4,009 research outputs found

    An Hedonic Analysis of the Effects of Lake Water Clarity on New Hampshire Lakefront Properties

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    Policy makers often face the problem of evaluating how water quality affects a region's economic well-being. Using water clarity as a measure of the degree of eutrophication levels (as a lake becomes inundated with nutrients, water clarity decreases markedly), analysis is performed on sales data collected over a six-year period. Our results indicate that water clarity has a significant effect on prices paid for residential properties. Effects of a one-meter change in clarity on property value are also estimated for an average lake in four real estate market areas in New Hampshire, with effects differing substantially by area. Our findings provide state and local policy makers a measure of the cost of water quality degradation as measured by changes in water clarity, and demonstrate that protecting water quality may have a positive effect on property tax revenues.Resource /Energy Economics and Policy,

    Multiband superconductivity in the correlated electron filled skutterudite system Pr(1-x)Ce(x)Pt4Ge12

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    Studies of superconductivity in multiband correlated electronic systems has become one of the central topics in condensed matter/materials physics. In this paper, we present the results of thermodynamic measurements on the superconducting filled skutterudite system Pr1−x_{1-x}Cex_xPt4_4Ge12_{12} (0≀x≀0.2 0 \leq x \leq 0.2) to investigate how substitution of Ce at Pr sites affects superconductivity. We find that an increase in Ce concentration leads to a suppression of the superconducting transition temperature from Tc∌7.9T_{c}\sim 7.9 K for x=0x=0 to Tc∌0.6T_c\sim 0.6 K for x=0.14x=0.14. Our analysis of the specific heat data for x≀0.07x\leq 0.07 reveals that superconductivity must develop in at least two bands: the superconducting order parameter has nodes on one Fermi pocket and remains fully gapped on the other. Both the nodal and nodeless gap values decrease, with the nodal gap being suppressed more strongly, with Ce substitution. Ultimately, the higher Ce concentration samples (x>0.07x>0.07) display a nodeless gap only.Comment: 6 pages, 6 figure

    Carvedilol inhibits EGF-mediated JB6 P+ colony formation through a mechanism independent of adrenoceptors

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    Carvedilol is reported to prevent cancers in humans and animal models. However, a molecular mechanism has yet to be established, and the extent to which other P-blockers are chemopreventive remains relatively unknown. A comparative pharmacological approach was utilized with the expectation that a mechanism of action could be devised. JB6 CI 41-5a (JB6 P+) murine epidermal cells were used to elucidate the chemopreventative properties of beta-blockers, as JB6 P+ cells recapitulate in vivo tumor promotion and chemoprevention. The initial hypothesis was that beta-blockers that are GRK/beta-arrestin biased agonists, like carvedilol, are chemopreventive. Sixteen beta-blockers of different classes, isoproterenol, and HEAT HCI were individually co-administered with epidermal growth factor (EGF) to JB6 P+ cells to examine the chemopreventative properties of each ligand. Cytotoxicity was examined to ensure that the anti-transformation effects of each ligand were not due to cellular growth inhibition. Many of the examined p-blockers suppressed EGF-induced JB6 P+ cell transformation in a non-cytotoxic and concentration-dependent manner. However, the IC50 values are high for the most potent inhibitors (243, 326, and 431 nM for carvedilol, labetalol, and alprenolol, respectively) and there is no correlation between pharmacological properties and inhibition of transformation. Therefore, the role of alpha 1- and beta 2-adrenergic receptors (AR) was examined by standard competition assays and shRNA targeting beta 2-ARs, the only beta-AR expressed in JB6 P+ cells. The results reveal that pharmacological inhibition of alpha 1- and beta 2-ARs and genetic knockdown of beta 2-ARs did not abrogate carvedilol-mediated inhibition of EGF-induced JB6 P+ cell transformation. Furthermore, topical administration of carvedilol protected mice from UV-induced skin damage, while genetic ablation of beta 2-ARs increased carvedilol-mediated effects. Therefore, the prevailing hypothesis that the chemopreventive property of carvedilol is mediated through P-ARs is not supported by this data.National Cancer Institute of the National Institutes of Health [R15CA227946]; Western University of Health Sciences; Summer Student Research Program (National Center for Toxicological Research, US. FDA)Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    A coupled terrestrial and aquatic biogeophysical model of the Upper Merrimack River watershed, New Hampshire, to inform ecosystem services evaluation and management under climate and land-cover change

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    Accurate quantification of ecosystem services (ES) at regional scales is increasingly important for making informed decisions in the face of environmental change. We linked terrestrial and aquatic ecosystem process models to simulate the spatial and temporal distribution of hydrological and water quality characteristics related to ecosystem services. The linked model integrates two existing models (a forest ecosystem model and a river network model) to establish consistent responses to changing drivers across climate, terrestrial, and aquatic domains. The linked model is spatially distributed, accounts for terrestrial–aquatic and upstream–downstream linkages, and operates on a daily time-step, all characteristics needed to understand regional responses. The model was applied to the diverse landscapes of the Upper Merrimack River watershed, New Hampshire, USA. Potential changes in future environmental functions were evaluated using statistically downscaled global climate model simulations (both a high and low emission scenario) coupled with scenarios of changing land cover (centralized vs. dispersed land development) for the time period of 1980–2099. Projections of climate, land cover, and water quality were translated into a suite of environmental indicators that represent conditions relevant to important ecosystem services and were designed to be readily understood by the public. Model projections show that climate will have a greater influence on future aquatic ecosystem services (flooding, drinking water, fish habitat, and nitrogen export) than plausible changes in land cover. Minimal changes in aquatic environmental indicators are predicted through 2050, after which the high emissions scenarios show intensifying impacts. The spatially distributed modeling approach indicates that heavily populated portions of the watershed will show the strongest responses. Management of land cover could attenuate some of the changes associated with climate change and should be considered in future planning for the region

    Extracting Signal from the Noisy Environment of an Ecosystem

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    The collection and storage of environmental and ecological data by researchers, government agencies and stewardship groups over the last decade has been remarkable. The proportional challenge to this data accretion lies in capitalizing on these resources for significant gain for both stewards and stakeholders. These trends highlight the role of data science as a critical component to the future of data-driven environmental management. Most critical are models of how data scientists can collaborate with policy makers and stewards to offer tools that leverage data and facilitate decisions. Our project aims to show how a successful collaboration between a management group, the Susquehanna River Basin Commission (SRBC), and an academic group of data scientists resulted in that clarifying insight. The mandate of SRBC is to manage stakeholder requirements while sustaining a healthy ecosystem. The challenge was to differentiate signal events in water quality measurement data from the noisy dynamics of a monitored complex system in a manner that could be applied to other ecosystems. Through the application of generalized additive models (GAM), we were able to clarify the relationship between environmental dynamics and two critical biological communities (macroinvertebrates and fish) that live within the watershed. The GAM model sensitivity was sufficient to identify signal from the noise, and flexible enough to operate across the spatial extent of the ecosystem. By identifying signal events, environmental stewards and policy makers will be able to define thresholds that need to be monitored to reduce pollution & raise diversity in the ecosystem
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