1,131 research outputs found
Carbon dioxide generation and drawdown during active orogenesis of siliciclastic rocks in the Southern Alps, New Zealand
C.D.M. was supported by NERC CASE PhD studentship award NE/G524160/1 (GNS Science, NZ, CASE partner). D.A.H.T. acknowledges support from research grants NE/H012842/1 and NE/J022128/1 and a Royal Society Wolfson Research Merit Award (WM130051). S.C.C. was funded under GNS Science's âImpacts of Global Plate Tectonics in and around New Zealand Programmeâ (PGST Contract CO5X0203). J.C.A. was supported by NSF OCE1334758. We also thank Matthew Cooper, Andy Milton, Darryl Green and Lora Wingate for laboratory assistance. We thank Mike Bickle for editorial advice and comments, and reviews from two anonymous reviewers that improved this manuscript.Peer reviewedPublisher PD
Uplift and exposure of serpentinized massifs: Modeling differential serpentinite diapirism and exhumation of the Troodos Mantle Sequence, Cyprus
Serpentinized mantle peridotites form prominent mountains, including the highest elevations of the Troodos ophiolite in Cyprus (Mount Olympus, 1,952 m), but to date, only qualitative mechanisms have been proposed to explain the uplift of mantle rocks to high altitudes. Serpentinization reactions between mantle rocks and water result in profound changes to the rheology and physical properties of peridotites including significant density reduction (âŒ900 kg/m3). Field observations, density measurements, and isostatic uplift and erosional modeling provide new constraints on the contribution of serpentinization to the uplift of the Troodos Mantle Sequence. Different serpentinization styles have resulted in two distinct serpentinite domains with contrasting densities. Our modeling shows that the Troodos Mountains can form within the geologically constrained uplift time frame (âŒ5.5 Myr) exclusively through partial serpentinization reactions. We interpret the serpentinite domains as two nested diapirs that formed due to different extents of serpentinization and density reduction. Differential uplift and exhumation have decoupled the two serpentinite diapirs from the originally overlying ocean crustal rocks. Once at high altitudes the incursion of meteoric water reinforced coupled deformation-alteration-recrystallization processes in the shallow subsurface producing a localized low density completely serpentinized diapir. A second decoupling between the contrasting serpentinite diapirs results in localized differential uplift and exhumation, extruding deep materials to the east of Mount Olympus. Application of our modeling to other serpentinite massifs (e.g., St. Peter and St. Paul Rocks, New Idria, California) highlights the contribution of isostasy to the uplift of serpentinized massifs
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âJust keep pushingâ: parentsâ experiences of accessing child and adolescent mental health services for child anxiety problems
Background:Anxiety disorders are among the most common psychopathologies in childhood, however a high proportion of children with anxiety disorders do not access effective treatments.The aim of the present qualitative study was to understand familiesâ experiences of seeking help and accessing specialist treatment for difficulties with childhood anxiety.Methods:Parents of 16 children (aged 7-12 years) referred to a child mental health service for difficulties with anxiety, were interviewed about their experiences of seeking and accessing treatment within CAMHS. All interviews were transcribed verbatim and thematically analysed for similarities and differences in familiesâ experiences. Results:Factors that helped and/or hindered families accessing treatment related to: i) parental recognition, ii) contact with professionals, iii) reaching CAMHS, iv) parental effort, and v) parental knowledge and concerns. High demands on services and parentsâ uncertainty surrounding the help-seeking process presented key hurdles for families. The critical role of parental persistence and support from GPs and school staff was evident across interviews.Conclusions:Findings highlighted the need for information and guidance on identifying child anxiety difficulties and professional, peer and self-help support; and ensuring sufficient provision is available to allow families prompt access to support
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Expedition 390 Preliminary Report. South Atlantic Transect 1
The South Atlantic Transect (SAT) is a multidisciplinary scientific ocean drilling project that comprises four International Ocean Discovery Program (IODP) expeditions: engineering Expeditions 390C and 395E as well as Expeditions 390 and 393. Altogether, the expeditions aim to recover complete sedimentary sections and the upper 100â350 m of the underlying oceanic crust along a slow/intermediate spreading rate Mid-Atlantic Ridge crustal flow line at ~31°S. The sediments along this transect were originally spot cored more than 50 y ago during Deep Sea Drilling Project Leg 3 (December 1968âJanuary 1969) to help verify the theories of seafloor spreading and plate tectonics. Given dramatic advances in drilling technology and analytical capabilities since Leg 3, many high-priority scientific objectives can be addressed by revisiting the transect. The SAT expeditions target six primary sites on 7, 15, 31, 49, and 61 Ma ocean crust, which fill critical gaps in our sampling of intact in situ ocean crust with regards to crustal age, spreading rate, and sediment thickness. Drilling these sites is required to investigate the history of the low-temperature hydrothermal interactions between the aging ocean crust and the evolving South Atlantic Ocean and quantify past hydrothermal contributions to global biogeochemical cycles. Samples from the transect of the previously unexplored sediment- and basalt-hosted deep biosphere beneath the South Atlantic Gyre are essential to refining global biomass estimates and examining microbial ecosystemsâ responses to variable conditions in a low-energy gyre and aging ocean crust. The transect is located near World Ocean Circulation Experiment Line A10, providing access to records of carbonate chemistry and deepwater mass properties across the western South Atlantic through key Cenozoic intervals of elevated atmospheric CO2 and rapid climate change. Reconstruction of the history of the deep western boundary current and deepwater formation in the Atlantic basins will yield crucial data to test hypotheses regarding the role of evolving thermohaline circulation patterns in climate change and the effects of tectonic gateways and climate on ocean acidification.
Engineering Expeditions 390C and 395E cored a single hole through the sediment/basement interface with the advanced piston corer/extended core barrel system at five of the six primary proposed SAT sites and installed a reentry system with casing either into basement or within 10 m of basement at each of those five sites. Expedition 390 (7 Aprilâ7 June 2022) conducted operations at three of the SAT sites, recovering 700 m of core (77% recovery) over 30.3 days of on-site operations. Sediment coring, basement drilling, and logging were conducted at two sites on 61 Ma crust, and sediment coring was completed at the 7 Ma crust site. At Site U1557 on 61 Ma crust, the drill bit was deposited on the seafloor prior to downhole logging, leaving Hole U1557D available for future deepening and to establish a legacy borehole for basement hydrothermal and microbiological experiments. Expedition 390 scientists additionally described, and analyzed data from, 792 m of core collected during Expeditions 390C and 395E. Expedition 393 plans to operate at four sites, conducting basement drilling and downhole logging at the 7 Ma site, in addition to sediment coring, basement drilling, and logging at the sites intermediate in age
Follow-up after curative treatment for colorectal cancer: longitudinal evaluation of patient initiated follow-up in the first 12 months
Purpose: To compare patient-triggered follow-up (PTFU) for curatively treated colorectal cancer against traditional outpatient follow-up (OPFU).
Methods: Questionnaires were mailed at four time points over one-year post-treatment to two prospectively-recruited cohorts: A, patients entering follow-up and receiving OPFU pre-implementation of PTFU; B, patients entering follow-up (FU) and receiving either OPFU (B1) or PTFU (B2) post-implementation of PTFU. Bi-variate tests were used to compare patient characteristics and outcomes eight months after entering follow-up (generic and cancer-specific quality of life (QoL), satisfaction). Regression analysis explored associations between follow-up model and outcomes. Resource implications and costs of models were compared.
Results: Patients in Cohort B1 were significantly more likely to have received chemotherapy (p<0.001), radiotherapy (p<0.05), and reported poorer QoL (p=0.001). Having a longstanding co-morbid condition was the most important determinant of QoL (p<0.001); model of care was not significant. Patients were satisfied with their follow-up care regardless of model. Health service costs were higher in PTFU over the first year.
Conclusions: PTFU is acceptable to patients with colorectal cancer and can be considered to be a realistic alternative to OPFU for clinically suitable patients. The initial costs are higher due to provision of a self-management (SM) programme and remote surveillance. Further research is needed to establish long-term outcomes and costs
Local flexibility in feeding behaviour and contrasting microhabitat use of an omnivore across latitudes
As the environment is getting warmer and species are redistributed, consumers can be forced to adjust their interactions with available prey, and this could have cascading effects within food webs. To better understand the capacity for foraging flexibility, our study aimed to determine the diet variability of an ectotherm omnivore inhabiting kelp forests, the sea urchin Echinus esculentus, along its entire latitudinal distribution in the northeast Atlantic. Using a combination of gut content and stable isotope analyses, we determined the diet and trophic position of sea urchins at sites in Portugal (42° N), France (49° N), southern Norway (63° N), and northern Norway (70° N), and related these results to the local abundance and distribution of putative food items. With mean estimated trophic levels ranging from 2.4 to 4.6, omnivory and diet varied substantially within and between sites but not across latitudes. Diet composition generally reflected prey availability within epiphyte or understorey assemblages, with local affinities demonstrating that the sea urchin adjusts its foraging to match the small-scale distribution of food items. A net âpreferenceâ for epiphytic food sources was found in northern Norway, where understorey food was limited compared to other regions. We conclude that diet change may occur in response to food source redistribution at multiple spatial scales (microhabitats, sites, regions). Across these scales, the way that key consumers alter their foraging in response to food availability can have important implication for food web dynamics and ecosystem functions along current and future environmental gradients
Petrophysical, Geochemical, and Hydrological Evidence for Extensive Fracture-Mediated Fluid and Heat Transport in the Alpine Fault's Hanging-Wall Damage Zone
Fault rock assemblages reflect interaction between deformation, stress, temperature, fluid, and chemical regimes on distinct spatial and temporal scales at various positions in the crust. Here we interpret measurements made in the hanging-wall of the Alpine Fault during the second stage of the Deep Fault Drilling Project (DFDP-2). We present observational evidence for extensive fracturing and high hanging-wall hydraulic conductivity (âŒ10â9 to 10â7 m/s, corresponding to permeability of âŒ10â16 to 10â14 m2) extending several hundred meters from the fault's principal slip zone. Mud losses, gas chemistry anomalies, and petrophysical data indicate that a subset of fractures intersected by the borehole are capable of transmitting fluid volumes of several cubic meters on time scales of hours. DFDP-2 observations and other data suggest that this hydrogeologically active portion of the fault zone in the hanging-wall is several kilometers wide in the uppermost crust. This finding is consistent with numerical models of earthquake rupture and off-fault damage. We conclude that the mechanically and hydrogeologically active part of the Alpine Fault is a more dynamic and extensive feature than commonly described in models based on exhumed faults. We propose that the hydrogeologically active damage zone of the Alpine Fault and other large active faults in areas of high topographic relief can be subdivided into an inner zone in which damage is controlled principally by earthquake rupture processes and an outer zone in which damage reflects coseismic shaking, strain accumulation and release on interseismic timescales, and inherited fracturing related to exhumation
In situ carbon mineralization in ultramafic rocks:Natural processes and possible engineered methods
Measurement of hadronic event shapes in high-p T multijet final states at âs = 13 TeV with the ATLAS detector
A measurement of event-shape variables in proton-proton collisions at large momentum transfer is presented using data collected at s = 13 TeV with the ATLAS detector at the Large Hadron Collider. Six event-shape variables calculated using hadronic jets are studied in inclusive multijet events using data corresponding to an integrated luminosity of 139 fbâ1. Measurements are performed in bins of jet multiplicity and in different ranges of the scalar sum of the transverse momenta of the two leading jets, reaching scales beyond 2 TeV. These measurements are compared with predictions from Monte Carlo event generators containing leading-order or next-to-leading order matrix elements matched to parton showers simulated to leading-logarithm accuracy. At low jet multiplicities, shape discrepancies between the measurements and the Monte Carlo predictions are observed. At high jet multiplicities, the shapes are better described but discrepancies in the normalisation are observed. [Figure not available: see fulltext.
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