Summary of electrical component development for a 400-hertz Brayton energy conversion system

Design, fabrication, and testing of 12-kilowatt inductor alternator, voltage regulator-exciter, and parasitic loading speed controller - summar

OXFAM Nicaraguan Operations

General Relief Operations or Program Reports. (70)The digital Cuny Archive was made available in part through funding assistance from USAID.INTERTEC

Sample Size and Robustness of Inferences from Logistic Regression in the Presence of Nonlinearity and Multicollinearity

The logistic regression models has been widely used in the social and natural sciences and results from studies using this model can have significant impact. Thus, confidence in the reliability of inferences drawn from these models is essential. The robustness of such inferences is dependent on sample size. The purpose of this study is to examine the impact of sample size on the mean estimated bias and efficiency of parameter estimation and inference for the logistic regression model. A number of simulations are conducted examining the impact of sample size, nonlinear predictors, and multicollinearity on substantive inferences (e.g. odds ratios, marginal effects) and goodness of fit (e.g. pseudo-R2, predictability) of logistic regression models. Findings suggest that sample size can affect parameter estimates and inferences in the presence of multicollinearity and nonlinear predictor functions, but marginal effects estimates are relatively robust to sample size.Logistic Regression Model, Multicollinearity, Nonlinearity, Robustness, Small Sample Bias, Research Methods/ Statistical Methods,

Race Gaps in School Trust: Where They Come from and How to Resolve Them

Trust in American institutions varies widely among adults from different racial-ethnic backgrounds. This brief, from PRC faculty research associate David Yeager and colleagues, demonstrates that unjust treatment causes minority adolescents to lose trust in school, but a respectful "wise feedback" intervention can repair distrust.Population Research Cente

Improvement Research Carried Out Through Networked Communities: Accelerating Learning about Practices that Support More Productive Student Mindsets

The research on academic mindsets shows significant promise for addressing important problems facing educators. However, the history of educational reform is replete with good ideas for improvement that fail to realize the promises that accompany their introduction. As a field, we are quick to implement new ideas but slow to learn how to execute well on them. If we continue to implement reform as we always have, we will continue to get what we have always gotten. Accelerating the field's capacity to learn in and through practice to improve is one key to transforming the good ideas discussed at the White House meeting into tools, interventions, and professional development initiatives that achieve effectiveness reliably at scale. Toward this end, this paper discusses the function of networked communities engaged in improvement research and illustrates the application of these ideas in promoting greater student success in community colleges. Specifically, this white paper:* Introduces improvement research and networked communities as ideas that we believe can enhance educators' capacities to advance positive change. * Explains why improvement research requires a different kind of measures -- what we call practical measurement -- that are distinct from those commonly used by schools for accountability or by researchers for theory development.* Illustrates through a case study how systematic improvement work to promote student mindsets can be carried out. The case is based on the Carnegie Foundation's effort to address the poor success rates for students in developmental math at community colleges.Specifically, this case details:- How a practical theory and set of practical measures were created to assess the causes of "productive persistence" -- the set of "non-cognitive factors" thought to powerfully affect community college student success. In doing this work, a broad set of potential factors was distilled into a digestible framework that was useful topractitioners working with researchers, and a large set of potential measures was reduced to a practical (3-minute) set of assessments.- How these measures were used by researchers and practitioners for practical purposes -- specifically, to assess changes, predict which students were at-risk for course failure, and set priorities for improvement work.-How we organized researchersto work with practitioners to accelerate field-based experimentation on everyday practices that promote academic mindsets(what we call alpha labs), and how we organized practitioners to work with researchers to test, revise, refine, and iteratively improve their everyday practices (using plando-study-act cycles).While significant progress has already occurred, robust, practical, reliable efforts to improve students' mindsets remains at an early formative stage. We hope the ideas presented here are an instructive starting point for new efforts that might attempt to address other problems facing educators, most notably issues of inequality and underperformance in K-12 settings

Replicator degrees of freedom allow publication of misleading failures to replicate

In recent years, the field of psychology has begun to conduct replication tests on a large scale. Here, we show that “replicator degrees of freedom” make it far too easy to obtain and publish false-negative replication results, even while appearing to adhere to strict methodological standards. Specifically, using data from an ongoing debate, we show that commonly exercised flexibility at the experimental design and data analysis stages of replication testing can make it appear that a finding was not replicated when, in fact, it was. The debate that we focus on is representative, on key dimensions, of a large number of other replication tests in psychology that have been published in recent years, suggesting that the lessons of this analysis may be far reaching. The problems with current practice in replication science that we uncover here are particularly worrisome because they are not adequately addressed by the field’s standard remedies, including preregistration. Implications for how the field could develop more effective methodological standards for replication are discussed. © 2019 National Academy of Sciences. All rights reserved

OXFAM Nicaraguan Operations

General Relief Operations or Program Reports. (70)The digital Cuny Archive was made available in part through funding assistance from USAID.INTERTEC

Comparison of ultrasonographic findings in cats with and without azotaemia

US findings in 238 cats with (serum creatinine >180 μmol/l) and 270 cats without azotaemia were compared in a retrospective case-control study. Cats with pre-renal azotaemia or urethral obstruction were excluded. Data extracted from the medical records included age, body weight and body condition score (BCS). Quantitative and subjective US findings were extracted from archived ultrasound images and contemporaneous reports