194 research outputs found

    Administrator Perceptions of School Improvement Policies in a High-Impact Policy Setting

    Get PDF
    This study investigated school administrators’ perceptions of school improvement policies in a high-impact policy environment by measuring the impact of accountability, site-based management, professional development, and scheduling reform on the three dependent variables of a) academic outcomes, b) staff morale, and c) parent and community involvement. Using a convenience sampling method, 49 public school principals from Texas participated and an online survey was constructed to gather both quantitative (i.e., Likert scale) and qualitative (i.e., open ended response) data. The findings clearly point to principals, regardless of geographical district type and grade level school type, viewing less controversial and more intrinsically oriented policies (i.e., site-based management and professional development) as having a greater positive impact on outcomes as a whole than more radical alternatives (i.e., accountability and time and schedule reform). The evidence suggests that more aggressive school improvement policy approaches are likely failing to generate enough convincing outcomes to generate high commitment and confidence from school leaders. Further studies may look at the interaction of policy impact with minority student enrollments and with subgroup populations

    Limited Range-Filling Among Endemic Forest Herbs of Eastern North America and Its Implications for Conservation With Climate Change

    Get PDF
    Biodiversity hotspots host a high diversity of narrowly distributed endemic species, which are increasingly threatened by climate change. In eastern North America, the highest concentration of plant diversity and endemism occurs in the Southern Appalachian Mountains (SAM). It has been hypothesized that this region served as a refugium during Pleistocene glacial cycles and that postglacial migration northward was dispersal limited. We tested this hypothesis using species distribution models for eight forest herb species. We also quantified the extent to which the geography of suitable habitat shifted away from the current range with climate change. We developed species distribution models for four forest herb species endemic to the SAM and four that co-occur in the same SAM habitats but have broader ranges. For widespread species, we built models using (1) all occurrences and (2) only those that overlap the SAM hotspot in order to evaluate the extent of Hutchinsonian shortfalls and the potential for models to predict suitable habitat beyond the SAM. We evaluated the extent to which predicted climatically suitable areas are projected to shift away from their current ranges under future climate change. We detected unoccupied but suitable habitat in regions up to 1,100 km north of the endemic species’ ranges. Endemic ranges are disjunct from suitable northern areas due to a ∼100–150 km gap of unsuitable habitat. Under future climate change, models predicted severe reductions in suitable habitat within current endemic ranges. For non-endemic species, we found similar overall patterns and gap of unsuitability in the same geographic location. Our results suggest a history of dispersal limitation following the last glacial maximum along with an environmental barrier to northward migration. Conservation of endemic species would likely require intervention and assisted migration to suitable habitat in northern New England and Canada

    Aging in HIV-Infected Subjects: A New Scenario and a New View

    Get PDF
    The prevalence of HIV-infected people aged 50 years or older is increasing rapidly; the proportion will increase from 28% to 73% in 2030. In addition, HIV-infected individuals may be more vulnerable to age-related condition. There is growing evidence that the prevalence of comorbidities and other age-related conditions (geriatric syndromes, functional or neurocognitive/mental problems, polypharmacy, and social difficulties) is higher in the HIV-infected population than in their uninfected counterparts. However, despite the potential impact of this situation on health care, little information exists about the optimal clinical management of older HIV-infected people. Here we examine the age-related conditions in older HIV-infected persons and address clinical management according to author expertise and published literature. Our aim is to advance the debate about the most appropriate management of this population, including less well-studied aspects, such as frequency of screening for psychological/mental and social and functional capabilities

    Factors influencing participation in outdoor physical activity promotion schemes: The case of South Staffordshire, England

    Get PDF
    Policy exhortations for promoting outdoor physical activity have increased considerably in England and Wales over the past 20 years. Despite a considerable number of schemes developing during this period to encourage physical activity and exercise, marked population-level changes in outdoor physical activity behaviour have not been seen. The paper explores the triggers to this participation using a five-fold classification: physical infrastructure; information infrastructure; administrative infrastructure; participant constraints and participant preferences. Through a series of interviews in a case study 'healthy exercise' scheme in South Staffordshire, a district local authority in England, these triggers to participation are identified and explored. It is concluded that whilst the infrastructure triggers can be manipulated by scheme providers in an attempt to improve scheme participation, participant triggers fall largely beyond the control of scheme providers. Research suggests, too, that participant triggers tend to be stronger than infrastructure ones. Because of this, where there is a lack of healthy exercise scheme success, this cannot necessarily be attributed to scheme providers as it might be as a result of user triggers. For the same reason, it might be beyond the influence of scheme providers to turn 'failing' exercise schemes into successful ones. © 2012 Copyright Taylor and Francis Group, LLC

    Case report 476

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46788/1/256_2004_Article_BF00351012.pd

    What Happened to Gray Whales during the Pleistocene? The Ecological Impact of Sea-Level Change on Benthic Feeding Areas in the North Pacific Ocean

    Get PDF
    Gray whales (Eschrichtius robustus) undertake long migrations, from Baja California to Alaska, to feed on seasonally productive benthos of the Bering and Chukchi seas. The invertebrates that form their primary prey are restricted to shallow water environments, but global sea-level changes during the Pleistocene eliminated or reduced this critical habitat multiple times. Because the fossil record of gray whales is coincident with the onset of Northern Hemisphere glaciation, gray whales survived these massive changes to their feeding habitat, but it is unclear how.We reconstructed gray whale carrying capacity fluctuations during the past 120,000 years by quantifying gray whale feeding habitat availability using bathymetric data for the North Pacific Ocean, constrained by their maximum diving depth. We calculated carrying capacity based on modern estimates of metabolic demand, prey availability, and feeding duration; we also constrained our estimates to reflect current population size and account for glaciated and non-glaciated areas in the North Pacific. Our results show that key feeding areas eliminated by sea-level lowstands were not replaced by commensurate areas. Our reconstructions show that such reductions affected carrying capacity, and harmonic means of these fluctuations do not differ dramatically from genetic estimates of carrying capacity.Assuming current carrying capacity estimates, Pleistocene glacial maxima may have created multiple, weak genetic bottlenecks, although the current temporal resolution of genetic datasets does not test for such signals. Our results do not, however, falsify molecular estimates of pre-whaling population size because those abundances would have been sufficient to survive the loss of major benthic feeding areas (i.e., the majority of the Bering Shelf) during glacial maxima. We propose that gray whales survived the disappearance of their primary feeding ground by employing generalist filter-feeding modes, similar to the resident gray whales found between northern Washington State and Vancouver Island

    Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Impact ∼12,800 Years Ago. 2. Lake, Marine, and Terrestrial Sediments

    Get PDF
    Part 1 of this study investigated evidence of biomass burning in global ice records, and here we continue to test the hypothesis that an impact event at the Younger Dryas boundary (YDB) caused an anomalously intense episode of biomass burning at ∼12.8 ka on a multicontinental scale (North and South America, Europe, and Asia). Quantitative analyses of charcoal and soot records from 152 lakes, marine cores, and terrestrial sequences reveal a major peak in biomass burning at the Younger Dryas (YD) onset that appears to be the highest during the latest Quaternary. For the Cretaceous-Tertiary boundary (K-Pg) impact event, concentrations of soot were previously utilized to estimate the global amount of biomass burned, and similar measurements suggest that wildfires at the YD onset rapidly consumed ∼10 million km2 of Earth’s surface, or ∼9% of Earth’s biomass, considerably more than for the K-Pg impact. Bayesian analyses and age regressions demonstrate that ages for YDB peaks in charcoal and soot across four continents are synchronous with the ages of an abundance peak in platinum in the Greenland Ice Sheet Project 2 (GISP2) ice core and of the YDB impact event (12,835–12,735 cal BP). Thus, existing evidence indicates that the YDB impact event caused an anomalously large episode of biomass burning, resulting in extensive atmospheric soot/dust loading that triggered an “impact winter.” This, in turn, triggered abrupt YD cooling and other climate changes, reinforced by climatic feedback mechanisms, including Arctic sea ice expansion, rerouting of North American continental runoff, and subsequent ocean circulation changes
    corecore