972 resultados para Movement Pattern
Resumo:
Sox18 encodes a member of the Sry-related high mobility group box (SOX) family of developmental transcription factors. Examination of Sox18 expression during embryogenesis has shown that Sox18 is expressed transiently in endothelial cells of developing blood vessels, and mutations in Sox18 have been found to underlie the mouse vascular and hair follicle mutant ragged. In this study we have examined the expression of Sox18 in angiogenesis during wound healing. Full-thickness skin wounds were created in mice, and subsequent expression of vascular endothelial growth factor (VEGF), the VEGF receptor Flk-1, alpha1 (iv) collagen (Col4a1), and Sox18 were studied using in situ hybridization. As has been previously reported, VEGF was expressed predominantly in the keratinocytes at the wound margins. Sox18 expression was found Rye days after wounding during capillary sprouting in granulation tissue and persisted through the proliferative phase of healing, but was not detected in fully epithelialized wounds 21 days after wounding. Sox18 mRNA expression was detected in capillaries within the granulation tissue and showed an identical pattern of distribution to Flk-1 and Col4a1 mRNA expression in endothelial cells. Immunostaining with a polyclonal anti-Sox18 antibody showed SOX18 protein localized in capillary endothelial cells within the granulation tissue. capillaries in the subcutaneous tissue of unwounded skin showed no Sox18 expression. Sox18 may therefore represent a transcription factor involved in the induction of angiogenesis during wound healing and tissue repair, but not in the maintenance of endothelial cells in undamaged tissue.
Resumo:
The homeotic genes are instrumental in establishing segment-specific characteristics. In Drosophila embryos there is ample evidence that the homeotic genes are involved in establishing the differences in the pattern of sense organs between segments. The chordotonal organs are compound sense organs made up of several stretch receptive sensilla. A set of serially homologous chordotonal organs, Ich3 in the 1(st) thoracic segment, dch3 in the 2(nd) and 3(rd) thoracic segments and Ich5 in abdominal segments 1 to 7, is composed of different numbers of sensilla with different positions and orientations. Here we examine this set of sense organs and a companion set, vchA/B and vch 1, in the wild type and mutants for Sex combs reduced, Antennapedia, Ultrabithorax, and abdominal-A, using immunostaining. Mutant phenotypes indicate that Ultrabithorax and abdominal-A in particular influence the formation of these sense organs. Differential expression of abdominal-A and Ultrabithorax within compartments of individual parasegments can precisely modulate the types of sense organs that will arise from a segment.
Resumo:
Observations of an insect's movement lead to theory on the insect's flight behaviour and the role of movement in the species' population dynamics. This theory leads to predictions of the way the population changes in time under different conditions. If a hypothesis on movement predicts a specific change in the population, then the hypothesis can be tested against observations of population change. Routine pest monitoring of agricultural crops provides a convenient source of data for studying movement into a region and among fields within a region. Examples of the use of statistical and computational methods for testing hypotheses with such data are presented. The types of questions that can be addressed with these methods and the limitations of pest monitoring data when used for this purpose are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
Resumo:
Objective: To document the acute characteristics of swallowing impairment in a group of children post moderate/severe traumatic brain injury (TBI) by means of videofluoroscopy. Participants: Eighteen children with moderate/severe TBI. Main Outcome Measure: Videofluoroscopy at an average of 27.7 days post-injury. Results: Subjects demonstrated a range of dysphagia severity levels: mild-moderate (n = 8), moderate (n = 6), moderate-severe (n = 3), and severe (n = 1) and had a combination of oral and pharyngeal phase characteristics. More specifically; observable features or physiological impairments that were identified included reduced lingual control, hesitancy of tongue movement, repetitive tongue pumping, the presence of aspiration (including silent aspiration), delayed swallow reflex trigger, reduced laryngeal elevation and closure, and reduced peristalsis. Conclusions: These data highlight the diversity of swallowing deficits and dysphagia severity levels in children following TBI and suggest that the former are consistent with a pattern of oropharyngeal impairments.
Resumo:
This article reviews the empirical and theoretical bases for recommendations regarding lifting technique. Lifting from postures involving extreme lumbar vertebral flexion, (approximately 60degrees of lumbar flexion, characterised by absence of electromyographical activity in erector spinae) has the potential to contribute to damage to ligaments and intervertebral discs, especially if combined with lateral flexion or rotation. The only appropriate recommendation regarding posture of the lumbar spine during lifting is to avoid postures involving extreme lumbar vertebral flexion (and rotation and lateral flexion). There is no empirical basis for avoiding postures involving moderate lumbar vertebral flexion, and no justification for advocating lifting from a full squat posture. Further, lifting from semi-squat postures, involving a moderate range of flexion at both knees and trunk, allows a pattern of interjoint coordination which appears to be functional in reducing muscular effort. Lifting training is generally ineffective, and there is unlikely to be a single best technique which is appropriate in all situations. Consequently, it may be preferable to provide education in general lifting guidelines and assist lifters to discover individually appropriate postures and patterns of movement. The article concludes by presenting recommendations for lifting technique which are justified by current knowledge.
Resumo:
Objective: To assess the intrarater and interrater reliability among rheumatologists of a standardised protocol for measurement of shoulder movements using a gravity inclinometer. Methods: After instruction, six rheurnatologists independently assessed eight movements of the shoulder, including total and glenohumeral flexion, total and glenohumeral abduction, external rotation in neutral and in abduction, internal rotation in abduction and hand behind back, in random order in six patients with shoulder pain and stiffness according to a 6x6 Latin square design using a standardised protocol. These assessments were then repeated. Analysis of variance was used to partition total variability into components of variance in order to calculate intraclass correlation coefficients (ICCs). Results: The intrarater and interrater reliability of different shoulder movements varied widely. The movement of hand behind back and total shoulder flexion yielded the highest ICC scores for both intrarater reliability (0.91 and 0.83, respectively) and interrater reliability (0.80 and 0.72, respectively). Low ICC scores were found for the movements of glenohumeral abduction, external rotation in abduction, and internal rotation in abduction (intrarater ICCs 0.35, 0.43, and 0.32, respectively), and external rotation in neutral, external rotation in abduction, and internal rotation in abduction (interrater ICCs 0.29, 0.11, and 0.06, respectively). Conclusions: The measurement of shoulder movements using a standardised protocol by rheumatologists produced variable intrarater and interrater reliability. Reasonable reliability was obtained only for the movement of hand behind back and total shoulder flexion.
Resumo:
The aim of this study was to determine the effects of 7 weeks of high- and low-velocity resistance training on strength and sprint running performance in nine male elite junior sprint runners (age 19.0 +/- 1.4 years, best 100 m times 10.89 +/- 0.21 s; mean +/- s). The athletes continued their sprint training throughout the study, but their resistance training programme was replaced by one in which the movement velocities of hip extension and flexion, knee extension and flexion and squat exercises varied according to the loads lifted (i.e. 30-50% and 70-90% of 1-RM in the high- and low-velocity training groups, respectively). There were no between-group differences in hip flexion or extension torque produced at 1.05, 4.74 or 8.42 rad . s(-1), 20 m acceleration or 20 m 'flying' running times, or 1-RM squat lift strength either before or after training. This was despite significant improvements in 20 m acceleration time (P < 0.01), squat strength (P< 0.05), isokinetic hip flexion torque at 4.74 rad . s(-1) and hip extension torque at 1.05 and 4.74 rad . s(-1) for the athletes as a whole over the training period. Although velocity-specific strength adaptations have been shown to occur rapidly in untrained and non-concurrently training individuals, the present results suggest a lack of velocity-specific performance changes in elite concurrently training sprint runners performing a combination of traditional and semi-specific resistance training exercises.
Resumo:
Developments in computer and three dimensional (3D) digitiser technologies have made it possible to keep track of the broad range of data required to simulate an insect moving around or over the highly heterogeneous habitat of a plant's surface. Properties of plant parts vary within a complex canopy architecture, and insect damage can induce further changes that affect an animal's movements, development and likelihood of survival. Models of plant architectural development based on Lindenmayer systems (L-systems) serve as dynamic platforms for simulation of insect movement, providing ail explicit model of the developing 3D structure of a plant as well as allowing physiological processes associated with plant growth and responses to damage to be described and Simulated. Simple examples of the use of the L-system formalism to model insect movement, operating Lit different spatial scales-from insects foraging on an individual plant to insects flying around plants in a field-are presented. Such models can be used to explore questions about the consequences of changes in environmental architecture and configuration on host finding, exploitation and its population consequences. In effect this model is a 'virtual ecosystem' laboratory to address local as well as landscape-level questions pertinent to plant-insect interactions, taking plant architecture into account. (C) 2002 Elsevier Science B.V. All rights reserved.
Resumo:
Here we consider the role of abstract models in advancing our understanding of movement pathology. Models of movement coordination and control provide the frameworks necessary for the design and interpretation of studies of acquired and developmental disorders. These models do not however provide the resolution necessary to reveal the nature of the functional impairments that characterise specific movement pathologies. In addition, they do not provide a mapping between the structural bases of various pathologies and the associated disorders of movement. Current and prospective approaches to the study and treatment of movement disorders are discussed. It is argued that the appreciation of structure-function relationships, to which these approaches give rise, represents a challenge to current models of interlimb coordination, and a stimulus for their continued development. (C) 2002 Elsevier Science B.V. All rights reserved.
Resumo:
AB Study Design. A cross-sectional study was conducted. Objective. To determine the activity of the deep and superficial fibers of the lumbar multifidus during voluntary movement of the arm. Summary of Background Data. The multifidus contributes to stability of the lumbar spine. Because the deep and superficial parts of the multifidus are near the center of lumbar joint rotation, the superficial fibers are well suited to control spine orientation, and the deep fibers to control intervertebral movement. However, there currently are limited in vivo data to support this distinction. Methods. Electromyographic activity was recorded in both the deep and superficial multifidus, transversus abdominis, erector spinae, and deltoid using selective intramuscular electrodes and surface electrodes during single and repetitive arm movements. The latency of electromyographic onset in each muscle during single movements and the pattern of electromyographic activity during repetitive movements were compared between muscles. Results. With single arm movements, the onset of electromyography in the erector spinae and superficial multifidus relative to the deltoid was dependent on the direction of movement, but the onset in the deep multifidus and transversus abdominis was not. With repetitive arm movements, peaks in superficial multifidus and erector spinae electromyography occurred only during flexion for most subjects, whereas peaks in deep multifidus electromyography occurred during movement in both directions. Conclusions. The deep and superficial fibers of the multifidus are differentially active during single and repetitive movements of the arm. The data from this study support the hypothesis that the superficial multifidus contributes to the control of spine orientation, and that the deep multifidus has a role in controlling intersegmental motion. (C) 2002 Lippincott Williams & Wilkins, Inc.
Resumo:
Although largely solitary, humpback whales exhibit a number of behaviours where individuals co-operate with one another, for example during bubble net feeding. Such cases could be due to reciprocal altruism brought on by exceptional circumstances, for example the presence of abundant shoaling fish. An alternative explanation is that these behaviours have evolved through kin selection. With little restriction to either communication or movement, diffuse groups of relatives could maintain some form of social organization without the need to travel in tight-nit units. To try to distinguish between these hypotheses, we took advantage of the fact that migrating humpback whales often swim together in small groups. If kin selection is important in humpback whale biology, these groups should be enriched for relatives. Consequently, we analysed biopsy samples from 57 groups of humpback whales migrating off Eastern Australia in 1992. A total of 142 whales were screened for eight microsatellite markers. Mitochondrial DNA sequences (371 bp) were also used to verify and assist kinship identification. Our data add support to the notion that mothers travel with their offspring for the first year of the calf's life. However, beyond the presence of mother-calf/yearling pairs, no obvious relatedness pattern was found among whales sampled either in the same pod or on the same day. Levels of relatedness did not vary between migratory phases (towards or away from the breeding ground), nor between the two sexes considered either overall or in the north or south migrations separately. These findings suggest that, if any social organization does exist, it is formed transiently when needed rather than being a constant feature of the population, and hence is more likely based on reciprocal altruism than kin selection.
Resumo:
Breast screening programmes have facilitated more conservative approaches to the surgical and radiotherapy management of women diagnosed with breast cancer. This study investigated changes in shoulder movement after surgery for primary, operable breast cancer to determine the effect of elective physiotherapy intervention. Sixty-five women were randomly assigned to either the treatment (TG) or control group (CG) and assessments were completed preoperatively, at day 5 and at 1 month, 3, 6, 12 and 24 months postoperatively. The CG only received an exercise instruction booklet in comparison to the TG who received the Physiotherapy Management Care Plan (PMCP). Analyses of variance revealed that abduction returned to preoperative levels more quickly in the TG than in the CG. The TG women had 14degrees more abduction at 3 months and 7degrees at 24 months. Functional recovery at 1 month was greater in those randomised to the TG, with a dominant operated arm (OA) or receiving breast-conserving surgery. However, it was not possible to predict recovery over the 2 years postoperatively on the basis of an individual woman's recovery at 1 month postoperatively. The eventual recovery of abduction or flexion range of movement was not related to the dominance of the OA nor to the surgical procedure performed. The PMCP provided in the early postoperative period is effective in facilitating and maintaining the recovery of shoulder movement over the first 2 years after breast cancer surgery.