1000 resultados para dinâmica temporal
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Introduction: Discrimination of species-specific vocalizations is fundamental for survival and social interactions. Its unique behavioral relevance has encouraged the identification of circumscribed brain regions exhibiting selective responses (Belin et al., 2004), while the role of network dynamics has received less attention. Those studies that have examined the brain dynamics of vocalization discrimination leave unresolved the timing and the inter-relationship between general categorization, attention, and speech-related processes (Levy et al., 2001, 2003; Charest et al., 2009). Given these discrepancies and the presence of several confounding factors, electrical neuroimaging analyses were applied to auditory evoked-potential (AEPs) to acoustically and psychophysically controlled non-verbal human and animal vocalizations. This revealed which region(s) exhibit voice-sensitive responses and in which sequence. Methods: Subjects (N=10) performed a living vs. man-made 'oddball' auditory discrimination task, such that on a given block of trials 'target' stimuli occurred 10% of the time. Stimuli were complex, meaningful sounds of 500ms duration. There were 120 different sound files in total, 60 of which represented sounds of living objects and 60 man-made objects. The stimuli that were the focus of the present investigation were restricted to those of living objects within blocks where no response was required. These stimuli were further sorted between human non-verbal vocalizations and animal vocalizations. They were also controlled in terms of their spectrograms and formant distributions. Continuous 64-channel EEG was acquired through Neuroscan Synamps referenced to the nose, band-pass filtered 0.05-200Hz, and digitized at 1000Hz. Peri-stimulus epochs of continuous EEG (-100ms to 900ms) were visually inspected for artifacts, 40Hz low-passed filtered and baseline corrected using the pre-stimulus period . Averages were computed from each subject separately. AEPs in response to animal and human vocalizations were analyzed with respect to differences of Global Field Power (GFP) and with respect to changes of the voltage configurations at the scalp (reviewed in Murray et al., 2008). The former provides a measure of the strength of the electric field irrespective of topographic differences; the latter identifies changes in spatial configurations of the underlying sources independently of the response strength. In addition, we utilized the local auto-regressive average distributed linear inverse solution (LAURA; Grave de Peralta Menendez et al., 2001) to visualize and statistically contrast the likely underlying sources of effects identified in the preceding analysis steps. Results: We found differential activity in response to human vocalizations over three periods in the post-stimulus interval, and this response was always stronger than that to animal vocalizations. The first differential response (169-219ms) was a consequence of a modulation in strength of a common brain network localized into the right superior temporal sulcus (STS; Brodmann's Area (BA) 22) and extending into the superior temporal gyrus (STG; BA 41). A second difference (291-357ms) also followed from strength modulations of a common network with statistical differences localized to the left inferior precentral and prefrontal gyrus (BA 6/45). These two first strength modulations correlated (Spearman's rho(8)=0.770; p=0.009) indicative of functional coupling between temporally segregated stages of vocalization discrimination. A third difference (389-667ms) followed from strength and topographic modulations and was localized to the left superior frontal gyrus (BA10) although this third difference did not reach our spatial criterion of 12 continuous voxels. Conclusions: We show that voice discrimination unfolds over multiple temporal stages, involving a wide network of brain regions. The initial stages of vocalization discrimination are based on modulations in response strength within a common brain network with no evidence for a voice-selective module. The latency of this effect parallels that of face discrimination (Bentin et al., 2007), supporting the possibility that voice and face processes can mutually inform one another. Putative underlying sources (localized in the right STS; BA 22) are consistent with prior hemodynamic imaging evidence in humans (Belin et al., 2004). Our effect over the 291-357ms post-stimulus period overlaps the 'voice-specific-response' reported by Levy et al. (Levy et al., 2001) and the estimated underlying sources (left BA6/45) were in agreement with previous findings in humans (Fecteau et al., 2005). These results challenge the idea that circumscribed and selective areas subserve con-specific vocalization processing.
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The organophosphate temephos has been the main insecticide used against larvae of the dengue and yellow fever mosquito (Aedes aegypti) in Brazil since the mid-1980s. Reports of resistance date back to 1995; however, no systematic reports of widespread temephos resistance have occurred to date. As resistance investigation is paramount for strategic decision-making by health officials, our objective here was to investigate the spatial and temporal spread of temephos resistance in Ae. aegypti in Brazil for the last 12 years using discriminating temephos concentrations and the bioassay protocols of the World Health Organization. The mortality results obtained were subjected to spatial analysis for distance interpolation using semi-variance models to generate maps that depict the spread of temephos resistance in Brazil since 1999. The problem has been expanding. Since 2002-2003, approximately half the country has exhibited mosquito populations resistant to temephos. The frequency of temephos resistance and, likely, control failures, which start when the insecticide mortality level drops below 80%, has increased even further since 2004. Few parts of Brazil are able to achieve the target 80% efficacy threshold by 2010/2011, resulting in a significant risk of control failure by temephos in most of the country. The widespread resistance to temephos in Brazilian Ae. aegypti populations greatly compromise effective mosquito control efforts using this insecticide and indicates the urgent need to identify alternative insecticides aided by the preventive elimination of potential mosquito breeding sites.
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O objetivo neste estudo é investigar o efeito direto e interativo do período de avaliação sobre a orientação temporal dos gestores (OTG), isto é, o horizonte de tempo entre o momento de alocação de recursos e o momento do impacto financeiro dessa alocação. Tendo por base a literatura contábil e econômica, são examinadas as seguintes hipóteses: um período de avaliação mais de longo prazo afeta positivamente a OTG e o efeito positivo de um período de avaliação mais de longo prazo sobre a OTG é maior no caso de maior importância atribuída a medidas não financeiras do que a medidas financeiras de desempenho. Aplica-se a técnica estatística de mínimos quadrados parciais (PLS) para testar as hipóteses deste estudo, sendo os dados coletados por meio de um levantamento realizado junto a 66 gestores de nível intermediário que atuam em 11 empresas. Os resultados sugerem que o período de avaliação não possui efeitos diretos sobre a OTG; no entanto, quando considerada sua interação com a medida de desempenho, os resultados indicam que o efeito do período de avaliação sobre a OTG depende da importância relativa de medidas financeiras versus não financeiras. A principal implicação desses resultados é que o uso de um período de avaliação de longo prazo em combinação com um peso maior atribuído a medidas não financeiras de desempenho não afeta positivamente a OTG; ao contrário, esse efeito positivo sobre a OTG está presente quando um período de avaliação de curto prazo está associado a menor importância de medidas não financeiras de desempenho.
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Amb aquest projecte es pretén dissenyar un sistema de recàrrega de les bateries delsvehicles elèctrics mentre aquests funcionen, i d’aquesta forma disminuir ladependència d’aquests al nivell de càrrega de la bateria, conferir-los més autonomia itransformar el temps de recàrrega del vehicle en temps útil de conducció. El sistema estarà format per un grup de bobines fixades al paviment i connectades enparal•lel al llarg de la calçada de la via per on el vehicle elèctric circularà, el qual tambéincorporarà, en la part inferior, una bobina en ressonància magnètica amb lesanteriorment anomenades. Les bobines immòbils, que estaran connectades a la xarxaelèctrica, induiran en la bobina fixada al vehicle un corrent elèctric a partir dels circuitsressonants als quals estan connectades. S’estudiarà la configuració més òptimad’aquest sistema per tal de subministrar la potència necessària per carregar la bateria,tenint en compte la despesa energètica extra derivada del fet de realitzar-ho enmoviment
Aspectos históricos e organizacionais da remoção aeromédica: a dinâmica da assistência de enfermagem
Resumo:
A dinâmica da assistência de enfermagem na Remoção Aeromédica (RAM), baseia-se no planejamento do Serviço de Remoção Aeromédica (SRA), que abrange a estrutura organizacional do serviço, fluxograma da solicitação da RAM e comunicação, planejamento físico da aeronave e a dinâmica da assistência ao paciente aerorremovido. O estudo apresenta uma retrospectiva histórica da RAM e a sistematização da assistência de enfermagem, utilizando uma proposta de relatório de enfermagem a ser usado durante a remoção do paciente.
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Este artigo resgata, descreve e remete a uma reflexão sobre nossa experiência com o ensino de dinâmica de grupos para graduandos de enfermagem, iniciada em 1992. Focaliza a questão da enfermagem e o trabalho com grupos; a estrutura, conteúdo e desenvolvimento da disciplina.
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Este estudo discute o método funcional na enfermagem, abordado através de uma dinâmica de grupo desenvolvida com mestrandos da EERP-USP, sendo divididos em três grupos. Após a dinâmica, responderam um questionário com 04 perguntas. As respostas do grupo I mostraram desvantagens da modalidade funcional que interferem no trabalho como: relações impessoais, fragmentação de tarefas e centralização das decisões, gerando insatisfação no trabalhador. Os grupos II e III apontaram algumas vantagens quando o trabalho é baseado em equipe, das quais destacamos a troca de experiências, o planejamento participativo e as decisões compartilhadas, sendo estes, fatores que levam à satisfação no trabalho.
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Utilizando uma metodologia qualitativa (entrevistas abertas, desenho-estória e análise temática) identificamos e analisamos 4 categorias (descompasso temporal, culpa, conflitos e perdas) presentes no discurso de mães (e uma irmã) de pacientes psiquiátricos do Núcleo de Atenção Psicossocial (NAPS) de Ribeirão Preto/SP, e avaliamos sua importância conforme o objetivo de se entender a dinâmica da relação entre serviço de saúde mental, paciente psiquiátrico e sua família.
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Este artigo apresenta concepções pedagógicas e aspectos sobre a legislação da educação a distância, assim como tece considerações sobre tecnologias educacionais e relata a experiência de utilização de ambiente on-line de aprendizagem na graduação de Enfermagem. Foi oferecido um curso via Internet, no ambiente WebCT. O tema do curso foi Terapia Intravenosa (TIV). Inscreveram-se 49 alunos, destes, 25 concluíram 50% das atividades previstas. A utilização da Internet pode motivar o aprendiz e facilitar a inclusão digital do aluno de Enfermagem. Assim, a Internet pode ser vista como uma ferramenta auxiliar útil que possibilita uma ruptura espaço/temporal, em que o tempo e o espaço são estabelecidos de acordo com as necessidades, os interesses e a disponibilidade dos discentes.
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In this study we investigated the effect of medial temporal lobe epilepsy (MTLE) on the global characteristics of brain connectivity estimated by topological measures. We used DSI (Diffusion Spectrum Imaging) to construct a connectivity matrix where the nodes represents the anatomical ROIs and the edges are the connections between any pair of ROIs weighted by the mean GFA/FA values. A significant difference was found between the patient group vs control group in characteristic path length, clustering coefficient and small-worldness. This suggests that the MTLE network is less efficient compared to the network of the control group.
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The central question addressed in this paper is to what extent the influence of social origin on life chances has changed over time for both men and women. In order to capture this change, intergenerational social mobility of eight different birth-cohorts, covering most of the entire twentieth century, is analysed using a unique collection of twelve Swiss national population sample surveys. The main results show that social mobility has remained constant across cohorts born in 1912 and those born in 1974. This suggests that unlike some other industrialised countries, inequality based on social origin is persistent in Switzerland.
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Aim The spotted knapweed (Centaurea stoebe), a plant native to south-east and central Europe, is highly invasive in North America. We investigated the spatio-temporal climatic niche dynamics of the spotted knapweed in North America along two putative eastern and western invasion routes. We then considered the patterns observed in the light of historical, ecological and evolutionary factors. Location Europe and North America. Methods The niche characteristics of the east and west invasive populations of spotted knapweed in North America were determined from documented occurrences over 120 consecutive years (1890-2010). The 2.5 and 97.5 percentiles of values along temperature and precipitation gradients, as given by the two first axes of a principal component axis (PCA), were then calculated. We additionally measured the climatic dissimilarity between invaded and native niches using a multivariate environmental similarity surface (MESS) analysis. Results Along both invasion routes, the species established in regions with climatic conditions that were similar to those in the native range in Europe. An initial spread in ruderal habitats always preceded spread in (semi-)natural habitats. In the east, the niche gradually increased over time until it reached limits similar to the native niche. Conversely, in the west the niche abruptly expanded after an extended time lag into climates not occupied in the native range; only the native cold niche limit was conserved. Main conclusions Our study reveals that different niche dynamics have taken place during the eastern and western invasions. This pattern indicates different combinations of historical, ecological and evolutionary factors in the two ranges. We hypothesize that the lack of a well-developed transportation network in the west at the time of the introduction of spotted knapweed confined the species to a geographically and climatically isolated region. The invasion of dry rangelands may have been favoured during the agricultural transition in the 1930s by release from natural enemies, local adaptation and less competitive vegetation, but further experimental and molecular studies are needed to explain these contrasting niche patterns fully. Our study illustrates the need and benefit of applying large-scale, temporally explicit approaches to understanding biological invasions.