May mothers given warfarin breast-feed their infants?

Warfarin was measured with a sensitive and specific method in the plasma and breast milk of 13 mothers. Less than 0-08 micronmol warfarin per litre (25 ng/ml) of breast milk was found in each instance. Seven of the mothers were breast-feeding their infants, in none of whom was warfarin detected in the plasma; furthermore, in three the British corrected ratio of the plasma was appreciably less than that of the mother and was within the expected range. We conclude that nursing mothers given warfarin may safely breast-feed their infants.     

Why do mothers favor girls and fathers, boys?

Growing evidence suggests mothers invest more in girls than boys and fathers more in boys than girls. We develop a hypothesis that predicts preference for girls by the parent facing more resource constraints and preference for boys by the parent facing less constraint. We test the hypothesis with panel data from the Tsimane’, a foraging-farming society in the Bolivian Amazon. Tsimane’ mothers face more resource constraints than fathers. As predicted, mother’s wealth protected girl’s BMI, but father’s wealth had weak effects on boy’s BMI. Numerous tests yielded robust results, including those that controlled for fixed effects of child and household.     

Do mothers producing large offspring have to sacrifice fecundity?

We artificially selected on egg size in a butterfly to study the consequences for fecundity, reproductive effort and offspring fitness. Correlated responses in either pupal mass, larval or pupal development time were virtually absent. Offspring size was positively related to fitness, but only partly traded off against fecundity. Rather, total reproductive effort (measured as fresh mass), egg water content and the decline of egg size with female age increased in the large-egg selected lines compared to either small-egg or control lines. Accounting for these effects showed that reproductive investment (in dry mass) was in fact similar across lines. Such mechanisms may enable increased investment in (early) offspring without a reduction in their number, revealing a much more complex picture than a simple trade-off between offspring size and number. Substantial variation among replicates suggests that there are different underlying mechanisms for change, rather than any single, unitary pathway.     

Children's health and their mothers’ risk of divorce or separation

Abstract

The purpose of this study is to determine how children's health conditions are related to their mothers’ risk of divorce or separation. The study is based on data from over 7,000 children born to once‐married mothers identified in the 1988 Child Health Supplement to the National Health Interview Survey. The effects of 15 childhood health conditions on the mothers’ risk of divorce are estimated with Cox's proportional hazard models. Controlling for demographic, marital, and reproductive measures, we find that mothers’ prospects for divorce are affected both positively or negatively by their children's health status, depending on the type of childhood condition and, in the case of low birth weight children, timing within the marriage. Women whose children have congenital heart disease, cerebral palsy, are blind, or had low birth weight appear to have higher risks of marital disruption than mothers of healthy children. In contrast, mothers whose children have migraines, learning disabilities, respiratory allergies, missing/deformed digits or limbs, or asthma have somewhat lower rates of divorce.     

Should mothers provision their offspring equally? A manipulative field test

Within‐brood variation in offspring size is universal, but its causes are unclear. Theoretical explanations for within‐brood variation commonly invoke bet‐hedging, although alternatives consider the role of sibling competition. Despite abundant theory, empirical manipulations of within‐brood variation in offspring size are rare. Using a field experiment, we investigate the consequences of unequal maternal provisioning for both maternal and offspring fitness in a marine invertebrate. We create experimental broods of siblings with identical mean, but different variance, in offspring size, and different sibling densities. Overall, more‐variable broods had higher mean performance than less‐variable broods, suggesting benefits of unequal provisioning that arise independently of bet‐hedging. Complementarity effects drove these benefits, apparently because offspring‐size variation promotes resource partitioning. We suggest that when siblings compete for the same resources, and offspring size affects niche usage, the production of more‐variable broods can provide greater fitness returns given the same maternal investment; a process unanticipated by the current theory.     

Why do large mothers produce large offspring? Theory and a test

To explain the general tendency of large mothers to produce large offspring, we developed two models in which either the rate at which each single offspring extracts resources from the mother or the rate at which the mother supplies resources to all the offspring is limited (terminal- or upper-stream-limitation on resource transport, respectively). We also reanalyzed the data of Erythronium japonicum to test the models. The terminal-stream-limitation model predicted that the optimal offspring size that maximizes the fitness of the mother increases with an increase in the maximum rate of resource extraction by each single offspring. Thus, large mothers produce large offspring if the maximum resource extraction rate is high in those mothers. The upper-stream-limitation model predicted that the optimal offspring size decreases with an increase in the maximum rate of resource supply by the mother to all the offspring. In E. japonicum, the maximum growth rate of a seed was independent of the number of seeds of a plant, suggesting that the resource extraction rate is limited at the individual seed level. The maximum growth rate was high in large plants and had a strong positive effect on final seed mass. Thus, the results were consistent with the terminal-stream-limitation model.     

Infant kidnapping among group-living rhesus macaques: Why don't mothers rescue their infants?

Observations of infant kidnapping among group-living rhesus macaques and anecdotal evidence in the literature indicate that monkey mothers do not attempt to forcibly retrieve their infants from kidnappers even though kidnapping may have potentially fatal consequences for the infant. Based on the available evidence, the potential risk of injury to the mother and/or the infant in case of precipitated conflict with the kidnapper may conceivably account for the lack of maternal intervention during kidnapping. Although this hypothesis requires further testing, maternal refrainment from intervention seems to be a maladaptive response in cases of long-lasting kidnappings by nonlactating females because the infant's life is at stake and the cost of the loss of an infant is presumably higher than the potential risk of injury in a fight.     

Elevated insulin sensitivity and β-cell function during pregnancy in mothers of growth-restricted newborns

The "Barker hypothesis" suggests that low birth weight might predict future risk of developing obesity, cardiovascular disease, and type 2 diabetes. Identification of the causes of fetal growth restriction (FGR) is critical for preventive and management strategies. Some studies indicate that maternal carbohydrate metabolism might be involved in FGR development. We aimed to evaluate, in a large number of normotensive pregnant women with normal glucose tolerance, the effect of insulin sensitivity and β-cell function on unexplained fetal growth. A total of 1,814 Caucasian pregnant women with normal prepregnancy body mass index were tested with a 75-g, 2-h glucose load (24-28 gestation wk). Insulin sensitivity was evaluated with fasting (QUICKI) and dynamic index (OGIS) and β-cell function with a modified insulinogenic index as ΔAUC(insulin)/ΔAUC(glucose) and disposition index. FGR was a birth weight below the 5th percentile for gestational age. FGR developed in 99 (5.5%) pregnant women that showed significantly higher QUICKI, OGIS, insulinogenic, and disposition index with respect to women with normal-weight babies (P < 0.0001). By using multiple regression analysis in the FRG group, QUICKI and OGIS appeared as significant independent variables (P < 0.0001 and P < 0.0366, respectively). We conclude that elevated insulin sensitivity seems to be one of the factors involved in determining unexplained fetal growth retardation; its assessment, even only in the fasting state, could be useful to guide any possible monitoring and therapeutic strategies to reduce fetal complications.     

Do mothers regulate facultative and obligate siblicide by differentially provisioning eggs with hormones?

We examined androgens in clutches of two booby species that differ in their sibling conflict. Blue-footed booby Sula nebouxii chicks show an aggression-submission relationship, aggression is normally moderate and siblicide is facultative. Brown booby Sula leucogaster chicks show an aggression-aggression relationship, aggression of both chicks can be relentless and siblicide is obligate. The parental favoritism hypothesis predicts that egg mass, yolk mass and yolk androgens should decline with laying order less in the blue-footed booby than in the brown booby, to promote the survival of the former's junior chick. The eggs of the blue-footed booby had higher yolk concentrations of 5α-dihydrotestosterone (DHT) and lower concentrations of testosterone (T); both species had similarly high yolk concentrations of androstenedione (A). Intra-clutch variation in yolk DHT, T and A failed to support our predictions. In both species, first and second eggs showed similar concentrations of all three hormones and were of similar size, although in the blue-footed booby (only) yolk masses declined with laying order. Brown booby mothers make junior chicks vulnerable to siblicide by hatching them 5 d after their broodmates, but not by differential allocation of egg androgens or nutrients. Blue-footed booby mothers appear to prepare junior chicks for thriving in a subordinate non-provocative role by hatching them 4 d after their broodmates and providing them with 10% less yolk. To orchestrate agonism within the brood, these boobies may rely more on hatch intervals and yolk provision than on androgens.     

Breast-milk mercury concentrations and amalgam surface in mothers from Brasília, Brazil

Human milk is the best source of nourishment for the newborn because of its incomparable balanced nutrition and psychological benefits to the infant's development. Dental fillings containing metallic Hg are the primary source of inorganic Hg contamination of humans. We studied Hg concentrations in the breast milk of mothers during the first month (7-30 d) postnatal in relation to the number of amalgam surfaces. The concentration of total Hg was determined in 23 samples of human milk collected from lactating mothers with a varied number of amalgam dental restorations. The average number of amalgam surfaces was 6.87 (5.81, SD) with a range of 0 to 20. The mean concentration of total Hg in breast milk was 5.73 ng/g (range: 0-23.07). The Pearson correlation coefficient was significant (r = 0.6087, p = 0.0057) between breast-milk Hg and number of amalgam surfaces. In 56.5% of low-fish-eating mothers, the amount of Hg likely to be ingested by breast-fed infants is above the World Health Organization reference.     

Skewed birth sex ratios in primates: Should high-ranking mothers have daughters or sons?

Numerous studies have been published on the skewed birth sex ratios among non-human primate populations. Sometimes the observed tendencies in sex ratio variations have been contradictory, and their adaptive significance has been controversial. Recent studies seem to reveal that the local resource competition among philopatric sex is the most important selective force affecting primate birth sex ratios. However, our understanding on this issue is still greatly hampered by the lack of exact knowledge on male reproductive success and the proximate mechanisms to vary sex ratios.     

RAS and RHO family GTPase mutations in cancer: twin sons of different mothers?

Abstract

The RAS and RHO family comprise two major branches of the RAS superfamily of small GTPases. These proteins function as regulated molecular switches and control cytoplasmic signaling networks that regulate a diversity of cellular processes, including cell proliferation and cell migration. In the early 1980s, mutationally activated RAS genes encoding KRAS, HRAS and NRAS were discovered in human cancer and now comprise the most frequently mutated oncogene family in cancer. Only recently, exome sequencing studies identified cancer-associated alterations in two RHO family GTPases, RAC1 and RHOA. RAS and RHO proteins share significant identity in their amino acid sequences, protein structure and biochemistry. Cancer-associated RAS mutant proteins harbor missense mutations that are found primarily at one of three mutational hotspots (G12, G13 and Q61) and have been identified as gain-of-function oncogenic alterations. Although these residues are conserved in RHO family proteins, the gain-of-function mutations found in RAC1 are found primarily at a distinct hotspot. Unexpectedly, the cancer-associated mutations found with RHOA are located at different hotspots than those found with RAS. Furthermore, since the RHOA mutations suggested a loss-of-function phenotype, it has been unclear whether RHOA functions as an oncogene or tumor suppressor in cancer development. Finally, whereas RAS mutations are found in a broad spectrum of cancer types, RHOA and RAC1 mutations occur in a highly restricted range of cancer types. In this review, we focus on RHOA missense mutations found in cancer and their role in driving tumorigenesis, with comparisons to cancer-associated mutations in RAC1 and RAS GTPases.     

Transracial adoption: white American adoptive mothers’ constructions of social capital in raising their adopted children

In the field of adoption and child welfare, there is ongoing debate and discussion about how white adoptive parents in transracial families construct personal and social relationships and networks to promote cultural belonging and identity development in their children. In spite of this however, there is, to date, no research study that has sought to apply the notion of social capital to understand transracial adoptive families. With its exploration of how white American adoptive mothers construct social capital in raising their transracially adopted children, this paper seeks to contribute to the literature on social capital and families in general, and social capital and transracial families in particular. By drawing upon a qualitative study involving white adoptive mothers’ discursive practices, and multiplex constructions of intersectionality, the paper seeks to offer rich theoretical and empirical insights into social capital and transracial adoption to contribute to the literature in this area.     

Measurement of breastfeeding initiation: Ethiopian mothers’ perception about survey questions assessing early initiation of breastfeeding

Background

Although breastfeeding is almost universal in Ethiopia, only 52% newborns benefited from early initiation in 2011. Early initiation is one of the recommended interventions for saving newborn lives but its potential seems not yet realized for Ethiopian newborns and there is a need for continued efforts to increase coverage. To do so, it is also relevant to focus on consistent and accurate reporting of coverage in early initiation.WHO recommends the question “how long after birth did you first put [name] to the breast?” in order to assess coverage in early initiation. It is designed to measure the time after birth when the mother attempted to initiate breastfeeding regardless of whether breast milk had arrived or not. However, it is unclear how mothers perceive this question and what their responses of time refer to. In this study, we assessed Ethiopian mothers’ perception about the question assessing early initiation.

Methods

Cognitive interviews were conducted between April and May 2013 with eligible mothers in Basona and Debrebirhan woredas (districts), 120 km away from Addis Ababa, Ethiopia.

Results

A total of 49 mothers, most from Basona (n =?36) and the rest from Debrebirhan woredas (n =?13) were interviewed. No probes or follow on questions were required for mothers to understand what the WHO recommended question was about. However, further probing was needed to ascertain what maternal responses of time refer to. Accordingly, mothers’ response about the timing of early initiation was related to the first time the newborn received breast milk rather than their first attempt to initiate breastfeeding. In addition, considerable probing was required to approximate and code responses of time based on the WHO coding format because some mothers were unable to assess time in minutes or hours.

Conclusion

The existing question is not adequate to identify intended attempts of mothers to initiate breastfeeding. We recommend revising the question as “how long after birth did you first put [name] to the breast even if your breast milk did not arrive yet?” Standard probes or follow on questions are required to avoid subjective interpretation of the indicator.

     

Effect of sleep environment of preschool children on children’s sleep problems and mothers’ mental health

Sleep and Biological Rhythms - We evaluated the sleep environment factors that influence children’s sleep, and the relationship between co-sleeping and parenting stress and parents’...