1,223 research outputs found

    Enhancing Students’ Mathematical Reasoning By Algebrator-Assisted Inquiry Method

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    Representation of safety standards with semantic technologies used in industrial environments

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    Proceedings of: 36th International Conference on Computer Safety, Reliability, and Security, (SAFECOMP 2017). Trento, Italy, September 13-15, 2017Understanding and following safety standards with their text can be difficult. Ambiguity and inconsistency, among other issues, can easily arise. As a solution, several authors argue for the explicit representation of the standards with models, which can be created with semantic technologies such as ontologies. However, this possibility has received little attention. The few authors that have addressed it have also only dealt with a subset of safety standard aspects and have used technologies not usually applied for critical systems engineering. As a first step towards addressing these issues, this position paper presents our initial work on the representation of safety standards with Knowledge Manager, a tool used in industrial environments that exploits semantic technologies to manage domain information. The proposal also builds on prior work on the specification of safety compliance needs with a holistic generic metamodel. We describe how to use Knowledge Manager to specify the concepts and relationships of the metamodel for a given safety standard, and discuss the application and benefits of the corresponding representation.The research leading to this paper has received funding from the AMASS project (H2020-ECSEL no. 692474; Spain’s MINECO ref. PCIN-2015-262)

    An experimental evaluation of the understanding of safety compliance needs with models

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    Proceedings of: 36th International Conference on Conceptual Modeling, ER 2017, Valencia, Spain, November 6–9, 2017Context: Most safety-critical systems have to fulfil compliance needs specified in safety standards. These needs can be difficult to understand from the text of the standards, and the use of conceptual models has been proposed as a solution. Goal: We aim to evaluate the understanding of safety compliance needs with models. Method: We have conducted an experiment to study the effectiveness, efficiency, and perceived benefits in understanding these needs, with text of safety standards and with UML object diagrams. Results: Sixteen Bachelor students participated in the experiment. Their average effectiveness in understanding compliance needs and their average efficiency were higher with models (17% and 15%, respectively). However, the difference is not statistically significant. The students found benefits in using models, but on average they are undecided about their ease of understanding. Conclusions: Although the results are not conclusive enough, they suggest that the use of models could improve the understanding of safety compliance needs.The research leading to this paper has received funding from the AMASS project (H2020-ECSEL grant agreement no 692474; Spain’s MINECO ref. PCIN-2015-262) and the AMoDDI project (Ref. 11130583). We also thank the subjects that participated in the experiment

    Geomagnetic storm effects on GPS based navigation

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    The energetic events on the sun, solar wind and subsequent effects on the Earth's geomagnetic field and upper atmosphere (ionosphere) comprise space weather. Modern navigation systems that use radio-wave signals, reflecting from or propagating through the ionosphere as a means of determining range or distance, are vulnerable to a variety of effects that can degrade the performance of the navigational systems. In particular, the Global Positioning System (GPS) that uses a constellation of earth orbiting satellites are affected due to the space weather phenomena. <br><br> Studies made during two successive geomagnetic storms that occurred during the period from 8 to 12 November 2004, have clearly revealed the adverse affects on the GPS range delay as inferred from the Total Electron Content (TEC) measurements made from a chain of seven dual frequency GPS receivers installed in the Indian sector. Significant increases in TEC at the Equatorial Ionization anomaly crest region are observed, resulting in increased range delay during the periods of the storm activity. Further, the storm time rapid changes occurring in TEC resulted in a number of phase slips in the GPS signal compared to those on quiet days. These phase slips often result in the loss of lock of the GPS receivers, similar to those that occur during strong(>10 dB) L-band scintillation events, adversely affecting the GPS based navigation

    Secreted proteins of normal and myc-ras oncogene transformed rat embryo fibroblasts

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    Quiescent cultures of rat embryo fibroblasts synthesize and secrete several proteins in response to mitogenic stimulation. Two of these proteins have been characterized in this study and the effect of oncogenic transformation on these proteins was monitored. A serum induced 48,000 protein was shown to be related to plasminogen activator inhibitor while another serum-induced protein of Mr 45,000 was found to be an inhibitor of DNA synthesis. Transformation of rat embryo fibroblasts with oncogenesmyc andras resulted in drastic reduction in the level of these proteins. The reduced levels of protease inhibitor may be responsible for the loss of anchorage dependence of the transformed cells. The DNA synthesis inhibitor protein may act as a negative growth regulator and reduced levels of this protein in myc-ras transformed cells may accelerate the proliferation of these cells

    ADICCIÓN A LOS VIDEOJUEGOS Y AGRESIVIDAD EN ESTUDIANTES DE SECUNDARIA DE DOS COLEGIOS PRIVADOS DE VILLA MARIA DEL TRIUNFO

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    Con el objetivo de establecer la relación entre la adicción a los videojuegos y la agresividad en 306 estudiantes de secundaria de dos colegios privados de Villa María del Triunfo, cuyas edades fluctuaron entre los 13 a 17 años. Se aplicaron como instrumentos de medición: el Test de Dependencia a los Videojuegos de Chóliz y Marco, y el Cuestionario de Agresión de Buss y Perry. Se encontró que existe una correlación positiva, moderada baja y altamente significativa (rho = 0.268; p < 0.001) entre la adicción a los videojuegos y agresividad. Se encontró que para la adicción a los videojuegos y sus dimensiones, existen diferencias altamente significativas (p < 0.001), de acuerdo al género y horas de uso a la semana. Entre la agresividad y sus componentes existen diferencias significativas (p < 0.05) en los componentes hostilidad, agresión física e ira de acuerdo al género, edad y grado escolar. Además, se encontró diferencias muy significativas (p < 0.01) para agresividad de acuerdo al grado escolar. Así mismo, se halló diferencias altamente significativas (p < 0.001) para el componente agresión verbal según el género de los participantes

    Variability of root traits in spring wheat germplasm

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    Citation: Narayanan S, Mohan A, Gill KS, Prasad PVV (2014) Variability of Root Traits in Spring Wheat Germplasm. PLoS ONE 9(6): e100317. https://doi.org/10.1371/journal.pone.0100317Root traits influence the amount of water and nutrient absorption, and are important for maintaining crop yield under drought conditions. The objectives of this research were to characterize variability of root traits among spring wheat genotypes and determine whether root traits are related to shoot traits (plant height, tiller number per plant, shoot dry weight, and coleoptile length), regions of origin, and market classes. Plants were grown in 150-cm columns for 61 days in a greenhouse under optimal growth conditions. Rooting depth, root dry weight, root: shoot ratio, and shoot traits were determined for 297 genotypes of the germplasm, Cultivated Wheat Collection (CWC). The remaining root traits such as total root length and surface area were measured for a subset of 30 genotypes selected based on rooting depth. Significant genetic variability was observed for root traits among spring wheat genotypes in CWC germplasm or its subset. Genotypes Sonora and Currawa were ranked high, and genotype Vandal was ranked low for most root traits. A positive relationship (R2≥0.35) was found between root and shoot dry weights within the CWC germplasm and between total root surface area and tiller number; total root surface area and shoot dry weight; and total root length and coleoptile length within the subset. No correlations were found between plant height and most root traits within the CWC germplasm or its subset. Region of origin had significant impact on rooting depth in the CWC germplasm. Wheat genotypes collected from Australia, Mediterranean, and west Asia had greater rooting depth than those from south Asia, Latin America, Mexico, and Canada. Soft wheat had greater rooting depth than hard wheat in the CWC germplasm. The genetic variability identified in this research for root traits can be exploited to improve drought tolerance and/or resource capture in wheat

    A rare association of Kimura’s disease with chronic pulmonary aspergillosis

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    Kimura’s disease is a rare chronic benign inflammatory condition characterised by nodules of skin and soft tissue and lymphnodes. Eosinophilic infiltration is a prominent finding. It has been reported in association with various conditions like nephrotic syndrome, bronchial asthma, ulcerative colitis and aortitis syndrome. Hereby we present a case in medical literature to the best of our knowledge in Kimura’s disease in association with chronic cavitary pulmonary aspergillosis, which has never been reported. He was treated with antifungals, after which he responded clinically, eosinophilia has subsided and he is under regular follow up. Now This case report suggest possible role of chronic aspergillosis as a cause for Kimura’s disease
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