147 research outputs found
Precipitation, Plant Communities and Methane Fluxes in the Ka‘au Crater Wetland, O‘ahu, Hawai‘i
OCN 499 - Undergraduate Thesi
Methane Emission from a Tropical Wetland in Ka‘au Crater, O‘ahu, Hawai‘i.
v. ill. 23 cm.QuarterlyNatural tropical wetlands constitute an important but still poorly studied source of atmospheric methane, a powerful greenhouse gas. We measured net methane emission, soil profiles of methane generation and oxidation, and related environmental parameters in a tropical wetland occupying the Ka‘au extinct volcanic crater on the Hawaiian island of O‘ahu. The wetland has a fluctuating water table with dynamics that can be reproduced using precipitation data and a simple model. Median net methane flux was 117 mg m_2 day_1 and is consistent with measurements at other tropical sites. Net methane flux in the Commelina diffusa–dominated vegetation pattern (honohono) was significantly higher than that of the invasive Psidium cattleianum–dominated pattern (strawberry guava). Net methane emission in the honohono vegetation pattern was also significantly higher during the ‘‘wet’’ season compared with the ‘‘dry’’ season, although we did not find a clear correlation between net methane emission, water table level, or precipitation. We show that the measured fluxes are consistent with the integrated potential methane generation over the uppermost 30 cm of soil and consumption of @50% of that methane in the soil. Absence of a correlation between net methane emission and water table level may be due to suppression of the activity of strictly anaerobic methanogens by dynamic redox conditions in the upper layers of soil and varying rates of methane oxidation by facultive methanotrophs
Enterococcus faecalis MalR acts as a repressor of the maltose operons and additionally mediates their catabolite repression via direct interaction with seryl-phosphorylated-HPr
Enterococci are gram-positive pathogens and lead to cause hospital-acquired infections worldwide. Central carbon metabolism was shown as highly induced in Enterococcus faecalis during infection context. Metabolism of α-polysaccharides was previously described as an important factor for host colonisation and biofilm formation. A better characterisation of the adaptation of this bacterium to carbohydrate availabilities may lead to a better understanding of the link between carbohydrate metabolism and the infection process of E. faecalis. Here we show that MalR, a LacI/GalR transcriptional regulator, is the main factor in the regulation of the two divergent operons involved in maltose metabolism in this bacterium. The malR gene is transcribed from the malP promoter, but also from an internal promoter inside the gene located upstream of malR. In the absence of maltose, MalR acts as a repressor and in the presence of glucose, it exerts efficient CcpA-independent carbon catabolite repression. The central PTS protein P-Ser-HPr interacts directly with MalR and enhances its DNA binding capacity, which allows E. faecalis to adapt its metabolism to environmental conditions.Fil: Grand, Maxime. Universite de Caen Basse Normandie; FranciaFil: Blancato, Victor Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Espariz, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Deutscher, Josef. Université Paris-Saclay; Francia. Universite de Paris; FranciaFil: Pikis, Andreas. Center For Drug Evaluation And Research; Estados UnidosFil: Hartke, Axel. Universite de Caen Basse Normandie; FranciaFil: Magni, Christian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Sauvageot, Nicolas. Universite de Caen Basse Normandie; Franci
Epidemiology of surgery associated acute kidney injury (EPIS-AKI): a prospective international observational multi-center clinical study
Purpose: The incidence, patient features, risk factors and outcomes of surgery-associated postoperative acute kidney injury (PO-AKI) across different countries and health care systems is unclear. Methods: We conducted an international prospective, observational, multi-center study in 30 countries in patients undergoing major surgery (> 2-h duration and postoperative intensive care unit (ICU) or high dependency unit admission). The primary endpoint was the occurrence of PO-AKI within 72 h of surgery defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Secondary endpoints included PO-AKI severity and duration, use of renal replacement therapy (RRT), mortality, and ICU and hospital length of stay. Results: We studied 10,568 patients and 1945 (18.4%) developed PO-AKI (1236 (63.5%) KDIGO stage 1500 (25.7%) KDIGO stage 2209 (10.7%) KDIGO stage 3). In 33.8% PO-AKI was persistent, and 170/1945 (8.7%) of patients with PO-AKI received RRT in the ICU. Patients with PO-AKI had greater ICU (6.3% vs. 0.7%) and hospital (8.6% vs. 1.4%) mortality, and longer ICU (median 2 (Q1-Q3, 1-3) days vs. 3 (Q1-Q3, 1-6) days) and hospital length of stay (median 14 (Q1-Q3, 9-24) days vs. 10 (Q1-Q3, 7-17) days). Risk factors for PO-AKI included older age, comorbidities (hypertension, diabetes, chronic kidney disease), type, duration and urgency of surgery as well as intraoperative vasopressors, and aminoglycosides administration. Conclusion: In a comprehensive multinational study, approximately one in five patients develop PO-AKI after major surgery. Increasing severity of PO-AKI is associated with a progressive increase in adverse outcomes. Our findings indicate that PO-AKI represents a significant burden for health care worldwide
Epidemiology of surgery associated acute kidney injury (EPIS-AKI) : a prospective international observational multi-center clinical study
The incidence, patient features, risk factors and outcomes of surgery-associated postoperative acute kidney injury (PO-AKI) across different countries and health care systems is unclear. We conducted an international prospective, observational, multi-center study in 30 countries in patients undergoing major surgery (> 2-h duration and postoperative intensive care unit (ICU) or high dependency unit admission). The primary endpoint was the occurrence of PO-AKI within 72 h of surgery defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Secondary endpoints included PO-AKI severity and duration, use of renal replacement therapy (RRT), mortality, and ICU and hospital length of stay. We studied 10,568 patients and 1945 (18.4%) developed PO-AKI (1236 (63.5%) KDIGO stage 1500 (25.7%) KDIGO stage 2209 (10.7%) KDIGO stage 3). In 33.8% PO-AKI was persistent, and 170/1945 (8.7%) of patients with PO-AKI received RRT in the ICU. Patients with PO-AKI had greater ICU (6.3% vs. 0.7%) and hospital (8.6% vs. 1.4%) mortality, and longer ICU (median 2 (Q1-Q3, 1-3) days vs. 3 (Q1-Q3, 1-6) days) and hospital length of stay (median 14 (Q1-Q3, 9-24) days vs. 10 (Q1-Q3, 7-17) days). Risk factors for PO-AKI included older age, comorbidities (hypertension, diabetes, chronic kidney disease), type, duration and urgency of surgery as well as intraoperative vasopressors, and aminoglycosides administration. In a comprehensive multinational study, approximately one in five patients develop PO-AKI after major surgery. Increasing severity of PO-AKI is associated with a progressive increase in adverse outcomes. Our findings indicate that PO-AKI represents a significant burden for health care worldwide
Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores
A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació
Régulation des opérons Maltose/Maltodextrines et Gentiobiose induits en contexte d'infection chez Enterococcus faecalis
Enterococci are commensal bacteria of Humans predominantly encountered in the digestive tract. Despite their beneficial activity for their host, these microorganisms became the second leading bacterial cause of hospital acquired infections in France for last decades. Some studies showed that the central metabolism is a critical factor for microorganisms infection process. In this study, we worked on the characterisation of metabolisms of the different glucose polymers maltodextrins and gentiobiose in Enterococcus faecalis. The maltose and maltodextrins utilization is coordinated in this bacterium transcriptionally by the MalR repressor. The MalR activity is rapidly modulated by the inducer maltose and by the co repressor P Ser HPr which strengthens the MalR DNA binding. The metabolism of long maltodextrins is also repressed by the pleiotropic regulator CcpA in complex with its essential cofactor P Ser HPr in presence of glucose. The Catabolite repression of the operon genBA, involved in metabolism of the β glycoside gentiobiose, is assumed by CcpA in presence of glucose. This operon genBA allows the gentiobiose uptake with a PTS and its catabolism by a hydrolase. The expression of this latter operon requires both the GenR transcriptional activator and the inducer gentiobiose 6' P.Les entérocoques sont des bactéries commensales de l'Homme majoritairement rencontrées dans le tractus digestif. En dépit du caractère bénéfique pour leur hôte, ces microorganismes sont retrouvés au deuxième rang des bactéries responsables d'infection nosocomiales en France ces dernières décennies. Diverses études tendent à montrer que le métabolisme énergétique constitue un facteur crucial pour le processus infectieux des microorganismes. Lors de ce travail, nous nous sommes intéressés à l'étude des métabolismes de différents polymères de glucoses chez Enterococcus faecalis : les maltodextrines et le gentiobiose. L'utilisation du maltose et des maltodextrines est, chez cette bactérie, directement coordonnée au niveau transcriptionnel par le répresseur MalR. L'activité de ce régulateur est rapidement modulée par le maltose qui représente l'inducteur du système et par un corépresseur protéique : la protéine P Ser HPr qui, à l'inverse, favorise la répression exercée par MalR. Le métabolisme des maltodextrines complexes, mais pas le métabolisme du maltose, est également réprimé par le régulateur pléiotrope CcpA en coordination avec son cofacteur P Ser HPr en présence de glucose. La répression catabolique de l'opéron genBA, impliqué dans le métabolisme du β glycoside gentiobiose, est aussi assurée par ce régulateur CcpA en présence de glucose. Cet opéron genBA est responsable de l'import du gentiobiose par un PTS ainsi que de son catabolisme grâce à une hydrolase. L'expression de cette structure opéronique nécessite la présence de l'activateur transcriptionnel GenR actif en présence de l'inducteur gentiobiose 6' P
Regulation of Maltose/Maltodextrin and gentiobiose operons induced during infection in Enterococcus faecalis
Les entérocoques sont des bactéries commensales de l'Homme majoritairement rencontrées dans le tractus digestif. En dépit du caractère bénéfique pour leur hôte, ces microorganismes sont retrouvés au deuxième rang des bactéries responsables d'infection nosocomiales en France ces dernières décennies. Diverses études tendent à montrer que le métabolisme énergétique constitue un facteur crucial pour le processus infectieux des microorganismes. Lors de ce travail, nous nous sommes intéressés à l'étude des métabolismes de différents polymères de glucoses chez Enterococcus faecalis : les maltodextrines et le gentiobiose. L'utilisation du maltose et des maltodextrines est, chez cette bactérie, directement coordonnée au niveau transcriptionnel par le répresseur MalR. L'activité de ce régulateur est rapidement modulée par le maltose qui représente l'inducteur du système et par un corépresseur protéique : la protéine P Ser HPr qui, à l'inverse, favorise la répression exercée par MalR. Le métabolisme des maltodextrines complexes, mais pas le métabolisme du maltose, est également réprimé par le régulateur pléiotrope CcpA en coordination avec son cofacteur P Ser HPr en présence de glucose. La répression catabolique de l'opéron genBA, impliqué dans le métabolisme du β glycoside gentiobiose, est aussi assurée par ce régulateur CcpA en présence de glucose. Cet opéron genBA est responsable de l'import du gentiobiose par un PTS ainsi que de son catabolisme grâce à une hydrolase. L'expression de cette structure opéronique nécessite la présence de l'activateur transcriptionnel GenR actif en présence de l'inducteur gentiobiose 6' P.Enterococci are commensal bacteria of Humans predominantly encountered in the digestive tract. Despite their beneficial activity for their host, these microorganisms became the second leading bacterial cause of hospital acquired infections in France for last decades. Some studies showed that the central metabolism is a critical factor for microorganisms infection process. In this study, we worked on the characterisation of metabolisms of the different glucose polymers maltodextrins and gentiobiose in Enterococcus faecalis. The maltose and maltodextrins utilization is coordinated in this bacterium transcriptionally by the MalR repressor. The MalR activity is rapidly modulated by the inducer maltose and by the co repressor P Ser HPr which strengthens the MalR DNA binding. The metabolism of long maltodextrins is also repressed by the pleiotropic regulator CcpA in complex with its essential cofactor P Ser HPr in presence of glucose. The Catabolite repression of the operon genBA, involved in metabolism of the β glycoside gentiobiose, is assumed by CcpA in presence of glucose. This operon genBA allows the gentiobiose uptake with a PTS and its catabolism by a hydrolase. The expression of this latter operon requires both the GenR transcriptional activator and the inducer gentiobiose 6' P
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