488 research outputs found

    Energy Comparison between a Load Sensing System and Electro-Hydraulic Solutions Applied to a 9-Ton Excavator

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    With the increasingly stringent regulations on air quality and the consequent emission limits for internal combustion engines, researchers are concentrating on studying new solutions for improving efficiency and energy saving even in off-road mobile machines. To achieve this task, pump-controlled or displacement-controlled systems have inspired interest for applications in offroad working machines. Generally, these systems are derived from the union of a hydraulic machine coupled to an electric one to create compact components that could be installed near the actuator. The object of study of this work is a 9-ton excavator, whose hydraulic circuit is grounded on load sensing logic. The validated mathematical model, created previously in the Simcenter Amesim© environment, represents the starting point for developing electro-hydraulic solutions. Electric components have been inserted to create different architectures, both with open-and closed-circuit layouts, in order to compare the energy efficiency of the different configurations with respect to the traditional load sensing system. The simulations of a typical working cycle show the energy benefits of electrohydraulic solutions that allow for drastically reducing the mechanical energy required by the diesel engine and, consequently, the fuel consumption. This is mainly possible because of the elimination of directional valves and pressure compensators, which are necessary in a load sensing circuit, but are also a source of great energy dissipations. The results show that closed-circuit solutions produce the greatest benefits, with higher energy efficiencies than the open-circuit solution. Furthermore, closed-circuit configurations require fewer components, allowing for more compact and lighter solutions, as well as being cheaper

    Beyond the TV borders: Second screen as a tool for audience engagement

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    The growing popularity of mobile connected devices has transformed the way TV content is conceived and consumed. Interacting with these devices while watching TV is a trending behaviour that represents a challenge for the TV industry as this interaction often distracts viewers from the TV content. Consumers use the second screen to retrieve further information about narratives, characters, purchasing goods and researching on products and services advertised. In a scenario of systematic live and linear TV audience erosion and ad-skipping broadcasters, marketers and producers are continuously looking for new ways to leverage different media strategies to keep TV viewers engaged with the primary content, promoting consumers’ loyalty and generating more revenue flows. In this paper, a set of second screen cases was selected to ground a reflection on how second screen solutions may be applied to foster the viewer and consumer engagement

    Extraordinary sensitivity of the electronic structure and properties of single-walled carbon nanotubes to molecular charge-transfer

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    Interaction of single-walled carbon nanotubes with electron donor and acceptor molecules causes significant changes in the electronic and Raman spectra, the relative proportion of the metallic species increasing on electron donation through molecular charge transfer, as also verified by electrical resistivity measurements.Comment: 15 pages, 5 figurre

    Physical descriptions of the bacterial nucleoid at large scales, and their biological implications.

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    Recent experimental and theoretical approaches have attempted to quantify the physical organization (compaction and geometry) of the bacterial chromosome with its complement of proteins (the nucleoid). The genomic DNA exists in a complex and dynamic protein-rich state, which is highly organized at various length scales. This has implications for modulating (when not directly enabling) the core biological processes of replication, transcription and segregation. We overview the progress in this area, driven in the last few years by new scientific ideas and new interdisciplinary experimental techniques, ranging from high space- and time-resolution microscopy to high-throughput genomics employing sequencing to map different aspects of the nucleoid-related interactome. The aim of this review is to present the wide spectrum of experimental and theoretical findings coherently, from a physics viewpoint. In particular, we highlight the role that statistical and soft condensed matter physics play in describing this system of fundamental biological importance, specifically reviewing classic and more modern tools from the theory of polymers. We also discuss some attempts toward unifying interpretations of the current results, pointing to possible directions for future investigation

    Insights into an unexplored component of the mosquito repeatome: Distribution and variability of viral sequences integrated into the genome of the arboviral vector aedes albopictus

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    The Asian tiger mosquito Aedes albopictus is an invasive mosquito and a competent vector for public-health relevant arboviruses such as Chikungunya (Alphavirus), Dengue and Zika (Flavivirus) viruses. Unexpectedly, the sequencing of the genome of this mosquito revealed an unusually high number of integrated sequences with similarities to non-retroviral RNA viruses of the Flavivirus and Rhabdovirus genera. These Non-retroviral Integrated RNA Virus Sequences (NIRVS) are enriched in piRNA clusters and coding sequences and have been proposed to constitute novel mosquito immune factors. However, given the abundance of NIRVS and their variable viral origin, their relative biological roles remain unexplored. Here we used an analytical approach that intersects computational, evolutionary and molecular methods to study the genomic landscape of mosquito NIRVS. We demonstrate that NIRVS are differentially distributed across mosquito genomes, with a core set of seemingly the oldest integrations with similarity to Rhabdoviruses. Additionally, we compare the polymorphisms of NIRVS with respect to that of fast and slow-evolving genes within the Ae. albopictus genome. Overall, NIRVS appear to be less polymorphic than slow-evolving genes, with differences depending on whether they occur in intergenic regions or in piRNA clusters. Finally, two NIRVS that map within the coding sequences of genes annotated as Rhabdovirus RNA-dependent RNA polymerase and the nucleocapsid-encoding gene, respectively, are highly polymorphic and are expressed, suggesting exaptation possibly to enhance the mosquito's antiviral responses. These results greatly advance our understanding of the complexity of the mosquito repeatome and the biology of viral integrations in mosquito genomes

    A qPCR targeted against the viral replication origin designed to quantify total amount of filamentous phages and phagemids

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    Filamentous bacteriophages are widely used in phage display technology. The most common quantification method is lysis plaque formation test (PFT). This technique has several disadvantages, and only quantifies infective phages and is not effective when phagemids are used. We developed a qPCR method directed against the M13 replication origin, which detects between 3.3 9 103 and 3.3 9 108 viral genome copies with a linearity of R2 = 0.9998. Using this method we were able to observe a difference of approximately ten more phages than with the PFT. This difference was not due to the presence of a free genome, which suggests the presence of non-infective particles. Using a DNaseI treatment, we observed the presence of 30% to 40% of unpackaged genome in recombinant phage modified in PIII or PVIII. The qPCR method with a DNase I treatment is an efficient method to quantify the total amount of filamentous phages.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

    A survey on features of allergic rhinitis in children

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    Objective: A number of epidemiologic studies evaluated the prevalence of allergic rhinitis (AR), but few data are available on its different clinical presentations. We addressed this survey to assess the features of AR in children and adolescents. Methods: Thirty-five centers in Italy included 2623 pediatric patients with rhinitis, of whom 2319 suffered from AR, while 304 had other kinds of rhinitis. For each patient a standardized questionnaire was filled in, including ARIA classification, the duration of symptoms, the allergen identified as clinically relevant, the co-morbidities, the kind of treatment, the response to treatment, the satisfaction with the treatment, and the feasibility of allergen immunotherapy (AIT). Results: Of the 2319 patients, 597 (25.7%) had mild intermittent, 701 (30.2%) mild persistent, 174 (7.5%) moderate-severe intermittent, and 773 (33.3%) moderate-severe persistent AR. The allergens most relevant were grass pollen and dust mites. The most frequently used drugs were oral antihistamines (83.1%) and topical corticosteroids (63.5%). The response to treatment was judged as excellent in 13.5%, good in 45.1%, fair in 30.8%, poor in 10%, and very bad in 0.6% of cases. The satisfaction with treatment was judged as very satisfactory in 15.2%, satisfactory in 61.8%, unsatisfactory in 22.4%, and very unsatisfactory in 0.5% of cases. AIT was considered indicated in 53.1% of patients with mild intermittent, 79.2% of moderate-severe intermittent, 72.6% of mild persistent, and 82.7% of moderate-severe persistent AR. Conclusions: The limitation of this study is that the population was not unselected and this prevents epidemiological significance. These results offer confirmation of the adequacy of ARIA guidelines in classifying patients with AR and of the association of severe phenotype with lack of success of drug treatment. \ua9 2013 Informa UK Ltd All rights reserved

    Active focal segmental glomerulosclerosis is associated with massive oxidation of plasma albumin

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    The basic mechanism for idiopathic FSGS still is obscure. Indirect evidence in humans and generation of FSGS by oxidants in experimental models suggest a role of free radicals. In vitro studies demonstrate a main role of plasma albumin as antioxidant, its modification representing a chemical marker of oxidative stress. With the use of complementary liquid chromatography electron spray ionization tandem mass spectrometry (LC-ESI-MS/MS) and biochemical methods, plasma albumin was characterized in 34 patients with FSGS; 18 had received a renal transplant, and 17 had IgM mesangial deposition. Patients with FSGS that was in remission or without recurrence after transplantation had normal plasma albumin, and the same occurred in patients with primary and secondary nephrites and with chronic renal failure. In contrast, patients with active FSGS or with posttransplantation recurrence had oxidized plasma albumin. This finding was based on the characterization of albumin Cys 34 with an mass-to-charge ratio of 511.71 in triple charge that was consistent with the formation of a cysteic acid carrying a sulfonic group (alb-SO3-). The exact mass of albumin was increased accordingly (+48 Da) for incorporation of three oxygen radicals. Direct titration of the free sulfhydryl group 34 of plasma albumin and electrophoretic titration curves confirmed loss of free sulfhydryl group and formation of a fast-moving isoform in all cases with disease activity. This is the first demonstration of in vivo plasma albumin oxidation that was obtained with an adequate structural approach. Albumin oxidation seems to be specific for FSGS, suggesting some pathogenetic implications. Free radical involvement in FSGS may lead to specific therapeutic interventions
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