Temperature shifts in the Sinai model: static and dynamical effects

We study analytically and numerically the role of temperature shifts in the simplest model where the energy landscape is explicitely hierarchical, namely the Sinai model. This model has both attractive features (there are valleys within valleys in a strict self similar sense), but also one important drawback: there is no phase transition so that the model is, in the large size limit, effectively at zero temperature. We compute various static chaos indicators, that are found to be trivial in the large size limit, but exhibit interesting features for finite sizes. Correspondingly, for finite times, some interesting rejuvenation effects, related to the self similar nature of the potential, are observed. Still, the separation of time scales/length scales with temperatures in this model is much weaker that in experimental spin-glasses.Comment: 19 pages, Revtex4, eps figure

Technology-Enhanced Reading Therapy for People With Aphasia: Findings From a Quasirandomized Waitlist Controlled Study.

Purpose This study investigated the effects of technology-enhanced reading therapy for people with reading impairments, using mainstream assistive reading technologies alongside reading strategies. Method The study used a quasirandomized waitlist controlled design. Twenty-one people with reading impairments following stroke were randomly assigned to receive 14 hr of therapy immediately or after a 6-week delay. During therapy, participants were trained to use assistive reading technology that offered a range of features to support reading comprehension. They developed skills in using the technology independently and in applying the technology to their personal reading goals. The primary outcome measure assessed reading comprehension, using Gray Oral Reading Test-Fourth Edition (GORT-4). Secondary measures were as follows: Reading Comprehension Battery for Aphasia-Second Edition, Reading Confidence and Emotions Questionnaire, Communication Activities of Daily Living-Second Edition, Visual Analog Mood Scales, and Assessment of Living With Aphasia. Matched texts were used with the GORT-4 to compare technology-assisted and unassisted reading comprehension. Mixed analyses of variance explored change between T1 and T2, when the immediate group had received therapy but the delayed group had not, thus serving as untreated controls. Pretherapy, posttherapy, and follow-up scores on the measures were also examined for all participants. Results GORT-4 results indicated that the immediately treated group improved significantly in technology-assisted reading following therapy, but not in unassisted reading. However, the data were not normally distributed, and secondary nonparametric analysis was not significant. The control group was unstable over the baseline, improving significantly in unassisted reading. The whole-group analysis showed significant gains in assisted (but not unassisted) reading after therapy that were maintained at follow-up. The Reading Confidence and Emotions Questionnaire results improved significantly following therapy, with good maintenance of change. Results on all other secondary measures were not significant. Conclusions Technology-assisted reading comprehension improved following the intervention, with treatment compensating for, rather than remediating, the reading impairment. Participants' confidence and emotions associated with reading also improved. Gains were achieved after 14 therapy sessions, using assistive technologies that are widely available and relatively affordable, meaning that this approach could be implemented in clinical practice

Comparing administrative and survey data for ascertaining cases of irritable bowel syndrome: a population-based investigation

<p>Abstract</p> <p>Background</p> <p>Administrative and survey data are two key data sources for population-based research about chronic disease. The objectives of this methodological paper are to: (1) estimate agreement between the two data sources for irritable bowel syndrome (IBS) and compare the results to those for inflammatory bowel disease (IBD); (2) compare the frequency of IBS-related diagnoses in administrative data for survey respondents with and without self-reported IBS, and (3) estimate IBS prevalence from both sources.</p> <p>Methods</p> <p>This retrospective cohort study used linked administrative and health survey data for 5,134 adults from the province of Manitoba, Canada. Diagnoses in hospital and physician administrative data were investigated for respondents with self-reported IBS, IBD, and no bowel disorder. Agreement between survey and administrative data was estimated using the κ statistic. The χ²statistic tested the association between the frequency of IBS-related diagnoses and self-reported IBS. Crude, sex-specific, and age-specific IBS prevalence estimates were calculated from both sources.</p> <p>Results</p> <p>Overall, 3.0% of the cohort had self-reported IBS, 0.8% had self-reported IBD, and 95.3% reported no bowel disorder. Agreement was poor to fair for IBS and substantially higher for IBD. The most frequent IBS-related diagnoses among the cohort were anxiety disorders (34.4%), symptoms of the abdomen and pelvis (26.9%), and diverticulitis of the intestine (10.6%). Crude IBS prevalence estimates from both sources were lower than those reported previously.</p> <p>Conclusions</p> <p>Poor agreement between administrative and survey data for IBS may account for differences in the results of health services and outcomes research using these sources. Further research is needed to identify the optimal method(s) to ascertain IBS cases in both data sources.</p

The prevalence of systemic autoimmune rheumatic diseases in Canadian pediatric populations: administrative database estimates

CI 17.9, 29.2). SARDs were more common in females than in males across all provinces. There was a slightly higher prevalence among those living in urban compared to rural areas of Alberta (rate difference 14.4, 95 % CI 8.6, 20.1) and Saskatchewan (rate difference 13.8, 95 % CI 1.0, 26.6). Our results provide population-based prevalence estimates of pediatric SARDs in four Canadian provinces. Keywords Pediatric rheumatic diseases · Systemic autoimmune rheumatic diseases · Epidemiology · Disease prevalence Abstract To estimate systemic autoimmune rheumatic disease (SARD) prevalence using administrative data for pediatric populations in four Canadian provinces. Physician billing claims and inpatient hospitalizations from Alberta, Manitoba, Quebec, and Saskatchewan were used to define cases aged ≤18 years with a SARD diagnosis code in: one or more hospitalization, two or more physician visits within 2 years and at least 2 months apart, or one or more physician visit to a rheumatologist. Estimates ranged from 15.9/100,000 in Quebec [95 % confidence interval (95 % CI) 14.1, 18.0] to 23.0/100,000 in Manitoba (95 % Rheumatology INTERNATIONA

Chemical and electronic structure of the heavily intermixed Cd,Zn S Ga CuSbS2 interface

The interface formation and chemical and electronic structure of the Cd,Zn S Ga CuSbS2 thin film solar cell heterojunction were studied using hard X ray photoelectron spectroscopy HAXPES of the bare absorber and a buffer absorber sample set for which the buffer thickness was varied between 1 and 50 nm. We find a heavily intermixed interface, involving Cu, Zn, and Cd as well as significant Ga and Cu profiles in the buffer. The valence band VB offset at the buffer absorber interface was derived as amp; 8722;1.3 0.1 eV, which must be considered an upper bound as the Cu diffused into the buffer might form a Cu derived VB maximum located closer to the Fermi level. The estimated conduction band minimum was cliff like; a situation made more severe considering the Cu deficiency found for the CuSbS2 surface. The complex interface structure s effect on the performance of Cd,Zn S Ga CuSbS2 based solar cells and its limitation is discussed together with possible mitigation strategie

Statistical practices of educational researchers: An analysis of their ANOVA, MANOVA, and ANCOVA analyses

Articles published in several prominent educational journals were examined to investigate the use of data-analysis tools by researchers in four research paradigms: between-subjects univariate designs, between-subjects multivariate designs, repeated measures designs, and covariance designs. In addition to examining specific details pertaining to the research design (e.g., sample size, group size equality/inequality) and methods employed for data analysis, we also catalogued whether: (a) validity assumptions were examined, (b) effect size indices were reported, (c) sample sizes were selected based on power considerations, and (d) appropriate textbooks and/or articles were cited to communicate the nature of the analyses that were performed. Our analyses imply that researchers rarely verify that validity assumptions are satisfied and accordingly typically use analyses that are nonrobust to assumption violations. In addition, researchers rarely report effect size statistics, nor do they routinely perform power analyses to determine sample size requirements. We offer many recommendations to rectify these shortcomings.Social Sciences and Humanities Research Counci

Osteoporosis-related fracture case definitions for population-based administrative data

<p>Abstract</p> <p>Background</p> <p>Population-based administrative data have been used to study osteoporosis-related fracture risk factors and outcomes, but there has been limited research about the validity of these data for ascertaining fracture cases. The objectives of this study were to: (a) compare fracture incidence estimates from administrative data with estimates from population-based clinically-validated data, and (b) test for differences in incidence estimates from multiple administrative data case definitions.</p> <p>Methods</p> <p>Thirty-five case definitions for incident fractures of the hip, wrist, humerus, and clinical vertebrae were constructed using diagnosis codes in hospital data and diagnosis and service codes in physician billing data from Manitoba, Canada. Clinically-validated fractures were identified from the Canadian Multicentre Osteoporosis Study (CaMos). Generalized linear models were used to test for differences in incidence estimates.</p> <p>Results</p> <p>For hip fracture, sex-specific differences were observed in the magnitude of under- and over-ascertainment of administrative data case definitions when compared with CaMos data. The length of the fracture-free period to ascertain incident cases had a variable effect on over-ascertainment across fracture sites, as did the use of imaging, fixation, or repair service codes. Case definitions based on hospital data resulted in under-ascertainment of incident clinical vertebral fractures. There were no significant differences in trend estimates for wrist, humerus, and clinical vertebral case definitions.</p> <p>Conclusions</p> <p>The validity of administrative data for estimating fracture incidence depends on the site and features of the case definition.</p