Movement through slits: cellular migration via the Slit family

First isolated in the fly and now characterised in vertebrates, the Slit proteins have emerged as pivotal components controlling the guidance of axonal growth cones and the directional migration of neuronal precursors. As well as extensive expression during development of the central nervous system (CNS), the Slit proteins exhibit a striking array of expression sites in non-neuronal tissues, including the urogenital system, limb primordia and developing eye. Zebrafish Slit has been shown to mediate mesodermal migration during gastrulation, while Drosophila slit guides the migration of mesodermal cells during myogenesis. This suggests that the actions of these secreted molecules are not simply confined to the sphere of CNS development, but rather act in a more general fashion during development and throughout the lifetime of an organism. This review focuses on the non-neuronal activities of Slit proteins, highlighting a common role for the Slit family in cellular migration.

Occlusable corneas in toadfishes: light transmission, movement and ultrastruture of pigment during light- and dark-adaptation

The toadfishes Tetractenos hamiltoni and Torquigener pleurogramma (Tetraodontidae) possess occlusable yellow corneas. We examine the light transmission and location of the yellow/orange pigment throughout the cornea, the temporal properties of pigment migration and the ultrastructure of the pigmented processes during light- and dark-adaptation. Each species was dark-adapted during the day and light-adapted during the night and then exposed to either sun illumination or darkness for different lengths of time (0-70 min). Movement of corneal pigment could be induced in both species regardless of time of day or night. The pigment was able to migrate in a dorsal or ventral direction and changed from minimal to maximal pigmentation within 60 min. Three types of transmission curves were found with varying degrees of transmission in the 400-500 nm waveband, indicating that the pigment distribution is not uniform across the cornea; some areas of the cornea transmit near UV light, while others absorb blue light. The gradual change of the transmission characteristics in different areas of the cornea indicates the presence of different concentrations of a single type of pigment. Ultrastructural examination of the corneas showed that the layer containing the pigment is situated within the scleral cornea either surrounding (T. pleurogramma) or abutting (T. hamiltoni) an iridescent layer. Long sheet-like processes or chromatophores extending centrally from dorsal and ventral reservoirs are filled with pigment during the light-adapted state but empty in the dark-adapted state.

A brief survey on online analysis of movement data

The increasing availability of mobility data and the awareness of its importance and value have been motivating many researchers to the development of models and tools for analyzing movement data. This paper presents a brief survey of significant research works about modeling, processing and visualization of data about moving objects. We identified some key research fields that will provide better features for online analysis of movement data. As result of the literature review, we suggest a generic multi-layer architecture for the development of an online analysis processing software tool, which will be used for the definition of the future work of our team.

Soleus activity in post-stroke subjects: movement sequence from standing to sitting

O documento em anexo encontra-se na versão post-print (versão corrigida pelo editor).

Eficácia do Constraint-Induced Movement Therapy, em utentes com sequelas de Acidente Vascular Encefálico, até 9 meses

O Acidente Vascular Encefálico é uma das principais causas de morte, tornando-se cada vez mais iminente processos de reabilitação que minimizem as sequelas, nomeadamente as limitações do membro superior que dificultam o envolvimento em atividades da vida diária. O Constraint-Induced Movement Therapy, surge como uma abordagem que incrementa o uso do membro superior mais afetado. A presente investigação trata-se de um estudo de casos múltiplos. Pretende-se verificar se existem melhorias na funcionalidade do membro superior mais afetado, analisar em que atividades da vida diária são visíveis melhorias funcionais e compreender se o maior envolvimento nas atividades diárias está diretamente relacionado com a melhoria na capacidade funcional. Pretende-se ainda que os valores obtidos no Wolf Motor Function Test sejam um contributo para a sua validação para a população portuguesa. Utilizou-se um questionário para recolha de dados pessoais e clínicos (amplitudes de movimento, dor e espasticidade); o Wolf Motor Function Test e o Action Research Arm Test para verificar a funcionalidade do membro superior mais afetado; e a Motor Activity Log que avalia o envolvimento em atividades da vida diária. O grupo é constituído por 3 utentes que sofreram um primeiro Acidente Vascular Encefálico até 9 meses de evolução, internados na Santa Casa da Misericórdia de Monção e que cumpriam os critérios de inclusão. O programa foi implementado três horas/dia, durante 10 dias, mantendo a restrição no membro superior menos afetado durante 90% do dia acordado. Como se trata de um estudo de casos múltiplos, analisou-se cada participante individualmente e verificou-se a diferença entre os resultados finais e iniciais para cada uma das variáveis. Os resultados obtidos revelam ganhos na amplitude de movimento, velocidade de execução e capacidade funcional do membro superior mais afetado, nomeadamente nas funções de preensão e pinça da mão, bem como se testemunhou minimização do fenómeno learned nonuse. Verificaram-se ganhos funcionais em todos os participantes nas atividades da vida diária apesar de serem diferentes de participante para participante. Dois participantes afirmaram que voltariam a participar no programa.Conclui-se, assim que a técnica resulta em ganhos funcionais nestes utentes, indicando um caminho alternativo a outras abordagens de reabilitação.

Modeling Movement of Tourists : Tools and Application in São Miguel Island, Portugal

Tourism contributes to the development of many regions. Different factors affect the movement of tourists within a destination. Those factors are related to the tourist characteristics, like the time budgets, preferences or destination knowledge, and to the destination features, like the attraction characteristics or accessibility level. Tourist decisions aren’t always done in a rational way. Emotions add further complexity to the human decision process. The use of footpaths can play an important role in the satisfaction of tourists, helping them discover the territory and giving them access to different types of attractions. The existence of a mathematical model that integrates the main factors related to the movement of independent tourists within a destination, in a dynamic way, will make possible the creation of an adaptable software tool. This tool will meet the specific needs of tourists, allowing the use of the network in an optimal way by the different tourist profiles, and the needs of the regional government and business, permitting better decisions and the offer of relevant tourism products. This article identifies the main tourists’ mobility criteria in the São Miguel island territory, Azores, Portugal, recognizes the necessary modelling process and identifies the basis for the construction of the mathematical model that explains the movement of tourists within the destination.

Anticipatory postural adjustments during sitting reach movement in post-stroke subjects

The study assessed the effect of velocity of arm movement on the generation of APAs in the contralateral and ipsilateral muscles of individuals with stroke in the sitting position. In the sitting position, 10 healthy and 8 post-stroke subjects reached for an object placed at the scapular plane and mid-sternum height at self-selected and fast velocities. Electromyography was recorded from the anterior deltoid (AD), upper (UT) and lower trapezius (LT), and latissimus dorsi (LD). Kinematic analysis was used to assess peak velocity and trunk displacement. Post-stroke subjects presented a delay of APAs on both sides of the body compared to healthy subjects. Differences were found between the timing of APAs on the ipsilateral and contralateral LD and LT in both movement speeds and in the ipsilateral UT during movement of the non-affected arm at a self-selected velocity. A delay in the contralateral LD in the reaching movement with the non-affected arm at fast velocity was also observed. Trunk displacement was greater in post-stroke subjects. In the sitting position, APAs were delayed in both fast and self-selected movements on both sides in post-stroke subjects, which also presented a higher trunk displacement.

Development of a system to monitor surfer’s balance and plantar pressure and surfboard’s movement

O uso da tecnologia tem crescido nas últimas décadas nas mais diversas áreas, seja na indústria ou no dia-a-dia, e é cada vez mais evidente os benefícios que traz. No desporto não é diferente. Cada dia surgem novos desenvolvimentos objetivando a melhoria do desempenho dos praticantes de atividades físicas, possibilitando atingir resultados nunca antes pensados. Além disto, a utilização da tecnologia no desporto permite a obtenção de dados biomecânicos que podem ser utilizados tanto no treinamento quando na melhoria da qualidade de vida dos atletas auxiliando na prevenção de lesões, por exemplo. Deste modo, o presente projeto se aplica na área do desporto, nomeadamente, na modalidade do surfe, onde a ausência de trabalhos científicos ainda é elevada, aliando a tecnologia eletrônica ao desporto para quantificar informações até então desconhecidas. Três fatores básicos de desempenho foram levantados, sendo eles: equilíbrio, posicionamento dos pés e movimentação da prancha de surfe. Estes fatores levaram ao desenvolvimento de um sistema capaz de medi-los dinamicamente através da medição das forças plantares e da rotação da prancha de surfe. Além da medição dos fatores, o sistema é capaz de armazenar os dados adquiridos localmente através de um cartão de memória, para posterior análise; e também enviá-los através de uma comunicação sem fio, permitindo a visualização do centro de pressões plantares; dos ângulos de rotação da prancha de surfe; e da ativação dos sensores; em tempo real. O dispositivo consiste em um sistema eletrônico embarcado composto por um microcontrolador ATMEGA1280; um circuito de aquisição e condicionamento de sinal analógico; uma central inercial; um módulo de comunicação sem fio RN131; e um conjunto de sensores de força Flexiforce. O firmware embarcado foi desenvolvido em linguagem C. O software Matlab foi utilizado para receção de dados e visualização em tempo real. Os testes realizados demostraram que o funcionamento do sistema atende aos requisitos propostos, fornecendo informação acerca do equilíbrio, através do centro de pressões; do posicionamento dos pés, através da distribuição das pressões plantares; e do movimento da prancha nos eixos pitch e roll, através da central inercial. O erro médio de medição de força verificado foi de -0.0012 ± 0.0064 N, enquanto a mínima distância alcançada na transmissão sem fios foi de 100 m. A potência medida do sistema foi de 330 mW.

Immediate effects of hip mobilization with movement in patients with hip osteoarthritis: A randomised controlled trial

Background Mobilization with movement (MWM) has been shown to reduce pain, increase range of motion (ROM) and physical function in a range of different musculoskeletal disorders. Despite this evidence, there is a lack of studies evaluating the effects of MWM for hip osteoarthritis (OA). Objectives To determine the immediate effects of MWM on pain, ROM and functional performance in patients with hip OA. Design Randomized controlled trial with immediate follow-up. Method Forty consenting patients (mean age 78 ± 6 years; 54% female) satisfied the eligibility criteria. All participants completed the study. Two forms of MWM techniques (n = 20) or a simulated MWM (sham) (n = 20) were applied. Primary outcomes: pain recorded by numerical rating scale (NRS). Secondary outcomes: hip flexion and internal rotation ROM, and physical performance (timed up and go, sit to stand, and 40 m self placed walk test) were assessed before and after the intervention. Results For the MWM group, pain decreased by 2 points on the NRS, hip flexion increased by 12.2°, internal rotation by 4.4°, and functional tests were also improved with clinically relevant effects following the MWM. There were no significant changes in the sham group for any outcome variable. Conclusions Pain, hip flexion ROM and physical performance immediately improved after the application of MWM in elderly patients suffering hip OA. The observed immediate changes were of clinical relevance. Future studies are required to determine the long-term effects of this intervention.

Cognitive assessment of topological movement Patterns and direction turns: An influence of scale

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Epidemiological aspects of schistosomiasis in workers of the Movement of Landless Rural Workers

Introduction Schistosomiasis is endemic in 74 countries and is considered a serious public health problem in some locations. Methods A transverse study was performed of 13 landless settlements in southern Sergipe from February to December 2009. The study included 822 settlers, of whom 601 underwent stool testing. Results The prevalence of schistosomiasis in landless workers was 4.3%. The population has a low education level, and basic sanitation services are not available to all residents. Conclusions The prevalence of schistosomiasis was low in the population and among different settlements, possibly because of different forms of water use by the settlers.

Predicting market movement with Artificial Neural Networks

This paper presents an application of an Artificial Neural Network (ANN) to the prediction of stock market direction in the US. Using a multilayer perceptron neural network and a backpropagation algorithm for the training process, the model aims at learning the hidden patterns in the daily movement of the S&P500 to correctly identify if the market will be in a Trend Following or Mean Reversion behavior. The ANN is able to produce a successful investment strategy which outperforms the buy and hold strategy, but presents instability in its overall results which compromises its practical application in real life investment decisions.

Global vs. local nonlinear optimization techniques for human-like movement of an anthropomorphic robot

In this paper a comparison between using global and local optimization techniques for solving the problem of generating human-like arm and hand movements for an anthropomorphic dual arm robot is made. Although the objective function involved in each optimization problem is convex, there is no evidence that the admissible regions of these problems are convex sets. For the sequence of movements for which the numerical tests were done there were no significant differences between the optimal solutions obtained using the global and the local techniques. This suggests that the optimal solution obtained using the local solver is indeed a global solution.

Comparing heritage speakers and late L2-learners of European Portuguese: verb movement, VP ellipsis and adverb placement

This study compares the performance of Portuguese-German heritage children and adult L2 speakers of European Portuguese whose L1 is German with respect to two aspects of grammar, adverb placement and VP-ellipsis, which depend on a core syntactic property of the language, verb movement. The results show that both groups have acquired V-to-I and adverb placement, showing no influence of a V2 grammar. Performance in the VP-ellipsis task is more complex: heritage children produce VP-ellipsis at the level of controls, as opposed to L2 speakers; however, both L2 and heritage speakers show that crosslinguistic influence may produce a preference for pronoun substitution over VP-ellipsis in a task asking for redundancy resolution. Nevertheless, given that overall results show that heritage children perform at the level of L1 children, we take our results to support approaches to heritage bilingualism which suggest the development of an intact grammar in childhood.