928 research outputs found
Skeletal Dysplasias Associated with Mild Myopathy—A Clinical and Molecular Review
Musculoskeletal system is a complex assembly of tissues which acts as scaffold for the body and enables locomotion. It is often overlooked that different components of this system may biomechanically interact and affect each other. Skeletal dysplasias are diseases predominantly affecting the development of the osseous skeleton. However, in some cases skeletal dysplasia patients are referred to neuromuscular clinics prior to the correct skeletal diagnosis. The muscular complications seen in these cases are usually mild and may stem directly from the muscle defect and/or from the altered interactions between the individual components of the musculoskeletal system. A correct early diagnosis may enable better management of the patients and a better quality of life. This paper attempts to summarise the different components of the musculoskeletal system which are affected in skeletal dysplasias and lists several interesting examples of such diseases in order to enable better understanding of the complexity of human musculoskeletal system
Pattern Formation by Boundary Forcing in Convectively Unstable, Oscillatory Media With and Without Differential Transport
Motivated by recent experiments and models of biological segmentation, we
analyze the exicitation of pattern-forming instabilities of convectively
unstable reaction-diffusion-advection (RDA) systems, occuring by means of
constant or periodic forcing at the upstream boundary. Such boundary-controlled
pattern selection is a generalization of the flow-distributed oscillation (FDO)
mechanism that can include Turing or differential flow instability (DIFI)
modes. Our goal is to clarify the relationships among these mechanisms in the
general case where there is differential flow as well as differential
diffusion. We do so by analyzing the dispersion relation for linear
perturbations and showing how its solutions are affected by differential
transport. We find a close relationship between DIFI and FDO, while the Turing
mechanism gives rise to a distinct set of unstable modes. Finally, we
illustrate the relevance of the dispersion relations using nonlinear
simulations and we discuss the experimental implications of our results.Comment: Revised version with added content (new section and figures added),
changes to wording and organizatio
Exercise dependence and muscle dysmorphia in novice and experienced female bodybuilders
Background and aims:
Extensive research has shown that male bodybuilders are at high risk for exercise dependence, but few studies have measured these variables in female bodybuilders. Prior research has postulated that muscular dysmorphia was more prevalent in men than women, but several qualitative studies of female bodybuilders have indicated that female bodybuilders show the same body image concerns. Only one study has compared female bodybuilders with control recreational female lifters on eating behaviors, body image, shape pre-occupation, body dissatisfaction, and steroid use. The purpose of this study was to compare exercise dependence and muscle dysmorphia measures between groups of female weight lifters.
Methods:
Seventy-four female lifters were classified into three lifting types (26 expert bodybuilders, 10 or more competitions; 29 novice bodybuilders, 3 or less competitions; and 19 fitness lifters, at least 6 months prior lifting) who each completed a demographic questionnaire, the Exercise Dependence Scale (EDS), the Drive for Thinness scale (DFT) of the Eating Disorder Inventory-2, the Bodybuilding Dependence Scale (BDS), and the Muscle Dysmorphia Inventory (MDI).
Results:
Female bodybuilders scored higher than fitness lifters for EDS Total, BDS Training and Social Dependence, and on Supplement Use, Dietary Behavior, Exercise Dependence, and Size Symmetry scales of the MDI.
Discussion and conclusions:
Female bodybuilders seem to be more at risk for exercise dependence and muscle dysmorphia symptoms than female recreational weight lifters
The classification and structure of megafaunal assemblages in the Venezuela Basin, Caribbean Sea
Data from 23 benthic trawls collected from the Venezuela Basin (3411–5062 m water depth) indicate that megafauna are less abundant than in basins of similar depths in the Atlantic and are segregated by sedimentary province. Taxonomic assemblages, in terms of abundance and biomass, from three sites coincide with distinctions of sedimentary characteristics among the pelagic, hemipelagic and turbidite sedimentary provinces. Mollusks, decapods and fishes are most abundant in trawls collected from the pelagic and hemipelagic provinces and anemones and holothurians are most abundant in trawls collected from the turbidite province. Sponges dominate the biomass of fauna in trawls collected in the turbidite and hemipelagic provinces and fishes dominate the biomass of trawls collected in the pelagic province. Several biological and physical aspects of the basin contribute to the segregation of the megafauna into distinct communities. Sponges and anthropogenic debris (coal, coal clinker and tar balls) reaching the sea floor create a habitat that is exploited by sessile suspension feeders requiring a hard substrate. Filter-feeding anemones attached to debris occur in such abundance that it elevates the importance of suspension feeders and depresses species diversity at the turbidite site. Biomass and average size of megafaunal deposit feeders in the basin decrease with decreasing amounts of organic carbon and nitrogen content of the sediment. Distribution and composition of filter-feeding megafaunal biomass in the Venezuela Basin are explained largely by proximity to sources of organic matter. Detrital carbonate may also play a role in controlling distribution and density of megafauna by diluting food resources in the sediments
Structural and magnetic properties of Co-Mn-Sb thin films
Thin Co-Mn-Sb films of different compositions were investigated and utilized
as electrodes in alumina based magnetic tunnel junctions with CoFe counter
electrode. The preparation conditions were optimized with respect to magnetic
and structural properties. The Co-Mn-Sb/Al-O interface was analyzed by X-ray
absorption spectroscopy and magnetic circular dichroism with particular focus
on the element-specific magnetic moments. Co-Mn-Sb crystallizes in different
complex cubic structures depending on its composition. The magnetic moments of
Co and Mn are ferromagnetically coupled in all cases. A tunnel magneto
resistance ratio of up to 24 % at 13K was found and indicates that Co-Mn-Sb is
not a ferromagnetic half-metal. These results are compared to recent works on
the structure and predictions of the electronic properties.Comment: 8 pages, 9 figure
A New Discriminator for Gamma-Ray Burst Classification: The Epeak-Fluence Energy Ratio
Using the derived gamma-ray burst E_peak and fluences from the complete BATSE
5B Spectral Catalog, we study the ensemble characteristics of the
E_peak-fluence relation for GRBs. This relation appears to be a physically
meaningful and insightful fundamental discriminator between long and short
bursts. We discuss the results of the lower limit test of the E_peak-E_iso
relations in the E_peak-fluence plane for BATSE bursts with no observed
redshift. Our results confirm the presence of two GRB classes as well as
heavily suggesting two different GRB progenitor types.Comment: 8 pages, 3 figures, accepted for publication in Ap
Average Emissivity Curve of BATSE Gamma-Ray Bursts with Different Intensities
Six intensity groups with ~150 BATSE gamma-ray bursts each are compared using
average emissivity curves. Time-stretch factors for each of the dimmer groups
are estimated with respect to the brightest group, which serves as the
reference, taking into account the systematics of counts-produced noise effects
and choice statistics. A stretching/intensity anti-correlation is found with
good statistical significance during the average back slopes of bursts. A
stretch factor ~2 is found between the 150 dimmest bursts, with peak flux
4.1 ph
cm^{-2} s^{-1}. On the other hand, while a trend of increasing stretching
factor may exist for rise fronts for burst with decreasing peak flux from >4.1
ph cm^{-2} s^{-1} down to 0.7 ph cm^{-2} s^{-1}, the magnitude of the
stretching factor is less than ~ 1.4 and is therefore inconsistent with
stretching factor of back slope.Comment: 21 pages, 3 figures. Accepted to Ap
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