936 resultados para multilayered objects
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Introduction: Bruxism is characterized by repeated tooth grinding or clenching. The condition can occur in all age ranges and in both genders, being related or not to other oral habits. Objective: The objective of the present study was to investigate the occurrence of bruxism in children with nasal obstruction and to determine its association with other factors. Methods: Sixty children with nasal obstruction seen at the Otorhinolaryngology Outpatient Clinic of the University Hospital. of Ribeirao Preto participated in the study. The data were obtained using a pre-established questionnaire applied to the person responsible and by orofacial evaluation of the patient. The participants were divided into two groups: group with bruxism (GB) as reported by the relatives and with the presence of tooth wear detected by clinical evaluation, and group without bruxism (GWB), consisting of children with none of the two symptoms of bruxism mentioned above. Results: The presence of bruxism exceeded its absence in the sample studied (65.22%). There was no significant difference (P < 0.05) between groups regarding gender, phase of dentition, presence of hearing diseases, degree of malocclusion, or child behavior. Conclusion: Bruxism and deleterious oral habits such as biting behavior (objects, tips and nails) were significantly present, together with the absence of suction habits, in the children with nasal obstruction. (c) 2007 Elsevier Iretand Ltd. All. rights reserved.
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The nervous system of temnocephalid flatworms consists of the brain and three pairs of longitudinal connectives extending into the trunk and tail. The connectives are crosslinked by an invariant number of regularly spaced commissures. Branches of the connectives innervate the tentacles of the head and the sucker organ in the tail. A set of nerve rings encircling the pharynx and connected to the brain and connectives constitute the pharyngeal nervous system. The nervous system is formed during early embryogenesis when the embryo represents a multilayered mesenchymal mass of cells. Gastrulation and the formation of separate epithelial germ layers that characterize most other animal groups are absent. The brain arises as a bilaterally symmetric condensation of postmitotic cells in the deep layers of the anterior region of the embryonic mesenchyme. The pattern of axon outgrowth, visualized by labeling with anti-acetylated tubulin (acTub) antibody, shows marked differences from the pattern observed in other flatworm taxa. in regard to the number of neurons that express the acTub epitope. Acetylated tubulin is only expressed in neurons that form long axon tracts. In other flatworm species, such as the typhloplanoid Mesostoma and the polyclad Imogine, which were investigated by us with the acTub antibody (Hartenstein and Ehlers [2000] Dev. Genes Evol. 210:399-415; Younossi-Hartenstein and Hartenstein [2000] Dev. Genes Evol. 210:383-398), only a small number of pioneer neurons become acTub positive during the embryonic period. By contrast, in temnocephalids, most, if not all, neurons express acTub and form long, large-diameter axons. Initially, the brain commissure, pharyngeal nerve ring, and the connectives are laid down. Commissural tracts and tentacle nerves branching off the connectives appear later. We speculate that the precocious differentiation of the nervous system may be related to the fact that temnocephalids move by muscle action, and possess a massive and complex muscular system when they hatch. In addition, they have muscular specializations such as the anterior tentacles and the posterior sucker that are used as soon as they hatch. By contrast, juveniles of Mesostoma and larvae of polyclads move predominantly by ciliary action that may not require a complex neural circuitry for coordination. (C) 2001 Wiley-Liss, Inc.
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The extrastriate cortex near the dorsal midline has been described as part of an 'express' pathway that provides visual input to the premotor cortex. This pathway is considered important for the integration of sensory information about the visual field periphery and the skeletomotor system, especially in relation to the control of arm movements. However, a better understanding of the functional contributions of different parts of this complex has been hampered by the lack of data on the extent and boundaries of its constituent visual areas. Recent studies in macaques have provided the first detailed view of the topographical organization of this region in Old World monkeys. Despite differences in nomenclature, a comparison of the visuotopic organization, myeloarchitecture and connections of the relevant visual areas with those previously studied in New World monkeys reveals a remarkable degree of similarity and helps to clarify the subdivision of function between different areas of the dorsomedial complex. A caudal visual area, named DM or V6, appears to be important for the detection of coherent patterns of movement across wide regions of the visual field, such as those induced during self-motion. A rostral area, named M or V6A, is more directly involved with visuomotor integration. This area receives projections both from DM/V6 and from a separate motion analysis channel, centred on the middle temporal visual area (or V5), which detects the movement of objects in extrapersonal space. These results support the suggestion, made earlier on the basis of more fragmentary evidence, that the areas rostral to the second visual area in dorsal cortex are homologous in all simian primates. Moreover, they emphasize the importance of determining the anatomical organization of the cortex as a prerequisite for elucidating the function of different cortical areas.
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Numerous everyday tasks require the nervous system to program a prehensile movement towards a target object positioned in a cluttered environment. Adult humans are extremely proficient in avoiding contact with any non-target objects (obstacles) whilst carrying out such movements. A number of recent studies have highlighted the importance of considering the control of reach-to-grasp (prehension) movements in the presence of such obstacles. The current study was constructed with the aim of beginning the task of studying the relative impact on prehension as the position of obstacles is varied within the workspace. The experimental design ensured that the obstacles were positioned within the workspace in locations where they did not interfere physically with the path taken by the hand when no obstacle was present. In all positions, the presence of an obstacle caused the hand to slow down and the maximum grip aperture to decrease. Nonetheless, the effect of the obstacle varied according to its position within the workspace. In the situation where an obstacle was located a small distance to the right of a target object, the obstacle showed a large effect on maximum grip aperture but a relatively small effect on movement time. In contrast, an object positioned in front and to the right of a target object had a large effect on movement speed but a relatively small effect on maximum grip aperture. It was found that the presence of two obstacles caused the system to decrease further the movement speed and maximum grip aperture. The position of the two obstacles dictated the extent to which their presence affected the movement parameters. These results show that the antic ipated likelihood of a collision with potential obstacles affects the planning of movement duration and maximum grip aperture in prehension.
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The influence of temporal association on the representation and recognition of objects was investigated. Observers were shown sequences of novel faces in which the identity of the face changed as the head rotated. As a result, observers showed a tendency to treat the views as if they were of the same person. Additional experiments revealed that this was only true if the training sequences depicted head rotations rather than jumbled views: in other words, the sequence had to be spatially as well as temporally smooth. Results suggest that we are continuously associating views of objects to support later recognition, and that we do so not only on the basis of the physical similarity, but also the correlated appearance in time of the objects.
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Most Internet search engines are keyword-based. They are not efficient for the queries where geographical location is important, such as finding hotels within an area or close to a place of interest. A natural interface for spatial searching is a map, which can be used not only to display locations of search results but also to assist forming search conditions. A map-based search engine requires a well-designed visual interface that is intuitive to use yet flexible and expressive enough to support various types of spatial queries as well as aspatial queries. Similar to hyperlinks for text and images in an HTML page, spatial objects in a map should support hyperlinks. Such an interface needs to be scalable with the size of the geographical regions and the number of websites it covers. In spite of handling typically a very large amount of spatial data, a map-based search interface should meet the expectation of fast response time for interactive applications. In this paper we discuss general requirements and the design for a new map-based web search interface, focusing on integration with the WWW and visual spatial query interface. A number of current and future research issues are discussed, and a prototype for the University of Queensland is presented. (C) 2001 Published by Elsevier Science Ltd.
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Under certain circumstances, external stimuli will elicit an involuntary shift of spatial attention, referred to as attentional capture. According to the contingent involuntary orienting account (Folk, Remington, & Johnston, 1992), capture is conditioned by top-down factors that set attention to respond involuntarily to stimulus properties relevant to one's behavioral goals. Evidence for this comes from spatial cuing studies showing that a spatial cuing effect is observed only when cues have goal-relevant properties. Here, we examine alternative, decision-level explanations of the spatial cuing effect that attribute evidence of capture to postpresentation delays in the voluntary allocation of attention, rather than to on-line involuntary shifts in direct response to the cue. In three spatial cuing experiments, delayed-allocation accounts were tested by examining whether items at the cued location were preferentially processed. The experiments provide evidence that costs and benefits in spatial cuing experiments do reflect the on-line capture of attention. The implications of these results for models of attentional control are discussed.
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The human nervous system constructs a Euclidean representation of near (personal) space by combining multiple sources of information (cues). We investigated the cues used for the representation of personal space in a patient with visual form agnosia (DF). Our results indicated that DF relies predominantly on binocular vergence information when determining the distance of a target despite the presence of other (retinal) cues. Notably, DF was able to construct an Euclidean representation of personal space from vergence alone. This finding supports previous assertions that vergence provides the nervous system with veridical information for the construction of personal space. The results from the current study, together with those of others, suggest that: (i) the ventral stream is responsible for extracting depth and distance information from monocular retinal cues (i.e. from shading, texture, perspective) and (ii) the dorsal stream has access to binocular information (from horizontal image disparities and vergence). These results also indicate that DF was not able to use size information to gauge target distance, suggesting that intact temporal cortex is necessary for learned size to influence distance processing. Our findings further suggest that in neurologically intact humans, object information extracted in the ventral pathway is combined with the products of dorsal stream processing for guiding prehension. Finally, we studied the size-distance paradox in visual form agnosia in order to explore the cognitive use of size information. The results of this experiment were consistent with a previous suggestion that the paradox is a cognitive phenomenon.
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Reaching out to grasp an object (prehension) is a deceptively elegant and skilled behavior. The movement prior to object contact can be described as having two components [1], the movement of the hand to an appropriate location for gripping the object, the transport component, and the opening and closing of the aperture between the fingers as they prepare to grip the target, the grasp component. The grasp component is sensitive to the size of the object, so that a larger grasp aperture is formed for wider objects [1]; the maximum grasp aperture (MGA) is a little wider than the width of the target object and occurs later in the movement for larger objects [1, 2]. We present a simple model that can account for the temporal relationship between the transport and grasp components, We report the results of an experiment providing empirical support for our rule of thumb. The model provides a simple, but plausible, account of a neural control strategy that has been the center of debate over the last two decades.
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We present some applications of high-efficiency quantum interrogation (interaction-free measurement) for the creation of entangled states of separate atoms and of separate photons. The quantum interrogation of a quantum object in a superposition of object-in and object-out leaves the object and probe in an entangled state. The probe can then be further entangled with other objects in subsequent quantum interrogations. By then projecting out those cases in which the probe is left in a particular final state, the quantum objects can themselves be left in various entangled states. In this way, we show how to generate two-, three-, and higher-qubit entanglement between atoms and between photons. The effect of finite efficiency for the quantum interrogation is delineated for the various schemes.
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The play of children with autistic spectrum disorder (ASD) is a valuable medium for assessment and intervention, and its analysis has the potential to aid diagnosis. This study investigated spontaneous play behavior and play object preferences for 24 preschool children with ASD in a typical occupational therapy clinical environment. Play behavior was rated and choice of play object noted at 10-second intervals from a 15-minute video recording of unstructured play. Statistical analyses indicated that play behavior was consistent with descriptions in the literature. In addition, the children demonstrated clear preferences for play objects in the form of popular characters (e.g., Thomas the Tank Engine) and those with sensorimotor properties. We propose that the inclusion of preferred play objects in a clinical environment may increase intrinsic motivation to play, and thereby enhance assessment and intervention.
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Indigenous studies (also referred to as Aboriginal and Torres Strait Islander studies) has a double identity in the Australian education system, consisting of the education of Indigenous students and education of all students about Aboriginal and Torres Strait Islander cultures and histories. Through explanations of the history of the inclusion of Aboriginal and Torres Strait Islander musics in Australian music education, this article critiques ways in which these musics have been positioned in relation to a number of agendas. These include definitions of Aboriginal and Torres Strait Islander musics as types of Australian music, as ethnomusicological objects, as examples of postcolonial discourse, and as empowerment for Indigenous students. The site of discussion is the work of the Australian Society for Music Education, as representative of trends in Australian school-based music education, and the Centre for Aboriginal Studies in Music at the University of Adelaide, as an example of a tertiary music program for Indigenous students.
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As questões formuladas no artigo foram disparadas por experiências vividas ao longo dos últimos anos em pesquisas que partem do princípio de que a temática saúde e trabalho, como objeto de investigação científica, tem uma especificidade que não pode ser tomada com posturas de exterritorialidade no que diz respeito à relação do pesquisador e do objeto a ser investigado. As questões dos mundos do trabalho não podem estar baseadas apenas em quadros analíticos construídos a partir de um distanciamento da complexidade engendrada onde o trabalho acontece. Propõe-se uma direção metodológica de pesquisa que articula investigação e intervenção na direção do diálogo, da interlocução entre os diferentes saberes - disciplinares ou não - com o objetivo de potencializar estratégias utilizadas pelos trabalhadores para lidar com a variabilidade das situações de trabalho. Com esse objetivo, traz a contribuição da Clínica da Atividade como importante ferramenta metodológica.
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Este estudo foi elaborado a partir da proposta de fortalecimento das relações comunitárias entre a Universidade Federal do Espírito Santo e as comunidades jongueiras e caxambuzeiras. Destina-se a apresentar a pesquisa realizada em territórios negros sob a inspiração do Jongo e do Caxambu, reconhecidos como Patrimônio Imaterial do Brasil pelo Instituto do Patrimônio Histórico e Artístico Nacional (Iphan). A pesquisa foi desenvolvida no norte do Estado do Espírito Santo e tem como recurso analítico e conceitual estudos sobre etnicidade no campo da educação. Sua proposta é ampliar e constituir-se como base para a implementação da Lei nº. 10.639/2003, considerando a descrição das categorias religiosidade, territorialidade, memórias, cultura negra, cultura popular e tradição, com base nas narrativas dos sujeitos. Relaciona as práticas culturais do jongo e do caxambu como elementos importantes para a reconstrução da história do negro no Sudeste brasileiro. O tema de investigação foi construído sob a inspiração teórica dos estudos culturais referenciados em Stuart Hall (2008), Canclini (1997), Santos (2008, 2009), Certeau (2005) e na produção simbólica das interpretações sociais, das fronteiras étnicas para descrever as diferenças percebidas pelos sujeitos. Trabalhou-se basicamente propondo as múltiplas interpretações a partir do vivido. O estudo reforça a importância das africanidades na formação de professores e a discussão do Patrimônio Imaterial do Jongo como possibilidades de saberes-fazeres no campo do currículo escolar. Os caminhos da pesquisa partem de uma base etnográfica, conjugando a metodologia da história oral temática com a pesquisa participante e a pesquisa ação, interligando as memórias dos sujeitos, suas narrativas e vivências ao fazer pedagógico no cotidiano das comunidades. Ressalta a relação intercultural e territorial que identifica jongueiros e caxambuzeiros. Os resultados da pesquisa descrevem as condições dessas práticas, da visibilidade das políticas culturais, da produção das identidades jongueiras no norte do Estado do Espírito Santo, sob o ponto de vista dos sujeitos elencados.
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Objetivo: Investigar a avaliação de mães de recém-nascidos pré-termo (RNPT) egressos de unidades de terapia intensiva neonatal (UTIN) quanto à interação mãe-bebê e uso de chupeta nos primeiros dois anos. Método: O planejamento do estudo longitudinal foi baseado na Teoria Bioecológica do Desenvolvimento Humano, com foco nos processos proximais (PP), utilizando entrevistas gravadas com 62 mães de RNPT no contexto da UTIN e 33 aos seis, 12, 18 e 24 meses de idade do bebê, considerando Grupo-A (chupeta) e Grupo-B (não usou chupeta). Resultados: A vivência em UTIN foi considerada evento impactante na vida das mães, mas expectativas futuras para a relação mãe-bebê foram positivas. A tentativa de oferta da chupeta foi 96,2% e seu uso aos seis meses foi 50% (n=52), significativamente associado com prematuridade pela relação peso/idade-gestacional (p-valor=0,044), dificuldades para estabelecer aleitamento materno exclusivo (AME) (p=0,012) e primiparidade (p=0,02). Apresentaram relação com menor frequência de chupeta: AME ≥3 meses (p=0,026) e tempo de aleitamento materno ≥6 meses. A chupeta configurou-se como uma das representações sociais sobre objetos de bebê, elaboradas pelas participantes aos 12 meses de idade do bebê. Características de temperamento calmo/tranquilo da mãe foram mais frequentes no Grupo-A e o temperamento nervoso/agitado/irritado no Grupo-B (p-valor=0,041). No Grupo-A predominou o temperamento do bebê calmo/fácil-de-cuidar/independente, enquanto no Grupo-B as características de temperamento agitado/bagunceiro/teimoso/agressivo (p-valor=0,026), associado também à necessidade de várias tentativas de oferta da chupeta (p-valor=0,006). No Grupo-A, o número de pessoas para apoio social foi uma ou duas (77,8%), enquanto no Grupo-B foram três a sete (66,7%), p-valor=0,001. A contribuição da chupeta como auxiliar nos PP foi indiferente para mães que controlavam o hábito, enquanto o uso irrestrito facilitava a resolução do choro, liberando a mãe para outras tarefas, atuando como limitador dos PP. A análise da evolução e complexidade dos PP demonstrou não haver interferência pelo uso da chupeta, tendo sido mais efetivos quando as mães tinham maior escolaridade e nas classes econômicas A e B. Conclusão: Aspectos culturais influenciaram na oferta da chupeta, mas sua aceitação ocorreu principalmente em RNPT pequeno para idade gestacional, diante das dificuldades para AME, menor extensão do apoio social e temperamento do bebê calmo/fácil-de-cuidar/independente, também associado à aceitação mais fácil da chupeta. O uso irrestrito da chupeta demonstrou atuar como limitador dos processos proximais.