323 research outputs found
Calibration and parametric study of the Alcator C-Mod charge exchange neutral particle analyzers
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1995.Includes bibliographical references (leaves 103-104).by Jody Christopher Miller.M.S
The effect of reciprocity priming on organ donor registration intentions and behavior
Background: Internationally the demand for organ transplants far exceeds the available supply of donated organs. Purpose: We examine if a digital reciprocity prime based on reciprocal altruism can be used to increase organ donor registration intentions and behavior. Methods: 420 participants (223 females) from England and Scotland aged 18+ who were not currently registered organ donors were randomized by block allocation using a 1:1 ratio to receive either a reciprocity prime or control message. After manipulation, they were asked to indicate their organ donation intentions and whether or not they would like to be taken to an organ donation registration and information page. Results: In line with our previous work, participants primed with a reciprocity statement reported greater intent to register as an organ donor than controls (using a 7-point Likert scale where higher scores = greater intention; prime mean = 4.3 (1.6) vs. control mean = 3.7 (1.4), P =< .001, d =0.4 [95%CI = 0.21-0.59]). There was again however, no effect on behavior as rates of participants agreeing to receive the donation register web-link were comparable between those primed at 11% (n= 23/210) [95%CI = 7.4-16.0] and controls at 12% (n= 25/210) [95%CI = 8.1-17.1], X²(1) = 0.09, p = .759. Conclusions: Reciprocal altruism appears useful for increasing intention towards joining the organ donation register. It does not however appear to increase organ donor behavior
Enhancing the Employability of Humanities Postgraduates: a Students as Academic Partners Project Report
In an increasingly competitive employment market, postgraduates need to demonstrate more than the ‘skills,
knowledge, attitudes and experiences that are closely
associated with the research process’ (Golovushkina &
Milligan, 2013: 199). Yet results indicate that Worcester
postgraduate students remain unaware of the full range of
opportunities that exist alongside postgraduate study, and
how this affects their subsequent employability. This
research, undertaken with humanities post-graduate
students at University of Worcester, aims to contribute to
discussions about how to enhance the employability of
humanities postgraduates through extra-curricular
activities. The project was implemented as a Students
-As-Partners-in-Learning-Project, using action research; the issue was identified, base-line data collected and this resulted in the creation of a postgraduate blog incorporating suggestions of possible opportunitie
s and links to relevant websites for further information. Informed by this research, the student partners then took active roles in the organization of the Women’s History Network National Conference, ‘Home Fronts: Gender, War and Conflict’, hosted at the University of Worcester in September 2014, to broaden their existing skills base and then to connect this involvement to their professional development through a group CV review. The participants’ own experiences of wider engagement can therefore illuminat
e new ways for understanding employability in relation to humanities postgraduate students
Study Methodology
Data for this investigation come from 36 qualitative in-depth interviews completed between February and April 2010. The aim of the research was to conduct a process evaluation of Gateway Foundation programming for state probation and parole clients in St. Louis and jointly produce a final report for the organization. The specific research questions focused on (1) the challenges men face as they attempt to overcome substance abuse; (2) how those challenges are related to past experiences with crime, including offending and victimization; and (3) the effectiveness of Gateway programming, from the points of view of program participants, including whether there are any perceived differences between men who participate in the program post-incarceration versus in lieu of incarceration
Adapting a number sense task to learn more about K-5 student reasoning
Look deeper into how 5th grade students think through a task by examining standards from earlier grades
Changes in insulin sensitivity over time and associated factors in HIV-infected adolescents
OBJECTIVE:
To compare prevalence of insulin resistance between perinatally HIV-infected (PHIV+) and perinatally HIV-exposed, but uninfected adolescents (PHEU), determine incidence of and contributory factors to new and resolved cases of insulin resistance in PHIV+, and evaluate glucose metabolism.
DESIGN:
Cross-sectional design for comparison of prevalence among PHIV+ and PHEU. Longitudinal design for incidence and resolution of insulin resistance among PHIV+ at risk for these outcomes.
METHODS:
The source population was adolescents from pediatric HIV clinics in the United States and Puerto Rico participating in the Pediatric HIV/AIDS Cohort Study, an ongoing prospective cohort study designed to evaluate impact of HIV infection and its treatment on multiple domains in preadolescents and adolescents. Insulin resistance was assessed by homeostatic model assessment of insulin resistance. Those with incident insulin resistance underwent 2-h oral glucose tolerance test and HbA1c. Baseline demographic, metabolic, and HIV-specific variables were evaluated for association with incident or resolved insulin resistance.
RESULTS:
Unadjusted prevalence of insulin resistance in PHIV+ was 27.3 versus 34.1% in PHEU. After adjustment for Tanner stage, age, sex, and race/ethnicity, there was no significant difference between groups. Factors positively associated with developing insulin resistance included female sex, higher BMI z score, and higher waist circumference; those associated with resolving insulin resistance included male sex and lower BMI z score.
CONCLUSION:
Prevalence of insulin resistance in PHIV+ and PHEU was substantially higher than that reported in HIV-uninfected nonoverweight youth, but similar to that in HIV-uninfected obese youth. Factors associated with incident or resolved insulin resistance among PHIV+ were similar to those reported in HIV-negative obese youth. However, a contributory role of HIV infection and/or its treatment to the incident risk of insulin resistance cannot be excluded
A cyclic-di-GMP receptor required for bacterial exopolysaccharide production
Bis-(3′,5′)-cyclic-dimeric-guanosine monophosphate (c-di-GMP) has been shown to be a global regulatory molecule that modulates the reciprocal responses of bacteria to activate either virulence pathways or biofilm formation. The mechanism of c-di-GMP signal transduction, including recognition of c-di-GMP and subsequent phenotypic regulation, remain largely uncharacterized. The key components of these regulatory pathways are the various adaptor proteins (c-di-GMP receptors). There is compelling evidence suggesting that, in addition to PilZ domains, there are other unidentified c-di-GMP receptors. Here we show that the PelD protein of Pseudomonas aeruginosa is a novel c-di-GMP receptor that mediates c-di-GMP regulation of PEL polysaccharide biosynthesis. Analysis of PelD orthologues identified a number of conserved residues that are required for c-di-GMP binding as well as synthesis of the PEL polysaccharide. Secondary structure similarities of PelD to the inhibitory site of diguanylate cyclase suggest that a common fold can act as a platform to bind c-di-GMP. The combination of a c-di-GMP binding site with a variety of output signalling motifs within one protein domain provides an explanation for the specificity for different cellular responses to this regulatory dinucleotide
Additive drug-specific and sex-specific risks associated with co-use of marijuana and tobacco during pregnancy: Evidence from 3 recent developmental cohorts (2003-2015).
BACKGROUND: Methodologic challenges related to the concomitant use (co-use) of substances and changes in policy and potency of marijuana contribute to ongoing uncertainty about risks to fetal neurodevelopment associated with prenatal marijuana use. In this study, we examined two biomarkers of fetal neurodevelopmental risk-birth weight and length of gestation-associated with prenatal marijuana use, independent of tobacco (TOB), alcohol (ALC), other drug use (OTH), and socioeconomic risk (SES), in a pooled sample (N = 1191) derived from 3 recent developmental cohorts (2003-2015) with state-of-the-art substance use measures. We examined differential associations by infant sex, and multiplicative effects associated with co-use of MJ and TOB.
METHODS: Participants were mother-infant dyads with complete data on all study variables derived from Growing Up Healthy (n = 251), Behavior and Mood in Babies and Mothers (Cohorts 1 and 2; n = 315), and the Early Growth and Development Study (N = 625). We estimated direct effects on birth weight and length of gestation associated with MJ, TOB, and co-use (MJ x TOB), using linear regression analysis in the full sample, and in male (n = 654) and female (n = 537) infants, separately.
RESULTS: Mean birth weight and length of gestation were 3277 g (SD = 543) and 37.8 weeks (SD = 2.0), respectively. Rates of prenatal use were as follows: any use, n = 748 (62.8%); MJ use, n = 273 (22.9%); TOB use, n = 608 (51.0%); co-use of MJ and TOB, n = 230 (19.3%); ALC use, n = 464 (39.0%); and OTH use n = 115 (9.7%.) For all infants, unique effects on birth weight were observed for any MJ use [B(SE) = -84.367(38.271), 95% C.I. -159.453 to -9.281, p = .028], any TOB use [B(SE) = -0.99.416(34.418), 95% C.I. -166.942 to -31.889, p = .004], and each cigarette/day in mean TOB use [B(SE) = -12.233(3.427), 95% C.I. -18.995 to -5.510, p \u3c .001]. Additional effects of co-use on birth weight, beyond these drug-specific effects, were not supported. In analyses stratified by sex, while TOB use was associated with lower birth weight in both sexes, MJ use during pregnancy was associated with lower birth weight of male infants [B(SE) = -153.1 (54.20); 95% C.I. -259.5 to -46.7, p = .005], but not female infants [B(SE) = 8.3(53.1), 95% C.I. -96.024 to 112.551, p = .876]. TOB, MJ, and their co-use were not associated with length of gestation.
CONCLUSIONS: In this sample, intrauterine co-exposure to MJ and TOB was associated with an estimated 18% reduction in birth weight not attributable to earlier delivery, exposure to ALC or OTH drugs, nor to maternal SES. We found evidence for greater susceptibility of male fetuses to any prenatal MJ exposure. Examination of dose-dependence in relationships found in this study, using continuous measures of exposure, is an important next step. Finally, we underscore the need to consider (a) the potential moderating influence of fetal sex on exposure-related neurodevelopmental risks; and (b) the importance of quantifying expressions of risk through subtle alterations, rather than dichotomous outcomes
A Comparison of Tandem Walk Performance Between Bed Rest Subjects and Astronauts
Astronauts experience a microgravity environment during spaceflight, which results in a central reinterpretation of both vestibular and body axial-loading information by the sensorimotor system. Subjects in bed rest studies lie at 6deg head-down in strict bed rest to simulate the fluid shift and gravity-unloading of the microgravity environment. However, bed rest subjects still sense gravity in the vestibular organs. Therefore, bed rest isolates the axial-unloading component, thus allowing for the direct study of its effects. The Tandem Walk is a standard sensorimotor test of dynamic postural stability. In a previous abstract, we compared performance on a Tandem Walk test between bed rest control subjects, and short- and long-duration astronauts both before and after flight/bed rest using a composite index of performance, called the Tandem Walk Parameter (TWP), that takes into account speed, accuracy, and balance control. This new study extends the previous data set to include bed rest subjects who performed exercise countermeasures. The purpose of this study was to compare performance during the Tandem Walk test between bed rest subjects (with and without exercise), short-duration (Space Shuttle) crewmembers, and long-duration International Space Station (ISS) crewmembers at various time points during their recovery from bed rest or spaceflight
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