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Left ventricular function and mechanics following prolonged endurance exercise: an update and meta-analysis with insights from novel techniques.
Get PDFBACKGROUND: The cardiac consequences of undertaking endurance exercise are the topic of recent debate. The purpose of this review is to provide an update on a growing body of literature, focusing on left ventricular (LV) function following prolonged endurance exercise over 2 h in duration which have employed novel techniques, including myocardial speckle tracking, to provide a more comprehensive global and regional assessment of LV mechanics. METHODS: Prospective studies were filtered independently following a pre-set criteria, resulting in the inclusion of 27 studies in the analyses. A random-effects meta-analysis was used to determine the weighted mean difference and 95% confidence intervals (CI) of LV functional and mechanical data from pre-to-post-exercise. Narrative commentary was also provided where volume of available evidence precluded meta-analysis. RESULTS: A significant overall reduction in LV longitudinal strain (Ɛ) n = 22 (- 18 ± 1 to - 17 ± 1%; effect size (d) - 9: - 1 to - 0.5%), strain rate n = 10 (SR; d - 0.9: - 0.1.3 to - 0.5 l/s) and twist n = 5 (11.9 ± 2.2 to 8.7 ± 2.2°, d - 1: - 1.6 to - 0.3°) was observed following strenuous endurance exercise (range 120-1740 min) (P 0.05). CONCLUSION: The meta-analysis and narrative commentary demonstrated that a reduction in LV function and mechanics is evident following prolonged endurance exercise. The mechanism(s) responsible for these changes are complex and likely multi-factorial in nature and may be linked to right and left ventricular interaction
50 facts everyone should know about crime and punishment in Britain
No full textA significant number of those serving a sentence in the criminal justice system in England and Wales are former military personnel
Exercise on Referral – Symposium hosted by the Physical Activity Special Interest Group of the Wolfson Research Institute for Health and Wellbeing, Durham University
Get PDFTHE Physical Activity Special Interest Group of the Wolfson Research Insti- tute for Health and Wellbeing (Durham University) hosted a symposium focused on exercise referral schemes (ERS), on 14 October 2016 at the College of St Hild and St Bede, Durham. Exercise referral schemes typically allow health professionals, such as general practitioners, nurses and physiotherapists to refer inactive individuals with long-term health conditions to a third party leisure provider for a supervised exercise programme, with the aim of increasing physical activity levels. The symposium was lively and thought-provoking with pres- entations divided into two core themes: ‘Emerging Evidence for ERS’ and ‘Future Developments for ERS’
The Development of a Low Carbon Cementitious Material Produced from Cement, Ground Granulated Blast Furnace Slag and High Calcium Fly Ash
Get PDFThis research represents experimental work for investigation of the influence of utilising Ground Granulated Blast Furnace Slag (GGBS) and High Calcium Fly Ash (HCFA) as a partial replacement for Ordinary Portland Cement (OPC) and produce a low carbon cementitious material with comparable compressive strength to OPC. Firstly, GGBS was used as a partial replacement to OPC to produce a binary blended cementitious material (BBCM); the replacements were 0, 10, 15, 20, 25, 30, 35, 40, 45 and 50% by the dry mass of OPC. The optimum BBCM was mixed with HCFA to produce a ternary blended cementitious material (TBCM). The replacements were 0, 10, 15, 20, 25, 30, 35, 40, 45 and 50% by the dry mass of BBCM. The compressive strength at ages of 7 and 28 days was utilised for assessing the performance of the test specimens in comparison to the reference mixture using 100% OPC as a binder. The results showed that the optimum BBCM was the mix produced from 25% GGBS and 75% OPC with compressive strength of 32.2 MPa at the age of 28 days. In addition, the results of the TBCM have shown that the addition of 10, 15, 20 and 25% of HCFA to the optimum BBCM improved the compressive strength by 22.7, 11.3, 5.2 and 2.1% respectively at 28 days. However, the replacement of optimum BBCM with more than 25% HCFA have showed a gradual drop in the compressive strength in comparison to the control mix. TBCM with 25% HCFA was considered to be the optimum as it showed better compressive strength than the control mix and at the same time reduced the amount of cement to 56%. Reducing the cement content to 56% will contribute to decrease the cost of construction materials, provide better compressive strength and also reduce the CO2 emissions into the atmosphere
Radio continuum emission in the northern Galactic plane: Sources and spectral indices from the THOR survey
Get PDFRadio continuum surveys of the Galactic plane can find and characterize HII regions, supernova remnants (SNRs), planetary nebulae (PNe), and extragalactic sources. A number of surveys at high angular resolution (<25") at different wavelengths exist to study the interstellar medium (ISM), but no comparable high-resolution and high-sensitivity survey exists at long radio wavelengths around 21cm. We observed a large fraction of the Galactic plane in the first quadrant of the Milky Way (l=14.0-67.4deg and |b| < 1.25deg) with the Karl G. Jansky Very Large Array (VLA) in the C-configuration covering six continuum spectral windows. These data provide a detailed view on the compact as well as extended radio emission of our Galaxy and thousands of extragalactic background sources. We used the BLOBCAT software and extracted 10916 sources. After removing spurious source detections caused by the sidelobes of the synthesised beam, we classified 10387 sources as reliable detections. We smoothed the images to a common resolution of 25" and extracted the peak flux density of each source in each spectral window (SPW) to determine the spectral indices (assuming ). By cross-matching with catalogs of HII regions, SNRs, PNe, and pulsars, we found radio counterparts for 840 HII regions, 52 SNRs, 164 PNe, and 38 pulsars. We found 79 continuum sources that are associated with X-ray sources. We identified 699 ultra-steep spectral sources () that could be high-redshift galaxies. Around 9000 of the sources we extracted are not classified specifically, but based on their spatial and spectral distribution, a large fraction of them is likely to be extragalactic background sources. More than 7750 sources do not have counterparts in the SIMBAD database, and more than 3760 sources do not have counterparts in the NED database
How Is Physical Literacy Defined? A Contemporary Update
Get PDFPhysical literacy continues to gain global momentum, yet the definition and underlying concept of physical literacy remain contested in both research and practice. This lack of clarity has the potential to undermine the operationalization of physical literacy. This paper considers the various definitions of physical literacy that are currently adopted internationally. Physical literacy experts identified seven leading groups that have established physical literacy initiatives. Although each group is unified in using the term physical literacy, there are contrasting definitions and interpretations of the concept. Common themes were identified, including the (a) influence of physical literacy philosophy, (b) core elements of physical literacy, (c) lifelong nature of physical literacy, and (d) the need to scientifically pursue a robust operationalization of the concept. We conclude by recommending that programs relating to physical literacy should provide a definition, a clear philosophical approach, and transparency with how their actions align with this approach
Compressive behaviour of high-strength steel cross-sections
Get PDFThe recent increase in the use of high-strength steels (HSSs) in modern engineering practice necessitates a deeper understanding of their structural response. Given that HSS design specifications are largely based on a limited number of test data and assumed analogies with mild steel, their applicability to HSS sections needs to be assessed. In the work reported in this paper, finite-element models were developed and validated against experimental data of hot-finished S460 and S690 grade steel stub columns. Parametric studies were conducted to generate a large volume of structural performance data over a wide range of cross-section slenderness values and aspect ratios. On the basis of the results, the suitability of the Eurocode 3 (EC3) class 3 slenderness limit and the effective width equations for HSS sections were assessed. Aiming to account for element interaction effects, which are not considered in EC3, an effective cross-section method applicable to HSS slender sections was developed. Finally, the continuous-strength method was extended to stocky S460 sections, for which overly conservative strength predictions were observed. The reliability of the proposed design methods was verified according to annex D of the Eurocode structural design basis (EN 1990)
Strength demands of tall wind turbines subject to earthquakes and wind load
Get PDFWind and earthquake load have historically been conceived to act independently. However, if we reflect on the fact that major seismic events are usually followed by a number of aftershocks and that wind is constantly flowing at high intensities around wind farms, which induces additional demands of resistance to infrastructure, then the joint probability of middle-to strong earthquakes and low-to mild wind events becomes more relevant. In this paper a generalised approach is used to estimate the ratio between earthquake and wind forces and their effect on infrastructure. Following, a probabilistic analysis is carried out to show that under certain conditions the combination of these natural events can induce additional demands of strength and ductility to wind turbines which could lead to unforeseen damage
THE WRITING LIFE OF ROBERT STORY, 1795-1860: ‘THE CONSERVATIVE BARD’
Get PDFThis thesis explores the writing life of the Northumbrian labouring-class poet Robert Story (1795-1860) who, during the political turmoil of the 1830s, achieved national celebrity for writing a series of songs and poems for Peel’s Conservative party. In his unpublished autobiography (c.1853) he alludes to building an archive of his work. Drawing on these manuscripts, all of which have until now remained hidden, and his published writing, this thesis investigates the relationship between Story’s apparent political conservatism and his progressive and experimental approach to writing. The study is organised into three main parts. The first forms a study of Story’s biographical manuscripts, using his accounts of reading to raise the wider complex theoretical questions that inform the thesis. It goes beyond Story’s connection with the pastoral tradition and hypothesises that Story’s writing was always rhetorical. Tracing Story’s circle of ‘brother’ poets, part two locates him in a distinctly labouring-class canon, imagined or otherwise, that he believed was at least equal to the polite realm of literature. This phase of research also resituates Story’s satirical modes of writing and his party ballads within the great body of political literature produced by working men during the first half of the nineteenth century. Story’s importance lies not only in his pursuit of politics but also in his cultural ambition: the third part of the thesis examines formal hybridity in his writing. It reveals how Story was searching for new forms of self-expression and asks to what extent his pursuit of literature was politicised and predicated on the belief that social and economic emancipation was contingent on cultural equality. Overall this thesis argues that Story was using literature to challenge the political, social and cultural boundaries imposed on him as both a workingman and a labouring-class writer
EFFICIENT RUNTIME SECURITY SYSTEM FOR DECENTRALISED DISTRIBUTED SYSTEMS
Get PDFDistributed systems can be defined as systems that are scattered over geographical distances and provide different activities through communication, processing, data transfer and so on. Thus, increasing the cooperation, efficiency, and reliability to deal with users and data resources jointly. For this reason, distributed systems have been shown to be a promising infrastructure for most applications in the digital world. Despite their advantages, keeping these systems secure, is a complex task because of the unconventional nature of distributed systems which can produce many security problems like phishing, denial of services or eavesdropping. Therefore, adopting security and privacy policies in distributed systems will increase the trustworthiness between the users and these systems. However, adding or updating security is considered one of the most challenging concerns and this relies on various security vulnerabilities which existing in distributed systems. The most significant one is inserting or modifying a new security concern or even removing it according to the security status which may appear at runtime. Moreover, these problems will be exacerbated when the system adopts the multi-hop concept as a way to deal with transmitting and processing information. This can pose many significant security challenges especially if dealing with decentralized distributed systems and the security must be furnished as end-to-end. Unfortunately, existing solutions are insufficient to deal with these problems like CORBA which is considered a one-to-one relationship only, or DSAW which deals with end-to-end security but without taking into account the possibility of changing information sensitivity during runtime. This thesis provides a proposed mechanism for enforcing security policies and dealing with distributed systems’ security weakness in term of the software perspective. The proposed solution utilised Aspect-Oriented Programming (AOP), to address security concerns during compilation and running time. The proposed solution is based on a decentralized distributed system that adopts the multi-hop concept to deal with different requested tasks. The proposed system focused on how to achieve high accuracy, data integrity and high efficiency of the distributed system in real time. This is done through modularising the most efficient security solutions, Access Control and Cryptography, by using Aspect-Oriented Programming language. The experiments’ results show the proposed solution overcomes the shortage of the existing solutions by fully integrating with the decentralized distributed system to achieve dynamic, high cooperation, high performance and end-to-end holistic security
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