Effect of birthplace on cardiometabolic risk among blacks in the Metabolic Syndrome Outcome Study (MetSO)

BACKGROUND: Metabolic syndrome poses an increased global burden of disease and causes immense financial burden, warranting heightened public health attention. The present study assessed the prevalence and severity of cardiometabolic risk among foreign-born versus US-born blacks, while exploring potential gender-based effects. METHODS: A total of 1035 patients from the Metabolic Syndrome Outcome Study (Trial registration: NCT01946659) provided sociodemographic, medical history, and clinical data. General Linear Model (GLM) was used to assess the effects of birthplace and gender on cardiometabolic parameters, adjusting for age differences in the sample. RESULTS: Of the sample, 61.6 % were foreign-born blacks (FBB) and 38.4 % were US-born blacks (USB). FBB had significantly lower BMI compared with USB (32.76 ± 0.35 vs. 35.41 ± 0.44, F = 22.57), but had significantly higher systolic blood pressure (136.70 ± 0.77 vs. 132.83 ± 0.98; F = 9.60) and fasting glucose levels than did USB (146.46 ± 3.37 vs. 135.02 ± 4.27; F = 4.40). Men had higher diastolic BP (76.67 ± 0.65 vs. 75.05 ± 0.45; F = 4.20), glucose (146.53 ± 4.48 vs. 134.95 ± 3.07; F = 4.55) and triglyceride levels (148.10 ± 4.51 vs. 130.60 ± 3.09; F = 10.25) compared with women, but women had higher LDL-cholesterol (109.24 ± 1.49 vs. 98.49 ± 2.18; F = 16.60) and HDL-cholesterol levels (50.71 ± 0.66 vs. 42.77 ± 0.97; F = 46.01) than did men. CONCLUSIONS: Results showed that birthplace has a significant influence on cardiometabolic profiles of blacks with metabolic syndrome. Patients’ gender also had an independent influence on cardiometabolic profile

Post-1980 shifts in the sensitivity of boreal tree growth to North Atlantic Ocean dynamics and seasonal climate

The mid-20th century changes in North Atlantic Ocean dynamics, e.g. slow-down of the Atlantic meridional overturning thermohaline circulation (AMOC), have been considered as early signs of tipping points in the Earth climate system. We hypothesized that these changes have significantly altered boreal forest growth dynamics in northeastern North America (NA) and northern Europe (NE), two areas geographically adjacent to the North Atlantic Ocean. To test our hypothesis, we investigated tree growth responses to seasonal large-scale oceanic and atmospheric indices (the AMOC, North Atlantic Oscillation (NAO), and Arctic Oscillation (AO)) and climate (temperature and precipitation) from 1950 onwards, both at the regional and local levels. We developed a network of 6876 black spruce (NA) and 14437 Norway spruce (NE) tree-ring width series, extracted from forest inventory databases. Analyses revealed post-1980 shifts from insignificant to significant tree growth responses to summer oceanic and atmospheric dynamics both in NA (negative responses to NAO and AO indices) and NE (positive response to NAO and AMOC indices). The strength and sign of these responses varied, however, through space with stronger responses in western and central boreal Quebec and in central and northern boreal Sweden, and across scales with stronger responses at the regional level than at the local level. Emerging post-1980 associations with North Atlantic Ocean dynamics synchronized with stronger tree growth responses to local seasonal climate, particularly to winter temperatures. Our results suggest that ongoing and future anomalies in oceanic and atmospheric dynamics may impact forest growth and carbon sequestration to a greater extent than previously thought. Cross-scale differences in responses to North Atlantic Ocean dynamics highlight complex interplays in the effects of local climate and ocean-atmosphere dynamics on tree growth processes and advocate for the use of different spatial scales in climate-growth research to better understand factors controlling tree growth

The North American tree-ring fire-scar network

Fire regimes in North American forests are diverse and modern fire records are often too short to capture important patterns, trends, feedbacks, and drivers of variability. Tree-ring fire scars provide valuable perspectives on fire regimes, including centuries-long records of fire year, season, frequency, severity, and size. Here, we introduce the newly compiled North American tree-ring fire-scar network (NAFSN), which contains 2562 sites, >37,000 fire-scarred trees, and covers large parts of North America. We investigate the NAFSN in terms of geography, sample depth, vegetation, topography, climate, and human land use. Fire scars are found in most ecoregions, from boreal forests in northern Alaska and Canada to subtropical forests in southern Florida and Mexico. The network includes 91 tree species, but is dominated by gymnosperms in the genus Pinus. Fire scars are found from sea level to >4000-m elevation and across a range of topographic settings that vary by ecoregion. Multiple regions are densely sampled (e.g., >1000 fire-scarred trees), enabling new spatial analyses such as reconstructions of area burned. To demonstrate the potential of the network, we compared the climate space of the NAFSN to those of modern fires and forests; the NAFSN spans a climate space largely representative of the forested areas in North America, with notable gaps in warmer tropical climates. Modern fires are burning in similar climate spaces as historical fires, but disproportionately in warmer regions compared to the historical record, possibly related to under-sampling of warm subtropical forests or supporting observations of changing fire regimes. The historical influence of Indigenous and non-Indigenous human land use on fire regimes varies in space and time. A 20th century fire deficit associated with human activities is evident in many regions, yet fire regimes characterized by frequent surface fires are still active in some areas (e.g., Mexico and the southeastern United States). These analyses provide a foundation and framework for future studies using the hundreds of thousands of annually- to sub-annually-resolved tree-ring records of fire spanning centuries, which will further advance our understanding of the interactions among fire, climate, topography, vegetation, and humans across North America

Probleme des moments et entropie. Application en probabilites

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 77705 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Relative entropy and spectral constraints: some invariance properties of the ARMA class

We determine the form of spectral densities of multidimensional scalar processes which minimize a relative entropy under a finite number of general moment-type constraints. The obtained theoretical results are applied to spectral densities of weakly stationary processes under covariances, inverse covariances and cepstral or impulse response constraints. Invariance properties of the class of autoregressive moving-average (ARMA) processes are shown to hold under the relative entropy minimization principle for many choices of entropy. Copyright 2007 The Author Journal compilation 2007 Blackwell Publishing Ltd.

How Variation of Scores of the Program for International Student Assessment Can Be Explained Through Analysis of Information

International audienc

一般醫學：醫療處置

International audienceThis paper mainly aims at unifying as a unique goodness-of-fit procedure the tests based on Shannon entropy–called S-tests–introduced by Vasicek in 1976, and the tests based on relative entropy–or Kullback-Leibler divergence, called KL-tests–introduced by Song in 2002. While Vasicek’s procedure is widely used in the literature, Song’s has remained more confidential. Both tests are known to have good power properties and to lead to straightforward computations. However, some asymptotic properties of the S-tests have never been checked and the link between the two procedures has never been highlighted. Mathematical justification of both tests is detailed here, leading to show their equivalence for testing any parametric composite null hypothesis of maximum entropy distributions. For testing any other distribution, the KL-tests are still reliable goodness-of-fit tests, whereas the S-tests become tests of entropy level. Moreover, for simple null hypothesis, only the KL-tests can be considered. The methodology is applied to a real dataset of a DNA replication process, issued from a collaboration with biologists. The objective is to validate an experimental protocol to detect chicken cell lines for which the spatiotemporal program of DNA replication is not correctly executed. We propose a two-step approach through entropy-based tests. First, a Fisher distribution with non integer parameters is retained as reference, and then the experimental protocol is validated