Adolescent Dating Violence Victimization and Psychological Well-Being

This study assesses the relationship between adolescents' dating violence victimization and their psychological well-being. The participants were 190high school students, ages 13 to 19 years, with just over half being boys (53%) and the remainder being girls (47%). Data were collected using self-administered questionnaires. For girls, increasing levels of dating violence (severity, frequency, injury) were related to higher levels of post-traumatic stress and dissociation, even after controlling for demographic, family violence, and social desirability variables. For boys, the levels of victimization were related to higher levels of anxiety, depression, and posttraumatic stress, even after controlling for other variables. For both boys and girls, victimization was related to lower levels of life satisfaction, but not after controlling for the demographic, family violence, and social desirability variables. The research questions and findings are discussed in relation to the developmental challenges faced by adolescents.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90512/1/Callahan-Tolman-Saunders 2003 Adolescent dating violence victimization JAR.pd

Sensitivity bond graphs

A sensitivity bond graph, of the same structure as the system bond graph, is shown to provide a simple and effective method of generating sensitivity functions of use in optimisation. The approach is illustrated in the context of partially known system parameter and state estimation

Searching for Inflow Towards Massive Starless Clump Candidates Identified in the Bolocam Galactic Plane Survey

Recent Galactic plane surveys of dust continuum emission at long wavelengths have identified a population of dense, massive clumps with no evidence for on-going star formation. These massive starless clump candidates are excellent sites to search for the initial phases of massive star formation before the feedback from massive star formation effects the clump. In this study, we search for the spectroscopic signature of inflowing gas toward starless clumps, some of which are massive enough to form a massive star. We observed 101 starless clump candidates identified in the Bolocam Galactic Plane Survey (BGPS) in HCO+ J = 1-0 using the 12m Arizona Radio Observatory telescope. We find a small blue excess of E = (Nblue - Nred)/Ntotal = 0.03 for the complete survey. We identified 6 clumps that are good candidates for inflow motion and used a radiative transfer model to calculate mass inflow rates that range from 500 - 2000 M /Myr. If the observed line profiles are indeed due to large-scale inflow motions, then these clumps will typically double their mass on a free fall time. Our survey finds that massive BGPS starless clump candidates with inflow signatures in HCO+ J = 1-0 are rare throughout our Galaxy.Comment: 14 pages, 9 figure

Principal/Instructional Leader Support for Teachers Through Mastery Experiences: A Mixed Methods Study of Teacher Self-Efficacy

This mixed method study examined the influence of mastery experience opportunities as principal support from teachers’ perceptions of their teacher efficacy. This study examined whether mastery experiences, provided through teacher support, influences teacher efficacy, providing a picture of how efficacy is developed and supported by instructional leaders and guided by Bandura’s (1995, 1997) theory. This study was executed in a small rural southeastern United States school district in three phases. Phase 1 included the administration of the Teacher Self-efficacy Survey (Woolfolk-Hoy & Tschanen-Moran’s, 2001) at three sites, as baseline data. Phase 2 included the pre-intervention Teacher Self-efficacy Survey (Woolfolk-Hoy & Tschanen-Moran’s, 2001) administered to teachers (N = 5) volunteering to participate in the mastery experience opportunity. After completing the mastery experience, teachers were interviewed and given a post-intervention Teacher Self-efficacy Survey (Woolfolk-Hoy & Tschanen-Moran’s, 2001) for phase 3 of the study.Data analysis yielded elements that suggested the mastery experience opportunity had a positive impact on teacher responses to the TSES as well as a perceived influence on teacher efficacy through interview responses and observation. The findings of this research study support Bandura’s (1997) theory that mastery experiences are influential to the development of efficacy beliefs. The teachers participating in the mastery opportunity experience expressed that the immediate feedback, positive and constructive feedback, and feedback in the classroom setting were specific elements of the mastery experience that influenced their perception of teacher efficacy. This also supports Bandura’s (1997) theory that mastery experiences are most influential on self-efficacy. Moreover, increased efficacy provided needed perseverance and resiliency to the individual when developing or improving a new skill. Finally, a model for mastery experience opportunity was provided that could be utilized to support instructional leaders as they assist teachers in ways that improve teacher efficacy

A massively-parallel Navier-Stokes implementation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76255/1/AIAA-1989-1940-323.pd

Correlating the Physicochemical Properties of Magnesium Stearate with Tablet Dissolution and Lubrication

Magnesium stearate (MgSt) is the most commonly used pharmaceutical excipient and is present in over half the tablet formulations on the market. In spite of its popularity as an effective lubricant, it has been repeatedly recognized that there is significant variability between MgSt samples, which can cause inconsistent lubrication between batches of MgSt. The hypothesis of this research is that the batch-to-batch variability in tablet lubrication and dissolution observed in tablet formulations containing different MgSt samples can be correlated with differences in MgSt physicochemical properties (fatty acid salt composition, crystal hydrate form, particle size and surface area). Developing correlations between MgSt properties has been challenging in part because there has not been a reliable method for determining crystal form. Recently, 13C solid-state nuclear magnetic resonance (SSNMR) has been used to clearly identifying the MgSt crystal forms. 13C SSNMR is used extensively throughout this work to identify the crystal forms of samples of MgSt. Thermogravimetric analysis and dynamic scanning calorimetry were used as complimentary techniques to understand thermal behavior of the samples. MgSt is typically used in tablets at low levels (0.2-5%), leading to challenges with detection of MgSt in formulations. To enhance detection in SSNMR, samples of MgSt have been synthesized in the lab using 13C-labeled stearic acid. Specific surface area (SSA) results were determined using N2 and Kr adsorption with BET calculations, and samples were dried using nitrogen flow for various times. A discriminating dissolution method was developed to differentiate between MgSt samples with varying properties. Lubrication efficiency was performed using a Presster compaction simulator and tensile strength determination using diametrical compression. Synthesis studies showed that the fatty acid composition and synthesis method affects the crystal form of MgSt produced, with higher stearic content preferring the dihydrate form. Temperature and humidity affect the form of MgSt and facilitate interconversion between forms. Drying MgSt was found to affect surface area results, with the dihydrate converting to the disordered form. Dissolution of indomethacin tablets containing various types of MgSt showed a strong dependence on particle size and surface area, with smaller particle size and higher SSA samples having slower dissolution rates. Fatty acid composition and hydrate form were investigated as secondary variables influencing dissolution, with fatty acid showing no correlation with dissolution. Lubrication efficiency and tabletability studies showed an effect of crystal form, with monohydrate and dihydrate forms showing good lubrication efficiency compared to the disordered form, but also poorer tabletability. In conclusion, the potential for variability in the crystal form of MgSt was found to be an important property of MgSt. There is variability in the form produced from synthesis, as well as interconversion between forms. Temperature, humidity and drying conditions are particularly important in controlling the crystal form of MgSt, as this can impact formulation stability and storage conditions. The primary variable affecting dissolution is particle size and surface area, but crystal form is a potential secondary variable. The physicochemical properties of MgSt, particularly crystal form and surface area, showed trends with lubrication and dissolution. This highlights the importance of choosing a MgSt material with the desired crystal form and surface area properties to match the lubrication and dissolution requirements for the formulation

Estimation and control of mechatronic systems using sensitivity bond graphs

A new bond graph framework for sensitivity theory is applied to model-based predictive control, state estimation, and parameter estimation in the context of physical systems. The approach is illustrated using a nonlinear mechatronic system

Performance of a finite volume CEM code on multicomputers

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77161/1/AIAA-1994-236-711.pd