273 research outputs found
Building Equalizing Schools Within Inclusive Communities: Strategies That Redirect the School to Prison Pipeline in the Classroom and Beyond
Exclusionary school discipline, also known as "zero tolerance," was chosen as the subject of this report for three reasons: it offers a window into inequalities in education, criminal justice, and broader social life; social scientists have come to a consensus about its harms and provided clear alternatives; and it illustrates the need for comprehensive knowledge and holistic solutions for complex problems
Optimizing the fine lock performance of the Hubble Space Telescope fine guidance sensors
This paper summarizes the on-orbit performance to date of the three Hubble Space Telescope Fine Guidance Sensors (FGS's) in Fine Lock mode, with respect to acquisition success rate, ability to maintain lock, and star brightness range. The process of optimizing Fine Lock performance, including the reasoning underlying the adjustment of uplink parameters, and the effects of optimization are described. The Fine Lock optimization process has combined theoretical and experimental approaches. Computer models of the FGS have improved understanding of the effects of uplink parameters and fine error averaging on the ability of the FGS to acquire stars and maintain lock. Empirical data have determined the variation of the interferometric error characteristics (so-called 's-curves') between FGS's and over each FGS field of view, identified binary stars, and quantified the systematic error in Coarse Track (the mode preceding Fine Lock). On the basis of these empirical data, the values of the uplink parameters can be selected more precisely. Since launch, optimization efforts have improved FGS Fine Lock performance, particularly acquisition, which now enjoys a nearly 100 percent success rate. More recent work has been directed towards improving FGS tolerance of two conditions that exceed its original design requirements. First, large amplitude spacecraft jitter is induced by solar panel vibrations following day/night transitions. This jitter is generally much greater than the FGS's were designed to track, and while the tracking ability of the FGS's has been shown to exceed design requirements, losses of Fine Lock after day/night transitions are frequent. Computer simulations have demonstrated a potential improvement in Fine Lock tracking of vehicle jitter near terminator crossings. Second, telescope spherical aberration degrades the interferometric error signal in Fine Lock, but use of the FGS two-thirds aperture stop restores the transfer function with a corresponding loss of throughput. This loss requires the minimum brightness of acquired stars to be about one magnitude brighter than originally planned
Associations of Trying to Lose Weight, Weight Control Behaviors, and Current Cigarette Use Among US High School Students
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72289/1/j.1746-1561.2009.00421.x.pd
Regulation of gastric epithelial cell homeostasis by gastrin and bone morphogenetic protein signaling
We reported that transgenic expression of the bone morphogenetic protein (BMP) signaling inhibitor noggin in the mouse stomach, leads to parietal‐cell (PC) loss, expansion of transitional cells expressing markers of both mucus neck and zymogenic lineages, and to activation of proliferative mechanisms. Because these cellular changes were associated with increased levels of the hormone gastrin, we investigated if gastrin mediates the expression of the phenotypic changes of the noggin transgenic mice (NogTG mice). Three‐month‐old NogTG mice were crossed to gastrin‐deficient (GasKO mice) to generate NogTG;GasKO mice. Morphology of the corpus of wild type, NogTG, GasKO, and NogTG;GasKO mice was analyzed by H&E staining. Distribution of PCs and zymogenic cells (ZCs) was analyzed by immunostaining for the H+/K+‐ATPase and intrinsic factor (IF). Expression of the H+/K+‐ATPase and IF genes and proteins were measured by QRT‐PCR and western blots. Cell proliferation was assessed by immunostaining for proliferating cell nuclear antigen. The corpus of the NogTG;GasKO mice displayed a marked reduction in the number of PCs and ZCs in comparison to NogTG mice. Further, cellular proliferation was significantly lower in NogTG;GasKO mice, than in the NogTG mice. Thus, gastrin mediates the increase in gastric epithelial cell proliferation induced by inhibition of BMP signaling in vivo. Moreover, gastrin and BMP signaling exert cooperative effects on the maturation and differentiation of both the zymogenic and PC lineages. These findings contribute to a better understanding of the factors involved in the control of gastric epithelial cell homeostasis.We investigated the role of gastrin and BMP signaling in the regulation of gastric epithelial homeostasis by crossing mice expressing the BMP inhibitor noggin in the stomach (NogTG mice) to gastrin‐deficient mice (GasKO mice). Analysis of these animals indicates that gastrin mediates the increase in gastric epithelial cell proliferation induced by inhibition of BMP signaling in vivo. Moreover, gastrin and BMP signaling exert cooperative effects on the maturation and differentiation of both the zymogenic and parietal‐cell lineages.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113157/1/phy212501.pd
Differential α4(+)/(-)β2 Agonist-Binding Site Contributions To α4β2 Nicotinic Acetylcholine Receptor Function Within And Between Isoforms
Two α4β2 nicotinic acetylcholine receptor (α4β2-nAChR) isoforms exist with (α4)2(β2)3 and (α4)2(β2)3 subunit stoichiometries and high versus low agonist sensitivities (HS and LS), respectively. Both isoforms contain a pair of α4(+)/(-)β2 agonist- binding sites. The LS isoform also contains a unique α4(+)/(-)α4 site with lower agonist affinity than the α4(+)/(-)β2 sites. However, the relative roles of the conserved α4(+)/(-)β2 agonist-binding sites in and between the isoforms have not been studied. We used a fully linked subunit concatemeric nAChR approach to express pure populations of HS or LS isoform α4β2∗-nAChR. This approach also allowed us to mutate individual subunit interfaces, or combinations thereof, on each isoform background. We used this approach to systematically mutate a triplet of β2 subunit (-)-face E-loop residues to their non-conserved α4 subunit counterparts or vice versa (β2HQT and α4VFL, respectively). Mutant-nAChR constructs (and unmodified controls) were expressed in Xenopus oocytes. Acetylcholine concentration-response curves and maximum function were measured using two-electrode voltage clamp electrophysiology. Surface expression was measured with 125I-mAb 295 binding and was used to define function/nAChR. If the α4(+)/(-)β2 sites contribute equally to function, making identical β2HQT substitutions at either site should produce similar functional outcomes. Instead, highly differential outcomes within the HS isoform, and between the two isoforms, were observed. In contrast, α4VFL mutation effects were very similar in all positions of both isoforms. Our results indicate that the identity of subunits neighboring the otherwise equivalent α4(+)/(-)β2 agonist sites modifies their contributions to nAChR activation and that E-loop residues are an important contributor to this neighbor effect
Self-esteem, self-efficacy and optimism as psychological resources among family caregivers of people with dementia: findings from the IDEAL study
YesBeing a family caregiver, and in particular giving care to someone with dementia, impacts
upon mental and physical health, and potentially reduces the ability of caregivers to ‘live
well’. This paper examines whether three key psychological resources, self-efficacy,
optimism and self-esteem, are associated with better outcomes for caregivers of people with
dementia.
Design and Participants
Caregivers of 1283 people with mild-to-moderate dementia in the Improving the experience
of Dementia and Enhancing Active Life (IDEAL) project responded to measures of selfefficacy,
optimism and self-esteem, and ‘living well’ (quality of life, life satisfaction and
well-being). Multivariate linear regression was used to examine the association between
psychological resources and ‘living well’.
Results
Self-efficacy, optimism and self-esteem were all independently associated with better
capability to ‘live well’ for caregivers. This association persisted when accounting for a
number of potential confounding variables (age group, sex, and hours of caregiving per day).
Conclusions
Low self-efficacy, optimism and self-esteem might present a risk of poor outcomes for
caregivers of people with dementia. These findings encourage us to consider how new or
established interventions might increase the psychological resilience of caregivers
"Cleanliness is next to Godliness": Religious change, hygiene and the renewal of Heraka Villages in Assam
Education, income, and incident heart failure in post-menopausal women: the Women\u27s Health Initiative Hormone Therapy Trials
OBJECTIVES: The purpose of this study is to estimate the effect of education and income on incident heart failure (HF) hospitalization among post-menopausal women.
BACKGROUND: Investigations of socioeconomic status have focused on outcomes after HF diagnosis, not associations with incident HF. We used data from the Women\u27s Health Initiative Hormone Trials to examine the association between socioeconomic status levels and incident HF hospitalization.
METHODS: We included 26,160 healthy, post-menopausal women. Education and income were self-reported. Analysis of variance, chi-square tests, and proportional hazards models were used for statistical analysis, with adjustment for demographics, comorbid conditions, behavioral factors, and hormone and dietary modification assignments.
RESULTS: Women with household incomes $50,000 a year (16.7/10,000 person-years; p \u3c 0.01). Women with less than a high school education had higher HF hospitalization incidence (51.2/10,000 person-years) than college graduates and above (25.5/10,000 person-years; p \u3c 0.01). In multivariable analyses, women with the lowest income levels had 56% higher risk (hazard ratio: 1.56, 95% confidence interval: 1.19 to 2.04) than the highest income women; women with the least amount of education had 21% higher risk for incident HF hospitalization (hazard ratio: 1.21, 95% confidence interval: 0.90 to 1.62) than the most educated women.
CONCLUSIONS: Lower income is associated with an increased incidence of HF hospitalization among healthy, post-menopausal women, whereas multivariable adjustment attenuated the association of education with incident HF. Elsevier Inc. All rights reserved
Fertility trajectories and later-life depression among parents in England
We examine pathways between indicators of fertility tempo/quantum and depressive symptoms among parents aged 55+ with at least two children, using three waves of the English Longitudinal Study of Ageing. Using standard regression approaches and path analysis within the structural equation framework, we also investigate whether fertility trajectories mediated the association between childhood disadvantage and later-life depression. Results provide limited support for direct influences of fertility trajectories on depression, but indicate indirect linkages for both women and men. Associations are mediated by partnership history, social support, wealth, later-life smoking, and functional limitation. Associations between childhood disadvantage and later-life depression are partially mediated by fertility stressors. Results confirm the influence of life course experiences on depression at older ages and demonstrate the interlinked role of family and other life course pathways on later-life well-being
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