400 research outputs found
Regge's Einstein-Hilbert Functional on the Double Tetrahedron
The double tetrahedron is the triangulation of the three-sphere gotten by
gluing together two congruent tetrahedra along their boundaries. As a piecewise
flat manifold, its geometry is determined by its six edge lengths, giving a
notion of a metric on the double tetrahedron. We study notions of Einstein
metrics, constant scalar curvature metrics, and the Yamabe problem on the
double tetrahedron, with some reference to the possibilities on a general
piecewise flat manifold. The main tool is analysis of Regge's Einstein-Hilbert
functional, a piecewise flat analogue of the Einstein-Hilbert (or total scalar
curvature) functional on Riemannian manifolds. We study the
Einstein-Hilbert-Regge functional on the space of metrics and on discrete
conformal classes of metrics
Constant Scalar Curvature Metrics on Boundary Complexes of Cyclic Polytopes
In [7], a notion of constant scalar curvature metrics on piecewise flat
manifolds is defined. Such metrics are candidates for canonical metrics on
discrete manifolds. In this paper, we define a class of vertex transitive
metrics on certain triangulations of ; namely, the boundary
complexes of cyclic polytopes. We use combinatorial properties of cyclic
polytopes to show that, for any number of vertices, these metrics have constant
scalar curvature.Comment: 15 pages, 4 figure
A Rhetorical Analysis of Selected Sermons by Sam Jones During His Emergence as a National Figure, 1872-1885.
With an inimitable style out of the rural south, peppered with caustic, biting criticism and practical illustrations, Sam Jones combined the rustic, earthy qualities of southern hill country religion with the full auditoriums, careful schedules and trained assistants of urban religion. After an apprenticeship in North Georgia Methodist Circuits and as an advocate for the Decatur Orphan\u27s Home, Sam Jones took his brand of revivalism throughout the United States and into Canada. He consistently attracted capacity crowds, large numbers of decisions, strong controversy and extensive press coverage. The purpose of this investigation was to study the preaching career and sermons of Sam Jones from the start of his career in 1872 through the middle of 1885, the year of his complete emergence as a national figure in revivalism. Sermons for analysis came from two campaigns, Memphis and Nashville, Tennessee, selected because of their significance in his emergence and the existence of reliable sermon texts. The first part of the investigation involved a survey of the speaker\u27s background, training, experience and other factors which may have contributed to his speaking success. The second part focused on the speaker\u27s approach to revivalism, including a survey of the theological, social and political views which he ultimately expressed in his sermons and a study of the organization and conduct of both the revival campaigns and individual services in which the analyzed sermons were preached. The third part of the study involved a rhetorical analysis of eight selected sermons preached in the 1884 Memphis campaign and the 1885 Nashville campaign. The structure, lines of reasoning, forms of support, style and responses to his sermons were studied. In both campaigns Jones accepted reluctant invitations and faced considerable opposition. In spite of these handicaps he generally preached two to three times a day to overflowing crowds. Jones saw his task to be that of aligning forces of God, born again church members, against the forces of evil, all others. The test which determined whether a person was among the forces of God was his deeds. A cardinal area of Jones\u27 advocacy of the importance of deeds concerned prohibition. Jones relied on six basic forms of support: Scripture, illustrations, examples, hypothetical reasoning, humor and comparison-contrasts. Emotional appeals occurred more in delivery than in content. Speaker credibility was his strength as people came more to hear Sam Jones than to hear a sermon. The study concluded that Jones drew from his own rural background and experiences for sermon illustrations. That content was conveyed with biting humor and a colloquial style that could both commend and condemn. He took the revivalistic traditions of his predecessors, altered them to meet the flavor of his personality, demands of the situations, nature of the audiences and speaker\u27s objectives, and passed on a legacy to revivalists who followed
THE EFFECT OF PROLONGED SITTING VERSUS USE OF A TREADMILL DESK ON POSTURAL STABILITY
Prolonged sitting is resulting in health risks to a growing number of the population. As a potential intervention, treadmill desks make it possible to interrupt prolonged sitting during the office worker’s day. This study aimed to investigate the acute effect of breaking up prolonged sitting with treadmill desk walking on postural stability. Thirteen sedentary adults participated in a randomised two treatment crossover design: 1) sitting for 6.5 hrs versus 2) accumulated 2 hrs of light-intensity treadmill desk walking during the 6.5 hrs. Pre and post condition, participants performed postural stability tests on a pressure plate. Centre of Pressure (CoP) AP amplitude showed a significant interaction in Bilateral Eyes Closed, Bilateral Eyes Open and Unilateral Eyes Open tests, and CoP ML Amplitude in both Bilateral tests, where sway amplitude was less in the walking condition. Breaking up prolonged sitting with an accumulated 2 hrs of light-intensity treadmill desk walking had a positive effect on postural stability, supporting the use of walking desks in the workplace
Sitting time and risk of cardiovascular disease and diabetes: a systematic review and meta-analysis
Context: Whether physical activity attenuates the association of total daily sitting time with cardiovascular disease (CVD) and diabetes incidence is unclear. This systematic review and meta-analysis examined the association of total daily sitting time with CVD and diabetes with and without adjustment for physical activity. Evidence Acquisition: PubMed, Web of Science, BASE, MEDLINE, Academic Search Elite and ScienceDirect were searched for prospective studies published between 1st January 1989 and 15th February 2019 examining the association of total daily sitting time with CVD or diabetes outcomes. Data extraction and study quality assessments were conducted by two independent reviewers. Pooled Hazard Ratios (HRs) were calculated using a fixed-effects model. The quality assessment and meta-analytic procedures were completed in 2018. Evidence Synthesis: Nine studies with 448,285 40 participants were included. Higher total daily sitting time was associated with a significantly increased risk of CVD (HR 1.29; 95%CI 1.27-1.30, p=<0.001) and diabetes (HR 1.13; 95%CI 1.04-1.22, p=<0.001) incidence when physical activity was not adjusted for. The increased risk for diabetes was unaffected when adjusting for physical activity (HR 1.11; 95%CI 1.01-1.19, p=<0.001). For CVD, the increased risk was attenuated but remained significant (HR 1.14; 95%CI 1.04-1.23, p=<0.001). Conclusions: Higher levels of total daily sitting time are associated with an increased risk of CVD and diabetes, independent of physical activity. Reductions in total daily sitting may thus be recommended in public health guidelines
Can PSMA PET/CT help in dose-tailoring in post-prostatectomy radiotherapy?
There are few randomized trials to evaluate the use of PSMA-PET in the planning of post-prostatectomy radiotherapy. There are two unresolved questions 1) should we increase the dose to lesions visible on PSMA-PET 2) can we reduce dose in the case of a negative PSMA-PET. In this review, we summarize and discuss the available evidence in the literature. We found that in general, there seems to be an advantage for dose-increase, but ta large recent study from the pre-PSMA era didn't show an advantage for dose escalation. Retrospective studies have shown that conventional doses to PSMA-PET-positive lesions seem sufficient. On the other hand, in the case of a negative PSMA-PET, there is no evidence that dose-reduction is possible. In the future, the combination of PSMA-PET with genomic classifiers could help in better identify patients who might benefit from either dose- de-or -increase. We further need to identify intraindividual references to help identify lesions with higher aggressiveness
Experimental study of radiative shocks at PALS facility
We report on the investigation of strong radiative shocks generated with the
high energy, sub-nanosecond iodine laser at PALS. These shock waves are
characterized by a developed radiative precursor and their dynamics is analyzed
over long time scales (~50 ns), approaching a quasi-stationary limit. We
present the first preliminary results on the rear side XUV spectroscopy. These
studies are relevant to the understanding of the spectroscopic signatures of
accretion shocks in Classical T Tauri Stars.Comment: 21 pages, 1 table, 7 figure
Reducing prolonged sedentary time using a treadmill desk acutely improves cardiometabolic risk markers in male and female adults
The objectives of this study were to evaluate the acute effects of interrupting prolonged sitting with an accumulated 2 h of light-intensity walking on postprandial cardiometabolic risk markers. In this randomised crossover trial, 24 participants (twelve males) aged 18-55 years took part in two, 6.5 h conditions: 1) prolonged sitting (SIT) and 2) sitting interrupted hourly with 20 min light-intensity treadmill desk walking at between 1.2-3.5 km/h-1 (INT-SIT). Standardized meals were provided at 0 h and 3 h. Blood samples and blood pressure measures were taken hourly. Statistical analyses were completed using linear mixed models. Postprandial incremental area under the curve responses (mmol/L∙6.5 h) for glucose (4.52 [3.47, 5.56] and 6.66 [5.62, 7.71] for INT-SIT and SIT, respectively) and triglycerides (1.96 [0.96, 2.96] and 2.71 [1.70, 3.71] mmol/L∙6.5 h, for INT-SIT and SIT, respectively) were significantly lower in INT-SIT than SIT. Mean systolic and diastolic blood pressure responses were lower by 3% and 4%, respectively, in INT-SIT than SIT (P0.05). These findings suggest that interrupting sitting with an accumulated 2 h of light-intensity walking acutely improves cardiometabolic risk levels in males and females compared with prolonged sitting
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