Eigenvalue Separation in Some Random Matrix Models

The eigenvalue density for members of the Gaussian orthogonal and unitary ensembles follows the Wigner semi-circle law. If the Gaussian entries are all shifted by a constant amount c/Sqrt(2N), where N is the size of the matrix, in the large N limit a single eigenvalue will separate from the support of the Wigner semi-circle provided c > 1. In this study, using an asymptotic analysis of the secular equation for the eigenvalue condition, we compare this effect to analogous effects occurring in general variance Wishart matrices and matrices from the shifted mean chiral ensemble. We undertake an analogous comparative study of eigenvalue separation properties when the size of the matrices are fixed and c goes to infinity, and higher rank analogues of this setting. This is done using exact expressions for eigenvalue probability densities in terms of generalized hypergeometric functions, and using the interpretation of the latter as a Green function in the Dyson Brownian motion model. For the shifted mean Gaussian unitary ensemble and its analogues an alternative approach is to use exact expressions for the correlation functions in terms of classical orthogonal polynomials and associated multiple generalizations. By using these exact expressions to compute and plot the eigenvalue density, illustrations of the various eigenvalue separation effects are obtained.Comment: 25 pages, 9 figures include

SENSORS: A Novel Lateral Field Excited Acoustic Wave Sensor for Chemical and Biological Agents

Sensors for the sensitive and selective detection of chemical agents and a biological agent are being developed. The sensor structure consists of a piezoelectric platform that is coated with a film that selectively sorbs a chemical or biological agent of interest. The sensitivity of the sensor is embodied in the sensor platform, which consists of a quartz crystal that is excited by a lateral electric field. The exciting electrodes are placed opposite to the sensing surface, and the sensing film is attached directly to the sensor platform. This arrangement is in contrast to the standard quartz microbalance (QCM), where the sensing surface is normally coated with a gold film, and it offers increased sensitivity along with selectivity. The high sensitivity exhibited by this novel lateral-field-excited (LFE) QCM is attributed to the fact that the sensor can measure both electrical and mechanical property changes in the sensing film caused by the sorbed chemical or biological agent. The selectivity of the LFE-QCM sensor is obtained by performing molecular filtering directly in the sensing film. In this specific project the LFE-QCM sensor is being designed to detect two specific chemicals and one biological agent. The target chemicals are dimethyl phosponate (DMMP), which simulates VX and G nerve agents, and an organophosphate pesticide that is chemically similar to many other chemical-warfare agents. The biological agent is E. coli O157:H7, which could appear in food or water supplies. In order to realize the desired chemical and biological sensors, the research team is exploring several issues relating to the LFE-QCM platform and the sensing film. These issues include the optimum electrode geometry in the LFE-QCM platform, the development of novel polymer and silica films for the detection of organophosphates in water, and the coupling of E. coli antibodies to the sensing surface. Homeland security as well as environmental and industrial health concerns dictate that improved chemical and biological sensors must be developed and deployed. After various sorbate-selective films have been attached to the LFE-QCM surface, they will be exposed to the chemical simulants and the biological agent in order to determine the sensing properties. It is anticipated that the proposed work on these organo-phosphorus chemicals and E. coli can be extended to development of selective sensors for other significant chemical and biological agents. In addition, by coupling with existing GK-12 and REU programs, this project will contribute to the education of a number of students and teachers who will participate in the research program

Efficacy and Safety of Once-Daily Vibegron for Treatment of Overactive Bladder in Patients Aged ≥65 and ≥75 Years: Subpopulation Analysis from the EMPOWUR Randomized, International, Phase III Study

Background Overactive bladder (OAB) is common among older adults. The efficacy and safety of vibegron for the treatment of OAB were demonstrated in the international, phase III EMPOWUR trial. This subpopulation analysis from EMPOWUR assessed the efficacy and safety of vibegron in patients aged ≥ 65 and ≥ 75 years. Methods In EMPOWUR, patients with OAB were randomly assigned 5:5:4 to receive once-daily vibegron 75 mg, placebo, or tolterodine 4 mg extended release, respectively, once daily for 12 weeks. Coprimary efficacy endpoints were change from baseline at week 12 in average daily number of micturitions and urge urinary incontinence (UUI) episodes; a key secondary efficacy endpoint was change from baseline at week 12 in average daily number of urgency episodes. Safety was assessed through adverse events (AEs). Efficacy analyses compared vibegron with placebo; no efficacy comparisons were made between vibegron and tolterodine. Results Of the 1463 patients with evaluable efficacy data, 628 patients were aged ≥ 65 years, and 179 were aged ≥ 75 years. After 12 weeks, patients treated with once-daily vibegron 75 mg in both age subgroups showed significant improvements from baseline versus placebo in all three symptoms of OAB: daily micturitions (≥ 65 years, P \u3c 0.0001; ≥75 years, P \u3c 0.05), UUI episodes (≥ 65 years, P \u3c 0.001; ≥ 75 years, P \u3c 0.0001), and urgency episodes (≥ 65 years, P \u3c 0.01; ≥ 75 years, P \u3c 0.01). Significant reductions from baseline versus placebo in daily micturitions, UUI episodes, and urgency episodes were observed beginning at week 2 for patients aged ≥ 65 years treated with vibegron. In patients aged ≥ 65 years, 50.0% of those receiving vibegron versus 29.8% receiving placebo experienced a ≥ 75% reduction in UUI episodes at week 12 (P\u3c 0.0001). Rates of cardiovascular-associated AEs were low for patients receiving vibegron ( Conclusions In this subpopulation analysis of patients with OAB aged ≥ 65 and ≥ 75 years from the EMPOWUR study, once-daily vibegron 75 mg showed rapid onset and robust efficacy versus placebo and was generally safe and well tolerated, consistent with results from the overall population

Animal spirits and credit cycles

In this paper we extend the behavioral macroeconomic model as proposed by De Grauwe (2012) to include a banking sector. The behavioral model takes the view that agents have limited cognitive abilities. As a result, it is “rational” to use simple forecasting rules and to subject the use of these rules to a fitness test. Agents are then driven to select the rule that performs best. The behavioral model produces endogenous and self-fulfilling movements of optimism and pessimism (animal spirits). Our main result is that the existence of banks intensifies these movements, creating a greater scope for booms and busts. Thus, banks do not create but amplify animal spirits. We find that increases in the equity ratios of banks tend to reduce the importance of animal spirits over the business cycle. The other policy conclusion we derive from our results is that the central bank has an important responsibility for stabilising output: output stabilization is an instrument to “tame the animal spirits”. This has the effect of improving the trade-off between inflation and output volatility

Speech recognition via phonetically-featured syllables

We describe recent work on two new automatic speech recognition systems. The first part of this paper describes the components of a system based on phonological features (which we call Espresso-P) in which the values of these features are estimated from the speech signal before being used as the basis for recognition. In the second part of the paper, another system (which we call Espresso-A) is described in which articulatory parameters are used instead of phonological features and a linear dynamical system model is used to perform recognition from automatically estimated values of these articulatory parameters

A Bound on the Energy Loss of Partons in Nuclei

We derive a quantum mechanical upper bound on the amount of radiative energy loss suffered by high energy quarks and gluons in nuclear matter. The bound shows that the nuclear suppression observed in quarkonium production at high $x_F$ cannot be explained in terms of energy loss of the initial or final parton states. We also argue that no nuclear suppression is expected in the photoproduction of light hadrons at large $x_F$.Comment: 15 pages, 1 figure included as a Postscript file, phyzzx.te

Complete Genome Sequence and Comparative Metabolic Profiling of the Prototypical Enteroaggregative Escherichia coli Strain 042

Background \ud Escherichia coli can experience a multifaceted life, in some cases acting as a commensal while in other cases causing intestinal and/or extraintestinal disease. Several studies suggest enteroaggregative E. coli are the predominant cause of E. coli-mediated diarrhea in the developed world and are second only to Campylobacter sp. as a cause of bacterial-mediated diarrhea. Furthermore, enteroaggregative E. coli are a predominant cause of persistent diarrhea in the developing world where infection has been associated with malnourishment and growth retardation. \ud \ud Methods \ud In this study we determined the complete genomic sequence of E. coli 042, the prototypical member of the enteroaggregative E. coli, which has been shown to cause disease in volunteer studies. We performed genomic and phylogenetic comparisons with other E. coli strains revealing previously uncharacterised virulence factors including a variety of secreted proteins and a capsular polysaccharide biosynthetic locus. In addition, by using Biolog™ Phenotype Microarrays we have provided a full metabolic profiling of E. coli 042 and the non-pathogenic lab strain E. coli K-12. We have highlighted the genetic basis for many of the metabolic differences between E. coli 042 and E. coli K-12. \ud \ud Conclusion \ud This study provides a genetic context for the vast amount of experimental and epidemiological data published thus far and provides a template for future diagnostic and intervention strategies

Early Changes in Tumor Perfusion from T1-Weighted Dynamic Contrast-Enhanced MRI following Neural Stem Cell-Mediated Therapy of Recurrent High-Grade Glioma Correlate with Overall Survival

Background. The aim of this study was to correlate T1-weighted dynamic contrast-enhanced MRI- (DCE-MRI-) derived perfusion parameters with overall survival of recurrent high-grade glioma patients who received neural stem cell- (NSC-) mediated enzyme/prodrug gene therapy. Methods. A total of 12 patients were included in this retrospective study. All patients were enrolled in a first-in-human study (NCT01172964) of NSC-mediated therapy for recurrent high-grade glioma. DCE-MRI data from all patients were collected and analyzed at three time points: MRI#1—day 1 postsurgery/treatment, MRI#2— day 7 ± 3 posttreatment, and MRI#3—one-month follow-up. Plasma volume (Vp), permeability (Ktr), and leakage (λtr) perfusion parameters were calculated by fitting a pharmacokinetic model to the DCE-MRI data. The contrast-enhancing (CE) volume was measured from the last dynamic phase acquired in the DCE sequence. Perfusion parameters and CE at each MRI time point were recorded along with their relative change between MRI#2 and MRI#3 (Δ32). Cox regression was used to analyze patient survival. Results. At MRI#1 and at MRI#3, none of the parameters showed a significant correlation with overall survival (OS). However, at MRI#2, CE and λtr were significantly associated with OS (p<0.05). The relative λtr and Vp from timepoint 2 to timepoint 3 (Δ32λtr and Δ32Vp) were each associated with a higher hazard ratio (p<0.05). All parameters were highly correlated, resulting in a multivariate model for OS including only CE at MRI#2 and Δ32Vp, with an R2 of 0.89. Conclusion. The change in perfusion parameter values from 1 week to 1 month following NSC-mediated therapy combined with contrast-enhancing volume may be a useful biomarker to predict overall survival in patients with recurrent high-grade glioma