1,390 research outputs found

    Reproductive Biology of Breeding Harlequin Ducks in Glacier National Park

    Get PDF
    Glacier National Park and The University of Montana partnered up in 2011-2013 to study the reproductive biology of Harlequin Ducks (Histrionicus histrionicus) breeding on Upper McDonald Creek (UMC) in Glacier National Park. The Harlequin Duck exhibits unusual migratory patterns compared to other ducks, moving east to west, rather than north to south; these birds winter along North America’s Pacific coast, then move inland to breed on alpine streams. The objectives of this study were to understand the environmental, physiological, and anthropogenic influences on reproduction. During the course of this study, 138 Harlequin Ducks were trapped and banded. We also attached radio transmitters to breeding females (n = 43) to enable daily tracking, behavioral observations, and nest discovery. Over the course of the study our team discovered 11 nests, tracked two broods, and located four females on their wintering grounds. With the use of radio telemetry, we documented novel habitat use and nesting habitat. Human presence along UMC is widespread. We used occupancy and presence/absence techniques to analyze these influences. To validate assumptions of stream flow on reproductive success, we used a 23-yr data set collected by park personnel and citizen scientists to confirm these assumptions. We found a strong relationship between unpredictable stream flow and reduced reproductive success. To further understand reproductive dynamics, we measured corticosterone concentrations in feathers, which significantly predicted reproductive decision. We address the management implications from this study for future Harlequin Duck conservation

    Correlates of criminal victimisation among police cell detainees in Victoria, Australia

    Full text link
    People with mental illness are more likely to be crime victims than others; however, little is known about the relationship between offending and victimisation among mentally ill offenders. This study investigated the rates and types of victimisation among people detained in police cells (N = 764), with and without histories of mental illness. Those with mental disorders were 1.56 times (95% CI = 1.11–2.17) more likely to be victims of violent crimes than other detainees. Some subgroups of people with mental disorders were not over-represented as victims, raising the possibility that they were less inclined to report certain types of crimes. Implications are discussed with reference to police practice

    Is there a correlation between infection control performance and other hospital quality measures?

    Get PDF
    Quality measures are increasingly reported by hospitals to the Centers for Medicare and Medicaid Services (CMS), yet there may be tradeoffs in performance between infection control (IC) and other quality measures. Hospitals that performed best on IC measures did not perform well on most CMS non–IC quality measures

    Updated reproductive parameters for the shortfin mako (Isurus oxyrinchus) in the North Atlantic Ocean with inferences of distribution by sex and reproductive stage

    Get PDF
    Prompted by recent concern about the stock status of the shortfin mako (Isurus oxyrinchus) in the North Atlantic Ocean, we examined reproductive data from 731 individuals (351 females and 380 males) collected by 3 scientific organizations to improve estimates of size and age at maturity. Males ranged in size from 70 to 283 cm fork length (FL) and females from 71 to 338 cm FL. Females matured between 263 and 291 cm FL, with an estimated median length at maturity (L50) of 280 cm FL and a median weight at maturity (WT50) of 275 kg. Males matured between 173 and 187 cm FL, with an L50 of 182 cm FL and WT50 of 64 kg. Catch records from 4 international programs were also examined to investigate spatiotemporal variation in the distribution of life history stages based on updated size-at-maturity estimates and to identify potential parturition and nursery grounds. These records identified the Gulf of Mexico and the eastern North Atlantic Ocean off Portugal as birthing and nursery areas, with the most important nursery area occurring in the western North Atlantic Ocean.FCT MAKO-WIDE (Ref. FAPESP/19740/2014)info:eu-repo/semantics/publishedVersio

    Conclusions about Niche Expansion in Introduced Impatiens walleriana Populations Depend on Method of Analysis

    Get PDF
    Determining the degree to which climate niches are conserved across plant species' native and introduced ranges is valuable to developing successful strategies to limit the introduction and spread of invasive plants, and also has important ecological and evolutionary implications. Here, we test whether climate niches differ between native and introduced populations of Impatiens walleriana, globally one of the most popular horticultural species. We use approaches based on both raw climate data associated with occurrence points and ecological niche models (ENMs) developed with Maxent. We include comparisons of climate niche breadth in both geographic and environmental spaces, taking into account differences in available habitats between the distributional areas. We find significant differences in climate envelopes between native and introduced populations when comparing raw climate variables, with introduced populations appearing to expand into wetter and cooler climates. However, analyses controlling for differences in available habitat in each region do not indicate expansion of climate niches. We therefore cannot reject the hypothesis that observed differences in climate envelopes reflect only the limited environments available within the species' native range in East Africa. Our results suggest that models built from only native range occurrence data will not provide an accurate prediction of the potential for invasiveness if applied to areas containing a greater range of environmental combinations, and that tests of niche expansion may overestimate shifts in climate niches if they do not control carefully for environmental differences between distributional areas

    Method of providing a lunar habitat from an external tank

    Get PDF
    A lunar habitat is provided by placing an external tank of an orbiter in a low Earth orbit where the hydrogen tank is separated from the intertank and oxygen tank which form a base structure. The base structure is then outfitted with an air lock, living quarters, a thermal control system, an environmental control and life support system, and a propulsion system. After the mounting of an outer sheath about the base structure to act as a micrometeoroid shield, the base structure is propelled to a soft landing on the moon. The sheath is mounted at a distance from the base structure to provide a space therebetween which is filled with regolith after landing. Conveniently, a space station is used to outfit the base structure. Various elements of the oxygen tank and intertank are used in outfitting

    MMT Extremely Metal Poor Galaxy Survey I. An Efficient Technique to Identify Metal Poor Galaxies

    Full text link
    We demonstrate a successful strategy for identifying extremely metal poor galaxies. Our preliminary survey of 24 candidates contains 10 metal poor galaxies of which 4 have 12+log(O/H)<7.65, some of the lowest metallicity blue compact galaxies known to date. Interestingly, our sample of metal poor galaxies have systematically lower metallicity for their luminosity than comparable samples of blue compact galaxies, dIrrs, and normal star-forming galaxies. Our metal poor galaxies share very similar properties, however, with the host galaxies of nearby long-duration gamma-ray bursts (GRBs), including similar metallicity, stellar ages, and star formation rates. We use H\beta to measure the number of OB stars present in our galaxies and estimate a core-collapse supernova rate of ~10^-3 yr^-1. A larger sample of metal poor galaxies may provide new clues into the environment where GRBs form and may provide a list of potential GRB hosts.Comment: Accepted to AJ, 8 pages using emulateap

    The \u27Ideal\u27 Climate Change Ph.D. Program

    Get PDF
    The training of the next generation of climate-change researchers is of utmost importance as climate change and its associated impacts take on increasing local, regional, and global relevance. This report seeks to address this issue by highlighting aspects of a successful climate-change Ph.D. program; a program which seeks to balance traditional disciplinary training with exposure to the broader, interdisciplinary climate-change community

    Decorin reduces intraocular pressure and retinal ganglion cell loss in rodents through fibrolysis of the scarred trabecular meshwork

    Get PDF
    Purpose. To investigate whether Decorin, a matrikine that regulates extracellular matrix (ECM) deposition, can reverse established trabecular meshwork (TM) fibrosis, lower IOP, and reduce progressive retinal ganglion cell (RGC) death in a novel rodent model of TM fibrosis. Methods. Adult rats had intracameral (IC) injections of human recombinant (hr) TGF-β over 30 days (30d; to induce TM fibrosis, raise IOP, and initiate RGC death by 17d) or PBS (controls) and visually evoked potentials (VEP) were measured at 30d to evaluate resultant visual pathway dysfunction. In some animals TGF-β injections were stopped at 17d when TM fibrosis and IOP were consistently raised and either hrDecorin or PBS IC injections were administered between 21d and 30d. Intraocular pressure was measured biweekly and eyes were processed for immunohistochemical analysis of ECM deposition to assess TM fibrosis and levels of matrix metalloproteinases (MMP) and tissue inhibitors of matrix metalloproteinases (TIMP) to assess fibrolysis. The effect of hrDecorin treatment on RGC survival was also assessed. Results. Transforming growth factor–β injections caused sustained increases in ECM deposition in the TM and raised IOP by 17d, responses that were associated with 42% RGC loss and a significant decrease in VEP amplitude measured at 30d. Decorin treatment from 17d reduced TGF-β–induced TM fibrosis, increased levels of MMP2 and MMP9 and lowered TIMP2 levels, and lowered IOP, preventing progressive RGC loss. Conclusions. Human recombinant Decorin reversed established TM fibrosis and lowered IOP, thereby rescuing RGC from progressive death. These data provide evidence for the candidacy of hrDecorin as a treatment for open-angle glaucoma
    • …
    corecore