTS: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. CONCLUSIONS: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care
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