Relationship between stress and healthy lifestyle factors of college students

OBJECTIVES: We assessed the correlation between college students' perceived stress (PS) and healthy lifestyle factors (HLFs) in this cross-sectional study. METHODS: Data were collected from 1396 undergraduates enrolled in an introductory nutrition course. We measured PS and 5 HLFs (physically active, healthy diet, non-smoker, non-binge drinker, healthy BMI). RESULTS: The mean PS score was 15.0 ± 0.2 (maximum, 40) and the mean number of HLFs reported was 2.9 ± 0.03. Females were more likely to report 4-5 HLFs than males (31% vs 20%). We found a statistically significant inverse correlation between PS and HLFs for women (p < .01). CONCLUSIONS: Health promotion interventions that support healthy food choices, physical activity and low-risk substance use may reduce perceived stress in the college population.Published versio

Numerical evaluation of one-loop QCD amplitudes

We present the publicly available program NGluon allowing the numerical evaluation of primitive amplitudes at one-loop order in massless QCD. The program allows the computation of one-loop amplitudes for an arbitrary number of gluons. The focus of the present article is the extension to one-loop amplitudes including an arbitrary number of massless quark pairs. We discuss in detail the algorithmic differences to the pure gluonic case and present cross checks to validate our implementation. The numerical accuracy is investigated in detail.Comment: Talk given at ACAT 2011 conference in London, 5-9 Septembe

Benzo-pyrones for reducing and controlling lymphoedema of the limbs.

Background Lymphoedema is the accumulation of excess fluid in the body caused by obstruction of the lymphatic drainage mechanisms. Treatment with Benzo-pyrones is thought to reduce fluid forming in the subcutaneous tissues and reduce pain and discomfort of the affected area. Objectives To assess the effectiveness of benzo-pyrones compared to placebo in the management of lymphoedema. Search strategy We searched the Cochrane Breast Cancer Group register (September 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4,2003), MEDLINE, EMBASE, CINAHL, UnCover, PASCAL, SIGLE, reference lists produced by The British Lymphology Society, the National Research Register (NRR) and The International Society of Lymphology congress proceedings. Selection criteria Randomised controlled trials comparing Benzo-pyrones with placebo. Data collection and analysis Trials were selected for eligibility and tested for quality by two blinded reviewers who independently extracted data. Meta-analysis was not performed due to the poor quality of the trials. Main results Fifteen trials were included. Three oxerutin trials tested the same dose over 6 months against placebo and included a total of 127 participants (data were available for 81). There were insufficient data from these to calculate the per cent reduction or increase in baseline excess limb volume. One trial testing Cyclo 3 Fort (approved name) was found (57 participants) but insufficient data was provided to allow a proper analysis of its findings. A single trial of Daflon (approved name) was found (104 participants) but this also provided insufficient information to reach a conclusion about the effectiveness of the drug. Three trials of coumarin combined with troxerutin were found which tested two different doses of the drug against each other with no placebo, however participant numbers and baseline data were not provided. Eight trials of coumarin were identified. Two of these reported the same trial and the other potentially also referred to the same trial but this could not be confirmed. A further two papers also appeared to refer to the same trial but again this was unconfirmed. Five studies added anti-filarial drugs to the interventions tested. Participant data could not be extracted and the reporting of outcome measures in most was unclear. Loprinzi's 1999 trial was reported in more detail but its conclusions were very much at odds with other findings. Authors' conclusions It is not possible to draw conclusions about the effectiveness of Benzopyrones in the management of lymphoedema from the current available trials

On-shell recursion relations for all Born QCD amplitudes

We consider on-shell recursion relations for all Born QCD amplitudes. This includes amplitudes with several pairs of quarks and massive quarks. We give a detailed description on how to shift the external particles in spinor space and clarify the allowed helicities of the shifted legs. We proof that the corresponding meromorphic functions vanish at z --> infinity. As an application we obtain compact expressions for helicity amplitudes including a pair of massive quarks, one negative helicity gluon and an arbitrary number of positive helicity gluons.Comment: 30 pages, minor change

A direct proof of the CSW rules

Using recursion methods similar to those of Britto, Cachazo, Feng and Witten (BCFW) a direct proof of the CSW rules for computing tree-level gluon amplitudes is given.Comment: 11 pages, uses axodraw.st

Loop amplitudes in gauge theories: modern analytic approaches

This article reviews on-shell methods for analytic computation of loop amplitudes, emphasizing techniques based on unitarity cuts. Unitarity techniques are formulated generally but have been especially useful for calculating one-loop amplitudes in massless theories such as Yang-Mills theory, QCD, and QED.Comment: 34 pages. Invited review for a special issue of Journal of Physics A devoted to "Scattering Amplitudes in Gauge Theories." v2: typesetting macro error fixe

MHV Techniques for QED Processes

Significant progress has been made in the past year in developing new `MHV' techniques for calculating multiparticle scattering amplitudes in Yang-Mills gauge theories. Most of the work so far has focussed on applications to Quantum Chromodynamics, both at tree and one-loop level. We show how such techniques can also be applied to abelian theories such as QED, by studying the simplest tree-level multiparticle process, e^+e^- to n \gamma. We compare explicit results for up to n=5 photons using both the Cachazo, Svrcek and Witten `MHV rules' and the related Britto-Cachazo-Feng `recursion relation' approaches with those using traditional spinor techniques.Comment: 19 pages, 10 figures. References adde

Scattering AMplitudes from Unitarity-based Reduction Algorithm at the Integrand-level

SAMURAI is a tool for the automated numerical evaluation of one-loop corrections to any scattering amplitudes within the dimensional-regularization scheme. It is based on the decomposition of the integrand according to the OPP-approach, extended to accommodate an implementation of the generalized d-dimensional unitarity-cuts technique, and uses a polynomial interpolation exploiting the Discrete Fourier Transform. SAMURAI can process integrands written either as numerator of Feynman diagrams or as product of tree-level amplitudes. We discuss some applications, among which the 6- and 8-photon scattering in QED, and the 6-quark scattering in QCD. SAMURAI has been implemented as a Fortran90 library, publicly available, and it could be a useful module for the systematic evaluation of the virtual corrections oriented towards automating next-to-leading order calculations relevant for the LHC phenomenology.Comment: 35 pages, 7 figure