B_K from quenched overlap QCD

We present an exploratory calculation of the standard model Delta S=2 matrix element relevant for indirect CP violation in K -> pi pi decays. The computation is performed with overlap fermions in the quenched approximation at beta=6.0 on a 16^3x32 lattice. The resulting bare matrix element is renormalized non-perturbatively. Our preliminary result is B_K^{NDR}(2 GeV)=0.61(7), where the error does not yet include an estimate of systematic uncertainties.Comment: 3 pages, 2 figures, Lattice2002(matrixel). Parallel session talk by L. Lellouch at the 20th International Symposium on Lattice Field Theory (Lattice 2002), Boston, Massachusetts, 24-29 June 200

Transport Properties of Highly Aligned Polymer Light-Emitting-Diodes

We investigate hole transport in polymer light-emitting-diodes in which the emissive layer is made of liquid-crystalline polymer chains aligned perpendicular to the direction of transport. Calculations of the current as a function of time via a random-walk model show excellent qualitative agreement with experiments conducted on electroluminescent polyfluorene demonstrating non-dispersive hole transport. The current exhibits a constant plateau as the charge carriers move with a time-independent drift velocity, followed by a long tail when they reach the collecting electrode. Variation of the parameters within the model allows the investigation of the transition from non-dispersive to dispersive transport in highly aligned polymers. It turns out that large inter-chain hopping is required for non-dispersive hole transport and that structural disorder obstructs the propagation of holes through the polymer film.Comment: 4 pages, 5 figure

Monte-Carlo simulations of the recombination dynamics in porous silicon

A simple lattice model describing the recombination dynamics in visible light emitting porous Silicon is presented. In the model, each occupied lattice site represents a Si crystal of nanometer size. The disordered structure of porous Silicon is modeled by modified random percolation networks in two and three dimensions. Both correlated (excitons) and uncorrelated electron-hole pairs have been studied. Radiative and non-radiative processes as well as hopping between nearest neighbor occupied sites are taken into account. By means of extensive Monte-Carlo simulations, we show that the recombination dynamics in porous Silicon is due to a dispersive diffusion of excitons in a disordered arrangement of interconnected Si quantum dots. The simulated luminescence decay for the excitons shows a stretched exponential lineshape while for uncorrelated electron-hole pairs a power law decay is suggested. Our results successfully account for the recombination dynamics recently observed in the experiments. The present model is a prototype for a larger class of models describing diffusion of particles in a complex disordered system.Comment: 33 pages, RevTeX, 19 figures available on request to [email protected]

Production of a0a_0-mesons in pp and pn reactions

We investigate the cross section for the reaction $NN \to NNa_0$ near threshold and at medium energies. An effective Lagrangian approach with one-pion exchange is applied to analyze different contributions to the cross section for different isospin channels. The Reggeon exchange mechanism is also considered. The results are used to calculate the contribution of the $a_0$ meson to the cross sections and invariant $K \bar K$ mass distributions of the reactions $pp\to pn K^+\bar K^0$ and $pp\to pp K^+K^-$. It is found that the experimental observation of $a_0^+$ mesons in the reaction $pp\to pn K^+\bar K^0$ is much more promising than the observation of $a_0^0$ mesons in the reaction $pp\to pp K^+K^-$.Comment: 26 pages, including 11 eps figures, to be bublished in J. Phys.

Temperature and Field Dependence of the Mobility in Liquid-Crystalline Conjugated Polymer Films

The transport properties of organic light-emitting diodes in which the emissive layer is composed of conjugated polymers in the liquid-crystalline phase have been investigated. We have performed simulations of the current transient response to an illumination pulse via the Monte Carlo approach, and from the transit times we have extracted the mobility of the charge carriers as a function of both the electric field and the temperature. The transport properties of such films are different from their disordered counterparts, with charge carrier mobilities exhibiting only a weak dependence on both the electric field and temperature. We show that for spatially ordered polymer films, this weak dependence arises for thermal energy being comparable to the energetic disorder, due to the combined effect of the electrostatic and thermal energies. The inclusion of spatial disorder, on the other hand, does not alter the qualitative behaviour of the mobility, but results in decreasing its absolute value.Comment: 9 pages, 8 figures, submitted to Phys. Rev.

Assessment of Adverse Events From the Patient Perspective in a Phase 3 Metastatic Castration-Resistant Prostate Cancer Clinical Trial

IMPORTANCE Standard adverse event (AE) reporting in oncology clinical trials has historically relied on clinician grading, which prior research has shown can lead to underestimation of rates of symptomatic AEs. Industry sponsors are beginning to implement in trials the National Cancer Institute’s Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE), which was developed to allow patients to self-report symptomatic AEs and improve the quality of symptomatic AE detection. OBJECTIVES To evaluate the feasibility of implementing PRO-CTCAE in a prespecified correlative analysis of the phase 3 COMET-2 trial and enumerate statistically significant between-group differences in symptomatic AEs using PRO-CTCAE and the CTCAE. DESIGN, SETTING, AND PARTICIPANTS This correlative study of 119 men in the randomized, double-blind, placebo-controlled phase 3 COMET-2 trial with metastatic castration-resistant prostate cancer who had undergone at least 2 prior lines of systemic treatment was conducted from March 2012 to July 2014. Participants completed PRO-CTCAE items using an automated telephone system from home prior to treatment and every 3 weeks during treatment. Statistical analysis was performed from May 2018 to June 2019. MAIN OUTCOMES AND MEASURES The proportion of patients who completed expected PRO-CTCAE self-reports was computed as a measure of feasibility. RESULTS Among the 119 men in the study (median age, 65 years [range, 44-80 years]), 534 of 587 (91.0%) expected PRO-CTCAE self-reports were completed, with consistently high rates of completion throughout participation. Rates of self-report adherence were similar between groups (cabozantinib s-maleate, 286 of 317 [90.2%]; and mitoxantrone hydrochloride-prednisone, 248 of 270 [91.9%]). Of 12 measured, patient-reported PRO-CTCAE symptomatic AEs, 4 reached statistical significance when comparing the proportion of patients with at least 1 postbaseline score greater than 0 between groups (differences ranged from 20.1% to 34.1% with higher proportions in the cabozantinib group; all P < .05), and use of a method for accounting for preexisting symptoms at baseline yielded 7 AEs with statistically significant differences between groups (differences ranged from 20.5%to 41.2%with higher proportions in the cabozantinib group; all P < .05). In the same analysis using investigator-reported CTCAE data, no statistically significant differences were found between groups for any symptomatic AEs. CONCLUSIONS AND RELEVANCE PRO-CTCAE data collection was feasible and improved the accuracy of symptomatic AE detection in a phase 3 cancer trial. This analysis adds to mounting evidence of the feasibility and value of patient-reported AEs in oncology, which should be considered for inclusion in cancer trials that incorporate AE evaluation

Theory of continuum percolation I. General formalism

The theoretical basis of continuum percolation has changed greatly since its beginning as little more than an analogy with lattice systems. Nevertheless, there is yet no comprehensive theory of this field. A basis for such a theory is provided here with the introduction of the Potts fluid, a system of interacting $s$-state spins which are free to move in the continuum. In the $s \to 1$ limit, the Potts magnetization, susceptibility and correlation functions are directly related to the percolation probability, the mean cluster size and the pair-connectedness, respectively. Through the Hamiltonian formulation of the Potts fluid, the standard methods of statistical mechanics can therefore be used in the continuum percolation problem.Comment: 26 pages, Late

Favorable outcome of early treatment of new onset child and adolescent migraine-implications for disease modification.

There is evidence that the prevalence of migraine in children and adolescents may be increasing. Current theories of migraine pathophysiology in adults suggest activation of central cortical and brainstem pathways in conjunction with the peripheral trigeminovascular system, which ultimately results in release of neuropeptides, facilitation of central pain pathways, neurogenic inflammation surrounding peripheral vessels, and vasodilatation. Although several risk factors for frequent episodic, chronic, and refractory migraine have been identified, the causes of migraine progression are not known. Migraine pathophysiology has not been fully evaluated in children. In this review, we will first discuss the evidence that early therapeutic interventions in the child or adolescent new onset migraineur, may halt or limit progression and disability. We will then review the evidence suggesting that many adults with chronic or refractory migraine developed their migraine as children or adolescents and may not have been treated adequately with migraine-specific therapy. Finally, we will show that early, appropriate and optimal treatment of migraine during childhood and adolescence may result in disease modification and prevent progression of this disease

Localized and Delocalized Charge Transport in Single-Wall Carbon-Nanotube Mats

We measured the complex dielectric constant in mats of single-wall carbon-nanotubes between 2.7 K and 300 K up to 0.5 THz. The data are well understood in a Drude approach with a negligible temperature dependence of the plasma frequency (omega_p) and scattering time (tau) with an additional contribution of localized charges. The dielectric properties resemble those of the best ''metallic'' polypyrroles and polyanilines. The absence of metallic islands makes the mats a relevant piece in the puzzle of the interpretation of tau and omega_p in these polymers.Comment: 4 pages including 4 figure

Vorinostat in advanced prostate cancer patients progressing on prior chemotherapy (National Cancer Institute Trial 6862)

BACKGROUND: This phase 2 trial was designed to evaluate the efficacy of vorinostat in chemotherapy-pretreated patients with metastatic castration-resistant prostate cancer. METHODS: Patients with disease progression on 1 prior chemotherapy, a prostate-specific antigen (PSA) ≥5 ng/mL, and adequate organ function were treated with 400 mg vorinostat orally daily. The primary endpoint was the 6-month progression rate. Secondary endpoints included safety, rate of PSA decline, objective response, overall survival, and effects of vorinostat on serum interleukin-6 (IL-6) levels. RESULTS: Twenty-seven eligible patients were accrued. The median number of cycles delivered was 2 (range, 1-7). All patients were taken off therapy before 6 months. The best objective response in the eligible patient was stable disease in 2 (7%) patients. No PSA decline of ≥50% was observed. There was 1 grade 4 adverse event (AE), and 44% of patients experienced grade 3 adverse events. The most common adverse events were fatigue (81%), nausea (74%), anorexia (59%), vomiting (33%), diarrhea (33%), and weight loss (26%). Median time to progression and overall survival were 2.8 and 11.7 months, respectively. Median IL-6 levels (pg/mL) were higher in patients removed from the protocol for toxicity compared with progression at all time points, including baseline (5.2 vs 2.1, P = .02), Day 15 Cycle 1 (9.5 vs 2.2, P = .01), Day 1 Cycle 2 (9.8 vs 2.2, P = .01), and end of study (11.0 vs 2.9, P = .09). CONCLUSIONS: Vorinostat at this dose was associated with significant toxicities limiting efficacy assessment in this patient population. The significant association between IL-6 levels and removal from the study for toxicities warrants further investigation. Cancer 2009. © 2009 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64445/1/24597_ftp.pd