1,551 research outputs found

    Observability of Linear Positive Dynamic Systems

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    Mathematical Modeling of Boson-Fermion Stars in the Generalized Scalar-Tensor Theories of Gravity

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    A model of static boson-fermion star with spherical symmetry based on the scalar-tensor theory of gravity with massive dilaton field is investigated numerically. Since the radius of star is \textit{a priori} an unknown quantity, the corresponding boundary value problem (BVP) is treated as a nonlinear spectral problem with a free internal boundary. The Continuous Analogue of Newton Method (CANM) for solving this problem is applied. Information about basic geometric functions and the functions describing the matter fields, which build the star is obtained. In a physical point of view the main result is that the structure and properties of the star in presence of massive dilaton field depend essentially both of its fermionic and bosonic components.Comment: 16 pages, amstex, 5 figures, changed conten

    Biorefinery concept for discarded potatoes: Recovery of starch and bioactive compounds

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    The integral valorisation of discarding potatoes from three local varieties using processes of low environmental impact to recover the starch contained in the flesh as well as the bioactive compounds present in the skin or in the processing wastewaters was studied. The remaining flesh after starch extraction was also recovered to further processing. The extraction of starch and active extracts using environmentally friendly technologies, the physicochemical and phytochemical characterisation of the extracts, the formulation and mechanical characterisation of the corresponding functional hydrogels, have allowed proposing potential food and non-food applications. Results indicated that subcritical water extraction (220 ºC) was an efficient technology to recover antioxidants from the potato skin. Processing wastewaters exhibited high protein content. The extracted starch featured comparable physicochemical properties to that available commercially and the corresponding hydrogels exhibited enhanced mechanical properties with absence of syneresis. It should be remarked that Agria and Neiker varieties provided the highest total starch and bioactive content in terms of phenolics, TEAC value and DPPH inhibition percentage, respectivelyinfo:eu-repo/semantics/publishedVersio

    Improving the nutritional performance of gluten-free pasta with potato peel autohydrolysis extract

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    The potato processing industry produces peels, a good source of fibres, minerals and antioxidants, which could be recovered and used in the production of added-value products, such as gluten-free (GF) foods especially designed for the celiac population. This work is focused on the application of the bioactive fraction extracted from potato peels into GF pasta. Subcritical water extraction (autohydrolysis, AH) was performed on potato peel, and the obtained AH liquid extract was characterized in terms of total phenolic content and antioxidant activity. The selected AH temperature (220 °C at 2.2 MPa) was applied to peels from Kennebec, Neiker and Agria potato varieties, and the Agria extract was selected for application in GF pasta, as this was the one with higher antioxidant activity. The impact of Agria potato peel autohydrolysis extract on the nutritional composition and cooking quality of pasta was assessed. Results confirmed that the GF pasta enriched with potato peel extract presented suitable technological properties, coupled with attractive colour and with increased total phenolic content and antioxidant activity, which can contribute to improve the offer of GF products in the marketinfo:eu-repo/semantics/publishedVersio

    Environmentally friendly processing of Laminaria ochroleuca for soft food applications with bioactive properties

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    Dehydrated Laminaria ochroleuca was processed by autohydrolysis with compressed hot water to extract bioactive compounds. Both the whole algae and individual fractions obtained (solid residue and liquor) were characterised to assess its functional properties for future innovative food applications. Purée-like systems were developed by combining ultrasonic and thermal technologies to maximise the antioxidant capacity and were evaluated by determining colour, texture, rheology, syneresis and the presence of bioactive compounds. Overall, the obtained results indicated that L. ochroleuca is a valuable resource that can be used as a whole or taking advantage of its bioactive fractions, in a concept of circular economy and sustainabilityinfo:eu-repo/semantics/publishedVersio

    Peroxidase expression in a cereal cyst nematode (Heterodera avenae) resistant hexaploid wheat line.

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    The incompatible interaction between plant and pathogen is often determined by the hypersensitive reaction (HR). This response is associated with accumulation of reactive oxygen species (ROS), which results in adverse growth conditions for pathogens. Two major mechanisms involving either NADPH oxidases or peroxidases have been proposed for generation of ROS. Peroxidases (PER, EC 1.11.1.7), present in all land plants, are members of a large multigenic family with high number of isoforms involved in a broad range of physiological processes. PER genes, which are expressed in nematode feeding sites, have been identified in several plant species (Zacheo et al. 1997). A strong correlation between HR and PER activities at four and seven days post nematode infection, was detected in roots of wheat lines carrying Cre2, Cre5 (from Ae. ventricosa) or Cre7 (from Ae. triuncialis) Heterodera avenae resistance genes (Andrés et al. 2001; Montes et al. 2003, 2004). We have studied changes in root of peroxidase mRNAs levels after infection by H. avenae of a wheat/Ae. ven¬tricosa introgression line (H-93-8) carrying Cre2 (Delibes et al. 1993). We also report and classify the predicted protein sequences derived from complete peroxidase transcripts

    Physical Properties and Chemical Characterization of Macro- and Micro-Nutriments of Elite Blue Maize Hybrids (Zea mays L.)

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    Five elite blue maize hybrids and two blue maize landraces were evaluated for various quality characteristics. Hybrids showed physical characteristics demanded by dry-millers and tortilla processors: above 290 g in one hundred-kernel weight test, higher test weight (76.1–78.5 kg hl−1) and lower flotation index (22–61%). Hybrid maize 613 × 27 (9.9%) and 611 × 8 (9.5%) contained the highest protein. Potassium, magnesium, manganese and zinc contents of hybrid maize were higher than landraces by 15, 30, 55 and 41%, respectively. Nutrimental profile showed linoleic acid contents above 50% in 503 × 67, 613 × 27 and 611 × 8 hybrid samples. Lysine levels of landraces and hybrids 503 × 67 (33.9 g kg−1 protein) and 631 × 27 (31.7 g kg−1 protein) were higher than reported for regular white corn (27 g kg−1 protein), as well as the highest tryptophan levels for Chalqueno (6.0 g kg−1 protein) and hybrid 503 × 67 (6.9 g kg−1 protein). Highest protein quality based on its digestibility was found in hybrid 503 × 67. Results indicated that elite blue maize hybrids could be an important source of nutrimental compounds with potential for functional food industries

    The influence of organic versus conventional feeding on the growth and survival of gilthead sea bream Sparus aurata L. juveniles

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    Sparus aurata specimens of 11 months of age (mean weight: 90.2 g, mean length: 18.3 cm) were classified in two diet groups: one control group was fed with conventional diet, and one experimental group was fed with an organic diet. The body and muscle parameters were studied at 0, 41 and 71 days of the experiment. The results showed the highest values of body length and weight as well as the best biological feed conversion rates in the organic group. The transverse area of white muscle, the hyperplasia and the muscle fibres density were also higher in the organic than in the conventional group (P>0.05). In contrast, hypertrophy was greater in the conventional than in the organic group (P<0.05). Survival was 100% in both groups. In conclusion, the organic feeding regime was more favourable for growth than conventional feeding.Versión del edito

    Aceite de oliva virgen y regulación hormonal de la presión arterial: una revisión del papel de los enzimas proteolíticos

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    Numerosos estudios realizados en los últimos años, han puesto de manifiesto que los niveles elevados de grasa en la dieta están directamente relacionados con el desarrollo de diversas patologías, entre las que destacan enfermedades cardiovasculares, diabetes o incluso diversos tipos de cánceres. Estudios epidemiológicos también han demostrado que no sólo es importante la cantidad, sino también el tipo de grasa de la dieta. Son especialmente conocidos los efectos beneficiosos de la dieta mediterránea, caracterizada entre otros aspectos, por un consumo elevado de ácidos grasos monoinsaturados como el oleico. En cualquier caso, no se conoce con exactitud las relaciones existentes entre el tipo de grasa de la dieta y el desarrollo de las distintas patologías. Las aminopeptidasas son enzimas proteolíticos implicados en una amplia variedad de procesos biológicos, destacando su papel en el control de la presión arterial a través del sistema renina-angiotensina. En esta revisión se estudia la influencia de una dieta enriquecida en aceite de oliva sobre la actividad aminopeptidásica sérica y de tejidos periféricos, analizando su influencia en la regulación del sistema renina-angiotensina para el control de la presión arterial y el balance de líquidos y electrolitos.The intake of high fat dietary levels is related to the development of several pathologies such as cardiovascular diseases, diabetes and cancer. However, epidemiological studies have demonstrated that not only the amount but also the type of dietary fat participates in the origin of the diseases. In fact, several important beneficts have been attributed to the Mediterranean diet, characterized by the high intake of monoinsaturated fatty acids such as oleic acid preferently. In any case, the relationship between the type of dietary fat an the development of diseases are unknown. Aminopeptidases are proteolytic enzymes involved in several biological proccesses, regulating blood pressure through the renin-angiotensin system. In this review, the influence of an olive oil-enriched diet is presented, analyzing their role in the regulation of blood pressure, local blood flow and fluid and electrolytic balance among other functions

    Disability and its influence in nutritional assessment tools in elderly people living in nursing homes

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    Introduction: Poor nutritional status is associated with increased morbidity and mortality, especially in older people. Objective: The aim of this study was to assess nutritional status in elderly nursing home residents with different nutritional test, and to determine which parameters used for nutritional assessment can be carried out in this population, which usually have a high prevalence of functionally dependent residents. Methods: A cross-sectional study was performed in 383 elderly. The nutritional assessment tools used were the Mini Nutritional Assessment (MNA), the new ESPEN consensus definition of malnutrition, and the tool for Controlling Nutritional Status (CONUT). Moreover, the ability to perform basic activities of daily living was assessed with the Barthel index (BI). Results: According to BI, 78.9% had a total dependence and only 20.9% could be weighed and heighed. The prevalence of malnutrition with MNA, ESPEN and CONUT was 21.3%, 17.6% and 20.7%, respectively. The agreement between MNA vs ESPEN criteria was moderate (?= 0.483), but with CONUT was low. Conclusions: Nursing homes had a high percentage of totally dependent residents. This high degree of functional dependence made difficult to obtain some anthropometric parameters such as weight and height, which are essential to carry out most nutritional tests. MNA, CONUT and the new ESPEN criteria of malnutrition showed a high prevalence of malnutrition and risk of malnutrition in subjects in which they could be performed. Introducción: un estado nutricional deficiente está asociado con un incremento de la morbilidad y la mortalidad, especialmente en personas ancianas. Objetivo: el objetivo de este estudio fue evaluar el estado nutricional en ancianos institucionalizados en residencias geriátricas mediante diferentes test nutricionales, y determinar qué parámetros utilizados en la valoración nutricional pueden ser realizados en esta población. Métodos: se llevó a cabo un estudio transversal en 383 ancianos. Las herramientas de valoración nutricional empleadas fueron el Mini Nutritional Assessment (MNA), el nuevo consenso de definición de malnutrición, y el CONUT. Además, la capacidad de realizar las actividades básicas de la vida diaria fue evaluada con el índice de Barthel. Resultados: según el índice de Barthel, hasta un 78, 9% de los residentes tenía una dependencia total, y en solo el 20, 9% se pudo determinar el peso y la talla. La prevalencia de malnutrición con MNA, el consenso de ESPEN y CONUT fueron 21, 3%, 17, 2% y 20, 7%, respectivamente. La concordancia (kappa) entre el MNA y el ESPEN fue moderada (? = 0, 483), pero con CONUT fue baja. Conclusiones: en las residencias geriátricas públicas existe un elevado porcentaje de ancianos totalmente dependientes. Este alto grado de dependencia funcional dificulta la obtención de algunos parámetros antropométricos como el peso y la talla, que son esenciales para llevar a cabo la mayoría de los test de valoración nutricional. El MNA, el CONUT y los nuevos criterios de desnutrición de la ESPEN mostraron una elevada prevalencia de desnutrición y de riesgo de desnutrición en esta población de ancianos institucionalizados, en aquellos en los que fue posible realizarlos
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