Cys mutants in functional regions of Sticholysin I clarify the participation of these residues in pore formation

Experimental evidence shows that the mechanism of pore formation by actinoporins is a multistep process, involving binding of the water-soluble monomer to the membrane and subsequent oligomerization on the membrane surface, leading to the formation of a functional pore. However, as for other eukaryotic pore-forming toxins, the molecular details of the mechanism of membrane insertion and oligomerization are not clear. In order to obtain further insight with regard to the structure-function relationship in sticholysins, we designed and produced three cysteine mutants of recombinant sticholysin I (rStI) in relevant functional regions for membrane interaction: StI E2C and StI F15C (in the N-terminal region) and StI R52C (in the membrane binding site). The conformational characterization derived from fluorescence and CD spectroscopic studies of StI E2C, StI F15C and StI R52C suggests that replacement of these residues by Cys in rStI did not noticeably change the conformation of the protein. The substitution by Cys of Arg(52) in the phosphocholine-binding site, provoked noticeable changes in rStI permeabilizing activity; however, the substitutions in the N-terminal region (Glu(2), Phe(15)) did not modify the toxin`s permeabilizing ability. The presence of a dimerized population stabilized by a disulfide bond in the StI E2C mutant showed higher pore-forming activity than when the protein is in the monomeric state, suggesting that sticholysins pre-ensembled at the N-terminal region could facilitate pore formation. (C) 2011 Elsevier Ltd. All rights reserved.

Chronic stress alters the density and morphology of microglia in a subset of stress-responsive brain regions

The current study, in parallel experiments, evaluated the impact of chronic psychological stress on physiological and behavioural measures, and on the activation status of microglia in 15 stress-responsive brain regions. Rats were subjected, for 14 days, to two 30 min sessions of restraint per day, applied at random times each day. In one experiment the effects of stress on sucrose preference, weight gain, core body temperature, and struggling behaviour during restraint, were determined. In the second experiment we used immunohistochemistry to investigate stress-induced changes in ionized calcium-binding adaptor molecule-1 (Iba1), a marker constitutively expressed by microglia, and major histocompatibility complex-II (MHC-II), a marker often expressed on activated microglia, in a total of 15 stress-responsive nuclei. We also investigated cellular proliferation in these regions using Ki67 immunolabelling, to check for the possibility of microglial proliferation. Collectively, the results we obtained showed that chronic stress induced a significant increase in anhedonia, a decrease in weight gain across the entire observation period, a significant elevation in core body temperature during restraint, and a progressive decrease in struggling behaviour within and over sessions. With regard to microglial activation, chronic stress induced a significant increase in the density of Iba1 immunolabelling (nine of 15 regions) and the number of Iba1-positive cells (eight of 15 regions). Within the regions that exhibited an increased number of Iba1-positive cells after chronic stress, we found no evidence of a between group difference in the number of MHC-II or Ki67 positive cells. In summary, these results clearly demonstrate that chronic stress selectively increases the number of microglia in certain stress-sensitive brain regions, and also causes a marked transition of microglia from a ramified-resting state to a non-resting state. These findings are consistent with the view that microglial activation could play an important role in controlling and/or adapting to stress.

Regional subsidies and industrial prospects of lagging regions

Large and sustained differences in economic performance across regions of developing countries have long provided motivation for fiscal incentives designed to encourage firm entry in lagging areas. Empirical evidence in support of these policies has, however, been weak at best. This paper undertakes a direct evaluation of the most prominent fiscal incentive policy in Brazil, the Fundos Constitucionais de Financiamento (Constitutional Funds). In doing so, we exploit valuable features of the Brazilian Ministry of Labor's RAIS data set to address two important elements of firm location decisions that have the potential to bias an assessment of the Funds: (i) firm “family structure” (in particular, proximity to headquarters for vertically integrated firms), and (ii) unobserved spatial heterogeneity (with the potential to confound the effects of the Funds). We find that the pull of firm headquarters is very strong relative to the Constitutional Funds for vertically integrated firms, but that, with non-parametric controls for time invariant spatial heterogeneity, the Funds provide statistically and economically significant incentives for firms in many of the targeted industries.

Reduction capability of soil humic substances from the Rio Negro basin, Brazil, towards Hg(II) studied by a multimethod approach and principal component analysis (PCA)

This paper characterizes humic substances (HS) extracted from soil samples collected in the Rio Negro basin in the state of Amazonas, Brazil, particularly investigating their reduction capabilities towards Hg(II) in order to elucidate potential mercury cycling/volatilization in this environment. For this reason, a multimethod approach was used, consisting of both instrumental methods (elemental analysis, EPR, solid-state NMR, FIA combined with cold-vapor AAS of Hg(0)) and statistical methods such as principal component analysis (PCA) and a central composite factorial planning method. The HS under study were divided into groups, complexing and reducing ones, owing to different distribution of their functionalities. The main functionalities (cor)related with reduction of Hg(II) were phenolic, carboxylic and amide groups, while the groups related with complexation of Hg(II) were ethers, hydroxyls, aldehydes and ketones. The HS extracted from floodable regions of the Rio Negro basin presented a greater capacity to retain (to complex, to adsorb physically and/or chemically) Hg(II), while nonfloodable regions showed a greater capacity to reduce Hg(II), indicating that HS extracted from different types of regions contribute in different ways to the biogeochemical mercury cycle in the basin of the mid-Rio Negro, AM, Brazil. (c) 2007 Published by Elsevier B.V.

Estruturação do grupo Serra Grande região de Santana do Acaraú- CE e a reativação do lineamento Sobral Pedro II, integração com dados geofísicos

The study area is located in the NW portion of the Ceará state nearby the city of Santana do Acaraú. Geologically it lies along the Sobral-Pedro II lineament which limits the domains of Ceará Central and Noroeste do Ceará, both belonging to the Borborema Province.The object of study was a NE trending 30km long siliciclastic body (sandstone and conglomerate) bounded by transcurrent dextral faults. The sediments are correlated to the Ipú Formation (Serra Grande Group) from the Parnaiba basin, which age is thought to be Siluro-Devonian. Existing structural data shown that bedding has higher but variable dips (70-45) near the borders faults and much lower to subhorizontal inward the body. The brittle deformation was related to a reactivation, in lower crustal level, of the Sobral-Pedro II lineament (Destro (1987, 1999; Galvão, 2002).The study presented here was focused in applying geophysicals methods (gravimetry and seismic) to determine the geometry of the sandstone/conglomeratic body and together with the structural data, to propose a model to explain its deformation. The residual anomalies maps indicate the presence of two main graben-like structures. The sedimentary pile width was estimated from 2D gravimetric models to be about 500-600 meters. The 3D gravimetric model stressed the two maximum width regions where a good correlation is observed between the isopach geometry and the centripetal strike/dip pattern displayed by the sediments bedding. Two main directions (N-S and E-W) of block moving are interpreted from the distribution pattern of the maximum width regions of the sedimentary rock

SPH simulations of clumps formation by dissipative collisions of molecular clouds - II. Magnetic case

We performed computer simulations of interstellar cloud-cloud collisions using the three-dimensional smoothed particle magnetohydrodynamics method. In order to study the role of the magnetic field on the process of collision-triggered fragmentation, we focused our attention on head-on supersonic collisions between two identical spherical molecular-clouds. Two extreme configurations of the magnetic field were adopted: parallel and perpendicular to the initial clouds motion. The initial magnetic field strength was approximately 12.0 muG. In the parallel case, much more of the collision debris were retained in the shocking region than in the non-magnetic case where gas escaped freely throughout the symmetry plane. Differently from the non-magnetic case, eddy-like vortices were formed. The regions of highest vorticity and the the regions of highest density are offset. We found clumps formation only in the parallel case, however, they were larger, hotter and less dense than in the analogous non-magnetic case. In the perpendicular case, the compressed field works as a magnetic wall, preventing a stronger compression of the colliding clouds. This last effect inhibits direct contact of the two clouds. In both cases, we found that the field lines show a chaotic aspect in large scales. Also, the field magnitude is considerably amplified in the shock layer. However, the field distribution is almost coherent in the higher density regions.

Analytical study of the nonlinear behavior of a shape memory oscillator: Part II-resonance secondary

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ceramic Crucible Corrosion by Heavy Metal Oxide Glasses, Part II: Diffusion Study

Due to their low cost and high resistance to corrosion, ceramic crucibles can be used for the melting of PBG glasses (PbO-BiO 1.5GaO 1.5). These glasses present good window transmission from ultra-violet to infrared, making their use as optical fibres promising. However, their disadvantage is the high reactivity, leading to the corrosion of different crucibles, including gold and platinum ones. In this work, the corrosion of Al 2O 3, SnO 2 and ZrO 2 crucibles after melting at temperatures varying from 850 to 1000°C, was evaluated by Scanning Electronic Microscopy (SEM) in conjunction with microanalysis by EDS. The lead diffusion profile in the crucible material was obtained. Diffusion coefficients were calculated according to the Fick and Fisher theories. Results indicated that the different crucibles presented similar behaviour: in the region near the interface, diffusion occurs in the volumetric way and in regions away from the interface, diffusion occurs through grain boundary.

Immunohistochemical, tomographic and histological study on onlay bone graft remodeling. Part II: Calvarial bone

Objectives: Little information is available on the molecular events that occur during graft incorporation over time. The calvarial bone (Cb) grafts have been reported to produce greater responses compared with other donor regions in maxillofacial reconstructions, but the scientific evidences for this are still lacking. The objectives of this study are (1) to study the morphological pattern of Cb onlay bone grafts and compare them with the biological events through immunohistochemical responses and (2) to establish the effects of perforations in maintaining the volume and bone density of the receptor bed. Material and methods: Sixty New Zealand White rabbits were submitted to Cb onlay bone grafts on the mandible. In 30 rabbits, the receptor bed was perforated (perforated group), while for the remaining animals the bed was kept intact (non-perforated group). Six animals from each group were sacrificed at 5, 7, 10, 20 and 60 days after surgery. Histological sections from the grafted area were prepared for immunohistochemical and histological analyses. Immuno-labeling was found for proteins Osteoprotegerin (OPG), receptor activator of nuclear factor-κβ ligand (RANKL), alkaline phosphatase (ALP), osteopontin (OPN), vascular endothelial growth factor (VEGF), tartrate-resistant acid phosphatase (TRAP), Type I collagen (COL I) and osteocalcin (OC). The tomography examination [computerized tomography (CT) scan] was conducted just after surgery and at the sacrifice. Results: The histological findings revealed that the perforations contributed to higher bone deposition during the initial stages at the graft-receptor bed interface, accelerating the graft incorporation process. The results of the CT scan showed lower resorption for the perforated group (P≤0.05), and both groups showed high bone density rates at 60 days. This set of evidences is corroborated by the immunohistochemical outcomes indicating that proteins associated with revascularization and osteogenesis (VEGF, OPN, TRAP and ALP) were found in higher levels in the perforated group. Conclusions: These findings indicate that the bone volume of calvarial grafts is better maintained when the receptor bed is perforated, probably resulting from more effective graft revascularization and greater bone deposition. The process of bone resorption peaked between 20 and 60 days post-operatively in both groups although significantly less in the perforated group. © 2009 John Wiley & Sons A/S.

A competitiveness index for the regions of a country

Includes bibliography

The Edinger-Westphal nucleus II: Hypothalamic afferents in the rat

Numerous functions have been attributed to the Edinger-Westphal nucleus (EW), including those related to feeding behavior, pain control, alcohol consumption and the stress response. The EW is thought to consist of two parts: one controls accommodation, choroidal blood flow and pupillary constriction, primarily comprising cholinergic cells and projecting to the ciliary ganglion; and the other would be involved in the non-ocular functions mentioned above, comprising peptide-producing neurons and projecting to the brainstem, spinal cord and prosencephalic regions. Despite the fact that the EW is well known, its connections have yet to be described in detail. The aim of this work was to produce a map of the hypothalamic sources of afferents to the EW in the rat. We injected the retrograde tracer Fluoro-Gold into the EW, and using biotinylated dextran amine, injected into afferent sources as the anterograde control. We found retrogradely labeled cells in the following regions: subfornical organ, paraventricular hypothalamic nucleus, arcuate nucleus, lateral hypothalamic area, zona incerta, posterior hypothalamic nucleus, medial vestibular nucleus and cerebellar interpositus nucleus. After injecting BDA into the paraventricular hypothalamic nucleus, lateral hypothalamic area and posterior hypothalamic nucleus, we found anterogradely labeled fibers in close apposition to and potential synaptic contact with urocortin 1-immunoreactive cells in the EW. On the basis of our findings, we can suggest that the connections between the EW and the hypothalamic nuclei are involved in controlling stress responses and feeding behavior. © 2013 The Authors.

Operários da undécima hora : os Agostinianos Recoletos no Brasil: criação da província de Santa Rita de Cássia e o impacto do Concílio Vaticano II

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tomografia computadorizada de feixe cônico para avaliação do tratamento da classe II divisão 1ª com o aparelho Herbst no espaço aéreo faríngeo

Pós-graduação em Ciências Odontológicas - FOAR

Programa Nacional de Produção e Uso de Biodiesel (PNPB) - possibilidades e limites do desenvolvimento econômico e da inclusão social para a agricultura familiar na Amazônia: o assentamento Calmaria II, Moju (PA)

A preocupação com o meio ambiente a partir dos anos 70, evidencia a necessidade de substituição dos combustíveis fósseis, e o Brasil, como referência mundial na produção e utilização de fontes renováveis de energia lança o Programa Nacional de Produção e Uso do Biodiesel (PNPB) em 2004 tendo como diferencial o estímulo à geração de renda através da produção e comercialização das matérias-primas pela agricultura familiar, através do “Selo Combustível Social”, o qual será concedido às empresas produtoras do biodiesel que adquiram matéria-prima desses agricultores. A pesquisa aborda a produção de dendê (Elaeis guineensis Jacq.) proveniente do trabalho dos agricultores familiares assentados via Instituto Nacional de Colonização e Reforma Agrária (INCRA), no Projeto de Assentamento (PA) Calmaria II, no município de Moju, com área contínua aos plantios da Empresa Agropalma que, organizados em uma associação, têm como foco a produção e a comercialização do dendê como vetor de renda e também inclusão social. Estes se inserem através dos financiamentos do PRONAF junto ao Banco da Amazônia S.A. Visa assim verificar de que forma se dá sua inclusão e sua conseqüente contribuição para o desenvolvimento sustentável da região, a qual ainda encontra-se distanciada da modernização do campo verificada nas demais regiões do país.

Estudo cefalométrico com implantes metálicos dos efeitos do aparelho Bionator de Balters no desenvolvimento esquelético maxilo-mandibular durante o tratamento da má oclusão classe II divisão 1

Pós-graduação em Odontologia - FOAR