1,209 research outputs found
In Which Schools Does Police Presence Most Exacerbate Racial Differentials in Arrest?
This study looks at racial disproportionalities in student arrests, particularly with school police presence. This study extends Homer and Fisher’s (2020) work, which finds higher arrest rates and stronger effects of police presence for Black than White students across schools, by investigating school racial compositions and context factors that are associated with the strongest relationships between police presence and higher arrest rates of Black than White students. Results show the largest within-school arrest rate differences between Black and White students in high schools with officers and that schools with lower Black student enrollment percentages show larger Black-White student arrest gaps
Large NaCl-effect on the Decomposition Rate of Chlorate Ions in HCl-containing Brine Solutions and Its Consequences for the Chlor-alkali Industry
The decomposition rate of chlorate (NaClO3) in aqueous solutions (brines) containing initially 6:1 mol/mol HCl:NaClO3 is studied at 90°C at various NaCl contents experimentally. A strong positive effect of NaCl addition is shown on the decomposition rate of chlorate. It is found more reasonable in the chlor-alkali industry first to saturate the brine by sodium chloride and only then to eliminate from it the chlorate by adding HCl (before the solution is transferred into the electrolysis cell to be protected from the chlorate ions)
Head Start at Ages 3 and 4 Versus Head Start Followed by State Pre-K: Which Is More Effective?
As policy-makers contemplate expanding preschool opportunities for low-income children, one possibility is to fund two, rather than one year of Head Start for children at ages 3 and 4. Another option is to offer one year of Head Start followed by one year of pre-k. We ask which of these options is more effective. We use data from the Oklahoma pre-k study to examine these two ‘pathways’ into kindergarten using regression discontinuity to estimate the effects of each age-4 program, and propensity score weighting to address selection. We find that children attending Head Start at age 3 develop stronger pre-reading skills in a high quality pre-kindergarten at age 4 compared with attending Head Start at age 4. Pre-k and Head Start were not differentially linked to improvements in children’s pre-writing skills or pre-math skills. This suggests that some impacts of early learning programs may be related to the sequencing of learning experiences to more academic programming
Development and validation of a duplex RT-qPCR assay for norovirus quantification in wastewater samples
Battery Study for the Shuttle Orbiter EAPU Upgrade
The use of Electric Auxiliary Power Unit (EAPU) in commercial, and military aviation, and in commercial electric automobiles, is reviewed. The specifications of the battery to be used in the space shuttle are reviewed, and the possible vendors discussed. The testing activity and the reliability and the safety features are presented
The Subcomponents of Affect Scale (SAS): Validating a Widely Used Affect Scale
Objective
There is a need for a brief affect scale that also encompasses different components of affect relevant for researchers interested in physiological and health outcomes. The Subcomponents of Affect Scale (SAS) meets this need. This 18-item scale has nine positive and nine negative affect items encompassing six subscales (calm, well-being, vigour, depression, anxiety, anger). Previous research using the SAS has demonstrated its predictive validity, but no work has tested its subscale structure or longitudinal validity. Design
Data from the Common Cold Project in which individuals (N = 610) completed the SAS over the course of seven days were used. Results
Confirmatory factor analysis demonstrated the reliability of the subscale structure of the SAS across seven days (positive affect subscale structure: CFIs ≥ 0.98; negative affect subscale structure: CFIs ≥ 0.94 with day 6 CFI = 0.91) and tests of factorial invariance showed the scale is valid to use over time. Conclusions
These results confirm the psychometric validity of the subscale structure of the SAS and imply that the subscales can be used longitudinally, allowing for its use in health research as well as non-health research that can benefit from its subscale structure and longitudinal capabilities
Preschool center care quality effects on academic achievement: An instrumental variables analysis.
Much of child care research has focused on the effects of the quality of care in early childhood settings on children's school readiness skills. Although researchers increased the statistical rigor of their approaches over the past 15 years, researchers' ability to draw causal inferences has been limited because the studies are based on nonexperimental designs. The purpose of the present study was to demonstrate how an instrumental variables approach can be used to estimate causal impacts of preschool center care quality on children's academic achievement when applied to a study in which preschool curricula were randomly assigned across multiple sites. We used data from the Preschool Curriculum Evaluation Research Initiative (PCER; n = 2,700), in which classrooms or preschools were randomly assigned to that grantee's treatment curriculum or "business as usual" conditions in 18 research sites. Using this method, we demonstrate how developmental researchers can exploit the random-assignment designs of multisite studies to investigate characteristics of programs, such as preschool center care quality, that cannot be randomly assigned and their impacts on children's development. We found that the quality of preschool care received by children has significant, albeit modest, effects on children's academic school readiness, with effect sizes of .03 to .14 standard deviation increases in academic achievement associated with a 1 standard deviation increase in quality. Applications and potential policy implications of this method are discussed
Elevated Systemic Pentraxin-3 Is Associated With Complement Consumption in the Acute Phase of Thrombotic Microangiopathies
Pentraxin-3 (PTX3) and C-reactive protein (CRP) have been shown to regulate complement activation in vitro, but their role has not been investigated in complement consumption in vivo. Thrombotic microangiopathies (TMA) are often accompanied by complement overactivation and consumption, therefore we analyzed the relation of the systemic pentraxin levels to the complement profile, laboratory parameters and clinical outcome of TMA patients. We determined the PTX3 and CRP levels, complement factor and activation product concentrations in blood samples of 171 subjects with the diagnosis of typical hemolytic uremic syndrome (STEC-HUS) (N = 34), atypical HUS (aHUS) (N = 44), secondary TMA (N = 63), thrombotic thrombocytopenic purpura (TTP) (N = 30) and 69 age-matched healthy individuals. Clinical data, blood count and chemistry were collected from medical records. To determine the in vitro effect of PTX3 on alternative pathway (AP) activation, sheep red blood cell-based hemolytic assay and AP activity ELISA were used. We found that PTX3 levels were elevated in the acute phase of STEC-HUS, aHUS and secondary TMA, whereas PTX3 elevation was exceptional is TTP. Conversely, a significantly higher median CRP was present in all patient groups compared to controls. PTX3, but not CRP was associated with signs of complement consumption in vivo, and PTX3 significantly decreased the AP hemolytic activity in vitro. Our results provide a detailed description of acute phase-TMA patients' complement profile linked to changes in the systemic pentraxin levels that may support further molecular studies on the function of PTX3 in disease pathogenesis and add to the laboratory assessment of complement consumption in TMA
The (Surprising) Efficacy of Academic and Behavioral Intervention with Disadvantaged Youth : Results from a Randomized Experiment in Chicago
There is growing concern that improving the academic skills of disadvantaged youth is too difficult and costly, so policymakers should instead focus either on vocationally oriented instruction for teens or else on early childhood education. Yet this conclusion may be premature given that so few previous interventions have targeted a potential fundamental barrier to school success: "mismatch" between what schools deliver and the needs of disadvantaged youth who have fallen behind in their academic or non-academic development. This paper reports on a randomized controlled trial of a two-pronged intervention that provides disadvantaged youth with non-academic supports that try to teach youth social-cognitive skills based on the principles of cognitive behavioral therapy (CBT), and intensive individualized academic remediation. The study sample consists of 106 male 9th and 10th graders in a public high school on the south side of Chicago, of whom 95% are black and 99% are free or reduced price lunch eligible. Participation increased math test scores by 0.65 of a control group standard deviation (SD) and 0.48 SD in the national distribution, increased math grades by 0.67 SD, and seems to have increased expected graduation rates by 14 percentage points (46%). While some questions remain about the intervention, given these effects and a cost per participant of around 3,000 to $6,000), this intervention seems to yield larger gains in adolescent outcomes per dollar spent than many other intervention strategies
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