Memory and adaptive behavior in population dynamics: anti-predator behavior as a case study.

Memory allows organisms to forecast the future on the basis of experience, and thus, in some form, is important for the development of flexible adaptive behavior by animal communities. To model memory, we use the concept of hysteresis, which mathematically is described by the Preisach operator. As a case study, we consider anti-predator adaptation in the classic Lotka-Volterra predator-prey model. Despite its simplicity, the model allows us to naturally incorporate essential features of an adaptive system and memory. Our analysis and simulations show that a system with memory can have a continuum of equilibrium states with non-trivial stability properties. The main factor that determines the actual equilibrium state to which a trajectory converges is the maximal number achieved by the population of predator along this trajectory.

Prem Baby Triple P: a randomised controlled trial of enhanced parenting capacity to improve developmental outcomes in preterm infants.

BACKGROUND: Very preterm birth (<32 weeks gestation) is associated with motor, cognitive, behavioural and educational problems in children and maternal depression and withdrawal. Early interventions that target parenting have the greatest potential to create sustained effects on child development and parental psychopathology. Triple P (Positive Parenting Program) has shown positive effects on child behaviour and adjustment, parenting practices and family functioning. Baby Triple P for Preterm infants, has been developed to target parents of very preterm infants. This study tests the effectiveness of Baby Triple P for Preterm infants in improving child and parent/couple outcomes at 24 months corrected age (CA). METHODS/DESIGN: Families will be randomised to receive either Baby Triple P for Preterm infants or Care as Usual (CAU). Baby Triple P for Preterm infants involves 4 × 2 hr group sessions at the hospital plus 4 × 30 min telephone consultations soon after transfer (42 weeks C.A.). After discharge participants will be linked to community based Triple P and intervention maintenance up to 24 months C.A. Assessments will be: baseline, post-intervention (6 weeks C.A.), at 12 and 24 months C.A. The primary outcome measure is the Infant Toddler Social & Emotional Assessment (ITSEA) at 24 months C.A. Child behavioural and emotional problems will be coded using the mother-toddler version of the Family Observation Schedule at 24 months C.A. Secondary outcome will be the Bayley Scales of Infant and Toddler Development (BSID III) cognitive development, language and motor abilities. Proximal targets of parenting style, parental self-efficacy, parental mental health, parental adjustment, parent-infant attachment, couple relationship satisfaction and couple communication will also be assessed. Our sample size based on the ITSEA, has 80% power, predicted effect size of 0.33 and an 85% retention rate, requires 165 families are required in each group (total sample of 330 families). DISCUSSION: This protocol presents the study design, methods and intervention to be analysed in a randomised trial of Baby Triple P for Preterm infants compared to Care as Usual (CAU) for families of very preterm infants. Publications of all outcomes will be published in peer reviewed journals according to CONSORT guidelines. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12612000194864.

Adaptive behaviour and multiple equilibrium states in a predator-prey model.

There is evidence that multiple stable equilibrium states are possible in real-life ecological systems. Phenomenological mathematical models which exhibit such properties can be constructed rather straightforwardly. For instance, for a predator-prey system this result can be achieved through the use of non-monotonic functional response for the predator. However, while formal formulation of such a model is not a problem, the biological justification for such functional responses and models is usually inconclusive. In this note, we explore a conjecture that a multitude of equilibrium states can be caused by an adaptation of animal behaviour to changes of environmental conditions. In order to verify this hypothesis, we consider a simple predator-prey model, which is a straightforward extension of the classic Lotka-Volterra predator-prey model. In this model, we made an intuitively transparent assumption that the prey can change a mode of behaviour in response to the pressure of predation, choosing either "safe" of "risky" (or "business as usual") behaviour. In order to avoid a situation where one of the modes gives an absolute advantage, we introduce the concept of the "cost of a policy" into the model. A simple conceptual two-dimensional predator-prey model, which is minimal with this property, and is not relying on odd functional responses, higher dimensionality or behaviour change for the predator, exhibits two stable co-existing equilibrium states with basins of attraction separated by a separatrix of a saddle point.

Screening for autism spectrum disorder in very preterm infants during early childhood.

AIM: The aim of the study was to screen very preterm infants for autism spectrum disorder (ASD) with comparisons to a group of term controls. The study also aimed to identify maternal and neonatal risk factors, development and behaviour associated with a positive screen in the preterm group. METHOD: Preterm infants born ≤ 30 weeks gestation and term infants were recruited at two years of age. The mothers were posted the questionnaires and completed the Modified Checklist for Autism in Toddlers (M-CHAT), the Child Behaviour Checklist (CBCL) and the Depression, Anxiety and Stress Scales (DASS). Previously collected data from the mothers at 12 months--the Edinburgh Postnatal Depression Scales (EPDS) were analysed. The children had neurodevelopmental assessment including the Bayley-III. Infants positive on M-CHAT screen had an M-CHAT follow-up interview by phone and then were assessed by a developmental paediatrician as indicated with a diagnosis of autism being made on clinical judgement. RESULTS: 13 (13.4%) of the 97 preterm infants screened positive on the M-CHAT compared to three (3.9%) of the 77 term infants (p = 0.036). On follow-up interview, three of the preterm infants remained positive (one was diagnosed with autism) compared to none of the term infants. The preterm infants who screened positive were born to younger, non-Caucasian mothers and were of lower birth weight and had a higher incidence of being small for gestational age (SGA). The infants had lower composite scores on Bayley-III and had more internalising and externalising behaviours on the CBCL. The mothers had more emotional problems on the DASS and higher scores on the EPDS. On multivariate analysis, SGA, greater internalising behaviours and higher EPDS scores remained statistically significant. CONCLUSIONS: A positive screen on the M-CHAT occurs more commonly in very preterm infants than those born at term. Internalising behaviours and maternal mental health are associated with a positive screen in the preterm cohort.

Polarization-stiffened ferroelectric liquid crystals: a thickness-independent bistable switching voltage with a lower limit of about 2 V and the transition to thresholdless switching.

Typical ferroelectric Sm-C(*) liquid crystal (FLC) cells exhibit a voltage threshold for switching from one stable state to another despite the FLC's response being inherently continuous and thresholdless (free rotation of the director around the tilt cone). This switching threshold is due to FLC-surface interactions and to the chevron smectic structure commonly formed in cells. It is shown here that the FLC electrostatic energy contribution ∼P(S)(2) responsible for thresholdless switching of high-P(S) FLCs also plays a key role in the bistable switching of lower-P(S) FLCs. Among the consequences are that it can be difficult to lower a cell's threshold below V(TB)∼3.4(B/ɛ(F))(1/2) (B and ɛ(F) are the FLC's elastic and dielectric constants), that a cell's threshold becomes independent of cell thickness once it substantially exceeds the characteristic length ξ(P)=(ɛ(F)B)(1/2)/P(S), and that there are conditions under which alignment layer capacitance can decrease rather than increase the threshold (i.e., transition to thresholdless switching). A model that predicts and explains these behaviors is presented along with threshold measurements of representative FLC cells.

Breastfeeding is protective to diabetes risk in young adults: a longitudinal study.

AIM: It is unclear whether any breastfeeding or a certain duration of breastfeeding is protective against the development of diabetes in adult offspring. METHODS: We followed a sub-sample of 3,595 offspring born in the Mater Hospital in Brisbane, Australia between 1981 and 1983 and for whom we had doctor diagnosed self-reported diabetes at age 21 years and maternal reported duration of breastfeeding at 6-month post-natal follow-up. Multiple logistic regression was used to examine the independent associations of duration of breastfeeding (never breastfeed, breastfed <4 months and breastfed ≥4 months) with offspring diabetes by age 21 years. RESULTS: Of 3,595 young adults, 45 (1.25 %) developed diabetes by age 21 years. The odds ratio of experiencing diabetes was 0.58 (95 % CI 0.29, 1.16) for offspring who were breastfed <4 months, and it was 0.29 (95 % CI 0.13, 0.63), for offspring who were breastfed at least 4 months compared to the never breastfed offspring. Adjusting for potential confounding and mediating factors including maternal age, education, pre-pregnancy body mass index (BMI), smoking, offspring sports, TV and their BMI at 21 years did not substantially alter this association. CONCLUSIONS: Findings of this study suggest that infants who are breastfed for longer than 4 months have a substantial protective effect against the development of diabetes in young adulthood, which is independent of current BMI. Promoting breastfeeding for a minimum of 4 months may be a useful strategy for the prevention of diabetes among young adults.

Rapid growth in early childhood associated with young adult overweight and obesity--evidence from a community based cohort study.

BACKGROUND: Rapid weight gain in early life may increase the risk of overweight and obesity in adulthood. We investigated the association between the rate of growth during early childhood and the development of overweight and obesity in young adults. METHODS: We used a prospective cohort study of 2077 young adults who were born between 1981 and 1984 in Brisbane, Australia and had anthropometry measurements available at birth, 6 months, 5 years, 14 years and 21 years of age. The associations of rate of early growth with body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) and their categories at 21 years were studied using multivariate analysis. RESULTS: We found that rapid weight gain [> + 0.67 standard deviation score (SDS)] in the first 5 years of life was associated with young adults' overweight status (BMI: adjusted OR = 2.35, 95% CI, 1.82-3.03; WC: adjusted OR = 2.20, 95% CI, 1.65-2.95). We also observed that slow weight gain in the first 5 years of age (< -0.67 SDS) was inversely associated with overweight (BMI: OR = 0.62, 95% CI, 0.45-0.84). Such associations were not found with WHR. Rapid weight gain in the first 6 months of life increased the risk of overweight as defined by BMI (adjusted OR = 1.13, 95% CI, 0.86-1.49) and WC (adjusted OR = 1.24, 95% CI, 0.92-1.67), but these associations were not statistically significant. CONCLUSION: Rapid weight gain in the first 5 years of life in children increased their risk of a higher BMI and WC in young adulthood, in contrast slow weight gain was inversely associated with weight status at 21 years.

Association between gestational weight gain and postpartum diabetes: evidence from a community based large cohort study.

We have investigated the prospective association between excess gestational weight gain (GWG) and development of diabetes by 21 years post-partum using a community-based large prospective cohort study in Brisbane, Australia. There were 3386 mothers for whom complete data were available on GWG, pre-pregnancy BMI and self-reported diabetes 21 years post-partum. We used The Institute of Medicine (IOM) definition to categorize GWG as inadequate, adequate and excessive. We found 839 (25.78%) mothers gained inadequate weight, 1,353 (39.96%) had adequate weight gain and 1,194 (35.26%) had gained excessive weight during pregnancy. At 21 years post-partum, 8.40% of mothers self-reported a diagnosis of diabetes made by their doctor. In the age adjusted model, we found mothers who gained excess weight during pregnancy were 1.47 (1.11,1.94) times more likely to experience diabetes at 21 years post-partum compared to the mothers who gained adequate weight. This association was not explained by the potential confounders including maternal age, parity, education, race, smoking, TV watching and exercise. However, this association was mediated by the current BMI. There was no association for the women who had normal BMI before pregnancy and gained excess weight during pregnancy. The findings of this study suggest that women who gain excess weight during pregnancy are at greater risk of being diagnosed with diabetes in later life. This relationship is likely mediated through the pathway of post-partum weight-retention and obesity. This study adds evidence to the argument that excessive GWG during pregnancy for overweight mothers has long term maternal health implications.

Family structure, marital discord and offspring's psychopathology in early adulthood: a prospective study.

With marital breakdown and discord relatively common, we examined whether family structure and the quality of marital relationship have a long-term impact on offspring's psychopathology in early adulthood. This study aimed to examine the association of family structure and marital discord in the family with a wide range of offspring's mental health and problem behaviours at 21 years. Data were from the Mater-University of Queensland Study of Pregnancy, a population based birth cohort study, which commenced in Brisbane, Australia in 1981. Mothers and children were followed up at birth, 6 months and 5, 14 and 21 years after the initial interview. Marital status and marital quality were assessed at the 14 year follow-up. Young Adult Self-Report sub-scales of mental health and problem behaviours were measured at the 21-year follow-up. Type of family structure and the quality of marital relationship (at the 14-year follow-up) predicted offspring's psychopathology at 21 years. When a selected group of confounding factors were included in the multivariate analyses, children who lived with a step-father, un-partnered mother, or in families where parents had conflict in marital relationship reported higher symptoms of psychopathology at 21 years. The association between marital problems and young adult psychopathology does not appear to be confounded by a wide range of confounding variables. Further research is needed to explore the mechanism of these associations to develop preventive programmes.

Fitness limitations in non-disabled extremely low birthweight adolescents.

AIM: This study aims to compare non-disabled otherwise healthy extremely low birthweight (ELBW) (<1000 g) children and term-born peers in an investigation of relationship between cardiorespiratory endurance and parent report of competence. METHODS: Forty-eight of 105 eligible ELBW 11- to 13-year-old children (27 male) and 55 term-born school peers (28 male) completed a 20-m shuttle run, anthropometric measures, respiratory function tests and the Motor Assessment Battery for Children. Parents completed the Child Behavior Checklist (CBCL). RESULTS: The ELBW group had poorer cardiorespiratory endurance (P = 0.002), growth (P = 0.002), respiratory function (P = 0.003) and motor ability (P < 0.001) than term-born peers. Parents reported the ELBW children to be less competent than term-born peers: CBCL total T score mean difference -9, 95% confidence interval -14, -5 (P < 0.001). Cardiorespiratory endurance predicted competence (regression coefficient 0.865; 95% confidence interval 0.352, 1.378; P = 0.001) independent of prematurity, growth, respiratory function, motor score, gender and socio-economic status. Cardiorespiratory endurance had association with social competence for all participating children, but was related to CBCL Activities Competence only for the ELBW children who were the significantly less fit group. CONCLUSIONS: The poor cardiorespiratory endurance prevalent in non-disabled otherwise healthy ELBW children is associated with general competence independent of prematurity and of the impact of other mild physical deficits, gender or socio-economic status. The relationship demonstrated between cardiorespiratory endurance and competence to engage in general activities of daily living, seen only in the less fit ELBW children, identifies the fitness levels in non-disabled ELBW children as a barrier to participation.

Early childhood predictors of early onset of smoking: a birth prospective study.

OBJECTIVE: Early onset of smoking is associated with subsequent abuse of other substances and development of negative health outcomes. This study aimed to examine early life predictors of onset of smoking in an Australian young cohort. METHODS: Data were from the Mater Hospital and University of Queensland Study of Pregnancy (MUSP), a population-based prospective birth cohort study (1981-2012). The present study is based on a cohort of 3714 young adults who self-reported smoking status and age of onset of smoking at the 21-year follow-up. Of these, data were available for 3039 on early childhood factors collected between the baseline and 14-year follow-up of the study. RESULTS: Of 3714 young adults, 49.6% (49.9% males and 49.3% females) reported having ever smoked cigarettes. For those who had ever smoked, mean and median ages at first smoke were 15.5 and 16.0years, respectively. In multivariate Cox proportional hazard analysis mother's education, change in maternal marital status, maternal cigarette smoking and alcohol consumption, maternal depression and child externalizing when the child was 5years statistically significantly predicted early onset of smoking. CONCLUSIONS: The data suggest that individuals exposed to personal and environmental risk factors during the early stage of childhood are at increased risk of initiation to cigarette smoking at an earlier age. Identification of the pathways of association between these early life factors and initiation to cigarette smoking may help reduce risk of tobacco smoking in adolescents and its adverse consequences.

Parenting stress in mothers of very preterm infants -- influence of development, temperament and maternal depression.

OBJECTIVE: To measure levels of parenting stress and postnatal depression in mothers of very preterm infants in comparison with mothers of infants born at term is the objective of this study. The study also aimed to explore factors associated with parenting stress in the mothers of the preterm infants. METHODS: One hundred and five mothers who delivered 124 babies at ≤30 weeks gestation were enrolled together with 105 term mothers who delivered 120 babies. At one year of age (corrected for prematurity for the preterm cohort), the mothers completed the Parenting Stress Index Short Form (PSI), the Edinburgh Postnatal Depression Scale (EPDS) and the Short Temperament Scale for Toddlers. The infants had neurodevelopmental assessment. The preterm and term groups were compared. RESULTS: Questionnaires were completed by 101 of the preterm mothers and 98 of the term mothers. The mean PSI Total Stress score was significantly higher for the preterm mothers (70.28 vs 64.52, p = 0.022), with 19% of the preterm group and 9% of the term group having high scores (p = 0.038).There was no group difference on the EPDS or measures of temperament, with disability being greater in the preterm infants. For the preterm group, maternal depression and infant temperament were independent predictors of Total Stress scores on multivariate analysis. CONCLUSIONS: Parenting stress in mothers of preterm infants at one year of age is significantly greater than that found in mothers of term infants. For preterm mothers, symptoms of depression and infant temperament are independent risk factors for higher levels of parenting stress.

Chaos in a seasonally perturbed SIR model: avian influenza in a seabird colony as a paradigm.

Seasonality is a complex force in nature that affects multiple processes in wild animal populations. In particular, seasonal variations in demographic processes may considerably affect the persistence of a pathogen in these populations. Furthermore, it has been long observed in computer simulations that under seasonal perturbations, a host-pathogen system can exhibit complex dynamics, including the transition to chaos, as the magnitude of the seasonal perturbation increases. In this paper, we develop a seasonally perturbed Susceptible-Infected-Recovered model of avian influenza in a seabird colony. Numerical simulations of the model give rise to chaotic recurrent epidemics for parameters that reflect the ecology of avian influenza in a seabird population, thereby providing a case study for chaos in a host- pathogen system. We give a computer-assisted exposition of the existence of chaos in the model using methods that are based on the concept of topological hyperbolicity. Our approach elucidates the geometry of the chaos in the phase space of the model, thereby offering a mechanism for the persistence of the infection. Finally, the methods described in this paper may be immediately extended to other infections and hosts, including humans.

Television watching from adolescence to adulthood and its association with BMI, waist circumference, waist-to-hip ratio and obesity: a longitudinal study.

OBJECTIVE: To examine the prospective association of television (TV) watching from adolescence to young adulthood with BMI, waist circumference (WC), waist-to-hip ratio (WHR) and obesity. DESIGN: A community-based longitudinal cohort study. SETTING: Mater-University of Queensland Study of Pregnancy (MUSP) Cohort, Brisbane, Australia. SUBJECTS: A sub-sample of 2439 children was followed up at ages 14 years and 21 years as part of a population-based birth cohort. Offspring reported the number of TV viewing hours each day at 14 and 21 years. BMI, WC and WHR were measured at 21 years. RESULTS: In the adjusted model, offspring who watched TV for <3 h/d at 14 years but for ≥ 3 h/d at 21 years, or who watched TV for ≥ 3 h/d at 14 and 21 years, had greater BMI, WC and WHR at 21 years. Offspring who watched TV for ≥ 3 h/d at 14 years but for <3 h/d at 21 years had similar mean BMI, WC and WHR at 21 years to those who watched TV for <3 h/d at 14 and 21 years. Those offspring who reduced their TV watching hours to <3 h/d during the transition from adolescence into young adulthood were at less risk of becoming obese and those who continued or increased their TV watching to ≥ 3 h/d were at greater risk of becoming obese. This association remained independent of the potential confounding factors considered. CONCLUSIONS: The present findings suggest that our efforts to decrease obesity by reducing TV watching hours among adults should consider interventions to reduce TV time among adolescents.

Change in maternal body mass index is associated with offspring body mass index: a 21-year prospective study.

PURPOSE: To examine whether changes in maternal overweight and obesity from pre-pregnancy to two decades postpartum predict the body mass index (BMI) of adult offspring. METHODS: We used a subsample of 1997 mother-offspring pairs from the 7,223 original cohorts of women who gave birth in Brisbane, Australia, between 1981 and 1984. Multiple linear regression and multinomial logistic regression were used to examine the relationship between change in maternal BMI from pre-pregnancy to 21-year postpartum, and offspring BMI at 21-year, adjusting for potential confounding factors. RESULTS: At 21-year postpartum, 31.15 % mothers were overweight and a further 30.80 % were obese. Mothers gained a mean weight of 16.07 kg over the 21 year. We found that the offspring of mothers who became overweight or remained overweight at 21-year postpartum were at greater risk of being overweight and obese at 21 years. In the adjusted model, offspring of mothers who had normal BMI before pregnancy but became overweight by 21-year postpartum were (odds ratio) 1.72 (95 % CI = 1.20, 2.47) times more likely to be overweight. Compared to offspring of mothers who maintained normal weight over two decades, offspring of mothers who remained persistently overweight were (odds ratio) 5.39 (95 % CI = 3.50, 8.30) times more likely to be obese by age 21 year. CONCLUSIONS: The findings of this study suggest that long-term changes in maternal BMI from pre-pregnancy to 21-year postpartum are independently associated with BMI in their young adult offspring.

Long-term outcomes of infant behavioral dysregulation.

OBJECTIVES: To determine whether maternal report of infant behavioral dysregulation at 6 months is associated with a higher prevalence of behavioral concerns at 5, 14, and 21 years of age; and to assess the extent to which maternal and social factors may affect reported child behavior outcomes. METHODS: From the Mater-University of Queensland Study of Pregnancy cohort of 7223 live singleton babies, information on dysregulation was available for 6389 children at 6 months. Of those children, behavior data were available for 4836 at 5 years by using a modified Child Behavior Checklist, 4746 at 14 years by using a full Child Behavior Checklist and Youth Self-Report, and 3558 at 21 years by using a Young Adult Self-Report. Of the youth with dysregulation data at 6 months, 2308 completed the Composite International Diagnostic Interview at 21 years. Potential confounding and mediating factors were analyzed by using logistic regression. RESULTS: Maternal-reported behavioral dysregulation at 6 months was associated with a significantly higher prevalence of maternal-reported behavior problems at 5 and 14 years (P < .001), but not youth self-reported problems at 14 or 21 years, or Composite International Diagnostic Interview-Diagnostic and Statistical Manual diagnoses at 21 years. The strength of association between infant dysregulation and maternal-reported behaviors was greater at 5 years than at 14 years, and was substantially reduced by adjusting for maternal, social, and infant factors, especially potentially the mediating factors of maternal anxiety and depression. CONCLUSIONS: Infant behavioral dysregulation was a risk factor for maternal-reported behavior concerns at 5 and 14 years, although was unrelated to young adult mental health.

An azo-bridged ferroelectric liquid crystal with highly enhanced second and third harmonic generation.

A laterally azo-bridged trimer ferroelectric liquid crystal (FLC) incorporating a strong chromophore along its polar axis was synthesized and characterized by polarized-light optical microscopy, differential scanning calorimetry, two-dimensional X-ray diffraction analysis, electro-optical measurements, and nonlinear optical (NLO) investigations. This mesogen exhibits a thermodynamically stable enantiotropic SmC* phase and a bistable ferroelectric switching in a surface stabilized cell with bookshelf geometry. It gives the resonance-enhanced d(22) coefficient of 28 pm V(-1) (λ = 1.369 µm) for second harmonic generation (SHG), the largest NLO susceptibility reported to date for all FLCs. At the same wavelength, a new type of helicoidal phase matching assisted by the helical SmC* structure was identified. When the second harmonic wavelength of 780 nm is far away from the resonance wavelength (λ(max) = 572 nm), the d(22) coefficient is reduced to 6.8 pm V(-1) (λ = 1.56 µm). In addition to a strong SHG activity, the trimer also shows a strong third harmonic generation (THG) with an estimated third-order nonlinear susceptibility of χ((3)) = ~3 × 10(-11) esu (λ = 1.56 µm), among the largest χ((3)) value reported from THG measurements for liquid crystals. This work enables viable applications of FLCs in nonlinear optics and offers an innovative approach to develop new FLCs with larger NLO strength.

Maternal smoking during pregnancy predicts adult offspring cardiovascular risk factors - evidence from a community-based large birth cohort study.

BACKGROUND: Maternal smoking during pregnancy is associated with offspring obesity. However, little is known about whether maternal smoking in pregnancy predicts other offspring cardiovascular risk factors including waist circumference (WC), waist-hip-ratio (WHR), pulse rate (PR), systolic (SBP), and diastolic blood pressure (DBP). METHODS: We studied a sub-sample of 2038 (50% males) young adults who were born in Brisbane, Australia to investigate the prospective association of maternal smoking during pregnancy with young adult cardiovascular risk factors. We compared offspring mean BMI, WC, WHR, SBP, DBP and PR and the risk of being overweight and obese at 21 years by three mutually exclusive categories of maternal smoking status defined as never smoked, smoked before and/or after pregnancy but not in pregnancy or smoked during pregnancy and other times. RESULTS: Offspring of mothers who smoked during pregnancy had greater mean BMI, WC, WHR and PR and they were at greater risk of being obese at 21 years compared to offspring of those mothers who never smoked. The mean of these risk factors among those adult offspring whose mothers stopped smoking during pregnancy, but who then smoked at other times in the child's life, were similar to those mothers who never smoked. These results were independent of a range of potential confounding factors. CONCLUSION: The findings of this study suggest a prospective association of maternal smoking during pregnancy and offspring obesity as well as PR in adulthood, and reinforce the need to persuade pregnant women not to smoke.

Sleepless nights: the effect of socioeconomic status, physical activity, and lifestyle factors on sleep quality in a large cohort of Australian women.

The aims of this study were to examine: (1) the association between sociodemographic and lifestyle factors and sleep quality in a population-based cohort of Australian women and (2) possible influence of reproductive status and mental and physical health factors on these associations. Data on 3,655 women (mean age = 46.6 years, range 34.3-67.4) were obtained from the Mater Hospital University of Queensland Study of Pregnancy for this cross-sectional study. Self-rated sleep quality was assessed using the Pittsburgh Sleep Quality Index. For the purpose of this study, two cutoff points (scores 5 and 10) were used to divide women into three categories: normal (65.2%), moderately poor (26.4%), and very poor sleep quality (8.5%). Other covariates were measured at 21-year follow-up as well. After adjusting for reproductive status, mental and physical health, there were significant associations between moderately poor sleep quality and education and between very poor sleep quality and unemployment, both measures of socioeconomic status. In addition, work-related exertion was associated with increased rates of moderately poor sleep quality, whereas those women undertaking moderate exercise were less likely to experience very poor sleep quality. Independent associations between sociodemographic factors and exercise with moderately poor and very poor sleep quality were identified. These findings demonstrate the dynamic nature of the association between exercise/exertion, socioeconomic status, and sleep quality and highlight the importance of taking these into consideration when dealing with issues of poor sleep quality in women.

Association of breastfeeding and adolescents' psychopathology: a large prospective study.

PURPOSE: There is little known about the association between breastfeeding and long-term child psychopathology. This study aimed to examine the impact of breastfeeding on child mental health and problem behavior at 14 years and whether this association is confounded by other variables. SUBJECTS AND METHODS: Data were from a pre-birth prospective study that included mothers and their children followed up from pregnancy to 14 years of the child's age in Brisbane, Australia. The child's anxiety/depression, withdrawal problems, somatic complaints, social problems, thought problems, attention problems, aggression, and delinquency were measured using the Achenbach Youth Self Report at 14 years. Breastfeeding was prospectively assessed at the 6-month follow-up of the study. The analysis was based on 4,502 adolescents who responded to the YSR questionnaire and for whom prospective data were available on breastfeeding. RESULTS: Breastfeeding as reported by mothers when the child was 6 months old predicted reduced symptoms of child mental health and problem behavior at 14 years. The impact of breastfeeding on the child's social problems, attention problems, and aggressive behavior remained statistically significant after controlling for the effect of other variables, such as unplanned pregnancy, maternal mental health, and substance use during pregnancy. CONCLUSIONS: Our data suggest that breastfeeding for at least 4 months can have a significant protective effect on a child's social, attention, and aggression problems in early adolescence. Given the limitations of the existing evidence, further research is needed to investigate the robustness of the findings of this study and the mechanisms of long-term association between breastfeeding and reduced social, attention, and aggression problems of the offspring in adolescence.