SELECTION OF NUMERICAL AND NOMINAL FEATURES BASED ON PROBABILISTIC DEPENDENCE BETWEEN FEATURES

Data classification tasks often concern objects described by tens or even hundreds of features. Classification of such high-dimensional data is a difficult computational problem. Feature selection techniques help reduce the number of computations and improve classification accuracy.

In Michalak and Kwasnicka (2006a Michalak , K. , and H. Kwasnicka . 2006a . Correlation-based feature selection strategy in classification problems . Applied Mathematics and Computer Science 16 ( 4 ): 503 – 511 . [Google Scholar], b Michalak , K. , and H. Kwasnicka . 2006b. Correlation-based feature selection strategy in neural classification. In ISDA'06: Proceedings of the sixth international conference on intelligent systems design and applications (ISDA'06) , 741–746. Washington , DC , USA : IEEE Computer Society. [Google Scholar]) we proposed a feature selection strategy that selects features in an individual or pairwise manner based on the assessed level of dependence between features. In the case of numerical features, this level of dependence can be expressed numerically using linear correlation coefficients. In this paper, the feature selection problem is addressed in the case of a mixture of nominal and numerical features. The feature similarity measure used in this case is based on the probabilistic dependence between features. This similarity function is used in an iterative feature selection procedure, which we proposed for selecting features prior to classification. Experiments prove that using the probabilistic dependence similarity function along with the presented feature selection procedure can improve computation speed while preserving classification accuracy in the case of mixed nominal and numerical features.     

Effects of Polar Organic Solvent on Separation of Y （edta）^-／Nd （edta）^- Complexes on Polyacrylic Anion Exchangers

The use of polar organic solvents for the separations of rare earth elements ( Ⅲ ) is effective especially for their extensive separations despite the solubility limitations.The study shows that polyaerylate anion exchangers, particularly the weakly basic, gel anion exchanger Ambedite IRA 68,can be applied to the separation of rare earth complexes with EDTA in H20-metthanol and H20-ethanol systems.In most cases the determined distribution coefficients of Ln^3 complexes with EDTA in mixed media like water-methanol on polyacrylate anion exchangers are larger than those in pure water media.     

Natural Fermentation of Lentils: Influence of Time,Concentration and Temperature on the Kinetics of Hydrolysis of Inositol Phosphates

Lentil (Lens culinaris var vulgaris) flour was naturally fermented for 96 h at various conditions of concentration (79, 150 and 221 g litre⁻¹) and temperature (28°C, 35°C and 42°C). The content of total inositol phosphates (IP-total) and individual inositol phosphates (hexa- (IP₆), penta- (IP₅), tetra- (IP₄) and tri- (IP₃) phosphates) were analysed to establish the changes of these compounds during natural fermentation of lentils. The preparation of the lentil suspension brought about 16–27% reduction of the total inositol phosphates. At the end of 96 h of natural fermentation maximum IP loss (70–75%) was achieved for an experiment carried out at minimum concentration. For IP₆, the largest decrease was achieved at the highest temperature, the fermentation condition that also brought about the highest IP₅ content.     

By-products of ethoxylation of simple alcohols in the presence of tripropylamine

Ethoxylation of simple alcohols such as methanol, ethanol and butanol in the presence of tripropylamine, in addition to the main reaction products, results in by-products from tripropylamine and ethylene oxide. This side-reaction consumes tripropylamine, forming dipropylamine ethoxylates and alcohol ethoxylates. These compounds remain in the product and influence the commercial properties of alcohol oxyethylates.     

Inhibitory Potential of New Phenolic Hydrazide-Hydrazones with a Decoy Substrate Fragment towards Laccase from a Phytopathogenic Fungus: SAR and Molecular Docking Studies

Laccase from pathogenic fungi participates in both the delignification and neutralization of phytoantibiotics. Furthermore, it interferes with the hormone signaling in plants and catalyzes melanization. Infections of these pathogens contribute to loss in forestry, agriculture, and horticulture. As there is still a need to expand knowledge on efficient defense strategies against phytopathogenic fungi, the present study aimed to reveal more information on the molecular mechanisms of laccase inhibition with natural and natural-like carboxylic acid semi-synthetic derivatives. A set of hydrazide-hydrazones derived from carboxylic acids, generally including electron-rich arene units that serve as a decoy substrate, was synthesized and tested with laccase from Trametes versicolor. The classic synthesis of the title inhibitors proceeded with good to almost quantitative yield. Ninety percent of the tested molecules were active in the range of K_I = 8–233 µM and showed different types of action. Such magnitude of inhibition constants qualified the hydrazide-hydrazones as strong laccase inhibitors. Molecular docking studies supporting the experimental data explained the selected derivatives’ interactions with the enzyme. The results are promising in developing new potential antifungal agents mitigating the damage scale in the plant cultivation, gardening, and horticulture sectors.     

Heme Oxygenase-1 Has a Greater Effect on Melanoma Stem Cell Properties Than the Expression of Melanoma-Initiating Cell Markers

Melanoma-initiating cells (MICs) contribute to the tumorigenicity and heterogeneity of melanoma. MICs are identified by surface and functional markers and have been shown to display cancer stem cell (CSC) properties. However, the existence of MICs that follow the hierarchical CSC model has been questioned by studies showing that single unselected melanoma cells are highly tumorigenic in xenotransplantation assays. Herein, we characterize cells expressing MIC markers (CD20, CD24, CD133, Sca-1, ABCB1, ABCB5, ALDH^high) in the B16-F10 murine melanoma cell line. We use flow cytometric phenotyping, single-cell sorting followed by in vitro clonogenic assays, and syngeneic in vivo serial transplantation assays to demonstrate that the expression of MIC markers does not select CSC-like cells in this cell line. Previously, our group showed that heme-degrading enzyme heme oxygenase-1 (HO-1) can be upregulated in melanoma and increase its aggressiveness. Here, we show that HO-1 activity is important for non-adherent growth of melanoma and HO-1 overexpression enhances the vasculogenic mimicry potential, which can be considered protumorigenic activity. However, HO-1 overexpression decreases clone formation in vitro and serial tumor initiation in vivo. Thus, HO-1 plays a dual role in melanoma, improving the progression of growing tumors but reducing the risk of melanoma initiation.     

The effects of cereal substrate and temperature on production of beauvericin, moniliformin and fusaproliferin by Fusarium subglutinans ITEM-1434

One strain of Fusarium subglutinans (ITEM-1434) isolated from maize ear rot in Poland was tested for the ability to synthesize moniliformin (MON), beauvericin (BEA) and fusaproliferin (FP) on six cereal substrates (wheat, rye, barley, oat, maize and rice kernels) for 3 weeks at 25oC and on rice at three different temperatures (20, 25 and 30oC). Most MON (497 mug/g) was produced on rice; most BEA (704 mug/g) on wheat or rice, and most FP (422 mug/g) on rye. When cultured on rice, F. subglutinans produced the highest levels of BEA and FP at 20-25oC, while MON production was best at 30oC.     

One-pot synthesis of (E)-2-nonenal from castor oil

A one-step procedure for the preparation of (E)-2-nonenal from commercial castor oil by ozonolysis in acetic acid, followed by exposure of the resulting intermediate product top-toluene sulfonic acid, is described. The manufactured aldehyde is of high purity and the method, by virtue of being simple and using inexpensive raw material, has advantages over those reported in the literature.     

Proteinous amino acids in muscle cytosol of rats' heart after exercise and hypoxia

Levels of 19 proteinous amino acids and of total free amino acids were assayed by gas-liquid chromatography in cytosols of rat atrial and ventricular heart muscle cardiomyocytes. These amino acids were assayed after the rats had been exposed to either exercise (swimming) or hypoxia (hypobaric pressure of 686 hectoPascals). Out of the total free amino acids levels of arginine, glutamine and cysteine in atrial and ventricular cardiac muscle cytosols of control rats were the highest of all amino acids assayed. The control levels of all other amino acids assayed in atrial or ventricular cardiac muscles ranged from 0.1% to 10.6% of the total free amino acids in the control rats. Physical stress (exercise and hypoxia) significantly reduced the total amount of cytosolic free amino acids in both heart muscles. While hypoxia decreased the levels of arginine in both heart muscles, exercise abolished the level of cysteine in the atrial heart muscle. Decrease in arginine levels, and elimination of cysteine from the heart's atrial muscle after physical stress, may be attributed to its utilization of nitric oxide and to its synthesis of atriopeptin and/or endothelin during stress. No change was recorded in either experimental group in the level of glutamine in heart muscle cytosol. Exercise and hypoxia affect, in different modes, the levels of all other amino acids assayed, except for tryptophan, tyrosine, and histidine, which are precursors of endogenous neurotransmitters. The impact of proteinous amino acids on some bodily functions is discussed.