Multi-domain Modelling in DESTECS and Ptolemy - a Tool Comparison

Developing embedded systems with high performance and safety requirements is notoriously hard. It is not enough to have a thorough understanding of the control algorithms used, but a deep understanding of the monitored and controlled physical environment is required to ensure that performance and safety requirements are met. Various tools deal with modeling such multi-domain systems and provide evaluation through simulation. Two such tools — DESTECS and Ptolemy — are examined and compared in this paper, using a case study of an aircraft fuel system. Usability, quantitative, and qualitative comparison criteria are used to give a thorough analysis of the capabilities of the two tools. The contribution of this paper is a description of pros and cons of each tool, helping future users to choose the right tool that suits their needs

Determinants of anemia and hemoglobin concentration in haitian school-aged children

Anemia diminishes oxygen transport in the body, resulting in potentially irreversible growth and developmental consequences for children. Limited evidence for determinants of anemia exists for school-aged children. We conducted a cluster randomized controlled trial in Haiti from 2012 to 2013 to test the efficacy of a fortified school snack. Children (N = 1,047) aged 3–13 years were followed longitudinally at three time points for hemoglobin (Hb) concentrations, anthropometry, and bioelectrical impedance measures. Dietary intakes, infectious disease morbidities, and socioeconomic and demographic factors were collected at baseline and endline. Longitudinal regression modeling with generalized least squares and logit models with random effects identified anemia risk factors beyond the intervention effect. At baseline, 70.6% of children were anemic and 2.6% were severely anemic. Stunting increased the odds of developing anemia (adjusted odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.05–2.08) and severe anemia (adjusted OR: 2.47, 95% CI: 1.30–4.71). Parent-reported vitamin A supplementation and deworming were positively associated with Hb concentrations, whereas fever and poultry ownership showed a negative relationship with Hb concentration and increased odds of severe anemia, respectively. Further research should explore the full spectrum of anemia etiologies in school children, including genetic causes

Salt-dependent regulation of a CNG channel subfamily in Arabidopsis

<p>Abstract</p> <p>Background</p> <p>In <it>Arabidopsis thaliana</it>, the family of cyclic nucleotide-gated channels (CNGCs) is composed of 20 members. Previous studies indicate that plant CNGCs are involved in the control of growth processes and responses to abiotic and biotic stresses. According to their proposed function as cation entry pathways these channels contribute to cellular cation homeostasis, including calcium and sodium, as well as to stress-related signal transduction. Here, we studied the expression patterns and regulation of <it>CNGC19 </it>and <it>CNGC20</it>, which constitute one of the five CNGC subfamilies.</p> <p>Results</p> <p>GUS, GFP and luciferase reporter assays were used to study the expression of <it>CNGC19 </it>and <it>CNGC20 </it>genes from <it>Arabidopsis thaliana </it>in response to developmental cues and salt stress. <it>CNGC19 </it>and <it>CNGC20 </it>were differentially expressed in roots and shoots. The <it>CNGC19 </it>gene was predominantly active in roots already at early growth stages. Major expression was observed in the phloem. <it>CNGC20 </it>showed highest promoter activity in mesophyll cells surrounding the veins. Its expression increased during development and was maximal in mature and senescent leaves. Both genes were upregulated in the shoot in response to elevated NaCl but not mannitol concentrations. While in the root, <it>CNGC19 </it>did not respond to changes in the salt concentration, in the shoot it was strongly upregulated in the observed time frame (6-72 hours). Salt-induction of <it>CNGC20 </it>was also observed in the shoot, starting already one hour after stress treatment. It occurred with similar kinetics, irrespective of whether NaCl was applied to roots of intact plants or to the petiole of detached leaves. No differences in K and Na contents of the shoots were measured in homozygous T-DNA insertion lines for <it>CNGC19 </it>and <it>CNGC20</it>, respectively, which developed a growth phenotype in the presence of up to 75 mM NaCl similar to that of the wild type.</p> <p>Conclusion</p> <p>Together, the results strongly suggest that both channels are involved in the salinity response of different cell types in the shoot. Upon salinity both genes are upregulated within hours. <it>CNGC19 </it>and <it>CNGC20 </it>could assist the plant to cope with toxic effects caused by salt stress, probably by contributing to a re-allocation of sodium within the plant.</p

Validierung von Web-Usability-Heuristiken für eine ältere Zielgruppe

Dieser Beitrag stellt die Validierung von spezifischen Web-Usability-Heuristiken für die ältere Zielgruppe vor. Das Heuristiken-Set stammt aus einer Vorarbeit und wurde literarturbasiert abgeleitet. Zur Validierung werden ein Nutzertest mit zehn Probanden aus der Zielgruppe sowie eine heuristische Evaluation mit drei Experten durchgeführt. Die Ergebnisse beider Evaluationsmethoden werden quantitativ und qualitativ miteinander verglichen und etablierte Kennwerte zum Methodenvergleich berechnet. Beide Evaluationen liefern ähnliche Werte bezogen auf Validität und Effektivität. Aufgrund der hohen Anzahl an unique problems fällt die Gründlichkeit geringer aus, als bei anderen Methodenvergleichen

Las evaluaciones educativas que América Latina necesita

Los autores de este documento son los miembros del Comité Gestor del Grupo de Trabajo sobre Estándares y Evaluación del PREAL.Este documento aborda la importancia, propósitos y usos de las evaluaciones estandarizadas a gran escala de aprendizajes y logros escolares que se vienen realizando en América Latina y el Caribe, entendiendo por evaluación estandarizada a gran escala a aquélla que permite producir información comparable acerca de los desempeños de estudiantes pertenecientes a distintos contextos culturales y regionales e, incluso, a distintos países, y que ofrece un panorama de la situación de un país o de un estado o provincia, aplicando pruebas y otros instrumentos a muestras o a censos de estudiantes. El texto puede ayudar a quienes toman decisiones de política educativa a comprender y analizar diversas opciones existentes en cuanto a los propósitos y usos de los sistemas de evaluación y las implicancias de cada una de ellas, evitando simplismos que puedan generar sistemas mal concebidos y deficientemente implementados y, como consecuencia de ello, efectos perversos para el sistema educativo, malgasto de recursos y descrédito de la evaluación externa entre los docentes. Argumentan los autores que, para que la inversión en evaluación valga la pena, debe tener propósitos claros, una filosofía orientada a construir una visión de responsabilidad compartida en relación a la educación, un diseño técnico de calidad y adecuado a los propósitos, una fuerte orientación a servir de apoyo a los docentes y una clara voluntad política de actuar para resolver los problemas y deficiencias que la evaluación ponga de manifiesto. Asimismo, se requiere invertir tiempo y recursos en construir una unidad técnica competente y un plan de largo plazo

Subjektive Komplexität und Usability bei Webshops

Diese Studie beschäftigt sich mit den Konsequenzen der Komplexität von Benutzerschnittstellen am Beispiel von Webshops und untersucht den Zusammenhang von subjektiver Komplexität und Usability. Als Untersuchungsobjekte dienen drei Webshops, die unterschiedlichen Stufen objektiver Komplexität entsprechen (niedrig-mittel-hoch). In einer Nutzerstudie mit 36 Probanden wurden die subjektive Komplexität und die Usability der drei Webshops erhoben. Eine multiple Regressionsanalyse zeigt, dass alle Dimensionen der subjektiven Komplexität einen signifikanten negativen Effekt auf die Usability besitzen. Der Einfluss der Dimension der dynamischen Komplexität, die die Ambiguität von Links und Informationen bemisst, ist dabei besonders hoch

Strategies to tailor the architecture of dual Ag/Fe-oxide nano-heterocrystals—interfacial and morphology effects on the magnetic behavior

Bifunctional nanostructured architectures have shown appealing properties, since a single entity can combine the diverse properties of its individual constituents. Particularly, by growing Fe-oxide domains over Ag nanoparticles, the plasmonic and superparamagnetic properties can be combined in a single particle. Beyond the multifunctionality of this system, there are several properties that emerge from intrinsic factors, such as: interface and/or morphology. In this study, we present the synthesis protocols to obtain two sets of heterocrystals, each one with different morphology: dimer and flower-like. In addition, the magnetization behavior of these hybrid nano-heterocrystals is investigated and discussed. These nanomaterials were built by a seed assisted heterogeneous nucleation process, carried out in organic solvents of high boiling point, using the same batch of silver nanoparticles with a mean size of 6 nm as seeds, and tuning the electron-donor capacity of the reaction environment at the thermal decomposition of the iron precursor. Ag/Fe3O4 heterocrystals with dimer and flower-like morphologies were obtained. The synthesis protocols for generating these types of nanomaterials are discussed step-by-step. Structural and morphological properties were determined by transmission electron microscopy, x-ray diffraction and x-ray absorption fine structure. DC magnetization results suggest that the silver/magnetite coupling generates an increase of the blocking temperature in comparison to those obtained from pure magnetite. This behavior could be linked to a possible increase in the magnetic anisotropy produced by an additional disorder at the Ag–Fe3O4 interface. The higher interface area of the Ag/Fe3O4 heterocrystals with flower-like architecture leads to a higher blocking temperature and a stronger magnetic anisotropy. These results are supported by AC susceptibility data.Fil: Tancredi Gentili, Pablo. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Laboratorio de Sólidos Amorfos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Moscoso Londoño, Oscar. Universidad Autónoma de Manizales; Colombia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidade Estadual de Campinas; BrasilFil: Rivas Rojas, Patricia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Laboratorio de Sólidos Amorfos; ArgentinaFil: Wolff, U.. Leibniz Institute for Solid State and Materials Research; AlemaniaFil: Socolovsky, Leandro Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santa Cruz. Universidad Tecnológica Nacional. Facultad Regional Santa Cruz. Centro de Investigaciones y Transferencia de Santa Cruz. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia de Santa Cruz; ArgentinaFil: Knobel, M.. Universidade Estadual de Campinas; BrasilFil: Muraca, D.. Universidade Estadual de Campinas; Brasi

O PROCESSO DE TOMADA DE DECISÃO DO ENFERMEIRO NO EXERCICIO DAS FUNCOES ADMINISTRATIVAS

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