Robust visualization of strange attractors using affine arithmetic

We propose the use of affine arithmetic in cell-mapping methods for the robust visualization of strange attractors and show that the resulting cellular approximations converge faster than those produced by cell-mapping methods based on classical interval arithmetic.     

Cytotoxic effects of permethrin on mouse liver and spleen cells

This study analyzed the histopathological and histochemical effects of different dosages of permethrin on liver and spleen cells of mice, in order to evaluate the toxic potential of this substance and the possible impairments that this chemical causes in different tissues of nontarget organisms (laboratorial conditions). The results showed that permethrin caused severe alterations in the liver cells, reducing the size of the nuclei and causing hydropic degeneration of the hepatocytes, in addition to stimulating the proliferation of Kupffer cells, altered the amount of proteins, polysaccharides, lipids, and vacuoles in the cytoplasm of the hepatocytes and congested the hepatic capillaries. As for the spleen of the treated mice, no alterations were observed in the morphology in relation to the control group, what would suggest that the spleen would continue performing its functions, without suffering morphological alterations even in the presence of the toxic agent.     

Morphological analysis of colon goblet cells and submucosa in type I diabetic rats submitted to physical training

Colon layers, especially the submucosa, as well as the secretion of goblet cells are extremely important for the functioning and transit of substances in this organ. However, the damages arising from type I diabetes and the effects of physical training, which plays crucial role in the treatment of this disease, are not yet known in these regions. To analyze the changes in colon submucosa and goblet cells of diabetic rats, as well as the effects of physical training, Wistar rats were divided into four groups: sedentary control, trained control, sedentary diabetic (SD), and trained diabetic (TD). The training protocol consisted of swimming for 60 min a day, 5 days per week, during 8 weeks. Colon samples were collected, processed, and evaluated by histochemical and ultrastructural techniques. Goblet and submucosa cells did not show alterations in shape, size, protein and carbohydrate content, in all treatment groups. Decreased amount of collagen fibers, however, was observed in the submucosa and lamina propria of SD rats, but this alteration was recovered in TDs. The ultrastructural analysis, in turn, revealed greater quantity of Golgi apparatus cisterns in SDs, distinctly than TDs, which showed improvement in this diabetic condition. Thus, physical training was responsible for the recovery of some important diabetic alterations, possibly improving the motility of substances in the large intestine. Nevertheless, it cannot be considered alone in the treatment of this disease, requiring the combined practice of other methods.     

Acquisition of Water Solubility Diagrams in Ternary Systems (AOT/Organic Solvent/Alcohol) and Extraction of α-Lactalbumin Using Reverse Micellar Systems

In this study water solubility curves were constructed and calorimetric measurements obtained for reverse micellar systems consisting of an alcohol (isopropanol or butanol), surfactant (AOT) and organic solvent (isooctane or hexane). Also evaluated were the effects of alcohol and solvent type and surfactant concentration on the extraction of the α-lactalbumin (α–la). From the obtained solubility diagrams for ternary systems, it was concluded that isooctane presented the highest water solubility capacity in the center of the micelle systems with hexane, since isooctane has greater molecular volume and greater effect of the surfactant aggregation number. With respect to the alcohols, it was observed that isopropanol and butanol act in the system as a co-surfactant, since they prefer to adsorb at the water/solvent interface. It was also verified that butanol improved water solubility inside the reverse micellar due to its contribution to increase the critical packing parameter. The amount of α-la extracted increased proportionally with the AOT concentration for systems with isooctane and hexane. However, for systems with the latter solvent, the concentration of extracted protein first increases and then decreases. The extraction power of reverse micellar systems with isooctane was influenced by the type of alcohol with butanol showing better results. For systems containing hexane there was no effect of the alcohol added to the system on extraction power of α-lactalbumin.     

Evaluation of the etching and chrome plating on the ABS,PVC, and PVC/ABS blends surface

As replacement for acrylonitrile‐butadiene‐styrene (ABS), which is commonly used in the manufacture of chrome parts, polyvinyl chloride (PVC) and PVC/ABS blend parts were produced by injection process, etched in sulfochromic solution in different concentrations, immersion time, and temperature, and they were subsequently chrome‐plated by conventional method. After etching, the sample surfaces were analyzed by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), roughness, and contact angle, and compared with the ABS surface. The metal deposition was assessed by visual inspection and adhesion test. The roughness influenced the adhesion of the metal layer directly. The chemical etching increased the surface wettability. To achieve a good metal layer adhesion, higher temperatures, immersion time, and etching solution concentration were necessary. A concentration of 350 g/L chromic acid and 400 g/L sulfuric acid, a 70 °C temperature and a 15 min immersion time resulted in good adhesion in PVC and PVC/ABS blends. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44571.     

β-Carotene and Milk Protein Complexation: a Thermodynamic Approach and a Photo Stabilization Study

The demand for bioactive molecules, such as β-carotene (β-car), has increased, but some characteristics such as low water solubility and low photo stability limit its application in many formulations. The bioactive entrapment into milk proteins may overcome this barrier. Thus, the aim of this work was to study the interaction between β-car and bovine serum albumin (BSA) or β-casein and the photo stability of this bioactive in the presence of the proteins. Fluorescence spectroscopy showed that at pH 7.0, increasing concentrations of β-carotene reduced the fluorescence intensity of both proteins, and the fluorescence-quenching mechanism is mainly static. The stoichiometry of the β-car/protein complex varied between proteins, being 1:1 to native BSA, 1:3 to denatured BSA (d-BSA), and 1:2 for β-casein. The standard Gibbs-free energy (ΔG°) of complex formation was negative for all systems studied and followed the order ΔG°_BSA?<?ΔG°_β-casein?<?ΔG°_d-BSA. The formation of β-car/protein complex was driven by entropy increasing in all studied conditions. Both proteins improved β-car photo stability, but β-casein micelle was more efficient, reducing and increasing four times, respectively, the bioactive degradation constant and the half-time of β-car. The overall results pointed to the strategic use of milk proteins, especially β-casein micelles as nanovehicle for β-car in food and other systems.     

Emergence of synchronicity in a self-organizing spiking neuron network: an approach via genetic algorithms

Based on the Theory of Neuronal Group Selection (TNGS), we have investigated the emergence of synchronicity in a network composed of spiking neurons via genetic algorithm. The TNGS establishes that a neuronal group is the most basic unit in the cortical area of the brain and, as a rule, it is not formed by a single neuron, but by a cluster of tightly coupled neural cells which fire and oscillate in synchrony at a predefined frequency. Thus, this paper describes a method of tuning the parameters of the Izhikevich spiking neuron model through genetic algorithm in order to enable the self-organization of the neural network. Computational experiments were performed considering a network composed of neurons of the same type and another composed of neurons of different types.     

The Use of Duo-Functional PVC Film for Conservation of Minimally Processed Apples

Several conservation strategies regarding minimally processed vegetables (MPV) are applied keep organoleptic features and quality, in particular the use of active packaging to slow down enzymatic browning reactions and microbial growth. Based on such context, polyvinyl chloride (PVC) films with antimicrobial and antibrowning properties—due to the addition of a mix of additives (MA) that comprise pure (KM) and encapsulated (EKM) potassium metabisulfite—are the core of the current study to find out their influence on the quality parameters applied to minimally processed apples. The sol–gel method was used in the encapsulation process and the PVC films were prepared by applying 0.1 (w/w; F01), 1.0 (w/w; F1), and 2.0 (w/w; F2) of MA (KM and EKM), as well as the use of control film, for industrial extrusion processing. The EKM was chemically and morphologically characterized and the mechanical properties of the films were set. Minimally processed apples were prepared and packed in films for 20 days. The prepared packages were stored at different temperatures and evaluated for color variations as well as for chemical and microbiological quality. The encapsulation process increased the additive's thermal resistance. It also preserved the main characteristics of the additives that were incorporated into the process. It did not interfere in the machinability conditions of the films. The outcomes showed satisfactory effects regarding the maintenance of color and microbiological qualities. The F2 film could show toxicological safety for the minimally processed apples for 10 days at 8 °C. Therefore, duofunctional films are a good alternative for minimally processed apples storage.     

Failure Analysis and Mechanical Performance Evaluation of a Cast Aluminum Hybrid-Iron Golf Club Hosel

This article details the failure analysis of a commercial golf club hybrid-iron that fractured through the hosel during normal use. The golf club hosel was manufactured from a cast aluminum alloy, and the optical analysis revealed casting pores up to 20% through the hosel thickness. Mechanical properties of the aluminum alloy were determined for material characterization and used to construct a finite element model to analyze the performance of the material under failure conditions. In addition, a full structural scale experiment was conducted to determine the failure strength.     

Action of andiroba oil (Carapa guianensis) on Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) semi‐engorged females: Morphophysiological evaluation of reproductive system

Because of the increasing medical‐veterinary importance of ticks, the development of alternative control methods, less aggressive to the host and the environment has become the target of several researches. In this sense, the present study analyzed the action of different concentrations (5, 10, and 20%) of andiroba seed oil (Carapa guianensis) on the reproductive system of Rhipicephalus sanguineus females, through histochemical techniques and the quantification of the reproductive efficiency index. The results showed that andiroba oil is a potent natural agent, able to cause several changes in the oocytes of this species, impairing the reproductive success, once this natural product induces great physiological changes in the oocytes in all development stages, such as drastic reduction in proteins, polysaccharides, and lipids in these cells, and these components are essential for the viability of the embryo. In addition, it was observed that this product stimulate the oviposition, mainly at the concentration of 20%. This higher production of eggs represents a defense mechanism developed by the organism in order to ensure the reproductive success of the species, even in the presence of the toxic agent. However, the results obtained suggested that the laid eggs would not be viable, due to the great changes undergone by the oocytes. Thus, the present study showed that the use of this vegetal product would be an alternative way to control the ticks, bringing benefits similar to the ones obtained through the use of synthetic acaricides; however, with less damage to nontarget organisms and the environment as well. Microsc. Res. Tech., 2012. © 2012 Wiley Periodicals, Inc.