Heart Rate Variability Measured Early in Patients with Evolving Acute Coronary Syndrome and 1-year Outcomes of Rehospitalization and Mortality

Objective: This study sought to examine the prognostic value of heart rate variability (HRV) measurement initiated immediately after emergency department presentation for patients with acute coronary syndrome (ACS). Background: Altered HRV has been associated with adverse outcomes in heart disease, but the value of HRV measured during the earliest phases of ACS related to risk of 1-year rehospitalization and death has not been established. Methods: Twenty-four-hour Holter recordings of 279 patients with ACS were initiated within 45 minutes of emergency department arrival; recordings with �18 hours of sinus rhythm were selected for HRV analysis (number [N] �193). Time domain, frequency domain, and nonlinear HRV were examined. Survival analysis was performed. Results: During the 1-year follow-up, 94 patients were event-free, 82 were readmitted, and 17 died. HRV was altered in relation to outcomes. Predictors of rehospitalization included increased normalized high frequency power, decreased normalized low frequency power, and decreased low/high frequency ratio. Normalized high frequency �42 ms2 predicted rehospitalization while controlling for clinical variables (hazard ratio [HR] �2.3; 95% confidence interval [CI] �1.4–3.8, P�0.001). Variables significantly associated with death included natural logs of total power and ultra low frequency power. A model with ultra low frequency power �8 ms2 ( HR �3.8; 95% CI �1.5–10.1; P�0.007) and troponin �0.3 ng/mL (HR �4.0; 95% CI �1.3–12.1; P�0.016) revealed that each contributed independently in predicting mortality. Nonlinear HRV variables were significant predictors of both outcomes. Conclusion: HRV measured close to the ACS onset may assist in risk stratification. HRV cut-points may provide additional, incremental prognostic information to established assessment guidelines, and may be worthy of additional study

A Model for the Schottky Anomaly in Metallic Nd2−yCeyCuO4Nd_{2-y}Ce_{y}CuO_{4}

We present a simple model for the doped compound $Nd_{2-y}Ce_{y}CuO_{4}$, in order to explain some recent experimental results on the latter. Within a Hartree-Fock context, we start from an impurity Anderson-like model and consider the magnetic splitting of the $Nd$-$4f$ ground state Kramers doublet due to exchange interactions with the ordered $Cu$ moments. Our results are in very good agreement with the experimental data, yielding a Schottky anomaly peak for the specific heat that reduces its amplitude, broadens and shifts to lower temperatures, upon $Ce$ doping. For overdoped compounds at low temperatures, the specific heat behaves linearly and the magnetic susceptibility is constant. A smooth transition from this Fermi liquid like behavior ocurrs as temperature is increased and at high temperatures the susceptibility exhibits a Curie-like behavior. Finally, we discuss some improvements our model is amenable to incorporate.Comment: 7 pages, 5 figures, and 13 reference

Heart Rate Variability Measurement and Clinical Depression in Acute Coronary Syndrome Patients: Narrative Review of Recent Literature

Aim: We aimed to explore links between heart rate variability (HRV) and clinical depression in patients with acute coronary syndrome (ACS), through a review of recent clinical research literature. Background: Patients with ACS are at risk for both cardiac autonomic dysfunction and clinical depression. Both conditions can negatively impact the ability to recover from an acute physiological insult, such as unstable angina or myocardial infarction, increasing the risk for adverse cardiovascular outcomes. HRV is recognized as a reflection of autonomic function. Methods: A narrative review was undertaken to evaluate state-of-the-art clinical research, using the PubMed database, January 2013. The search terms “heart rate variability” and “depression” were used in conjunction with “acute coronary syndrome”, “unstable angina”, or “myocardial infarction” to find clinical studies published within the past 10 years related to HRV and clinical depression, in patients with an ACS episode. Studies were included if HRV measurement and depression screening were undertaken during an ACS hospitalization or within 2 months of hospital discharge. Results: Nine clinical studies met the inclusion criteria. The studies’ results indicate that there may be a relationship between abnormal HRV and clinical depression when assessed early after an ACS event, offering the possibility that these risk factors play a modest role in patient outcomes. Conclusion: While a definitive conclusion about the relevance of HRV and clinical depression measurement in ACS patients would be premature, the literature suggests that these measures may provide additional information in risk assessment. Potential avenues for further research are proposed

The (d,6-Li) Reaction Studies

Supported by the National Science Foundation and Indiana Universit

On the well-posedness for the Ideal MHD equations in the Triebel-Lizorkin spaces

In this paper, we prove the local well-posedness for the Ideal MHD equations in the Triebel-Lizorkin spaces and obtain blow-up criterion of smooth solutions. Specially, we fill a gap in a step of the proof of the local well-posedness part for the incompressible Euler equation in \cite{Chae1}.Comment: 16page

Multi-spectroscopic and elemental characterization of southern Australian asphaltites

Strandings of various types of bitumen along the coast of southern Australia are long known. Among these, brittle, angular lumps termed ‘asphaltites’ are possibly sourced from Cretaceous source rocks linked to an oceanic anoxic event (OAE), but the exact source remains unclear. The unusual chemical composition of these asphaltites and their survival during transport and shoreline stranding suggest that they formed by nearby submarine seepage of asphaltene-rich crude oils. Here, we provide a detailed organic and inorganic geochemical characterization of asphaltites to constrain their origin and age. High-pressure hydropyrolysis (HyPy) of asphaltene fractions from ten asphaltites released similar assemblages of macromolecularly bound compounds, suggesting a common source for all asphaltites. Comprehensive gas chromatography–time-of-flight mass spectrometry (GC×GC-TOFMS) was used to compare these asphaltene-derived compounds with the maltene fractions, while compound specific isotope analysis (CSIA) was used to compare δ13C and δ2H of n-alkanes and isoprenoids. A large offset between the δ2H of the n-alkanes and isoprenoids suggests oil generation and expulsion at low thermal maturity. The mean concentrations of isorenieratane and chlorobactane, carotenoid derivatives indicative of photic zone euxinia (PZE), in the asphaltites were 8.8 ± 0.8 SEM µg g−1 and 1.4 ± 0.1 SEM µg g−1, respectively. A mean Aryl Isoprenoid Ratio of 0.75 (SD = 0.17) is accompanied by Pr/Ph of ∼1.2. These features strongly support persistent PZE conditions at the level expected for an OAE. Trace metal contents of the asphaltites, including low selenium and high vanadium concentrations, also support anoxic conditions. Rhenium-osmium (Re-Os) analyses constrain the age of asphaltite generation to 103 ± 22 Ma, with a relatively low initial 187Os/188Os ratio of 0.44 ± 0.18. Integrating local geologic knowledge with organic and inorganic geochemistry and Re-Os isotopic results, we identify a Cretaceous unit associated with OAE1a (∼125 Ma) as the most likely source of the asphaltites. Alternative scenarios involving source rocks deposited during OAE1b (∼112 Ma) are possible, but require rapid burial of organic-rich sediments to reach required maturation levels in a shorter time

Geodesic distance for right invariant Sobolev metrics of fractional order on the diffeomorphism group

We study Sobolev-type metrics of fractional order $s\geq0$ on the group \Diff_c(M) of compactly supported diffeomorphisms of a manifold $M$. We show that for the important special case $M=S^1$ the geodesic distance on \Diff_c(S^1) vanishes if and only if $s\leq\frac12$. For other manifolds we obtain a partial characterization: the geodesic distance on \Diff_c(M) vanishes for $M=\R\times N, s<\frac12$ and for $M=S^1\times N, s\leq\frac12$, with $N$ being a compact Riemannian manifold. On the other hand the geodesic distance on \Diff_c(M) is positive for $\dim(M)=1, s>\frac12$ and $\dim(M)\geq2, s\geq1$. For $M=\R^n$ we discuss the geodesic equations for these metrics. For $n=1$ we obtain some well known PDEs of hydrodynamics: Burgers' equation for $s=0$, the modified Constantin-Lax-Majda equation for $s=\frac 12$ and the Camassa-Holm equation for $s=1$.Comment: 16 pages. Final versio

The Beale-Kato-Majda criterion to the 3D Magneto-hydrodynamics equations

We study the blow-up criterion of smooth solutions to the 3D MHD equations. By means of the Littlewood-Paley decomposition, we prove a Beale-Kato-Majda type blow-up criterion of smooth solutions via the vorticity of velocity only, i. e. \sup_{j\in\Z}\int_0^T\|\Delta_j(\na\times u)\|_\infty dt, where $\Delta_j$ is a frequency localization on $|\xi|\approx 2^j$.Comment: 12page

Spatial variation in avian bill size is associated with humidity in summer among Australian passerines

Background: Climate imposes multiple selection pressures on animal morphology. Allen&rsquo;s Rule proposes thatgeographic variation in the appendage size of endotherms, relative to body size, is linked to climatic variation,thereby facilitating heat exchange and body temperature regulation. Thus relatively larger appendages tend to befound in animals in warmer climates. Despite growing understanding of the role of the avian bill as an organ forheat exchange, few studies have tested the ecological significance of bill size for heat dissipation across speciesand environmental gradients. Amongst those that have, most have focused on the relationship with ambienttemperature, but there is growing evidence that humidity also has a strong influence on heat dissipation. Inparticular, increasing humidity reduces the potential for evaporative cooling, favouring radiative and convectiveheat loss via the bill, and hence potentially favouring larger bills in humid environments. Here, we usedphylogenetically-controlled analyses of the bill morphology of 36 species of Australian passerines to explore therelationship between bill size and multiple aspects of climate.Results: Humidity during the hot summer months (December-February) was positively associated with relative billsurface area across species. There was no overall association between bill size and summer temperatures per se, butthe association with humidity was mediated by temperature, with a significant interaction indicating strongerassociations with humidity at cooler summer temperatures. This is consistent with the idea that larger bills maybecome disadvantageous in humid conditions as ambient temperature approaches body temperature. Relative billsize was similar among closely related species, with phylogeny explaining 63.3% of the variance, and there wassignificant variation among species in their response to humidity. However, the relationship between relative billsize and humidity was not associated with phylogeny.Conclusions: Our results are consistent with the idea that body temperature regulation underlies continent-widepatterns of bill size variation in a broad range of Australian passerines, and suggests that Allen&rsquo;s Rule may apply tohumidity gradients as well as temperature gradients. They add to growing evidence that a narrow focus ontemperature alone in studies of responses to climate change may limit our understanding of species&rsquo; sensitivities toclimatic variation, and of their capacity to adapt

A dimensionally continued Poisson summation formula

We generalize the standard Poisson summation formula for lattices so that it operates on the level of theta series, allowing us to introduce noninteger dimension parameters (using the dimensionally continued Fourier transform). When combined with one of the proofs of the Jacobi imaginary transformation of theta functions that does not use the Poisson summation formula, our proof of this generalized Poisson summation formula also provides a new proof of the standard Poisson summation formula for dimensions greater than 2 (with appropriate hypotheses on the function being summed). In general, our methods work to establish the (Voronoi) summation formulae associated with functions satisfying (modular) transformations of the Jacobi imaginary type by means of a density argument (as opposed to the usual Mellin transform approach). In particular, we construct a family of generalized theta series from Jacobi theta functions from which these summation formulae can be obtained. This family contains several families of modular forms, but is significantly more general than any of them. Our result also relaxes several of the hypotheses in the standard statements of these summation formulae. The density result we prove for Gaussians in the Schwartz space may be of independent interest.Comment: 12 pages, version accepted by JFAA, with various additions and improvement