"Petit spot" rejuvenated volcanism superimposed on plume-derived Samoan shield volcanoes: Evidence from a 645-m drill core from Tutuila Island, American Samoa

Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 20(3), (2019): 1485-1507, doi:10.1029/2018GC007985.In 2015 a geothermal exploration well was drilled on the island of Tutuila, American Samoa. The sample suite from the drill core provides 645 m of volcanic stratigraphy from a Samoan volcano, spanning 1.45 million years of volcanic history. In the Tutuila drill core, shield lavas with an EM2 (enriched mantle 2) signature are observed at depth, spanning 1.46 to 1.44 Ma. These are overlain by younger (1.35 to 1.17 Ma) shield lavas with a primordial “common” (focus zone) component interlayered with lavas that sample a depleted mantle component. Following ~1.15 Myr of volcanic quiescence, rejuvenated volcanism initiated at 24.3 ka and samples an EM1 (enriched mantle 1) component. The timing of the initiation of rejuvenated volcanism on Tutuila suggests that rejuvenated volcanism may be tectonically driven, as Samoan hotspot volcanoes approach the northern terminus of the Tonga Trench. This is consistent with a model where the timing of rejuvenated volcanism at Tutuila and at other Samoan volcanoes relates to their distance from the Tonga Trench. Notably, the Samoan rejuvenated lavas have EM1 isotopic compositions distinct from shield lavas that are geochemically similar to “petit spot” lavas erupted outboard of the Japan Trench and late stage lavas erupted at Christmas Island located outboard of the Sunda Trench. Therefore, like the Samoan rejuvenated lavas, petit spot volcanism in general appears to be related to tectonic uplift outboard of subduction zones, and existing geochemical data suggest that petit spots share similar EM1 isotopic signatures.Reviews from Kaj Hoernle and three anonymous reviewers are gratefully acknowledged. M. G. J. acknowledges support from the American Samoa Power Authority and National Science Foundation grants OCE‐1736984 and EAR‐1624840. The Tutuila drill core was the brainchild of Tim Bodell, without whom we would still have no stratigraphic record of Tutuila volcanism. The support of Utu Abe Malae and Matamua Katrina Mariner was instrumental to the project's success. We dedicate this paper to the memory of Abe Malae and his efforts to support science and education in American Samoa. Images of the entire drill core are available online (escholarship.org/uc/item/6gg6p61w). All data presented are either part of this study or previously published and are referenced in text.2019-08-1

Natural gas flaring management system: a novel tool for sustainable gas flaring reduction in Nigeria

The use of hydrocarbon fuels increases with population growth and rising standards of living, and so does natural gas flaring. Natural gas flaring is both a waste of natural resources and a violation of Nigeria’s energy policy for sustainable development through natural gas conservation. However, it remains the most cost-efficient and effective associated natural gas (ANG) management option in developing countries such as Nigeria. The World Bank’s initiative to eliminate routine gas flaring by 2030 has increased the need to limit or eliminate routine gas flaring. Often, studies on natural gas utilisation techniques fail to consider the lack of practical tools that integrate economic, technical, and regulatory factors into a gas flaring management framework, and the intricacies of existing tools, which often come at the expense of simplicity to achieve real-time information output. This paper aims to establish a framework and ANG management tool to reduce regular gas flaring in Nigeria. This research established a management framework (using a flowchart decision tree) and models to provide a user-friendly ANG flaring tool (using a MATLAB graphical front end user interface with back-end ASPEN HYSYS thermodynamic models). This was combined with techno-economic models for liquefied natural gas, gas-to-methanol, and gas-to-wire ANG utilisation options. The tool was then tested with data obtained from Fields Y and X in the Niger Delta region of Nigeria. The results, considering both economic and technical factors, showed that the choice of liquefied natural gas for Field Y was best due to its proximity to the pipeline infrastructure and its cost-effectiveness, and the availability of a high-demand LNG market for that area. For Field X, gas-to-wire was best due to its proximity to the electrical grid and high electricity requirements for that area. Additional geographical profiles in West Africa and ANG utilisation alternatives were recommended for further investigation. This paper developed and validated a one-of-a-kind ANG flaring management tool that incorporates techno-economic analysis of selected ANG utilisation options to assist operators and investors in making more profitable investment decisions

Effect of co-firing coal and biomass blends on the gaseous environments and ash deposition during pilot-scale oxy-combustion trials

This paper presents the experimental results from co-firing blends of El Cerrejon (EC) coal and cereal co-product (CCP) using several ratios (100/0; 75/25; 50/50; 0/100 (w/w)) under air- and oxy-firing conditions, in a retrofitted 100 kWth pulverised fuel combustor. An on-line high-resolution multi-component Fourier Transform Infra-red (FTIR) analyser was used to measure CO2, O2, H2O, CO, NO, NO2, N2O, NH3, SO2, HCl, HF and CH4. A comprehensive evaluation of the major and minor species present in the flue gas was carried out to study the effects of the addition of biomass, the firing mode (air/oxy) and the type of recycle (wet/dry) on the gaseous environment in the combustor. It was found that similar CO2 levels can be reached when using pure coal or pure biomass, on a dry basis. For the minor species, the increase in the share of biomass had the effect of decreasing the SO2 levels reached in the flue gas and increasing the HCl content. No significant variation in the NOx levels was observed as a consequence of using high percentages of biomass. For ash deposit characterisation, two probes were used for which surface temperatures were controlled at 650° and 750 °C. Environmental scanning electron microscopy (ESEM) with energy dispersive X-ray (EDX) analysis, supported by X-ray diffraction (XRD), were used to study the deposits. The ESEM/EDX and XRD results showed similar sulphur levels in the deposits when varying the share of biomass even though EC coal contains 3.5 times more sulphur than CCP. This is thought to be a consequence of the reaction of sulphur with the alkalis, especially potassium, present at higher levels in the CCP, which produces higher levels of K2SO4 in the combustion gas. Chlorine was only found in the deposits generated using pure CCP under oxy-firing conditions. An evaluation of the different mineral species formed when varying the biomass share and the firing mode was also performed. Results obtained comparing the mineral species in deposits when using 100% CCP, switching from air to oxy-firing conditions, showed that in air-firing CCP deposits had higher levels of aluminium phosphate and arcanite (K2SO4). Also, under oxy-firing conditions, 100% CCP-derived deposits had a higher level of potassium magnesium chloride compared 100% EC

Genome-wide meta-analysis identifies five new susceptibility loci for cutaneous malignant melanoma.

Thirteen common susceptibility loci have been reproducibly associated with cutaneous malignant melanoma (CMM). We report the results of an international 2-stage meta-analysis of CMM genome-wide association studies (GWAS). This meta-analysis combines 11 GWAS (5 previously unpublished) and a further three stage 2 data sets, totaling 15,990 CMM cases and 26,409 controls. Five loci not previously associated with CMM risk reached genome-wide significance (P < 5 × 10(-8)), as did 2 previously reported but unreplicated loci and all 13 established loci. Newly associated SNPs fall within putative melanocyte regulatory elements, and bioinformatic and expression quantitative trait locus (eQTL) data highlight candidate genes in the associated regions, including one involved in telomere biology.[Please see the Supplementary Note for acknowledgments.]This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ng.337

澳大利亚矿产勘查——趋势、经济影响和政策问题

一、导言矿产勘查活动近来在澳大利亚及海外经历了大幅度的衰退。从1996-97到2001-02这五年间,澳大利亚的矿产勘查费(除石油外,以2000-01年澳元计算)从12.29亿澳元下降

Dual bronchodilators in Bronchiectasis study (DIBS): protocol for a pragmatic, multicentre, placebo-controlled, three-arm, double-blinded, randomised controlled trial studying bronchodilators in preventing exacerbations of bronchiectasis

INTRODUCTION: Bronchiectasis is a long-term lung condition, with dilated bronchi, chronic inflammation, chronic infection and acute exacerbations. Recurrent exacerbations are associated with poorer clinical outcomes such as increased severity of lung disease, further exacerbations, hospitalisations, reduced quality of life and increased risk of death. Despite an increasing prevalence of bronchiectasis, there is a critical lack of high-quality studies into the disease and no treatments specifically approved for its treatment. This trial aims to establish whether inhaled dual bronchodilators (long acting beta agonist (LABA) and long acting muscarinic antagonist (LAMA)) taken as either a stand-alone therapy or in combination with inhaled corticosteroid (ICS) reduce the number of exacerbations of bronchiectasis requiring treatment with antibiotics during a 12 month treatment period. METHODS: This is a multicentre, pragmatic, double-blind, randomised controlled trial, incorporating an internal pilot and embedded economic evaluation. 600 adult patients (≥18 years) with CT confirmed bronchiectasis will be recruited and randomised to either inhaled dual therapy (LABA+LAMA), triple therapy (LABA+LAMA+ICS) or matched placebo, in a 2:2:1 ratio (respectively). The primary outcome is the number of protocol defined exacerbations requiring treatment with antibiotics during the 12 month treatment period. ETHICS AND DISSEMINATION: Favourable ethical opinion was received from the North East-Newcastle and North Tyneside 2 Research Ethics Committee (reference: 21/NE/0020). Results will be disseminated in peer-reviewed publications, at national and international conferences, in the NIHR Health Technology Assessments journal and to participants and the public (using lay language). TRIAL REGISTRATION NUMBER: ISRCTN15988757

Does a lack of juveniles indicate a threat?:Understanding body size distributions in a group of long-lived vertebrates

Turtles are declining globally, and absences of juveniles during surveys are often interpreted as evidence of threats to early life stages. In Australia, for example, it is widely argued that a low number of juveniles is likely due to nest predation by introduced red foxes (Vulpes vulpes). However, small sample sizes within populations, low detectability of juveniles and turtles' long lifespans often confound the conclusion that a paucity of juveniles indicates a declining population. Because turtles have long reproductive lifespans, we might intuitively expect most turtle populations to be heavily weighted towards large individuals, but a 'typical' or 'healthy' size distribution for turtle populations has not been well established. Therefore, we collated data on 41,021 freshwater turtles from 38 species and 428 populations located in parts of Australia both with and without introduced foxes, as well as populations in the United States of America, which naturally have raccoons (Procyon lotor), foxes and other nest predators. We examined population-level body size distributions to establish a baseline for 'typical' turtle populations and test whether populations that are exposed to introduced foxes have proportionately fewer juveniles compared to both AU populations that lack introduced foxes and USA populations that are naturally exposed to nest predators. We found that most turtle populations in AU and the United States were heavily skewed towards adults and had few juveniles, regardless of the presence of foxes or other nest predators. There were, however, clear differences among population survey methods: those that target shallow areas (e.g. crawfish traps) tended to capture proportionately more juveniles, and small sample sizes (∼&lt;50) often produced inaccurate representations of size distributions. Additionally, we used a simulation to demonstrate that, given common turtle life history parameters, even stable populations should generally have low proportions of juveniles. Based on our results, we encourage caution when interpreting turtle size distributions. A small number of juveniles does not inherently suggest that a population is declining due to high egg and/or juvenile mortality, and researchers should pay careful attention to the biases in their methods and strive to capture a minimum of 50-100 turtles before drawing inferences.</p

Should young people be paid for getting tested? A national comparative study to evaluate patient financial incentives for chlamydia screening

<p>Abstract</p> <p>Background</p> <p>Patient financial incentives ("incentives") have been widely used to promote chlamydia screening uptake amongst 15-24 year olds in England, but there is scarce evidence of their effectiveness. The objectives of the study were to describe incentives used to promote chlamydia screening in Primary Care Trusts (PCTs) in England and to evaluate their impact on coverage and positivity rate.</p> <p>Methods</p> <p>PCTs that had used incentives between 1/1/2007 and 30/6/2009 (exposed) were matched by socio-demographic profile and initial screening coverage with PCTs that had not (unexposed). For each PCT, percentage point change in chlamydia screening coverage and positivity for the period before and during the incentive was calculated. Differences in average change of coverage and positivity rate between exposed and unexposed PCTs were compared using linear regression to adjust for matching and potential confounders.</p> <p>Results</p> <p>Incentives had a significant effect in increasing average coverage in exposed PCTs (0.43%, CI 0.04%-0.82%). The effect for voucher schemes (2.35%) was larger than for prize draws (0.16%). The difference was greater in females (0.73%) than males (0.14%). The effect on positivity rates was not significant (0.07%, CI -1.53% to 1.67%).</p> <p>Conclusions</p> <p>Vouchers, but not prize draws, led to a small absolute but large relative increase in chlamydia screening coverage. Incentives increased coverage more in females than males but had no impact on reported positivity rates. These findings support recommendations not to use prize draws to promote chlamydia screening and contribute to the evidence base of the operational effectiveness of using patient incentives in encouraging public health action.</p

The effect of intact vs hydrolysed collagen on recovery from exercise induced muscle damage: A double-blind, randomised, placebo-controlled trial

Collagen supplementation has the potential to aid in the recovery from exercise-induced muscle damage (EIMD). A novel collagen supplement, rich in intact type I collagen (Natiiv™, Trinsic Collagen Limited), potentially increases delivery of its constituent amino acids and intact alpha helices to the extracellular matrix (ECM) for remodelling. Thirty-six healthy, young and active adults (M = 27, age: 21.3 ± 4.3 years, body mass index; 25.2 ± 5.7 kg m−2) were assigned (1:1:1) in a double-blind, randomised, placebo-controlled trial, to consume either: Natiiv™ collagen (0.255 g·day−1 of Natiiv™ collagen), hydrolysed collagen (20 g·day−1 of collagen; Peptan®, Rousselot, Belgium), or placebo (collagen depleted alkaline water; Natiiv™), for 30-days. On day-28, muscle damage-inducing exercise (150 drop jumps) was undertaken. Exercise performance (counter movement, squat, and drop jumps), quadriceps strength (maximal voluntary isometric contraction; leg pain (visual analogue scale, pain pressure threshold, short recovery and stress scale questionnaire); and knee inflammation (via colour fraction ultrasonography) and systemic inflammation (IL-6, IL-10, TNFα); ECM damage (hydroxyproline) and; bone turnover (β-CTX and P1NP) were assessed at baseline, 2.5-h, 24-h, 48-h and 72-h following EIMD. Thirty days of Natiiv™ collagen supplementation had no significant effect on any outcome measure (P > 0.05 with small-medium effect sizes) compared to hydrolysed collagen or placebo. Future studies should explore the potential efficacy of Natiiv™ collagen supplementation in other relevant populations/scenarios and assess the post-prandial bioavailability of Natiiv™ collagen and, if impaired, explore interventions that can increase its bioavailability and optimise recovery from EIMD