200 research outputs found

    Beaver Lake Water Quality Monitoring Plan

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    The Beaver Lake basin is located in Northwest Arkansas, and includes portions of Washington, Madison, Benton, Carroll and Franklin counties. The White River is the :major tributary to Beaver lake, with minor tributaries including the Middle and West Forks of the Whi 1:e River, Richland Creek and War Eagle Creek. The basin encompassing 1,186 square miles of drainage area provides a usable storage capacity of 1.22 :million acre-feet, 300,000 of which are designated as flood control, the remainder is utilized for power generation and water supply. Beaver Lake is the water source for both the Beaver and Carroll County Water Districts. Ten recreational facilities hav\u27e been developed around the lake by the U.S. Army Corps of Engineers (COE)

    Front propagation into unstable and metastable states in Smectic C* liquid crystals: linear and nonlinear marginal stability analysis

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    We discuss the front propagation in ferroelectric chiral smectics (SmC*) subjected to electric and magnetic fields applied parallel to smectic layers. The reversal of the electric field induces the motion of domain walls or fronts that propagate into either an unstable or a metastable state. In both regimes, the front velocity is calculated exactly. Depending on the field, the speed of a front propagating into the unstable state is given either by the so-called linear marginal stability velocity or by the nonlinear marginal stability expression. The cross-over between these two regimes can be tuned by a magnetic field. The influence of initial conditions on the velocity selection problem can also be studied in such experiments. SmC^* therefore offers a unique opportunity to study different aspects of front propagation in an experimental system

    A comparison of hematological, immunological, and stress responses to capture and transport in wild White Rhinoceros Bulls (Ceratotherium simum simum) supplemented with azaperone or midazolam

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    Capture and transport are essential procedures for the management and conservation of southern white rhinoceroses (Ceratotherium simum simum), but are associated with stress-induced morbidity and mortality. To improve conservation efforts, it is crucial to understand the pathophysiology of rhinoceros stress responses and investigate drug combinations that could reduce these responses. In this study we measured rhinoceros stress responses to capture and transport by quantifying hematological and immunological changes together with adrenal hormone concentrations. We investigated whether the potent anxiolytic drug midazolam was able to mitigate these responses compared to azaperone, which is more commonly used during rhinoceros transport. Twenty three wild white rhinoceros bulls were transported for 6 h (280 km) within the Kruger National Park for reasons unrelated to this study. Rhinoceroses were immobilized with either etorphine-azaperone (group A, n = 11) or etorphine-midazolam (group M, n = 12) intramuscularly by darting from a helicopter. Azaperone (group A) or midazolam (group M) were re-administered intramuscularly every 2 h during transport. Serial blood samples were collected at capture (TC), the start of transport (T0) and after 6 h of transport (T6). Changes in hematological and immunological variables over time and between groups were compared using general mixed models. Increases in plasma epinephrine and serum cortisol concentrations indicated that rhinoceroses mounted a stress response to capture and transport. Packed cell volume decreased from TC to T6 indicating that stress hemoconcentration occurred at TC. Neutrophils progressively increased and lymphocytes and eosinophils progressively decreased from T0 to T6, resulting in an increase in neutrophil to lymphocyte ratio; a characteristic leukocyte response to circulating glucocorticoids. A reduction in serum iron concentrations may suggest the mounting of an acute phase response. Rhinoceroses experienced a decrease in unsaturated fatty acids and an increase in lipid peroxidation products at capture and toward the end of transport indicating oxidative stress. Midazolam, at the dose used in this study, was not able to mitigate adrenal responses to stress and appeared to directly influence leukocyte responses.The International Rhino Foundation, the Cayman Supporting Women in Research Grant, the Wildlife Group of the South African Veterinary Association, the South African National Research Foundation and the research fund of the Department of Paraclinical Sciences of the Faculty of Veterinary Science, University of Pretoria.https://www.frontiersin.org/journals/veterinary-science#pm2021Centre for Veterinary Wildlife StudiesCompanion Animal Clinical StudiesParaclinical Science

    Musical events and perceptual ecologies

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    This paper, followed by two responses, discusses the application of ecological theory to an understanding of a number of issues in the aesthetics of music. It argues for an understanding of music as based in event perception, with an expanded conception of the sources that are specified by those events. Building on the theory of affordances, it considers the limitations of an information theoretic conception of musical complexity, discusses the importance of perceptual learning (understood as shaping by a structured environment) in understanding the affordances of music for different listeners, and raises the challenging problem of the terms in which musical materials might be appropriately described. The apparent tension between ecological and aesthetic positions—in which adaptation and accommodation seem to be at odds with a modernist aesthetic perspective which prioritizes the unsettling and defamiliarizing function of art—is confronted, before the paper concludes with some observations about different disciplinary perspectives on aesthetics, and matters of specificity and generality

    The relationship between the perception of distributed leadership in secondary schools and teachers' and teacher leaders' job satisfaction and organizational commitment

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    This study investigates the relation between distributed leadership, the cohesion of the leadership team, participative decision-making, context variables, and the organizational commitment and job satisfaction of teachers and teacher leaders. A questionnaire was administered to teachers and teacher leaders (n=1770) from 46 large secondary schools. Multiple regression analyses and path analyses revealed that the study variables explained significant variance in organizational commitment. The degree of explained variance for job satisfaction was considerably lower compared to organizational commitment. Most striking was that the cohesion of the leadership team and the amount of leadership support was strongly related to organizational commitment, and indirectly to job satisfaction. Decentralization of leadership functions was weakly related to organizational commitment and job satisfaction

    Whole Genome Sequence Analysis of Cryptococcus gattii from the Pacific Northwest Reveals Unexpected Diversity

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    A recent emergence of Cryptococcus gattii in the Pacific Northwest involves strains that fall into three primarily clonal molecular subtypes: VGIIa, VGIIb and VGIIc. Multilocus sequence typing (MLST) and variable number tandem repeat analysis appear to identify little diversity within these molecular subtypes. Given the apparent expansion of these subtypes into new geographic areas and their ability to cause disease in immunocompetent individuals, differentiation of isolates belonging to these subtypes could be very important from a public health perspective. We used whole genome sequence typing (WGST) to perform fine-scale phylogenetic analysis on 20 C. gattii isolates, 18 of which are from the VGII molecular type largely responsible for the Pacific Northwest emergence. Analysis both including and excluding (289,586 SNPs and 56,845 SNPs, respectively) molecular types VGI and VGIII isolates resulted in phylogenetic reconstructions consistent, for the most part, with MLST analysis but with far greater resolution among isolates. The WGST analysis presented here resulted in identification of over 100 SNPs among eight VGIIc isolates as well as unique genotypes for each of the VGIIa, VGIIb and VGIIc isolates. Similar levels of genetic diversity were found within each of the molecular subtype isolates, despite the fact that the VGIIb clade is thought to have emerged much earlier. The analysis presented here is the first multi-genome WGST study to focus on the C. gattii molecular subtypes involved in the Pacific Northwest emergence and describes the tools that will further our understanding of this emerging pathogen

    Nation-Building Through Compulsory Schooling During the Age of Mass Migration

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    By the mid-19th century, America was the most educated nation on Earth: significant financial investments in education were being undertaken and the majority of children voluntarily attended public schools. So why did states across America start introducing compulsory schooling laws at this time in history? We provide qualitative and quantitative evidence that states adopted compulsory schooling laws as a nation-building tool to instill civic values to the tens of millions of culturally diverse migrants who arrived during the ‘Age of Mass Migration’ between 1850 and 1914. We show the adoption of state level compulsory schooling laws occurred significantly earlier in states that hosted a subgroup of European migrants with lower exposure to civic values in their home countries. We then use cross-county data to show the same subgroup of European migrants had significantly lower demand for American common schooling pre-compulsion, and so would have been less exposed to the kinds of civic value or discipline instilled by the American education system had compulsory schooling not been passed. By studying the link between mass migration and the endogenous policy responses of American-born voters in receiving states, our analysis provides new micro-foundations for compulsory schooling laws, the legislative bedrock on which all future developments of the American schooling system were built
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