Antigenic stimuli do not influence thymic B lymphocytes: a morphological and functional study in germ-free and conventionally reared piglets

We have recently reported that thymic B lymphocytes (TBL) are the first B-cell subpopulation undergoing isotype switching to IgG and IgA during embryonic life. The aim of this study is to analyze the influence of antigenic stimulation on TBL location and activity using a germ-free (GF) newborn pig model, in which maternal antibodies and antigens do not affect B-cell development. Immunohistological analysis showed that TBL were disseminated mainly in the thymic medulla. There were no differences in the distribution of TBL, both in GF newborn piglets before and after colonization with Escherichia coli and in older conventionally reared (CONV) piglets. The number of immunoglobulin (Ig)-secreting cells measured by the ELISPOT method was not influenced by microflora and food antigens. IgM-positive cells secreting IgM and CD45RC-positive cells spontaneously producing IgM, IgG, and IgA were detected in newborn thymus. Our findings suggest that TBL differentiation and Ig switching to IgG and IgA-secreting cells is not influenced by external antigens and that the thymic microenvironment plays an important role in this process.     

Improving the testability of switched-capacitor filters

A design-for-test methodology for SC filters is presented, based on an architecture using some additional circuitry and providing extra capabilities for both off- and on-line tests. The approach uses a comparison (voting) mechanism to indicate whether or not two copies of a filter element (a biquad, for instance) have a similar response during their actual operation. The design and implementation of a few filter examples are included to assess the potential usefulness of this new approach.     

Amoebapore homologs of Caenorhabditis elegans

It is shown that the Caenorhabditis elegans genome contains several distantly related members of the gene family of saposin-like proteins. The putative products of genes T07C4.4, T08A9.7A, T08A9.7B, T08A9.8, T08A9.9, T08A9.10 are similar to the amoebapores of Entamoeba histolytica, granulysin of cytotoxic T lymphocytes and a putative amoebapore-related protein of the liver fluke Fasciola hepatica inasmuch as they consist of only a single saposin-like domain and a secretory signal peptide. The saposin-like domain of protein T07C4.4, which is most closely related to NK-lysin and granulysin, has been expressed in Escherichia coli and the recombinant protein was shown to have a circular dichroism spectrum consistent with the helix bundle structure characteristic of saposin-like domains. Recombinant T07C4.4 protein was found to have antibacterial activity, suggesting that these amoebapore homologs may play a role in antibacterial mechanisms of C. elegans.     

Implicit and hybrid methods for attribute weighting in multi-attribute decision-making: a review study

Artificial Intelligence Review - Attribute weighting is a task of paramount relevance in multi-attribute decision-making (MADM). Over the years, different approaches have been developed to face...     

Extension of belief functions to infinite-valued events

We generalise belief functions to many-valued events which are represented by elements of Lindenbaum algebra of infinite-valued ?ukasiewicz propositional logic. Our approach is based on mass assignments used in the Dempster–Shafer theory of evidence. A generalised belief function is totally monotone and it has Choquet integral representation with respect to a unique belief measure on Boolean events.     

Current oscillations in austenitic stainless steel induced by the presence of chloride ions

The conditions for current oscillations in austenitic stainless steel (AISI Type 303) in 1M H₂SO₄ containing Cl^? ions are given. The periodic oscillations are produced in a close potential range determined at the active-passive transition region. It requires a non-homogeneous distribution of inclusions and carbides at the metal surface and a concentration range of Cl^? ion where active and passive areas coexist on the metal surface. The constraints at the surface determining these two regions are related to the Cl^? ion competitive adsorption and the local accumulation of corrosion products. Electrochemical data and SEM observations are correlated.     

Determination of the solubility parameter of poly(ethylene oxide) at 25°C by gas-liquid chromatography

The solubility parameter of poly(ethylene oxide) at 25°C has been determined using the method developed by DiPaola-Baranyi and Guillet, by the extrapolation of the values of the interaction parameter χ, at high temperatures, ranging from 70°–90°, 90°–110° and 110°–130°C down to 25°C. The values of the solubility parameter obtained, depending on the temperature ranges employed, are 9.8, 9.9 and 10.1, respectively.     

Nature-Inspired Meta-Heuristics on Modern GPUs: State of the Art and Brief Survey of Selected Algorithms

Graphic processing units (GPUs) emerged recently as an exciting new hardware environment for a truly parallel implementation and execution of Nature and Bio-inspired Algorithms with excellent price-to-power ratio. In contrast to common multicore CPUs that contain up to tens of independent cores, the GPUs represent a massively parallel single-instruction multiple-data devices that can nowadays reach peak performance of hundreds and thousands of giga floating-point operations per second. Nature and Bio-inspired Algorithms implement parallel optimization strategies in which a single candidate solution, a group of candidate solutions (population), or multiple populations seek for optimal solution or set of solutions of given problem. Genetic algorithms (GA) constitute a family of traditional and very well-known nature-inspired populational meta-heuristic algorithms that have proved its usefulness on a plethora of tasks through the years. Differential evolution (DE) is another efficient populational meta-heuristic algorithm for real-parameter optimization. Particle swarm optimization (PSO) can be seen as nature-inspired multiagent method in which the interaction of simple independent agents yields intelligent collective behavior. Simulated annealing (SA) is global optimization algorithm which combines statistical mechanics and combinatorial optimization with inspiration in metallurgy. This survey provides a brief overview of the latest state-of-the-art research on the design, implementation, and applications of parallel GA, DE, PSO, and SA-based methods on the GPUs.     

Effects of the nitrification inhibitor N-Serve on the utilization of fall-applied urea by wheat

Four-year microplot tests were performed to study the utilization by wheat, in the presence and absence of the nitrification inhibitor N-Serve, of¹⁵N labeled urea spread in fall. The percentages of fertilizer nitrogen taken up by winter wheat (grains and straw) were 18 to 37 percent when urea was spread in fall, 33 to 45 percent when urea plus N-Serve was applied in fall, and 36 to 49 percent when urea was spread in spring. In the 0–30 cm layer of soil there were found, for the treatments listed above, 15 to 23 percent, 24 to 45 percent, and 15 to 47 percent of urea nitrogen after the harvesting of winter wheat. Application of urea plus N-Serve in fall and of urea alone in spring resulted in similar amounts of fertilizer nitrogen being taken up by spring wheat to those taken up by winter wheat. Of the urea nitrogen applied in fall, 20 to 28 percent and 47 to 50 percent were not recovered from the plants and 0–30 cm soil layer with and without additional N-Serve treatment, respectively. The utilization by winter wheat of urea nitrogen spread, with no additional N-Serve, in fall from mid-October onward was considerably lower in those cases where, after fertilizing, weather conditions were such as to favour both nitrification and leaching. On heavy and loamy soil such influences of weather were offset by application of N-Serve.     

Experimental observation of temperature gradients occurring in a single zeolite pellet

An experimental study has been made of temperature profiles incident within a zeolite adsorbent particle in the course of adsorption of n-heptan. Using thermocouple wires 0.1 mm in diameter it has been possible to measure simultaneously the temperatures of the surface and in the centre. It was observed that temperature differences between center of the pellet and ambient stagnant gas may be more than 20°C. The results of this work indicate that the overheating of an adsorbent particle is a very rapid process which is followed by a slow cooling of the hot particle. Experimental data are compared with predictions calculated from the theoretical model.