Aluminum inhibits the plasma membrane and sarcoplasmic reticulum Ca2+-ATPases by different mechanisms

Aluminum (Al 3+ ) is involved in the pathophysiology of neurodegenerative disorders. The mechanisms that have been proposed to explain the action of Al 3+ toxicity are linked to changes in the cellular calcium homeostasis, placing the transporting calcium pumps as potential targets. The aim of this work was to study the molecular inhibitory mechanism of Al 3+ on Ca 2+ -ATPases such as the plasma membrane and the sarcoplasmic reticulum calcium pumps (PMCA and SERCA, respectively). These P-ATPases transport Ca 2+ actively from the cytoplasm towards the extracellular medium and to the sarcoplasmic reticulum, respectively. For this purpose, we performed enzymatic measurements of the effect of Al 3+ on purified preparations of PMCA and SERCA. Our results show that Al 3+ is an irreversible inhibitor of PMCA and a slowly-reversible inhibitor of SERCA. The binding of Al 3+ is affected by Ca 2+ in SERCA, though not in PMCA. Al 3+ prevents the phosphorylation of SERCA and, conversely, the dephosphorylation of PMCA. The dephosphorylation time courses of the complex formed by PMCA and Al 3+ (EPAl) in the presence of ADP or ATP show that EPAl is composed mainly by the conformer E 2 P. This work shows for the first time a distinct mechanism of Al 3+ inhibition that involves different intermediates of the reaction cycle of these two Ca 2+ -ATPases.Fil: de Sautu, Marilina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Saffioti, Nicolas Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Ferreira Gomes, Mariela Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Rossi, Rolando Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Rossi, Juan Pablo Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Mangialavori, Irene Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentin

Boundaries and mosaics: an approach to evaluate changes and to profit landscape planning, São Sebastião Island, SP/Brazil

This study assumed that the spatial identification of mosaics obtained by the analysis of interactions between frontiers over time would be a great strategy to obtain planning units, since the boundaries reveal the changes, heterogeneity and fluxes in a landscape. For this purpose, we selected 16 watersheds in São Sebastião Island (São Paulo, BR), mapped the land use and cover (1962 and 2009) and built matrices of patches by boundaries. The analysis of these matrices using multivariate ordination and clustering allowed us to identify mosaics. The mosaics showed very well the temporal diversity of interactions across frontiers and the landscape conservation status, but had limitations to indicate management practices

AGROCLIMATIC RISK ZONING OF PINEAPPLE (Ananas comosus) IN THE HYDROGRAPHIC BASIN OF PARANÁ RIVER 3, BRAZIL

Fruticulture is a prominent segment of Brazilian agriculture. It presents a continuous evolution of production, attending to the growing internal and external demand, besides being one of the main activities of family agriculture. Despite of recent technological and scientific advances, climate is still the most important variable in agricultural productivity. Studies that show the climatic variability and the impact on the physiological development of plant species are fundamental for the planning and agricultural calendar, aiming the conservation of resources and a sustainable management of the production. In this context, one of the first information to be considered when starting a crop is agro-climatic zoning, since it provides climate-related risk information and helps in decision-making and agricultural planning. Thus, the objective of this work was to carry out agroclimatic risk zoning for the Pineapple (Ananas comosus) in the Paraná River basin 3, Paraná state, Brazil. For this, meteorological data of 43 stations with series from 1976 to 2018 we used. The climatic risk analysis was based on the requirements of the species of precipitation, average annual temperature and in the coldest month, risk of frost and insolation. Statistical and geoprocessing techniques were applied to ensure full regional coverage of information and to contribute to decision-making. Favorable climatic conditions were identified for all climatic variables in the western portion of the river basin, while in the eastern portion the risk of frost restricted the aptitude

Ciclização do lapachol induzida por sais de tálio III

This work describes the cyclization of lapachol (1) induced by thallium triacetate (TTA) and thallium trinitrate (TTN) in several solvents using magnetic stirring and under microwave irradiation. alpha-Xyloidone (2) - dehydro-alpha-lapachone - was obtained as the main product in these reactions in 20 75% yield. However, rhinacanthin-A (4) was isolated as main product in a 40% yield, using TTA and acetic anhydride:water (1:1) as solvent, and dehydro-iso-alpha-lapachone (3) in 21% yield, using TTA and dichloromethane as solvent. The reaction time decreased drastically under microwave conditions, but the yields of these reactions were not the expected

Rhizophagus Clarus and Phosphorus in Crotalaria juncea: growth, glomalin content and acid phosphatase activity in a copper-contaminated soil

Crotalaria juncea is used as plant cover in grape vineyards in Brazil, which usually present soils with high copper (Cu) levels due to the application of Cu-based phyto-sanitary products. Under this condition an increase growth and cover of C. juncea is needed to improve the phytoremediation processes in those soils. Some alternatives to achieve this condition is the inoculation with arbuscular mycorrhizal fungi (AMF), which has demonstrated an important increase of plant growth in Cu-contaminated soils at different soil P levels. The aims of this study were to evaluate the effect of AMF inoculation in soils with high Cu contents on the growth of C. juncea, the acid phosphatase (APase) enzyme activity in plants and soil, and the presence of glomalin under different P supply conditions, as a basis to identify if there is a synergistic interaction between AMF inoculation and P supply on soils with high Cu levels. The experiment was carried under greenhouse conditions in a factorial 3 × 2 design (natural P content, addition of 40 and 100 mg kg-1 P, with and without the inoculation of the AMF Rhizophagus clarus with three replicates) in a soil with high Cu content (60 mg kg-1). The addition of 40 and 100 mg kg-1 P favored plant growth both in the presence and in the absence of AMF. However, when plants were grown in soil with a natural P level, the inoculation with AMF increased by 116 % the shoot biomass, compared to the non-inoculated treatment. Our results showed that the combination of P supply and R. clarus inoculation could be an adequate strategy to reduce Cu phytotoxicity in C. juncea, as it increases plant biomass and modify the APase enzyme activity in the soil and plant. Additionally, glomalin produced by the AMF and accumulated in the soil can decrease the availability of Cu to the plants by means of sequestration beyond the root surface, with a consequent plant protective effect

Preparo da semente de colubrina para execução do teste de tetrazólio

Colubrina glandulosa Perkins, conhecida popularmente como sobrasil, é uma espécie de importância ecológica e socioeconômica, porém ameaçada de extinção. Suas sementes apresentam germinação baixa, lenta e desuniforme. Sabendo que o teste de tetrazólio tem se destacado por sua eficácia e rapidez quando se deseja respostas rápidas sobre a qualidade das sementes, este estudo objetivou estabelecer a melhor concentração da solução de tetrazólio e o período de coloração para avaliar a viabilidade das sementes de Colubrina glandulosa. As sementes foram pré-umedecidas em papel toalha e colocadas em uma câmara de germinação a 30 °C por cinco horas. Posteriormente, a porção do cotilédone contendo o embrião foi imersa em solução de 2,3,5-trifenil cloreto de tetrazólio em quatro concentrações de 0,075; 0,1; 0,5 e 1,0% por três períodos de coloração (2, 4 e 6 horas) a 30 ºC no escuro. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 4 x 3 + 1 (4 concentrações de solução de tetrazólio x 3 períodos de coloração + 1 controle – teste de germinação). O teste de tetrazólio foi eficiente para estimar a viabilidade de sementes de C. glandulosa, e a concentração de 0,075% por quatro horas a 30 ºC foi a melhor condição

A importância do trabalho das Cooperativas na reciclagem de resíduos sólidos e a conscientização das práticas ambientais: The importance of the work of Cooperatives in the recycling of solid waste and awareness of environmental practices

A revolução tecnológica vem sendo acompanhada por alterações no estilo de vida, nos modos de produção e consumo da população, como decorrência direta desses processos vem ocorrendo um aumento na produção de resíduos sólidos, tanto em quantidade, quanto em diversidade, principalmente nos grandes centros urbanos. Atualmente passaram a abrigar em sua composição elementos sintéticos e perigosos aos ecossistemas e à saúde humana. Entretanto, as Cooperativas foram originadas pelas necessidades sociais e econômicas, com a finalidade de diminuir os resíduos sólidos urbano, auxiliando na questão ambiental, gerando trabalho e aumento de renda para a população. O objetivo do presente trabalho foi analisar a importância do trabalho das Cooperativas na reciclagem dos resíduos sólidos e a influência na conscientização da prática ambiental. Portanto, conscientizar e sensibilizar as pessoas são atitudes importantes quando se trata sobre às questões ambientais, envolvendo as Cooperativas de reciclagens como alternativa para a reduzir os impactos causados pelo lixo, podendo influenciar em uma sociedade mais justa, igualitária, apresentando maior consciência ambiental e comprometida com a sustentabilidade, protegendo o meio ambiente e garantindo a preservação dos ecossistemas para as futuras gerações