Heavy metal toxicity in rice and soybean plants cultivated in contaminated soil

Heavy metals can accumulate in soil and cause phytotoxicity in plants with some specific symptoms. The present study evaluated the specific symptoms on rice and soybeans plants caused by excess of heavy metals in soil. Rice and soybean were grown in pots containing soil with different levels of heavy metals. A completely randomized design was used, with four replications, using two crop species and seven sample soils with different contamination levels. Rice and soybean exhibited different responses to the high concentrations of heavy metals in the soil. Rice plants accumulated higher Cu, Mn, Pb and Zn concentrations and were more sensitive to high concentrations of these elements in the soil, absorbing them more easily compared to the soybean plants. However, high available Zn concentrations in the soil caused phytotoxicity symptoms in rice and soybean, mainly chlorosis and inhibited plant growth. Further, high Zn concentrations in the soil reduced the Fe concentration in the shoots of soybean and rice plants to levels considered deficient.

Nutrient accumulation and biomass production of alfafa after soil amendment with silicates

Studies on the use of silicate correctives in agriculture show that they have great potential to improve soil chemical characteristics, however, little information is available on the reactivity rates of their particle-size fractions. This study investigated whether the reactivity rates obtained experimentally could be considered in the calculation of ECC (effective calcium carbonate) for soil liming, promoting adequate development of alfalfa plants. Six treatments were evaluated in the experiment, consisting of two slag types applied in two rates. The experimental ECC was used to calculate one of the rates and the ECC determined in the laboratory was used to calculate the other. Rates of limestone and wollastonite were based on the ECC determined in laboratory. The rates of each soil acidity corretive were calculated to increase the base saturation to 80%. The treatments were applied to a Rhodic Hapludox and an Alfisol Ferrudalfs. The methods for ECC determination established for lime can be applied to steel slag. The application of slag corrected soil acidity with consequent accumulation of Ca, P, and Si in alfalfa, favoring DM production.

Modelo para avaliação da qualidade de conteúdos de sítios Web de Unidades de Saúde

Os sítios Web são a face das instituições, mas há evidências de frequentemente serem pouco cuidados, sobretudo ao nível dos seus conteúdos. Nesta tese apresentamos uma investigação que desenvolve um modelo de avaliação da qualidade dos conteúdos de sítios Web de unidades de saúde. A revisão bibliográfica, realizada neste trabalho, permitiu identificar as dimensões e atributos de avaliação da qualidade de conteúdos de sítios Web mais considerados pelos diversos autores dos trabalhos mais importantes da área, mas não um modelo que, a partir deles, fosse capaz de os avaliar objetivamente. Assim, levantou-se o problema de saber se todos os atributos têm a mesma importância. Atributos mais importantes devem dar maior contributo na avaliação pretendida e o modelo a ser considerado deve refletir isso, adicionalmente a ferramenta de avaliação deveria ser intuitiva e rápida na aplicação. Para determinar a importância de cada atributo aplicou-se o Método Delphi tendo sido necessário três rondas para encontrar consenso relativamente à importância dos atributos a que se seguiu a aplicação de um conjunto de modelos estatísticos de forma a determinar uma métrica consistente e que permitisse a comparação de pontuações entre sítios web. De acordo com as questões de investigação e os objetivos definidos foi possível encontrar um modelo que fornecesse uma medida objetiva, normalizada e consistente acerca da qualidade de conteúdos de sítios web de unidades de saúde

Variations of the soft tissue thicknesses external to the ribs in pectus excavatum patients

Background: Surgical repair of pectus excavatum (PE) has become more popular due to improvements in the minimally invasive Nuss procedure. The pre-surgical assessment of PE patients requires Computerized Tomography (CT), as the malformation characteristics vary from patient to patient. Objective: This work aims to characterize soft tissue thickness (STT) external to the ribs among PE patients. It also presents a comparative analysis between the anterior chest wall surface before and after surgical correction. Methods: Through surrounding tissue segmentation in CT data, STT values were calculated at different lines along the thoracic wall, with a reference point in the intersection of coronal and median planes. The comparative analysis between the two 3D anterior chest surfaces sets a surgical correction influence area (SCIA) and a volume of interest (VOI) based on image processing algorithms, 3D surface algorithms, and registration methods. Results: There are always variations between left and right side STTs (2.54±2.05 mm and 2.95±2.97 mm for female and male patients, respectively). STTs are dependent on age, sex, and body mass index of each patient. On female patients, breast tissue induces additional errors in bar manual

Definição de um modelo de integração dos sistemas de gestão, da qualidade, do ambiente e da segurança, aplicado ao setor da cerâmica

A integração dos vários SsG que a organização pretenda implementar, contribui para a simplificação ao nível da sua gestão e aumento da eficácia. No entanto, a integração de múltiplos SsG pode acarretar alguma complexidade, quer na fase da implementação propriamente dita, quer ao nível da sua posterior gestão, caso o processo não seja conduzido de forma rigorosa. Considerando a escassez de diretivas orientadoras para a integração de SsG e a dificuldade de integração no momento da sua implementação, a presente dissertação propõe um modelo de integração dos SsGQAS, aplicado ao setor da cerâmica. Os referenciais normativos utilizados para o desenvolvimento do estudo foram: a NP EN ISO 9001: 2008, a NP EN ISO 14001: 2012, a BS OHSAS 18001: 2007/NP 4397:2008 e a UNE 66177:2005, com base nos quais se definiu um modelo de integração para os SsGQAS.Numa primeira fase procedeu-se à análise da perceção dos colaboradores da organização face às vantagens, desvantagens, motivações e dificuldades da implementação do SIGQAS, efetuada através de inquérito por questionário. Desta análise conclui-se que são percetíveis para os colaboradores da Aleluia Cerâmicas S.A., as vantagens / melhorias para a organização decorrentes da integração dos SsG. Por fim, procedeu-se à definição do modelo de integração dos SsGQAS. O modelo baseou-se na metodologia proposta pela UNE 66177, que contempla orientações para o desenvolvimento, implementação e avaliação do processo de integração dos SsGQAS. Esta dissertação tem como objetivo auxiliar as organizações a gerir de forma eficaz as diretrizes dos diferentes referenciais normativos e a obterem benefícios resultantes da sua integração, alcançando maior eficácia na sua gestão e aumento de rentabilidade.

Soil chemical properties affected by cover crops under no-tillage system

The use of cover crops in no-tillage systems (NTS) can significantly improve the soil's fertility. Thus, a study was performed to evaluate changes in chemical properties of soil caused by cover crops in a no-tillage system. The field experiment consisted of the following crop rotation: cover crops/rice/cover crops/rice. The experimental design was in randomized blocks with three replications. Treatments consisted of four cover crops (Brachiaria brizantha(Hochst. ex A. Rich.) Stapf. cv. Marandu, Brachiaria ruziziensis R. Germ. and C.M. Evrard, Panicum maximum Jacq. cv. Colonião, and Pennisetum glaucum(L.) R. Br. cv. BN-2) and fallow (control treatment). Soil samples were collected at the beginning of the summer crop in Oct 2007, Oct 2008 and Oct 2009 at 0-5 cm soil depth. The use of cover crops provided for a significant increase in the level of nutrients, soil organic matter, cation exchange capacity, and base saturation in the soil. Soil fertility improved from the first to second year with the growing of cover crops. The soil under cover crops P. glaucum, B. ruziziensis, and B. brizantha showed higher fertility than the area under fallow.

Absorption of primary macronutrients and soybean growth at different compactation densities and moisture levels in a silt loam soil

ABSTRACT Soybean cultivation is increasing rapidly in the region of Alto Vale do Itajaí, State of Santa Catarina, where there is a predominance of silt soils. The objective of this work was to evaluate the content of primary macronutrients in shoots and shoot and root vegetative growth of soybean (Glicine max L. Merrill) grown in a silt-loam soil under different compactation densities and moisture levels. A randomized block design in a 4x4 factorial arrangement was used, with four compactation densities: 1.00; 1.20; 1.40 and 1.60 Mg m-3, and four soil moisture levels: 0.130; 0.160; 0.190 and 0.220 kg kg-1 and four replications. Each pot consisted of the overlapping of three 150-mm PVC rings, where soil was maintained in the higher and lower part of the pot with a density of 1.00 Mg m-3 and in the intermediate ring, the compactation densities were increased. Values of soil density higher than 120 Mg m-3 negatively affected N, P and K uptake by soybean plants, as well as the plant mass of the shoots and roots. The higher levels of soil moisture reduced the compaction effect and promoted better absorption of P and K.