Bistable Gradient Networks II: Storage Capacity and Behaviour Near Saturation

We examine numerically the storage capacity and the behaviour near saturation of an attractor neural network consisting of bistable elements with an adjustable coupling strength, the Bistable Gradient Network (BGN). For strong coupling, we find evidence of a first-order "memory blackout" phase transition as in the Hopfield network. For weak coupling, on the other hand, there is no evidence of such a transition and memorized patterns can be stable even at high levels of loading. The enhanced storage capacity comes, however, at the cost of imperfect retrieval of the patterns from corrupted versions.Comment: 15 pages, 12 eps figures. Submitted to Phys. Rev. E. Sequel to cond-mat/020356

Effect of metformin therapy and dietary supplements on semen parameters in hyperinsulinaemic males

Previous reports indicated that hyperinsulinaemic men may exhibit a higher percentage of poorly compacted DNA in their spermatozoa and less success in an IVF programme (Andrologia, 45, 2003, 18; Andrologia, 2014, doi: 10.1111/ and.12227). The aim of this study was to investigate the effect of metformin (Glucophage ) and antioxidant treatment (StaminoGro ) on the semen parameters of hyperinsulinaemic men. Nineteen hyperinsulinaemic male patients were treated for 3 months with metformin alone (Group A), and fifteen patients used metformin in combination with the nutritional supplement (Group B). Combined data of the two groups (pre- and post-treatment) differ significantly regarding sperm morphology (P = 0.0003) and CMA3 (P < 0.0001) values. The improvement in sperm morphology after treatment was similar for the two respective groups (P < 0.05). The morphological normal sperm forms increased from the mean percentage of 3.9 to 5.5% and from 4.2 to 5.5% for Group A and B respectively. Where a combination of metformin and the supplement were used (Group B), the combination treatment proved to be superior in obtaining enhanced chromatin packaging quality although not statistically significant (P = 0.5929) when compared with the metformin (Group A) group. The chromatin packaging quality in Group B improved with 10% while the improvement in Group A was approximately 8.3%. Therefore, infertile hyperinsulinaemic men can benefit from metformin treatment and should be advised on the use of nutritional supplements with antioxidant properties.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1439-02722016-11-30hb2016Clinical Epidemiolog

Entanglement between Demand and Supply in Markets with Bandwagon Goods

Whenever customers' choices (e.g. to buy or not a given good) depend on others choices (cases coined 'positive externalities' or 'bandwagon effect' in the economic literature), the demand may be multiply valued: for a same posted price, there is either a small number of buyers, or a large one -- in which case one says that the customers coordinate. This leads to a dilemma for the seller: should he sell at a high price, targeting a small number of buyers, or at low price targeting a large number of buyers? In this paper we show that the interaction between demand and supply is even more complex than expected, leading to what we call the curse of coordination: the pricing strategy for the seller which aimed at maximizing his profit corresponds to posting a price which, not only assumes that the customers will coordinate, but also lies very near the critical price value at which such high demand no more exists. This is obtained by the detailed mathematical analysis of a particular model formally related to the Random Field Ising Model and to a model introduced in social sciences by T C Schelling in the 70's.Comment: Updated version, accepted for publication, Journal of Statistical Physics, online Dec 201

Oscillation enhanced search for new interaction with neutrinos

We discuss the measurement of new physics in long baseline neutrino oscillation experiments. Through the neutrino oscillation, the probability to detect the new physics effects such as flavor violation is enhanced by the interference with the weak interaction. We carefully explain the situations that the interference can take place. Assuming a neutrino factory and an upgraded conventional beam, we estimate the feasibility to observe new physics numerically and point out that we can search new interactions using some channels, for example $\nu_{\mu} \to \nu_{\mu}$, in these experiments. We also discuss several models which induce the effective interactions interfering with the weak interaction, and show that some new physics effects are large enough to be observed in the oscillation enhanced way.Comment: 25 pages, 20 figure

Astrophysical Reaction Rates for 10^{10}B(p,α\alpha)7^{7}Be and 11^{11}B(p,α\alpha)8^{8}Be From a Direct Model

The reactions $^{10}$B(p,$\alpha$)$^{7}$Be and $^{11}$B(p,$\alpha$)$^{8}$Be are studied at thermonuclear energies using DWBA calculations. For both reactions, transitions to the ground states and first excited states are investigated. In the case of $^{10}$B(p,$\alpha$)$^{7}$Be, a resonance at $E_{Res}=10$ keV can be consistently described in the potential model, thereby allowing the extension of the astrophysical $S$-factor data to very low energies. Strong interference with a resonance at about $E_{Res}=550$ keV require a Breit-Wigner description of that resonance and the introduction of an interference term for the reaction $^{10}$B(p,$\alpha_1$)$^{7}$Be$^*$. Two isospin $T=1$ resonances (at $E_{Res1}=149$ keV and $E_{Res2}=619$ keV) observed in the $^{11}$B+p reactions necessitate Breit-Wigner resonance and interference terms to fit the data of the $^{11}$B(p,$\alpha$)$^{8}$Be reaction. $S$-factors and thermonuclear reaction rates are given for each reaction. The present calculation is the first consistent parametrization for the transition to the ground states and first excited states at low energies.Comment: 27 pages, 5 Postscript figures, uses RevTex and aps.sty; preprint also available at http://quasar.physik.unibas.ch/ Phys. Rev. C, in pres

Neutrino oscillation parameters from MINOS, ICARUS and OPERA combined

We perform a detailed analysis of the capabilities of the MINOS, ICARUS and OPERA experiments to measure neutrino oscillation parameters at the atmospheric scale with their data taken separately and in combination. MINOS will determine $\Delta m^2_{32}$ and $\sin^2 2\theta_{23}$ to within 10% at the 99% C.L. with 10 kton-years of data. While no one experiment will determine $\sin^2 2\theta_{13}$ with much precision, if its value lies in the combined sensitivity region of the three experiments, it will be possible to place a lower bound of O(0.01) at the 95% C.L. on this parameter by combining the data from the three experiments. The same bound can be placed with a combination of MINOS and ICARUS data alone.Comment: Version to appear in PR

Can a CPT Violating Ether Solve ALL Electron (Anti)Neutrino Puzzles?

Assuming that CPT is violated in the neutrino sector seems to be a viable alternative to sterile neutrinos when it comes to reconciling the LSND anomaly with the remainder of the neutrino data. There are different (distinguishable) ways of incorporating CPT violation into the standard model, including postulating m different from \bar{m}. Here, I investigate the possibility of introducing CPT violation via Lorentz-invariance violating effective operators (``Ether'' potentials) which modify neutrino oscillation patterns like ordinary matter effects. I argue that, within a simplified two-flavor like oscillation analysis, one cannot solve the solar neutrino puzzle and LSND anomaly while still respecting constraints imposed by other neutrino experiments, and comment on whether significant improvements should be expected from a three-flavor analysis. If one turns the picture upside down, some of the most severe constrains on such CPT violating terms can already be obtained from the current neutrino data, while much more severe constraints can arise from future neutrino oscillation experiments.Comment: 10 pages, 1 eps figure; version to appear in PRD. Comment added, mistake corrected, results and conclusions unchange

COMPORTAMENTO HIDROLÓGICO DE ENCOSTA EM SUBSTRATO ROCHOSO GRANÍTICO SOB INFLUÊNCIA DE DESLIZAMENTO RASO - NOVA FRIBURGO, RIO DE JANEIRO

Tendo a água como principal agente deflagrador dos deslizamentos em regiões tropicais, este trabalho objetivou o estudo hidrológico de uma encosta com um cicatriz de deslizamento do tipo translacional raso, no evento extremo de chuva de Janeiro de 2011, Nova Friburgo-RJ. Para o entendimento da influência da água subterrânea na deflagração dos movimentos de massa, a área foi sondada e instrumenta, visando a caracterização física da encosta

Measuring the Spectra of High Energy Neutrinos with a Kilometer-Scale Neutrino Telescope

We investigate the potential of a future kilometer-scale neutrino telescope such as the proposed IceCube detector in the South Pole, to measure and disentangle the yet unknown components of the cosmic neutrino flux, the prompt atmospheric neutrinos coming from the decay of charmed particles and the extra-galactic neutrinos, in the 10 TeV to 1 EeV energy range. Assuming a power law type spectra, $d\phi_\nu/dE_\nu \sim \alpha E_\nu^\beta$, we quantify the discriminating power of the IceCube detector and discuss how well we can determine magnitude ($\alpha$) as well as slope ($\beta$) of these two components of the high energy neutrino spectrum, taking into account the background coming from the conventional atmospheric neutrinos.Comment: 21 pages, 7 figure