Long duration stimuli and nonlinearities in the neural–haemodynamic coupling

Recent studies have shown that the haemodynamic responses to brief (<2 secs) stimuli can be well characterised as a linear convolution of neural activity with a suitable haemodynamic impulse response. In this paper, we show that the linear convolution model cannot predict measurements of blood flow responses to stimuli of longer duration (>2 secs), regardless of the impulse response function chosen. Modifying the linear convolution scheme to a nonlinear convolution scheme was found to provide a good prediction of the observed data. Whereas several studies have found a nonlinear coupling between stimulus input and blood flow responses, the current modelling scheme uses neural activity as an input, and thus implies nonlinearity in the coupling between neural activity and blood flow responses. Neural activity was assessed by current source density analysis of depth-resolved evoked field potentials, while blood flow responses were measured using laser Doppler flowmetry. All measurements were made in rat whisker barrel cortex after electrical stimulation of the whisker pad for 1 to 16 secs at 5 Hz and 1.2 mA (individual pulse width 0.3 ms).

The hemodynamic impulse response to a single neural event

This article investigates the relation between stimulus-evoked neural activity and cerebral hemodynamics. Specifically, the hypothesis is tested that hemodynamic responses can be modeled as a linear convolution of experimentally obtained measures of neural activity with a suitable hemodynamic impulse response function. To obtain a range of neural and hemodynamic responses, rat whisker pad was stimulated using brief (less than or equal to2 seconds) electrical stimuli consisting of single pulses (0.3 millisecond, 1.2 mA) combined both at different frequencies and in a paired-pulse design. Hemodynamic responses were measured using concurrent optical imaging spectroscopy and laser Doppler flowmetry, whereas neural responses were assessed through current source density analysis of multielectrode recordings from a single barrel. General linear modeling was used to deconvolve the hemodynamic impulse response to a single "neural event" from the hemodynamic and neural responses to stimulation. The model provided an excellent fit to the empirical data. The implications of these results for modeling schemes and for physiologic systems coupling neural and hemodynamic activity are discussed.

A intenção e o gesto :ações gerenciais de enfermeiros em espaços hospitalares

The present study analyses the supervisory practice of the nurse in the hospital environment. It has, as its main objective identify the use of planning, supervision and evaluation, as managerial instruments in the daily nursing practice. It tries also to identify the importance given to these instruments in their supervisory actions and the difficulties encountered in their use. It deals with an exploratory and analytical investigation with a qualitative approach having as its main point of analysis the principles of strategic planning. In order for it to be done 10 nurses were interviewed, distributed in three public hospitals in the city of Natal/RN. The results show that, although the nurses recognize the importance of the managerial instruments, they do not put them into practice in an effective and systematic way. They justify it because of the existence of personal, professional and institutional difficulties. On the other hand we could conclude from what they say that there is the desire to overcome the eminently burocratic vision of the management. Thus, they express a feeling for change and point in the direction of looking for ways that will contribute to innovate this practice

Effect of cosurfactant on the supramolecular structure and physicochemical properties of non-ionic biocompatible microemulsions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Trabalho e saúde na sociedade capitalista: uma relação inversamente proporciona

It is a dissertation which has the Area of Concentration: Social Services, Vocational Training, Labour and Social Protection. Research Line: Social Services, Labor, Social Protection and Citizenship. Brings an approach to health and worker safety, approached on the organization of work in their processes of worker exploitation, analyzed from the critical perspective and all. Its central objective of uncovering how the organization of work affects the health of their workers, considering the working process in the capitalist mode of production, the health-disease relationship. Displays the worker, as determined by the work process, emphasizing, along the lines of capitalism, the consequences for the physical well-being, mental and social workers. To this end, we make a documentary and bibliographic research, whose point of analysis is based on the perspective of the centrality of work, recovering their sense of ontological Marx, through which the transformations are discussed in the working world, listed based on context productive restructuring of capital, which occurs along the imperialist stage of capitalist mode of production. It is problematized, though, worker health, analyzed from the wider definition of health as a field of public health, considering the work process in health-disease relationship. Finally, the research developed raised between 2006 and 2010, the Graduate Programs UFRN that address the range of issues studied in this dissertation. The scientific outputs are problematized as a way to reveal the theoretical trends (critical or conservative) which facilitate the thematic area

Crytallization and high-resolution X-ray diffraction data collection of an Asp49 PLA(2) from Bothrops jararacussu venom both in the presence and absence of Ca2+ ions

Snake venom PLA(2)s have been extensively studied due to their role in mediating and disrupting physiological processes such as coagulation, platelet aggregation and myotoxicity. The Ca2+ ion bound to the putative calcium-binding loop is essential for hydrolytic activity. We report the crystallization in the presence and absence of Ca2+ and X-ray diffraction data collection at 1.60 Angstrom (with Ca2+) and 1.36 Angstrom (without Ca2+) of an Asp49 PLA(2) from Bothrops jararacussu venom. The crystals belong to orthorhombic space group C222(1). Initial refinement and electron density analysis indicate significant conformational. changes upon Ca2+ binding. (C) 2004 Elsevier B.V. All fights reserved.

Análise de técnicas de distribuição espacial com padrões pontuais e aplicação a dados de acidentes de trânsito e a dados da dengue de Rio Claro-SP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo comparativo de reparação óssea em ratas ovariectomizadas tratadas com risedronato e Calcarea fluorica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise densitométrica, histomorfométrica e biomecânica em fêmures de ratos submetidos à ausência de carga e atividade física em esteira

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise da resistência a cobre e zinco sobre o crescimento e expressão gênica em Xylella fastidiosa em condições de biofilme

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da influência da força de mordida na prótese parcial removível classe I mandibular associada ao implante osseointegrado, pelo método dos elementos finitos

Pós-graduação em Odontologia - FOA

O inconsciente entendido à luz de Gilles Deleuze e Félix Guattari: intersecções entre a psicanálise de Melanie Klein e a esquizoanálise

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Memórias Póstumas de Brás Cubas e a Consciência de Zeno: representações históricas das sociedades brasileira e italiana

Pós-graduação em Letras - IBILCE

Método da continuação aplicado na análise de contingência de linhas de transmissão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo das modificações na superfície do Ti cp titânio comercialmente puro e da liga Ti-6AI-4V usados como biomateriais utilizando-se deposição por plasma spray

Pós-graduação em Química - IQ