474 research outputs found
Preassociative aggregation functions
The classical property of associativity is very often considered in
aggregation function theory and fuzzy logic. In this paper we provide
axiomatizations of various classes of preassociative functions, where
preassociativity is a generalization of associativity recently introduced by
the authors. These axiomatizations are based on existing characterizations of
some noteworthy classes of associative operations, such as the class of
Acz\'elian semigroups and the class of t-norms.Comment: arXiv admin note: text overlap with arXiv:1309.730
Condições bióticas da distribuição de Pontoscolex corethrurus (Glossocolecidae), em diferentes tipos de uso de solo.
FORMACIÓN DEL DIREGENTE ESTUDIANTIL UNIVERSITARIO PARA EL LIDERAZGO
Los dirigentes estudiantiles universitarios se distinguen del resto del estudiantado por sus manifestaciones de liderazgo dentro del grupo escolar, sin embargo, no es lo mismo ser líder en el grupo, que ejercer el liderazgo en su desempeño directivo. Para diagnosticar la influencia de los dirigentes estudiantiles en los procesos institucionales de la Universidad de Ciego de Ávila, se determinaron dimensiones e indicadores que evidenciaron como contradicción las necesidades formativas para el ejercicio de la dirección estudiantil y su desempeño directivo. Este trabajo tiene el objetivo de contribuir a la formación del liderazgo en los dirigentes estudiantiles, y para atender esta carencia en el proceso de formación profesional, se elaboró un sistema de actividades extracurriculares, sustentado en elementos de psicología de la dirección, con métodos y técnicas encaminadas a la formación del liderazgo de estos dirigentes, supliendo con ello las necesidades cognitivas, procedimentales y actitudinales detectadas desde la caracterización de su desempeño directivo
Subset sum phase transitions and data compression
We propose a rigorous analysis approach for the subset sum problem in the
context of lossless data compression, where the phase transition of the subset
sum problem is directly related to the passage between ambiguous and
non-ambiguous decompression, for a compression scheme that is based on
specifying the sequence composition. The proposed analysis lends itself to
straightforward extensions in several directions of interest, including
non-binary alphabets, incorporation of side information at the decoder
(Slepian-Wolf coding), and coding schemes based on multiple subset sums. It is
also demonstrated that the proposed technique can be used to analyze the
critical behavior in a more involved situation where the sequence composition
is not specified by the encoder.Comment: 14 pages, submitted to the Journal of Statistical Mechanics: Theory
and Experimen
Impacto do uso do solo nas comunidades de aracnídeos de solo em três áreas do Sudoeste do Pará, Brasil.
A novel substitution 1381V in the sterol 14alpha-demethylase (CYP51) of Mycosphaerella graminicola is differentially selected by azole fungicides
The recent reduction in the efficacy of azole fungicides in controlling Septoria leaf blotch of wheat, caused by Mycosphaerella graminicola, has prompted concerns over possible development of resistance, particularly in light of the recent emergence of widespread resistance to quinone outside inhibitors (QoIs). We have recently implicated alterations in the target-encoding sterol 14 alpha-demethylase protein (CYP51), and over-expression of genes encoding efflux pumps, in reducing sensitivity to the azole class of sterol demethylation inhibitors (DMIs) in M. graminicola. Here we report on the prevalence and selection of two CYP51 alterations, substitution I381V and deletion of codons 459 and 460 (Delta Y459/G460), in populations of M. graminicola. Neither alteration has previously been identified in human or plant pathogenic fungi resistant to azoles. The presence of Delta Y459/G460 showed a continuous distribution of EC50 values across isolates with either I381 or V381, and had no measurable effect on azole sensitivity. Data linking fungicide sensitivity with the presence of I381V in M. graminicola show for the first time that a particular CYP51 alteration is differentially selected by different azoles in field populations of a plant pathogen. Substitution I381V although not an absolute requirement for reduced azole sensitivity, is selected by tebuconazole and difenoconazole treatment, suggesting an adaptive advantage in the presence of these two compounds. Prochloraz treatments appeared to select negatively for I381V, whereas other azole treatments did not or only weakly impacted on the prevalence of this substitution. These findings suggest treatments with different members of the azole class of fungicides could offer a resistance management strategy
Gestión de la formación permanente de directivos educacionales
En la dirección educacional se manifiestan insuficiencias en el desempeño de los directivos, como por ejemplo el predominio de una dirección por crisis, la adopción de posiciones defensivas de carácter operativo, deficiencias en la planificación del trabajo, la delegación y otras herramientas, habilidades y capacidades de dirección, la centralización excesiva de las funciones, o el empleo de prácticas y patrones aprendidos de la observación de modelos empíricos no idóneos.
Por lo general, las acciones de formación de directivos se proyectan a partir de una determinación insuficiente de las necesidades y potencialidades reales. Estas insuficiencias están asociadas a la carencia de un modelo ideal de desempeño de los directivos educacionales; y en la dirección educacional se hace poco énfasis en las competencias profesionales que deben poseer los directivos para desempeñarse de manera eficiente.
En el presente trabajo se distinguen los objetivos y principios que deben conducir a la formación permanente de los directivos, y se integran varios resultados científicos, como un modelo por competencias de desempeño ideal del directivo educacional, una tecnología para la determinación de necesidades formativas de los directivos, una estrategia para la formación permanente y una metodología para la evaluación del impacto de las acciones de formación permanente de los directivos educacionales
Influenza A virus-derived defective interfering particles for antiviral treatment
Here, we report on genetically engineered, propagation-incompetent influenza A virus (IAV) particles, so-called defective interfering particles (DIPs) that have been suggested as a promising novel antiviral agent. Typically, IAV DIPs harbor a large internal deletion in one of their eight genomic viral RNA (vRNA) segments. Further, DIPs are capable of hijacking cellular and viral resources upon co-infection with fully infectious standard virus (STV), resulting in an antiviral effect. Besides this replication interference, DIP infection also stimulates innate immunity, adding to the antiviral efficacy.
So far, DIPs were produced in embryonated chicken eggs. To improve scalability and flexibility of processes as well as to increase product quality, we established a cell culture-based DIP production system [1,2]. This includes the development of a genetically engineered virus-cell propagation system that allows production of DIPs without the need to add infectious STV to complement missing gene functions of DIPs. Specifically, the MDCK suspension cell line generated expresses the PB2 protein [2], encoded by segment 1 (S1) of IAV, which is not expressed by “DI244” - a prototypic, well-characterized DIP harboring a deletion in S1. Using this cell culture-based production process in batch [2,3] and perfusion mode [4] at laboratory scale, we show that we can achieve very high DI244 titers of up to 2.6E+11 DIPs/mL. Infections of mice demonstrated that intranasal administration of the produced DI244 material resulted in no apparent toxic effects and in a full rescue of mice co-treated with an otherwise lethal dose of IAV [2].
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