14 research outputs found

    Flow transformations and mud partitioning across submarine fan fringes

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    Highly efficient sediment gravity flows can bypass mid-fan channels and lobes and deposit significant volumes of sand, mud, and particulate organic matter in outer-fan and basin-plain settings. The Serpukhovian to Bashkirian fill in the Shannon Basin, western Ireland, includes deep-water fan deposits (Ross Sandstone Fm) that gradationally overlie basin-floor shales (Clare Shale Fm). As part of a broader progradational succession, the upward transition from muddy basin floor to sandy fan preserves the stacked deposits of settings present prior to, and outboard of, mid-fan channels and lobes. Three fully cored boreholes and associated wireline data constrain the facies tracts in an 18-km-long panel oriented oblique to original depositional dip. Two distal successions dominated by hybrid event beds (HEBs) are recognized, separated by a prominent condensed section. The lower Cos-heen system includes m-thick, tabular HEBs with prominent linked debrites that pass down dip into much thinner sandstones overlain by sand-speckled mudstone caps that thicken distally before thinning. The latter are interpreted as secondary mudflows released following reconstitution of more thoroughly mixed sections of the up-dip linked debrites. Significant bypass and accumulation of mud by this mechanism helped heal local topography and maintain a relatively flat sea floor, promoting an overall tabular geometry for the deposits of larger volume hybrid flows reaching the distal sector of the basin. The overlying distal Ross system fringe is characterized by very fine- to fine-grained sandstones and is lateral to compensationally stacked lobes farther to the west. It has a progradational (at least initially) stacking pattern, facies transitions developed over shorter length scales, and includes outsized event beds, but these are thinner than those in the Cosheen system. Common banding and evidence for turbulence suppression by dispersed clay rather than entrained mud clasts indicate that these were transitional flows. In this case, event beds are inferred to taper distally, with significant mud emplaced by plug flow retained as caps to sandy event beds rather than bypassing down-dip. Different flow transformation mechanisms thus impacted how mud was partitioned across the fringe of the two systems, and this influenced bed geometries, larger scale bed stacking patterns, and stratigraphy. Whereas the flow-efficiency concept stresses the ability of flows to carry sand in a basinward direction, it is also imperative to consider the variable efficiency of mud transport given the operation of clay-induced flow transformations. These can either promote bypass or trigger premature fallout of mud, with implications for how systems fill accommodation, bed-scale facies transitions, and the burial and preservation of particulate organic carbon fractionated along with the clay in deep-water system fringes.Science Foundation IrelandGeological Survey Ireland (GSI) Griffith Geoscience AwardEquinor AS

    Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

    The genetic architecture of the human cerebral cortex

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    The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

    Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019

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    Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019

    Life at the continental–marine interface: palaeoenvironments and biota of the Alcobaça Formation (Late Jurassic, Central Portugal), with a formal definition of the unit appended

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    The Kimmeridgian Alcobaça Formation of the Lusitanian Basin forms a mixed carbonate–siliciclastic unit between basinal deposits of the Abadia Formation, and fluvial–terrestrial strata of the Lourinhã Formation. This study presents >2.5 km of detailed logs of nine outcrop sections of the Alcobaça Formation in its type region. Eight of these sections encircle the Caldas da Rainha Diapir, which was a prominent, emergent, passive salt diapir during the time of deposition. Palaeoenvironments of the unit form a complex mosaic of low- to high-energy, carbonate- or siliciclastic-dominated shallow shelf settings; coastal embayments and lagoons; and coastal plains with rivers, lakes and playas. In the strata, abundant microfauna is often joined by a rich macrofauna, usually dominated by bivalves. Locally, corals, calcareous sponges or oysters form meadows or patch reefs. These autochthonous to parautochthonous remnants of former communities are assigned to 35 benthic macrofaunal associations. The integration of palaeoecological analysis of these associations with microfaunal and sedimentological data provides constraint on their salinity ranges, which range from slightly hypersaline to freshwater. Frequent temporal and spatial salinity fluctuations are attributed to variations in relative sea-level, salt tectonics or climate. The NNE-trending Caldas da Rainha Diapir induced pronounced facies differentiation. Predominantly, non-marine siliciclastic facies in the northwest and carbonate to siliciclastic, marine to brackish facies in the southwest are contrasted by shallow-marine carbonate facies east of the diapir. Comprehensive exposure and well-preserved fossils make the Alcobaça Formation an excellent showcase to demonstrate how biofacies analysis can help to disentangle the interplay of climate changes, sea-level fluctuations and salt tectonics. Based on the improved characterisation of the unit, the Alcobaça Formation is formally defined, and seven members are established.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/50110000165

    Facies and internal stratigraphic variability in the Ross Sandstone Formation (Pennsylvanian), western Ireland - new borehole data from south of the Shannon Estuary

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    30th IAS Meeting of Sedimentologists, Manchester, United Kingdom, 2-5 September, 2013The 500 m thick Ross Sandstone Formation is well exposed in sea cliffs facing the Atlantic and along the Shannon Estuary in western Ireland. It forms the sandy deep-water part of a major shallowing-upward Pennsylvanian succession. Over the last four years, a major behind-outcrop drilling program targeting the Ross Sandstone Formation has been undertaken, focussing primarily on the Loop Head peninsula in west Clare. This has provided a full composite Ross cored section that underpins a new understanding of bed-scale variability and the wider evolution of the system. The focus has recently shifted to the key Ballybunion section on the south side of the River Shannon, obliquely down-dip from the Loop Head area (c. 18 km from the tip of the Loop) and is important in that previous outcrop studies have inferred that (1) the distinctive character of the lower Ross here with its abundant hybrid event beds may reflect a marginal position; and (2) extra sandy section may be present in the uppermost Ross due to offset stacking of the youngest sandy lobes. Two new cores are now available ¿behind¿ the Ballybunion section - a 200 m PQ borehole straddling the lower Ross and the upper part of the underlying Clare Shale Formation (12-CE-UCD-09), and a 151.5 m long, cored slimhole with associated wireline log data acquired by the Geological Survey of Ireland (GSI 09/05). The latter is 1.1 km along strike from coastal exposures of the upper Ross and the study reported here focusses on the relationship of the section acquired in this borehole to the local cliffs and to upper Ross outcrops on the north side of the River Shannon at Kilcredaun, some 4.6 km away. Correlation is based on goniatite-rich ¿marine bands¿, legacy biostratigraphic data (new determinations are underway), and a number of laterally extensive slump bodies which form distinctive marker beds.   The GSI 09/05 core contains three thin goniatite-rich levels, and a fourth candidate level, each interpreted as marine bands. These separate sand-prone packages, interpreted as stacked isolated to amalgamated lobe units, and at least two mass-transport units (MTDs), the lower and thickest of which is 25.5 m thick (true thickness). In the local cliffs to the west, all four marine bands can be identified, as well as the two MTDs. In addition, a third MTD is more obvious in the cliff. The lobe sandstones are dominated by deposits of high-density turbidity currents; amalgamated sandbodies become more abundant upwards. Hybrid event beds are rare (<10%) compared to lower in the formation. At least 50% of the sandbodies extend from the core to the adjacent outcrop without change; the remainder show a change from deposition from high- to low-concentration flows or vice versa. Overall, the Ballybunion Ross section is 480 m thick, broadly similar to the thickness established by drilling on the Loop. At longer length scales, all but the upper marine band are found at Kilcredaun. Correlatives of the two MTD units also occur in the core here, although the thickest slump has become thinner and muddier. Nonetheless this MTD unit can be traced widely across the Loop as a distinctive couplet. As correlated, the Ballybunion outcrop and core suggest there may not be an additional younger sandbody in this area, however the location appears axial and down-dip rather than marginal in character overall.Four-year Griffith Geoscience funded PhD StudentshipDM, 3/12/201

    Life at the continental–marine interface: palaeoenvironments and biota of the Alcobaça Formation (Late Jurassic, Central Portugal), with a formal definition of the unit appended

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    <jats:title>Abstract</jats:title><jats:p>The Kimmeridgian Alcobaça Formation of the Lusitanian Basin forms a mixed carbonate–siliciclastic unit between basinal deposits of the Abadia Formation, and fluvial–terrestrial strata of the Lourinhã Formation. This study presents >2.5 km of detailed logs of nine outcrop sections of the Alcobaça Formation in its type region. Eight of these sections encircle the Caldas da Rainha Diapir, which was a prominent, emergent, passive salt diapir during the time of deposition. Palaeoenvironments of the unit form a complex mosaic of low- to high-energy, carbonate- or siliciclastic-dominated shallow shelf settings; coastal embayments and lagoons; and coastal plains with rivers, lakes and playas. In the strata, abundant microfauna is often joined by a rich macrofauna, usually dominated by bivalves. Locally, corals, calcareous sponges or oysters form meadows or patch reefs. These autochthonous to parautochthonous remnants of former communities are assigned to 35 benthic macrofaunal associations. The integration of palaeoecological analysis of these associations with microfaunal and sedimentological data provides constraint on their salinity ranges, which range from slightly hypersaline to freshwater. Frequent temporal and spatial salinity fluctuations are attributed to variations in relative sea-level, salt tectonics or climate. The NNE-trending Caldas da Rainha Diapir induced pronounced facies differentiation. Predominantly, non-marine siliciclastic facies in the northwest and carbonate to siliciclastic, marine to brackish facies in the southwest are contrasted by shallow-marine carbonate facies east of the diapir. Comprehensive exposure and well-preserved fossils make the Alcobaça Formation an excellent showcase to demonstrate how biofacies analysis can help to disentangle the interplay of climate changes, sea-level fluctuations and salt tectonics. Based on the improved characterisation of the unit, the Alcobaça Formation is formally defined, and seven members are established.</jats:p&gt

    Facies Trends and Large-Scale Architecture of the Pennsylvanian Ross Formation, Western Ireland - New Insight from Cores South of the Shannon

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    BSRG Annual Meeting, Hull, United Kingdom, 18-21 December, 2013The Ross Formation is well exposed in sea cliffs facing the Atlantic and Shannon estuary in western Ireland. It forms the sandy deep-water part of a major shallowing-upward Pennsylvanian succession. Over the last four years, a major behind-outcrop drilling program targeting the Ross Formation has focussed primarily on the Loop Head peninsula in west Clare. This has provided a composite Ross cored section (490 m thick) that underpins a new understanding of bed-scale variability and the wider vertical evolution of the system. The focus has now shifted to the key Ballybunion section on the south side of the Shannon, which sits obliquely down-dip (to the east) of the Loop Head area (c. 18 km away). This area is important in that previous outcrop studies have suggested that (1) the character of the lower Ross with its abundant hybrid event beds may reflect a marginal fringe position; (2) an extra sandy section may be present in the uppermost Ross due to offset stacking of the youngest lobes and (3) some of the upper Ross mass transport units may extend across the estuary from Clare. Two new cores are now available ¿behind¿ the Ballybunion cliff section: a 200 m long PQ borehole straddling the lower Ross and the upper part of the underlying Clare Shale (12-KY-UCD-09), and a 151.5 m long slimhole core acquired by the Geological Survey of Ireland (GSI 09/05). In addition, a re-analysis of the biostratigraphy is underway. Together the matched pair of Kerry boreholes with the outcrop section provide a reference section (480 m thick) that can be compared with the Loop composite section. Both sections have a distinctive precursor cycle involving first stacked thin mudflows and then outsized and coarse grained hybrid event beds. The muddier make-up of the latter at Ballybunion is consistent with a down-dip position based on trends in other basins. The onset of the main Ross system that follows is sandier at Ballybunion than at Loop suggesting the former was more axial at this time. Thereafter hybrid event beds appear not to be as important at Ballybunion. Several of the mass transport units and condensed sections extend across the Shannon and tie the sections.Four-year Griffith Geoscience funded PhD StudentshipCheck if there are siginficant differences from identically entitled paper presented at a different conference 2013-12-02 JGDM, 3/12/201

    Down-dip Termination of Sandy Fan Systems - New Insight from the Pennsylvanian Ross Sandstone Formation, Western Ireland

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    British Sedimentological Research Group (BSRG) AGM, Keele University, UK, 19 - 22 December 2015New and legacy borehole constraints and outcrop work on the eastward extension of the Ross Formation help constrain the down-dip character of the fan stack

    Down-dip Termination of Sandy Fan Systems - New Insight from the Pennsylvanian Ross Sandstone Formation, Western Ireland

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    AAPG General Meeting, Calgary, Alberta, Canada, 19 - 22 June 2016The Pennsylvanian Ross Sandstone Fm. in western Ireland forms part of a thick (>2200m) progradational and shallowing-upward basin-fill succession. New and legacy borehole constraints and outcrop work on the eastward extension of the Ross help constrain the down-dip character at different levels in the fan stack
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