Realismo y racionalidad científica: un viaje desde la lógica a la ética

La relación de Mariano Artigas con la obra y la persona de Karl Popper pasó por tres fases. La primera culmina con el libro de Artigas titulado Karl Popper: búsqueda sin término (1979). Artigas encontró en Popper una poderosa fuente de inspiración. Pero también manifestó diversas discrepancias con el pensador vienés, especialmente en lo que hace a la tesis de la naturaleza conjetural del conocimiento. En conjunto, Artigas entendió que era posible un diálogo fructífero con Popper. La segunda fase comienza con la correspondencia entre Artigas y Popper, en la que el primero señala los puntos de discrepancia que les separan, y culmina con la publicación por parte de Artigas de El desafío de la racionalidad (1994). Aquí se ponen de manifiesto las afinidades y diferencias entre ambos en cuanto a la teoría de la racionalidad. La tercera fase se abre el mismo año de 1994, con la lectura por parte de Artigas de varios textos popperianos hasta entonces inéditos y que resultan cruciales para entender la posición de Karl Popper respecto al problema de la racionalidad. En ellos queda claro que la idea popperiana de racionalidad crítica tiene su apoyo e inspiración más en el terreno de la ética que en el de la lógica. Esta constatación dejó abierto un camino de mayor proximidad y simpatía entre ambos autores, como se constata en el libro de Artigas titulado Lógica y ética en Karl Popper (1998); una senda que, por motivos biográficos, no llegaron a recorrer juntos, pero que resulta toda una invitación para los filósofos actuales.Mariano Artigas’s relationship with the work and person of Karl Popper went through three phases. The first one ends with Artigas’s book entitled Karl Popper: búsqueda sin término (1979). Artigas found in Popper a powerful source of inspiration. But he also stated several discrepancies with Popper, especially in regard to the thesis of the conjectural nature of knowledge. However, Artigas saw the possibility of a fruitful dialogue with Popper. The second phase begins with the correspondence between Artigas and Popper, and culminates with the publication by Artigas of a book entitled El desafío de la racionalidad (1994). Here, some affinities and differences appear in regard to the theory of rationality of both authors. The third phase was opened precisely in 1994, with the reading by Artigas of several Popperians hitherto unpublished texts. These texts revealed themselves crucial to the understanding of the Popper’s position on the problem of rationality. It became clear that the Popperian idea of critical rationality has its support and inspiration more in the field of ethics than in the domain of logic. This finding left open a path of greater proximity and sympathy between them, as it is stated in Artigas’ book Lógica y ética en Karl Popper (1998); a path that, for biographical reasons, they were unable to travel together, but that represents a challenging invitation for today’s philosophers

Análisis Preliminar de la Influencia del Proceso de Torneado en la vida a fatiga de la Aleación de Aluminio UNS A92024-T351

Generalmente los elementos estructurales metálicos de las aeronaves se ubican en zonas de carga crítica, en la mayoría de los casos, estos elementos son conformados mediante procesos de mecanizado. La vida a fatiga de estos componentes es una propiedad dinámica muy importante que puede verse intensamente afectada por las condiciones superficiales producidas durante el proceso de mecanizado. En este trabajo se lleva a cabo un primer estudio de la influencia de los parámetros de corte en la resistencia a la fatiga de piezas torneadas de la aleación de aluminio aeronáutico UNS A92024-T351. Se ha prestado especial atención a la relación con el acabado superficial evaluado a partir de la rugosidad media aritmétic

Caverna 2.0. Las raíces dualistas del transhumanismo

El transhumanismo (TH) es una moda intelectual que propone la transformación de los seres humanos mediante diversas tecnologías. Expondremos los rasgos más conspicuos del TH, así como las principales críticas que se le han hecho (sección 1). Pero la intención de este artículo no es entrar en esta polémica; aportaremos solo las claves imprescindibles para seguir adelante. Una de las claves intrigantes del TH es que, bajo su pátina tecno-futurista, remite a ideas filosóficas tan viejas como, en apariencia, incompatibles entre sí. Remite al naturalismo radical, tanto como al nihilismo existencialista. Nuestra tesis es que tanto el naturalismo radical como el nihilismo existencialista son producto de las diversas oleadas del dualismo (platónico, cartesiano…). Una vez que escindimos la libertad de la naturaleza, podemos contar hasta dos, como hacen los dualistas, o quedarnos solo en uno, como hacen los existencialistas, que se paran en la libertad, y los naturalistas, que solo cuentan con la naturaleza. En cualquier caso, la imagen del ser humano, que es libertad y naturaleza (pero sin “y”), sale dañada. Asoma entonces el animal aporético y enfermizo al cual hay que salvar… de sí mismo. ¿Cómo? Siguiendo el método de Procusto, pero ahora con los prefijos bio e info en lugar de sierra y martillo. Hasta que el pobre ser humano encaje en el lecho de la utopía que algunos visionarios han urdido (sección 2). ¿Y no hay otra vía, otra forma de mejorar la vida humana más respetuosa para con la humana envergadura? Quizá sí, mas para trazar esa tercera vía, entre el naturalismo radical que mutila y el nihilismo existencialista que descoyunta, habría que negar de antemano el dualismo que a los dos engendra, y atenerse a la sensatez común, en línea con la tradición aristotélica, antes que a las ensoñaciones utópicas (sección 3). En nuestra opinión, el concepto aristotélico de naturaleza humana nos habilita para juzgar las antropotecnias mejor que la normatividad extraída de las visiones futuristas propias del TH (sección 4).Transhumanism (TH) is an intellectual trend that promotes the technological transformation of human beings. We will briefly expose the most conspicuous features of the TH, as well as the main criticisms that have been made to it (section 1). The aim of this article, however, is not to enter into this controversy, so we will provide only the essential keys to be able to move forward. And one of the most intriguing keys of the TH is that, beneath its techno-futurist patina, it refers to certain philosophical ideas as old as incompatible –in appearance– with each other. The TH refers to radical naturalism, as well as to existentialist nihilism. The thesis advocated here is that both, radical naturalism and existentialist nihilism, are products of the various waves of dualism. Once we separate, in the dualistic way, freedom on the one hand and nature on the other, we can count up to two, as the dualists do, or remain just in one, as existentialists do, who stand in freedom, and naturalists as well, who only count on nature. In any case, the image of the human being, which is freedom and nature (without “and”), is damaged. Then the aporetic and sickly animal appears, which has to be saved... from itself. How? Following the Procrustean method, but now with the bio and info prefixes instead of saw and hammer, until the poor human being fits into the utopian bed that some visionaries have dreamed (section 2). But there could be perhaps a way to improve human life without forcing the human scale. In order to draw this way between the radical naturalism, that mutilates, and the existentialist nihilism, that dislodges and stretches, we should deny in advance the dualism that generates both, and follow the common sense, in line with the Aristotelian tradition, rather than utopian daydreams (section 3). In our opinion, the Aristotelian concept of human nature enables us to judge anthropotechnics better than the normativity extracted from the futuristic visions of the TH (section 4)

Influence of the Lubrication Conditions on the Surface Finish of Turned Aeronautical Aluminium Alloys. A preliminary Study

Nowadays, one of the main objectives that affects the development of any new product is the respect for the environment. Until the late 80's, the development and manufacture of the most of the product were aimed to achieve maximum quality in time and costs with environmental issues relegated to secondary importance. On the other hand, in the 90's, the pressure from factors such as markets, financial and legislative factors, led to environmental considerations being taken into account. In this context, the current aeronautical industry strategies are based on the search for economic, environmental and energy efficiency considerations for all the processes involved in the aircraft manufacturing

Treatment of obesity in children and adolescents. How nutrition can work?

Overweight appears when persistent positive energy imbalances occur for long periods of time. Knowledge of dietary risk factors during childhood and adolescence is needed in order to design preventive measures against the increase in the prevalence of obesity and its consequences but is, however, largely missing. Longitudinal studies in children have not found clear causal associations between energy intake or diet composition and overweight development. Research has been ongoing to develop effective intervention studies for obese children but it is not clear which intervention is the most effective in assisting overweight/obese children to improve body composition without affecting growth rates. The objective of this article is to review the available knowledge on dietary risk factors for the development of childhood obesity, to discuss different dietary treatment strategies, and to propose an evidence-based approach to treat obese adolescents

Influence of the BaTiO3 addition to K0.5Na0.5NbO3 lead-free ceramics on the vacancy-like defect structure and dielectric properties

A study on the induced changes in the vacancy-like defect structure and the dielectric properties of K0.5Na0.5NbO3 ceramics by the addition of different amounts, between 0% and 7%, of BaTiO3 is presented. The samples were prepared by a mechanochemically activated solid-state reaction method. The structural evolution due to the orthorhombic to the tetragonal phase transition of the KNN doped samples was followed using X-ray diffraction and Raman spectroscopy. The use of positron annihilation lifetime spectroscopy allowed to identify the defect structure at sub-nanometric scale and the nature of the vacancy-like defects generated by the phase transition. The obtained results are discussed considering the lattice symmetry change and the defects structure formed due to the replacement of alkaline and niobium ions by barium and titanium ones. Additionally, changes in the dielectric properties are discussed in terms of the structural modifications of the different KNN-based ceramics involving different kinds of vacancy-like defects.Fil: Prado Espinosa, Fabiola Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Ramajo, Leandro Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Rubio Marcos, Fernando. Instituto de Cerámica y Vidrio de Madrid; EspañaFil: Macchi, Carlos Jorge. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Física de Materiales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Somoza, A.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Física de Materiales; ArgentinaFil: Castro, Miriam Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Influence of the sintering temperature on ferroelectric properties of potassium-sodium niobate piezoelectric ceramics

The effect of sintering condition on structure, microstructure, and ferroelectric properties of (K0.44Na0.52Li0.04) (Nb0.86Ta0.10Sb0.04)- O3 (KNL-NTS) has been investigated. Ceramic powders have been synthesized by the solid-state reaction method and sintered at different temperatures (1115°C, 1125°C, and 1140°C). Then, samples were characterized by thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, and impedance spectroscopy. Through XRD results, the perovskite structure and small peaks corresponding to a secondary phase were detected. Ceramics processed at the highest temperatures showed higher densities and good piezoelectric properties (d33, Kp, and Kt), particularly specimens sintered at 1125°C presented the highest piezoelectric performance.Fil: Cortés, J. A.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Camargo, Javier Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Rachia, M. F.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Rubio Marcos, Fernando. Instituto de Cerámica y Vidrio de Madrid; España. Universidad Nebrija; EspañaFil: Ramajo, Leandro Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Castro, Miriam Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Ramírez, M. A.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi

Effect of lead acetate on the in vitro engulfment and killing capability of toad (<i>Bufo arenarum</i>) neutrophils

Lead is an element of risk for the environment and human health and has harmful effects that may exceed those of other inorganic toxicants. The immune system is one ofthe targets of lead. Its immunomodulatory actions depend on the level of exposure, and it has been demonstrated that environmental amounts of the metal alter immune function. Very little information is available regarding the effect of the metal on different aspects of the immune system of lower vertebrates, in particular of amphibians. The aim of this study was to investigate the effect of sublethal lead (as acetate) on the function of polymorphonuclear cells of Bufo arenarum. The results revealed that phagocytic and lytic functions ofthe adherent blood cells collected from sublethal lead-injected toads and incubated with suspensions of Candida pseudotropicalis were affected negatively. The decrease of the phagocytic activity was correlated with increased blood lead levels (P-0.0001). Additional information referred to the total and differential leukocyte counts was presented; the only difference found was in the number of blast-like cells that resulted augmented in the samples of lead-injected toads. It was concluded that the evaluation ofthese parameters might be a reliable tool for the biological monitoring of the immune status of amphibians.Facultad de Ciencias ExactasComisión de Investigaciones Científicas de la provincia de Buenos Aire

A fuzzy method for the usability evaluation of nuclear medical equipment

To avoid errors when handling nuclear medical equipment, it is important to develop products with a high degree of usability. This can be achieved by performing usability evaluations in the product development process to detect and mitigate potential usability problems. Usability evaluation focuses on how well users can learn and use a product to achieve their goals. Thus, the usability evaluation has become recognized as a valuable complement to the established approaches to design good user interfaces, to reduce incidents and accidents as well the time required to learn how to use the equipment. To gather information about usability, practitioners use a variety of methods that gather feedback from users about an existing interface or plans related to a new interface. A wide range of usability evaluation methods have been proposed, but few methods focus on developing an objective and practical evaluation method for usability. Moreover, the usability evaluations are based on human judgments and most methods cannot fully solve the subjectivity of these evaluations. In order to remedy this deficiency, the purpose of this work is to adopt a Fuzzy Set Theory (FST) approach to establish a method for the usability evaluation of nuclear medical equipment based on usability heuristics for user interface design and international standards for ergonomics of human-system interaction. To exemplify the method we performed a usability evaluating of the Digital Spectrometer ESP 13004 by testing it with representative users. The results showed that the method is a proactive tool to provide a basis for checking usability of medical device interfaces

Asociación micorrízica entre Moringa oleífera Lam y el Glomus fasciculatum

The mycorrhizal association of forest plant Moringa oleifera Lam and the theme of mutualism in conditions of low fertility soils. To evaluate whether the AMF Glomus fasciculatum establishes mycorrhizal associations with this plant, an experiment was carried out on a chess design with two variants and three replications at Pinar del Rio Biofactory, nearby the Provincial Delegation of the Ministry of Agriculture, at Hermanos Cruz neighbourhood. As a result of the analysis performed in the microbiology laboratory of the University, it was found that there exists and mycorrhizal association between the plant and the fungus, so it is found that the species Moringa oleifera Lam is included between 95-96% of the plant species that establish association with arbuscular mycorrhizal fungi.La asociación micorrízica de la planta forestal Moringa oleífera Lam es un tema muy poco estudiado. Menos aún se ha trabajado este mutualismo en condiciones de árbol fuera del bosque (AFB) con esta especie en suelos de baja fertilidad. Para evaluar si el HMA Glomus fasciculatum establece micorrización con esta planta, se montó un experimento en diseño de ajedrez con dos variantes y tres réplicas, en la Biofábrica de Pinar del Río, aledaña a la Delegación Provincial del Ministerio de la Agricultura, en el Reparto Hermanos Cruz de la Capital Provincial. Como resultado de los análisis realizados en el laboratorio de microbiología de la Universidad, se pudo comprobar que existe asociación micorrízica entre la planta y el hongo, por lo que se comprueba que la especie Moringa oleífera Lam está incluida entre el 95-96 % de las especies vegetales que establecen asociación con los hongos micorrizógenos arbusculares