Analytical description of CP violation in oscillations of atmospheric neutrinos traversing the Earth

Flavour oscillations of sub-GeV atmospheric neutrinos and antineutrinos, traversing different distances inside the Earth, are a promising source of information on the leptonic CP phase δ. In that energy range, the oscillations are very fast, far beyond the resolution of modern neutrino detectors. However, the necessary averaging over the experimentally typical energy and azimuthal angle bins does not wash out the CP violation effects. In this paper we derive very accurate analytic compact expressions for the averaged oscillations probabilities. Assuming spherically symmetric Earth, the averaged oscillation probabilities are described in terms of two analytically calculable effective parameters. Based on those expressions, we estimate maximal magnitude of CP-violation effects in such measurements and propose optimal observables best suited to determine the value of the CP phase in the PMNS mixing matrix.

Stochastic generator of earthquakes in French territories

<p>Both French mainland and Lesser Antilles are characterized by sparse earthquake catalogues respectively due to the low-to-moderate seismic activity and the low recording historical depth. However, it is known that major earthquakes could strike French mainland (e.g. Ligure in 1887 or Basel in 1356) and even more French Lesser Antilles (e.g. Guadeloupe 1943 or Martinique 1839). Assessing seismic hazard in these territories is necessary to support building codes and prevention actions to population. One approach to estimate seismic hazard despite lack of data is to generate a set of plausible seismic scenarios over a large time span. A generator of earthquakes is thus presented in this paper. Its first step is to generate only main shocks. The second step consists of trigger aftershocks related to main shocks.<br>To draw the time occurrence of main shocks, original draw of frequencies and year-by-year summation of it is proceeded. The frequencies are drawn, for each magnitude step, in probability density functions computed through the inter event time method (Hainzl et al. 2006). By propagating magnitude uncertainties contained in the initial catalogue through a Monte Carlo Markov Chain, each magnitude step has not only one main shock frequency but a distribution of it. Once a main shock is temporally drawn, its 2D location is drawn thanks to the cumulative seismic moment recorded on each 5x5 km cell in the French territories. A seismotectonic zoning is used to limit both the spatial distribution and magnitude of large earthquakes. Finally, the other parameters (strike, dip, rake and depth) are drawn in ranges of values depending on the seismotectonic zone where the main shock is located. <br>For purpose of trigger aftershocks from the main shocks, an approximation of the Bath law (Richter 1958; Båth 1965) is proceeded during the computation of the frequency – magnitude distributions. Thus, for each magnitude step, an α–value distribution is obtained in which, for each main shock an α–value is drawn. In this way, the maximal magnitude of triggered aftershocks is known.</p>

On the gravitational field of a point-like body immersed in a quantum vacuum

ABSTRACT Quantum vacuum and the matter immersed in it interact through electromagnetic, strong and weak interactions. However, we have zero knowledge of the gravitational properties of the quantum vacuum. As an illustration of the possible fundamental gravitational impact of the quantum vacuum, we study the gravitational field of an immersed point-like body. This is done under the working hypothesis, that quantum vacuum fluctuations are virtual gravitational dipoles (i.e. two gravitational charges of the same magnitude but opposite sign); coincidentally, this hypothesis makes quantum vacuum free of the cosmological constant problem. The major result is that a point-like body creates a halo of polarized quantum vacuum around itself, which acts as an additional source of gravity. There is a maximal magnitude ${g_{\rm qv\max}}$ of gravitational acceleration that can be caused by a polarized quantum vacuum; the small size of this magnitude (${g_{\rm qv\max}} < 6\ \times {10^{ - 11}}\,\mathrm{ m\,s}{^{-2}}$) is the reason why in some cases (for instance within the Solar system) the quantum vacuum can be neglected. Advanced experiments at CERN and forthcoming astronomical observations will reveal if this is true or not, but we point to already existing empirical evidence that seemingly supports this fascinating possibility.

Numerical Simulation of Accumulative Forming Bipolar Plates of Fuel Cell

The bipolar plate is the key part in the fuel cell. It is difficult to produce the micro flow channel of bipolar plates with high accuracy. In order to solve this problem, we present one new forming techniques, accumulative forming, for the fabrication of micro flow channels. With the utilization of the software ABAQUS, finite element model of the bipolar plate with the 20mm×20mm×0.2mm is developed to simulate the accumulative forming and obtain the forming rules. The simulation results are about the plate’s thickness change and deformation. It shows that the thickness reduction decreases gradually from the center of the channel to the outside with the maximal magnitude in the starting point of accumulative forming. The maximum thinning ratio is 15.85%, which is in the forming limit scope. The simulation demonstrates the feasibility of the accumulative forming and good formability.

Suramin Interacts with the Calmodulin Binding Site on the Ryanodine Receptor, RYR1

Apocalmodulin and Ca2+calmodulin bind to overlapping sites on the ryanodine receptor skeletal form, RYR1, but have opposite functional effects on channel activity. Suramin, a polysulfonated napthylurea, displaces both forms of calmodulin, leading to an inhibition of activity at low Ca2+and an enhancement of activity at high Ca2+. Calmodulin binding motifs on RYR1 are also able to directly interact with the carboxy-terminal tail of the transverse tubule dihydropyridine receptor (DHPR) (Sencer, S., Papineni, R. V., Halling, D. B., Pate, P., Krol, J., Zhang, J. Z., and Hamilton, S. L. (2001)J. Biol. Chem.276, 38237–38241). Suramin binds directly to a peptide that corresponds to the calmodulin binding site of RYR1 (amino acids 3609–3643) and blocks the interaction of this peptide with both calmodulin and the carboxyl-terminal tail of the DHPR α1-subunit. Suramin, added to the internal solution of voltage-clamped skeletal myotubes, produces a concentration-dependent increase in the maximal magnitude of voltage-gated Ca2+transients without significantly altering L-channel Ca2+channel conducting activity. Together, these results suggest that an interaction between the carboxyl-terminal tail of the DHPR α1-subunit with the calmodulin binding region of RYR1 serves to limit sarcoplasmic reticulum Ca2+release during excitation-contraction coupling and that suramin-induced potentiation of voltage-gated Ca2+release involves a relief of this inhibitory interaction.

Predictive Modulation of Muscle Coordination Pattern Magnitude Scales Fingertip Force Magnitude Over the Voluntary Range

Human fingers have sufficiently more muscles than joints such that every fingertip force of submaximal magnitude can be produced by an infinite number of muscle coordination patterns. Nevertheless, the nervous system seems to effortlessly select muscle coordination patterns when sequentially producing fingertip forces of low, moderate, and maximal magnitude. The hypothesis of this study is that the selection of coordination patterns to produce submaximal forces is simplified by the appropriate modulation of the magnitude of a muscle coordination pattern capable of producing the largest expected fingertip force. In each of three directions, eight subjects were asked to sequentially produce fingertip forces of low, moderate, and maximal magnitude with their dominant forefinger. Muscle activity was described by fine-wire electromyograms (EMGs) simultaneously collected from all muscles of the forefinger. A muscle coordination pattern was defined as the vector list of the EMG activity of each muscle. For all force directions, statistically significant muscle coordination patterns similar to those previously reported for 100% of maximal fingertip forces were found for 50% of maximal voluntary force. Furthermore the coordination pattern and fingertip force vector magnitudes were highly correlated ( r > 0.88). Average coordination pattern vectors at 50 and 100% of maximal force were highly correlated with each other, as well as with individual coordination pattern vectors in the ramp transitions preceding them. In contrast to this consistency of EMG coordination patterns, predictions using a musculoskeletal computer model of the forefinger show that force magnitudes ≤50% of maximal fingertip force can be produced by coordination patterns drastically different from those needed for maximal force. Thus when modulating fingertip force magnitude across the voluntary range, the number of contributing muscles and the relative activity among them was not changed. Rather, the production of low and moderate forces seems to be simplified by appropriately scaling the magnitude of a coordination pattern capable of producing the highest force expected.

Electrical Response and Growth of Olfactory Cilia of the Olfactory Epithelium of the Newt in Water and on Land

A correlation between the length of the olfactory cilia and the electrical activity of the olfactory epithelium was studied in newts living in water and on land. The olfactory cilia grew when newts were transferred onto land. The cilia in the olfactory bud became longest in 108 hours after the transfer and then became shorter, while those in the interstitium only gradually elongated. Slow potentials were evoked in the epithelium by the application of odorous fluids but not by odorous vapors for 20 hours after the transfer. Thereafter, the slow potential began to appear in response to odorous vapors and reached maximal magnitude between 60 and 70 hours after the transfer, while it was not evoked by odorous fluids in this period. In the later stage, the slow potential to odorous vapors decreased in magnitude and disappeared 120 hours after the transfer, while it began to reappear in response to odorous fluids. When these changes in the slow potential were compared with those in the cilium, a discrepancy was found between the period of maximal potential magnitude and that of maximal cilium length.