Screening process for activity determination of conductive oxide electrodes for organic oxidation

A modified method for the calculation of the normalized faradaic charge (q fN) is proposed. The method involves the simulation of an oxidation process, by cyclic voltammetry, by employing potentials in the oxygen evolution reaction region. The method is applicable to organic species whose oxidation is not manifested by a defined oxidation peak at conductive oxide electrodes. The variation of q fN for electrodes of nominal composition Ti/RuX Sn1-X O2 (x = 0.3, 0.2 and 0.1), Ti/Ir0.3Ti0.7O2 and Ti/Ru0.3Ti0.7O2 in the presence of various concentrations of formaldehyde was analyzed. It was observed that electrodes containing SnO2 are the most active for formaldehyde oxidation. Subsequently, in order to test the validity of the proposed model, galvanostatic electrolyses (40 mA cm-2) of two different formaldehyde concentrations (0.10 and 0.01 mol dm-3) were performed. The results are in agreement with the proposed model and indicate that this new method can be used to determine the relative activity of conductive oxide electrodes. In agreement with previous studies, it can be concluded that not only the nature of the electrode material, but also the organic species in solution and its concentration are important factors to be considered in the oxidation of organic compounds.

Contribution margin model applied to the marketing planning of a container liner carrier

The implementation of confidential contracts between a container liner carrier and its customers, because of the Ocean Shipping Reform Act (OSRA) 1998, demands a revision in the methodology applied in the carrier's planning of marketing and sales. The marketing and sales planning process should be more scientific and with a better use of operational research tools considering the selection of the customers under contracts, the duration of the contracts, the freight, and the container imbalances of these contracts are basic factors for the carrier's yield. This work aims to develop a decision support system based on a linear programming model to generate the business plan for a container liner carrier, maximizing the contribution margin of its freight.

Multidisciplinary optimization of a catamaran's hydrofoil design with dynamic response surface and distributive processing

This paper presents a rational approach to the design of a catamaran's hydrofoil applied within a modern context of multidisciplinary optimization. The approach used includes the use of response surfaces represented by neural networks and a distributed programming environment that increases the optimization speed. A rational approach to the problem simplifies the complex optimization model; when combined with the distributed dynamic training used for the response surfaces, this model increases the efficiency of the process. The results achieved using this approach have justified this publication.

Photolysis of ferric ions in the presence of sulfate or chloride ions: implications for the photo-Fenton process

The photo-Fenton process (Fe(2+)/Fe(3+), H(2)O(2), UV light) is one of the most efficient and advanced oxidation processes for the mineralization of the organic pollutants of industrial effluents and wastewater. The overall rate of the photo-Fenton process is controlled by the rate of the photolytic step that converts Fe(3+) back to Fe(2+). In this paper, the effect of sulfate or chloride ions on the net yield of Fe(2+) during the photolysis of Fe(3+) has been investigated in aqueous solution at pH 3.0 and 1.0 in the absence of hydrogen peroxide. A kinetic model based on the principal reactions that occur in the system fits the data for formation of Fe(2+) satisfactorily. Both experimental data and model prediction show that the availability of Fe(2+) produced by photolysis of Fe(3+) is inhibited much more in the presence of sulfate ion than in the presence of chloride ion as a function of the irradiation time at pH 3.0.

The Brain as a Distributed Intelligent Processing System: An EEG Study

Background: Various neuroimaging studies, both structural and functional, have provided support for the proposal that a distributed brain network is likely to be the neural basis of intelligence. The theory of Distributed Intelligent Processing Systems (DIPS), first developed in the field of Artificial Intelligence, was proposed to adequately model distributed neural intelligent processing. In addition, the neural efficiency hypothesis suggests that individuals with higher intelligence display more focused cortical activation during cognitive performance, resulting in lower total brain activation when compared with individuals who have lower intelligence. This may be understood as a property of the DIPS. Methodology and Principal Findings: In our study, a new EEG brain mapping technique, based on the neural efficiency hypothesis and the notion of the brain as a Distributed Intelligence Processing System, was used to investigate the correlations between IQ evaluated with WAIS (Whechsler Adult Intelligence Scale) and WISC (Wechsler Intelligence Scale for Children), and the brain activity associated with visual and verbal processing, in order to test the validity of a distributed neural basis for intelligence. Conclusion: The present results support these claims and the neural efficiency hypothesis.

Abnormal collagen deposition in synovia after collagen type V immunization in rabbits

Sinovitis in Scleroderma (SSc) is rare, usually aggressive and fully resembles rheumatoid arthritis. Experimental models of SSc have been used in an attempt to understand its pathogenesis. Previous studies done in our laboratory had already revealed the presence of a synovial remodeling process in rabbits immunized with collagen V. To validate the importance of collagen type V and to explore the quantitative relationship between this factor and synovia remodeling as well as the relationship between collagen type V and other collagens, we studied the synovial tissue in immunized rabbits. Rabbits (N= 10) were immunized with collagen V plus Freund's adjuvant and compared with animals inoculated with adjuvant only (N= 10). Synovial tissues were submitted to histological analysis, immunolocalization to collagen I, III and V and biochemical analysis by eletrophoresis, immunoblot and densitometric method. The synovial tissue presented an intense remodeling process with deposits of collagen types I, III and V after 75 and 120 days of immunization, mainly distributed around the vessels and interstitium of synovial extracellular matrix. Densitometric analysis confirmed the increased synthesis of collagen I, III and V chains (407.69 +/- 80.31; 24.46 +/- 2.58; 70.51 +/- 7.66, respectively) in immunized rabbits when compared with animals from control group (164.91 +/- 15.67; 12.89 +/- 1.05; 32 +/- 3.57) (p<0.0001). We conclude that synovial remodeling observed in the experimental model can reflect the articular compromise present in patients with scleroderma. Certainly, this experimental model induced by collagen V immunization will bring new insights in to pathogenic mechanisms and allow the testing of new therapeutic strategies to ameliorate the prognosis for scleroderma patients.

Tumor slices as a model to evaluate doxorubicin in vitro treatment and expression of trios of genes PRSS11, MTSS1, CLPTM1 and PRSS11, MTSS1, SMYD2 in canine mammary gland cancer

Background: In women with breast cancer submitted to neoadjuvant chemotherapy based in doxorubicin, tumor expression of groups of three genes (PRSS11, MTSS1, CLPTM1 and PRSS11, MTSS1, SMYD2) have classified them as responsive or resistant. We have investigated whether expression of these trios of genes could predict mammary carcinoma response in dogs and whether tumor slices, which maintain epithelial-mesenchymal interactions, could be used to evaluate drug response in vitro. Methods: Tumors from 38 dogs were sliced and cultured with or without doxorubicin 1 mu M for 24 h. Tumor cells were counted by two observers to establish a percentage variation in cell number, between slices. Based on these results, a reduction in cell number between treated and control samples >= 21.7%, arbitrarily classified samples, as drug responsive. Tumor expression of PRSS11, MTSS1, CLPTM1 and SMYD2, was evaluated by real time PCR. Relative expression results were then transformed to their natural logarithm values, which were spatially disposed according to the expression of trios of genes, comprising PRSS11, MTSS1, CLPTM1 and PRSS11, MTSS1, SMYD2. Fisher linear discrimination test was used to generate a separation plane between responsive and non-responsive tumors. Results: Culture of tumor slices for 24 h was feasible. Nine samples were considered responsive and 29 non-responsive to doxorubicin, considering the pre-established cut-off value of cell number reduction = 21.7%, between doxorubicin treated and control samples. Relative gene expression was evaluated and tumor samples were then spatially distributed according to the expression of the trios of genes: PRSS11, MTSS1, CLPTM1 and PRSS11, MTSS1, SMYD2. A separation plane was generated. However, no clear separation between responsive and non-responsive samples could be observed. Conclusion: Three-dimensional distribution of samples according to the expression of the trios of genes PRSS11, MTSS1, CLPTM1 and PRSS11, MTSS1, SMYD2 could not predict doxorubicin in vitro responsiveness. Short term culture of mammary gland cancer slices may be an interesting model to evaluate chemotherapy activity.

A Paradigm Shift in Predoctoral Dental Curricula in Brazil: Evaluating the Process of Change

In 2002, the Brazilian Ministry of Education approved the official curricular guidelines for undergraduate courses in Brazil to be adopted by the nation's 188 dental schools. In 2005-06, the Brazilian Dental Education Association (BDEA) promoted workshops in forty-eight of the schools to verify the degree of transformation of the curriculum based on these guidelines. Among the areas analyzed were course philosophy (variables were v1: knowledge production based on the needs of the Brazilian Public Health System [BPHS]; v2: health determinants; and v3: postgraduate studies and permanent education); pedagogical skills (v4: curricular structure; v5: changes in pedagogic and didactic skills; and v6: course program orientation); and dental practice scenarios (v7: diversity of the scenarios for training/learning; v8: academic health care centers opened to the BPHS; and v9: participation of students in health care delivery for the population). The subjects consisted of faculty members (n=711), students (n=228), and employees (n=14). The results showed an incipient degree of curriculum transformation. The degree of innovation was statistically different depending on the type of university (public or private) for variables I, 2, 4, 5, 6, and 7. Private schools reported a higher level of innovation than public institutions. Resistance to transforming the dental curriculum according to the official guidelines may be linked to an ideological conception that supports the private practice model, continues to have faculty members direct all classroom activities, and prevents students from developing an understanding of professional practice as targeted towards the oral health needs of all segments of society.

Simplified Mathematical Model for an Anaerobic Sequencing Batch Biofilm Reactor Treating Lipid-Rich Wastewater Subject to Rising Organic Loading Rates

This study proposes a simplified mathematical model to describe the processes occurring in an anaerobic sequencing batch biofilm reactor (ASBBR) treating lipid-rich wastewater. The reactor, subjected to rising organic loading rates, contained biomass immobilized cubic polyurethane foam matrices, and was operated at 32 degrees C +/- 2 degrees C, using 24-h batch cycles. In the adaptation period, the reactor was fed with synthetic substrate for 46 days and was operated without agitation. Whereas agitation was raised to 500 rpm, the organic loading rate (OLR) rose from 0.3 g chemical oxygen demand (COD) . L(-1) . day(-1) to 1.2 g COD . L(-1) . day(-1). The ASBBR was fed fat-rich wastewater (dairy wastewater), in an operation period lasting for 116 days, during which four operational conditions (OCs) were tested: 1.1 +/- 0.2 g COD . L(-1) . day(-1) (OC1), 4.5 +/- 0.4 g COD . L(-1) . day(-1) (OC2), 8.0 +/- 0.8 g COD . L(-1) . day(-1) (OC3), and 12.1 +/- 2.4 g COD . L(-1) . day(-1) (OC4). The bicarbonate alkalinity (BA)/COD supplementation ratio was 1:1 at OC1, 1:2 at OC2, and 1:3 at OC3 and OC4. Total COD removal efficiencies were higher than 90%, with a constant production of bicarbonate alkalinity, in all OCs tested. After the process reached stability, temporal profiles of substrate consumption were obtained. Based on these experimental data a simplified first-order model was fit, making possible the inference of kinetic parameters. A simplified mathematical model correlating soluble COD with volatile fatty acids (VFA) was also proposed, and through it the consumption rates of intermediate products as propionic and acetic acid were inferred. Results showed that the microbial consortium worked properly and high efficiencies were obtained, even with high initial substrate concentrations, which led to the accumulation of intermediate metabolites and caused low specific consumption rates.

Human Dental Pulp Cells: A New Source of Cell Therapy in a Mouse Model of Compressive Spinal Cord Injury

Strategies aimed at improving spinal cord regeneration after trauma are still challenging neurologists and neuroscientists throughout the world. Many cell-based therapies have been tested, with limited success in terms of functional outcome. In this study, we investigated the effects of human dental pulp cells (HDPCs) in a mouse model of compressive spinal cord injury (SCI). These cells present some advantages, such as the ease of the extraction process, and expression of trophic factors and embryonic markers from both ecto-mesenchymal and mesenchymal components. Young adult female C57/BL6 mice were subjected to laminectomy at T9 and compression of the spinal cord with a vascular clip for 1 min. The cells were transplanted 7 days or 28 days after the lesion, in order to compare the recovery when treatment is applied in a subacute or chronic phase. We performed quantitative analyses of white-matter preservation, trophic-factor expression and quantification, and ultrastructural and functional analysis. Our results for the HDPC-transplanted animals showed better white-matter preservation than the DMEM groups, higher levels of trophic-factor expression in the tissue, better tissue organization, and the presence of many axons being myelinated by either Schwann cells or oligodendrocytes, in addition to the presence of some healthy-appearing intact neurons with synapse contacts on their cell bodies. We also demonstrated that HDPCs were able to express some glial markers such as GFAP and S-100. The functional analysis also showed locomotor improvement in these animals. Based on these findings, we propose that HDPCs may be feasible candidates for therapeutic intervention after SCI and central nervous system disorders in humans.

The Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System (CATT-BRAMS) - Part 2: Model sensitivity to the biomass burning

We describe an estimation technique for biomass burning emissions in South America based on a combination of remote-sensing fire products and field observations, the Brazilian Biomass Burning Emission Model (3BEM). For each fire pixel detected by remote sensing, the mass of the emitted tracer is calculated based on field observations of fire properties related to the type of vegetation burning. The burnt area is estimated from the instantaneous fire size retrieved by remote sensing, when available, or from statistical properties of the burn scars. The sources are then spatially and temporally distributed and assimilated daily by the Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System (CATT-BRAMS) in order to perform the prognosis of related tracer concentrations. Three other biomass burning inventories, including GFEDv2 and EDGAR, are simultaneously used to compare the emission strength in terms of the resultant tracer distribution. We also assess the effect of using the daily time resolution of fire emissions by including runs with monthly-averaged emissions. We evaluate the performance of the model using the different emission estimation techniques by comparing the model results with direct measurements of carbon monoxide both near-surface and airborne, as well as remote sensing derived products. The model results obtained using the 3BEM methodology of estimation introduced in this paper show relatively good agreement with the direct measurements and MOPITT data product, suggesting the reliability of the model at local to regional scales.

Numerical study of a model for nonequilibrium wetting

We revisit the scaling properties of a model for nonequilibrium wetting [Phys. Rev. Lett. 79, 2710 (1997)], correcting previous estimates of the critical exponents and providing a complete scaling scheme. Moreover, we investigate a special point in the phase diagram, where the model exhibits a roughening transition related to directed percolation. We argue that in the vicinity of this point evaporation from the middle of plateaus can be interpreted as an external field in the language of directed percolation. This analogy allows us to compute the crossover exponent and to predict the form of the phase transition line close to its terminal point.

The gross theory model for neutrino-nucleus cross-section

The nuclear gross theory, originally formulated by Takahashi and Yamada (1969 Prog. Theor. Phys. 41 1470) for the beta-decay, is applied to the electronic-neutrino nucleus reactions, employing a more realistic description of the energetics of the Gamow-Teller resonances. The model parameters are gauged from the most recent experimental data, both for beta(-)-decay and electron capture, separately for even-even, even-odd, odd-odd and odd-even nuclei. The numerical estimates for neutrino-nucleus cross-sections agree fairly well with previous evaluations done within the framework of microscopic models. The formalism presented here can be extended to the heavy nuclei mass region, where weak processes are quite relevant, which is of astrophysical interest because of its applications in supernova explosive nucleosynthesis.

Statistics of opinion domains of the majority-vote model on a square lattice

The existence of juxtaposed regions of distinct cultures in spite of the fact that people's beliefs have a tendency to become more similar to each other's as the individuals interact repeatedly is a puzzling phenomenon in the social sciences. Here we study an extreme version of the frequency-dependent bias model of social influence in which an individual adopts the opinion shared by the majority of the members of its extended neighborhood, which includes the individual itself. This is a variant of the majority-vote model in which the individual retains its opinion in case there is a tie among the neighbors' opinions. We assume that the individuals are fixed in the sites of a square lattice of linear size L and that they interact with their nearest neighbors only. Within a mean-field framework, we derive the equations of motion for the density of individuals adopting a particular opinion in the single-site and pair approximations. Although the single-site approximation predicts a single opinion domain that takes over the entire lattice, the pair approximation yields a qualitatively correct picture with the coexistence of different opinion domains and a strong dependence on the initial conditions. Extensive Monte Carlo simulations indicate the existence of a rich distribution of opinion domains or clusters, the number of which grows with L(2) whereas the size of the largest cluster grows with ln L(2). The analysis of the sizes of the opinion domains shows that they obey a power-law distribution for not too large sizes but that they are exponentially distributed in the limit of very large clusters. In addition, similarly to other well-known social influence model-Axelrod's model-we found that these opinion domains are unstable to the effect of a thermal-like noise.

Multiclass Hammersley-Aldous-Diaconis process and multiclass-customer queues

In the Hammersley-Aldous-Diaconis process, infinitely many particles sit in R and at most one particle is allowed at each position. A particle at x, whose nearest neighbor to the right is at y, jumps at rate y - x to a position uniformly distributed in the interval (x, y). The basic coupling between trajectories with different initial configuration induces a process with different classes of particles. We show that the invariant measures for the two-class process can be obtained as follows. First, a stationary M/M/1 queue is constructed as a function of two homogeneous Poisson processes, the arrivals with rate, and the (attempted) services with rate rho > lambda Then put first class particles at the instants of departures (effective services) and second class particles at the instants of unused services. The procedure is generalized for the n-class case by using n - 1 queues in tandem with n - 1 priority types of customers. A multi-line process is introduced; it consists of a coupling (different from Liggett's basic coupling), having as invariant measure the product of Poisson processes. The definition of the multi-line process involves the dual points of the space-time Poisson process used in the graphical construction of the reversed process. The coupled process is a transformation of the multi-line process and its invariant measure is the transformation described above of the product measure.