90 research outputs found

    Magmatically folded and faulted schlieren zones formed by magma avalanching in the Sonora Pass Intrusive Suite, Sierra Nevada, California

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    The southwestern margin of the Late Cretaceous Sonora Pass Intrusive Suite, northern Sierra Nevada, California (USA), preserves a densely populated zone of magmatic structures that record dynamic magmatic layer formation and deformation (faulting and folding) within a solidifying upper-crustal magma mush. This zone consists largely of coupled melanocratic (or schlieren) and leucocratic bands hosted within the 95.6 ± 1.5 Ma Kinney Lakes granodiorite (Leopold, 2016), with orientations approximately parallel to the intrusive margin and with inward younging directions. Schlieren consist of a high modal abundance of medium-grained ferromagnesian minerals (hornblende + biotite), zircon, sphene, apatite, opaque minerals, and minor plagioclase and interstitial quartz. Leucocratic bands are dominated by coarse-grained feldspar + quartz with minor ferromagnesian and accessory minerals. Whole-rock geochemical and Sr and Nd isotopic data indicate that the schlieren are derived from the Kinney Lakes granodiorite by effective mechanical separation of mafic minerals and accessory phases. We interpret that the schlieren zone at the margin of the Kinney Lakes granodiorite formed by large-scale collapse of crystal mush by “magma avalanching,” facilitated by gravity, local convection, and possibly by host-rock stoping at the margin. This process eroded a significant portion of the solidifying margin of the chamber and resulted in the formation of magmatically deformed layered structures, which experienced further mingling, re-intrusion, magmatic erosion, and recycling processes. We envisage that magma avalanching of magma mushes in plutons can be achieved by any unstable process (e.g., tectonic, fluid-assisted, stoping, or gravity-driven) in large, long-lived magma-mush chambers

    Using historical fisheries data to predict tuna distribution within the British Indian Ocean Territory marine protected area, and implications for its management

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    1. Recently, several large marine protected areas (MPAs) have been established globally and it is hoped that they will aid the recovery of populations of highly-mobile, large pelagic species. Understanding the distribution of these species within MPAs is key to delivering effective management but monitoring can be challenging over such vast areas of open ocean. 2. Historical fisheries data, collected prior to reserve establishment, can provide an insight into the past distributions of target species. We investigated the 10spatial and temporal distribution of yellowfin (Thunnus albacares) and skipjack (Katsuwonus pelamis) tuna catch using logbook data from the purse seine fishery in British Indian Ocean Territory (BIOT) from 1996 to 2010, before it was established as an MPA in April 2010. 3. Generalized additive models (GAMs) were used to predict tuna presence and relative abundance from fishing records in relation to temporal and environmental variables. Significant variables included sea salinity, temperature and water velocity. 4. Predictions from the models identified a distinct hotspot for large yellowfin tuna within the MPA, and areas of high predicted relative abundance of skipjack tuna. We recommend that these areas are used as focal points from which populations can be monitored and investigations into tuna residency time can occur, so that the effectiveness of the MPA in conserving highly-mobile pelagic fish can be determined

    Validation of the EORTC QLQ-GINET21 questionnaire for assessing quality of life of patients with gastrointestinal neuroendocrine tumours

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    Background:Quality of life is an important end point in clinical trials, yet there are few quality of life questionnaires for neuroendocrine tumours.Methods:This international multicentre validation study assesses the QLQ-GINET21 Quality of Life Questionnaire in 253 patients with gastrointestinal neuroendocrine tumours. All patients were requested to complete two quality of life questionnaires - the EORTC Core Quality of Life questionnaire (QLQ-C30) and the QLQ-GINET21 - at baseline, and at 3 and 6 months post-baseline; the psychometric properties of the questionnaire were then analysed.Results:Analysis of QLQ-GINET21 scales confirmed appropriate aggregation of the items, except for treatment-related symptoms, where weight gain showed low correlation with other questions in the scale; weight gain was therefore analysed as a single item. Internal consistency of scales using Cronbach's α coefficient was >0.7 for all parts of the QLQ-GINET21 at 6 months. Intraclass correlation was >0.85 for all scales. Discriminant validity was confirmed, with values <0.70 for all scales compared with each other.Scores changed in accordance with alterations in performance status and in response to expected clinical changes after therapies. Mean scores were similar for pancreatic and other tumours.Conclusion:The QLQ-GINET21 is a valid and responsive tool for assessing quality of life in the gut, pancreas and liver neuroendocrine tumours

    PPI-Delayed Diagnosis of Gastrinoma: Oncologic Victim of Pharmacologic Success

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    Functional neuroendocrine tumors are often low-grade malignant neoplasms that can be cured by surgery if detected early, and such detection may in turn be accelerated by the recognition of neuropeptide hypersecretion syndromes. Uniquely, however, relief of peptic symptoms induced by hypergastrinemia is now available from acid-suppressive drugs such as proton-pump inhibitors (PPIs). Here we describe a clinical case in which time to diagnosis from the onset of peptic symptoms was delayed more than 10 years, in part reflecting symptom masking by continuous prescription of the PPI omeprazole. We propose diagnostic criteria for this under-recognized new clinical syndrome, and recommend that physicians routinely measure serum gastrin levels in persistent cases of PPI-dependent dyspepsia unassociated with H. pylori

    Questions of presence

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    This article considers some of the ways in which ‘the black woman’ as both representation and embodied, sentient being is rendered visible and invisible and to link these to the multiple and competing ways in which she is ‘present’. The issues are engaged through three distinct but overlapping conceptualisations of ‘presence’. ‘Presence’ as conceived (and highly contested) in performance studies; ‘presence’ as conceived and worked with in psychoanalysis; and ‘presence’ as decolonising political praxis among indigenous communities. I use these conceptualisations of presence to consider the various ways in which the black woman as figure and as embodied/sentient subject has been made present/absent in different discursive registers. I also explore what is foreclosed and how this is itself linked to legacies of colonial ‘worlding’. I end with consideration of alternative modes of black women’s presence and how this offers a resource for new modes of sociality. Keywords Black women; presence; colonial violence; de-gendering; psychosocial; triangular spac

    Use of anticoagulants and antiplatelet agents in stable outpatients with coronary artery disease and atrial fibrillation. International CLARIFY registry

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