140 research outputs found

    Analysis of the neural hypercolumn in parallel PCSIM simulations

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    AbstractLarge and sudden changes in pitch or loudness occur statistically less frequently than gradual fluctuations, which means that natural sounds typically exhibit 1/f spectra. Experiments conducted on human subjects showed that listeners indeed prefer 1/f distributed melodies to melodies with faster or slower dynamics. It was recently demonstrated by using animal models, that neurons in primary auditory cortex of anesthetized ferrets exhibit a pronounced preference to stimuli that exhibit 1/f statistics. In the visual modality, it was shown that neurons in primary visual cortex of macaque monkeys exhibit tuning to sinusoidal gratings featuring 1/f dynamics.One might therefore suspect that neurons in mammalian cortex exhibit Self-Organizing Criticality. Indeed, we have found SOC-like phenomena in neurophysiological data collected in rat primary somatosensory cortex. In this paper we concentrated on investigation of the dynamics of cortical hypercolumn consisting of about 128 thousand simulated neurons. The set of 128 Liquid State Machines, each consisting 1024 neurons, was simulated on a simple cluster built of two double quad-core machines (16 cores).PCSIM was designed as a tool for simulating artificial biological-like neural networks composed of different models of neurons and different types of synapses. The simulator was written in C++ with a primary interface dedicated for the Python programming language. As its authors ensure it is intended to simulate networks containing up to millions of neurons and on the order of billions of synapses. This is achieved by distributing the network over different nodes of a computing cluster by using Message Passing Interface.The results obtained for Leaky Integrate-and-Fire model of neurons used for the construction of the hypercolumn and varying density of inter-column connections will be discussed. Benchmarking results for using the PCSIM on the cluster and predictions for grid computing will be presented to some extent. Research presented herein makes a good starting point for the simulations of very large parts of mammalian brain cortex and in some way leading to better understanding of the functionality of human brain

    Dramaturgia en la modernidad: alguna teoría y alguna práctica (Las últimas miradas de Vladímir)

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    Este trabajo se ocupa de la dramaturgia, la creación literaria en las artes escénicas. La investigación se divide en dos secciones, la primera teórica, la segunda práctica. El tema de este trabajo es un estudio de los principales elementos que caracterizan la teoría del teatro literario al final de la Modernidad. Parte uno: teoría y análisis La creación dramatúrgica, porque está escrita para ser leída y representada, tiene sus propios méritos como actividad literaria. La narrativa literaria en el teatro posee diferentes elementos, cada uno de los cuales se utiliza de una manera particular. Estas son la historia, los personajes, las Tres Unidades (acción, tiempo y espacio), la estructura del discurso y el género. Al examinar siete autores fundamentales, esta disertación discute las diversas formas en que se transforman estos conceptos diferentes. El resultado de esta transformación es lo que ahora se llama "teoría dramatúrgica en la modernidad". Entre estos autores, tres se consideran paradigmas fundamentales: Aristóteles, Frederich Hegel y Bertolt Brecht. Parte dos: el trabajo práctico En la primera parte de este trabajo, la investigación considera los elementos utilizados en su "praxis". Se presenta la obra de teatro del autor, The Last Look of Vladimir Maiakovski. Esta disertación va más allá de los comentarios técnicos de la Parte Uno para abrir una discusión conceptual cuya forma es simbólica. Dado que el personaje, Vladimir Maiakovski, así como la obra misma son metáforas, su objetivo es la discusión y expresión de los conflictos del hombre y del artista en estado de crisis en la Modernidad.Tesi

    Adsorbent materials from paper industry waste materials and their use in Cu(II) removal from water.

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    This paper deals with the removal of Cu2+ from water using adsorbent materials prepared from paper industry waste materials (one de-inking paper sludge and other sludge from virgin pulp mill). Experimental results showed that de-inking paper sludge leads to mesoporous materials (Vmic/VT = 0.13 and 0.14), whereas the sludge from virgin pulp mill produces high microporous adsorbents (Vmic/VT = 0.39 and 0.41). Adsorbent materials were then used for Cu2+ removal from water at acid pH. During water treatment, heavy metals lixiviation from adsorbent materials was not produced. However, important Ca and Mg leaching was observed. Final pH significantly increases after treatment of water with adsorbent materials probably due to their elevated CaCO3 content. In general, highest Cu2+ removal was obtained using adsorbent materials from de-inking paper sludge. This result could be due to their higher content in oxygenated surface groups, high average pore diameter, elevated superficial charge density, high CaCO3 amount and high Ca and Mg exchange conten

    Evaluation of compliance with the Spanish Code of self-regulation of food and drinks advertising directed at children under the age of 12 years in Spain, 2012

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    OBJECTIVE: To evaluate compliance levels with the Spanish Code of self-regulation of food and drinks advertising directed at children under the age of 12 years (Publicidad, Actividad, Obesidad, Salud [PAOS] Code) in 2012; and compare these against the figures for 2008. STUDY DESIGN: Cross-sectional study. METHODS: Television advertisements of food and drinks (AFD) were recorded over 7 days in 2012 (8am-midnight) of five Spanish channels popular to children. AFD were classified as core (nutrient-rich/low-calorie products), non-core (nutrient-poor/rich-calorie products) or miscellaneous. Compliance with each standard of the PAOS Code was evaluated. AFD were deemed to be fully compliant when it met all the standards. RESULTS: Two thousand five hundred and eighty-two AFDs came within the purview of the PAOS Code. Some of the standards that registered the highest levels of non-compliance were those regulating the suitability of the information presented (79.4%) and those prohibiting the use of characters popular with children (25%). Overall non-compliance with the Code was greater in 2012 than in 2008 (88.3% vs 49.3%). Non-compliance was highest for advertisements screened on children's/youth channels (92.3% vs. 81.5%; P < 0.001) and for those aired outside the enhanced protection time slot (89.3% vs. 86%; P = 0.015). CONCLUSIONS: Non-compliance with the PAOS Code is higher than for 2008. Given the lack of effectiveness of self-regulation, a statutory system should be adopted to ban AFD directed at minors, or at least restrict it to healthy products.S

    Proteomic approach in the search of new cardiovascular biomarkers

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    Proteomic approach in the search of new cardiovascular biomarkers With the increasing incidence of cardiovascular diseases worldwide, specifically atherosclerosis and heart failure, the search for novel biomarkers remains a priority. As opposed to complex diagnostic techniques that may not be suitable to be applied to the wider population, biomarkers are useful for population screening. The search for novel biomarkers is based on knowledge of the molecular and cellular processes that take place in the development of a specific disease. Atherosclerosis and heart failure are characterized by a long period of silent disease progression, allowing early diagnosis and the potential of early therapeutic intervention. The use of the so-called proteomic techniques allows not only protein identification but partial characterization, which includes expression and also post-translational modification of these proteins. This allows for the discovery of previously unknown proteins involved in cardiovascular diseases, including some that may be suitable to be used as biomarkers. However, to approach this issue, we have to overcome difficulties such as tissue heterogeneity (vessel wall or myocardium) and the lack of fresh human samples. We discuss the proteomic study of human plaques, secreted proteins by pathologic and normal vessel wall, and left ventricular hypertrophy as potential sources of new biologic markers of cardiovascular disease

    Applications of long period gratings in solid core photonic bandgap fibers

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    Solid core photonic bandgap fibres are photonic crystal fibres with a solid core surrounded by high index inclusions. The guidance properties of these fibers are very sensitive to the refractive index of the inclusions, making them widely tunable and making them very promising for sensing applications. Combining these fibers with long period gratings unleashes their full potential, enabling narrow band notch filters tunable over hundreds of nm, refractive index sensors with sensitivity comparable to that of surface plasmon resonance sensors, but also the extraction of the full band diagrams of these bandgap fibres

    Adipose Tissue Protects against Hepatic Steatosis in Male Rats Fed a High-Fat Diet plus Liquid Fructose: Sex-Related Differences

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    Non-alcoholic fatty liver disease is a sexual dimorphic disease, with adipose tissue playing an essential role. Our previous work showed that female rats fed a high-fat high-fructose diet devoid of cholesterol (HFHFr) developed simple hepatic steatosis dissociated from obesity. This study assessed the impact of the HFHFr diet on the male rat metabolism compared with data obtained for female rats. A total of 16 Sprague Dawley (SD) male rats were fed either a control (standard rodent chow and water) or HFHFr (high-fat diet devoid of cholesterol, plus 10% fructose in drinking water) diet for 3 months. Unlike female rats, and despite similar increases in energy consumption, HFHFr males showed increased adiposity and hyperleptinemia. The expression of hormone-sensitive lipase in the subcutaneous white adipose tissue was enhanced, leading to high free fatty acid and glycerol serum levels. HFHFr males presented hypertriglyceridemia, but not hepatic steatosis, partially due to enhanced liver PPARα-related fatty acid β-oxidation and the VLDL-promoting effect of leptin. In conclusion, the SD rats showed a sex-related dimorphic response to the HFHFr diet. Contrary to previous results for HFHFr female rats, the male rats were able to expand the adipose tissue, increase fatty acid catabolism, or export it as VLDL, avoiding liver lipid deposition. Keywords: adipose tissue; fructose; high-fat diet; leptin; non-esterified fatty acids

    Diagnostic imaging of the diabetic foot: an EANM evidence-based guidance

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    Purpose: Consensus on the choice of the most accurate imaging strategy in diabetic foot infective and non-infective complications is still lacking. This document provides evidence-based recommendations, aiming at defining which imaging modality should be preferred in different clinical settings. Methods: This working group includes 8 nuclear medicine physicians appointed by the European Association of Nuclear Medicine (EANM), 3 radiologists and 3 clinicians (one diabetologist, one podiatrist and one infectious diseases specialist) selected for their expertise in diabetic foot. The latter members formulated some clinical questions that are not completely covered by current guidelines. These questions were converted into statements and addressed through a systematic analysis of available literature by using the PICO (Population/Problem–Intervention/Indicator–Comparator–Outcome) strategy. Each consensus statement was scored for level of evidence and for recommendation grade, according to the Oxford Centre for Evidence-Based Medicine (OCEBM) criteria. Results: Nine clinical questions were formulated by clinicians and used to provide 7 evidence-based recommendations: (1) A patient with a positive probe-to-bone test, positive plain X-rays and elevated ESR should be treated for presumptive osteomyelitis (OM). (2) Advanced imaging with MRI and WBC scintigraphy, or [18F]FDG PET/CT, should be considered when it is needed to better evaluate the location, extent or severity of the infection, in order to plan more tailored treatment. (3) In a patient with suspected OM, positive PTB test but negative plain X-rays, advanced imaging with MRI or WBC scintigraphy + SPECT/CT, or with [18F]FDG PET/CT, is needed to accurately assess the extent of the infection. (4) There are no evidence-based data to definitively prefer one imaging modality over the others for detecting OM or STI in fore- mid- and hind-foot. MRI is generally the first advanced imaging modality to be performed. In case of equivocal results, radiolabelled WBC imaging or [18F]FDG PET/CT should be used to detect OM or STI. (5) MRI is the method of choice for diagnosing or excluding Charcot neuro-osteoarthropathy; [18F]FDG PET/CT can be used as an alternative. (6) If assessing whether a patient with a Charcot foot has a superimposed infection, however, WBC scintigraphy may be more accurate than [18F]FDG PET/CT in differentiating OM from Charcot arthropathy. (7) Whenever possible, microbiological or histological assessment should be performed to confirm the diagnosis. (8) Consider appealing to an additional imaging modality in a patient with persisting clinical suspicion of infection, but negative imaging. Conclusion: These practical recommendations highlight, and should assist clinicians in understanding, the role of imaging in the diagnostic workup of diabetic foot complications
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