Holocene record of Tuggerah Lake estuary development on the Australian east coast: sedimentary responses to sea-level fluctuations and climate variability

We investigated the Holocene palaeo-environmental record of the Tuggerah Lake barrier estuary on the south-east coast of Australia to determine the influence of local, regional and global environmental changes on estuary development. Using multi-proxy approaches, we identified significant down-core variation in sediment cores relating to sea-level rise and regional climate change. Following erosion of the antecedent land surface during the post-glacial marine transgression, sediment began to accumulate at the more seaward location at ~8500. years before present, some 1500. years prior to barrier emplacement and ~4000. years earlier than at the landward site. The delay in sediment accumulation at the landward site was a consequence of exposure to wave action prior to barrier emplacement, and due to high river flows of the mid-Holocene post-barrier emplacement. As a consequence of the mid-Holocene reduction in river flows, coupled with a moderate decline in sea-level, the lake experienced major changes in conditions at ~4000. years before present. The entrance channel connecting the lake with the ocean became periodically constricted, producing cyclic alternation between intervals of fluvial- and marine-dominated conditions. Overall, this study provides a detailed, multi-proxy investigation of the physical evolution of Tuggerah Lake with causative environmental processes that have influenced development of the estuary

Do ENSO and coastal development enhance coastal burial of terrestrial carbon?

Carbon cycling on the east coast of Australia has the potential to be strongly affected by El Niño-Southern Oscillation (ENSO) intensification and coastal development (industrialization and urbanization). We performed paleoreconstructions of estuarine sediments from a seagrass-dominated estuary on the east coast of Australia (Tuggerah Lake, New South Wales) to test the hypothesis that millennial-scale ENSO intensification and European settlement in Australia have increased the transfer of organic carbon from land into coastal waters. Our data show that carbon accumulation rates within coastal sediments increased significantly during periods of maximum millennial-scale ENSO intensity ("super-ENSO") and coastal development. We suggest that ENSO and coastal development destabilize and liberate terrestrial soil carbon, which, during rainfall events (e.g., La Niña), washes into estuaries and becomes trapped and buried by coastal vegetation (seagrass in this case). Indeed, periods of high carbon burial were generally characterized as having rapid sedimentation rates, higher content of fine-grained sediments, and increased content of wood and charcoal fragments. These results, though preliminary, suggest that coastal development and ENSO intensificationboth of which are predicted to increase over the coming centurycan enhance capture and burial of terrestrial carbon by coastal ecosystems. These findings have important relevance for current efforts to build an understanding of terrestrial- marine carbon connectivity into global carbon budgets

Experimental Confirmation of the General Solution to the Multiple Phase Matching Problem

We recently described a general solution to the phase matching problem that arises when one wishes to perform an arbitrary number of nonlinear optical processes in a single medium [PRL 95 (2005) 133901]. Here we outline in detail the implementation of the solution for a one dimensional photonic quasicrystal which acts as a simultaneous frequency doubler for three independent optical beams. We confirm this solution experimentally using an electric field poled KTiOPO$_4$ crystal. In optimizing the device, we find - contrary to common practice - that simple duty cycles of 100% and 0% may yield the highest efficiencies, and show that our device is more efficient than a comparable device based on periodic quasi-phase-matching

Decade time-scale modulation of low mass X-ray binaries

Regular observations by the All Sky Monitor aboard the Rossi X-ray Timing Explorer satellite have yielded well-sampled light-curves with a time baseline of over ten years. We find that up to eight of the sixteen brightest persistent low mass X-ray binaries show significant, possible sinusoidal, variations with periods of order ten years. We speculate on its possible origin and prevalence in the population of low mass X-ray binaries and we find the presence of a third object in the system, or long-period variability intrinsic to the donor star, as being attractive origins for the X-ray flux modulation we detect. For some of the objects in which we do not detect a signal, there is substantial short-term variation which may hide modest modulation on long time-scales. Decade time-scale modulations may thus be even more common.Comment: 8 pages, 4 figures, 2 tables. Accepted by MNRA

Identification of C-C Chemokine Receptor 1 (CCR1) as the Monocyte Hemofiltrate C-C Chemokine (HCC)-1 Receptor

Hemofiltrate C-C chemokine (HCC)-1 is a recently cloned C-C chemokine that is structurally similar to macrophage inflammatory protein (MIP)-1α. Unlike most chemokines, it is constitutively secreted by tissues and is present at high concentrations in normal human plasma. Also atypical for chemokines, HCC-1 is reported not to be chemotactic for leukocytes. In this paper, we have investigated the chemokine receptor usage and downstream signaling pathways of HCC-1. Cross-desensitization experiments using THP-1 cells suggested that HCC-1 and MIP-1α activated the same receptor. Experiments using a panel of cloned chemokine receptors revealed that HCC-1 specifically activated C-C chemokine receptor (CCR)1, but not closely related receptors, including CCR5. HCC-1 competed with MIP-1α for binding to CCR1-transfected cells, but with a markedly reduced affinity (IC50 = 93 nM versus 1.3 nM for MIP-1α). Similarly, HCC-1 was less potent than MIP-1α in inducing inhibition of adenylyl cyclase in CCR1-transfected cells. HCC-1 induced chemotaxis of freshly isolated human monocytes, THP-1 cells, and CCR1-transfected cells, and the optimal concentration for cell migration (100 nM) was ∼100-fold lower than that of MIP-1α (1 nM). These data demonstrate that HCC-1 is a chemoattractant and identify CCR1 as a functional HCC-1 receptor on human monocytes

Implementation of Client-Centered Care Coordination for HIV Prevention with Black Men Who Have Sex with Men: Activities, Personnel Costs, and Outcomes—HPTN 073

Background: Black men who have sex with men (MSM) experience disproportionate rates of HIV infection in the USA, despite being no more likely to engage in sexual risk behaviors than other MSM racial/ethnic groups. HIV pre-exposure prophylaxis (PrEP) has been shown to reduce risk of HIV acquisition; however, rates of PrEP use among Black MSM remain low. Clinical, psychosocial, and structural factors have been shown to impact PrEP use and adherence among Black MSM. Care coordination of HIV prevention services has the potential to improve PrEP use and adherence for Black MSM, as it has been shown to improve HIV-related care outcomes among people living with HIV. Methods: Client-centered care coordination (C4) is a multi-level intervention designed to address clinical, psychosocial, and structural barriers to HIV prevention services for Black MSM within HPTN 073, a PrEP demonstration project among Black MSM in three cities in the USA. The current study examined the implementation process of C4, specifically investigating the activities, cost, time, and outcomes associated with the C4 intervention. Results: On average, participants engaged in five care coordination encounters. The vast majority of care coordination activities were conducted by counselors, averaging 30 min per encounter. The cost of care coordination was relatively low with a mean cost of $8.70 per client encounter. Conclusion: Although client-centered care coordination was initially implemented in well-resourced communities with robust HIV research and service infrastructure, our findings suggest that C4 can be successfully implemented in resource constrained communities

Methylation diet and methyl group genetics in risk for adenomatous polyp occurrence

PurposeThe aim of this study is to explore whether a methylation diet influences risk for adenomatous polyps (AP) either independently, or interactively with one-carbon metabolism-dependent gene variants, and whether such a diet modifies blood homocysteine, a biochemical phenotype closely related to the phenomenon of methylation.Methods249 subjects were examined using selective fluorescence, PCR and food frequency questionnaire to determine homocysteine, nine methylation-related gene polymorphisms, dietary methionine, 5-methyltetrahydrofolate, vitamins B6 and B12.Results1). Both dietary methionine and 5-methyltetrahydrofolate intake are significantly associated with plasma homocysteine. 2). Dietary methionine is related to AP risk in 2R3R-TS wildtype subjects, while dietary B12 is similarly related to this phenotype in individuals heterozygous for C1420T-SHMT, A2756G-MS and 844ins68-CBS, and in those recessive for 2R3R-TS. 3). Dietary methionine has a marginal influence on plasma homocysteine level in C1420T-SHMT heterozygotes, while B6 exhibits the same effect on homocysteine in C776G-TCN2 homozygote recessive subjects. Natural 5-methyltetrahydrofolate intake is interesting: Wildtype A1298C-MTHFR, heterozygote C677T-MTHFR, wildtype A2756G-MS and recessive A66G-MSR individuals all show a significant reciprocal association with homocysteine. 4). Stepwise regression of all genotypes to predict risk for AP indicated A2756G-MS and A66G-MSR to be most relevant (p = 0.0176 and 0.0408 respectively). Results were corrected for age and gender.ConclusionA methylation diet influences methyl group synthesis in the regulation of blood homocysteine level, and is modulated by genetic interactions. Methylation-related nutrients also interact with key genes to modify risk of AP, a precursor of colorectal cancer. Independent of diet, two methylation-related genes (A2756G-MS and A66G-MSR) were directly associated with AP occurrence

Genetic and transcriptional dissection of resistance to Claviceps purpurea in the durum wheat cultivar Greenshank.

Funder: Canadian Seed Growers' Association; doi: http://dx.doi.org/10.13039/501100000071Funder: National Research Council of Canada: Canadian Wheat Improvement programFour QTL for ergot resistance (causal pathogen Claviceps purpurea) have been identified in the durum wheat cultivar Greenshank. Claviceps purpurea is a pathogen of grasses that infects flowers, replacing the seed with an ergot sclerotium. Ergot presents a significant problem to rye, barley and wheat, in particular hybrid seed production systems. In addition, there is evidence that the highly toxic alkaloids that accumulate within sclerotia can cross-contaminate otherwise healthy grain. Host resistance to C. purpurea is rare, few resistance loci having been identified. In this study, four ergot resistance loci are located on chromosomes 1B, 2A, 5A and 5B in the durum wheat cv. Greenshank. Ergot resistance was assessed through analysis of phenotypes associated with C. purpurea infection, namely the number of inoculated flowers that produced sclerotia, or resulted in ovary death but no sclerotia, the levels of honeydew produced, total sclerotia weight and average sclerotia weight and size per spike. Ergot testing was undertaken in Canada and the UK. A major effect QTL, QCp.aafc.DH-2A, was detected in both the Canadian and UK experiments and had a significant effect on honeydew production levels. QCp.aafc.DH-5B had the biggest influence on total sclerotia weight per spike. QCp.aafc.DH-1B was only detected in the Canadian experiments and QCp.aafc.DH-5A in the UK experiment. An RNASeq analysis, undertaken to identify wheat differentially expressed genes associated with different combinations of the four ergot resistance QTL, revealed a disproportionate number of DEGs locating to the QCp.aafc.DH-1B, QCp.aafc.DH-2A and QCp.aafc.DH-5B QTL intervals