The Study of Optimization of Thrust Vector Control Systems

Reliability analyses and failure probabilities of S-4B stage automatic pilots and hydraulic thrust vector control system configurations, and compatibility with actuato

Youth Definitions of Success, Obstacles to Success, and How Significant Others Can Help: Providing Youth a Voice in Their Own Development

Positive Youth Development (PYD) programmes are often conceptualized and led by adults with little or no youth input. The purpose of this study was to better understand youth definitions of success, obstacles they face in achieving success, and how they perceive others can help. Interviews were conducted with 24 youth from three different contexts (swim club, church group, and reform home) in Trinidad and Tobago. The results indicated that youth have a varied understanding of success. Further, many youths’ definitions mirror those prescribed in PYD literature. Youth identified a variety of obstacles in their quest for success, and though similarities existed, several obstacles were context dependent. Finally, youth identified support and assistance as the best mechanisms to propel them to success. Support, both informal and formal, points to the significant role non-parent adults serve in the lives of youth. Implications for youth programmes and future research are discussed

Gauged motion in general relativity and in Kaluza-Klein theories

In a recent paper [1] a new generalization of the Killing motion, the {\it gauged motion}, has been introduced for stationary spacetimes where it was shown that the physical symmetries of such spacetimes are well described through this new symmetry. In this article after a more detailed study in the stationary case we present the definition of gauged motion for general spacetimes. The definition is based on the gauged Lie derivative induced by a threading family of observers and the relevant reparametrization invariance. We also extend the gauged motion to the case of Kaluza-Klein theories.Comment: 42 pages, revised version, typos correction along with some minor changes, Revtex forma

Psychotropic drug influences on brain acetylcholine utilization

The cholinergic antisynthesis agent HC-3 was given intraventricularly to young male rats 20–30 days old to deplete brain acetylcholine (ACh). The rate of HC-3 induced depletion of ACh was used as an index of ACh utilization. Total brain ACh was determined following various doses of chlordiazepoxide, pentobarbital, chlorpromazine, methotrimeprazine, imipramine, morphine, d -amphetamine, scopolamine, LSD-25, and phencyclidine given i.p. alone and after intraventricular administration of HC-3. It was found that psychotropic drugs have marked differential effects on the rate of HC-3 induced ACh depletion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46382/1/213_2004_Article_BF00421968.pd

To Act or Not to Act?: Student-Athlete Perceptions of Social Justice Activism

Issues related to social justice and activism have always permeated sports, but recently, due to the high profile cases of several elite-level athletes (i.e., Colin Kaepernick, Megan Rapinoe), these issues have become much more prominent in the contemporary sporting climate. Even though these highly visible actions are publicized in today’s media environment, little is known about how collegiate student-athletes perceive engaging in social justice activism. Therefore, the current study surveyed 2,092 collegiate student-athletes on their attitudes toward activism engagement using a theory of planned behavior framework with particular attention paid to how gender and ethnicity/race influenced these relationships. A series of MANOVAs indicated that female student-athletes, in relation to male student athletes, and student-athletes of color, in comparison to White student-athletes, held higher perceptions on most of the subscales related to activism. A hierarchical multiple regression analysis indicated attitudes, perceived behavioral control, and subjective norms were significant predictors of athletes’ intention to engage in activism. In addition, interactions of the three predictors with race and gender influenced the final regression model indicating the strength of each predictor was impacted by athlete race and gender. Future research directions and implications for programming in relation to study findings are discussed

A non-uniqueness problem in solar hard X-ray spectroscopy

We consider the hard x-ray emission process by interaction between the electrons and the ions in the solar atmosphere. We provide the integral equations describing this process as an inverse problem in the case of uniform ionization of the plasma and of a simple but rather realistic approximation of non-uniform conditions. The singular system of the integral operators is computed analytically in the continuous case for the uniform ionization model and numerically in the case of discrete data for both uniform and non-uniform ionization conditions. By analytical arguments and analysis of the singular spectrum we point out that non-uniform ionization results in an ambiguous interpretation of the solution of the integral equation, this solution not being unique. Finally, we briefly recall that this analysis facilitates methods for recovering unique and regularized solutions from high-resolution hard x-ray spectral data soon to be forthcoming from the HESSI space mission