285 research outputs found

    Magnetic and spin waves studies in amorphous Gd 0.7 Y 0.3

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    In this paper, magnetic properties of amorphous Gd0.7 Y0.3 alloys have been studied using a linear dependence on H-1/2 of the saturation magnetization M(H); this dependence has been proved to be necessary for an adequate interpretation of magnetic behaviour of ferromagnetic amorphous compounds. Indeed, in a previous work, assuming a linear dependence on H-1 of M(H), magnetic parameters (magnetic moment, ”Gd , of Gd, mean exchange integral (J)) relevant to Gd0.7 Y0.3 have been undervalued. In the present work, these parameters, in addition to the stiffness constant, have been improved.In this paper, magnetic properties of amorphous Gd0.7 Y0.3 alloys have been studied using a linear dependence on H-1/2 of the saturation magnetization M(H); this dependence has been proved to be necessary for an adequate interpretation of magnetic behaviour of ferromagnetic amorphous compounds. Indeed, in a previous work, assuming a linear dependence on H-1 of M(H), magnetic parameters (magnetic moment, ”Gd , of Gd, mean exchange integral (J)) relevant to Gd0.7 Y0.3 have been undervalued. In the present work, these parameters, in addition to the stiffness constant, have been improved

    Random anisotropy studies in amorphous Fe80-x+x' Hox B20-x' alloys (0

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    In this paper, we have carried out a systematic study of the exchange and anisotropy effects on magnetic behavior of amorphous Fe80-x+x' Hox B20-x' (0<x<17; 0<x'<4) alloys. Primary analysis of magnetization data have led to the conclusion that the holmium magnetic structure is collinear. Exchange parameters, governing the magnetic ordering of our alloys, have been calculated from both mean field theory and high-field magnetization analyses. Study of the magnetization using the Chudnovsky's real space model has allowed us to determine the overall anisotropy constant, KL, from which we have determined, separately, the anisotropy energies for the iron and the holmium sublattices. Comparison of these two parameters to the exchange energies shows that the anisotropy to exchange ratio is small in these alloys.In this paper, we have carried out a systematic study of the exchange and anisotropy effects on magnetic behavior of amorphous Fe80-x+x' Hox B20-x' (0<x<17; 0<x'<4) alloys. Primary analysis of magnetization data have led to the conclusion that the holmium magnetic structure is collinear. Exchange parameters, governing the magnetic ordering of our alloys, have been calculated from both mean field theory and high-field magnetization analyses. Study of the magnetization using the Chudnovsky's real space model has allowed us to determine the overall anisotropy constant, KL, from which we have determined, separately, the anisotropy energies for the iron and the holmium sublattices. Comparison of these two parameters to the exchange energies shows that the anisotropy to exchange ratio is small in these alloys

    Meningeal carcinomatosis diagnosed during stroke evaluation in the emergency department

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    A 70-year-old female presented to the emergency department with a 3-day history of intermittent dysphasia and right facial droop. Computed tomography (CT) and magnetic resonance imaging (MRI) were obtained, and the patient was found to have meningeal carcinomatosis, also known as leptomeningeal metastases. Meningeal carcinomatosis is a rare metastatic complication of some solid tumors and hematopoietic neoplasms, and has a median survival rate of 2.4 months. The role of the emergency physician is to appropriately diagnose this condition, treat emergent side effects, provide symptomatic relief, and ensure multi-disciplinary management

    AYAs' online information and ehealth needs:A comparison with healthcare professionals' perceptions

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    Background Adolescents and young adults (AYAs) diagnosed with cancer fulfill their cancer-related information needs often via the Internet. Healthcare professionals (HCPs) have a crucial role in guiding patients in finding appropriate online information and eHealth sources, a role that is often overlooked. Misperceptions of AYAs' needs by HCPs may lead to suboptimal guidance. We aimed to examine the extent to which AYAs' online information and eHealth needs corresponded with HCPs' perceptions of these needs. Methods Two cross-sectional online surveys (AYAs, n = 299; HCP, n = 80) on online information and eHealth needs were conducted. HCPs provided indications of their perceptions of AYA's needs. Results AYAs reported significantly more online information needs compared with HCPs' perceptions regarding: survival rates (AYA = 69%, HCP = 35%, p < 0.001), treatment guidelines (AYA = 65%, HCP = 41%, p < 0.001), return of cancer (AYA = 76%, HCP = 59%, p = 0.004), “what can I do myself” (AYA = 68%, HCP = 54%, p = 0.029), and metastases (AYA = 64%, HCP = 50%, p = 0.040). Significantly more unmet eHealth needs were reported by AYAs compared with HCPs relating to access to own test results (AYA = 25, HCP = 0%, p < 0.001), request tests (AYA = 30%, HCP = 7%, p < 0.001), medical information (AYA = 22%, HCP = 0%, p = 0.001), e-consult with nurses (AYA = 30%, HCP = 10%, p < 0.001), e-consult with physicians (AYA = 38%, HCP = 13%, p = 0.001), and request prescriptions (AYA = 33%, HCP = 21%, p = 0.009). Conclusion AYAs' online information and eHealth needs are partially discrepant with the impression HCPs have, which could result in insufficient guidance related to AYAs' needs. AYAs and HCPs should get guidance regarding where to find optimal information in a language they understand. This may contribute to AYAs' access, understanding, and satisfaction regarding online information and eHealth

    Fingerprinting blue carbon: Rationale and tools to determine the source of organic carbon in marine depositional environments

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    Blue carbon is the organic carbon in oceanic and coastal ecosystems that is captured on centennial to millennial timescales. Maintaining and increasing blue carbon is an integral component of strategies to mitigate global warming. Marine vegetated ecosystems (especially seagrass meadows, mangrove forests, and tidal marshes) are blue carbon hotspots and their degradation and loss worldwide have reduced organic carbon stocks and increased CO2 emissions. Carbon markets, and conservation and restoration schemes aimed at enhancing blue carbon sequestration and avoiding greenhouse gas emissions, will be aided by knowing the provenance and fate of blue carbon. We review and critique current methods and the potential of nascent methods to track the provenance and fate of organic carbon, including: bulk isotopes, compound-specific isotopes, biomarkers, molecular properties, and environmental DNA (eDNA). We find that most studies to date have used bulk isotopes to determine provenance, but this approach often cannot distinguish the contribution of different primary producers to organic carbon in depositional marine environments. Based on our assessment, we recommend application of multiple complementary methods. In particular, the use of carbon and nitrogen isotopes of lipids along with eDNA have a great potential to identify the source and quantify the contribution of different primary producers to sedimentary organic carbon in marine ecosystems. Despite the promising potential of these new techniques, further research is needed to validate them. This critical overview can inform future research to help underpin methodologies for the implementation of blue carbon focused climate change mitigation schemes

    Reconstructing the impact of human activities in a NW Iberian Roman mining landscape for the last 2500 years

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    This article was made available through the Brunel Open Access Publishing Fund.Little is known about the impact of human activities during Roman times on NW Iberian mining landscapes beyond the geomorphological transformations brought about by the use of hydraulic power for gold extraction. We present the high-resolution pollen record of La Molina mire, located in an area intensely used for gold mining (Asturias, NW Spain), combined with other proxy data from the same peat core to identify different human activities, evaluate the strategies followed for the management of the resources and describe the landscape response to human disturbances. We reconstructed the timing and synchronicity of landscape changes of varying intensity and form occurred before, during and after Roman times. An open landscape was prevalent during the local Late Iron Age, a period of relatively environmental stability. During the Early Roman Empire more significant vegetation shifts took place, reflected by changes in both forest (Corylus and Quercus) and heathland cover, as mining/metallurgy peaked and grazing and cultivation increased. In the Late Roman Empire, the influence of mining/metallurgy on landscape change started to disappear. This decoupling was further consolidated in the Germanic period (i.e., Visigothic and Sueve domination of the region), with a sharp decrease in mining/metallurgy but continued grazing. Although human impact was intense in some periods, mostly during the Early Roman Empire, forest regeneration occurred afterwards: clearances were local and short-lived. However, the Roman mining landscape turned into an agrarian one at the onset of the Middle Ages, characterized by a profound deforestation at a regional level due to a myriad of human activities that resulted in an irreversible openness of the landscape. © 2014 The Authors

    Evaluating the effects of multisystemic therapy for adolescents with intellectual disabilities and antisocial or delinquent behaviour and their parents

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    Background: An adaptation of multisystemic therapy (MST) was piloted to find out whether it would yield better outcomes than standard MST in families where the adolescent not only shows antisocial or delinquent behaviour, but also has an intel‐ lectual disability. Method: To establish the comparative effectiveness of MST‐ID (n = 55) versus stand‐ ard MST (n = 73), treatment outcomes were compared at the end of treatment and at 6‐month follow‐up. Pre‐treatment differences were controlled for using the propen‐ sity score method. Results: Multisystemic therapy‐ID resulted in reduced police contact and reduced rule breaking behaviour that lasted up to 6 months post‐treatment. Compared to standard MST, MST‐ID more frequently resulted in improvements in parenting skills, family relations, social support, involvement with pro‐social peers and sustained pos‐ itive behavioural changes. At follow‐up, more adolescents who had received MST‐ID were still living at home. Conclusions: These results support further development of and research into the MST‐ID adaptation

    The Effects of Ash and Black Carbon (Biochar) on Germination of Different Tree Species

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    Forest fires generate large amounts of ash and biochar, or black carbon (BC), that cover the soil surface, interacting with the soil’s constituents and its seedbank. This study concerns reproductive ecology assessments supported by molecular characterisation to improve our understanding of the effects of fire and fire residues on the germination behaviour of 12 arboreal species with a wide geographic distribution. For this purpose, we analysed the effects of three ash and one BC concentration on the germination of Acacia dealbata Link, A. longifolia (Andrews) Willd., A. mearnsii De Wild., A. melanoxylon R. Br., Pinus nigra Arnold, P. pinaster Aiton, P. radiata D. Don, P. sylvestris L., Quercus ilex L., Q. pyrenaica Willd., Q. robur L., and Q. rubra L. Each tree species was exposed to ash and BC created from its foliage or twigs (except for Q. rubra, which was exposed to ash and BC of Ulex europaeus L.). We monitored germination percentage, the T50 parameter, and tracked the development of germination over time (up to 1 yr). The BC of A. dealbata, P. pinaster, and Q. robur was analysed by pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS) to assess the molecular composition. In six species, ash inhibited the germination, while in another five species, germination was not affected by ash or by BC. In Q. rubra, ash and BC stimulated its germination. This stimulating effect of the BC on Q. rubra is likely to be related to the chemical composition of the ash and BC obtained from Ulex feedstock. The BC of U. europaeus has a very different molecular composition than the other BC samples analysed, which, together with other factors, probably allowed for its germination stimulating effects.This study was carried out within the Project 10MDS200007PR, financed by the Xunta de Galicia; the Project AGL2013-48189-C2-2-R, financed by the Ministerio de Economía y Competitividad, Spain; and FEDERS

    Biomass-modulated fire dynamics during the last glacial-interglacial transition at the central pyrenees (Spain)

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    Understanding long-term fire ecology is essential for current day interpretation of ecosystem fire responses. However palaeoecology of fire is still poorly understood, especially at high-altitude mountain environments, despite the fact that these are fire-sensitive ecosystems and their resilience might be affected by changing fire regimes. We reconstruct wildfire occurrence since the Lateglacial (14.7. cal. ka BP) to the Mid-Holocene (6. cal. ka BP) and investigate the climate-fuel-fire relationships in a sedimentary sequence located at the treeline in the Central Spanish Pyrenees. Pollen, macro- and micro-charcoal were analysed for the identification of fire events (FE) in order to detect vegetation post-fire response and to define biomass-fire interactions. mean fire intervals (mfi) reduced since the Lateglacial, peaking at 9-7.7. cal. ka BP while from 7.7 to 6. cal. ka BP no fire is recorded. We hypothesise that Early Holocene maximum summer insolation, as climate forcing, and mesophyte forest expansion, as a fuel-creating factor, were responsible for accelerating fire occurrence in the Central Pyrenees treeline. We also found that fire had long-lasting negative effects on most of the treeline plant communities and that forest contraction from 7.7. cal. ka BP is likely linked to the ecosystem's threshold response to high fire frequencies.This research has been funded by the projects DINAMO (CGL2009-07992) (funding EGPF — grant ref. BES-2010-038593 and MSC), DINAMO2 (CGL2012-33063), ARAFIRE (2012 GA LC 064), GRACCIE-CONSOLIDER (CSD2007-00067). GGR was funded by the Juan de la Cierva Program (grant ref. JCI2009-04345) and JAE-Doc CSIC Program, LLM was supported by a postdoctoral MINT fellowship funded by the Institute for the Environment (Brunel University), AMC is a Ramón y Cajal fellow (ref: RYC-2008-02431), APS holds a grant funded by the Aragon Government (ref. 17030G/5423/480072/14003) and JAE holds a grant funded by the Basque Country Government (BFI-2010-5)

    Adolescent and young adult (AYA) lymphoma survivors report lower health-related quality of life compared to a normative population: results from the PROFILES registry.

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    BackgroundTrying to simultaneously achieve developmental milestones and cope with a life-threatening disease may place adolescents and young adults (AYAs) at risk for impaired health-related quality of life (HRQoL) later in life. The aim of this study was to examine differences in HRQoL between AYA lymphoma survivors and a normative population and to determine sociodemographic, clinical and long-term symptom-related factors associated with HRQoL.Material and methodsThis study was part of a longitudinal, population-based survey among lymphoma survivors diagnosed between 1999 and 2012. The AYA survivor sample (18-39 years at time diagnosis) was compared to a sex- and age-matched normative population on HRQoL (EORTC-QLQ-C30) and psychological distress (HADS). Multiple linear regression analyses were conducted to determine factors associated with HRQoL among survivors.ResultsOne hundred and ninety-eight AYA lymphoma survivors (58%) responded to the study invitation. Compared to an age- and sex-matched normative population (N = 380), significantly and clinically relevant poorer HRQoL was observed for AYA lymphoma survivors in seven specific domains of HRQoL: physical, role, cognitive, emotional, social functioning, fatigue and financial difficulties (all p ConclusionsThese findings identify specific domains of life in which cancer has a significant and long-term impact for AYA lymphoma survivors. Future investigations are needed to identify and test administrations and timing of psychosocial support interventions having potential to reduce long-term late effects in specific HRQoL domains and promote function and adaptability after cancer treatment
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