Recife, Brazil

The Universidade Federal Rural de Pernambuco is an of high education institution in Brazil, specializing in courses in agricultural science and other courses that "compete or will compete for the development of rural areas." The university also conducts research in these areas. However, in recent years the university has added a wider variety of courses .It has three campuses, one in Recife , one in Garanhuns and another in Serra Talhada , UFRPE still possesses advanced campuses throughout the state. Wikipedia.

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Ludermir T.B.,Federal University of Pernambuco | De Oliveira W.R.,Federal Rural University of Pernambuco
Expert Systems with Applications | Year: 2013

Social class differences in the prevalence of Common Mental Disorder (CMD) are likely to vary according to time, culture and stage of economic development. The present study aimed to investigate the use of optimization of architecture and weights of Artificial Neural Network (ANN) for identification of the factors related to CMDs. The identification of the factors was possible by optimizing the architecture and weights of the network. The optimization of architecture and weights of ANNs is based on Particle Swarm Optimization with early stopping criteria. This approach achieved a good generalization control, as well as similar or better results than other techniques, but with a lower computational cost, with the ability to generate small networks and with the advantage of the automated architecture selection, which simplify the training process. This paper presents the results obtained in the experiments with ANNs in which it was observed an average percentage of correct classification of individuals with positive diagnostic for the CMDs of 90.59%. © 2013 Elsevier Ltd. All rights reserved.

Montenegro A.,Federal Rural University of Pernambuco | Ragab R.,UK Center for Ecology and Hydrology
Hydrological Processes | Year: 2010

Brazilian semi-arid regions are characterized by water scarcity, vulnerability to desertification, and climate variability. The investigation of hydrological processes in this region is of major interest not only for water planning strategies but also to address the possible impact of future climate and land-use changes on water resources. A hydrological distributed catchment-scale model (DiCaSM) has been applied to simulate hydrological processes in a small representative catchment of the Brazilian northeast semi-arid region, and also to investigate the impact of climate and land-use changes, as well as changes associated with biofuel/energy crops production. The catchment is part of the Brazilian network for semi-arid hydrology, established by the Brazilian Federal Government. Estimating and modelling streamflow (STF) and recharge in semi-arid areas is a challenging task, mainly because of limitation in in situ measurements, and also due to the local nature of some processes. Direct recharge measurements are very difficult in semi-arid catchments and contain a high level of uncertainty. The latter is usually addressed by short- and long-time-scale calibration and validation at catchment scale, as well as by examining the model sensitivity to the physical parameters responsible for the recharge. The DiCaSM model was run from 2000 to 2008, and streamflow was successfully simulated, with a Nash-Sutcliffe (NS) efficiency coefficient of 0.73, and R2 of 0.79. On the basis of a range of climate change scenarios for the region, the DiCaSM model forecasted a reduction by 35%, 68%, and 77%, in groundwater recharge (GWR), and by 34%, 65%, and 72%, in streamflow, for the time spans 2010-2039, 2040-2069, and 2070-2099, respectively, could take place for a dry future climate scenario. These reductions would produce severe impact on water availability in the region. Introducing castor beans to the catchment would increase the GWR and streamflow, mainly if the caatinga areas would be converted into castor beans production. Changing an area of 1000 ha from caatinga to castor beans would increase the GWR by 46% and streamflow by 3%. If the same area of pasture is converted into castor beans, there would be an increase in GWR and streamflow by 24% and 5%, respectively. Such results are expected to contribute towards environmental policies for north-east Brazil (NEB), and to biofuel production perspectives in the region. © 2010 John Wiley & Sons, Ltd.

The intensive traffic of agricultural machinery of cultivation and harvesting operations of sugarcane can promote soil compaction and affect crop yield and longevity. One of the ways to evaluate soil degradation due to compaction is by analyses of soil compressibility and least limiting water range. The objective of this study was to evaluate the effect of sugarcane cultivation on pre-compaction pressure (σ p), laboratory-determined soil penetration resistance (LPS) and on the least limiting water range (LLWR) of a cohesive Yellow Ultisol of the coastal tablelands of Alagoas. The study was conducted on the Fazenda Progresso, of the Usina Coruripe, where five sugarcane areas were selected, representing different use periods and crop systems: four years under winter cropping (4 year W), 14 years under winter cropping (14 year W), 14 years under summer cropping (14 year S), thirty years under winter cropping (30 year W), and 30 years under summer cropping (30 year S). A native subperennial forest fragment (Forest) was alsoincluded in this study as a reference area. To determine the effect of sugarcane cultivation on soil compaction, σ p, LPS and LLWR were determined in soil samples from the layers 0-0,20 m, 0,20-0,40 m and 0,40-0,60 m, corresponding to the horizons A (Forest) or Ap (agricultural areas), AB and Bt. Sugarcane cultivation increased the σp and LPS of the Ap, AB and Bt horizons of the Yellow Ultisol, however, in the Ap horizon of the soil of the agricultural areas the LPS did not reach the value considered critical for root development, and the LLWR was higher than in the surface horizon of native forest. The mechanized operations for sugarcanecultivation increased LPS to critical levels for root development, even at moisture contents near field capacity, which decreased LLWR of AB and Bt horizons in the agricultural areas. Precompaction pressure can be used as an indicator of load support capacity in the strategicplanning of machinery operations in sugarcane fields, in order to avoid further soil compactionin the subsurface horizons of cohesive Yellow Ultisol.

Marques M.C.,Federal Rural University of Pernambuco | Do Nascimento C.W.A.,Federal Rural University of Pernambuco
Journal of Photochemistry and Photobiology B: Biology | Year: 2013

The vegetation of metal-contaminated soils using non-edible crops can be a safe and economical technique for Cd immobilization and the remediation of contaminated sites. Jatropha (Jatropha curcas L.) exhibits a relative tolerance to heavy metals and potential for biofuel production. The study was performed to monitor the Cd-induced alterations in jatropha plants by X-ray chlorophyll fluorescence. The Cd effects on photosynthetic pigments, the mineral composition of plants, defense enzyme activity and soluble proteins were also studied. Plants were grown for 20 days in a nutrient solution with five Cd contents: 5, 10, 20, 30 and 40 μmol L-1; a control with no Cd addition was also monitored. The analysis of the chlorophyll fluorescence spectra allowed detecting alterations caused by Cd toxicity in the jatropha plants. The mineral composition of the plants was affected by the Cd doses; however, the Fe and Mg contents were not significantly reduced, which most likely improved the effects on the contents of the photosynthetic pigments. Because of its relative tolerance to Cd, Jatropha curcas may be a promising species to revegetate Cd-contaminated sites. Considering the long period needed to phytoremediate soils, the combination of remediation with bioenergy production could be an attractive option. © 2013 Elsevier B.V. All rights reserved.

Veerman J.J.P.,Portland State University | Stosic B.D.,Federal Rural University of Pernambuco
IEEE Transactions on Automatic Control | Year: 2012

This paper analyzes the transient dynamics of one dimensional flocks, platoons, i.e., a finite collection of identical vehicles moving on the line, with a single leader with independent motion. We show for a class of platoon control laws that if the information flow is asymmetric then a motion change of the leader will cause system transients with amplitudes that grow at an exponential rate as the length of the platoon increases. With suitable choice of the control parameters the system is asymptotically stable and in steady state all vehicles move at the same velocity as the leader and at the required separation. When the leader changes velocity, over very long time scales the vehicles in the platoon tend to the steady state dictated by the leader's new velocity. The transient dynamics in the intermediary regime can however appear quite unstable, where the trailing vehicle can undergo oscillatory motion with amplitudes that grow exponentially large with the number of cars N in the platoon, or may be irresponsive over an exponentially long time to the change in the motion of the leader. In this paper we prove that if the control law is asymmetric then such transient errors, measured in terms of displacement between the leader and the trailing car, grow at an exponential rate in N, the length of the platoon. This contrasts sharply with the symmetric (bidirectional) case when such transient errors grow only linearly in the length of the platoon, the theoretical minimum for decentralized linear time-invariant platoon control systems with a constant vehicle spacing policy. These results suggest that symmetry of the information flow is an important design parameter for safe control laws for platoons. © 2012 IEEE.

De Araujo J.D.C.T.,Federal Rural University of Pernambuco | Do Nascimento C.W.A.,Federal Rural University of Pernambuco
Water, Air, and Soil Pollution | Year: 2010

Phytoextraction is a soil remediation technique involving plants that concentrate heavy metals in their shoots, which may be removed from the area by harvest. The application of synthetic chelants to soil increases metal solubility, and therefore enhances phytoextraction. However, synthetic chelants degrade poorly in soil, and metal leaching poses a threat to human and animal health. The aim of this study is to assess the use of two biodegradable chelants (citric acid and nitrilotriacetic acid (NTA)) for Pb phytoextraction by maize from a soil contaminated by battery-casing disposal. In order to assess the behavior of a non-degradable chelant, ethylenediaminetetraacetic acid (EDTA) was also included in the experiment. The chelants NTA and EDTA were applied to soil pots at rates of 0, 3, 5, 7, and 10 mmol kg-1 of soil. The rates used to citric acid were 0, 5, 10, 15, and 30 mmol kg-1. Maize plants were grown for 72 days and chelants were applied 9 days before harvest. Soil samples were extracted with CaCl2 to assess the Pb solubility after chelants application. The results showed that NTA was more efficient than citric acid to solubilize Pb from soil; however, citric acid promoted higher net removal of Pb (120 mg pot-1) than NTA (57 mg pot-1). Thus, the use of citric acid, a biodegradable organic acid, could be feasible for enhancing the phytoextraction of Pb from the site studied with no environmental constraints. © 2009 Springer Science+Business Media B.V.

Farrapeira C.M.R.,Federal Rural University of Pernambuco
Biological Invasions | Year: 2010

This paper records the new occurrence of spaghetti bryozoan Zoobotryon verticillatum at the Port of Natal, Rio Grande do Norte, Brazil. The study, carried out between 2006 and 2007, also monitored its proliferation. Six observation stations were selected from the estuarine area, as well as samples of benthic invertebrates. The species was initially detected on the pilings of the port and on the hull of a fishing boat. 9 months later it was also found in four stations and on another fishing boat. The luxuriant colonial growth in the lower intertidal zone by the end of the study indicates that this species is well established in the estuarine area. This observation is consistent with the species' biological characteristics; thus, it can be defined as an invasive organism due to its aggressive behavior when occupying the substrate. Its presence in port installations and vessels provide evidence that biofouling on ships' hulls has been the most likely vector of introduction. © 2010 Springer Science+Business Media B.V.

Pessoa W.S.,Federal Rural University of Pernambuco
Acta cirúrgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia | Year: 2012

To study the effects of the angico extract (Anadenanthera colubrina var. cebil) on the healing of rat skin. Twenty adult rats were divided into four groups of five animals each, the G4, G7, G14 and G21, which corresponds to the respective postoperative days. Each group received two incisions on skin and subcutaneous tissue in the right and left antimere of the thoracic region, separated by a distance of 2 cm. The right lesion was treated daily with saline and the left with the angico alcoholic extract (5%). At the end of each experimental period, animals were euthanized and fragments of the wound area, together with the edges were removed, fixed in 10% formaldehyde solution and processed for paraffin embedding. In the histological sections with 5 μm of thickness, were carried out immunohistochemical methods for detection of blood vessels (VEGF) and stained with hematoxylin and eosin for morphological analysis. Statistical analysis was done by ANOVA and Tukey test (p<0.05). Morphological analysis showed larger fibroblasts and a higher concentration of collagen fibers in days 7 and 14 in wounds treated with the angico extract. Morphometric analysis demonstrated a significant increase in the number of blood vessels in both the seventh and 14th days (p<0.01) in wounds treated with the angico extract. The angico alcoholic extract (Anadenanthera colubrina var. cebil) induces the acceleration of wound healing in skin wounds of rats.

Ramos M.A.,Federal Rural University of Pernambuco | Albuquerque U.P.D.,Federal Rural University of Pernambuco
Biomass and Bioenergy | Year: 2012

One of the main methods of extracting vegetation from the Caatinga is the cutting of wood for firewood. However, despite its social importance and its capacity for having environmental impacts, there are no studies that evaluate the dynamics of the collection of this resource in relation to temporal factors in the semi-arid regions of Brazil. Thus, the main purpose of this study was to show that the seasonality of the savanna climate might influence local patterns of collecting firewood. Between December 2008 and February 2010, interviews and eleven in situ inventories were performed in the residences of two rural communities in the municipality of Soledad in the state of Paraíba (Northeast Brazil). During the in situ inventories, all stocks were measured (m 3), and species diversity was recorded. A total of 22 species were cataloged, but the pressure of collection was not distributed across all plants; there was a small group of species that were collected throughout the year, and these were found more frequently and with greater abundance in the residences. Although species richness was not influenced by seasonality, the volume of wood varied significantly between the dry and rainy seasons. More collections are performed in the dry season, and the local vegetation suffers greater extraction pressure from this use. The results obtained reinforce the need for studies that examine the potential for regrowth, plant productivity after selective cutting and the resting time necessary before performing a new cutting cycle, as this is the only way to better understand the implications regarding the use of firewood and its effects on local conservation. © 2012 Elsevier Ltd.

Lima A.L.A.,Federal Rural University of Pernambuco | Rodal M.J.N.,Federal Rural University of Pernambuco
Journal of Arid Environments | Year: 2010

Nineteen woody species growing in the semi-arid region of northeastern Brazil were examined to evaluate the relationship between wood density and their vegetative and reproductive phenophases. Wood density varied between 0.29 g/cm3 and 0.83 g/cm3, and these values were inversely related to the quantity of water stored at saturation. The six species that initiated vegetative and/or reproductive phenophases during the dry season had low wood densities (<0.55 g/cm3) and were able to store large quantities of water (110-271% of the dry weight of the wood). Leaf fall in these species occurred during the transition period between the rainy and the dry season, and it occurred earlier than in species with denser wood. Leaf flush among low wood density species was positively related to the photoperiod. Species with high wood densities, on the other hand, were strongly dependent on rainfall for leaf flush, flowering, and fruiting, as they are able to store only limited quantities of water in their trunks; leaf fall in these species occurred during the dry season. These results point to a strong correlation between wood density and phenology among the species studied. © 2010 Elsevier Ltd.

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