scholarly journals Women Born to Older Mothers Have Reduced Fertility. Evidence From a Natural Fertility Population

2021 ◽  
Vol 10 ◽  
pp. 112-118
Author(s):  
Niels Van den Berg ◽  
Ingrid K. Van Dijk ◽  
Rick J. Mourits
Keyword(s):  
Neonatal Mortality ◽  
Linear Models ◽  
Natural Fertility ◽  
Mixed Effect ◽  
Older Mothers ◽  
Number Of Children ◽  
Sibling Relations ◽  
Two Generations ◽  
Human Mutation ◽  
Children Ever Born

Are daughters of older mothers less fertile? The human mutation rate is high and increases with chronological age. As female oocytes age, they become less functional, reducing female chances at successful reproduction. Increased oocyte mutation loads at advanced age may be passed on to offspring, decreasing fertility among daughters born to older mothers. In this paper we study the effects of maternal ageing on her daughter's fertility, including total number of children, age at last birth, and neonatal mortality among her children. We study fertility histories of two generations of women from mutually exclusive families from a pre-demographic transition historical population in the Dutch province of Zeeland. Using mixed effect Poisson and linear models to take within family (sibling) relations into account, we show that among married daughters fertility is reduced for those who were born to mothers with an advanced maternal age, resulting in fewer children ever born and earlier ages at last birth. We do not find consistent evidence for effects on neonatal mortality. These results may indicate that women born to older mothers are negatively affected by their mothers' increased age.

scholarly journals Women born to older mothers have reduced fertility: Evidence from a natural fertility population

2020 ◽  
Author(s):  
Niels van den Berg ◽  
Ingrid van Dijk ◽  
Rick Mourits
Keyword(s):  
Neonatal Mortality ◽  
Natural Fertility ◽  
Mixed Effect ◽  
Older Mothers ◽  
Number Of Children ◽  
Sibling Relations ◽  
Poisson Models ◽  
Two Generations ◽  
Human Mutation ◽  
Children Ever Born

AbstractAre daughters of older mothers less fertile? The human mutation rate is high and increases with chronological age. As female oocytes age, they become less functional, reducing female chances at successful reproduction. Increased oocyte mutation loads at advanced age may be passed on to offspring, decreasing fertility among daughters born to older mothers. In this paper we study the effects of maternal ageing on her daughter’s fertility, including total number of children, age at last birth, and neonatal mortality among her children. We study fertility histories of two generations of women from disjoint families from a pre-transitional historical population in the Dutch province of Zeeland. Using mixed effect Poisson models to take within family (sibling) relations into account, we show that fertility is reduced among married daughters who were born at advanced maternal age, with fewer children ever born and earlier ages at last birth. We do not find consistent evidence for effects on neonatal mortality. These results may indicate that women born to older mothers are negatively affected by their mothers’ increased oocyte mutation load.

scholarly journals Genome-wide analysis identifies genetic effects on reproductive success and ongoing natural selection at the FADS locus

2020 ◽  
Author(s):  
Iain Mathieson ◽  
Felix R. Day ◽  
Nicola Barban ◽  
Felix C. Tropf ◽  
David M. Brazel ◽  
...  
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
European Ancestry ◽  
Age At First Birth ◽  
Hormone Regulation ◽  
Number Of Children ◽  
Two Generations ◽  
Reproductive Ageing ◽  
Children Ever Born ◽  
Using Data

AbstractIdentifying genetic determinants of reproductive success may highlight mechanisms underlying fertility and also identify alleles under present-day selection. Using data in 785,604 individuals of European ancestry, we identify 43 genomic loci associated with either number of children ever born (NEB) or childlessness. These loci span diverse aspects of reproductive biology across the life course, including puberty timing, age at first birth, sex hormone regulation and age at menopause. Missense alleles in ARHGAP27 were associated with increased NEB but reduced reproductive lifespan, suggesting a trade-off between reproductive ageing and intensity. As NEB is one component of evolutionary fitness, our identified associations indicate loci under present-day natural selection. Accordingly, we find that NEB-increasing alleles have increased in frequency over the past two generations. Furthermore, integration with data from ancient selection scans identifies a unique example of an allele—FADS1/2 gene locus—that has been under selection for thousands of years and remains under selection today. Collectively, our findings demonstrate that diverse biological mechanisms contribute to reproductive success, implicating both neuro-endocrine and behavioural influences.

Age pattern of fertility in the Sudan

1983 ◽  
Vol 15 (3) ◽  
pp. 317-324 ◽  
Author(s):  
M. A. Khalifa
Keyword(s):  
Birth Rate ◽  
Crude Birth Rate ◽  
Sample Survey ◽  
Natural Fertility ◽  
Fertility Survey ◽  
World Fertility Survey ◽  
Number Of Children ◽  
Sample Survey Data ◽  
Children Ever Born

SummaryIn the absence of reliable fertility statistics in the Sudan, estimates are based on census or sample survey data. Methods of analysis are applied which are suitable to the kind and quality of the collected information. This paper uses data provided by the World Fertility Survey of the Sudan. The number of children ever born tabulated by the duration of marriage is used to derive an estimate of the age pattern of fertility. The level of natural fertility is found to be low. However, the calculated crude birth rate is high and consistent with rates calculated by other methods using different data.

scholarly journals Estimation of Cohort Fertility Using Parity Progression Ratio

2020 ◽  
pp. 18-28
Author(s):  
Dhanendra Veer Shakya
Keyword(s):  
Age Groups ◽  
Fertility Level ◽  
Parity Progression ◽  
Birth Cohorts ◽  
Number Of Children ◽  
Parity Progression Ratio ◽  
History Of ◽  
Cohort Fertility ◽  
Children Ever Born ◽  
Using Data

This study attempts to analyze the levels and patterns of cohort fertility in Nepal in 2016 using data on parity progression ratios (PPRs). Simple PPRs, rather than synthetic PPRs or birth history of women, are used in this study from distribution of women by age and children ever born. Data on PPRs are used from 2016 Nepal Demographic and Health Survey to estimate cohort fertility of currently married and all women separately. Fertility is analyzed for different birth cohorts of women, specifically for birth cohorts of age groups 45-49, 20-24, 25-29, and 30-34 years, beside overall span of reproductive ages (15-49) for different purposes. The PPRs data are employed in this study in three different ways such as PPRs itself, proportion of women with at least ‘N’ number of children ever born (CEB), and cohort fertility rates. All three measures are implied to estimate cohort fertility of both currently married and all women separately. Fertility patterns are almost similar in all the three methods and other the measures show that the level of cohort fertility is still a little higher in Nepal, although it is declining gradually over time. The completed cohort fertility is estimated at around 4 in Nepal in 2016. The contribution of this article will be to check fertility level by applying this simple, but less common, method in estimating cohort fertility.

scholarly journals Invasive alien palm Pinanga coronata threatens native tree ferns in an oceanic island rainforest

2018 ◽  
Vol 66 (8) ◽  
pp. 647 ◽  
Author(s):  
Michael J. B. Dyer ◽  
Gunnar Keppel ◽  
Marika Tuiwawa ◽  
Sainivalati Vido ◽  
Hans Juergen Boehmer
Keyword(s):  
Linear Models ◽  
Management Strategies ◽  
Ornamental Plants ◽  
Native Plant ◽  
Ecological Processes ◽  
Mixed Effect ◽  
Mixed Effect Models ◽  
Tree Ferns ◽  
Native Tree ◽  
Negative Impacts

Invasive ornamental plants are a global problem that can have severe impacts on native biodiversity, especially on islands. To determine whether the invasive, ornamental ivory-cane palm Pinanga coronata could be displacing native biodiversity, we investigated its co-distribution with native tree ferns in a Fijian rainforest. We recorded the abundances of P. coronata and tree ferns and related these to environmental variables using linear models and generalised linear mixed-effect models (GLMMs). Distance to an introduction site was the most significant factor predicting the palm’s distribution and abundance, suggesting that its current distribution is limited by insufficient time for wider dispersal. P. coronata cover was strongly and negatively related with the abundance of native tree ferns and the palm may therefore be displacing native tree ferns. This relationship was strongest with tree fern seedlings and weakest with mature tree ferns, implying that the palm is preventing the establishment of native tree ferns. This study thus provides strong circumstantial evidence that P. coronata is progressively displacing native tree ferns by preventing seedling establishment and poses a severe threat to Fiji’s native biodiversity and ecological processes. Therefore, urgent management is required to control and prevent the further spread of P. coronata and its negative impacts on native plant biodiversity. Management should involve an initial feasibility study to determine the effectiveness of various management strategies, followed by targeted control and/or eradication campaigns and long-term monitoring. Ultimately, well implemented legislation to prevent the spread and introduction of P. coronata and other ornamental plants will be crucial to protect native biodiversity in Fiji and elsewhere.

scholarly journals Effects of supplementary feed for game birds on activity of brown rats Rattus norvegicus on arable farms

2020 ◽  
Author(s):  
Siti Md Saad ◽  
Roy Sanderson ◽  
Peter Robertson ◽  
Mark Lambert
Keyword(s):  
Linear Models ◽  
Camera Traps ◽  
Monitoring Methods ◽  
Mixed Effect ◽  
Factors Affecting ◽  
Game Bird ◽  
Game Birds ◽  
Bird Feeders ◽  
Brown Rat ◽  
Supplementary Feed

Abstract Brown rats are widespread in agroecosystems, but our understanding of factors affecting their activity is incomplete due to cryptic, nocturnal behaviours. Indirect monitoring methods include tracking plates and camera traps. Supplementary feeding of game birds may provide resources for rats away from farm buildings, allowing them to persist in winter when there is little other food available. Developing reliable methods to monitor such populations will facilitate landscape-scale studies of rat populations in farm environments and aid ecologically based approaches for controlling rats on farms. We compared camera traps and tracking plates to monitor brown rat activity near game bird feeders at a mixed farm in Northumberland, UK. Generalized linear models (GLM) were used to compare rat incidence estimated from camera traps and tracking plates. A strong positive relationship was found between the two methods, although tracking plate estimates were less reliable when rat activity was very low. Factors that affected populations of brown rats near game bird feeders were assessed via linear mixed-effect models (LMM) of monthly tracking plate data (October 2017 to September 2018). Populations were highest at the feeders (0 m) compared with further away (10 m, 20 m) and were also higher in periods of cold, wet weather and when more food was available from the feeders. Rodenticide application near feeders did not significantly affect activity, nor did land cover 100 m around each feeder. A highly significant relationship was detected with food supply, suggesting that the use of game bird feeders could potentially have major impacts on rat population dynamics.

scholarly journals Linear models for diallel crosses: a review with R functions

2020 ◽  
Author(s):  
Andrea Onofri ◽  
Niccolò Terzaroli ◽  
Luigi Russi
Keyword(s):  
Linear Model ◽  
Combining Ability ◽  
Linear Models ◽  
General Linear Model ◽  
Ordinary Least Squares ◽  
General Purpose ◽  
General Linear ◽  
Mixed Effect ◽  
Typical Process ◽  
R Functions

Abstract Key message A new R-software procedure for fixed/random Diallel models was developed. We eased the diallel schemes approach by considering them as specific cases with different parameterisations of a general linear model. Abstract Diallel experiments are based on a set of possible crosses between some homozygous (inbred) lines. For these experiments, six main diallel models are available in literature, to quantify genetic effects, such as general combining ability (GCA), specific combining ability (SCA), reciprocal (maternal) effects and heterosis. Those models tend to be presented as separate entities, to be fitted by using specialised software. In this manuscript, we reinforce the idea that diallel models should be better regarded as specific cases (different parameterisations) of a general linear model and might be fitted with general purpose software facilities, as used for all other types of linear models. We start from the estimation of fixed genetical effects within the R environment and try to bridge the gap between diallel models, linear models and ordinary least squares estimation (OLS). First, we review the main diallel models in literature. Second, we build a set of tools to enable geneticists, plant/animal breeders and students to fit diallel models by using the most widely known R functions for OLS fitting, i.e. the ‘lm()’ function and related methods. Here, we give three examples to show how diallel models can be built by using the typical process of GLMs and fitted, inspected and processed as all other types of linear models in R. Finally, we give a fourth example to show how our tools can be also used to fit random/mixed effect diallel models in the Bayesian framework.

scholarly journals Intergenerational Transmission of Reproductive Behavior during the Demographic Transition

2012 ◽  
Vol 42 (4) ◽  
pp. 543-569 ◽  
Author(s):  
Julia A. Jennings ◽  
Allison R. Sullivan ◽  
J. David Hacker
Keyword(s):  
Reproductive Behavior ◽  
Marital Fertility ◽  
Fertility Transition ◽  
Fertility Control ◽  
Population Database ◽  
Marriage Age ◽  
Number Of Children ◽  
Intergenerational Ties ◽  
Children Ever Born ◽  
New Evidence

New evidence from the Utah Population Database (updp) reveals that at the onset of the fertility transition, reproductive behavior was transmitted across generations—between women and their mothers, as well as between women and their husbands' family of origin. Age at marriage, age at last birth, and the number of children ever born are positively correlated in the data, most strongly among first-born daughters and among cohorts born later in the fertility transition. Intergenerational ties, including the presence of mothers and mothers-in-law, influenced the hazard of progressing to a next birth. The findings suggest that the practice of parity-dependent marital fertility control and inter-birth spacing behavior derived, in part, from the previous generation and that the potential for mothers and mothers-in-law to help in the rearing of children encouraged higher marital fertility.

scholarly journals Age differences between distributions of genotypes among pregnant women: evidence of fertility selection

1989 ◽  
Vol 53 (3) ◽  
pp. 207-214 ◽  
Author(s):  
A. Gimelfarb ◽  
E. Bottini
Keyword(s):  
Natural Selection ◽  
Pregnant Women ◽  
Genetic Markers ◽  
Age Differences ◽  
Reproductive Capacity ◽  
Natural Fertility ◽  
Number Of Children ◽  
Age Related ◽  
Different Types ◽  
Fertility Selection

SummaryThe number of children produced by a modern woman is usually below her total reproductive capacity and is determined by circumstances other than natural selection. It is, therefore, practically impossible to detect differences in natural fertilities associated with different types (e.g. phenotypes, genotypes) of women. This does not mean, however, that natural selection at the reproductive level cannot at all be detected today. If women of a particular type have high natural fertility, this usually means that they reproduce (become pregnant) at a higher rate than women of a type with lower natural fertility. Hence, when there is a limit on the number of children, women of the first type will reach the limit at an earlier age than women of the second type. As a result, types that have a higher natural fertility should be overrepresented among pregnant women of younger ages and, consequently, underrepresented among older ones, as compared to types with a lower natural fertility. Based on this notion, a model of age-related differences between distributions of types among pregnant women is suggested. The model is applied to data on MNSs-blood group and PGM1 (phosphoglucomutase) types in a sample of pregnant women and an evidence of natural selection at the reproduction level associated with these genetic markers is obtained.

Factors Influencing Domestic Violence Against Married Women in Bangladesh : Evidence From Bangladesh Demographic and Health Survey

2013 ◽  
Vol 20 (Number 1) ◽  
pp. 40-51
Author(s):  
F Alam ◽  
B U Khan ◽  
M Shakil ◽  
MS Laskar
Keyword(s):  
Domestic Violence ◽  
Violence Against Women ◽  
Rural Areas ◽  
Suspected Case ◽  
Government Organization ◽  
Number Of Children ◽  
Factors Influencing ◽  
Victims Of Violence ◽  
Children Ever Born ◽  
Source Of Information

Violence against women is a common and menacing phenomenon in Bangladesh-and domestic violence is the most common form which includes pushing, shaking or throwing of any objects, slapping, punching with fist or something harmful, kicking or dragging, trying of choke or burn, threatening with knife/gun or other weapon, twisting arm or pulling hair. In the study mean age of the respondents were 30.66 (±8.904) and 62.5% respondents lived in Rural areas where higher prevalence of abuse has been observed. The reasons mentioned through out the country for abuse were inconsequential and included failure to perform household work and care of children, economic problems, food crisis, refusal to bring dowry, disobeying husband/elder, unemployment status of husband, suspected case of infidelity etc. Factors influencing domestic violence were lack of education both in respondents or their spouse, lack of exposure to magazine or source of information, current married, large number of children ever born etc. The majority of abused women remained silent about their experience because of the high acceptance of violence within society, only a few shared the matter with neighbor, father/mother or other relatives. A very small proportion of women approached institutional sources for help. Interestingly, violence increased with membership of women in any non government organization or mother club or relating to any income generating process. It is furthermore disgraceful to find that the women with lower body mass index are the higher group of population who are the high-flying victims of violence. In rural or urban Bangladesh, women's physical, mental, social and economic circumstances may influence their risk of domestic violence in multifaceted and paradoxical ways. Therefore findings suggest discussing policy propositions to overcome current realities.

Sign in / Sign up

Export Citation Format

Share Document