Trajectory Sensitivity Method and Master-Slave Synchronization to Estimate Parameters of Nonlinear Systems

A combination of trajectory sensitivity method and master-slave synchronization was proposed to parameter estimation of nonlinear systems. It was shown that master-slave coupling increases the robustness of the trajectory sensitivity algorithm with respect to the initial guess of parameters. Since synchronization is not a guarantee that the estimation process converges to the correct parameters, a conditional test that guarantees that the new combined methodology estimates the true values of parameters was proposed. This conditional test was successfully applied to Lorenz's and Chua's systems, and the proposed parameter estimation algorithm has shown to be very robust with respect to parameter initial guesses and measurement noise for these examples. Copyright (C) 2009 Elmer P. T. Cari et al.

Genetic trend estimates of meat quality traits in a male broiler line

The present research was conducted to estimate the genetic trends for meat quality traits in a male broiler line. The traits analyzed were initial pH, pH at 6 h after slaughter, final pH, initial range of falling pH, final range of falling pH, lightness, redness, yellowness, weep loss, drip loss, shrink loss, and shear force. The number of observations varied between 618 and 2125 for each trait. Genetic values were obtained by restricted maximum likelihood, and the numerator relationship matrix had 107,154 animals. The genetic trends were estimated by regression of the broiler average genetic values with respect to unit of time (generations), and the average genetic trend was estimated by regression coefficients. Generally, for the traits analyzed, small genetic trends were obtained, except for drip loss and shear force, which were higher. The small magnitude of the trends found could be a consequence of the absence of selection for meat quality traits in the line analyzed. The estimates of genetic trends obtained were an indication of an improvement in the meat quality traits in the line analyzed, except for drip loss.

Seasonality Role on the Phenolics from Cultivated Baccharis dracunculifolia

Baccharis dracunculifolia is the source of Brazilian green propolis (BGP). Considering the broad spectrum of biological activities attributed to green proplis, B. dracunculifolia has a great potential for the development of new cosmetic and pharmaceutical products. In this work, the cultivation of 10 different populations of native B. dracunculifolia had been undertaken aiming to determine the role of seasonality on its phenolic compounds. For this purpose, fruits of this plant were collected from populations of 10 different regions, and 100 individuals of each population were cultivated in an experimental area of 1800 m(2). With respect to cultivation, the yields of dry plant, essential oil and crude extract were measured monthly resulting in mean values of 399 +/- 80 g, 0.6 +/- 0.1% and 20 +/- 4%, respectively. The HPLC analysis allowed detecting seven phenolic compounds: caffeic acid, ferulic acid, aromadendrin-4'-methyl ether (AME), isosakuranetin, artepillin C, baccharin and 2-dimethyl-6-carboxyethenyl-2H-1-benzopyran acid, which were the major ones throughout the 1-year monthly analysis. Caffeic acid was detected in all cultivated populations with mean of 4.0%. AME displayed the wide variation in relation to other compounds showing means values of 0.65 +/- 0.13% at last quarter. Isosakuranetin and artepillin C showed increasing concentrations with values between 0% and 1.4% and 0% and 1.09%, respectively. The obtained results allow suggesting that the best time for harvesting this plant, in order to obtain good qualitative and quantitative results for these phenolic compounds, is between December and April.

Do labor aos mitos: uma nova linha no mapa das pesquisas em Etnomatemática

In this paper we highlight the existence of a new line of research within the Ethnomathematics Program. In its origin, research in this area has sought to contribute to understanding regarding the diversity of mathematical thought through a careful look at work activities. In recent years, however, we have paid increasing attention to the affirmations of anthropologists that myths can be used to understand the most basic questions of human thought as well as specific questions regarding the society that produced them. Based on this idea, the myths of different peoples are perceived as informative with respect to their Ethnomathematics. Thus, together with work activities, myths constitute a source of support on which we draw to develop this line of research.

The role of disulfide bridges in the 3-D structures of the antimicrobial peptides gomesin and protegrin-1: a molecular dynamics study

Some antimicrobial peptides have a broad spectrum of action against many different kinds of microorganisms. Gomesin and protegrin-1 are examples of such antimicrobial peptides, and they were studied by molecular dynamics in this research. Both have a beta-hairpin conformation stabilized by two disulfide bridges and are active against Gram-positive and Gram-negative bacteria, as well as fungi. In this study, the role of the disulfide bridge in the maintenance of the tertiary peptide structure of protegrin-1 and gomesin is analyzed by the structural characteristics of these peptides and two of their respective variants, gomy4 and proty4, in which the four cysteines are replaced by four tyrosine residues. The absence of disulfide bridges in gomy4 and proty4 is compensated by overall reinforcement of the original hydrogen bonds and extra attractive interactions between the aromatic rings of the tyrosine residues. The net effects on the variants with respect to the corresponding natural peptides are: i) maintenance of the original beta-hairpin conformation, with great structural similarities between the mutant and the corresponding natural peptide; ii) combination of positive F and. Ramachandran angles within the hairpin head region with a qualitative change to a combination of positive (F) and negative (.) angles, and iii) significant increase in structural flexibility. Experimental facts about the antimicrobial activity of the gomesin and protegrin-1 variants have also been established here, in the hope that the detailed data provided in the present study may be useful for understanding the mechanism of action of these peptides.

Spin alignment measurements of the K*(0)(892) and phi(1020) vector mesons in heavy ion collisions at root S(NN)=200 GeV

We present the first spin alignment measurements for the K*(0)(892) and phi(1020) vector mesons produced at midrapidity with transverse momenta up to 5 GeV/c at root s(NN) = 200 GeV at RHIC. The diagonal spin-density matrix elements with respect to the reaction plane in Au+Au collisions are rho(00) = 0.32 +/- 0.04 (stat) +/- 0.09 (syst) for the K*(0) (0.8 < p(T) < 5.0 GeV/c) and rho(00) = 0.34 +/- 0.02 (stat) +/- 0.03 (syst) for the phi (0.4 < p(T) < 5.0 GeV/c) and are constant with transverse momentum and collision centrality. The data are consistent with the unpolarized expectation of 1/3 and thus no evidence is found for the transfer of the orbital angular momentum of the colliding system to the vector-meson spins. Spin alignments for K(*0) and phi in Au+Au collisions were also measured with respect to the particle's production plane. The phi result, rho(00) = 0.41 +/- 0.02 (stat) +/- 0.04 (syst), is consistent with that in p+p collisions, rho(00) = 0.39 +/- 0.03 (stat) +/- 0.06 (syst), also measured in this work. The measurements thus constrain the possible size of polarization phenomena in the production dynamics of vector mesons.

Minor and Unsystematic Cortical Topographic Changes of Attention Correlates between Modalities

In this study we analyzed the topography of induced cortical oscillations in 20 healthy individuals performing simple attention tasks. We were interested in qualitatively replicating our recent findings on the localization of attention-induced beta bands during a visual task [1], and verifying whether significant topographic changes would follow the change of attention to the auditory modality. We computed corrected latency averaging of each induced frequency bands, and modeled their generators by current density reconstruction with Lp-norm minimization. We quantified topographic similarity between conditions by an analysis of correlations, whereas the inter-modality significant differences in attention correlates were illustrated in each individual case. We replicated the qualitative result of highly idiosyncratic topography of attention-related activity to individuals, manifested both in the beta bands, and previously studied slow potential distributions [2]. Visual inspection of both scalp potentials and distribution of cortical currents showed minor changes in attention-related bands with respect to modality, as compared to the theta and delta bands, known to be major contributors to the sensory-related potentials. Quantitative results agreed with visual inspection, supporting to the conclusion that attention-related activity does not change much between modalities, and whatever individual changes do occur, they are not systematic in cortical localization across subjects. We discuss our results, combined with results from other studies that present individual data, with respect to the function of cortical association areas.

Association of alpha1a-adrenergic receptor polymorphism and blood pressure phenotypes in the Brazilian population

Background: The alpha1A-adrenergic receptor (alpha(1A)-AR) regulates the cardiac and peripheral vascular system through sympathetic activation. Due to its important role in the regulation of vascular tone and blood pressure, we aimed to investigate the association between the Arg347Cys polymorphism in the alpha(1A)-AR gene and blood pressure phenotypes, in a large sample of Brazilians from an urban population. Methods: A total of 1568 individuals were randomly selected from the general population of the Vitoria City metropolitan area. Genetic analysis of the Arg347Cys polymorphism was conducted by polymerase chain reaction/restriction fragment length polymorphism. We have compared cardiovascular risk variables and genotypes using ANOVA, and Chi-square test for univariate comparisons and logistic regression for multivariate comparisons. Results: Association analysis indicated a significant difference between genotype groups with respect to diastolic blood pressure (p = 0.04), but not systolic blood pressure (p = 0.12). In addition, presence of the Cys/Cys genotype was marginally associated with hypertension in our population (p = 0.06). Significant interaction effects were observed between the studied genetic variant, age and physical activity. Presence of the Cys/Cys genotype was associated with hypertension only in individuals with regular physical activity (odds ratio = 1.86; p = 0.03) or younger than 45 years (odds ratio = 1.27; p = 0.04). Conclusion: Physical activity and age may potentially play a role by disclosing the effects of the Cys allele on blood pressure. According to our data it is possible that the Arg347Cys polymorphism can be used as a biomarker to disease risk in a selected group of individuals.

Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and high plasma homocysteine in chronic hepatitis C (CHC) infected patients from the Northeast of Brazil

Background/Aim: Hyperhomocysteinemia due to Methylenetetrahydrofolate Reductase (MTHFR) gene, in particular the C677T (Ala222Val) polymorphism were recently associated to steatosis and fibrosis. We analyzed the frequency of MTHFR gene in a cross-sectional study of patients affected by Chronic Hepatitis C (CHC) from Northeast of Brazil. Method: One hundred seven-four untreated patients with CHC were genotyped for the C677T MTHFR. Genomic DNA was extracted from peripheral blood cells and the C677T MTHFR polymorphism was identified by PCR-RFLP. The homocysteine (Hcy) levels were determined by chemiluminescence method. All patients were negative for markers of Wilson's disease, hemochromatosis and autoimmune diseases and have current and past daily alcohol intake less than 100 g/week. Results: Among subjects infected with CHC genotype non-1 the frequency of MTHFR genotypes TT was 9.8% versus 4.4% genotype 1 (p = 0.01). Nevertheless, association was found between the MTHFR genotype TT x CT/CC polymorphism and the degree of steatosis and fibrosis in both hepatitis C genotype (p < 0.05). A significant difference was found on plasma Hcy levels in patients with steatosis regardless of HCV genotype (p = 0.03). Conclusion: Our results indicate that plasma Hcy levels is highly prevalent in subjects with chronic hepatits C with steatosis regardless of HCV genotype and vitamin deficiency. The presence of genotype TT of MTHFR C677T polymorphism was more common in CHC genotype non-1 infected patient regardless of histopathological classification and genotype TT+CT frequencies were significant in the presence of fibrosis grade 1+2 and of steatosis in CHC infected patients from the northeast of Brazil regardless of HCV genotype. The genetic susceptibility of MTHFR C677T polymorphism should be confirmed in a large population.

Analysis of the histologic features in the differential diagnosis of intrahepatic neonatal cholestasis

AIM: To compare the histologic features of the liver in intrahepatic neonatal cholestasis (IHNC) with infectious, genetic-endocrine-metabolic, and idiopathic etiologies. METHODS: Liver biopsies from 86 infants with IHNC were evaluated. The inclusion criteria consisted of jaundice beginning at 3 mo of age and a hepatic biopsy during the 1st year of life. The following histologic features were evaluated: cholestasis, eosinophilia, giant cells, erythropoiesis, siderosis, portal fibrosis, and the presence of a septum. RESULTS: Based on the diagnosis, patients were classified into three groups: group 1 (infectious; n = 18), group 2 (genetic-endocrine-metabolic; n = 18), and group 3 (idiopathic; n = 50). There were no significant differences with respect to the following variables: cholestasis, eosinophilia, giant cells, siderosis, portal fibrosis, and presence of a septum. A significant difference was observed with respect to erythropoiesis, which was more severe in group 1 (Fisher's exact test, P = 0.016). CONCLUSION: A significant difference was observed in IHNC of infectious etiology, in which erythropoiesis was more severe than that in genetic-endocrine-metabolic and idiopathic etiologies, whereas there were no significant differences among cholestasis, eosinophilia, giant cells, siderosis, portal fibrosis, and the presence of a septum. (C) 2009 The WIG Press and Baishideng. All rights reserved.

Incidence and predictors of severe liver fibrosis in HIV-infected patients with chronic hepatitis C in Brazil

The aim of this study was to examine the incidence and factors associated with the severity of liver fibrosis in 234 coinfected patients in Brazil. Patients were cared for in our clinic, from 1996 to 2004. Eligible patients were defined as patients with documented HIV and hepatitis C virus (HCV) infections and had previously undergone a liver biopsy. Patients with persistently normal alanine aminotransferase (ALT) were also included. The variables selected for study were age, gender, risk category, history of high alcohol consumption, CD4(+) T cell count, antiretroviral therapy usage, HCV genotype and duration of HCV infection. Stage of fibrosis was scored as follows: F0, no fibrosis; F1, portal fibrosis with no septa; F2, portal fibrosis with few septa; F3, bridging fibrosis with many septa; and F4, cirrhosis. The liver fibrosis stage was F3 in 39 (16.6%) and F4 in 20(8.5%) patients. Among patients with normal ALT, the liver fibrosis stage was F3-F4 in three patients (5.6%). Predictors of severe liver fibrosis (17344) by multivariate analysis were age (older patients) and genotype 3 (genotype I odds ratio [OR], 0.28; 95% confidence interval [0], 0.12 0.65). In summary, in the present study severe liver fibrosis was found in 25% of our patients and was associated with an age of more than 38 years at the time of liver biopsy as well as, HCV genotype 3. No differences were found with respect to CD4(+) T cell counts although patients with a CD4(+) T cell count greater than 50 were excluded.

Endothelial Nitric Oxide Genotypes and Haplotypes Are Not Associated with End-Stage Renal Disease

The identification of genetic markers associated with chronic kidney disease (CKD) may help to predict its development. Because reduced nitric oxide (NO) bioavailability and endothelial dysfunction are involved in CKD, genetic polymorphisms in the gene encoding the enzyme involved in NO synthesis (endothelial NO synthase [eNos]) may affect the susceptibility to CKD and the development of end-stage renal disease (ESRD). We compared genotype and haplotype distributions of three relevant eNOS polymorphisms (T(-786) C in the promoter region, Glu298Asp in exon 7, and 4b/4a in intron 4) in 110 healthy control subjects and 127 ESRD patients. Genotypes for the T(-786) C and Glu298Asp polymorphisms were determined by TaqMan (R) Allele Discrimination assay and real-time polymerase chain reaction. Genotypes for the intron 4 polymorphism were determined by polymerase chain reaction and fragment separation by electrophoresis. The software program PHASE 2.1 was used to estimate the haplotypes frequencies. We considered significant a probability value of p < 0.05/number of haplotypes (p < 0.05/8 = 0.0063). We found no significant differences between groups with respect to age, ethnicity, and gender. CKD patients had higher blood pressure, total cholesterol, and creatinine levels than healthy control subjects (all p < 0.05). Genotype and allele distributions for the three eNOS polymorphisms were similar in both groups (p > 0.05). We found no significant differences in haplotype distribution between groups (p > 0.05). The lack of significant associations between eNOS polymorphisms and ESRD suggests that eNOS polymorphisms may not be relevant to the genetic component of CKD that leads to ESRD.

Management of Bell's Palsy: A Report of 2 Cases

Bell's palsy is a neuropathy of the peripheral seventh cranial nerve, resulting from traumatic, compressive, infective, inflammatory or metabolic abnormalities or it can be idiopathic. HIV, Epstein-Barr virus and hepatitis B virus have been suspected as initiating organisms, but herpes simplex virus is the most frequently implicated. This report describes 2 cases of Bell's palsy in children that were managed with antiviral agents. Both patients experienced complete recovery within 28 days; after 1 year follow-up, no recurrence was observed and both patients have normal facial movement. Differential diagnosis is essential to guide the treatment plan in Bell's palsy. Special attention should be given to children with respect to prescription of medications that can cause important side effects.

Rest energy expenditure is decreased during the acute as compared to the recovery phase of sepsis in newborns

Background: Little is known with respect to the metabolic response and the requirements of infected newborns. Moreover, the nutritional needs and particularly the energy metabolism of newborns with sepsis are controversial matter. In this investigation we aimed to evaluate the rest energy expenditure (REE) of newborns with bacterial sepsis during the acute and the recovery phases. Methods: We studied nineteen neonates (27.3 +/- 17.2 days old) with bacterial sepsis during the acute phase and recovery of their illness. REE was determined by indirect calorimetry and VO(2) and VCO(2) measured by gas chromatography. Results: REE significantly increased from 49.4 +/- 13.1 kcal/kg/day during the acute to 68.3 +/- 10.9 kcal/kg/day during recovery phase of sepsis (P < 0.01). Similarly, VO(2) (7.4 +/- 1.9 vs 10 +/- 1.5 ml/kg/min) and VCO(2) (5.1 +/- 1.7 vs 7.4 +/- 1.5 ml/kg/min) were also increased during the course of the disease (P < 0.01). Conclusion: REE was increased during recovery compared to the sepsis phase. REE of septic newborns should be calculated on individualized basis, bearing in mind their metabolic capabilities.

Chorioallantoic placentation in Galea spixii (Rodentia, Caviomorpha, Caviidae)

Background: Placentas of guinea pig-related rodents are appropriate animal models for human placentation because of their striking similarities to those of humans. To optimize the pool of potential models in this context, it is essential to identify the occurrence of characters in close relatives. Methods: In this study we first analyzed chorioallantoic placentation in the prea, Galea spixii, as one of the guinea pig's closest relatives. Material was collected from a breeding group at the University of Mossoro, Brazil, including 18 individuals covering an ontogenetic sequence from initial pregnancy to term. Placentas were investigated by means of histology, electron microscopy, immunohistochemistry (vimentin, alpha-smooth muscle actin, cytokeration) and proliferation activity (PCNA). Results: Placentation in Galea is primarily characterized by an apparent regionalization into labyrinth, trophospongium and subplacenta. It also has associated growing processes with clusters of proliferating trophoblast cells at the placental margin, internally directed projections and a second centre of proliferation in the labyrinth. Finally, the subplacenta, which is temporarily supplied in parallel by the maternal and fetal blood systems, served as the center of origin for trophoblast invasion. Conclusion: Placentation in Galea reveals major parallels to the guinea pig and other caviomorphs with respect to the regionalization of the placenta, the associated growing processes, as well as trophoblast invasion. A principal difference compared to the guinea pig occurred in the blood supply of the subplacenta. Characteristics of the invasion and expanding processes indicate that Galea may serve as an additional animal model that is much smaller than the guinea pig and where the subplacenta partly has access to both maternal and fetal blood systems.