Mechanical properties of the gastrocnemius aponeurosis in wild turkeys

In many muscles, the tendinous structures include both an extramuscular free tendon as well as a sheet-like aponeurosis. In both free tendons and aponeuroses the collagen fascicles are oriented primarily longitudinally, along the muscle's line of action. It is generally assumed that this axis represents the direction of loading for these structures. This assumption is well founded for free tendons, but aponeuroses undergo a more complex loading regime. Unlike free tendons, aponeuroses surround a substantial portion of the muscle belly and are therefore loaded both parallel (longitudinal) and perpendicular (transverse) to a muscle's line of action when contracting muscles bulge to maintain a constant volume. Given this biaxial loading pattern, it is critical to understand the mechanical properties of aponeuroses in both the longitudinal and transverse directions. In this study, we use uniaxial testing of isolated tissue samples from the aponeurosis of the lateral gastrocnemius of wild turkeys to determine mechanical properties of samples loaded longitudinally (along the muscle's line of action) and transversely (orthogonal to the line of action). We find that the aponeurosis has a significantly higher Young's modulus in the longitudinal than in the transverse direction. Our results also show that aponeuroses can behave as efficient springs in both the longitudinal and transverse directions, losing little energy to hysteresis. We also test the failure properties of aponeuroses to quantify the likely safety factor with which these structures operate during muscular force production. These results provide an essential foundation for understanding the mechanical function of aponeuroses as biaxially loaded biological springs.     

Convergent evolution of the head retraction escape response in elongate fishes and amphibians

Aquatic escape responses have typically been described as C-starts. However, another aquatic escape response, head retraction, occurs in several elongate species, but has never been studied in detail. The goals of this study are to describe the head retraction escape response in a phylogenetically diverse sample of species, to trace the evolution of head retraction in anamniote vertebrates, and to correlate key morphological traits with escape response behavior. In analyzing the evolution of escape behavior, we found that the head retraction escape response has evolved at least six times in anamniote vertebrates. Using independent contrast analysis, the head retraction escape response was found to be correlated with an increase in the total number of vertebrae and an increase in the elongation of an animal. Results from this study indicate a correlation between head retraction as an escape response, elongation of the axial skeleton, and living in structured habitats.     

The effect of high concentrations and orientations of Stone–Wales defects on the thermal conductivity of graphene nanoribbons

The influence of the orientations and concentrations of the Stone–Wales (SW) defects on the thermal conductivity of zigzag and armchair graphene nanoribbons (GNRs) is explored using the reverse non-equilibrium molecular dynamics method. The results show that the thermal conductivity of GNRs with two different chirality cases reaches the minimum in the range of 0.1–0.7% defect concentration. Beyond a critical value of the SW defect concentration, the thermal conductivity increases with the increase in SW concentration for both zigzag and armchair GNRs. It is shown that at high concentrations of the SW defects, the thermal conductivity of zigzag GNRs with Type II defects is larger than the GNRs with Type I defects. Finally, the dependence of the SW defect concentration and orientation on the power spectra overlaps have also been explored.     

The toxicity and synergistic effects of alkyl-succinate oil on the first nymphal instars of the citrus cottony scale,Pulvinaria aurantii Cock. (Hem.: Coccidae)

The citrus cottony scale, Pulvinaria aurantii Cock. (Hem.: Coccidae) is one of the most important citrus pests in Iran. This study investigated the toxicity and synergistic effects of organophosphorous insecticides (Malathion, Chlorpyrifos, Buprofezin and DG oil) on first nymphal instars of P. aurantii in the laboratory conditions (25?±?1?°C, 75?±?5% RH and 16L:8D photoperiod). The values of LC₅₀ for Malathion, Chlorpyrifos and Buprofezin insecticides on the first nymphal instars were calculated as 76.90, 105.25 and 24.70?ppm, respectively. Also, results indicated that Buprofezin and Pyriproxifen are the most effective insecticides on first nymphal instars of P. aurantii. The values of LC₅₀ for each insecticide without oil and in half dose along with DG oil were equal. This was an indication for synergism role of DG oil combination. The results of this study showed that DG oil not only decreases the consumption of insecticides, but also increases their efficacy.     

Yoga for Multiple Sclerosis: A Systematic Review and Meta-Analysis

While yoga seems to be effective in a number of neuropsychiatric disorders, the evidence of efficacy in multiple sclerosis remains unclear. The aim of this review was to systematically assess and meta-analyze the available data on efficacy and safety of yoga in patients with multiple sclerosis. Medline/PubMed, Scopus, the Cochrane Central Register of Controlled Trials, PsycINFO, CAM-Quest, CAMbase, and IndMED were searched through March 2014. Randomized controlled trials (RCTs) of yoga for patients with multiple sclerosis were included if they assessed health-related quality of life, fatigue, and/or mobility. Mood, cognitive function, and safety were defined as secondary outcome measures. Risk of bias was assessed using the Cochrane tool. Seven RCTs with a total of 670 patients were included. Evidence for short-term effects of yoga compared to usual care were found for fatigue (standardized mean difference [SMD] = −0.52; 95% confidence intervals (CI) = −1.02 to −0.02; p = 0.04; heterogeneity: I² = 60%; Chi² = 7.43; p = 0.06) and mood (SMD = −0.55; 95%CI = −0.96 to −0.13; p = 0.01; heterogeneity: I² = 0%; Chi² = 1.25; p = 0.53), but not for health-related quality of life, muscle function, or cognitive function. The effects on fatigue and mood were not robust against bias. No short-term or longer term effects of yoga compared to exercise were found. Yoga was not associated with serious adverse events. In conclusion, since no methodological sound evidence was found, no recommendation can be made regarding yoga as a routine intervention for patients with multiple sclerosis. Yoga might be considered a treatment option for patients who are not adherent to recommended exercise regimens.     

Pyramidal and extrapyramidal dysfunction as a sequela of hypoxic injury: case report

Background  

The clinical and radiological aspects of hypoxic brain injury without ischemia are not well characterized. A spectrum of clinical manifestations have been observed in patients that recover from hypoxic brain injury, including a subset that demonstrate persistent motor system disturbances. Early Magnetic Resonance Imaging (MRI) studies have shown abnormalities in basal ganglia, cerebral and cerebellar cortex.