1,048 research outputs found

    The Repercussions of Business Process Modeling Notations on Mental Load and Mental Effort

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    Over the last decade, plenty business process modeling notations emerged for the documentation of business processes in enterprises. During the learning of a modeling notation, an individual is confronted with a cognitive load that has an impact on the comprehension of a notation with its underlying formalisms and concepts. To address the cognitive load, this paper presents the results from an exploratory study, in which a sample of 94 participants, divided into novices, intermediates, and experts, needed to assess process models expressed in terms of eight different process modeling notations, i.e., BPMN 2.0, Declarative Process Modeling, eGantt Charts, EPCs, Flow Charts, IDEF3, Petri Nets, and UML Activity Diagrams. The study focus was set on the subjective comprehensibility and accessibility of process models reflecting participant's cognitive load (i.e., mental load and mental effort). Based on the cognitive load, a factor reflecting the mental difficulty for comprehending process models in different modeling notations was derived. The results indicate that established modeling notations from industry (e.g., BPMN) should be the first choice for enterprises when striving for process management. Moreover, study insights may be used to determine which modeling notations should be taught for an introduction in process modeling or which notation is useful to teach and train process modelers or analysts. \keywords{Business Process Modeling Notations, Cognitive Load, Mental Load, Mental Effort, Human-centered Desig

    Evaluation of cytotoxicity, antimicrobial activity and physicochemical properties of a calcium aluminate-based endodontic material

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    A calcium aluminate-based endodontic material, EndoBinder, has been developed in order to reduce MTA negative characteristics, preserving its biological properties and clinical applications. OBJECTIVES: The aim of this study was to evaluate the cytotoxicity, antimicrobial activity, pH, solubility and water sorption of EndoBinder and to compare them with those of white MTA (WMTA). MATERIAL AND METHODS: Cytotoxicity was assessed through a multiparametric analysis employing 3T3 cells. Antimicrobial activity against Enterococcus faecalis (ATCC 29212), Staphylococcus aureus. (ATCC 25923) and Candida albicans (ATCC 10556) was determined by the agar diffusion method. pH was measured at periods of 3, 24, 72 and 168 hours. Solubility and water sorption evaluation were performed following ISO requirements. Data were statistically analyzed by ANOVA and Tukey`s test with a significance level of 5%. RESULTS: EndoBinder and WMTA were non-cytotoxic in all tested periods and with the different cell viability parameters. There was no statistical differences between both materials (P>.05). All tested materials were inhibitory by direct contact against all microbial strains tested. EndoBinder and WMTA presented alkaline pH in all tested times with higher values of pH for WMTA (P<.05). Both materials showed values complying with the solubility minimum requirements. However, EndoBinder showed lower solubility than WMTA (P<.05). No statistical differences were observed regarding water sorption (P>.05). CONCLUSION: Under these experimental conditions, we concluded that the calcium aluminate-based endodontic material EndoBinder demonstrated suitable biological and physicochemical properties, so it can be suggested as a material of choice in root resorption, perforations and root-end filling

    Epidemiological investigation of an acute case of Chagas disease in an area of active transmission in Peruvian Amazon region

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    The study objective was to investigate an acute case of Chagas disease in the San Pedro de Shishita community, Pebas District, in the Peruvian Amazon basin, a non-endemic area. Both parents of the index case (acute case) were thoroughly interviewed, a seroepidemiological survey was carried out in the community, parasitological exams were carried out only in relatives of the index case, and triatomine bugs were searched for inside houses, peridomiciliary, and in wild environments. Seroprevalence for IgG anti-T. cruzi antibodies was 1/104 (0.96%), using an ELISA test and an indirect immunofluorescence assay. Panstrongylus geniculatus and Rhodnius pictipes adults were found. The index case is autochthonous from San Pedro de Shishita, but the source of transmission is unknown.O objetivo deste trabalho foi estudar caso da doença de Chagas aguda na comunidade indígena de San Pedro de Shishita, sem conhecimento da origem da transmissão. San Pedro de Shishita, distrito Pebas, região da Amazônia peruana é uma área não endêmica. Foram entrevistados os pais do paciente e feito inquérito soroepidemiológico dos participantes e estudos parasitológicos da família e procurou-se também triatomíneos no ambiente doméstico, peridomiciliar e silvestre. A soroprevalência de anticorpos IgG anti-T. cruzi foi 1/ 104 (0,96%) por ELISA e imunofluorescência indireta. Foram encontrados adultos de Panstrongylus geniculatus e Rhodnius pictipe

    Circumstellar disks and planets. Science cases for next-generation optical/infrared long-baseline interferometers

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    We present a review of the interplay between the evolution of circumstellar disks and the formation of planets, both from the perspective of theoretical models and dedicated observations. Based on this, we identify and discuss fundamental questions concerning the formation and evolution of circumstellar disks and planets which can be addressed in the near future with optical and infrared long-baseline interferometers. Furthermore, the importance of complementary observations with long-baseline (sub)millimeter interferometers and high-sensitivity infrared observatories is outlined.Comment: 83 pages; Accepted for publication in "Astronomy and Astrophysics Review"; The final publication is available at http://www.springerlink.co

    A new investigation of electron neutrino appearance oscillations with improved sensitivity in the MiniBooNE+ experiment

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    Submitted as whitepaper for Snowmass'13 proceedings - 8 pages, 3 figures; version 2: Minor change to title and author listSubmitted as whitepaper for Snowmass'13 proceedings - 8 pages, 3 figures; version 2: Minor change to title and author listWe propose the addition of scintillator to the existing MiniBooNE detector to allow a test of the neutral-current/charged-current (NC/CC) nature of the MiniBooNE low-energy excess. Scintillator will enable the reconstruction of 2.2 MeV γ\gammas from neutron-capture on protons following neutrino interactions. Low-energy CC interactions where the oscillation excess is observed should have associated neutrons with less than a 10% probability. This is in contrast to the NC backgrounds that should have associated neutrons in approximately 50% of events. We will measure these neutron fractions with νμ\nu_\mu CC and NC events to eliminate that systematic uncertainty. This neutron-fraction measurement requires 6.5×10206.5\times10^{20} protons on target delivered to MiniBooNE with scintillator added in order to increase the significance of an oscillation excess to over 5σ5\sigma. This new phase of MiniBooNE will also enable additional important studies such as the spin structure of nucleon (Δs\Delta s) via NC elastic scattering, a low-energy measurement of the neutrino flux via \numu ^{12}C \rightarrow \mu^{-} ^{12}N_\textrm{g.s.} scattering, and a test of the quasielastic assumption in neutrino energy reconstruction. These topics will yield important, highly-cited results over the next 5 years for a modest cost, and will help to train Ph.D. students and postdocs. This enterprise offers complementary information to that from the upcoming liquid Argon based MicroBooNE experiment. In addition, MicroBooNE is scheduled to receive neutrinos in early 2014, and there is minimal additional cost to also deliver beam to MiniBooNE

    Improved Search for νˉμνˉe\bar ν_μ\rightarrow \bar ν_e Oscillations in the MiniBooNE Experiment

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    Submitted to PRL. Further information provided in arXiv:1207.4809Submitted to PRL. Further information provided in arXiv:1207.4809The MiniBooNE experiment at Fermilab reports results from an analysis of νˉe\bar \nu_e appearance data from 11.27×102011.27 \times 10^{20} protons on target in antineutrino mode, an increase of approximately a factor of two over the previously reported results. An event excess of 78.4±28.578.4 \pm 28.5 events (2.8σ2.8 \sigma) is observed in the energy range 200<EνQE<1250200<E_\nu^{QE}<1250 MeV. If interpreted in a two-neutrino oscillation model, νˉμνˉe\bar{\nu}_{\mu}\rightarrow\bar{\nu}_e, the best oscillation fit to the excess has a probability of 66% while the background-only fit has a χ2\chi^2-probability of 0.5% relative to the best fit. The data are consistent with antineutrino oscillations in the 0.01<Δm2<1.00.01 < \Delta m^2 < 1.0 eV2^2 range and have some overlap with the evidence for antineutrino oscillations from the Liquid Scintillator Neutrino Detector (LSND). All of the major backgrounds are constrained by in-situ event measurements so non-oscillation explanations would need to invoke new anomalous background processes. The neutrino mode running also shows an excess at low energy of 162.0±47.8162.0 \pm 47.8 events (3.4σ3.4 \sigma) but the energy distribution of the excess is marginally compatible with a simple two neutrino oscillation formalism. Expanded models with several sterile neutrinos can reduce the incompatibility by allowing for CP violating effects between neutrino and antineutrino oscillations
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