Religious Service Attendance and Volunteering: A Growth Curve Analysis

Despite methodological advances in studying the relationship between religious attendance and volunteering, its dynamic nature still needs to be elucidated. We apply growth curve modeling to examine whether trajectories of religious attendance and volunteering are related to each other over a 15-year period in a nationally representative sample from the Americans’ Changing Lives data (1986-2002). Multivariate results showed that the rates of change in religious attendance and volunteering were positively related, and excluding religious volunteering did not alter the finding. It was also found that the initial level of religious attendance was positively associated with the rate of increase in volunteer hours over the period. Mediation analyses revealed that participation in voluntary associations explained the dynamic relationships between religious attendance and volunteering. These results provide evidence that involvement in organized religion and volunteering are dual activities that change together over the adult life course

Tying Knots With Communities: Youth Involvement in Scouting and Civic Engagement in Adulthood

Using data from a nationally representative sample of American adult males (N = 2,512), this study examines (a) whether duration of membership in the Boy Scouts of America is associated with adult civic engagement and (b) whether five characteristics of positive youth development (confidence, competence, connection, character, and caring) account for the relationship between duration of Scouting membership and adult civic engagement. The results from structural equation modeling indicate that duration of participation in Scouting is positively associated with four indicators of civic engagement: community involvement, community volunteering, community activism, and environmental activism. Among the five positive characteristics, confidence and competence were found to fully mediate the effects of Scouting on all four types of civic engagement, whereas the other three only to partly mediate the effects

Effect of Cr and N on the Stress Corrosion Cracking Behavior of Fe-18Mn Steel

High-Mn steels developed for offshore industries require good resistance to stress corrosion cracking (SCC) in seawater. Elements like Cr and N are often added to improve the resistance to SCC. In this study, the SCC behavior of Fe18Mn3Cr0.1N and Fe19Mn19Cr0.6N steels in artificial seawater was examined. Slow strain rate tests were conducted at a nominal strain rate of 10(-6)/sec in air and artificial seawater under anodic and cathodic applied potentials. The tensile ductility drop in artificial seawater was compared to air and evaluated as the resistance to SCC. It was found that both specimens showed intergranular cracking in artificial seawater under both anodic and cathodic applied potentials. The intergranular SCC was more severe under anodic applied potential than cathodic applied potential. However the sensitivity to SCC in artificial seawater was substantially reduced in Fe19Mn19Cr0.6N specimen with higher Cr and N content, as compared to the Fe18Mn3Cr0.1N specimen under both applied potentials. Potentiodynamic tests in artificial seawater showed an increase in pitting corrosion potential, rather than corrosion potential, with increasing Cr and N content in high-Mn steel. The SCC behavior of high-Mn steels with different Cr and N contents was discussed based on micrographic and fractographic observations.11Ysciescopuskc

Low-temperature ion beam mixing of Pt and Si markers in Ge

The mixing of Pt and Si marker atoms in Ge during 750-keV Xe irradiation was measured at temperatures between 6 and 500 K. The low-temperature measurements show that the mixing parameter for Pt is nearly twice that for Si. This result is in strong contradiction to the collisional theory of ion beam mixing. A weak temperature dependence in the mixing is found for both markers

Final Evaluation Report: A Randomized Controlled Trial of the Effectiveness of a Responsible Fatherhood Program: The Case of TYRO Dads

Despite the growing number of responsible fatherhood programs, only a few of them have been evaluated based on a randomized controlled trial. To fill this gap in evaluation research on fatherhood programs, we conducted a single-blind, randomized, controlled trial to assess the effectiveness of an Ohio-based fatherhood program called “TYRO Dads” in improving the father-child relationship among low-income, primarily unmarried, nonresidential fathers. We collected data from 252 fathers who participated in the study at 17 research sites in eight cities in Ohio by conducting a survey three times between February 2015 and September 2016: before the intervention (pretest), immediately after the intervention (post-test), and three months after the intervention (follow-up). Study participants were randomly assigned to two groups: 137 in the intervention or treatment group who took “TYRO Dads,” a five-week fatherhood course (which consists of 10 sessions of 20 hours in total; i.e., two two-hour sessions per week) and 115 in the control group who only were offered the opportunity to attend an informational session about employment resources and other resources available to help them achieve their goals. The primary outcomes of interest include fathers’ reports of satisfaction with parenting their child and the frequency of father-child activities. Also measured were secondary outcomes of intervention: fathers’ parenting efficacy, role identity, coparenting relationship with their child’s mother, and perceived challenges in parenting

Explaining Gender Differences in Changes in Volunteering after Divorce

Although there is evidence that divorce and volunteering are related, little is known about the process by which divorce affects volunteering. Using four-wave panel data spanning 16 years, this study examines the causal mechanisms underlying changes in volunteering following divorce. Results from estimating structural equation models indicated that divorce affects volunteering through different mechanisms for women and men. For women, increased financial strain explained a decline in volunteering after divorce. For men, decreased social integration measured by formal group participation accounted for a decline in volunteering after divorce. Domain-specific analyses further showed that decreased religious attendance following divorce explained a decline in religious volunteering and, at the same time, an increase in secular volunteering among men but not women. Men appear to switch their volunteering domains from religious to secular organizations after divorce

I. Ion-Solid Interactions with Markers. II. Oxidation Phenomena in Silicides and Aluminides

This thesis consists of two main topics: a) study of ion-solid interactions, or "ion mixing", by markers and b) oxidation phenomena of metal silicides and gold aluminides. There are many well-developed theories describing atomic collisions in solids. However, the basic aspects of ion mixing, such as the magnitude of atomic relocation and the formation of certain compounds, have proven elusive to theoretical understanding. We have conducted experiments that provide a data base for an understanding of atomic motion during ion irradiation. In these experiments the so-called "marker" sample configuration was used, where a layer of about 10 Å of an impurity is buried in an otherwise homogeneous medium. When the sample is irradiated, the layer is dispersed. This irradiation-induced spreading of marker layer is measured by backscattering spectrometry. The different amount of spreading in different samples under various experimental conditions yields insight into the atomic displacement mechanisms. Three major mechanisms are known to contribute to the atomic displacements during ion irradiation on solids: a) collisional displacements, b) intermixing by a thermal spike and c) radiation-enhanced diffusion (see chap. 1 for definitions). At low temperatures only the first two mechanisms play role in the atomic displacements; at high temperatures radiation-enhanced diffusion is significant. The irradiations were conducted at temperatures ranging from 7 to 500 K using Kr and Xe ions of energies from 0.3 to 1.0 MeV. The matrix atoms studied range in mass from C to Au. The marker impurities used go from Al to Bi. At low temperatures, the effects of material properties and parameters such as -vmass and cohesive energy of the target, damage energy density in the material, thermal diffusivity, and heat of mixing are investigated. At high temperatures, the effects of the defect creation rate in the material by irradiation and the diffusion mechanisms are studied. The second part of the thesis deals with oxidation phenomena The oxidation of Co and Ni disilicides on SiO₂ substrates is investigated. The motivation of this work is the desire to produce an elemental metal film encapsuled by a protective insulating SiO₂ layer for low resistivity interconnection in VLSI circuits. Electrical, chemical, and morphological properties of the oxidized films were investigated as a function of oxidation duration under various oxidation conditions and Si content in the silicide films. The oxidation of Au aluminides was also investigated. Gold bonds on aluminum metallization for semiconductor devices are under constant physical and chemical changes due to joule heating, electromigration and outgassing of packaging materials. Water and oxygen are some of the main undesirable components in the outgassing of packaging material. We investigate the effects of 50, 70, and 100° C water and wet oxidation at 773 K on thin films of Al and of all five existing binary Au-Al compounds (AuAl₂, AuAl, AU₂Al, Au₅Al₂, and Au₄Al) on SiO₂ substrates.</p

Peptidoglycan architecture of Gram-positive bacteria by solid-state NMR

AbstractPeptidoglycan is an essential component of cell wall in Gram-positive bacteria with unknown architecture. In this review, we summarize solid-state NMR approaches to address some of the unknowns in the Gram-positive bacteria peptidoglycan architecture: 1) peptidoglycan backbone conformation, 2) PG-lattice structure, 3) variations in the peptidoglycan architecture and composition, 4) the effects of peptidoglycan bridge-length on the peptidoglycan architecture in Fem mutants, 5) the orientation of glycan strands with respect to the membrane, and 6) the relationship between the peptidoglycan structure and the glycopeptide antibiotic mode of action. Solid-state NMR analyses of Staphylococcus aureus cell wall show that peptidoglycan chains are surprisingly ordered and densely packed. The peptidoglycan disaccharide backbone adopts 4-fold screw helical symmetry with the disaccharide unit periodicity of 40Å. Peptidoglycan lattice in the S. aureus cell wall is formed by cross-linked PG stems that have parallel orientations. The structural characterization of Fem-mutants of S. aureus with varying lengths of bridge structures suggests that the PG-bridge length is an important determining factor for the PG architecture. This article is part of a Special Issue entitled: NMR Spectroscopy for Atomistic Views of Biomembranes and Cell Surfaces. Guest Editors: Lynette Cegelski and David P. Weliky

Statistical analysis of IMRT dosimetry quality assurance measurements for local delivery guideline

<p>Abstract</p> <p>Purpose</p> <p>To establish our institutional guideline for IMRT delivery, we statistically evaluated the results of dosimetry quality assurance (DQA) measurements and derived local confidence limits using the concept confidence limit of |mean|+1.96σ.</p> <p>Materials and methods</p> <p>From June 2006 to March 2009, 206 patients with head and neck cancer, prostate cancer, liver cancer, or brain tumor were treated using LINAC-based IMRT technique. In order to determine site specific DQA tolerances at a later stage, a hybrid plan with the same fluence maps as in the treatment plan was generated on CT images of a cylindrical phantom of acryl. Points of measurement using a 0.125 cm³ion-chamber were typically located in the region of high and uniform doses. The planar dose distributions perpendicular to the central axis were measured by using a diode array in solid water with all fields delivered, and assessed using gamma criteria of 3%/3 mm. The mean values and standard deviations were used to develop the local confidence and tolerance limits. The dose differences and gamma pass rates for the different treatment sites were also evaluated in terms of total monitor uints (MU), MU/cGy, and the number of PTV's pieces.</p> <p>Results</p> <p>The mean values and standard deviations of ion-chamber dosimetry differences between calculated and measured doses were -1.6 ± 1.2% for H&N cancer, -0.4 ± 1.2% for prostate and abdominal cancer, and -0.6 ± 1.5% for brain tumor. Most of measured doses (92.2%) agreed with the calculated doses within a tolerance limit of ±3% recommended in the literature. However, we found some systematic under-dosage for all treatment sites. The percentage of points passing the gamma criteria, averaged over all treatment sites was 97.3 ± 3.7%. The gamma pass rate and the agreement of ion-chamber dosimetry generally decreased with increasing the number of PTV's pieces, the degree of modulation (MU/cGy), and the total MU beyond 700. Our local confidence limits were comparable to those of AAPM TG 119 and ESTRO guidelines that were provided as a practical baseline for center-to-center commissioning comparison. Thus, our institutional confidence and action limits for IMRT delivery were set into the same levels of those guidelines.</p> <p>Discussion and Conclusions</p> <p>The systematic under-dosage were corrected by tuning up the MLC-related factors (dosimetric gap and transmission) in treatment planning system (TPS) and further by incorporating the tongue-and groove effect into TPS. Institutions that have performed IMRT DQA measurements over a certain period of time need to analyze their accrued DQA data. We confirmed the overall integrity of our IMRT system and established the IMRT delivery guideline during this procedure. Dosimetric corrections for the treatment plans outside of the action level can be suggested only with such rigorous DQA and statistical analysis.</p