127 research outputs found
Entrevista a Carles Barceló i Vidal : Premi Jaume Vicens Vives a la qualitat docent universitària i impulsor del 3E d'eines per a l'ensenyament de l'estadística a secundària
ANÁLISIS ECONÓMICO DE UNA FUNCIÓN CUADRÁTICA DE GASTOS DE PRODUCCIÓN CON COEFICIENTES BORROSOS Y CON RESTRICCIONES
En el ámbito de la Economía de la Empresa tiene mucha importancia el estudio de los gastos de producción E(Q) que se originarán en el proceso y que generalmente vendrán
expresados matemáticamente por una dependencia lineal o cuadrática de las unidades Q que se proponen fabricar. Supondremos, además, que esta función está afectada por
dos restricciones: una es de productividad, Q1 ≤ Q2 ≤ Q3 , y otra de limitación de gastos máximos permitidos, ( ) E Q ≤ EM .
En el presente artículo partiremos de una función cuadrática nítida, en la cual justificaremos el signo de los coeficientes que hemos empleado. Después, para adentrarnos en el campo fuzzy, la generalizaremos con otra de coeficientes borrosos.
Naturalmente, la nueva función borrosa ya no se expresará a través de una única curva, sino que estará constituida por un haz infinito de curvas nítidas, cada una de ellas con un determinado grado de posibilidad. Centramos nuestra atención en las curvas que llamamos central, inferior y superior.
El núcleo de nuestro análisis consistirá básicamente en reducir paulatinamente los soportes de los coeficientes hasta hallar un cierto valor k del α-corte, de manera que a partir de él todas las curvas del haz borroso tengan sentido económico y cumplan las dos restricciones impuestas. En último lugar, y a través de un caso numérico,
comprobaremos las deducciones teóricas que hemos obtenido en el análisis anterior.
Palabras clave: economía aplicada, números borrosos, incertidumbre.
Abstract
In the context of Business Economics it is essential to carry out studies of the costs of production E(Q) . Obviously, these kinds of costs originated in the production process
will depend on the number Q of units produced by the company and, generally, can be mathematically expressed by a quadratic function, E(Q)= a.Q2 − b.Q + c , where all three
coefficients must be positive real numbers.
We will suppose that in this process there is also a production constraint, normally due to productivity, Q1 ≤ Q2 ≤ Q3 , or cost limitations, ( ) E Q ≤ EM . Of course, in the production
costs there must always be a non negativity constraint because the costs must always be positive. And, moreover, for reasons of security, another cost constraint is desirable, so that they do not exceed a previously fixed maximum, EMAX . We summarise the last two constraints in the inequality ( ) 0 ≤ E Q ≤ EMAX .
Afterwards, to enter into the uncertainty field, we must generalise the function E = f (Q) into one of fuzzy coefficients. Of course, the new fuzzy function will not be a single curve,
but rather an infinite set or sheaf of sharp curves, each one associated with a particular degree of possibility. In this study we concentrate on three special curves of this infinite
sheaf: the central, lower and upper curves.
However, the focus of our attention will consist basically in gradually reducing the supports of the coefficients until we find a certain value k of the α-cuts, such that if α > k , then all the infinite curves of this fuzzy beam will make economic sense and,besides, will meet the two imposed constraints. To conclude this paper, we confirm, using a numerical example, all the conclusions deduced in the preceding analysis.
Key words: applied economy, fuzzy numbers, uncertainty
Inadequate Content of Docosahexaenoic Acid (DHA) of Donor Human Milk for Feeding Preterm Infants: A Comparison with Mother's Own Milk at Different Stages of Lactation
A cross-sectional single-center study was designed to compare the fatty acids profile, particularly docosahexaenoic acid (DHA) levels, between milk banking samples of donor human milk and mother's own milk (MOM) for feeding preterm infants born before 32 weeks' gestation. MOM samples from 118 mothers included colostrum (1-7 days after delivery), transitional milk (9-14 days), and mature milk (15-28 days and ≥29 days). In the n-3 polyunsaturated fatty acids (PUFAs) group, the levels of α-linolenic acid (C18:3 n3) and DHA (C22:6 n3) showed opposite trends, whereas α-linolenic acid was higher in donor human milk as compared with MOM, with increasing levels as stages of lactation progressed, DHA levels were significantly lower in donor human milk than in MOM samples, which, in turn, showed decreasing levels along stages of lactation. DHA levels in donor human milk were 53% lower than in colostrum. Therefore, in preterm infants born before 32 weeks' gestation, the use of pasteurized donor human milk as exclusive feeding or combined with breastfeeding provides an inadequate supply of DHA. Nursing mothers should increase DHA intake through fish consumption or nutritional supplements with high-dose DHA while breastfeeding. Milk banking fortified with DHA would guarantee adequate DHA levels in donor human milk
Evicur, una herramienta para acercar conocimiento científico a la práctica de clínica enfermera
Loose Morphology and High Dynamism of OSER Structures Induced by the Membrane Domain of HMG-CoA Reductase
The membrane domain of eukaryotic HMG-CoA reductase (HMGR) has the conserved capacity to induce endoplasmic reticulum (ER) proliferation and membrane association into Organized Smooth Endoplasmic Reticulum (OSER) structures. These formations develop in response to overexpression of particular proteins, but also occur naturally in cells of the three eukaryotic kingdoms. Here, we characterize OSER structures induced by the membrane domain of Arabidopsis HMGR (1S domain). Immunochemical confocal and electron microscopy studies demonstrate that the 1S:GFP chimera co-localizes with high levels of endogenous HMGR in several ER compartments, such as the ER network, the nuclear envelope, the outer and internal membranes of HMGR vesicles and the OSER structures, which we name ER-HMGR domains. After highpressure freezing, ER-HMGR domains show typical crystalloid, whorled and lamellar ultrastructural patterns, but with wide heterogeneous luminal spaces, indicating that the native OSER is looser and more flexible than previously reported. The formation of ER-HMGR domains is reversible. OSER structures grow by incorporation of ER membranes on their periphery and progressive compaction to the inside. The ER-HMGR domains are highly dynamic in their formation versus their disassembly, their variable spherical-ovoid shape, their fluctuating borders and their rapid intracellular movement, indicating that they are not mere ER membrane aggregates, but active components of the eukaryotic cell
Analysis of ISSQ/IDDQ testing implementation and circuit partitioning in CMOS cell-based design
© 1996 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Difference between ISSQ and IDDQ testing strategies is presented, discussing the dependency of area overhead and sensing speed on the technology. The current sensor implementation style suitable for cell-based design methodology or semi-custom design style is proposed Experimental results for each strategy are discussed. Finally, different types of partitioning strategies are showed, taken into account the parallelism of the gates.Peer ReviewedPostprint (published version
Sensing solutions for improving the performance, health and wellbeing of small ruminants
Diversity of production systems and specific socio-economic barriers are key reasons explaining
why the implementation of new technologies in small ruminants, despite being needed
and beneficial for farmers, is harder than in other livestock species. There are, however, helpful
peculiarities where small ruminants are concerned: the compulsory use of electronic identification
created a unique scenario in Europe in which all small ruminant breeding stock
became searchable by appropriate sensing solutions, and the largest small ruminant population
in the world is located in Asia, close to the areas producing new technologies.
Notwithstanding, only a few research initiatives and literature reviews have addressed the
development of new technologies in small ruminants. This Research Reflection focuses on
small ruminants (with emphasis on dairy goats and sheep) and reviews in a non-exhaustive
way the basic concepts, the currently available sensor solutions and the structure and elements
needed for the implementation of sensor-based husbandry decision support. Finally, some
examples of results obtained using several sensor solutions adapted from large animals or
newly developed for small ruminants are discussed. Significant room for improvement is
recognized and a large number of multiple-sensor solutions are expected to be developed
in the relatively near future
Erythrocyte Membrane Docosahexaenoic Acid (DHA) and Lipid Profile in Preterm Infants at Birth and Over the First Month of Life: A Comparative Study with Infants at Term
An observational comparative study was designed to assess the fatty acids profile in erythrocyte membrane phospholipids of 30 preterm neonates (<32 weeks gestation) at birth and after 1 month of life versus a convenience sample of 10 infants born at term. The panel of fatty acids included the families and components of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and n-6 and n-3 polyunsaturated fatty acids (PUFAs) as well as enzyme activity indexes and fatty acids ratios. At birth, the comparison of fatty acid families between preterm and term neonates showed a significantly higher content of SFAs and n-6 PUFAs, and a significantly lower content of MUFAs and n-3 PUFAs in the preterm group. After 30 days of life, significantly higher levels of n-6 PUFAs and significantly lower levels of n-3 PUFAs among preterm neonates persisted. At 30 days of birth, n-6 PUFA/n-3 PUFA and arachidonic acid (ARA) ARA/DHA remained significantly elevated, and DHA sufficiency index significantly decreased in the preterm group. The pattern of n-3 PUFA deficiency at birth and sustained for the first month of life would support the need of milk banking fortified with DHA and the use of DHA supplementation in breastfeeding mothers
Krill-Oil-Dependent Increases in HS-Omega-3 Index, Plasma Choline and Antioxidant Capacity in Well-Conditioned Power Training Athletes
There is evidence that both omega-3 polyunsaturated fatty acids (n-3 PUFAs) and choline can influence sports performance, but information establishing their combined effects when given in the form of krill oil during power training protocols is missing. The purpose of this study was therefore to characterize n-3 PUFA and choline profiles after a one-hour period of high-intensity physical workout after 12 weeks of supplementation. Thirty-five healthy power training athletes received either 2.5 g/day of Neptune krill oilTM (550 mg EPA/DHA and 150 mg choline) or olive oil (placebo) in a randomized double-blind design. After 12 weeks, only the krill oil group showed a significant HS-Omega-3 Index increase from 4.82 to 6.77% and a reduction in the ARA/EPA ratio (from 50.72 to 13.61%) (p < 0.001). The krill oil group showed significantly higher recovery of choline concentrations relative to the placebo group from the end of the first to the beginning of the second exercise test (p = 0.04) and an 8% decrease in total antioxidant capacity post-exercise versus 21% in the placebo group (p = 0.35). In conclusion, krill oil can be used as a nutritional strategy for increasing the HS-Omega-3 Index, recover choline concentrations and address oxidative stress after intense power trainings
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