Littérature scientifique sur le sujet « Bonferroni index, decomposition by subpopulations »

Background and objectives T-cell activation may be one of the pathogenic mechanisms of systemic lupus erythematosus (SLE). After repeated antigenic stimulation, T-cells undergo different modifications, leading to the differentiation into effector memory T-cells (CCR7−CD45RA−) and terminally differentiated effector memory (TDEM) T-cells (CCR7−CD45RA+). Similarly, down-modulation of CD28 may lead to the expansion of the CD28− T-cells, a subpopulation with peculiar effector activities. The aim of this study was the characterization of T-cell phenotype in a cohort of patients with SLE according to disease activity and damage index. Materials and methods Phenotypic analysis of peripheral blood T lymphocytes of 51 SLE patients and 21 healthy controls was done by flow-cytometry. SLE disease activity was evaluated by SLE Disease Activity Index-2000 (SLEDAI-2K) and damage by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index (SDI). The variations between different groups were evaluated by Mann–Whitney test. Bonferroni correction was applied to adjust for multiple comparisons ( padj). Spearman rank test was used to evaluate the correlations between quantitative variables. Results CD4+ lymphopenia was found among SLE patients. Patients showed a trend for a higher percentage of TDEM among the CD4+ T-cell subpopulation in comparison with healthy controls ( p = .04). SLE patients were divided into two groups according to disease activity: patients with SLEDAI-2K ≥ 6 ( n = 13) had a higher percentage of circulating CD4+ T-cells with CD28− phenotype ( padj = .005) as well as those with an effector memory ( padj = .004) and TDEM ( padj = .002) phenotype and a trend of decrease of regulatory T-cells (TREGs) ( p = .02), in comparison with patients with low disease activity ( n = 38). Patients with damage (SDI ≥ 1) tended to show an expansion of TDEM among CD4+ T-cells as compared with patients with no damage ( p = .01). In SLE patients an inverse correlation was found between the percentages of TREGs and those of TDEM ( p < .01) or CD4 + CD28− ( p < .01) T-cells. Conclusions CD4+ T-cell subpopulations displaying phenotype characteristics of effector lymphocytes are proportionally expanded in patients with active SLE and a higher damage index. These findings may suggest a role of effector T-cells in the pathogenesis of the disease and in the mechanisms of damage in SLE.

ObjectiveTeenage pregnancy has become a public health concern in Uganda because of its negative consequences to both the mother and child. The objective of this study was to examine the determinants of change in the inequality and associated predictors of teenage pregnancy in Uganda for the period 2006–2016.Study designA retrospective national cross-sectional study.SettingUganda.ParticipantsUganda Demographic and Health Survey secondary data of only female teenagers aged 15–19 years. The samples selected for analyses were 1936 in 2006; 2048 in 2011 and 4264 in 2016.Outcome measureThe primary outcome was teenage pregnancy. Analysis was performed using the logistic regression, equiplots, concentration curve, normalised concentration index, decomposition of the concentration index and Oaxaca-type decomposition.ResultsThe prevalence of teenage pregnancy has seemingly remained high and almost constant from 2006 to 2016 with the risk worsening to the disadvantage of the poor. Household wealth-index, teenagers’ years of education, early sexual debut and child marriage were the main key predictors and contributors of the large inequality in teenage pregnancy from 2006 to 2016.ConclusionTeenage pregnancy is disproportionately prevalent among different subpopulations of adolescent girls in Uganda. We therefore recommend policy actions to sensitise communities and enforcement of child rights and child protection laws to stop child marriages. There is also need to promote girl child education, improving household incomes, and intensifying mass media awareness on the risks of early pregnancies. Further, ensuring that villages have operational adolescent and youth friendly services as well as incorporating sex education and other different adolescent reproductive health programmes in school curriculum will be key measures in reducing the large inequality in teenage pregnancy.

AbstractIn this paper two innovative procedures for the decomposition of the Pietra index are proposed. The first one allows the decomposition by sources, while the second one provides the decomposition by subpopulations. As special case of the latter procedure, the “classical” decomposition in two components (within and between) can be easily obtained. A remarkable feature of both the proposed procedures is that they permit the assessment of the contribution to the Pietra index at the smallest possible level: each source for the first one and each subpopulation for the second one. To highlight the usefulness of these procedures, two applications are provided regarding Italian professional football (soccer) teams.

Abstract Background To examine the influence of solar cycle and geomagnetic effects on SLE disease activity. Methods The data used for the analysis consisted of 327 observations of 27-day Physician Global Assessment (PGA) averages from January 1996 to February 2020. The considered geomagnetic indices were the AP index (a daily average level for geomagnetic activity), sunspot number index R (measure of the area of solar surface covered by spots), the F10.7 index (measure of the noise level generated by the sun at a wavelength of 10.7 cm at the earth’s orbit), the AU index (upper auroral electrojet index), and high energy (> 60 Mev) proton flux events. Geomagnetic data were obtained from the Goddard Space Flight Center Space Physics Data Facility. A time series decomposition of the PGA averages was performed as the first step. The linear relationships between the PGA and the geomagnetic indices were examined using parametric statistical methods such as Pearson correlation and linear regression, while the nonlinear relationships were examined using nonparametric statistical methods such as Spearman’s rho and Kernel regression. Results After time series deconstruction of PGA averages, the seasonality explained a significant fraction of the variance of the time series (R2 = 38.7%) with one cycle completed every 16 years. The analysis of the short-term (27-day) relationships indicated that increases in geomagnetic activity Ap index (p < 0.1) and high energy proton fluxes (> 60 Mev) (p < 0.05) were associated with decreases in SLE disease activity, while increases in the sunspot number index R anticipated decreases in the SLE disease activity expressed as PGA (p < 0.05). The short-term correlations became statistically insignificant after adjusting for multiple comparisons using Bonferroni correction. The analysis of the long-term (297 day) relationships indicated stronger negative association between changes in the PGA and changes in the sunspot number index R (p < 0.01), AP index (p < 0.01), and the F10.7 index (p < 0.01). The long-term correlations remained statistically significant after adjusting for multiple comparisons using Bonferroni correction. Conclusion The seasonality of the PGA averages (one cycle every 16 years) explains a significant fraction of the variance of the time series. Geomagnetic disturbances, including the level of geomagnetic activity, sunspot numbers, and high proton flux events may influence SLE disease activity. Studies of other geographic locales are needed to validate these findings.

AbstractNigeria is a high burden country for stunting. Stunting reduction has been slow and characterized by unequal progress across the 36 states and federal capital territory of the country. This study aimed to assess the changes in prevalence of stunting and growth determinants from 2003 to 2018, identify factors that predicted the change in stunting, and project future stunting prevalence if these predicted determinants improve. Trend and linear decomposition analyses of growth outcomes and determinants were conducted using 2003, 2008, 2013, and 2018 Nigeria Demographic and Health Survey data. Pooled data included 57,507 children 0 to 59 months old. Findings show that stunting and severe stunting significantly reduced from 43 to 37% and 23% to 17%, respectively (p < 0.001), between 2003 and 2018. Disturbingly, height-for-age z-scores at birth significantly decreased, indicating risks of potential future stunting increase. Improvements in nine stunting determinants (maternal body mass index, maternal height, ≥ 4 antenatal care visits, health facility delivery, reduced child illnesses, asset index, maternal education, paternal education, and preceding birth interval) predicted stunting reductions in children 0–59 months. Few of these nine determinants improved in subpopulations with limited stunting progress. Intra-sectoral and multisectoral coordination were potentially inadequate; 12% of children had received all of three selected health sector interventions along a continuum of care and 6% had received all of six selected multisector interventions. Forward looking projections suggest that increased efforts to improve the nine predictors of stunting change can reduce under-five stunting in Nigeria to ≤ 27% in the short term.

Introduction: Hypertension is a multifactorial process. Activation of the innate immune system and subsequent upregulation of adaptive immunity have been shown to promote hypertension in various mouse models Large scale human population studies examining the composition of the innate and adaptive immune system as it pertains to hypertension are lacking. Hypothesis: The composition of innate and adaptive immune cells are risk factors for increased systolic blood pressure (SBP). Methods: Using cells cryopreserved from the baseline exam, we measured 34 immune cell subsets from participants of the Multi-Ethnic Study of Atherosclerosis (MESA) (mean age 64 years, 53% male), sampled from a case-cohort study of myocardial infarction (n=1,200). SBP was assessed at baseline and at four follow-up exams over the succeeding ten years. Our approach to anti-hypertensive medication use was to add 10mmHG to SBP for treated participants. Associations between immune cell subpopulations and SBP were conducted using linear mixed models, with sampling weights to account for the sampling strategy and robust confidence intervals; immune cells were modeled per standard (SD) deviation higher value. We adjusted for age, sex, race/ethnicity, smoking, exercise, body mass index, education, diabetes, and log- transformed cytomegalovirus levels. Results: After adjustment for potential confounders, 5 of 34 immune cells subsets were significantly associated with mean levels of SBP. For each standard deviation increment higher immune cell proportion, natural killer (NK) cells, defined as CD3-CD56+CD16+, (1.9 mmHG; 95% CI: 0.8-2.9), classic monocytes, defined as CD14++CD16-, (-1.3 mmHG; 95% CI: -2.5 to -0.1) and non-classic monocytes, defined as CD14+CD16++, (1.4 mmHG; 95% CI: 0.3 to 2.6) had the strongest associations with SBP changes over 10-years of follow-up. Sensitivity analyses with principal components analysis were supportive of these findings. After using a Bonferroni corrected threshold to account for for multiple testing only NK remained significant. Conclusions: NK cells, classic monocytes and non-classic monocytes, all components of the innate immune system, were associated with higher levels of SBP over follow-up. The strongest association was with natural killer cells; in agreement with previous studies that showed circulating levels of interferon gamma and tumor necrosis factor alpha, the two main cytokines produced by NK cells, correlate with systolic blood pressure.

In this thesis it is suggested a decomposition by subpopulation of the Bonferoni index. This purpose is attained at first suggesting a definition of the Bonferroni index for data expressed in terms of frequency distribution and then, using the approach proposed by Zenga (Zenga, 2012) for the decomposition of his index, it follow a decomposition by subpopulation of the Bonferroni index in two steps. The Bonferroni and Zenga indexes, as well as the Gini index (Gini, 1914), are implemented in two steps: in the first step, point measures are made, whereas in the second steps, a synthetic index is obtained averaging the point measures. Until now the proposals suggested for the decompositions of the Gini and Bonferroni indexes were based on the decomposition of the synthetic indexes; in this works, the decomposition by subpopulation is based instead on the decompositions of the point measures. Following this approach, in the first part of the suggested procedure, an additive decomposition is obtained and the contributions of each subpopulation to the point inequality measure, evaluated on the whole population, is computed. From this decomposition, other two decomposition terms are deduced: a within term, that is a measure of inequality evaluated within a subpopulation, and a between term that informs on the inequality derived from the comparison between different subpopulation. In the second part of this work, exploiting these decomposition, an additive decomposition is obtained for the synthetic index. Finally, the methodology proposed is applied on data on the net disposable households income provided by Banca d’Italia in 2014 and comparison among inequality indexes are made.