1,743 research outputs found

    A class of non-supersymmetric orientifolds

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    We study type IIB orientifolds on T^{2d}/Z_N with supersymmetry broken by the compactification. We determine tadpole cancellation conditions including anti-branes and considering different actions for the parity Omega. Using these conditions we then obtain the spectrum of tachyons and massless states. Various examples with N even correspond to type 0B orientifolds.Comment: 49 pages, Late

    Crossing the cosmological constant line in a dilatonic brane-world model with and without curvature corrections

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    We construct a new brane-world model composed of a bulk -with a dilatonic field-, plus a brane -with brane tension coupled to the dilaton-, cold dark matter and an induced gravity term. It is possible to show that depending on the nature of the coupling between the brane tension and the dilaton this model can describe the late-time acceleration of the brane expansion (for the normal branch) as it moves within the bulk. The acceleration is produced together with a mimicry of the crossing of the cosmological constant line (w=-1) on the brane, although this crossing of the phantom divide is obtained without invoking any phantom matter neither on the brane nor in the bulk. The role of dark energy is played by the brane tension, which reaches a maximum positive value along the cosmological expansion of the brane. It is precisely at that maximum that the crossing of the phantom divide takes place. We also show that these results remain valid when the induced gravity term on the brane is switched off.Comment: 12 pages, 2 figures, RevTeX

    Efecto de la adición de proteínas solubles recuperadas del agua de lavado de surimi de Pacific Whiting sobre las propiedades funcionales y mecánicas de surimi de Alaska pollock grado FA

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    Soluble proteins from surimi wash water (SWW) can be insolubilized by complexing with chitosan-alginate allowing its recovery and the reduction of the organic matter in the processing water discharged from surimi processing plants. The objective of this work was to evaluate the effect of adding soluble proteins recovered from Pacific whiting SWW on the mechanical and functional properties of commercial Alaska Pollock surimi grade FA. Levels evaluated were 0 (control), 10, 30 and 50 g insolubilized SWW solids/kg Alaska Pollock grade FA surimi. The mechanical and functional properties of Alaska Pollock surimi pastes and gels were characterized by texture profile analysis (TPA), puncture test, expressible water (EW) and color attributes. TPA and puncture test parameters increased significantly (P≤0.05) when 10–30 g/kg of soluble proteins from Pacific whiting SWW were added. EW values increased also, indicating a decrease of the water holding capacity. Color parameters showed that all surimi gels increased in redness, an undesirable effect in the production of Alaska Pollock grade FA surimiLas proteínas solubles del agua de lavado del surimi (ALS) pueden ser insolubilizadas por medio de la formación de complejos con quitosano y alginato. Su recuperación por este método permite reducir la materia orgánica en el agua de proceso. El objetivo de este trabajo fue evaluar el efecto de la adición de proteína soluble recuperada del ALS de Pacific whiting sobre las propiedades mecánicas y funcionales de surimi comercial de Alaska Pollock de grado FA. Los niveles de adición evaluados fueron 0 (control), 10, 30 y 50 g sólidos insolubilizados de ALS/kg de surimi de Alaska Pollock de grade FA. Las propiedades mecánicas y funcionales se caracterizaron por medio del análisis de perfil de textura (TPA), prueba de punción, agua extraíble y atributos de color. Los valores de los parámetros de TPA y prueba de punción incrementaron significativamente (P≤0.05) cuando se adicionaron de 10 a 30 g/kg de proteínas solubles de ALS de Pacific whiting. El agua extraíble también se incrementó, indicando un descenso de la capacidad de retención de agua. Los atributos de color indicaron que todos los geles de surimi incrementaron su color rojo, lo cual podría ser desfavorable para la producción de surimi de Alaska Pollock grado FAThis work was partially supported by Grant no. NA 16RG 1039 (Project no. R/SF-29) from the National Oceanic and Atmospheric Administration to the Sea Grant College Program at Oregon State University, and appropriations made by the Oregon State Legislature. Part of this study was supported by Grant no. TAMPS-2003-C02-14, FOMIXCONACYT, MéxicoS

    Preparation and characterization of 33-S samples for 33-S(n,alpha)30-Si cross-section measurements at the n_TOF facility at CERN

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    Thin 33S samples for the study of the 33S(n,a)30Si cross-section at the n_TOF facility at CERN were made by thermal evaporation of 33S powder onto a dedicated substrate made of kapton covered with thin layers of copper, chromium and titanium. This method has provided for the first time bare sulfur samples a few centimeters in diameter. The samples have shown an excellent adherence with no mass loss after few years and no sublimation in vacuum at room temperature. The determination of the mass thickness of 33S has been performed by means of Rutherford backscattering spectrometry. The samples have been successfully tested under neutron irradiation.Ministerio de Economía y Competitividad de España-FPA2013-47327- C2-1-R, FPA2014-53290-C2-2-P, FPA2016-77689-C2-1-RJunta de Andalucía-P11-FQM-8229Ministerio de Economía y Empresa de España (Fondos FEDER)-FIS2015-69941-C2-1-PAECC (Asociación Española Contra el Cáncer)-PS16163811POR

    Study design and rationale for the Olpasiran trials of Cardiovascular Events And lipoproteiN(a) reduction-DOSE finding study (OCEAN(a)-DOSE).

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    BACKGROUND Data support lipoprotein(a) (Lp[Lp(a)]) being a risk factor for atherosclerotic cardiovascular disease (ASCVD). Olpasiran is a small interfering RNA molecule that markedly reduces Lp(a) production in hepatocytes. STUDY DESIGN The Olpasiran trials of Cardiovascular Events And lipoproteiN(a) reduction-DOSE finding study is a multicenter, randomized, double-blind, placebo-controlled dose-finding study in 281 subjects with established ASCVD and Lp(a) > 150 nmol/L. Patients were randomly allocated to one of 4 active subcutaneous doses of olpasiran (10 mg q12 weeks, 75 mg q12 weeks, 225 mg q 12 weeks, or 225 mg q24 weeks) or matched placebo. The primary objective is to evaluate the effects of olpasiran dosed every 12 weeks compared with placebo on the percent change in Lp(a) from baseline at 36 weeks. Enrollment is now complete and follow-up is ongoing. CONCLUSIONS OCEAN(a)-DOSE trial is assessing the Lp(a)-lowering efficacy and safety of olpasiran. These data will be used to determine optimal dosing and design for a cardiovascular outcomes trial

    Proposing new variables for the identification of strategic groups in franchising

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    The identification of strategic groups in the Spanish franchising area is the main aim of this study. The authors have added some new strategic variables (not used before) to the study and have classified franchisors between sectors and distribution strategy. The results reveal the existence of four perfectly differentiated strategic groups (types of franchisors). One of the major implications of this study is that the variables that build a strategic group vary depending on the respective sector the network operates in and its distribution strategy. This fact indicates that including sector and distribution strategy is absolutely necessary to achieve good classifications of franchisor type

    Raman-Mössbauer-XRD studies of selected samples from “Los Azulejos” outcrop: A possible analogue for assessing the alteration processes on Mars

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    The outcrop of “Los Azulejos” is visible at the interior of the Cañadas Caldera in Tenerife Island (Spain). It exhibits a great variety of alteration processes that could be considered as terrestrial analogue for several geological processes on Mars. This outcrop is particularly interesting due to the content of clays, zeolite, iron oxides, and sulfates corresponding to a hydrothermal alteration catalogued as “Azulejos” type alteration. A detailed analysis by portable and laboratory Raman systems as well as other different techniques such as X ray diffraction (XRD) and Mössbauer spectroscopy has been carried out (using twin-instruments from Martian lander missions: Mössbauer spectrometer MIMOS-II from the NASA-MER mission of 2001 and the XRD diffractometer from the NASA-MSL Curiosity mission of 2012). The mineral identification presents the following mineral species: magnetite, goethite, hematite, anatase, rutile, quartz, gregoryite, sulphate (thenardite and hexahydrite), diopside, feldspar, analcime, kaolinite and muscovite. Moreover, the in-situ Raman and Micro-Raman measurements have been performed in order to compare the capabilities of the portable system specially focused for the next ESA Exo-Mars mission. The mineral detection confirms the sub-aerial alteration on the surface and the hydrothermal processes by the volcanic fluid circulations in the fresh part. Therefore, the secondary more abundant mineralization acts as the color agent of the rocks. Thus, the zeolite-illite group is the responsible for the bluish coloration, as well as the feldspars and carbonates for the whitish and the iron oxide for the redish parts. The XRD system was capable to detect a minor proportion of pyroxene, which is not visible by Raman and Mössbauer spectroscopy due to the “Azulejos” alteration of the parent material on the outcrop. On the other hand, Mössbauer spectroscopy was capable of detecting different types of iron-oxides (Fe3+/2+-oxide phases). These analyses emphasize the strength of the different techniques and the working synergy of the three different techniques together for planetary space missions.The work was supported by the MICINN with the Project AYA-2008-04529.Peer reviewe

    Reactive oxygen-related diseases: therapeutic targets and emerging clinical indications

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    SIGNIFICANCE Enhanced levels of reactive oxygen species (ROS) have been associated with different disease states. Most attempts to validate and exploit these associations by chronic antioxidant therapies have provided disappointing results. Hence, the clinical relevance of ROS is still largely unclear. RECENT ADVANCES We are now beginning to understand the reasons for these failures, which reside in the many important physiological roles of ROS in cell signaling. To exploit ROS therapeutically, it would be essential to define and treat the disease-relevant ROS at the right moment and leave physiological ROS formation intact. This breakthrough seems now within reach. CRITICAL ISSUES Rather than antioxidants, a new generation of protein targets for classical pharmacological agents includes ROS-forming or toxifying enzymes or proteins that are oxidatively damaged and can be functionally repaired. FUTURE DIRECTIONS Linking these target proteins in future to specific disease states and providing in each case proof of principle will be essential for translating the oxidative stress concept into the clinic. Antioxid. Redox Signal. 23, 1171-1185

    Resultados preliminares de un estudio de caracterización de purines de porcino obtenido en fosa bajo condiciones mediterráneas

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    El conocimiento de la composición del purín recién excretado y en distintos momentos del ciclo productivo del animal es importante, ya que permite conocer de una manera más precisa la evolución que experimenta éste con el tiempo. Esto posibilitaría adecuar las estrategias de gestión y tratamiento del mismo desde una perspectiva temporal a cada tipo de explotación. El purín contiene una gran cantidad de flora bacteriana que lo degrada en función de su composición, de la duración del almacenamiento y de las condiciones ambientales. Existe bastante información sobre la composición de purines en balsa, sin embargo apenas existen datos sobre éstos en fosa. Es por ello que para identificar tanto la variabilidad en función del tipo de animal como sus características en el tiempo es interesante disponer de información obtenida en fosa. El objetivo de este trabajo es presentar los primeros resultados de composición del purín de cerdos en granjas de la Comunidad Valenciana para estudiar la variabilidad existente en función del tipo de animal y del tiempo de almacenamiento. Para ello se tomaron 36 muestras en fosa, en varias explotaciones según la orientación productiva, analizándose materia seca (MS), sólidos volátiles (SV), cenizas (ASH), pH, nitrógeno total (NT), nitrógeno amoniacal (NH4), conductividad eléctrica (CE) y demanda biológica de oxígeno (DBO). Asimismo se ha obtenido un perfil de ácidos grasos (AGV) para cada tipo de purín. De los resultados obtenidos, se observa una importante variabilidad según la categoría animal, apreciándose en cebo mayores contenidos en MS, SV y NH4. Finalmente, también se ha encontrado una elevada correlación entre la conductividad eléctrica y el nitrógeno total excretado (R2 = 0,76), lo que podría utilizarse como un “test rápido” de determinación de la composición de purín en campo

    Radiation tests on commercial instrumentation amplifiers, analog switches & DAC's

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    A study of several commercial instrumentation amplifiers (INA110, INA111, INA114, INA116, INA118 & INA121) under neutron and vestigial gamma radiation was done. Some parameters (Gain, input offset voltage, input bias currents) were measured on-line and bandwidth, and slew rate were determined before and after radiation. The results of the testing of some voltage references REF102 and ADR290GR and the DG412 analog switch are shown. Finally, different digital-to-analog converters were tested under radiation
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