20518 research outputs found
Sort by
Acute simulated soccer-specific training increases PGC-1 alpha mRNA expression in human skeletal muscle
Get PDFThe aim of the current study is to quantify oxygen uptake, heart rate and molecular responses of human skeletal muscle associated with mitochondrial biogenesis following an acute bout of simulated soccer training. Muscle biopsies (vastus lateralis) were obtained from nine active men immediately pre-, post- and 3 h post-completion of a laboratory-based soccer-specific training simulation (LSSTS) on a motorised treadmill. The LSSTS was a similar intensity (55 ± 6% V˙ O2max) and duration (60-min) as that observed in professional soccer training (e.g. standing 41%, walking 37%, jogging 11%, high-speed running 9% and sprinting 2%). Post-exercise, muscle glycogen decreased (Pre; 397 ± 86 mmol∙kg-1 dw, Post; 344 ± 64 mmol∙kg-1 dw; P = 0.03), plasma lactate increased (P < 0.001) up to ~4-5 mmol.L-1, NEFA and glycerol increased (P < 0.001) to values of 0.6 ± 0.2 mmol.L-1 and 145 ± 54 μmol.L-1, respectively. PGC-1α mRNA increased (P = 0.009) 5-fold 3 h post-exercise. We provide novel data by demonstrating that soccer-specific training is associated with increases in PGC-1α mRNA. These data may have implications for practitioners in better understanding the specific ‘muscle’ responses to soccer-specific training protocols in the field
Scalable Traffic-Aware Virtual Machine Management for Cloud Data Centers
No full textVirtual Machine (VM) management is a powerful mechanism for providing elastic services over Cloud Data Centers (DC)s. At the same time, the resulting network congestion has
been repeatedly reported as the main bottleneck in DCs, even
when the overall resource utilization of the infrastructure remains low. However, most current VM management strategies are traffic-agnostic, while the few that are traffic-aware only concern a static initial allocation, ignore bandwidth oversubscription, or do not scale.
In this paper we present S-CORE, a scalable VM migration algorithm to dynamically reallocate VMs to servers while minimizing the overall communication footprint of active traffic flows. We formulate the aggregate VM communication as an optimization problem and we then define a novel distributed migration scheme that iteratively adapts to dynamic traffic changes. Through extensive simulation and implementation results, we show that S-CORE achieves significant (up to 87%) communication cost reduction while incurring minimal overhead and downtime.
Index Terms—Virtual Machine, Migration, Consolidation,
Communication Cost, Scalable, Traffic-Aware, Data Center Networ
Power Consumption Profiling Using Energy Time-Frequency Distributions in Smart Grids
No full textSmart grids are power distribution networks that include a significant communication infrastructure, which is used to collect usage data and monitor the operational status of the grid. As a consequence of this additional infrastructure, power networks are at an increased risk of cyber-attacks. In this letter, we address the problem of detecting and attributing anomalies that occur in the sub-meter power consumption measurements of a smart grid, which could be indicative of malicious behavior. We achieve this by clustering a set of statistical features of power measurements that are determined using the Smoothed Pseudo Wigner Ville (SPWV) energy Time-Frequency (TF)distribution. We show how this approach is able to more accurately distinguish clusters of energy consumption than simply using raw power measurements. Our ultimate goal is to apply the principles of profiling power consumption measurements as part of an enhanced anomaly detection system for smart grids
Sudomotor and cardiovascular dysfunction in patients with early untreated Parkinson's disease.
No full textBACKGROUND: According to Braak staging of Parkinson's disease (PD), detection of autonomic dysfunction would help with early diagnosis of PD. OBJECTIVE: To determine whether the autonomic nervous system is involved in the early stage of PD, we evaluated cardiovascular and sudomotor function in early untreated PD patients. METHODS: Orthostatic blood pressure regulation, heart rate variability, skin vasomotor function, and palmar sympathetic sweat responses were examined in 50 early untreated PD patients and 20 healthy control subjects. RESULTS: The mean decrease in systolic blood pressure during head-up tilt in PD patients was mildly but significantly larger than in controls (p = 0.0001). There were no differences between the 2 groups in heart rate variability, with analysis of low frequency (LF; mediated by baroreflex feedback), and high frequency (HF; mainly reflecting parasympathetic vagal) modulation. However, LF/HF, an index of sympatho-parasympathetic balance, was lower in the PD group than in controls (p = 0.02). Amplitudes of palmar sweat responses to deep inspiration (p = 0.004), mental arithmetic (p = 0.01), and exercise (p = 0.01) in PD patients were lower than in controls, with negative correlations with motor severity. Amplitudes of palmar skin vasomotor reflexes in PD patients did not differ from controls. CONCLUSIONS: Our study indicates impairment of sympathetic cardiovascular and sudomotor function with orthostatic dysregulation of blood pressure control, reduced LF/HF and reduction in palm sweat responses even in early untreated PD patients
Simulation of heat transfer to separation Air flow in a concentric pipe
No full textFlow separations occur in various engineering applications. Computational simulation by using standard k-ε turbulence model was performed to investigate numerically the characteristic of backward-facing step flow in a concentric configuration. This research is focused on the variation of Reynolds number, heat flux and step height in a fully developed turbulent air flow. The design consists of entrance tube, inner and outer tubes at the test section. The inner tube is placed along the entrance tube at the test section with an outer tube to form annular conduit. The entrance tube diameter was varied to create step height, s of 18.5 mm. The Reynolds number was set between 17050 and 44545 and heat flux was set between 719 W/m2 and 2098 W/m2 respectively. It is observed that the higher Reynolds number with step flow contribute to the enhancement of heat transfer. The reattachment point for q=719 W/m2 is observed at 0.542 m, which is the minimum surface temperature. The experimental data shows slightly lower distribution of surface temperature compared to simulation data. As for the same case in experimental result, the minimum surface temperature is obtained at 0.55 m. The difference between numerical and experimental result is 0.008 m. Finally, it can be inferred that utilizing the computational fluid dynamic package software, agreeable results could be obtained for the present research.
Keywords: Numerical Simulation; Heat Transfer; Turbulent Flow; Computational Fluid Dynamics; Backward Facing Ste
Maturity and maturity models in lean construction
No full textIn recent years there has been an increasing interest in maturity models in management-related disciplines; which reflects a growing recognition that becoming more mature and having a model to guide the route to maturity can help organisations in managing major transformational change. Lean Construction (LC) is an increasingly important improvement approach that organisations seek to embed. This study explores how to apply the maturity models to LC. Hence the attitudes, opinions and experiences of key industry informants with high levels of knowledge of LC were investigated. To achieve this, a review of maturity models was conducted, and data for the analysis was collected through a sequential process involving three methods. First a group interview with seven key informants. Second a follow up discussion with the same individuals to investigate some of the issues raised in more depth. Third an online discussion held via LinkedIn in which members shared their views on some of the results. Overall, we found that there is a lack of common understanding as to what maturity means in LC, though there is general agreement that the concept of maturity is a suitable one to reflect the path of evolution for LC within organisations
Is translation semantically mediated? Evidence from Welsh-English bilingual aphasia
No full textThe involvement of the semantic system in picture naming is undisputed. However, it has been proposed that translation could take place via direct lexical links between L1 and L2 word forms in addition to or instead of via semantics(i.e., with translation going from a spoken word in L1 accessing its meaning and this meaning then leading to the retrieval of the translation equivalent in L2). There is conflicting evidence in the psycholinguistic literature as to the extent of semantic mediation in translation vs. picture naming tasks (Potter et al, 1984; Kroll and Stewart, 1994). More recently, Hernandez et al (2010) investigated this question in a case study of JFF, a proficient bilingual Spanish-Catalan speaker with Alzheimer’s disease and naming difficulties due to a semantic deficit. As JFF’s semantic deficit did not only affect picture naming but also translation tasks, the authors concluded against the existence of functional direct lexical links to support translation. The goal of our study was to explore this issue further in a larger sample of proficient bilingual patients with aphasia and word finding difficulties in both languages. More specifically, we compare the rate of semantic errors produced in naming vs. translation tasks
The extended ROSAT-ESO flux-limited X-ray galaxy cluster survey (REFLEX II): V. Exploring a local underdensity in the southern sky
No full textSeveral claims have been made that we are located in a locally underdense region of the Universe based on observations of supernovae and galaxy density distributions. Two recent studies of K-band galaxy surveys have, in particular, provided new support for a local underdensity in the galaxy distribution out to distances of 200-300 Mpc. If confirmed, such local underdensities would have important implications interpreting local measurements of cosmological parameters. Galaxy clusters have been shown to be ideal probes for tracing the large-scale structure of the Universe. In this paper we study the local density distribution in the southern sky with the X-ray detected galaxy clusters from the REFLEX II cluster survey. From the normalised comoving number density of clusters, we find an average underdensity of ∼30-40% in the redshift range out to z ∼ 0.04 (∼170 Mpc) in the southern extragalactic sky with a significance greater than 3.4σ. On larger scales from 300 Mpc to over 1 Gpc, the density distribution appears remarkably homogeneous. The local underdensity seems to be dominated by the south Galactic cap region. A comparison of the cluster distribution with that of galaxies in the K -band from a recent study shows that galaxies and clusters trace each other very closely in density. In the south Galactic cap region both surveys find a local underdensity in the redshift range z = 0 to 0.05 and no significant underdensity in the north Galactic cap at southern latitudes. Cosmological models that attempt to interpret the cosmic acceleration, deduced from observations of type Ia supernovae, by a large local void without the need for reacceleration, require that we are located close to the centre of a roughly spherical void with a minimum size of ∼300 Mpc. In contrast our results show that the local underdensity is not isotropic and limited to a size significantly smaller than 300 Mpc radius
Nurture, nature and some very dubious social skills: An interpretative phenomenological analysis of talent identification practices in elite English youth soccer
Get PDFThis paper reports qualitative findings regarding the concepts and practices utilised in talent identification (TI) among professional coaches working in English youth soccer. Using interpretative phenomenological analysis, detailed interviews with seven such coaches are explored, with a view to elucidating the links between understanding, practice, experience and professional context. Findings reveal three superordinate themes, relating to (1) a primarily ‘nurtured’ and trainable understanding of the broad concept of talent itself, (2) an ostensibly contradictory model of semi-static player psychology, and (3) a highly selective mechanism for separating evidence for ‘mental strength’ and ‘social skills’. It is contended that these findings underscore a case for more thorough interrogation of the real worlds inhabited by coaches, such that ideas about ‘good practice’ in TI might be more effectively reconciled with grounded knowledge of the practical everyday necessities of being a coach
Ethnography in the Performing Arts: A Student Guide
No full textIn order to understand the individual and group creativity, expression and experience that lies at the heart of the performing arts, ethnography is a particularly suitable tool, allowing us both to study and reach our own understandings while gathering those of the people involved and situating them within their broader social and cultural contexts. Yet what is ethnography, and how do we approach ethnography in a performing arts culture, be it in music, dance or drama? This is the concern of the student guide here, which illustrates the multiple, complex steps of ethnographic research and writing, and presents them one-by-one in simple, reader-friendly language. Written with the novice fieldworker in mind, the content is informed by the multifaceted experiences of university students when conducting their own ethnographic research project in music, dance and drama. Their ethnographies, as well as fieldnotes and other collected materials serve as illustrative matter and case studies. Hopefully you will find the student guide useful and meaningful for the conduct of your own ethnographic project in the performing arts
Data sources:
LJMU Research Online (Liverpool John Moo...PATT40 (LJMU)Biomolecular Research Reports (BRR) (LJM...Design and Technology Education (LJMU)BLResearchDay (LJMU)Journal of Living Labs (LJMU)Journal of Natural Products Discovery (L...Journal of Social Media for Learning (LJ...Student Law Journal (LJMU)PRISM (LJMU)Public Health Institute Journal (LJMU)SPARK (LJMU)Student Experience Proceedings (LJMU)Transformation in Education (LJMU)Innovations in Practice (LJMU)Links to Health and Social Care (LJMU)Access Repository Dashboard
Do you manage Liverpool John Moores University Research Archive? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!