Consulta: subjectFacets:"Genetic modification"
Registros recuperados: 23
Data/hora: 18/06/2024 17:31:38

Safe use of genetically modified lactic acid bacteria in food: Bridging the gap between consumers, green groups, and industry
Provedor de dados: 69
Autores: Sybesma,Wilbert; Hugenholtz,Jeroen; de Vos,Willem M.; Smid,Eddy J.
Within the European Union (EU), the use of genetically modified organisms (GMOs) in food production is not widely applied and accepted. In contrast to the United States of America, the current EU legislation limits the introduction of functional foods derived from GMOs that may bring a clear benefit to the consumer. Genetically modified lactic acid bacteria (GM-LAB) can be considered as a different class of GMOs, and the European Union is preparing regulations for the risk assessment of genetically modified microorganisms. Since these procedures are not yet implemented, the current risk assessment procedure is shared for GMOs derived from micro organisms, plants, or animals. At present, the use of organisms in food production that have uncontrolled genetic...
Tipo: Journal article
Palavras-chave: Lactic acid bacteria; Genetic modification; Legislation; Novel foods; Safety assessment.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000400011

Sugarcane: Sugarcane variety resistant to insect pests and herbicides.
Provedor de dados: 14
Autores: MOLINARI, H. B. C.
Genetically modified sugarcane with resistance to sugarcane borer (Diatraea saccharalis) and glyphosate. A technology of great economic importance for the sugar-energy sector, the result of a partnership between startup PangeiaBiotech and Embrapa Agroenergia.
Tipo: Folders
Palavras-chave: Genetic modification; Sugarcane; Herbicides; Pests; Genetic improvement.
Ano: 2021
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1133110

Sugarcane: Sugarcane variety with higher cell wall digestibility.
Provedor de dados: 14
Autores: MOLINARI, H. B. C.
Genetically modified sugarcane with increased cell wall digestibility. The technology aims to improve plant biomass for production of cellulosic ethanol (2G), animal feed, and high value-added chemical compounds.
Tipo: Folders
Palavras-chave: Genetic modification; Sugarcane; Digestibility.
Ano: 2021
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1133111

Watermelon transformation with Zucchini yellow mosaic virus coat protein gene and comparison with parental cultivar
Provedor de dados: 86
Autores: Çürük,Sebahattin; Meşe,Ebru.
The objective of this work was to transfer Zucchini yellow mosaic virus coat protein (ZYMV-CP) and neomycin phosphotransferase II (NPT II) genes to the watermelon 'Crimson Sweet'(CS) genome, and to compare the transgenic progenies T1 and T2 with the nontransformed parental cultivar for morphological, pomological, growth and yield characteristics. The ZYMV-CP gene was transferred by Agrobacterium tumefaciens. The presence of the gene in transgenic T0, T1 and T2 plants was determined by polymerase chain reaction, and the results were confirmed by Southern blot. Two experiments were performed, one in the winter-spring and the other in the summer-autumn. In both experiments, the hypocotyl length of transgenic seedlings was significantly higher than that of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrullus lanatus; Comparative safety analysis; Genetic modification; Neomycin phosphotrans-ferase II; Nontransgenic watermelon; Transgenic watermelon.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000100010

The Relative Importance of Preferences for Country-of-Origin in China, France, Niger and the United States
Provedor de dados: 31
Autores: Ehmke,   Mariah D.; Lusk,   Jayson L.; Tyner,   Wallace E.
Country-of-origin (COO) is an increasingly politicized credence attribute in the globalizing food system. While international policy development in this area is geographically far-reaching, the benefits of country-of-origin labels (COOL) to producers and consumers from countries in different locations and levels of economic development are not clear. Previous work investigates the importance of COO to consumers, but is typically limited in scope to consumers in one nation. In addition, little is known about the importance of COO information relative to other credence attributes, especially in non-meat food products. This study measures the benefits of COOL to an internationally diverse set of consumers (in developed and developing countries) and estimates...
Tipo: Conference Paper or Presentation
Palavras-chave: Country-of-origin; Genetic modification; Organic; Conjoint; Onion; Information; Food policy; International Relations/Trade; Q13; Q18; Q17.
Ano: 2006
URL: http://purl.umn.edu/25408

Improving the Nutrient Content of Food through Genetic Modification: Evidence from Experimental Auctions on Consumer Acceptance
Provedor de dados: 31
Autores: Colson,   Gregory; Huffman,   Wallace E.; Rousu,   Matthew C.
This paper assesses consumers’ acceptance of nutritionally enhanced vegetables using a series of auction experiments administered to a random sample of adult consumers. Evidence suggests that consumers are willing to pay significantly more for fresh produce with labels signaling enhanced levels of antioxidants and vitamin C achieved by moving genes from within the species, as opposed to across species. However, this premium is significantly affected by diverse information treatments injected into the experiments.
Tipo: Journal Article
Palavras-chave: Bayesian analysis; Experimental auction; Food products; Genetic modification; Consumer/Household Economics; Food Consumption/Nutrition/Food Safety.
Ano: 2011
URL: http://purl.umn.edu/117201

Consumer Acceptance of GM Applications in the Pork Production Chain: A Choice Modelling Approach
Provedor de dados: 31
Autores: Novoselova,   Tatiana A.; van der Lans,   Ivo A.C.M.; Meuwissen,   Miranda P.M.; Huirne,   Ruud B.M.
This study evaluates consumer acceptance of different GM applications in the pork production chain. In general, results indicate that consumers prefer conventional pork over pork for which genetic modification was applied. However, the negative impact of the GM applications is compensated by improvements in quality, increased animal welfare, a lower impact on the environment, less residues and a price discount. Of these benefits, increased animal welfare has the most positive effect on consumer choices. With substantial monetary compensation and presence of various benefits the consumers will attach higher utility to the GM pork than to the conventional pork. The amount of monetary compensation is dependent on the type of GM application.
Tipo: Conference Paper or Presentation
Palavras-chave: Consumer acceptance; Genetic modification; Choice modelling; Consumer/Household Economics; C25; D12; Q13.
Ano: 2005
URL: http://purl.umn.edu/24527

The market acceptance and welfare impacts of genetic use restriction technologies (GURTS)
Provedor de dados: 31
Autores: Khachaturyan,   Marianna; Yiannaka,   Amalia.
The paper develops a theoretical framework of heterogeneous consumers and producers to examine the market and welfare effects of the introduction of variety-level genetic use restriction technologies (V-GURTs) under the current No-Labeling regime of GMPs in the US market. Specifically, the study examines how the agronomic characteristics of GURTs, consumer perceptions and preferences regarding interventions in the production process (i.e., genetic modification) and producer cost structures (e.g., dependency on saving seed) affect the adoption of the technology by producers, the market acceptance of GURTs by consumers and consequently the innovator's incentive to introduce the new technology. Analytical results show that the introduction of GURTs may be...
Tipo: Conference Paper or Presentation
Palavras-chave: Genetic use restriction technologies; Genetic modification; Producer and consumer welfare; Research and Development/Tech Change/Emerging Technologies.
Ano: 2006
URL: http://purl.umn.edu/10097

A Critical Account of the Relationship between Institutional Trust, Risk Perception, and Technology Acceptance with an Application to Genetically  Modified Foods
Provedor de dados: 31
Autores: Boecker,   Andreas; Nocella,   Giuseppe.
This article critically reflects on the widely held view of a causal chain with trust in public authorities impacting technology acceptance via perceived risk. It first puts forward conceptual reason against this view, as the presence of risk is a precondition for trust playing a role in decision making. Second, results from consumer surveys in Italy and Germany are presented that support the associationist model as counter hypothesis. In that view, trust and risk judgments are driven by and thus simply indicators of higher order attitudes toward a certain technology which determine acceptance instead. The implications of these findings are discussed.
Tipo: Conference Paper or Presentation
Palavras-chave: Consumer trust; Risk perception; Technology acceptance; Genetic modification; Food Consumption/Nutrition/Food Safety; Institutional and Behavioral Economics.
Ano: 2006
URL: http://purl.umn.edu/7749

ISSUES IN DEVELOPMENT AND ADOPTION OF GENETICALLY MODIFIED (GM) WHEATS
Provedor de dados: 31
Autores: Wilson,   William W.; Janzen,   Edward L.; Dahl,   Bruce L.; Wachenheim,   Cheryl J.
Development of genetically modified (GM) wheat varieties is proceeding; however, several critical issues remain the focus of contention.  This project summarizes the current state of knowledge on some of these critical issues for commercialization of GM wheats.  Background on the evolution of GM Wheats is presented.  Then, agronomic adoption and competitiveness of GM crops; research on GM traits in wheat; consumer acceptance of GM crops (a separate section is included on issues related to consumer acceptance of GM crops); regulatory issues and status; international trade; testing, segregation, and identity preservation; and production and marketing risks are examined.  Finally, there is a description of the likely marketing system to evolve and a...
Tipo: Working or Discussion Paper
Palavras-chave: Wheat; Genetic modification; Transgenic; Marketing; Crop Production/Industries; Research and Development/Tech Change/Emerging Technologies.
Ano: 2003
URL: http://purl.umn.edu/23497

Biotechnology and Planted Forests: Assessment of Potential and Possibilities
Provedor de dados: 31
Autores: Sedjo,   Roger A.
This paper addresses the potential impact of the introduction and development of biotechnology on planted forests. It includes a description of some recent innovations in forestry including the use of traditional breeding, and also more recent innovations involving biotechnology, including the development of clonal propagation and the use of modern molecular biology techniques. In addition to describing these innovations, the paper undertakes an assessment of their probable impact on future production of the forest industry, on the global timber supply, and on future markets for timber and wood products. The paper offers a description of recent innovations in tree breeding and biotechnology, including a discussion of innovations in agriculture that have...
Tipo: Working or Discussion Paper
Palavras-chave: Biotechnology; Plantation forests; Genetic modification; Genetic research; Economic benefits; Transgenic; GMO; Resource /Energy Economics and Policy; Q21; Q23; Q16; O32; L73.
Ano: 1999
URL: http://purl.umn.edu/10862

Consumer Acceptance of Nutritionally Enhanced Genetically Modified Food: Relevance of Gene Transfer Technology
Provedor de dados: 31
Autores: Onyango,   Benjamin M.; Nayga,   Rodolfo M., Jr.
This study examines consumer's willingness to consume different types of a nutritionally enhanced food product (i.e., breakfast cereal with calcium, omega fatty acids, or anti-oxidants) derived from grains genetically modified using two types of technologies: plant-to-plant gene transfer technology and animal-to plant gene transfer technology. Findings indicate a majority of the respondents are willing or somewhat willing to consume the three types of nutritionally enhanced genetically modified breakfast cereal, but are less willing if the genetically modified product is derived from animal-to-plant gene transfer technology than from plant-to-plant gene transfer technology. However, the results of the ordered probit models suggest there are groups of...
Tipo: Journal Article
Palavras-chave: Consumer acceptance; Gene transfer technology; Genetic modification; Nutritionally enhanced food products; Willingness to consume; Consumer/Household Economics.
Ano: 2004
URL: http://purl.umn.edu/30919

TO REACH THE POOR: RESULTS FROM THE ISNAR-IFPRI NEXT HARVEST STUDY ON GENETICALLY MODIFIED CROPS, PUBLIC RESEARCH, AND POLICY IMPLICATIONS
Provedor de dados: 31
Autores: Atanassov,   Atannas; Bahieldin,   Ahmed; Brink,   Johan; Burachik,   Moises; Cohen,   Joel I.; Dhawan,   Vibha; Ebora,   Reynaldo V.; Falck-Zepeda,   Jose Benjamin; Herrera-Estrella,   Luis; Komen,   John; Low,   Fee Chon; Omaliko,   Emeka; Odhiambo,   Benjamin; Quemada,   Hector; Peng,   Yufa; Sampaio,   Maria Jose; Sithole-Niang,   Idah; Sittenfeld,   Ana; Smale,   Melinda; Sutrisno; Valyasevi,   Ruud; Zafar,   Yusuf; Zambrano,   Patricia.
Local farming communities throughout the world face productivity constraints, environmental concerns, and diverse nutritional needs. Developing countries address these challenges in a number of ways. One way is public research that produces genetically modified (GM) crops and recognize biotechnology as a part of the solution. To reach these communities, GM crops, after receiving biosafety agreement, must be approved for evaluation under local conditions. However, gaps between approvals in the developed and developing world grow larger, as the process of advancing GM crops in developing countries becomes increasingly difficult. In several countries, only insect resistant cotton has successfully moved from small, confined experimental trials to larger, open...
Tipo: Working or Discussion Paper
Palavras-chave: Biosafety; Regulation; Biotechnology; Genetic modification; Public research; Crop Production/Industries; Research and Development/Tech Change/Emerging Technologies.
Ano: 2004
URL: http://purl.umn.edu/16065

Consumer Acceptance of Genetically Modified Foods in South Korea: Factor and Cluster Analysis
Provedor de dados: 31
Autores: Onyango,   Benjamin M.; Govindasamy,   Ramu; Hallman,   William K.; Jang,   Ho-Min; Puduri,   Venkata S.
This study extends biotechnology discourse to cover South Korea in the Asian sub-continent showing a marked difference in perceptions between traditional and GM foods. Factor analysis suggests South Koreans may treat foods that are locally produced and those with no artificial flavors or colorings preferentially to GM foods. Additionally, South Koreans have concerns about perceived risks related to biotechnology, and, given a choice, they may pay more to avoid GM foods. Cluster analysis results yielded four consumer segments: (a) ardent supporters of the attribute of “naturalness” in foods, (b) those apprehensive about biotechnology, (c) the food adventurous, and (d) information seekers about biotechnology.
Tipo: Journal Article
Palavras-chave: Consumer perceptions; Factor and cluster analysis; Food attributes; Genetic modification; Consumer/Household Economics; Food Consumption/Nutrition/Food Safety.
Ano: 2006
URL: http://purl.umn.edu/57700

IMPACTS OF GENETICALLY MODIFIED (GM) TRAITS ON CONVENTIONAL TECHNOLOGIES - SUMMARY
Provedor de dados: 31
Autores: Huso,   Scott R.; Wilson,   William W.
In hard red spring (HRS) wheat, the two GM traits nearest to commercialization are fusarium resistant wheat (FRW) from Syngenta and Roundup Ready® wheat (RRW).  Monsanto announced that it has deferred the commercialization of RRW until issues of market acceptance are alleviated.  Monsanto acknowledged that it might reconsider its position if another agbiotechnology firm enters the GM wheat market.   A Cournot quantity competition model was developed to determine the equilibrium quantities of conventional pesticide and agbiotechnology firms.  The Cournot model was used because firms that must make production decisions ahead of the selling period, and firms with extensive research and development costs are not able to aggressively set prices.  Rather, the...
Tipo: Working or Discussion Paper
Palavras-chave: Genetic modification; Fusarium resistance; Roundup Ready®; Technology; Crop Production/Industries; Research and Development/Tech Change/Emerging Technologies.
Ano: 2005
URL: http://purl.umn.edu/23560

IMPACTS OF GENETICALLY MODIFIED (GM) TRAITS ON CONVENTIONAL TECHNOLOGIES
Provedor de dados: 31
Autores: Huso,   Scott R.; Wilson,   William W.
In hard red spring (HRS) wheat, the two GM traits nearest to commercialization are fusarium resistant wheat (FRW) from Syngenta and Roundup Ready® wheat (RRW).  Monsanto announced that it has deferred the commercialization of RRW until issues of market acceptance are alleviated.  Monsanto acknowledged that it might reconsider its position if another agbiotechnology firm enters the GM wheat market.  A Cournot quantity competition model was developed to determine the equilibrium quantities of conventional pesticide and agbiotechnology firms.  The Cournot model was used because firms that must make production decisions ahead of the selling period, and firms with extensive research and development costs are not able to aggressively set prices.  Rather, the...
Tipo: Working or Discussion Paper
Palavras-chave: Genetic modification; Fusarium resistance; Roundup Ready®; Technology; Crop Production/Industries; Research and Development/Tech Change/Emerging Technologies.
Ano: 2005
URL: http://purl.umn.edu/23491

Consumer Willingness to Pay for Genetically Modified Food Labels in a Market with Diverse Information: Evidence from Experimental Auctions
Provedor de dados: 31
Autores: Huffman,   Wallace E.; Shogren,   Jason F.; Rousu,   Matthew C.; Tegene,   Abebayehu.
With the continuing controversy over genetically modified (GM) foods, some groups advocate mandatory labeling of these products, while other groups oppose labeling. An important issue is how GM labels affect consumers' willingness to pay for these food products in the market. Using a statistically based economics experiment with adult consumers as subjects, we examine how willingness to pay changes for three food products--vegetable oil, tortilla chips, and potatoes--when GM labels are introduced. Participants in the experiments discounted GM-labeled foods by approximately 14% relative to their standard-labeled counterparts. The evidence also showed that sequencing of food labels affects willingness to pay, and that randomizing treatments is an important...
Tipo: Journal Article
Palavras-chave: Consumer demand; Corn chips; Experimental economics; Food labels; Genetic modification; GM foods; Laboratory auctions; Potatoes; Vegetable oil; Willingness to pay; Consumer/Household Economics.
Ano: 2003
URL: http://purl.umn.edu/31071

Trust in Scientists and Food Manufacturers: Implications for the Public Support of Biotechnology
Provedor de dados: 31
Autores: James,   Harvey S., Jr.
An analysis of data from the U.S. Biotechnology Study, 1997S1998 reveals that few variables affect public trust in scientists, while variables representing perceived benefits, risks, trustworthiness, and competence affect trust in food manufacturers on matters of biotechnology. Both trust in scientists and trust in food manufacturers have a large and important effect on public support for biotechnology, although trust in scientists is found to be more important than trust in food manufacturers. Findings of this analysis suggest that trust in scientists is relatively generalized, while trust in food manufacturers is particularized.
Tipo: Journal Article
Palavras-chave: Biotechnology; Genetic modification; Public support of biotechnology; Public trust; Trust; Agribusiness; Food Consumption/Nutrition/Food Safety.
Ano: 2006
URL: http://purl.umn.edu/62273

Process versus product: which determines consumer demand for genetically modified apples?
Provedor de dados: 31
Autores: Kaye-Blake,   William; Bicknell,   Kathryn; Saunders,   Caroline M.
One debate in the literature regarding consumers’ reactions to genetically modified food (GMF) centres on whether consumers react to the process of gene technology or to the specific GMF products. Results from a choice experiment survey in New Zealand indicate that consumers are heterogeneous with regard to GMF and that some modifications are viewed more positively than others. These findings suggest that for some consumers the process of gene technology is the decisive factor in evaluatingGMF, while for others the different potential GMF products are valued according to their enhanced attributes.
Tipo: Article
Palavras-chave: Choice modelling; Consumer surveys; Food; Genetic modification; Preferences; Consumer/Household Economics; Demand and Price Analysis.
Ano: 2005
URL: http://purl.umn.edu/118587

Comparing Consumer Attitudes towards Genetically Modified Food in Europe
Provedor de dados: 31
Autores: Springer,   A.; Mattas,   Konstadinos; Papastefanou,   G.; Tsioumanis,   Asterios.
As biotechnology evolves new methods of genetic engineering are now being applied to the production and processing of foods. This paper is trying to explore the attitudes of the European consumers towards genetic modification of food. Using survey data of the EU member countries the proposed research paper is planned to have a threefold output: 1) providing a comparative ranking of the EU member countries in relation to the prevalence of rejection of genetically modified food, 2) uncovering intra-european differences in genetic food engineering rejection as being based on socio-demographic and informational resp. knowledge based differentials between EU countries and 3) specifying the importance of socio-economic and informational determinants of a...
Tipo: Conference Paper or Presentation
Palavras-chave: Genetic modification; Attitudes towards genetic modification; Biotechnology; Food; Consumer/Household Economics.
Ano: 2002
URL: http://purl.umn.edu/24858

แนวทางการควบคุมโรคใบขาวอ้อยโดยการใช้เชื้อแบคทีเรียร่วมอาศัยในแมลงพาหะ
Provedor de dados: 106
Autores: Jureemart Wangkeeree; Yupa Hanboonsong.
Sugarcane white leaf (SCWL) disease is one of the most destructive sugarcane disease, threatening the sugarcane industry in Thailand. Up to now there are no effective methods to control SCWL disease. The purpose of this study was to identify bacterial symbionts in the leafhopper Matsumuratettix hiroglyphicus (Matsumura) vector sugarcane white leaf disease for possible use in the symbiotic control method. The results from 16S rRNA analysis was found the most dominant bacterial type which belonging to Betaproteobacteria and did not closely match any sequences in the database. It was named “Bacterium Associated with M. hiroglyphicus” (BAMH). Natural population of the leafhopper was found BAMH in 98% of female and 94% of male leafhoppers. BAMH was found in all...
Tipo: PhysicalObject
Palavras-chave: Sugarcane; Sugarcane white leaf disease; SCWL; Leafhopper vector; Matsumuratettix hiroglyphicus; Matsumura; Bacterial symbiont; Betaproteobacteria; BAMH; Symbiotic control; Genetic modification; Pathogens resistance; อ้อย; โรคใบขาวอ้อย; เชื้อไฟโตพลาสมา; เพลี้ยจักจั่น; แมลงพาหะ; เชื้อแบคทีเรีย; เชื้อแบคทีเรียร่วมอาศัยในแมลงพาหะ; การควบคุมโรค; การป้องกันแพร่ระบาดของโรค; การดัดแปลงลักษณะทางพันธุกรรม; ความต้านทานเชื้อสาเหตุโรค.
Ano: 2012
URL: http://anchan.lib.ku.ac.th/agnet/handle/001/5762

Morphological attributes and production components of potato cv. Baronesa and its transformed genotype - doi: 10.4025/actasciagron.v33i4.10918
Provedor de dados: 1
Autores: Pohl, Simone; Universidade Federal de Pelotas; Lopes, Nei Fernandes; Universidade Federal de Pelotas; Braga, Eugenia Jacira; Universidade Federal de Pelotas; Danielowski, Rodrigo; Universidade Federal de Pelotas; Silva, Ilda Mariclei de Castro da; Universidade Federal de Pelotas; Peters, Jose Antonio; Universidade Federal de Pelotas.
The aim of this paper was to compare the morphological attributes and production components of the wild-type Baronesa cultivar potato with those of Baronesa potato plants that have been genetically modified using the potato virus Y coat protein (CP) gene. The experiment was conducted under greenhouse conditions (Biosecurity Quality Certificate no. 081/98 issued by the National Biosecurity Technical Committee) at the Federal University of Pelotas (UFPel), Pelotas-RS. The shoot and root lengths and the mean leaf number were determined six times at 14-day intervals after sowing; the length, width and fresh weight of the tubers were measured during the last harvest, which occurred 84 days after sowing. There were no statistical differences between the two...
Tipo: Pesquisa em casa de vegetação
Palavras-chave: 5.01.03.00-8 Solanum tuberosum; Genetic modification; Virus resistance Fitotecnia Solanum tuberosum; Genetic modification; Virus resistance.
Ano: 2011
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/10918

Delivery of the Sox9 gene promotes chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells in an in vitro model
Provedor de dados: 56
Autores: Wang,Z.H.; Li,X.L.; He,X.J.; Wu,B.J.; Xu,M.; Chang,H.M.; Zhang,X.H.; Xing,Z.; Jing,X.H.; Kong,D.M.; Kou,X.H.; Yang,Y.Y.
SRY-related high-mobility-group box 9 (Sox9) gene is a cartilage-specific transcription factor that plays essential roles in chondrocyte differentiation and cartilage formation. The aim of this study was to investigate the feasibility of genetic delivery of Sox9 to enhance chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells (hUC-MSCs). After they were isolated from human umbilical cord blood within 24 h after delivery of neonates, hUC-MSCs were untreated or transfected with a human Sox9-expressing plasmid or an empty vector. The cells were assessed for morphology and chondrogenic differentiation. The isolated cells with a fibroblast-like morphology in monolayer culture were positive for the MSC markers CD44, CD105,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Genetic modification; Tissue engineering; Stem cells; Sox9; Chondrogenesis.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2014000400279