Consulta: creatorFacets:"Ventura,Maurício Ursi"
Registros recuperados: 20
Data/hora: 10/06/2024 18:53:03

Feeding and arrestment responses of Diabrotica speciosa to cucurbitacin-content formulations
Provedor de dados: 86
Autores: Arruda,Iara Cintra; Ventura,Maurício Ursi; Scarminio,Ieda Spacino.
The objective of this work was to evaluate arrestant and stimulant feeding effects on Diabrotica speciosa (Ger.), using cucurbitacin-content starch-based formulations prepared with varying starch sources, and adding potassium lignate. In a glass slide assay, the wash off resistance of formulations was compared. Potassium lignate did not improve wash off resistance. Lagenaria vulgaris L. powder, in which cucurbitacin B concentration was determined as 0.28%, was added to the most adhesive formulation. The resultant material was used in a two-choice assay in which leaves of common bean, Phaseolus vulgaris L., treated with concentrations of 2.5%, 5%, 10%, 15% and 20% were offered to insects together with untreated control leaves. Greater number of insects and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Insecta; Coleoptera; Bait; Semiochemical; Rootworm.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2005000700003

Viabilidade da cultura do morangueiro no Paraná - BR
Provedor de dados: 94
Autores: Ronque,Edson Roberto Vaz; Ventura,Maurício Ursi; Soares Júnior,Dimas; Macedo,Rogério Barbosa; Campos,Bruce Roberto Scheidl.
Avaliou-se a viabilidade da exploração do morangueiro, no Paraná, em duas áreas, 0,3 ha (área média cultivada pela agricultura familiar) e 1 ha, por um ano. Elaborou-se uma planilha de fluxo de caixa a partir da qual se calcularam: Período de Recuperação do Capital (PRC), Retorno sobre Investimento (RI), Valor Presente Líquido (VPL) e Taxa Interna de Retorno (TIR). Todos para Custo Operacional Efetivo (COE), Custo Operacional Total (COT) e Custo Total de Produção (CTP). Para uma situação considerada normal, os indicadores de rentabilidade calculados foram (Tipo de custo: VPL área-padrão (TIR área- padrão) / VPL área efetiva (TIR área efetiva)) COE: US$ 17.856,55 (42%) / US$ 4.795,85 (39%); COT: US$ 5.182,40 (11%) / - US$ 1.691,97 (-13%); CPT: US$ 4.846,26...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Análise econômica da cultura de morango; Análise de sensibilidade; Produção de morango.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452013000400014

Trap attributes influencing capture of Diabrotica speciosa (Coleoptera: Chrysomelidae) on common bean fields
Provedor de dados: 63
Autores: Ventura,Maurício Ursi; Resta,Claudio Cezar Mariano; Nunes,Daiane Heloísa; Fujimoto,Fabio.
Refinements in trap characteristics may improve ability to monitor and mass-trap beetles. Field assays were conducted in common bean fields to assess responses of Diabrotica speciosa (Germar) to some trap characteristics. Golden yellow plastic cups (750 mL) traps caught more D. speciosa females and males than did clear traps. Carrot slices in Petri dishes baited with Lagenaria vulagaris L. powder (cucurbitacin source - 0.28%) caught more beetles than did dishes with carrot alone. Dispensers for the floral volatile attractant 1,4-dimethoxybenze were also compared. Rubber septa dispenser attracted more beetles than did control (dental wicks saturated with acetone). Captures on dental wick, starch matrix and feminine pad dispensers were intermediate and did...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Attractant; Feeding stimulant; Semiochemical; Integrated pest management.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162005000400008

Feeding preferences of Microtheca punctigera (Achard) (Coleoptera: Chrysomelidae) for some Brassicaceae plants in multiple-choice assays
Provedor de dados: 63
Autores: Menezes Jr.,Ayres Oliveira; Mikami,Adriana Yatie; Ide,André Keiiti; Ventura,Maurício Ursi.
Host plant feeding preference is important basic information for the development of insect management strategies. Multiple-choice feeding preference assays were conducted in the laboratory for the chrysomelid beetle, Microtheca punctigera (Achard). Feeding was assessed 72 h after onset of experiments. With one larva per Petri dish, food items comprised watercress, Nasturtium officinale L., arugula, Eruca sativa L., mustard, Brassica juncea Cosson, Chinese cabbage, B. pekinensis (Lour.) Rupr. and wild radish (Raphanus raphanistrum L.). Feeding ranking preferences were Chinese cabbage, mustard, wild radish, arugula and watercress (7.97, 1.85, 0.98, 0.36 and 0.11 mm², respectively). Feeding on Chinese cabbage was 4.31 times more intense than on mustard. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brassicaceae; Insecta; Host plants; Consumption.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162005000100014

Attraction of Astylus variegatus (Germ.) (Coleoptera: Melyridae) by volatile floral attractants
Provedor de dados: 63
Autores: Ventura,Maurício Ursi; Pereira,Tania; Nunes,Daiane Heloisa; Arruda,Iara Cintra de.
The beetle Astylus variegatus (Germ.) (Coleoptera: Melyridae) is frequently found in flowers feeding on pollen. Responses of A. variegatus to volatile floral attractants were studied in common beans (Phaseolus vulgaris L.) fields. Traps originally designed to capture Diabrotica speciosa (Germ.) (Coleoptera: Chrysomelidae), consisted of plastic bottles (2 L) with 150 holes (5-mm diameter) yellow gold painted and containing inside a plastic strip (3.5 &lt;FONT FACE=Symbol&gt;´&lt;/FONT&gt; 25 cm) with Lagenaria vulgaris (L.) powder (0.28% B cucurbitacin - feeding stimulant and arrestant for diabroticites) sprayed with carbaril insecticide. Treatments consisted of 1,4-dimethoxybenzene (one or two dispensers per trap), 1,4-dimethoxybenze + indole,...
Tipo: Info:eu-repo/semantics/report
Palavras-chave: Diabrotica speciosa; Semiochemical; Trap.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162007000300016

Capture of hypothenemus hampei ferrari (coleoptera, scolytidae) in response to trap characteristics
Provedor de dados: 63
Autores: Silva,Flávia Cloclet da; Ventura,Maurício Ursi; Morales,Lauro.
Traps lured with semiochemical have been proposed to manage the coffee berry borer, coffee planting is however made under several environmental conditions that may affect the efficacy of traps. Several trap designs and variations were proposed and, therefore, a series of field experiments was carried out to capture coffee berry bores in traps disposed in a low density coffee plantations in the Northern part of the State of Paraná, Brazil. Traps were composed of plastic bottles (2 L) with a window (13 × 18 cm). Ethanol (E), Methanol (M) and coffee oil alone did not improve the capture when transparent traps with a 2 mm hole in the vial dispenser were used; traps lured with E : M mixtures (1:1, 1:2, 1:3) caught similar and higher number of insects than the...
Tipo: Info:eu-repo/semantics/report
Palavras-chave: Semiochemical; Attractant; Volatile; Trap color.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162006000600010

Morphology of olfactory sensilla and its role in host plant recognition by Neomegalotomus parvus (Westwood) (Heteroptera: Alydidae)
Provedor de dados: 52
Autores: Ventura,Maurício Ursi; Panizzi,Antônio Ricardo.
The external morphology of the sensilla, including pores and permeable points on the cuticle of the antennae of adults of Neomegalotomus parvus (West.) (Heteroptera: Alydidae) was investigated with regard to their olfactory function. Behavioural evidence of olfaction, the importance of the different antennal segments in locating the host under still-air, and the responses of the insects to plants' scents and to pheromones in wind assays were also studied. With the scanning electronic microscope mechanoreceptor sensilla were found on the four segments of the antennae of N. parvus. The density of the sensilla was greater on the 4th segment. On the apical segment, sensilla with olfactory morphological traits were observed. Bugs with intact antennae located...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sensilla; Host plant; Behaviour; Antenna.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000500012

Antifeedant activity of Melia azedarach (L.) extracts to Diabrotica speciosa (Genn.)(Coleoptera: Chrysomelidae) beetles
Provedor de dados: 52
Autores: Ventura,Maurício Ursi; Ito,Márcio.
Studies were carried out to determine the antifeedant activity of extracts of leaves, stems, flowers and fruits of Melia azedarach (L.), the dosage activity responses to the most active extract and the effects of sunlight in the activity persistence to Diabrotica speciosa (Genn.) beetles. Extracts efficiency was determined by evaluating leaf consumption. Insect feeding was deterred by stems, fruits and flowers extracts. Flowers and fruits extracts were the most efficient. Stems extract was in an intermediate position between the two most efficient and the least one (leaf extracts). The most active extract (flowers) was sprayed at concentrations of 0, 1, 2, 3, 4, 5, 6 and 7 g/100 ml. Feeding of D. speciosa on common bean leaves extracts decreased...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Insecta; Leaf beetle; Phaeolus vulgaris (L.); Deterrence; Botanical insecticide.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132000000200011

Repellent, antifeedant and insecticidal effects of neem oil on Microtheca punctigera
Provedor de dados: 52
Autores: Mikami,Adriana Yatie; Ventura,Maurício Ursi.
The effects of concentrations (0.00, 0.25, 0.50 and 1.00%) of the neem tree (Azadirachta indica - Meliaceae) oil emulsion on the behavioral and biological parameters of M. punctigera were investigated in the laboratory. Wild radish (Raphanus raphanistrum L.) host plant was used. Multiple and no-choice feeding preference assays were conducted which shown multiple effects. The males were repelled by the neem oil in multiple-choice assay. The adult (multiple-choice) and larvae (multiple and no-choice) feeding were deterred. The larvae mortality was higher in the neem oil treated than the control leaves. Further investigations are suggested to test neem oil in the management of the pest in the field.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Insecta; Yellowmargined leaf beetles; Botanical insecticide.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000600006

Population dynamics, gregarious behavior and oviposition preference of Neomegalotomus parvus (Westwood) (Hemiptera: Heteroptera: Alydidae)
Provedor de dados: 52
Autores: Ventura,Maurício Ursi; Panizzi,Antônio Ricardo.
Interactions between Neomegalotomus parvus (Westwood) (Coreoidea: Heteroptera: Alydidae) and host plants were investigated including population monitoring throughout the year, gregarious behavior in the field, and oviposition preference among host plants and one non-host plant in field cages. Cowpea, Vigna unguiculata (L.) Walp., soybean, Glycine max (L.) Mill. cv. BR 37, pigeon pea, Cajanus cajan (L.) Mill., pigeon pea cv. Anão, and lablab, Dolichos lablab L. were monitored in the field. N. parvus was found on host plants during 11 months. The shortest period of occurrence was observed on soybean and the longest on lablab. Insects were found mostly on mature pods. Contagious distribution (negative bionomial) was detected, characterizing the aggregation....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hemiptera; Alydidae; Host plants; Phenology; Oviposition.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132003000100006

Responses of Diabrotica speciosa to a semiochemical trap characteristics
Provedor de dados: 52
Autores: Arruda-Gatti,Iara Cintra de; Silva,Flávia Augusta Cloclet da; Ventura,Maurício Ursi.
Responses of Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae) to a semiochemical trap characteristics were investigated in the field. The trap consisted of plastic bottles with several perforations (0.5 cm diameter and 2.0 cm distance each other) and containing Lagenaria vulgaris L. (Cucurbitaceae) powder as cucurbitacin (arrestant and phagostimulant) source (0.28%). In common bean fields, transparent green traps caught significantly more males and females beetles than yellow, transparent and white traps. Yellow traps caught significantly more females than white traps. Transparent green and yellow traps baited with the volatile attractant 1,4-dimethoxybenzene caught 4.08 and 2.72 times more beetles than unbaited, respectively. Higher number of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Insecta; Kairomones; Diabroticite; Cucurbitacin; Volatile attractant.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000700015

Brown Stink Bug Mortality by Seed Extracts of Tephrosia Vogelii Containing Deguelin and Tephrosin
Provedor de dados: 52
Autores: Mikami,Adriana Yatie; Ventura,Maurício Ursi; Andrei,Cesar Cornelio.
ABSTRACT Extracts of the seeds of Tephrosia vogelii Hook. f. were studied in relation to its chemical composition and toxicity to the brown stink bug Euschistus heros (F.). The extracts were obtained in ethyl acetate and ethanol in the sequence according to the polar nature of the solvents. Extracts were sprayed in concentration of 1.0, 2.5, 5.0, 7.5 and 10% on third-instars nymphs and adults, and mortality was recorded. Presence two rotenoids in ethyl acetate was detected, with analyzed with gas chromatography-mass spectrometry (GC-MS). Crude fraction analyses confirmed the presence of these rotenoids (tephrosin - 2.71% in ethyl acetate and 3.66% in methanol; and deguelin - 10.46% in ethyl acetate and 1.22% in methanol) and three other rotenoids in small...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Euschistus heros; Rotenoid; Botanical insecticide; Glycine max; Soybeans.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132018000100325

Responses of Neomegalotomus parvus (Hemiptera: Alydidae) to color and male-lured traps
Provedor de dados: 52
Autores: Ventura,Maurício Ursi; Panizzi,Antônio Ricardo.
In 1998, the relative responses of Neomegalotomus parvus (Westwood) (Hemiptera: Alydidae) to colors in traps were assessed in the field. Colors were printed in white alkaline paper and covered with transparent plastic. Printed colors were black, green, yellow, red and blue. Treatments also included white paper and aluminum foil. Green traps captured more bugs than the other traps (except yellow). Yellow traps caught significantly more N. parvus males than blue, black and aluminum traps. White, red and blue traps captured significantly more N. parvus males than black traps. In 1999, the same treatments were used and additionally included the factor presence (X absence) of males in cages in the traps. Four males were confined in the cages together with...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Insecta; Semiochemical; Color responses; Aggregation pheromone.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000400005

Response of Diabrotica speciosa (Coleoptera: Chrysomelidae) to 1,4-dimethoxybenzene and analogs in common bean crop
Provedor de dados: 52
Autores: Marques,Francisco de Assis; Wendler,Edison Perevalo; Macedo,Alexandra; Wosch,Celso Luiz; Maia,Beatriz Helena Sales; Mikami,Adriana Yatie; Arruda-Gatti,Iara Cintra; Pissinati,Aline; Mingotte,Fábio Luiz Checchio; Alves,Amilton; Ventura,Maurício Ursi.
Several synthetic and commercial analogs of 1,4-dimethoxybenzene, a kairomone of Diabrotica speciosa, along with other compounds already shown to be attractive to other species of Diabrotica, were tested as attractant to D. speciosa. Yellow cup traps were lured with the compounds and installed in a common bean field. Assessments were conducted 24 h later. 1,4-dimethoxybenzene lured traps caught significantly more beetles than the control traps. Captures of traps lured with 1,4-dimethoxybenzene analogs did not differ from the control traps. Results showed that position and nature of the substituents on the aromatic ring played a crucial role in the activity of the natural compound. The aromatic ring was also very important to the activity of the kairomone.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diabrotica speciosa 1; 4-dimethoxybenzene analogs kairomone parakairomone field test.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000600003

Population Study of Diabrotica speciosa (Ger.) (Coleoptera: Chrysomelidae) in Fall / Winter Season
Provedor de dados: 65
Autores: Ventura,Maurício Ursi; Gomes,Marcos Roberto.
Population studies of D. speciosa on fall / winter crops were conducted. Larvae were monitored on maize (Zea mays L.), wheat (Triticum aestivum L.) and black oats (Avena strigosa Schreb.) and beetles on soybeans (Glycine max (L.) Mill., maize, common beans (Phaseolus vulgaris L.), wheat and black oats from March 23, 2001 to August 24, 2001. Soybean, maize, common beans, wheat and oats were sown on December 28, 2000; February 9, 2001; March 2, 2001; April 26, 2001 and May 11, 2001, respectively. Maize and common beans were grown on latter growing season. Adult beetles of D. speciosa were collected throughout the sampling period. Greatest beetles population peak occurred on wheat in August 3, 2001 which coincided with flowering period. Population dynamics of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Insecta; Host plants; Phenology; Latter growing season; Samples.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782004000600042

Control of the Mexican bean weevil Zabrotes subfasciatus with kaolin
Provedor de dados: 65
Autores: Mikami,Adriana Yatie; Pissinati,Aline; Fagotti,Dáfila; Menezes Júnior,Ayres de Oliveira; Ventura,Maurício Ursi.
The Mexican bean weevil Zabrotes subfasciatus (Coleoptera: Chrysomelidae: Bruchinae) is an important pest of stored beans in tropical regions. The efficiency of kaolin [with or without neem (Azadirachta indica) oil] and diatomaceous earth (DE) (standard treatment) was studied in laboratory aiming to obtain alternatives for chemical control of this insect. Insects were confined in plastic vials containing beans treated with kaolin (2, 4 and 8g kg-1), kaolin + neem [2g kg-1(5% neem oil)], diatomaceous earth (1g kg-1) and control. Mortality of adult insects, number of eggs and F1generation beetles emergency were assessed. Kaolin caused mortality of Z. subfasciatus, however higher periods and doses than DE were necessary to promote high mortality (100% or...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bruchids; Inert dusts; Phaseolus vulgaris.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782010000700003

Isca amilácea de cucurbitacina (Lagenaria vulgaris L.) promove maior eficiência do inseticida carbaril no controle de Diabrotica speciosa, em laboratório
Provedor de dados: 65
Autores: Mikami,Adriana Yatie; Ventura,Maurício Ursi.
Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae: Galerucinae) é uma importante praga polífaga na América Latina. Seu controle é realizado com inseticidas sintéticos, o que causa problemas ambientais. Desse modo, o objetivo do trabalho foi avaliar a isca amilácea de cucurbitacina (Lagenaria vulgaris L.) associada ao inseticida carbaril no controle de D. speciosa em laboratório. Foram realizados testes de múltipla escolha pareados e confinamento com insetos adultos. Os tratamentos foram: isca amilácea de cucurbitacina, isca + carbaril, apenas carbaril e a testemunha (água destilada). As soluções foram pulverizadas em plantas de milho mantidas em casa-de-vegetação. Folhas foram retiradas para realização dos ensaios em laboratório e sete...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tribo Luperini; Larva-alfinete; Zea mays; Semioquímico; Controle alternativo.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782008000800005

Organic fertilization and botanical insecticides to control two-spotted spider mite in strawberry
Provedor de dados: 65
Autores: Marques-Francovig,Camila Regina; Mikami,Adriana Yatie; Dutra,Viviane; Carvalho,Mateus Gimenez; Picareli,Bruno; Ventura,Maurício Ursi.
Strawberry fields receive several pesticides spraying and residues in fruits are recurrent. Development and application of methods that avoid applying pesticides mostly during fructification period are imminent needs. Comparison of population of two-sppoted spider mite (TSSM) Tetranychus urticae Koch. in organic and mineral fertilized plants (as used by growers) and treated with alternative products were done. Plants were grown in vessels in a greenhouse infested with local population of TSSM. Extracts of Tephrosia voggeli (Hook), neem oil (Azadirachta indica A. Juss.), and lime sulfur were applied three times against TSSM in ten days intervals. Assessments were done three times after each spraying. Interaction between fertilization and spraying...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Integrated pest management; Botanical insecticide; Organic agriculture.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782014001101908

Comportamento de larvas de Diabrotica speciosa (Coleoptera: Chrysomelidae) em resposta ao CO2 e a plântulas de espécies cultivadas
Provedor de dados: 65
Autores: Pereira,Tânia; Ventura,Maurício Ursi; Marques,Francisco Assis.
As respostas de larvas de Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae) ao CO2 e o comportamento destas larvas quando expostas a plantas hospedeiras e não hospedeiras foram estudadas em laboratório. Larvas de primeiro ínstar de D. speciosa foram utilizadas. Num primeiro bioensaio, as larvas preferiram o tratamento com CO2, que foi gerado a partir da reação de bicarbonato de potássio com ácido acético em oposição a água destilada. Quando se observou o comportamento das larvas em relação a plantas hospedeiras, verificou-se que ocorreu um número significativamente maior de "mudanças de direção" em milho e milho pipoca do que em feijão, soja, trigo e sorgo. Este parâmetro foi inferior no sorgo em relação a todos os outros tratamentos. Valores...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Plantas hospedeiras; Semioquímicos; Atraentes; Cairomônios.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782005000500001

Atração do predador Doru luteipes (Scudder) (Dermaptera: Forficulidae) por estímulos olfativos de dietas alternativas em laboratório
Provedor de dados: 65
Autores: Nonino,Mariana Campana; Pasini,Amarildo; Ventura,Maurício Ursi.
Doru luteipes consome lagartas de Spodoptera frugiperda, que é atualmente a principal praga da cultura do milho no Brasil. Normalmente, se 70% das plantas tivessem o predador, a praga seria mantida abaixo do nível de dano econômico. Entretanto, o predador ocorre após a praga danificar as plantas. Assim, a disponibilidade de materiais que atraíssem e antecipassem a presença do predador na lavoura poderia reduzir populações da praga. Desta forma, estudou-se em laboratório a atratividade de dietas artificiais para machos e fêmeas do predador D. luteipes. Os tratamentos foram: pupa desidratada e moída do bicho-da-seda; pólen misto, nas quantidades de 0,05; 0,1; 0,2; 0,5 e 1,0g para ambas as dietas. Em olfatômetro, os estímulos da dieta foram comparados à...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Spodoptera frugiperda; Zea Mays; Controle biológico e dermaptera.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782007000300004