1,846 research outputs found

    Science Leadership: Impact of the New Science Coordinators Academy

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    This article discusses the impact of the New Science Coordinators Academy (NSCA) on two cohorts of participants. The NSCA is one of four components of the Virginia Initiative for Science Teaching and Achievement (VISTA), a United States Department of Education (USED) science education reform grant. The NSCA is designed to support new school district science coordinators (with less than five years of experience) and to continue building the state science education infrastructure. Research in education leadership traditionally focuses on teacher leaders, principals, and district office personnel. Interestingly, research on district office personnel rarely distinguishes between the different roles of district personnel. This article seeks to inform the field by sharing the impact of an academy designed for new science coordinators on their learning, and to begin to understand their role and impact in their district. The five-day Academy engaged participants in a variety of experiences designed to facilitate the following: 1) build leadership skills; 2) build a common understanding and vision for hands-on science, inquiry, problem-based learning, and nature of science in the science classroom; 3) investigate data to improve student learning goals; 4) and, develop a science strategic plan. The data indicate that the NSCA was successful at meeting its goals to support the participants and to build a common language among these new coordinators. Initial data also support the variety of responsibilities of these participants and the positive impact of the Academy on their district work

    Fingerprints of biocomplexity: Taxon‐specific growth of phytoplankton in relation to environmental factors

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110012/1/lno2004494part21446.pd

    Meta-Analysis of Perceived Stress and Its Association With Incident Coronary Heart Disease

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    Most studies examining potential associations between psychological factors and cardiovascular outcomes have focused on depression or anxiety. The effect of perceived stress on incident coronary heart disease (CHD) has yet to be reviewed systematically. We conducted a systematic review and meta-analysis of the association between perceived stress and incident CHD. Ovid, MEDLINE, and PsycINFO were searched as data sources. Prospective observational cohort studies were selected that measured self-reported perceived stress and assessed incident CHD at ≄6 months. We extracted study characteristics and estimates of the risk of incident CHD associated with high perceived stress versus low perceived stress. We identified 23 potentially relevant articles, of which 6 met our criteria (n = 118,696). Included studies measured perceived stress with validated measurements and nonvalidated simple self-report surveys. Incident CHD was defined as new diagnosis of, hospitalization for, or mortality secondary to CHD. Meta-analysis yielded an aggregate risk ratio of 1.27 (95% confidence interval 1.12 to 1.45) for the magnitude of the relation between high perceived stress and incident CHD. In conclusion, this meta-analysis suggests that high perceived stress is associated with a moderately increased risk of incident CHD

    Cladoceran birth and death rates estimates

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    I. Birth and death rates of natural cladoceran populations cannot be measured directly. Estimates of these population parameters must be calculated using methods that make assumptions about the form of population growth. These methods generally assume that the population has a stable age distribution. 2. To assess the effect of variable age distributions, we tested six egg ratio methods for estimating birth and death rates with data from thirty-seven laboratory populations of Daphnia pulicaria. The populations were grown under constant conditions, but the initial age distributions and egg ratios of the populations varied. Actual death rates were virtually zero, so the difference between the estimated and actual death rates measured the error in both birth and death rate estimates. 3. The results demonstrate that unstable population structures may produce large errors in the birth and death rates estimated by any of these methods. Among the methods tested, Taylor and Slatkin's formula and Paloheimo's formula were most reliable for the experimental data. 4. Further analyses of three of the methods were made using computer simulations of growth of age-structured populations with initially unstable age distributions. These analyses show that the time interval between sampling strongly influences the reliability of birth and death rate estimates. At a sampling interval of 2.5 days (equal to the duration of the egg stage), Paloheimo's formula was most accurate. At longer intervals (7.5–10 days), Taylor and Slatkin's formula which includes information on population structure was most accurate

    An inexpensive device for monitoring patients' weights via automated hovering

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    Daily weight monitoring is integral to the management of heart failure (HF) [1]. Indeed, weight gain is a marker of HF decompensation, and daily weight monitoring has been associated with favorable prognosis [2]. Until now, assessment of weight has required patients to attend an in-person visit, which provides only an infrequent snapshot of their weight. Remote hovering practices have gained considerable traction during the past several years [3–7], but their use outside of research settings has been limited

    Preliminary assessment of the irradiation behaviour of the FeCrMnNi High-Entropy Alloy for nuclear applications

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    In the search for new nuclear materials with improved radiation tolerance and behavior, the high-entropy alloys (HEAs) have arisen as new candidates for structural components in nuclear reactors due to their suspected superior stability under irradiation. The metallurgical definition of HEAs is any alloy with multiple elements, five or more all in equiatomic compositions. The basic principle is the high mixing entropy of its solid solution lowers the Gibbs free energy giving a strong enhancement of the microstructural stability at low and high temperatures. The objective of this project is to assess the irradiation behaviour of the FeCrMnNi HEA system in order to investigate whether the high entropy effect is responsible for a microstructure with better radiation resistance compared to conventional alloys. In this work transmission electron microscopy (TEM) with in-situ ion irradiation has been used at the MIAMI-1 facility at the University of Huddersfield, UK: a 100 kV ion accelerator coupled with a JEOL JEM-2000FX TEM. This methodology allows the evolution of the HEA microstructure to be studied on the nanoscale during the ion irradiation
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