1,889 research outputs found

    Ergodicity breaking in strong and network-forming glassy system

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    The temperature dependence of the non-ergodicity factor of vitreous GeO2_2, fq(T)f_{q}(T), as deduced from elastic and quasi-elastic neutron scattering experiments, is analyzed. The data are collected in a wide range of temperatures from the glassy phase, up to the glass transition temperature, and well above into the undercooled liquid state. Notwithstanding the investigated system is classified as prototype of strong glass, it is found that the temperature- and the qq-behavior of fq(T)f_{q}(T) follow some of the predictions of Mode Coupling Theory. The experimental data support the hypothesis of the existence of an ergodic to non-ergodic transition occurring also in network forming glassy systems

    The ship model basin of Naples' University Federico II: Facilities, experimental tests, measurement systems

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    This work presents the main facilities of the Naples Towing Tank, LEIN: the instruments and the potential of the laboratory are presented, highlighting some strategies to resolve critical points typical of the towing tank tests. As example we point the attention on three aspects, typically critical: towing point of planing vessels, the accuracy of wave spectra generation and the settings of the radii of gyration for the seakeeping models

    Bimanual coupling effect during a proprioceptive stimulation

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    Circle-line drawing paradigm is used to study bimanual coupling. In the standard paradigm, subjects are asked to draw circles with one hand and lines with the other hand; the influence of the concomitant tasks results in two "elliptical" figures. Here we tested whether proprioceptive information evoked by muscle vibration inducing a proprioceptive illusion (PI) of movement at central level, was able to affect the contralateral hand drawing circles or lines. A multisite 80 Hz-muscle vibration paradigm was used to induce the illusion of circle- and line-drawing on the right hand of 15 healthy participants. During muscle vibration, subjects had to draw a congruent or an incongruent figure with the left hand. The ovalization induced by PI was compared with Real and Motor Imagery conditions, which already have proved to induce bimanual coupling. We showed that the ovalization of a perceived circle over a line drawing during PI was comparable to that observed in Real and Motor Imagery condition. This finding indicates that PI can induce bimanual coupling, and proprioceptive information can influence the motor programs of the contralateral hand

    Photopolymerization of Ceramic Resins by Stereolithography Process: A Review

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    Stereolithography is known as one of the best Additive Manufacturing technologies in terms of geometrical and dimensional precision for polymeric materials. In recent years, a lot of studies have shown that the creation of ceramic resins, through a particular combination of monomeric components and ceramic powders, allows to obtain complex shape geometries thanks to the photopolymerization process. This review highlights the characteristics and properties of ceramic resins, peculiarities of the ceramic stereolithography processes, up to the relationship between the composition of the ceramic resin and the complexity of the post-processing phases. The comparison of different studies allows outlining the most common steps for the production of ceramic resins, as well as the physical and chemical compatibility of the different compounds that must be studied for the good feasibility of the process

    A Real-Time PCR Assay for the Quantification of Plasmopara viticola Oospores in Grapevine Leaves

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    Grapevine downy mildew caused by Plasmopara viticola is one of the most important diseases in vineyards. Oospores that overwinter in the leaf litter above the soil are the sole source of inoculum for primary infections of P. viticola; in addition to triggering the first infections in the season, the oospores in leaf litter also contribute to disease development during the season. In the current study, a quantitative polymerase chain reaction (qPCR) method that was previously developed to detect P. viticola DNA in fresh grapevine leaves was assessed for its ability to quantify P. viticola oospores in diseased, senescent grapevine leaves. The qPCR assay was specific to P. viticola and sensitive to decreasing amounts of both genomic DNA and numbers of P. viticola oospores used to generate qPCR standard curves. When the qPCR assay was compared to microscope counts of oospores in leaves with different levels of P. viticola infestation, a strong linear relationship (R2 = 0.70) was obtained between the numbers of P. viticola oospores per gram of leaves as determined by qPCR vs. microscopic observation. Unlike microscopic observation, the qPCR assay was able to detect significant differences between leaf samples with a low level of oospore infestation (25% infested leaves and 75% non-infested leaves) vs. samples without infestation, and this ability was not influenced by the weight of the leaf sample. The results indicate that the qPCR method is sensitive and provides reliable estimates of the number of P. viticola oospores in grapevine leaves. Additional research is needed to determine whether the qPCR method is useful for quantifying P. viticola oospores in grapevine leaf litter

    Group IV Nociceptors Develop Axonal Chemical Sensitivity During Neuritis And Following Treatment Of The Sciatic Nerve With Vinblastine

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    We have previously shown that nerve inflammation (neuritis) and transient vinblastine application lead to axonal mechanical sensitivity in nociceptors innervating deep structures. We have also shown that these treatments reduce axonal transport, and proposed that this leads to functional accumulation of mechanically sensitive channels in the affected part of the axons. While informing the etiology of mechanically induced pain, axonal mechanical sensitivity does not address the common report of ongoing radiating pain during neuritis, which could be secondary to the provocation of axonal chemical sensitivity. We proposed that neuritis and vinblastine application would induce sensitivities to noxious chemicals, and that the number of chemo-sensitive channels would be increased at the affected site. In adult female rats, nerves were either untreated, or treated with complete Freund’s adjuvant (to induce neuritis) or vinblastine. After 3-7 days, dorsal root teased fiber recordings were taken from Group IV neurons with axons within the sciatic nerve. Sciatic nerves were injected intraneurally with a combination of noxious inflammatory chemicals. While no normal sciatic axons responded to this stimulus, 80% and 38% of axons responded in the neuritis and vinblastine groups, respectively. In separate experiments, sciatic nerves were partially ligated and treated with complete Freund’s adjuvant or vinblastine (with controls), and after 3-5 days were immunolabeled for the histamine 3 receptor. The results supported that both neuritis and vinblastine treatment reduce transport of the histamine 3 receptor. The finding that nociceptor axons can develop ectopic chemical sensitivity is consistent with ongoing radiating pain due to nerve inflammation
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