390 research outputs found

    Examining the USCG Alternate Compliance Program Risk-Based Oversight Initiatives

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    The goal of this project was to analyze the U.S. Coast Guard\u27s Alternate Compliance Program targeted vessel oversight initiatives, and to determine if an effective degree of oversight has been realized. We performed archival research and conducted surveys and interviews to complete our objectives. Our results indicate that improvements to the program\u27s oversight could be achieved by improving the MISLE database, adopting a more sustainable vessel targeting matrix, and increasing inspector training opportunities

    Physical and social access to land: Spatio-temporal patterns of agricultural expansion

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    Abstract The expansion of agriculture is posited as one of the main dynamics of land cover change globally, and the robust modeling of these processes is important for policy as well as academic concerns. Madagascar's farmers stand accused as the "proximate agents" of land conversion in one of the world's "hottest" biodiversity hotspots, and numerous studies have been conducted to describe and model the processes by which the country's forests are giving way to agriculture. This paper concerns a relatively small area on the island's eastern escarpment where considerable national and international attention has been paid to slow the expansion of agriculture into the remaining natural forests. The approach adopted here is to begin by examining the degree to which patterns of agricultural conversion can be attributed to a set of factors that have been identified as significant at broader scales in Madagascar and elsewhere, namely topography and prior human settlement and land use patterns. A regression model is constructed, and its predictions compared to the observed land conversion over a 43-year period. The study then examines in detail the spatial patterns highlighted by the failure of the model (the residuals of the regression), breaking the study area into smaller zones, or landscapes. The spatio-temporal trajectories of these zones are then contrasted, with particular attention to the institutional arrangements governing access to land resources. The study finds that while overall land change patterns in the region are largely explained by elevation and village proximity, more specific, sub-regional, trajectories reflect the signatures of institutions governing access to land

    A–C Estrogens as Potent and Selective Estrogen Receptor-Beta Agonists (SERBAs) to Enhance Memory Consolidation under Low-Estrogen Conditions

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    Estrogen receptor-beta (ERβ) is a drug target for memory consolidation in postmenopausal women. Herein is reported a series of potent and selective ERβ agonists (SERBAs) with in vivo efficacy that are A–C estrogens, lacking the B and D estrogen rings. The most potent and selective A–C estrogen is selective for activating ER relative to seven other nuclear hormone receptors, with a surprising 750-fold selectivity for the β over α isoform and with EC50s of 20–30 nM in cell-based and direct binding assays. Comparison of potency in different assays suggests that the ER isoform selectivity is related to the compound’s ability to drive the productive conformational change needed to activate transcription. The compound also shows in vivo efficacy after microinfusion into the dorsal hippocampus and after intraperitoneal injection (0.5 mg/kg) or oral gavage (0.5 mg/kg). This simple yet novel A–C estrogen is selective, brain penetrant, and facilitates memory consolidation

    Characterizing the impacts of multi-scale heterogeneity on solute transport in fracture networks

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    We model flow and transport in three-dimensional fracture networks with varying degrees of fracture-to-fracture aperture/permeability heterogeneity and network density to show how changes in these properties can cause the emergence of anomalous flow and transport behavior. If fracture-to-fracture aperture heterogeneity is increased in sparse networks, velocity fluctuations can inhibit high flow rates and solute transport can be delayed, even in cases where hydraulic aperture is monotonically increased. As the density of the networks is increased, more connected pathways allow for particles to bypass these effects. We discover transition behavior where with relatively few connected pathways in a network from inflow to outflow boundaries, the first arrival times of particles are not heavily affected by fracture-to-fracture aperture heterogeneity, but the scaling behavior of the tails is strongly influenced due to the particles being forced to sample some of the heterogeneity in the velocity field caused by aperture differences. These results reinforce the importance of considering multi-scale effects in fractured systems and can inform flow and transport processes in both natural and engineered fracture systems, especially the latter where high aperture fractures are often stimulated and connect to existing fracture networks with smaller apertures

    Population Dynamics Of A Diverse Rodent Assemblage In Mixed Grass-Shrub Habitat, Southeastern Colorado, 1995–2000

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    We followed seasonal and year-to-year population dynamics for a diverse rodent assemblage in a short-grass prairie ecosystem in southeastern Colorado (USA) for 6 yr. We captured 2,798 individual rodents (range, one to 812 individuals per species) belonging to 19 species. The two most common species, deer mice (Peromyscus maniculatus) and western harvest mice (Reithrodontomys megalotis), generally had population peaks in winter and nadirs in summer; several other murid species demonstrated autumn peaks and spring nadirs; heteromyids were infrequently captured in winter, and populations generally peaked in summer or autumn. Interannual trends indicated an interactive effect between temperature and precipitation. Conditions associated with low rodent populations or population declines were high precipitation during cold periods (autumn and winter) and low precipitation during warm periods (spring and summer). Severity of adverse effects varied by species. Heteromyids, for example, were apparently not negatively affected by the hot, dry spring and summer of 2000. Cross-correlations for the temporal series of relative population abundances between species pairs (which are affected by both seasonal and interannual population dynamics) revealed positive associations among most murids and among most heteromyids, but there were negative associations between murids and heteromyids. These results have important implications for those attempting to model population dynamics of rodent populations for purposes of predicting disease risk

    Natural history of Sin Nombre virus in western Colorado.

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    A mark-recapture longitudinal study of immunoglobulin G (IgG) antibody to Sin Nombre virus (SNV) in rodent populations in western Colorado (1994-results summarized to October 1997) indicates the presence of SNV or a closely related hantavirus at two sites. Most rodents (principally deer mice, Peromyscus maniculatus, and pinyon mice, P. truei) did not persist on the trapping webs much beyond 1 month after first capture. Some persisted more than 1 year, which suggests that even a few infected deer mice could serve as transseasonal reservoirs and mechanisms for over-winter virus maintenance. A positive association between wounds and SNV antibody in adult animals at both sites suggests that when infected rodents in certain populations fight with uninfected rodents, virus amplification occurs. At both sites, male rodents comprised a larger percentage of seropositive mice than recaptured mice, which suggests that male mice contribute more to the SNV epizootic cycle than female mice. In deer mice, IgG antibody prevalence fluctuations were positively associated with population fluctuations. The rates of seroconversion, which in deer mice at both sites occurred mostly during late summer and midwinter, were higher than the seroprevalence, which suggests that the longer deer mice live, the greater the probability they will become infected with SNV

    2003 Manifesto on the California Electricity Crisis

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    The authors, an ad-hocgroup of professionals with experience in regulatory and energy economics, share a common concern with the continuing turmoil facing the electricity industry ("the industry") in California. Most ofthe authorsendorsed the first California Electricity Manifesto issued on January 25, 2001. Almost two years have passed since that first Manifesto. While wholesale electric prices have moderated and California no longer faces the risk of blackouts, in many ways the industry is in worse shape now than it was at the start of 2001. As a result, the group of signatories continues to have a deep concern with the conflicting policy directions being pursued for the industry at both the State and Federal levels of government and the impact the uncertainties associated with these conflicting policies will have, long term, on the economy of California. Theauthorshave once again convened under the auspices of the Institute of Management, Innovation and Organization at the University of California, Berkeley, to put forward ourtheir ideas on a basic set of necessary policies to move the industry forward for the benefit of all Californians and the nation. The authors point out that theydo not pretend to be "representative." They do bring, however, a very diverse range of backgrounds and expertise.Technology and Industry, Regulatory Reform

    Identification and analysis of hepatitis C virus NS3 helicase inhibitors using nucleic acid binding assays

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    Typical assays used to discover and analyze small molecules that inhibit the hepatitis C virus (HCV) NS3 helicase yield few hits and are often confounded by compound interference. Oligonucleotide binding assays are examined here as an alternative. After comparing fluorescence polarization (FP), homogeneous time-resolved fluorescence (HTRF®; Cisbio) and AlphaScreen® (Perkin Elmer) assays, an FP-based assay was chosen to screen Sigma’s Library of Pharmacologically Active Compounds (LOPAC) for compounds that inhibit NS3-DNA complex formation. Four LOPAC compounds inhibited the FP-based assay: aurintricarboxylic acid (ATA) (IC50 = 1.4 μM), suramin sodium salt (IC50 = 3.6 μM), NF 023 hydrate (IC50 = 6.2 μM) and tyrphostin AG 538 (IC50 = 3.6 μM). All but AG 538 inhibited helicase-catalyzed strand separation, and all but NF 023 inhibited replication of subgenomic HCV replicons. A counterscreen using Escherichia coli single-stranded DNA binding protein (SSB) revealed that none of the new HCV helicase inhibitors were specific for NS3h. However, when the SSB-based assay was used to analyze derivatives of another non-specific helicase inhibitor, the main component of the dye primuline, it revealed that some primuline derivatives (e.g. PubChem CID50930730) are up to 30-fold more specific for HCV NS3h than similarly potent HCV helicase inhibitors.National Institutes of Health [RO1 AI088001]; Research Growth Initiative Award [101X219] from the University of Wisconsin-Milwaukee Research Foundation; National Institutes of Health Molecular Libraries Initiative [U54 HG005031]. Funding for open access charge: University of Wisconsin-Milwaukee Research Foundation

    Substituting carbohydrate at lunch for added protein increases fat oxidation during subsequent exercise in healthy males

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    Context How pre-exercise meal composition influences metabolic and health responses to exercise later in the day is currently unclear. Objective Examine the effects of substituting carbohydrate for protein at lunch on subsequent exercise metabolism, appetite, and energy intake. Methods Twelve healthy males completed three trials in randomized, counterbalanced order. Following a standardized breakfast (779 ± 66 kcal; ∼08:15), participants consumed a lunch (1186 ± 140 kcal; ∼13:15) containing either 0.2 g·kg-1 carbohydrate and ∼2 g·kg-1 protein (LO-CARB), 2 g·kg-1 carbohydrate and ∼0.4 g·kg-1 protein (HI-CARB), or fasted (FAST). Participants later cycled at ∼60% V̇O2peak for 1 h (∼16:15) and post-exercise ad-libitum energy intake was measured (∼18:30). Substrate oxidation, subjective appetite, and plasma concentrations of glucose, insulin, non-esterified fatty acids (NEFA), peptide YY (PYY), glucagon-like peptide-1 (GLP-1), and acylated ghrelin (AG) were measured for 5 h post-lunch. Results Fat oxidation was greater during FAST (+11.66 ± 6.63 g) and LO-CARB (+8.00 ± 3.83 g) than HI-CARB (p < 0.001), with FAST greater than LO-CARB (+3.67 ± 5.07 g; p < 0.05). NEFA were lowest in HI-CARB and highest in FAST, with insulin demonstrating the inverse response (all p < 0.01). PYY and GLP-1 demonstrated a stepwise pattern, with LO-CARB greatest and FAST lowest (all p < 0.01). AG was lower during HI-CARB and LO-CARB versus FAST (p < 0.01). Energy intake in LO-CARB was lower than FAST (-383 ± 233 kcal; p < 0.001) and HI-CARB (-313 ± 284 kcal; p < 0.001). Conclusion Substituting carbohydrate for protein in a pre-exercise lunch increased fat oxidation, suppressed subjective and hormonal appetite, and reduced post-exercise energy intake
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