Crateús, Brazil
Crateús, Brazil

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Bedor C.N.G.,Federal University of Vale do São Francisco | Morais R.J.L.,Federal University of Vale do São Francisco | Cavalcanti L.S.,Federal University of Vale do São Francisco | Ferreira J.V.,Instituto Federal Of Alagoas | Pavao A.C.,Federal University of Pernambuco
Science of the Total Environment | Year: 2010

The aim of the present study was to investigate the carcinogenic potential of endosulfan and its metabolites through electronic parameters that characterize the action of carcinogens, i.e. descriptors such as electron affinity, Δ (HOMO-LUMO), dipole moments, electrostatic attraction, formation heat (Hf) and permeability of the cell membrane (c Log P). The results reveal that both endosulfan and its metabolites are electrophilic and have carcinogenic potential. Although there are few data on its carcinogenicity in the literature, the findings of the present study indicate that the use of this pesticide represents a risk to the health of the general population, especially rural workers. © 2010 Elsevier B.V.


Mello F.F.C.,University of Sao Paulo | Mello F.F.C.,Harvard University | Cerri C.E.P.,University of Sao Paulo | Davies C.A.,Royal Dutch Shell | And 6 more authors.
Nature Climate Change | Year: 2014

The effects of land-use change (LUC) on soil carbon (C) balance has to be taken into account in calculating the CO2 savings attributed to bioenergy crops1-3. There have been few direct field measurements that quantify the effects of LUC on soil C for the most common land-use transitions into sugar cane in Brazil, the world's largest producer 1-3. We quantified the C balance for LUC as a net loss (carbon debt) or net gain (carbon credit) in soil C for sugar-cane expansion in Brazil. We sampled 135 field sites to 1 m depth, representing three major LUC scenarios. Our results demonstrate that soil C stocks decrease following LUC from native vegetation and pastures, and increase where cropland is converted to sugar cane. The payback time for the soil C debt was eight years for native vegetation and two to three years for pastures. With an increasing need for biofuels and the potential for Brazil to help meet global demand4, our results will be invaluable for guiding expansion policies of sugar-cane production towards greater sustainability. © 2014 Macmillan Publishers Limited. All rights reserved.


Roa-Fuentes C.A.,Paulista University | Casatti L.,Paulista University | Romero R.M.,Instituto Federal Of Alagoas
Neotropical Ichthyology | Year: 2015

We tested the contribution of the phylogenetic and specific components to the ecomorphological structure of stream fish from the upper Paraguai River and upper São Francisco River basins, and identified nodes in the phylogenetic tree at which major ecological shifts occurred. Fish were sampled between June and October of 2008 in 12 streams (six in each basin). In total, 22 species from the upper Paraguai River basin and 12 from the upper São Francisco River were analyzed. The ecomorphological patterns exhibited phylogenetic signal, indicating that the ecomorphological similarity among species is associated with the degree of relatedness. A strong habitat template is most likely to be the primary cause for a high phylogenetic signal. A significant contribution from the specific component was also detected, supporting the idea that the phylogenetic signal occurs in some clades for some traits, but not in others. The major ecological shifts were observed in the basal nodes, suggesting that ecological niche differences appear to accumulate early in the evolutionary history of major clades. This finding reinforces the role of key traits in the diversification of Neotropical fishes. Ecological shifts in recent groups could be related to morphological modifications associated with habitat use. © 2015 Sociedade Brasileira de Ictiologia.


da Silva G.L.,Federal University of Alagoas | da Silva G.L.,Instituto Federal Of Alagoas | Canabarro A.A.,Federal University of Alagoas | Canabarro A.A.,Boston University | de Lima Bernardo B.,Harvard University
Annals of Physics | Year: 2015

Motivated by experimental evidences of spectral broadening of partial coherent pulses emitted by a P2O5-doped Raman fiber laser in a silica fiber, we theoretically study the propagation of a partially coherent optical beam through a noninstantaneous media by using extensions of the nonlinear Schrödinger equation (NLSE) including a phase-diffusion model for the partially coherent beam. The finite response time of the medium is incorporated by means of the Debye relaxation model. The dispersion relation is analytically calculated, and the gain spectra together with relevant second-order statistical quantities are numerically computed. Moreover, we provide a complete description of how these statistical properties vary as a function of the delayed nonlinear response of the medium; specifically in the regime of fast nonlinear response in which modulation instability is not expected to occur for genuine incoherent pulses. © 2015 Elsevier Inc..


Paulino A.S.,Instituto Federal Of Alagoas | Albuquerque A.W.,Federal University of Alagoas | Filho G.M.,Federal University of Alagoas | Pereira F.R.S.,Instituto Federal Of Alagoas
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2013

The objective of this study was to evaluate productivity and postharvest quality of helicônia "Golden Torch" under different sources and doses of silicon. The experiment was conducted in randomized blocks in 3 x 3 factorial design with four replications, using the sources ash from sugarcane bagasse, MB-4 and Rocksil® in doses of 0, 400 and 800 kg ha-1 from each source. The results showed that the number of inflorescences increased with the source Rocksil®, the length of bracts was higher with interaction between ash and dose of 400 kg ha-1, the mass loss on the 8th day postharvest was lower with the interaction between Rocksil® and dose of 400 kg ha-1, the burning of bracts on the 8th day post-harvest was lowest with source Rocksil® under the dose of 800 kg ha-1 and Si content in the soil in the depth of 0-0.20 m increased with increasing dose of silicon. As for the variables length of flower stalks and mass of flower stalks on the day of harvest and on the 8th day after harvest, content of silicon in leaf and in soil in the depth of 0.20-0.40 m there was no significant difference between treatments by grouping test of Scott-Knott. The silicon fertilization increased production and post-harvest quality, especially the source Rocksil® in the dose of 800 kg ha-1.


Filho C.A.S.,Federal University of Campina Grande | Lima A.M.N.,Federal University of Campina Grande | Moreira C.S.,Federal University of Campina Grande | Moreira C.S.,Instituto Federal Of Alagoas | And 2 more authors.
Plasmonics | Year: 2010

Line shape effects of the surface plasmon resonance (SPR) at the gold-water interface have been exploited, towards extending instrumental performance in the angular interrogation mode. Comprising a micro-fluidic set-up both, SPR-line broadening and associated signal symmetry/asymmetry features have been monitored in real time for selected adsorption systems and are compared with the simultaneously taken resonance angle that represents the commonly recorded SPR feature. Four angular broadening contributions have been identified: an intrinsic, temperature independent fraction, a temperature dependent part that dominates at ambient temperature, a surface morphology/roughness contribution and an adsorption related fraction. The latter, and substantially smaller contribution, is crucially affected by surface conditions, as the transition from hydrophobic to a hydrophilic surface state. Anionic sub-monolayer adsorption has been clearly resolved, along with detection of a pronounced calorimetric effect that originates from an exothermic surface reaction upon exposure of the protein covered gold surface to a strong chemical oxidant. © 2010 Springer Science+Business Media, LLC.


Costa A.E.B.,Instituto Federal Of Alagoas | Costa A.E.B.,Federal University of Alagoas | Mejia-Salazar J.R.,Federal University of Alagoas | Cavalcanti S.B.,Federal University of Alagoas
Journal of the Optical Society of America B: Optical Physics | Year: 2016

Within an effective medium theory, the transmission spectra of metamaterial defective photonic superlattices composed of subwavelength slab widths are shown, with very good accuracy, to be equivalent to those found in trilayer systems with a metamaterial inclusion. Furthermore, we have derived a general condition which should be satisfied to observe resonance tunneling in these systems. Our analytical results may be useful from the applied point of view as they yield the ability to tailor and tune suitable resonance frequencies in the design and the development of photonic-based filtering and light-Trapping compact devices. © 2016 Optical Society of America.


de Farias A.P.,Instituto Federal Of Alagoas | de Albuquerque A.W.,CECA | Filho G.M.,CECA | Reis L.S.,CECA
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2013

The present study was aimed to evaluate the productivity of Heliconia psittacorum x Heliconia pathocircinada, cv. Golden Torch, when submitted to different sources of organic manure. The experiment was conducted at Escola Agrotécnica Federal, in Satuba, Alagoas State (Brazil). The experimental design was randomized blocks with 5 replications and 10 treatments: T1(control, without fertilization; T2) mineral fertilizer; T3) farm yard manure; T4) chicken bedding; T5) filter cake; T6) urban garbage compound; T7) farm yard manure + mineral fertilizer; T8) chicken bedding + mineral fertilizer; T9) filter cake + mineral fertilizer; T10) urban garbage compound + mineral fertilizer. The following variables were evaluated: number of the tillers per clump, the beginning of the flowering, number of the flower stem per clump, length of flower stem, diameter of flower stem, length of bract, interval of the flowering, number of leaves per flower stem and leaf area of flower stem. The fertilization organomineral provided a significant increase in the variables: number of tillers per clump, length of flower stem, number of flower stem per clump, length of bract, floral stem, diameter of flower stem and leaf area, contributing also to the precocity harvest and smaller flowering interval, when compared with organic fertilizers and control.


Araujo D.D.M.,Instituto Federal Of Alagoas | Pezzato A.C.,São Paulo State University | Barros M.M.,São Paulo State University | Pezzato L.E.,São Paulo State University | Nakagome F.K.,São Paulo State University
Pesquisa Agropecuaria Brasileira | Year: 2011

The objective of this work was to evaluate the effect of diets with different omega-6 and omega-3 polyunsaturated fatty acid ratios on the hematological parameters and plasma lipids of Nile tilapia before and after cold stress. A total of 320 tilapia juveniles sex-inverted males (±7.50 g) were randomly distributed into 40 tanks (250 L) and feed with eight diets: basal (without oil supplementation), 6% sunflower oil (SO), 5% SO + 1% linseed oil (LO), 4% SO + 2% LO, 3% SO + 3% LO, 2% SO + 4% LO, 1% SO + 5% LO, and 6% LO. Hematological parameters and plasma lipids were evaluated 85 days after cultivation and three days after cold stress. Diets had no effect on any of the analyzed variables before cold stress. The number of leukocytes decreased in fish fed the 6% LO diet, after cold stress. Cold stress worsened fish health, causing leukopoenia. Nile tilapia fed 6% LO diet presented less resistance to cold.


da Costa Andrade B.,Federal University of Sergipe | Macedo M.A.,Instituto Federal Of Alagoas
Advanced Materials Research | Year: 2014

A new W-type hexaferrite (Sr0.85Ce0.15Co2Fe16O27-Δ) was synthesized through proteic solgel using coconut water as a solvent for the precursor salts. Structural analysis was carried out using an X-ray diffractometer (XRD). The XRD results showed that the resulting ceramic exhibited preferential orientations along the crystal planes in addition to lattice displacements. The magnetic properties evaluated using a vibrating sample magnetometer indicated a high saturation magnetization value and low coercive field and remnant magnetization values. The Curie temperature determined through differential scanning calorimetry was 473 °C. The electric resistivity value determined through complex impedance was similar to those already reported in the literature, thus promising the use of this hexaferrite in electronic and microwave device applications. © (2014) Trans Tech Publications, Switzerland.

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