Seizure clusters in drug-resistant focal epilepsy.

We investigated clinical factors associated with seizure clustering in patients with drug-resistant focal epilepsy and any association between seizure clustering and outcome after surgery. We performed a retrospective study including patients with a diagnosis of drug-resistant focal epilepsy who underwent epilepsy surgery. Patients were prospectively registered in a database from 1986 until 2015. Seizure cluster was defined as two or more seizures occurring within 2 days. Potential risk factors for seizure clustering were assessed. To investigate any potential association between seizure clusters and seizure outcome after surgery, time to event analysis was used to produce a Kaplan-Meier estimate of seizure recurrence. We studied 764 patients. Seizure clusters were reported in 23.6% of patients with temporal lobe epilepsy (TLE) and 16.9% of extratemporal patients (p = 0.2). We could not identify any significant clinical factors associated with seizure clustering. Among patients with TLE, those who had history of seizure clusters fared better after surgery (p \u3c 0.01). We found that seizure clusters relate to prognosis after temporal lobe surgery in drug-resistant TLE. These data may provide added value for surgical prognostication when combined with other data types. A better understanding of the neurobiology underlying seizure clusters is needed

Fast and accurate con-eigenvalue algorithm for optimal rational approximations

The need to compute small con-eigenvalues and the associated con-eigenvectors of positive-definite Cauchy matrices naturally arises when constructing rational approximations with a (near) optimally small $L^{\infty}$ error. Specifically, given a rational function with $n$ poles in the unit disk, a rational approximation with $m\ll n$ poles in the unit disk may be obtained from the $m$th con-eigenvector of an $n\times n$ Cauchy matrix, where the associated con-eigenvalue $\lambda_{m}>0$ gives the approximation error in the $L^{\infty}$ norm. Unfortunately, standard algorithms do not accurately compute small con-eigenvalues (and the associated con-eigenvectors) and, in particular, yield few or no correct digits for con-eigenvalues smaller than the machine roundoff. We develop a fast and accurate algorithm for computing con-eigenvalues and con-eigenvectors of positive-definite Cauchy matrices, yielding even the tiniest con-eigenvalues with high relative accuracy. The algorithm computes the $m$th con-eigenvalue in $\mathcal{O}(m^{2}n)$ operations and, since the con-eigenvalues of positive-definite Cauchy matrices decay exponentially fast, we obtain (near) optimal rational approximations in $\mathcal{O}(n(\log\delta^{-1})^{2})$ operations, where $\delta$ is the approximation error in the $L^{\infty}$ norm. We derive error bounds demonstrating high relative accuracy of the computed con-eigenvalues and the high accuracy of the unit con-eigenvectors. We also provide examples of using the algorithm to compute (near) optimal rational approximations of functions with singularities and sharp transitions, where approximation errors close to machine precision are obtained. Finally, we present numerical tests on random (complex-valued) Cauchy matrices to show that the algorithm computes all the con-eigenvalues and con-eigenvectors with nearly full precision

A new role for exhaled nitric oxide as a functional marker of peripheral airway caliber changes: a theoretical study

Though considered as an inflammation marker, exhaled nitric oxide (FENO) was shown to be sensitive to airway caliber changes to such an extent that it might be considered as a marker of them. It is thus important to understand how these changes and their localization mechanically affect the total NO flux penetrating the airway lumen (JawNO), hence FENO, independently from any inflammatory status change. A new model was used which simulates NO production, consumption and diffusion inside the airway epithelium wall, then, NO excretion through the epithelial wall into the airway lumen and, finally, its axial transport by diffusion and convection in the airway lumen. This model may also consider the presence of a mucus layer coating the epithelial wall. Simulations were performed that showed the great sensitivity of JawNO to peripheral airways caliber changes. Moreover, FENO showed distinct behaviors depending on the location of the caliber change. Considering a bronchodilation, absence of FENO change was associated with dilation of central airways, FENO increase with dilation up to pre-acinar small airways, and FENO decrease with intra-acinar dilation due to amplification of the back-diffusion flux. The presence of a mucus layer was also shown to play a significant role in FENO changes. Altogether, the present work provides theoretical evidences that specific FENO changes in acute situations are linked to specifically located airway caliber changes in the lung periphery. This opens the way for a new role for FENO as a functional marker of peripheral airway caliber change

Prandtl-Meyer flow tables for parahydrogen at total temperatures from 30K to 290K and for nitrogen at total temperatures from 100K to 300K at total pressures from 1 ATM to 10 ATM

The dependency of Mach number on the Prandtl-Meyer function was numerically determined by iterating the Prandtl-Meyer function and applying the Muller method to converge on the Mach number for flows in cryogenic parahydrogen and nitrogen at various total pressures and total temperatures. The results are compared with the ideal diatomic gas values and are presented in tabular form

Tables of isentropic expansions of parahydrogen and related transport properties for total temperatures from 25 K to 300 K and for total pressures from 1 ATM to 10 ATM

The isentropic expansions of parahydrogen at various total pressures and total temperatures were numerically determined by iterating Mach number and by using a modified interval halving method. The calculated isentropic values and related properties are presented in tabulated form

A new multigroup method for cross-sections that vary rapidly in energy

We present a numerical method for solving the time-independent thermal radiative transfer (TRT) equation or the neutron transport (NT) equation when the opacity or cross-section varies rapidly in energy (frequency). The approach is based on a rigorous homogenization of the TRT/NT equation in the energy (frequency) variable. Discretization of the homogenized TRT/NT equation results in a multigroup-type system, and can therefore be solved by standard methods. We demonstrate the accuracy and efficiency of the approach on three model problems. First we consider the Elsasser band model with constant temperature and a small line spacing. Second, we consider a neutron transport application for fast neutrons incident on iron, where the characteristic resonance spacing necessitates about 16,000 energy discretization parameters if Planck-weighted cross sections are used. Third, we consider an atmospheric TRT problem with an opacity corresponding to water vapor. For all three problems, we demonstrate that we can achieve between 0.1 and 1 percent relative error in the solution, and with several orders of magnitude fewer parameters than a standard multigroup formulation with a comparable accuracy

The protective scale of the Armidilo‐S:the importance of forensic and clinical outcomes

Background: The Armidilo has two scales—the risk scale and the protective scale. Research has been confined to the risk scale which appears to predict future incidents with medium to large effect sizes. There have been no publications on the use of the protective scale.Methods: The Armidilo was completed on four individuals with IDD who were either moving on from their placement or whose placement was in jeopardy because of new information or altered policies in the organization. The Armidilo was completed in the usual fashion.Results: Risk and protective results show that for each individual, recommendations could be made that ensured the best outcome. For two participants, restrictive placements were avoided because of the data on protective factors.Conclusions: The protective scale can be a powerful support for the clinician's case in offenders with IDD. The protective scale should be completed routinely for clinical evaluation

A Decentralized Parallelization-in-Time Approach with Parareal

With steadily increasing parallelism for high-performance architectures, simulations requiring a good strong scalability are prone to be limited in scalability with standard spatial-decomposition strategies at a certain amount of parallel processors. This can be a show-stopper if the simulation results have to be computed with wallclock time restrictions (e.g.\,for weather forecasts) or as fast as possible (e.g. for urgent computing). Here, the time-dimension is the only one left for parallelization and we focus on Parareal as one particular parallelization-in-time method. We discuss a software approach for making Parareal parallelization transparent for application developers, hence allowing fast prototyping for Parareal. Further, we introduce a decentralized Parareal which results in autonomous simulation instances which only require communicating with the previous and next simulation instances, hence with strong locality for communication. This concept is evaluated by a prototypical solver for the rotational shallow-water equations which we use as a representative black-box solver

Absorption of spherical bubbles in a square microchannel

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Microfluidics is a fast growing field in which the manipulation of bubbles in liquid phase is of utmost importance. In this paper, the absorption of spherical bubbles in a square microchannel is investigated for a bubbly flow. Numerical simulations of the gas-liquid two-phase flow and the mass transfer around spherical bubbles in a square microchannel are carried out. Correlations are established for the bubble velocity and the mass transfer rate. A model for the dissolution of spherical bubbles along a square microchannel is proposed in the case of the bubbly flow regime and validated using existing experimental data. This model can be used, for instance, for designing microabsorbers for lab-on-a-chip applications