A search space reduction methodology for data mining in large databases

Given the present need for Customer Relationship and the increased growth of the size of databases, many new approaches to large database clustering and processing have been attempted. In this work, we propose a methodology based on the idea that statistically proven search space reduction is possible in practice. Two clustering models are generated: one corresponding to the full data set and another pertaining to the sampled data set. The resulting empirical distributions were mathematically tested to verify a tight non-linear significant approximation.     

Pheromone Response Inhibitors of the Corn Stalk Borer Sesamia nonagrioides. Biological Evaluation and Toxicology

The behavioral activity of some trifluoromethyl ketones (TFMKs) as inhibitors of the pheromone activity of the corn stalk borer Sesamia nonagrioides (Lef.) (Lepidoptera: Noctuidae) is reported. The most closely-related analogue to the pheromone tested, (Z)-11-hexadecenyl trifluoromethyl ketone (Z11-16:TFMK), elicited a significant decrease in the number of male catches in traps baited with mixtures with the pheromone in 1:1 and 10:1 ratios in comparison to the pheromone alone. The E isomer of the analogue as well as two highly hydrated ketones, 3-octylthio-1,1,1-trifluoropropan-2-one (OTFP) and 1,1-difluoropentadecyl trifluoromethyl ketone, were inactive. Conversely, the saturated TFMKs n-dodecyl trifluoromethyl ketone and, particularly, n-hexadecyl trifluoromethyl ketone induced a synergistic effect when mixed with the synthetic pheromone in 10:1 ratio. However, in a wind tunnel these chemicals did not elicit any differential effect on flying moths attracted to a source containing a 10:1 blend of the analogue and the pheromone. In a dual choice bioassay with two dispensers, containing the pheromone alone, and mixtures of Z11-16:TFMK and the pheromone and separated 5 cm apart, males showed no particular preference for either dispenser. The ketone mixture, however, induced moths to execute erratic flights with frequent crosswind counter-turns and intersections with plume boundaries. The total number of contacts with the source were reduced when a control dispenser was paired with a dispenser containing Z11-16:TFMK and pheromone. Z11-16:TFMK and OTFP showed little toxicity on mice with a LD₅₀ of 1 g/kg after the 6th day of treatment. For comparitive purposes, the major component of the pheromone, Z11-16:Ac, displayed a LD₅₀ of 5 g/kg 6 days after application. Our results provide additional information about the activity of the TFMKs, which might be useful for the utilization of these chemicals in future pest control studies.     

Structural and electrical properties of grain boundaries in Ce0.85Gd0.15O1.925 solid electrolyte modified by addition of transition metal ions

In this work we present studies on applicability of transition metal additives as sintering and electrical conductivity aids for cerium gadolinium oxide electrolyte. The nanosized Ce_0.85Gd_0.15O_1.925 powder obtained by coprecipitation method was modified with Cr³⁺, Fe³⁺, Ni²⁺ or Cu²⁺ ions. Using high-intensity high-resolution X-ray powder diffraction data we have determined that Cr, Fe and Ni ions do not incorporate into the cerium gadolinium oxide surface or bulk when sintered at 1300 °C, but react with Gd ions to form Cr_0.9Gd_0.1O, GdFeO₃ and GdNiO₃ phases, while Cu incorporates in the material up to 0.7 mol% with a significant fraction of remaining material showing poorly crystalline CuO phase. The nanosized Ce_0.85Gd_0.15O_1.925 material shows already improved sintering properties than previous reports but full sintering is not achieved below 1300 °C, however Cr, Fe and mainly Cu impregnation allows full sintering at 1300 °C. 0.5 mol% Ni impregnated material sintered at 1500 °C shows enhanced grain boundary conductivity that probably indicates that Ni incorporates into Ce_0.84Gd_0.15O_1.925 above 1300 °C. The global results indicate, however, that optimization of ceria microstructure is at least of equal importance for sinterability and grain boundary conductivity than impregnation of the material with transition metal ions.     

Molecular identification of nine commercial flaffish species by polymerase chain reaction-restriction fragment length polymorphism analysis of a segment of the cytochrome b region

Commercial refrigerated or frozen flatfish fillets are sometimes mislabeled, and identification of these mislabeled products is necessary to prevent fraudulent substitution. Identification of nine commercial flatfish species (order Pleuronectiformes), Hippoglossus hippoglossus (halibut), Lepidorhombus boscii (four-spotted scaldfish), Lepidorhombus whiffiagonis (megrin), Platichthys flesus (flounder), Pleuronectes platessa (European plaice), Reinhardtius hippoglossoides (Greenland halibut), Scophthalmus maximus (turbot), Scophthalmus rhombus (brill), and Solea vulgaris (=Solea solea) (sole), was carried out on the basis of the amplification of a 486-bp segment of the mitochondrial genome (tRNA(Glu)/cytochrome b) by using the polymerase chain reaction (PCR) and universal primers. Sequences of PCR-amplified DNA from the flatfish species were used to select eight restriction enzymes (REs). The PCR products were cut with each RE, resulting in species-specific restriction fragment length polymorphism. Seven species groups could be identified by application of the single RE DdeI and six species groups by using HaeIII, HinfI, MaeI, or MboI. Different combinations of only a couple of these REs could unambiguously identify the nine flatfish species. Genetic polymorphisms of the target sequence were examined by comparison with previously published DNA sequences, and the results of this comparison confirmed the usefulness of this technique in distinguishing and genetically characterizing refrigerated or frozen pieces of these nine flatfish species.     

A fiber-optic fluorescence sensor for lithium ion in acetonitrile

A novel fiber-optic fluorescence sensor based on a controlled-release reagent for the determination of lithium ion in organic solvents is proposed. The fluorogenic indicator 2-(2-hydroxyphenyl)benzoxazole is contained in a mini-polyethylene tube as the reagent reservoir and is brought into contact with the analyte solution by diffusion across a poly(vinyl chloride) (PVC) membrane to form a strongly fluorescent complex at the membrane/solution interface. The fluorescence signals produced are measured via two joined optical fibers positioned closely to the backside of the PVC membrane for light illumination and collection. The sensor is useful for measuring Li+ at concentrations in acetonitrile ranging from 1.0 x 10(-6) to 1.0 x 10(-2) M with a detection limit of 3.0 x 10(-7) M. The steady-state response can be reached within seconds, and the signal changes are fully reversible. The sensor shows minimal interference effects from other alkali metal and alkaline earth metal cations and has good stability and durability when stored in acetonitrile solutions.     

Control of a Robotic Wheelchair Using Recurrent Networks

This paper describes an adaptive neural control system for governing the movements of a robotic wheelchair. It presents a new model of recurrent neural network based on a RBF architecture and combining in its architecture local recurrence and synaptic connections with FIR filters. This model is used in two different control architectures to command the movements of a robotic wheelchair. The training equations and the stability conditions of the control system are obtained. Practical tests show that the results achieved using the proposed method are better than those obtained using PID controllers or other recurrent neural networks models     

Automatic texture feature selection for image pixel classification

Pixel-based texture classifiers and segmenters are typically based on the combination of texture feature extraction methods that belong to a single family (e.g., Gabor filters). However, combining texture methods from different families has proven to produce better classification results both quantitatively and qualitatively. Given a set of multiple texture feature extraction methods from different families, this paper presents a new texture feature selection scheme that automatically determines a reduced subset of methods whose integration produces classification results comparable to those obtained when all the available methods are integrated, but with a significantly lower computational cost. Experiments with both Brodatz and real outdoor images show that the proposed selection scheme is more advantageous than well-known general purpose feature selection algorithms applied to the same problem.     

Circadian rhythm of fatty acid desaturation in mouse liver

A study was made of the diurnal changes in liver microsomal desaturation of labeled stearic, linoleic and α-linolenic acids to oleic, γ-linolenic and octadeca-6,9,12,15-tetraenoic acids, respectively. C3H-S mice were used and were exposed to light-dark cycles. A circadian rhythm was observed for stearic acid desaturation, and a different one for linoleic acid. Linoleic and α-linolenic desaturation had similar responses in the day cycle. This would indicate that different mechanisms control the oxidative desaturations of the fatty acids in the 9 and 6 carbons. The fatty acid composition of the whole liver and liver microsomes also showed variations. Remarkable oscillations were observed for stearic and oleic acids. Neither the total protein synthesis nor the free fatty acid concentration in the microsomes followed a rhythm parallel to the desaturation of the studied fatty acids. The injection of cycloheximide 4 hr before measuring the desaturation modified the circadian variation of both the 9 and 6 desaturations. The modification induced by cycloheximide was considered to indicate that both variations are related to the synthesis of specific proteins but not to that of a degradative or inhibitory protein.     

Nutritional and antioxidant status of an institutionalized elderly group in Murcia (Spain)

The aging of the population is giving rise to a large number of studies aimed at improving the quality of life, considering diet as a major contributing factor in this life stage. The objectives of the present study were to evaluate the nutritional status of a group of institutionalized elderly in Murcia, Spain, and to relate the diet to anthropometric and biochemical indices, paying special attention to total antioxidant status. The dietary evaluation showed excessive intakes of proteins and lipids, and deficiencies in those of carbohydrates, dietary fiber, zinc, iodine and vitamins A, E and D. The high proportion of overweight observed were not significantly correlated to the energy intakes. Although total plasma antioxidant status was low (0.62 mM eq Trolox and 0.98 mM eq Fe(II)) compared with reference values, estimated oxidative risk in this group of elderly was low according to plasma levels of vitamins C, A & E.