827 research outputs found
El perfil afectivo/matemático de estudiantes de ciencias e ingeniería
En la investigación en educación matemática, el rendimiento se ha estudiado desde diferentes ópticas: cognitiva, social y emocional, entre otras. Este estudio analiza las creencias y actitudes de estudiantes de ingeniería y de ciencias a través de una metodología basada en la lógica fuzzy. Los resultados muestran, que a los de ingeniería les gustan más las matemáticas, presentan mayor autoestima matemática y creen que las matemáticas son importantes de un modo significativamente mayor que para los estudiantes de ciencias. No obstante, todos son conscientes de su responsabilidad en el aprendizaje de las matemáticas, y coinciden en valorar el papel del profesor, aunque no se considere un elemento influyente a nivel emocional
Defining a methodology to design and implement business process models in BPMN according to the standard ANSI/ISA-95 in a manufacturing enterprise
Nowadays, extended enterprise requires flexible and adaptable platforms which enable technology and internal integration between ERP and MES levels of manufacturing industry. Under the EAI perspective, it is proposed the use of ESB and BPMS technologies to improve integration between business and manufacturing layers. In order to enable this integration, it should be considered standard ANSI/ISA-95 Enterprise/Control System Integration due to it defines an effective model for business integration/manufacturing. In this paper, in order to develop applications that allow the orchestration of information exchanges between ERP/MES, a methodology is defined to design BPMN process models according to the standard ANSI/ISA-95 because it enables B2M integration projects development
Adaptive Control Optimization of Cutting Parameters for High Quality Machining Operations Based on Neural Networks and Search Algorithms
This book chapter presents an Adaptive Control with Optimization (ACO) system for optimising a multi-objective function based on material removal rate, quality loss function related to surface roughness, and cutting-tool life subjected to surface roughness specifications constraint
Relationship between weight and linear dimensions of Bluefin tuna (Thunnus thynnus) following fattening on western Mediterranean farms
This study presents various models based on formulae relating weight and dimensions (length, height and width) of Bluefin tuna, Thunnus thynnus (L.), fattened in captivity. The main aim of establishing these expressions is to design tools for indirectly predicting the weight of a Bluefin tuna from measurements of one or more dimensions obtained using non- invasive methods such as stereoscopic cameras. Measurements of maximum length, height and width following slaughter were taken of fish fattened in captivity (n = 2078). Different relationships drawn from the dimensions of the tuna against their weight are fitted with part of the data collection and later checked against a reserved sample set. The resulting formu- lae are compared with the formulae most commonly used in the case of wild tuna. The results of this study confirm that, for tuna fattened in cages, the availability of more than one dimension to estimate weight improves the predictive power of the model and reduces error in the estimate.En prensa4,41
Cordage, basketry and containers at the Pleistocene-Holocene boundary in southwest Europe. Evidence from Coves de Santa Maira (Valencian region, Spain)
In this study we present evidence of braided plant fibres and basketry imprints on clay recovered from Coves de Santa Maira, a Palaeolithic-Mesolithic cave site located in the Mediterranean region of Spain. The anatomical features of these organic fibre remains were identified in the archaeological material and compared with modern Stipa tenacissima (esparto grass). Based on direct dating, the fragments of esparto cord from our site are the oldest worked plant fibres in Europe. Sixty fragments of fired clay are described. The clay impressions have allowed us to discuss the making of baskets and containers. According to their attributes and their functional interpretation, we have grouped them into five types within two broad categories, hearth plates and baskets or containers. The clay pieces identified as fragments of containers with basketry impressions are less common than those of hearth plate remains and they are concentrated in the Epipalaeolithic occupation material (13.2-10.2 ka cal bp). The clay impressions from Santa Maira indicate that some fibres were treated or flattened, a preparation process that is known from historical and ethnological sources
Revalorisation of chito-oligosaccharides obtained from fishery by-products as natural antimicrobials
La quitina es el polímero más común en la Tierra después de la celulosa y se encuentra principalmente en los caparazones de los crustáceos, entre otros. A partir de la quitina se puede obtener como derivado desacetilado el quitosano, con propiedades específicas como su capacidad biocida, que le ha proporcionado múltiples aplicaciones potenciales. No obstante, debido a su baja so-lubilidad, estas aplicaciones están limitadas y cobran especial importancia los quito-oligosacáridos (COS), productos obtenidos a partir del quitosano. Por ello y ante el aumento significativo de los subproductos de la industria pesquera en los últimos años, el objetivo del presente trabajo fue evaluar la capacidad biocida de diferentes formulaciones desarrolladas a partir de COS extraídos de subproductos de la industria pesquera frente a los principales microorganismos alimentarios, para su revalorización como antimicrobianos naturales. Con dicho fin, se evaluó la capacidad biocida de siete formulaciones siguiendo la norma UNE-EN 1276, frente a distintas especies de hongos y bacterias, mediante el recuento en placa. Los resultados obtenidos mostraron que todos los formulados presentaron capacidad biocida frente a los microorganismos estudiados y, en base a ellos, se pudo concluir que el formulado basado en COS3 es el candidato que mayor proyección presenta para el desarrollo de un futuro producto biocida sostenible.Chitin is the most common polymer on Earth after cellulose and it is found mainly in the shells of crustaceans, among others. Chitosan can be obtained from chitin, it is a deacetylated deriva-tive with specific properties such as biocide capacity, which has provided it with many potential applications. However, due to its low solubility these applications are limited and chito-oligosaccharides (COS), products obtained from chitosan, take on special interest. For this reason and before the significant increase in by-products of the fishing industry in recent years, the objective of this project was to evaluate the biocide capacity of different formulations developed from COS extracted from by-products of the fishing industry against the main food microorga-nisms, for their revaluation as natural antimicrobials. For that purpose, the biocide capacity of seven formulations was evaluated by plate count following the UNE-EN 1276 standard, against different species of fungi and bacteria. The results obtained showed that all the formulations pre-sented biocide capacity against the studied microorganisms and, based on them, it was possible to conclude that the formula based on COS3 is the candidate with the greatest projection for the development of a future sustainable biocide product.Ciencias Experimentale
A survey of cost-sensitive decision tree induction algorithms
The past decade has seen a significant interest on the problem of inducing decision trees that take account of costs of misclassification and costs of acquiring the features used for decision making. This survey identifies over 50 algorithms including approaches that are direct adaptations of accuracy based methods, use genetic algorithms, use anytime methods and utilize boosting and bagging. The survey brings together these different studies and novel approaches to cost-sensitive decision tree learning, provides a useful taxonomy, a historical timeline of how the field has developed and should provide a useful reference point for future research in this field
Automatic Bluefin Tuna (Thunnus thynnus) Biomass Estimation during Transfers Using Acoustic and Computer Vision Techniques
In this work, acoustic and computer vision techniques are combined to develop an automatic procedure for biomass estimation of tuna during transfers. A side scan sonar working at 200 kHz and a stereo camera, posi- tioned facing towards the surface to record the ventral aspect of fish, are set as acquisition equipment. Moreover, a floating structure has been devised to place the sensors between cages in transfers, creating a transfer canal that allows data acquisition while fish swim from donor to receiving cage. Biomass assessment is computed by counting transferred tuna and sizing a representative sample of the stock. The number of transferred tuna is automatically deduced from acoustic echograms by means of image processing techniques, whereas tuna size is computed from the stereo videos using our automatic computer vision procedure based on a deformable model of the fish ventral silhouette. The results show that the system achieves automatic tuna counting with error below 10%, achieving around 1% error in the best configuration, and automatic tuna sizing of more than 20% of the stock, with highly accurate Snout Fork Length estimation when compared to true data from harvests. These results fulfil the requirements imposed by International Commission for the Conservation of Atlantic Tunas for compliant transfer operations.Versión del editor1,42
Reduction in the Incidence of Type 2 Diabetes With the Mediterranean Diet: Results of the PREDIMED-Reus nutrition intervention randomized trial
OBJECTIVE - To test the effects of two Mediterranean diet (MedDiet) interventions versus a low-fat diet on incidence of diabetes. RESEARCH DESIGN AND METHODS - This was a three-arm randomized trial in 418 nondiabetic subjects aged 55-80 years recruited in one center (PREDIMED-Reus, northeastern Spain) of the Prevención con Dieta Mediterránea [PREDIMED] study, a large nutrition intervention trial for primary cardiovascular prevention in individuals at high cardiovascular risk. Participants were randomly assigned to education on a low-fat diet (control group) or to one of two MedDiets, supplemented with either free virgin olive oil (1 liter/week) or nuts (30 g/day). Diets were ad libitum, and no advice on physical activity was given. The main outcome was diabetes incidence diagnosed by the 2009 American Diabetes Association criteria. RESULTS - After a median follow-up of 4.0 years, diabetes incidence was 10.1% (95% CI 5.1-15.1), 11.0% (5.9 -16.1), and 17.9% (11.4 -24.4) in the MedDiet with olive oil group, the MedDiet with nuts group, and the control group, respectively. Multivariable adjusted hazard ratios of diabetes were 0.49 (0.25- 0.97) and 0.48 (0.24-0.96) in the MedDiet supplemented with olive oil and nuts groups, respectively, compared with the control group. When the two MedDiet groups were pooled and compared with the control group, diabetes incidence was reduced by 52% (27- 86). In all study arms, increased adherence to the MedDiet was inversely associated with diabetes incidence. Diabetes risk reduction occurred in the absence of significant changes in body weight or physical activity. CONCLUSIONS - MedDiets without calorie restriction seem to be effective in the prevention of diabetes in subjects at high cardiovascular risk. © 2011 by the American Diabetes Association.This study was funded, in part, by the Spanish Ministry of Health (Instituto de Salud Carlos III) (projects PI051839, PI070240, PI1001407, G03/140, and RD06/0045), Fondo Europeo de Desarrollo Regional, and the Public Health Division of the Department of Health of the Autonomous Government of Catalonia in collaboration with Merck Sharp & Dohme. The Fundación Patrimonio Comunal Olivarero and Hojiblanca SA (Málaga, Spain), California Walnut Commission (Sacramento, CA), Borges SA (Reus, Spain), and Morella Nuts SA (Reus, Spain) donated the olive oil, walnuts, almonds, and hazelnuts, respectively, used in the study.Peer Reviewe
Deficiency of Pkc1 activity affects glycerol metabolism in Saccharomyces cerevisiae
In pressProtein kinase C is apparently involved in the control of many cellular systems: the cell wall integrity pathway, the synthesis of ribosomes, the appropriated reallocation of transcription factors under specific stress conditions and also the regulation of N-glycosylation activity. All these observations suggest the existence of additional targets not yet identified. In the context of the control of carbon metabolism, previous data demonstrated that Pkc1 p might play a central role in the control of cellular growth and metabolism in yeast. In particular, it has been suggested that it might be involved in the derepression of genes under glucose-repression by driving an appropriated subcellular localization of transcriptional factors, such as Mig1 p. In this work, we show that pkc1∆ mutant is unable to grow on glycerol because it cannot perform the derepression of GUT1 gene that encodes for glycerol kinase. Additionally, active transport is also partially affected. Using this phenotype, we were able to isolate a new pkc1∆ revertant. We also isolated two transformants identified as the nuclear exportin Msn5 and the histone deacetylase Hos2 extragenic suppressors of this mutation. Based on these results, we postulate that Pkc1 p may be involved in the control of the cellular localization and/or regulation of the activity of nuclear proteins implicated in gene expression.Fundação Universidade Federal de Ouro Preto (FUFOP).
Fundação de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG) - CBS-1875/95.
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) - 300998/89-9 to R.L.B., 301255/01-6 to L.G.F
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