General static spherically symmetric solutions in Horava gravity

We derive general static spherically symmetric solutions in the Horava theory of gravity with nonzero shift field. These represent "hedgehog" versions of black holes with radial "hair" arising from the shift field. For the case of the standard de Witt kinetic term (lambda =1) there is an infinity of solutions that exhibit a deformed version of reparametrization invariance away from the general relativistic limit. Special solutions also arise in the anisotropic conformal point lambda = 1/3.Comment: References adde

On the evolution of the entropy and pressure profiles in X-ray luminous galaxy clusters at z > 0.4

Galaxy clusters are the most recent products of hierarchical accretion over cosmological scales. The gas accreted from the cosmic field is thermalized inside the cluster halo. Gas entropy and pressure are expected to have a self-similar behaviour with their radial distribution following a power law and a generalized Navarro-Frenk-White profile, respectively. This has been shown also in many different hydrodynamical simulations. We derive the spatially-resolved thermodynamical properties of 47 X-ray galaxy clusters observed with Chandra in the redshift range 0.4 < z < 1.2, the largest sample investigated so far in this redshift range with X-rays spectroscopy, with a particular care in reconstructing the gas entropy and pressure radial profiles. We search for deviation from the self-similar behaviour and look for possible evolution with redshift. The entropy and pressure profiles lie very close to the baseline prediction from gravitational structure formation. We show that these profiles deviate from the baseline prediction as function of redshift, in particular at z > 0.75, where, in the central regions, we observe higher values of the entropy (by a factor of 2.2) and systematically lower estimates (by a factor of 2.5) of the pressure. The effective polytropic index, which retains informations about the thermal distribution of the gas, shows a slight linear positive evolution with the redshift and the concentration of the dark matter distribution. A prevalence of non-cool-core, disturbed systems, as we observe at higher redshifts, can explain such behaviours.Comment: 14 pages, 18 figures, accepted for publication by A&

A re-description of <i>Hensodon spinosus</i>, a remarkable coccodontid fish (Actinopterygii, †Pycnodontiformes) from the Cenomanian (Late Cretaceous) of Haqel, Lebanon

Hensodon spinosus, a rare and very peculiar pycnodontiform fish from the Upper Cenomanian limestone of the Haqel fossils quarry (Lebanon) is re-described on the basis of four new specimens. It is the only species assigned to the genus. It shares with the family Coccodontidae (sensu Poyato-Ariza & Wenz, 2002) almost all its synapomorphies but is also characterized by several unique autapomorphies. The species exhibits a rounded general shape of the body, an enormous head, an extremely reduced snout with a minute mouth gash, a horny frontal showing modifications that we interpret as dimorphic sexual differences, styliform teeth, a giant occipital process with many spines on its margins and formed by the dermosupraoccipital, the parietal and the supratemporal, a prefrontal, an edentulous, unornamented, elongated rhomboid maxilla, a very massive spiny cleithrum, a big spiny post-coelomic bone, and a few elongated bar scales. All those characters award a unique impressive aspect to the fish. Remains of the original colour pattern add information about the external aspect of this remarkable fish

Nonlinear Micromechanical Casimir Oscillator

The Casimir force between uncharged metallic surfaces originates from quantum mechanical zero point fluctuations of the electromagnetic field. We demonstrate that this quantum electrodynamical effect has a profound influence on the oscillatory behavior of microstructures when surfaces are in close proximity (<= 100 nm). Frequency shifts, hysteretic behavior and bistability caused by the Casimir force are observed in the frequency response of a periodically driven micromachined torsional oscillator.Comment: 4 pages, 4 figures; added and rearranged references; added comments on sensitivit

Stellar Mass to Halo Mass Scaling Relation for X-ray Selected Low Mass Galaxy Clusters and Groups out to Redshift z≈1z\approx1

We present the stellar mass-halo mass scaling relation for 46 X-ray selected low-mass clusters or groups detected in the XMM-BCS survey with masses $2\times10^{13}M_{\odot}\lesssim M_{500}\lesssim2.5\times10^{14}M_{\odot}$ at redshift $0.1\le z \le1.02$. The cluster binding masses $M_{500}$ are inferred from the measured X-ray luminosities \Lx, while the stellar masses $M_{\star}$ of the galaxy populations are estimated using near-infrared imaging from the SSDF survey and optical imaging from the BCS survey. With the measured \Lx\ and stellar mass $M_{\star}$, we determine the best fit stellar mass-halo mass relation, accounting for selection effects, measurement uncertainties and the intrinsic scatter in the scaling relation. The resulting mass trend is $M_{\star}\propto M_{500}^{0.69\pm0.15}$, the intrinsic (log-normal) scatter is $\sigma_{\ln M_{\star}|M_{500}}=0.36^{+0.07}_{-0.06}$, and there is no significant redshift trend $M_{\star}\propto (1+z)^{-0.04\pm0.47}$, although the uncertainties are still large. We also examine $M_{\star}$ within a fixed projected radius of $0.5$~Mpc, showing that it provides a cluster binding mass proxy with intrinsic scatter of $\approx93\%$ (1$\sigma$ in $M_{500}$). We compare our $M_{\star}=M_{\star}(M_{500}, z)$ scaling relation from the XMM-BCS clusters with samples of massive, SZE-selected clusters ($M_{500}\approx6\times10^{14}M_{\odot}$) and low mass NIR-selected clusters ($M_{500}\approx10^{14}M_{\odot}$) at redshift $0.6\lesssim z \lesssim1.3$. After correcting for the known mass measurement systematics in the compared samples, we find that the scaling relation is in good agreement with the high redshift samples, suggesting that for both groups and clusters the stellar content of the galaxy populations within $R_{500}$ depends strongly on mass but only weakly on redshift out to $z\approx1$.Comment: 15 pages, 10 figures. Accepted for publication in MNRA

Assessment of poststress left ventricular ejection fraction by gated SPECT: comparison with equilibrium radionuclide angiocardiography

PURPOSE: We compared left ventricular (LV) ejection fraction obtained by gated SPECT with that obtained by equilibrium radionuclide angiocardiography in a large cohort of patients. METHODS: Within 1 week, 514 subjects with suspected or known coronary artery disease underwent same-day stress-rest (99m)Tc-sestamibi gated SPECT and radionuclide angiocardiography. For both studies, data were acquired 30 min after completion of exercise and after 3 h rest. RESULTS: In the overall study population, a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.82, p<0.0001) and after stress (r=0.83, p<0.0001). In Bland-Altman analysis, the mean differences in ejection fraction (radionuclide angiocardiography minus gated SPECT) were -0.6% at rest and 1.7% after stress. In subjects with normal perfusion (n=362), a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.72, p<0.0001) and after stress (r=0.70, p<0.0001) and the mean differences in ejection fraction were -0.9% at rest and 1.4% after stress. Also in patients with abnormal perfusion (n=152), a good correlation between the two techniques was observed both at rest (r=0.89, p<0.0001) and after stress (r=0.90, p<0.0001) and the mean differences in ejection fraction were 0.1% at rest and 2.5% after stress. CONCLUSION: In a large study population, a good agreement was observed in the evaluation of LV ejection fraction between gated SPECT and radionuclide angiocardiography. However, in patients with perfusion abnormalities, a slight underestimation in poststress LV ejection fraction was observed using gated SPECT as compared to equilibrium radionuclide angiocardiography

Ethnicity and work-related stress in Eastern European care workers for the elderly: an application of a proposed multi-dimensional model

The present study aims to test the application of a multi-dimensional model of stress that takes as a framework of reference the DRIVE (Demands, Resources, and Individual Effects) model and previous studies on occupational health and cultural aspects in a sample of Eastern European eldercare workers. This model integrated ethnicity and work-related stress dimensions in a transactional perspective combining individual differences, ethnicity aspects, work characteristics in the prediction of psychophysical health giving closer attention to specificassociations between cultural dimensions such as cultural identity, acculturation strategies and health outcomes. Therefore the study hypothesized significant profiles of associations between individual differences, work characteristics, ethnicity dimensions, perceived job satisfaction/stress and health outcomes among these workers. A questionnaire measuring the following dimensions was submitted to 250 Eastern European eldercare workers in Southern Italy: coping strategies, personality behaviours, acculturation strategies, perceived work demands, resources/rewards, perceived job stress/satisfaction, psychological disorders and general health. Around one third (38.6%) lived in Italy from more than 5 years, all were women (Age Mean=43.18; SD=4.25) and most of them were married (94.8 %), with a high level of education (94.4 %), worked full-time (93.2 %) and had fixed contracts (97.2 %)Data were analysed using LR logistic regression to evaluate the effects of all the dimensions reported on the risk of suffering health problems. Results showed that work demands, type A and negative affectivity behavioural patterns significantlyassociated with high levels of anxious-depressive disorders, relational disorders and general health. Moreover positive coping strategies, specificacculturation strategies and perceived job satisfaction significantlyassociated with low levels of psychophysical disorders. Findings supported different aspects of the proposed stress model and will be helpful in definingpsychological interventions to support this particular type of migrant workers