567 research outputs found

    Biochar reduces the efficiency of nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) mitigating N2O emissions

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    Among strategies suggested to decrease agricultural soil N2O losses, the use of nitrification inhibitors such as DMPP (3,4-dimethylpyrazole phosphate) has been proposed. However, the efficiency of DMPP might be affected by soil amendments, such as biochar, which has been shown to reduce N2O emissions. This study evaluated the synergic effect of a woody biochar applied with DMPP on soil N2O emissions. A incubation study was conducted with a silt loam soil and a biochar obtained from Pinus taeda at 500 degrees C. Two biochar rates (0 and 2% (w/w)) and three different nitrogen treatments (unfertilized, fertilized and fertilized + DMPP) were assayed under two contrasting soil water content levels (40% and 80% of water filled pore space (WFPS)) over a 163 day incubation period. Results showed that DMPP reduced N2O emissions by reducing ammonia-oxidizing bacteria (AOB) populations and promoting the last step of denitrification (measured by the ratio nosZI + nosZII/nirS + nirK genes). Biochar mitigated N2O emissions only at 40% WFPS due to a reduction in AOB population. However, when DMPP was applied to the biochar amended soil, a counteracting effect was observed, since the N2O mitigation induced by DMPP was lower than in control soil, demonstrating that this biochar diminishes the efficiency of the DMPP both at low and high soil water contents.This work was funded by the Spanish Government (AGL2015-64582-C3-2-R MINECO/FEDER), by the Basque Government (IT-932-16) and by the European Union (FACCE-CSA no 276610/MIT04-DESIGN-UPVASC, FACCE-CSA no 2814ERA01A and 2814ERA02A). This work is also supported by the USDA/NIFA Interagency Climate Change Grant Proposal number 2014-02114 [Project number 6657-12130-002-08I, Accession number 1003011] under the Multi-Partner Call on Agricultural Greenhouse Gas Research of the FACCE-Joint Program Initiative. Any opinions, findings, or recommendation expressed in this publication are those of the authors and do not necessarily reflect the view of the USDA. MLC was supported by a Ramon y Cajal contract from the Spanish Ministry of Economy and Competitiveness and thanks Fundacion Seneca for financing the project 19281/PI/14

    Opinion dynamics: models, extensions and external effects

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    Recently, social phenomena have received a lot of attention not only from social scientists, but also from physicists, mathematicians and computer scientists, in the emerging interdisciplinary field of complex system science. Opinion dynamics is one of the processes studied, since opinions are the drivers of human behaviour, and play a crucial role in many global challenges that our complex world and societies are facing: global financial crises, global pandemics, growth of cities, urbanisation and migration patterns, and last but not least important, climate change and environmental sustainability and protection. Opinion formation is a complex process affected by the interplay of different elements, including the individual predisposition, the influence of positive and negative peer interaction (social networks playing a crucial role in this respect), the information each individual is exposed to, and many others. Several models inspired from those in use in physics have been developed to encompass many of these elements, and to allow for the identification of the mechanisms involved in the opinion formation process and the understanding of their role, with the practical aim of simulating opinion formation and spreading under various conditions. These modelling schemes range from binary simple models such as the voter model, to multi-dimensional continuous approaches. Here, we provide a review of recent methods, focusing on models employing both peer interaction and external information, and emphasising the role that less studied mechanisms, such as disagreement, has in driving the opinion dynamics. [...]Comment: 42 pages, 6 figure

    Exploration of cannabis use and polygenic risk scores on the psychotic symptom progression of a FEP cohort

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    Cannabis use is highly prevalent in first-episode psychosis (FEP) and plays a critical role in its onset and prognosis, but the genetic underpinnings promoting both conditions are poorly understood. Current treatment strategies for cannabis cessation in FEP are clearly inefficacious. Here, we aimed to characterize the association between cannabis-related polygenic risk scores (PRS) on cannabis use and clinical course after a FEP. A cohort of 249 FEP individuals were evaluated during 12 months. Symptom severity was measured with the Positive and Negative Severity Scale and cannabis use with the EuropASI scale. Individual PRS for lifetime cannabis initiation (PRSCI) and cannabis use disorder (PRSCUD) were constructed. Current cannabis use was associated with increased positive symptoms. Cannabis initiation at younger ages conditioned the 12-month symptom progression. FEP patients with higher cannabis PRSCUD reported increased baseline cannabis use. PRSCI was associated with the course of negative and general symptomatology over follow-up. Cannabis use and symptom progression after a FEP were modulated by cannabis PRS, suggesting that lifetime initiation and use disorders may have partially independent genetic factors. These exploratory results may be the first step to identify those FEP patients more vulnerable to cannabis use and worse outcomes to ultimately develop tailored treatments

    A method to design job rotation schedules to prevent work-related musculoskeletal disorders in repetitive work

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    This is an Accepted Manuscript of an article published by Taylor & Francis Group in International Journal of Production Research in 2012, available online: http://www.tandfonline.com/10.1080/00207543.2011.653452.Job rotation is an organisational strategy widely used in human-based production lines with the aim of preventing work-related musculoskeletal disorders (WMSDs). These work environments are characterised by the presence of a high repetition of movements, which is a major risk factor associated with WMSDs. This article presents a genetic algorithm to obtain rotation schedules aimed at preventing WMSDs in such environments. To do this, it combines the effectiveness of genetic algorithms optimisation with the ability to evaluate the presence of risk by repeated movements by following the OCRA ergonomic assessment method. The proposed algorithm can design solutions in which workers will switch jobs with high repeatability of movements with other less demanding jobs that support their recovery. In addition, these solutions are able to diversify the tasks performed by workers during the day, consider their disabilities and comply with restrictions arising from the work organisation.The authors wish to thank the Universitat Politecnica de Valencia which supported this research through its Program for the Support of Research and Development 2009 and its financing through the project PAID-06-09/2902.Asensio Cuesta, S.; Diego-Mas, JA.; Cremades Oliver, L.; González-Cruz, M. (2012). A method to design job rotation schedules to prevent work-related musculoskeletal disorders in repetitive work. International Journal of Production Research. 50(24):7467-7478. https://doi.org/10.1080/00207543.2011.653452S74677478502

    Application of Quality by Design to the robust preparation of a liposomal GLA formulation by DELOS-susp method

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    Fabry disease is a lysosomal storage disease arising from a deficiency of the enzyme α-galactosidase A (GLA). The enzyme deficiency results in an accumulation of glycolipids, which over time, leads to cardiovascular, cerebrovascular, and renal disease, ultimately leading to death in the fourth or fifth decade of life. Currently, lysosomal storage disorders are treated by enzyme replacement therapy (ERT) through the direct administration of the missing enzyme to the patients. In view of their advantages as drug delivery systems, liposomes are increasingly being researched and utilized in the pharmaceutical, food and cosmetic industries, but one of the main barriers to market is their scalability. Depressurization of an Expanded Liquid Organic Solution into aqueous solution (DELOS-susp) is a compressed fluid-based method that allows the reproducible and scalable production of nanovesicular systems with remarkable physicochemical characteristics, in terms of homogeneity, morphology, and particle size. The objective of this work was to optimize and reach a suitable formulation for in vivo preclinical studies by implementing a Quality by Design (QbD) approach, a methodology recommended by the FDA and the EMA to develop robust drug manufacturing and control methods, to the preparation of α-galactosidase-loaded nanoliposomes (nanoGLA) for the treatment of Fabry disease. Through a risk analysis and a Design of Experiments (DoE), we obtained the Design Space in which GLA concentration and lipid concentration were found as critical parameters for achieving a stable nanoformulation. This Design Space allowed the optimization of the process to produce a nanoformulation suitable for in vivo preclinical testing

    Neutral Bremsstrahlung Emission in Xenon Unveiled

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    [EN] We present evidence of non-excimer-based secondary scintillation in gaseous xenon, obtained using both the NEXT-White time projection chamber (TPC) and a dedicated setup. Detailed comparison with first-principle calculations allows us to assign this scintillation mechanism to neutral bremsstrahlung (NBrS), a process that is postulated to exist in xenon that has been largely overlooked.The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under Advanced Grant No. 339787-NEXT; the European Unions Framework Program for Research and Innovation Horizon 2020 (20142020) under Grant Agreements No. 674896, No. 690575, and No. 740055; the Ministerio de Economa y Competitividad and the Ministerio de Ciencia, Innovacin y Universidades of Spain under Grants No. FIS2014-53371-C04 and No. RTI2018-095979, the Severo Ochoa Program Grants No. SEV-2014-0398 and No. CEX2018-000867-S, and the Mara de Maeztu Program MDM-2016-0692; the Generalitat Valenciana under Grants No. PROMETEO/2016/120 and No. SEJI/2017/011; the Portuguese FCT under Project No. PTDC/FIS-NUC/3933/2021 and under Project No. UIDP/04559/2020 to fund the activities of LIBPhys-UC; the U.S. Department of Energy under Contracts No. DE-AC02-06CH11357 (Argonne National Laboratory), No. DE-AC02-07CH11359 (Fermi National Accelerator Laboratory), No. DE-FG02-13ER42020 (Texas A&M), and No. DE-SC0019223/DE-SC0019054 (University of Texas at Arlington); and the University of Texas at Arlington (USA). D. G.-D. acknowledges Ramon y Cajal program (Spain) under Contract No. RYC- 2015-18820. J. M.-A. acknowledges support from Fundacin Bancaria la Caixa (ID 100010434), Grant No. LCF/BQ/PI19/11690012. We would like to thank Lorenzo Muniz for insightful discussions on the subtleties of electron transport in gases.Henriques, C.; Amedo, P.; Teixeira, JMR.; González-Díaz, D.; Azevedo, C.; Para, A.; Martín-Albo, J.... (2022). Neutral Bremsstrahlung Emission in Xenon Unveiled. Physical Review X. 12(2):021005-1-021028-23. https://doi.org/10.1103/PhysRevX.12.021005021005-1021028-2312

    A new view of electrochemistry at highly oriented pyrolytic graphite

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    Major new insights on electrochemical processes at graphite electrodes are reported, following extensive investigations of two of the most studied redox couples, Fe(CN)64–/3– and Ru(NH3)63+/2+. Experiments have been carried out on five different grades of highly oriented pyrolytic graphite (HOPG) that vary in step-edge height and surface coverage. Significantly, the same electrochemical characteristic is observed on all surfaces, independent of surface quality: initial cyclic voltammetry (CV) is close to reversible on freshly cleaved surfaces (>400 measurements for Fe(CN)64–/3– and >100 for Ru(NH3)63+/2+), in marked contrast to previous studies that have found very slow electron transfer (ET) kinetics, with an interpretation that ET only occurs at step edges. Significantly, high spatial resolution electrochemical imaging with scanning electrochemical cell microscopy, on the highest quality mechanically cleaved HOPG, demonstrates definitively that the pristine basal surface supports fast ET, and that ET is not confined to step edges. However, the history of the HOPG surface strongly influences the electrochemical behavior. Thus, Fe(CN)64–/3– shows markedly diminished ET kinetics with either extended exposure of the HOPG surface to the ambient environment or repeated CV measurements. In situ atomic force microscopy (AFM) reveals that the deterioration in apparent ET kinetics is coupled with the deposition of material on the HOPG electrode, while conducting-AFM highlights that, after cleaving, the local surface conductivity of HOPG deteriorates significantly with time. These observations and new insights are not only important for graphite, but have significant implications for electrochemistry at related carbon materials such as graphene and carbon nanotubes
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