1,594 research outputs found
The cAMP-producing agonist beraprost inhibits human vascular smooth muscle cell migration via exchange protein directly activated by cAMP
This work was supported by the British Heart foundation (grant FS/11/23/28730). J.S.M. was funded by a British Heart Foundation PhD studentship. Funding to pay the Open Access publication charges for this article was provided by the Charities Open Access Fund (UK).Peer reviewedPublisher PD
COMPARISON OF MUSCLE ACTIVITY DURING STEP UPS AND SINGLE LEG SQUATS
The purpose of this study was to evaluate muscle activity of the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM), biceps femoris (BF), gluteus maximus (GM), gluteus medius (GME), adductors (A), and gastrocnemius (G) during step ups (SU) and single leg squats (SLS). Subjects were 12 weight trained adults. Muscle activity was averaged by root mean square and normalized to maximum isometric contractions. Repeated measures ANOVA results revealed interaction effects (
The Effects of Wearing a Portable Media Armband on Muscle Activation of the Biceps Brachii
International Journal of Exercise Science 16(1): 1461-1470, 2023. Portable media armbands are commonly used among the physically active population. Their effect on muscle function has not been established. The purpose of this study was to determine if muscle activation of the biceps brachii is influenced by wearing a portable media armband during an elbow flexion exercise. Eighteen participants (11 males: age = 22.5 ± 2.1 years, height = 178.3 ± 5.2 cm, mass = 85.0 ± 6.5 kg; 7 females: age = 22.9 ± 2.5 years, height = 168.3 ± 5.7 cm, mass = 72.3 ± 12.2 kg) with no history of upper extremity injury volunteered for the study. Participants performed elbow flexion trials with a hand-held dumbbell with and without wearing a portable media armband. Dumbbell weight was determined by an 8-10 repetition maximum, and the condition was counterbalanced. The average concentric and eccentric phases for five trials for each condition were normalized to a maximum voluntary isometric contraction using electromyography. The independent variable was condition (with-PMAB and without-PMAB). The dependent variable was the muscle activation of the biceps brachii. Mean data for each condition were analyzed using separate paired-samples t-tests for the concentric and eccentric phases (p \u3c 0.05). Statistical analysis revealed a significant difference for the concentric phase (t17 = 2.905; p = 0.010). The with-PMAB condition elicited greater muscle activation (72.57 ± 36.31%) compared to the without-PMAB (63.67 ± 26.2%), with a medium effect size (d = 0.69). There was no statistical difference for the eccentric phase (t17 = 1.964; p = 0.066), and a small effect size (d = 0.46). The increase in muscle activation during the concentric phase is likely due to a change in the muscle properties due to the compressive force applied to the muscle fibers by the portable media armband
Comparison of Muscle Activity During a Ring Muscle Up and a Bar Muscle Up
International Journal of Exercise Science 16(1): 1451-1460, 2023. The muscle up (MU) is a variation of a common gymnastics movement that combines a pull up and a dip. It can be performed on a bar (BMU) or a set of rings (RMU). The difference in upper extremity muscle recruitment (MR) between BMU and RMU has not been evaluated. Therefore, the purpose of this study was to compare the MR of select muscles during BMU and RMU. Ten active males (27.6 ± 7.9 years) performed 5 repetitions of BMU and RMU in randomized order. Muscle recruitment of the upper (UT) and lower trapezius (LT), serratus anterior (SA), pectoralis major (PM), latissimus dorsi (LD), triceps brachii (TB), biceps brachii (BB), and forearm flexors (FF) was assessed using electromyography. A 2 X 2 ANOVA (ring vs bar, pull phase vs push phase) with repeated measures was performed for each muscle. Least significant differences post hoc tests were performed when a significant interaction effect occurred. The RMU significantly elicited more muscle activation in the UT (p = 0.007), BB (p = 0.001), and FF (p = 0.001) during the pull phase. The RMU also significantly elicited more muscle activation in the TB (p = 0.025) and BB (p = 0.001) during the push phase. These results suggest that the instability of the RMU primarily increases the required recruitment of the upper limbs but does not significantly change the recruitment of the shoulder stabilizers. Appropriate upper limb development is needed to perform the RMU and the BMU may be a better technique to learn first due to its lower difficulty
Histological Lesions in Mink Jaws are a Highly Sensitive Biomarker of Effect after Exposure to TCDD-like Chemicals: Field and Literature-based Confirmations
The mink (Mustela vison) is one of the most sensitive mammals to 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD)-like chemicals. By literature review we established that a histological lesion of the jaw bone of mink, evidenced by squamous epithelial hyperplasia in the gingival tissue that forms nests or cords that infiltrate the periodontal ligament and alveolar bone causing osteolysis of the mandible and maxilla that could lead to squamous cell carcinoma, is the most sensitive known biomarker of effect following exposure of mink to TCDD-like chemicals. Lesions have been observed when total TCDD toxic equivalents (TEQ: dioxins, furans, co-planar polychlorinated biphenyls or PCBs) in liver exceed 40 ng/kg-ww or when total PCB exceeds 1,698 ng/g-ww. This is the second report of histological evidence of this lesion in wild-caught mink, and it is the first report of the lesion being grossly detectable in naturally exposed mink. Some mink living near the south shore of Lake Ontario (exposed to the lake’s food web) but not inland mink (not exposed to the lake’s food web) accumulate more than 40 ng total TEQ/kg or 2 1,698 ng total PCB/kg in liver. Because of its sensitivity, the jaw lesion biomarker is very useful for assessing the health of wildlife populations exposed to TCDD-like chemicals
Direct Inference of SNP Heterozygosity Rates and Resolution of LOH Detection
Single nucleotide polymorphisms (SNPs) have been increasingly utilized to investigate somatic genetic abnormalities in premalignancy and cancer. LOH is a common alteration observed during cancer development, and SNP assays have been used to identify LOH at specific chromosomal regions. The design of such studies requires consideration of the resolution for detecting LOH throughout the genome and identification of the number and location of SNPs required to detect genetic alterations in specific genomic regions. Our study evaluated SNP distribution patterns and used probability models, Monte Carlo simulation, and real human subject genotype data to investigate the relationships between the number of SNPs, SNP HET rates, and the sensitivity (resolution) for detecting LOH. We report that variances of SNP heterozygosity rate in dbSNP are high for a large proportion of SNPs. Two statistical methods proposed for directly inferring SNP heterozygosity rates require much smaller sample sizes (intermediate sizes) and are feasible for practical use in SNP selection or verification. Using HapMap data, we showed that a region of LOH greater than 200 kb can be reliably detected, with losses smaller than 50 kb having a substantially lower detection probability when using all SNPs currently in the HapMap database. Higher densities of SNPs may exist in certain local chromosomal regions that provide some opportunities for reliably detecting LOH of segment sizes smaller than 50 kb. These results suggest that the interpretation of the results from genome-wide scans for LOH using commercial arrays need to consider the relationships among inter-SNP distance, detection probability, and sample size for a specific study. New experimental designs for LOH studies would also benefit from considering the power of detection and sample sizes required to accomplish the proposed aims
ISS Operations Cost Reductions Through Automation of Real-Time Planning Tasks
In 2007 the Johnson Space Center s Mission Operations Directorate (MOD) management team challenged their organizations to find ways to reduce the cost of operations for supporting the International Space Station (ISS) in the Mission Control Center (MCC). Each MOD organization was asked to define and execute projects that would help them attain cost reductions by 2012. The MOD Operations Division Flight Planning Branch responded to this challenge by launching several software automation projects that would allow them to greatly improve console operations and reduce ISS console staffing and intern reduce operating costs. These tasks ranged from improving the management and integration mission plan changes, to automating the uploading and downloading of information to and from the ISS and the associated ground complex tasks that required multiple decision points. The software solutions leveraged several different technologies including customized web applications and implementation of industry standard web services architecture; as well as engaging a previously TRL 4-5 technology developed by Ames Research Center (ARC) that utilized an intelligent agent-based system to manage and automate file traffic flow, archive data, and generate console logs. These projects to date have allowed the MOD Operations organization to remove one full time (7 x 24 x 365) ISS console position in 2010; with the goal of eliminating a second full time ISS console support position by 2012. The team will also reduce one long range planning console position by 2014. When complete, these Flight Planning Branch projects will account for the elimination of 3 console positions and a reduction in staffing of 11 engineering personnel (EP) for ISS
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Succession of physiological stages hallmarks the transcriptomic response of the fungus Aspergillus niger to lignocellulose.
BackgroundUnderstanding how fungi degrade lignocellulose is a cornerstone of improving renewables-based biotechnology, in particular for the production of hydrolytic enzymes. Considerable progress has been made in investigating fungal degradation during time-points where CAZyme expression peaks. However, a robust understanding of the fungal survival strategies over its life time on lignocellulose is thereby missed. Here we aimed to uncover the physiological responses of the biotechnological workhorse and enzyme producer Aspergillus niger over its life time to six substrates important for biofuel production.ResultsWe analysed the response of A. niger to the feedstock Miscanthus and compared it with our previous study on wheat straw, alone or in combination with hydrothermal or ionic liquid feedstock pretreatments. Conserved (substrate-independent) metabolic responses as well as those affected by pretreatment and feedstock were identified via multivariate analysis of genome-wide transcriptomics combined with targeted transcript and protein analyses and mapping to a metabolic model. Initial exposure to all substrates increased fatty acid beta-oxidation and lipid metabolism transcripts. In a strain carrying a deletion of the ortholog of the Aspergillus nidulans fatty acid beta-oxidation transcriptional regulator farA, there was a reduction in expression of selected lignocellulose degradative CAZyme-encoding genes suggesting that beta-oxidation contributes to adaptation to lignocellulose. Mannan degradation expression was wheat straw feedstock-dependent and pectin degradation was higher on the untreated substrates. In the later life stages, known and novel secondary metabolite gene clusters were activated, which are of high interest due to their potential to synthesize bioactive compounds.ConclusionIn this study, which includes the first transcriptional response of Aspergilli to Miscanthus, we highlighted that life time as well as substrate composition and structure (via variations in pretreatment and feedstock) influence the fungal responses to lignocellulose. We also demonstrated that the fungal response contains physiological stages that are conserved across substrates and are typically found outside of the conditions with high CAZyme expression, as exemplified by the stages that are dominated by lipid and secondary metabolism
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