Immediate post-isometric exercise cardiovascular responses are associated with training-induced resting systolicblood pressure reductions

Purpose: The purpose of this study was twofold: (1) to investigate the effect of four-weeks of bilateral-leg isometric exercise training on the immediate isometric post-exercise cardiovascular responses, and (2) to ascertain whether any changes in immediate post-exercise cardiovascular responses may be associated with training-induced adaptations in resting blood pressure. Methods: Thirteen normotensive males completed both isometric exercise training (IET) and control conditions, which were separated by 6 weeks. Participants performed a total of twelve training sessions; 4 * 2-minute bilateral-leg isometric exercise bouts separated by 3-minute rest periods, 3 days.wk-1. Results: 4-weeks of bilateral-leg IET resulted in a reduction in resting SBP (120 ± 12 to 115 ± 12 mmHg, p = 0.01). The intercept of the 5-minute post-exercise systolic blood pressure slope was lower (p = 0.015) following the 4-week training intervention. Individual changes in immediate post-exercise response SBP were also significantly correlated with reductions in resting SBP following 4-weeks of training. There were significant differences in the slopes of the first vs. final post-exercise BRS response (p = 0.009), and the intercepts of the HRR slopes (p = 0.04) recorded during the 5-minute post-exercise periods Conclusions: Four weeks of IET altered immediate cardiovascular responses to an individual IET session. Altered immediate responses were also associated with training induced reductions in resting SBP. To our knowledge, this is the first evidence suggesting very short-term (immediate) cardiovascular responses may be important in defining chronic reductions in resting blood pressure following a period of IET

Tropical–North Pacific Climate Linkages over the Past Four Centuries

Analyses of instrumental data demonstrate robust linkages between decadal-scale North Pacific and tropical Indo-Pacific climatic variability. These linkages encompass common regime shifts, including the noteworthy 1976 transition in Pacific climate. However, information on Pacific decadal variability and the tropical high-latitude climate connection is limited prior to the twentieth century. Herein tree-ring analysis is employed to extend the understanding of North Pacific climatic variability and related tropical linkages over the past four centuries. To this end, a tree-ring reconstruction of the December-May North Pacific index (NPI)-an index of the atmospheric circulation related to the Aleutian low pressure cell-is presented (1600-1983). The NPI reconstruction shows evidence for the three regime shifts seen in the instrumental NPI data, and for seven events in prior centuries. It correlates significantly with both instrumental tropical climate indices and a coral-based reconstruction of an optimal tropical Indo-Pacific climate index, supporting evidence for a tropical-North Pacific link extending as far west as the western Indian Ocean. The coral-based reconstruction (1781-1993) shows the twentieth-century regime shifts evident in the instrumental NPI and instrumental tropical Indo-Pacific climate index, and three previous shifts. Changes in the strength of correlation between the reconstructions over time, and the different identified shifts in both series prior to the twentieth century, suggest a varying tropical influence on North Pacific climate, with greater influence in the twentieth century. One likely mechanism is the low-frequency variability of the El Nino-Southern Oscillation (ENSO) and its varying impact on Indo-Pacific climate.</p

Doping of inorganic materials in microreactors – preparation of Zn doped Fe₃O₄ nanoparticles

Microreactor systems are now used more and more for the continuous production of metal nanoparticles and metal oxide nanoparticles owing to the controllability of the particle size, an important property in many applications. Here, for the first time, we used microreactors to prepare metal oxide nanoparticles with controlled and varying metal stoichiometry. We prepared and characterised Zn-substituted Fe₃O₄ nanoparticles with linear increase of Zn content (ZnxFe₃−xO₄ with 0 ≤ x ≤ 0.48), which causes linear increases in properties such as the saturation magnetization, relative to pure Fe₃O₄. The methodology is simple and low cost and has great potential to be adapted to the targeted doping of a vast array of other inorganic materials, allowing greater control on the chemical stoichiometry for nanoparticles prepared in microreactors

An evidence-based guide to the efficacy and safety of isometric resistance training in hypertension and clinical implications.

More than 30 randomized controlled trials, supported by individual patient-level and group-level meta-analyses and a Delphi analysis of expert opinion, unequivocally show isometric resistance training (IRT) elicits antihypertensive benefits in healthy people and those with chronic illness. We aim to provide efficacy and safety evidence, and a guide for IRT prescription and delivery. Recommendations are made for the use of IRT in specific patient populations and appropriate methods for IRT delivery. Published data suggest IRT consistently elicits mean blood pressure reductions of 7.4/3.3 mmHg systolic blood pressure/diastolic blood pressure, equivalent to antihypertensive medication monotherapy. Blood pressure reductions of this size are associated with an approximate 13% to 22% reduction in major cardiovascular events. Moreover, IRT is safe in a range of patient populations. We suggest that IRT has the greatest potential benefit when used as an antihypertensive therapy in individuals unwilling and/or unable to complete aerobic exercise, or who have had limited adherence or success with it; individuals with resistant or uncontrolled hypertension, already taking at least two pharmacological antihypertensive agents; and healthy or clinical populations, as an adjunct to aerobic exercise and dietary intervention in those who have not yet attained control of their hypertension. IRT is efficacious and produces clinically meaningful blood pressure reductions (systolic blood pressure, 7 mmHg; diastolic blood pressure, 3 mmHg). IRT is safe and typical program delivery requires only about 17 min weekly. IRT should be used as an adjunct to other exercise modalities, in people unable to complete other types of exercise, or in resistant hypertension. [Abstract copyright: © 2023. The Author(s).

Risk of atrial fibrillation in athletes: a systematic review and meta-analysis

Objective A systematic review, meta-analysis and meta-regression were performed on selected studies to investigate the incidence of atrial fibrillation (AF) among athletes compared with non-athlete controls. Design Meta-analysis with heterogeneity analysis and subsequent meta-regression to model covariates were performed. The mode of exercise (endurance and mixed sports) and age were the a priori determined covariates. Data sources PubMed, MEDLINE, Science Direct, SPORTDiscus and the Cochrane library were searched. Eligibility criteria Research articles published after 1990 and before 2 December 2020 were included if they reported the number of AF cases in athletes with non-athlete (physically active or inactive) control groups, were case–control or cohort studies and if data allowed calculation of OR. Results The risk of developing AF was significantly higher in athletes than in non-athlete controls (OR: 2.46; 95% CI 1.73 to 3.51; p<0.001, Z=4.97). Mode of exercise and risk of AF were moderately correlated (B=0.1259, p=0.0193), with mixed sport conferring a greater risk of AF than endurance sport (B=−0.5476, p=0.0204). Younger (<55 years) athletes were significantly more likely to develop AF compared with older (≥55 years) athletes (B=−0.02293, p<0.001). Conclusion Athletes have a significantly greater likelihood of developing AF compared with non-athlete controls, with those participating in mixed sport and younger athletes at the greatest risk. Future studies of AF prevalence in athletes according to specific exercise dose parameters, including training and competition history, may aid further in delineating those at risk

Effect of Shear Work Input on Steady Shear Rheology and Melt Functionality of Model Mozzarella Cheeses

Model Mozzarella cheeses with varied amounts of shear work input were prepared by working molten cheese mass at 70 °C in a twin screw cooker. Rheology and melt functionality were found to be strongly dependent on total shear work input. A non-linear increase in consistency coefficient (K from power law model) and apparent viscosity and decrease in flow behaviour index (n from power law model) were observed with increasing amounts of accumulated shear work, indicating work thickening behaviour. An exponential work thickening equation is proposed to describe this behaviour. Excessively worked cheese samples exhibited liquid exudation, poor melting and poor stretch. Nonfat cheese exhibited similar but smaller changes after excessive shear work input. We concluded that the dominant contributor to the changes in properties with increased shear work was shear induced structural changes to the protein matrix. A good correlation was found between the steady shear rheological properties and the melting properties of the cheeses

Individuals' Long Term Use of Cognitive Behavioural Skills to Manage their Depression: A Qualitative Study

Background: Cognitive Behavioural Therapy (CBT) aims to teach people skills to help them self-manage their depression. Trial evidence shows that CBT is an effective treatment for depression and individuals may experience benefits long-term. However, there is little research about individuals’ continued use of CBT skills once treatment has finished. Aims: To explore whether individuals who had attended at least 12 sessions of CBT continued to use and value the CBT skills they had learnt during therapy. Method: Semi-structured interviews were held with participants from the CoBalT trial who had received CBT, approximately 4 years earlier. Interviews were audio-recorded, transcribed and analysed thematically. Results: 20 participants were interviewed. Analysis of the interviews suggested that individuals who viewed CBT as a learning process, at the time of treatment, recalled and used specific skills to manage their depression once treatment had finished. In contrast, individuals who viewed CBT only as an opportunity to talk about their problems did not appear to utilize any of the CBT skills they had been taught and reported struggling to manage their depression once treatment had ended. Conclusions: Our findings suggest individuals may value and use CBT skills if they engage with CBT as a learning opportunity at the time of treatment. Our findings underline the importance of the educational model in CBT and the need to emphasize this to individuals receiving treatment

Elliptic Curves over Real Quadratic Fields are Modular

We prove that all elliptic curves defined over real quadratic fields are modular.Comment: 38 pages. Magma scripts available as ancillary files with this arXiv versio

Auto-driven Photo Elicitation Interviews in Research with Children: Ethical and Practical Considerations

Children can sometimes find it difficult to articulate their experiences if they have to rely solely on words. Giving children the opportunity to use arts-based research approaches can support their participation in research and create a bridge that enables them to express their perspectives and feelings. This paper focuses on the ethical and practical considerations when using photo elicitation interviews (PEI) in research with children. The discussion and examples provided are drawn from an international study that used auto-driven PEI, where photographs are taken by children themselves, to explore children’s experiences of living with a chronic condition and the impact condition management may have on their everyday lives. In this paper we critically explore the issues arising from our use of PEI including children’s participation and engagement, balancing power and control, and keeping children safe. The main areas of focus for the paper are how PEI provided a means of shifting control; how setting photographic boundaries influenced our PEI study with children; and how we addressed risks associated with the method. Our experience shows that PEI is an engaging and valuable research method, providing a powerful medium for obtaining rich data with children. However, PEI is challenging and it requires researchers to conscientiously address ethical and practical aspects that extend beyond those inherent to standard (words-alone) interviews

Modular symbols in Iwasawa theory

This survey paper is focused on a connection between the geometry of $\mathrm{GL}_d$ and the arithmetic of $\mathrm{GL}_{d-1}$ over global fields, for integers $d \ge 2$. For $d = 2$ over $\mathbb{Q}$, there is an explicit conjecture of the third author relating the geometry of modular curves and the arithmetic of cyclotomic fields, and it is proven in many instances by the work of the first two authors. The paper is divided into three parts: in the first, we explain the conjecture of the third author and the main result of the first two authors on it. In the second, we explain an analogous conjecture and result for $d = 2$ over $\mathbb{F}_q(t)$. In the third, we pose questions for general $d$ over the rationals, imaginary quadratic fields, and global function fields.Comment: 43 page