Study of gas turbulent dispersion process in the Alcântara Launch Center

The Alcântara Launch Center (ALC) is the Brazilian gate to the space located at the north coast of Maranhão State, close to the Equator. Topographical local characteristics modify the parameters of incident atmospheric winds and it can cause great influence on the gas dispersion process. In this work, detailed scale models of the ALC region was experimentally evaluated using a wind tunnel. The topographical scale models were built where mean and fluctuating flow characteristics were analysed in order to understand the real behaviour of ALC winds and then, simulations of the effluent dispersion process were made using these scale models. The wind velocity was measured by a hot wire anemometer and the concentration fields in the proximities of a gas emission source were analysed by an aspirating probe connected to the anemometer system. The results obtained show similarity with numerical outputs from previous study in the case of the emission at ground level. A coherent behaviour with the physic of the phenomena was observed for the case of emission downward

DenseNet and Support Vector Machine classifications of major depressive disorder using vertex-wise cortical features

Major depressive disorder (MDD) is a complex psychiatric disorder that affects the lives of hundreds of millions of individuals around the globe. Even today, researchers debate if morphological alterations in the brain are linked to MDD, likely due to the heterogeneity of this disorder. The application of deep learning tools to neuroimaging data, capable of capturing complex non-linear patterns, has the potential to provide diagnostic and predictive biomarkers for MDD. However, previous attempts to demarcate MDD patients and healthy controls (HC) based on segmented cortical features via linear machine learning approaches have reported low accuracies. In this study, we used globally representative data from the ENIGMA-MDD working group containing an extensive sample of people with MDD (N=2,772) and HC (N=4,240), which allows a comprehensive analysis with generalizable results. Based on the hypothesis that integration of vertex-wise cortical features can improve classification performance, we evaluated the classification of a DenseNet and a Support Vector Machine (SVM), with the expectation that the former would outperform the latter. As we analyzed a multi-site sample, we additionally applied the ComBat harmonization tool to remove potential nuisance effects of site. We found that both classifiers exhibited close to chance performance (balanced accuracy DenseNet: 51%; SVM: 53%), when estimated on unseen sites. Slightly higher classification performance (balanced accuracy DenseNet: 58%; SVM: 55%) was found when the cross-validation folds contained subjects from all sites, indicating site effect. In conclusion, the integration of vertex-wise morphometric features and the use of the non-linear classifier did not lead to the differentiability between MDD and HC. Our results support the notion that MDD classification on this combination of features and classifiers is unfeasible

Microbial contamination of luncheon meat sliced and packaged at supermarkets in Porto Alegre, Brazil

Background: Ready-to-eat (RTE) foods are considered a high risk food group, since they are often consumed without a cooking step. Luncheon meat, a RTE food widely consumed in Brazil, is traditionally produced as industrially vacuum-packaged loaves and afterwards is sliced and re-packaged at retail stores. Since this practice may pose an additional hazard of contamination, the purpose of this study was to evaluate total coliform counts (TCC), coagulase-positive staphylococci counts (CPS), and the occurrence of Escherichia coli and Listeria sp. in luncheon meat samples sliced and packaged at supermarkets. Materials, Methods & Results: Three supermarket stores belonging to either regional or national chains located in Porto Alegre were intentionally chosen, and luncheon meat samples were purchased from the same sampled stores weekly during a 20-week period. In each sampling event, five store-packaged luncheon meat samples were obtained and analyzed. Individual samples (25 g) were homogenized, decimally diluted in buffered peptone water and submitted to TCC in Violet Red Bile Agar. Thermotolerant coliform (FC) were confirmed in EC broth incubated at 45°C. Confirmed tubes were streaked on McConkey agar and submitted to E.coli identification. Isolation and enumeration of coagulase-positive staphylococci (CPS) were performed on Baird-Parker agar. The presence of Listeria sp. was tested in pooled samples submitted to pre-enrichment in University of Vermont (UVM) Listeria Enrichment broth, followed by incubation in Fraser broth and isolation on tryptose agar with nalidixic acid and Palcam agar. TCC mean varied from 1.2 log10 CFU.g-1 (store B) to 5.5 log10 CFU.g-1 (store C), while CPS mean counts were similar (0.63; 0.65 and 0.86 log10 CFU.g-1) for samples purchased at the three stores. Considering Brazilian standards for FCC, in stores A (n=6) and C (n=8) samples considered unsafe (above 3log. g-1) were found, while all samples purchased at store B are considered sound according to that standard. Moreover, three samples from each store (A and C) confirmed for the presence of E. coli. Samples contaminated with Listeria sp. (n=16) were also found. Listeria monocytogenes was isolated from six samples, and was found in all sampled supermarkets. A trend of Listeria sp. isolation frequency in samples with higher TCC was observed. Discussion: The results demonstrated that bacteria may be introduced in luncheon meat during the slicing and packaging at supermarkets. Our data are in accordance with other reports that indicate slicing as a critical control point of contamination and transfer of pathogen, including L. monocytogenes, to foods during processing. Differences observed on extend of product contamination may have resulted from variable levels of cleanliness during handling and slicing procedures at the three supermarkets. Specifically, the cleaning of equipment surfaces represents a challenge for sanitation programs, since most equipment is not hygienically designed and must be unassembled prior to sanitization procedures. This fact may lead to the decrease of cleaning and disinfection frequency and to the hazard of biofilm formation. In conclusion, luncheon meat sliced and packaged in supermarkets may pose a hazard to the consumers, and the adoption of more rigorous disinfection protocols for equipment and surfaces in contact with ready-to-eat foods in these stores is advisable

Atividade antibacteriana desinfetante "in vitro" de extração vegetal (decocto) frente microorganismos padronizados de interesse em medicina veterinária : IV-resultados preliminares do sub-projeto Achyrocline satureoides D.C-Asteraceae ("Macela")

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Atividade antibacteriana desinfetante "in vitro" de extração vegetal (decocto) frente microorganismos padronizados de interesse em medicina veterinária : III-resultados preliminares do sub-projeto Achyrocline satureoides d.c-asteraceae ("macela")

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Atividade antibacteriana desinfetante "in vitro" de extração vegetal (decocto) frente microorganismos padronizados de interesse em medicina veterinária : IV-resultados preliminares do sub-projeto Achyrocline satureoides D.C-Asteraceae ("Macela")

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Microbial contamination of luncheon meat sliced and packaged at supermarkets in Porto Alegre, Brazil

Background: Ready-to-eat (RTE) foods are considered a high risk food group, since they are often consumed without a cooking step. Luncheon meat, a RTE food widely consumed in Brazil, is traditionally produced as industrially vacuum-packaged loaves and afterwards is sliced and re-packaged at retail stores. Since this practice may pose an additional hazard of contamination, the purpose of this study was to evaluate total coliform counts (TCC), coagulase-positive staphylococci counts (CPS), and the occurrence of Escherichia coli and Listeria sp. in luncheon meat samples sliced and packaged at supermarkets. Materials, Methods & Results: Three supermarket stores belonging to either regional or national chains located in Porto Alegre were intentionally chosen, and luncheon meat samples were purchased from the same sampled stores weekly during a 20-week period. In each sampling event, five store-packaged luncheon meat samples were obtained and analyzed. Individual samples (25 g) were homogenized, decimally diluted in buffered peptone water and submitted to TCC in Violet Red Bile Agar. Thermotolerant coliform (FC) were confirmed in EC broth incubated at 45°C. Confirmed tubes were streaked on McConkey agar and submitted to E.coli identification. Isolation and enumeration of coagulase-positive staphylococci (CPS) were performed on Baird-Parker agar. The presence of Listeria sp. was tested in pooled samples submitted to pre-enrichment in University of Vermont (UVM) Listeria Enrichment broth, followed by incubation in Fraser broth and isolation on tryptose agar with nalidixic acid and Palcam agar. TCC mean varied from 1.2 log10 CFU.g-1 (store B) to 5.5 log10 CFU.g-1 (store C), while CPS mean counts were similar (0.63; 0.65 and 0.86 log10 CFU.g-1) for samples purchased at the three stores. Considering Brazilian standards for FCC, in stores A (n=6) and C (n=8) samples considered unsafe (above 3log. g-1) were found, while all samples purchased at store B are considered sound according to that standard. Moreover, three samples from each store (A and C) confirmed for the presence of E. coli. Samples contaminated with Listeria sp. (n=16) were also found. Listeria monocytogenes was isolated from six samples, and was found in all sampled supermarkets. A trend of Listeria sp. isolation frequency in samples with higher TCC was observed. Discussion: The results demonstrated that bacteria may be introduced in luncheon meat during the slicing and packaging at supermarkets. Our data are in accordance with other reports that indicate slicing as a critical control point of contamination and transfer of pathogen, including L. monocytogenes, to foods during processing. Differences observed on extend of product contamination may have resulted from variable levels of cleanliness during handling and slicing procedures at the three supermarkets. Specifically, the cleaning of equipment surfaces represents a challenge for sanitation programs, since most equipment is not hygienically designed and must be unassembled prior to sanitization procedures. This fact may lead to the decrease of cleaning and disinfection frequency and to the hazard of biofilm formation. In conclusion, luncheon meat sliced and packaged in supermarkets may pose a hazard to the consumers, and the adoption of more rigorous disinfection protocols for equipment and surfaces in contact with ready-to-eat foods in these stores is advisable

Atividade antibacteriana desinfetante "in vitro" de extração vegetal (decocto) frente microorganismos padronizados de interesse em medicina veterinária : I-resultados preliminares do sub-projeto Pterocaulon sp.. c-asteraceae ("Quitoco-amarelo")

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