Western Indian Ocean marine and terrestrial records of climate variability: a review and new concepts on land-ocean interactions since AD 1660

We examine the relationship between three tropical and two subtropical western Indian Ocean coral oxygen isotope time series to surface air temperatures (SAT) and rainfall over India, tropical East Africa and southeast Africa. We review established relationships, provide new concepts with regard to distinct rainfall seasons, and mean annual temperatures. Tropical corals are coherent with SAT over western India and East Africa at interannual and multidecadal periodicities. The subtropical corals correlate with Southeast African SAT at periodicities of 16–30 years. The relationship between the coral records and land rainfall is more complex. Running correlations suggest varying strength of interannual teleconnections between the tropical coral oxygen isotope records and rainfall over equatorial East Africa. The relationship with rainfall over India changed in the 1970s. The subtropical oxygen isotope records are coherent with South African rainfall at interdecadal periodicities. Paleoclimatological reconstructions of land rainfall and SAT reveal that the inferred relationships generally hold during the last 350 years. Thus, the Indian Ocean corals prove invaluable for investigating land–ocean interactions during past centuries

Why Functional Pre-Erythrocytic and Bloodstage Malaria Vaccines Fail: A Meta-Analysis of Fully Protective Immunizations and Novel Immunological Model

Background: Clinically protective malaria vaccines consistently fail to protect adults and children in endemic settings, and at best only partially protect infants. Methodology/Principal Findings: We identify and evaluate 1916 immunization studies between 1965-February 2010, and exclude partially or nonprotective results to find 177 completely protective immunization experiments. Detailed reexamination reveals an unexpectedly mundane basis for selective vaccine failure: live malaria parasites in the skin inhibit vaccine function. We next show published molecular and cellular data support a testable, novel model where parasite-host interactions in the skin induce malaria-specific regulatory T cells, and subvert early antigen-specific immunity to parasite-specific immunotolerance. This ensures infection and tolerance to reinfection. Exposure to Plasmodium-infected mosquito bites therefore systematically triggers immunosuppression of endemic vaccine-elicited responses. The extensive vaccine trial data solidly substantiate this model experimentally. Conclusions/Significance: We conclude skinstage-initiated immunosuppression, unassociated with bloodstage parasites, systematically blocks vaccine function in the field. Our model exposes novel molecular and procedural strategies to significantly and quickly increase protective efficacy in both pipeline and currently ineffective malaria vaccines, and forces fundamental reassessment of central precepts determining vaccine development. This has major implications fo

Disability and Depressive Symptoms in Later Life: The Stress-Buffering Role of Informal and Formal Support

Background: Despite the increasing utilization of formal services by older adults in many nations, there is a paucity of research that has examined the relationships between disability, formal support and depressive symptoms in later life. Objective: We investigated whether support received for daily activities, either from formal and/or informal sources, weakened the deleterious relationship between disability and depression symptoms in later life and whether these stress-buffering effects were stronger in later years of older adulthood. Methods: Participants were 1,359 community-dwelling older adults drawn from Wave 1 of the Australian Longitudinal Study of Ageing. Hierarchical multiple regression was used. Results: Individuals receiving support from (1) informal sources only and (2) both informal and formal sources had weaker relationships between disability and depressive symptoms, relative to those receiving no support. The interaction between informal and formal support and disability also revealed that for individuals with above average functional limitations, receipt of this support type was associated with fewer depressive symptoms. However, for individuals with no functional limitations, receipt of both informal and formal support was not associated with depressive symptoms. The stress-buffer age variation hypothesis received no support. Conclusions: Findings suggest that receiving a combination of informal and formal support may be sufficient to offset the harmful association between disability and depressive symptoms in later life. In addition, findings further emphasized the importance of informal support in later life. In contrast, formal support in isolation may not be sufficient to confer a protective effect. Given the expected increase in utilization of formal services among older adults in the coming decades, it is essential that future research investigates the possible factors that underlie this null result