Simulations of an ASA flow crystallizer with a coupled stochastic-deterministic approach

A coupled solver for population balance systems is presented, where the flow, temperature, and concentration equations are solved with finite element methods, and the particle size distribution is simulated with a stochastic simulation algorithm, a so-called kinetic Monte-Carlo method. This novel approach is applied for the simulation of an axisymmetric model of a tubular flow crystallizer. The numerical results are compared with experimental data

Designing Group Examinations to Decrease Social Loafing and Increase Learning

This study examines a method to decrease social loafing in a group examination. Students who met in teams during the semester took an exam in groups. Rules for the exam, based on the Jeopardy game show, facilitated both group and individual accountability. Feedback from students indicated that compared to a class that did not have group exams, students taking the group exam had less social loafing and had higher perceived levels of learning. Furthermore, among students taking the group exams, higher group participation was related to higher perceived performance and more positive attitudes about the exam. We developed a model for how the environment affects group processes which, in turn, affects group and individual outcomes

Topology and Homoclinic Trajectories of Discrete Dynamical Systems

We show that nontrivial homoclinic trajectories of a family of discrete, nonautonomous, asymptotically hyperbolic systems parametrized by a circle bifurcate from a stationary solution if the asymptotic stable bundles Es(+{\infty}) and Es(-{\infty}) of the linearization at the stationary branch are twisted in different ways.Comment: 19 pages, canceled the appendix (Properties of the index bundle) in order to avoid any text overlap with arXiv:1005.207

Low Inductance pulser system drives a fast magnet at DARHT.

The DARHT facility [Dual Axis Radiographic Hydrodynamic Test] uses bremsstrahlung radiation from focused electron beams to produce radiographs. To produce a smaller spot size and, thus, a higher quality radiograph, one must be able to control the emittance of the electron beam. To that end, it is necessary to measure emittance. Emittance is measured by focusing the electron beam to a small size, such that the size is dominated by the emittance, as opposed to the space charge. Our electron beam, at 2 kA, 18 MV and 2 ps, would destroy any imaging target, were the full beam to be focused to minimal spot size for the full beam duration. The solution is to focus the beam for a short duration, a few tens of nanoseconds, using a fast solenoid magnet. This paper reports details of the pulsed power system used to drive the segmented magnet. The system consists of twenty pulsers, driving 60 cables to feed two headers on the magnet. The magnet itself consists of 12 individual loops, each segmented in three parts, for inductance reduction. The system is designed to produce one kilogauss over a 15-cm diameter and 60-cm length. The pulsers incorporate spark gaps that produce the main pulse with a half sine period of 125 ns and also clip the tail of the pulse to prevent refocusing of the beam. A five-to-one ratio between the first and second current peaks has been demonstrated [same polarity peaks]

Filament‐Free Bulk Resistive Memory Enables Deterministic Analogue Switching

Digital computing is nearing its physical limits as computing needs and energy consumption rapidly increase. Analogue‐memory‐based neuromorphic computing can be orders of magnitude more energy efficient at data‐intensive tasks like deep neural networks, but has been limited by the inaccurate and unpredictable switching of analogue resistive memory. Filamentary resistive random access memory (RRAM) suffers from stochastic switching due to the random kinetic motion of discrete defects in the nanometer‐sized filament. In this work, this stochasticity is overcome by incorporating a solid electrolyte interlayer, in this case, yttria‐stabilized zirconia (YSZ), toward eliminating filaments. Filament‐free, bulk‐RRAM cells instead store analogue states using the bulk point defect concentration, yielding predictable switching because the statistical ensemble behavior of oxygen vacancy defects is deterministic even when individual defects are stochastic. Both experiments and modeling show bulk‐RRAM devices using TiO2‐X switching layers and YSZ electrolytes yield deterministic and linear analogue switching for efficient inference and training. Bulk‐RRAM solves many outstanding issues with memristor unpredictability that have inhibited commercialization, and can, therefore, enable unprecedented new applications for energy‐efficient neuromorphic computing. Beyond RRAM, this work shows how harnessing bulk point defects in ionic materials can be used to engineer deterministic nanoelectronic materials and devices.A resistive memory cell based on the electrochemical migration of oxygen vacancies for in‐memory neuromorphic computing is presented. By using the average statistical behavior of all oxygen vacancies to store analogue information states, this cell overcomes the stochastic and unpredictable switching plaguing filament‐forming memristors, and instead achieves linear, predictable, and deterministic switching.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163547/3/adma202003984_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163547/2/adma202003984-sup-0001-SuppMat.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163547/1/adma202003984.pd

The first determination of Generalized Polarizabilities of the proton by a Virtual Compton Scattering experiment

Absolute differential cross sections for the reaction (e+p -> e+p+gamma) have been measured at a four-momentum transfer with virtuality Q^2=0.33 GeV^2 and polarization \epsilon = 0.62 in the range 33.6 to 111.5 MeV/c for the momentum of the outgoing photon in the photon-proton center of mass frame. The experiment has been performed with the high resolution spectrometers at the Mainz Microtron MAMI. From the photon angular distributions, two structure functions which are a linear combination of the generalized polarizabilities have been determined for the first time.Comment: 4 pages, 3 figure

Cigarette smoking, cytochrome P4501A1 polymorphisms, and breast cancer among African-American and white women

INTRODUCTION: Previous epidemiologic studies suggest that women with variant cytochrome P4501A1 (CYP1A1) genotypes who smoke cigarettes are at increased risk for breast cancer. METHODS: We evaluated the association of breast cancer with CYP1A1 polymorphisms and cigarette smoking in a population-based, case–control study of invasive breast cancer in North Carolina. The study population consisted of 688 cases (271 African Americans and 417 whites) and 702 controls (285 African Americans and 417 whites). Four polymorphisms in CYP1A1 were genotyped using PCR/restriction fragment length polymorphism analysis: M1 (also known as CYP1A1*2A), M2 (CYP1A1*2C), M3 (CYP1A1*3), and M4 (CYP1A1*4) RESULTS: No associations were observed for CYP1A1 variant alleles and breast cancer, ignoring smoking. Among women who smoked for longer than 20 years, a modest positive association was found among women with one or more M1 alleles (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.2–3.5) but not among women with non-M1 alleles (OR = 1.2, 95% CI = 0.9–1.6). Odds ratios for smoking longer than 20 years were higher among African-American women with one or more M3 alleles (OR = 2.5, 95% CI = 0.9–7.1) compared with women with non-M3 alleles (OR = 1.3, 95% CI = 0.8–2.2). ORs for smoking in white women did not differ appreciably based upon M2 or M4 genotypes. CONCLUSIONS: Cigarette smoking increases breast cancer risk in women with CYP1A1 M1 variant genotypes and in African-American women with CYP1A1 M3 variant genotypes, but the modifying effects of the CYP1A1 genotype are quite weak

Influence of HER2 expression on prognosis in metastatic triple-negative breast cancer—results from an international, multicenter analysis coordinated by the AGMT Study Group

Background: Triple-negative breast cancer (TNBC) is associated with poor prognosis, and new treatment options are urgently needed. About 34%-39% of primary TNBCs show a low expression of human epidermal growth factor receptor 2 (HER2-low), which is a target for new anti-HER2 drugs. However, little is known about the frequency and the prognostic value of HER2-low in metastatic TNBC. Patients and methods: We retrospectively included patients with TNBC from five European countries for this international, multicenter analysis. Triple-negativity had to be shown in a metastatic site or in the primary breast tumor diagnosed simultaneously or within 3 years before metastatic disease. HER2-low was defined as immunohistochemically (IHC) 1+ or 2+ without ERBB2 gene amplification. Survival probabilities were calculated by the Kaplan-Meier method, and multivariable hazard ratios (HRs) were estimated by Cox regression models. Results: In total, 691 patients, diagnosed between January 2006 and February 2021, were assessable. The incidence of HER2-low was 32.0% [95% confidence interval (CI) 28.5% to 35.5%], with similar proportions in metastases (n = 265; 29.8%) and primary tumors (n = 425; 33.4%; P = 0.324). The median overall survival (OS) in HER2-low and HER2-0 TNBC was 18.6 and 16.1 months, respectively (HR 1.00; 95% CI 0.83-1.19; P = 0.969). Similarly, in multivariable analysis, HER2-low had no significant impact on OS (HR 0.95; 95% CI 0.79-1.13; P = 0.545). No difference in prognosis was observed between HER2 IHC 0/1+ and IHC 2+ tumors (HR 0.89; 95% CI 0.69-1.17; P = 0.414). Conclusions: In this large international dataset of metastatic TNBC, the frequency of HER2-low was 32.0%. Neither in univariable nor in multivariable analysis HER2-low showed any influence on OS.info:eu-repo/semantics/publishedVersio

Prognostic value of monitoring tumour markers CA 15-3 and CEA during fulvestrant treatment

BACKGROUND: At many centres tumour markers are used to detect disease recurrence and to monitor response to therapy in patients with advanced disease, although the real value of serial observation of marker levels remains disputed. In this study, we evaluated the prognostic value of tumour markers for predicting response (partial response [PR], stable disease [SD] ≥ 6 months), de novo disease progression (PD) and secondary PD in patients receiving fulvestrant ('Faslodex') 250 mg/month for the treatment of metastatic breast cancer (MBC). METHODS: Changes in cancer antigen 15–3 (CA 15-3) and carcinoembryonic antigen (CEA) were prospectively monitored (monthly) and were also evaluated for the 3 months preceding secondary PD. Data from 67 patients with previously treated MBC participating in a Compassionate Use Programme were analysed. RESULTS: In patients with a PR (n = 7 [10.4%]), a non-significant increase in CA 15-3 occurred during the first 6 months of treatment; CEA was significantly reduced (P = 0.0165). In patients with SD ≥ 6 months (n = 28 [41.8%]), both CA 15-3 (P < 0.0001) and CEA (P = 0.0399) levels increased significantly after 6 months treatment. In those experiencing de novo PD (n = 32 [47.8%]), CA 15-3 increased significantly (P < 0.0001) after 4 months; CEA also increased significantly (P = 0.0002) during the same time period. Both CA 15-3 (P < 0.0001) and CEA (P < 0.0001) increased significantly in the 3 months preceding secondary PD. CONCLUSION: CA 15-3 increases in patients progressing on fulvestrant but may also increase in those experiencing clinical benefit; this should not be taken as a sign of PD without verification. Overall, both CA 15-3 and CEA appear to be poor prognostic markers for determining progression in patients receiving fulvestrant

Atheisms and the purification of faith

Philosophers of religion have distinguished between ‘negative’ and ‘positive’ atheism. This article considers further conceptions of atheism, especially the idea that atheism can facilitate a faith in God purified of idolatrous assumptions. After introducing Bultmann’s contention that a ‘conscious atheist’ can find something transcendent in the world, this contention is interpreted through reflection on Ricoeur’s claim that the atheisms of Nietzsche and Freud serve to mediate a transition to a purified faith – a faith involving heightened receptivity to agapeic love. The troubling question of what differentiates atheism from belief in God is then discussed in the light of Simone Weil’s meditations on God’s secret presence