The Likelihood Ratio Test and Full Bayesian Significance Test under small sample sizes for contingency tables

Hypothesis testing in contingency tables is usually based on asymptotic results, thereby restricting its proper use to large samples. To study these tests in small samples, we consider the likelihood ratio test and define an accurate index, the P-value, for the celebrated hypotheses of homogeneity, independence, and Hardy-Weinberg equilibrium. The aim is to understand the use of the asymptotic results of the frequentist Likelihood Ratio Test and the Bayesian FBST -- Full Bayesian Significance Test -- under small-sample scenarios. The proposed exact P-value is used as a benchmark to understand the other indices. We perform analysis in different scenarios, considering different sample sizes and different table dimensions. The exact Fisher test for $2 \times 2$ tables that drastically reduces the sample space is also discussed. The main message of this paper is that all indices have very similar behavior, so the tests based on asymptotic results are very good to be used in any circumstance, even with small sample sizes

Efeitos da adubação orgânica e do fósforo sobre a produção de alho em Rio Branco-AC.

O alho é a quarta hortaliça em importância econômica para o Brasil (Filgueira 1982), e o seu cultivo continua em expansão, porém, apresentando de modo geral rendimentos baixos. Segundo Galli et al (1968), citado por Mascarenhas et al (1985), as principais causas desses baixos rendimentos são as doenças causadas por fungos. No Estado do Acre, além das condições climáticas favoráveis às doenças fúngicas, a baixa produtividade deve-se à falta de práticas culturais e fórmulas de adubação adequadas para a cultura. Todos esses fatores são imperativos na pesquisa do alho para essa região. O alho é bastante exigente em nutrientes, principalmente o fósforo e o nitrogênio, e os solos do Acre na sua maioria necessitam de correção de fertilidade, sendo este outro fator limitante a produção de alho, já que os insumos disponíveis no mercado alcançam preços proibitivos e os produtores de hortaliças geralmente não dispõem de muitos recursos financeiros. Segundo Moura et al (1982), o emprego de leguminosas como biofertilizantes proporciona entre outras vantagens a melhoria das propriedades físicas e químicas do solo. A incorporação da matéria orgânica que resulta em húmus e a mineralização do nitrogênio e outros elementos, tem como consequência o aumento do rendimento das culturas.bitstream/item/117368/1/1134.pd

Características físico-químicas de sucos de uvas Isabel Precoce e BRS Violeta elaborados no Nordeste do Brasil.

A avaliação da adaptação de variedades de uva destinadas à elaboração de sucos a determinadas condições de clima e solo requer estudos específicos, contando com uma avaliação analítica do produto elaborado. O objetivo do presente trabalho foi comparar os sucos obtidos a partir de duas variedades de uvas labruscas produzidas no Vale do São Francisco. Os sucos foram elaborados em triplicata pelo método artesanal, a partir de uvas das variedades BRS Violeta e Isabel Precoce. As variáveis analisadas foram pH, sólidos solúveis totais, acidez total e volátil, dióxido de enxofre livre e total, teor alcoólico, índice de cor, antocianinas totais e índice de polifenóis totais (I-280). As médias foram comparadas pelo teste de Tukey a 5% de probabilidade. Apenas para o pH não houve diferença significativa, sendo as demais variáveis significativamente diferentes entre as variedades, nos sucos analisados. A variedade BRS Violeta apresentou excelente potencial para a elaboração comercial de sucos na região

Aromatic stability of Syrah and Petit Verdot tropical wines from Brazil.

The production of fine wines in the Sub-middle of the São Francisco River Valley, Northeast of Brazil, is relatively recent, about twenty-five years ago. This region presents different characteristics, with a tropical semiarid climate, in a flat landscape. Presenting high annual average temperature, solar radiation and water in abundance for irrigation, it?s possible the scaling the grape harvests for winemaking throughout the year, allowing to obtain until two harvests per year. Several factors may affect the aromatic compounds in wines, such as viticulture practices, climatic conditions, cultivars and winemaking process. This study aimed to evaluate the aromatic stability of Syrah and Petit Verdot tropical wines elaborated in two different periods in the year. The grapes were harvested in the first and second semesters of 2009, in June and November. The wines were elaborated and then, they were bottled and analyzed in triplicate, thirty days and one year after bottling, by gas chromatography with ionization detector flame (GC-FID), to evaluate the profile and the stability of the aroma compounds. Principal component analysis was applied to discriminate between wine samples and to find the compounds responsible by the variability. The results showed that Syrah and Petit Verdot tropical wines presented different responses, for stability of higher alcohols, esters and carboxylic acids

Aromatic stability of Syrah and Petit Verdot tropical wines from Brazil.

The production of fine wines in the Sub-middle of the São Francisco River Valley, Northeast of Brazil, is relatively recent, about twenty-five years ago. This region presents different characteristics, with a tropical semiarid climate, in a flat landscape. Presenting high annual average temperature, solar radiation and water in abundance for irrigation, it?s possible the scaling the grape harvests for winemaking throughout the year, allowing to obtain until two harvests per year. Several factors may affect the aromatic compounds in wines, such as viticulture practices, climatic conditions, cultivars and winemaking process. This study aimed to evaluate the aromatic stability of Syrah and Petit Verdot tropical wines elaborated in two different periods in the year. The grapes were harvested in the first and second semesters of 2009, in June and November. The wines were elaborated and then, they were bottled and analyzed in triplicate, thirty days and one year after bottling, by gas chromatography with ionization detector flame (GC-FID), to evaluate the profile and the stability of the aroma compounds. Principal component analysis was applied to discriminate between wine samples and to find the compounds responsible by the variability. The results showed that Syrah and Petit Verdot tropical wines presented different responses, for stability of higher alcohols, esters and carboxylic acids

Ant-Balanced multiple traveling salesmen: ACO-BmTSP

A new algorithm based on the ant colony optimization (ACO) method for the multiple traveling salesman problem (mTSP) is presented and defined as ACO-BmTSP. This paper addresses the problem of solving the mTSP while considering several salesmen and keeping both the total travel cost at the minimum and the tours balanced. Eleven different problems with several variants were analyzed to validate the method. The 20 variants considered three to twenty salesmen regarding 11 to 783 cities. The results were compared with best-known solutions (BKSs) in the literature. Computational experiments showed that a total of eight final results were better than those of the BKSs, and the others were quite promising, showing that with few adaptations, it will be possible to obtain better results than those of the BKSs. Although the ACO metaheuristic does not guarantee that the best solution will be found, it is essential in problems with non-deterministic polynomial time complexity resolution or when used as an initial bound solution in an integer programming formulation. Computational experiments on a wide range of benchmark problems within an acceptable time limit showed that compared with four existing algorithms, the proposed algorithm presented better results for several problems than the other algorithms did.info:eu-repo/semantics/publishedVersio

Reação de genótipos de cebola a mancha-púrpura (Alternaria porri).

O objetivo deste trabalho foi avaliar a resistência de genótipos de cebola a mancha-púrpura no campo. Foram avaliados 64 genótipos (cultivares, populações e linhagens do programa de melhoramento de cebola da Embrapa) em sistema convencional de cultivo. Como testemunha resistente foi utilizada a população CNPH 6342 e como testemunha suscetível a linha macho-fértil 420B.bitstream/item/84970/1/bpd-98.pd

Características físico-químicas de sucos de uvas Isabel Precoce e BRS Violeta elaborados no Nordeste do Brasil.

A avaliação da adaptação de variedades de uva destinadas à elaboração de sucos a determinadas condições de clima e solo requer estudos específicos, contando com uma avaliação analítica do produto elaborado. O objetivo do presente trabalho foi comparar os sucos obtidos a partir de duas variedades de uvas labruscas produzidas no Vale do São Francisco. Os sucos foram elaborados em triplicata pelo método artesanal, a partir de uvas das variedades BRS Violeta e Isabel Precoce. As variáveis analisadas foram pH, sólidos solúveis totais, acidez total e volátil, dióxido de enxofre livre e total, teor alcoólico, índice de cor, antocianinas totais e índice de polifenóis totais (I-280). As médias foram comparadas pelo teste de Tukey a 5% de probabilidade. Apenas para o pH não houve diferença significativa, sendo as demais variáveis significativamente diferentes entre as variedades, nos sucos analisados. A variedade BRS Violeta apresentou excelente potencial para a elaboração comercial de sucos na região

Glass waste powder addition used as mitigator of concrete alkali-silica reaction

The recycled aggregates from demolition of concrete structures affected by alkali silica reaction as well as the potentially reactive natural aggregates are often a matter of great concern and fear in case of new structures construction. Thus, to encourage the recycling and use of some potential reactive aggregates under scientific basis, this paper presents an experimental study where suspected alkali-silica reactive recycled aggregates was used. The main goal of this study is evaluate the influence of waste glass powder addition as mitigator of the concrete expansive reaction. In a first phase, the level of expansibility of different aggregates was identified using accelerated tests in mortars bars, method ASTM C1260 and an adapted accelerated test on specimens of 40 x 40 x 160 mm. In a second phase, tests were performed on concrete mixtures, according to CMBT method, with 100% recycled reactive coarse aggregates and powder addition, such as the glass powder and metakaolin. The powder additions percentages were incorporated at 20%, 40% and 60% of cement weight. The results of mortars bars test showed opposite results according to the method applied, i.e. , the same aggregates considered as harmless by the adapted method are considered reactive by the ASTM method, if the same expansion limit of 0,10% for 16 days was adopted for both methods. Finally, the concrete results obtained with CMBT method showed that glass powder and metakaolin had a significant mitigation effect in alkali-aggregate reaction development