53 research outputs found
Effectiveness of SCRUM in project based learning: Students view
Project and team management play a major role in the student team’s project performance. This is more evident when projects last a long time and the teams are large. In this work, a student team accepted to use SCRUM as their project management methodology during their Project Based Learning (PjBL) experience. This PjBL experience took place on the 7th semester of the Integrated Master in Industrial Engineering and Management degree. The team had a short period of time to train the technique and apply it throughout the entire semester. Although not very enthusiastic in the beginning of the project, the team gradually became aware of the advantages of SCRUM features, recognizing the feeling of having the project under control and gaining management effectiveness throughout the semester. In the end, the team performed well above the average, being one of the two teams with the highest score of the class.This work has been partially supported by projects COMPETE-POCI-01-0145-FEDER-007043 and FCT UID/CEC/00319/2013, from Portugal
Live-cell FRET imaging reveals clustering of the prion protein at the cell surface induced by infectious prions
Prion diseases are associated to the conversion of the prion protein into a misfolded pathological isoform. The mechanism of propagation of protein misfolding by protein templating remains largely unknown. Neuroblastoma cells were transfected with constructs of the prion protein fused to both CFP-GPI-anchored and to YFP-GPI-anchored and directed to its cell membrane location. Live-cell FRET imaging between the prion protein fused to CFP or YFP was measured giving consistent values of 10 +/- 2%. This result was confirmed by fluorescence lifetime imaging microscopy and indicates intermolecular interactions between neighbor prion proteins. In particular, considering that a maximum FRET efficiency of 17 +/- 2% was determined from a positive control consisting of a fusion CFP-YFP-GPI-anchored. A stable cell clone expressing the two fusions containing the prion protein was also selected to minimize cell-to-cell variability. In both, stable and transiently transfected cells, the FRET efficiency consistently increased in the presence of infectious prions - from 4 +/- 1% to 7 +/- 1% in the stable clone and from 10 +/- 2% to 16 +/- 1% in transiently transfected cells. These results clearly reflect an increased clustering of the prion protein on the membrane in the presence of infectious prions, which was not observed in negative control using constructs without the prion protein and upon addition of non-infected brain. Our data corroborates the recent view that the primary site for prion conversion is the cell membrane. Since our fluorescent cell clone is not susceptible to propagate infectivity, we hypothesize that the initial event of prion infectivity might be the clustering of the GPI-anchored prion protein. (C) 2014 Elsevier B.V. All rights reserved.Fundacao para a Ciencia e Tecnologia (FCT), Portugal [PTDC/QUI-BIQ/119677/2010, PTDC/CTM-NAN/2700/2012]; FCT [PEst-OE/EQB/LA0023/2011, SFRH/BD/48664/2008, SFRH/BPD/64932/2009]info:eu-repo/semantics/publishedVersio
Triatoma jatai sp. nov. in the state of Tocantins, Brazil (Hemiptera: Reduviidae: Triatominae)
Triatoma jatai sp. nov. is the first new species of triatomine to be described in the state of Tocantins, in the northern region of Brazil. It was caught on rock outcrops in the wild environment and, more recently, invading homes. While T. jatai sp. nov. is morphologically similar to Triatoma costalimai, it is distinguished by its general colouring, differences in the blotches on the connexivum, wing size in females and external structures of the male genitalia. The type series has been deposited in the Entomological Collection and Herman Lent Collection, Oswaldo Cruz Institute-Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.Fil: Monte Gonçalves, Teresa Cristina. Ministerio de Salud de Brasil. Fundacion Oswaldo Cruz; Brasil;Fil: Teves Neves, Simone. Ministerio de Salud de Brasil. Fundacion Oswaldo Cruz; Brasil;Fil: Santos Mallet, Jacenir. Ministerio de Salud de Brasil. Fundacion Oswaldo Cruz; Brasil;Fil: Carbajal de la Fuente, Ana Laura. Consejo Nacional de Invest. Científ.y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Bs. As; Argentina;Fil: Macedo Lopes, Catarina. Ministerio de Salud de Brasil. Fundacion Oswaldo Cruz; Brasil
Microscopia eletrônica de varredura de ovos de Haemagogus leucocelaenus (Diptera: Culicidae)
OBJECTIVE: To observe morphological details of the eggs of Haemagogus (Conopostegus) leucocelaenus, seen for the first time via scanning electron microscopy (SEM), with morphometric analysis of the main structures. METHODS: Eggs of Hg. leucocelaenus were obtained from females captured in the Biological Reserve of Tinguá, State of Rio de Janeiro. Some of the eggs were kept for hatching and others underwent processing for scanning electron microscopy studies. Three eggs were submitted to morphometric analysis. The material was fixed in 2.5% glutaraldehyde and postfixed in 1% osmium tetroxide, both in 0.1M, pH 7.2 sodium cacodylate buffer, then dehydrated in ethanol and dried using the critical point method. This was then set up on metallic supports, covered with gold and observed using the Jeol 5310 scanning electron microscope. Measurements were made with the aid of the Semafore analysis software coupled to the electron microscope. RESULTS: The eggs presented elliptical outlines of approximately 574 mm in length and 169 mm in width, with an egg index (l/w ratio) of 3.39 mm. The exochorion was extremely regular and had ornamentation that was usually hexagonal but sometimes pentagonal. Tubercles were observed on the chorionic cells, symmetrically arranged in relation to the longitudinal axis. Inside the cells, there were smaller, individualized tubercles, some arranged peripherally and others grouped to a greater or lesser extent in the center. The surface of the chorionic reticulum did not present rugosity. The micropylar apparatus was formed by a prominent continuous collar of 8.32 mm in thickness, with a slightly irregular surface. The micropylar disk was very evident, and was continuous with the collar. The micropyle was seen at the center of this disk, measuring 1.6 mm and with a micropylar apparatus of 27.3 mm in diameter. CONCLUSIONS: The ornamentation of the exochorion presents differences in relation to the tubercles of chorionic cells and the external chorionic reticulum between the eggs of Hg. Leucocelaenus, in comparison with the eggs of Hg. janthinomys and Hg. equinus, and also in relation to those of Aedes aegypti, Ae. albopictus and Ae bahamensis. In various aspects, the eggs of Hg. leucocelaenus have more resemblance to those of Hg. Equinus than those of Hg. janthinomys, with greater differences presented in relation to the eggs of Hg. spegazzinii and Hg. lucifer.OBJETIVO: Observar detalhes morfológicos de ovos de Haemagogus leucocelaenus visualizados pela primeira vez por microscopia eletrônica de varredura (MEV) e realizar morfometria das principais estruturas. MÉTODOS: Foram utilizados ovos de Hg. leucocelaenus provenientes de fêmeas capturadas na Reserva Biológica do Tinguá, RJ, sendo parte destinada à eclosão e outra ao processamento de MEV, dos quais três foram submetidos à análise morfométrica. O material foi fixado em glutaraldeído 2,5% e pós-fixado em tetróxido de ósmio 1%, ambos em tampão cacodilato de sódio 0.1M, pH 7.2, processado e observado ao MEV Jeol 5310. Medições foram realizadas com o auxílio do software de análise Semafore. RESULTADOS: Os ovos apresentaram contorno elíptico com aproximadamente 574 µm de comprimento e 169 µm de largura, sendo o índice do ovo (l/wratio) 3,39 µm. O exocório é extremamente regular, possuindo ornamentação hexagonal e algumas vezes pentagonal. Nas células coriônicas, observaram-se tubérculos simetricamente dispostos com relação ao eixo longitudinal, e, no interior delas, tubérculos menores, individualizados, dispostos na periferia, e poucos agrupados no centro. A superfície do retículo coriônico não apresentou rugosidades. O aparelho micropilar apresenta colar proeminente, contínuo, com disco micropilar bem evidente. CONCLUSÕES: A ornamentação do exocório apresenta diferenças em relação aos tubérculos das células coriônicas e ao retículo coriônico externo entre os ovos de Hg. leucocelaenus comparados aos ovos de Hg. janthinomys e Hg. equinus, bem como com relação aos de Aedes aegypti, Ae. albopictus e Ae bahamensis
Does antennal sensilla pattern of different populations of Triatoma maculata (Hemiptera: Reduviidae) reveal phenotypic variability?
Background: In Brazil, Triatoma maculata is only found in the State of Roraima and is a vector of Trypanosoma cruzi, the etiological agent of Chagas disease. It occurs in wild, peridomestic and domestic habitats, with an urban infestation in Boa Vista, the capital of this Brazilian state. The aim of this study was to assess the morphological variability of the T. maculata antennal phenotype in three populations of Roraima State, using the antennal sensilla pattern analyzed under optical microscopy. Methods: The number and distribution of four antennal sensilla types (bristles, thin and thick walled trichoidea, and basiconic) of three Brazilian populations of T. maculata from Roraima State were compared. Univariate and multivariate analyses were performed. Results: The antenna of T. maculata presented the four types of sensilla. According to the density and distribution of the antennal sensilla characteristics, the multivariate analyses showed that the laboratory population is morphologically structured. Urban specimens showed a pronounced phenotypic variability. The main differences were observed in the pedicel segment, and between males and females. Conclusions: We determined the antennal phenotype in three Roraima populations of T. maculata. These results support the idea that the patterns of antennal sensilla are sensitive markers for distinct populations in the Triatominae. The infestations of T. maculata in different habitats reinforces the ability of this vector to become adapted to a variety of environments, which, could have eco-epidemiological implications for the T. cruzi transmission that are still not well understood.Fil: Nogueira Müller, Josiane. Instituto Oswaldo Cruz; BrasilFil: Monte Gonçalves, Teresa. Instituto Oswaldo Cruz; BrasilFil: Ricardo Silva, Alice Helena. Instituto Oswaldo Cruz; BrasilFil: Coutinho Souza, Amanda. Instituto Oswaldo Cruz; BrasilFil: Maciel Santos, Francisco. No especifíca;Fil: Santos, Rosangela. No especifíca;Fil: Coelho Vargas, Nathalia. No especifíca;Fil: Macedo Lopes, Catarina. Instituto Oswaldo Cruz; BrasilFil: Carbajal de la Fuente, Ana Laura. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Centro Nacional de Diagnóstico e Investigaciones Endemo-epidémicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin
Virulence-linked mutations in rubredoxin reductase and glutaredoxin: impact on antibiotic susceptibility and phage therapy in Pseudomonas aeruginosa
Pseudomonas aeruginosa (PAO1) is an opportunistic pathogen, lethal in immunocompromised individuals. The clinical management of PAO1 infections still depends deeply on antibiotic therapy. However, this therapy has been alarmingly overpowered by growing bacterial resistance mechanisms over the years. One of these bacterial mechanisms is quorum sensing (QS). QS is involved in the production of biofilm, rhamnolipids and pyocyanin, among other factors. The present study aimed to study the effect of the mutations in the genes of rubredoxin (Rub A1 and Rub A2) and glutaredoxin (GLRx) in the production of virulence traits and susceptibility of PAO1 to the antibiotic ciprofloxacin (CIP) and to infection by a phage cocktail. Rub A1, Rub A2, and GLRx showed a decrease in the expression of genes lasI, lasR, mvfR, and rpsL when compared to the wild type, PAO1. Rub A1 and Rub A2 also showed a decrease in the expression of the gene pqsA, while the mutant GLRx showed an increase of over 200% in expression compared to PAO1. The biofilm produced by the mutants Rub A1, Rub A2, and GLRx increased more than 1.5 times in comparison to PAO1, with statistical significance (p < 0.0001). In the viability assay, the mutant strain Rub A2 was the most susceptible to ciprofloxacin in both concentrations tested (p < 0.0001). The production of proteases increased in the mutant strains when compared to PAO1 (p < 0.05). However, there was a decrease in the production of rhamnolipids and pyocyanins in the mutant strains. In the phage assay, we could perceive a reduction in the growth of the mutant strains when compared to PAO1. Additionally, after the addition of the phages, all the strains showed susceptibility to the phage assay (p < 0.0001), observed in the decrease in the absorbance values. These results may highlight the relevance of the genes Rub A1, Rub A2, and GLRX in the proliferation and treatment of infections with PAO1. Overall, this study gives preliminary insights into how gene expression may be helpful in strategies to overcome antibiotic resistance.info:eu-repo/semantics/publishedVersio
Desenvolvimento de litíase biliar secundária ao uso de ceftriaxona / Development of biliary lithiasis secondary to the use of ceftriaxone
A ceftriaxona é uma cefalosporina de terceira geração, utilizada principalmente no combate as bactérias gran negativas e algumas gran positivas, no tratamento de várias infecções. A ceftriaxona, induz à formação de lama biliar ou colelitíase tanto em adultos como em crianças, que na maioria dos casos é assintomática. Deste modo, objetivou-se com este estudo realizar uma revisão integrativa com ênfase no desenvolvimento de litíase biliar secundária ao uso de ceftriaxona. Realizou-se um levantamento nas principais bases de dados internacionais e nacionais: PubMed, Science Direct, Scielo e Google Acadêmico. Os artigos foram selecionados a partir do ano de 2005 a 2020 nos idiomas inglês e português com os descritores: ceftriaxone and biliary lithiasis. Após as etapas de seleção com leitura do resumo, bem como leitura dos artigos, selecionou-se 13. Constatou-se que a Ceftriaxona é um antibiótico administrado, na maioria dos casos, em crianças e gestantes. O principal efeito indesejável que pode ocorrer com o uso dessa droga é a pseudocolelitíase. Estudos que correlacionam a litíase biliar e a ceftriaxona são escassos, no entanto, pode-se concluir que o amplo uso de ceftriaxona, em especial na pediatria, gera a possibilidade de formação de pseudo-cálculos biliares, neste caso a equipe de saúde deve ficar atenta aos possíveis sintomas
Dynamics and determinants of SARS-CoV-2 RT-PCR testing on symptomatic individuals attending healthcare centers during 2020 in Bahia, Brazil
RT-PCR testing data provides opportunities to explore regional and individual determinants of test positivity and surveillance infrastructure. Using Generalized Additive Models, we explored 222,515 tests of a random sample of individuals with COVID-19 compatible symptoms in the Brazilian state of Bahia during 2020. We found that age and male gender were the most significant determinants of test positivity. There was evidence of an unequal impact among socio-demographic strata, with higher positivity among those living in areas with low education levels during the first epidemic wave, followed by those living in areas with higher education levels in the second wave. Our estimated probability of testing positive after symptom onset corroborates previous reports that the probability decreases with time, more than halving by about two weeks and converging to zero by three weeks. Test positivity rates generally followed state-level reported cases, and while a single laboratory performed ~90% of tests covering ~99% of the state's area, test turn-around time generally remained below four days. This testing effort is a testimony to the Bahian surveillance capacity during public health emergencies, as previously witnessed during the recent Zika and Yellow Fever outbreaks
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