Automated conceptual model clustering: a relator-centric approach.

In recent years, there has been a growing interest in the use of reference conceptual models to capture information about complex and sensitive business domains (e.g., finance, healthcare, space). These models play a fundamental role in different types of critical semantic interoperability tasks. Therefore, domain experts must be able to understand and reason with their content. In other words, these models need to be cognitively tractable. This paper contributes to this goal by proposing a model clustering technique that leverages on the rich semantics of ontology-driven conceptual models (ODCM). In particular, we propose a formal notion of Relational Context to guide the automated clusterization (or modular breakdown) of conceptual models. Such Relational Contexts capture all the information needed for understanding entities "qua players of roles" in the scope of an objectified (reified) relationship (relator). The paper also presents computational support for automating the identification of Relational Contexts and this modular breakdown procedure. Finally, we report the results of an empirical study assessing the cognitive effectiveness of this approach.

XadA2 Adhesin Decreases Biofilm Formation and Transmission of Xylella fastidiosa subsp. pauca.

Xylella fastidiosa is a vector-borne bacterium that causes diseases in many plants of economic interest. The bacterium-vector initial interactions involve bacterial membrane-bound adhesins that mediate cell attachment to the foregut of insect vectors. We investigated the role of the afimbrial adhesin XadA2 in the binding and biofilm formation of X. fastidiosa subsp. pauca to vector surfaces in vitro, as well as its potential to disrupt pathogen transmission. We showed that XadA2 has binding affinity for polysaccharides on sharpshooter hindwings, used as a proxy for the interactions between X. fastidiosa and vectors. When in a medium without carbon sources, the bacterium used wing components, likely chitin, as a source of nutrients and formed a biofilm on the wing surface. There was a significant reduction in X. fastidiosa biofilm formation and cell aggregation on vector wings in competition assays with XadA2 or its specific antibody (anti-XadA2). Finally, pathogen acquisition and transmission to plant were significantly reduced when the vectors acquired X. fastidiosa from an artificial diet supplemented with anti-XadA2. These results show that XadA2 is important in mediating bacterial colonization in the insect and that it could be used as a target for blocking X. fastidiosa transmission.

Transmission Efficiency of Xylella fastidiosa subsp. pauca Sequence Types by Sharpshooter Vectors after In Vitro Acquisition.

Xylella fastidiosa subsp. pauca is genetically diverse and has many vector species. However, there is limited information on vector specificity and efficiency for different sequence types (STs) within the pathogen subspecies. Both STs of X. fastidiosa and vectors differ in their associations with plants; therefore, assessment of vector competence should include the standardized vector acquisition ability of bacteria from artificial diets. This work aimed to adapt and validate an in vitro acquisition system for strains of X. fastidiosa that cause citrus variegated chlorosis, and to compare the transmission efficiency of STs of subsp. pauca by different species of sharpshooter vector. First, acquisition and transmission of ST13 by Bucephalogonia xanthophis and Macugonalia leucomelas was tested using an artificial diet with bacteria grown on minimum defined medium (X. fastidiosa medium) with or without 1% galacturonic acid (GA). Subsequently, four sharpshooter species (B. xanthophis, M. leucomelas, M. cavifrons, and Sibovia sagata) were compared as vectors of ST13 acquired from artificial diets, and four STs of subsp. pauca (11, 13, 65, and 70) were tested for acquisition and transmission by M. leucomelas. The artificial system allowed efficient acquisition and transmission of ST13 to plants, with no differences between the media tested. ST13 was transmitted more efficiently by B. xanthophis and M. leucomelas when compared with M. cavifrons and S. sagata. Different STs influenced acquisition and transmission rates by M. leucomelas. The differences in vector competence, despite the standardized acquisition system, suggest that ST-vector foregut or vector-plant interactions may influence bacterial acquisition, retention and inoculation by the insect.

Effects of X-radiation on lung cancer cells: the interplay between oxidative stress and P53 levels.

Lung cancer (LC) ranks as the most prevalent and deadliest cause of cancer death worldwide. Treatment options include surgery, chemotherapy and/or radiotherapy, depending on LC staging, without specific highlight. The aim was to evaluate the effects of X-radiation in three LC cell lines. H69, A549 and H1299 cell lines were cultured and irradiated with 0.5-60 Gy of X-radiation. Cell survival was evaluated by clonogenic assay. Cell death and the role of reactive oxygen species, mitochondrial membrane potential, BAX, BCL-2 and cell cycle were analyzed by flow cytometry. Total and phosphorylated P53 were assessed by western blotting. Ionizing radiation decreases cell proliferation and viability in a dose-, time- and cell line-dependent manner, inducing cell death preferentially by apoptosis with cell cycle arrest. These results may be related to differences in P53 expression and oxidative stress response. The results obtained indicate that sensibility and/or resistance to radiation may be dependent on molecular LC characteristics which could influence response to radiotherapy and treatment success.

Suscetibilidade à novobiocina na identificação de amostras de Staphylococcus coagulase negativos (SCoN) isolados de hemoculturas / Susceptibility to the novobiocin in the identification of isolates of Staphylococcus negative (SCoN) isolated from blood cultures

Tradicionalmente o Laboratório de Microbiologia Clínica utiliza a prova de suscetibilidade a novobiocina para distinguir as espécies clinicamente significativas de SCoN, entre elas o Staphylococcus saprophyticus. Devido ao aumento destes microrganismos nas infecções relacionadas à assistência à saúde, este estudo teve como objetivo relatar duas bacteremias por SCoN resistentes a novobiocina ocorridas em maio e setembro de 2006, em um hospital geral, na cidade de São Paulo. Primeiramente o teste fenotípico apontou resistência a novobiocina, mas com padrões distintos de identificação ao S. saprophyticus. Na identificação convencional, asamostras fermentaram trealose, manitol e manose, sendo positivas nos testes da urease e fosfatase alcalina. No sistema semi-automatizado, a confirmação da espécie apontou o Staphylococcus cohnii subsp. urealyticus com 99,99 de probabilidade. No teste de disco difusão, os isolados mostraram-se resistentes à oxacilina, mas suscetível a cefoxitina, vancomicina e teicoplanina. Houve confirmação pela metodologia do Etest® mostrando CIM para oxacilina superior a 256 μg/ml, e suscetibilidade a vancomicina e a teicoplanina.A reação da PCR confirmou a presença do gene mecA nos isolados. Estes dados demonstram a importância dos SCoN isolados em hemoculturas, sendo necessária uma correta identificação destes microrganismos.

Prevalência de obesidade e fatores associados em mulheres idosas / Prevalence of obesity and associated factors in elderly women

OBJETIVO: Analisar a prevalência de obesidade em mulheres idosas e sua associação com variáveis sócio-demográficas, bioquímicas e hipertensão arterial. MATERIAL E MÉTODOS: Mediante estudo de corte seccional, 188 pacientes ambulatoriais, mulheres, com idade entre 60 e 89 anos foram avaliadas, sendo a obesidade definida a partir do IMC > 30Kg/m2 (WHO, 1998). As variáveis investigadas foram idade, escolaridade, situação conjugal, glicemia de jejum, colesterol total, lipoproteínas de alta e baixa densidade colesterol, triglicerídeos e presença de hipertensão arterial. Para análise dos dados foram empregados o teste Qui-quadrado de Pearson ou Teste Exato de Fisher, Análise Multivariada por Regressão Logística, estimando-se as probabilidades de ocorrência de obesidade. RESULTADOS/CONCLUSÕES: Entre as mulheres idosas, 25,6 por cento eram obesas. A obesidade esteve concentrada nos intervalos etários de 60 a 69 e 70 a 79 anos e associada positivamente (p= 0,050) à glicemia de jejum > 126mg/dL, com um risco maior (Odds= 1,76) para as idosas diabéticas, em relação às não-diabéticas. A maior probabilidade de ocorrência de obesidade, em torno de 18 por cento, foi observada nas mulheres com menos de 70 anos, triglicerídeos > 200mg/dL, diabéticas e hipertensas, destacando a importância da morbidade associada.

[Prevalence of obesity and associated factors in elderly women]. / Prevalência de obesidade e fatores associados em mulheres idosas.

OBJECTIVE: To analyze the prevalence of obesity in elderly women and its association with socio-demographic, biochemical and hypertension variables. MATERIAL AND METHODS: By means of a cross sectional study, 188 outpatient women, 60 to 89 years-old were assessed. Obesity was defined by a BMI > 30 Kg/m2 (WHO, 1998). The parameters examined were age, education, marital status, fasting glycemia, total cholesterol, high and low density cholesterol lipoproteins, triglycerides and presence or absence of blood hypertension. Data analysis was performed by Pearson's Chi-square or Exact Test of Fisher and Multivariate Analysis of Logistic Regression, estimating the probability of obesity. RESULTS/CONCLUSIONS: Among elderly women, 25.6% were obese. Obesity was present in the age ranges of 60 to 69 and 70 to 79 years, and positively associated (p = 0.050) to fasting glycemia > or = 126 mg/dL, with increased risk (Odds = 1.76) for elder diabetic, compared to non-diabetics women. The highest probability for obesity, around 18%, was observed in women younger than 70 years-old, triglycerides > or = 200 mg/dL, diabetic and hypertensive, emphasizing the role of associated morbidity.