AbstractOrganisms living at high elevations generally grow and develop more slowly than those at lower elevations. Slow montane ontogeny is thought to be an evolved adaptation to harsh environments that improves juvenile quality via physiological trade-offs. However, slower montane ontogeny may also reflect proximate influences of harsh weather on parental care and offspring development. We experimentally heated and protected nests from rain to ameliorate harsh montane weather conditions for mountain blackeyes (Chlorocharis emiliae), a montane songbird living at approximately 3,200 m asl in Malaysian Borneo. This experiment was designed to test whether cold and wet montane conditions contribute to parental care and postnatal growth and development rates at high elevations. We found that parents increased provisioning and reduced time spent warming offspring, which grew faster and departed the nest earlier compared with offspring from unmanipulated nests. Earlier departure reduces time-dependent predation risk, benefitting parents and offspring. These plastic responses highlight the importance of proximate weather contributions to broad patterns of montane ontogeny and parental care.
The discus fish (Symphysodon aequifasciata) is a cichlid demonstrating advanced mode of parental care towards fry. Both male and female fish utilized epidermal mucus secreted from specialized epidermal cells to feed developing fry. We utilized proteomics to compare protein profile from parental and nonparental fish. Gel analysis revealed a total of 35 spots that were up-regulated in parental mucus. In tandem, another 18 spots were uniquely expressed in parental mucus. MS analysis of these spots identified proteins such as fructose biphosphate aldolase, nucleoside diphosphate kinase, and heat shock proteins, which are essential to support energy provision, cell repair and proliferation, stress mediation, and defense mechanism in parental fish during parental-care period. Concurrently, the detection of several antioxidant-related proteins such as thioredoxin peroxidase and hemopexin suggests a need to overcome oxidative stress during hypermucosal production in parental-care behavior. A C-type lectin was also found to be uniquely expressed in parental mucus and could have important role in providing antimicrobial defense to both parental fish and fry. In summary, our study shows that discus mucus proteome undergoes changes in protein expression during parental-care period.
OBJECTIVE: The aim of the study was to determine the prevalence of mother-infant bed sharing in Klang district, Peninsular Malaysia and to identify factors associated with bed sharing.
METHOD: This was a cross-sectional study involving 682 mother-infant pairs with infants up to 6 months attending government clinics in Klang district, Peninsular Malaysia. Data were collected by face-to-face interview using a pretested structured questionnaire for a 4-month period in 2006. Data regarding maternal, paternal, obstetric, infant, occupancy, breast-feeding characteristics, and bed-sharing practice were collected. Data on bed sharing were based on practice in the past 1-month period. Bed sharing was defined as an infant sharing a bed with mother, and infant must be within arms reach from the mother, whereas a bed was defined as either a sleeping mattress placed on a bed frame or placed on the floor. The prevalence of bed sharing was estimated. Relationship and magnitude of association between independent factors and bed sharing were examined using odds ratio and 95% confidence interval. Logistic regression analysis was used to control for confounding factors.
RESULTS: The prevalence of bed sharing among mothers with infants aged between 1 and 6 months was 73.5% (95% confidence interval: 70.0-76.7). In multivariate analysis, urban/rural differences, mothers' ethnicity, occupation, family income, husbands' support on bed sharing, number of children younger than 12 years staying in the house, and breast-feeding were associated with bed sharing.
CONCLUSIONS: These factors need to be considered in analyzing the overall risks and benefits of bed sharing, paying attention to breastfeeding practices.