3,550 research outputs found
Nonparametric Conditional Inference for Regression Coefficients with Application to Configural Polysampling
We consider inference procedures, conditional on an observed ancillary
statistic, for regression coefficients under a linear regression setup where
the unknown error distribution is specified nonparametrically. We establish
conditional asymptotic normality of the regression coefficient estimators under
regularity conditions, and formally justify the approach of plugging in
kernel-type density estimators in conditional inference procedures. Simulation
results show that the approach yields accurate conditional coverage
probabilities when used for constructing confidence intervals. The plug-in
approach can be applied in conjunction with configural polysampling to derive
robust conditional estimators adaptive to a confrontation of contrasting
scenarios. We demonstrate this by investigating the conditional mean squared
error of location estimators under various confrontations in a simulation
study, which successfully extends configural polysampling to a nonparametric
context
Iterated smoothed bootstrap confidence intervals for population quantiles
This paper investigates the effects of smoothed bootstrap iterations on
coverage probabilities of smoothed bootstrap and bootstrap-t confidence
intervals for population quantiles, and establishes the optimal kernel
bandwidths at various stages of the smoothing procedures. The conventional
smoothed bootstrap and bootstrap-t methods have been known to yield one-sided
coverage errors of orders O(n^{-1/2}) and o(n^{-2/3}), respectively, for
intervals based on the sample quantile of a random sample of size n. We sharpen
the latter result to O(n^{-5/6}) with proper choices of bandwidths at the
bootstrapping and Studentization steps. We show further that calibration of the
nominal coverage level by means of the iterated bootstrap succeeds in reducing
the coverage error of the smoothed bootstrap percentile interval to the order
O(n^{-2/3}) and that of the smoothed bootstrap-t interval to O(n^{-58/57}),
provided that bandwidths are selected of appropriate orders. Simulation results
confirm our asymptotic findings, suggesting that the iterated smoothed
bootstrap-t method yields the most accurate coverage. On the other hand, the
iterated smoothed bootstrap percentile method interval has the advantage of
being shorter and more stable than the bootstrap-t intervals.Comment: Published at http://dx.doi.org/10.1214/009053604000000878 in the
Annals of Statistics (http://www.imstat.org/aos/) by the Institute of
Mathematical Statistics (http://www.imstat.org
The Governance of Contemporary Sovereign Wealth Funds
Recent contemporary sovereign wealth funds developments, viewed against the historical backdrop of international law and practice, particularly foreign investment law and practice, underscore the inter-action between economics, law and politics. This article first introduces the issues that have emerged as a result of sovereign wealth funds contemporary investments and observes how sovereign wealth funds and recipient countries have reacted to these developments. It proposes a model of sovereign wealth fund governance based on consultation, cooperation and coordination. This model draws on the experience of current deliberative fora such as the G20 summits and the International Working Group of Sovereign Wealth Funds, International Monetary Funl\u27s forum, the bilateral arrangements between countries and the laws and practices of some sovereign wealth fund countries, particularly Singapore. This article further examines the oversight regimes to which Singapore sovereign wealth funds are subject, and recommends the approach of the Singapore sovereign wealth funds as a starting point for achieving an optimal balance between nationalism and global financial stability based on free capital and investment flows
An Investigation of the Knowledge and Beliefs Held by Teachers and Parents in a Parochial School System Regarding Attention-Deficit/Hyperactivity Disorder and the Variables that Predict their Knowledge
Problem
Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most prevalent childhood disorders affecting 3 to 5% of school populations in the United States and other countries. Due to the behavioral and/or academic challenges of children with ADHD, they are at risk for grade retention, dropping out of high school, and teenage delinquency, which can lead to negative consequences in society. Children with ADHD are found in every school setting, including parochial schools. Past studies have found teachers and parents have inadequate knowledge about ADHD, which can negatively affect these children. This study investigated what teachers and parents of children in a parochial school system know and believe about ADHD and what predicts their knowledge.
Method
A four-section questionnaire was compiled for this study to investigate the knowledge and beliefs of a convenience sample of 76 regular education teachers and 373 parents in a parochial school system. Questionnaires consisted of knowledge and belief statements, demographic questions, and experience with/exposure to ADHD questions. Descriptive statistics assessed knowledge and belief scores; one-way ANOVA and chisquare analyzed differences between teachersâ and parentsâ knowledge and beliefs, and Categorical Regression investigated important contributors to knowledge of ADHD.
Results
Teachers and parents of children in a parochial school system have inadequate knowledge regarding ADHD, but they have positive beliefs in many areas of ADHD. They also believe some of the myths associated with ADHD. Demographic variables and experience with ADHD contributed to teachersâ knowledge regarding ADHD, while exposure to information about ADHD possibly contributed to teachersâ knowledge. Exposure to information about ADHD and experience with an ADHD variable contributed to parentsâ knowledge regarding ADHD. Both groups believe they would benefit from additional training and information about ADHD.
Conclusion
Teachers and parents have inadequate knowledge of ADHD. Nonetheless, they have positive beliefs in many areas, but they have negative beliefs about stimulant medication. Experience with ADHD and exposure to information about ADHD can increase teachersâ and parentsâ knowledge regarding ADHD. Adequate knowledge and positive beliefs can ensure children with ADHD in a parochial school system can have a positive outlook at school, at home, and in society
THE MEANING OF BEING CANADIAN: A COMPARISON BETWEEN YOUTH OF IMMIGRANT AND NONâIMMIGRANT ORIGINS
The meanings attached to national identity are the most salient citizenship issue today. We analyzed over 300 written responses of Canadian high school youth, of immigrant and nonâimmigrant origins, to the question of âWhat does it mean for me to be/become a Canadian?â The participants related a greater sense of national identity than of ethnic and/or supranational belonging. Youth of immigrant origins used a discourse of becoming and understand multiculturalism to recognize ethnic identities associated with Charter rights. The findings are contextualized in social unrest in other countries, a global migration pattern, and new forms of economic, social, and political domination. Keywords: Canadian identity, immigrant youth, ethnic identity, changing economic conditions Les divers sens donnĂ©s Ă la notion dâidentitĂ© nationale, telle est la question la plus importante de lâheure en matiĂšre de citoyennetĂ©. Les auteures ont analysĂ© plus de 300 rĂ©ponses Ă©crites de jeunes Canadiens au secondaire, immigrants et nonâimmigrants, Ă la question : « Que veut dire ĂȘtre ou devenir Canadien pour moi ? ». Les participants font Ă©tat dâun plus grand sentiment dâappartenance au pays quâĂ des groupes ethniques ou supranationaux. Les jeunes immigrĂ©s adoptent un discours axĂ© sur le devenir et considĂšrent le multiculturalisme comme la reconnaissance des identitĂ©s ethniques dans le cadre de la Charte canadienne des droits et libertĂ©s. Les rĂ©sultats de lâĂ©tude sont mis en contexte : agitation sociale dans dâautres pays, mouvements migratoires Ă lâĂ©chelle mondiale et nouvelles formes de domination politique, sociale et Ă©conomique. Mots clĂ©s : identitĂ© canadienne, jeunes immigrants, identitĂ© ethnique, Ă©volution des conditions Ă©conomiques.
Small Column Experiments for Continuous Radial Flow Chromatography
Continuous radial flow chromatography (CRFC) combines radial flow and rotating annular bed chromatography. Solution flows radially from eight fixed ports around the periphery through a rotating annular packed bed towards the axis. Loading, equilibration, elution and reequilibration solutions can be applied simultaneously at different feed ports. Protein is captured on resin in the loading zone and carried around by the annulus to the elution zone to be eluted, making the CRFC a continuous process.
Small axial flow columns experiments were carried out to represent continuous BSA purification in the CRFC for a range of rotation speeds, flow rates, feed concentration, elution buffer concentration, loading sections and elution secions. Quality of the separation was measured based on productivity and height to width ratio.
Best operating conditions for BSA purification in the CRFC include 720 deg/hr rotation speed, 1 mL/min flow rate, 1M elution buffer (NaCl) solution, and either 5 or 1.5 mg/mL feed solution. A wide range of loading sections and elution sections can be allocated. Combinations of these best conditions are restricted by total protein load per chromatography cycle.
Mathematical models solved by finite difference method in Matlab were used to predict CRFC operation under the best conditions. Model accounts for change in solute concentration by convection, film diffusion and uptake into resin. Protein and salt parameters were adjusted to achieve best mached protein peaks. Model simulations agreed well with experimental results. Loading peak width was similar but experimental data showed broader elution peaks. Elution peak height for all simulations was greater while loading peak height were more variable than in the experiments. Peak tailing was observed in both experimental and model data
Kenneth Lee Houp Interview
Transcript of an oral history interview with Kenneth Lee Houp by Yvonne Baldwin on his experiences during the Vietnam War on June 26, 1997
Greening of ILL at Himmelfarb Library
Traditionally, the Interlibrary Loan (ILL) Department consumed the largest amount of paper from routine printing of articles/chapters before delivery. In 2010, staff examined existing processes to find ways to print only when necessary and become a greener department. This poster presentation explains the implementation and the outcomes of the greening initiative in the Interlibrary Loan (ILL) Department of the Himmelfarb Health Sciences Library
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