728 research outputs found

    Sedimentary mechanisms of a modern banded iron formation on Milos Island, Greece

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    An Early Quaternary shallow submarine hydrothermal iron formation (IF) in the Cape Vani sedimentary basin (CVSB) on Milos Island, Greece, displays banded rhythmicity similar to Precambrian banded iron formation (BIF). Sedimentary, stratigraphic reconstruction, biogeochemical analysis and micro-nanoscale mineralogical characterization confirms the Milos rocks as modern Precambrian BIF analogues. Spatial coverage of the BIF-type rocks in relation to the economic grade Mn ore that brought prominence to the CVSB implicates tectonic activity and changing redox in the deposition of the BIF-type rocks. Field-wide stratigraphic and biogeochemical reconstruction demonstrates two temporal and spatially isolated iron deposits in the CVSB with distinct sedimentological character. Petrographic screening suggest the previously described photoferrotrophic-like microfossil-rich IF (MFIF), accumulated on basement andesite in a ~ 150 m wide basin, in the SW margin of the basin. A strongly banded non-fossiliferous IF (NFIF) caps the Mn-rich sandstones at the transition to the renowned Mn-rich formation. Geochemical evidence relates the origin of the NFIF to periodic submarine volcanism and water column oxidation of released Fe(II) in conditions apparently predominated by anoxia, similar to the MFIF. This is manifested in the lack of shale-normalized Ce anomalies. Raman spectroscopy pairs hematite-rich grains in the NFIF with relics of a carbonaceous material carrying an average δ13Corg signature of ~ −25 ‰. However, a similar δ13Corg signature in the MFIF is not directly coupled to hematite by mineralogy. The NFIF, which post dates large-scale Mn deposition in the CVSB, is composed primarily of amorphous Si (opal-SiO2 · nH2O) while crystalline quartz (SiO2) predominates the MFIF. An intricate interaction between tectonic processes, changing redox, biological activity and abiotic Si precipitation, formed the unmetamorphosed BIF-type deposits

    Investigation of frontal lobe activation with fNIRS and systemic changes during video gaming.

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    Frontal lobe activation caused by tasks such as videogames can be investigated using multichannel near-infrared spectroscopy (fNIRS), sometimes called optical topography. The aims of this study are to investigate the effects of video gaming (fighting and puzzle games) in the brain and the systemic physiology and to determine whether systemic responses during the gaming task are associated with the measurement of localised cerebral haemodynamic changes as measured by fNIRS. We used a continuous-wave 8-channel fNIRS system to measure the changes in concentration of oxy-haemoglobin (HbO2) and deoxy-haemoglobin (HHb) and changes in total haemoglobin (ΔtHb = ΔHbO2 + ΔHHb) over the frontal lobe in 30 healthy volunteers. The Portapres system was used to measure mean blood pressure (MBP) and heart rate (HR), and a laser Doppler was employed to measure the changes in scalp blood flow (or flux). Even though we observed significant changes in systemic variables during gaming, in particular in scalp flow, we also managed to see localised activation patterns over the frontal polar (FP1) region. However, in some channels over the frontal lobe, we also observed significant correlations between the HbO2 and systemic variables

    The Swedish challenge – interdisciplinarity, collaboration and integration for research and development in organic farming

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    Organic farming is an example of the integration of non-monetary valued goals (as for example environmental concerns and animal welfare) in a market driven production. The main tool is the use of certification of the production. In this perspective organic farming becomes an interesting model for the entire food system. Current fast structural changes in Swedish agricultural primary production with decreasing numbers of farmers and an increasing size of farms on the one hand and increasing market competition and decreasing food prices on the other hand are well known realities. Reports on the decreasing capacity of the global ecosystems to generate non-monetary valued life supporting ecosystem services also emphasize the role of agriculture to fulfil these functions (Millennium Assessment, 2005). Multifunctional agriculture, making use of ecosystem services for biomass production, collective utilities and new workplaces, is highlighted. In order to play an important role on these issues, the sustainable development of organic farming requires research covering a wide scope of aspects, from environmental issues in the farm and food production system to questions about ethics, precaution and feedback at different levels. Knowledge from different disciplines, areas and perspectives need to be integrated. Scarce resources for research and development, along with the historical development of organic farming (to a substantial part based on experiential learning and knowledge) highlight the importance of relevance and validity in organic research

    Why are thoracic operations postponed?

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    <p>Abstract</p> <p>Aim</p> <p>To investigate and present the reasons that cause the postponement of thoracic surgical operations.</p> <p>Methods</p> <p>We retrospectively included in the study all patients submitted to elective thoracic surgery in our department during the 4-year period 2007-2010 and noted all cases of postponement after official inclusion in the operating schedule.</p> <p>Results</p> <p>81 out of a total of 542 patients (14.9%) scheduled for elective thoracic operation had their procedure postponed. The reasons were mainly organisatory (in 42 cases, 51.85%), which in order of significance were: shortage in matching erythrocyte units, shortage in anaesthetic/nursing staff and unavailability in operating rooms. The rest of the cases (39, 48.1%) were postponed due to medical reasons, which in descending order of significance were: respiratory infections and exacerbations of COPD, cardiological problems, misregulation of antiplatelet/antithrombotic drugs and infections from other systems (gastrointestinal, urinary, etc.). Elderly male patients planned for major/oncologic surgery were most possible to have their operation postponed for medical reasons.</p> <p>Discussion-Conclusions</p> <p>Thoracic operations are postponed owed to organisatory as well as medical reasons, the latter mainly affecting elderly, morbid patients awaiting for major/oncologic surgery.</p

    Feasibility, reliability and validity of the health-related quality of life instrument Child Health Utility 9D (CHU9D) among school-aged children and adolescents in Sweden

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    Background This study was conducted in a general population of schoolchildren in Sweden, with the aim to assess the psychometric properties of a generic preference-based health related quality of life (HRQoL) instrument, the Swedish Child Health Utility 9D (CHU9D), among schoolchildren aged 7–15 years, and in subgroups aged 7–9, 10–12 and 13–15 years. Methods In total, 486 school aged children, aged 7–15 years, completed a questionnaire including the CHU9D, the Pediatric quality of life inventory 4.0 (PedsQL), KIDSCREEN-10, questions on general health, long-term illness, and sociodemographic characteristics. Psychometric testing was undertaken of feasibility, internal consistency reliability, test–retest reliability, construct validity, factorial validity, concurrent validity, convergent validity and divergent validity. Results The CHU9D evidenced very few missing values, minimal ceiling, and no floor effects. The instrument achieved satisfactory internal consistency (Cronbach’s Alfa > 0.7) and strong test–retest reliability (r > 0.6). Confirmatory factor analyses supported the proposed one-factor structure of the CHU9D. For child algorithm, RMSEA = 0.05, CFI = 0.95, TLI = 0.94, and SRMR = 0.04. For adult algorithm RMSEA = 0.04, CFI = 0.96, TLI = 0.95, and SRMR = 0.04. The CHU9D utility value correlated moderately or strongly with KIDSCREEN-10 and PedsQL total scores (r > 0.5–0.7). The CHU9D discriminated as anticipated on health and on three of five sociodemographic characteristics (sex, age, and custody arrangement, but not socioeconomic status and ethnic origin). Conclusions This study provides evidence that the Swedish CHU9D is a feasible, reliable and valid measure of preference-based HRQoL in children. The study furthermore suggests that the CHU9D is appropriate for use among children 7–15 years of age in the general population, as well as among subgroups aged 7– 9, 10–12 and 13–15 years

    Characterization of electrochemical systems using potential step voltammetry. Part II: Modeling of reversible systems

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    [EN] This study was carried out to compare the results obtained using potential step voltammetry and linear sweep voltammetry with a rotating gold disc electrode (RDE), when models based on equivalent circuits (EC) were used. The results lead to an equivalent circuit model that allows us to interpret the electrochemical behavior of aqueous solutions containing Fe(CN)(6)(-4) and Fe(CN)(6)(-3). With this model, we determined the values of the electrical resistance of the medium (R-s) as well as its polarization resistance (R-p), and established correlations between these values and the kinetic parameters of the system. The proposal highlights the need to introduce a new component for modeling using EC, which we have called the electrochemical diode. (C) 2019 Elsevier Ltd. All rights reserved.The authors gratefully acknowledge the financial support of BIA2016-78460-C3-3-R, MAT2015-64139-C4-3-R and RTI2018-100910-B-C43 (MINECO/FEDER) projects. We would also like to extend our appreciation for the pre-doctoral FPU scholarships (University Teacher Training scholarship) granted to Ana Martinez Ibernon (FPU 16/00723) and Jose Enrique Ramon Zamora (FPU13/00911) by the Spanish Ministry of Science and Innovation.Martínez-Ibernón, A.; Ramón Zamora, JE.; Gandía-Romero, JM.; Gasch, I.; Valcuende Payá, MO.; Alcañiz Fillol, M.; Soto Camino, J. (2019). Characterization of electrochemical systems using potential step voltammetry. Part II: Modeling of reversible systems. Electrochimica Acta. 328:1-10. https://doi.org/10.1016/j.electacta.2019.135111S11032

    The breakdown of the municipality as caring platform: lessons for co-design and co-learning in the age of platform capitalism

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    If municipalities were the caring platforms of the 19-20th century sharing economy, how does care manifest in civic structures of the current period? We consider how platforms - from the local initiatives of communities transforming neighbourhoods, to the city, in the form of the local authority - are involved, trusted and/or relied on in the design of shared services and amenities for the public good. We use contrasting cases of interaction between local government and civil society organisations in Sweden and the UK to explore trends in public service provision. We look at how care can manifest between state and citizens and at the roles that co-design and co-learning play in developing contextually sensitive opportunities for caring platforms. In this way, we seek to learn from platforms in transition about the importance of co-learning in political and structural contexts and make recommendations for the co-design of (digital) platforms to care with and for civil society

    New Rare Earth Element Abundance Distributions for the Sun and Five r-Process-Rich Very Metal-Poor Stars

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    We have derived new abundances of the rare-earth elements Pr, Dy, Tm, Yb, and Lu for the solar photosphere and for five very metal-poor, neutron-capture r-process-rich giant stars. The photospheric values for all five elements are in good agreement with meteoritic abundances. For the low metallicity sample, these abundances have been combined with new Ce abundances from a companion paper, and reconsideration of a few other elements in individual stars, to produce internally-consistent Ba, rare-earth, and Hf (56<= Z <= 72) element distributions. These have been used in a critical comparison between stellar and solar r-process abundance mixes.Comment: 48 pages, 11 figures, 12 tables: To appear in the Astrophysical Journal Supplemen

    Paediatric obsessive-compulsive disorder and depressive symptoms: clinical correlates and CBT treatment outcomes.

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    Depression frequently co-occurs with paediatric obsessive-compulsive disorder (OCD), yet the clinical correlates and impact of depression on CBT outcomes remain unclear. The prevalence and clinical correlates of depression were examined in a paediatric specialist OCD-clinic sample (N = 295; Mean = 15 [7 - 18] years, 42 % female), using both dimensional (Beck Depression Inventory-youth; n = 261) and diagnostic (Development and Wellbeing Assessment; n = 127) measures of depression. The impact of depressive symptoms and suspected disorders on post-treatment OCD severity was examined in a sub-sample who received CBT, with or without SSRI medication (N = 100). Fifty-one per-cent of patients reported moderately or extremely elevated depressive symptoms and 26 % (95 % CI: 18 - 34) met criteria for a suspected depressive disorder. Depressive symptoms and depressive disorders were associated with worse OCD symptom severity and global functioning prior to CBT. Individuals with depression were more likely to be female, have had a psychiatric inpatient admission and less likely to be attending school (ps < 0.01). OCD and depressive symptom severity significantly decreased after CBT. Depressive symptoms and depressive disorders predicted worse post-treatment OCD severity (βs = 0.19 and 0.26, ps < 0.05) but became non-significant when controlling for pre-treatment OCD severity (βs = 0.05 and 0.13, ns). Depression is common in paediatric OCD and is associated with more severe OCD and poorer functioning. However, depression severity decreases over the course of CBT for OCD and is not independently associated with worse outcomes, supporting the recommendation for treatment as usual in the presence of depressive symptoms
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