Sales and usage of dietary supplements have significantly risen in recent years, bringing along various health risks such as liver damage and adverse effects on cardiovascular health. In Sweden, dietary supplements are classified as regular foods under Swedish law and are subject to monitoring by local municipalities. This study aimed to examine how Swedish municipalities oversee the regulation of dietary supplements, while also investigating differences between larger and smaller municipalities. Data were collected through a web-based questionnaire comprising nineteen questions. The questionary covered topics including general supervision practices, inspection frequency at facilities, and knowledge levels concerning different dietary supplement products. The questionary achieved a response rate of 56% (163 out of 290). Among the respondents, 95% were involved in the supervision of dietary supplements, 80% had established plans, and 67% had implemented specific policies. A majority of the stores were inspected every three years, with some receiving annual inspections. Respondents' overall knowledge level was considered moderate, with significant disparities between larger and smaller municipalities. While most municipalities are actively engaged in regulating dietary supplements, there are still certain deficiencies in their management practices. The inspection frequency of most municipalities inspected facilities based on the Swedish Food Agency's risk classification model. Knowledge levels regarding dietary supplements among municipalities are generally satisfactory, though notable discrepancies exist between large, medium-sized, and small municipalities.

This thesis investigates the use of scientific evidence in the process of making public health policy. A case study located within a food regulation setting is used. The aim is to test theory against this case study. The outcome is a theoretical understanding of the use of scientific evidence in the policy-making process in a food regulation setting. Food regulation can influence food composition and food labelling and thereby affect the population's dietary intake. Frequently there are contested values, beliefs, ideologies and interests among stakeholders regarding the use of food regulation as a policy instrument to effect public health outcomes. The protection of public health and safety, taking into account evidence based practice, is generally employed by food regulators as the priority objective during the policy-making process to adjudicate among the competing expectations of stakeholders. However, this policy objective has not been clearly defined and is vulnerable to interpretation and application. The process by which folate fortification policy was made in Australia, in response to epidemiological evidence of a relationship between folate intake during the periconceptional period and reduced risk of neural tube defects, was analysed as a case study of the policy-making process. The folate fortification policy created a precedent for both food fortification and subsequently health claims policy in Australia. A social constructivist method was used to analyse the case study. The method involved deconstructing the food regulatory system into three levels; decision-making process; procedural; and political environment. Data aligned with each level of analysis was collected from 22 key informant interviews, documentary sources, field notes and surveys of both a random sample of the Australian population's knowledge of folate and use of folic acid-containing supplements (n = 5422), and the implementation of folate fortified food products into stores (n = 60). The insights that emerged from each of the three levels of analysis were assessed iteratively to identify a pattern of interrelationships associated with the policy-making process within the food regulatory system. The identified pattern was interpreted against existing theory to gain a theoretical understanding of the public health policy-making process in this political setting. The central argument of this thesis extends Sabatier and Jenkins-Smith's Advocacy Coalition Framework theory to a food regulation setting. The argument is that within the contemporary political climates of neoliberalism and globalisation, a coalition between corporate interests and the values of scientists with a positivist-reductionist approach to public health research is privileged so as to invoke certain scientific evidence to, in turn, legitimise food regulation policy decisions. The theory will help to inform policy-makers about how and why the public health policy objective in a food regulation setting is interpreted and applied. This will contribute to improving policy practice intended to effect public health outcomes. It is concluded that irrespective of the quantity and quality of the scientific evidence that is being made available, scientific evidence cannot be assumed to speak for itself Policy-making is an inherently political and value-laden process and the potential for politically motivated interpretation and application of otherwise value-neutral scientific evidence can undermine the investment in its generation. From this perspective, evidence based practice, far from liberating policy-making from political influence, can itself become part of the problem rather than the solution. Nevertheless, rational evidence based practice is an ideal to strive for and a series of recommendations is proposed to help make the use of evidence in current food regulation policy processes more transparent and democratic.

The demand for the control of safe food, from consumers the world over, has revolutionized the manner in which wild game meat harvesting occurs. In developed countries, food quality, food and human safety with quality controlling systems embracing environmental carbon footprint issues are constantly improving, for international harmonization at each level of production “from stable to table”, “farm to fork”, “field to yield” as well as from “cradle to grave”. Food industries globally have adopted the in Hazard Analysis Critical control Point (HACCP) system. This is a risk assessment process using Hygiene Assessment Systems (HAS) as a mitigating strategy for risk communication through training. It is also a holistic system that is compatible with international trends designed not only for food safety and quality, but it also embraces other aspects of farming such as animal welfare, environmental management and Occupational Safety and Health. Global marketing for international trade demands quality assurance from trading partners thereby promoting economic growth for developing countries. The watch dog bodies such as the World Trade Organisation (WTO) prohibit trading for non-compliance, therefore trade barriers are in place for uncertified food of animal origin, EU regulations are stringent requirements that need compliance and so too the OIE regulations for disease control, while the Codex Alimentarius Commission maintains trade harmonization. In South Africa Hygiene Assessment Systems (HAS) is a National Hygiene management strategy implemented at abattoirs, that promotes and facilitates quality and hygiene and is reflective of South African quality abroad. It is prescribed under the section, “Essential National Standards” in the Meat Safety Act, 2000, (Act 40 of 2000). This Act covers red meat and includes both domestic animals and game. The Veterinary Procedural Notices (VPN’s) are used for export of game and give far more detailed guidelines than the legislation for game meat sold and consumed locally in South Africa. The objective of the Hygiene Assessment System (HAS) is to create a national awareness of quality to better improve the quality of life of all South Africans, whilst at the same time it is used as an auditing tool for Veterinary Public Health to effectively compare essential standards within the nine provinces. Currently this programme is referred to as the National Abattoir Rating Scheme (NARS), which is only applicable to the high and low throughput Red Meat and Poultry abattoirs in South Africa and not to the Game or Rural abattoirs, thereby further compounding the duality of food standards with food safety being compromised. This study has been undertaken because there are inadequate risk control measures such as introduction of Hazard Analysis Critical Control Point (HACCP) guidelines on primary and secondary meat inspection, specifically on game for local consumption, not only within South Africa, but in the international arena as well. A revision of the HAS document and audit will also be needed to meet with the local (not just export) criteria for wild game harvesting, to enable food safety, thus enabling food security in the remote non - agricultural areas in KwaZulu -Natal. Venison is the meat of today because of health priorities that have arisen over the last ten years. It is low in trans - fatty acids and is regarded internationally as a healthy product produced organically in a free range situation. South Africa has a large potential export market for venison to the European Union because the demand, for venison, exceeds supply in Europe. However, the European Union’s “safe food regulation” that was introduced between 2005 and 2007 with an implementation date of 2008 (Regulation1021/2008) has made it imperative that the HACCP principle is applied to any food or food product of animal origin imported into the European Union or its member states. Also, HACCP specifies that a multidisciplinary team of experts is selected. This then lends itself to a participatory approach to risk assessment as wide consultation is required. This participatory approach was used, including expert opinion surveys and focus group discussions with stakeholders and role-players in the game industry such as commercial hunters, state veterinary services and game ranch owners. Such participants may have better insight into existing conditions than external experts with recognised educational qualifications, usually used in the HACCP team. From this and the relevant Veterinary Procedural Notices for game harvesting, a HACCP process flow and critical control points were derived for the primary phase of meat inspection, including slaughter, primary meat inspection and loading for transport to the abattoir. This was modified during a phase or trial harvesting and then implemented during the harvest of 1758 impala carcasses which were subsequently exported. In addition, environmental risks were considered and a risk mitigation strategy designed, to reduce any possible environmental impacts. In northern Kwazulu Natal, game ranches and conservation areas are in close proximity to the rural poor where food is scarce and comes at a premium price. These game farms harvest seasonally for either the local or export market, hence there is abundance of game offal and by-products available, yet it is at present left in the field or taken to the vulture restaurants (in line with the VPN). Participatory risk analysis was thus also used to investigate the feasibility of using edible offal from impala (Aepyceros melampus) as a source of renewable protein, to address food security issues in impoverished communities in the study area, the districts of uPongola and Jozini, in northern KwaZulu Natal. Structured interviews on the cultural acceptability of impala offal were held with 162 randomly sampled adult respondents in veterinary districts associated with dip tanks. A two stage cluster design was used where the state veterinary areas were stage one and the dip tanks (with proportional random sampling of community members) were the second stage. Offal is a popular food in South Africa in different cultures, called “ithumbu” in IsiZulu, “ boti” by the Indian group, “afval” in Afrikaans and “tripe” in English. Generally demand outstrips supply of offal at red meat abattoirs in South Africa. It was found that there was no significant difference between those who would eat impala offal and those who would eat the offal of sheep. It was concluded that it is feasible to use inspected game offal from impala as a protein source in much the same way as red meat offal is used and that the current practice of leaving the offal for predators was likely, if it continues, to cause imbalances in the predator/ prey ratio on game farms. It is recommended that the VPN for game be amended to encompass inspected offal being allowed into the formal food chain, in line with the standard operating procedure developed during this study. Also that current fragmentation of legislation and the implementation thereof is revisited for effective control for harmonisation of food safety standards for game meat within South Africa. / Dissertation (MMedVet)--University of Pretoria, 2012. / Paraclinical Sciences / unrestricted

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-06-21T17:56:23Z No. of bitstreams: 1 2016 - Ros?ngela Pezza Cintr?o.pdf: 3487632 bytes, checksum: b58a311d44d01ef224bccf9be913f986 (MD5) / Made available in DSpace on 2017-06-21T17:56:23Z (GMT). No. of bitstreams: 1 2016 - Ros?ngela Pezza Cintr?o.pdf: 3487632 bytes, checksum: b58a311d44d01ef224bccf9be913f986 (MD5) Previous issue date: 2016-09-06 / CNPq / The dissertation focuses on conflicts and disputes about the sanitary (il)legalization of artisanal raw milk cheese in the state of Minas Gerais, which have become stronger since the 1990?s. It shows how State apparatus, laws, rules and regulations conceived with the aim of protecting the health of the population and usually presented as neutral and scientific end up, through various and complex ways, serving as instruments to establish barriers to entry amidst the disputes on dairy products? markets. The sanitary regulation of artisanal cheese is analyzed as a part of a process of progressive governamentalization of the State, which favors industrial, large-scale patterns of production, processing and distribution of food. The need to pasteurize and the minimum time for ripening are in the core of the debates and of the international regulations (Codex Alimentarius). In the case in focus, the legitimization of sanitary regulation is achieved by means of standards of ?quality?, ?risk?, and ?food safety? based in laboratory exams that search for the presence, in levels higher than legally permitted, of two groups of microorganisms (faecal coliforms and Staphiylococcus aureus), leading to the legal classification as ?improper for human consumption?. This conflicts with the population?s perception of these cheeses as a tasty and safe food, part of the cultural identity of people from Minas Gerais. As cheese is an essentially ?living? product, that may have ?bad? microorganisms but also has ?good? microorganisms that are responsible for unique characteristics of flavor and texture, sanitary rules based on industrial criteria are in conflict with traditional ways of producing and consuming cheese. Thus, illegalization processes lead to reactions, such as looking for possibilities of legalization amidst legal and institutional tangles that are ever more complex and permit the inclusion of only a minority of cheese-producing families. The majority of these families remain informal, which is increasingly constructed as illegal. Fieldwork was done in two municipalities in the region of the cheese known as Canastra, and the analysis points to a set of elements enabling people to remain in cheese-related activities, both as producers and as traders, in forms that are culturally established as part of a way of life and that ensure the families? social reproduction and their resiliency in face of external pressures. The study of this case thus brings forth more general issues about the relation between State, Law, Science and markets, and about their relation with peasant populations. It also discusses hegemonic notions of risk concerning health and food, and its effects on the way of life of peasant populations and on the consumers? possibilities of choice. / A tese aborda os conflitos e disputas em torno da (i)legaliza??o sanit?ria dos queijos artesanais de leite cru em Minas Gerais, que se acentuam ap?s a d?cada de 1990. Aponta como aparatos estatais, leis, normas e regulamentos, criados tendo como objetivo a defesa da sa?de da popula??o e normalmente apresentados como neutros e cient?ficos, por caminhos m?ltiplos e complexos acabam servindo como instrumentos para a cria??o de barreiras ? entrada em disputas por mercados de produtos l?cteos. A regula??o sanit?ria dos queijos artesanais ? analisada como parte de um processo de progressiva governamentaliza??o do Estado, que termina favorecendo padr?es industriais de produ??o, processamento e distribui??o de alimentos em maior escala. No centro das controv?rsias est? a exig?ncia de pasteuriza??o dos queijos ou de tempos m?nimos de cura, presentes em normas internacionais (Codex Alimentarius). No caso analisado, a legitima??o da regula??o sanit?ria se d? atrav?s da constru??o de padr?es de 'qualidade', 'risco' e 'seguran?a do alimentos', baseados em exames laboratoriais que apontam a presen?a, acima dos n?veis legais, em especial de dois grupos de microorganismos (coliformes fecais e Staphylococcus aureos), que levam ? classifica??o legal dos queijos como 'impr?prios ao consumo humano', entrando em choque com a percep??o da popula??o desses queijos como alimentos saborosos e seguros, parte da identidade cultural dos mineiros. Por serem produtos essencialmente 'vivos', contendo 'maus microrganismos' mas tamb?m 'bons microrganismos', respons?veis por caracter?sticas ?nicas de sabor e textura, as normas sanit?rias baseadas em crit?rios industriais entram em choque com tradi??es de produ??o e consumo dos queijos. Assim, os processos de ilegaliza??o geram rea??es, que buscam possibilidades de legaliza??o em emaranhados legais e institucionais cada vez mais complexos e que permitem a inclus?o apenas de uma minoria de fam?lias produtoras. A grande maioria permanece na informalidade, cada vez mais constru?da como ilegalidade. O trabalho de campo analisa dois munic?pios na regi?o do queijo Canastra e aponta um conjunto de elementos que comp?em um modo de se manter na atividade do queijo, que envolve tanto formas de produ??o quanto de comercializa??o, inseridas culturalmente num modo de vida, que garantem a reprodu??o das fam?lias e sua resili?ncia frente ?s press?es externas. O estudo desse caso coloca quest?es mais gerais sobre a rela??o entre Estado, Direito, Ci?ncia e mercados, assim como destes com popula??es camponesas. Discute tamb?m com no??es hegem?nicas de risco no que diz respeito ? sa?de e ? alimenta??o e seus efeitos sobre o modo de vida dessas mesmas popula??es e sobre as op??es de escolha dos consumidores.

Made available in DSpace on 2016-04-28T20:13:48Z (GMT). No. of bitstreams: 1 2008 - Marco Antonio Ferreira de Souza.pdf: 2114565 bytes, checksum: 0c343463353326e5371d4a8d0734a377 (MD5) Previous issue date: 2008-04-28 / Functional foods and nutraceuticals represent a kind of food that provides physiological and health benefits beside basic nutrition. Far from being conventional food, they are positioned as an alternative for some traditional and complimentary medicinal products. The first appearance of this novel type of food occurred in Japan in the 80?s, when some food were researched and used to tackle the progressive increase of health related diseases that promoted drastic drop in public health indices. This experience lead to the creation of a new product category initially called functional food, renamed later as food for special health use or FOSHU. The USA amplified this experience giving to it a remarkable visibility. Although they had not formalized a new product category this food begin to be called as nutraceutical. This new perspective of tackling the diet and health relation meant a significative change in the institutional environment of producing and promoting public health since it offers to agro food system players a primacy up to now permitted only to Pharmaceuticals Company. This thesis searched to provide a wide visibility panel of the raising of this novel type of food and an analysis of its repercussion on the agro food system. It began with the characterization of food provisioning modes considering the centrality exerted by quality over the agro food system competition dynamics. Convention economy concepts were applied to uncover different food quality justifications. An institutionalization approach was assumed in order to provide a deep compreenhension of the meaning of these novel types of food and of its raising. It resulted in a framework that accounted for three different arenas in that the process itself develops: scientific, regulatory and market. The analysis involved the experiences of Brasil, Japan, USA and European Union. Even though this process represent a new momentum for the agro food question, it favors most those player concerned with the industrial mode of food provisioning, mainly the ingredient and final food industry giants. Those players concerned with alternative food initiatives face obstacles related to complex regulatory framework and scientific requirements. These reflect the trend of regulatory framework in focusing on functional substances rather than products, even those in natura. To come into reality functional foods and nutraceuticals demands truly value systems based on the complex coordination of expensive and time-consuming scientific and productive activities. All of them completely adverse for small and medium size companies to cope with. / Alimentos funcionais e nutrac?uticos s?o apresentados como alimentos que, al?m de suas fun??es b?sicas nutricionais, demonstram benef?cios fisiol?gicos e/ou reduzem o risco de doen?as cr?nicas. Eles se afastam dos alimentos ditos convencionais e ficam posicionados como produtos diferenciados e uma alternativa para o processo de cuidado com a sa?de. Tais alimentos acabam dividindo com alguns produtos da medicina tradicional e alternativa o importante espa?o simb?lico de produ??o de sa?de. A primeira experi?ncia pr?tica ocorreu no Jap?o nos anos 80, quando o governo estimulou a pesquisa e uso de alimentos como aliados na melhoria dos ?ndices de sa?de publica do pa?s. O esfor?o originou o conceito de alimentos funcionais e estimulou a cria??o de uma categoria de alimentos classificada como alimentos funcionais, mais tarde modificada para FOSHU ou food for special health purpose. Nos EUA essa experi?ncia foi amplificada e esses alimentos s?o mais conhecidos como nutrac?uticos, por?m sem reconhecimento formal. Esta nova perspectiva para abordar a rela??o dieta e sa?de representa uma mudan?a significativa no ambiente institucional relativo a produ??o e promo??o de sa?de p?blica, pois concede aos atores do sistema agroalimentar uma primazia at? ent?o permitida apenas ?s empresas de medicamentos. Esta tese teve como objetivo a constru??o de um amplo painel de visibilidade da ascens?o desses novos alimentos, baseado na descri??o da trajet?ria desses termos e na an?lise das repercuss?es dessa transforma??o institucional sobre a quest?o agroalimentar. A quest?o agroalimentar foi caracterizada a partir da an?lise das modalidades correntes de fornecimento de alimento, objetivo alcan?ado atrav?s do uso dos conceitos da Economia das Conven??es. Para fins de conceitua??o e descri??o da trajet?ria procurou-se caracterizar o processo de institucionaliza??o dos novos alimentos, explorando os aspectos cient?ficos, regulamentares e mercadol?gicos. Al?m do Brasil foram analisadas as experi?ncias japonesa, americana e europ?ia. Embora represente um novo momento para a quest?o agroalimentar, verificou-se que a institucionaliza??o favorece principalmente aos atores associados ? modalidade industrial de fornecimento de alimentos: ind?stria processadora e fabricantes de alimentos finais. Em detrimentos aos interesses de projetos alternativos de fornecimento de alimentos com qualidade diferenciada, como os org?nicos e a produ??o local. Os pa?ses que aderiram a esta reclassifica??o dos alimentos t?m privilegiado a cria??o de complexas estruturas regulamentares para avaliar e liberar o uso de alega??es de sa?de para alimentos e o foco sobre subst?ncias e n?o sobre os alimentos, mesmo aqueles in natura. Para se tornarem realidade, tais alimentos demandam a cria??o de verdadeiros sistemas de valor que implicam a coordena??o de atividades cient?ficas e produtivas bastante onerosas para pequenas e m?dias empresas.

This thesis investigates challenges to promoting socially just, locally focused agriculture faced by the organic certification program that now regulates organic farming in British Columbia. This inquiry into how organic certification works is conducted as an institutional ethnography. Institutional ethnography is the methodological foundation of Dorothy Smith’s feminist sociology for people. For the institutional ethnographer, ordinary daily activity is the site for investigation of social organization. Small scale organic farmers who are committed to sustainable, socially and ecologically just agriculture offer a critical standpoint from which to explicate extra-local text mediated ruling relations. This inquiry draws on data from open-ended interviews with farmers and an independent organic certification inspector. From these accounts I begin to address how it is that BC’s organic farming certification program actually enters into and reconstitutes the everyday work of farmers and inspectors. From my findings I argue that corporate interests and a focus on global free trade in organic produce and products increasingly guide the institutional structure of organic certification programs. This in turn moves organic farming out of local, farmer control.

This thesis investigates challenges to promoting socially just, locally focused agriculture faced by the organic certification program that now regulates organic farming in British Columbia. This inquiry into how organic certification works is conducted as an institutional ethnography. Institutional ethnography is the methodological foundation of Dorothy Smith’s feminist sociology for people. For the institutional ethnographer, ordinary daily activity is the site for investigation of social organization. Small scale organic farmers who are committed to sustainable, socially and ecologically just agriculture offer a critical standpoint from which to explicate extra-local text mediated ruling relations. This inquiry draws on data from open-ended interviews with farmers and an independent organic certification inspector. From these accounts I begin to address how it is that BC’s organic farming certification program actually enters into and reconstitutes the everyday work of farmers and inspectors. From my findings I argue that corporate interests and a focus on global free trade in organic produce and products increasingly guide the institutional structure of organic certification programs. This in turn moves organic farming out of local, farmer control.

Made available in DSpace on 2015-03-03T15:47:46Z (GMT). No. of bitstreams: 1 LeonardoCTB_DISSERT.pdf: 2119704 bytes, checksum: 5bdd21de8bfa668bba821593cdd5289f (MD5) Previous issue date: 2011-02-07 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Multi-objective combinatorial optimization problems have peculiar characteristics that require optimization methods to adapt for this context. Since many of these problems are NP-Hard, the use of metaheuristics has grown over the last years. Particularly, many different approaches using Ant Colony Optimization (ACO) have been proposed. In this work, an ACO is proposed for the Multi-objective Shortest Path Problem, and is compared to two other optimizers found in the literature. A set of 18 instances from two distinct types of graphs are used, as well as a specific multiobjective performance assessment methodology. Initial experiments showed that the proposed algorithm is able to generate better approximation sets than the other optimizers for all instances. In the second part of this work, an experimental analysis is conducted, using several different multiobjective ACO proposals recently published and the same instances used in the first part. Results show each type of instance benefits a particular type of instance benefits a particular algorithmic approach. A new metaphor for the development of multiobjective ACOs is, then, proposed. Usually, ants share the same characteristics and only few works address multi-species approaches. This works proposes an approach where multi-species ants compete for food resources. Each specie has its own search strategy and different species do not access pheromone information of each other. As in nature, the successful ant populations are allowed to grow, whereas unsuccessful ones shrink. The approach introduced here shows to be able to inherit the behavior of strategies that are successful for different types of problems. Results of computational experiments are reported and show that the proposed approach is able to produce significantly better approximation sets than other methods / Problemas de otimiza??o combinat?ria multiobjetivo apresentam caracter?sticas peculiares que exigem que t?cnicas de otimiza??o se adaptem a esse contexto. Como muitos desses problemas s?o NP-?rduos, o uso de metaheur?sticas tem crescido nos ?ltimos anos. Particularmente, muitas abordagens que utilizam a Otimiza??o por Col?nias de Formigas t?m sido propostas. Neste trabalho, prop?e-se um algoritmo baseado em col?nias de formigas para o Problema do Caminho mais Curto Multiobjetivo, e compara-se o algoritmo proposto com dois otimizadores encontrados na literatura. Um conjunto de 18 inst?ncias oriundas de dois tipos de grafos ? utilizado, al?m de uma metodologia espec?fica para a avalia??o de otimizadores multiobjetivo. Os experimentos iniciais mostram que o algoritmo proposto consegue gerar conjuntos de aproxima??o melhores que os demais otimizadores para todas as inst?ncias. Na segunda parte do trabalho, uma an?lise experimental de diferentes abordagens publicadas para col?nias de formigas multiobjetivo ? realizada, usando as mesmas inst?ncias. Os experimentos mostram que cada tipo de inst?ncia privilegia uma abordagem algor?tmica diferente. Uma nova met?fora para o desenvolvimento deste tipo de metaheur?stica ? ent?o proposta. Geralmente, formigas possuem caracter?sticas comuns e poucos artigos abordam o uso de m?ltiplas esp?cies. Neste trabalho, uma abordagem com m?ltiplas esp?cies competindo por fontes de comida ? proposta. Cada esp?cie possui sua pr?pria estrat?gia de busca e diferentes esp?cies n?o tem acesso ? informa??o dada pelo ferom?nio das outras. Como na natureza, as popula??es de formigas bem sucedidas tem a chance de crescer, enquanto as demais se reduzem. A abordagem apresentada aqui mostra-se capaz de herdar o comportamento de estrat?gias bem-sucedidas em diferentes tipos de inst?ncias. Resultados de experimentos computacionais s?o relatados e mostram que a abordagem proposta produz conjuntos de aproxima??o significativamente melhores que os outros m?todos