pinecone/core-2020-05-10-deduplication huggingface dataset:
A numerical strategy to discretize and solve the Poisson equation on dynamically adapted multiresolution grids for time-dependent streamer discharge simulations

International audienceWe develop a numerical strategy to solve multi-dimensional Poisson equations on dynamically adapted grids for evolutionary problems disclosing propagating fronts. The method is an extension of the multiresolution finite volume scheme used to solve hyperbolic and parabolic time-dependent PDEs. Such an approach guarantees a numerical solution of the Poisson equation within a user-defined accuracy tolerance. Most adaptive meshing approaches in the literature solve elliptic PDEs level-wise and hence at uniform resolution throughout the set of adapted grids. Here we introduce a numerical procedure to represent the elliptic operators on the adapted grid, strongly coupling inter grid relations that guarantee the conservation and accuracy properties of multiresolution finite volume schemes. The discrete Poisson equation is solved at once over the entire computational domain as a completely separate process. The accuracy and numerical performance of the method is assessed in the context of streamer discharge simulations
Free energy molecular dynamics simulations of pulsed-laser-irradiated SiO2: Si–Si bond formation in a matrix of SiO2

Recent experiments have shown that pure Si structures in a matrix of SiO2 can be formed by electron excitation techniques, with appealing applications in nanotechnology. Our ab initio simulations provide an insight into the underlying mechanism, showing that electron excitations weaken Si–O bonds in SiO2, dislodge O atoms and allow Si dangling bonds to reconstruct in stable Si–Si structures below the melting temperature. Differences in diffusivity of O (fast) and Si (slow) are shown to play a decisive role in the process
Effects of Nano/Microstructures on Performance of Si-based Microfuel Cells

We investigated the effects of the contact surface structure of porous Si-based membrane electrode assemblies (MEAs) on the performance of microfuel cells, because the contact area of the triple-phase boundary among the MEA components plays an important role in the performance of polymer electrolyte fuel cells (PEFCs). An n-type silicon substrate was first wet-etched with KOH and subsequently anodically etched to fabricate a porous Si substrate. The cross section of the mechanically polished Si wafer showed pores with high aspect ratios. Electrolyte solutions were filled into the pores to prepare a porous Si membrane (PSM), and the MEA was fabricated by hot-pressing the PSM between two conventional catalyst-coated carbon-paper electrodes. The porous Si-based MEA worked well and showed a power density higher than that of the Nafion®-212-based membrane. Further, we examined the effects of the nano/microstructures at the triple-phase boundary and found that the more densely arranged nano/microstructures reduced the magnitudes of the activation overvoltage and ohmic overvoltage, thereby improving the cell performance
Examining the Joint Effects of Strategic Priorities, Use of Management Control Systems, and Personal Background on Hospital Performance

This study aims to respond to recent calls for a better understanding of the factors that support the effectiveness of formal control practices in hospitals. Based on survey data from 117 top-level managers in Belgian hospitals, the study investigates the performance effects of the alignment between the use of performance measurement systems (PMS), strategic priorities, and the particular role top-level managers’ personal background plays in this context. The quantitative results suggest that it is the top-level managers’ personal background that brings to life the benefits of the alignment between the use of PMS and strategic priorities in hospitals. Specifically, this paper shows that when the emphasis on partnership or governance strategic priority is high, the effect of the interactive use of PMS on hospital performance is more positive for top-level managers with a clinical background than for those with an administrative background. This study offers value for practitioners in that it supports the argument that hospitals can benefit from involving physicians in the top-level management team
A common variant at the 14q32 endometrial cancer risk locus activates AKT1 through YY1 binding

A recent meta-analysis of multiple genome-wide association and follow-up endometrial cancer case-control datasets identified a novel genetic risk locus for this disease at chromosome 14q32.33. To prioritize the functional SNP(s) and target gene(s) at this locus, we employed an in silico fine-mapping approach using genotyped and imputed SNP data for 6,608 endometrial cancer cases and 37,925 controls of European ancestry. Association and functional analyses provide evidence that the best candidate causal SNP is rs2494737. Multiple experimental analyses show that SNP rs2494737 maps to a silencer element located within AKT1, a member of the PI3K/AKT/MTOR intracellular signaling pathway activated in endometrial tumors. The rs2494737 risk A allele creates a YY1 transcription factor-binding site and abrogates the silencer activity in luciferase assays, an effect mimicked by transfection of YY1 siRNA. Our findings suggest YY1 is a positive regulator of AKT1, mediating the stimulatory effects of rs2494737 increasing endometrial cancer risk. Identification of an endometrial cancer risk allele within a member of the PI3K/AKT signaling pathway, more commonly activated in tumors by somatic alterations, raises the possibility that well tolerated inhibitors targeting this pathway could be candidates for evaluation as chemopreventive agents in individuals at high risk of developing endometrial cancer
Relationship of Structural to Functional Impairment during Alveolar-Capillary Membrane Development

Bronchopulmonary dysplasia is a chronic lung disease of extreme preterm infants and results in impaired gas exchange. Although bronchopulmonary dysplasia is characterized histologically by alveolar-capillary simplification in animal models, it is clinically defined by impaired gas diffusion. With the use of a developmentally relevant model, we correlated alveolar-capillary structural simplification with reduced functional gas exchange as measured by the diffusing factor for carbon monoxide (DFCO). Neonatal mouse pups were exposed to >90% hyperoxia or room air during postnatal days 0 to 7, and then all pups were returned to room air from days 7 to 56. At day 56, DFCO was measured as the ratio of carbon monoxide uptake to neon dilution, and lungs were fixed for histologic assessment of alveolar-capillary development. Neonatal hyperoxia exposure inhibited alveolar-capillary septal development as evidenced by significantly increased mean linear intercept, increased airspace-to-septal ratio, decreased nodal density, and decreased pulmonary microvasculature. Importantly, alveolar-capillary structural deficits in hyperoxia-exposed pups were accompanied by a significant 28% decrease in DFCO (0.555 versus 0.400; P < 0.0001). In addition, DFCO was highly and significantly correlated with structural measures of reduced alveolar-capillary growth. Simplification of alveolar-capillary structure is highly correlated with impaired gas exchange function. Current mechanistic and therapeutic animal models of inhibited alveolar development may benefit from application of DFCO as an alternative physiologic indicator of alveolar-capillary development
Rights to the forest, REDD+ and elections: Mining in Guyana

This paper examines the impact of electoral cycles and the introduction of Reducing Emissions from Deforestation and Degradation (REDD+) policy upon the holding of small-scale mining property rights in Guyana. Mining is both the major cause of deforestation and the main economic activity in the country. A simple model of the incentives to hold mining property rights is developed and tested using a unique data-set of small-scale mining property rights data. Econometric techniques are used to test the findings of the model, concluding that the number of mining rights issued fall after election years, with the number rescinded rising. The introduction of REDD+ in Guyana also seems to have increased the number of mining claims being relinquished, and reduce the number being issued. The findings highlight the importance of political economy events in the evolution of small-scale mining activity, and show some evidence that the introduction of a REDD+ framework in Guyana has impacted the main driver of deforestation, despite the absence of specific policy targeting the sector
The innovation debt penalty: Cost of debt, loan default, and the effects of a public loan guarantee on high-tech firms

High-technology firms per se are perceived to be more risky than other, more conventional, firms. It follows that financial institutions will take this into account when designing loan contracts, and that this will manifest itself in more costly debt. In this paper we empirically test whether the provision of a government loan guarantee fundamentally changes the way lenders price debt to high-tech firms. Further, we also examine whether there are differential loan price effects of a public guarantee depending on the nature of the firms themselves and the nature of the economic and innovation environment that surrounds them. Using a large UK dataset of 29,266 guarantee backed loans we find that there is a high-tech risk premium which is justified by higher default, but, in general, that this premium is altered significantly when a public guarantee is provided for all firms. Further, all these loan price effects differ on precise spatial economic and innovation attributes
DIII Topological Superconductivity with Emergent Time-Reversal Symmetry

We find a new class of topological superconductors which possess an emergent
time-reversal symmetry that is present only after projecting to an effective
low-dimensional model. We show that a topological phase in symmetry class DIII
can be realized in a noninteracting system coupled to an $s$-wave
superconductor only if the physical time-reversal symmetry of the system is
broken, and we provide three general criteria that must be satisfied in order
to have such a phase. We also provide an explicit model which realizes the
class DIII topological superconductor in 1D. We show that, just as in
time-reversal invariant topological superconductors, the topological phase is
characterized by a Kramers pair of Majorana fermions that are protected by the
emergent time-reversal symmetry
Cysteinyl-tRNA synthetase governs cysteine polysulfidation and mitochondrial bioenergetics

Cysteine hydropersulfide (CysSSH) occurs in abundant quantities in various organisms, yet little is known about its biosynthesis and physiological functions. Extensive persulfide formation is apparent in cysteine-containing proteins in Escherichia coli and mammalian cells and is believed to result from post-translational processes involving hydrogen sulfide-related chemistry. Here we demonstrate effective CysSSH synthesis from the substrate l-cysteine, a reaction catalyzed by prokaryotic and mammalian cysteinyl-tRNA synthetases (CARSs). Targeted disruption of the genes encoding mitochondrial CARSs in mice and human cells shows that CARSs have a crucial role in endogenous CysSSH production and suggests that these enzymes serve as the principal cysteine persulfide synthases in vivo. CARSs also catalyze co-translational cysteine polysulfidation and are involved in the regulation of mitochondrial biogenesis and bioenergetics. Investigating CARS-dependent persulfide production may thus clarify aberrant redox signaling in physiological and pathophysiological conditions, and suggest therapeutic targets based on oxidative stress and mitochondrial dysfunction
Diffusion at the liquid-vapor interface

Recently, the intrinsic sampling method has been developed in order to obtain, from molecular\ud
simulations, the intrinsic structure of the liquid-vapor interface that is presupposed in the classical\ud
capillary wave theory. Our purpose here is to study dynamical processes at the liquid-vapor\ud
interface, since this method allows tracking down and analyzing the movement of surface\ud
molecules, thus providing, with great accuracy, dynamical information on molecules that are “at”\ud
the interface. We present results for the coefficients for diffusion parallel and perpendicular to the\ud
liquid-vapor interface of the Lennard-Jones fluid, as well as other time and length parameters that\ud
characterize the diffusion process in this system. We also obtain statistics of permanence and\ud
residence time. The generality of our results is tested by varying the system size and the\ud
temperature; for the latter case, an existing model for alkali metals is also considered. Our main\ud
conclusion is that, even if diffusion coefficients can still be computed, the turnover processes, by\ud
which molecules enter and leave the intrinsic surface, are as important as diffusion. For example, the\ud
typical time required for a molecule to traverse a molecular diameter is very similar to its residence\ud
time at the surface
Measurement of branching fractions and spectral functions in $\tau$ decays

Full LEP-I data collected by the ALEPH detector during 1991-1995 running are analyzed in order to measure the $\tau$ decay branching fractions and the hadronic spectral functions. The analysis follows the global method used in the published study based on 1991-1993 data, with several improvements, especially concerning the treatment of photons and $\pi^0$'s. Extensive systematic studies are performed, in order to match the large statistics of the data sample corresponding to 327148 measured and identified $\tau$ decays. Preliminary values for the branching fractions are obtained for the 2 leptonic channels and 11 hadronic channels defined by their respective numbers of charged particles and $\pi^0$'s. Using previously published ALEPH results on final states with charged and neutral kaons, corrections are applied so that branching ratios for exclusive final states without kaons are derived. Some physics implications of the results are given, in particular concerning universality in the leptonic charged weak current, isospin invariance in $a_1$ decays, and the separation of vector and axial-vector components of the total hadronic rate. Spectral functions are obtained for the main exclusive channels and the total inclusive rate, with separation of the vector and axial-vector states
Defects and moisture problems in buildings from historical city centres : a case study in Portugal

Conservation of ancient buildings is a major issue for modern societies, both from economical and cultural viewpoints. Information about the ancient built heritage is vital to plan adequate remedial measures. Using a historic centre in Portugal as a case study, this paper presents an extensive survey of building typology and materials, damage in the building envelope, indoor survey of damage, and measurements in indoor air temperature and relative humidity. Water-related problems can be confirmed as the single most important defect, which are combined with inadequate sun exposure, ventilation and heating, and excessive moisture indoor production. Extremely low temperatures, high humidity and presence of mould therefore compromise the indoor quality of life of the inhabitants, being urgent repair needed at many levels
Hybrid Control to Improve Transient Response of Integral Action in Dynamic Positioning of Marine Vessels

A hybrid control approach for integral action in the PID control law for dynamically
positioned marine vessels is considered. The proposed method is essentially a resetting of the
integration gain when the control performance deteriorates. The method allows for a 
exible
tuning, and could be useful when there are long periods of normal operating conditions, but
abnormal events may occur. In that case the hybrid controller will have a low tuning in the
normal regime and switch to a more aggressive tuning in the abnormal regime. Stability of the
hybrid system is investigated, and a simulation case is performed.(c) 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved. This is the author' accepted and refereed manuscript to the article. Locked until 2017-01-01
Short-term load forecast using trend information and process reconstruction

The algorithms for short-term load forecast (STLF), especially within the next-hour horizon, belong to a group of methodologies that aim to render more effective the actions of planning, operating and controlling electric energy systems (EES). In the context of the progressive liberalization of the electricity sector, unbundling of the previous monopolistic structure emphasizes the need for load forecast, particularly at the network level. Methodologies such as artificial neural networks (ANN) have been widely used in next-hour load forecast. Designing an ANN requires the proper choice of input variables, avoiding overfitting and an unnecessarily complex input vector (IV). This may be achieved by trying to reduce the arbitrariness in the choice of endogenous variables. At a first stage, we have applied the mathematical techniques of process-reconstruction to the underlying stochastic process, using coding and block entropies to characterize the measure and memory range. At a second stage, the concept of consumption trend in homologous days of previous weeks has been used. The possibility to include weather-related variables in the IV has also been analysed, the option finally being to establish a model of the non-weather sensitive type. The paper uses a real-life case study. Copyright © 2006 John Wiley & Sons, Ltd.http://dx.doi.org/10.1002/er.118
Incompressibility Estimates for the Laughlin Phase

This paper has its motivation in the study of the Fractional Quantum Hall
Effect. We consider 2D quantum particles submitted to a strong perpendicular
magnetic field, reducing admissible wave functions to those of the Lowest
Landau Level. When repulsive interactions are strong enough in this model,
highly correlated states emerge, built on Laughlin's famous wave function. We
investigate a model for the response of such strongly correlated ground states
to variations of an external potential. This leads to a family of variational
problems of a new type. Our main results are rigorous energy estimates
demonstrating a strong rigidity of the response of strongly correlated states
to the external potential. In particular we obtain estimates indicating that
there is a universal bound on the maximum local density of these states in the
limit of large particle number. We refer to these as incompressibility
estimates
Phase-resolved energy spectra of the Crab Pulsar in the range of 50-400
  GeV measured with the MAGIC Telescopes

We use 73 h of stereoscopic data taken with the MAGIC telescopes to
investigate the very high-energy (VHE) gamma-ray emission of the Crab pulsar.
Our data show a highly significant pulsed signal in the energy range from 50 to
400 GeV in both the main pulse (P1) and the interpulse (P2) phase regions. We
provide the widest spectra to date of the VHE components of both peaks, and
these spectra extend to the energy range of satellite-borne observatories. The
good resolution and background rejection of the stereoscopic MAGIC system
allows us to cross-check the correctness of each spectral point of the pulsar
by comparison with the corresponding (strong and well-known) Crab nebula flux.
The spectra of both P1 and P2 are compatible with power laws with photon
indices of 4.0 \pm 0.8 (P1) and 3.42 \pm 0.26 (P2), respectively, and the ratio
P1/P2 between the photon counts of the two pulses is 0.54 \pm 0.12. The VHE
emission can be understood as an additional component produced by the inverse
Compton scattering of secondary and tertiary e\pm pairs on IR-UV photons
Large-scale association analysis identifies new risk loci for coronary artery disease.

Coronary artery disease (CAD) is the commonest cause of death. Here, we report an association analysis in 63,746 CAD cases and 130,681 controls identifying 15 loci reaching genome-wide significance, taking the number of susceptibility loci for CAD to 46, and a further 104 independent variants (r(2) < 0.2) strongly associated with CAD at a 5% false discovery rate (FDR). Together, these variants explain approximately 10.6% of CAD heritability. Of the 46 genome-wide significant lead SNPs, 12 show a significant association with a lipid trait, and 5 show a significant association with blood pressure, but none is significantly associated with diabetes. Network analysis with 233 candidate genes (loci at 10% FDR) generated 5 interaction networks comprising 85% of these putative genes involved in CAD. The four most significant pathways mapping to these networks are linked to lipid metabolism and inflammation, underscoring the causal role of these activities in the genetic etiology of CAD. Our study provides insights into the genetic basis of CAD and identifies key biological pathways
New perspectives on rare connective tissue calcifying diseases

Connective tissue calcifying diseases (CTCs) are characterized by abnormal calcium deposition in connective tissues. CTCs are caused by multiple factors including chronic diseases (Type II diabetes mellitus, chronic kidney disease), the use of pharmaceuticals (e.g. warfarin, glucocorticoids) and inherited rare genetic diseases such as pseudoxanthoma elasticum (PXE), generalized arterial calcification in infancy (GACI) and Keutel syndrome (KTLS). This review explores  our current knowledge of these rare inherited CTCs, and highlights the most promising avenues for pharmaceutical intervention. Advancing our understanding of rare inherited forms of CTC is not only essential for the development of therapeutic strategies for patients suffering from these diseases, but also fundamental to delineating the mechanisms underpinning acquired chronic forms of  CTC