Feasibility of a Sequencing Reactor Operated in Batch and Fed-batch Mode Applied to Nitrification and Denitrification Processes

The objective of this work was to study the operational feasibility of nitrification and denitrification processes in a mechanically stirred sequencing batch reactor (SBR) operated in batch and fed-batch mode. The reactor was equipped with a draft-tube to improve mass transfer and contained dispersed (aerobic) and granulated (anaerobic) biomass. The following reactor variables were adjusted: aeration time during the nitrification step; dissolved oxygen concentration, feed time defining batch and fed-batch phases, concentration of external carbon source used as electron donor during the denitrification stage and volumetric ammonium nitrogen load in the influent. The reactor (5 L volume) was maintained at 30 +/- 1 degrees C and treated either 1.0 or 1.5 L wastewater in 8-h cycles. Ammonium nitrogen concentrations assessed were: 50 (condition 1) and 100 mgN-NH(4)(+).L(-1) (condition 2), resulting in 29 and 67 mgN-NH(4)(+).L-1-d(-1), respectively. A synthetic medium and ethanol were used as external carbon sources (ECS). Total nitrogen removal efficiencies were 94.4 and 95.9% when the reactor was operated under conditions 1 and 2, respectively. Low nitrite (0.2 and 0.3 mgN-NO(2)(-).L(-1), respectively) and nitrate (0.01 and 0.3 mgN-NO(3)(-).L(-1), respectively) concentrations were detected in the effluent and ammonium nitrogen removal efficiencies were 97.6% and 99.6% under conditions 1 and 2, respectively.

Influence of chloride ion concentration and temperature on the electrochemical properties of passive films formed on a superduplex stainless steel

Polarization measurements were conducted to monitor the corrosion behavior of superduplex stainless steel ASTM A995M-Gr.SA/EN 10283-Mat#1.4469(GX2CrNiMo26-7-4) when exposed to a) an electrolyte containing 22,700 parts per million (ppm) of chloride ions at seven different temperatures and b) an electrolyte at 25 GC and different chloride ion concentrations (5800, 22,700, 58,000 and 80,000 ppm of Cl(-)). The polarization curves indicate that the passive films formed are only slightly affected by NaCl concentration, but the pitting potential decreases drastically increasing the temperature, in particular >60 degrees C. The image analysis of the microstructure after potentiodynamic polarization showed that the pitting number and size vary in function of the temperature of the tested medium. Nyquist diagrams were determined by electrochemical impedance spectroscopy to characterize the resistance of the passive layer. According to Nyquist plots, the arc polarization resistance decreases increasing the temperature due to a catalytic degradation of the oxide passive films. (C) 2009 Elsevier Inc. All rights reserved.

Tailoring vibration mode shapes using topology optimization and functionally graded material concepts

Tailoring specified vibration modes is a requirement for designing piezoelectric devices aimed at dynamic-type applications. A technique for designing the shape of specified vibration modes is the topology optimization method (TOM) which finds an optimum material distribution inside a design domain to obtain a structure that vibrates according to specified eigenfrequencies and eigenmodes. Nevertheless, when the TOM is applied to dynamic problems, the well-known grayscale or intermediate material problem arises which can invalidate the post-processing of the optimal result. Thus, a more natural way for solving dynamic problems using TOM is to allow intermediate material values. This idea leads to the functionally graded material (FGM) concept. In fact, FGMs are materials whose properties and microstructure continuously change along a specific direction. Therefore, in this paper, an approach is presented for tailoring user-defined vibration modes, by applying the TOM and FGM concepts to design functionally graded piezoelectric transducers (FGPT) and non-piezoelectric structures (functionally graded structures-FGS) in order to achieve maximum and/or minimum vibration amplitudes at certain points of the structure, by simultaneously finding the topology and material gradation function. The optimization problem is solved by using sequential linear programming. Two-dimensional results are presented to illustrate the method.

A TRIPLE-MODE BANDPASS FILTER USING A MODIFIED CIRCULAR PATCH RESONATOR

This article presents a triple-mode bandpass filter using a modified circular patch resonator. Etched slots in the resonator split the TM(1, 1, 0)(z) degenerate fundamental modes and also perturb the TM(2, 1, 0)(z) mode, approximating their resonant frequencies to form a third-order bandpass filter. A 2.42 GHz centered filter was designed and fabricated. Experimental results showed a fractional bandwidth of 29%, return loss better than 16 dB, insertion loss of 0.5 dB, and good second harmonic band rejection. The filter exhibited a size reduction of 51% compared with a filter using an unperturbed circular patch resonator at the same frequency. (C) 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 178-182, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23950

Dynamic positioning systems: An experimental analysis of sliding mode control

Vessel dynamic positioning (DP) systems are based on conventional PID-type controllers and an extended Kalman filter. However, they present a difficult tuning procedure, and the closed-loop performance varies with environmental or loading conditions since the dynamics of the vessel are eminently nonlinear. Gain scheduling is normally used to address the nonlinearity of the system. To overcome these problems, a sliding mode control was evaluated. This controller is robust to variations in environmental and loading conditions, it maintains performance and stability for a large range of conditions, and presents an easy tuning methodology. The performance of the controller was evaluated numerically and experimentally in order to address its effectiveness. The results are compared with those obtained from conventional PID controller. (c) 2010 Elsevier Ltd. All rights reserved.

QUALITY EVALUATION OF MINIMALLY PROCESSED `REGIS` PEACH

The aim of this work was evaluate the effect of citric acid at 1% and 2% in the maintenance of the quality of minimally processed `Regis` peaches, during 9 days storage under refrigeration (5+/-1 degrees C, 85-87% RU) and passive modified atmospheres. The following analyses were realized: color, firmness, texture, soluble solids, titratable acidity, pH, CO(2) and O(2). Increasing in a value and decreasing in b and L values on minimally processed peaches were observed, independent of the citric acid treatment, indicating a browning on the product mainly on the 9(th) day of storage. Overall, the levels of titratable acidity and pH changed at the storage period and at the concentrations studied, unlike the content of soluble solids that remained unchanged. The texture, CO(2) and O(2) changed only for the storage period unlike texture that was higher with the treatment of citric acid 2%. It can be concluded that neither tested concentration of citric acid was effective in preventing enzymatic browning of minimally processed peaches stored the 5+/-1 degrees C and 85-87% RU and passive modified atmosphere.

Passive immunization with monoclonal antibody against a 70-kDa putative adhesin of Sporothrix schenckii induces protection in murine sporotrichosis

Cell-mediated and innate immunity are considered the most important mechanisms of host defense against fungus infections. However, recent studies demonstrated that specific antibodies show different degrees of protection against mycosis. In a previous study, antigens secreted by Sporothrix schenckii induced a specific humoral response in infected animals, mainly against the 70-kDa molecule, indicating a possible participation of antibodies to this antigen in infection control. in the present study, an IgG1 mAb was produced against a 70-kDa glycoprotein of S. schenckii in order to better understand the effect of passive immunization of mice infected with S. schenckii. Results showed a significant reduction in the number of CFU in organs of mice when the mAb was injected before and during S. schenckii infection. Similar results were observed when T-cell-deficient mice were used. Moreover, in a second schedule treatment, the mAb was injected after infection was established, and again we observed a significant reduction in CFU associated with an increase of IFN-gamma production. Also, the 70-kDa antigen is shown to be a putative adhesin present on the surface of this fungus. In conclusion, we report for the first time the protective effect of a specific antibody against S. schenckii.

The influence of positive or negative charges in the passive and iontophoretic skin penetration of porphyrins used in photodynamic therapy

Meso-tetra-(N-methylpiridinium-4-yl)-porphyrin (TMPyP) and meso-tetra-(4-sulfonatophenyl)-porphyrin (TPPS(4)) are photosensitizing drugs (PS) used in photodynamic therapy (PDT). Based on the fact that these compounds present similar chemical structures but opposite charges at pH levels near physiological conditions, this work aims to evaluate the in vitro and in vivo influence of these electrical charges on the iontophoretic delivery of TMPyP and TPPS4, attempting to achieve maximum accumulation of PS in skin tissue. The iontophoretic transport of these drugs from a hydrophilic gel was investigated in vitro using porcine ear skin and vertical, flow-through diffusion cells. In vivo experiments using rats were also carried out, and the penetration of the PSs was analyzed by fluorescence microscopy to visualize the manner of how these compounds were distributed in the skin after a short period of iontophoresis application. In vitro, both passive and iontophoretic delivery of the positively charged TMPyP were much greater (20-fold and 67-fold, respectively) than those of the negatively charged TPPS(4). TPPS(4) iontophoresis in vivo increased the fluorescence of the skin only in the very superficial layers. On the other hand, iontophoresis of the positively charged drug expressively increased the rat epidermis and dermis fluorescence, indicating high amounts of this drug throughout the skin layers. Moreover, TMPyP was homogeneously distributed around and into the nuclei of the skin cells, suggesting its potential use in topical PDT. (C) 2010 Elsevier B.V. All rights reserved.

Pollen abortion rates, nitrogen dioxide by passive diffusive tubes and bioaccumulation in tree barks are effective in the characterization of air pollution

This study aims to evaluate the feasibility of using simple techniques - pollen abortion rates, passive diffusive tubes (NO(2)) and trace element accumulation in tree barks - when determining the area of influence of pollution emissions produced in a traffic corridor. Measurements were performed at 0, 60 and 120 meters from a major road with high vehicular traffic, taking advantage of a sharp gradient that exists between the road and a cemetery. NO(2) values and trace elements measured at 0 meters were significantly higher than those measured at more distant points. Al, S. Cl, V. Fe, Cu, and Zn exhibited a higher concentration in tree barks at the vicinity of the traffic corridor. The same pattern was observed for the pollen abortion rates measured at the three different sites. Our data suggests that simple techniques may be applied either to validate dispersion land-based models in an urban settings or, alternatively, to provide better spatial resolution to air pollution exposure when high-resolution pollution monitoring data are not available. (C) 2011 Elsevier B.V. All rights reserved.

White matter microstructure underlying default mode network connectivity in the human brain

Resting state functional magnetic resonance imaging (fMRI) reveals a distinct network of correlated brain function representing a default mode state of the human brain The underlying structural basis of this functional connectivity pattern is still widely unexplored We combined fractional anisotropy measures of fiber tract integrity derived from diffusion tensor imaging (DTI) and resting state fMRI data obtained at 3 Tesla from 20 healthy elderly subjects (56 to 83 years of age) to determine white matter microstructure e 7 underlying default mode connectivity We hypothesized that the functional connectivity between the posterior cingulate and hippocampus from resting state fMRI data Would be associated with the white matter microstructure in the cingulate bundle and fiber tracts connecting posterior cingulate gyrus With lateral temporal lobes, medial temporal lobes, and precuneus This was demonstrated at the p<0001 level using a voxel-based multivariate analysis of covariance (MANCOVA) approach In addition, we used a data-driven technique of joint independent component analysis (ICA) that uncovers spatial pattern that are linked across modalities. It revealed a pattern of white matter tracts including cingulate bundle and associated fiber tracts resembling the findings from the hypothesis-driven analysis and was linked to the pattern of default mode network (DMN) connectivity in the resting state fMRI data Out findings support the notion that the functional connectivity between the posterior cingulate and hippocampus and the functional connectivity across the entire DMN is based oil distinct pattern of anatomical connectivity within the cerebral white matter (C) 2009 Elsevier Inc All rights reserved

THE TEMPO AND MODE OF EVOLUTION OF TRANSPOSABLE ELEMENTS AS REVEALED BY MOLECULAR PHYLOGENIES RECONSTRUCTED FROM MOSQUITO GENOMES

Although many mathematical models exist predicting the dynamics of transposable elements (TEs), there is a lack of available empirical data to validate these models and inherent assumptions. Genomes can provide a snapshot of several TE families in a single organism, and these could have their demographics inferred by coalescent analysis, allowing for the testing of theories on TE amplification dynamics. Using the available genomes of the mosquitoes Aedes aegypti and Anopheles gambiae, we indicate that such an approach is feasible. Our analysis follows four steps: (1) mining the two mosquito genomes currently available in search of TE families; (2) fitting, to selected families found in (1), a phylogeny tree under the general time-reversible (GTR) nucleotide substitution model with an uncorrelated lognormal (UCLN) relaxed clock and a nonparametric demographic model; (3) fitting a nonparametric coalescent model to the tree generated in (2); and (4) fitting parametric models motivated by ecological theories to the curve generated in (3).

Passive Acquisition of Protective Antibodies Reactive with Bordetella pertussis in Newborns via Placental Transfer and Breast-feeding

Although acquisition of anti-pertussis antibodies by the newborn via placental transfer has been demonstrated, a subsequent recrudescence of pertussis infection is often observed, particularly in infants. The present study investigated the passive transfer of anti-pertussis IgG and IgA antibodies to term newborns and their ability to neutralize bacterial pathogenicity in an in vivo experimental model using mice intracerebrally challenged with viable Bordetella pertussis. Forty paired samples of maternal/umbilical cord sera and colostrum were obtained. Anti-pertussis antibodies were analysed by immunoenzymatic assay and by Immunoblotting. Antibody neutralizing ability was assessed through intracerebral B. pertussis challenges in mice. Anti-pertussis IgG titres were equivalent in both maternal and newborn sera (medians = 1:225 and 1:265), with a transfer rate of 118%. The colostrum samples had variable specific IgA titres (median = 1:74). The immunoblotting assays demonstrated identical recognition profiles of paired maternal and newborn serum pools but different bacterial recognition intensities by colostrum pools. In the animal model, significant differences were always observed when the serum and colostrum samples and pools were compared with the positive control (P < 0.05). Unlike samples with lower anti-pertussis titres, samples with high titres showed protective capacities above 50%. Pertussis-absorbed serum and colostrum pools protected 30% of mice and purified IgG antibodies protected 65%. Both pooled and single-sample protective abilities were correlated with antibody titres (P < 0.01). Our data demonstrated the effectiveness of anti-pertussis antibodies in bacterial pathogenesis neutralization, emphasizing the importance of placental transfer and breast-feeding in protecting infants against respiratory infections caused by Bordetella pertussis.

Women`s opinions about mode of birth in Brazil: a qualitative study in a public teaching hospital

Objective: to describe women`s feelings about mode of birth. Design: exploratory descriptive design. Semi-structured interviews were conducted using a questionnaire that had been developed previously (categorical data and open-and closed-ended questions). Qualitative analysis of the results was performed through a context analysis technique. Setting: the largest public university hospital in Brazil. Participants: 48 women in their third trimester of pregnancy. Findings: most women expressed a preference for vaginal birth, as they perceived that they would have a faster recovery. Women who expressed a preference for caesarean section did so because of lack of pain during the birth and the need for tubal sterilisation. The majority of women considered it important to have experience with a mode of birth in order to choose a preference. Complications associated with maternal illness were very influential in the decision-making process. Key conclusions: these results provide a useful first step towards the identification of aspects of women`s feelings about modes of birth. Most women expressed a preference for vaginal birth. Further exploration of women`s feelings regarding parturition and the decision-making process is required. (C) 2008 Elsevier Ltd. All rights reserved.

REDUCED ERYTHROCITARY GLUTATHIONE AND HEINZ BODIES IN CATS EXPERIMENTALLY INFECTED WITH THE FELINE IMMUNODEFICIENCY VIRUS

Santos, K.B.; Daniel, A.G.T. & Hagiwara, M.K. [Reduced erythrocitary Glutathione and Heinz bodies in cats experimentally infected with the Feline Immunodeficiency Virus.] Glutationa Reduzida Eritrocitaria e Corpusculos de Heinz em gatos infectados experimentalmente pelo Virus da Imunodeficieneia Felina. Revista Brasileira de Medicina Veterinaria, 30(1):26-30, 2008. Centro Universitario Serra dos Orgaos, Rua Comendador Queiroz 52, Apto. 1403, Niteroi, RJ 24230-220, Brasil. E-mail: keilabsantos@)gmail.com The Feline Immunodeficiency Virus (FIV) produces a chronic infection with immunologic system disfunctions in domestic cats developing non-responsive anaemia. The feline immunologic status depression produces free radicals, whose imbalance between production and removal in the organism favour the oxidative injury occurrence. Heinz bodies in large amounts also can evident in vivo oxidative damage. Glutatione, a tripeptide found in the animal cells, is an important protection mechanism against oxidative damages. In this work erythrocyte reduced glutathione (GSH) concentrations for healthy and cats experimentally infected by FIV were determinated in relation to the hemogram and the Heinz bodies presence. All of the animals presents normal values for hemogram and Heinz bodies, however the GSH erythrocyte concentrations in the FIV positive cats were below the normality probably due to an passive depletion to GSH.

Effect of argon purity on mechanical properties, microstructure and fracture mode of commercially pure (cp) Ti and Ti-6Al-4V alloys for ceramometal dental prostheses

Provision of an inert gas atmosphere with high-purity argon gas is recommended for preventing titanium castings from contamination although the effects of the level of argon purity on the mechanical properties and the clinical performance of Ti castings have not yet been investigated. The purpose of this study was to evaluate the effect of argon purity on the mechanical properties and microstructure of commercially pure (cp) Ti and Ti-6Al-4V alloys. The castings were made using either high-purity and/or industrial argon gas. The ultimate tensile strength (UTS), proportional limit (PL), elongation (EL) and microhardness (VHN) at different depths were evaluated. The microstructure of the alloys was also revealed and the fracture mode was analyzed by scanning electron microscopy. The data from the mechanical tests and hardness were subjected to a two-and three-way ANOVA and Tukey`s test (alpha = 0.05). The mean values of mechanical properties were not affected by the argon gas purity. Higher UTS, PL and VHN, and lower EL were observed for Ti-6Al-4V. The microhardness was not influenced by the argon gas purity. The industrial argon gas can be used to cast cp Ti and Ti-6Al-4V.