62 research outputs found
A organização do espaço na sala do maternal i-a por meio da casa de brincar
Trabalho de Conclusão do Curso de Especialização em Educação Infantil - 1ª Edição – Polo Joinville - SC, para a obtenção do Grau de Especialista em Educação InfantilEste artigo trata dos resultados de um trabalho realizado em sala de aula no ano de 2011 com crianças de dois a três anos. O objetivo foi repensar a organização do espaço da sala do maternal. O tema é relevante na medida em que se busca valorizar a participação da criança na criação dos espaços com foco na sua aprendizagem e socialização. Vale salientar que a educação deve ocorrer de forma lúdica, onde a criança participe efetivamente de seu aprendizado; através de jogos e brincadeiras os professores ensinam seus alunos regras básicas de convivência, as crianças aprendem a construir seus conhecimentos através das experiências vivenciadas. É através da ludicidade que a criança vai demonstrar seus conhecimentos, expressar sentimentos, externar conceitos prévios e as ideias que possui, oportunizando a criança um momento de troca de informações com seus colegas e professores. A criação de uma casinha de brincar favoreceu a participação efetiva das crianças no processo de construção de seus conhecimentos, foi um momento de aprendizagens ricas, onde puderam internalizar diversos conceitos, que agora podem não fazer sentido da forma como está sendo aplicada, mas daqui a alguns anos a criança saberá como utilizá-los para sua vida em sociedade
Adaptation to an Intracellular Lifestyle by a Nitrogen-Fixing, Heterocyst-Forming Cyanobacterial Endosymbiont of a Diatom
The symbiosis between the diatom Hemiaulus hauckii and the heterocyst-forming cyanobacterium Richelia intracellularis makes an important contribution to new production in the world’s oceans, but its study is limited by short-term survival in the laboratory. In this symbiosis, R. intracellularis fixes atmospheric dinitrogen in the heterocyst and provides H. hauckii with fixed nitrogen. Here, we conducted an electron microscopy study of H. hauckii and found that the filaments of the R. intracellularis symbiont, typically composed of one terminal heterocyst and three or four vegetative cells, are located in the diatom’s cytoplasm not enclosed by a host membrane. A second prokaryotic cell was also detected in the cytoplasm of H. hauckii, but observations were infrequent. The heterocysts of R. intracellularis differ from those of free-living heterocyst-forming cyanobacteria in that the specific components of the heterocyst envelope seem to be located in the periplasmic space instead of outside the outer membrane. This specialized arrangement of the heterocyst envelope and a possible association of the cyanobacterium with oxygen-respiring mitochondria may be important for protection of the nitrogen-fixing enzyme, nitrogenase, from photosynthetically produced oxygen. The cell envelope of the vegetative cells of R. intracellularis contained numerous membrane vesicles that resemble the outer-inner membrane vesicles of Gram-negative bacteria. These vesicles can export cytoplasmic material from the bacterial cell and, therefore, may represent a vehicle for transfer of fixed nitrogen from R. intracellularis to the diatom’s cytoplasm. The specific morphological features of R. intracellularis described here, together with its known streamlined genome, likely represent specific adaptations of this cyanobacterium to an intracellular lifestyle
Incorporation of Farnesol Significantly Increases the Efficacy of Liposomal Ciprofloxacin against Pseudomonas aeruginosa Biofilms in Vitro
The challenge of eliminating Pseudomonas aeruginosa infections, such as in cystic fibrosis lungs, remains unchanged due to the rapid development of antibiotic resistance. Poor drug penetration into dense P. aeruginosa biofilms plays a vital role in ineffective clearance of the infection. Thus, the current antibiotic therapy against P. aeruginosa biofilms need to be revisited and alternative antibiofilm strategies need to be invented. Fungal quorum sensing molecule (QSM), farnesol, appears to have detrimental effects on P. aeruginosa. Thus, this study aimed to codeliver naturally occurring QSM farnesol, with the antibiotic ciprofloxacin as a liposomal formulation to eradicate P. aeruginosa biofilms. Four different liposomes (with ciprofloxacin and farnesol, L; with ciprofloxacin, L; with farnesol, L; control, L) were prepared using dehydration-rehydration method and characterized. Drug entrapment and release were evaluated by spectrometry and high performance liquid chromatography (HPLC). The efficacy of liposomes was assessed using standard biofilm assay. Liposome-treated 24 h P. aeruginosa biofilms were quantitatively assessed by XTT reduction assay and crystal violet assay, and qualitatively by confocal laser scanning microscopy (CLSM) and transmission electron microscopy (TEM). Ciprofloxacin release from liposomes was higher when encapsulated with farnesol (L) compared to L (3.06% vs 1.48%), whereas farnesol release was lower when encapsulated with ciprofloxacin (L) compared to L (1.81% vs 4.75%). The biofilm metabolism was significantly lower when treated with L or L compared to free ciprofloxacin (XTT, P < 0.05). When administered as L, the ciprofloxacin concentration required to achieve similar biofilm inhibition was 125-fold or 10-fold lower compared to free ciprofloxacin or L, respectively (P < 0.05). CLSM and TEM confirmed predominant biofilm disruption, greater dead cell ratio, and increased depth of biofilm killing when treated with L compared to other liposomal preparations. Thus, codelivery of farnesol and ciprofloxacin is likely to be a promising approach to battle antibiotic resistant P. aeruginosa biofilms by enhancing biofilm killing at significantly lower antibiotic doses
A Microchip CD4 Counting Method for HIV Monitoring in Resource-Poor Settings
BACKGROUND: More than 35 million people in developing countries are living with HIV infection. An enormous global effort is now underway to bring antiretroviral treatment to at least 3 million of those infected. While drug prices have dropped considerably, the cost and technical complexity of laboratory tests essential for the management of HIV disease, such as CD4 cell counts, remain prohibitive. New, simple, and affordable methods for measuring CD4 cells that can be implemented in resource-scarce settings are urgently needed. METHODS AND FINDINGS: Here we describe the development of a prototype for a simple, rapid, and affordable method for counting CD4 lymphocytes. Microliter volumes of blood without further sample preparation are stained with fluorescent antibodies, captured on a membrane within a miniaturized flow cell and imaged through microscope optics with the type of charge-coupled device developed for digital camera technology. An associated computer algorithm converts the raw digital image into absolute CD4 counts and CD4 percentages in real time. The accuracy of this prototype system was validated through testing in the United States and Botswana, and showed close agreement with standard flow cytometry (r = 0.95) over a range of absolute CD4 counts, and the ability to discriminate clinically relevant CD4 count thresholds with high sensitivity and specificity. CONCLUSION: Advances in the adaptation of new technologies to biomedical detection systems, such as the one described here, promise to make complex diagnostics for HIV and other infectious diseases a practical global reality
Grasping the unavoidable subjectivity in calibration of flood inundation models : a vulnerability weighted approach.
Quantitative modeling of risk and hazard from flooding involves decisions regarding the choice of model and goal of the modeling exercise, expressed by some measure of performance. This paper shows how the subjectivity in the choices of performance measures and observation sets used for model calibration inevitably results in variability in the estimation of flood hazard. We compare the predictions of a 2D flood inundation model obtained using different global and local evaluation criteria. It is shown that traditional area averaging performance measures are inadequate in the face of model imperfection, especially when such models are calibrated for flood hazard studies. In this study we include flood risk weighting into the performance measure of the model. This allows us to calibrate the model to places that are important, e.g. location of houses. The quantification of the importance of places requires the necessity of engaging stakeholders into the model calibration process
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Progression of lipid profile and cell structure in a research-scale production pathway for algal biocrude
Although there has been a large research effort associated with individual parts of various algal biofuel production pathways, few studies have tracked changes in product composition throughout an integrated biofuel production process. This study uses microscopy and chromatography to analyze the progression of lipid profile and cell structure of algal cells throughout a research-scale production pathway for biocrude. For the specific processing methods used in this pathway, it is shown that TAG content decreased, while DAG and FFA content increased during processing. The changes in the lipid content corresponded to cell degradation that was observed by SEM and TEM throughout processing. These results demonstrate the dynamic nature of lipid composition in an algal culture used for biofuel production and emphasize the need to monitor changes in lipid profile, as those changes can directly impact biofuel productivity.Center for Electromechanic
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