36 research outputs found

    Genetic defects in common variable immunodeficiency

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    Common variable immunodeficiency (CVID) is the most frequent clinically manifested primary immunodeficiency. According to clinical and laboratory findings, CVID is a heterogeneous group of diseases. Recently, the defects of molecules regulating activation and terminal differentiation of B lymphocytes have been described in some patients with CVID. In this study, we show the overview of deficiencies of inducible costimulator, transmembrane activator and calcium-modulator and cytophilin ligand interactor, CD19 molecules, their genetic basis, pathogenesis and clinical manifestations

    Computational and Statistical Analyses of Amino Acid Usage and Physico-Chemical Properties of the Twelve Late Embryogenesis Abundant Protein Classes

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    Late Embryogenesis Abundant Proteins (LEAPs) are ubiquitous proteins expected to play major roles in desiccation tolerance. Little is known about their structure - function relationships because of the scarcity of 3-D structures for LEAPs. The previous building of LEAPdb, a database dedicated to LEAPs from plants and other organisms, led to the classification of 710 LEAPs into 12 non-overlapping classes with distinct properties. Using this resource, numerous physico-chemical properties of LEAPs and amino acid usage by LEAPs have been computed and statistically analyzed, revealing distinctive features for each class. This unprecedented analysis allowed a rigorous characterization of the 12 LEAP classes, which differed also in multiple structural and physico-chemical features. Although most LEAPs can be predicted as intrinsically disordered proteins, the analysis indicates that LEAP class 7 (PF03168) and probably LEAP class 11 (PF04927) are natively folded proteins. This study thus provides a detailed description of the structural properties of this protein family opening the path toward further LEAP structure - function analysis. Finally, since each LEAP class can be clearly characterized by a unique set of physico-chemical properties, this will allow development of software to predict proteins as LEAPs

    Zic3 is required in the migrating primitive streak for node morphogenesis and left-right patterning

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    In humans, loss-of-function mutations in ZIC3 cause isolated cardiovascular malformations and X-linked heterotaxy, a disorder with abnormal left–right asymmetry of organs. Zic3 null mice recapitulate the human heterotaxy phenotype but also have early gastrulation defects, axial patterning defects and neural tube defects complicating an assessment of the role of Zic3 in cardiac development. Zic3 is expressed ubiquitously during critical stages of left–right patterning but its later expression in the developing heart remains controversial and the molecular mechanism(s) by which it causes heterotaxy are unknown. To define the temporal and spatial requirements, for Zic3 in left–right patterning, we generated conditional Zic3 mice and Zic3-LacZ-BAC reporter mice. The latter provide compelling evidence that Zic3 is expressed in the mouse node and absent in the heart. Conditional deletion using T-Cre identifies a requirement for Zic3 in the primitive streak and migrating mesoderm for proper left–right patterning and cardiac development. In contrast, Zic3 is not required in heart progenitors or the cardiac compartment. In addition, the data demonstrate abnormal node morphogenesis in Zic3 null mice and identify similar node dysplasia when Zic3 was specifically deleted from the migrating mesoderm and primitive streak. These results define the temporal and spatial requirements for Zic3 in node morphogenesis, left–right patterning and cardiac development and suggest the possibility that a requirement for Zic3 in node ultrastructure underlies its role in heterotaxy and laterality disorders

    Stomatal design principles in synthetic and real leaves

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    Stomata are portals in plant leaves that control gas exchange for photosynthesis, a process fundamental to life on Earth. Gas fluxes and plant productivity depend on external factors such as light, water and CO(2) availability and on the geometrical properties of the stoma pores. The link between stoma geometry and environmental factors has informed a wide range of scientific fields—from agriculture to climate science, where observed variations in stoma size and density are used to infer prehistoric atmospheric CO(2) content. However, the physical mechanisms and design principles responsible for major trends in stomatal patterning are not well understood. Here, we use a combination of biomimetic experiments and theory to rationalize the observed changes in stoma geometry. We show that the observed correlations between stoma size and density are consistent with the hypothesis that plants favour efficient use of space and maximum control of dynamic gas conductivity, and that the capacity for gas exchange in plants has remained constant over at least the last 325 Myr. Our analysis provides a new measure to gauge the relative performance of species based on their stomatal characteristics

    Separation and pattern formation in hydraulic jumps

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    We present theory and experiments on the circular hydraulic jump in the stationary regime. The theory can handle the situation in which the fluid flows over an edge far away from the jump. In the experiments the external height is controlled, and a series of transitions in the flow structure appears. First the steepening of the jump causes a transition akin to the breaking of a wave, and subsequently a series of shapes appear, which break the azimuthal symmetry. 1 Introduction One of the most well-known examples of strongly non-linear waves is the river bore, which appears when rivers experience strong tides. The tidal waves created at the mouth of the river appears almost like a step in the water level and can run for several miles upstream with almost no change of form [1]. Considering the strong interest in non-linear phenomena and the enormous progress in the understanding of solitary wave motion, it is quite surprising that no theory yet exists for this phenomenon, describing the..

    Supplemental online material from Stomatal design principles in synthetic and real leaves

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    Stomata are portals in plant leaves that control gas exchange for photosynthesis, a process fundamental to life on the Earth. Gas fluxes and plant productivity depend on external factors such as light, water and CO<sub>2</sub> availability and on geometrical properties of the stomata pores. The link between stomata geometry and environmental factors has informed a wide range of scientific fields - from agriculture to climate science, where observed variations in stomata size and density are used to infer prehistoric atmospheric CO<sub>2</sub> content. However, the physical mechanisms and design principles, responsible for major trends in stomatal patterning, are not well understood. Here, we use a combination of biomimetic experiments and theory to rationalize the observed changes in stomatal geometry. We show that the observed correlations between stomatal size and density are consistent with the hypothesis that plants favour efficient use of space and maximum control of dynamic gas conductivity, and that the capacity for gas exchange in plants has remained constant over at least the last 325 myr. Our analysis provides a new measure to gauge the relative performance of species based on their stomatal characteristics
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