pinecone/core-2020-05-10-deduplication huggingface dataset:
Evaluating multicenter DTI data in Huntington's disease on site specific effects: An ex post facto approach

AbstractPurposeAssessment of the feasibility to average diffusion tensor imaging (DTI) metrics of MRI data acquired in the course of a multicenter study.Materials and methodsSixty-one early stage Huntington's disease patients and forty healthy controls were studied using four different MR scanners at four European sites with acquisition protocols as close as possible to a given standard protocol. The potential and feasibility of averaging data acquired at different sites was evaluated quantitatively by region-of-interest (ROI) based statistical comparisons of coefficients of variation (CV) across centers, as well as by testing for significant group-by-center differences on averaged fractional anisotropy (FA) values between patients and controls. In addition, a whole-brain based statistical between-group comparison was performed using FA maps.ResultsThe ex post facto statistical evaluation of CV and FA-values in a priori defined ROIs showed no differences between sites above chance indicating that data were not systematically biased by center specific factors.ConclusionAveraging FA-maps from DTI data acquired at different study sites and different MR scanner types does not appear to be systematically biased. A suitable recipe for testing on the possibility to pool multicenter DTI data is provided to permit averaging of DTI-derived metrics to differentiate patients from healthy controls at a larger scale
Hypervulnerability to Sound Exposure through Impaired Adaptive Proliferation of Peroxisomes

SummaryA deficiency in pejvakin, a protein of unknown function, causes a strikingly heterogeneous form of human deafness. Pejvakin-deficient (Pjvk−/−) mice also exhibit variable auditory phenotypes. Correlation between their hearing thresholds and the number of pups per cage suggest a possible harmful effect of pup vocalizations. Direct sound or electrical stimulation show that the cochlear sensory hair cells and auditory pathway neurons of Pjvk−/− mice and patients are exceptionally vulnerable to sound. Subcellular analysis revealed that pejvakin is associated with peroxisomes and required for their oxidative-stress-induced proliferation. Pjvk−/− cochleas display features of marked oxidative stress and impaired antioxidant defenses, and peroxisomes in Pjvk−/− hair cells show structural abnormalities after the onset of hearing. Noise exposure rapidly upregulates Pjvk cochlear transcription in wild-type mice and triggers peroxisome proliferation in hair cells and primary auditory neurons. Our results reveal that the antioxidant activity of peroxisomes protects the auditory system against noise-induced damage
Massive charged scalar field in a Reissner–Nordstrom black hole background: quasinormal ringing

AbstractWe compute characteristic (quasinormal) frequencies corresponding to decay of a massive charged scalar field in a Reissner–Nordstrom black hole background. It proves that, contrary to the behavior at very late times, at the stage of quasinormal ringing the neutral perturbations will damp slower than the charged ones. In the limit of the extremal black hole the damping rate of charged and neutral perturbations coincides. Possible connection of this with the critical collapse in a massive scalar electrodynamics is discussed
Pattern Formation of an Epithelial Tubule by Mechanical Instability during Epididymal Development

SummaryA single epithelial tubule undergoes morphogenesis to form a functional shape during the development of internal organs; however, the mechanical processes that are directed by the molecular signals regulating tubular morphogenesis are poorly understood. Here, axial tubular buckling triggered by cell proliferation is shown to drive the morphogenesis of murine epididymal tubules through mechanical interactions between the developing epithelial tubule and its surrounding tissues. Through immunofluorescence labeling and mathematical modeling, epididymal tubule shape formation is found to depend on two factors: cell proliferation area in the tubule and mechanical resistance from the tissues surrounding the tubule. Moreover, experimental perturbations of these two factors alter the shape of the epididymal tubule as predicted by the mathematical model, suggesting that the shape of the epididymal tubule spontaneously emerges through mechanical coupling between developing tissues instead of by growing according to a predetermined fate
Correlations between jets and charged particles in PbPb and pp collisions at √sNN = 2.76  TeV

The quark-gluon plasma is studied via medium-induced changes to correlations between jets and charged particles in PbPb collisions compared to pp reference data. This analysis uses data sets from PbPb and pp collisions with integrated luminosities of 166 μb[superscript −1] and 5.3 pb[subscript −1], respectively, collected at  √s[subscript NN] = 2.76  TeV. The angular distributions of charged particles are studied as a function of relative pseudorapidity (Δη) and relative azimuthal angle (Δϕ) with respect to reconstructed jet directions. Charged particles are correlated with all jets with transverse momentum (pT) above 120 GeV, and with the leading and subleading jets (the highest and second-highest in pT, respectively) in a selection of back-to-back dijet events. Modifications in PbPb data relative to pp reference data are characterized as a function of PbPb collision centrality and charged particle pT. A centrality-dependent excess of low-pT particles is present for all jets studied, and is most pronounced in the most central events. This excess of low-pT particles follows a Gaussian-like distribution around the jet axis, and extends to large relative angles of Δη ≈ 1 and Δϕ ≈ 1.United States. Dept. of EnergyNational Science Foundation (U.S.
Angular analysis of the decay B0→K*0μ+μ- from pp collisions at s=8 TeV

The angular distributions and the differential branching fraction of the decay B0→K*(892)0μ+μ- are studied using data corresponding to an integrated luminosity of 20.5 fb-1 collected with the CMS detector at the LHC in pp collisions at s=8 TeV. From 1430 signal decays, the forward-backward asymmetry of the muons, the K*(892)0 longitudinal polarization fraction, and the differential branching fraction are determined as a function of the dimuon invariant mass squared. The measurements are among the most precise to date and are in good agreement with standard model predictions. © 2015 CERN for the benefit of the CMS Collaboration.The Scientific and Technical Research Council of Turkey, and Turkish Atomic Energy Authorit
Learning quadratic receptive fields from neural responses to natural
  stimuli

Models of neural responses to stimuli with complex spatiotemporal correlation
structure often assume that neurons are only selective for a small number of
linear projections of a potentially high-dimensional input. Here we explore
recent modeling approaches where the neural response depends on the quadratic
form of the input rather than on its linear projection, that is, the neuron is
sensitive to the local covariance structure of the signal preceding the spike.
To infer this quadratic dependence in the presence of arbitrary (e.g.
naturalistic) stimulus distribution, we review several inference methods,
focussing in particular on two information-theory-based approaches
(maximization of stimulus energy or of noise entropy) and a likelihood-based
approach (Bayesian spike-triggered covariance, extensions of generalized linear
models). We analyze the formal connection between the likelihood-based and
information-based approaches to show how they lead to consistent inference. We
demonstrate the practical feasibility of these procedures by using model
neurons responding to a flickering variance stimulus.Comment: Review, 17 page
Globally and locally attractive solutions for quasi-periodic ally forced systems

We consider a class of differential equations, x¨ + γ x˙ + g(x) = f (ωt), with ω ∈ Rd , describing onedimensional\ud
dissipative systems subject to a periodic or quasi-periodic (Diophantine) forcing. We study\ud
existence and properties of trajectories with the same quasi-periodicity as the forcing. For g(x) = x2p+1,\ud
p ∈ N, we show that, when the dissipation coefficient is large enough, there is only one such trajectory\ud
and that it describes a global attractor. In the case of more general nonlinearities, including g(x) = x2\ud
(describing the varactor equation), we find that there is at least one trajectory which describes a local\ud
attractor
Asset–liability modelling and pension schemes: the application of robust optimization to USS

This paper uses a novel numerical optimization technique – robust optimization – that is well suited to solving the asset–liability management (ALM) problem for pension schemes. It requires the estimation of fewer stochastic parameters, reduces estimation risk and adopts a prudent approach to asset allocation. This study is the first to apply it to a real-world pension scheme, and the first ALM model of a pension scheme to maximize the Sharpe ratio. We disaggregate pension liabilities into three components – active members, deferred members and pensioners, and transform the optimal asset allocation into the scheme's projected contribution rate. The robust optimization model is extended to include liabilities and used to derive optimal investment policies for the Universities Superannuation Scheme (USS), benchmarked against the Sharpe and Tint, Bayes–Stein and Black–Litterman models as well as the actual USS investment decisions. Over a 144-month out-of-sample period, robust optimization is superior to the four benchmarks across 20 performance criteria and has a remarkably stable asset allocation – essentially fix-mix. These conclusions are supported by six robustness checks
Nonlinear Pricing with Arbitrage: On the Role of Correlation

In nonlinear pricing environment with correlated types, we characterize optimal selling mechanisms when buyers could form a coalition to coordinate their reports and to arbitrage on the goods. We find that when the types of agents are weakly positively correlated, the
optimal weakly collusion-proof mechanism calls for distortions away from e±ciency obtained
without arbitrage; when the types are weakly negatively correlated, the monopolist can achieve the same profit regardless of whether or not buyers can arbitrage on their goods. Allowing arbitrage within coalitions result in right discontinuity between the correlated and uncorrelated environment, but the left continuity is still available.
The effect of substrate roughness on air entrainment in dip coating

YesDynamic wetting failure was observed in the simple dip coating flow with a series of substrates, which had a rough side and a comparatively smoother side. When we compared the air entrainment speeds on both sides, we found a switch in behaviour at a critical viscosity. At viscosity lower than a critical value, the rough side entrained air at lower speeds than the smooth side. Above the critical viscosity the reverse was observed, the smooth side entraining air at lower speed than the rough side. Only substrates with significant roughness showed this behaviour. Below a critical roughness, the rough side always entrained air at lower speeds than the smooth side. These results have both fundamental and practical merits. They support the hydrodynamic theory of dynamic wetting failure and imply that one can coat viscous fluids at higher speeds than normal by roughening substrates. A mechanism and a model are presented to explain dynamic wetting failure on rough surfaces
Modifiable arousal in ADHD and its etiological association with fluctuating reaction times

BACKGROUND: Cognitive theories of attention-deficit/hyperactivity disorder (ADHD) propose that high within-subject fluctuations of cognitive performance in ADHD, particularly reaction time (RT) variability (RTV), may reflect arousal dysregulation. Yet, direct evidence of arousal dysregulation and how it may account for fluctuating reaction times in ADHD is limited. We used skin conductance (SC) as a measure of peripheral arousal and aimed to investigate its phenotypic and familial association with RTV in a large sample of ADHD and control sibling pairs.\ud
METHODS: 292 adolescents and young adults, consisting of 73 participants with ADHD and their 75 siblings, as well as 72 controls and their 72 siblings, completed the baseline (slow, unrewarded) and fast-incentive conditions of a RT task, whilst SC was simultaneously recorded.\ud
RESULTS: A significant group by condition interaction emerged for SC level (SCL). Participants with ADHD had decreased SCL, compared to controls, in the baseline but not fast-incentive condition. Baseline SCL was negatively associated with RTV and multivariate model fitting demonstrated that the covariance of SCL with RTV, and of SCL with ADHD, was mostly explained by shared familial effects.\ud
CPNCLUSIONS: ADHD is associated with decreased, but modifiable, tonic peripheral arousal. A shared familial etiology underlies the relationship between arousal and RTV, and between arousal and ADHD. Given the malleability of SCL, if our findings are replicated, it warrants further exploration as a potential treatment target for ADHD
QCD corrections to vector boson pair production in gluon fusion including interference effects with off-shell Higgs at the LHC.

We compute next-to-leading order (NLO) QCD corrections to the production of two massive electroweak bosons in gluon fusion. We consider both the prompt production process gg → V V and the production mediated by an exchange of an s-channel Higgs boson, gg → H ∗ → V V . We include final states with both on- and off-shell vector bosons with leptonic decays. The gluonic production of vector bosons is a loop-induced process, including both massless and massive quarks in the loop. For gg → ZZ production, we obtain the NLO QCD corrections to the massive loops through an expansion around the heavy top limit. This approximation is valid below the top production threshold, giving a broad range of invariant masses between the Higgs production and the top production thresholds in which our results are valid. We explore the NLO QCD effects in gg → ZZ focusing, in particular, on the interference between prompt and Higgs-mediated processes. We find that the QCD corrections to the interference are large and similar in size to the corrections to both the signal and the background processes. At the same time, we observe that corrections to the interference change rapidly with the four-lepton invariant mass in the region around the ZZ production threshold. We also study the interference effects in gg → W + W − production where, due to technical limitations, we only consider contributions of massless loops. We find that the QCD corrections to the interference in this case are somewhat larger than those for either the signal or the background
Image quality in CT: From physical measurements to model observers

Evaluation of image quality (IQ) in Computed Tomography (CT) is important to ensure that diagnostic questions are correctly answered, whilst keeping radiation dose to the patient as low as is reasonably possible. The assessment of individual aspects of IQ is already a key component of routine quality control of medical x-ray devices. These values together with standard dose indicators can be used to give rise to 'figures of merit' (FOM) to characterise the dose efficiency of the CT scanners operating in certain modes. The demand for clinically relevant IQ characterisation has naturally increased with the development of CT technology (detectors efficiency, image reconstruction and processing), resulting in the adaptation and evolution of assessment methods. The purpose of this review is to present the spectrum of various methods that have been used to characterise image quality in CT: from objective measurements of physical parameters to clinically task-based approaches (i.e. model observer (MO) approach) including pure human observer approach. When combined together with a dose indicator, a generalised dose efficiency index can be explored in a framework of system and patient dose optimisation. We will focus on the IQ methodologies that are required for dealing with standard reconstruction, but also for iterative reconstruction algorithms. With this concept the previously used FOM will be presented with a proposal to update them in order to make them relevant and up to date with technological progress. The MO that objectively assesses IQ for clinically relevant tasks represents the most promising method in terms of radiologist sensitivity performance and therefore of most relevance in the clinical environment.status: publishe
BPS Skyrmions as neutron stars.

The BPS Skyrme model has been demonstrated already to provide a physically intriguing and quantitatively reliable description of nuclear matter. Indeed, the model has both the symmetries and the energy–momentum tensor of a perfect fluid, and thus represents a field theoretic realization of the “liquid droplet” model of nuclear matter. In addition, the classical soliton solutions together with some obvious corrections (spin–isospin quantization, Coulomb energy, proton–neutron mass difference) provide an accurate modeling of nuclear binding energies for heavier nuclei. These results lead to the rather natural proposal to try to describe also neutron stars by the BPS Skyrme model coupled to gravity. We find that the resulting self-gravitating BPS Skyrmions provide excellent results as well as some new perspectives for the description of bulk properties of neutron stars when the parameter values of the model are extracted from nuclear physics. Specifically, the maximum possible mass of a neutron star before black-hole formation sets in is a few solar masses, the precise value of which depends on the precise values of the model parameters, and the resulting neutron star radius is of the order of 10 km
Effect of mobile telephones on sperm quality: a systematic review and meta-analysis

Mobile phones are owned by most of the adult population worldwide. Radio-frequencyelectromagnetic radiation (RF-EMR) from these devices could potentially affect sperm development and function. Around 14% of couples in high- and middle-income countries have difficulty conceiving, and there are unexplained declines in semen quality reported in several countries. Given the ubiquity of mobile phone use, the potential role of this environmental exposure needs to be clarified. A systematic review was therefore conducted, followed by meta-analysis using random effects models, to determine whether exposure to RF-EMR emitted from mobile phones affects human sperm quality. Participants were from fertility clinic and research centres. The sperm quality outcome measures were motility, viability and concentration, which are the parameters most frequently used in clinical settings to assess fertility.\ud
We used ten studies in the meta-analysis, including 1492 samples. Exposure to mobile phones was associated with reduced sperm motility (mean difference − 8.1% (95% CI − 13.1, − 3.2)) and viability (mean difference − 9.1% (95% CI − 18.4, 0.2)), but the effects on concentration were more equivocal. The results were consistent across experimental in vitroand observational in vivo studies. We conclude that pooled results from in vitro and in vivostudies suggest that mobile phone exposure negatively affects sperm quality. Further study is required to determine the full clinical implications for both sub-fertile men and the general population
A new low magnetic field magnetar: the 2011 outburst of Swift J1822.3–1606

We report on the long-term X-ray monitoring with Swift, RXTE, Suzaku, Chandra, and XMM-Newton of the outburst of the newly discovered magnetar Swift J1822.3–1606 (SGR 1822–1606), from the first observations soon after the detection of the short X-ray bursts which led to its discovery, through the first stages of its outburst decay (covering the time span from 2011 July until the end of 2012 April). We also report on archival ROSAT observations which detected the source during its likely quiescent state, and on upper limits on Swift J1822.3–1606's radio-pulsed and optical emission during outburst, with the Green Bank Telescope and the Gran Telescopio Canarias, respectively. Our X-ray timing analysis finds the source rotating with a period of P = 8.43772016(2) s and a period derivative P = 8.3(2)×10−14 s s−1, which implies an inferred dipolar surface magnetic field of B sime 2.7 × 1013 G at the equator. This measurement makes Swift J1822.3–1606 the second lowest magnetic field magnetar (after SGR 0418+5729). Following the flux and spectral evolution from the beginning of the outburst, we find that the flux decreased by about an order of magnitude, with a subtle softening of the spectrum, both typical of the outburst decay of magnetars. By modeling the secular thermal evolution of Swift J1822.3–1606, we find that the observed timing properties of the source, as well as its quiescent X-ray luminosity, can be reproduced if it was born with a poloidal and crustal toroidal fields of Bp ~ 1.5 × 1014 G and B tor ~ 7 × 1014 G, respectively, and if its current age is ~550 kyr.N.R. is supported by a Ramon y Cajal Research Fellowship, and by grants AYA2009-07391, SGR2009-811, TW2010005, and iLINK 2011-0303. The Italian authors are supported by Agenzia Spaziale Italiana (ASI), Ministero dell’Istruzione, Università e Ricerca Scientifica e Tecnologica (MIUR–COFIN), and Istituto Nazionale di Astrofisica (PRIN-INAF) grants. P.E. acknowledges financial support from the Autonomous Region of Sardinia through a research grant under the program PO Sardegna FSE 2007–2013, L.R. 7/2007 “Promoting scientific research and innovation technology in Sardinia.” C.K. was partially supported by NASA grant NNH07ZDA001-GLAST
Human and mouse homologs of the Saccharomyces cerevisiae RAD54 DNA repair gene: evidence for functional conservation.

BACKGROUND: Homologous recombination is of eminent importance both in germ cells, to generate genetic diversity during meiosis, and in somatic cells, to safeguard DNA from genotoxic damage. The genetically well-defined RAD52 pathway is required for these processes in the yeast Saccharomyces cerevisiae. Genes similar to those in the RAD52 group have been identified in mammals. It is not known whether this conservation of primary sequence extends to conservation of function. RESULTS: Here we report the isolation of cDNAs encoding a human and a mouse homolog of RAD54. The human (hHR54) and mouse (mHR54) proteins were 48% identical to Rad54 and belonged to the SNF2/SW12 family, which is characterized by amino-acid motifs found in DNA-dependent ATPases. The hHR54 gene was mapped to chromosome 1p32, and the hHR54 protein was located in the nucleus. We found that the levels of hHR54 mRNA increased in late G1 phase, as has been found for RAD54 mRNA. The level of mHR54 mRNA was elevated in organs of germ cell and lymphoid development and increased mHR54 expression correlated with the meiotic phase of spermatogenesis. The hHR54 cDNA could partially complement the methyl methanesulfonate-sensitive phenotype of S. cerevisiae rad54 delta cells. CONCLUSIONS: The tissue-specific expression of mHR54 is consistent with a role for the gene in recombination. The complementation experiments show that the DNA repair function of Rad54 is conserved from yeast to humans. Our findings underscore the fundamental importance of DNA repair pathways: even though they are complex and involve multiple proteins, they seem to be functionally conserved throughout the eukaryotic kingdom