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Validation of a computational hydrodynamics model for horizontal-axis marine current turbines
No full textResults of a computational study to analyse the hydrodynamic performance of horizontal-axis marine current turbines are presented. The methodology is valid for arbitrary three-dimensional unsteady inviscid flows around lifting bodies that results into a Bou7ndary Integral Equation (BIE) model. A viscosity-correction model accounts for performance deviations from idealised potential flow conditions. The methodology is validated by comparison with experimental data from flume tank tests caried out at CNR-INSEAN in the framework of an application by company SABELLA SAS to the Trans-national Access program of the EU-FP7 Project MARINET. Results allow to estimate the accuracy of the proposed methodology to predict turbine performance and its reliability as design tool
Functional classification of phytoplankton: materials and methods for developing non-taxonomic quality indices
Get PDFNo abstract availableTra le maggiori difficolt? nell\u27utilizzo degli indici biotici basati sulla composizione in specie delle comunit? fitoplanctoniche, vi ? quella di classificare correttamente, dal punto di vista tassonomico, gli organismi rinvenuti. Per superare, almeno in parte, questa difficolt?, ? possibile ricorrere ad una classificazione su base morfo-funzionale, invece che tassonomica. La classificazione funzionale si fonda sulla relazione che lega le propriet? morfologiche e fisiologiche delle cellule algali alla loro risposta ai gradienti dei parametri ambientali: in teoria, dunque, ? possibile sviluppare indici di qualit? per la classificazione dei corpi idrici, basati su una classificazione morfo-funzionale degli organismi fitoplanctonici. Nella presentazione viene spiegato come si ? arrivati a sviluppare un indice di qualit? morfo-funzionale e come quest\u27ultimo abbia una performance comparabile a quelle di indici tradizionali, basati sulla classificazione tassonomica. Infine, vengono illustrati recenti sviluppi sullo studio delle relazioni tra alcuni tratti funzionali del fitoplancton lacustre e la composizione delle comunit? a scala europea
Ecology and distribution of Thaumarchaea in the deep hypolimnion of Lake Maggiore
Get PDFAmmonia-oxidizing Archaea (AOA) play an important role in the oxidation of ammonia in terrestrial, marine, and geothermal habitats, as confirmed by a number of studies specifically focused on those environments. Much less is known about the ecological role of AOA in freshwaters. In order to reach a high resolution at the Thaumarchaea community level, the probe MGI-535 was specifically designed for this study and applied to fluorescence in situ hybridization and catalyzed reporter deposition (CARD-FISH) analysis. We then applied it to a fine analysis of diversity and relative abundance of AOA in the deepest layers of the oligotrophic Lake Maggiore, confirming previous published results of AOA presence, but showing differences in abundance and distribution within the water column without significant seasonal trends with respect to Bacteria. Furthermore, phylogenetic analysis of AOA clone libraries from deep lake water and from a lake tributary, River Maggia, suggested the riverine origin of AOA of the deep hypolimnion of the lake
A quantitative micro-macro link for collective decisions: the shortest path discovery/selection example
Get PDFIn this paper, we study how to obtain a quantitative correspondence between the dynamics of the microscopic implementation of a robot swarm and the dynamics of a macroscopic model of nest-site selection in honeybees. We do so by considering a collec- tive decision-making case study: the shortest path discovery/selection problem. In this case study, obtaining a quantitative correspondence between the microscopic and macroscopic dynamics-the so-called micro-macro link problem-is particularly challenging because the macroscopic model does not take into account the spatial factors inherent to the path discovery/selection problem. We frame this study in the context of a general engineering methodology that prescribes the inclusion of available theoretical knowledge about target macroscopic models into design patterns for the microscopic implementation. The attain- ment of the micro-macro link presented in this paper represents a necessary step towards the formalisation of a design pattern for collective decision making in distributed systems
Self-control depletion in capuchin monkeys: does delay of gratification rely on a limited resource?
No full textSelf-control failure has enormous personal and societal consequences. One of the most debated models explaining why self-control breaks down is the Strength Model, according to which self-control depends on a limited resource. Either previous acts of self-control or taking part in highly demanding cognitive tasks have been shown to reduce self-control, possibly due to a reduction in blood glucose levels. However, several studies yielded negative ?ndings, and recent meta-analyses questioned the robustness of the depletion effect in humans. We investigated, for the ?rst time, whether the Strength Model applies to a non-human primate species, the tufted capuchin monkey. We tested ?ve capuchins in a self-control task (the Accumulation task) in which food items were accumulated within individual\u27s reach for as long as the subject refrained from taking them. We evaluated whether capuchins\u27 performance decreases: (i) when tested before receiving their daily meal rather than after consuming it (Energy Depletion Experiment), and (ii) after being tested in two tasks with different levels of cognitive complexity (Cognitive Depletion Experiment). We also tested, in both experiments, how implementing self-control in each trial of the Accumulation task affected this capacity within each session and/or across consecutive sessions. Repeated acts of self- control in each trial of the Accumulation task progressively reduced this capacity within each session, as predicted by the Strength Model. However, neither experiencing a reduction in energy level nor taking part in a highly demanding cognitive task decreased performance in the subsequent Accumulation task. Thus, whereas capuchins seem to be vulnerable to within-session depletion effects, to other extents our ?ndings are in line with the growing body of studies that failed to ?nd a depletion effect in humans. Methodological issues potentially affecting the lack of depletion effects in capuchins are discussed
Correlatos de la terapia EMDR en la neuroimagen funcional y estructural: Un resumen cr?tico de los hallazgos recientes
Get PDFNeuroimaging investigations of the effects of psychotherapies treating posttraumatic stress disorder (PTSD), including eye movement desensitization and reprocessing (EMDR), have reported findings consistent with modifications in cerebral blood flow (CBF; single photon emission computed tomography [SPECT]), in neuronal volume and density (magnetic resonance imaging [MRI]), and more recently in brain electric signal (electroencephalography [EEG]). Additionally in the recent past, EMDR- related neurobiological changes were monitored by EEG during therapy itself and showed a shift of the maximal activation from emotional limbic to cortical cognitive brain regions. This was the first time in which neurobiological changes occurring during any psychotherapy session have been reported, making EMDR the first psychotherapy with a proven neurobiological effect. The purpose of this article was to review the results of functional and structural changes taking place at PTSD treatment and presented during the period of 1999-2012 by various research groups. The reported pathophysiological changes are presented by neuropsychological technique and implemented methodology and critically analyzed.Las investigaciones con neuroimagen sobre los efectos de las psicoterapias que tratan el trastorno de estr?s postraum?tico (TEPT), incluyendo la terapia de desensibilizaci?n y reprocesamiento por movimientos oculares (EMDR), han mostrado hallazgos conformes con modificaciones en el flujo sangu?neo cerebral (FSC; tomograf?a computerizada de emisi?n monofot?nica [SPECT]), en el volumen y la densidad neuronal (im?genes por resonancia magn?tica [MRI]) y, m?s recientemente, en las se?ales el?ctricas del cerebro (electroencefalograf?a [EEG]). Adem?s, en el pasado reciente, se han monitorizado, por medio de EEG, cambios neurobiol?gicos relacionados con EMDR durante la misma terapia y han mostrado un cambio en la activaci?n m?xima desde las regiones l?mbicas emocionales a las regiones cognitivas corticales del cerebro. Esta ha sido la primera vez que se han se?alado los cambios neurobiol?gicos que tienen lugar durante una sesi?n de psicoterapia, lo que ha hecho que EMDR sea la primera psicoterapia con un efecto neurobiol?gico probado. El prop?sito de este art?culo ha sido analizar los resultados de los cambios funcionales y estructurales que han tenido lugar durante el tratamiento del TEPT y que han sido presentados por diversos grupos de investigaci?n durante el per?odo entre 1999 y 2012. Los cambios fisiopatol?gicos referidos se presentan en funci?n de las t?cnicas neuropsicol?gicas y la metodolog?a implementadas y son analizados de manera cr?tica
Uncommon 18F-FDG-PET/CT findings in patients affected by limbic encephalitis: Hyper-hypometabolic pattern with double antibody positivity and migrating foci of hypermetabolism
Get PDFAutoimmune limbic encephalitis (LE) is a rare disorder; its diagnosis can be challenging.We report two uncommon cases of LE evaluated by brain 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) positron emission tomography/ computed tomography describing themetabolic imaging patterns, which were different from those observed in previous studies: the first one presented an unprecedented 18F-FDG brain mixed pattern, involving also themidbrain, despite negative magnetic resonance imaging exams; the second one showed migrating foci of hypermetabolism, one of which turned into hypometabolism at a later examination
Tracking Second Thoughts: Continuous and Discrete Revision Processes during Visual Lexical Decision
Get PDFWe studied the dynamics of lexical decisions by asking participants to categorize lexical and nonlexical stimuli and recording their mouse movements toward response buttons during the choice. In a previous report we revealed greater trajectory curvature and attraction to competitors for Low Frequency words and Pseudowords. This analysis did not clarify whether the trajectory curvature in the two conditions was due to a continuous dynamic competition between the response alternatives or if a discrete revision process (a "change of mind") took place during the choice from an initially selected response to the opposite one. To disentangle these two possibilities, here we analyse the velocity and acceleration profiles of mouse movements during the choice. Pseudowords\u27 peak movement velocity occurred with 100ms delay with respect to words and Letters Strings. Acceleration profile for High and Low Frequency words and Letters Strings exhibited a butterfly plot with one acceleration peak at 400ms and one deceleration peak at 650ms. Differently, Pseudowords\u27 acceleration profile had double positive peaks (at 400 and 600ms) followed by movement deceleration, in correspondence with changes in the decision from lexical to nonlexical response buttons. These results speak to different online processes during the categorization of Low Frequency words and Pseudowords, with a continuous competition process for the former and a discrete revision process for the latter
Violence and Complexity
Get PDFLike all the phenomena that the human mind is knowledgeable about, the phenomenon of violence should be regarded as a complex macrosystem, where systems of networks and agents are linked and interact at different interconnected levels. This means that complexity refers to the phenomenon per se, to the various cognitive and emotional processes through which the human mind should examine and evaluate it and to the development of solutions to eradicate violence itself. It is clear that the complexity of these processes of examination and evaluation should be a requisite both of scientists and of laypeople. This does not mean that the scientist or the layperson should be knowledgeable about all the components and aspects of the macrosystem in their complex interconnections but that they should think and act on the grounds of their awareness of this complexity. One of the main issues relating to the study of violence is the definition of violence itself. In this respect, it is here suggested that thoughts and emotions, and not only behaviors, should be included in the definition of violence. As an exemplar of the difficulty regarding this specific issue, some considerations will draw on data obtained in a previous study on children and adolescents\u27 animal abuse experiences. It is also important to point out that complexity does not only refer to the explorations of the connections between systems taken from different research fields (e.g., neurology, biology, psychology, sociology, etc.). It can also refer, for example, to the theoretical premises of the research and of the questions at stake, to the scope and aims of the research and of these questions, and to the methods used in the investigation. In the same way, it is also important to bear in mind that, rooted in the theoretical premises and in the aims, are also specific views of society and life in general and that these views deeply and unavoidably affect the whole investigation process. It is clear that focusing on complexity also means opposing the fragmentation which usually characterizes the scientific study of violence and the interventions aiming to countervail it. Finally, as complexity theory indicates, through this "holistic" approach, a new conceptualization and understanding of violence could emerge so as to lead to more innovative and effective solutions to the problem of violence
Stress affects articulation planning in reading aloud.
Get PDFThree experiments of pseudoword reading assessed whether stress assignment affects reading aloud at the level of articulation planning. In experiment 1 (immediate reading) both stimulus length (in syllables) and stress type affected reading latency and accuracy. Italian pseudowords were named faster and more accurately when they were assigned stress on the antepenultimate than on the penultimate syllable. In experiment 2 (delayed reading) reading aloud of the same stimuli was not affected by length but was still affected by stress type, with shorter latencies for pseudowords stressed on the antepenultimate syllable. Experiment 3 replicated the results of the first two experiments with new materials and with a tightly controlled procedure. These results indicate that stress assignment exerts an effect in a processing component where articulation is planned as articulation can not start until stress is assigned. Our results also suggest that, in reading aloud, the minimal planning unit for articulation is smaller than the whole stimulus, including the first syllable up to the stressed unit