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Picuí, Brazil

Gomes S.M.S.,Federal University of Paraiba | De Lima V.A.,Federal University of Campina Grande | De Souza A.P.,Federal University of Paraiba | Do Nascimxento J.J.V.R.,IFPB | Do Nascimento E.S.,Federal University of Paraiba
Engenharia Agricola | Year: 2014

Plants respond to environmental adversities, becoming an indicator for assessing the environment quality. In this aspect, chlorophyll contents as well, carotenoids are used as a reliable indicator to associate environmental quality and pollution, mainly regarding the toxicity of heavy metals in higher plants. So, we aimed to evaluate the content of chlorophyll a, b, and total chlorophylls and carotenoids in plants vetiver [Vetiveria zizanioides (L.) Nash], maize (Zea mays L.) cv. AG 1051, sunflower (Helianthus annuus L.) cv. BRS 122/V-2000, and castor beans (Ricinus communis L.) cv. Northeastern BRS grown in contaminated soil with lead, with and without correction of soil pH, so they were used as indicators of metal stress by the soil. From the biochemical point of view, the correction of soil pH values caused chlorophyll a, b and total statistically higher for vetiver species and castor beans in the analyzed periods, except for the analysis performed 60 days after transplanting where only the species vetiver benefited from the correction of soil pH on the content of chlorophyll b and total. On the other hand plants without correction of soil pH showed a decrease of all chlorophyll levels. In addition, the largest increase in the synthesis of carotenoids, indicated that under stress the plants have developed alternative routes of dissipation of energy in order to avoid problems of photo-inhibition and photo-oxidation. Source


Melo J.,IFPB | Melo E.,Federal University of Rio Grande do Norte
Advances in Intelligent Systems and Computing | Year: 2015

This paper presents a preliminary discussion of the possibilities and limitations of Massive Open Online Courses (MOOC), a model of an online course whose contents are open and freely offered over the internet to anyone and anywhere. The main characteristic of this model is to allow an active engagement of tens or hundreds of thousands of students who self organize their own participation according to their goals, background, abilities and common interest. Advances in studies about Web Semantics and Adaptive Learning Systems are examples of research results in some of the various research areas of Computing in Education which are still incipient in MOOCs. © Springer International Publishing Switzerland 2015 Source


de Oliveira L.M.M.,Federal University of Pernambuco | Montenegro S.M.G.L.,Federal University of Pernambuco | da Silva B.B.,Federal University of Pernambuco | Antonino A.C.D.,Federal University of Pernambuco | de Moura A.E.S.S.,IFPB
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2014

This study aimed to evaluate the real daily evapotranspiration - ETr by remote sensing and to compare it with ETr according to the Bowen ratio technique in the Tapacurá River basin, Pernambuco state, Brazil. The Surface Energy Balance Algorithm for Land (SEBAL) was used with data from Moderate Resolution Imaging Spectroradiometer (MODIS) and meteorological data obtained in a field experiment inside the basin from January 2010 to August 2011. The ETr from SEBAL ranged between 0 and 6 mm d-1, with the highest values registered in the Tapacurá reservoir and the smallest in urban areas inside the basin. The ETr from the Bowen ratio in a pasture area ranged from 3.6 to 4.9 mm d-1. The SEBAL provided good results of the daily evapotranspiration when compared with ETr estimated according to the Bowen ratio technique, resulting in Mean Absolute Error, Relative Error and Average Root Mean Square Error, respectively of 0.40 mm d-1; 9.63% and 0.51 mm d-1. It was concluded that, despite the intense presence of clouds in the region, it was possible to obtain the real daily evapotranspiration in Tapacurá River basin based on MODIS images with good precision. © 2014, Departamento de Engenharia Agricola - UFCG/Cnpq. All rights reserved. Source


We evaluated vegetative and reproductive events of Ocotea pulchella (Nees) Mez (Lauraceae), Myrcia brasiliensis Kiaersk and Psidium cattleyanum Sabine (Myrtaceae) in a secondary semideciduous forest fragment for two years. We performed a circular data analysis and we correlated phenophases to temperature, daylenght and rainfall. Leaf fall and leaf appearance occurred continuously during the biennium featuring a low seasonality. The flowering, including the emergence of floral buds and anthesis, featured a seasonal pattern. Myrcia brasiliensis and Psidium cattleyanum showed great concentration of immature fruits around the average date (r), while fruit production of O. pulchella was almost constant (low r). The appearance of the fruits in P. cattleyanum and O. pulchella revealed a connection between daylenght and temperature in both years. All species had high concentration of individuals with mature fruits at some time of the year, allowing estimation of the average date of the reproductive event and indicating seasonality of maturation. The three species may potentially provide food resources for local animals, mainly birds, because mature fruits were available throughout the entire period. Source


Pimentel B.A.,Federal University of Pernambuco | Da Costa A.F.B.F.,IFPB | De Souza R.M.C.R.,Federal University of Pernambuco
Proceedings of the International Joint Conference on Neural Networks | Year: 2015

The main property of kernel methods is that they can implicitly perform a nonlinear mapping of the input data into a high-dimensional space. This mapping allows to find a simpler structure within space without increasing the number of parameters increasing the clustering quality. Therefore, kernel methods may find better results for data arranged not linearly. Many methods presented in the literature only use point data. However, real problems need more complex representation. In this work, we propose a new kernel-based fuzzy method using feature space metric for interval-valued data. Moreover, a comparative study between input space and feature space is set up in this paper. In order to evaluate the performance of the proposed method, experiments with synthetic and real interval data set were carried out. © 2015 IEEE. Source

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