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Network and Hypervisor-Based Attacks in Cloud Computing Environments
No full textCloud Computing (CC) has become one of the most transform ativ e
computing technologies and a key business avenue, following in the footsteps
of main-frames, minicomputers, personal computers, the World Wide Web an d
smartphones. Its vital features have considerably reduced IT costs, contributing
to its rapid adoption by businesses and governments worldwide. Despite the
many technological and economic benefits that CC offers, at the same t im e, it
poses complex security threats resulting from the use of virtualisation
technology. Compromising the security of any component in the cloud v irt ual
infrastructure will negatively affect the security of other elements and so
impact the overall system security. Therefore, to create a practical
understanding of such threats, this paper provides an analysis of common and
underexplored network- and hypervisor-based attacks against CC systems from
a technical viewpoint
Muscle architecture and maturation influences sprint and jump ability in young boys: a multi-study approach
Get PDFThis series of experiments examined the influence of medial gastrocnemius (GM) and vastus lateralis (VL) muscle architecture (muscle thickness, pennation angle, and fascicle length) on sprint and jump performance in pre-, circa- and post-peak height velocity (PHV) boys. In experiment 1, one-way ANOVA’s and Cohen’s d effect-sizes demonstrated that most muscle architecture measures were significantly greater in post- compared to pre-PHV boys (d = 0.77 - 1.41; p < 0.05). For the majority of sprint and jump variables, there were small to moderate differences between pre- to circa-, and circa- to post-PHV groups (d = 0.58 – 0.93; p < 0.05), and moderate to large differences between pre- and post-PHV groups (d = 1.01 - 1.47; p < 0.05). Pearson’s correlation analyses in experiment 2 determined that muscle architecture had small to moderate correlations with sprint and jump performance (r = 0.228 – 0.707, p < 0.05), with strongest associations within the post-PHV cohort. Chi squared analyses in experiment 3 identified that, over 18-months, more POST-POST responders than expected made positive changes in GM and VL muscle thickness. Significantly more PRE-POST subjects than expected displayed changes in maximal sprint speed, while significantly more POST-POST individuals than expected showed positive changes in jump height. Muscle architecture appears to be larger in more mature boys compared to their less mature peers, and likely underlies their greater performance in sprinting and jumping tasks. Boys experiencing, or having experienced, PHV make the largest increases in muscle architecture, and sprinting and jumping performance when tracked over 18-months
How do patients receiving prescribed B12 injections for the treatment of PA perceive changes in treatment during the covid-19 pandemic? A UK based survey study
Get PDFPernicious Anaemia (PA) is a chronic condition which is usually treated using B12 injections. Due to the pandemic many patients were prescribed an alternative oral B12 treatment. There is limited evidence that this is effective at managing symptoms of PA. The aim of this study was to document treatment changes across the UK and the impact on patient experience. An online survey explored how the treatment of PA has been managed during the early stages of the pandemic; responses were analysed for a sub-sample of participants receiving prescribed B12 injections and where changes in treatment applied (n=329) using content analysis. The most common reported change was suspension of injections, with oral B12 being offered as an alternative treatment. Patients were concerned about the long-term impact that changes would have on their condition management and many stated that they were dissatisfied with the level of care received. Those who were supported by healthcare providers to continue their usual treatment reported experiencing improved health and wellbeing. This study highlights the major impact of treatment changes on patient health outcomes, and the need to further support healthcare professionals with PA management during and beyond the pandemic
The endurance athlete's circulation: Ultra-risky or a long road to safety?
No full textThe positive effects of regular participation in physical activity are well documented. Meeting the minimum physical activity guidelines reduces the risk of many diseases, and physically active individuals generally live longer, healthier lives than inactive people [ [1] ]. Accordingly, current guidelines [ 2 , 3 , 4 ] recommend 2.5–5h/week of moderate-intensity exercise or 1.25–2.5h/week of vigorous-intensity exercise (a metabolic equivalent of 8–17 MET-h/week). However, the health status of individuals who markedly exceed the minimum recommendations remains a matter of debate. One major concern pertains to the possible mal-adaptation of the cardiovascular system that would predispose athletes to a greater risk of all-cause and cardiovascular morbidity and mortality, raising the question whether excessive volumes of exercise could be “too much of a good thing” [ [5] ]. In agreement with this concern is the observation of a reverse J-curve association between exercise and cardiovascular health (Fig. 1) [ [6] ]. Specifically, the reverse J-curve represents the fact that mild-to-moderate volume and intensity exercise (in accordance with physical activity guidelines) seems to improve cardiovascular health compared with inactivity, while cardiovascular risk in individuals who perform a large volume of exercise may increase again. Such a concern is far from trivial because the participation in ultra-endurance events has steadily increased over the last decades. In 2017, more than 300,000 men and women participated in ultra-marathons alone, and several thousand more took part in other long-distance competitions [ [7] ]. Reports of increased coronary artery calcium scores and “hearts of stone” [ [8] ] in some endurance athletes have alarmed medical professionals and indicated the need for further data on the health risks associated with excessive amounts of endurance exercise. On the other hand, readers of this journal will be interested to note that several studies have reported an increased coronary artery calcium score (CACS) in middle-aged athletes, but with more stable atherosclerotic plaques and a similar or reduced morbidity and mortality compared with less active, age-matched individuals [ 9 , 10 , 11 , 12 ]. In accordance, a recent meta-analysis surmises that the previously proposed reverse J-curve association between volume of exercise and cardiovascular health can now be “refuted” [ [1] ]. Yet, the story seems far from over because some humans are pushing the boundaries of exercise further, and the effects of extreme volumes of exercise on cardiovascular adaptation and health remain poorly understood
Comparative Study of Modelling and Forecasting Volatility: The Case of Egypt, and Japan
Get PDFThe purpose of this paper is to evaluate the forecasting performance of linear and
non-linear (GARCH) models in terms of their in-sample and out-of-sample forecasting
accuracy for EGX30 and Nikkei225 indices as an example of an emerging and developed
markets respectively.
We employ GARCH, GARCH-IN-MEAN, EGARCH, GJR-GARCH, Multivariate
GARCH, and Nelson's EGARCH for forecasting using daily price data of the indices for
the period of 2001 to 2019. We find that the volatility shocks on the indices returns are
quite persistent. Furthermore, our findings show that the indices have leverage effect, and
the impact of shocks is asymmetric, and consequently it can be stated that the impact of
negative shocks on volatility are higher than positive shocks.
The results suggest that the Nelson's EGARCH model is the most accurate model in
the GARCH class for forecasting, as this model outperforms the other models.
Additionally, we find that emerging stock markets have higher volatilities than those in
developed markets. Further, these results imply that the EGARCH model might be more
useful than other models when implementing risk management strategies and developing
stock pricing model.
This paper contributes to the literature by comparing two significant global markets;
one of the largest developed economies in the world, Japan, and one of Africa’s largest
developing economies, Egypt
A service evaluation specifying the active components of a Functional Restorative Programme to promote management of persistent non-specific low back pain
No full textBackground: Functional Restorative Programmes (FRP) for persistent non- specific lower back pain have been shown to be effective, but they often lack sufficient detailed reporting of the intervention components to allow for accurate replication.
Objectives: This study used the Behaviour Change Technique Taxonomy (v1) (BCTi) [1] to identify the main components of one such programme and interviewed patients to identify the most effective programme components and areas for improvement.
Design: A mixed methods design was used. Methods: Intervention data were coded using the BCT Taxonomy (v1) to identify the BCTs utilised. Following this, semi-structured interviews with nine patients evaluated the BCTs included using thematic analysis and identified possible techniques for inclusion in future developments of the programme.
Results: Forty-one different BCTs were identified in the coding phase with frequency of occurrence in the programme ranging from forty-nine to one. Four main themes emerged from the interviews: Social Support, Shaping Knowledge, Repetition and Substitution and Changes in Mindset.
Conclusion: The results of this study identify the key ingredients in a programme for persistent, non-specific lower back pain, which facilitates the replication of this intervention and identified areas patients appreciated most as well as areas for improvement
Right ventricular function and region-specific adaptation in athletes engaged in high-dynamic sports: A meta-analysis
Get PDFBackground
Structural remodeling of the right ventricle (RV) is widely documented in athletes. However, functional
adaptation, including RV pressure generation and systolic free-wall longitudinal mechanics, remains
equivocal. This meta-analysis compared RV pressure and function in athletes and controls.
Methods
A systematic review of online databases was conducted up to June 4, 2020. Meta-analyses were
performed on RV systolic pressures (RVSP), at rest and during exercise, tricuspid annular plane systolic
displacement (TAPSE), myocardial velocity (S’), and global and regional longitudinal strain. Bias was
assessed using Egger’s regression for asymmetry. Data were analyzed using random-effects models
with weighted mean difference (WMD) and 95% confidence interval (95%CI).
Results
Fifty-three studies were eligible for inclusion. RVSP was obtained from 21 studies at rest
(n=1043:1651; controls:athletes) and 8 studies during exercise (n=240:495) and was significantly
greater in athletes at rest (WMD: 2.9mmHg, CI: 1.3-to-4.5mmHg; P=0.0005) and during exercise (11.0,
6.5-to-15.6 mmHg; P<0.0001) vs. controls. Resting TAPSE (P<0.0001) and S’ (P=0.001) were greater
in athletes. In contrast, athletes had similar RV free-wall longitudinal strain (17 studies; n=450:605),
compared to controls, but showed greater longitudinal apical strain (16 studies; n=455:669; 0.9%, 0.1-
to-1.8%;P=0.03) and lower basal strain (-2.5%, -1.4-to -3.5%;P<0.0001).
Conclusions
Functional RV adaptation, characterized by increased tricuspid annular displacement and velocity and
a greater base-to-apex strain gradient, is a normal feature of the athlete’s heart, together with a slightly
elevated RVSP. These findings contribute to our understanding of RV in athletes and highlight the
importance of considering RV function in combination with structure in the clinical interpretation of
the athlete’s heart
Maturity alters drop vertical jump landing force-time profiles but not performance outcomes in adolescent females
No full textThe stretch-shortening cycle (SSC) assists in effective force attenuation upon landing and augments force generation at take-off during a drop vertical jump (DVJ). General performance outcomes such as jump height or peak measures have been used to assess SSC function in youth populations; however, these discrete metrics fail to provide insight into temporal jump-landing characteristics. This study assessed DVJ force-time profiles in 1013 middle and high-school female athletes (n = 279 prepubertal, n = 401 pubertal, n = 333 postpubertal). Maturity status was determined using the Pubertal Maturation Observation Scale. Ground reaction force data were analysed to extract a range of variables to characterize force-time profiles. SSC function was categorized as poor, moderate or good dependent on the presence of an impact peak and spring-like behaviour. No differences in jump height or ground contact time were observed between maturity groups (p > 0.05). Significant differences in absolute peak landing and take-off force were evident between all maturational statuses (p < 0.05). Relative to bodyweight normalized forces, only peak take-off force was significantly different between prepubertal and postpubertal groups (p < 0.05; d = 0.22). Spring-like behaviour showed small improvements from pubertal to postpubertal (p < 0.05; d = 0.25). Most females displayed poor SSC function at prepubertal (79.6%), pubertal (77.3%) and postpubertal (65.5%) stages of maturity. Large increases in absolute forces occur throughout maturation in female athletes, however, only small maturational differences were found in relative force or spring-like behaviour. Consequently, most girls display poor SSC function irrespective of maturity
‘People miss people’: A study of school leadership and management in the four nations of the United Kingdom in the early stage of the COVID-19 pandemic
Get PDFThe COVID-19 pandemic has confronted school leaders across the four devolved nations of the United Kingdom (UK) with a period of exceptional crisis. This responsive, small-scale, but UK-wide study focuses on headteacher perspectives on leadership and management in the initial stages of this pandemic, contributing to our understanding of this crucial period. The headteacher respondents met the multiple predicaments and situational ambiguities of the pandemic with a resilience which drew heavily upon the strengths of pre-existing structures and teams. They were required to provide effective emotional and moral leadership in uncharted and rapidly shifting territory. They spoke most eloquently of how they developed pragmatic, versatile and personally reassuring approaches to communication with parents, staff, pupils, and a range of external agencies, all of which were also facing extraordinary circumstances with varying degrees of resilience. The paper concludes by conceptualising the key elements of headteachers’ leadership and management, both inside and outside of school, at in the early stages of societal crisis
The use of the soluble receptor for advanced glycation-end products (sRAGE) as a potential biomarker of disease risk and adverse outcomes
Get PDFThe soluble receptor for advanced glycation end-products (sRAGE) has been classically considered a sink for pro-inflammatory RAGE ligands and as such has been associated with protection from inflammatory stress and disease. An alternative, though not mutually exclusive view is that high levels of sRAGE in circulation reflect the overstimulation of cell surface RAGE which if persistent, lead to the amplification of pro-inflammatory processes and the exacerbation of pathological states. With these two scenarios in mind this review focuses on the potential role of sRAGE as a prospective biomarker of disease risk and adverse outcomes