Conformational changes in SP-B as a function of surface pressure

X-ray reflectivity of bovine and sheep surfactant-associated protein B (SP-B) monolayers is used in conjunction with pressure-area isotherms and protein models to suggest that the protein undergoes changes in its tertiary structure at the air/water interface under the influence of surface pressure, indicating the likely importance of such changes to the phenomena of protein squeeze out as well as lipid exchange between the air-water interface and subphase structures. We describe an algorithm based on the well-established box- or layer-models that greatly assists the fitting of such unknown scattering-length density profiles, and which takes the available instrumental resolution into account. Scattering-length density profiles from neutron reflectivity of bovine SP-B monolayers on aqueous subphases are shown to be consistent with the exchange of a large number of labile protons as well as the inclusion of a significant amount of water, which is partly squeezed out of the protein monolayer at elevated surface pressures.

Cortex, cognition and the cell: New insights into the pyramidal neuron and prefrontal function

Arguably the most complex conical functions are seated in human cognition, the how and why of which have been debated for centuries by theologians, philosophers and scientists alike. In his best-selling book, An Astonishing Hypothesis: A Scientific Search for the Soul, Francis Crick refined the view that these qualities are determined solely by cortical cells and circuitry. Put simply, cognition is nothing more, or less, than a biological function. Accepting this to be the case, it should be possible to identify the mechanisms that subserve cognitive processing. Since the pioneering studies of Lorent de No and Hebb, and the more recent studies of Fuster, Miller and Goldman-Rakic, to mention but a few, much attention has been focused on the role of persistent neural activity in cognitive processes. Application of modern technologies and modelling techniques has led to new hypotheses about the mechanisms of persistent activity. Here I focus on how regional variations in the pyramidal cell phenotype may determine the complexity of cortical circuitry and, in turn, influence neural activity. Data obtained from thousands of individually injected pyramidal cells in sensory, motor, association and executive cortex reveal marked differences in the numbers of putative excitatory inputs received by these cells. Pyramidal cells in prefrontal cortex have, on average, up to 23 times more dendritic spines than those in the primary visual area. I propose that without these specializations in the structure of pyramidal cells, and the circuits they form, human cognitive processing would not have evolved to its present state. I also present data from both New World and Old World monkeys that show varying degrees of complexity in the pyramidal cell phenotype in their prefrontal cortices, suggesting that cortical circuitry and, thus, cognitive styles are evolving independently in different species.

Surface diffusion of strongly adsorbing vapors in activated carbon by a differential permeation method

Conventional methods to determine surface diffusion of adsorbed molecules are proven to be inadequate for strongly adsorbing vapors on activated carbon. Knudsen diffusion permeability (B-k) for strongly adsorbing vapors cannot be directly estimated from that of inert gases such as helium. In this paper three models are considered to elucidate the mechanism of surface diffusion in activated carbon. The transport mechanism in all three models is a combination of Knudsen diffusion, viscous flow and surface diffusion. The collision reflection factor f (which is the fraction of molecules undergoing collision to the solid surface over reflection from the surface) of the Knudsen diffusivity is assumed to be a function of loading. It was found to be 1.79 in the limit of zero loading, and decreases as loading increases. The surface diffusion permeability increases sharply at very low pressures and then starts to decrease after it has reached a maximum (B(mum)s) at a threshold pressure. The initial rapid increase in the total permeability is mainly attributed to surface diffusion. Interestingly the B(mum)s for all adsorbates appear at the same volumetric adsorbed phase concentration, suggesting that the volume of adsorbed molecules may play an important role in the surface diffusion mechanism in activated carbon. (C) 2003 Elsevier Ltd. All rights reserved.

Utiliza????o do QFD: Quality Function Deployment como ferramenta de planejamento

A utiliza????o da matriz do QFD (em portugu??s, Desdobramento da Fun????o Qualidade) como entrada para o planejamento estrat??gico regional solidificou o entendimento da Diretoria Regional sobre as expectativas dos clientes ante seus principais processos, avaliados por meio de pesquisa externa realizada bianualmente. Direcionou as a????es a serem tomadas por meio da prioriza????o, da tradu????o e do desdobramento dos requisitos mais importantes para os clientes em todos os n??veis dos processos, alinhando essas a????es com as estrat??gias, a pol??tica da qualidade e o or??amento. Da mesma forma, serviu para estabelecer metas globais de satisfa????o por segmento, de forma mais estruturada, sistematizando a avalia????o dos resultados e focando sempre a satisfa????o dos clientes cujos resultados j?? se comprovaram: ??ndice de 8,6 em 2000 para 9,2 em 2004

Efeito da privação de sono paradoxal e do bloqueio da síntese da corticosterona sobre os limiares da reação de defesa induzida pela estimulação elétrica da matéria cinzenta periaquedutal e colículo superior

O Transtorno do pânico (TP) é um transtorno mental comum que afeta até 5% da população em algum momento da vida, sendo caracterizada pela presença de ataques de pânico (AP) recorrentes. Constitui uma psicopatologia que pode ser afetada pela privação do sono (PS), relação que ainda é pouco compreendida. Neste contexto, modelos experimentais de AP e de PS são ferramentas úteis na investigação dessa possível correlação, especialmente motivado pela crescente condição de privação de sono, que tem se tornado cada vez mais frequente na sociedade moderna. Assim, este estudo avaliou os efeitos da privação de sono paradoxal (PSP) sobre os limiares dos comportamentos defensivos induzidos por estimulação intracraniana (EI) da MCPD e CS de ratos num modelo experimental de AP, assim como verificou a influência da corticosterona sobre esses limiares. Foram utilizados 160 ratos Wistar machos (300g), organizados em 4 grupos com 40 animais cada, como se segue: Grupo Controle (CTR) submetido à EI, porém sem PSP; Grupo Privação (PRV), submetido à EI e privado por 96 horas; Grupo Privação + Bloqueio da corticosterona (PRB), submetido ao tratamento com metirapona, EI, e privado por 96 horas, e Grupo Controle + Bloqueio da corticosterona (CTB), submetido ao tratamento com metirapona e EI, porém sem privação de sono. Após 10 dias do implante cirúrgico intracraniano de eletrodo na MCPD e CS, os animais passaram por 5 sessões de estimulação, como se segue: 1ª (TRI) considerada triagem - imediatamente antes da privação, 2ª (P48) após 48h de privação, 3ª (P96) após 96h de privação, 4ª (R48) após 48h de retirada da privação e 5ª (R96) após 96h de retirada da privação. As curvas de limiares das respostas individuais de defesa obtidas nas várias sessões de estimulação da MCPD e CS (TRI, P48, P96, R48 e R96) dos ratos foram comparadas entre si, bem como as curvas de limiares de uma dada resposta nos diferentes grupos (CTR, PRV, CTB e PRB). Além disso, os níveis de corticosterona (CORT) foram dosados nas diferentes sessões de EI, e comparadas num mesmo grupo, bem como nos diferentes grupos. No grupo CTR, todos os comportamentos foram iguais em todas as sessões quando comparados à TRI, entretanto, nos animais privados (PRV), o limiar do galope (GLP) reduziu significativamente em R48 e R96, não ocorrendo xix alterações nos demais comportamentos. Em contraste, no grupo PRB, o Trote (TRT) aumentou a partir de P48, enquanto o GLP não foi alterado em nenhuma sessão de EI. Na comparação entre os grupos, em Salto (SLT), Micção (MIC), Exoftalmia (EXO), Imobilidade (IMO), Defecação (DEF), TRT e GLP, não sofreram alterações decorrentes da CORT produzida decorrente da PSP, sugerindo que a corticosterona não altera os comportamentos defensivos característicos do Ataque de Pânico. Em adição, tais resultados sugerem que os efeitos tardios da PSP sobre os limiares de GLP possivelmente se devam a mecanismos neuroquímicos tempo-dependente.

Contribution towards a reflection about methodological strategies in design education and the function of drawing in design

This work presents a reflection on Design education and specifically on the role of Drawing in this area. As a subject, Design has expanded its field of action expanding into new areas such as Experience Design or Service Design. It became necessary for the designer to have more than an education based on technological knowledge or know-how. Many authors like Meredith Davis, Don Norman or Jamie Hobson point out the urgency to review the curricula of Design courses because nowadays “… design is more than appearance, design is about interaction, about strategy and about services. Designers change social behavior” (Norman 2011). When shifting from a product-centered design to a person-centered design (in a structure, a service or in a relationship) what should the function of drawing in a design course be? What should its curriculum be? Our work methodology will be to confront today’s perspectives on design theory and practice in an attempt to add to the discussion on the methodological strategies in design teaching in the contemporary context.

Contribution towards a reflection about methodological strategies in Design Education and the function of Drawing in Design

This work presents a reflection on Design education and specifically on the role of Drawing in this area. As a subject, Design has expanded its field of action expanding into new areas such as Experience Design or Service Design. It became necessary for the designer to have more than an education based on technological knowledge or know-how. Many authors like Meredith Davis, Don Norman or Jamie Hobson point out the urgency to review the curricula of Design courses because nowadays “ … design is more than appearance, design is about interaction, about strategy and about services. Designers change social behavior” (Norman, 2011) When shifting from a product-centered design to a person-centered design (in a structure, a service or in a relationship) what should the function of drawing in a design course be? What should its curriculum be? Our work methodology will be to confront today’s perspectives on design theory and practice in an attempt to add to the discussion on the methodological strategies in design teaching in the contemporary context.

Thermal degradation of Pb(Zr0.53Ti0.47)O3/poly(vinylidene fluoride) composites as a function of ceramic grain size and concentration

Poly(vinylidene fluoride)/Pb(Zr0.53Ti0.47)O3,([PVDF]1−x/[PZT]x) composites of volume fractions x and (0–3) type connectivity were prepared in the form of thin films. PZT powders with average grain sizes of 0.2, 0.84, and 2.35 μm in different volume fraction of PZT up to 40 % were mixed with the polymeric matrix. The influence of the inorganic particle size and its content on the thermal degradation properties of the composites was then investigated by means of thermo-gravimetric analysis. It is observed that filler size affects more than filler concentration the degradation temperature and activation energy of the polymer. In the same way and due to their larger specific area, smaller particles leave larger solid residuals after the polymer degradation. The polymer degradation mechanism is not significantly modified by the presence of the inorganic fillers. On the other hand, an inhibition effect occurs due to the presence of the fillers, affecting particularly the activation energy of the process.

Options listing and the volatility of the underling asset: a study on the derivative market function

There are basic misunderstandings on derivative markets. Some professionals believe that they are a kind of casinos and have no utility for the investors. This work looks at the effects of options introduction in the Brazilian market, seeking for another benefit for this introduction: changes in the stocks risk leveI. Our results are the same found in the US and other markets: the options introduction reduces the stocks volatility. We also found that there is a slight indication that the volatility becames more stochastic with this alternative.

Impact of the background region of interest in the relative renal function

Renal scintigraphy with 99mTc-dimercaptosuccinic acid (99mTc-DMSA) is performed with the aim of detect cortical abnormalities related to urinary tract infection and accurately quantify relative renal function (RRF). For this quantitative assessment Nuclear Medicine Technologist should draw regions of interest (ROI) around each kidney (KROI) and peri-renal background (BKG) ROI, although, controversy still exists about BKG-ROI. The aim of this work was to evaluate the effect of the normalization procedure, number and location of BKG-ROI on the RRF in 99mTc-DMSA scintigraphy.

Relationship of balance to function independence in stroke survivors

Cerebral vascular disease is the primary cause of permanent disability in Portugal. Impaired stability is considered an important feature after stroke as it is related with higher risk of falls and functional dependence. Physiotherapy intervention usually starts early after stroke in order to direct motor recovery and help patients to improve their ability to perform activities of daily living (ADL). Purpose: to investigate the relationship of balance to functionality in acute stroke patients. Methods: 16 subjects (8 women and 8 men), mean age 63,62 ± 2,16y, with unilateral ischemic stroke in the middle cerebral artery territory, who were admitted to physiotherapy department of Fernando Fonseca Hospital in Portugal, within the first month after stroke were recruited to participate in this study. All subjects have no cognitive impairment according to Mini Mental State, no history of lower extremity orthopedic problems and no other disease that could interfere with treatments. All patients gave their inform consent to participate in this study. Subjects were assessed with the Modified Barthel Index (MBI) and the Berg Balance Scale (BBS).

Multi-scaled femtosecond laser structuring of stationary titanium surfaces

The evolution of the topography of titanium surfaces treated with femtosecond laser radiation in stationary conditions as a function of radiation fluence and number of laser pulses is investigated. Depending on the processing parameters, ripples, microcolumns, wavy or smooth surfaces can be obtained. The ripples predominate for fluences near the damage threshold of titanium (0.2+/-0.1) J/cm(2), while microcolumns form during the first 200 pulses for fluences between (0.6+/-0.2) and (1.7+/-0.2) J/cm(2). A wavy topography develops for fluences and number of pulses higher than (1.7+/-0.2) J/cm(2) and 300, respectively. A bimodal surface topography consisting of surface ripples overlapping a microcolumnar topography can be obtained if the surfaces are firstly treated to create microcolumns followed by laser treatment with a lower fluence near the ablation threshold of the material, in order to generate periodic ripple

Avaliação do risco associado a movimentos verticais de navios em manobra no porto da Praia da Vitória

O risco associado a um navio em manobra pode ser avaliado pela probabilidade do movimento vertical de um ponto do navio ultrapassar um determinado limiar pré-definido. Essa excedência pode originar danos tanto no próprio navio como nas estruturas portuárias envolventes. Este trabalho surge no seguimento de um estudo efectuado no Laboratório Nacional de Engenharia Civil (LNEC), no qual foi desenvolvido um conjunto de ferramentas de avaliação da função resposta do navio quando sujeito à agitação marítima e, partindo dessas ferramentas, foi obtido um procedimento para determinação do espectro dos movimentos verticais de um ponto de um navio parado sujeito àquele estado de agitação (Rodrigues, 2010). No presente estudo, estendeu-se esse procedimento de modo a avaliar a influência da velocidade de avanço do navio no espectro dos movimentos verticais do mesmo. O percurso de entrada do “N/M Fernão Gomes” no porto da Praia da Vitória foi o caso de estudo considerado. A agitação marítima incidente no navio cobriu o período de Janeiro de 2009 a Dezembro de 2010 e foi obtida com base no modelo previsão de escala regional (WAVEWATCH III) e posteriormente transferida para o interior do porto com o recurso a modelos numéricos de propagação de ondas (SWAN e DREAMS). Foi também assumido que a altura do movimento vertical do navio segue uma distribuição de Rayleigh, a qual possibilita a determinação da altura significativa desse movimento vertical, bem como a implementação de um procedimento para determinar a probabilidade de a altura do movimento vertical do navio não exceder um limiar pré-definido e consequentemente mostrar, através da análise dos resultados, a influência da velocidade de avanço do navio. Da análise dos resultados concluiu-se que a velocidade tem uma influência significativa nos resultados. No final avaliou-se a contribuição dos resultados anteriormente determinados, para a análise do risco associado aos movimentos verticais do navio quando em manobra no porto em estudo.

Effects of lower limb strengthening on balance and function in persons who suffered a stroke

Introduction - Cerebrovascular diseases, and among them, cerebral vascular accidents, are one of the main causes of morbidity and disability at European Union countries. Clinical framework resulting from these diseases include important limitations in functional ability of the these patients Postural control dysfunctions are one of the most common and devastating consequences of a stroke interfering with function and autonomy and affecting different aspects of people’s life and contributing to decrease quality of life. Neurological physiotherapy plays a central role in the recovery of movement and posture, however it is necessary to study the efficacy of techniques that physiotherapists use to treat these problems. Objectives - The aim of this study was to investigate the effects of a physiotherapy intervention program, based on oriented tasks and strengthening of the affected lower limb, on balance and functionality of individuals who have suffered a stroke. In addition our study aimed to investigate the effect of strength training of the affected lower limb on muscle tone.

Influence of reconstruction parameters during filtered backprojection and ordered-subset expectation maximization in the measurement of the left-ventricular volumes and function during gated SPECT

A crucial method for investigating patients with coronary artery disease (CAD) is the calculation of the left ventricular ejection fraction (LVEF). It is, consequently, imperative to precisely estimate the value of LVEF--a process that can be done with myocardial perfusion scintigraphy. Therefore, the present study aimed to establish and compare the estimation performance of the quantitative parameters of the reconstruction methods filtered backprojection (FBP) and ordered-subset expectation maximization (OSEM). Methods: A beating-heart phantom with known values of end-diastolic volume, end-systolic volume, and LVEF was used. Quantitative gated SPECT/quantitative perfusion SPECT software was used to obtain these quantitative parameters in a semiautomatic mode. The Butterworth filter was used in FBP, with the cutoff frequencies between 0.2 and 0.8 cycles per pixel combined with the orders of 5, 10, 15, and 20. Sixty-three reconstructions were performed using 2, 4, 6, 8, 10, 12, and 16 OSEM subsets, combined with several iterations: 2, 4, 6, 8, 10, 12, 16, 32, and 64. Results: With FBP, the values of end-diastolic, end-systolic, and the stroke volumes rise as the cutoff frequency increases, whereas the value of LVEF diminishes. This same pattern is verified with the OSEM reconstruction. However, with OSEM there is a more precise estimation of the quantitative parameters, especially with the combinations 2 iterations × 10 subsets and 2 iterations × 12 subsets. Conclusion: The OSEM reconstruction presents better estimations of the quantitative parameters than does FBP. This study recommends the use of 2 iterations with 10 or 12 subsets for OSEM and a cutoff frequency of 0.5 cycles per pixel with the orders 5, 10, or 15 for FBP as the best estimations for the left ventricular volumes and ejection fraction quantification in myocardial perfusion scintigraphy.