1,771 research outputs found

    Análisis de los materiales tipo de Pleurosigma formosum y P. decorum (Pleurosigmataceae, Bacillariophyta)

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    Los materiales tipo de Pleurosigma formosum W. Smith y P. decorum W. Smith fueron examinados. Ambas especies fueron separadas hasta ahora por el rango de tamaño, la forma de la valva y la densidad de las estrías sobre la base de su análisis con microscopio óptico (MO). Sin embargo, los materiales tipo muestran alguna superposición en los rangos de tamaño y densidad de estrías, con sutiles diferencias en el ángulo de intersección de las estrías oblicuas, el cual es algo más pequeño en P. decorum. El análisis con microscopio electrónico de barrido (MEB) muestra que ambas especies comparten algunos caracteres ultraestructurales tales como el engrosamiento en forma de silla de montar del nódulo central del rafe, la amplia superposición de las fisuras centrales del rafe, la forma de las fisuras terminales del rafe, en gancho corto, la morfología general de los poros internos ocluidos por un himen cruzado por una barra hundida y la presencia de algunos pares esparcidos de poros más profundamente excavados, carentes de barra. Sin embargo, los especímenes tipo difieren en la morfología interna de los poros areolares ocluidos por un himen. Estos son circulares, cruzados por una barra hundida y con bordes engrosados en P. formosum y sub-circulares a elípticos, cruzados por una barra menos hundida y sin bordes engrosados en P. decorum. Los resultados del análisis con MEB apoyan el punto de vista de Hendey acerca de que P. decorum y P. formosum son especies separadas pero cercanamente relacionadas.The type materials of Pleurosigma formosum W. Smith and P. decorum W. Smith were examined. Both species were separated hitherto by size range, valve shape and stria density based on light microscopy (LM) analysis. However, the type materials show some overlap in the size and stria density ranges, with subtle differences in the oblique stria intersection angle, which is somewhat smaller for P. decorum. Scanning electron microscopy (SEM) analysis shows that both species share several ultrastructural features such as a thick saddle-shaped central raphe nodule, very long overlapping central raphe fissures, short hook-shaped terminal raphe fissures, general morphology of the internal hymenoccluded pores crossed by a recessed bar and presence of some scattered pairs of more deeply recessed pores lacking a bar. However, the type specimens differ in the internal morphology of the hymen-occluded areolar pores, circular, crossed by a recessed bar and rimmed in P. formosum and subcircular to elliptical, crossed by a less recessed bar, not rimmed in P. decorum. The SEM findings thus support Hendey’s view that P. decorum and P. formosum are separate but closely allied species.Fil: Sterrenburg, Frithjof A. S.. No especifica;Fil: Sar, Eugenia Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Ficología; ArgentinaFil: Sunesen, Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Ficología; Argentin

    Summing Up: Based on Selective Hearing

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    Intelligent agent for formal modelling of temporal multi-agent systems

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    Software systems are becoming complex and dynamic with the passage of time, and to provide better fault tolerance and resource management they need to have the ability of self-adaptation. Multi-agent systems paradigm is an active area of research for modeling real-time systems. In this research, we have proposed a new agent named SA-ARTIS-agent, which is designed to work in hard real-time temporal constraints with the ability of self-adaptation. This agent can be used for the formal modeling of any self-adaptive real-time multi-agent system. Our agent integrates the MAPE-K feedback loop with ARTIS agent for the provision of self-adaptation. For an unambiguous description, we formally specify our SA-ARTIS-agent using Time-Communicating Object-Z (TCOZ) language. The objective of this research is to provide an intelligent agent with self-adaptive abilities for the execution of tasks with temporal constraints. Previous works in this domain have used Z language which is not expressive to model the distributed communication process of agents. The novelty of our work is that we specified the non-terminating behavior of agents using active class concept of TCOZ and expressed the distributed communication among agents. For communication between active entities, channel communication mechanism of TCOZ is utilized. We demonstrate the effectiveness of the proposed agent using a real-time case study of traffic monitoring system

    Spectral Data for Generation of Molecular Complexity from Cyclooctatetraene: Preparation of Optically Active Protected Aminocycloheptitols and Bicyclo[4.4.1]undecatriene

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    Spectral data created in the course of the research project. Supports specific findings in Generation of Molecular Complexity from Cyclooctatetraene: Preparation of Optically Active Protected Aminocycloheptitols and Bicyclo[4.4.1]undecatriene . The racemic (6-cyclo-heptadienyl)Fe(CO)3+ cation ((±)-7), prepared from cyclooctatetraene, was treated with a variety of carbon and heteroatom nucleophiles. Attack took place at the less hindered C1 dienyl carbon and decomplexation of the (cycloheptadiene)Fe(CO)3 complexes gave products rich in functionality for further synthetic manipulation. In particular, a seven-step route was developed from racemic (6-styryl-2,4-cycloheptadien-1-yl)phthalimide ((±)-9 d) to afford the optically active aminocycloheptitols (−)-20 and (+)-20

    The epizoic marine diatom Sceptronema orientale (Licmophoraceae, Licmophorales): epitypification and emendation of specific and generic descriptions

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    Sceptronema orientale was found epizoic on the harpacticoid copepod Euterpina acutifrons (Dana) collected from several locations along Bahía Anegada, Province of Buenos Aires, Argentina. Material was examined with light and scanning electron microscopy and new data about the morphology of the chloroplast and ultrastructural details of the girdle, valves, apical slit fields and rimoportulae pattern were obtained. Based on this new knowledge the descriptions of the species and of the monotypic genus Sceptronema are emended. Considering that in the protologue three pictures were designated as iconotype, the material from Ría del Jabalí is chosen as an epitype to serve as the interpretative type of Sceptronema orientale. A comparison with the morphologically similar genera Licmophora and Gato was conducted and the inclusion of Sceptronema in the Family Licmophoraceae, Order Licmophorales is proposed.Facultad de Ciencias Naturales y Muse

    A Continued Federal Commitment

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    Levitan and Gallo make use of their considerable experience and prior research to provide a critical assessment of the Job Training Partnership Act (JTPA). The authors evaluate state governments\u27 role in guiding and monitoring the program, and suggest that the success rates are actually lower than the reported official figures. Anyone interested in the JTPA or other job training program will benefit from the assessments provided by the authors in this book.https://research.upjohn.org/up_press/1109/thumbnail.jp

    A Second Chance: Training for Jobs

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    Levitan and Gallo make use of their considerable experience and prior research to provide a critical assessment of the Job Training Partnership Act (JTPA). The authors evaluate state governments\u27 role in guiding and monitoring the program, and suggest that the success rates are actually lower than the reported official figures. Anyone interested in the JTPA or other job training program will benefit from the assessments provided by the authors in this book.https://research.upjohn.org/up_press/1109/thumbnail.jp

    Sprectral data for Generation of Molecular Complexity from Cyclooctatetraene Using Dienyliron and Olefin Metathesis

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    Spectral data used in the course of researching Generation of molecular complexity from cyclooctatetraene using dienyliron and olefin metathesis methodology . Transformation of the simple hydrocarbon cyclooctatetraene into a variety of polycyclic skeletons was achieved by sequential coordination to iron, reaction with electrophiles followed by allylated nucleophiles, decomplexation and olefin metathesis

    Summary of Findings and Recommendations

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    The T in CETA: Local and National Perspectives

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    The editors present a comprehensive study of training programs under CETA based on 11 case studies and national longitudinal data.https://research.upjohn.org/up_press/1214/thumbnail.jp
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