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New Layer (new + layer)
Selected AbstractsType III IFNs: New layers of complexity in innate antiviral immunityBIOFACTORS, Issue 1 2009Nina Ank Abstract Cytokines are small secreted molecules, which mediate cross-talk between cells involved in the immune response. Interferons (IFN)s, constitute a class of cytokines with antiviral activities, and the type I IFNs have been ascribed particularly important roles in the innate antiviral response. Type III IFNs (also known as IFN-, or interleukin 28/29) represent a class of novel cytokines with biological activities similar to the type I IFNs, but seem to have a more specialized role in antiviral defense by exerting host-protection primarily at epithelial surfaces. In this review, we describe the current knowledge on the role of type III IFNs in antiviral defense. © 2009 International Union of Biochemistry and Molecular Biology, Inc. [source] A strategy for adding fuzzy types to an object-oriented database systemINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 7 2001N. Marín Fuzzy types have been developed as a new way of managing fuzzy structures. With types of this kind, properties are ordered on different levels of precision or amplitude, according to their relationship with the concept represented by the type. In order to implement this new tool, two different strategies can be followed. On the one hand, a new system incorporating fuzzy types as an intrinsic capability can be developed. On the other hand, a new layer that implements fuzzy types can be added to an existing object-oriented database system (OODB). This paper shows how the typical classes of an OODB can be used to represent a fuzzy type and how the mechanisms of instantiation and inheritance can be modeled using this kind of new type on an OODB. © 2001 John Wiley & Sons, Inc. [source] PHYLOGENETIC ANALYSIS OF PSEUDOCHLORODESMIS STRAINS REVEALS CRYPTIC DIVERSITY ABOVE THE FAMILY LEVEL IN THE SIPHONOUS GREEN ALGAE (BRYOPSIDALES, CHLOROPHYTA),JOURNAL OF PHYCOLOGY, Issue 3 2009Heroen Verbruggen The genus Pseudochlorodesmis (Bryopsidales) is composed of diminutive siphons of extreme morphological simplicity. The discovery of Pseudochlorodesmis -like juveniles in more complex Bryopsidales (e.g., the Halimeda microthallus stage) jeopardized the recognition of this genus. Confronted with this uncertainty, taxonomists transferred many simple siphons into a new genus, Siphonogramen. In this study, we used a multimarker approach to clarify the phylogenetic and taxonomic affinities of the Pseudochlorodesmis-Siphonogramen (PS) complex within the more morphologically complex bryopsidalean taxa. Our analyses reveal a new layer of diversity largely distinct from the lineages containing the structurally complex genera. The PS complex shows profound cryptic diversity exceeding the family level. We discuss a potential link between thallus complexity and the prevalence and profundity of cryptic diversity. For taxonomic simplicity and as a first step toward clarifying the taxonomy of these simple siphons, we propose to maintain Pseudochlorodesmis as a form genus and subsume Siphonogramen and Botryodesmis therein. [source] Snow metamorphism as revealed by scanning electron microscopyMICROSCOPY RESEARCH AND TECHNIQUE, Issue 1 2003Florent Dominé Abstract Current theories of snow metamorphism indicate that sublimating snow crystals have rounded shapes, while growing crystals have shapes that depend on growth rates. At slow growth rates, crystals are rounded. At moderate rates, they have flat faces with rounded edges. At fast growth rates, crystals have flat faces with sharp edges, and they have hollow faces at very fast growth rates. The main growth/sublimation mechanism is thought to be by the homogeneous nucleation of new layers at or near crystal edges. It was also suggested that the equilibrium shape of snow crystals would be temperature dependent: rounded above ,10.5°C, and faceted below. To test these paradigms, we have performed SEM investigations of snow samples having undergone metamorphism under natural conditions, and of snow samples subjected to isothermal metamorphism at ,4° and ,15°C in the laboratory. In general, current theories predicting crystal shapes as a function of growth rates, and of whether crystals are growing or sublimating, are verified. However, the transition in equilibrium shapes from rounded to faceted at ,10.5°C is not observed in our isothermal experiments that reveal a predominance of rounded shapes after more than a month of metamorphism at ,4 and ,15°C. Some small crystals with flat faces that also have sharp angles at ,15°C, are observed in our isothermal experiments. These faces are newly formed, and contradict current theory. Several hypotheses are proposed to explain their occurrence. One is that they are due to sublimation at emerging dislocations. Microsc. Res. Tech. 62:33,48, 2003. © 2003 Wiley-Liss, Inc. [source] | ||||||||||