Neural compensation for compliant loads during rhythmic movement

An experiment was performed to characterise the movement kinematics and the electromyogram (EMG) during rhythmic voluntary flexion and extension of the wrist against different compliant (elastic-viscous-inertial) loads. Three levels of each type of load, and an unloaded condition, were employed. The movements were paced at a frequency of I Hz by an auditory metronome, and visual feedback of wrist displacement in relation to a target amplitude of 100degrees was provided. Electro-myographic recordings were obtained from flexor carpi radialis (FCR) and extensor carpi radialis brevis (ECR). The movement profiles generated in the ten experimental conditions were indistinguishable, indicating that the CNS was able to compensate completely for the imposed changes in the task dynamics. When the level of viscous load was elevated, this compensation took the form of an increase in the rate of initial rise of the flexor and the extensor EMG burst. In response to increases in inertial load, the flexor and extensor EMG bursts commenced and terminated earlier in the movement cycle, and tended to be of greater duration. When the movements were performed in opposition to an elastic load, both the onset and offset of EMG activity occurred later than in the unloaded condition. There was also a net reduction in extensor burst duration with increases in elastic load, and an increase in the rate of initial rise of the extensor burst. Less pronounced alterations in the rate of initial rise of the flexor EMG burst were also observed. In all instances, increases in the magnitude of the external load led to elevations in the overall level of muscle activation. These data reveal that the elements of the central command that are modified in response to the imposition of a compliant load are contingent, not only upon the magnitude, but also upon the character of the load.

Postural control and movement performance during upper limb tasks in children with developmental co-ordination disorder (DCD)

At least 6% of primary school aged children present with DCD, where co-ordination is substantially below the normal range for the child’s age and intelligence. Motor skill difficulties negatively affect academic achievement, recreation and activities of daily living. Poor upper-limb co-ordination is a common difficulty for children with DCD. A possible cause of this problem is deviant muscle timing in proximal muscle groups, which results in poor postural and movement control. While studies have been published investigating postural control in response to external perturbations, detail about postural muscle activity during voluntary movement is limited even in children with normal motor development. No studies have investigated the relationship between muscle timing, resultant arm motion and upper-limb coordination deficits. Objectives: To investigate the relationship between functional difficulties with upper-limb motor skills and neuromuscular components of postural stability and coordination. Specifically, to investigate onset-timing of muscle activity, timing of arm movement, and resultant three-dimensional (3D) arm co-ordination during rapid, voluntary arm movement and to analyse differences arising due to the presence of DCD. This study is part of a larger research program investigating postural stability and control of upper limb movement in children. Design: A controlled, cross-sectional study of differences between children with and without DCD. Methods: This study included 50 children aged eight to 10 years (25 with DCD and 25 without DCD). Children participated in assessment of motor skills according to the Movement ABC Test and a laboratory study of rapid, voluntary arm movements. Parameters investigated included muscle activation timing of shoulder and trunk muscles (surface electromyography), arm movement timing (light sensor) and resultant 3D arm motion (Fastrak). Results: A MANOVA is being used to analyse between-group differences. Preliminary results indicate children with DCD demonstrate altered muscle timing during a rapid arm raise when compared with the control group of children. Conclusion: Differences in proximal muscle timing in children with DCD support the hypothesis that altered proximal muscle activity may contribute to poor proximal stability and consequently poor arm movement control. This has implications for clinical physiotherapy.

The tidiest revolution: Regulative feminist autobiography and the de-facement of the Australian women's movement

Examines the use of writing autobiographies as a feminist strategy for expanding and realigning the historical record. Significance of autobiographies in describing the oppression experienced by women in the society; Discussion on three memoirs by Australian feminist activists Susan Ryan, Wendy McCarthy and Anne Summers; Analysis of the textual strategies employed and the paradoxes that emerged from the memoirs; Details on the use of prosopopoeia in autobiographies.

Comparison of lumbar range of movement and lumbar lordosis in back pain patients and matched controls

Inconclusive findings have been shown in previous studies comparing lumbar range of movement (LROM) and lumbar lordosis between back pain patients and healthy subjects. In these studies, confounding variables such as age, gender, height, obesity, and pain level were usually not well controlled. The present study aimed to compare LROM and lumbar lordosis between back pain patients and matched controls. Fifteen male back pain patients and 15 age-, height-, obesity-, and physical activity-matched male controls were investigated. To minimize the effect of pain on the measurements, only patients with minimal or no pain at the time of testing were included in the study. Inclinometer technique was used for the evaluation of LROM in flexion, extension and lateral flexion as well as lumbar lordosis. A lumbar rotameter was used for measuring axial rotation. Pelvic motion was limited by a pelvic restraint device during LROM measurements. Results showed that there were no significant differences between the back pain and control groups in flexion, extension, lateral flexion and axial rotation LROM and also in lumbar lordosis. This may indicate that when a back pain patient is not in pain, LROM and lumbar lordosis may not be the measures that distinguish between back pain patients and subjects without back pain.

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.

Um corpo-dissertação em movimento : uma questão de aprendizagem

Este trabalho ganha corpo a partir das experiências do antropólogo Carlos Castaneda. Além de ponto de partida para pensar as questões relativas ao corpo, o movimento e aprendizagem, as obras A Erva do diabo, Uma estranha realidade e Porta para o infinito, do autor mencionado, comparecem aqui para 1) investigarmos os relatos de experiência; 2) apresentarmos alguns conceitos-chaves, relativos a aprendizagem da “feitiçaria”, tal como a vontade. Vale frisar que nosso interesse na obra de Castaneda, não está nas questões místicas do xamanismo, nem mesmo nos pontos relativos ao campo da antropologia, mas na questão da aprendizagem. Para Dom Juan, o vellho índio feiticeiro e principal mestre de Carlos Castaneda, o propósito final do aprendizado da feitiçaria é justamente tornar-se um homem de conhecimento. Com o objetivo de analisar o lugar do movimento e do corpo no processo de aprendizagem, faremos o seguinte percurso analítico: de Skinner e Piaget abordaremos respectivamente a aprendizagem do comportamento operante e a aprendizagem em sentido amplo. Em seguida, apresentamos o pensamento de Francisco Varela e Bruno Latour, principalmente os conceitos de enação, corpos articulados e aprendizagem por afetação. Com Vincianne Despret discutiremos o aspecto afectivo, corporal e involuntário da aprendizagem. Com este apanhado conceitual, visamos então colocar em análise os efeitos ético-políticos dos modos de produção de conhecimento, efeitos irremediavelmente neste corpo-dissertação, e mais ainda efeitos na vida. Por fim, ao que parece, as modulações nos conceitos de corpo, movimento/ação, ao longo da exposição dos autores indicaram, por vezes, a participação de outros elementos, tais como a vontade e a percepção-atenção, implicando variações na forma de conceber a aprendizagem. Percebemos que de acordo com a formulação de aprendizagem e as nuances do movimento/ação e do corpo, isto implica produções diferenciadas de conhecimento e de realidade.

Evaluating the Guimarães 2012 European Capital of Culture (ECOC): a Tourist Perception Approach

Guimarães has hosted, during the year of 2012, one of the European Capital of Culture (ECOC). The evaluation of the event is needed as public, private and community funds are involved. The approach considers the tourists (domestic and international) as external and independent stakeholders who assessed the cultural activities developed during the event and the attributes of the city. The results of the survey show that hosting the 2012 ECOC was a major contribution for attracting new visitors to the city, although many of them just for a short period of time. The main source of general information collected by tourists was the Internet, and the traditional media. Only a small amount of respondents demonstrated a specialized knowledge of the cultural program. The most cited and appreciated performances came from the areas of music, exhibitions, and theatre. According to the perceptions of tourists, the tangible assets were clearly detached from the set of attributes of Guimarães, including buildings, churches and chapels, whereas intangible assets were less noted. Overall, Guimarães received a very positive evaluation related to city image and stay and is highly recommended by tourists to friends and relatives.

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.

Residents’ perception of the benefits of cultural tourism: the case of Guimarães

In many cities throughout Europe and the rest of the world, cultural tourism plays a major role in local economic development. Tourism also acts to preserve cultural heritage, as it provides a way to acquire the revenue needed to restore and preserve historical buildings, and encourages local people to value their traditions and festivals. However, tourism success can be a double-edged sword with tourist flows having a strong impact on the quality of life of residents when certain tourist thresholds are surpassed. This paper aims to address local residents’ perception of the benefits of cultural tourism. To capture their perception, a survey was implemented, addressed to both the city centre inhabitants and the non-urban residents of the Guimarães municipality.