914 research outputs found
COMPARING THE ACUTE EFFECTS OF WARM-UP STRATEGIES USING FREE-WEIGHT AND VARIABLE RESISTANCE ON STRENGTH AND POWER PERFORMANCE
Warm-up routines are typically designed to precondition the neuromuscular system for enhanced performance and reduced injury risk during subsequent high-intensity physical activities, including during strength training. As such, identifying an effective warm-up routine to augment muscular performance is of clear importance to strength (and other) coaches and athletes. Incorporating variable resistance (VR) via the use of chains or elastic bands during strength training alters the loading characteristics during exercises to impose a greater mechanical stimulus, however the impact of VR on subsequent free-weight exercise performance is unknown. Therefore, the aims of this thesis were to examine the acute effects of conditioning VR exercise compared to free-weight resistance (FWR) exercise on subsequent one-repetition maximum (1-RM) back squat and countermovement vertical jump (CMJ) height performance after the performance of a comprehensive, test-specific warm-up, and to examine possible alterations to mechanics and neuromuscular activity underpinning any changes. Techniques including 3D motion analysis, electromyography (EMG) and ground reaction force measurement were used in three studies on recreationally active volunteers experienced in squatting and jumping. In Study 1, significantly greater 1-RM squat-lift load (6.2 ± 5.0%; p 0.05) were detected in concentric phase EMG, knee angular velocity or peak knee flexion angle. Thus, performing a CLR warm-up enhanced subsequent free-weight 1-RM performance without kinematic changes; these data were considered to indicate a real 1-RM increase as the mechanics of the lift were not influenced. Study 2 followed an identical methodological design, however elastic bands were used to provide an inexpensive, portable, easily-implemented, and therefore more practical method of altering the load-time characteristics of the squat lift through VR. Significantly greater 1-RM squat load (7.7 ± 6.2%; p 0.05). However, statistical (p < 0.05) and practically-meaningful increases were detected in CMJ height (5.3-6.5%), net impulse (2.7-3.3%), take-off velocity (2.7-3.8%), peak power (4.4-5.9%), kinetic (7.1-7.2%) and potential (5.4-6.7%) energy, peak normalised rate of force development (12.9-19.1%), peak concentric knee angular velocities (3.1-4.1%) and mean concentric vastus lateralis (VL) EMG activity (27.5-33.4%) at all time points after the EB warm-up condition. Thus, when a complete CMJ-specific warm-up was provided, FWR squat had no additional effect on CMJ performance however the alteration of the squat lift force-time characteristics using EB led to a substantial CMJ enhancement. The findings from the present series of studies have important implications for research study design as the warm-up imposed and the resistive modality selected appear to influence subsequent movement performances, i.e. 1-RM back squat or CMJ performances. In previous studies, standardised (or no) warm-up protocols imposed before the baseline testing have been associated with subsequent enhancements in squat lift and CMJ performances following conditioning contractions, although it is unclear whether this is a consequence of acute neuromuscular alteration relating to the conditioning contractions or to the warm-up itself. Collectively, the present findings, show that physical performance can be enhanced in at least some conditions by application of conditioning contractions even after completion of a comprehensive, test-specific warm-up, which have important practical implications in the formulation of pre-performance warm-up routines where maximal force production is an important goal.N/
Global mental health and psychiatric institutions in the 21st century.
In the 19th century, psychiatric institutions were the focus of thousands of articles in the leading English-language medical and psychiatric journals. This area of concern remained important through the first half of the 20th century, with some decline in the number of published articles in the second half of the 20th century as de-institutionalisation gathered pace. The number of articles about this topic has declined sharply in the past 25 years, and psychiatric institutions are not the focus of any of the Grand Challenges in Global Mental Health even though psychiatric institutions of all kinds are widely acknowledged to be the among the main sites of human rights abuses. In this commentary we present examples of impressive transformations of institutions in Sri Lanka and Vietnam, and suggest that the field of global mental health should devote more of its efforts to improving the lives of persons with mental disorders who have been incarcerated in a variety of settings, often under the care of mental health specialists
Experimental data on the properties of polymer-modified cement grouts using epoxy and acrylic resin emulsions
AbstractThe use of additives to improve the quality of cement grouts is crucial for civil engineering, especially in foundation construction. This article presents experimental data concerning the compressive strength, elastic modulus, bleeding and injectability of microfine cement grouts modified with epoxy and acrylic resin emulsions. Strength properties were obtained at different curing ages. For further analysis and detailed discussion of properties of polymer-modified cement grouts, see “Fundamental properties of epoxy resin-modified cement grouts” (C.A. Anagnostopoulos, G. Sapidis, E. Papastergiadis, 2016) [1]
Suicide first aid guidelines for assisting persons from immigrant or refugee background: a Delphi study
Objective: Suicide rates vary across different cultural groups and some immigrant or refugee populations display higher risk for suicide. This study aimed to produce guidelines to help members of the public provide assistance to a person from an immigrant or refugee background who is having suicidal thoughts or displaying suicidal behaviour.
Method: The Delphi expert consensus method was used to identify warning signs and first aid actions to include in guidelines. Forty- four professionals and/or advocates with lived experience were asked to rate whether each statement contained in an online questionnaire should be included in the guidelines and to suggest additional statements considered by the respondent to be particularly relevant to a person from an immigrant or refugee background. The Delphi process started with 473 statements and 80 new items were written based on suggestions from panel members.
Results: Out of the total 553 statements, 345 were endorsed as appropriate warning signs or helping actions. These statements were used to develop the guidelines.
Discussion: The guidelines specific to people from immigrant or refugee backgrounds contain additional items to those included in similar guidelines for English-speaking countries. The guidelines may be used for gatekeeper training for suicide prevention in culturally diverse societies
Climate Change and National Laws across Commonwealth Countries
This paper furthers the Commonwealth agenda on climate action by exploring the kinds of ‘practical and swift action’ that might be taken through national legal frameworks to implement the Paris Agreement. The paper reviews national laws of Commonwealth member countries as they currently apply to and intersect with climate change. The paper investigates legal measures that relate directly to implement climate change policy, including climate change legislation and regulatory instruments such as emissions trading schemes and energy efficiency measures. It also considers indirect legal measures that can provide ‘co-benefits’ in relation to climate change policy, such as waste legislation and air quality measures. The paper presents examples of these different kinds of climate intersections in different Commonwealth legal systems, highlighting examples of what has worked well and what has not worked well to date, within different legal, economic and political cultures, and in different geographies and climates
Biodesalination: an emerging technology for targeted removal of Na+and Cl−from seawater by cyanobacteria
Although desalination by membrane processes is a possible solution to the problem of freshwater supply, related cost and energy demands prohibit its use on a global scale. Hence, there is an emerging necessity for alternative, energy and cost-efficient methods for water desalination. Cyanobacteria are oxygen-producing, photosynthetic bacteria that actively grow in vast blooms both in fresh and seawater bodies. Moreover, cyanobacteria can grow with minimal nutrient requirements and under natural sunlight. Taking these observations together, a consortium of five British Universities was formed to test the principle of using cyanobacteria as ion exchangers, for the specific removal of Na+ and Cl− from seawater. This project consisted of the isolation and characterisation of candidate strains, with central focus on their potential to be osmotically and ionically adaptable. The selection panel resulted in the identification of two Euryhaline strains, one of freshwater (Synechocystis sp. Strain PCC 6803) and one of marine origin (Synechococcus sp. Strain PCC 7002) (Robert Gordon University, Aberdeen). Other work packages were as follows. Genetic manipulations potentially allowed for the expression of a light-driven, Cl−-selective pump in both strains, therefore, enhancing the bioaccumulation of specific ions within the cell (University of Glasgow). Characterisation of surface properties under different salinities (University of Sheffield), ensured that cell–liquid separation efficiency would be maximised post-treatment, as well as monitoring the secretion of mucopolysaccharides in the medium during cell growth. Work at Newcastle University is focused on the social acceptance of this scenario, together with an assessment of the potential risks through the generation and application of a Hazard Analysis and Critical Control Points plan. Finally, researchers in Imperial College (London) designed the process, from biomass production to water treatment and generation of a model photobioreactor. This multimodal approach has produced promising first results, and further optimisation is expected to result in mass scaling of this process
Design of a lab-on-a-chip for clinical tests of human physiological fluids
Labs-on-a-chip are useful to perform in situ clinical tests with instantaneous results.
In this work, the design phase of the development of a lab-on-a-chip is presented.
The device will be used to perform tests on physiological fluids. It will be able to test
8 components: calcium, chloride, creatinine, glucose, magnesium, total protein, urea
and uric acid. A sample of the physiological fluid reacts with several reagents and the
device measures the absorbance of the reaction products.
The lab-on-a-chip is composed of a microfluidic system and an optical detection
system. The first contains microchannels and micro-reactors fabricated using SU-8
techniques. The second includes CMOS photodetectors and readout electronics, as
well as optical filters fabricated using CMOS-compatible post-processing on top of
the photodetectors.
Careful design of the microfluidic system of a lab-on-a-chip requires knowledge of
the transport phenomena in the microchannels. Numerical methods are used to
simulate the electroosmotic flow, reaction and mixture in the system. Velocitypressure
formulation of the Navier-Stokes equations is solved by a finite difference
method. Mass transport equation is solved by a second order finite difference
method. For enzymatic reactions, biochemical reaction kinetics is considered.
Design choices are presented and explained. The final design of the microfluidic
system complies with layout restriction and kinetic, mass transport and other physical
limitations. The dimensions of the micro-reactors are optimized to maximize mixing.
The design of the optical detection system involves selection of the dielectric layers
available in the CMOS process for the photodetectors and selection of the dielectric
thin-films layers for the optical filters. An array of 8 selective optical filters is
designed for parallel testing of the 8 reported components. They are structurally
optimized for an optical response at the absorption peak of each reaction product.
The lab-on-a-chip output provides a digital signal for computer interfacing.R&D Centre Algoritmi.Escola de Engenharia da Universidade do Minho - Program IN2TEC.Fundação para a Ciência e a Tecnologia (FCT) - Grant SFRH/BPD/17689/2004
Do large governments decrease happiness? New evidence of a negative effect in Europe
Until now little evidence has been found about the relationship between governments and happiness, but when cited, it has suggested a positive influence. Using micro-data from the last three waves of the European Quality of Life Survey and several measures for the weight of the government, such as structural government consumption, structural balance, and public debt, we show that government consumption and the other measures of government imbalances significantly decrease happiness in European countries. Additionally, we present robust evidence of a positive relationship between the quality of government and happiness. This evidence may lead politicians to reject the idea that bigger Governments lead to greater satisfaction. This result is consistent with people valuing (negatively) expectations for future tax increases, austerity, and possible corruption-related events.info:eu-repo/semantics/submittedVersio
Suicide first aid guidelines for Sri Lanka: a Delphi consensus study
Background: Sri Lanka has one of the highest suicide rates in the world. Gatekeeper programs aimed at specific target groups could be a promising suicide prevention strategy in the country. The aim of this study was to develop guidelines that help members of the public to provide first aid to persons in Sri Lanka who are at risk of suicide.
Methods: The Delphi method was used to elicit consensus on potential helping statements to include in the guidelines. These statements describe information members of the public should have and actions they can take to help a person who is experiencing suicidal thoughts. An expert panel, comprised of mental health and suicide experts in Sri Lanka, rated each statement. The panellists were encouraged to suggest any additional action that was not included in the original questionnaire and, in particular, to include items that were culturally appropriate or gender specific. Responses to open-ended questions were used to generate new items. These items were included in the subsequent Delphi rounds. Three Delphi rounds were carried out. Statements were accepted for inclusion in the guidelines if they were endorsed (rated as essential or important) by at least 80 % of the panel. Statements endorsed by 70–79 % of the panel were re-rated in the following round. Statements with less than 70 % endorsement, or re-rated items that did not receive 80 % or higher endorsement were rejected.
Results: The output from the Delphi process was a set of endorsed statements. In the first round questionnaire 473 statements were presented to the panel and 58 new items were generated from responses to the open-ended questions. Of the total 531 statements presented, 304 were endorsed. These statements were used to develop the suicide first aid guidelines for Sri Lanka.
Conclusion: By engaging Sri Lankans who are experts in the field of mental health or suicide this research developed culturally appropriate guidelines for providing mental health first aid to a person at risk of suicide in Sri Lanka. The guidelines may serve as a basis for developing training for members of the public to provide mental health first aid to persons at risk of suicide as part of Sri Lanka’s suicide prevention strategy
- …