On stochastic sea of the standard map

Consider a generic one-parameter unfolding of a homoclinic tangency of an area preserving surface diffeomorphism. We show that for many parameters (residual subset in an open set approaching the critical value) the corresponding diffeomorphism has a transitive invariant set $\Omega$ of full Hausdorff dimension. The set $\Omega$ is a topological limit of hyperbolic sets and is accumulated by elliptic islands. As an application we prove that stochastic sea of the standard map has full Hausdorff dimension for sufficiently large topologically generic parameters.Comment: 36 pages, 5 figure

Attenuation and speed of 10 MHz ultrasound in canine blood of various packed cell volumes at 37C

The attenuation coefficient and the speed of 10 MHz ultrasound were determined in canine blood at 37 oC by a differential path length technique. Blood specimens with packed cell volumes (PCV) ranging from 0 to 53% were prepared by separating the cells from the plasma and mixing the two components. The mean attenuation coefficient increased linearly with packed cell volume, the least squares regression function being (dB/cm) = 0.992 +0.039 PCV with a standard error of the estimate = 0.255. The speed of 10 MHz ultrasound, c, in millimetres per second, increased with packed cell volume, the regression function for a wave equation model being 1/C2 = 0.418 +2.09 10-4 (PCV) 1.75 105 (PCV)2 with a standard error of the estimate = 0.0049 (mm/s)2. Both the attention coefficient and speed of 10 MHz ultrasound were greater in blood than in plasma to a degree dependent on the packed cell volume

On two-dimensional surface attractors and repellers on 3-manifolds

We show that if $f: M^3\to M^3$ is an $A$-diffeomorphism with a surface two-dimensional attractor or repeller $\mathcal B$ and $M^2_ \mathcal B$ is a supporting surface for $\mathcal B$, then $\mathcal B = M^2_{\mathcal B}$ and there is $k\geq 1$ such that: 1) $M^2_{\mathcal B}$ is a union $M^2_1\cup...\cup M^2_k$ of disjoint tame surfaces such that every $M^2_i$ is homeomorphic to the 2-torus $T^2$. 2) the restriction of $f^k$ to $M^2_i$ $(i\in\{1,...,k\})$ is conjugate to Anosov automorphism of $T^2$

Arene oxidation with malonoyl peroxides

Malonoyl peroxide 7, prepared in a single step from the commercially available diacid, is an effective reagent for the oxidation of aromatics. Reaction of an arene with peroxide 7 at room temperature leads to the corresponding protected phenol which can be unmasked by aminolysis. An ionic mechanism consistent with the experimental findings and supported by isotopic labeling, Hammett analysis, EPR investigations and reactivity profile studies is proposed

Sensitivity of a tonne-scale NEXT detector for neutrinoless double beta decay searches

The Neutrino Experiment with a Xenon TPC (NEXT) searches for the neutrinoless double-beta decay of Xe-136 using high-pressure xenon gas TPCs with electroluminescent amplification. A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of neutrinoless double-beta decay decay better than 1E27 years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond.Comment: 22 pages, 11 figure

Entropy production and Lyapunov instability at the onset of turbulent convection

Computer simulations of a compressible fluid, convecting heat in two dimensions, suggest that, within a range of Rayleigh numbers, two distinctly different, but stable, time-dependent flow morphologies are possible. The simpler of the flows has two characteristic frequencies: the rotation frequency of the convecting rolls, and the vertical oscillation frequency of the rolls. Observables, such as the heat flux, have a simple-periodic (harmonic) time dependence. The more complex flow has at least one additional characteristic frequency -- the horizontal frequency of the cold, downward- and the warm, upward-flowing plumes. Observables of this latter flow have a broadband frequency distribution. The two flow morphologies, at the same Rayleigh number, have different rates of entropy production and different Lyapunov exponents. The simpler "harmonic" flow transports more heat (produces entropy at a greater rate), whereas the more complex "chaotic" flow has a larger maximum Lyapunov exponent (corresponding to a larger rate of phase-space information loss). A linear combination of these two rates is invariant for the two flow morphologies over the entire range of Rayleigh numbers for which the flows coexist, suggesting a relation between the two rates near the onset of convective turbulence.Comment: 5 pages, 4 figure

Behaviour in therapeutic medical care: evidence from general practitioners in Austria

Aim: The present study examines monetary effects of general practioners’ behaviour in therapeutic medical care to identify sample characteristics that allow differentiating between the individual general practitioner and the basic population. Subjects and methods: Medical services, provided by 3,919 general practitioners in Austria, were operationalized by means of the dependent variable “costs per patient”. Statistical outliers were identified using Chebyshev’s inequality and categorized by investigating bivariate correlations between the dependent variable and the personal characteristics of each physician. Results: Variables that relate to the size of the customer base such as number of consultations (r = 0.385) and office days (r = 0.376), correlate positively with the costs for medical services. By analyzing the portfolio of the general practitioners, we found a correlation of 0.451 between this coefficient and the costs. Statistical outliers feature an average portfolio of 44.5 different services, compared to 30.45 among non-outliers. Laboratory services especially were identified as cost drivers (r = 0.408). Statistical outliers generate at least one laboratory parameter for 44.34% of their patients, opposed to 27.2% within the rest of the sample. Consequently outliers produce higher laboratory costs than their counterparts. Conclusion: We found some evidence that physicians have influence in the provision of their services. Considering entrepreneurial objectives, the extension of the portfolio can increase their profit. Our findings indicate supplier-induced demand for several groups of services. We assume that the effect is consolidated by the fee for service system and could be compensated by adequate reform

Mechanism of 150-cavity formation in influenza neuraminidase

The recently discovered 150-cavity in the active site of group-1 influenza A neuraminidase (NA) proteins provides a target for rational structure-based drug development to counter the increasing frequency of antiviral resistance in influenza. Surprisingly, the 2009 H1N1 pandemic virus (09N1) neuramidase was crystalized without the 150-cavity characteristic of group-1 NAs. Here we demonstrate, through a total sum of 1.6 μs of biophysical simulations, that 09N1 NA exists in solution preferentially with an open 150-cavity. Comparison with simulations using avian N1, human N2 and 09N1 with a I149V mutation and an extensive bioinformatics analysis suggests that the conservation of a key salt bridge is crucial in the stabilization of the 150-cavity across both subtypes. This result provides an atomic-level structural understanding of the recent finding that antiviral compounds designed to take advantage of contacts in the 150-cavity can inactivate both 2009 H1N1 pandemic and avian H5N1 viruses