2,479 research outputs found

    Summary of Coral Cay Conservation's habitat mapping data from Utila, Honduras

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    IIThe coral reefs of Honduras are of vital national and international importance,both ecologically and economically, but are threatened because of rapid economicand population growth.? During work on Utila between 1999 and 2000 (the ?Bay Islands 2000? project),Coral Cay Conservation developed a programme of surveys, training andconservation education aimed at assessing the status of local reefs and improvingenvironmental awareness amongst neighbouring communities.? This summary report provides an overview of the habitat mapping data collectedby the Bay Islands 2000 project.? CASA provided software, hardware and skills, on a charitable basis to ensure thatthe data collected by CCC could be developed into a GIS, not only for mappingthe status of the coral reefs of Honduras, but also to provide analysis of the aerialextent of these reefs.? Data were collected within individual ?study areas?, to facilitate analysis at a rangeof spatial scales, and utilised the CCC standard baseline survey technique for therapid assessment of the characteristics of reef communities. The surveys,therefore, utilised a series of transects, perpendicular to the reef.? Baseline transects discriminated nine benthic and six geomorpholgical classeswhich indicates Utila has a high habitat diversity. Habitat diversity is importantsince the number of habitat types has been shown to be a good representation ofspecies biodiversity.? The nine benthic classes that were distinguished were all relatively coral poorbecause of a suite of relatively long-term local and regional factors, exacerbatedby the combination of Hurricane Mitch and coral bleaching in 1995 and 1998.? Damselfish were the most abundant reef associated fish recorded during baselinetransect surveys. Commercially important fish were less abundant that wouldnormally be expected in unfished systems.? A recurring pattern in the baseline transect data was the greater abundance anddiversity of fish in coral rich classes. However, although the link between fishabundance and coral cover was clear, not all species were necessarily mostabundant in the most coral rich areas.? Invertebrates were generally uncommon, partly because of fishing pressure, andthe abundances of many invertebrate taxa were correlated with coral cover.? A habitat map is presented within this report as an indication of the distribution ofhabitat types around Utila.? Using the map, estimates of areal extents of each benthic class and habitat type areinstructive. For example, there is only approximately 27 km2 of reefal habitatsaround Utila. Furthermore, the area supporting the most coral rich benthic classesis only approximately 4 km2 (15%). These statistics both highlight the damagecaused by the bleaching event and Hurricane Mitch and other anthropogenicimpacts and the need to conserve remaining coral rich areas.? If further reserves were to be created, it would be important to try to protect arange of reef and habitat types. For this reason, it appears that the Turtle HarbourWildlife Refuge is well placed since this areas includes a wide range of habitattypes. However, placement of reserves in Utila should favour relatively coral richhabitats over sand dominated areas.? This study led to six recommendations:Summary Utila habitat mapping reportIII? One or more agencies should collect additional ground-truthing data fromaround Utila to facilitate both classification of currently ?Unknown? polygonsand an accuracy assessment of the map.? Establish an integrated GIS and associated meta-database for Utila, includingdata from the Bay Islands 2000 project.? Examine the potential of using data collected by the Bay Islands 2000 projectas the basis of national habitat classification scheme and subsequent nationalhabitat map.? Continue to aim to establish one or more additional multiple use marineprotected areas around Utila, with an integrated monitoring programme tomeasure their efficacy, and strengthen the enforcement of regulations in theTurtle Harbour Wildlife Sanctuary. Establish regulations, and enforce existinglegislation, to minimise the detrimental effects of coastal development on reefhealth.? Additional marine reserves in Utila should integrate factors such as thepreference of many fish species for coral rich habitats and the protection ofareas incorporating a range of habitat types, including mangroves and seagrassbeds, in order to allow for nursery areas, ontogenetic shifts and species thatrely on non-coral rich habitats. The corollary of the preference of fish speciesfor coral rich habitats is to protect coral cover within the reserves.? The reef on the south coast of Utila appears to be a good candidate forprotection because it is relatively sheltered from storm and hurricane damage

    N-acetylgalatosamine-Mediated Regulation of the aga Operon by AgaR in Streptococcus pneumoniae

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    Here, we analyze the transcriptomic response of Streptococcus pneumoniae D39 to N-acetylgalactosamine (NAGa). Transcriptome comparison of S. pneumoniae D39 grown in NAGaM17 (0.5% NAGa + M17) to that grown in GM17 (0.5% Glucose + M17) revealed the elevated expression of various carbon metabolic genes/operons, including a PTS operon (denoted here as the aga operon), which is putatively involved in NAGa transport and utilization, in the presence of NAGa. We further studied the role of a GntR-family transcriptional regulator (denoted here as AgaR) in the regulation of aga operon. Our transcriptome and RT-PCR data suggest the role of AgaR as a transcriptional repressor of the aga operon. We predicted a 20-bp operator site of AagR (5'-ATAATTAATATAACAACAAA-3') in the promoter region of the aga operon (PbgaC), which was further verified by mutating the AgaR operator site in the respective promoter. The role of CcpA in the additional regulation of the aga operon was elucidated by further transcriptome analyses and confirmed by quantitative RT-PCR.</p

    Overview of the JET results in support to ITER

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    The 2014–2016 JET results are reviewed in the light of their significance for optimising the ITER research plan for the active and non-active operation. More than 60 h of plasma operation with ITER first wall materials successfully took place since its installation in 2011. New multi-machine scaling of the type I-ELM divertor energy flux density to ITER is supported by first principle modelling. ITER relevant disruption experiments and first principle modelling are reported with a set of three disruption mitigation valves mimicking the ITER setup. Insights of the L–H power threshold in Deuterium and Hydrogen are given, stressing the importance of the magnetic configurations and the recent measurements of fine-scale structures in the edge radial electric. Dimensionless scans of the core and pedestal confinement provide new information to elucidate the importance of the first wall material on the fusion performance. H-mode plasmas at ITER triangularity (H = 1 at βN ~ 1.8 and n/nGW ~ 0.6) have been sustained at 2 MA during 5 s. The ITER neutronics codes have been validated on high performance experiments. Prospects for the coming D–T campaign and 14 MeV neutron calibration strategy are reviewed.European Commission (EUROfusion 633053

    Ascorbic acid-dependent gene expression in Streptococcus pneumoniae and the activator function of the transcriptional regulator UlaR2

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    In this study, we have explored the impact of ascorbic acid on the transcriptome of Streptococcus pneumoniae D39. The expression of several genes and operons, including the ula operon (which has been previously shown to be involved in ascorbic acid utilization), the AdcR regulon (which has been previously shown to be involved in zinc transport and virulence) and a PTS operon (which we denote here as ula2 operon) were altered in the presence of ascorbic acid. The ula2 operon consists of five genes, including the transcriptional activator ulaR2. Our β-galactosidase assay data and transcriptome comparison of the ulaR2 mutant with the wild-type demonstrated that the transcriptional activator UlaR2 in the presence of ascorbic acid activates the expression of the ula2 operon. We further predict a 16-bp regulatory site (5'-ATATTGTGCTCAAATA-3') for UlaR2 in the Pula2. Furthermore, we have explored the effect of ascorbic acid on the expression of the AdcR regulon. Our ICP-MS analysis showed that addition of ascorbic acid to the medium causes zinc starvation in the cell which leads to the activation of the AdcR regulon

    NADH-Mediated Gene Expression in Streptococcus pneumoniae and Role of Rex as a Transcriptional Repressor of the Rex-Regulon

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    Nicotinamide adenine dinucleotides (NAD(H)) play a vital role in various biological processes, including keeping the cellular redox balance. In this study, we investigate the regulatory responses of Streptococcus pneumoniae D39 to NADH and characterize the role of the Rex protein as a transcriptional repressor of the gapN, fba, pncB, adhB2, gap, and adhE genes. Transcriptomic analysis was used to observe the response of S. pneumoniae D39 to NADH. Our microarray studies revealed elevated expression of various genes/operons involved in transport and biosynthesis of niacin (gapN, fba, pncB, adhB2, gap, and adhE). Promoter lacZ-fusion assays and microarray studies with the rex mutant revealed the role of Rex as a transcriptional repressor of gapN, fba, pncB, adhB2, gap, and adhE involved in niacin uptake and biosynthesis, in the presence of NADH. We predict the operator site (5 ' TTGTKAWAAWWTTCACAA-3 ' of Rex in the regulatory regions of Rex-regulated genes that was subsequently validated by promoter mutational experiments

    Evidence of scawtite and tilleyite formation at ambient conditions in hydrated Portland cement blended with freshly-precipitated nano-size calcium carbonate to reduce greenhouse gas emissions

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    Acknowledgements We thank CCM for its financial support of a PhD student ship tenable by LJM. Electron Microscopy was performed in the ACEMAC Facility at the University of Aberdeen by Mr. J. Still. Several of our group have contributed to discussion and provided samples, so thanks go to Wanawan Pragot and M. Ara Carballo-MeilanPeer reviewedPostprin

    Constipation in children

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    Constipation remains a frequent presentation to paediatricians, with significant health resource implications. We present a practical guide to the management of paediatric constipation and evaluate the current evidence for treatment regimens, to help the clinician in treating a condition that can be distressing and has a significant impact on affected families

    The Regulation of the AdcR Regulon in Streptococcus pneumoniae Depends Both on Zn(2+)- and Ni(2+)-Availability

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    By using a transcriptomic approach, we have elucidated the effect of Ni(2+) on the global gene expression of S. pneumoniae D39 by identifying several differentially expressed genes/operons in the presence of a high extracellular concentration of Ni(2+). The genes belonging to the AdcR regulon (adcRCBA, adcAII-phtD, phtA, phtB, and phtE) and the PsaR regulon (pcpA, prtA, and psaBCA) were highly upregulated in the presence of Ni(2+). We have further studied the role of Ni(2+) in the regulation of the AdcR regulon by using ICP-MS analysis, electrophoretic mobility shift assays and transcriptional lacZ-reporter studies, and demonstrate that Ni(2+) is directly involved in the derepression of the AdcR regulon via the Zn(2+)-dependent repressor AdcR, and has an opposite effect on the expression of the AdcR regulon compared to Zn(2+)
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