Brane Gas Inflation

We consider the brane gas picture of the early universe. At later stages, when there are no winding modes and the background is free to expand, we show that a moving 3-brane, which we identify with our universe, can inflate even though it is radiation-dominated. The crucial ingredients for successful inflation are the coupling to the dilaton and the equation of state of the bulk. If we suppose the brane initially forms in a collision of higher-dimensional branes, then the spectrum of primordial density fluctuations naturally has a thermal origin.Comment: 4 pages, 1 figur

Development of uniform and predictable battery materials for nickel cadmium aerospace cells Quarterly report, 8 Aug. - 7 Nov. 1968

Sintering of carbonyl nickel powders for nickel cadmium batteries fabricatio

Two-point correlations of the Gaussian symplectic ensemble from periodic orbits

We determine the asymptotics of the two-point correlation function for quantum systems with half-integer spin which show chaotic behaviour in the classical limit using a method introduced by Bogomolny and Keating [Phys. Rev. Lett. 77 (1996) 1472-1475]. For time-reversal invariant systems we obtain the leading terms of the two-point correlation function of the Gaussian symplectic ensemble. Special attention has to be paid to the role of Kramers' degeneracy.Comment: 7 pages, no figure

A four-season prospective study of muscle strain reoccurrences in a professional football club

The aim of this investigation was to characterise muscle strain reinjuries and examine their impact on playing resources in a professional football club. Muscle strains and reoccurrences were prospectively diagnosed over four seasons in first-team players (n = 46). Altogether, 188 muscle strains were diagnosed with 44 (23.4%) of these classed as reinjuries, leading to an incidence of 1.32 strain reoccurrences per 1,000 hours exposure (95% Confidence Interval [CI], 0.93–1.71). The incidence of recurrent strains was higher in match-play compared with training (4.51, 95% CI, 2.30–6.72 vs 0.94, 95% CI, 0.59–1.29). Altogether, 50.0% of players sustained at least 1 reoccurrence of a muscle strain, leading to approximately 3 days lost and 0.4 matches missed per player per season. The incidence of recurrent strains was highest in centre-forwards (2.15, 95% CI, 1.06–3.24), peaked in May (3.78, 95% CI, 0.47–7.09), and mostly affected the hamstrings (38.6% of all reoccurrences). Mean layoff for nonreoccurrences and recurrences was similar: ∼7.5 days. These results provide greater insight into the extent of the problem of recurrent muscle strains in professional football

Late time evolution of brane gas cosmology and compact internal dimensions

We study the late-time behavior of a universe in the framework of brane gas cosmology. We investigate the evolution of a universe with a gas of supergravity particles and a gas of branes. Considering the case when different dimensions are anisotropically wrapped by various branes, we have derived Friedman-like equations governing the dynamics of wrapped and unwrapped subvolumes. We point out that the compact internal dimensions are wrapped by three or higher dimensional branes.Comment: 16 pages, typos, references, comment on the possibility of stabilizing the internal dimensions with fluxe

Injection into the jugular vein among people who inject drugs in the United Kingdom: Prevalence, associated factors and harms

Background: While people who inject drugs (PWID) typically use peripheral veins, some inject into their central veins, including the femoral and jugular veins. Injection into the jugular vein can have serious adverse health consequences, including jugular vein thrombosis, deep neck infections, pneumothorax, endocarditis and sepsis. This study examined the prevalence of, and factors associated with, jugular vein injection among a large sample of PWID in the United Kingdom. Method: Unlinked anonymous surveys (2011–14) recruited PWID from agencies providing services to this population. Self-reported demographic and injection-related data were collected from consenting respondents using a brief questionnaire and dried blood spot samples were tested for exposure to HIV, hepatitis C virus (HCV) and hepatitis B virus (HBV). Univariate and multivariable logistic regression were used to examine factors associated with jugular vein injection. Results: Among 5261 PWID, one third had injected into a central vein in the previous 28 days, including 6% (n = 339) who had injected into their jugular vein and 1% (n = 52) who had used this site exclusively for recent injections. Factors independently associated with recent jugular vein injection in multivariable analysis included female gender, a lifetime history of imprisonment, sharing needles and syringes, poly-drug injection and injection into multiple body sites. Jugular vein injection was also associated with experiencing injection-related injuries, although no associations were identified with respect to exposure to blood borne viral infections. Conclusion: A significant minority of PWID inject into the jugular vein in the United Kingdom. Public health responses should investigate ways to support and promote good injection site management in order to minimise vascular damage and reduce problems with peripheral venous access. Women who inject drugs, PWID with a history of imprisonment and those people who are experiencing early signs of injection-related skin and soft tissue injuries are priority sub-populations for interventions

Renormalisation group determination of the order of the DNA denaturation transition

We report on the nature of the thermal denaturation transition of homogeneous DNA as determined from a renormalisation group analysis of the Peyrard-Bishop-Dauxois model. Our approach is based on an analogy with the phenomenon of critical wetting that goes further than previous qualitative comparisons, and shows that the transition is continuous for the average base-pair separation. However, since the range of universal critical behaviour appears to be very narrow, numerically observed denaturation transitions may look first-order, as it has been reported in the literature.Comment: 6 pages; no figures; to appear in Europhysics Letter

Adiabatic Gravitational Perturbation During Reheating

We study the possibilities of parametric amplification of the gravitational perturbation during reheating in single-field inflation models. Our result shows that there is no additional growth of the super-horizon modes beyond the usual predictions.Comment: Refs added; New version to appear in PR