498 research outputs found
Oral Health - A Neglected Aspect of Subjective Well-Being in Later Life
OBJECTIVES: This study examined whether oral health is a neglected aspect of subjective well-being (SWB) among older adults. The key research question was whether deterioration in oral health among dentate older adults living in England was associated with decreases in SWB, using measures of eudemonic, evaluative, and affective dimensions of well-being. METHODS: This secondary analysis used data from the third (2006-2007) and fifth (2010-2011) waves of respondents aged 50 and older from the English Longitudinal Study of Ageing (ELSA). We fitted multivariable regression models to examine the effects of changes in oral impacts on daily life and edentulism (complete tooth loss) on SWB (quality of life, life satisfaction, and depressive symptomatology). RESULTS: A worsening in both oral health measures was associated with an increase in depressive symptoms even after adjusting for time-varying confounders including declining health, activities of daily living, and reduced social support. Becoming edentate was also associated with decreases in quality of life and life satisfaction. DISCUSSION: A deterioration in oral health and oral health-related quality of life increases the risk of depressive symptoms among older adults and highlights the importance of oral health as a determinant of subjective well-being in later life
X-ray Absorption Linear Dichroism at the Ti K-edge of TiO2 anatase single crystal
Anatase TiO2 (a-TiO2) exhibits a strong X-ray absorption linear dichroism
with the X-ray incidence angle in the pre-edge, the XANES and the EXAFS at the
titanium K-edge. In the pre-edge region the behaviour of the A1-A3 and B peaks,
originating from the 1s-3d transitions, is due to the strong -orbital
polarization and strong orbital mixing. An unambiguous assignment of the
pre-edge peak transitions is made in the monoelectronic approximation with the
support of ab initio finite difference method calculations and spherical tensor
analysis in quantitative agreement with the experiment. It is found that A1 is
mostly an on-site 3d-4p hybridized transition, while peaks A3 and B are
non-local transitions, with A3 being mostly dipolar and influence by the 3d-4p
intersite hybridization, while B is due to interactions at longer range.
Finally, peak A2 which was previously assigned to a transition involving
pentacoordinated titanium atoms exhibits a quadrupolar angular evolution with
incidence angle. These results pave the way to the use of the pre-edge peaks at
the K-edge of a-TiO2 to characterize the electronic structure of related
materials and in the field of ultrafast XAS where the linear dichroism can be
used to compare the photophysics along different axes.Comment: 43 pages, 19 figure
Socioeconomic and ethnic inequalities in oral health among children and adolescents living in England, Wales and Northern Ireland
OBJECTIVES: Although adolescence is a sensitive developmental period in oral health, the social equalization hypothesis that suggests health inequalities attenuate in adolescence has not been examined. This study analyses whether the socioeconomic gap and ethnic disadvantage in oral health among children aged 5 reduces among adolescents aged 15. METHODS: Data from the cross-sectional Children's Dental Health Survey 2013 were analysed, comprising of 8541 children aged 5, 8, 12 and 15 attending schools in England, Wales and Northern Ireland. Oral health indicators included decayed and filled teeth, plaque, gingivitis and periodontal health. Ethnicity was measured using the 2011 UK census ethnic categories. Socioeconomic position was measured by family, school and residential deprivation. Negative binomial and probit regression models estimated the levels of oral health by ethnicity and socioeconomic position, adjusted for demographic and tooth characteristics. RESULTS: The predicted rate of decayed teeth for White British/Irish children aged 5 was 1.54 (95%CI 1.30-1.77). In contrast, the predicted rate for Indian and Pakistani children was about 2-2.5 times higher. At age 15, ethnic differences had reduced considerably. Family deprivation was associated with higher levels of tooth decay among younger children but not among adolescents aged 15. The influence of residential deprivation on the rate of tooth decay and filled teeth was similar among younger and older children. Moreover, inequalities in poor periodontal health by residential deprivation was significantly greater among 15-year-old children compared to younger children. CONCLUSIONS: This study found some evidence of smaller ethnic and family socioeconomic differences in oral health among British adolescents compared to younger children. However, substantial differences in oral health by residential deprivation remain among adolescents. Community levels of deprivation may be particularly important for the health of adolescents
A novel mode of chromosomal evolution peculiar to filamentous Ascomycete fungi
Background: Gene loss, inversions, translocations, and other chromosomal rearrangements vary among species, resulting in different rates of structural genome evolution. Major chromosomal rearrangements are rare in most eukaryotes, giving large regions with the same genes in the same order and orientation across species. These regions of macrosynteny have been very useful for locating homologous genes in different species and to guide the assembly of genome sequences. Previous analyses in the fungi have indicated that macrosynteny is rare; instead, comparisons across species show no synteny or only microsyntenic regions encompassing usually five or fewer genes. To test the hypothesis that chromosomal evolution is different in the fungi compared to other eukaryotes, synteny was compared between species of the major fungal taxa. Results: These analyses identified a novel form of evolution in which genes are conserved within homologous chromosomes, but with randomized orders and orientations. This mode of evolution is designated mesosynteny, to differentiate it from micro-and macrosynteny seen in other organisms. Mesosynteny is an alternative evolutionary pathway very different from macrosyntenic conservation. Surprisingly, mesosynteny was not found in all fungal groups. Instead, mesosynteny appears to be restricted to filamentous Ascomycetes and was most striking between species in the Dothideomycetes. Conclusions: The existence of mesosynteny between relatively distantly related Ascomycetes could be explained by a high frequency of chromosomal inversions, but translocations must be extremely rare. The mechanism for this phenomenon is not known, but presumably involves generation of frequent inversions during meiosis
Variation in frequency of avirulence genes in Leptosphaeria maculans in western Canada
Non-Peer Reviewe
The neighbouring genes <i>AvrLm10A</i> and <i>AvrLm10B</i> are part of a large multigene family of cooperating effector genes conserved in Dothideomycetes and Sordariomycetes
Fungal effectors (small-secreted proteins) have long been considered as species or even subpopulation-specific. The increasing availability of high-quality fungal genomes and annotations has allowed the identification of trans-species or trans-genera families of effectors. Two avirulence effectors, AvrLm10A and AvrLm10B, of Leptosphaeria maculans, the fungus causing stem canker of oilseed rape, are members of such a large family of effectors. AvrLm10A and AvrLm10B are neighbouring genes, organized in divergent transcriptional orientation. Sequence searches within the L. maculans genome showed that AvrLm10A/AvrLm10B belong to a multigene family comprising five pairs of genes with a similar tail-to-tail organization. The two genes, in a pair, always had the same expression pattern and two expression profiles were distinguished, associated with the biotrophic colonization of cotyledons and/or petioles and stems. Of the two protein pairs further investigated, AvrLm10A_like1/AvrLm10B_like1 and AvrLm10A_like2/AvrLm10B_like2, the second one had the ability to physically interact, similarly to what was previously described for the AvrLm10A/AvrLm10B pair, and cross-interactions were also detected for two pairs. AvrLm10A homologues were identified in more than 30 Dothideomycete and Sordariomycete plant-pathogenic fungi. One of them, SIX5, is an effector from Fusarium oxysporum f. sp. lycopersici physically interacting with the avirulence effector Avr2. We found that AvrLm10A/SIX5 homologues were associated with at least eight distinct putative effector families, suggesting that AvrLm10A/SIX5 is able to cooperate with different effectors. These results point to a general role of the AvrLm10A/SIX5 proteins as “cooperating proteins”, able to interact with diverse families of effectors whose encoding gene is co-regulated with the neighbouring AvrLm10A homologue
A factorization of a super-conformal map
A super-conformal map and a minimal surface are factored into a product of
two maps by modeling the Euclidean four-space and the complex Euclidean plane
on the set of all quaternions. One of these two maps is a holomorphic map or a
meromorphic map. These conformal maps adopt properties of a holomorphic
function or a meromorphic function. Analogs of the Liouville theorem, the
Schwarz lemma, the Schwarz-Pick theorem, the Weierstrass factorization theorem,
the Abel-Jacobi theorem, and a relation between zeros of a minimal surface and
branch points of a super-conformal map are obtained.Comment: 21 page
Combining estimates of interest in prognostic modelling studies after multiple imputation: current practice and guidelines
Background: Multiple imputation (MI) provides an effective approach to handle missing covariate
data within prognostic modelling studies, as it can properly account for the missing data
uncertainty. The multiply imputed datasets are each analysed using standard prognostic modelling
techniques to obtain the estimates of interest. The estimates from each imputed dataset are then
combined into one overall estimate and variance, incorporating both the within and between
imputation variability. Rubin's rules for combining these multiply imputed estimates are based on
asymptotic theory. The resulting combined estimates may be more accurate if the posterior
distribution of the population parameter of interest is better approximated by the normal
distribution. However, the normality assumption may not be appropriate for all the parameters of
interest when analysing prognostic modelling studies, such as predicted survival probabilities and
model performance measures.
Methods: Guidelines for combining the estimates of interest when analysing prognostic modelling
studies are provided. A literature review is performed to identify current practice for combining
such estimates in prognostic modelling studies.
Results: Methods for combining all reported estimates after MI were not well reported in the
current literature. Rubin's rules without applying any transformations were the standard approach
used, when any method was stated.
Conclusion: The proposed simple guidelines for combining estimates after MI may lead to a wider
and more appropriate use of MI in future prognostic modelling studies
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