Entity

Time filter

Source Type

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.


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. Source


The effect of acibenzolar-S-methyl (ASM), mannano-oligosaccharides (MOS) and citrus bioflavonoids (BFC) was studied for control of bacterial fruit blotch of yellow melon (hybrid AF4945) and Pele de Sapo melon (hybrid Nilo), evaluating different application periods (10 and 15 days after plant emergence), and dosages (acibenzolar-S-methyl 25; 50 and 75 mg a.i. L-1; mannano-oligosaccharides 0.5; 1.0 and 1.5 c.p. L-1; citrus bioflavonoids 2; 3 and 4 mL c.p. L-1) and also on plant growth in soil supplemented or not with NPK. The best period for application was 10 days after plant emergence. Considering both genotypes, ASM (50 mg a.i. L-1) and BFC (3 mL c.p. L-1) increased incubation period until 13 and 8 days and reduced disease incidence by 88 and 60%; disease index by 96 and 88%; and area under disease progress curve by 94 and 74%, respectively. However, independent of NPK level in the soil ASM and BFC reduced melon plant height by 24%; they also reduced fresh and dry shoot biomass by 41% and 34%, respectively. Source


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. Source


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. Source


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. Source

Discover hidden collaborations