Racial Disparities in the Cognition-Health Relationship

This paper investigates how the association between cognitive achievement and self-rated health in middle age differs by race, and attempts to explain these differences. The role of cognition in health determination has received only limited empirical attention, and even less is known about how race may affect this relationship. Using data from the NLSY, I find that while whites with higher cognitive achievement scores tend to report substantially better general health, this relationship is far weaker or wholly absent among blacks. Further tests suggest that about 35% of this racial difference can be explained by behavioral decisions during adulthood, and that another portion of the disparity may trace back to prenatal and early childhood experiences. The paper closes by noting that its results are broadly consistent with explanations of the racial health gap that emphasize entrenched forms of racial discrimination. JEL Categories:Cognition, Health, Race, AFQT, Birth Weight

The Returns to Skill and Racial Difference in Parenting: Evidence from the Civil Rights Movement

On average, the parental practices adopted by African American parents of young children are much less cognitively stimulating than those of their white counterparts. This paper argues that these differences stem from the low rates of return to human capital historically experienced by African Americans. To study the relationship between the race-specific returns to skill and parenting, I use intergenerational data containing direct measures of parental behaviors, and examine the child rearing practices of mothers who came of age in the wake of the Civil Rights Movement, during a period of rapidly increasing returns to skill for African Americans in the US South. I find that among Southern African American mothers born between 1957 and 1964, each yearly birth cohort increased their parental investment levels by over .07 standard deviations, but that there was no increase among Southern whites or non-Southern African Americans. These differences are interpreted as being due to the disproportionately large increase in the rate of return to skill experienced by Southern African Americans, suggesting a strong relationship between the returns to human capital and parental behaviors. JEL Categories: J01; I24; J24; J71race, parenting, returns to skill, achievement gap and human capital development

Human Capital and Black-White Earnings Gaps, 1996–2017

This paper estimates the contribution of human capital to the Black-white earnings gap in three separate samples of men spanning from 1966 through 2017, using both educational attainment and performance on standardized tests to measure human capital. There are three main findings. First, the magnitude of reductions in the Black-white earnings gap that occur after controlling for human capital has become much larger over time, suggesting a growing contribution of human capital to Black-white earnings disparities. Second, these increases are almost entirely due to growth in the returns to human capital, which magnify the impact of any racial differences in human capital levels, rather than to increasing racial gaps in the human capital traits themselves. Finally, growth in the explanatory power of human capital has been primarily due to increases in the association between human capital and the likelihood of nonwork, with no clear increases in the extent to which human capital explains Black-white wage differences. These findings highlight how apparently race-neutral structural developments in the U.S. labor market, such as increasing skill prices and falling labor force participation rates among less-skilled men, have had large impacts on racial inequity

Characteristics of the Rachitogenic Activity in Isolated Soybean Protein

The characteristics of the rachitogenic activity in isolated soybean protein were investigated. Day-old Broad Breasted White and/or Wrolstad Small White turkey poults were used. Levels of calcium, phosphorus and vitamin D3 were equal to or greater than National Research Council recommendations. Criteria used for evaluation were body weight gains, tibia ash, serum alkaline phosphate, serum inorganic phosphate and serum calcium. Trays containing dry isolated soybean protein spread to a uniform depth of two and one-half centimeters were placed in an autoclave and brought to 100oC by steaming and then 120oC for a designated period of time. The poults were kept in electrically heated wire-floor batteris. Water and food supplied ad libitum for the 4 week experimental periods. When serum values were studied, blood was taken by heart puncture from a representative sample of birds (five when possible) from each group. The serum was removed, placed in vials and stored at -20oC. Under the conditions of this investigation the following observations were made: 1. In general, poults fed untreated isolated soybean protein consistently exhibited rachitic symptoms, namely low tibia ash values and concomitant elevated serum alkaline phosphatase levels. The effects of the isolated soybean protein as measured by the other criteria were less consistent. 2. Subjecting isolated soybean protein to autoclaving destroyed its rachitogenic activity. Autoclaving proved to be the most effective way of reducing the rachitogenic property of isolated soybean protein. 3. Sixty minutes autoclaving time at 120oC proved optimum in destroying the rachitogenic activity of isolated soybean protein. 4. Substituting dibasic calcium phosphate, hydrous, U.S.P., for dicalcium phosphate, feed grade, markedly reduced the rachitogenic activity of the isolated soybean protein. 5. The inclusion of vitamin D3 levels four times the National Research Council recommendations was less effective than autoclaving in reducing the rachitogenic activity of isolated soybean protein. 6. It appears that the Broad Breasted White strain of poults is more susceptible to the onset of rickets as induced by untreated isolated soybean protein compared to the Wrolstad Small White strain. 7. Tibia ash gains should be studied when investigating the effect of ration treatments on tibia ash differences that might be present due to strain or nutritional effects. 8. The dilution of isolated soybean protein with autoclaved isolated soybean protein in the ratio of 2:2 was effective in reducing the rachitogentic activity of isolated soybean protein, however, it required one part of untreated isolated soybean protein to three parts of autoclaved isolated soybean protein to three parts of autoclaved isolated soybean protein to overcome the growth depressing action of isolated soybean protein. 9. The rachitogenic effect of isolated soybean protein exerts its greatest effect on the birds between 2 and 4 weeks of age. 10. Two-way interrelationships existed between autoclaving vitamin D3, autoclaving x source of calcium and phosphate, autoclaving x strain and vitamin D3 x strain; also there was a three-way interrelationship between autoclaving x source of calcium and phosphate x vitamin D3 level. 11. The variability in the Ca45 experiment was great and consequently raises a question as to the reliability of the data. Nevertheless, the data suggest that feeding autoclaved isolated soybean protein like increasing vitamin D3 does play a role in increasing calcium deposition by increasing calcium absorption and/or decreasing calcium secretion into the intestine

Costs of hauling bulk milk from farm to plant

Also available online.Digitized 2007 AES

Feature-based reverse engineering of mechanical parts

Journal ArticleReverse engineering of mechanical parts requires extraction of information about an instance of a particular part sufficient to replicate the part using appropriate manufacturing techniques. This is important in a wide variety of situations, since functioning CAD models are often unavailable or unusable for parts which must be duplicated or modified. Computer vision techniques applied to 3-D data acquired using non-contact, three-dimensional position digitizers have the potential for significantly aiding the process. Serious challenges must be overcome, however, if sufficient accuracy is to be obtained and if models produced from sensed data are truly useful for manufacturing operations. This paper describes a prototype of a reverse engineering system which uses geometric representations natural to the manufacturing process. The system is interactive, which improves performance and allows for human entry of information that cannot be acquired from sensed data alone

Examining heterogeneity of education intervention effects using quantile mixed models: a re-analysis of a cluster-randomized controlled trial of a fluency-based mathematics intervention

Traditionally, cluster randomized controlled trials are analyzed with the average intervention effect of interest. However, in populations that contain higher degrees of heterogeneity or variation may differ across different values of a covariate, which may not be optimal. Within education and social science contexts, exploring the variation in magnitude of treatment effect at different points in the population can indicate where the intervention is most effective rather than assuming an average effect. Data from [Owen, K.L., et al., 2021. Implementation support improves outcomes of a fluency-based mathematics strategy: A cluster-randomized controlled trial. Journal of research on educational effectiveness, 14 (3), 523–542.] were reanalyzed using three modeling approaches: conditional mean-modeling reporting the average treatment effect using linear mixed models, and two quantile regression-based methods. Quantile regressions report the quantile treatment effects at different percentiles: 10th, 25th, 50th, 75th and 90th. For the Quantile approaches, a significant intervention effect in the median to upper quantiles was found and linear quantile mixed model showed improved fit over the other approaches. An improved picture of intervention effects may be apparent using quantile regression methods when analyzing cluster randomized trials that have heterogeneous error variance. In particular, the linear quantile mixed model shows improved model fit allowing a multilevel framework to include random effects. There is considerable scope to extend this framework to incorporate more complex RCT designs

Southern California Elementary Physical Education Specialists and Non- Specialists: Beliefs and Behaviors of the Ideal Purpose and Actual Function of Elementary Physical Education

This study explored the beliefs and behaviors of elementary physical education providers in California relative to the purpose and function of elementary physical education. Research on these types of beliefs and behaviors is important because of the implications on physical education programs conducted in the elementary schools. Properly implemented physical education has been demonstrated to have a positive impact on the fitness levels and motor skill development of students, and such education may lead to the habituation of lifelong physical activity. Randomly selected teachers in southern California school districts completed a three-part questionnaire assessing their beliefs and behaviors regarding the ideal purpose and actual function of elementary physical education. Results of this study indicate that participants were aware of the importance of physical education, but overall, failed to exhibit behaviors that matched their beliefs. These results are pertinent because, in many school districts, primarily nonspecialists will be providing physical education instruction at the elementary level. Understanding the beliefs of non-specialists will help university teacher education programs identify programmatic changes to better prepare elementary school teachers

My Way or the Highway: a More Naturalistic Model of Altruism Tested in an Iterative Prisoners' Dilemma

There are three prominent solutions to the Darwinian problem of altruism, kin selection, reciprocal altruism, and trait group selection. Only one, reciprocal altruism, most commonly implemented in game theory as a TIT FOR TAT strategy, is not based on the principle of conditional association. On the contrary, TIT FOR TAT implements conditional altruism in the context of unconditionally determined associates. Simulations based on Axelrod\'s famous tournament have led many to conclude that conditional altruism among unconditional partners lies at the core of much human and animal social behavior. But the results that have been used to support this conclusion are largely artifacts of the structure of the Axelrod tournament, which explicitly disallowed conditional association as a strategy. In this study, we modify the rules of the tournament to permit competition between conditional associates and conditional altruists. We provide evidence that when unconditional altruism is paired with conditional association, a strategy we called MOTH, it can out compete TIT FOR TAT under a wide range of conditions.Game Theory; Altruism; Prisoners' Dilemma; TIT FOR TAT; MOTH; Docking; Netlogo

Start to end simulations of the ERL prototype at Daresbury Laboratory

Daresbury Laboratory is currently building an Energy Recovery Linac Prototype (ERLP) that will serve as a research and development facility for the study of beam dynamics and accelerator technology important to the design and construction of the proposed 4th Generation Light Source (4GLS) project. Two major objectives of the ERLP are the demonstration of energy recovery and of energy recovery from a beam disrupted by an FEL interaction as supplied by an infrared oscillator system. In this paper we present start-to-end simulations of the ERLP including such an FEL interaction. The beam dynamics in the highbrightness injector, which consists of a DC photocathode Gun and a superconducting booster, have been modelled using the particle tracking code ASTRA. After the booster the particles have been tracked with the code elegant. The 3D code GENESIS 1.3 was used to model the FEL interaction with the electron beam at 35 MeV. A brief summary of impedance and wakefield calculations for the whole machine is also given