1,526 research outputs found

    Applying Biomedical Ontologies on Semantic Query Expansion

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    *1- Introduction*

The interpretation of a question (or information need) depends, among other things, of a series of lexicalsemantic relations that complement and help the cognitive process of answering that information need. Despite this fact, currently used information retrieval mechanisms take few advantages of the semantic interpretation of users’ information needs (usually specified through keywords). In most of the cases, those mechanisms are based on keyword matching, and thus are excessively dependant on the query and document terms.

There are several past results showing that, in general, information retrieval based on domain knowledge decreases the accuracy of keyword based search engines. We believe this approach deserves further discussion and experimentation, looking for more strong evidences that these negative results can really be generalized. Moreover, there are some questions left unanswered by previous work that our experiment is addressing:

(_i_) Using a scientific ontology, with formal construction and maintenance processes, such as the OBO ontologies, would produce better results? 

(_ii_) Are there more efficient query expansion techniques using available domain knowledge?

(_iii_) Is a scientific ontology complete enough to fulfill the information retrieval researchers’ needs, in general?

*2- Semantic Query Expansion*

To try to answer some of these questions, we run a query expansion experiment using the Gene Ontology (GO) as domain knowledge. As the document repository, we used an extraction of 10 years of PubMed publications (from 1994 to 2004), which contains approximately 4.6 Million documents. This dataset is a test collection used by the information retrieval community, called Genomic TREC.

*3- Results*
To evaluate our ontology-based semantic query expansion technique, we measured the effectiveness of the information retrieval mechanism with and without expansion. In a nutshell, the average result showed an increase of 28% on synonyms relations and a small decrease on other relations.

Our results show a lot of consistence with past related work. In fact, if the expansion strategy does not selectively choose when and how to expand, only synonym relations are worth to be used. However, looking further, it is possible to find several opportunities to try other expansion strategies. For example, the problem with query expansion using generalization/specialization relationships is that, if it is always applied, the bad results are more frequent than the good ones. But, if the strategy is to be selective on when to use these relations for expansion, the increasing on accuracy can be outstanding. As shown by our experiment, there was a query with 98% increment on effectiveness. 

*4- Conclusion*
We strongly believe that it is premature to assume that semantics-based query expansion is, in general, a recall-enhancing, precision-degrading technique. Our experiments suggest that by using scientific based ontologies (like OBO ontologies) with formal relations, it is possible to increase both recall and precision. Our group is currently revising this first experiment towards a better semantic query expansion strategy.

*5- Acknowledgements*
This work was partially funded by CAPES and CNPq research grants 311454/2006-2, 306889/2007-2 and 484713/2007-8.

*References*
_Fox E. Lexical relations enhancing effectiveness of information retrieval systems. SIGIR Forum, New York, v.15, n.3, p.5-3._

_Voorhees E. Query expansion using lexicalsemantic relations. In: ACM SIGIR conference on research and development in information retrieval, Proceedings, Dublin:17, p.61–69, 1994

    Brand gender and consumer-based brand equity on Facebook: The mediating role of consumer-brand engagement and brand love

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    Brand gender has been suggested as a relevant source of consumer-based brand equity (CBBE). The purpose of this paper is to deepen understanding of the relationship between brand gender and CBBE by analyzing the mediating roleofconsumer–brandengagement (CBE)andbrandlove(BL)onthisrelationship.Thisresearchwas conducted on Facebook, the dominant global social media platform. The hypotheses were tested using structural equation modeling. Results support 6 of the 9 hypotheses, with a significant relationship between analyzed constructs. This study advances prior work by showing that brand gender has an indirect and relevant impact on CBBE through BL and CBE. Therefore, this research confirms the advantages of clear gender positioning and extends prior research by suggesting that brands with a strong gender identity will encourage BL and CB

    VARIAÇÃO DO NÍVEL GERAL DE PREÇOS DE HORTIFRUTIGRANJEIROS COMERCIALIZADOS NO CEASA-GO

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    O objetivo do presente trabalho é desenvolver um índice de preços para produtos hortifrutigranjeiros comercializados no atacado em Goiás. A pesquisa foi motivada pelo interesse no estudo do comportamento dos preços de produtos hortifrutigranjeiros e pela necessidade e importância do desenvolvimento de indicadores econômicos regionais. Foram utilizados dados mensais referentes aos volumes comercializados em toneladas e ao preço médio (R/toneladas)detodosos283produtoscomercializadospeloCEASAGO,eprocurouseseguiralgunspassosfundamentaisapontadospelaliteraturaparaoprocessodeconstruc\ca~odeıˊndicedeprec\cos.Comoresultado,foramselecionados34produtosparacomporacesta,eenta~ocalculadososıˊndicesparaseusdadospelassoluc\co~esdeLaspeyresePaasche.ComparandoasduasseˊriespodeseperceberqueoıˊndicecalculadoporLaspeyrestendeasermaisalto,assimcomoapontaaliteratura.ConcluisequeosubsıˊdiofornecidopelateoriadosnuˊmerosıˊndiceseosdadossinalizadospeloCEASAGOpossibilitaramaconstruc\ca~odeumıˊndicedeprec\cosparaprodutoshortifrutigranjeiroscomercializadosnoatacadoemGoiaˊsdemodosatisfatoˊrio.ThispaperhasasobjectivedevelopsapriceindexforfruitsandvegetablesmarketedinthewholesaleinGoias.Theresearchwasmotivatedbytheinterestinthestudyofthebehaviorofthepricesofthoseproductsandfortheneedandimportanceofthedevelopmentofregionaleconomicalindicators.Monthlydatawereusedregardingthevolumesmarketedintonsandtothemediumprice(R/toneladas) de todos os 283 produtos comercializados pelo CEASA-GO, e procurou-se seguir alguns passos fundamentais apontados pela literatura para o processo de construção de índice de preços. Como resultado, foram selecionados 34 produtos para compor a cesta, e então calculados os índices para seus dados pelas soluções de Laspeyres e Paasche. Comparando as duas séries pode-se perceber que o índice calculado por Laspeyres tende a ser mais alto, assim como aponta a literatura. Conclui-se que o subsídio fornecido pela teoria dos números índices e os dados sinalizados pelo CEASA-GO possibilitaram a construção de um índice de preços para produtos hortifrutigranjeiros comercializados no atacado em Goiás de modo satisfatório.------------------------------------------This paper has as objective develops a price index for fruits and vegetables marketed in the wholesale in Goias. The research was motivated by the interest in the study of the behavior of the prices of those products and for the need and importance of the development of regional economical indicators. Monthly data were used regarding the volumes marketed in tons and to the medium price (R/tons) of all the 283 products marketed by Goias state’s wholesale supply center (CEASA-GO), and it tried to follow some fundamental steps pointed for the literature for the process of price indexes construction. As result, 34 products were selected to compose the basket, and then calculated the indexes for the solutions of Laspeyres and Paasche. Comparing the two series can be noticed that the Laspeyres index tends to be higher, as well as it points the literature. It is ended that the subsidy supplied by the theory of the index numbers and the data signaled by CEASA-GO made possible the construction of a price indexes for fruits and vegetables marketed in the wholesale in Goias in a satisfactory way.variação de preços, produtos hortifrutigranjeiros, Goiás, price variation, fruits and vegetables, Goias, Brazil, Crop Production/Industries,

    PESQUISA EM ÍNDICE DE PREÇOS: ANTECEDENTES HISTÓRICOS E PRINCIPAIS ABORDAGENS

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    O presente trabalho objetiva revisar os antecedentes históricos da pesquisa de uma das ferramentas mais utilizadas e divulgadas em estudos econômicos em todo o mundo e de grande atratividade e aplicação no agronegócio: os índices de preços. Observa-se que o volume de trabalhos, discussões e estudos no decorrer do tempo, além de ilustrar a importância do assunto, permitiu o constante melhoramento dos métodos de cálculo e a defesa de diferentes pontos de vistas, levando inclusive à divisão de seu corpo teórico em algumas principais linhas ou correntes de pesquisa. A história da pesquisa tem seus primeiros registros no início do século XVIII, desenvolve-se sob vários enfoques e se enriquece ainda mais a partir do século XX. Esses enfoques gradualmente ajudaram a formar as três mais importantes abordagens da teoria de índices de preço, tais como são representados na literatura atual: a “abordagem estatística”, a “abordagem axiomática” e a “abordagem econômica”. Apesar da divisão, observa-se certa complementaridade já que a elaboração prática de índices de preços utiliza conceitos relacionados às três abordagens de forma integrada, dependendo de cada etapa de sua elaboração. ---------------------------------------------The present work aims at to revise the historical antecedents of the research of a tool very used and published in economical studies in world and of great attractiveness and application in the agribusiness studies: the price indexes. It was observed that the volume of works, discussions and studies of the price indexes theory in elapsing of the time, besides illustrating the importance of the subject, it allowed the constant improvement of the calculation methods and the defense of different points of views, taking besides to the division of your theoretical body in some main lines or research currents. The history of the research has their first registrations in the beginning of the century XVIII, it grows under several focuses and still gets rich more starting from the century XX. Those focuses gradually helped to form the three more important approaches of the price index theory, such as they are represented in the current literature: the "statistical approach", the "axiomatic approach" and the "economical approach". In spite of the division, certain complementarity is observed since the practical elaboration of price indexes uses concepts related to the three approaches in an integrated way, depending on each stage of your elaboration.índice de preços, abordagem estatística, abordagem axiomática, abordagem econômica, price indexes, statistical approach, axiomatic approach, economical approach, Research Methods/ Statistical Methods,

    MULTIFUNCIONALIDADE E PLURIATIVIDADE COMO ALTERNATIVAS DE DESENVOLVIMENTO DA AGRICULTURA FAMILIAR NO BRASIL

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    O objetivo deste trabalho é discutir, por meio de uma revisão teórica, alternativas de desenvolvimento da agricultura familiar no Brasil com um enfoque voltado aos conceitos de pluriatividade da agricultura familiar e multifuncionalidade do espaço agrário. Dentro dessa abordagem, e procurando comparar com a situação de outros países, objetiva-se explicar as especificidades, assim como as oportunidades e limitações da aplicação desses conceitos no país. A conjugação desses conceitos tem o potencial de levar a uma reorientação do modelo de desenvolvimento do meio rural brasileiro. A reorientação pode vir por meio de um modelo sustentável, ecologicamente correto e socialmente igualitário, proporcionando a fixação e manutenção de famílias no campo ligadas a atividades como a agricultura orgânica, agroecologia, turismo rural, ecoturismo, práticas de esporte ligadas à natureza, artesanato e pequenos beneficiamentos de alimentos. Conclui-se que os formuladores de políticas voltadas ao desenvolvimento rural podem se beneficiar dessas idéias, e mais iniciativas deveriam ser tomadas relacionando os dois conceitos.------------------The objective of this work is to discuss, through a theoretical revision, alternatives of the family agriculture development in Brazil with a focus returned to the concepts of pluriactivity of the family agriculture and multifunctionality of the agrarian space. Inside of that approach, and trying to compare with the other countries situation, it tries to explain the specificities, as well as the opportunities and limitations of the application of those concepts in the country. The conjugation of those concepts has the potential of taking a reorientation of the development model of the brazilian rural zone. The reorientation can come through a maintainable model, ecologically correct and socially equalitarian, providing the fixation and maintenance of families in the field linked to activities as the organic agriculture, agroecology, rural tourism, ecotourism, sport practices linked to the nature, workmanship and small processing of foods. It is concluded that the makers of politics returned to the rural development can benefit of those ideas, and more initiatives should be taken relating the two concepts.agricultura familiar, desenvolvimento, mutifuncionalidade, pluriatividade, family agriculture, development, multifunctionality, pluriactivity, Brazil, International Development,

    Postoperative Braces For Degenerative Lumbar Diseases

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    Lumbar pain due to generative disease is a public health problem and a cause of labor productivity loss and therefore generates cost to the country. Surgery is an option and orthotics are commonly used postoperatively. However, in the literature there is still no evidence if the braces are effective for a good functional outcome of the surgery. Objective: to develop a systematic review research project to evaluate the effectiveness of orthosis used after lumbar spine surgery in patients with degenerative disease regarding pain reduction and improvement of functional status. Method: This is a protocol for performing a systematic review of the literature, with the high quality standards of the Cochrane Group. From this, primary studies pertinent to the clinical question will be selected and its data will be extracted so that an answer can be achieved. Results: A protocol was elaborated containing the approach for a systematic review detailing the judgment criteria that will be used in the selection and evaluation of the primary studies and the management of its information. Conclusion: The protocol is already accepted and published in the Cochrane database. It aims to guide a systematic review that will answer the controversial clinical question if the postoperative orthoses is fundamental for the success of the surgery of lumbar degenerative diseases.A dor lombar, por alteração generativa, é um problema de saúde pública e causa de perda de produtividade laboral e custos ao país. A cirurgia é uma opção e as órteses são comumente usadas no pós-operatório. No entanto, na literatura não há evidencias se elas são efetivas para um bom resultado funcional da cirurgia. Objetivo: Desenvolver o projeto de pesquisa de uma revisão sistemática para avaliar a efetividade da órtese usada após a cirurgia da coluna vertebral lombar, em pessoas com doença degenerativa, em relação a redução da dor e melhora do estado funcional. Método: Trata-se de um protocolo para realização de uma revisão sistemática da literatura nos padrões de qualidade da Colaboração Cochrane. A partir dele serão selecionados estudos primários pertinentes a pergunta clínica e seus dados extraídos para que se possa chegar a uma resposta. Resultado: Foi elaborado um protocolo em que há a abordagem proposta para revisão sistemática, detalhando os critérios de julgamento que serão usados na escolha e avaliação dos estudos primários, e o gerenciamento das informações neles contidas. Conclusão: O protocolo está aceito e publicado na base de dados da Colaboração Cochrane, e visa orientar uma revisão sistemática que responderá a pergunta clínica ainda polêmica, isto é, se as órteses usadas no período pós-operatório, são fundamentais para o sucesso da cirurgia nas doenças degenerativas lombares.Dados abertos - Sucupira - Teses e dissertações (2018

    Temporal Abstraction in Reinforcement Learning with the Successor Representation

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    Reasoning at multiple levels of temporal abstraction is one of the key attributes of intelligence. In reinforcement learning, this is often modeled through temporally extended courses of actions called options. Options allow agents to make predictions and to operate at different levels of abstraction within an environment. Nevertheless, approaches based on the options framework often start with the assumption that a reasonable set of options is known beforehand. When this is not the case, there are no definitive answers for which options one should consider. In this paper, we argue that the successor representation (SR), which encodes states based on the pattern of state visitation that follows them, can be seen as a natural substrate for the discovery and use of temporal abstractions. To support our claim, we take a big picture view of recent results, showing how the SR can be used to discover options that facilitate either temporally-extended exploration or planning. We cast these results as instantiations of a general framework for option discovery in which the agent's representation is used to identify useful options, which are then used to further improve its representation. This results in a virtuous, never-ending, cycle in which both the representation and the options are constantly refined based on each other. Beyond option discovery itself, we also discuss how the SR allows us to augment a set of options into a combinatorially large counterpart without additional learning. This is achieved through the combination of previously learned options. Our empirical evaluation focuses on options discovered for exploration and on the use of the SR to combine them. The results of our experiments shed light on important design decisions involved in the definition of options and demonstrate the synergy of different methods based on the SR, such as eigenoptions and the option keyboard.Comment: 69 pages, 30 figure

    GESTÃO AMBIENTAL EMPRESARIAL E COMPETITIVIDADE DE SISTEMAS AGROINDUSTRIAIS

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    A preocupação com o meio ambiente por parte da sociedade mundial vem ganhando força a cada dia, levando as empresas a dar uma maior atenção à dimensão ambiental de suas atividades econômicas. Cada vez mais a classe empresarial visualiza a importância da gestão ambiental como fator de competitividade e sustentabilidade de seus negócios. Procurando avançar nesse sentido, objetiva-se nesse trabalho analisar, através de uma revisão teórica, como estratégias de gestão ambiental, através de seus benefícios, podem se conformar como um fator de competitividade para empresas inseridas no agronegócio e para sistemas agroindustriais. O trabalho de revisão aborda a idéia do enfoque sistêmico, necessária para estudos referentes ao agronegócio, conceitos e definições de competitividade e suas especificidades para uma cadeia ou um sistema agroindustrial, e tipos de estratégias ambientais e os seus potenciais benefícios para as empresas. Por fim, procura-se caracterizar as particularidades de aplicação da gestão ambiental para um sistema ou cadeia agroindustrial. Como resultados são apontadas as evidências teóricas que levam à convergência dos potenciais benefícios da gestão ambiental empresarial com alguns conceitos e pontos de vista sobre a competitividade no agronegócio.----------------------------------------------The concern with the environment on the part of the world society is winning force every day, taking the companies to give larger attention to the environmental dimension of their economical activities. More and more the business class visualizes the importance of the environmental management as factor of competitiveness and sustainability of their businesses. Trying to move forward in that sense, aimed in this work to analyze, through a theoretical revision, as strategies of environmental management and their benefits can conform as a factor of competitiveness for companies inserted in the agribusiness and for agrifood systems. The revision work involves the idea of the systems approach, necessary for studies regarding the agribusiness, concepts and definitions of competitiveness and their specificities for a chain or an agrifood system, concepts of environmental management, types of environmental strategies and their potentials benefits for the companies. As results are pointed the theoretical evidences that take the convergence of the potentials benefits of the environmental management with some concepts and point of view about the competitiveness in the agibusiness.Gestão Ambiental, competitividade, agronegócio, Environmental management, competitiveness, agribusiness, Agribusiness,

    Origin, evolution, and distribution of the molecular machinery for biosynthesis of sialylated lipooligosaccharide structures in Campylobacter coli

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    Campylobacter jejuni and Campylobacter coli are the most common cause of bacterial gastroenteritis worldwide. Additionally, C. jejuni is the most common bacterial etiological agent in the autoimmune Guillain-Barre syndrome (GBS). Ganglioside mimicry by C. jejuni lipooligosaccharide (LOS) is the triggering factor of the disease. LOS-associated genes involved in the synthesis and transfer of sialic acid (glycosyltranferases belonging to family GT-42) are essential in C. jejuni to synthesize ganglioside-like LOS. Despite being isolated from GBS patients, scarce genetic evidence supports C. coli role in the disease. In this study, through data mining and bioinformatics analysis, C. coli is shown to possess a larger GT-42 glycosyltransferase repertoire than C. jejuni. Although GT-42 glycosyltransferases are widely distributed in C. coli population, only a fraction of C. coli strains (1%) are very likely able to express ganglioside mimics. Even though the activity of C. coli specific GT-42 enzymes and their role in shaping the bacterial population are yet to be explored, evidence presented herein suggest that loss of function of some LOS-associated genes occurred during agriculture niche adaptation.Peer reviewe
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