45 research outputs found
Effects of immobilization by 60 days of experimental bed rest on endomysium of the soleus muscle in humans
Movements result from contracting skeletal muscles. Muscles adapt to changing loads through hypertrophy (enlargement of muscle mass due to increased load) and atrophy (loss of muscle mass due to decreased load). Muscles are known to atrophy during immobilization and disuse. The two primary components of muscle are the muscle fibers (muscle cells) and intramuscular connective tissue. Intramuscular connective tissue can be categorized into endomysium (the smallest component which engulfs each individual muscle fiber), perimysium (which engulfs muscle bundles), and epimysium (which engulfs the muscle as a whole). It has been suggested that endomysium plays a key role for intramuscular force transmission. Animal data suggests that long-term immobilization results in increased endomysium content in the muscle while the muscle fibers themselves atrophy. This result has to date not been demonstrated in humans. Our objective was therefore to examine the endomysium content of the human soleus muscle during 60 days of bed rest.
Bed rest is an established model to investigate changes occurring in microgravity conditions. For muscle, these changes include, muscle fiber atrophy and a loss of muscle strength. A 6° head down tilt is commonly applied to simulate the altered fluid distribution which occurs in microgravity. The 60-day 6° head-down tilt AGBRESA bed rest study, on which this work is based, sought to examine short duration continuous and intermittent centrifugation, i.e., artificial gravity, as a countermeasure to the adverse effects of microgravity on the human body. A short-arm centrifuge at the :envihab in Cologne, Germany, was used to simulate gravity by pulling blood towards the lower extremities. Muscle biopsies of the soleus muscle, a muscle which bears significant loads during daily tasks such as walking and standing, were extracted from 21 healthy volunteers (14 men and 7 women) at three timepoints: at baseline before bed rest (BDC), and during day 6 and day 55 (HDT6 and HDT55) of the head-down tilt bed rest. The biopsies were frozen, sectioned, and stained for laminin γ-1, a protein of the muscle basement membrane, which surrounds each cell. Laminin γ-1 can be used to determine the intramuscular connective tissue area located in between the individual fibers. Two parameters were calculated: the endomysium-to-fiber-area ratio (EFAr, in %) and the endomysium-to-fiber number ratio (EFNr). EFAr can show an increase in endomysium while EFNr can differentiate between a relative increase, attributed to muscle fiber atrophy, and an absolute endomysium increase.
Muscle fibers atrophied by 16.6 % (SD 28.2 %) at HDT55 (p=0.0031) during bed rest. EFAr increased on day 55 (p<0.001), while EFNr showed no significant effect of bed rest (p=0.62). Neither intervention group showed significant effects in response to the use of short-arm centrifugation as a countermeasure to the adverse effects of microgravity on muscle fiber atrophy.
The results of an EFAr increase and EFNr stability are explainable by immobilization-induced muscle fiber atrophy. Assuming that the number of fibers remains constant during long-term immobilization, these results suggest an unchanged amount of endomysial connective tissue content coupled with an increase in the relative amount of connective tissue per muscle fiber. This change is likely to affect muscle stiffness and thus muscle function
Factors that Affect the Adoption of Mobile Banking in Case Commercial Bank of Ethiopia, Gambella People’s National Regional State Branch, Gambella, Ethiopia
The primary aim of this study was to examine factors influencing consumers’ adoption of mobile banking services Gambella region, Ethiopia. From the literature, seven determinant factors were identified. Each variable were measured by using yes or no questions. This study combines TAM and IDT along with perceived risk, awareness constructs and perceive trust. The primary data were collected using questionnaires distributed to customers of Commercial bank of Ethiopia for mobile banking users. The Statistical Package for Social Sciences (SPSS) version 20 was used to analyze the data. Descriptive and inferential statistics were used to address the research objectives and binary logistic regression analysis employed. The results revealed that, with exception of perceived risk, perceived usefulness, perceive ease of use; perceive trust, performance expectancy and awareness have positive and statistically significant with the adoption of mobile banking. This study recommended that, banks should encourage and create awareness to the public through emphasizing the benefits or advantages that can be gained from the mobile banking services to increase the adoption level and to provide further directions into mobile banking strategies for mobile network operators, banks and service provider to design and implement mobile banking services to yield higher consumer acceptance
The beneficial effect of physiotherapy on the cervical spine mobility of ACDF patients and healthy individuals: An original observational cohort comparison research protocol
Purpose: Population aging and certain behaviors associated with modern life are contributing factors for the increasing incidence of degenerative cervical spine conditions (DCSC), and the number of cervical spine surgeries every year is. Our aim was to determine, with an original research protocol, the impact of ACDF and physiotherapy on the range of motion and EMG parameters of patients suffering from DCSC. Patients and Methods: Two comparable subgroups of 29 patients each were recruited for the present investigation. The first cohort was composed of ACDF patients, whereas the second cohort was composed by healthy subjects. Inclinometry/Range of Motion (RoM) analyses of the neck, and cervical muscles electromyography (EMG) were used to evaluate the neck mobility. We investigated the effects of physiotherapy on ROM and EMG results in order to identify possible significant differences between healthy subjects and ACDF patients. Results: A total of 58 patients were included in the final cohort. Extensive statistical analysis disclosed that higher NDI values were associated with a reduction of the Extension and Rotation movements, NDI scores, were found to be negatively associated to EMG voltages for Rotation, independently of the physiotherapy performed either. Extension, Lateral Bending, and Rotation showed significant improvement after just one session of physiotherapy, whereas Flexion and Extension proved to be those that contributed most to the overall neck mobility. Conclusion: The cervical spine fusion contributes to an overall reduction of cervical mobility. This data is confirmed by inclinometer and EMG parameters. Physiotherapy increases neck mobility thus possibly improving the clinical status of patients
Estimación de Erosión Hidrica de Suelos para plan de Manejo del Campo Forestal Aguas Frías, Patagonia Argentina
AbstractIn Argentine Patagonia there exist large extensions of lands degraded by overgrazing, this favours soil water erosion. Two million hectares are eligible for forestation (Gallo et al. 2005), with some environmental limitations that require previous studies to prepare development and sustainability proposals. The study area is located in the right margin of the Litrán River, 25 kms of its estuary in Aluminé Lake (Province of Neuquén). In this area, some Mapuche (araucanian) communities carry out stock breeding (mainly goats) using a migrating system. This region presents very severe Aeolian and hydrological erosion.The objective of the afforestation management plan of this land, is the design of control measures, to stop erosion, like perimeter close, afforestation and structural measures for controlling erosional gully. It is then necessary, to characterize the actual and potential erosion, that would allow to carry out with measures monitoring to implement controls and mitigation.Paper presents, pedology map by interpreting and georreferencing satellite images by a Geographical Information System. (GIS).The mapping methodology was based in Hierarchical Classification of Landforms, which is the structure of the geopedology focus for mapping soil (Zinck, 1989). The classification of actual erosion was obtained from the method of the Bureau of Land Management (USDI) by visual inspection of seven aspects of erosion in surface. The estimation of the potential erosion of the floors of the forest field was carried out utilizing the Universal Soil Lost Equation (USLE) and ArcGis 9,2 (ESRI, 2006) to carry out the spatial analysis, obtaining a map of annual soil loss ( tn/has/year) with a spatial resolution of 30 m.The application of spatial analysis tools in the study of soil water erosion in Patagonia, Argentina contributes to the objective of defining define a program of development and adequate management, as a function of the state and degree of potential soil erosion.En la Patagonia Argentina existen grandes extensiones de tierras degradadas por sobrepastoreo lo cual favorece la erosión hídrica de los suelos. De éstas existen más de dos millones de hectáreas aptas para la forestación (Gallo et al. 2005), pero con limitaciones ambientales que requieren estudios tendientes a elaborar propuestas de desarrollo y sostenibilidad.El área en estudio situada en la margen derecha del Río Litrán, a 25 km de su desembocadura al Lago Aluminé de la Provincia de Neuquén, es utilizada por comunidades mapuche para realizar su actividad agropecuaria de producción caprina bajo un sistema trashumante y presenta erosión hídrica y eólica muy severa.Unos de los objetivos del plan de manejo del campo forestal es diseñar un conjunto de medidas de control de la erosión que incluyen cierre perimetral, forestación y medidas estructurales para el control de cárcavas.Resulta así necesario, caracterizar la erosión actual y la potencial, que además permitirá realizar el seguimiento de las medidas de control y mitigación a implementar.Con estos fines, para el campo forestal en estudio, se confeccionó un mapa geoedafológico a partir de la fotointerpretación y posterior georeferenciación utilizando un Sistema de Información Geográfica (SIG). La metodología de mapeo de suelos se basa en la Clasificación Jerárquica de Geoformas, que es la estructura del Enfoque Geoedafológico para el mapeo de suelos (Zinck, 1989). La clasificación de la erosión actual se realizó por el método del Bureau of Land Management (USDI) mediante inspección visual en el terreno de siete aspectos de erosión en superficie. La estimación de la erosión potencial de los suelos del campo forestal se realizó utilizando la Ecuación Universal de Perdida de Suelos (USLE) y ArcGis 9.2 (ESRI, 2006) para realizar el análisis espacial, obteniendo un mapa de pérdida anual de suelos en tn/ha/año con una resolución espacial de 30 m.La aplicación de herramientas de análisis espacial al estudio de la erosión hídrica de los suelos de la Patagonia Argentina contribuye al objetivo de definir un programa de desarrollo y manejo adecuado, en función del estado y grado de erosión potencial de los mismos.AbstractIn Argentine Patagonia there exist large extensions of lands degraded by overgrazing, this favours soil water erosion. Two million hectares are eligible for forestation (Gallo et al. 2005), with some environmental limitations that requireprevious studies to prepare development and sustainability proposals. The study area is located in the right margin of the Litrán River, 25 kms of its estuary in Aluminé Lake (Province of Neuquén). In this area, some Mapuche (araucanian) communities carry out stock breeding (mainly goats) using a migrating system. This region presents very severe Aeolian and hydrological erosion.The objective of the afforestation management plan of this land, is the design of control measures, to stop erosion, like perimeter close, afforestation and structural measures for controlling erosional gully.It is then necessary, to characterize the actual and potential erosion, that would allow to carry out with measures monitoring to implement controls and mitigation.Paper presents, pedology map by interpreting and georreferencing satellite images by a Geographical Information System. (GIS).The mapping methodology was based in Hierarchical Classification of Landforms, which is the structure of the geopedology focus for mapping soil (Zinck, 1989). The classification of actual erosion was obtained from the method of theBureau of Land Management (USDI) by visual inspection of seven aspects of erosion in surface. The estimation of the potential erosion of the floors of the forest field was carried out utilizing the Universal Soil Lost Equation (USLE) and ArcGis 9,2 (ESRI, 2006) to carry out the spatial analysis, obtaining a map of annual soil loss ( tn/has/year) with a spatial resolution of 30 m.The application of spatial analysis tools in the study of soil water erosion in Patagonia, Argentina contributes to the objective of defining define a program of development and adequate management, as a function of the state and degree of potential soil erosion
Effects of long-term immobilisation on endomysium of the soleus muscle in humans
Muscle fibres atrophy during conditions of disuse. Whilst animal data suggest
an increase in endomysium content with disuse, that information is not available
for humans. We hypothesised that endomysium content increases during
immobilisation. To test this hypothesis, biopsy samples of the soleus muscle
obtained from 21 volunteers who underwent 60 days of bed rest were analysed
using immunofluorescence-labelled laminin γ-1 to delineate individual muscle fibres
as well as the endomysium space. The endomysium-to-fibre-area ratio (EFAr, as a
percentage) was assessed as a measure related to stiffness, and the endomysium-tofibre-number ratio (EFNr) was calculated to determine whether any increase in EFAr
was absolute, or could be attributed to muscle fibre shrinkage. As expected, we found
muscle fibre atrophy (P = 0.0031) that amounted to shrinkage by 16.6% (SD 28.2%) on
day 55 of bed rest. ENAr increased on day 55 of bed rest (P < 0.001). However, when
analysing EFNr, no effect of bed rest was found (P = 0.62). These results demonstrate
that an increase in EFAr is likely to be a direct effect of muscle fibre atrophy. Based
on the assumption that the total number of muscle fibres remains unchanged during
55 days of bed rest, this implies that the absolute amount of connective tissue in
the soleus muscle remained unchanged. The increased relative endomysium content,
however, could be functionally related to an increase in muscle stiffness
Coupling climate and economic models in a cost-benefit framework: a convex optimization approach
In this paper we present a general method, based on a convex optimisation technique, that facilitates the coupling of climate and economic models in a cost-benefit framework. As a demonstration of the method, we couple an economic growth model à la Ramsey adapted from DICE-99 with an efficient intermediate complexity climate model, C-GOLDSTEIN, which has highly simplified physics, but fully 3-D ocean dynamics. As in DICE-99 we assume that an economic cost is associated with global temperature change: this change is obtained from the climate model which is driven by the GHG concentrations computed from the economic growth path. The work extends a previous paper in which these models were coupled in cost-effectiveness mode. Here we consider the more intricate cost-benefit coupling in which the climate impact is not fixed a priori. We implement the coupled model using an oracle-based optimisation technique. Each model is contained in an oracle which supplies model output and information on its sensitivity to a master program. The algorithm Proximal-ACCPM guarantees the convergence of the procedure under sufficient convexity assumptions. Our results demonstrate the possibility of a consistent, cost-benefit, climate-damage optimisation analysis with a 3-D climate model
Effects of long-term immobilisation on endomysium of the soleus muscle in humans
New Findings: What is the central question of this study? While muscle fibre atrophy in response to immobilisation has been extensively examined, intramuscular connective tissue, particularly endomysium, has been largely neglected: does endomysium content of the soleus muscle increase during bed rest? What is the main finding and its importance? Absolute endomysium content did not change, and previous studies reporting an increase are explicable by muscle fibre atrophy. It must be expected that even a relative connective tissue accumulation will lead to an increase in muscle stiffness. Abstract: Muscle fibres atrophy during conditions of disuse. Whilst animal data suggest an increase in endomysium content with disuse, that information is not available for humans. We hypothesised that endomysium content increases during immobilisation. To test this hypothesis, biopsy samples of the soleus muscle obtained from 21 volunteers who underwent 60 days of bed rest were analysed using immunofluorescence-labelled laminin γ-1 to delineate individual muscle fibres as well as the endomysium space. The endomysium-to-fibre-area ratio (EFAr, as a percentage) was assessed as a measure related to stiffness, and the endomysium-to-fibre-number ratio (EFNr) was calculated to determine whether any increase in EFAr was absolute, or could be attributed to muscle fibre shrinkage. As expected, we found muscle fibre atrophy (P = 0.0031) that amounted to shrinkage by 16.6% (SD 28.2%) on day 55 of bed rest. ENAr increased on day 55 of bed rest (P < 0.001). However, when analysing EFNr, no effect of bed rest was found (P = 0.62). These results demonstrate that an increase in EFAr is likely to be a direct effect of muscle fibre atrophy. Based on the assumption that the total number of muscle fibres remains unchanged during 55 days of bed rest, this implies that the absolute amount of connective tissue in the soleus muscle remained unchanged. The increased relative endomysium content, however, could be functionally related to an increase in muscle stiffness
Effects of long‐term immobilisation on endomysium of the soleus muscle in humans
New findings: What is the central question of this study? While muscle fibre atrophy in response to immobilisation has been extensively examined, intramuscular connective tissue, particularly endomysium, has been largely neglected: does endomysium content of the soleus muscle increase during bed rest? What is the main finding and its importance? Absolute endomysium content did not change, and previous studies reporting an increase are explicable by muscle fibre atrophy. It must be expected that even a relative connective tissue accumulation will lead to an increase in muscle stiffness.
Abstract: Muscle fibres atrophy during conditions of disuse. Whilst animal data suggest an increase in endomysium content with disuse, that information is not available for humans. We hypothesised that endomysium content increases during immobilisation. To test this hypothesis, biopsy samples of the soleus muscle obtained from 21 volunteers who underwent 60 days of bed rest were analysed using immunofluorescence-labelled laminin γ-1 to delineate individual muscle fibres as well as the endomysium space. The endomysium-to-fibre-area ratio (EFAr, as a percentage) was assessed as a measure related to stiffness, and the endomysium-to-fibre-number ratio (EFNr) was calculated to determine whether any increase in EFAr was absolute, or could be attributed to muscle fibre shrinkage. As expected, we found muscle fibre atrophy (P = 0.0031) that amounted to shrinkage by 16.6% (SD 28.2%) on day 55 of bed rest. ENAr increased on day 55 of bed rest (P < 0.001). However, when analysing EFNr, no effect of bed rest was found (P = 0.62). These results demonstrate that an increase in EFAr is likely to be a direct effect of muscle fibre atrophy. Based on the assumption that the total number of muscle fibres remains unchanged during 55 days of bed rest, this implies that the absolute amount of connective tissue in the soleus muscle remained unchanged. The increased relative endomysium content, however, could be functionally related to an increase in muscle stiffness
Modulation of apoptosis by V protein mumps virus
<p>Abstract</p> <p>Background</p> <p>The Urabe AM9 vaccine strain of mumps virus contains two variants of V protein: VWT (of HN-A1081 viral population) and VGly (of HN-G1081). The V protein is a promoting factor of viral replication by blocking the IFN antiviral pathway.</p> <p>Findings</p> <p>We studied the relationship between V protein variants and IFN-α2b-induced apoptosis. V proteins decrease activation of the extrinsic IFN-α2b-induced apoptotic pathway monitored by the caspase 8 activity, being the effect greater with the VWT protein. Both V proteins decrease the activity of caspase 9 of the intrinsic apoptotic pathway. In a system without IFN, the VWT and VGly proteins expression promotes activation of caspases 3 and 7. However, when the cellular system was stimulated with IFN-α, this activity decreased partially. TUNEL assay shows that for treatment with IFN-α and ibuprofen of cervical adenocarcinoma cells there is nuclear DNA fragmentation but the V protein expression reduces this process.</p> <p>Conclusions</p> <p>The reduction in the levels of caspases and DNA fragmentation, suggesting that V protein, particularly VWT protein of Urabe AM9 vaccine strain, modulates apoptosis. In addition, the VWT protein shows a protective role for cell proliferation in the presence of antiproliferative signals.</p