1,529 research outputs found

    Protective coatings for chromium alloys Final summary report, Nov. 1, 1965 - Jul. 13, 1967

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    Aluminum protective coatings for chromium alloy

    Full vs. Light-Handed Regulation of a Network Industry

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    The access pricing problem emerges when a vertically integrated firm (the incumbent) provides an essential service in the upstream market, to an entrant. Both firms produce a final service and compete in the downstream market. The standard treatment of this problem has been to add the access price to the list of instruments available to a regulator who maximizes a social welfare function. Motivated by the international trend to reduce the number of prices set by regulation, we use a light handed regulation approach in which the only tool available to the regulator is the access price, and where retail prices are set by quantity competition in the downstream market. In this setup, we find that a regulator seeking to maximize total market surplus will set an access price that subsidizes the entrant, so that entrants that are less efficient than the incumbent firm can survive in the market. We then compare the outcomes of the full regulation model with those of the light-handed regulation model, in terms of final prices, firm profits, and consumer surplus. When the regulator faces incomplete information about entrant firms' costs and cannot offer a menu of contracts to potential entrants, we find examples in which light handed regulation can dominate full regulationRegulation, essential input, access pricing, vertical integration, regulatory discretion

    Complex Roles of Macrophages in Lipid Metabolism and Metabolic Disease: A Dissertation

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    The worldwide prevalence of obesity and metabolic disease is increasing at an exponential rate and current projections provide no indication of relief. This growing burden of obesity-related metabolic disorders, including type 2 diabetes mellitus (T2DM), highlights the importance of identifying how lifestyle choices, genetics and physiology play a role in metabolic disease and place obese individuals at a greater risk for obesity-related complications including insulin resistance (IR). This increased risk of IR, which is characterized by a decreased response to insulin in peripheral tissues including adipose tissue (AT) and liver, is associated with a chronic, low grade inflammatory state; however, the causative connections between obesity and inflammation remains in question. Experimental evidence suggests that adipocytes and macrophages can profoundly influence obesity-induced IR because adipocyte dysfunction leads to ectopic lipid deposition in peripheral insulin sensitive tissues, and obese AT is characterized by increased local inflammation and macrophage and other immune cell populations. Attempts to delineate the individual roles of macrophage-derived pro-inflammatory cytokines, like tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ÎČ), have demonstrated causative roles in impaired systemic insulin sensitivity, adipocyte function and hepatic glucose and lipid metabolism in obese animal models. Thus, the attenuation of macrophage-derived inflammation is an evolving area of interest to provide insight into the underlying mechanism(s) leading to obesity-induced IR. Thus, in the first chapter of this thesis, I describe experiments to refine the current paradigm of obesity-induced AT inflammation by combining gene expression profiling with computational analysis of two anatomically distinct AT depots, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) to address whether the inflammatory signature of AT is influenced by diet-induced obesity (DIO). Microarray and qRT-PCR analysis data revealed that DIO mouse SAT is resistant to high fat diet (HFD)-induced inflammation and macrophage infiltration, and our data support the current model of obesity-induced visceral adipose tissue macrophage (VATM) enrichment. Our data demonstrated robust increases in VAT pro-inflammatory cytokine expression, which are consistent with the significant increases in macrophage-specific gene expression and consistent with previous reports in which VAT inflammation is enhanced and attributed to classically activated (M1) macrophage infiltration. However, these data are only observed relative to the expression of invariant housekeeping gene expression. When M1-specific genes are expressed relative to macrophage-specific standards like F4/80 expression, these inflammatory makers are unchanged. These data indicate that the changes in the overall inflammatory profile of DIO mouse VAT is because of quantitative changes in adipose tissue macrophage (ATM) number and not qualitative changes in activation state. These observations are consistent with the idea that infiltrating ATMs may have roles other than the previously described role in mediating inflammation in obese adipose tissue. Hepatic IR occurs partly as a consequence of adipocyte dysfunction because the liver becomes a reservoir for AT-derived fatty acids (FAs), which leads to obesity-related non-alcoholic fatty liver disease (NAFLD). In the second part of my thesis, I used clodronate liposome-mediated macrophage depletion to define the role of macrophages in hepatic lipid metabolism regulation. We discovered that i.p. administration of clodronate liposomes depletes Kupffer cells (KCs) in ob/ob mice without affecting VATM content, whereas clodronate liposomes depletes both KCs and VATMs in DIO mice. To this end, we established that clodronate liposome-mediated KC depletion, regardless of VATM content in obese mice, abrogated hepatic steatosis by reducing hepatic de novo lipogenic gene expression. The observed reductions in hepatic inflammation in macrophage-depleted obese mice led to the hypothesis that IL-1ÎČ may be responsible for obesity-induced increased hepatic triglyceride (TG) accumulation. We determined that IL-1ÎČ treatment increases fatty acid synthase (Fas) protein expression and TG accumulation in primary mouse hepatocytes. Pharmacological inhibition of interleukin-1 (IL-1) signaling by interleukin-1 receptor antagonist (IL-1Ra) administration recapitulated these results by reducing hepatic TG accumulation and lipogenic gene expression in DIO mice. Thus, these data highlight the importance of the inflammatory cytokine IL-1ÎČ in obesity-driven hepatic steatosis and suggests that liver inflammation controls hepatic lipogenesis in obesity. To this end, the studies described herein provide new insight and appreciation to the multi-functional nature of macrophages and clinical implications for anti-inflammatory therapy in obesity and NAFLD treatment. We demonstrate the complexities of macrophage-mediated functions in insulin sensitive tissues and a role for obesity-induced inflammatory cytokine IL-1ÎČ in hepatic lipid metabolism modulation, which is reversed via IL-1Ra intervention. The use of anti-inflammatory therapy to ameliorate obesity-associated NAFLD was perhaps the most important contribution to this body of work and is full of promise for future clinical application. It is likely that the future of therapeutics will be multi-faceted and combine therapeutic approaches to enhance glucose tolerance and overall health in obese, IR and T2DM patients

    No Data -- No Progress: Data Collection in Countries Participating in the Decade of Roma Inclusion 2005-2015

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    Evaluates the first five years of the common framework for action on the inclusion of Roma communities, the lack of comprehensive data for assessing progress, and barriers to disaggregating data by ethnicity. Outlines best practices and recommendations

    GREEN INFRASTRUCTURE, ECOLOGICAL INFRASTRUCTURE AND SYSTEMS OF OPEN SPACES: HOW LIMA, PERUVIAN CAPITAL, IS APPROPRIATING THESE CONCEPTS IN FACE OF THE CLIMATE CHANGES

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    Os desafios frente aos incertos impactos das Mudanças ClimĂĄticas vem fazendo com que pesquisadores, gestores pĂșblicos e privados, planejadores e atores cada vez mais diversos discutam, desenvolvam e apliquem conceitos ecolĂłgicos Ă s infraestruturas.Tanto nos meios urbanos quanto nos ecossistemas provedores da maioria dos recursos consumidos nas cidades, os objetivos propostos sĂŁo variĂĄveis em sua espeficidade, mas de forma geral focam em garantir o fornecimento dos recursos naturais para as prĂłximas geraçÔes e/ou criar capacidade de resiliĂȘncia no meio urbano. Nesse cenĂĄrio, o PerĂș vem apresentando avanços importantes e inovadores, embora incipientes, quanto Ă  aplicação de conceitos tais como Infraestrutura Verde, Infraestrutura EcolĂłgica e Sistema de Espacos Abertos, abordando tanto escalas de paisagem como escalas locais.Challenges of the uncertain impacts of climate change are compelling researchers, public and private managers, planners and protagonists of a wide range to discuss, develop and apply ecological concepts to infrastructures. Both urban environments and ecosystems providers of the most of the consumed resources in cities, the proposed objectives are variable in their specificity, but generally focus on securing the supply of natural resources for the next generations and/or creating capacity for resilience in the urban environment. In this scenario, Peru has been presenting important and innovative advances, although incipient, regarding the application of concepts such as Green Infrastructure, Ecological Infrastructure and Open Spaces System, approaching landscape and local scales

    Uptake and accumulation of metals in Spartina alterniflora salt marshes from a South American estuary

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    Salt marshes are capable of reducing metal pollution in coastal waters, but this capacity is highly dependent on the metal, the physico-chemical characteristics of the sediment, the plant species, the production of biomass, the time of the year, etc. The aim of this study was to assess the uptake and accumulation of Pb, Ni, Cu and Zn in Spartina alterniflora from three salt marshes within the BahĂ­a Blanca estuary (BBE), a human-impacted Argentinean system. Metal concentrations in sediments and plants showed the same order at all sites: Zn > Cu > Pb ≄ Ni. The site with lower organic matter and fine sediment content had lower metal concentrations in the sediments, but not a lower metal content in the plant tissues, meaning that the sediment characteristics influenced the metal concentrations in the sediment and their uptake by plants. Despite differences in sediment characteristics between sites, metals were always higher in the belowground tissues than in aboveground ones and, in general, higher in dead than in live tissues. Some metals were accumulated in plant tissues, but not others, and this is dependent on the metal and the sediment characteristics. Allocation patterns of metals in tissues of S. alterniflora were mainly dependent on metal concentrations, determining higher belowground pools, but the aboveground pools were important in some cases due to higher biomass. Partitioning of metals in above or belowground pools determines their fate within the estuarine system, since tissues can decompose in situ (belowground) or be exported (aboveground). Seasonal dynamics were important for some variables but were less noticeable than the differences between sites and tissues. Our results indicate that S. alterniflora from the BBE is efficient in accumulating some metals, despite usually low metal concentrations in sediments and plants. This accumulation capacity has implications for the whole system through the fate of the tissues.Fil: Negrin, Vanesa Lorena. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Instituto Argentino de OceanografĂ­a. Universidad Nacional del Sur. Instituto Argentino de OceanografĂ­a; Argentina. Universidad Nacional del Sur. Departamento de BiologĂ­a, BioquĂ­mica y Farmacia; ArgentinaFil: BottĂ©, Sandra Elizabeth. Universidad Nacional del Sur. Departamento de BiologĂ­a, BioquĂ­mica y Farmacia; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Instituto Argentino de OceanografĂ­a. Universidad Nacional del Sur. Instituto Argentino de OceanografĂ­a; ArgentinaFil: la Colla, Noelia Soledad. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Instituto Argentino de OceanografĂ­a. Universidad Nacional del Sur. Instituto Argentino de OceanografĂ­a; ArgentinaFil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Instituto Argentino de OceanografĂ­a. Universidad Nacional del Sur. Instituto Argentino de OceanografĂ­a; Argentina. Universidad TecnolĂłgica Nacional. Facultad Regional BahĂ­a Blanca; Argentina. Universidad FASTA "Santo Tomas de Aquino"; Argentin
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