Griffiths phase in the thermal quantum Hall effect

Two dimensional disordered superconductors with broken spin-rotation and time-reversal invariance, e.g. with p_x+ip_y pairing, can exhibit plateaus in the thermal Hall coefficient (the thermal quantum Hall effect). Our numerical simulations show that the Hall insulating regions of the phase diagram can support a sub-phase where the quasiparticle density of states is divergent at zero energy, \rho(E)\sim |E|^{1/z-1}, with a non-universal exponent $z>1$, due to the effects of rare configurations of disorder (``Griffiths phase'').Comment: 4+ pages, 5 figure

Residual-based localization and quantification of peaks in x-ray diffractograms

We consider data consisting of photon counts of diffracted x-ray radiation as a function of the angle of diffraction. The problem is to determine the positions, powers and shapes of the relevant peaks. An additional difficulty is that the power of the peaks is to be measured from a baseline which itself must be identified. Most methods of de-noising data of this kind do not explicitly take into account the modality of the final estimate. The residual-based procedure we propose uses the so-called taut string method, which minimizes the number of peaks subject to a tube constraint on the integrated data. The baseline is identified by combining the result of the taut string with an estimate of the first derivative of the baseline obtained using a weighted smoothing spline. Finally, each individual peak is expressed as the finite sum of kernels chosen from a parametric family.Comment: Published in at http://dx.doi.org/10.1214/08-AOAS181 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Fluctuation of the Correlation Dimension and the Inverse Participation Number at the Anderson Transition

The distribution of the correlation dimension in a power law band random matrix model having critical, i.e. multifractal, eigenstates is numerically investigated. It is shown that their probability distribution function has a fixed point as the system size is varied exactly at a value obtained from the scaling properties of the typical value of the inverse participation number. Therefore the state-to-state fluctuation of the correlation dimension is tightly linked to the scaling properties of the joint probability distribution of the eigenstates.Comment: 4 pages, 5 figure

Multifractality at the spin quantum Hall transition

Statistical properties of critical wave functions at the spin quantum Hall transition are studied both numerically and analytically (via mapping onto the classical percolation). It is shown that the index $\eta$ characterizing the decay of wave function correlations is equal to 1/4, at variance with the $r^{-1/2}$ decay of the diffusion propagator. The multifractality spectra of eigenfunctions and of two-point conductances are found to be close-to-parabolic, $\Delta_q\simeq q(1-q)/8$ and $X_q\simeq q(3-q)/4$.Comment: 4 pages, 3 figure

Haemonchus contortus con resistencia múltiple a los antihelmínticos de corta y larga acción y consideraciones sobre el impacto sanitario-productivo de este fenómeno en una majada de ovinos lecheros de la provincia de Santa Fe

Entre Octubre y Noviembre del 2012 se realizaron evaluaciones sobre la actividad de cuatro antihelmínticos con diferente mecanismo de acción (levamisol, ivermectina, closantel y febendazol) en ovinos lecheros naturalmente parasitados por nematodes gastrointestinales en un establecimiento del área central de Santa Fe. Las determinaciones de susceptibilidad o resistencia se realizaron a través del test de reducción en el conteo de huevos (TRCH) y como animales experimentales se utilizaron 40 corderos destetados de la raza Pampinta de aproximadamente dos meses y medio de edad. Estos animales fueron asignados a cuatro grupos de tratamientos de diez animales cada uno en función del número de huevos de nematodes por gramo de heces o hpg (p>0,005). El TRCH se determinó estableciendo el porcentaje de reducción observado en el promedio del hpg en las muestras de materia fecal pre y post tratamiento de los mismos animales. Los resultados indicaron la presencia predominante de Haemonchus contortus con resistencia múltiple a ivermectina, febendazol y clo-santel así como de Nematodirus spp con resistencia a las dos primeras de estas drogas. El levamisol presentó una eficacia muy alta (> al 99 %) para controlar cualquiera de estos aislamientos. Ante la presencia de resistencia con los otros antihelmínticos, todos los corderos experimentales fueron re-tratados con levamisol observándose en este segundo TRCH una eficacia similar al primero. No obstante, debido a su baja actividad larvicida y su corta acción, aproximadamente 30 días posteriores al tratamiento de todos los corderos con levamisol se produjo un severo caso de haemonchosis con elevados índices de mortalidadBetween October and November 2012 a field trial was carried out in dairy sheep naturally parasi-tized by gastrointestinal nematodes in central Santa Fe (Argentina) to investigate the activity of four anthelmintic with different mechanism of action (levamisole, ivermectin, fenbendazole and closantel). The status of susceptibility or resistance was performed through the test of reduction in egg count (TRCH) on 40 Pampinta lambs about two and half months old. These lambs were assigned to four treatment groups of ten animals each according to the number of nematode eggs per gram of feces or hpg (p> 0.005). TRCH was determined by establishing the percentage reduction in the average observed epg in fecal samples before and after treatment of the same animals. The results indicated the predominance of Haemonchus contortus with multiple resistance to ivermectin, febendazole and closantel as well as Nematodirus spp with resistance to the first two of these drugs. Levamisole showed a very high efficacy (> 99%) to control any of these isolates. Due to the presence of Haemonchus spp with resistance to ivermectin, febendazole and closantel, all experimental lambs were re-treated with levamisole and similar efficacy in the TRCH was observed in this second trial. However, due to its low larvicidal activity and short action, approximately 30 days after levamisol treatment, a severe outbreak of acute haemonchosis with high mortality rates was observedEEA RafaelaFil: Muchiut, Sebastian. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Mildenberger, M. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Pujato, Andrés. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Anziani, Oscar Sergio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentin

Moderate inappropriately high aldosterone/NaCl constellation in mice: cardiovascular effects and the role of cardiovascular epidermal growth factor receptor

Non-physiological activation of the mineralocorticoid receptor (MR), e.g. by aldosterone under conditions of high salt intake, contributes to the pathogenesis of cardiovascular diseases, although beneficial effects of aldosterone also have been described. The epidermal growth factor receptor (EGFR) contributes to cardiovascular alterations and mediates part of the MR effects. Recently, we showed that EGFR is required for physiological homeostasis and function of heart and arteries in adult animals. We hypothesize that moderate high aldosterone/NaCl, at normal blood pressure, affects the cardiovascular system depending on cardiovascular EGFR. Therefore we performed an experimental series in male and female animals each, using a recently established mouse model with EGFR knockout in vascular smooth muscle cells and cardiomyocytes and determined the effects of a mild-high aldosterone-to-NaCl constellation on a.o. marker gene expression, heart size, systolic blood pressure, impulse conduction and heart rate. Our data show that (i) cardiac tissue of male but not of female mice is sensitive to mild aldosterone/NaCl treatment, (ii) EGFR knockout induces stronger cardiac disturbances in male as compared to female animals and (iii) mild aldosterone/NaCl treatment requires the EGFR in order to disturb cardiac tissue homeostasis whereas beneficial effects of aldosterone seem to be independent of EGFR

On the length of chains of proper subgroups covering a topological group

We prove that if an ultrafilter L is not coherent to a Q-point, then each analytic non-sigma-bounded topological group G admits an increasing chain <G_a : a of its proper subgroups such that: (i) U_{a in b(L)} G_a=G; and $(ii)$ For every sigma-bounded subgroup H of G there exists a such that H is a subset of G_a. In case of the group Sym(w) of all permutations of w with the topology inherited from w^w this improves upon earlier results of S. Thomas

Multifractality of wavefunctions at the quantum Hall transition revisited

We investigate numerically the statistics of wavefunction amplitudes $\psi({\bf r})$ at the integer quantum Hall transition. It is demonstrated that in the limit of a large system size the distribution function of $|\psi|^2$ is log-normal, so that the multifractal spectrum $f(\alpha)$ is exactly parabolic. Our findings lend strong support to a recent conjecture for a critical theory of the quantum Hall transition.Comment: 4 pages Late