688 research outputs found

    Dataset from chemical gas sensor array in turbulent wind tunnel

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    The dataset includes the acquired time series of a chemical detection platform exposed to different gas conditions in a turbulent wind tunnel. The chemo-sensory elements were sampling directly the environment. In contrast to traditional approaches that include measurement chambers, open sampling systems are sensitive to dispersion mechanisms of gaseous chemical analytes, namely diffusion, turbulence, and advection, making the identification and monitoring of chemical substances more challenging. The sensing platform included 72 metal-oxide gas sensors that were positioned at 6 different locations of the wind tunnel. At each location, 10 distinct chemical gases were released in the wind tunnel, the sensors were evaluated at 5 different operating temperatures, and 3 different wind speeds were generated in the wind tunnel to induce different levels of turbulence. Moreover, each configuration was repeated 20 times, yielding a dataset of 18,000 measurements. The dataset was collected over a period of 16 months. The data is related to "On the performance of gas sensor arrays in open sampling systems using Inhibitory Support Vector Machines", by Vergara et al.[1]. The dataset can be accessed publicly at the UCI repository upon citation of [1]: http://archive.ics.uci.edu/ml/datasets/Gas+sensor+arrays+in+open+sampling+settings.This work has been supported by the California Institute for Telecommunications and Information Technology (CALIT2) under Grant number 2014 CSRO 136

    Data set from chemical sensor array exposed to turbulent gas mixtures

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    A chemical detection platform composed of 8 chemo-resistive gas sensors was exposed to turbulent gas mixtures generated naturally in a wind tunnel. The acquired time series of the sensors are provided. The experimental setup was designed to test gas sensors in realistic environments. Traditionally, chemical detection systems based on chemo-resistive sensors include a gas chamber to control the sample air flow and minimize turbulence. Instead, we utilized a wind tunnel with two independent gas sources that generate two gas plumes. The plumes get naturally mixed along a turbulent flow and reproduce the gas concentration fluctuations observed in natural environments. Hence, the gas sensors can capture the spatio-temporal information contained in the gas plumes. The sensor array was exposed to binary mixtures of ethylene with either methane or carbon monoxide. Volatiles were released at four different rates to induce different concentration levels in the vicinity of the sensor array. Each configuration was repeated 6 times, for a total of 180 measurements. The data is related to "Chemical Discrimination in Turbulent Gas Mixtures with MOX Sensors Validated by Gas Chromatography-Mass Spectrometry", by Fonollosa et al. [1]. The dataset can be accessed publicly at the UCI repository upon citation of [1]: http://archive.ics.uci.edu/ml/datasets/Gas+senso+rarray+exposed+to+turbulent+gas+mixtures.This work has been supported by the California Institute for Telecommunications and Information Technology (CALIT2) under Grant Number 2014 CSRO 136

    Redes sociales y desarrollo de carrera

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    El presente trabajo pretende abordar el impacto del surgimiento de las redes sociales (fundamentalmente, de profesionales) en la gestión de las carreras de los miembros de la comunidad laboral, así como explorar la potencialidad y eficacia de la Web 2.0 en el desarrollo y progreso de aquéllos. Principalmente, esta tesis se enfoca en dimensiones estratégicas tales como inserción laboral, reclutamiento, networking, desarrollo de carrera, impacto generacional, y personal branding (marca personal), por citar algunos tópicos tratados

    L-shell ionization of Cd: Structure of the x-ray emission spectrum

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    The cadmium L x-ray spectrum induced by electron impact was analyzed in detail. The measurements were performed on a bulk pure sample using a commercial wavelength dispersive spectrometer, and the spectrum was processed with a parameter optimization method previously developed. This procedure permitted the determination of characteristic energies, relative transition probabilities and natural linewidths for this element. The results obtained here were compared to the data found in the literature, when available. Spectral structures related to satellite and radiative Auger Effect emissions were also analyzed, assessing energy shifts and relative intensities. Some of these parameters were determined for the first time, even in overlapping peaks and weak transitions, which was possible due to the robustness of the spectral processing method used.Fil: Fernandez, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Sepúlveda, A.. Universidad Tecnológica Metropolitana; ChileFil: Trincavelli, Jorge Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Castellano, Gustavo Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentin

    El estudio de triángulos contextualizado en el Nivel Secundario

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    Informe Final (Profesorado en Matemática)--Universidad Nacional de Córdoba. Facultad de Matemática Astronomía y Física, 2014.A lo largo de este informe final comunicaremos la experiencia de práctica docente llevadas a cabo en tres divisiones de un primer año del Nivel Secundario de una institución pública de gestión estatal. Se trabajó como contenido temático la Geometría, por este motivo, la construcción con regla y compás ha atravesado toda la práctica, ya sea teniéndolos como instrumentos tangibles o como recurso tecnológico (GeoGebra). Se incluye una breve descripción del colegio y los alumnos, la planificación y su cotejo con lo que se llevó a cabo en el aula, como así también la evaluación efectuada y sus resultados. Asimismo, adscribiendo para ello a una postura teórica considerada pertinente, se analiza una problemática surgida durante las prácticas a la cual se denominará: Incidencias de las distintas representaciones de triángulos contextualizadas en los primeros años del Nivel Secundario

    High adenosine extracellular levels induce glioblastoma aggressive traits modulating the mesenchymal stromal cell secretome

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    Glioblastoma is an aggressive, fast-growing brain tumor influenced by the composition of the tumor microenvironment (TME) in which mesenchymal stromal cell (MSCs) play a pivotal role. Adenosine (ADO), a purinergic signal molecule, can reach up to high micromolar concentrations in TME. The activity of specific adenosine receptor subtypes on glioma cells has been widely explored, as have the effects of MSCs on tumor progression. However, the effects of high levels of ADO on glioma aggressive traits are still unclear as is its role in cancer cells-MSC cross-talk. Herein, we first studied the role of extracellular Adenosine (ADO) on isolated human U343MG cells as a glioblastoma cellular model, finding that at high concentrations it was able to prompt the gene expression of Snail and ZEB1, which regulate the epithelial–mesenchymal transition (EMT) process, even if a complete transition was not reached. These effects were mediated by the induction of ERK1/2 phosphorylation. Additionally, ADO affected isolated bone marrow derived MSCs (BM-MSCs) by modifying the pattern of secreted inflammatory cytokines. Then, the conditioned medium (CM) of BM-MSCs stimulated with ADO and a co-culture system were used to investigate the role of extracellular ADO in GBM–MSC cross-talk. The CM promoted the increase of glioma motility and induced a partial phenotypic change of glioblastoma cells. These effects were maintained when U343MG cells and BM-MSCs were co-cultured. In conclusion, ADO may affect glioma biology directly and through the modulation of the paracrine factors released by MSCs overall promoting a more aggressive phenotype. These results point out the importance to deeply investigate the role of extracellular soluble factors in the glioma cross-talk with other cell types of the TME to better understand its pathological mechanisms

    Mobile Robots for Localizing Gas Emission Sources on Landfill Sites: Is Bio-Inspiration the Way to Go?

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    Roboticists often take inspiration from animals for designing sensors, actuators, or algorithms that control the behavior of robots. Bio-inspiration is motivated with the uncanny ability of animals to solve complex tasks like recognizing and manipulating objects, walking on uneven terrains, or navigating to the source of an odor plume. In particular the task of tracking an odor plume up to its source has nearly exclusively been addressed using biologically inspired algorithms and robots have been developed, for example, to mimic the behavior of moths, dung beetles, or lobsters. In this paper we argue that biomimetic approaches to gas source localization are of limited use, primarily because animals differ fundamentally in their sensing and actuation capabilities from state-of-the-art gas-sensitive mobile robots. To support our claim, we compare actuation and chemical sensing available to mobile robots to the corresponding capabilities of moths. We further characterize airflow and chemosensor measurements obtained with three different robot platforms (two wheeled robots and one flying micro-drone) in four prototypical environments and show that the assumption of a constant and unidirectional airflow, which is the basis of many gas source localization approaches, is usually far from being valid. This analysis should help to identify how underlying principles, which govern the gas source tracking behavior of animals, can be usefully “translated” into gas source localization approaches that fully take into account the capabilities of mobile robots. We also describe the requirements for a reference application, monitoring of gas emissions at landfill sites with mobile robots, and discuss an engineered gas source localization approach based on statistics as an alternative to biologically inspired algorithms

    TUMOR NECROSIS FACTOR ALPHA TRIGGERS OSTEOGENESIS THROUGH THE INVOVLVEMENT OF Gs-COUPLED RECEPTOR SIGNALS

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    Tumor Necrosis Factor alpha (TNF-α) plays a role in several chronic immune and inflammatory diseases, where inhibition of TNF has led to significant clinical improvement. Actually, this cytokine is involved in bone healing by affecting mesenchymal stem cell (MSC) behaviour in a dose- and time-dependent manner1,2. Indeed, in the early inflammatory phase after fracture, low doses of TNF-α are required to favour MSC migration, survival and differentiation, thus initiating bone repair. At high dose, in the chronic uncontrolled phase of inflammation, the same cytokine has destructive effects on bone and contribute to bone loss1,2. As other soluble factors released in cell microenvironment, the cytokine modulates expression and functioning of different G protein coupled receptors (GPCRs) and of their regulatory proteins (GPCR regulated kinases, GRKs)3, thus dictating the final biological outcome of these receptor proteins in controlling bone anabolic processes. Herein, we investigated the effects of TNF-α low doses on the expression and functional responsiveness of A2B adenosine receptor (A2B AR), a Gs-coupled puringergic receptor that controls mesenchymal stem cell (MSC) differentiation to osteoblasts4,5. In our hands, TNF-α exerted a pro-differentiating action on MSCs, pushing towards an osteoblast phenotype, and without any effects on cell proliferation. The cytokine increased the A2B AR-mediated pro-osteogenic effects, through the A2B AR desensitization impairment mediated by GRK2 inhibition. These data i) support the anabolic effect of sub-massimal concentration of TNF-α in bone reparative processes and ii) demonstrate that the cytokine regulates GPCR responses by interfering with desensitization machinery and potentiating in turn the anabolic responses evoked by Gs-GPCRs. Overall these results indicated that manipulating MSC local environment by lregulates membrane receptors favouring bone remodelling

    Experimental determination of cross sections for K-shell ionization by electron impact for C, O, Al, Si, and Ti

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    Cross sections for K-shell ionization by electron impact were determined from films of Al, Si, and Ti and their oxides deposited on carbon substrates, for incident energies between 2.5 and 25 keV. The spectral processing of the x-ray emission spectra took into account corrections due to the presence of a spontaneous oxide layer formed on the monoelemental films and to the supporting material. CarbonK-shell ionization cross sections were determined from the contribution of the substrate to the measured spectra, while for oxygen, data from the three oxide films were taken. The mass thickness of the coatings was characterized by x-ray reflectivity. The results obtained were compared with other experimental data sets, semiempirical approaches, and theoretical models

    Experimental x-ray-production cross sections for the M3, M4, and M5 subshells of Pt and Au by electron impact

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    X-ray-production cross sections for M3, M4, and M5 subshells of Pt and Au by electron impact were experimentally determined at incident energies ranging between 2.8 and 28 keV. To this purpose, Pt and Au thick targets were irradiated by an electron beam in a field-emission-gun scanning electron microscope, and the x-ray-emission spectra were recorded with an energy-dispersive spectrometer. The x-ray-production cross sections were obtained as a result of the spectral processing performed through a careful parameter optimization routine previously developed, which involves an analytical function for the prediction of the experimental spectra, on the basis of ionization depth distribution functions. The results are compared with the scarce data available in the literature.Fil: Carreras, Alejo Cristian. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Castellano, Gustavo Eugenio. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Segui Osorio, Silvina Inda Maria. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Trincavelli, Jorge Carlos. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentin
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