1,295 research outputs found

    EVIDENCE-SCIENTIFIC TESTS FOR lNTOXICATION-ADMISSIBILITY

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    It is the purpose of this comment to examine the admissibility and probative value of the tests available for determining the amount of alcohol in the human system

    Fast electrochemical doping due to front instability in organic semiconductors

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    The electrochemical doping transformation in organic semiconductor devices is studied in application to light-emitting cells. It is shown that the device performance can be significantly improved by utilizing new fundamental properties of the doping process. We obtain an instability, which distorts the doping fronts and increases the doping rate considerably. We explain the physical mechanism of the instability, develop theory, provide experimental evidence, and perform numerical simulations. We further show how improved device design can amplify the instability thus leading to a much faster doping process and device kinetics.Comment: 4 pages, 4 figure

    Inter-Intra Molecular Dynamics as an Iterated Function System

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    The dynamics of units (molecules) with slowly relaxing internal states is studied as an iterated function system (IFS) for the situation common in e.g. biological systems where these units are subjected to frequent collisional interactions. It is found that an increase in the collision frequency leads to successive discrete states that can be analyzed as partial steps to form a Cantor set. By considering the interactions among the units, a self-consistent IFS is derived, which leads to the formation and stabilization of multiple such discrete states. The relevance of the results to dynamical multiple states in biomolecules in crowded conditions is discussed.Comment: 7 pages, 7 figures. submitted to Europhysics Letter

    Discapacidad visual y orientación urbana. Estudio piloto sobre planos táctiles producidos en Impresión 3D

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    [EN] This article presents a pilot study conducted in Barcelona with blind and visually-impaired people. The aim was to analyze the use and efficacy of tactile maps produced by means of 3D printing. For this purpose, structured interviews were used, along with direct observation, the creation of cognitive maps and tasks with prototypes. The aim has been to examine the instrumental and communicative value of these products in terms of interpreting, memorizing and understanding a certain urban route, comparing this with experience in situ, focusing on the difficulties faced by the visually disabled when visiting new places. Findings show the utility of this type of technique in aiding visually disabled users to memorize routes. As a limitation, this study shows that tactile maps are not wholly efficient since they require verbal support, which makes it hard for them to be used autonomously.[ES] El trabajo aquí expuesto presenta un estudio piloto llevado a cabo en Barcelona con personas invidentes y deficientes visuales. El objetivo del mismo ha sido analizar el uso y la eficacia de los planos táctiles producidos mediante Impresión en 3D. Para ello se han empleado entrevistas estructuradas, observación directa, realización de mapas cognitivos y tareas con prototipos. De esta manera se ha tratado deprofundizar en elvalor instrumentalycomunicativo de estosproductos a la hora de interpretar, memorizar y comprender un determinado recorrido urbano, contrastándolo con la experiencia in situ, atendiendo a las dificultades que este tipo de personas presentan a la hora de visitar nuevos lugares. Los resultados obtenidos demuestran la utilidad de este tipo de técnica para memorizar recorridos por parte de este tipo de usuarios. Como limitación, el estudio muestra que los planos táctiles no resultan del todo eficientes pues precisan de apoyo verbal, hecho que dificulta su uso autónomo.This research has been funded by the Spanish Ministry of Science and Innovation as part of the National Fundamental Research Programme, the National R&D/Innovation Plan, within the project “Study and design of orientation elements, communication support and other accessories to improve accessibility in different spheres of interpreting natural and/or built heritage’ (DPI2008-03981/DPI). The authors would also like particularly to thank the following for their selfless collaboration: the ONCE Educational Resources Centre in Barcelona and staff from the Disabled Service Programme at the Universitat Politècnica de Catalunya. The study was also carried out as part of the Research Staff Mobility Programme at Universitat Jaume I (E-2010-32) funded by the Caixa Castelló-Bancaixa Foundation.Gual Ortí, J.; Puyuelo Cazorla, M.; Lloveras, J.; Merino Sanjuan, L. (2012). Visual Impairment and urban orientation. Pilot study with tactile maps produced through 3D Printing. Psyecology. 3(2):239-250. https://doi.org/10.1174/217119712800337747S2392503

    Augmented Reality for People with Visual Impairments: Designing and Creating Audio-Tactile Content from Existing Objects

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    ISBN: 978-3-319-94273-5International audienceTactile maps and diagrams are widely used as accessible graphical media for people with visual impairments, in particular in the context of education. They can be made interactive by augmenting them with audio feedback. It is however complicated to create audio-tactile graphics that have rich and realistic tactile textures. To overcome these limitations, we propose a new augmented reality approach allowing novices to easily and quickly augment real objects with audio feedback. In our user study, six teachers created their own audio-augmentation of objects, such as a botanical atlas, within 30 minutes or less. Teachers found the tool easy to use and were confident about re-using it. The resulting augmented objects allow two modes: exploration mode provides feedback on demand about an element, while quiz mode provides questions and answers. We evaluated the resulting audio-tactile material with five visually impaired children. Participants found the resulting interactive graphics exciting to use independently of their mental imagery skills

    Synchronization of active mechanical oscillators by an inertial load

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    Motivated by the operation of myogenic (self-oscillatory) insect flight muscle, we study a model consisting of a large number of identical oscillatory contractile elements joined in a chain, whose end is attached to a damped mass-spring oscillator. When the inertial load is small, the serial coupling favors an antisynchronous state in which the extension of one oscillator is compensated by the contraction of another, in order to preserve the total length. However, a sufficiently massive load can sychronize the oscillators and can even induce oscillation in situations where isolated elements would be stable. The system has a complex phase diagram displaying quiescent, synchronous and antisynchrononous phases, as well as an unsual asynchronous phase in which the total length of the chain oscillates at a different frequency from the individual active elements.Comment: 5 pages, 4 figures, To appear in Phys. Rev. Let

    Survival and residence times in disordered chains with bias

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    We present a unified framework for first-passage time and residence time of random walks in finite one-dimensional disordered biased systems. The derivation is based on exact expansion of the backward master equation in cumulants. The dependence on initial condition, system size, and bias strength is explicitly studied for models with weak and strong disorder. Application to thermally activated processes is also developed.Comment: 13 pages with 2 figures, RevTeX4; v2:minor grammatical changes, typos correcte

    Biochemistry and functional aspects of human glandular kallikreins

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    Human urinary kallikrein was purified by gel filtration on Sephacryl S-200 and affinity chromatography on aprotinin-Sepharose, followed by ion exchange chromatography on DEAE-Sepharose. In dodecylsulfate gel electrophoresis two protein bands with molecular weights of 41,000 and 34,000 were separated. The amino acid composition and the carbohydrate content of the kallikrein preparation were determined; isoleucine was identified as the only aminoterminal amino acid. The bimolecular velocity constant for the inhibition by diisopropyl fluorophosphate was determined as 9±2 l mol–1 min–1. The hydrolysis of a number of substrates was investigated and AcPheArgOEt was found to be the most sensitive substrate for human urinary kallikrein. Using this substrate an assay method for kallikrein in human urine was developed. It was shown by radioimmunoassay that pig pancreatic kallikrein can be absorbed in the rat intestinal tract. Furthermore, in dogs the renal excretion of glandular kallikrein from blood was demonstrated by radioimmunological methods

    The fitness of African malaria vectors in the presence and limitation of host behaviour

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    <p>Background Host responses are important sources of selection upon the host species range of ectoparasites and phytophagous insects. However little is known about the role of host responses in defining the host species range of malaria vectors. This study aimed to estimate the relative importance of host behaviour to the feeding success and fitness of African malaria vectors, and assess its ability to predict their known host species preferences in nature.</p> <p>Methods Paired evaluations of the feeding success and fitness of African vectors Anopheles arabiensis and Anopheles gambiae s.s in the presence and limitation of host behaviour were conducted in a semi-field system (SFS) at Ifakara Health Institute, Tanzania. In one set of trials, mosquitoes were released within the SFS and allowed to forage overnight on a host that was free to exhibit natural behaviour in response to insect biting. In the other, mosquitoes were allowed to feed directly on from the skin surface of immobile hosts. The feeding success and subsequent fitness of vectors under these conditions were investigated on 6 host types (humans, calves, chickens, cows, dogs and goats) to assess whether physical movements of preferred host species (cattle for An. arabiensis, humans for An. gambiae s.s.) were less effective at preventing mosquito bites than those of common alternatives.</p> <p>Results Anopheles arabiensis generally had greater feeding success when applied directly to host skin than when foraging on unrestricted hosts (in five of six host species). However, An. gambiae s.s obtained blood meals from free and restrained hosts with similar success from most host types (four out of six). Overall, the blood meal size, oviposition rate, fecundity and post-feeding survival of mosquito vectors were significantly higher after feeding on hosts free to exhibit behaviour, than those who were immobilized during feeding trials.</p> <p>Conclusions Allowing hosts to move freely during exposure to mosquitoes was associated with moderate reductions in mosquito feeding success, but no detrimental impact to the subsequent fitness of mosquitoes that were able to feed upon them. This suggests that physical defensive behaviours exhibited by common host species including humans do not impose substantial fitness costs on African malaria vectors.</p&gt

    Assessment of the dining environment on and near the campuses of fifteen post-secondary institutions

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    Objective: The present study evaluated the restaurant and dining venues on and near post-secondary campuses varying in institution size. Design: The Nutrition Environment Measures Survey for Restaurants (NEMS-R) was modified to evaluate restaurants as fast food, sit down and fast casual; and campus dining venues as dining halls, student unions and snack bar/cafe ́s. ANOVA with post hoc Tukey’s B and T tests were used to distinguish differences between dining venues and associated institutions by size. Setting: The study was conducted at fifteen US post-secondary institutions, 2009–2011. Subjects: Data presented are from a sample of 175 restaurants and sixty-eight on-campus dining venues. Results: There were minimal differences in dining halls by institution size, although medium-sized institutions as compared with small-sized institutions offered significantly more healthful side dish/salad bar items. Dining halls scored significantly higher than student unions or snack bar/cafe ́s on healthful entre ́es, side dish/salad bar and beverages offerings, but they also had the most barriers to healthful dietary habits (i.e. all-you-can-eat). No differences were found by restaurant type for NEMS-R scores for total restaurant dining environment or healthful entre ́es and barriers. Snack bars had more healthful side dishes (P 5 0?002) and fast-food restaurants had the highest level of facilitators (i.e. nutrition information; P 5 0?002). Conclusions: Based on this evaluation in fifteen institutions, the full campus dining environment provides limited support for healthy eating and obesity prevention. The quality of campus dining environments can be improved via healthful offerings, providing nutrition information and other supports to facilitate healthy eating and prevent unwanted weight gain
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