A review of the potential local mechanisms by which exercise improves functional outcomes in intermittent claudication

© 2016 Elsevier Inc. All rights reserved. Background Intermittent claudication (IC) is a common condition which is associated with significant quality of life limitation. National Institute for Health and Care Excellence guidelines recommend a group-based supervised exercise program as the primary treatment option for claudication, based on clinical and cost effectiveness. This review aims to assess the mechanisms by which exercise improves outcomes in patients with IC. Methods MEDLINE, EMBASE, and PubMed were searched using the search strategy "claudication" [AND] "exercise" [AND] "mechanisms." Searches were limited from 1947 to October 2014. Only full-text articles published in the English language in adults (over 18 years of age) were eligible for the review. Any trial involving a nonsupervised exercise program was excluded. Abstracts identified by the database search were interrogated for relevance and citations from the shortlisted papers were hand searched for relevant references. Results The search yielded a total of 112 studies, of which 42 were duplicates. Forty-seven of the remaining 70 were deemed appropriate for inclusion in the review. Exercise is the first-line treatment for IC. Supervised exercise programs improve walking distances, endothelial and mitochondrial function, muscle strength, and endurance. Furthermore, it leads to a generalized improvement in cardiovascular fitness and overall quality of life. Conclusions The mechanism by which exercise improves outcome in claudicants is complicated and multifactorial. Further research is required in this area to fully elucidate the precise and predominant mechanisms and to assess whether targeted exercise program modification maximizes mechanism efficacy and patient outcome

Examination of factors contributing to the achievement gap of Native American students in select school districts in Michigan

Most of the studies on student achievement gaps involve the Black-White achievement gap due to the availability of significant sample populations in order to draw scientific conclusions from the analysis of the student achievement data. However, there are few empirical quantitative studies that analyze a similar gap in achievement between the Native American student and their White cohort. Such studies have been limited due to a small and isolated Native American population in regions across the nation. In Michigan, less than 1% of the student population in the schools is Native American. This study identified 20 select school districts (both urban and rural) in the state of Michigan where the total student population was 26,659 and 4,388 (16.5%) were Native American. School districts in the study were selected based on a total Native American population greater than 50. A large scale quantitative study analyzed the financial status, student assessment, socioeconomic status, and special education rates of the selected districts to determine the presence of a significant achievement gap over a period from 2008 to 2011. The sample population in the study involved disaggregation of data by school district, school buildings, grade, subgroup population, core subject areas assessed by the state (Michigan Educational Assessment Program and Michigan Merit Exam), and socioeconomic status. An analysis of the variance that existed between the Native American cohort and White cohort was performed using a t-test measure with significance at p \u3c .05. The key findings from this study indicate the presence of an achievement gap between Native American student assessments on state measures and those of their White peer group. Statistical significance between the two subgroups was commonly represented when comparing students scoring in the top level category of proficiency on the assessment measures. There is a strong correlation with student performance and socioeconomic factors as demonstrated through correlation analysis of free and reduced lunch eligibility and state performance ranking of the school building. An inconsistent lower identification of Native American students who are receiving special education services was also demonstrated when compared to their White peer group

Embedding Population Dynamics Models in Inference

Increasing pressures on the environment are generating an ever-increasing need to manage animal and plant populations sustainably, and to protect and rebuild endangered populations. Effective management requires reliable mathematical models, so that the effects of management action can be predicted, and the uncertainty in these predictions quantified. These models must be able to predict the response of populations to anthropogenic change, while handling the major sources of uncertainty. We describe a simple ``building block'' approach to formulating discrete-time models. We show how to estimate the parameters of such models from time series of data, and how to quantify uncertainty in those estimates and in numbers of individuals of different types in populations, using computer-intensive Bayesian methods. We also discuss advantages and pitfalls of the approach, and give an example using the British grey seal population.Comment: Published at http://dx.doi.org/10.1214/088342306000000673 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

A Systematic Review of the Uptake and Adherence Rates to Supervised Exercise Programs in Patients with Intermittent Claudication

Background Intermittent claudication (IC) is a common and debilitating symptom of peripheral arterial disease and is associated with a significant reduction in a sufferer's quality of life. Guidelines recommend a supervised exercise program (SEP) as the primary treatment option; however, anecdotally there is a low participation rate for exercise in this group of patients. We undertook a systematic review of the uptake and adherence rates to SEPs for individuals with IC. Methods The MEDLINE, Embase, and PubMed databases were searched up to January 2015 for terms related to supervised exercise in peripheral arterial disease. The review had 3 aims: first, to establish the rates of uptake to SEPs, second, the rates of adherence to programs, and finally to determine the reasons reported for poor uptake and adherence. Separate inclusion and/or exclusion criteria were applied in selecting reports for each aim of the review. Results Only 23 of the 53 potentially eligible articles for uptake analysis identified on literature searches reported any details of screened patients (n = 7,517) with only 24.2% of patients subsequently recruited to SEPs. Forty-five percent of screen failures had no reason for exclusion reported. Sixty-seven articles with 4,012 patients were included for analysis of SEP adherence. Overall, 75.1% of patients reportedly completed an SEP; however, only one article defined a minimal attendance required for SEP completion. Overall, 54.1% of incomplete adherence was due to patient withdrawal and no reason for incomplete adherence was reported for 16% of cases. Conclusions Reporting of SEP trials was poor with regard to the numbers of subjects screened and reasons for exclusions. Only approximately 1 in 3 screened IC patients was suitable for and willing to undertake SEP. Levels of adherence to SEPs and definitions of satisfactory adherence were also lacking in most the current literature. Current clinical guidelines based on this evidence base may not be applicable to most IC patients and changes to SEPs may be needed to encourage and/or retain participants

Extracorporeal shockwave therapy for the treatment of lower limb intermittent claudication: Study protocol for a randomised controlled trial (the SHOCKWAVE 1 trial)

© 2017 The Author(s). Background: Peripheral arterial disease (PAD) has a population prevalence of 4.6% with intermittent claudication (IC) presenting as one of the earliest and most common symptoms. PAD has detrimental effects on patients' walking ability in terms of maximum walking distance (MWD) and pain-free walking distance (PFWD). Research has suggested extracorporeal shockwave therapy (ESWT) may induce angiogenesis in treated tissue; therefore, our objective is to assess the tolerability and efficacy of ESWT as a novel treatment of intermittent claudication. Methods/design: Patients with unilateral claudication will be randomised to receive either ESWT (PiezoWave 2 shockwave system) or sham treatment to the calf muscle bulk three times per week for 3 weeks. All patients are blinded to treatment group, and all assessments will be performed by a masked assessor. Treatment tolerability using a visual analogue scale, ankle-brachial pressure index, MWD, PFWD and safety will all be formally assessed as outcome measures at baseline and at 4, 8 and 12 weeks follow-up. Discussion: This trial will be the first of its kind in terms of methodology in relation to ESWT for intermittent claudication. A double-masked randomised controlled trial will provide useful information about the potential for the use of ESWT as a non-invasive treatment option and the need for further robust research. Trial registration: ClinicalTrials.gov, NCT02652078. Registered on 17 October 2014

Achievement goals and motivational responses in tennis: Does the context matter?

Objectives: This study examined: (a) whether athletes’ goal orientations differ across training and competition; (b) whether goal orientations predict effort, enjoyment, and psychological skill use differently in training and competition; and (c) whether goal orientations predict perceived improvement in training and perceived performance in competition. Method: Participants were 116 competitive tennis players (mean age = 19.99, SD = 5.82), who completed questionnaires measuring goal orientations, effort, enjoyment, and psychological skill use in training and competition, perceived improvement in training, and perceived performance in competition. Results: Dependent t-tests revealed that athletes reported higher task orientation in training than in competition and higher ego orientation in competition than in training, while Pearson product-moment correlations revealed a high cross-contextual consistency for both task and ego goal orientations between training and competition. Regression analyses indicated that task orientation predicted positively effort, enjoyment, self-talk, and goal setting in both contexts, perceived improvement in training, and perceived performance in competition. An interaction effect also emerged whereby ego orientation predicted positively effort in competition only when task orientation was low or average. Conclusions: The findings suggest that goal orientations may differ between training and competition; task orientation is the goal that should be promoted in both contexts; and the context may affect the relationship between goal orientations and effort, enjoyment, and goal setting

A systematic review and meta-analysis of systemic intraoperative anticoagulation during arteriovenous access formation for dialysis

Purpose: Surgical arteriovenous fistula (AVF) or graft (AVG) is preferred to a central venous catheter for dialysis access. Surgical access may suffer thrombosis early after placement and systemic anticoagulation during surgical access formation may increase patency rates but would be expected to increase bleeding-related complications. A systematic review and meta-analysis of randomised controlled trials was conducted to examine the impact of systemic anticoagulation on access surgery perioperative bleeding and patency rates. Methods: We included randomised controlled trials testing systemic anticoagulation during access formation versus a control group without systemic anticoagulation reporting bleeding complications and access patency. Medline, Embase, CENTRAL and CINAHL were searched up to March 2015. Risk of bias was assessed using the Cochrane risk of bias tool and the Jadad score. Meta-analysis was performed using Cochrane Revman ® software. Results: Searches identified 445 reports of which four randomised studies involving 411 participants were included. Three studies pertained to AVF only and one included both AVF and AVG. Systemic anticoagulation led to increased bleeding events in all access [four trials; risk ratio (RR) 7.18; confidence interval (CI), 2.41 to 21.38; p < 0.001]. Patency was not improved for all access (four trials; RR, 0.64; CI, 0.37 to 1.09; p = 0.10) but was improved when AVF analysed alone (three trials; RR, 0.57; CI, 0.33 to 0.97; p = 0.04). Conclusions: The use of intraoperative systemic anticoagulation during access formation is associated with a highly significant increased risk of bleeding-related complications. A significant improvement in AVF patency was seen, though not when AVF and AVG were analysed together

Whales of the Inuvialuit Settlement Region in Canada's Western Arctic: An Overview and Outlook

The beluga whale (Delphinapterus leucas) and the bowhead whale (Balaena mysticetus) are seasonal migrants to Canada's Western Arctic, occupying summer range in the southeastern Beaufort Sea and Amundsen Gulf within the Inuvialuit Settlement Region (ISR). These whales also travel through United States (Alaskan) and Russian offshore waters, which include migration routes and overwintering areas for both species. The beluga has for centuries been an important food resource of the aboriginal people of the Mackenzie Delta. From 1990 to 1999, the annual subsistence harvest of beluga in the ISR averaged 111, while only two bowheads were landed during this same period. The minimum size of the Eastern Beaufort Sea beluga stock has been estimated at 32 453 whales. The total annual removal of beluga by subsistence hunters from the ISR and Alaska is estimated at 189 whales, which is less than 0.6% of the minimum estimate of stock size. This level of harvest is sustainable. Between 1848 and 1921, commercial whalers decimated the Bering Sea population of bowhead whales. The size of the population, based on 1993 data, is estimated at 8200 (95% estimation interval of 7200-9400), constituting more than 90% of the world's remaining bowheads. This population increased at a rate of 3.2% from 1978 to 1993, while sustaining a harvest of about 0.6% per year. To ensure the continued well-being of these whales and their habitats, it is recommended that existing monitoring programs, commitments, and co-management partnerships be nurtured and maintained.Le béluga (Delphinapterus leucas) et la baleine boréale (Balaena mysticetus) sont des migrateurs saisonniers qui fréquentent l'ouest de l'Arctique canadien, occupant un territoire estival dans le sud-est de la mer de Beaufort et le golfe Amundsen au sein de la Région désignée des Inuvialuit (RDI). Ces baleines se déplacent également dans les eaux situées au large des États-Unis (alaskiennes) et de la Russie, qui comprennent des voies migratoires et des aires d'hivernage pour les deux espèces. Le béluga représente depuis des siècles une importante ressource alimentaire pour les Autochtones du delta du Mackenzie. De 1990 à 1999, la moyenne annuelle des prélèvements de subsistance du béluga dans la RDI était de 111, alors que seulement deux baleines boréales avaient été débarquées durant la même période. La taille minimum du stock de bélugas dans l'est de la mer de Beaufort est évaluée à 32 453 individus, et les prises annuelles de bélugas effectuées au sein de la RDI et de l'Alaska dans le cadre de la chasse de subsistance sont évaluées à 189 individus, ce qui représente moins de 0,6 p. cent de la taille minimum du stock. Ce niveau de prélèvement est par conséquent durable. Entre 1848 et 1921, les baleiniers commerciaux ont décimé la population des baleines boréales dans la mer de Béring. D'après les données de 1993, on estime la taille de la population à 8200 (comprise entre 7200 et 9400 avec 95 p. cent de probabilité), soit plus de 90 p. cent du nombre de baleines boréales qui existent aujourd'hui dans le monde. Cette population a augmenté à un taux de 3,2 p. cent de 1978 à 1993, tout en faisant l'objet d'un prélèvement annuel d'environ 0,6 p. cent. Afin d'assurer le bien-être permanent de ces baleines et de leurs habitats, on recommande d'appuyer et de conserver les programmes de surveillance, les engagements et les partenariats de cogestion actuellement en place

Confirmatory factor analysis of the Test of Performance Strategies (TOPS) among adolescent athletes

The aim of the present study was to examine the factorial validity of the Test of Performance Strategies (TOPS; Thomas et al., 1999) among adolescent athletes using confirmatory factor analysis. The TOPS was designed to assess eight psychological strategies used in competition (i.e. activation, automaticity, emotional control, goal-setting, imagery, negative thinking, relaxation and self-talk,) and eight used in practice (the same strategies except negative thinking is replaced by attentional control). National-level athletes (n = 584) completed the 64-item TOPS during training camps. Fit indices provided partial support for the overall measurement model for the competition items (robust comparative fit index = 0.92, Tucker-Lewis index = 0.88, root mean square error of approximation = 0.05) but minimal support for the training items (robust comparative fit index = 0.86, Tucker-Lewis index = 0.81, root mean square error of approximation = 0.06). For the competition items, the automaticity, goal-setting, relaxation and self-talk scales showed good fit, whereas the activation, emotional control, imagery and negative thinking scales did not. For the practice items, the attentional control, emotional control, goal-setting, imagery and self-talk scales showed good fit, whereas the activation, automaticity and relaxation scales did not. Overall, it appears that the factorial validity of the TOPS for use with adolescents is questionable at present and further development is required

Observation of coherent delocalized phonon-like modes in DNA under physiological conditions

Underdamped terahertz-frequency delocalized phonon-like modes have long been suggested to play a role in the biological function of DNA. Such phonon modes involve the collective motion of many atoms and are prerequisite to understanding the molecular nature of macroscopic conformational changes and related biochemical phenomena. Initial predictions were based on simple theoretical models of DNA. However, such models do not take into account strong interactions with the surrounding water, which is likely to cause phonon modes to be heavily damped and localized. Here we apply state-of-the-art femtosecond optical Kerr effect spectroscopy, which is currently the only technique capable of taking low-frequency (GHz to THz) vibrational spectra in solution. We are able to demonstrate that phonon modes involving the hydrogen bond network between the strands exist in DNA at physiologically relevant conditions. In addition, the dynamics of the solvating water molecules is slowed down by about a factor of 20 compared with the bulk