893 resultados para Hearning and visual problem
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[Excerpt] Synchronization of periodic movements like side-by-side walking [7] is frequently modeled by coupled oscillators [5] and the coupling strength is defined quantitatively [3]. In contrast, in most studies on sensorimotor synchronization (SMS), simple movements like finger taps are synchronized with simple stimuli like metronomes [4]. While the latter paradigm simplifies matters and allows for the assessment of the relative weights of sensory modalities through systematic variation of the stimuli [1], it might lack ecological validity. Conversely, using more complex movements and stimuli might complicate the specification of mechanisms underlying coupling. We merged the positive aspects of both approaches to study the contribution of auditory and visual information on synchronization during side-by-side walking. As stimuli, we used Point Light Walkers (PLWs) and auralized steps sound; both were constructed from previously captured walking individuals [2][6]. PLWs were retro-projected on a screen and matched according to gender, hip height, and velocity. The participant walked for 7.20m side by side with 1) a PLW, 2) steps sound, or 3) both displayed in temporal congruence. Instruction to participants was to synchronize with the available stimuli. [...]
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Purpose: To evaluate how soft lens power affects rigid gas-permeable (RGP) lens power and visual acuity (VA) in piggyback fittings for keratoconus. Methods: Sixteen keratoconus subjects (30 eyes) were included in the study. Piggyback contact lens fittings combining Senofilcon-A soft lenses of −6.00, −3.00, +3.00 and +6.00 D with Rose K2 RGP contact lenses were performed. Corneal topography was taken on the naked eye and over each soft contact lens before fitting RGP lenses. Mean central keratometry, over-refraction, RGP back optic zone radius (BOZR) and estimated final power as well as VA were recorded and analyzed. Results: In comparison to the naked eye, the mean central keratometry flattened with both negative lens powers (p < 0.05 in all cases), did not change with the +3.00 soft lens power (p = 1.0); and steepened with the +6.00 soft lens power (p = 0.02). Rigid gas-permeable over-refraction did not change significantly between different soft lens powers (all p > 0.05). RGP’s BOZR decreased significantly with both positive in comparison with both negative soft lens powers (all p < 0.001), but no significant differences were found among negative- or positive-powers separately (both p > 0.05). Estimated RGP’s final power increased significantly with positive in comparison with negative lens powers (all p < 0.001), but no significant differences were found among negative or positive lens powers separately (both p > 0.05). Visual acuity did not change significantly between the different soft lens powers assessed (all p > 0.05). Conclusion: The use of negative-powered soft lenses in piggyback fitting reduces RGP lens power without impacting VA in keratoconus subjects.
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Dissertação de mestrado em Engenharia Industrial
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Dissertação de mestrado integrado em Engenharia e Gestão Industrial
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Objective To determine whether the use of 3-dimensional (3D) imaging translates into a better surgical performance of naïve urologic laparoscopic surgeons during pyeloplasty (PY) and partial nephrectomy (PN) procedures. Materials and Methods Eighteen surgeons without any previous laparoscopic experience were randomly assigned to perform PY and PN in a porcine model using initially 2-dimensional (2D) and 3D laparoscopy. A surgical performance score was rated by an "expert" tutor through a modified 5-item global rating scale contemplating operative field view, bimanual dexterity, efficiency, tissue handling, and autonomy. Overall surgical time, complications, subjective perception of participating surgeons, and inconveniences related to the 3D vision were recorded. Results No difference in terms if operative time was found between 2D or 3D laparoscopy for both the PY (P =.51) and the PN (P =.28) procedures. A better rate in terms of surgical performance score was noted by the tutors when the study participants were using 3D vs 2D, for both PY (3.6 [0.8] vs 3.0 [0.4]; P =.034) and PN (3.6 [0.51] vs 3.15 [0.63]; P =.001). No complications occurred in any of the procedures. Most (77.2%) of the participating na??ve laparoscopic surgeons had the perception that 3D laparoscopy was overall easier than 2D. Headache (18.1%), nausea (18.1%), and visual disturbance (18.1%) were the most common issues reported by the surgeons during 3D procedures. Conclusion Despite the absence of translation in a shorter operative time, the use of 3D technology seems to facilitate the surgical performance of naive surgeons during laparoscopic kidney procedures on a porcine model.
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O presente trabalho de investigação avalia a situação atual relativa à adoção do disposto na IAS 38 e suas consequências no reconhecimento, mensuração e divulgação obrigatória, e à divulgação voluntária, interna e externa, dos intangíveis nas empresas brasileiras cotadas na BM&FBOVESPA. Adotando a perspectiva positivista e uma abordagem quantitativa, foi utilizado o inquérito por questionário como método de recolha de dados. O questionário foi elaborado de raiz, suportado pelo arcabouço teórico. Os resultados são interpretados à luz dos argumentos da teoria dos stakeholders e da teoria institucional, que revelaram um bom potencial explicativo para o fenômeno em análise. Com a adoção das IAS/IFRS para elaboração dos balanços consolidados de empresas cotadas e não cotadas, o Brasil passa a utilizar a IAS 38, para o registro das operações envolvendo os ativos intangíveis, obrigatoriamente no exercício de 2010. A adoção deste normativo se deu essencialmente por pressões legais. No entanto, as empresas que adotaram a IAS 38 de forma voluntária validaram as razões apresentadas na literatura. Constatou-se que existe concordância quanto à nova forma de contabilização dos intangíveis prevista, sendo o grau de satisfação relativamente ao tratamento contábil dos ativos intangíveis de acordo com o novo modelo contábil adotado no Brasil (IAS 38 e CPC 04) elevado. Como principais dificuldades no reconhecimento contábil dos ativos intangíveis segundo o normativo em vigor, foram confirmados os problemas evidenciados na literatura, tais como incerteza quanto aos benefícios econômicos futuros e falta de medida com confiabilidade suficiente para o registro das transações. As empresas brasileiras acreditam ser importante que haja uma expansão da divulgação sobre intangíveis, no entanto a divulgação interna e externa está ainda em fase embrionária, não sendo uma prática generalizada. Contudo, os objetivos apresentados na literatura para a divulgação interna e externa de informações sobre intangíveis encontram suporte empírico no estudo desenvolvido. No que diz respeito aos stakeholders, conclui-se que as empresas brasileiras têm grande preocupação em atendê-los quando se trata de divulgação voluntária sobre intangíveis, entendendo que todos eles poderão beneficiar com estas informações.
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Tese de Doutoramento em Estudos da Criança - Especialidade Comunicação Visual e Expressão Plástica
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Relatório de estágio de mestrado em Ensino do 1.º e 2.º Ciclo do Ensino Básico
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Within the last few years, several reports have revealed that cell transplantation can be an effective way to replace lost neurons in the central nervous system (CNS) of patients affected with neurodegenerative diseases. Concerning the retina, the concept that newborn photoreceptors can integrate the retina and restore some visual functions was univocally demonstrated recently in the mouse eye (MacLaren et al. 2006) and remains to be achieved in human. These results pave the way to a standard approach in regenerative medicine aiming to replace lost photoreceptors. With the discovery of stem cells a great hope has appeared towards elaborating protocols to generate adequate cells to restore visual function in different retinal degeneration processes. Retinal stem cells (RSCs) are good candidates to repair the retina and are present throughout the retina development, including adulthood. However, neonatal mouse RSCs derived from the radial glia population have a different potential to proliferate and differentiate in comparison to adult RSCs. Moreover, we observed that adult mouse RSCs, depending on the culture conditions, have a marked tendency to transform, whereas neonatal RSCs show subtle chromosome abnormalities only after extensive expansion. These characteristics should help to identify the optimal cell source and culture conditions for cell transplantation studies. These results will be discussed in light of other studies using RSCs as well as embryonic stem cells. Another important factor to consider is the host environment, which plays a crucial role for cell integration and which was poorly studied in the normal and the diseased retina. Nonetheless, important results were recently generated to reconsider cell transplantation strategy. Perspectives to enhance cell integration by manipulating the environment will also be presented.
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Els refugis de muntanya es troben situats en zones d’interès natural, sovint protegides, com és el cas dels deu refugis del Parc Natural de l’Alt Pirineu. En els darrers anys s’ha observat una diversificació en l’ús dels refugis de muntanya, originalment construïts per donar aixopluc als excursionistes, degut a l’augment del turisme i la popularització dels esports de neu i d’aventura. Els refugis estudiats es poden agrupar en tres tipologies diferents: refugis guardats, refugis alberg i refugis associats a pistes d’esquí, cadascuna de les quals presenta una realitat i unes problemàtiques diferents. Mitjançant una metodologia pròpia, es pretén fer una anàlisi i una diagnosi ambiental de cada cas d’estudi i de les diferents tipologies a partir dels vectors que poden generar un major impacte en l’entorn immediat dels refugis: aspectes socioeconòmics, arquitectura, paisatge i impacte visual, energia elèctrica i tèrmica, aigua potable i residual i residus sòlids. La diagnosi permet identificar els aspectes de cada refugi i tipologia que requereixen propostes de millora. Finalment es fa una proposta d’ecoetiqueta de serveis per a refugis guardats basada en el Distintiu de Garantia de Qualitat Ambiental de la Generalitat de Catalunya, ja aplicat amb èxit a altres establiments de serveis.
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The aim of the present study was to assess the influence of local environmental olfactory cues on place learning in rats. We developed a new experimental design allowing the comparison of the use of local olfactory and visual cues in spatial and discrimination learning. We compared the effect of both types of cues on the discrimination of a single food source in an open-field arena. The goal was either in a fixed or in a variable location, and could be indicated by local olfactory and/or visual cues. The local cues enhanced the discrimination of the goal dish, whether it was in a fixed or in a variable location. However, we did not observe any overshadowing of the spatial information by the local olfactory or visual cue. Rats relied primarily on distant visuospatial information to locate the goal, neglecting local information when it was in conflict with the spatial information.
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Questions: A multiple plot design was developed for permanent vegetation plots. How reliable are the different methods used in this design and which changes can we measure? Location: Alpine meadows (2430 m a.s.l.) in the Swiss Alps. Methods: Four inventories were obtained from 40 m(2) plots: four subplots (0.4 m(2)) with a list of species, two 10m transects with the point method (50 points on each), one subplot (4 m2) with a list of species and visual cover estimates as a percentage and the complete plot (40 m(2)) with a list of species and visual estimates in classes. This design was tested by five to seven experienced botanists in three plots. Results: Whatever the sampling size, only 45-63% of the species were seen by all the observers. However, the majority of the overlooked species had cover < 0.1%. Pairs of observers overlooked 10-20% less species than single observers. The point method was the best method for cover estimate, but it took much longer than visual cover estimates, and 100 points allowed for the monitoring of only a very limited number of species. The visual estimate as a percentage was more precise than classes. Working in pairs did not improve the estimates, but one botanist repeating the survey is more reliable than a succession of different observers. Conclusion: Lists of species are insufficient for monitoring. It is necessary to add cover estimates to allow for subsequent interpretations in spite of the overlooked species. The choice of the method depends on the available resources: the point method is time consuming but gives precise data for a limited number of species, while visual estimates are quick but allow for recording only large changes in cover. Constant pairs of observers improve the reliability of the records.
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PURPOSE: We determined the effect of entrance pupil size on retinal illumination. The influence of unilateral miosis on the magnitude of the pupil light reflex was studied to ascertain how a clinically significant anisocoria influences the relative afferent pupil defect (RAPD). METHODS: Miosis was induced by topical 1% pilocarpine in the right eye of 14 healthy subjects with normal eyes. The interocular difference in retinal illumination was assessed by computerized pupillometry from the stimulus response curve of the right and left eyes. The main outcome measure was the RAPD, determined by computerized pupillography, at baseline and after pilocarpine-induced anisocoria. RESULTS: Induced anisocoria produced a significant change in RAPD from baseline (mean = 1.60 dB in the miotic eye, P = 0.007). However, anisocoria correlated with RAPD only in subjects with darkly pigmented irides (Pearson correlation coefficient 0.793, P = 0.05). CONCLUSIONS: In darkly pigmented eyes, entrance pupil size significantly influenced the retinal illumination. However, retinal illumination of lightly pigmented eyes is relatively independent of entrance pupil size, presumably due to extrapupillary transmission of light through the iris and sclera. This has important implications in understanding the potential influence of anisocoria on the RAPD and also greater susceptibility of lightly pigmented eyes to light toxicity.
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Leg ulcers are a major health and economic problem especially in elderly. More than 70% are associated with venous disease. Compressive therapy is the most effective treatment but bandages are often poorly tolerated and well trained nurses are required to apply them effectively. In recent years, the VAC system (vacuum assisted closure) has profoundly changed the wound healing approach. The objective is now to regenerate the tissues and not to replace them with skin grafts which give uncertain results. The other important challenge is to prevent recurrences. New pharmacologic treatments acting on microcirculation and hemostasis would probably appear in the near future opening new therapeutic perspectives.
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BACKGROUND: Iron deficiency is a common and undertreated problem in inflammatory bowel disease (IBD). AIM: To develop an online tool to support treatment choice at the patient-specific level. METHODS: Using the RAND/UCLA Appropriateness Method (RUAM), a European expert panel assessed the appropriateness of treatment regimens for a variety of clinical scenarios in patients with non-anaemic iron deficiency (NAID) and iron deficiency anaemia (IDA). Treatment options included adjustment of IBD medication only, oral iron supplementation, high-/low-dose intravenous (IV) regimens, IV iron plus erythropoietin-stimulating agent (ESA), and blood transfusion. The panel process consisted of two individual rating rounds (1148 treatment indications; 9-point scale) and three plenary discussion meetings. RESULTS: The panel reached agreement on 71% of treatment indications. 'No treatment' was never considered appropriate, and repeat treatment after previous failure was generally discouraged. For 98% of scenarios, at least one treatment was appropriate. Adjustment of IBD medication was deemed appropriate in all patients with active disease. Use of oral iron was mainly considered an option in NAID and mildly anaemic patients without disease activity. IV regimens were often judged appropriate, with high-dose IV iron being the preferred option in 77% of IDA scenarios. Blood transfusion and IV+ESA were indicated in exceptional cases only. CONCLUSIONS: The RUAM revealed high agreement amongst experts on the management of iron deficiency in patients with IBD. High-dose IV iron was more often considered appropriate than other options. To facilitate dissemination of the recommendations, panel outcomes were embedded in an online tool, accessible via http://ferroscope.com/.