43,371 research outputs found

    Used food oils: physical-chemical indicators of quality degradation

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    Comunicação apresentada em 11th Baltic Conference on Food Science and Technology “Food science and technology in achanging world” FOODBALT 2017 Conference Proceedings. Jelgava, LLUUsed food oil (UFO), designated as frying oil, is a residue. Degradation by reuse or during storage, may occur by contacting, chemical, enzymatic and microbiological pathways, but oxidation is a major concern of the industry, as it affects sensory and nutritional quality of edible oils, with potentially toxic compounds formation. In Portugal, UFO's main destination still is the sewerage system, an environmental problem and waste of raw material, which can be re-qualified for non-food uses. However, quality control applied to UFO's, often results into expensive analysis inappropriate for small laboratories and catering industry. This project, developed with the Musketeers Group Portugal co-promotion (2012-2016), aimed to identify low-cost physicochemical parameters for further implementation as UFO's Quality Degradation Indicators (QDI) indicating defects quickly and accurately. UFO's analysis was tested on the use, for industrial frying, and by degradation induced in the laboratory (frying and heat stability tests) by applying following parameters: moisture, water activity (a(w)), total acidity, peroxide index, iodine index, colour (CIE, CIE Lab), UV absorbency, total polar compounds and microbiological indicators. Internal procedures (ESAS) were validated, redefining working ranges and test conditions, as standards procedures did not provide reliable results for the entire life cycle of oils, whose profile changes with time and reuse. Results demonstrate significant differences with quick response parameters as Total Acidity, Peroxide Index and CIE Lab colour, outlined as QDI's. Moisture, aw and CIE Lab colour proved to be inadequate for this purpose. Iodine Index and UV Absorbency are more complex and time-consuming and were profiled as reference methods.info:eu-repo/semantics/publishedVersio

    Diffusion of multiple species with excluded-volume effects

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    Stochastic models of diffusion with excluded-volume effects are used to model many biological and physical systems at a discrete level. The average properties of the population may be described by a continuum model based on partial differential equations. In this paper we consider multiple interacting subpopulations/species and study how the inter-species competition emerges at the population level. Each individual is described as a finite-size hard core interacting particle undergoing Brownian motion. The link between the discrete stochastic equations of motion and the continuum model is considered systematically using the method of matched asymptotic expansions. The system for two species leads to a nonlinear cross-diffusion system for each subpopulation, which captures the enhancement of the effective diffusion rate due to excluded-volume interactions between particles of the same species, and the diminishment due to particles of the other species. This model can explain two alternative notions of the diffusion coefficient that are often confounded, namely collective diffusion and self-diffusion. Simulations of the discrete system show good agreement with the analytic results

    Fuzzy Subset Theory in the Measurement of Poverty

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    What has not been explored in the traditional measures of poverty is the extensive set of categorical variables that indicate standard of living and are already available from existing survey data. What precluded researchers from deriving poverty and welfare gauges from these data is the difficulty of incorporating these indicators in their measurement. This article offers a new approach to the traditional measures that allow these available data to be readily utilized. While accounting for the multi-dimensionality of the poverty phenomenon, the approach still provides formalism in the use of other variable parallel to and complementary with income and expenditure.poverty, econometric modeling, data and statistics

    Do Better Neighborhoods for MTO Families Mean Better Schools?

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    Explores the factors that kept children who moved to safer, lower-poverty neighborhoods through the Moving to Opportunity program from accessing better schools, such as lack of change in school district, lack of parental choice, and lack of information

    Cold-electron bolometers for future mm and sub-mm sky surveys

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    Future sky surveys in the mm/sub-mm range, like the forthcoming balloon-borne missions LSPE, OLIMPO, SPIDER etc., will need detectors insensitive to cosmic rays (CRs) and with a NEP of the order of 1017÷101810^{-17} \div 10^{-18}\,W/sqrt(Hz). The Cold-Electron Bolometers (CEBs) technology is promising, having the required properties, since the absorber volume is extremely small and the electron system of the absorber is thermally insulated from the phonon system. We have developed an experimental setup to test the optical performance and the CRs insensitivity of CEBs, with the target of integrating them in the OLIMPO and LSPE focal planes.Comment: 6 figure

    Telephone-cord instabilities in thin smectic capillaries

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    Telephone-cord patterns have been recently observed in smectic liquid crystal capillaries. In this paper we analyse the effects that may induce them. As long as the capillary keeps its linear shape, we show that a nonzero chiral cholesteric pitch favors the SmA*-SmC* transition. However, neither the cholesteric pitch nor the presence of an intrinsic bending stress are able to give rise to a curved capillary shape. The key ingredient for the telephone-cord instability is spontaneous polarization. The free energy minimizer of a spontaneously polarized SmA* is attained on a planar capillary, characterized by a nonzero curvature. More interestingly, in the SmC* phase the combined effect of the molecular tilt and the spontaneous polarization pushes towards a helicoidal capillary shape, with nonzero curvature and torsion.Comment: Submitte

    Análisis diagenético de tetrápodos del Triásico Superior, Grupo Puesto Viejo, Argentina

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    The Puesto Viejo Group crops out in the San Rafael Block, southwest Mendoza, Argentina. This group is an important unit for the knowledge theTriassic faunas. It is composed of basal Quebrada de los Fósiles Formation (QF) overlying by the Río Seco de la Quebrada Formation (RSQ). In this study, we report tetrapod remains from the RSQ Formation that includes, until now, exclusively therapsids. Non-mammalian therapsids predominated in terrestrial ecosystems during the Late Paleozoic and Early Mesozoic. Although cynodonts and dicynodonts have been studied from several perspectives, the relation between taxa and sedimentary context has been scarcely documented. This study is aimed to elucidate the diagenesis of tetrapods from the Puesto Viejo Group and its relation to depositional environment. Diagenetic features of therapsid bones from the RSQ Formation were analyzed through thin sections to interpret the degree of taphonomic alteration. Diagenetic processes inferred include substitution; fracturing; brittle deformation and different permineralization events. Combined analyses through scanning electron microscopy; energy-dispersive X-ray spectrometry (SEM-EDX); X-ray diffractometry (XRD) and petrographic studies reveals the substitution of hydroxyapatite by francolite. The presence of fluorine in some samples suggests a link between the elemental composition and depositional environments: floodplain and crevasse splay. Permineralization stages include infilling of vascular canals, trabeculae and fractures with iron oxides and iron carbonate minerals during the burial history. This contribution represents a relevant approach to elucidate the relation between diagenesis on tetrapods and their paleoenvironments, as exemplified in this case study from the Puesto Viejo Group during the Upper Triassic.El Grupo Puesto Viejo aflora en el Bloque San Rafael, en el suroeste de Mendoza, Argentina. Este grupo constituye una importante unidad para el conocimiento de las faunas del Triásico y está compuesto en su base, por la Formación Quebrada de los Fósiles (QF), superpuesta por la Formación Río Seco de la Quebrada (RSQ). En este estudio, se reportan restos de tetrápodos de la Formación RSQ que incluye, hasta ahora, exclusivamente terápsidos. Los terápsidos no-mamiferoides predominaron en los ecosistemas terrestres durante el Paleozoico tardío y el Mesozoico temprano. A pesar de que cinodontes y dicinodontes han sido estudiados desde varias perspectivas, la relación entre los taxones y su contexto sedimentario está escasamente documentado. Este estudio tiene como objetivo dilucidar la diagénesis de los tetrápodos del grupo Puesto Viejo y su relación con el ambiente depositacional. Las características diagenéticas de los huesos de terápsidos de la Formación RSQ se analizaron a través de secciones delgadas para interpretar el grado de alteración tafonómica. Los procesos diagenéticos inferidos incluyen la sustitución, fracturación, deformación frágil y diferentes eventos de permineralización. El análisis combinado a través de microscopía electrónica de barrido, espectrometría de rayos X de energía dispersiva (SEM-EDX), difractometría de rayos X (DRX) y estudios petrográficos revelaron la sustitución de la hidroxiapatita por francolita. La presencia de flúor en algunas muestras sugiere la vinculación entre la composición elemental y los ambientes depositacionales: llanura de inundación y lóbulo de desbordamiento. Las etapas de permineralización incluyen el relleno de canales vasculares, trabéculas y fracturas con óxidos de hierro y carbonatos de hierro durante la historia de enterramiento. Esta contribución representa un enfoque relevante para dilucidar la relación entre la diagénesis de tetrápodos y sus paleoambientes, como lo demuestra este estudio de caso del Grupo Puesto Viejo durante el Triásico Superior.Fil: Previtera, Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Mancuso, Adriana Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: de la Fuente, Marcelo Saul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla | Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla | Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla; ArgentinaFil: Sánchez, Eloy S.. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Laboratorio de Microscopia Electrónica y Microanálisis; Argentin

    Institutions, impact synergies and food security: a methodology with results from the Kala Oya Basin, Sri Lanka

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    Institutional development / Development plans / Development policy / Impact assessment / River basins / Food security / Models

    Hydra tropomyosin TROP1 is expressed in head-specific epithelial cells and is a major component of the cytoskeletal structure that anchors nematocytes

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    A cDNA clone encoding a 253 amino acid tropomyosin was isolated from Hydra in a differential screen for headspecific genes. The Hydra tropomyosin gene, designated trop1, is a single copy gene, lacks introns and is strongly expressed in tentacle-specific epithelial cells. Analysis of protein synthesis in head and gastric tissue indicated a high rate of tropomyosin synthesis in head tissue. Immunolocalization of tropomyosin in tentacle tissue revealed a cushion-like tropomyosin-containing structure within battery cells at the base of nematocytes. The structure appears to form part of the cytoskeletal anchor for nematocytes. Tropomyosin cushions were also observed in epithelial cells along the body column, which contain mounted stenotele nematocytes
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