Effects of high energy photon emissions in laser generated ultra-relativistic plasmas: real-time synchrotron simulations

We model the emission of high energy photons due to relativistic charged particle motion in intense laser-plasma interactions. This is done within a particle-in-cell code, for which high frequency radiation normally cannot be resolved due to finite time steps and grid size. A simple expression for the synchrotron radiation spectra is used together with a Monte-Carlo method for the emittance. We extend previous work by allowing for arbitrary fields, considering the particles to be in instantaneous circular motion due to an effective magnetic field. Furthermore we implement noise reduction techniques and present validity estimates of the method. Finally, we perform a rigorous comparison to the mechanism of radiation reaction, and find the emitted energy to be in excellent agreement with the losses calculated using radiation reaction

Contributing Factors to the Successful Completion of Online Courses at the Community College Level

This study sought to determine if the discrepancy between successful completion rates of online and face-to-face courses at the community college level is partially due to differences in the proportion of part-time students and the proportion of students without clear academic goals in each modality. In addition, this study looked to see if relationships exist between successful completion of online courses and the proportion of coursework taken online in a given term. An archival data set containing 20,119 student records for the fall of 2016 from a community college in the western United States was utilized for this study. The data supported that part-time students successfully complete their courses at a lower rate than full-time students (p\u3c.01) and proportionally there are more part-time students in online courses than in face-to-face courses (p\u3c.01), students without clear academic goals successfully complete their courses at a higher rate than students with clear academic goals (p\u3c.01) and proportionally there are more students without clear academic goals in online courses than in face-to-face courses (p\u3c.01), and successful completion of online courses is related to the proportion of coursework taken online in a given term for both full-time students (p\u3c.01) and part-time students (p\u3c.01). In addition, the evidence supported that the proportion of coursework taken online in a given term is related to successful completion of face-to-face courses for full-time students who take online courses (p\u3c.01) and also for full-time students in general (p\u3c.01). The same conclusions were not supported for part-time students

Galantamine treatment in Alzheimer’s disease: response and long-term outcome in a routine clinical setting

BACKGROUND: In the absence of long-term, placebo-controlled studies of cholinesterase inhibitors in Alzheimer's disease (AD), analysis of the results of open-label trials becomes crucial. This study aimed to explore the three-year effects of galantamine treatment, as well as subgroups of response and adherence to treatment. METHODS: Two hundred and eighty patients with a clinical diagnosis of AD were included in the prospective, open-label, multicenter Swedish Alzheimer Treatment Study, and received galantamine treatment. Efficacy measures included cognitive tests, ie, the Mini-Mental State Examination (MMSE) and Alzheimer's Disease Assessment Scale Cognitive Subscale (ADAS-cog), functional rating (Instrumental Activities of Daily Living Scale [IADL]), and global rating. Assessments were carried out before treatment and every six months for a period of three years. K-means cluster analysis was used to identify response subgroups. RESULTS: After three years of treatment, the mean change from baseline was 2.6 points in MMSE and 5.6 points in ADAS-cog scores. Globally, half of the patients improved or remained unchanged for two years. Cluster analysis identified two response clusters. Cluster 1 included patients with low ability in ADAS-cog and IADL scores at baseline. Even though the patients in cluster 1 were older and less educated, they responded better at six months compared with patients in cluster 2. Cluster 2 included patients with better ADAS-cog and IADL scores at baseline. Patients in cluster 2 had a higher frequency of the APOE ɛ4 allele, a slower pretreatment progression rate, and remained in the study longer than those in cluster 1. Three-year completers (n = 129, 46%) received higher doses of galantamine compared with dropouts. CONCLUSION: AD patients who received long-term galantamine treatment were cognitively and globally stabilized. Subgroup response analysis identified a better short-term response in older patients with lower cognitive and functional abilities at baseline, a faster pretreatment progression rate, and a lower incidence of the APOE ɛ4 allele. The galantamine dose was higher in the population of completers

Educators Voices from Integrated Writing and Problem Solving Common Core Workshop

This article provides an opportunity to discuss and examine information gathered during a focus group of K-12 educators involved in an integrated writing and problem solving workshop. Findings demonstrate that some educators are frustrated by the culture of testing versus the culture of learning that exist as a result of the Common Core Standards implementation. Educators are eager to learn and implement new ways of learning in order to promote deeper learning and critical thinking skills. Strategies and recommendations for providing support and resources for educators to meet the expectations to prepare students to be college and career ready are discussed

Conformation of a Polyelectrolyte Complexed to a Like-Charged Colloid

We report results from a molecular dynamics (MD) simulation on the conformations of a long flexible polyelectrolyte complexed to a charged sphere, \textit{both negatively charged}, in the presence of neutralizing counterions in the strong Coulomb coupling regime. The structure of this complex is very sensitive to the charge density of the polyelectrolyte. For a fully charged polyelectrolyte the polymer forms a dense two-dimensional "disk", whereas for a partially charged polyelectrolyte the monomers are spread over the colloidal surface. A mechanism involving the \textit{overcharging} of the polyelectrolyte by counterions is proposed to explain the observed conformations.Comment: 4 pages, 4 figures (6 EPS files

The Generic, Incommensurate Transition in the two-dimensional Boson Hubbard Model

The generic transition in the boson Hubbard model, occurring at an incommensurate chemical potential, is studied in the link-current representation using the recently developed directed geometrical worm algorithm. We find clear evidence for a multi-peak structure in the energy distribution for finite lattices, usually indicative of a first order phase transition. However, this multi-peak structure is shown to disappear in the thermodynamic limit revealing that the true phase transition is second order. These findings cast doubts over the conclusion drawn in a number of previous works considering the relevance of disorder at this transition.Comment: 13 pages, 10 figure

Predictors of long-term cognitive outcome in Alzheimer's disease

Introduction: The objective of this study was to describe the longitudinal cognitive outcome in Alzheimer’s disease (AD) and analyze factors that affect the outcome, including the impact of different cholinesterase inhibitors (ChEI). Methods: In an open, three-year, nonrandomized, prospective, multicenter study, 843 patients were treated with donepezil, rivastigmine, or galantamine in a routine clinical setting. At baseline and every six months, patients were assessed using several rating scales, including the Mini-Mental State Examination (MMSE) and the Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-cog) and the dose of ChEI was recorded. Sociodemographic and clinical characteristics were investigated. The relationships of these predictors with longitudinal cognitive ability were analyzed using mixed-effects models. Results: Slower long-term cognitive decline was associated with a higher cognitive ability at baseline or a lower level of education. The improvement in cognitive response after six months of ChEI therapy and a more positive longitudinal outcome were related to a higher mean dose of ChEI, nonsteroidal anti-inflammatory drug (NSAID)/ acetylsalicylic acid usage, male gender, older age, and absence of the apolipoprotein E (APOE) ε4 allele. More severe cognitive impairment at baseline also predicted an improved response to ChEI treatment after six months. The type of ChEI agent did not influence the short-term response or the long-term outcome. Conclusions: In this three-year AD study performed in a routine clinical practice, the response to ChEI treatment and longitudinal cognitive outcome were better in males, older individuals, non-carriers of the APOE ε4 allele, patients treated with NSAIDs/acetylsalicylic acid, and those receiving a higher dose of ChEI, regardless of the drug agent

Application and validation of the notch master curve in medium and high strength structural steels

This paper applies and validates the Notch master curve in two ferritic steels with medium (steel S460M) and high (steel S690Q) strength. The Notch master curve is an engineering tool that allows the fracture resistance of notched ferritic steels operating within their corresponding ductile-to-brittle transition zone to be estimated. It combines the Master curve and the Theory of critical distances in order to take into account the temperature and the notch effect respectively, assuming that both effects are independent. The results, derived from 168 fracture tests on notched specimens, demonstrate the capability of the Notch master curve for the prediction of the fracture resistance of medium and high strength ferritic steels operating within their ductile-to-brittle transition zone and containing notches