Variation in maternal provisioning by lactating Antarctic fur seals: response to experimental manipulation in pup demand

An experiment involving the supplementary feeding of pups was conducted on Antarctic fur seals to investigate the factors influencing maternal foraging-attendance cycles and the differential use of nutritional resources for growth, maintenance and storage by pups. For 40% of the lactation period, male pups were given a supplement mimicking the chemical composition of Antarctic fur seal milk at a dose equivalent to 35% of the normal mass-specific milk energy intake for the species. Milk consumption, body composition and growth rates were monitored during and after the supplementary feeding period and maternal foraging-attendance cycles were monitored throughout lactation. During the supplementary feeding period, treatment pups (n=8) grew 32% faster and deposited greater adipose tissue stores than controls (n=8) but consumed the same amount of maternal-delivered milk. When supplementary feeding was stopped (timed to coincide with peak maternal milk yield in this species), treatment pups lost mass whereas control group pups continued to grow. Treatment pups weaned at a younger age (109 days) than control pups (116 days) but at the same mass (13 kg). Maternal attendance durations did not differ between the treatment and control groups throughout lactation. However, mothers of treatment pups had significantly shorter foraging trip durations (3.74 days) than mothers of control pups (4.74 days) during the period of supplementary feeding (there were no significant differences throughout the rest of lactation). These findings are in accordance with predictions of a marginal-value model of fur seal lactation behaviour.

Maternal postpartum adjustment in Victoria's south west : a rural perspective

Aims & Rationale/Objectives
This study examined maternal postpartum adjustment in the first 12 months. Firstly, we were interested in examining whether Parental Functioning would be affected by living or not living in a major South West regional centre. Secondly, we were interested in whether Parental Functioning would differ as a function of infants being under or over 6 months of age. Thirdly, we were interested in whether Parental Functioning would differ as a function of pregnancy and birth complications. Finally, we were interested in whether postpartum perceptions of Role Competence/Satisfaction and Social Support would be associated with the Postnatal Depression.

Methods
The (preliminary) sample included 69 rural mothers recruited from across five shire regions within South West Victoria. Indicators of Parental Functioning were assessed using self-report questionnaires. Demographic and medical information was also collected. Respondents to the study were mailed a questionnaire pack which was returned in a reply-paid envelope.

Principal Findings
The results regarding geographical location were non-significant. There were significant differences in Wellbeing but not Role Competence/Satisfaction, or Social Support as a function of infant age. There were significant differences in Wellbeing, Role Competence/Satisfaction, and Social Connectedness (but not actual social support) as a function of Pregnancy Complications but not Birth Complications. Finally, Role Competence/Satisfaction and Social Connectedness (but not actual social support) significantly contributed to the variance in Postnatal Depression.

Discussion
Findings suggest that mothers did not differ as a function of their geographical location. Overall, mothers had higher levels of parental functioning when their infants were over 6 months of age, and also, if they did not experience pregnancy complications (physical, emotional, both). Additionally, findings suggest that perceptions of competence in and satisfaction with the parenting role, and also feelings of 'connectedness' to social others, are protective factors against the development of postpartum adjustment disorders.

Implications
Given that depressive episodes are common during childbearing years, and have both short- and long-term developmental effects on the infant, these findings support a need for the development and examination of a perinatal and infant mental health programme for rural mothers and infants.

Milk consumption, body composition and pre-weaning growth rates of Australian fur seal

Pre-weaning growth rates, body composition, milk consumption and mass gain efficiency were measured in Australian fur seal Arctocephalus pusillus doriferus pups born in two consecutive breeding periods. Australian fur seals have the highest birth mass of any fur seal species (male 8.3 kg; female 7.2 kg). While their absolute pre-weaning growth rate (male 62 g·day⁻¹; female 53 g·day⁻¹) is similar to that of other temperate latitude fur seals, they have the longest birth-mass doubling time of any otariid species (134–136 days). Daily milk consumption increased from 400 g·day−1 (5 MJ·day−1) after birth to 675 g·day⁻¹ (13.7 MJ·day⁻¹) at age 210 day. However, mean mass-specific milk consumption (41 g·kg⁻¹) is substantially lower than in other otariid species (58–70 g·kg⁻¹) and, combined with a low mass gain efficiency (0.12 g·g⁻¹), contributes to the low mass-specific growth rates observed. There were no significant differences in either absolute or mass-specific milk consumption between the sexes. Significant differences, however, were found between the sexes in the body composition of pups with females generally having larger body lipid stores than males for any given mass. Peak milk yield by Australian fur seal females is estimated at 0.60 MJkg−0.75, substantially less than in Antarctic fur seals. The low level of maternal energy transfer in Australian fur seals may reflect the relatively low marine productivity of their foraging areas.

Maternal creatine : does it reach the fetus and improve survival after an acute hypoxic episode in the spiny mouse (Acomys cahirinus)?

Objective
We hypothesized that elevating creatine in the maternal diet would reach fetal and placental tissues and improve fetal survival after acute hypoxia at birth.
Study Design
Pregnant spiny mice were fed a control or 5% creatine-supplemented diet from day 20 of gestation (term, approximately 39 days). On days 37-38, intrauterine hypoxia was induced by placement of the isolated uterus in a saline solution bath for 7.5-8 minutes, after which fetuses were expelled from the uterus and resuscitation was attempted by manual palpation of the chest. Total creatine content (creatine + phosphocreatine) of placental, fetal, and maternal organs was measured.
Results
The maternal creatine diet significantly increased total creatine content in the placenta, fetal brain, heart, liver, and kidney and increased the capacity of offspring to survive birth hypoxia. Maternal creatine improved postnatal growth after birth hypoxia.
Conclusion
This study provides evidence that creatine has potential as a prophylactic therapy for pregnancies that are classified as high risk for fetal hypoxia.

Short-term changes in endogenous estrogen levels and consumption of soy isoflavones affect working and verbal memory in young adult females

Estrogen is known to modulate certain cognitive functions, most notably improving working memory and verbal memory. Soy foods contain isoflavones, phytoestrogens structurally similar to estrogen that weakly bind to estrogen receptors.We investigated the effects of natural variations in estrogen levels and short-term dietary supplementation with soy isoflavones on cognitive function in 28 young women. Performance was examined across a range of cognitive tasks on three occasions during separate menstrual cycles: during a menses phase (low estrogen), during a luteal phase (highest estrogen), and once during a menses phase after a 3-day phytoestrogen-rich dietary intervention. Soy supplementation during menses led to an improvement in working memory and verbal memory. The menstrual cycle effects were mixed, with high estrogen improving performance on a verbal memory task but not on working memory. Our results suggest that soy phytoestrogens may improve working memory through estrogen-independent mechanisms.

Consequences of maternal yolk testosterone for offspring development and survival : experimental test in a lizard

1. Hormone-mediated maternal effects and developmental plasticity are important sources of phenotypic variation, with potential consequences for trait evolution. Yet our understanding of the importance of maternal hormones for offspring fitness in natural populations is very limited, particularly in non-avian species.

2. We experimentally elevated yolk testosterone by injection of a physiological dose into eggs of the lizard Ctenophorus fordi Storr, to investigate its roles in offspring development, growth and survival.

3. Yolk testosterone did not influence incubation period, basic hatchling morphology or survival under natural conditions. However, there was evidence for increased growth in hatchlings from testosterone-treated eggs, suggesting that maternal hormones have potential fitness consequences in natural populations.

4. The positive effect of prenatal testosterone exposure on postnatal growth could represent a taxonomically widespread developmental mechanism that has evolved into an adaptive maternal effect in some taxa, but remains deleterious or selectively neutral in others.

5. A broader taxonomic perspective should increase our understanding of the role of physiological constraints in the evolution of endocrine maternal effects.

The effects of an area-based intervention on the uptake of maternal and child health assessments in Australia : a community trial

Background
Recognition of the importance of the early years in determining health and educational attainment and promotion of the World Health Organization Health for All (HFA) principles has led to an international trend towards community-based initiatives to improve developmental outcomes among socio-economically disadvantaged children. In this study we examine whether, Best Start, an Australian area-based initiative to improve child health was effective in improving access to Maternal and Child Health (MCH) services.

Methods
The study compares access to information, parental confidence and annual 3.5 year Ages and Stages visiting rates before (2001/02) and after (2004/05) the introduction of Best Start. Access to information and parental confidence were measured in surveys of parents with 3 year old children. There were 1666 surveys in the first wave and 1838 surveys in the second wave. The analysis of visiting rates for the 3.5 year Ages and Stages visit included all eligible Victorian children. Best Start sites included 1,739 eligible children in 2001/02 and 1437 eligible children in 2004/05. The comparable figures in the rest of the state were and 45, 497 and 45, 953 respectively.

Results
There was a significant increase in attendance at the 3.5 year Ages and Stages visit in 2004/05 compared to 2001/02 in all areas. However the increase in attendance was significantly greater at Best Start sites than the rest of the state. Access to information and parental confidence improved over the course of the intervention in Best Start sites with MCH projects compared to other Best Start sites.

Conclusion
These results suggest that community-based initiatives in disadvantaged areas may improve parents' access to child health information, improve their confidence and increase MCH service use. These outcomes suggest such programmes could potentially contribute to strategies to reduce child health inequalities.

Body image and body change strategies among adolescent males and females from Fiji, Tonga and Australia

The current study was designed to investigate the body image and body change strategies of adolescents from Fiji, Tonga and Australia. Participants were 628 Fijians, 463 Indo-Fijians, 598 Tongans and 535 European Australians. Adolescents completed measures of height, weight, body dissatisfaction, strategies to lose weight, increase weight and increase muscles. The results demonstrated that overweight adolescents were more dissatisfied with their bodies than those who were normal weight. Overweight Fijians and Tongans were more satisfied with their body than Indo-Fijian or Australian adolescents. Tongans, followed by Fijians and Indo-Fijians, were more likely to engage in strategies to lose weight, increase weight and increase muscles. These results are consistent with the focus in Fiji and Tonga on the value of the large body ideal, but may also reflect the recent focus on the attainment of a healthy body size.