FLSOM with individual kernel radii formation and application to optimization of a pickling line

Updating individually the kernel radii of the neurons according to Van Hulle's approach in the Fuzzy Labeled Self-Organizing Map (FLSOM) algorithm can produce a significant reduction of the mean quantization error as it is demonstrated in this paper using four datasets. The algorithm takes advantage of the available classification of the instances of the dataset since FLSOM is a version of SOM algorithm where the prototype vectors are influenced by the labeling data vectors that define the clusters of the dataset. In this work, the proposed modified version of the FLSOM is able to achieve a better approximation to the numerical variables by means of decreasing the mean quantization error using an individual adaptation of the kernel radii. The aim of this paper is to apply this idea to a pickling line of the steel industry to obtain a model trained with categorical and numerical process variables preserving the topological distribution of the output space in order to reach a visualization of the industrial process and estimate the optimum line speed that minimizes the pickling defects over the steel strip.     

Biotransamination of Furan-Based Aldehydes with Isopropylamine: Enzyme Screening and pH Influence

Furan-based amines are highly valuable compounds which can be directly obtained via reductive amination from easily accessible furfural, 5-(hydroxymethyl)furfural (HMF) and 2,5-diformylfuran (DFF). Herein the biocatalytic amination of these carbonyl derivatives is disclosed using amine transaminases (ATAs) and isopropylamine (IPA) as amine donors. Among the different biocatalysts tested, the ones from Chromobacterium violaceum (Cv-TA), Arthrobacter citreus (ArS-TA), and variants from Arthrobacter sp. (ArRmut11-TA) and Vibrio fluvialis (Vf-mut-TA), afforded high levels of product formation (>80 %) at 100–200 mM aldehyde concentration. The transformations were studied in terms of enzyme and IPA loading. The pH influence was found as a key factor and attributed to the imine/aldehyde equilibrium that can arise from the high reactivity of the carbonyl substrates with a nucleophilic amine such as IPA.     

Rosette formation by macrophages with adhered T lymphocytes is precluded by inhibitors of antigen processing and presentation

We had previously found in autologous human leukocyte cultures, in which dead neutrophils phagocytosis by macrophages occur, macrophages and T CD4 lymphocytes perform a selective cell-cell interaction showing many figures of either one, two or several T- lymphocytes adhering to a central macrophage were seen. Considering that antigen presentation would be necessary for the formation of these immune synapses, we attempted to block rosette formation (i.e., the formation of macrophage associations with at least three lymphocytes) by interfering with both antigen processing and presentation. Culture samples of autologous leukocytes from 7 healthy donors were subjected to either brefeldin A, chloroquine or to an anti-HLA DR antibody. Rosette formation was significantly inhibited in the treated samples (either with brefeldin A, chloroquine or the anti- HLA DR; ANOVA, p<0.001, as compared with the untreated controls). It is concluded that interference with antigen processing and presentation precludes the formation of these cell-cell interactions.     

Physical-Chemical Characterization of Nanodispersed Powders Produced by a Plasma-Chemical Technique

This article presents a review on the physical-chemical properties and characteristics of plasma-chemically produced nanodispersed powders （NDP）, such as metals, oxides, nitrides, carbides, and catalysts. The plasma-chemical preparatior~ of the powders was carried out in thermal plasma （TP） created by means of high-current electric arcs, plasma jets, high-frequency （HF） discharges, etc. We also discuss certain properties and characteristics of the NDPs, which are determined largely by the conditions of preparation.     

Content of trans-fatty acids in edible margarines

Fatty acid composition, including trans-isomers, was determined for four types of imported margarines consumed by the Bulgarian population. The results were compared with data obtained from a Bulgarian edible margarine produced under German license. Fatty acid composition and trans-isomer content were determined by gas chromatography of fatty acid methyl esters on a packed and capillary column, respectively. The total contents of trans-isomers of oleic and linoleic acid were within the ranges of 1.9–8.0% and 0.4–1.4%, respectively. The Bulgarian margarine contained similar quantities of trans-isomers.     

Indoor air pollution in a Mexican indigenous community: evaluation of risk reduction program using biomarkers of exposure and effect

Indoor air pollution can be an important risk factor for human health, considering that people spend more than 60% of their time indoors. Fifty percent of the world population and approximately 90% of the rural population in developing countries are using biomass as energy source. Latin America represents 12% of the global consumption of biomass; in Mexico, 27 million people use wood as an energy source. Therefore, in this study we evaluated a 3-stage risk reduction program. The stages were: 1) removal of indoor soot adhered to roofs and internal walls; 2) paving the dirt floors; and 3) introduction of a new wood stove with a metal chimney that expels smoke outdoors. The complete intervention program was applied. In 20 healthy subject residents from an indigenous community in San Luis Potosí, Mexico, we measured blood carboxyhemoglobin (% COHb), DNA damage (comet assay) in nucleated blood cells, and urinary 1-OHP levels before and after the program. Before intervention individuals had a geometric mean COHb level of 4.93% and 53% of the population presented levels above 2.5% considered a safe level. However, in all the studied individuals the levels of COHb were reduced to below 2.5% (mean level 1.0%) one month after the intervention. Moreover, when compared, DNA damage in people exposed before the intervention was higher (5.8+/-1.3 of Tail Moment) than when the program was introduced (2.8+/-0.9 of Tail Moment) (P>0.05) and a same trend was observed with urinary 1-OHP levels; 6.71+/-3.58 micromol/mol creatinine was the concentration before intervention; whereas, 4.80+/-3.29 micromol/mol creatinine was the one after the program. The results suggest that the intervention program offers an acceptable risk reduction to those families that use biomass for food cooking.     

Visual 3-D SLAM from UAVs

The aim of the paper is to present, test and discuss the implementation of Visual SLAM techniques to images taken from Unmanned Aerial Vehicles (UAVs) outdoors, in partially structured environments. Every issue of the whole process is discussed in order to obtain more accurate localization and mapping from UAVs flights. Firstly, the issues related to the visual features of objects in the scene, their distance to the UAV, and the related image acquisition system and their calibration are evaluated for improving the whole process. Other important, considered issues are related to the image processing techniques, such as interest point detection, the matching procedure and the scaling factor. The whole system has been tested using the COLIBRI mini UAV in partially structured environments. The results that have been obtained for localization, tested against the GPS information of the flights, show that Visual SLAM delivers reliable localization and mapping that makes it suitable for some outdoors applications when flying UAVs.     

Slow initiation by tert-butoxybenzenes in living cationic polymerization of isobutylene

Summary tert-Butoxybenzenes including the 4-substituted derivatives of anisole, toluene and p-chlorobenzene have been synthesized and studied as initiators in combination with TiCl₄ for polymerization of isobutylene (IB) in CH₂Cl₂/methylcyclohexane (MeCHx) solvent mixtures at -78°C. Living polymerizations with slow initiation were observed by the allmonomer-in (AMI) and incremental monomer addition (IMA) techniques, and polymers with narrow molecular weight distribution (MWD) (M_w/M_n>1.1) were obtained under certain conditions. Aging of the initiating system prior to charging the monomer does not improve the initiating efficiency. It has been found that the initiating efficiency can be increased by increasing the solvent polarity, however, the relative volume of CH₂Cl₂ is limited in order to avoid polymer precipitation and bimodal MWD.     

Freeze substitution followed by low melting point wax embedding preserves histomorphology and allows protein and mRNA localization techniques

Fixation and embedding are major steps in tissue preservation for histological analysis. However, conventional fixatives like aldehyde‐based solutions usually mask tissular epitopes preventing their immunolocalization. Alternative fixation methods used to avoid this drawback, such as cryopreservation, alcohol‐ or zinc salts‐based fixatives do not efficiently preserve tissue and cell morphology. Likewise, paraffin and resin embedding, commonly used for thin sectioning, frequently damage epitopes due to the clearing agents and high temperatures needed along the embedding procedure. Alternatives like cryosectioning avoid the embedding steps but yield sections of poorer quality and are not suitable for all kinds of samples. To overcome these handicaps, we have developed a method that preserves histoarchitecture as well as tissue antigenic properties. This method, which we have named CryoWax, involves freeze substitution of the samples in isopentane and methanol, followed by embedding in low melting point polyester wax. CryoWax has proven efficient in obtaining thin sections of embryos and adult tissues from different species, including amphioxus, zebrafish, and mouse. CryoWax sections displayed optimal preservation of tissue morphology and were successfully immunostained for fixation‐ and temperature‐sensitive antigens. Furthermore, CryoWax has been tested for in situ hybridization application, obtaining positive results. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.     

Note: Coherent detection of terahertz radiation employing a continuous wave optical parametric source

The combination of an all-optical terahertz source with a photoconductive antenna to achieve coherent detection is presented. This approach aims to overcome the frequency limits introduced by optoelectronic terahertz sources commonly used. Here the Gaussian-shaped and linearly polarized terahertz waves are generated by a continuous wave optical parametric oscillator with a power of 3 μW at 1.4 THz. The infrared signal light of the optical parametric oscillator can be used to coherently detect the generated terahertz wave with a photoconductive antenna. As a proof-of-principle experiment we determine the thickness profile of a plastic lens using phase shifting interferometry.