New form of adrenoleukodystrophy

Summary Male and female siblings demonstrated similar facial features and had seizures from birth. Neurologic development, which was delayed, began to deteriorate at 1 year. Sudden death occurred at 2 8/12 and 2 3/12 years of age associated with respiratory infections. Tanning of the skin was noted 2 months before death in the first child. In the second child, blood cortisol levels failed to increase after intravenous ACTH administration, and computerized axial tomography (CAT) scans were normal.At autopsy both patients demonstrated adrenal atrophy and degenerative changes of the white matter throughout the neuraxis. We propose that these siblings have a new form of adrenoleukodystrophy that can be distinguished from the X-linked form by onset at birth, clinical appearance, and pattern of inheritance.A comparison of these cases with a second disorder, Zellweger's syndrome, suggests that a distinctive phenotype is associated with intrauterine degeneration of white matter.     

Season of birth and reproductive performance: an analysis of family reconstitutions of 800 women born in The Netherlands at the end of the 19th century

Background: Several studies have reported associations between season of birth and reproductive characteristics such as menarcheal age, fecundability, and twinning, but the results are inconsistent with respect to the location of high- and low-risk seasons. To assess whether this disagreement could be due to the use of populations from different geographic areas and time frames instead of different etiologic pathways, we investigated the season-of-birth dependency of a variety of reproductive outcomes within one time- and arealimited population. Methods: In a historic follow-up study, the reconstituted families of 800 women born between 1873 and 1887 in or near Rotterdam, The Netherlands, were used to determine eight types of reproductive outcome: childlessness, interval to first pregnancy, pregnancy interval, stillbirth, neonatal death, postneonatal death, multiple birth, and gender of offspring. The relation of these outcomes with season of birth was modeled using cosinor functions with periods of 1 year or a half year. Data were analyzed by use of logistic regression or general estimation equations (GEE), dependent on whether outcomes could occur more than once per woman. Results: Peaks in the model-based risks of reproductive failure were found within two small temporal ranges, January 1 to February 11 and July 1 to August 11 for all outcomes except gender. The picture did not change after controlling for known and possible risk factors, including age, offspring's birth cohort, and some social variables. Conclusions: This study reconfirms the idea that seasonal factors around conception or birth influence later reproductive characteristics. Observing the consistency of the location of high-risk seasons across a variety of outcomes, the explanation of season-of-birth dependency of different reproductive outcomes need not involve multiple etiological pathways. (Chronobiology International, 18(3), 525-539, 2001)     

Are all born equal? Incidence of febrile convulsions by seasons of birth.

To test whether the seasons of birth had an effect on subsequent experience of illness, details were obtained of all Sheffield children born between 1973 and 1977 who were admitted to hospital before their second birthday with a first febrile convulsion. Analysis by date of birth in consecutive 28-day cohorts showed that the incidence of febrile convulsions ranged from 2.5 per thousand live births to 30.2 per thousand in different "month" cohorts. Statistically significant variations were noted in the incidence rates in relation to season and year of birth. The implication is that even large scale epidemiological studies which have been confined to children born in a particular week or month may not be representative of the whole child population.     

Measurement of child mortality in association with a multipurpose birth certificate programme in the Southern Highlands Province of Papua New Guinea.

A simple and inexpensive method for monitoring child mortality in association with birth registration was introduced into the Southern Highlands of Papua New Guinea. Eight thousand two hundred and one newborn infants were registered in 1988, approximately 77% of all children born in that year. The risk of death by age 2 was determined from reports given by the mother on the present status of a previously born child at the time of a recent delivery or during clinic registration of the current birth. This was 91 per 1000 for the province and corresponds to a risk of death by age 1 of 77/1000 by extrapolation using standard lifetables. This method was validated by comparison with a continuing demographic surveillance system covering 30,000 people in the western part of the province. The new birth certificate has been an incentive to increase supervised delivery rates and to generate a register that can be used to increase vaccination coverage.     

Survival analysis of mortality in pre-weaning kids of Sirohi goat

Pre-weaning animals exit a flock through death induced by various reasons, causing significant economic losses to the goat producers. In this study, we investigated the survival from birth to weaning of Sirohi goat kids within framework of the survival analysis. Kid records were accessed from 1997 to 2017, with the information on 4417 pre-weaning animals of farmed Sirohi goat native to the Rajasthan State of India. A multivariable Cox regression was fitted to the data after checking the assumptions of regression. The explanatory variables were sex, type of birth, season of birth, birthweight, doe weight at kidding and year of birth. Model selection eliminated doe weight from the model, and sex, type of birth, season of birth, birthweight and year of birth were retained in the model. With model calibration also, these five covariates were retained in the model. The mortality on the first day after birth was 0.3%, constituting 3.5% of all pre-weaning mortality. The mortality until the end of weaning period was 7.8%. Regression analysis revealed that the higher birthweight at kidding was associated with reduced hazard of death among the kids. Male kids had higher hazards of death compared with female kids. The single-born kids had lower risks of death compared with twin-born kids after accounting for heterogeneity. The winter season had a very high adverse effect on the survival of the kids. With each passing year, risks of death decreased. The results of this study indicate that better survival of kids can be achieved by controlling both environmental and animal-related factors.     

Son preference and fertility in China

This paper examines the effect of son preference on the hazards of having a second and a third birth. With data from the Two-per-thousand National Sample Survey on Fertility and Contraception conducted in 1988 by the State Family Planning Commission of China, the hazard of having a second birth among 62+ thousand married women who have had a first birth, and the hazard of having a third birth among 43+ thousand married women who have had two births was examined. These two hazards (i.e. the hazard of moving from the first to the second birth, and the hazard of moving from the second to the third birth) were analysed by estimating Cox proportional hazard models. The major covariate in the first analysis is whether or not the first-born was a daughter. In the second analysis the main covariate is whether both of the first two children were girls. In both models seven covariates known to have independent effects on the transition to a second (or third) birth are controlled for, namely, whether the woman is a Han, whether she is a farmer, her age at the birth of the first (or second) child, whether she had her first (or second) birth prior to the initiation in 1979 of the one-child policy, and three dummy variables reflecting her level of education. The results show the important influence of son preference on the hazard of having another birth.     

Demography,female life history,and reproductive profiles among the chimpanzees of Mahale

Demography provides critical data to increase our understanding of the evolution, ecology, and conservation of primate populations. The chimpanzees of the Mahale Mountains National Park, Tanzania, have been studied for more than 34 yr on the basis of individual identification and standardized attendance records. From this long-term study, we derived the following demographic data: The major cause of death was disease (48%), followed by senescence (24%) and within-species aggression (16%). Fifty percent of Mahale chimpanzees died before weaning. The median ages of female life history variables were: first maximal swelling, 10.0 yr (n = 5); emigration, 11.0 yr (n = 11); and first birth, 13.1 yr (n = 5). The median period of adolescent infertility was 2.8 yr (n = 4) when calculated from the age at immigration to that at first birth. Female fecundity was highest between 20 and 35 yr of age, with an annual birth rate of 0.2. Twenty-six females that were observed from a young age (10-13 yr) to death at various ages (15-40 yr) gave birth to an average of 3.9 and weaned an average of 1.4 offspring. Twenty-five females that were observed from middle age (18-33 yr) to death in older age (31-48) gave birth to an average of 2.7 and weaned an average of 2.0 offspring. The post-reproductive lifespan for female chimpanzees was defined as the number of years that passed from the year when the last offspring was born to the year when the female died, minus 5. Twenty-five percent of old females had a post-reproductive lifespan. The interbirth interval after the birth of a son (x = 72 mo) tended to be longer than that after the birth of a daughter (x = 66 mo). The extent of female transfer, which is a rule in chimpanzees, is influenced by the size and composition of the unit group and size of the overall local community.     

SEASON OF BIRTH AND REPRODUCTIVE PERFORMANCE: AN ANALYSIS OF FAMILY RECONSTITUTIONS OF 800 WOMEN BORN IN THE NETHERLANDS AT THE END OF THE 19TH CENTURY

Background: Several studies have reported associations between season of birth and reproductive characteristics such as menarcheal age, fecundability, and twinning, but the results are inconsistent with respect to the location of high- and low-risk seasons. To assess whether this disagreement could be due to the use of populations from different geographic areas and time frames instead of different etiologic pathways, we investigated the season-of-birth dependency of a variety of reproductive outcomes within one time- and arealimited population. Methods: In a historic follow-up study, the reconstituted families of 800 women born between 1873 and 1887 in or near Rotterdam, The Netherlands, were used to determine eight types of reproductive outcome: childlessness, interval to first pregnancy, pregnancy interval, stillbirth, neonatal death, postneonatal death, multiple birth, and gender of offspring. The relation of these outcomes with season of birth was modeled using cosinor functions with periods of 1 year or a half year. Data were analyzed by use of logistic regression or general estimation equations (GEE), dependent on whether outcomes could occur more than once per woman. Results: Peaks in the model-based risks of reproductive failure were found within two small temporal ranges, January 1 to February 11 and July 1 to August 11 for all outcomes except gender. The picture did not change after controlling for known and possible risk factors, including age, offspring's birth cohort, and some social variables. Conclusions: This study reconfirms the idea that seasonal factors around conception or birth influence later reproductive characteristics. Observing the consistency of the location of high-risk seasons across a variety of outcomes, the explanation of season-of-birth dependency of different reproductive outcomes need not involve multiple etiological pathways. (Chronobiology International, 18(3), 525–539, 2001)     

Early growth and death from cardiovascular disease in women.

OBJECTIVE--To determine whether the link suggested between growth in utero and during infancy and death from cardiovascular disease in men is also present in women. DESIGN--Follow up study of women and men whose birth weight and weight at 1 year of age had been recorded. SETTING--Hertfordshire, England. SUBJECTS--5585 women and 10,141 men born during 1911-30. MAIN OUTCOME MEASURES--Standardised mortality ratios for cardiovascular disease. RESULTS--Among women and men death rates from cardiovascular disease fell progressively between the low and high birth weights groups (chi 2 = 4.3, p = 0.04 for women, chi 2 = 8.5, p < 0.005 for men). Cardiovascular deaths in men but not women were also strongly related to weight at 1 year, falling progressively between the low and high weight groups (chi 2 = 27.5, p < 0.0001). The highest cardiovascular death rates in women were among those with below average birth weight but above average weight at 1 year. In men the highest rates were among those with below average birth weight and below average weight at 1 year. CONCLUSION--Relations between cardiovascular disease and birth weight are similar in men and women. In men cardiovascular disease is also related to weight gain in infancy.     

Is there a link between cot death and child abuse?

Forty five babies delivered in Oxford obstetric units who subsequently died unexpectedly in infancy were compared with 134 controls matched for maternal age, social class, parity, and year of birth to see whether five factors identified in an earlier study as predictive of subsequent child abuse would also predict the sudden infant death syndrome. Epidemiological findings had suggested certain similarities between the two events. In contrast with babies who were abused, four of the five factors did not distinguish between babies who died suddenly and unexpectedly and their controls, but there was a slight increase in the proportion of mothers of babies who died suddenly and unexpectedly for whom nursing staff thought that support and advice on feeding the baby were needed. Factors predictive of child abuse did not predict sudden infant death in this study.     

Reproductive efficiency of captive Chinese- and Indian-origin rhesus macaque (Macaca mulatta) females

Reproductive and survival records (n=2,913) from 313 Chinese-origin and 365 Indian-derived rhesus macaques at the Tulane National Primate Research Center (TNPRC) spanning three generations were studied. Least-squares analysis of variance procedures were used to compare reproductive and infant survival traits while proportional hazards regression procedures were used to study female age at death, number of infants born per female, and time from last birth to death. Chinese females were older at first parturition than Indian females because they were older when placed with males, but the two subspecies had similar first postpartum birth interval (1st PPBI) and lifetime postpartum birth interval (LPPBI). Females that gave birth to stillborn infants had shorter first postpartum birth intervals (1st PPBI) than females giving birth to live infants. Postpartum birth intervals decreased in females from age 3 to 12 but then increased again with advancing age. Chinese infants had a greater survival rate than Indian infants at 30 days, 6 months, and 1 year of age. Five hundred and forty-three females (80.01%) had uncensored, or true records for age at death, number of infants born per female, and time from the birth until death whereas 135 females (19.91%) had censored records for these traits. Low- and high-uncensored observations for age at death were 3 and 26 years for Chinese, and 3 and 23 years for Indian females. Uncensored number of infants born per female ranged from 1 to 15 for Chinese females and 1 to 18 for Indian females. Each of these traits was significantly influenced by the origin×generation interaction in the proportional hazards regression analyses, indicating that probabilities associated with age at death, number of infants born per female, and time from last birth to death for Chinese and Indian females did not rank the same across generations.     

Unemployment and mortality among Finnish men, 1981-5.

OBJECTIVE--To ascertain whether, after controlling for several relevant background variables simultaneously, unemployment is related to mortality and to assess whether this relation is causal or whether unhealthy people are more likely to become unemployed. DESIGN--Prospective study of mortality in Finland during 1981-5 based on 1980 census data on 30-54 year old wage earner men and with particular attention to unemployment in the year before the census. SETTING--Research project at the University of Helsinki. SUBJECTS--All wage earner men in Finland aged 30-54 at the 1980 census. MAIN OUTCOME MEASURES--Causes of death during 1981-5 and duration of unemployment in the year before the census. Background variables controlled for were age, socioeconomic state, marital state, and health. The data were analysed by log linear regression models. RESULTS--During the study period 1981-5, which covered almost 2.7 million person years, there were 9810 deaths. After controlling for all background variables relative total mortality among unemployed versus employed men was 1.93 (95% confidence interval 1.82 to 2.05). The excess mortality was highest in accidental and violent causes of death (relative mortality 2.51; 95% confidence interval 2.28 to 2.76). For circulatory diseases the relative death rate was 1.54 (95% confidence interval 1.40 to 1.70), but among neoplasms only lung cancer was associated with excess mortality. Selection for unemployment based on age, socioeconomic state, and marital state was evident but no such selection was detected based on health. Effects of unemployment on mortality were more pronounced with increasing duration of unemployment. CONCLUSIONS--The relative excess mortality of unemployed men in Finland cannot fully be explained by demographic, social, and health variables preceding unemployment. Unemployment therefore seems to have an independent causal effect on male mortality. Further studies are needed to elucidate the mechanisms between unemployment and mortality.     

Gestational and Early Infancy Exposure to Margarine Fortified with Vitamin D through a National Danish Programme and the Risk of Type 1 Diabetes: The D-Tect Study

The objective of the study was to assess whether gestational and early infancy exposure to low dose vitamin D from a mandatory margarine fortification programme in Denmark influenced the risk of developing type 1 diabetes (T1D) before age of 15 years. The study population included all individuals born in Denmark from 1983 to 1988 and consisted of 331,623 individuals. The 1^st of June 1985, which was the date of issue of the new ministerial order cancelling mandatory fortification of margarine with vitamin D in Denmark, served as a reference point separating the studied population into various exposure groups. We further modelled birth cohort effects in children developing T1D as a linear spline, and compared the slopes between the birth cohorts with various prenatal and infancy exposures to vitamin D fortification. In total, 886 (0.26%) individuals developed T1D before the age of 15 years. The beta coefficients (95% CI), or slopes, for linear birth cohort effect in log Hazard Ratio (HR) per one month of birth in individuals born during the periods of gestational exposure, wash-out, and non-exposure were: 0.010 (-0.002/0.021), -0.010 (-0.035/0.018), and 0.008 (- 0.017/0.032), respectively. The beta coefficients (95% CI) for individuals born during the periods of first postnatal year exposure, wash-out, and non-exposure were: 0.007 (-0.016/0.030), 0.006 (-0.004/0.016), and 0.007 (-0.002/0.016), respectively. In conclusion, we found no evidence to support that exposure to low dose vitamin D from the Danish mandatory margarine fortification regimen during gestational and first postnatal year of life changed the risk of developing T1D before the age of 15 years.     

A mechanistic model based analysis of cotton aphid population dynamics data

1 A 2‐year field study was conducted to generate data on seasonal abundance patterns of cotton aphids Aphis gossypii Glover and to develop a mechanistic model based on cumulative population size. The treatments consisted of three irrigation levels (Low, Medium and High) with 65%, 75% and 85% evapotranspiration replacement and three nitrogen fertility treatments (blanket‐rate‐N, variable‐rate‐N and no nitrogen). 2 A nonlinear regression equation, the analytical solution of a cumulative size mechanistic model, was fitted to each of the 27 individual data sets collected in 2003 and in 2004. The size and time of the peak, the cumulative aphid density, and the birth and death rates were estimated for each population, and each of these five variables was analyzed as a response variable in the analysis of variance. 3 For 2003 (a dry year), the Water (irrigation) main effect was found to be significant for the time of peak, the death rate and the cumulative density. The lower aphid death rate at low water levels might be due to the water stress in plants. 4 For 2004 (a year with moderate precipitation), the Nitrogen main effect was significant for both the birth and death rates. As nitrogen applications were increased, the decrease in both the aphid birth and death rates translates into a decrease in crowding and an increase in aphid survival. 5 The fact that treatment effects may be manifested through birth and death rate parameters in the new mechanistic model opens up new avenues for analyzing population size data of this kind.     

Factors influencing prereproductive mortality in the isolated and preindustrial western Mediterranean population of La Alpujarra, 1900-1950

We study the effects of several variables on the prereproductive mortality pattern in the isolated and rural population of La Alpujarra, located on the western Mediterranean coast (southeast Spain), in the first half of the 20th century. The study is a retrospective analysis from a total sample of 2,200 deliveries, 2,085 of which were born alive and 171 of which did not survive to the 20th birthday. The potential influences of birthdate of children, twinning, firstborn, parental inbreeding, and sex on Alpujarran mortality were analyzed through logistic regression. Parity, family size, and birth interval effects were estimated through the difference between observed and expected mortality rates. In every case four age groups of mortality were considered because of the large influence of child growth: neonatal (less than 1 month of life), postneonatal infant (between 1 month and 1 year old), childhood (1-5 years old), and youth (5-20 years old). The Alpujarran prereproductive mortality pattern can be summarized as the result of three main risk factors: biodemographic, biomechanical, and social and health determinants. In general, every factor showed a decreased effect as children grew. The most significant determinants were birthdate of children, which is more related to increased mother's awareness of child care than to health improvement, and family size associated with decreasing alimentary resources as the sibling number increased. Male mortality was higher than female mortality in children older than 1 year but not for infant mortality, possibly as a result of a reproductive behavior favorable to males. Although firstborn status and twinning appeared associated with high mortality, maternal age and birth interval were related to low risk, but these influences always ceased after the first month of life. Parental inbreeding did not show any effect on infant, childhood, or youth mortality.     

Son preference and child replacement in Bangladesh: a new look at the child survival hypothesis

Birth history data from women in the 1975-76 Bangladesh Fertility Survey were used to search for intentions to replace dead children. The median intervals between successive births of orders (i) and (i + 1) were not shorter when some siblings of orders below (i) had died. Nor was the median duration between the death of a child and the first posthumous birth shorter when the dead child was a boy or when it was survived by fewer than two brothers. The median intervals were generally shorter when the mother lived in an urban rather than a rural area but this difference was attributable only to the shorter duration of breast-feeding by urban women. These results disputed the notions that the timing of births was deliberately quicker to replace a dead child, that attempts at replacement were sex-selective, or that child replacement intentions were stronger in urban than in rural populations.     

Modelling Survival and Mortality Risk to 15 Years of Age for a National Cohort of Children with Serious Congenital Heart Defects Diagnosed in Infancy

Background

Congenital heart defects (CHDs) are a significant cause of death in infancy. Although contemporary management ensures that 80% of affected children reach adulthood, post-infant mortality and factors associated with death during childhood are not well-characterised. Using data from a UK-wide multicentre birth cohort of children with serious CHDs, we observed survival and investigated independent predictors of mortality up to age 15 years.

Methods

Data were extracted retrospectively from hospital records and death certificates of 3,897 children (57% boys) in a prospectively identified cohort, born 1992–1995 with CHDs requiring intervention or resulting in death before age one year. A discrete-time survival model accounted for time-varying predictors; hazards ratios were estimated for mortality. Incomplete data were addressed through multilevel multiple imputation.

Findings

By age 15 years, 932 children had died; 144 died without any procedure. Survival to one year was 79.8% (95% confidence intervals [CI] 78.5, 81.1%) and to 15 years was 71.7% (63.9, 73.4%), with variation by cardiac diagnosis. Importantly, 20% of cohort deaths occurred after age one year. Models using imputed data (including all children from birth) demonstrated higher mortality risk as independently associated with cardiac diagnosis, female sex, preterm birth, having additional cardiac defects or non-cardiac malformations. In models excluding children who had no procedure, additional predictors of higher mortality were younger age at first procedure, lower weight or height, longer cardiopulmonary bypass or circulatory arrest duration, and peri-procedural complications; non-cardiac malformations were no longer significant.

Interpretation

We confirm the high mortality risk associated with CHDs in the first year of life and demonstrate an important persisting risk of death throughout childhood. Late mortality may be underestimated by procedure-based audit focusing on shorter-term surgical outcomes. National monitoring systems should emphasise the importance of routinely capturing longer-term survival and exploring the mechanisms of mortality risk in children with serious CHDs.     

Analyzing infant mortality with geoadditive categorical regression models: a case study for Nigeria

In this paper, we analyze infant mortality in Nigeria based on the data set from the 1999 Nigeria Demographic and Health Survey (NDHS). We investigate spatial patterns at a highly disaggregated level of Nigerian states and consider non-linear effects of mother's age at birth. Time to the occurrence of a child's death can intuitively be considered to be categorical in nature and the determinants of a child's death may differ in different age groups. Thus, it may be desirable to investigate separately the death of a child in the first month and in the remaining 11 months of the first year of life. To avoid selection bias, the data set used for this case study is based on information on children who were born 12 months preceding the survey. Inference is Bayesian and is based on Markov chain Monte Carlo (MCMC) techniques. We find that spatial variation and the determinants of death indeed differ considerably for the two age groups considered.     

Life history of yellow baboons: Physical development,reproductive parameters,and infant mortality

Longitudinal data from a population of yellow baboons,Papio cynocephalus, in the Amboseli National Park, Kenya, provide life history parameter estimates. Females reached menarche at approximately four-and-a-half years of age and then cycled for approximately a year before first conception. Postpartum anestrum averaged 12 months but ranged from six to 16 months. In cases of still births or infant death during postpartum amenorrhea, females commenced cycling after approximately one month. In mature females the time spent cycling before conception was five months on the average with a range from one to over 18 months. Only half of all full-term pregnancies resulted in infants who survived the first year of life; only a third, in infants who survived until the birth of their mother’s next infant. In comparison with data from laboratory colonies, our data indicate that female baboons in Amboseli are older at birth of first infant. They have, on the average, a somewhat shorter interbirth interval than was estimated from earlier crossectional field data, and therefore spend a larger portion of their adult life pregnant, but have a much longer interval—at least three years on the average—between the birth of an infant and the birth of that infant’s next older surviving sibling. A number of morphological changes in immature baboons are described.