3,876 research outputs found

    Postseismic deformation and body forces shaping the Apennines and adjacent sedimentary basins in Umbria-Marche

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    The geodynamic complexity of the Apennines and adjacent sedimentary basins in Umbria-Marche (North-Central Italy) makes the dynamics of the present day deformation and its relationships with the seismicity less well understood. In this paper, we argue that, further to buoyancy forces, postseismic deformation of earthquakes taking place on the Apennines contributes to the regional deformation. We investigate the interaction between the normal faulting system responsible of the 1997 Umbria-Marche earthquake sequence (Colfiorito fault) and the low angle normal faulting system bordering the sedimentary basins, namely the Altotiberina fault. We set-up a 2D finite element model of the lithosphere-asthenosphere accounting for lateral heterogeneities and investigate how this heterogeneous structure is capable of localizing strain under the Umbria-Marche sedimentary basins, providing a way for the Colfiorito fault to influence the evolution of the Altotiberina fault. We show how the two different length and time scale processes, namely postseismic deformation and buoyancy, are complementary in shaping the Apennines and adjacent sedimentary basins. The high resolution deformation patterns modeled in this study can hardly be reproduced by a model accounting only for external forces such as a rotating or subducting or retreating Adria

    Polysaccharide Layer-by-Layer Coating for Polyimide-Based Neural Interfaces

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    Implantable flexible neural interfaces (IfNIs) are capable of directly modulating signals of the central and peripheral nervous system by stimulating or recording the action potential. Despite outstanding results in acute experiments on animals and humans, their long-term biocompatibility is hampered by the effects of foreign body reactions that worsen electrical performance and cause tissue damage. We report on the fabrication of a polysaccharide nanostructured thin film as a coating of polyimide (PI)-based IfNIs. The layer-by-layer technique was used to coat the PI surface due to its versatility and ease of manufacturing. Two different LbL deposition techniques were tested and compared: dip coating and spin coating. Morphological and physiochemical characterization showed the presence of a very smooth and nanostructured thin film coating on the PI surface that remarkably enhanced surface hydrophilicity with respect to the bare PI surface for both the deposition techniques. However, spin coating offered more control over the fabrication properties, with the possibility to tune the coating’s physiochemical and morphological properties. Overall, the proposed coating strategies allowed the deposition of a biocompatible nanostructured film onto the PI surface and could represent a valid tool to enhance long-term IfNI biocompatibility by improving tissue/electrode integration

    Notas sobre los artropodos que viven en el pijuayo (Bactris gasipaes H.B.K. : Palmae) en la Amazonia peruana

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    The peachpalm, #Bactris gasipaes$ H.B.K. is cultivated in the Amazon basin and in Central America for its fruits and for the production of heart palm. Several insects and mites attack it. Some observations in Peruvian Amazonia on those pests and other associated insects are reported. Some species are new for Peru. (Résumé d'auteur

    Frequency Dynamics in Fully Non-Synchronous Electrical Grids: A Case Study of an Existing Island

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    The operation of a power system with 100% converter-interfaced generation poses several questions and challenges regarding various aspects of the design and the control of the system. Existing literature on the integration of renewable energy sources in isolated systems mainly focuses on energy aspects or steady-state issues, and only a few studies examine the dynamic issues of autonomous networks operated with fully non-synchronous generation. A lack of research can be found in particular in the determination of the required amount of grid-forming power, the selection of the number and rated power of the units which should implement the grid-forming controls, and the relative locations of the grid-forming converters. The paper aims to address those research gaps starting from a theoretical point of view and then by examining the actual electrical network of an existing island as a case study. The results obtained from the investigations indicate specific observations and design opportunities, which are essential for securing the synchronization and the stability of the grid. Possible solutions for a fully non-synchronous operation of autonomous systems, in terms of dynamic characteristics and frequency stability, are presented and discussed

    Chronic mild stress-induced alterations of clock gene expression in rat prefrontal cortex: modulatory effects of prolonged lurasidone treatment

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    Disruptions of biological rhythms are known to be associated with depressive disorders, suggesting that abnormalities in the molecular clock may contribute to the development of these disorders. These mechanisms have been extensively characterized in the suprachiasmatic nucleus, but little is know about the role exerted by individual clock genes in brain structures that are important for depressive disorders. Using the chronic mild stress model we found a significant reduction of BMAL1 and CLOCK protein levels in the nuclear compartment of the prefrontal cortex of CMS rats, which was paralleled by a down-regulation of the expression of several target genes, including Pers and Crys but also Reverb\u3b2 and Ppar\u3b1. Interestingly, chronic treatment with the multi receptor modulator lurasidone (3 mg/kg for 5 weeks) was able to normalize the molecular changes induced by CMS exposure in prefrontal cortex, but it was also able to regulate some of these genes within the hippocampus. We believe that changes in clock genes expression after CMS exposure may contribute to the disturbances associated with depressive disorders and that the ability of chronic lurasidone to normalize such alterations may be relevant for its therapeutic properties in ameliorating functions that are deteriorated in patients with major depression and other stress-related disorders

    Electrochemical nanolithography on silicon: An easy and scalable method to control pore formation at the nanoscale

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    Lithography on a sub-100 nm scale is beyond the diffraction limits of standard optical lithography but is nonetheless a key step in many modern technological applications. At this length scale, there are several possible approaches that require either the preliminary surface deposition of materials or the use of expensive and time-consuming techniques. In our approach, we demonstrate a simple process, easily scalable to large surfaces, where the surface patterning that controls pore formation on highly doped silicon wafers is obtained by an electrochemical process. This method joins the advantages of the low cost of an electrochemical approach with its immediate scalability to large wafers

    Root Bacteria Recruited by Phragmites australis in Constructed Wetlands Have the Potential to Enhance Azo-Dye Phytodepuration

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    The microbiome associated with plants used in phytodepuration systems can boost plant growth and services, especially in ecosystems dealing with recalcitrant compounds, hardly removed via traditional wastewater (WW) treatments, such as azo-dyes used in textile industry. In this context, we aimed to study the cultivable microbiome selected by Phragmites australis plants in a Constructed Wetland (CW) in Morocco, in order to obtain candidate inoculants for the phytodepuration of azo-dye contaminated WW. A collection of 152 rhizospheric and endophytic bacteria was established. The strains were phylogenetically identified and characterized for traits of interest in the phytodepuration context. All strains showed Plant Growth Promotion potential in vitro and 67% of them significantly improved the growth of a model plant in vivo compared to the non bacterized control plants. Moreover, most of the isolates were able to grow in presence of several model micropollutants typically found in WW, indicating their potential use in phytodepuration of a wide spectrum of effluents. The six most promising strains of the collection were tested in CW microcosms alone or as consortium: the consortium and two single inocula demonstrated to significantly increase the removal of the model azo-dye Reactive Black 5 compared to the non bacterized controls

    Comparison and interpretation of impressed marks left by a firearm on cartridge cases - Towards an operational implementation of a likelihood ratio based technique.

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    Firearm examination is subject to increased scrutiny regarding its foundational validity and inherent subjective nature. The increased use of automatic comparison systems may help to reduce subjectivity. In this paper, we present the performance and limits of an automatic comparison system that assigns a weight to the forensic findings for the comparisons between firing pin marks, breechface marks, or a combination of the two. This weight is expressed by a likelihood ratio (LR) based on 3D topographical measurements coupled with a bi-dimensional statistical model. As the performance of such systems may depend on the reference databases used to inform the model, we investigated the impact of the brand of ammunition and the number of samples. We show that reference databases used to calculate LRs should ideally consist of the same type of ammunition as is seen in the case under investigation and that 7 specimens fired by the same firearm are enough to obtain rates of misleading evidence of a similar magnitude compared to those obtained when far more specimens (60) are used. Additionally, the automatic system was used to assess the outcomes of 7 cases with known same-source or different-source ground truths. These cases were also examined by 8 qualified firearm examiners. In all cases, the experts' appraisals were in line with the ground truth. The automatic system showed some limitations in cases were the data were not sufficient to calculate a robust LR, but also that it can assist and enhance the examiners in their decision process
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