2,499 research outputs found

    Control of fructose 2,6-bisphosphate levels in rat macrophages by glucose and phorbol ester

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    AbstractThe presence of fructose 2,6-bisphosphate (Fru 2,6-P2) in elicited peritoneal macrophages of rat was examined. These cells possess an active phosphofructokinase-2 which is diminished by citrate and only slightly inhibited by glycerol 3-phosphate. Phosphofructokinase-1 submaximal activity was increased 26-fold by the addition of 1 μM Fru 2,6-P2. Incubation of cells without glucose decreased the amount of Fru 2,6-P2 to zero, but further addition of 5 mM glucose increased the levels of the sugar ester 20-fold. In addition, the presence of phorbol ester potentiated the synthesis of Fru 2,6-P2. By contrast phenylisopropyladenosine or prostaglandin F2α inhibited the production of Fru 2,6-P2

    Relative deprivation, and procedural and distributive justice in National Environmental Policy Act scoping documents

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    2011 Fall.Includes bibliographical references.The U.S. Forest Service often deals with very contentious resource management issues. This contention is wrought by the nature and diversity of people using National Forest system lands. The process for making decisions on the management of these issues is called the National Environmental Policy Act (NEPA). This act describes how decisions will be made and how the public will be involved with these decisions based on the comparison of environmental impacts to alternatives usually developed by Forest Service resource managers before the public input process. The first step in NEPA is called scoping. In many cases this scoping is accomplished by sending a letter out to interested parties, called a scoping letter which describes the proposed action. This study examined NEPA-required scoping using a letter. Participants' attitudes toward the Forest Service and their feelings of justice were measured in reaction to information provided in a scoping letter. Participants were assigned to read one of three scoping letters. One letter provided a proposed action that decreased recreational shooting opportunities by eliminating shooting over a large area of National Forest System lands. The second scoping letter provided a proposed action that increased recreational shooting activities by opening up large areas of National Forest System land to shooting activities. The third scoping letter did not mention any proposed action. This letter described the processes that would be used to decide what the problem was regarding shooting and another process that would be used to decide on solutions to the problem. Participants who received the scoping letter that only provided processes had a more positive attitude toward the Forest Service than participants who received a scoping letter with a proposed action. Participants who received a letter with a proposed action that was not in their favor did not have a significantly more negative attitude toward the Forest Service than those who received a decision that was in their favor. In terms of justice, participants with a negative attitude toward the Forest Service who received a scoping letter with a process did not have significantly different feelings of justice than those who received either letter with a proposed action. Finally, no matter what participant's attitude toward the Forest Service, there was no significant difference in their feelings of justice

    The REMSDB Macroeconomic Database of The Spanish Economy

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    This paper presents a new macroeconomic database for the Spanish economy, REMSDB. The construction of this database has been oriented to conducting medium-term simulations for policy evaluation with the REMS model, a large Rational Expectations macroeconomic Model for Spain. The paper provides a detailed description of the data and documents its main statistical properties. The database is thought to be of major interest to related applications,whether strictly associated with the REMS model or, rather, with empirical macroeconomic studies.Spanish Data, Growth Data, Business Cycle Data, REMS

    Astrometric Effects of a Stochastic Gravitational Wave Background

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    A stochastic gravitational wave background causes the apparent positions of distant sources to fluctuate, with angular deflections of order the characteristic strain amplitude of the gravitational waves. These fluctuations may be detectable with high precision astrometry, as first suggested by Braginsky et al. in 1990. Several researchers have made order of magnitude estimates of the upper limits obtainable on the gravitational wave spectrum \Omega_gw(f), at frequencies of order f ~ 1 yr^-1, both for the future space-based optical interferometry missions GAIA and SIM, and for VLBI interferometry in radio wavelengths with the SKA. For GAIA, tracking N ~ 10^6 quasars over a time of T ~ 1 yr with an angular accuracy of \Delta \theta ~ 10 \mu as would yield a sensitivity level of \Omega_gw ~ (\Delta \theta)^2/(N T^2 H_0^2) ~ 10^-6, which would be comparable with pulsar timing. In this paper we take a first step toward firming up these estimates by computing in detail the statistical properties of the angular deflections caused by a stochastic background. We compute analytically the two point correlation function of the deflections on the sphere, and the spectrum as a function of frequency and angular scale. The fluctuations are concentrated at low frequencies (for a scale invariant stochastic background), and at large angular scales, starting with the quadrupole. The magnetic-type and electric-type pieces of the fluctuations have equal amounts of power.Comment: 23 pages, 2 figures, references added and minor text correction

    Síntesis hidrotermal de zeolita a partir de ceniza volante tipo F: influencia de la temperatura = Influence of temperature of alkaline hydrothermal treatment on the zeolite conversion of spanish coal class F fly ash

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    En este trabajo se presenta el papel que juega la temperatura durante el tratamiento hidrotermal en medio alcalino para convertir una ceniza volante de bajo contenido en cal (clase F, según la norma ASTM) en zeolita. Durante este tratamiento a la temperatura de 100 ºC se forma zeolita Na-P1 tipo gismondina (Na6Al6Si10O32.12H2O); al elevar la temperatura a 200 ºC, dicha zeolita se transforma en zeolita analcima C (Na(Si2Al)O6H2O) y en fase sodalita (1.08 Na2O.Al2O3.1.68SiO2.1.8H2O) junto con trazas de tobermorita-11Å (Ca5(OH)2Si6O16.4H2O). A esta temperatura y en estas condiciones se ha conseguido un 100% de reacción. Un estudio equivalente se ha llevado a cabo empleando agua como medio de referencia. La conversión de ceniza volante en zeolita se ha caracterizado mediante técnicas, como difracción de Rayos X (DRX), espectroscopia infrarroja por transformada de Fourier (FTIR) y análisis térmico (TG/ATD); asimismo los cambios en el área superficial se han llevado a cabo mediante la técnica BET-N

    Redox-Active Nanomaterials For Nanomedicine Applications

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    Nanomedicine utilizes the remarkable properties of nanomaterials for the diagnosis, treatment, and prevention of disease. Many of these nanomaterials have been shown to have robust antioxidative properties, potentially functioning as strong scavengers of reactive oxygen species. Conversely, several nanomaterials have also been shown to promote the generation of reactive oxygen species, which may precipitate the onset of oxidative stress, a state that is thought to contribute to the development of a variety of adverse conditions. As such, the impacts of nanomaterials on biological entities are often associated with and influenced by their specific redox properties. In this review, we overview several classes of nanomaterials that have been or projected to be used across a wide range of biomedical applications, with discussion focusing on their unique redox properties. Nanomaterials examined include iron, cerium, and titanium metal oxide nanoparticles, gold, silver, and selenium nanoparticles, and various nanoscale carbon allotropes such as graphene, carbon nanotubes, fullerenes, and their derivatives/variations. Principal topics of discussion include the chemical mechanisms by which the nanomaterials directly interact with biological entities and the biological cascades that are thus indirectly impacted. Selected case studies highlighting the redox properties of nanomaterials and how they affect biological responses are used to exemplify the biologically-relevant redox mechanisms for each of the described nanomaterials

    Propiedad Extranjera y Especialización Productiva en la Industria del Vino en Chile

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    En este trabajo se analizan los diferentes patrones de especialización productiva seguidos por inversionistas extranjeros en la industria del vino en Chile; en particular, su efecto sobre la estructura de propiedad que la firma escoge para su nuevo negocio vitivinícola. Existe evidencia que viñas organizadas como Joint Venture (JV) tienen mayor participación en los segmentos de vinos exportados con mayor valor unitario, respecto al caso de viñas que son filiales de inversionistas extranjeros. La hipótesis central bajo estudio es que para inversionistas extranjeros con producción más especializada en vinos de mayor valor, acuerdos de ‘propiedad compartida’ o JV pueden ser un mecanismo eficiente para incentivar las inversiones y esfuerzos productivos requeridos por tal tipo de producción. Las razones analizadas se refieren fundamentalmente al diseño de incentivos contractuales eficientes.Inversión Extranjera; Joint Venture; Industria Vitivinícola
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