Study of Eu3+ -> Eu2+ reduction in BaAl2O4:Eu prepared in different gas atmospheres

The effect of different gas atmospheres such as H2(g), synthetic air, carbon monoxide (CO) and nitrogen (N2) on the Eu3+ → Eu2+ reduction process during the synthesis of Eu-doped BaAl2O4 was studied using synchrotron radiation. The Eu3+ → Eu2+ reduction was monitored analyzing XANES region when the sample are excited at the Eu LIII-edge. The results show that the hydrogen reducing agent are the most appropriate gas for Eu2+ stabilization in BaAl2O4 and that only a part of the Eu ions can be stabilized in the divalent state. A model of Eu reduction process, based on the incorporation of charge compensation defects, is proposed

Computer modelling of hafnium doping in lithium niobate

Lithium niobate, LiNbO3, is an important technological material with good electro-optic, acousto-optic, elasto-optic, piezoelectric and nonlinear properties. Doping LiNbO3 with hafnium, Hf has been shown to improve the resistance of the material to optical damage. Computer modelling provides a useful means of determining the properties of doped and undoped LiNbO3, including its defect chemistry, and the effect of doping on the structure. In this paper, Hf doped LiNbO3 has been modelled, and the final defect configurations are found to be consistent with experimental results

T cells in aging mice: genetic, developmental, and biochemical analyses

A combination of approaches – gene mapping, biomarker analysis, and studies of signal transduction – has helped to clarify the mechanisms of age-related change in mouse immune status and the implications of immune aging for late-life disease. Mapping studies have documented multiple quantitative trait loci (QTL) that influence the levels of age-sensitive T-cell subsets. Some of these QTL have effects that are demonstrable in young-adult mice (8 months of age) and others demonstrable only in middle-aged mice (18 months). Biomarker studies show that T-cell subset levels measured at 8 or 18 months are significant predictors of lifespan for mice dying of lymphoma, fibrosarcoma, mammary adenocarcinoma, or all causes combined. Mice whose immune systems resemble that of young animals, i.e. with low levels of CD4 + and CD8 + memory T cells and relatively high levels of CD4 + T cells, tend to outlive their siblings with the opposite subset pattern. Biochemical analyses show that T cells from aged mice show defects in the activation process within a few minutes of encountering a stimulus and that the defects precede the recognition by the T-cell receptor of agonist peptides on the antigen-presenting cell. Defective assembly of cytoskeletal fibers and hyperglycosylation of T-cell surface glycoproteins contribute to the immunodeficiency state, and indeed treatment with a sialylglycoprotein endopeptidase can restore full function to CD4 + T cells from aged donors in vitro .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75195/1/j.0105-2896.2005.00254.x.pd

Disability discrimination and well-being in the United Kingdom: a prospective cohort study

Objectives: Disability discrimination is linked with poorer well-being cross-sectionally. The aim of this study was to explore prospective associations between disability discrimination and well-being. / Design: Prospective cohort study. / Setting: The United Kingdom Household Longitudinal Study. / Participants: Data were from 871 individuals with a self-reported physical, cognitive or sensory disability. / Primary outcome measures: Depression was assessed in 2009/10. Psychological distress, mental functioning, life satisfaction and self-rated health were assessed in 2009/10 and 2013/14. / Results: Data were analysed using linear and logistic regression with adjustment for age, sex, household income, education, ethnicity and impairment category. Perceived disability discrimination was reported by 117 (13.4%) participants. Cross-sectionally, discrimination was associated with depression (OR=5.40, 95% CI 3.25 to 8.97) fair/poor self-rated health (OR=2.05; 95% CI 1.19 to 3.51), greater psychological distress (B=3.28, 95% CI 2.41 to 4.14), poorer mental functioning (B=−7.35; 95% CI −9.70 to −5.02) and life satisfaction (B=−1.27, 95% CI −1.66 to −0.87). Prospectively, discrimination was associated with increased psychological distress (B=2.88, 95% CI 1.39 to 4.36) and poorer mental functioning (B=−5.12; 95% CI −8.91 to −1.34), adjusting for baseline scores. / Conclusions: Perceived disability-related discrimination is linked with poorer well-being. These findings underscore the need for interventions to combat disability discrimination

Dietary patterns and nutrient intakes of a South African population and asymptomatic people infected with Human Immunodeficiency Virus: The transition health and urbanisation in South Africa (Thusa) study

There is increased emphasis on the quality of food and the overall pattern of micronutrient intake as an integral consideration for food security particularly among people living with HIV/AIDS (PLWHA). However, limited data exist on food consumption and nutrient intakes for populations in sub-Saharan Africa. The study examined dietary patterns and their relationship with nutrient intakes in HIV uninfected (HIV-) and infected (HIV+) adults in North-West Province, South Africa. In this cross-sectional study, dietary and nutrient intakes were assessed with Quantitative Food Frequency Questionnaire (QFFQ) and FoodFinder software, respectively. Dietary patterns were determined using Principal Component Analysis. Participants’ scores for the dietary patterns were related to nutrient intakes using Spearman Rank correlation and Generalised Linear Modelling (GENLIN). Four main dietary patterns were found in each population. The first three patterns were similar between the HIV- and HIV+ populations: “animal-based”, associated with intake of foods of animal origin; “recommended” associated with a varied diet; and “staple-based”. The fourth pattern was described as either ‘eggs-and-breakfast-cereals’ for the HIV- group or ‘legumes-and-vegetables’ for HIV+ group. Scores for animal-based pattern showed strongest correlations (r) with nutrient intakes for both populations, notably zinc (r=0.54), calcium (r=0.5), potassium (r=0.54), vitamin A (r=0.5), and vitamin C (r=0.5), (p<0.001 for all). In the HIV+ group, the legumes-and-vegetables pattern was strongly associated with energy (r=0.64), vitamins D (r=0.51), E (0.51) and B1 (r=0.55) (p<0.001 for all). Compared with the other patterns, the Staple-based and the recommended patterns showed the weakest associations with nutrient intakes. Generalised Linear Modelling confirmed stronger positive linear associations between scores of the animal-based diet and nutrients intake, compared with the other patterns. The findings suggest that the animal-based pattern was strongly associated with nutrients intake in both HIV + and HIV- populations. This raises the need for studies into dietary recommendations for promoting nutritional wellbeing for PLWHA in sub-Saharan Africa.Keywords: Dietary patterns; HIV/AIDS; THUSA, Nutrient

In their own words: A qualitative study exploring influences on the food choices of university students

Issue addressed: University students generally make independent decisions regarding food choices. Current research about knowledge of Australian Dietary Guidelines (ADG), sources of nutrition information and influences on food choices for this group is scarce. Methods: Qualitative data were collected from gender‐separated focus groups comprising four female (n = 31) and four male (n = 18) to identify: knowledge of ADG; sources of nutrition information; factors that influence food choices; perceived relevant nutrition messages and how best to deliver them. Results: Gaps in knowledge were identified particularly regarding number of serves and serving size for food groups. Social media was the most commonly reported source of knowledge. Social media was also a major influence on food choice due to its impact on body ideals. Conclusion: Current health promotion nutrition messages were perceived irrelevant given the focus on long‐term health risks. Health and adhering to the ADG were not identified as important. The desire to look a particular way was the major influence on food choices. So what? While there is an awareness of ADG, our participants made a deliberate decision not to follow them. This provides a challenge for developing relevant preventive health messages for this target audience

Estimating δ15N fractionation and adjusting the lipid correction equation using Southern African freshwater fishes

Stable isotope analysis is an important tool for characterising food web structure; however, interpretation of isotope data can often be flawed. For instance, lipid normalisation and trophic fractionation values are often assumed to be constant, but can vary considerably between ecosystems, species and tissues. Here, previously determined lipid normalisation equations and trophic fractionation values were re-evaluated using freshwater fish species from three rivers in the Upper Zambezian floodplain ecoregion in southern Africa. The parameters commonly used in lipid normalisation equations were not correct for the 18 model species (new D and I parameters were estimated as D = 4.46‰ [95% CI: 2.62, 4.85] and constant I = 0 [95% CI: 0, 0.17]). We suggest that future isotopic analyses on freshwater fishes use our new values if the species under consideration do not have a high lipid content in their white muscle tissue. Nitrogen fractionation values varied between species and river basin; however, the average value closely matched that calculated in previous studies on other species (δ15N fractionation factor of 3.37 ± 1.30 ‰). Here we have highlighted the need to treat stable isotope data correctly in food web studies to avoid misinterpretation of the data

Racial discrimination and health: a prospective study of ethnic minorities in the United Kingdom

BACKGROUND: Racism has been linked with poor health in studies in the United States. Little is known about prospective associations between racial discrimination and health outcomes in the United Kingdom (UK). METHODS: Data were from 4883 ethnic minority (i.e. non-white) participants in the UK Household Longitudinal Study. Perceived discrimination in the last 12 months on the basis of ethnicity or nationality was reported in 2009/10. Psychological distress, mental functioning, life satisfaction, self-rated health, physical functioning and reports of limiting longstanding illness were assessed in 2009/10 and 2011/12. Linear and logistic regression analyses adjusted for age, sex, income, education and ethnicity. Prospective analyses also adjusted for baseline status on the outcome being evaluated. RESULTS: Racial discrimination was reported by 998 (20.4%) of the sample. Cross-sectionally, those who reported racial discrimination had a greater likelihood on average of limiting longstanding illness (odds ratio (OR) = 1.78, 95% confidence interval (CI) 1.49; 2.13) and fair/poor self-rated health (OR = 1.50; 95% CI 1.24; 1.82) than those who did not report racial discrimination. Racial discrimination was associated with greater psychological distress (B = 1.11, 95% CI 0.88; 1.34), poorer mental functioning (B = - 3.61; 95% CI -4.29; - 2.93), poorer physical functioning (B = - 0.86; 95% CI -1.50; - 0.27), and lower life satisfaction (B = - 0.40, 95% CI -0.52; - 0.27). Prospectively, those who reported racial discrimination had a greater likelihood on average of limiting longstanding illness (OR = 1.31, 95% CI 1.01; 1.69) and fair/poor self-rated health (OR = 1.30; 95% CI 1.00; 1.69), than those who did not report racial discrimination. Racial discrimination was associated increased psychological distress (B = 0.52, 95% CI 0.20; 0.85) and poorer mental functioning (B = - 1.77; 95% CI -2.70; - 0.83) over two-year follow-up, adjusting for baseline scores. CONCLUSIONS: UK adults belonging to ethnic minority groups who perceive racial discrimination experience poorer mental and physical health than those who do not. These results highlight the need for effective interventions to combat racial discrimination in order to reduce inequalities in health