2,758 research outputs found

    Sulphide sinking in magma conduits: Evidence from mafic–ultramafic plugs on Rum and the wider North Atlantic Igneous Province

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    This is the final version of the article. Available from the publisher via the DOI in this record.Ni–Cu–PGE (platinum group element) sulphide mineralization is commonly found in magmatic conduit systems. In many cases the trigger for formation of an immiscible sulphide liquid involves assimilation of S-bearing crustal rocks. Conceptually, the fluid dynamics of sulphide liquid droplets within such conduits is essentially a balance between gravitational sinking and upwards entrainment. Thus, crustal contamination signatures may be present in sulphides preserved both up- and down-flow from the point of interaction with the contaminant. We examine a suite of ultramafic volcanic plugs on the Isle of Rum, Scotland, to decipher controls on sulphide accumulation in near-surface magma conduits intruded into a variable sedimentary stratigraphy. The whole-rock compositions of the plugs broadly overlap with the compositions of ultramafic units within the Rum Layered Complex, although subtle differences between each plug highlight their individuality. Interstitial base metal sulphide minerals occur in all ultramafic plugs on Rum. Sulphide minerals have magmatic δ34S (ranging from –1·3 to +2·1‰) and S/Se ratios (mean = 2299), and demonstrate that the conduit magmas were already S-saturated. However, two plugs in NW Rum contain substantially coarser (sometimes net-textured) sulphides with unusually light δ34S (–14·7 to +0·3‰) and elevated S/Se ratios (mean = 4457), not represented by the immediate host-rocks. Based on the Hebrides Basin sedimentary stratigraphy, it is likely that the volcanic con duits would have intruded through a package of Jurassic mudrocks with characteristically light δ34S (–33·8 to –14·7‰). We propose that a secondary crustal S contamination event took place at a level above that currently exposed, and that these sulphides sank back to their present position. Modelling suggests that upon the cessation of active magma transport, sulphide liquids could have sunk back through the conduit over a distance of several hundreds of metres, over a period of a few days. This sulphide ‘withdrawal’ process may be observed in other vertical or steeply inclined magma conduits globally; for example, in the macrodykes of East Greenland. Sulphide liquid sinking within a non-active conduit or during magma ‘suck-back’ may help to explain crustal S-isotopic compositions in magma conduits that appear to lack appropriate lithologies to support this contamination, either locally or deeper in the system.Sulphur isotope analyses were funded by NERC Isotope Geosciences Facilities grant, IP-1356-1112. H.S.R.H. acknowledges the financial support of the Natural Environment Research Council (NERC) for her PhD studentship (NE/J50029X) and funding of open access publication. This is a contribution to the TeaSe (Te and Se Cycling and Supply) research consortium supported by NERC award NE/M011615/1 to Cardiff University and the University of Leicester

    Repetitive Transcranial Magnetic Stimulation (rTMS) for depression : outcomes in a United Kingdom (UK) clinical practice

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    Objective: The aim of this paper is to present the outcomes data from the largest United Kingdom’s (UK) National Health Service (NHS) clinical rTMS service treating treatment resistant depression (TRD). Methods: The study was a retrospective investigation of routinely collected data on patients receiving rTMS between 2015 and 2017. Measures used were the clinician-rated Clinical Global Impression (CGI) and Hamilton Depression Rating Scale (HAM-D), and patient rated Beck Depression Inventory (BDI). The outcome data of 73 patients with TRD was analysed. The sample included patients with co-morbid psychiatric diagnosis. Results: Response and remission rates respectively were 40.4% and 25.5% for the HAM-D; 35.6% and 20.8% for the BDI; and 51.1% and 52.1% for the CGI. Effect sizes were medium (.54, .52 and .56 respectively). Conclusions: The results show that a UK based clinical service achieves similar results to those published internationally and that clinical rTMS can have significant impact on symptoms of depression in many patients with TRD. Health services are under pressure to make financial savings, investment in rTMS could reduce the long term treatment costs associated with TRD

    Repetitive Transcranial Magnetic Stimulation (rTMS) in Treatment Resistant Depression : Retrospective Data Analysis from Clinical Practice

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    Objective: The aim of this paper is to present the service data results from a clinical repetitive Transcranial Magnetic Stimulation (rTMS) service treating treatment resistant depression (TRD). Methods The study was a retrospective investigation of routinely collected data on patients receiving rTMS between 2015 and 2018. Measures used were the clinician-rated Clinical Global Impression (CGI) and Hamilton Depression Rating Scale (HAM-D), and patient rated Physical Health Questionnaire (PHQ-9) and Generalised Anxiety Disorder 7 (GAD-7). The outcome data of 144 patients with TRD was analysed. The sample included patients with co-morbid psychiatric diagnosis. Results Response and remission rates respectively were 34.6% and 20.6% for the HAM-D; 10% and 28.6% for the PHQ-9; 31% and 31.8% for the CGI; and 24.6% and 28.8% for GAD-7. Effect sizes were mostly medium (0.48, 0.27, 0.51, 0.43 respectively). GAD-7 reliable change improvement was 56.1% and PHQ-9 reliable change improvement was 40%. There was a medium positive correlation between anxiety (GAD-7) and depression recovery (HAM-D), r = .31, n = 46, p = .039, with lower pre-treatment anxiety associated with lower post-treatment HAM-D scores. Conclusions TRD patients with low pre-treatment anxiety levels respond to treatment better than those with high pre-treatment anxiety. The results show that a clinical rTMS service can have a significant impact on symptoms of depression and anxiety in TRD. The findings support wider availability of rTMS as a treatment option for people with TRD

    Computer-Generated Ovaries to Assist Follicle Counting Experiments

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    Precise estimation of the number of follicles in ovaries is of key importance in the field of reproductive biology, both from a developmental point of view, where follicle numbers are determined at specific time points, as well as from a therapeutic perspective, determining the adverse effects of environmental toxins and cancer chemotherapeutics on the reproductive system. The two main factors affecting follicle number estimates are the sampling method and the variation in follicle numbers within animals of the same strain, due to biological variability. This study aims at assessing the effect of these two factors, when estimating ovarian follicle numbers of neonatal mice. We developed computer algorithms, which generate models of neonatal mouse ovaries (simulated ovaries), with characteristics derived from experimental measurements already available in the published literature. The simulated ovaries are used to reproduce in-silico counting experiments based on unbiased stereological techniques; the proposed approach provides the necessary number of ovaries and sampling frequency to be used in the experiments given a specific biological variability and a desirable degree of accuracy. The simulated ovary is a novel, versatile tool which can be used in the planning phase of experiments to estimate the expected number of animals and workload, ensuring appropriate statistical power of the resulting measurements. Moreover, the idea of the simulated ovary can be applied to other organs made up of large numbers of individual functional units

    CDK-dependent nuclear localization of B-Cyclin Clb1 promotes FEAR activation during meiosis I in budding yeast

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    Cyclin-dependent kinases (CDK) are master regulators of the cell cycle in eukaryotes. CDK activity is regulated by the presence, post-translational modification and spatial localization of its regulatory subunit cyclin. In budding yeast, the B-cyclin Clb1 is phosphorylated and localizes to the nucleus during meiosis I. However the functional significance of Clb1's phosphorylation and nuclear localization and their mutual dependency is unknown. In this paper, we demonstrate that meiosis-specific phosphorylation of Clb1 requires its import to the nucleus but not vice versa. While Clb1 phosphorylation is dependent on activity of both CDK and polo-like kinase Cdc5, its nuclear localization requires CDK but not Cdc5 activity. Furthermore we show that increased nuclear localization of Clb1 during meiosis enhances activation of FEAR (Cdc Fourteen Early Anaphase Release) pathway. We discuss the significance of our results in relation to regulation of exit from meiosis I

    Desarrollo, soberanía y geopolítca: el papel de la integración de infraestructura energética en América del Sur

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    Eis que esta edição renova a parceria pedagógico-científica, estabelecida no ano de 2018 com a, Universidade Federal da Integração Latino-Americana (UNILA), representada pelo professor Rodrigo Cantu, presidente do Comitê Local de Iniciação Científica da UNILA. Aqui, apresentamos o fruto dessa parceria, para publicação de uma edição especial contendo trabalhos apresentados no VII Encontro de Iniciação Científica e III Encontro de Iniciação em Desenvolvimento Tecnológico e Inovação (EICTI) em 2018.As relações internacionais contemporâneas são marcadas pela tendência do acirramento da disputa interestatal entre as grandes potências, inserindo a América do Sul em um contexto geopolítico intrincado, uma vez que a região é rica em recursos naturais estratégicos, especialmente recursos energéticos, parte central das disputas políticas da contemporaneidade. Neste sentido, a integração de infraestrutura energética se trata de uma importante estratégia de longo prazo para assegurar a soberania da exploração dos recursos energéticos na América do Sul, além de ser um importante pilar para a capacidade de projeção geopolítica da região e um elemento fundamental para o desenvolvimento sul-americano.Contemporary international relations are marked by the tendency of the intensification of the interstate dispute between the great powers. This trend places South America in an intricate geopolitical context, since the region is rich in strategic natural resources, especially energy resources, which are at the center of contemporary political disputes. In this sense, the integration of energy infrastructure is an important long-term strategy to ensure the sovereignty of the exploitation of energy resources in South America, as well as being an important pillar for the geopolitical projection capacity of the region and a fundamental element for the South American development.Las relaciones internacionales contemporáneas están marcadas por la tendencia del agravamiento de la disputa interestatal entre las grandes potencias, insertando a América del Sur en un contexto geopolítico intrincado, una vez que la región es rica en recursos naturales estratégicos, especialmente recursos energéticos, parte central de las disputas políticas de la contemporaneidad. En este sentido, la integración de infraestructura energética se trata de una importante estrategia a largo plazo para asegurar la soberanía de la explotación de los recursos energéticos en América del Sur, además de ser un importante pilar para la capacidad de proyección geopolítica de la región y un elemento fundamental para el desarrollo sudamericano

    The effect of distance on reaction time in aiming movements

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    Target distance affects movement duration in aiming tasks but its effect on reaction time (RT) is poorly documented. RT is a function of both preparation and initiation. Experiment 1 pre-cued movement (allowing advanced preparation) and found no influence of distance on RT. Thus, target distance does not affect initiation time. Experiment 2 removed pre-cue information and found that preparing a movement of increased distance lengthens RT. Experiment 3 explored movements to targets of cued size at non-cued distances and found size altered peak speed and movement duration but RT was influenced by distance alone. Thus, amplitude influences preparation time (for reasons other than altered duration) but not initiation time. We hypothesise that the RT distance effect might be due to the increased number of possible trajectories associated with further targets: a hypothesis that can be tested in future experiments
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