42 research outputs found

    The Southwest Pacific Ocean circulation and climate experiment (SPICE) : report to CLIVAR SSG

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    The Southwest Pacific Ocean Circulation and Climate Experiment (SPICE) is an international research program under the auspices of CLIVAR. The key objectives are to understand the Southwest Pacific Ocean circulation and the South Pacific Convergence Zone (SPCZ) dynamics, as well as their influence on regional and basin-scale climate patterns. South Pacific thermocline waters are transported in the westward flowing South Equatorial Current (SEC) toward Australia and Papua-New Guinea. On its way, the SEC encounters the numerous islands and straits of the Southwest Pacific and forms boundary currents and jets that eventually redistribute water to the equator and high latitudes. The transit in the Coral, Solomon, and Tasman Seas is of great importance to the climate system because changes in either the temperature or the amount of water arriving at the equator have the capability to modulate the El Nino-Southern Oscillation, while the southward transports influence the climate and biodiversity in the Tasman Sea. After 7 years of substantial in situ oceanic observational and modeling efforts, our understanding of the region has much improved. We have a refined description of the SPCZ behavior, boundary currents, pathways, and water mass transformation, including the previously undocumented Solomon Sea. The transports are large and vary substantially in a counter-intuitive way, with asymmetries and gating effects that depend on time scales. This paper provides a review of recent advancements and discusses our current knowledge gaps and important emerging research directions

    Large avian frugivores in the Philippines show linear responses to improvements in forest quality

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    Large avian frugivores are important in ecosystem function, but are seriously threatened across the tropics. To conserve them we must understand their habitat needs and the effects of improved forest management on individual species and the community as a whole. We recorded the presence/absence of 18 parrot, pigeon and hornbill species along nearly 500 km of transects at 24 sites in Luzon, Philippines, and used logistic GLMMs to identify bird-habitat associations based on topographical, forest structure and floristic data taken at 1227 habitat plots. We then searched for more complex relationships and thresholds in species responses along forest quality/restoration gradients using GAMMs. Frugivore species richness was highest in forest with large-girthed trees, although some small-scale agricultural disturbance was tolerated or even favoured. Importantly, richness was highest in forests on flat ground, areas which are usually the first to be converted to agriculture. Individual species were positively associated with large trees but responses to floristic gradients were more variable. Very few species had complex relationships with forest quality; for the great majority, the probability of occurrence increased linearly along the forest quality/restoration gradient. While the precise benefits in terms of seed dispersal, and costs of management, at different points along the quality/restoration gradient are likely to be themselves complex, avian frugivores benefit proportionately from step improvements right along the gradient. Thus, any actions to improve forest quality on Luzon, from reforesting the most degraded lands to preventing degradation of relatively healthy forests, are likely to benefit frugivores

    Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

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    We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10-11 to 5.0 × 10-21). The sentinel blood pressure SNPs are enriched for association with DNA methylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNA methylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10-6). Our results provide new evidence for the role of DNA methylation in blood pressure regulation

    Do multiple peaks in the Radon Transform of westward propagating sea surface height anomalies correspond to higher order Rossby wave Baroclinic modes?

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    This study examines the presence of multiple peaks from 2 dimensional Fourier and Radon Transform analysis for the entire South Pacific basin from 10 years of sea level anomalies determined from ERS (European Remote Sensing satellite) and T/P altimeter observations and attempts to determine whether their speeds resemble those of higher order baroclinic Rossby wave modes

    T-cell restricted and unrestricted expression of transfected human interleukin-2 gene: phorbol ester- and calcium-inducible versus constitutive expression.

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    Interleukin-2 (IL-2) gene expression is tightly controlled and generally limited to antigenic stimulation of T cells. To study the cell-specific expression of the IL-2 gene, we transfected the intact human IL-2 gene, including 2.0 kb of 5' and 0.3 kb of 3' flanking sequences, into mouse NIH-3T3 fibroblasts and BFS lymphoma T cells and into human epithelial HeLa cells. Stable transformants (NIH-3T3,HeLa and BFS cells) carried an intact transfected IL-2 gene and constitutively expressed cytoplasmic human IL-2 mRNA which was not detected in vector-transfected cells. Constitutive expression of IL-2 mRNA in human IL-2 gene-transfected NIH-3T3 and HeLa cells was associated to the secretion of bioactive IL-2 protein, while no IL-2 production was observed in untransfected or vector-transfected cells. Cytoplasmic IL-2 mRNA observed in transfectants was larger (1.4 kb) than endogenous IL-2 mRNA of human T cells, although smaller than RNA containing unspliced intact introns. No alternative promoters or polyadenylation signals were used by these cells, but some intronic sequences were present in the 1.4 kb mRNA. Phorbol ester and calcium ionophore did not modulate the expression of the transfected IL-2 gene in NIH-3T3 and HeLa cells, while these agents increased its expression in transfected BFS lymphoma T cells. We conclude that when transfected into lymphoid and non-lymphoid cells the intact human IL-2 gene is constitutively expressed, while its phorbol ester/calcium-mediated inducible expression is restricted to T cells. This suggests that the constitutive and inducible expression of the IL-2 gene can be dissociated and are presumably subjected to separate regulatory pathways

    From physics to fish to folk: Supporting coastal regional communities to understand their vulnerability to climate change in Australia

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    Our oceans comprise valuable assets that provide a range of social and economic benefits directly and indirectly through provisioning, regulating, cultural and supporting services. Fisheries rely on these services and are regionally important industries for many coastal communities. With a growing population and increasing demand for seafood production, impacts from climate change that alter the productivity of marine ecosystems will have flow-on implications for economic and social systems. As small coastal communities are often highly dependent on marine-based activities they are also expected to experience greater impacts from changes in productivity of marine resources than their larger and/or non-coastal counterparts. To assist coastal communities in evaluating their vulnerability to climate change we have developed a hybrid socio-ecological vulnerability index that combines an ecocentric index – i.e., an ecological vulnerability index – with a sociocentric index that focuses on adaptive capacity as a measure of vulnerability, and embeds a sustainable livelihoods approach. Through the use of an on-line tool, coastal communities can improve their understanding of their vulnerability to more appropriately adapt, embrace opportunities and minimize negative impacts that may arise from climate change and its effect on marine resource availability

    Natural hazards in Australia: sea level and coastal extremes

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    The Australian coastal zone encompasses tropical, sub- and extra-tropical climates and accommodates about 80 % of Australia’s population. Sea level extremes and their physical impacts in the coastal zone arise from a complex set of atmospheric, oceanic and terrestrial processes that interact on a range of spatial and temporal scales and will be modified by a changing climate, including sea level rise. This review details significant progress over recent years in understanding the causes of past and projections of future changes in sea level and coastal extremes, yet a number of research questions, knowledge gaps and challenges remain. These include efforts to improve knowledge on past sea level extremes, integrate a wider range of processes in projections of future changes to sea level extremes, and focus efforts on understanding long-term coastline response from the combination of contributing factors
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