Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
271
result(s) for
"Todd, Nicolas"
Sort by:
Drive angry
Strong brutal violence throughout, grisly images, some graphic sexual content, nudity and pervasive language.
DVD
Projection of US adult obesity trends based on individual BMI trajectories
Adult obesity has been increasing in the United States since the 1980s. Its future prevalence will be a key determinant for public health. For the cohorts now in young adulthood, the future prevalence of obesity will depend on current prevalence and future increase in weight. We pooled 92,615 body-mass index (BMI) measures from 26,337 adults interviewed and examined by the National Health and Nutrition Examination Survey (NHANES). We analyzed participants examined between ages 25 and 55 in the years 1998-2018. We applied a functional data analysis technique to probabilistically reconstruct individual BMI trajectories in order to investigate the future prevalence of obesity and severe obesity at age 55, and the mean time spent being obese and severely obese between ages 25 and 55. We found that the prevalence of obesity at age 55 is expected to reach 58% (95% UI, 54%- 61%) for females born in 1984-1988 and 57% (95% UI, 53%-61%) for males born in the same cohort. The prevalence of severe obesity at age 55 will increase rapidly in both sexes. Time spent being obese will increase; e.g., for females from 10.7 years (95% UI, 10.4-10.9 years) in the 1964-1968 cohort to 14.7 years (95% UI, 14.2-15.3 years) in the 1984-1988 birth cohort. Although obesity prevalence may level off in the coming decades, higher prevalence of severe obesity and longer durations of obesity are expected to increase the population burden of this disease.
Journal Article
Modelling the age pattern of fertility: an individual-level approach
Fitting statistical models to aggregate data is still the dominant approach in many demographic and biodemographic applications. Although these macro-level models have proven useful for a variety of tasks, they often have no demographic interpretation. Individual-level modelling, on the other hand, offers a deeper understanding of the mechanisms underlying observed patterns. Their parameters represent quantities in the real world, instead of pure mathematical abstractions. However, estimating these parameters using real-world data has remained a challenge. The approach we introduce in this article attempts to overcome this limitation. Using a likelihood-free inference technique, we show that it is possible to estimate the parameters of a simple but demographically interpretable individual-level model of the reproductive process by exclusively relying on the information contained in a set of age-specific fertility rates. By estimating individual-level models from widely available aggregate data, this approach can contribute to a better understanding of reproductive behaviour and its driving mechanisms, bridging the gap between individual-level and population-level processes. We illustrate our approach using data from three natural fertility populations.
Journal Article
Two-phase model of ageing in mice for improved identification of age-related and late life metabolic decline
Living animals reach their end-of-life through a stereotypic set of fascinating but poorly understood processes. The discovery, first in flies and later in nematodes and zebrafish, of the “Smurf phenotype” has provided a valuable tool to investigate ageing and its associated physiological changes. Using the Smurfs, we have shown an evolutionarily conserved end-of-life transition across Drosophilids, nematodes, and zebrafish. This tool has been key to identify the discontinuous nature of ageing and predict impending death from natural causes as well as from environmental stresses. This phenotype led us to propose a two-phase perspective of ageing: a first phase where individuals are apparently healthy and have low risk of mortality, but show an age-dependent and increasing risk of entering a second phase, marked by more pronounced hallmarks of ageing and a markedly increased risk of death. Here, we test whether these two consecutive phases of ageing separated by the Smurf transition are a conserved feature of ageing in the mammals using
Mus musculus as a
model. We performed a longitudinal longevity study using both males and females from two different mouse genetic backgrounds and by integrating physiological, metabolic, and molecular measurements with the life history of approximately 150 mice. We show the existence of a phenotypic signature typical of the last phase of life, observable at any chronological age. Validating the two-phase ageing model in a mammalian organism allows better characterization of the high risk of imminent death and would extend its implications to a broader range of species for ageing research. The Stage 1 version of this Registered Report was submitted on 19th January 2022.
Journal Article
Impact of social inequalities at birth on the longevity of children born 1914–1916: A cohort study
Testing whether familial socioeconomic status (SES) in childhood is a predictor of mortality has rarely been done on historical cohorts.
The birth certificates of 4,805 individuals born 1914-1916 in 16 districts of the Paris region were retrieved. The handwritten information provided the occupation of parents, the legitimacy status, life events (e.g. marriage, divorce), and the precise date of death when after 1945 (i.e. age 31 years (y) in the cohort). We used the median age at death (MAD) as a global measure of mortality, then studied separately survival to and after 31 y. Multivariate Imputation by Chained Equations (MICE), Generalized Additive Models (GAMs) and mixed effect Cox models were used.
MAD showed large variations according to paternal occupation. The lowest MAD in both sexes was that of workers' children: it was 56.3 y (95% CI: [48.6-62.7]) in men and 67.4 y (95% CI: [60.8-72.7]) in women, respectively (95% CI: 13.4 y [5.7-21.3]) and 12.3 y (95% CI: [4.0-19.2]) below the highest MAD attained. MAD experienced by illegitimate children was 18.9 y (95% CI: [13.3-32.3]) shorter than of legitimate children. The multivariate analysis revealed that in both sexes survival to age 31 y was predicted independently by legitimacy and paternal occupation. Paternal occupation was found significantly associated with mortality after age 31 y in females only: accordingly difference in life expectancy at age 31 y was 4.4 y (95% CI: [1.2-7.6]) between upper class and workers' daughters.
Paternal occupation and legitimacy status were strong predictors of offspring longevity in this one-century historical cohort born during World War One.
Journal Article
Socioeconomic development predicts a weaker contraceptive effect of breastfeeding
The contraceptive effect of breastfeeding remains essential to controlling fertility in many developing regions of the world. The extent to which this negative effect of breastfeeding on ovarian activity is sensitive to ecological conditions, notably maternal energetic status, has remained controversial. We assess the relationship between breastfeeding duration and postpartum amenorrhea (the absence of menstruation following a birth) in 17 World Fertility Surveys and 284 Demographic Health Surveys conducted between 1975 and 2019 in 84 low- and middle-income countries. We then analyze the resumption of menses in women during unsupplemented lactation. We find that a sharp weakening of the breastfeeding–postpartum amenorrhea relationship has globally occurred over the time period analyzed. The slope of the breastfeeding–postpartum amenorrhea relationship is negatively associated with development: higher values of the Human Development Index, urbanization, access to electricity, easier access to water, and education are predictive of a weaker association between breastfeeding and postpartum amenorrhea. Low parity also predicts shorter postpartum amenorrhea. The association between exclusive breastfeeding and maintenance of amenorrhea in the early postpartum period is also found in rapid decline in Asia and in moderate decline in sub- Saharan Africa. These findings indicate that the effect of breastfeeding on ovarian function is partly mediated by external factors that likely include negative maternal energy balance and support the notion that prolonged breastfeeding significantly helps control fertility only under harsh environmental conditions.
Journal Article
Ethical and social implications of approaching death prediction in humans - when the biology of ageing meets existential issues
Background
The discovery of biomarkers of ageing has led to the development of predictors of impending natural death and has paved the way for personalised estimation of the risk of death in the general population. This study intends to identify the ethical resources available to approach the idea of a long-lasting dying process and consider the perspective of death prediction. The reflection on human mortality is necessary but not sufficient to face this issue. Knowledge about death anticipation in clinical contexts allows for a better understanding of it. Still, the very notion of prediction and its implications must be clarified. This study outlines in a prospective way issues that call for further investigation in the various fields concerned: ethical, psychological, medical and social.
Methods
The study is based on an interdisciplinary approach, a combination of philosophy, clinical psychology, medicine, demography, biology and actuarial science.
Results
The present study proposes an understanding of death prediction based on its distinction with the relationship to human mortality and death anticipation, and on the analogy with the implications of genetic testing performed in pre-symptomatic stages of a disease. It leads to the identification of a multi-layered issue, including the individual and personal relationship to death prediction, the potential medical uses of biomarkers of ageing, the social and economic implications of the latter, especially in regard to the way longevity risk is perceived.
Conclusions
The present study work strives to propose a first sketch of what the implications of death prediction as such could be - from an individual, medical and social point of view. Both with anti-ageing medicine and the transhumanist quest for immortality, research on biomarkers of ageing brings back to the forefront crucial ethical matters: should we, as human beings, keep ignoring certain things, primarily the moment of our death, be it an estimation of it? If such knowledge was available, who should be informed about it and how such information should be given? Is it a knowledge that could be socially shared?
Journal Article
Fetal growth is associated with CpG methylation in the P2 promoter of the IGF1 gene
Background
There are many reasons to think that epigenetics is a key determinant of fetal growth variability across the normal population. Since
IGF1
and
INS
genes are major determinants of intrauterine growth, we examined the methylation of selected CpGs located in the regulatory region of these two genes.
Methods
Cord blood was sampled in 159 newborns born to mothers prospectively followed during their pregnancy. A 142-item questionnaire was filled by mothers at inclusion, during the last trimester of the pregnancy and at the delivery. The methylation of selected CpGs located in the promoters of the
IGF1
and
INS
genes was measured in cord blood mononuclear cells collected at birth using bisulfite-PCR-pyrosequencing.
Results
Methylation at
IGF1
CpG-137 correlated negatively with birth length (
r
= 0.27,
P
= 3.5 × 10
−4
). The same effect size was found after adjustment for maternal age, parity, and smoking: a 10% increase in CpG-137 methylation was associated with a decrease of length by 0.23 SDS.
Conclusion
The current results suggest that the methylation of
IGF1
CpG-137 contributes to the individual variation of fetal growth by regulating
IGF1
expression in fetal tissues.
Journal Article
Space–Time Covariation of Mortality with Temperature: A Systematic Study of Deaths in France, 1968–2009
The temperature-mortality relationship has repeatedly been found, mostly in large cities, to be U/J-shaped, with higher minimum mortality temperature (MMT) at low latitudes being interpreted as indicating human adaptation to climate.
Our aim was to partition space with a high-resolution grid to assess the temperature-mortality relationship in a territory with wide climate diversity, over a period with notable climate warming.
The 16,487,668 death certificates of persons > 65 years of age who died of natural causes in continental France (1968-2009) were analyzed. A 30-km × 30-km grid was placed over the map of France. Generalized additive model regression was used to assess the temperature-mortality relationship for each grid square, and extract the MMT and the RM25 and RM25/18 (respectively, the ratios of mortality at 25°C/MMT and 25°C/18°C). Three periods were considered: 1968-1981 (P1), 1982-1995 (P2), and 1996-2009 (P3).
All temperature-mortality curves computed over the 42-year period were U/J-shaped. MMT and mean summer temperature were strongly correlated. Mean MMT increased from 17.5°C for P1 to 17.8°C for P2 and to 18.2°C for P3 and paralleled the summer temperature increase observed between P1 and P3. The temporal MMT rise was below that expected from the geographic analysis. The RM25/18 ratio of mortality at 25°C versus that at 18°C declined significantly (p = 5 × 10-5) as warming increased: 18% for P1, 16% for P2, and 15% for P3.
Results of this spatiotemporal analysis indicated some human adaptation to climate change, even in rural areas.
Journal Article