Reading Comprehension: Strategies for Elementary and Secondary School Students

The purpose of this paper is to discuss several strategies that can be used for elementary and secondary school students who have disabilities but would also benefit those without disabilities as well

TIME-SERIES MODELS WITH AN EGB2 CONDITIONAL DISTRIBUTION

A time series model in which the signal is buried in noise that is non-Gaussian may throw up observations that, when judged by the Gaussian yardstick, are outliers. We describe an observation driven model, based on an exponential generalized beta distribution of the second kind (EGB2), in which the signal is a linear function of past values of the score of the conditional distribution. This specification produces a model that is not only easy to implement, but which also facilitates the development of a comprehensive and relatively straight forward theory for the asymptotic distribution of the maximum likelihood estimator. Score driven models of this kind can also be based on conditional t-distributions, but whereas these models carry out what, in the robustness literature, is called a soft form of trimming, the EGB2 distribution leads to a soft form of Winsorizing. An EGARCH model based on the EGB2 distribution is also developed. This model complements the score driven EGARCH model with a conditional t-distribution. Finally dynamic location and scale models are combined and applied to data on the UK rate of inflation.This version is the author accepted manuscript. The final version is available from Wiley at http://onlinelibrary.wiley.com/doi/10.1111/jtsa.12081/full

Two EGARCH models and one fat tail

We compare two EGARCH models which belong to a new class of models in which the dynamics are driven by the score of the conditional distribution of the observations. Models of this kind are called dynamic conditional score (DCS) models and their form facilitates the development of a comprehensive and relatively straightforward theory for the asymptotic distribution of the maximum likelihood estimator. The EGB2 distribution is light-tailed, but with higher kurtosis than the normal. Hence it is complementary to the fat-tailed t. The EGB2-EGARCH model gives a good fit to many exchange rate return series, prompting an investigation into the misleading conclusions liable to be drawn from tail index estimates

Estimating reliability statistics and measurement error variances using instrumental variables with longitudinal data

The presence of randomly distributed measurement errors in scale scores such as those used in educational and behavioural assessments implies that careful adjustments are required to statistical model estimation procedures if inferences are required for ‘true’ as opposed to ‘observed’ relationships. In many cases this requires the use of external values for ‘reliability’ statistics or ‘measurement error variances’ which may be provided by a test constructor or else inferred or estimated by the data analyst. Popular measures are those described as ‘internal consistency’ estimates and sometimes other measures based on data grouping. All such measures, however, make particular assumptions that may be questionable but are often not examined. In this paper we focus on scaled scores derived from aggregating a set of indicators, and set out a general methodological framework for exploring different ways of estimating reliability statistics and measurement error variances, critiquing certain approaches and suggesting more satisfactory methods in the presence of longitudinal data. In particular, we explore the assumption of local (conditional) item response independence and show how a failure of this assumption can lead to biased estimates in statistical models using scaled scores as explanatory variables. We illustrate our methods using a large longitudinal data set of mathematics test scores from Queensland, Australia

Quantifying the resolution of spatial and temporal representation in children with 22q11.2 deletion syndrome.

ObjectivesOur ability to generate mental representation of magnitude from sensory information affects how we perceive and experience the world. Reduced resolution of the mental representations formed from sensory inputs may generate impairment in the proximal and distal information processes that utilize these representations. Impairment of spatial and temporal information processing likely underpins the non-verbal cognitive impairments observed in 22q11.2 deletion syndrome (22q11DS). The present study builds on prior research by seeking to quantify the resolution of spatial and temporal representation in children with 22q11DS, sex chromosome aneuploidy (SCA), and a typically developing (TD) control group.Participants and methodsChildren (22q11DS = 70, SCA = 49, TD = 46) responded to visual or auditory stimuli with varying difference ratios. The participant's task was to identify which of two sequentially presented stimuli was of larger magnitude in terms of, size, duration, or auditory frequency. Detection threshold was calculated as the minimum difference ratio between the "standard" and the "target" stimuli required to achieve 75% accuracy in detecting that the two stimuli were different.ResultsChildren with 22q11DS required larger magnitude difference between spatial stimuli for accurate identification compared with both the SCA and TD groups (% difference from standard: 22q11DS = 14; SCA = 8; TD: 7; F  = 8.42, p < 0.001). Temporal detection threshold was also higher for the 22q11DS group to both visual (% difference from standard: 22q11DS = 14; SCA = 8; TD = 7; F  = 8.33, p < 0.001) and auditory (% difference from standard: 22q11DS = 23; SCA = 12; TD: 8; F  = 8.99, p < 0.001) stimuli compared with both the SCA and TD groups, while the SCA and TD groups displayed equivalent performance on these measures (p's > 0.05). Pitch detection threshold did not differ among the groups (p's > 0.05).ConclusionsThe observation of higher detection thresholds to spatial and temporal stimuli indicates further evidence for reduced resolution in both spatial and temporal magnitude representation in 22q11DS, that does not extend to frequency magnitude representation (pitch detection), and which is not explained by generalized cognitive impairment alone. These findings generate further support for the hypothesis that spatiotemporal hypergranularity of mental representations contributes to the non-verbal cognitive impairment seen in 22q11DS

Cognitive Rehabilitation for Executive Dysfunction in Parkinson's Disease: Application and Current Directions

Cognitive dysfunction in Parkinson's disease contributes to disability, caregiver strain, and diminished quality of life. Cognitive rehabilitation, a behavioral approach to improve cognitive skills, has potential as a treatment option to improve and maintain cognitive skills and increase quality of life for those with Parkinson's disease-related cognitive dysfunction. Four cognitive rehabilitation programs in individuals with PD are identified from the literature. Characteristics of the programs and outcomes are reviewed and critiqued. Current studies on cognitive rehabilitation in PD demonstrate feasibility and acceptability of a cognitive rehabilitation program for patients with PD, but are limited by their small sample size and data regarding generalization of effects over the long term. Because PD involves progressive heterogeneous physical, neurological, and affective difficulties, future cognitive rehabilitation programs should aim for flexibility and individualization, according to each patient's strengths and deficits

Study of the anomalous magnetic moment of the muon computed from the Adler function

We compute the Adler function on the lattice from vacuum polarization data with twisted boundary conditions using numerical derivatives. The study is based on CLS ensembles with two flavours of $O(a)$ improved Wilson fermions. We extrapolate the lattice data for the Adler function to the continuum limit and to the physical pion mass and analyze its dependence on the momentum transfer. We discuss the application of this method to the extraction of the $u,d$ contribution to $a_\mu^{\mathrm{HLO}}$.Comment: 7 pages, 3 figures, presented at the 32nd International Symposium on Lattice Field Theory (Lattice 2014), June 23-28 2014, New York, US

Extrapleural pneumonectomy versus pleurectomy/decortication in the surgical management of malignant pleural mesothelioma: Results in 663 patients

ObjectiveThe optimal procedure for resection of malignant pleural mesothelioma is controversial, partly because previous analyses include small numbers of patients. We performed a multi-institutional study to increase statistical power to detect significant differences in outcome between extrapleural pneumonectomy and pleurectomy/decortication.MethodsPatients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy or pleurectomy/decortication at 3 institutions were identified. Survival and prognostic factors were analyzed by the Kaplan–Meier method, log-rank test, and Cox proportional hazards analysis.ResultsFrom 1990 to 2006, 663 consecutive patients (538 men and 125 women) underwent resection. The median age was 63 years (range, 26–93 years). The operative mortality was 7% for extrapleural pneumonectomy (n = 27/385) and 4% for pleurectomy/decortication (n = 13/278). Significant survival differences were seen for American Joint Committee on Cancer stages 1 to 4 (P < .001), epithelioid versus non-epithelioid histology (P < .001), extrapleural pneumonectomy versus pleurectomy/decortication (P < .001), multimodality therapy versus surgery alone (P < .001), and gender (P < .001). Multivariate analysis demonstrated a hazard rate of 1.4 for extrapleural pneumonectomy (P < .001) controlling for stage, histology, gender, and multimodality therapy.ConclusionPatients who underwent pleurectomy/decortication had a better survival than those who underwent extrapleural pneumonectomy; however, the reasons are multifactorial and subject to selection bias. At present, the choice of resection should be tailored to the extent of disease, patient comorbidities, and type of multimodality therapy planned