996 resultados para face muscle


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Natural ecosystems are increasingly exposed to multiple anthropogenic stressors, including land-use change, deforestation, agricultural intensification, and urbanisation, all of which have led to widespread habitat fragmentation, which is also likely to be amplified further by predicted climate change. The potential interactive effects of these different stressors cannot be determined by studying each in isolation, although such synergies have been largely ignored in ecological field studies to date. Here, we use a model system of naturally fragmented islands in a braided river network, which is exposed to periodic inundation, to investigate the interactive effects of habitat isolation and flood disturbance. Food web structure was similar across the islands during periods of hydrological stability, but several key properties were altered in the aftermath of flood disturbance, based on distance of the islands from the regional source pool of species: taxon richness and mean food chain length declined with habitat isolation after flooding, while the proportion of basal species increased. Greater species turnover through time reflected the slower process of re-colonisation on the more distant islands following disturbance. Increased variability of several food web properties over a 1-year period highlighted the reduced temporal stability of isolated habitat fragments. Many of these effects reflected the differential successes of predator and prey species at re-colonising the islands: even though larger, more mobile consumers may reach the more distant islands first, they cannot establish populations until the lower trophic levels have successfully reassembled. These results highlight the susceptibility of fragmented ecosystems to environmental perturbations. © 2013 Elsevier Ltd.

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This chapter describes an experimental system for the recognition of human faces from surveillance video. In surveillance applications, the system must be robust to changes in illumination, scale, pose and expression. The system must also be able to perform detection and recognition rapidly in real time. Our system detects faces using the Viola-Jones face detector, then extracts local features to build a shape-based feature vector. The feature vector is constructed from ratios of lengths and differences in tangents of angles, so as to be robust to changes in scale and rotations in-plane and out-of-plane. Consideration was given to improving the performance and accuracy of both the detection and recognition steps.

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Aim: To determine whether the use of an online or blended learning paradigm has the potential to enhance the teaching of clinical skills in undergraduate nursing.

Background: The need to adequately support and develop students in clinical skills is now arguably more important than previously considered due to reductions in practice opportunities. Online and blended teaching methods are being developed to try and meet this requirement, but knowledge about their effectiveness in teaching clinical skills is limited.

Design: Mixed methods systematic review, which follows the Joanna Briggs Institute User guide version 5.

Data Sources: Computerized searches of five databases were undertaken for the period 1995-August 2013.

Review Methods: Critical appraisal and data extraction were undertaken using Joanna Briggs Institute tools for experimental/observational studies and interpretative and critical research. A narrative synthesis was used to report results.

Results: Nineteen published papers were identified. Seventeen papers reported on online approaches and only two papers reported on a blended approach. The synthesis of findings focused on the following four areas: performance/clinical skill, knowledge, self-efficacy/clinical confidence and user experience/satisfaction. The e-learning interventions used varied throughout all the studies.

Conclusion: The available evidence suggests that online learning for teaching clinical skills is no less effective than traditional means. Highlighted by this review is the lack of available evidence on the implementation of a blended learning approach to teaching clinical skills in undergraduate nurse education. Further research is required to assess the effectiveness of this teaching methodology.

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Objectives: To examine the association between fruit and vegetable (FV) consumption and muscle strength and power in an adolescent population. Methods: We conducted a cross-sectional analysis among 1019 boys and 998 girls, aged 12 and 15 years, who participated in The Young Hearts Project. FV consumption (excluding potatoes) was assessed by 7-d diet history. Grip strength and jump power was assessed with a dynamometer and Jump-MD meter, respectively. Associations between FV consumption and strength and power were assessed by regression modelling. Results: Boys and girls with the highest FV intakes (>237.71 g/d and >267.57 g/d, respectively, based on the highest tertile) had significantly higher jump power than those with the lowest intakes (<135.09 g/d and <147.43 g/d, respectively), after adjustment for confounding factors. Although girls with the highest FV intakes had higher grip strength than those with the lowest intakes, no significant independent associations were evident between FV intake and grip strength in boys or girls. Similar findings were observed when FV were analysed separately.Conclusions: Higher FV consumption in this group of adolescents was positively associated with muscle power. There was no independent association between higher FV consumption and muscle strength. Intervention studies are required to determine whether muscle strength and power can be improved through increased FV consumption.

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The particular microenvironment of the skeletal muscle can be the site of complex immune reactions. Toll-like receptors (TLRs) mediate inflammatory stimuli from pathogens and endogenous danger signals and link the innate and adaptive immune system. We investigated innate immune responses in human muscle. Analyzing TLR1-9 mRNA in cultured myoblasts and rhabdomyosarcoma cells, we found constitutive expression of TLR3. The TLR3 ligand Poly (I:C), a synthetic analog of dsRNA, and IFN-gamma increased TLR3 levels. TLR3 was mainly localized intracellularly and regulated at the protein level. Poly (I:C) challenge 1) activated nuclear factor-kappaB (NF-kappaB), 2) increased IL-8 release, and 3) up-regulated NKG2D ligands and NK-cell-mediated lysis of muscle cells. We examined muscle biopsy specimens of 6 HIV patients with inclusion body myositis/polymyositis (IBM/PM), 7 cases of sporadic IBM and 9 nonmyopathic controls for TLR3 expression. TLR3 mRNA levels were elevated in biopsy specimens from patients with IBM and HIV-myopathies. Muscle fibers in inflammatory myopathies expressed TLR3 in close proximity of infiltrating mononuclear cells. Taken together, our study suggests an important role of TLR3 in the immunobiology of muscle, and has substantial implications for the understanding of the pathogenesis of inflammatory myopathies or therapeutic interventions like vaccinations or gene transfer.

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Recent work suggests that the human ear varies significantly between different subjects and can be used for identification. In principle, therefore, using ears in addition to the face within a recognition system could improve accuracy and robustness, particularly for non-frontal views. The paper describes work that investigates this hypothesis using an approach based on the construction of a 3D morphable model of the head and ear. One issue with creating a model that includes the ear is that existing training datasets contain noise and partial occlusion. Rather than exclude these regions manually, a classifier has been developed which automates this process. When combined with a robust registration algorithm the resulting system enables full head morphable models to be constructed efficiently using less constrained datasets. The algorithm has been evaluated using registration consistency, model coverage and minimalism metrics, which together demonstrate the accuracy of the approach. To make it easier to build on this work, the source code has been made available online.

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Background: This study was designed to evaluate the structures, muscles, and fasciae of which the modiolus is composed. It can aid in the understanding and, therefore, the utilization of plastic surgery for the aesthetic or reconstructive treatment of that region, especially the angle of the mouth. Methods: Dissections of the midface were done on five different cadavers. They were of different races (3 males, 2 females). The anatomy of the modiolus was studied in detail. New anatomical observations were classified as type I through type VI. Results: The perifacial artery fascia contributed to the modiolus in four (80%) specimens and was not part of it in 1 (20%) specimen. The facial artery was anterior to it in one (20%) specimen, lateral in four (80%) specimens, and never medial to it. No significant relationship was observed between the perifacial artery fascia contribution to the modiolus and gender or race. Also, the location of the facial artery lateral or anterior to the modiolus was not significantly related to gender or race. In addition, the deep and superficial fasciae of the face converged not anterior to the masseter muscle but actually at the modiolus, which was different from observations made by others. Conclusion: The modiolus is of critical importance in aesthetic and reconstructive plastic surgery of the face. © 2008 Springer Science+Business Media, LLC and International Society of Aesthetic Plastic Surgery.

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Objective: The present investigation has been designed to study the incidence of the rectus stern muscle in German human cadavers dissected in the Kingdom of Saudi Arabia, trying to find a postulation for the development of such muscle when present. Design: Gross dissection of 130 cadavers, of both sexes, was performed throughout a period of 10 years. Setting: Department of Anatomy College of Medicine, King Faisal University, Dammam, Saudi Arabia. Intervention: Investigation of the origin and insertion of the rectus sterni and measurements of its length and width. Results: Two adult cadavers, one of each sex, had shown well-developed bilateral rectus stern muscles. All muscles identified were parasternal in position, being superficial to the medial portion of the pectoralis major muscle. Minor morphological differences were observed among the four muscle masses concerning their length, breadth, origin and insertion. Conclusion: The current study has determined the incidence of the rectus sterni muscle, in German cadavers to be 1.54% per bodies examined compared to 4% in cadavers from Saudis. Such a frequency is compared to that reported in different geographic populations. The rectus sterni muscle is innervated by the anterior cutaneous branches of the intercostal nerves. The description of the rectus sterni muscle and its incidence determined in the present study, might be of a great help for clinicians radiographing or tackling the pectoral region.

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The abductor hallucis flap is commonly used as a pedicled flap (distally or proximally based) in the management of ankle, heel, and mid-foot lesions, where it is ideally used for closing defects. This study investigates the anatomical details of this muscle regarding its various forms of insertion and its arterial supply in 15 cadaveric feet. Four types of insertion could be distinguished: type A, insertion at the proximal phalanx of the big toe (46.7%); type B, insertion by two slips into the base of the proximal phalanx and the sesamoid bone (33.3%); type C, insertion at the sesamoid bone (6.7%); And type D, the insertion is divided into superficial tendinous and deep fleshy parts which are attached to the base of the proximal phalanx and to the metatarsophalangeal joint capsule of the big toe, respectively (13.3%). As regards the arterial supply, three patterns were noticed: pattern A (40%) where the medial plantar artery (MPA) is divided into superficial and deep branches that supplied the muscle; pattern B (53.3%) where the MPA failed to produce a deep branch but instead continued as the superficial branch supplying the two ends of the muscle; and pattern C (6.6%) where the MPA continued as a deep branch supplying the muscle. A superficial branch of MPA provided a branch to the abductor hallucis muscle from its proximal part. In two specimens (13.3%), the lateral plantar artery shared in the supply of the most proximal part of the muscle. These results can be useful in determining the appropriate flap design based on the abductor hallucis type of insertion and the pattern of its arterial supply in the patients.