Stretching the spines of gymnasts: a review

Gymnastics is noted for involving highly specialized strength, power, agility and flexibility. Flexibility is perhaps the single greatest discriminator of gymnastics from other sports. The extreme ranges of motion achieved by gymnasts require long periods of training, often occupying more than a decade. Gymnasts also start training at an early age (particularly female gymnasts), and the effect of gymnastics training on these young athletes is poorly understood. One of the concerns of many gymnastics professionals is the training of the spine in hyperextension-the ubiquitous 'arch' seen in many gymnastics positions and movements. Training in spine hyperextension usually begins in early childhood through performance of a skill known as a back-bend. Does practising a back-bend and other hyperextension exercises harm young gymnasts? Current information on spine stretching among gymnasts indicates that, within reason, spine stretching does not appear to be an unusual threat to gymnasts' health. However, the paucity of information demands that further study be undertaken

The Bactofilin Cytoskeleton Protein BacM of Myxococcus xanthus Forms an Extended β-Sheet Structure Likely Mediated by Hydrophobic Interactions

Bactofilins are novel cytoskeleton proteins that are widespread in Gram-negative bacteria. Myxococcus xanthus, an important predatory soil bacterium, possesses four bactofilins of which one, BacM (Mxan_7475) plays an important role in cell shape maintenance. Electron and fluorescence light microscopy, as well as studies using over-expressed, purified BacM, indicate that this protein polymerizes in vivo and in vitro into ~3 nm wide filaments that further associate into higher ordered fibers of about 10 nm. Here we use a multipronged approach combining secondary structure determination, molecular modeling, biochemistry, and genetics to identify and characterize critical molecular elements that enable BacM to polymerize. Our results indicate that the bactofilin-determining domain DUF583 folds into an extended β-sheet structure, and we hypothesize a left-handed β-helix with polymerization into 3 nm filaments primarily via patches of hydrophobic amino acid residues. These patches form the interface allowing head-to-tail polymerization during filament formation. Biochemical analyses of these processes show that folding and polymerization occur across a wide variety of conditions and even in the presence of chaotropic agents such as one molar urea. Together, these data suggest that bactofilins are comprised of a structure unique to cytoskeleton proteins, which enables robust polymerization

Virtual field trips as physically active lessons for children: a pilot study.

The modern classroom is an inherently sedentary environment. Virtual Field Trips (VFTs) using interactive whiteboards to explore virtual scenes are a potential method of converting sedentary class-time into physically active teaching. This pilot aimed to assess the effects of a developed VFT on physical activity and learning in primary-school children.Participants (n = 85) were randomly assigned to a) a 30-minute physically active London 2012 Olympics-themed VFT, or b) a 30-minute sedentary version of the same VFT. Activity was measured using GT1M Actigraphs, content recall was assessed with a quiz and user evaluations were gained from teacher and pupil questionnaires.Pupils in the active VFT displayed significantly less sedentary time (p < 0.001), and significantly more light (p < 0.001), moderate (p = 0.01) and vigorous physical activity (p < 0.001) than sedentary VFT pupils. No differences in content recall were found between intervention groups: suggesting that adding physical activity into classroom teaching may not compromise attainment. High acceptability was found in teachers and active VFT students rated their session significantly higher than sedentary pupils (p < 0.002).This one-day pilot provides early evidence of the ability of VFTs to convert sedentary academic time into active time. Longitudinal research is needed to assess prolonged effects of active VFTs in reducing sedentary time.University College Londo

Assessments Related to the Physical, Affective and Cognitive Domains of Physical Literacy Amongst Children Aged 7–11.9 Years: A Systematic Review

Background Over the past decade, there has been increased interest amongst researchers, practitioners and policymakers in physical literacy for children and young people and the assessment of the concept within physical education (PE). This systematic review aimed to identify tools to assess physical literacy and its physical, cognitive and affective domains within children aged 7–11.9 years, and to examine the measurement properties, feasibility and elements of physical literacy assessed within each tool. Methods Six databases (EBSCO host platform, MEDLINE, PsycINFO, Scopus, Education Research Complete, SPORTDiscus) were searched up to 10th September 2020. Studies were included if they sampled children aged between 7 and 11.9 years, employed field-based assessments of physical literacy and/or related affective, physical or cognitive domains, reported measurement properties (quantitative) or theoretical development (qualitative), and were published in English in peer-reviewed journals. The methodological quality and measurement properties of studies and assessment tools were appraised using the COnsensus-based Standards for the selection of health Measurement INstruments risk of bias checklist. The feasibility of each assessment was considered using a utility matrix and elements of physical literacy element were recorded using a descriptive checklist. Results The search strategy resulted in a total of 11467 initial results. After full text screening, 11 studies (3 assessments) related to explicit physical literacy assessments. Forty-four studies (32 assessments) were relevant to the affective domain, 31 studies (15 assessments) were relevant to the physical domain and 2 studies (2 assessments) were included within the cognitive domain. Methodological quality and reporting of measurement properties within the included studies were mixed. The Canadian Assessment of Physical Literacy-2 and the Passport For Life had evidence of acceptable measurement properties from studies of very good methodological quality and assessed a wide range of physical literacy elements. Feasibility results indicated that many tools would be suitable for a primary PE setting, though some require a level of expertise to administer and score that would require training. Conclusions This review has identified a number of existing assessments that could be useful in a physical literacy assessment approach within PE and provides further information to empower researchers and practitioners to make informed decisions when selecting the most appropriate assessment for their needs, purpose and context. The review indicates that researchers and tool developers should aim to improve the methodological quality and reporting of measurement properties of assessments to better inform the field. Trial registration PROSPERO: CRD4201706221

What determines cell size?

AbstractFirst paragraph (this article has no abstract) For well over 100 years, cell biologists have been wondering what determines the size of cells. In modern times, we know all of the molecules that control the cell cycle and cell division, but we still do not understand how cell size is determined. To check whether modern cell biology has made any inroads on this age-old question, BMC Biology asked several heavyweights in the field to tell us how they think cell size is controlled, drawing on a range of different cell types. The essays in this collection address two related questions - why does cell size matter, and how do cells control it

Targeting RNS/caveolin-1/MMP signaling cascades to protect against cerebral ischemia-reperfusion injuries: potential application for drug discovery

Reactive nitrogen species (RNS) play important roles in mediating cerebral ischemia-reperfusion injury. RNS activate multiple signaling pathways and participate in different cellular events in cerebral ischemia-reperfusion injury. Recent studies have indicated that caveolin-1 and matrix metalloproteinase (MMP) are important signaling molecules in the pathological process of ischemic brain injury. During cerebral ischemia-reperfusion, the production of nitric oxide (NO) and peroxynitrite (ONOO-), two representative RNS, down-regulates the expression of caveolin-1 (Cav-1) and, in turn, further activates nitric oxide synthase (NOS) to promote RNS generation. The increased RNS further induce MMP activation and mediate disruption of the blood-brain barrier (BBB), aggravating the brain damage in cerebral ischemia-reperfusion injury. Therefore, the feedback interaction among RNS/Cav-1/MMPs provides an amplified mechanism for aggravating ischemic brain damage during cerebral ischemia-reperfusion injury. Targeting the RNS/Cav-1/MMP pathway could be a promising therapeutic strategy for protecting against cerebral ischemia-reperfusion injury. In this mini-review article, we highlight the important role of the RNS/Cav-1/MMP signaling cascades in ischemic stroke injury and review the current progress of studies seeking therapeutic compounds targeting the RNS/Cav-1/MMP signaling cascades to attenuate cerebral ischemia-reperfusion injury. Several representative natural compounds, including calycosin-7-O-β-D-glucoside, baicalin, Momordica charantia polysaccharide (MCP), chlorogenic acid, lutein and lycopene, have shown potential for targeting the RNS/Cav-1/MMP signaling pathway to protect the brain in ischemic stroke. Therefore, the RNS/Cav-1/MMP pathway is an important therapeutic target in ischemic stroke treatment.published_or_final_versio

Clinical effectiveness in everyday practice: Improving outcomes for all patients through a national acute coronary syndrome data collaborative

The management of acute coronary syndromes (ACS) has an extensive and impressive evidence-base with which to guide clinical practice. Despite this, translation to the clinical environment has proved to be challenging and incomplete and can be attributed to patient, provider and system factors. Causes of suboptimal guideline adherence relate to diverse issues, including patient complexity, barriers in knowledge translation of guideline recommendations and a limited capacity within health services. Addressing these factors may enable more effective guideline implementation. In Australia, the infrastructure for clinical data management is fragmented, uncoordinated and often administratively driven, compromising access to important information, which might improve clinical effectiveness. An integrated approach is required to improve clinical effectiveness in ACS care in Australia. Greater access to information both to assist in clinical decision-making and monitoring outcomes may help direct the focus towards understudied populations and improve performance and clinically relevant outcomes. A peer-led initiative based on common datasets, providing rapid feedback, while developing and disseminating a 'toolbox' of proven and sustainable interventions, could improve clinical effectiveness in the Australian management of ACS and provides a rationale for a national ACS registry. © 2011 The Authors. Internal Medicine Journal © 2011 Royal Australasian College of Physicians