One-Loop Renormalization of a Self-Interacting Scalar Field in Nonsimply Connected Spacetimes

Using the effective potential, we study the one-loop renormalization of a massive self-interacting scalar field at finite temperature in flat manifolds with one or more compactified spatial dimensions. We prove that, owing to the compactification and finite temperature, the renormalized physical parameters of the theory (mass and coupling constant) acquire thermal and topological contributions. In the case of one compactified spatial dimension at finite temperature, we find that the corrections to the mass are positive, but those to the coupling constant are negative. We discuss the possibility of triviality, i.e. that the renormalized coupling constant goes to zero at some temperature or at some radius of the compactified spatial dimension.Comment: 16 pages, plain LATE

Two-loop two-point functions with masses: asymptotic expansions and Taylor series, in any dimension

In all mass cases needed for quark and gluon self-energies, the two-loop master diagram is expanded at large and small $q^2$, in $d$ dimensions, using identities derived from integration by parts. Expansions are given, in terms of hypergeometric series, for all gluon diagrams and for all but one of the quark diagrams; expansions of the latter are obtained from differential equations. Pad\'{e} approximants to truncations of the expansions are shown to be of great utility. As an application, we obtain the two-loop photon self-energy, for all $d$, and achieve highly accelerated convergence of its expansions in powers of $q^2/m^2$ or $m^2/q^2$, for $d=4$.Comment: 25 pages, OUT--4102--43, BI--TP/92--5

Effect of statins on atrial fibrillation: collaborative meta-analysis of published and unpublished evidence from randomised controlled trials

Objective To examine whether statins can reduce the risk of atrial fibrillation. Design Meta-analysis of published and unpublished results from larger scale statin trials, with comparison of the findings against the published results from smaller scale or shorter duration studies. Data sources Medline, Embase, and Cochrane's CENTRAL up to October 2010. Unpublished data from longer term trials were obtained through contact with investigators. Study selection Randomised controlled trials comparing statin with no statin or comparing high dose versus standard dose statin; all longer term trials had at least 100 participants and at least six months' follow-up. Results In published data from 13 short term trials (4414 randomised patients, 659 events), statin treatment seemed to reduce the odds of an episode of atrial fibrillation by 39% (odds ratio 0.61, 95% confidence interval 0.51 to 0.74; P<0.001), but there was significant heterogeneity (P<0.001) between the trials. In contrast, among 22 longer term and mostly larger trials of statin versus control (105 791 randomised patients, 2535 events), statin treatment was not associated with a significant reduction in atrial fibrillation (0.95, 0.88 to 1.03; P=0.24) (P<0.001 for test of difference between the two sets of trials). Seven longer term trials of more intensive versus standard statin regimens (28 964 randomised patients and 1419 events) also showed no evidence of a reduction in the risk of atrial fibrillation (1.00, 0.90 to 1.12; P=0.99). Conclusions The suggested beneficial effect of statins on atrial fibrillation from published shorter term studies is not supported by a comprehensive review of published and unpublished evidence from larger scale trials

Circulating interleukin-10 and risk of cardiovascular events: a prospective study in the elderly at risk

<p><b>Objective:</b> The goal of this study was to examine the association of the antiinflammatory interleukin-10 (IL-10) with risk of cardiovascular disease (CVD).</p> <p><b>Methods and Results:</b> In the PROSPER (PROspective Study of Pravastatin in the Elderly at Risk) cohort, we related baseline concentrations of circulating IL-10 to risk of CVD events in a nested case (n=819)-control (n=1618) study of 3.2 years of follow-up. Circulating IL-10 showed few strong associations with classical risk factors but was positively correlated with IL-6 and C-reactive protein. IL-10 was positively associated with risk of CVD events (odds ratio [OR] 1.17, 95% CI 1.05 to 1.31 per unit increase in log IL-10) after adjusting for classical risk factors and C-reactive protein. Furthermore, IL-10 was associated more strongly with CVD risk among those with no previous history of CVD (OR 1.42, 95% CI 1.18 to 1.70), compared with those with previous CVD (OR 1.04, 95% CI 0.90 to 1.19; P=0.018). Overall, IL-10 showed a modest ability to add discrimination to classical risk factors (C-statistic +0.005, P=0.002).</p> <p><b>Conclusion:</b> Baseline circulating levels of the antiinflammatory IL-10 are positively associated with risk of CVD among the elderly without prior CVD events, although the association is less evident in those with a history of CVD. Additional epidemiological and mechanistic studies investigating the role of IL-10 in CVD are warranted.</p&gt

Homocysteine levels and treatment effect in the prospective study of pravastatin in the elderly at risk

Objectives: To assess the effect of preventive pravastatin treatment on coronary heart disease (CHD) morbidity and mortality in older persons at risk for cardiovascular disease (CVD), stratified according to plasma levels of homocysteine.<p></p> Design: A post hoc subanalysis in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), started in 1997, which is a double-blind, randomized, placebo-controlled trial with a mean follow-up of 3.2 years.<p></p> Setting: Primary care setting in two of the three PROSPER study sites (Netherlands and Scotland).<p></p> Participants: Individuals (n = 3,522, aged 70–82, 1,765 male) with a history of or risk factors for CVD were ranked in three groups depending on baseline homocysteine level, sex, and study site.<p></p> Intervention: Pravastatin (40 mg) versus placebo.<p></p> Measurements: Fatal and nonfatal CHD and mortality.<p></p> Results: In the placebo group, participants with a high homocysteine level (n = 588) had a 1.8 higher risk (95% confidence interval (CI) = 1.2–2.5, P = .001) of fatal and nonfatal CHD than those with a low homocysteine level (n = 597). The absolute risk reduction in fatal and nonfatal CHD with pravastatin treatment was 1.6% (95% CI = −1.6 to 4.7%) in the low homocysteine group and 6.7% (95% CI = 2.7–10.7%) in the high homocysteine group (difference 5.2%, 95% CI = 0.11–10.3, P = .046). Therefore, the number needed to treat (NNT) with pravastatin for 3.2 years for benefit related to fatal and nonfatal CHD events was 14.8 (95% CI = 9.3–36.6) for high homocysteine and 64.5 (95% CI = 21.4–∞) for low homocysteine.<p></p> Conclusion: In older persons at risk of CVD, those with high homocysteine are at highest risk for fatal and nonfatal CHD. With pravastatin treatment, this group has the highest absolute risk reduction and the lowest NNT to prevent fatal and nonfatal CHD.<p></p&gt

Applications of patching to quadratic forms and central simple algebras

This paper provides applications of patching to quadratic forms and central simple algebras over function fields of curves over henselian valued fields. In particular, we use a patching approach to reprove and generalize a recent result of Parimala and Suresh on the u-invariant of p-adic function fields, for p odd. The strategy relies on a local-global principle for homogeneous spaces for rational algebraic groups, combined with local computations.Comment: 48 pages; connectivity now required in the definition of rational group; beginning of Section 4 reorganized; other minor change

Linux kernel compaction through cold code swapping

There is a growing trend to use general-purpose operating systems like Linux in embedded systems. Previous research focused on using compaction and specialization techniques to adapt a general-purpose OS to the memory-constrained environment, presented by most, embedded systems. However, there is still room for improvement: it has been shown that even after application of the aforementioned techniques more than 50% of the kernel code remains unexecuted under normal system operation. We introduce a new technique that reduces the Linux kernel code memory footprint, through on-demand code loading of infrequently executed code, for systems that support virtual memory. In this paper, we describe our general approach, and we study code placement algorithms to minimize the performance impact of the code loading. A code, size reduction of 68% is achieved, with a 2.2% execution speedup of the system-mode execution time, for a case study based on the MediaBench II benchmark suite

Coarse-Graining and Renormalization Group in the Einstein Universe

The Kadanoff-Wilson renormalization group approach for a scalar self-interacting field theor generally coupled with gravity is presented. An average potential that monitors the fluctuations of the blocked field in different scaling regimes is constructed in a nonflat background and explicitly computed within the loop-expansion approximation for an Einstein universe. The curvature turns out to be dominant in setting the crossover scale from a double-peak and a symmetric distribution of the block variables. The evolution of all the coupling constants generated by the blocking procedure is examined: the renormalized trajectories agree with the standard perturbative results for the relevant vertices near the ultraviolet fixed point, but new effective interactions between gravity and matter are present. The flow of the conformal coupling constant is therefore analyzed in the improved scheme and the infrared fixed point is reached for arbitrary values of the renormalized parameters.Comment: 18 pages, REVTex, two uuencoded figures. (to appear in Phys. Rev. D15, July) Transmission errors have been correcte

Efficacy of psychological therapies in people with inflammatory bowel disease: a systematic review and meta-analysis

Background There is increasing evidence for an influence of the gut–brain axis on the natural history of inflammatory bowel disease (IBD). Psychological therapies could, therefore, have beneficial effects in individuals with IBD, but data are conflicting. We aimed to update our previous systematic review and meta-analysis to assess whether the inclusion of more randomised controlled trials (RCTs) showed any beneficial effects and whether these effects varied by treatment modality. Methods In this systematic review and meta-analysis, we searched MEDLINE, Embase, Embase Classic, PsychINFO, and the Cochrane Central Register of Controlled Trials from Jan 1, 2016, to April 30, 2023, for RCTs published in any language recruiting individuals aged 16 years or older with IBD that compared psychological therapy with a control intervention or treatment as usual. We pooled dichotomous data to obtain relative risks (RR) with 95% CIs of inducing remission in people with active disease or of relapse in people with quiescent disease at final follow-up. We pooled continuous data to estimate standardised mean differences (SMD) with 95% CIs in disease activity indices, anxiety scores, depression scores, stress scores, and quality-of-life scores at completion of therapy and at final follow-up. We pooled all data using a random-effects model. Trials were analysed separately according to whether they recruited people with clinically active IBD or predominantly individuals whose disease was quiescent. We conducted subgroup analyses by mode of therapy and according to whether trials recruited selected groups of people with IBD. We used the Cochrane risk of bias tool to assess bias at the study level and assessed funnel plots using the Egger test. We assessed heterogeneity using the I2 statistic. Findings The updated literature search identified a total of 469 new records, 11 of which met eligibility criteria. 14 studies were included from our previous meta-analysis published in 2017. In total, 25 RCTs were eligible for this meta-analysis, all of which were at high risk of bias. Only four RCTs recruited patients with active IBD; there were insufficient data for meta-analysis of remission, disease activity indices, depression scores, and stress scores. In patients with active IBD, psychological therapy had no benefit compared with control for anxiety scores at completion of therapy (two RCTs; 79 people; SMD –1·04, 95% CI –2·46 to 0·39), but did have significant benefit for quality-of-life scores at completion of therapy (four RCTs; 309 people; 0·68, 0·09 to 1·26), although heterogeneity between studies was high (I2=82%). In individuals with quiescent IBD, RR of relapse of disease activity was not reduced with psychological therapy (ten RCTs; 861 people; RR 0·83, 95% CI 0·62 to 1·12), with moderate heterogeneity (I2=60%), and the funnel plot suggested evidence of publication bias or other small study effects (Egger test p=0·046). For people with quiescent IBD at completion of therapy, there was no difference in disease activity indices between psychological therapy and control (13 RCTs; 1015 people; SMD –0·01, 95% CI –0·13 to 0·12; I2=0%). Anxiety scores (13 RCTs; 1088 people; –0·23, –0·36 to –0·09; 18%), depression scores (15 RCTs; 1189 people; –0·26, –0·38 to –0·15; 2%), and stress scores (11 RCTs; 813 people; –0·22, –0·42 to –0·03; 47%) were significantly lower, and quality-of-life scores (16 RCTs; 1080 people; 0·31, 0·16 to 0·46; 30%) were significantly higher, with psychological therapy versus control at treatment completion. Statistically significant benefits persisted up to final follow-up for depression scores (12 RCTs; 856 people; –0·16, –0·30 to –0·03; 0%). Effects were strongest in RCTs of third-wave therapies and in RCTs that recruited people with impaired psychological health, fatigue, or reduced quality of life at baseline. Interpretation Psychological therapies have beneficial, short-term effects on anxiety, depression, stress, and quality-of-life scores, but not on disease activity. Further RCTs in selected groups are needed to establish the place for such therapies in IBD care