2,036 research outputs found

    La Escuela de Pensamiento y Creatividad (EPC) como forma de descubrimiento y autoconocimiento en la infancia: el planteamiento de Alfonso López Quintás

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    Para un niño, la capacidad de relacionarse con el entorno resulta vital para un correcto autoconocimiento y desarrollo individual. Para ello debe recurrir a una realidad primordial, un modelo comunicativo que tenga carácter referencial en su vida como la figura de los padres. Es en ellos en los que podemos hallar un primer estadio prefilosófico – desde el punto de vista personalista- pues por su condición ambital es capaz de crear las formas más elevadas de unidad (padres-hijos) cuya realidad no es algo cerrado sino que concierne al entorno, la comunidad en la que son acogidas ambas partes por la sociedad. Mediante la pedagogía de la admiración, los niños son capaces de sentir afectos y crear vínculos, generando ámbitos en virtud de sus propias cualidades. En los padres se concentra la unidad entre pensamiento creativo y la capacidad para fundar un sentimiento comunicable mediante experiencias reversibles que pueden marcar el umbral de las experiencias éticas y estéticas -según el prof. López Quintás- al ser estos procesos en los que la vida se transfigura, mediante un correcto ejercicio de colaboración respetuosa. Sólo a partir de entonces, los niños comienzan a construir un espacio de convivencia y su ser, al saber dirigirse al otro, puede ascender a otro nivel - según la metodología de la EPC- convirtiéndolos en sujeto de conocimiento. Por este motivo, para posibilitar que el desarrollo cognitivo de los niños sea de largo alcance, se debe transcender lo inmediato para hacerles ver el sentido último de las cosas, especialmente, cuando comienza a aflorar la dialéctica pregunta-respuesta

    Discrete time piecewise affine models of genetic regulatory networks

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    We introduce simple models of genetic regulatory networks and we proceed to the mathematical analysis of their dynamics. The models are discrete time dynamical systems generated by piecewise affine contracting mappings whose variables represent gene expression levels. When compared to other models of regulatory networks, these models have an additional parameter which is identified as quantifying interaction delays. In spite of their simplicity, their dynamics presents a rich variety of behaviours. This phenomenology is not limited to piecewise affine model but extends to smooth nonlinear discrete time models of regulatory networks. In a first step, our analysis concerns general properties of networks on arbitrary graphs (characterisation of the attractor, symbolic dynamics, Lyapunov stability, structural stability, symmetries, etc). In a second step, focus is made on simple circuits for which the attractor and its changes with parameters are described. In the negative circuit of 2 genes, a thorough study is presented which concern stable (quasi-)periodic oscillations governed by rotations on the unit circle -- with a rotation number depending continuously and monotonically on threshold parameters. These regular oscillations exist in negative circuits with arbitrary number of genes where they are most likely to be observed in genetic systems with non-negligible delay effects.Comment: 34 page

    Anti-microbial Use in Animals: How to Assess the Trade-offs

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    Antimicrobials are widely used in preventive and curative medicine in animals. Benefits from curative use are clear – it allows sick animals to be healthy with a gain in human welfare. The case for preventive use of antimicrobials is less clear cut with debates on the value of antimicrobials as growth promoters in the intensive livestock industries. The possible benefits from the use of antimicrobials need to be balanced against their cost and the increased risk of emergence of resistance due to their use in animals. The study examines the importance of animals in society and how the role and management of animals is changing including the use of antimicrobials. It proposes an economic framework to assess the trade-offs of anti-microbial use and examines the current level of data collection and analysis of these trade-offs. An exploratory review identifies a number of weaknesses. Rarely are we consistent in the frameworks applied to the economic assessment anti-microbial use in animals, which may well be due to gaps in data or the prejudices of the analysts. There is a need for more careful data collection that would allow information on (i) which species and production systems antimicrobials are used in, (ii) what active substance of antimicrobials and the application method and (iii) what dosage rates. The species need to include companion animals as well as the farmed animals as it is still not known how important direct versus indirect spread of resistance to humans is. In addition, research is needed on pricing antimicrobials used in animals to ensure that prices reflect production and marketing costs, the fixed costs of anti-microbial development and the externalities of resistance emergence. Overall, much work is needed to provide greater guidance to policy, and such work should be informed by rigorous data collection and analysis systems

    Preliminary characterization of a Moroccan honey with a predominance of Bupleurum spinosum pollen

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    Honey with Bupleurum spinosum (zandaz) as a main pollen source has not been the subject of previous detailed study. Therefore, twelve Moroccan samples of this honey were subjected to melissopalynological, physicochemical and microbiological quality characterization, as well as antioxidant activity assessment. From a quality point of view, almost all samples were within the limits established by Codex Alimentarius, and/or the European legislation. All samples presented predominance of B. spinosum pollen (more than 48%). Relatively high levels of trehalose (1.3-4.0 g/100 g) and melezitose (1.5-2.8 g/100 g) were detected. Those sugars, not common in monofloral honeys, could be used as an important factor to discriminate zandaz honey. Flavonoid content correlated positively with the honey color, melanoidin and polyphenol content, and negatively with the IC50 values of scavenging ABTS (2,2' - azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radicals, while proline amount correlated negatively with IC50 values of nitric oxide scavenging activity and chelating power. This correlation supports the use of anti-oxidant activities as important variables for PCA (principal component analysis). Both components explained 70% from the given data, and showed certain homogeneity upon analyzed samples independent of the region, suggesting the importance of B. spinosum nectar in the resulting honey characteristics.Fundacao para a Ciencia e Tecnologia for Research Center [UID/BIM/04773/2013 CBMR 1334, UID/AGR/00239/2013, UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569)]; ERDF through the COMPETE - Programa Operacional Competitividade e Internacionalizacao (POCI

    The emergence of international food safety standards and guidelines: understanding the current landscape through a historical approach

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    Following the Second World War, the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) teamed up to construct an International Codex Alimentarius (or 'food code') which emerged in 1963. The Codex Committee on Food Hygiene (CCFH) was charged with the task of developing microbial hygiene standards, although it found itself embroiled in debate with the WHO over the nature these standards should take. The WHO was increasingly relying upon the input of biometricians and especially the International Commission on Microbial Specifications for Foods (ICMSF) which had developed statistical sampling plans for determining the microbial counts in the final end products. The CCFH, however, was initially more focused on a qualitative approach which looked at the entire food production system and developed codes of practice as well as more descriptive end-product specifications which the WHO argued were 'not scientifically correct'. Drawing upon historical archival material (correspondence and reports) from the WHO and FAO, this article examines this debate over microbial hygiene standards and suggests that there are many lessons from history which could shed light upon current debates and efforts in international food safety management systems and approaches

    The Variations in Religious and Legal Understandings on Halal Slaughter

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    Purpose: This paper attempts to provide an overview of different understandings regarding the concept of "what constitutes halal" and "who determines this concept?" In practice, this equates to contemporary legal understandings versus religious understandings. The paper further aims to provide an overview of competing Muslim understandings regarding the concept of "What does or does not constitute halal slaughter?" In practice, this equates to evaluating the application of no stunning at all upon an animal (unanimous acceptance) versus the application of reversible stunning upon an animal (contested). Design: The study includes a review of priori literature and considers the current scenario of the halal poultry trade and raises important questions regarding Islamic dietary practices, halal food integrity, religious and animal welfare understandings. Three key questions were raised: "To what extent does stunning impact halal slaughter?’, ‘Who determines what is halal slaughter?’ and ‘What are the variations and tensions between legal and religious understandings of halal slaughter?’ Findings: The examination of such requirements and concomitant consumer and provider expectations is underpinned by a study of an operational framework, i.e. industry practices with poultry (hand slaughter, stunning, mechanical slaughter, etc.), ethical values and market forces to appraise whether there is a point of convergence for these that can be beneficial for both seller and consumer concerns. This paper has considered different perspectives on the religious slaughter and provided an overview of competing understandings regarding the above concepts. Originality/value – This study although academic and philosophical in nature, raises questions on route to suggesting future research directions. It provides real value in stimulating more research in the area of halal food production and contributes to the understanding of different slaughter requirements for religious slaughter and the meat industry. It further sheds light on not only the religious and secular legal frameworks on animal slaughter and welfare but also the variations in understanding between them and provides examples of attempts to bridge any gap. The paper highlights the importance of halal food based on religious values and its implications for wider society

    Microwave heating induces changes in the physicochemical properties of baru (Dipteryx alata Vog.) and soybean crude oils

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    Baru oil is extracted from baru nuts (Dipteryx alata Vog.) by cold mechanical pressing, and is exploited as a source of vitamins, fatty acids and antioxidants in the Brazilian food and pharmaceutical sectors. No information is available on this oil under domestic culinary processes and thermal conditions. So, in the present study we evaluated the response of crude baru oil under microwave heating (0, 1, 3, 5, 10, and 15min), using crude soybean oil as comparison. Physical and chemical parameters were evaluated (free acidity, peroxide value, specific extinction coefficient at 232 and 270nm, ΔK and color by CIELAB method), fatty acid profile, tocopherol composition, antioxidant activity, and oxidative stability. Until 3min (1000W) no significant adverse changes were observed in either oil. However, higher exposition times are more adverse to baru oil than to soybean oil. Tocopherols, oils stability and antioxidant activity drop abruptly. The typical yellow coloration is lost with heating, giving a less appealing appearance to the oils. By a principal component analysis, it was verified that microwave heating differently influenced each oil, and within the same oil, exposure time also caused distinct effect on properties, quality, and composition. Based on the obtained results, we discourage the use of baru oil for culinary process. Practical applications: The use of baru oil for prolonged culinary processes is discouraged due to lower stability and low content in antioxidants. Baru oil is more suitable for seasoning for usage in domestic consumption at RT. Exposure to microwave heating is completely discouraged at an exposure higher than 3min.Thays Borges acknowledges Polytechnic Institute of Bragança for the scholarship support and Mountain Research Centre (CIMO) and University of Porto for the facilities granted during the development of this work. This work has been supported by FCT (Fundação para a Ciência e a Tecnologia) and FEDER through the COMPETE program under the projects PEst‐OE/AGR/UI0690/2011 and PEst‐C/EQB/LA0006/2011.info:eu-repo/semantics/publishedVersio

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    EDITORIA

    INSTRUCCIONES PARA AUTORES

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    INSTRUCCIONES PARA AUTORE

    EDITORIAL

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    En la presente editorial se hace homenaje al Maestro Roberto Santa-Cruz Moncayo, ilustre jurista del Departamento de Nariño con gran trayectoria tanto laboral como en la academia
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