Multiple trap optical tweezers for cell force measurements

Adherent cells establish transient adhesion sites that serve as stable anchors of the cell cytoskeleton to the substrate and concomitantly allow for force transduction and cell motility. We established a multiple trap optical tweezers system for non-invasive cell force measurements at individual adhesion sites. A force study was conducted to analyze the impact of bead functionalization, adhesion site area, location, spacing, and orientation as well as the role of vinculin on adhesion formation

Two matrix group algorithms with applications to computing the automorphism group of a finite p-group

A theoretical description of an algorithm to determine the automorphism group of a finite p-group P was first given by Newman. Implementations of this algorithm with substantial improvements by O’Brien are available in GAP and Magma. The original algorithm, starting with the Frattini quotient V = P/$(P), computes recursively the automorphism group G of the quotient Q of P by successive terms of the lower p-central series of P. Thus the first step returns - G = GL(V). . The heart of the algorithm is the computation of the subgroup of G that normalises a certain subspace of the p-multiplicator M of Q. A refinement in the algorithm replaces G by a subgroup H that normalises certain subspaces of V corresponding to heuristically determined characteristic subgroups of P. In this thesis we describe and give the GAP3 code for two substantial improvements to the algorithm. The first improvement is an algorithm that returns a generating set for the stabiliser in GL(V) of any given sequence of subspaces of a finite dimensional vector space V over any finite field. This is an algorithm of independent interest, as the intersection problem for subgroups of GL(d,pn) is both important and hard. In the algorithm for computing the automorphism group of the p-group P this intersection algorithm is used to compute the precise subgroup K of GL(V) that stabilises the given sequence of subspaces rather than the over-group H of K currently computed. The theoretical basis for the intersection algorithm is a new Galois correspondence between lattices of subspaces of V and subgroups of GL(V). The basic computational tool is the ‘meataxe’ algorithm. As a second contribution, we give an efficient algorithm to compute a canonical form for a subspace U of M under the action of a p-subgroup G of GL(M), and also to compute generators for the subgroup of G that normalises U. Here ‘efficient’ means ‘polynomial in the size of the input’, and M can be any finite dimensional vector space over GF{p). This is important as the kernel of the action of G on V is a p-group; and G itself is often a p-group

As vozes dos pais sobre o dia-a-dia dos filhos após o divórcio

O estudo centra-se na criança, na família e na relação de parentalidade numa situação de divórcio. O objectivo foi compreender como a parentalidade é vivida pelos pais após o divórcio. Na escolha dos participantes privilegiou-se: ser separado/divorciado, ter pelo menos um filho em idade de creche/ jardim-de-infância antes e após a separação/divórcio e residir no distrito de Santarém. Aos seis ex-casais seleccionados colocaram-se questões acerca da relação de parentalidade e do dia-a-dia da criança. Optouse por uma investigação qualitativa. o instrumento de recolha de dados foi a entrevista, questionando-se individualmente os participantes. Os resultados revelaram que os pais se preocupam com: as consequências psicológicos do divórcio nos filhos; a flexibilidade e a organização da rotina diária das crianças mesmo quando não partilhadas por ambos. a parentalidade é vista como a satisfação das necessidades básicas da criança, nomeadamente, as de afecto, confiança e segurança, bem como uma educação com valores e regras. os pais revelaram ser difícil cuidar e educar do filho num divórcio, afirmando que esse desafio é facilitado quando ambos estão juntos

Force mapping during the formation and maturation of cell adhesion sites with multiple optical tweezers

<div><p>Focal contacts act as mechanosensors allowing cells to respond to their biomechanical environment. Force transmission through newly formed contact sites is a highly dynamic process requiring a stable link between the intracellular cytoskeleton and the extracellular environment. To simultaneously investigate cellular traction forces in several individual maturing adhesion sites within the same cell, we established a custom-built multiple trap optical tweezers setup. Beads functionalized with fibronectin or RGD-peptides were placed onto the apical surface of a cell and trapped with a maximum force of 160 pN. Cells form adhesion contacts around the beads as demonstrated by vinculin accumulation and start to apply traction forces after 30 seconds. Force transmission was found to strongly depend on bead size, surface density of integrin ligands and bead location on the cell surface. Highest traction forces were measured for beads positioned on the leading edge. For mouse embryonic fibroblasts, traction forces acting on single beads are in the range of 80 pN after 5 minutes. If two beads were positioned parallel to the leading edge and with a center-to-center distance less than 10 µm, traction forces acting on single beads were reduced by 40%. This indicates a spatial and temporal coordination of force development in closely related adhesion sites. We also used our setup to compare traction forces, retrograde transport velocities, and migration velocities between two cell lines (mouse melanoma and fibroblasts) and primary chick fibroblasts. We find that maximal force development differs considerably between the three cell types with the primary cells being the strongest. In addition, we observe a linear relation between force and retrograde transport velocity: a high retrograde transport velocity is associated with strong cellular traction forces. In contrast, migration velocity is inversely related to traction forces and retrograde transport velocity.</p> </div

ÍNDICE DE ATIVIDADE ECONÔMICA: OS MODELOS DE FILTRO DE KALMAN E BOX-JENKINS COMPARADOS

This paper has as objective to build a composite economic activity index for the local economy, created as form of measuring the economic activity. We use the factor analysis technique to determinate the components and their weights. This local index is then compared to national ones. As a result, the index behaves nicely as a local coincident index of the economic activities. Two techniques are used in their forecast; the first was the Kalman Filter and the second one the Box-Jenkins model. The presence of outliers required that we use a new technique in order the coefficients of the Kalman Filter model to be stable. The two techniques are then compared using a statistic test developed by Diebold and Mariano (1995). As a final result, the two models' forecasting are the same.

Ìndice de Atividade Econômica: Construção e Testes de Previsão dos Modelos de Filtro de Kalman e Box-Jenkins

This paper has as objective to present a practical method for building a composite economic activity index for local economies. As an example, the index was built using data for the city of Maringá-PR. In its development we employed factor analysis technique to find the principal components considering their common factor in order to build the index. This local index is then compared to national ones. As a result we found that national indexes move first comparative to our local index. Thus, the forecast of our local index should anticipate future economic changes. Two techniques are used in forecasting the local index; the first was the Kalman Filter and the second one the Box-Jenkins. The presence of outliers required that we use the technique proposed by Lin e Guttman (1993) in order to obtain stable coefficients for the Kalman Filter model. The two techniques are then compared using a statistic test developed by Diebold e Mariano (1995). As a final result the two models’ forecasting results showed to be equivalent.Ìndice de Atividade Econômica, Filtro de Kalman, ARIMA, Box-Jenkins

Diretrizes brasileiras para atividade física como estratégia de promoção da saúde

Public health actions endorsed by the federal government, for instance, health promotion initiatives, usually have greater impact at population level compared to other types of initiatives. This commentary aims to instigate debate on the importance and necessity of producing federally endorsed brazilian physical activity guidelines as a strategy for health promotion.Ações de saúde pública sancionadas pelo governo, como iniciativas de promoção da saúde, normalmente apresentam maior impacto em nível populacional. O objetivo deste comentário é instigar o debate sobre a importância e a necessidade de desenvolver diretrizes brasileiras de atividade física como estratégia de promoção da saúde

A importância estratégica dos países Bálticos para a OTAN no pós-Guerra Fria

Os Estados Bálticos readquiriam sua independência com a queda da União das Repúblicas Socialistas Soviéticas no pós-Guerra Fria, no início dos anos 1990. Em pouco tempo, apresentaram não só uma economia estável, como também desenvolveram todos os pré-requisitos para a adesão tanto à União Europeia quanto à Organização do Tratado do Atlântico Norte (OTAN), sendo as primeiras repúblicas do leste europeu a aderir a ambas organizações. Objetiva-se analisar a importância da Estônia, Letônia e Lituânia para a OTAN, levando em consideração as questões geopolíticas e comerciais, compreendendo o interesse da organização na região por meio de uma análise desde o período da ocupação soviética e alemã nos Bálticos, nos anos 1940, até o período pós-independência, nos anos 2000. Utiliza-se o referencial teórico proposto por Buzan (2009) a respeito da perspectiva abrangente de segurança internacional, que considera aspectos econômicos, sociais e culturais para o exame do tema, além das questões políticas e militares. A metodologia aplicada nesta pesquisa é a análise de textos, esclarecida por Cardoso e Vainfas (1997), para os quais a interpretação das fontes requer o estudo do contexto histórico por elas referido. Vale esclarecer que as fontes desta pesquisa são os pronunciamentos de lideranças dos países Bálticos e da OTAN, bem como a bibliografia específica sobre o tema

Central nervous system lymphoma: iconographic essay

The authors illustrate the present pictorial essay about central nervous system lymphoma with magnetic resonance images obtained in their institution over the past 13 years. Some of the main radiological findings in primary and secondary presentations of this type of lymphoma are discussed. Central nervous system lymphoma is a relatively uncommon tumor, but magnetic resonance imaging findings may suggest the diagnosis.Ilustramos este ensaio iconográfico de linfoma do sistema nervoso central com imagens de ressonância magnética obtidas em nosso serviço nos últimos 13 anos e discutimos algumas das principais características radiológicas deste tipo de linfoma, primário e secundário. O linfoma sistema nervoso central é um tumor relativamente infrequente, mas alguns achados na ressonância magnética podem sugerir este diagnóstico.11011

Un análisis crítico sobre las recomendaciones de actividad física en España

ResumenObjetivoIdentificar los documentos oficiales de las comunidades autónomas en España que contengan recomendaciones sobre actividad física, para evaluar el grado de conformidad con las recomendaciones sobre actividad física para la salud de la Organización Mundial de la Salud (OMS).MétodosSe realizó un análisis de contenido sobre 55 documentos de las consejerías de sanidad de los distintos gobiernos autonómicos que contienen recomendaciones sobre actividad física.ResultadosEl 84% de las comunidades autónomas en España hacen algún tipo de recomendación sobre actividad física aeróbica y el 37% sobre fortalecimiento muscular. Sin embargo, las que tienen documentos en consonancia con los criterios de la OMS son: actividad física aeróbica (n=11, 58%), personas adultas (n=10, 53%), personas mayores (n=5, 26%), infancia/adolescentes (n=1, 5%); fortalecimiento muscular, personas adultas (n=6, 32%), personas mayores (n=3, 16%), infancia/adolescentes (n=1, 5%); equilibrio (n=5, 26%); al menos 10 minutos continuados de actividad física (n=6, 32%); recomiendan hasta 300 minutos semanales (n=10, 53%); intensidad de la actividad física (n=2, 11%).ConclusionesLas recomendaciones hacen referencia a la actividad física aeróbica y apenas tienen en cuenta el fortalecimiento muscular. Una comunidad autónoma se ajusta a las recomendaciones de la OMS. Las comunidades con mayores índices de envejecimiento y mayor porcentaje de infancia/adolescentes casi no hacen recomendaciones sobre actividad física de acuerdo con las directrices de la OMS.AbstractObjectiveTo identify official documents with recommendations on physical activity published by the autonomous regions of Spain with the goal of evaluating their compliance with the physical activity recommendations of the World Health Organization (WHO).MethodsWe conducted a content analysis of 55 documents of the ministries of health of several regional governments containing recommendations on physical activity.ResultsEighty-four percent of the autonomous regions in Spain made recommendations on aerobic physical activity and 37% made recommendations on strength training. However, the number of documents consistent with the WHO criteria was as follows: aerobic activity (n=11, 58%), adults (n=10, 53%), the elderly (n=5, 26%), children/adolescents (n=1, 5%); strength training, adults (n=6, 32%), the elderly (n=3, 16%), children/adolescents (n=1, 5%); balance (n=5, 26%); at least 10minutes continuous physical activity (n=6, 32%); recommendation of up to 300minutes per week (n=10, 53%); intensity of physical activity (n=2, 11%).ConclusionsThe recommendations of the autonomous regions tend to focus on aerobic physical activity and to under-represent strength training. Moreover, only one autonomous region conforms to the WHO recommendations for physical activity. The regions with higher rates of population aging and a higher percentage of children and adolescents fail to make recommendations on physical activity consistent with the WHO guidelines