416 research outputs found

    Tool Embodiment Is Reflected in Movement Multifractal Nonlinearity

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    Recent advances in neuroscience have linked dynamical systems theory to cognition. The main contention is that extended cognition relies on a unitary brain-body-tool system showing the expected signatures of interaction-dominance reflected in a multifractal behavior. This might be particularly relevant when it comes to understanding how the brain is able to embody a tool to perform a task. Here we applied the multifractal formalism to the dynamics of hand movement while one was performing a computer task (the herding task) using a mouse or its own hand as a tool to move an object on the screen. We applied a focus-based multifractal detrended fluctuation analysis to acceleration time series. Then, multifractal nonlinearity was assessed by comparing original series to a finite set of surrogates obtained after Iterated Amplitude Adjusted Fourier transformation, a method that removes nonlinear multiscale dependencies while preserving the linear structure of the time series. Both hand and mouse task execution demonstrated multifractal nonlinearity, a typical form of across-scales interactivity in cognitive control. In addition, a wider multifractal spectrum was observed in mouse condition, which might highlight a richer set of interactions when the cognitive system is extended to the embodied mouse. We conclude that the emergence of multifractal nonlinearity from a brain-body-tool system pleads for recent theories of radical tool embodiment. Multifractal nonlinearity may be a promising metric to appreciate how physical objects—but also virtual tools and potentially prosthetics—are efficiently embodied by the brain

    La ética del psicoanálisis

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    Este trabajo se ocupa de la ética del psicoanálisis que, aún sin estar formulada como concepto en S. Freud, se desprende del modo en que trabaja, de la teoría que elabora y del método que diseña como adecuado a los fines que persigue. En cada concepto se considera tanto el aporte freudiano, cuanto el trabajo que a partir de ese punto realiza J. Lacan. Este último, se sirve de las contribuciones de ciencias nuevas y de los avances de otras ya consolidadas, los toma y usa con libertad para construir niveles nuevos de formalización de conceptos. Colabora así, en impedir que el psicoanálisis quede reducido a una teoría que repita conceptos paralizados por sentidos sancionados de una vez y para siempre, y a una práctica que sea aplicación mecánica de rituales. De este modo, se exponen las características de una ética solidaria a la función deseo del analista y las implicaciones que tiene para analista y analizante. El psicoanalista debe asumir la responsabilidad de dirigir la cura operando en una posición y discurso que son los que corresponden para abordar al sujeto que, en psicoanálisis, no es óntico sino ético. En torno a este eje se jalonan los otros temas de este trabajo, el saber a-subjetivo del inconsciente, la verdad en relación con lo contingente y lo necesario y la producción del objeto a con relación a la alienación y la separación. J. Lacan no permanece estéril, sometido a la sombra de un ideal sin falta, ni reniega de lo que hereda, tiene por S. Freud un amor hereje , toma con respeto y reconocimiento los dones que recibe del padre del psicoanálisis, pero no teme avanzar más allá de él. Asume por esto, las consecuencias de sus actos, así como S. Freud asumió las consecuencias de los suyos.This work deals with the ethics of psychoanalysis which, although was not explicitly elaborated as a concept by Freud, follows from his working style, the theory he develops and the method he designs as appropiate to accomplish his purposes. For each concept that is discussed both the freudian thought as the takens of Lacan about it, are considered. This author uses the contributions of new sciences as well as advances in already consolidated ones, and elaborates upon them freely to construct new levels of concept formalization. Thus he contributes to avoid the reduction of psychoanalysis to a theory that reiterates concepts, staled by meanings sanctioned once and for all, and to a practice which applies sterotyped rituals. In this way, the characteristics of an ethic which corresponds to the “analyst’s wish” function are delineated, as well as its implications for both analyst and analysand. The psychoanalyst must take responsbility for guiding the cure by taken a stand and a discourse appropiate to approach the subject who, in psychoanalysis, is ethic, non ontic. Around this axis, the other topics of this work are vertebrated, the a- subjective knowledge of the unconscious, the truth related to the contingent and the necessary and the production of the a object as it relates to alienation and separation. Lacan does not remain barren, bowing at the shadow of a faultless ideal, nor does he renegates of his inheritance. He has a ‘heretic love’ for Freud; he takes with respect and recognition the gifts he recibes from psycoanalysis’s father, but is not afraid to go beyond him. He assumes for this the consequenses of his acts, as Freud assumed the consequences of his.Fil: Arsac, Silvia Els

    A mathematical modelling study of an athlete's sprint time when towing a weighted sled

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    This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s12283-013-0114-2.This study used a mathematical model to examine the effects of the sled, the running surface, and the athlete on sprint time when towing a weighted sled. Simulations showed that ratio scaling is an appropriate method of normalising the weight of the sled for athletes of different body size. The relationship between sprint time and the weight of the sled was almost linear, as long as the sled was not excessively heavy. The athlete’s sprint time and rate of increase in sprint time were greater on running surfaces with a greater coefficient of friction, and on any given running surface an athlete with a greater power-to-weight ratio had a lower rate of increase in sprint time. The angle of the tow cord did not have a substantial effect on an athlete’s sprint time. This greater understanding should help coaches set the training intensity experienced by an athlete when performing a sled-towing exercise

    Highlighting the History of French Radio Astronomy. 4. Early Solar Research at the École Normale Supérieure, Marcoussis and Nancay

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    The first tentative steps in solar radio astronomy took place during the 1940s and early 1950s as physicists and engineers in a number of countries used recycled World War II equipment to investigate the flux levels and polarisation of solar bursts and emission from the quiet Sun, and sought to understand the connection between this emission and optical features in the solar photosphere and chromosphere. There was also an abiding interest in the terrestrial effects of this solar radio emission. Among these solar pioneers were French radio astronomers from the École Normale Supérieure in Paris. In this paper we review the early solar observations made by them from Paris, Marcoussis and Nançay prior to the construction of a number of innovative multi-element solar interferometers at the Nançay field station in the mid-1950s

    Alteration of mitochondrial oxidative phosphorylation in aged skeletal muscle involves modification of adenine nucleotide translocator

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    AbstractThe process of skeletal muscle aging is characterized by a progressive loss of muscle mass and functionality. The underlying mechanisms are highly complex and remain unclear. This study was designed to further investigate the consequences of aging on mitochondrial oxidative phosphorylation in rat gastrocnemius muscle, by comparing young (6 months) and aged (21 months) rats. Maximal oxidative phosphorylation capacity was clearly reduced in older rats, while mitochondrial efficiency was unaffected. Inner membrane properties were unaffected in aged rats since proton leak kinetics were identical to young rats. Application of top-down control analysis revealed a dysfunction of the phosphorylation module in older rats, responsible for a dysregulation of oxidative phosphorylation under low activities close to in vivo ATP turnover. This dysregulation is responsible for an impaired mitochondrial response toward changes in cellular ATP demand, leading to a decreased membrane potential which may in turn affect ROS production and ion homeostasis. Based on our data, we propose that modification of ANT properties with aging could partly explain these mitochondrial dysfunctions

    Improved Energy Supply Regulation in Chronic Hypoxic Mouse Counteracts Hypoxia-Induced Altered Cardiac Energetics

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    Hypoxic states of the cardiovacular system are undoubtedly associated with the most frequent diseases of modern time. Therefore, understanding hypoxic resistance encountered after physiological adaptation such as chronic hypoxia, is crucial to better deal with hypoxic insult. In this study, we examine the role of energetic modifications induced by chronic hypoxia (CH) in the higher tolerance to oxygen deprivation.P-NMR), and to describe the integrated changes in cardiac energetics regulation by using Modular Control Analysis (MoCA). Oxygen reduction induced a concomitant decrease in RPP (−46%) and in [PCr] (−23%) in Control hearts while CH hearts energetics was unchanged. MoCA demonstrated that this adaptation to hypoxia is the direct consequence of the higher responsiveness (elasticity) of ATP production of CH hearts compared with Controls (−1.88±0.38 vs −0.89±0.41, p<0.01) measured under low oxygen perfusion. This higher elasticity induces an improved response of energy supply to cellular energy demand. The result is the conservation of a healthy control pattern of contraction in CH hearts, whereas Control hearts are severely controlled by energy supply.As suggested by the present study, the mechanisms responsible for this increase in elasticity and the consequent improved ability of CH heart metabolism to respond to oxygen deprivation could participate to limit the damages induced by hypoxia

    El puente de Brotonne sobre el Sena - Francia

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    This bridge solves the connection problem between Rouen and Le Havre. The need to preserve the maritime tradition of Rouen and to permit the heavy shipping traffic through the estuary forced a structural design which main part, 696.5 m long, consists of a 5-span triss-braced bridge. The central span, 320 m long, is the longest pre-stressed concrete span in the world. The structure also includes two access ramps. This article analyses the features and construction procedures of each element in the structure, namely: — Foundations, consisting on cylindrical piers for the main spans and piers on piles for the access ramps and viaducts. — The curved octagonal piles, creating an interesting aesthetical effect. — The deck consisting on a single monocelular girder, formed by twincore wedged, pieces, prestressed in all directions. — The tower with a constant 2.60 dimension crosswise and tapered from 4.80 to 2.84 meters lengthwise. — Tensors, prestressing, etc.Este puente resuelve el problema de comunicación entre Rouen y Le Havre. La necesidad de respetar la tradición marítima de Rouen y la navegación de barcos de gran tonelaje obligó a realizar una estructura cuya obra principal, de una longitud de 696,5 m, es un puente atirantado que tiene cinco tramos, de los cuales el central, de 320 m, constituye el récord del mundo de luz en hormigón pretensado. La estructura comprende, además, dos viaductos de acceso. En este artículo se hace un análisis de las características y procedimientos de construcción de cada uno de los elementos que componen la obra: — Las cimentaciones, que son columnas cilíndricas para las pilas principales, y sobre pilotes en las pilas de los viaductos de acceso. — Las pilas, de forma octogonal curvilínea, que producen un gran efecto estético. — El tablero es una viga monocelular, formada por dovelas de dos almas pretensadas en todas direcciones. — Las torres, cuya sección es constante en sentido transversal (2,60 m), y varía de 4,80 a 2,84 m en sentido longitudinal. — Tirantes, pretensado, etc

    Molecular Typing of Protease-Resistant Prion Protein in Transmissible Spongiform Encephalopathies of Small Ruminants, France, 2002–2009

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    The agent that causes bovine spongiform encephalopathy (BSE) may be infecting small ruminants, which could have serious implications for human health. To distinguish BSE from scrapie and to examine the molecular characteristics of the protease-resistant prion protein (PrPres), we used a specifically designed Western blot method to test isolates from 648 sheep and 53 goats. During 2002–2009, classical non-Nor98 transmissible spongiform encephalopathy had been confirmed among ≈1.7 million small ruminants in France. Five sheep and 2 goats that showed a PrPres pattern consistent with BSE, or with the CH1641 experimental scrapie source, were identified. Later, bioassays confirmed infection by the BSE agent in 1 of the 2 goats. Western blot testing of the 6 other isolates showed an additional C-terminally cleaved PrPres product, with an unglycosylated band at ≈14 kDa, similar to that found in the CH1641 experimental scrapie isolate and different from the BSE isolate

    Atypical/Nor98 scrapie:properties of the agent, genetics, and epidemiology

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    Atypical/Nor98 scrapie cases in sheep were diagnosed for the first time in Norway in 1998. They are now identified in small ruminants in most European countries and represent an increasingly large proportion of the scrapie cases diagnosed in Europe. Atypical/Nor98 scrapie isolates have shown to be experimentally transmissible into transgenic mice and sheep but the properties of the TSE agent involved, like its biological and biochemical features, are so clearly distinct from the agent involved in classical scrapie that they have provided a challenging diagnostic for many years. No strain diversity has yet been identified among the atypical/Nor98 scrapie sample cases. The genetic predisposition of the sheep affected by atypical/Nor98 scrapie is almost inverted compared to classical scrapie, and the exact origin of this sporadic TSE strain is still speculative, but a spontaneous, non-contagious origin, like sporadic Creutzfeldt-Jakob disease in humans, can not be excluded. Further transmission and epidemiological studies are needed to better address this hypothesis
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