Quasiperiodic oscillations in a strong gravitational field around neutron stars testing braneworld models

The strong gravitational field of neutron stars in the brany universe could be described by spherically symmetric solutions with a metric in the exterior to the brany stars being of the Reissner-Nordstrom type containing a brany tidal charge representing the tidal effect of the bulk spacetime onto the star structure. We investigate the role of the tidal charge in orbital models of high-frequency quasiperiodic oscillations (QPOs) observed in neutron star binary systems. We focus on the relativistic precession model. We give the radial profiles of frequencies of the Keplerian (vertical) and radial epicyclic oscillations. We show how the standard relativistic precession model modified by the tidal charge fits the observational data, giving estimates of the allowed values of the tidal charge and the brane tension based on the processes going in the vicinity of neutron stars. We compare the strong field regime restrictions with those given in the weak-field limit of solar system experiments.Comment: 26 pages, 6 figure

Perspectives of patients with metastatic breast cancer on physical exercise programs: results from a survey in five European countries

Background: To successfully implement exercise programs for patients with metastatic breast cancer (MBC), services and patient education should consider patients’ knowledge, preferences, values, and goals. Hence, gaining insight into their perspectives on exercise and exercise programming is important. Method: In this cross-sectional survey, we recruited patients with MBC from the Netherlands, Germany, Poland, Spain, and Sweden. We collected data on patients’ knowledge and skills about exercise and outcome expectations. We identified barriers to and facilitators of participation in exercise programs, and patients’ preferences for program content and modes of exercise delivery. Results: A total of 420 patients participated in the survey. Respondents were, on average, 56.5 years old (SD 10.8) and 70% had bone metastases. Sixty-eight percent reported sufficient skills to engage in aerobic exercise, but only 35% did so for resistance exercise. Respondents expected exercise to have multiple physical benefits, but a few patients expected exercise to worsen their pain (5%). Not having access to an exercise program for cancer patients (27%), feeling too tired (23%), and/or weak (23%) were the most often reported barriers. Facilitators for exercising regularly were previous positive physical (72%) and emotional (68%) experiences with exercising, and receiving personalized advice from a physiotherapist or sport/fitness instructor (62%). Patients were most interested in walking and preferred exercising at a public gym, although there were differences by country. Fifty-seven percent did not know whether their insurance company reimburses exercise programs and only 9% would be willing to pay more than €50 per month to participate. Conclusion: A large percentage of patients with MBC lack the skills to engage in regular exercise as recommended by exercise guidelines for people with cancer. Patients may benefit from personalized advice and appropriate training facilities to overcome barriers. When implementing exercise interventions, attention should be given to reimbursement and the relatively low willingness-to-pay

Involvement of Dopamine Receptors in Binge Methamphetamine-Induced Activation of Endoplasmic Reticulum and Mitochondrial Stress Pathways

Single large doses of methamphetamine (METH) cause endoplasmic reticulum (ER) stress and mitochondrial dysfunctions in rodent striata. The dopamine D1 receptor appears to be involved in these METH-mediated stresses. The purpose of this study was to investigate if dopamine D1 and D2 receptors are involved in ER and mitochondrial stresses caused by single-day METH binges in the rat striatum. Male Sprague-Dawley rats received 4 injections of 10 mg/kg of METH alone or in combination with a putative D1 or D2 receptor antagonist, SCH23390 or raclopride, respectively, given 30 min prior to each METH injection. Rats were euthanized at various timepoints afterwards. Striatal tissues were used in quantitative RT-PCR and western blot analyses. We found that binge METH injections caused increased expression of the pro-survival genes, BiP/GRP-78 and P58IPK, in a SCH23390-sensitive manner. METH also caused up-regulation of ER-stress genes, Atf2, Atf3, Atf4, CHOP/Gadd153 and Gadd34. The expression of heat shock proteins (HSPs) was increased after METH injections. SCH23390 completely blocked induction in all analyzed ER stress-related proteins that included ATF3, ATF4, CHOP/Gadd153, HSPs and caspase-12. The dopamine D2-like antagonist, raclopride, exerted small to moderate inhibitory influence on some METH-induced changes in ER stress proteins. Importantly, METH caused decreases in the mitochondrial anti-apoptotic protein, Bcl-2, but increases in the pro-apoptotic proteins, Bax, Bad and cytochrome c, in a SCH23390-sensitive fashion. In contrast, raclopride provided only small inhibition of METH-induced changes in mitochondrial proteins. These findings indicate that METH-induced activation of striatal ER and mitochondrial stress pathways might be more related to activation of SCH23390-sensitive receptors

Easy-Plane Magnetic Anisotropy Induced by Stress-Annealing in Finemet-Type Materials

It is shown that annealing under stress of FINEMET-type metallic glass ribbon (FeCuNbSiB) induces magnetic anisotropy of an easy-plane type (cross-section of the ribbon). This conclusion has been drawn analyzing experimental results obtained by means of Kerr-effect (domain structure) and Mössbauer spectroscopy operating in the so-called "magic angle" configuration which allows us to calculate all three spatial components of magnetization. Additionally, it is also shown that no crystallographic texture is created in the sample after stress-annealing, the feature which would have been an origin of the observed anisotropy