Constraining mean-field models of the nuclear matter equation of state at low densities

An extension of the generalized relativistic mean-field (gRMF) model with density dependent couplings is introduced in order to describe thermodynamical properties and the composition of dense nuclear matter for astrophysical applications. Bound states of light nuclei and two-nucleon scattering correlations are considered as explicit degrees of freedom in the thermodynamical potential. They are represented by quasiparticles with medium-dependent properties. The model describes the correct low-density limit given by the virial equation of state (VEoS) and reproduces RMF results around nuclear saturation density where clusters are dissolved. A comparison between the fugacity expansions of the VEoS and the gRMF model provides consistency relations between the quasiparticles properties, the nucleon-nucleon scattering phase shifts and the meson-nucleon couplings of the gRMF model at zero density. Relativistic effects are found to be important at temperatures that are typical in astrophysical applications. Neutron matter and symmetric matter are studied in detail.Comment: 50 pages, 21 figure

Ethical Considerations in Chronic Brain Injury

A growing number of individuals are living with chronic traumatic brain injury. As these individuals and their families attempt to reintegrate into their communities, several ethical questions arise for clinicians and researchers. These include issues around alignment of perspectives and priorities, as well as responsibilities for ongoing treatment, education, community outreach, and research. An action plan for addressing these questions is outlined

Preseason Functional Movement Screen Component Tests Predict Severe Contact Injuries in Professional Rugby Union Players.

Tee, JC, Klingbiel, JFG, Collins, R, Lambert, MI, and Coopoo, Y. Preseason Functional Movement Screen component tests predict severe contact injuries in professional rugby union players. J Strength Cond Res 30(11): 3194-3203, 2016-Rugby union is a collision sport with a relatively high risk of injury. The ability of the Functional Movement Screen (FMS) or its component tests to predict the occurrence of severe (≥28 days) injuries in professional players was assessed. Ninety FMS test observations from 62 players across 4 different time periods were compared with severe injuries sustained during 6 months after FMS testing. Mean composite FMS scores were significantly lower in players who sustained severe injury (injured 13.2 ± 1.5 vs. noninjured 14.5 ± 1.4, Effect Size = 0.83, large) because of differences in in-line lunge (ILL) and active straight leg raise scores (ASLR). Receiver-operated characteristic curves and 2 × 2 contingency tables were used to determine that ASLR (cut-off 2/3) was the injury predictor with the greatest sensitivity (0.96, 95% confidence interval [CI] = 0.79-1.0). Adding the ILL in combination with ASLR (ILL + ASLR) improved the specificity of the injury prediction model (ASLR specificity = 0.29, 95% CI = 0.18-0.43 vs. ASLR + ILL specificity = 0.53, 95% CI = 0.39-0.66, p ≤ 0.05). Further analysis was performed to determine whether FMS tests could predict contact and noncontact injuries. The FMS composite score and various combinations of component tests (deep squat [DS] + ILL, ILL + ASLR, and DS + ILL + ASLR) were all significant predictors of contact injury. The FMS composite score also predicted noncontact injury, but no component test or combination thereof produced a similar result. These findings indicate that low scores on various FMS component tests are risk factors for injury in professional rugby players

Renal Perfusion Changes During Treatment of Essential Hypertension: Prazosin Versus Propranolol

SUMMARYTo evaluate renal hemodynamic changes during therapy of essential hypertension, we treated 12 essential hypertensives in crossover fashion, with 1 month each of placebo, prazosin, and propranolol alone. During prazosin treatment, blood pressure was normalized with preservation of glomerular filtration rate, renal plasma flow, and renal blood flow. Propranolol, however, normalized blood pressure with an associated significant decline in glomerular filtration rate, renal plasma flow, and renal blood flow. The potential mechanisms are discussed

Prazosin and Renal Hemodynamics: Arteriolar Vasodilation During Therapy of Essential Hypertension in Man

Renal hemodynamic effects of chronic prazosin therapy were studied in 10 men with essential hypertension. Successful antihypertensive therapy was accompanied by diminution in total renovascular resistance, probably at the level of the afferent arteriole. The resistance change was unexplained by alterations in intravascular volume, the vasodilatory renal kallikrein-kinin system, or sympathetic nervous system activity, but was associated with a diminution in plasma renin activity. Potential mechanisms for the resistance decrement are discussed, including renal perfusion auto-regulation, diminished activity of the vasoconstrictive renin-angiotensin system, and direct intrarenal afferent arteriolar alpha adrenergic blockade