A simple stress test of experimenter demand effects

As a stress test of experimenter demand effects, we run an experiment where subjects can physically destroy coupons awarded to them. About one subject out of three does. Giving money back to the experimenter is possible in a separate task but is more consistent with an experimenter demand effect than an explanation based on altruism towards the experimenter. A measure of sensitivity to social pressure helps predict destruction when social information is provided

Modelo de la Central Nuclear Embalse con RELAP5 : Accidente de pérdida de refrigerante en la tubería de aspiración de una de sus bombas

En el marco de la extensión de vida de la Central Nuclear Embalse, la Autoridad Regulatoria Nuclear con soporte externo del Centro de Investigación de Métodos Computacionales (CIMEC) ha desarrollado un modelo termo-hidráulico de la planta en RELAP5 mod. 3.3 patch4 que incluye la cinética puntual, con el fin de simular accidentes dentro de la base de diseño. Este modelo independiente es utilizado para la revisión del análisis de seguridad de la Central Nuclear Embalse. El presente trabajo tiene por objetivo la simulación de un accidente de pérdida de refrigerante primario (LOCA), debido a la rotura de la cañería de aspiración de una de las bombas principales, con pérdida del suministro eléctrico normal. En el caso de este tipo de reactores, la rotura conduce a una rápida descarga de refrigerante provocando el incremento de la fracción de vacío en el núcleo y una rápida inserción de reactividad que causa un aumento de la potencia que es controlado por los mecanismos de extinción para el apagado del reactor. El aumento de la presión en el edificio de la contención, produce el inicio del sistema de rociado para mitigar ese aumento de presión. Como la presión del circuito primario se reduce considerablemente (debido a la pérdida de inventario) y aumenta la presión en la contención, se dispara la señal de LOCA que habilita al sistema de inyección de refrigeración de emergencia del núcleo (ECCS). El presente análisis consiste en la verificación de la secuencia del accionamiento de los sistemas de seguridad, los tiempos de disparo del correspondiente mapa de cobertura de los sistemas de extinción y la acción del ECCS para reinundar el núcleo con refrigerante líquido. Se verifica el cumplimiento de las funciones de los sistemas de seguridad y que los tiempos de disparo se producen de acuerdo con lo esperado por diseño, demostrándose que el modelo independiente es una herramienta útil con la capacidad para realizar estudios de licenciamiento.Publicado en: Mecánica Computacional vol. XXXV no.31Facultad de Ingenierí

Review of the effects of protection in marine protected areas: current knowledge and gaps

The effectiveness of marine protected areas (MPAs) and the conservation of marine environments must be based on reliable information on the quality of the marine environment that can be obtained in a reasonable timeframe. We reviewed studies that evaluated all aspects related to the effectiveness of MPAs in order to describe how the studies were conducted and to detect fields in which research is lacking. Existing parameters used to evaluate the effectiveness of MPAs are summarised. Two-hundred and twenty-two publications were reviewed. We identified the most commonly used study subjects and methodological approaches. Most of the studies concentrated on biological parameters. Peer reviewed studies were based on control vs. impact design. BACI and mBACI designs were used in very few studies. Through this review, we have identified gaps in the objectives assigned to MPAs and the way in which they have been evaluated. We suggest some guidelines aimedat improving the assessment of the effects of protection in MPAs

Reasons and Means to Model Preferences as Incomplete

Literature involving preferences of artificial agents or human beings often assume their preferences can be represented using a complete transitive binary relation. Much has been written however on different models of preferences. We review some of the reasons that have been put forward to justify more complex modeling, and review some of the techniques that have been proposed to obtain models of such preferences

Review of the effects of protection in marine protected areas: current knowledge and gaps

The effectiveness of marine protected areas (MPAs) and the conservation of marine environments must be based on reliable information on the quality of the marine environment that can be obtained in a reasonable timeframe. We reviewed studies that evaluated all aspects related to the effectiveness of MPAs in order to describe how the studies were conducted and to detect fields in which research is lacking. Existing parameters used to evaluate the effectiveness of MPAs are summarised. Two–hundred and twenty–two publications were reviewed. We identified the most commonly used study subjects and methodological approaches. Most of the studies concentrated on biological parameters. Peer reviewed studies were based on control vs. impact design. BACI and mBACI designs were used in very few studies. Through this review, we have identified gaps in the objectives assigned to MPAs and the way in which they have been evaluated. We suggest some guidelines aimed at improving the assessment of the effects of protection in MPAsRevisión de los efectos de la protección en las áreas marinas protegidas: conocimiento y deficiencias actuales.— La efectividad de las áreas marinas protegidas (AMPs) y la conservación del medio ambiente marino debe basarse en información fiable sobre la calidad del medio marino que pueda obtenerse en un plazo de tiempo razonable. Se revisaron estudios que evalúan aspectos relacionados con la efectividad de las AMPs con el fin de describir cómo se realizaron los estudios y detectar donde existen vacíos en la investigación. En este estudio se enumeran los parámetros existentes para evaluar la efectividad de las AMPs. Se revisaron 224 publicaciones. Identificamos los objetos de estudio más utilizados y los enfoques metodológicos. La mayoría de los estudios se centran en el estudio de parámetros biológicos. Los estudios publicados se basaron en el diseño control frente a impacto. En muy pocos estudios se utilizaron diseños de muestreo BACI y mBACI. A través de esta revisión, se han identificado deficiencias en los objetivos de las AMPs y en la manera como han sido evaluados. Como conclusión sugerimos algunas pautas para mejorar la evaluación de los efectos de la protección en estas zonasPublicado

Marine reserves: Fish life history and ecological traits matter

Copyright by the Ecological Society of AmericaMarine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data sets from 12 European marine reserves, we show that there is significant variation in the response of different species of fish to protection and that this heterogeneity can be explained, in part, by differences in their traits. Densities of targeted size-classes of commercial species were greater in protected than unprotected areas. This effect of protection increased as the maximum body size of the targeted species increased, and it was greater for species that were not obligate schoolers. However, contrary to previous theoretical findings, even mobile species with wide home ranges benefited from protection: the effect of protection was at least as strong for mobile species as it was for sedentary ones. Noncommercial bycatch and unexploited species rarely responded to protection, and when they did (in the case of unexploited bentho-pelagic species), they exhibited the opposite response: their densities were lower inside reserves. The use of marine reserves for marine conservation and fisheries management implies that they should ensure protection for a wide range of species with different life-history and ecological traits. Our results suggest this is not the case, and instead that effects vary with economic value, body size, habitat, depth range, and schooling behavior.Publicado

Approaching Proof in the Classroom Through the Logic of Inquiry

The paper analyses a basic gap, highlighted by most of the literature concerning the teaching of proofs, namely, the distance between students' argumentative and proving processes. The analysis is developed from both epistemological and cognitive standpoints: it critiques the Toulmin model of reasoning and introduces a new model, the Logic of Inquiry of Hintikka, more suitable for bridging this gap. An example of didactical activity within Dynamic Geometry Environments is sketched in order to present a concrete illustration of this approach and to show the pedagogical effectiveness of the model

Mowat-Wilson syndrome: growth charts

Background Mowat-Wilson syndrome (MWS; OMIM #235730) is a genetic condition caused by heterozygous mutations or deletions of theZEB2gene. It is characterized by moderate-severe intellectual disability, epilepsy, Hirschsprung disease and multiple organ malformations of which congenital heart defects and urogenital anomalies are the most frequent ones. To date, a clear description of the physical development of MWS patients does not exist. The aim of this study is to provide up-to-date growth charts specific for infants and children with MWS. Charts for males and females aged from 0 to 16 years were generated using a total of 2865 measurements from 99 MWS patients of different ancestries. All data were collected through extensive collaborations with the Italian MWS association (AIMW) and the MWS Foundation. The GAMLSS package for the R statistical computing software was used to model the growth charts. Height, weight, body mass index (BMI) and head circumference were compared to those from standard international growth charts for healthy children. Results In newborns, weight and length were distributed as in the general population, while head circumference was slightly smaller, with an average below the 30th centile. Up to the age of 7 years, weight and height distribution was shifted to slightly lower values than in the general population; after that, the difference increased further, with 50% of the affected children below the 5th centile of the general population. BMI distribution was similar to that of non-affected children until the age of 7 years, at which point values in MWS children increased with a less steep slope, particularly in males. Microcephaly was sometimes present at birth, but in most cases it developed gradually during infancy; many children had a small head circumference, between the 3rd and the 10th centile, rather than being truly microcephalic (at least 2 SD below the mean). Most patients were of slender build. Conclusions These charts contribute to the understanding of the natural history of MWS and should assist pediatricians and other caregivers in providing optimal care to MWS individuals who show problems related to physical growth. This is the first study on growth in patients with MWS

The differential impact of friendship on cooperative and competitive coordination

Friendship is commonly assumed to reduce strategic uncertainty and enhance tacit coordination. However, this assumption has never been tested across two opposite poles of coordination involving either strategic complementarity or substitutability. We had participants interact with friends or strangers in two classic coordination games: the stag hunt game, which exhibits strategic complementarity and may foster "cooperation", and the entry game, which exhibits strategic substitutability and may foster "competition". Both games capture a frequent trade-off between a potentially high paying but uncertain option and a low paying but safe alternative. We find that, relative to strangers, friends are more likely to choose options involving uncertainty in stag hunt games but the opposite is true in entry games. Furthermore, in stag hunt games, friends "tremble" less between options, coordinate better and earn more, but these advantages are largely decreased or lost in entry games. We further investigate how these effects are modulated by risk attitudes, friendship qualities and interpersonal similarities