The combined effect of copper and low pH on antioxidant defenses and biochemical parameters in neotropical fish pacu, Piaractus mesopotamicus (Holmberg, 1887)

Copper sulfate is widely used in aquaculture. Exposure to this compound can be harmful to fish, resulting in oxidative metabolism alterations and gill tissue damage. Pacu, Piaractus mesopotamicus, (wt = 43.4 +/- A 3.35 g) were distributed in experimental tanks (n = 10; 180 l) and exposed for 48 h to control (without copper addition), 0.4Cu (0.4 mg l(-1)), 0CupH (without copper addition, pH = 5.0) and 0.4CupH (0.4 mg l(-1), pH = 5.0). In liver and red muscle, the superoxide dismutase (SOD) was responsive to the increases in the aquatic copper. The plasmatic intermediary metabolites and hematological variables in the fish of group 0.4Cu were similar to those of the control group. Conversely, the exposure to 0.4CupH caused an increase in the plasmatic lactate, number of red blood cells (RBC) and hemoglobin (Hb). Plasmatic copper concentration [Cu(p)] increased in group 0.4Cu and 0.4CupH, which is higher in group 0.4CupH, suggests an effect of water pH on the absorbed copper. Exposure to 0.4Cu and 0.4CupH resulted in a reduction in the Na(+)/K(+)-ATPase activity and an increase in metallothionein (MT) in the gills. Exposure to 0CupH caused a decrease in glucose and pyruvate concentrations and an increase in RBC, Hb, and the branchial Na(+)/K(+)-ATPase activity. These responses suggest that the fish triggered mechanisms to revert the blood acidosis, save energy and increase the oxygen uptake. MT was an effective biomarker, responding to copper in different pHs and dissolved oxygen. Combined-factors caused more significant disturbance in the biomarkers than single-factors.

On the Hartman-Grobman Theorem with Parameters

The Hartman-Grobman Theorem of linearization is extended to families of dynamical systems in a Banach space X, depending continuously on parameters. We prove that the conjugacy also changes continuously. The cases of nonlinear maps and flows are considered, and both in global and local versions, but global in the parameters. To use a special version of the Banach-Caccioppoli Theorem we introduce equivalent norms on X depending on the parameters. The functional setting is suitable for applications to some nonlinear evolution partial differential equations like the nonlinear beam equation.

Immunological parameters related to the adjuvant effect of the ordered mesoporous silica SBA-15

In 2006, the first report of a nanostructured material as adjuvant was described establishing the effectiveness of the ordered mesoporous SBA-15 silica as an immune adjuvant. The present study evaluated the SBA-15 capacity to modulate the immune responsiveness of High and Low responder mice immunized with BSA encapsulated/adsorbed in SBA-15 by the intramuscular or oral route and the adjuvant effect was compared with the responsiveness induced by BSA in aluminum hydroxide salts or emulsified in Incomplete Freund adjuvant. These results demonstrate the ability of the non-toxic SBA-15 nanoparticles to increase the immunogenicity and repair the responsiveness of the constitutively low responder individuals inducing both the IgG2a and the IgG1 isotypes, independently of the immune cell committed and conditioning the low phenotype. This new adjuvant may reveal novel therapeutic targets for immune modulation and vaccine design. (C) 2010 Elsevier Ltd. All rights reserved.

Cobalt-related impurity centers in diamond: electronic properties and hyperfine parameters

Cobalt-related impurity centers in diamond have been studied using first principles calculations. We computed the symmetry, formation and transition energies, and hyperfine parameters of cobalt impurities in isolated configurations and in complexes involving vacancies and nitrogen atoms. We found that the Co impurity in a divacant site is energetically favorable and segregates nitrogen atoms in its neighborhood. Our results are discussed in the context of the recently observed Co-related electrically active centers in synthetic diamond.

A dedicated setup for the measurement of the electron transport parameters in gases at large electric fields

Electron transport parameters are important in several areas ranging from particle detectors to plasma-assisted processing reactors. Nevertheless, especially at high fields strengths and for complex gases, relatively few data are published. A dedicated setup has been developed to measure the electron drift velocity and the first Townsend coefficient in parallel plate geometry. An RPC-like cell has been adopted to reach high field strengths without the risk of destructive sparks. The validation data obtained with pure Nitrogen will be presented and compared to a selection of the available literature and to calculations performed with Magboltz 2 version 8.6. The new data collected in pure Isobutane will then be discussed. This is the first time the electron drift velocity in pure Isobutane is measured well into the saturation region. Good agreement is found with expectations from Magboltz. (C) 2009 Elsevier B.V. All rights reserved.

Dentin hypersensitivity clinical study comparing LILT and LEDT keeping the same irradiation parameters

Dentin hypersensitivity is a common condition associated with high dental pain. A new LED-based (light emitting diode) light source has been used as an experimental tool in some studies. Purpose: The main objective was to compare these two light sources emitting in the same spectral band (red from 625 to 660 nm) to promote pain relief. Material and methods: A total of 6 sessions were accomplished, being three irradiation sessions and three follow-up sessions. This single-blind study compared a control group (Placebo) and two other groups with different equipments: low laser intensity treatment (LILT) and a light emitting diode system treatment (LEDT). Results: The results showed that there is no statistical difference between LILT and LEDT groups, however, both were better than control group (p=0.01) in terms of treatment efficiency; there is no difference between the second and the third sessions for both treatment, it means that the third session was not necessary; finally, the improvement at the end of the entire research (follow up care of 30 days) was very expressive in comparison to pre-treatment situation for all teeth (p=0.01). Conclusion: LILT and LEDT were equally effective to treat dentine hypersensitivity, a 3rd treatment session was not necessary/two sessions are enough.

Thermo-optics parameters measurements in photorefractive sillenite Bi(12)SiO(20) crystals by thermal lens technique

The present work reports on the thermo-optical properties of photorefractive sillenite Bi(12)SiO(20) (BSO) crystals obtained by applying the Thermal Lens Spectrometry technique (TLS). This crystals presents one high photorefractive sensitivity in the region blue-green spectra, since the measurements were carried out at two pump beam wavelengths (514.5 nm and 750 nm) to study of the light-induced effects in this material (thermal and/or photorefractive). We determine thermo-optical parameters like thermal diffusivity (D), thermal conductivity (K) and temperature coefficient of the optical path length change (ds/dT) in sillenite crystals. These aspects, for what we know, not was studied in details up to now using the lens spectrometry technique and are very important against of the promising potentiality of applications these crystals in non linear optics, real time holography and optical processing data.

Bayesian estimation of regression parameters in elliptical measurement error models

The main object of this paper is to discuss the Bayes estimation of the regression coefficients in the elliptically distributed simple regression model with measurement errors. The posterior distribution for the line parameters is obtained in a closed form, considering the following: the ratio of the error variances is known, informative prior distribution for the error variance, and non-informative prior distributions for the regression coefficients and for the incidental parameters. We proved that the posterior distribution of the regression coefficients has at most two real modes. Situations with a single mode are more likely than those with two modes, especially in large samples. The precision of the modal estimators is studied by deriving the Hessian matrix, which although complicated can be computed numerically. The posterior mean is estimated by using the Gibbs sampling algorithm and approximations by normal distributions. The results are applied to a real data set and connections with results in the literature are reported. (C) 2011 Elsevier B.V. All rights reserved.

Cardiovascular Disease Parameters in Periodontitis

Background: Recently, there has been an increasing in the impact of oral health on atherosclerosis and subsequent cardiovascular disease. The aim of this study is to investigate the association between chronic periodontitis and cardiovascular risk markers. Methods: Forty patients with periodontitis and 40 healthy gender-, body mass index-, and age-matched individuals were compared by measuring total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, levels of cytokines, antibodies against oxidized low-density lipoprotein, thiobarbituric acid reactive substances, total and differential white blood cell counts, and the non-linear index of refraction. Results: The levels of triglycerides and high-density lipoprotein in periodontitis patients were significantly higher and lower, respectively (P=0.002 and P=0.0126), compared to controls. Total cholesterol, low-density lipoprotein, and lipid peroxide levels were the same in both groups (P = 0.2943, P = 0.1284, and P = 0.067, respectively). Interleukin (IL)-6 and -8, antibodies against oxidized low-density lipoprotein, and leukocyte and neutrophil counts were significantly higher in periodontitis patients (P<0.05). The value of the non-linear index of refraction of low-density lipoprotein solutions was higher in the controls (P = 0.015) compared to individuals with periodontitis. Conclusion: Our results confirmed and further strengthened the suggested association between coronary artery disease and periodontitis. J Periodontol 2009;80:378-388.

The influence of ARIMA-GARCH parameters in feed forward neural networks prediction

The objective of this article is to find out the influence of the parameters of the ARIMA-GARCH models in the prediction of artificial neural networks (ANN) of the feed forward type, trained with the Levenberg-Marquardt algorithm, through Monte Carlo simulations. The paper presents a study of the relationship between ANN performance and ARIMA-GARCH model parameters, i.e. the fact that depending on the stationarity and other parameters of the time series, the ANN structure should be selected differently. Neural networks have been widely used to predict time series and their capacity for dealing with non-linearities is a normally outstanding advantage. However, the values of the parameters of the models of generalized autoregressive conditional heteroscedasticity have an influence on ANN prediction performance. The combination of the values of the GARCH parameters with the ARIMA autoregressive terms also implies in ANN performance variation. Combining the parameters of the ARIMA-GARCH models and changing the ANN`s topologies, we used the Theil inequality coefficient to measure the prediction of the feed forward ANN.

Global Gene Expression Analysis during Germination in the Chytridiomycete Blastocladiella emersonii

Blastocladiella emersonii is an aquatic fungus of the Chytridiomycete class. During germination, the zoospore, a motile nongrowing cell, goes through a cascade of morphological changes that culminates with its differentiation into the germling cell, capable of coenocytic vegetative growth. Transcriptome analyses of B. emersonii cells were carried out during germination induced under various environmental conditions. Microarray data analyzing 3,563 distinct B. emersonii genes revealed that 26% of them are differentially expressed during germination in nutrient medium at at least one of the time points investigated. Over 500 genes are upregulated during the time course of germination under those conditions, most being related to cell growth, including genes involved in protein biosynthesis, DNA transcription, energetic metabolism, carbohydrate and oligopeptide transport, and cell cycle control. On the other hand, several transcripts stored in the zoospores are downregulated during germination in nutrient medium, such as genes involved in signal transduction, amino acid transport, and chromosome organization. In addition, germination induced in the presence of nutrients was compared with that triggered either by adenine or potassium ions in inorganic salt solution. Several genes involved in cell growth, induced during germination in nutrient medium, do not show increased expression when B. emersonii zoospores germinate in inorganic solution, suggesting that nutrients exert a positive effect on gene transcription. The transcriptome data also revealed that most genes involved in cell signaling show the same expression pattern irrespective of the initial germination stimulus.