How foam-like is the shear-induced lamellar phase of an ionic liquid crystal?

Philosophical Magazine Letters Volume 88, Issue 9-10, 2008 Special Issue: Solid and Liquid Foams. In commemoration of Manuel Amaral Fortes

Bradykinin-induced Ca2+ signaling in human subcutaneous fibroblasts involves ATP release via hemichannels leading to P2Y12 receptors activation

Background: Chronic musculoskeletal pain involves connective tissue remodeling triggered by inflammatory mediators, such as bradykinin. Fibroblast cells signaling involve changes in intracellular Ca2+ ([Ca2+]i). ATP has been related to connective tissue mechanotransduction, remodeling and chronic inflammatory pain, via P2 purinoceptors activation. Here, we investigated the involvement of ATP in bradykinin-induced Ca2+ signals in human subcutaneous fibroblasts. Results: Bradykinin, via B2 receptors, caused an abrupt rise in [Ca2+]i to a peak that declined to a plateau, which concentration remained constant until washout. The plateau phase was absent in Ca2+-free medium; [Ca2+]i signal was substantially reduced after depleting intracellular Ca2+ stores with thapsigargin. Extracellular ATP inactivation with apyrase decreased the [Ca2+]i plateau. Human subcutaneous fibroblasts respond to bradykinin by releasing ATP via connexin and pannexin hemichannels, since blockade of connexins, with 2- octanol or carbenoxolone, and pannexin-1, with 10Panx, attenuated bradykinin-induced [Ca2+]i plateau, whereas inhibitors of vesicular exocytosis, such as brefeldin A and bafilomycin A1, were inactive. The kinetics of extracellular ATP catabolism favors ADP accumulation in human fibroblast cultures. Inhibition of ectonucleotidase activity and, thus, ADP formation from released ATP with POM-1 or by Mg2+ removal from media reduced bradykinin-induced [Ca2+]i plateau. Selective blockade of the ADP-sensitive P2Y12 receptor with AR-C66096 attenuated bradykinin [Ca2+]i plateau, whereas the P2Y1 and P2Y13 receptor antagonists, respectively MRS 2179 and MRS 2211, were inactive. Human fibroblasts exhibited immunoreactivity against connexin-43, pannexin-1 and P2Y12 receptor. Conclusions: Bradykinin induces ATP release from human subcutaneous fibroblasts via connexin and pannexin-1-containing hemichannels leading to [Ca2+]i mobilization through the cooperation of B2 and P2Y12 receptors.

Living bacteria rheology: Population growth, aggregation patterns, and collective behaviour under diferente shear flows

The activity of growing living bacteria was investigated using real-time and in situ rheology-in stationary and oscillatory shear. Two different strains of the human pathogen Staphylococcus aureus-strain COL and its isogenic cell wall autolysis mutant, RUSAL9-were considered in this work. For low bacteria density, strain COL forms small clusters, while the mutant, presenting deficient cell separation, forms irregular larger aggregates. In the early stages of growth, when subjected to a stationary shear, the viscosity of the cultures of both strains increases with the population of cells. As the bacteria reach the exponential phase of growth, the viscosity of the cultures of the two strains follows different and rich behaviors, with no counterpart in the optical density or in the population's colony-forming units measurements. While the viscosity of strain COL culture keeps increasing during the exponential phase and returns close to its initial value for the late phase of growth, where the population stabilizes, the viscosity of the mutant strain culture decreases steeply, still in the exponential phase, remains constant for some time, and increases again, reaching a constant plateau at a maximum value for the late phase of growth. These complex viscoelastic behaviors, which were observed to be shear-stress-dependent, are a consequence of two coupled effects: the cell density continuous increase and its changing interacting properties. The viscous and elastic moduli of strain COL culture, obtained with oscillatory shear, exhibit power-law behaviors whose exponents are dependent on the bacteria growth stage. The viscous and elastic moduli of the mutant culture have complex behaviors, emerging from the different relaxation times that are associated with the large molecules of the medium and the self-organized structures of bacteria. Nevertheless, these behaviors reflect the bacteria growth stage.

Single-lap joints of similar and dissimilar adherends bonded with an acrylic adhesive

In this study, the tensile strength of single-lap joints (SLJs) between similar and dissimilar adherends bonded with an acrylic adhesive was evaluated experimentally and numerically. The adherend materials included polyethylene (PE), polypropylene (PP), carbon-epoxy (CFRP), and glass-polyester (GFRP) composites. The following adherend combinations were tested: PE/PE, PE/PP, PE/CFRP, PE/GFRP, PP/PP, CFRP/CFRP, and GFRP/GFRP. One of the objectives of this work was to assess the influence of the adherends stiffness on the strength of the joints since it significantly affects the peel stresses magnitude in the adhesive layer. The experimental results were also used to validate a new mixed-mode cohesive damage model developed to simulate the adhesive layer. Thus, the experimental results were compared with numerical simulations performed in ABAQUS��, including a developed mixed-mode (I+II) cohesive damage model, based on the indirect use of fracture mechanics and implemented within interface finite elements. The cohesive laws present a trapezoidal shape with an increasing stress plateau, to reproduce the behaviour of the ductile adhesive used. A good agreement was found between the experimental and numerical results.

Obstru����o br��nquica m��xima induzida em crian��as asm��ticas: an��lise dos indicadores de susceptibilidade br��nquica aumentada �� metacolina

Rev. Port. de Pneumologia. 1997,1:p. 5-37.

Interesses, atividades e oportunidades di��rias de aprendizagem

As respostas da Interven����o Precoce (IP) come��aram por se focar exclusivamente na crian��a (Serrano & Correia, 2000), apoiando-se num modelo m��dico que procurava remediar os d��fices, identificados atrav��s de testes, descurando os contextos dos quais a crian��a faz parte. Inicialmente a IP focava-se na crian��a com Necessidades Especiais (NE), considerada de forma isolada em rela����o aos seus contextos de vida, sendo a atividade do profissional de IP direcionada para a avalia����o das crian��as e para o delineamento de atividades para estimula����o do seu desenvolvimento (Cruz et al., 2003). Nos anos 80, a fam��lia e a crian��a passaram a ser o alvo das interven����es. A fam��lia foi considerada como recetora de servi��os, apresentando necessidades espec��ficas, particularmente a n��vel de recursos e informa����es, inerentes ao fato de existir uma crian��a em risco (Simeonsson & Bailey, 1990 citados por Serrano & Correia, 2000). Houve uma mudan��a gradual de modelos de servi��os centrados na crian��a e no profissional, onde o papel da fam��lia era desvalorizado, at�� aqueles onde os profissionais trabalham em parceria com as fam��lias que acompanham. Dunst et al. (1994 citado por McWilliam, 2003) desempenharam um papel fundamental na promo����o da ado����o de princ��pios centrados na fam��lia pelos profissionais de IP. Esta altera����o do foco de aten����o baseou-se em contributos concetuais com origens diversas, das quais se destacam o Modelo Ecol��gico de Desenvolvimento Humano, de Bronfenbrenner (1979) e o Modelo de Desenvolvimento Transacional, de Sameroff e Chandler (1975). A presta����o de servi��os centrados na fam��lia reconhece a import��ncia fulcral da fam��lia nas vidas dos indiv��duos. Orienta-se por um conjunto de escolhas devidamente informadas feitas pela fam��lia e foca-se nos pontos fortes e capacidades das fam��lias (Carvalho, 2002). Foram introduzidos por McWilliam (2003) os termos ���corresponsabiliza����o��� (capacidade de a fam��lia satisfazer as suas necessidades e desejos, criando um sentimento de controlo) e ���capacita����o��� (criar oportunidades para que todos os membros da fam��lia possam demonstrar e adquirir compet��ncias), que constituem conceitos centrais na filosofia da IP. Na ��ltima d��cada, Dunst (2001) prop��e uma perspetiva alargada do enfoque da IP. Para ele as diferentes pessoas e as experi��ncias ambientais servem como contexto para as aprendizagens da crian��a, considerando desta forma, que a vida na comunidade �� constitu��da por m��ltiplas possibilidades para promover o desenvolvimento. De uma forma geral, o dia-a-dia da crian��a e da sua fam��lia na comunidade n��o tem sido habitualmente visto como poss��vel enquadramento para as pr��ticas da IP (Dunst, 2000a). No entanto, para Dunst (2000a) a participa����o em oportunidades de aprendizagem da comunidade �� considerada IP pois elas constituem fontes de experi��ncias de aprendizagem e possuem caracter��sticas e consequ��ncias que promovem o desenvolvimento da crian��a e a normaliza����o do dia-a-dia das fam��lias na sociedade. Dunst (2001) refere que esta conceptualiza����o de IP baseia-se em teoria e investiga����o, indicando que ���as experi��ncias ambientais providenciadas ��s crian��as, independentemente de serem, ou n��o intencionalmente manipuladas funcionam como uma forma de interven����o precoce��� (p.71). Da mesma forma, a participa����o da crian��a em atividades contextualizadas e oportunidades de aprendizagem, quer estas sejam planeadas, ou n��o, �� vista como oportunidades ambientais que fornecem um contexto para a aprendizagem e desenvolvimento. Durante a realiza����o de um estudo no ��mbito de uma disserta����o de mestrado, profissionais de IP, a exercer em Equipas Locais de Interven����o (ELI), da Regi��o Norte de Portugal, responderam �� Early Childhood Intervention Competency Checklists (Roper & Dunst, 2006). Com a an��lise dos resultados obtidos verificou-se que os profissionais de IP preocupam-se e usam pr��ticas centradas na fam��lia, havendo atualmente um maior envolvimento dos pais. No entanto, ainda n��o se verifica o envolvimento das fam��lias em todo o processo de avalia����o e/ou interven����o. Verificou-se uma utiliza����o insuficiente dos cen��rios de atividades di��rias das crian��as, das fam��lias e da comunidade, com reflexos negativos ao n��vel do aproveitamento das oportunidades de aprendizagem da crian��a. Por fim, verificou-se ainda pouco fortalecimento das redes de apoio social da fam��lia, pelos profissionais (Pinto, 2012). De acordo com a revis��o da literatura efetuada e com base nos resultados obtidos no estudo realizado, no ��mbito da disserta����o de mestrado, a autora considerou a necessidade de demonstrar aos profissionais de IP, que as pr��ticas contextualmente mediadas podem ser um modelo de interven����o eficaz com as fam��lias e as crian��as que s��o apoiadas na IP. Este estudo tem como objetivo, mostrar como �� que os profissionais de IP podem usar as atividades di��rias da fam��lia e da comunidade, como contextos de oportunidades de aprendizagem, para promover a aprendizagem e o desenvolvimento. A autora pretende que este possa ser um trabalho que contribua para a melhoria das pr��ticas de IP, pelos t��cnicos de IP, na sua pr��tica profissional, com as crian��as e fam��lias a que d��o apoio.

Pliocene-quaternary upwelling in the SoutheasternAtlantic may reflect changes in water mass production

Proceedings of tile 1" R.C.A.N.S. Congress, Lisboa, October 1992

Three year seroepidemiological study of varicella-zoster virus in S��o Paulo, Brazil

A serosurvey of varicella has been carried out in children attending the public school network of S��o Paulo city, Brazil, from 1992 to 1994. This study was performed in order to establish the age related prevalence of antibodies against varicella-zoster virus (VZV) and its age specific transmission dynamics pattern in these children. Among 2500 schools in the city of S��o Paulo public network, 304 were randomly selected; 7 children of a given age (ranging from 1 to 15 years) were randomly selected in each school, and blood samples were obtained by fingerprick into filter paper. Blood eluates were analyzed for the presence of antibodies to VZV by ELISA. Proportion of seropositivity were calculated for each age group. Samples consisted of 1768 individuals in 1992, 1758 in 1993, and 1817 in 1994, resulting in 5343 eluates. A high proportion of seropositive children from 1 to 3 years of age was observed, ascending until 10 years of age and reaching a plateau around 90% afterwards. VZV transmission in this community was similar along the three years of the study. In children attending public schools in the city of S��o Paulo, contact with VZV occurs in early childhood. If immunization against VZV is considered it should be introduced as soon as possible.

Calcium signaling and the novel anti-proliferative effect of the UTP-sensitive P2Y11 receptor in rat cardiac myofibroblasts

During myocardial ischemia and reperfusion both purines and pyrimidines are released into the extracellular milieu, thus creating a signaling wave that propagates to neighboring cells via membrane-bound P2 purinoceptors activation. Cardiac fibroblasts (CF) are important players in heart remodeling, electrophysiological changes and hemodynamic alterations following myocardial infarction. Here, we investigated the role UTP on calcium signaling and proliferation of CF cultured from ventricles of adult rats. Co-expression of discoidin domain receptor 2 and -smooth muscle actin indicate that cultured CF are activated myofibroblasts. Intracellular calcium ([Ca2+]i) signals were monitored in cells loaded with Fluo-4 NW. CF proliferation was evaluated by the MTT assay. UTP and the selective P2Y4 agonist, MRS4062, caused a fast desensitizing [Ca2+]i rise originated from thapsigargin-sensitive internal stores, which partially declined to a plateau providing the existence of Ca2+ in the extracellular fluid. The biphasic [Ca2+]i response to UTP was attenuated respectively by P2Y4 blockers, like reactive blue-2 and suramin, and by the P2Y11 antagonist, NF340. UTP and the P2Y2 receptor agonist MRS2768 increased, whereas the selective P2Y11 agonist NF546 decreased, CF growth; MRS4062 was ineffective. Blockage of the P2Y11receptor or its coupling to adenylate cyclase boosted UTP-induced CF proliferation. Confocal microscopy and Western blot analysis confirmed the presence of P2Y2, P2Y4 and P2Y11 receptors. Data indicate that besides P2Y4 and P2Y2 receptors which are responsible for UTP-induced [Ca2+]i transients and growth of CF, respectively, synchronous activation of the previously unrecognized P2Y11 receptor may represent an important target for anti-fibrotic intervention in cardiac remodeling.

Epidemiological study on leishmaniasis in an area of environmental tourism and ecotourism, State of Mato Grosso do Sul, 2006-2007

The aims of this study were to carry out a serological survey of canine leishmaniasis and identify the phlebotomine fauna in the urban area of Bonito, Mato Grosso do Sul. The serological survey was conducted on a sample of 303 dogs, by means of the indirect immunofluorescence test. Phlebotomines were captured using automated light traps. The serological survey found that 30% of the dogs were seropositive, both from the center and from all districts of the town. A total of 2,772 specimens of phlebotomines were caught and the species most found was Lutzomyia longipalpis (90.4%), which corroborated its role as the vector of for canine visceral leishmaniasis in the region. Phlebotomines of the species Bichromomyia flaviscutellata (the main vector for Leishmania (Leishmania) amazonensis) and Nyssomyia whitmani (the vector for Leishmania (Viannia) brasiliensis) were also caught. The findings indicate the need for continuous epidemiological surveillance, with attention towards diminishing the vector breeding sites and the transmission of these diseases in that region.

Clustering barotrauma patients in ICU���A data mining based approach using ventilator variables

Lecture Notes in Computer Science, 9273

Intelligent decision support to predict patient barotrauma risk in intensive care units

The occurrence of Barotrauma is identified as a major concern for health professionals, since it can be fatal for patients. In order to support the decision process and to predict the risk of occurring barotrauma Data Mining models were induced. Based on this principle, the present study addresses the Data Mining process aiming to provide hourly probability of a patient has Barotrauma. The process of discovering implicit knowledge in data collected from Intensive Care Units patientswas achieved through the standard process Cross Industry Standard Process for Data Mining. With the goal of making predictions according to the classification approach they several DM techniques were selected: Decision Trees, Naive Bayes and Support Vector Machine. The study was focused on identifying the validity and viability to predict a composite variable. To predict the Barotrauma two classes were created: ���risk��� and ���no risk���. Such target come from combining two variables: Plateau Pressure and PCO2. The best models presented a sensitivity between 96.19% and 100%. In terms of accuracy the values varied between 87.5% and 100%. This study and the achieved results demonstrated the feasibility of predicting the risk of a patient having Barotrauma by presenting the probability associated.

Abundance of two Dendrocincla woodcreepers (aves: Dendrocolaptidae) in relation to forest structure in Central Amazonia

Few studies have been conducted to verify how the structure of the forest affects the occurence and abundance of neotropical birds. Our research was undertaken between January 2002 and July 2004 at the Reserva Ducke, near Manaus (02��55',03��01'S; 59��53',59��59'W) in central Amazonia, to verify how the forest structure affects the occurrence and abundance of two bird species: the Plain-brown Woodcreeper Dendrocincla fuliginosa and the White-chinned Woodcreeper Dendrocincla merula. Bird species occurrence was recorded using lines of 20 mist-nets (one sample unit), along 51 1-km transects distributed along 9 pararel 8 km trails covering an area of 6400 ha. Along these transects, we placed 50 x 50m plots where we recorded forest structure components (tree abundance, canopy openness, leaf litter, standing dead trees, logs, proximity to streams, and altitude). We then related these variables to bird occurence and abundance using multiple logistic and multiple linear regression models, respectively. We found that D. fuliginosa frequently used plateau areas; being more abundant in areas with more trees. On the other hand, D. merula occurred more frequently and was more abundant in areas with low tree abundance. Our results suggest that although both species overlap in the reserve (both were recorded in at least 68% of the sampled sites), they differ in the way they use the forest microhabitats. Therefore, local variation in the forest structure may contribute to the coexistence of congeneric species and may help to maintain local alpha diversity.

Effects of forest structure components on the occurence, group size and density of groups of bare-face tamarin (Saguinus bicolor - primates: Callitrichinae) in Central Amazonia

This study analyzed the influence of forest structural components on the occurence, size and density of groups of Bare-face Tamarin (Saguinus bicolor) - the most threatened species in the Amazon - and produced the first map of distribution of groups in large-scale spatial within the area of continuous forest. Population censuses were conducted between November 2002 and July 2003, covering 6400 hectares in the Ducke Reserve, Manaus-AM, Brazil. Groups of S. bicolor were recorded 41 times accordingly distributed in the environments: plateau (20); slopes (12); and lowlands (09). The mean group size was 4.8 indiv./group, and ranged from 2 to 11 individuals. In the sites where the groups were recorded, and in an equivalent number of sites where no tamarins were found located at least 500 m from those where they had been recorded, we placed 50 m x 50 m plots to record the following forest structural components: abundance of trees; abundance of lianas; abundance of fruiting trees and lianas; abundance of snags; abundance of logs; percentage of canopy opening; leaf litter depth; and altitude. Bare-face Tamarin more often uses areas with lower abundance of forest logs, smaller canopy opening and with higher abundance of snags, areas in the forest with smaller canopy opening present higher density of S. bicolor groups. Apparently this species does not use the forest in a random way, and may select areas for its daily activities depending on the micro-environmental heterogeneity produced by the forest structural components.

Measurement of charged-particle spectra in Pb+Pb collisions at ���sNN = 2.76TeV with the ATLAS detector at the LHC

Charged-particle spectra obtained in 0.15nb���1 of Pb+Pb interactions at sNN������������=2.76TeV and 4.2pb���1 of pp interactions at s���=2.76TeV with the ATLAS detector at the LHC are presented in a wide transverse momentum (0.5<pT<150GeV) and pseudorapidity (|��|<2) range. For Pb+Pb collisions, the spectra are presented as a function of collision centrality, which is determined by the response of the forward calorimeter located on both sides of the interaction point. The nuclear modification factors RAA and RCP are presented in detail as function of centrality, pT and ��. They show a distinct pT-dependence with a pronounced minimum at about 7GeV. Above 60GeV, RAA is consistent with a plateau at a centrality-dependent value, within the uncertainties. The value is 0.55��0.01(stat.)��0.04(syst.) in the most central collisions. The RAA distribution is consistent with flat |��| dependence over the whole transverse momentum range in all centrality classes.