Towards an optimization of the LHC intersection region using new magnet technology

A strategy for optimizing the intersection region of LHC is presented. The quadrupole triplet is moved closer to the intersection point, within the footprint of the detectors. The 350 T/m inner quadrupole is designed using a structured cable that incorporates internal refrigeration with supercritical helium. The separation dipole utilizes a levitated-pole design. This approach opens the possibility to achieve a minimum β* without increase of the chromatic and geometric aberrations. The crossing angle can be reduced, and the aperture required in the quadrupole triplet is reduced significantly. The additional space that is opened in the lattice can be used for additional quads to improve the insertion matching

Rapid virological surveillance of community influenza infection in general practice

No abstract available

Effect of Long-Term Physical Exercise on Blood Pressure in African Americans

International Journal of Exercise Science 7(3) : 186-193, 2014. Long-term physical exercise has been shown to noticeably reduce blood pressure (BP) and remarkably attenuate symptoms of hypertension. It is believed that physical exercise induces these beneficial effects by increasing the blood supply to the brain, enhancing the release of growth factors from skeletal muscles into the bloodstream, facilitating neurogenesis, stimulating angiogenesis, and influencing endothelial cell proliferation and subsequent endothelial cell membrane permeability. Previous findings also revealed that physical exercise significantly elevates brain-derived neurotrophic factor (BDNF) concentrations which appear to increase dramatically in BP-sensing neurons during hypertension. Elevating BDNF levels is the proposed mechanism by which physical exercise reduces BP and lowers hypertension risk. Relatively effective measures exist today to prevent or delay much of the burden of hypertension and curtail or remediate the devastating consequences of chronic elevated BP over time. Nevertheless, this medical problem contributes to excess risk for morbidity and mortality and is a major public health concern, especially among minority populations. To date, however, it appears as though few studies have focused on the impact of non-pharmacological, behavioral interventions such as physical exercise on BP in minorities. Therefore, the purpose of the present study was to examine the effect of long-term exercise on BP in an African American sample. Specifically, the aim was to determine whether a 12-week moderate intensity physical exercise program would significantly decrease BP. Because data provided evidence to support the hypothesis tested, it was concluded that physical exercise resulted in a significant reduction in BP in the African Americans sampled

Dietary Omega-3 Polyunsaturated Fatty Acid Deprivation Does Not Alter Seizure Thresholds but May Prevent the Anti-seizure Effects of Injected Docosahexaenoic Acid in Rats.

Background: Brain concentrations of omega-3 docosahexaenoic acid (DHA, 22:6n-3) have been reported to positively correlate with seizure thresholds in rodent seizure models. It is not known whether brain DHA depletion, achieved by chronic dietary omega-3 polyunsaturated fatty acid (PUFA) deficiency, lowers seizure thresholds in rats. Objective: The present study tested the hypothesis that lowering brain DHA concentration with chronic dietary n-3 PUFA deprivation in rats will reduce seizure thresholds, and that compared to injected oleic acid (OA), injected DHA will raise seizure thresholds in rats maintained on n-3 PUFA adequate and deficient diets. Methods: Rats (60 days old) were surgically implanted with electrodes in the amygdala, and subsequently randomized to the AIN-93G diet containing adequate levels of n-3 PUFA derived from soybean oil or an n-3 PUFA-deficient diet derived from coconut and safflower oil. The rats were maintained on the diets for 37 weeks. Afterdischarge seizure thresholds (ADTs) were measured every 4-6 weeks by electrically stimulating the amygdala. Between weeks 35 and 37, ADTs were assessed within 1 h of subcutaneous OA or DHA injection (600 mg/kg). Seizure thresholds were also measured in a parallel group of non-implanted rats subjected to the maximal pentylenetetrazol (PTZ, 110 mg/kg) seizure test. PUFA composition was measured in the pyriform-amygdala complex of another group of non-implanted rats sacrificed at 16 and 32 weeks. Results: Dietary n-3 PUFA deprivation did not significantly alter amygdaloid seizure thresholds or latency to PTZ-induced seizures. Acute injection of OA did not alter amygdaloid ADTs of rats on the n-3 PUFA adequate or deficient diets, whereas acute injection of DHA significantly increased amygdaloid ADTs in rats on the n-3 PUFA adequate control diet as compared to rats on the n-3 PUFA deficient diet (P < 0.05). Pyriform-amygdala DHA percent composition did not significantly differ between the groups, while n-6 docosapentaenoic acid, a marker of n-3 PUFA deficiency, was significantly increased by 2.9-fold at 32 weeks. Conclusion: Chronic dietary n-3 PUFA deficiency does not alter seizure thresholds in rats, but may prevent the anti-seizure effects of DHA

Cooperative Jahn-Teller Distortion in PrO2

We report neutron diffraction data on single crystal PrO2 which reveal a cooperative Jahn-Teller distortion at TD = 120 +/- 2 K. Below this temperature an internal distortion of the oxygen sublattice causes the unit cell of the crystallographic structure to become doubled along one crystal axis. We discuss several possible models for this structure. The antiferromagnetic structure below TN = 13.5 K is found to consist of two components, one of which shares the same doubled unit cell as the distorted crystallographic structure. We also present measurements of the magnetic susceptibility, the specific heat capacity and the electrical conductivity of PrO2. The susceptibility data show an anomaly at a temperature close to TD. From the specific heat capacity data we deduce that the ground state is doubly degenerate, consistent with a distortion of the cubic local symmetry. We discuss possible mechanisms for this. The conductivity shows an activated behaviour with an activation energy Ea = 0.262 +/- 0.003 eV.Comment: 12 pages, 14 figures, 2 tables. Additional suggested structure in v