Combined methods of optical spectroscopy and artificial intelligence in the assessment of experimentally induced non-alcoholic fatty liver.

BACKGROUND AND OBJECTIVE: Due to the existing prevalence of nonalcoholic fatty liver disease (NAFLD) and its relation to the epidemic of obesity in the general population, it is imperative to develop detection and evaluation methods of the early stages of the disease with improved efficacy over the current diagnostic approaches. We aimed to obtain an improved diagnosis, combining methods of optical spectroscopy -diffuse reflectance and fluorescence- with statistical data analysis applied to detect early stages of NAFLD. METHODS: Statistical analysis scheme based on quadratic discriminant analysis followed by canonical discriminant analysis were applied to the diffuse reflectance data combined with endogenous fluorescence spectral data excited at one of these wavelengths: 330, 365, 385, 405 or 415 nm. The statistical scheme was also applied to the combinations of fluorescence spectrum (405 nm) with each one of the other fluorescence spectra. Details of the developed software, including the application of machine learning algorithms to the combination of spectral data followed by classification statistical schemes, are discussed. RESULTS: Steatosis progression was differentiated with little classification error (≤1.3%) by using diffuse reflectance and endogenous fluorescence at different wavelengths. Similar results were obtained using fluorescence at 405 nm and one of the other fluorescence spectra (classification error ≤1.0%). Adding the corresponding areas under the curves to the above combinations of spectra diminished errors to 0.6% and 0.3% or less, respectively. The best results for the compounded reflectance-plus-fluorescence spectra were obtained with fluorescence spectra excited at 415 nm with a total classification error of 0.2%; for the combination of the 405nm-excited fluorescence spectrum with another fluorescence spectrum, the best results were achieved for 385 nm, for which total relative classification error amounted 0.4%. The consideration of the area under the spectral curves further improved both classifiers, reducing the error to 0.0% in both cases. CONCLUSION: Spectrometric techniques combined with statistical processing are a promising tool to improve steatosis classification through a label free approach. However, statistical schemes here applied, might result complex for the everyday medical practice, the designed software including machine learning algorithms is able to render automatic classification of samples according to their steatosis grade with low error.

Selection of Indicators to Discriminate Soil Tillage Systems and to Assess Soil Quality in a Red Latosol

Abstract The soil tillage practiced over a long period of time impacts soil quality. The first step in soil quality assessment is to select which indicators should be used. The objective of this study was to identify the soil attributes that discriminate soil tillage systems and can be used as indicators for soil quality assessments. Sixteen soil physical and chemical attributes were evaluated: macroporosity (MaP), microporosity (MiP), total porosity (TP), bulk density (BD), field-saturated hydraulic conductivity (Kfs), soil resistance to penetration (SRP), pH (H2O), pH (CaCl2), aluminium (Al), calcium (Ca), magnesium (Mg), potassium (K), available phosphorus (P), total organic carbon (TOC), cation exchange capacity (CEC) and base saturation (BS), of a very clayey Red Latosol, cultivated for a long period in no-till (NT), conventional tillage (CT) and minimum tillage (MT). The soil attributes (indicators) were selected using canonical discriminant analysis. MiP, Kfs, pH (CaCl2), Ca, Mg, CEC e BS were the most efficient indicators to discriminate soil tillage systems. In the indicator interpretation step was sustained MiP as the indicator that represents the function of physical stability and support, Kfs as the indicator that represents the function of water relations, BS as the indicator that represents the function of nutrient cycling and pH (CaCl2) as the indicator that represents the function of filtering and buffering. These indicators can be used for future soil quality assessment and monitoring of tillage systems in similar regions and conditions.

Multivariate techniques in the analysis of carcass traits of Morada Nova breed sheep / Aplicação de técnicas multivariadas em características de carcaça de ovinos da raça Morada Nova

ABSTRACT: This study aimed to use multivariate techniques of principal component analysis and canonical discriminant analysis in a data set from Morada Nova sheep carcass to reduce the dimensions of the original data set, identify variables with the best discriminatory power among the treatments, and quantify the association between biometric and performance traits. The principal components obtained were efficient in reducing the total variation accumulated in 19 original variables correlated to five linear combinations, which explained 80% of the total variation present in the original variables. The first two principal components together accounted for 56.12% of the total variation of the evaluated variables. Eight variables were selected using the stepwise method. The first three canonical variables were significant, explaining 92.25% of the total variation. The first canonical variable showed a canonical correlation coefficient of 0.94, indicating a strong association between biometric traits and animal performance. Slaughter weight and hind width were selected because these variables presented the highest discriminatory power among all treatments, based on standard canonical coefficients.

RESUMO: Este estudo teve o objetivo de aplicar as técnicas multivariadas de componentes principais e discriminante canônica em um conjunto de dados de carcaça de ovinos da raça Morada Nova, a fim de reduzir a dimensionalidade do conjunto de variáveis originais, identificar quais as variáveis com o melhor poder discriminatório entre os tratamentos, além de quantificar a associação entre características biométricas e de desempenho. Os componentes principais gerados foram eficientes em reduzir a variação total acumulada em 19 variáveis originais, correlacionadas para cinco combinações lineares, os quais explicaram 80% da variação total contida nas variáveis originais. Os dois primeiros componentes principais juntos explicam 56,12% da variação total das variáveis avaliadas. Oito variáveis foram selecionadas pelo método stepwise. As três primeiras variáveis canônicas foram significativas, explicando 92,25% da variação total. A primeira variável canônica apresentou o coeficiente de correlação canônica de 0,94, o que indica uma alta associação entre as características de medidas biométricas e de desempenho animal. O peso corporal ao abate e a largura de garupa foram as variáveis selecionadas por apresentar o mais alto poder discriminatório dos tratamentos, com base nos coeficientes canônicos padronizados.

Multivariate techniques in the analysis of carcass traits of Morada Nova breed sheep / Aplicação de técnicas multivariadas em características de carcaça de ovinos da raça Morada Nova

This study aimed to use multivariate techniques of principal component analysis and canonical discriminant analysis in a data set from Morada Nova sheep carcass to reduce the dimensions of the original data set, identify variables with the best discriminatory power among the treatments, and quantify the association between biometric and performance traits. The principal components obtained were efficient in reducing the total variation accumulated in 19 original variables correlated to five linear combinations, which explained 80% of the total variation present in the original variables. The first two principal components together accounted for 56.12% of the total variation of the evaluated variables. Eight variables were selected using the stepwise method. The first three canonical variables were significant, explaining 92.25% of the total variation. The first canonical variable showed a canonical correlation coefficient of 0.94, indicating a strong association between biometric traits and animal performance. Slaughter weight and hind width were selected because these variables presented the highest discriminatory power among all treatments, based on standard canonical coefficients.(AU)

Este estudo teve o objetivo de aplicar as técnicas multivariadas de componentes principais e discriminante canônica em um conjunto de dados de carcaça de ovinos da raça Morada Nova, a fim de reduzir a dimensionalidade do conjunto de variáveis originais, identificar quais as variáveis com o melhor poder discriminatório entre os tratamentos, além de quantificar a associação entre características biométricas e de desempenho. Os componentes principais gerados foram eficientes em reduzir a variação total acumulada em 19 variáveis originais, correlacionadas para cinco combinações lineares, os quais explicaram 80% da variação total contida nas variáveis originais. Os dois primeiros componentes principais juntos explicam 56,12% da variação total das variáveis avaliadas. Oito variáveis foram selecionadas pelo método stepwise. As três primeiras variáveis canônicas foram significativas, explicando 92,25% da variação total. A primeira variável canônica apresentou o coeficiente de correlação canônica de 0,94, o que indica uma alta associação entre as características de medidas biométricas e de desempenho animal. O peso corporal ao abate e a largura de garupa foram as variáveis selecionadas por apresentar o mais alto poder discriminatório dos tratamentos, com base nos coeficientes canônicos padronizados.(AU)

Protein profiles of Taenia solium cysts obtained from skeletal muscles and the central nervous system of pigs: Search for tissue-specific proteins.

Taeniasis/cysticercosis caused by the tapeworm Taenia solium is a parasite disease transmitted among humans and pigs, the main intermediate host. The larvae/cysts can lodge in several tissues of the pig, i.e. skeletal muscles and different locations of the central nervous system. The molecular mechanisms associated to tissue preferences of the cysts remain poorly understood. The major public health concern about this zoonosis is due to the human infections by the larval form in the central nervous system, causing a highly pleomorphic and debilitating disease known as neurocysticercosis. This study was aimed to explore the 2DE protein maps of T. solium cysts obtained from skeletal muscles and central nervous system of naturally infected pigs. The gel images were analyzed through a combination of PDQuest™ and multivariate analysis. Results showed that differences in the protein patterns of cysts obtained from both tissues were remarkably discrete. Only 7 protein spots were found specifically associated to the skeletal muscle localization of the cysts; none was found significantly associated to the central nervous system. The use of distinct protein fractions of cysts allowed preliminary identification of several tissue-specific antigenic bands. The implications of these findings are discussed, as well as several strategies directed to achieve the complete characterization of this parasite's proteome, in order to extend our understanding of the molecular mechanisms underlying tissue localization of the cysts and to open avenues for the development of immunological tissue-specific diagnosis of the disease.

Application of multivariate techniques in the evaluation of pure lines of beans / Aplicação de técnicas multivariadas na avaliação de linhas puras de feijão

ABSTRACT: The objective of this study was to apply multivariate techniques, canonical discriminant analysis, and multivariate contrasts, indicating the most favorable inferences in the evaluation of pure lines of beans. The study was conducted at the experimental field of the Institute for Breeding and Molecular Genetics, in Lages, SC, Brazil. The experiment was composed of 24 pure lines of beans from the Santa Catarina test of cultivars. Plant height, numbers of pods and grains per plant, and stem diameter were the variables measured. The complete randomized block design was used with four replications. The data were subjected to multivariate analysis of variance, canonical discriminant analysis, multivariate contrasts and univariate contrasts. The first canonical discriminant function has captured 81% of the total variation in the data. The Scott-Knott test showed two groups of inbred lines at the average -of scores of the first canonical discriminant function. It was considered that testing hypotheses with the canonical scores may result in loss of information obtained from the original data. Multivariate contrasts indicated differences within the group formed by the Scott-Knott test. The canonical discriminant analysis and multivariate contrasts are excellent techniques to be combined in the multivariate assessment, being used to explore and test hypotheses, respectively.

RESUMO: O objetivo deste estudo foi aplicar técnicas multivariadas (análise discriminante canônica e contrastes multivariados) indicando as inferências mais vantajosas na avaliação de linhas puras de feijão. O estudo foi conduzido na área experimental do Instituto de Melhoramento e Genética Molecular em Lages, SC. O experimento foi composto por 24 linhas puras de feijão provenientes do ensaio catarinense de cultivares. Os caracteres mensurados foram: estatura da planta, números de legumes e grãos por planta e diâmetro do caule. Foi usado o delineamento experimental em blocos casualizados, com quatro repetições. Os dados foram submetidos à análise de variância multivariada, análise discriminante canônica, contrastes multivariados e univariados. A primeira função linear discriminante canônica captou 81% da variação total contida nos dados. O teste de Scott-Knott formou dois grupos de linhas puras na média dos escores da primeira função linear discriminante canônica. Considera-se que testar as hipóteses com os escores canônicos pode causar perda de informações valiosas obtidas pelos dados originais. Os contrastes multivariados evidenciaram diferenças dentro do grupo formado pelo teste de Scott-Knott. A análise discriminante canônica e os contrastes multivariados são técnicas excelentes para serem combinadas na avaliação multivariada, sendo efetuadas para explorar e testar hipóteses, respectivamente.

Application of multivariate techniques in the evaluation of pure lines of beans / Aplicação de técnicas multivariadas na avaliação de linhas puras de feijão

The objective of this study was to apply multivariate techniques, canonical discriminant analysis, and multivariate contrasts, indicating the most favorable inferences in the evaluation of pure lines of beans. The study was conducted at the experimental field of the Institute for Breeding and Molecular Genetics, in Lages, SC, Brazil. The experiment was composed of 24 pure lines of beans from the Santa Catarina test of cultivars. Plant height, numbers of pods and grains per plant, and stem diameter were the variables measured. The complete randomized block design was used with four replications. The data were subjected to multivariate analysis of variance, canonical discriminant analysis, multivariate contrasts and univariate contrasts. The first canonical discriminant function has captured 81% of the total variation in the data. The Scott-Knott test showed two groups of inbred lines at the average -of scores of the first canonical discriminant function. It was considered that testing hypotheses with the canonical scores may result in loss of information obtained from the original data. Multivariate contrasts indicated differences within the group formed by the Scott-Knott test. The canonical discriminant analysis and multivariate contrasts are excellent techniques to be combined in the multivariate assessment, being used to explore and test hypotheses, respectively.(AU)

O objetivo deste estudo foi aplicar técnicas multivariadas (análise discriminante canônica e contrastes multivariados) indicando as inferências mais vantajosas na avaliação de linhas puras de feijão. O estudo foi conduzido na área experimental do Instituto de Melhoramento e Genética Molecular em Lages, SC. O experimento foi composto por 24 linhas puras de feijão provenientes do ensaio catarinense de cultivares. Os caracteres mensurados foram: estatura da planta, números de legumes e grãos por planta e diâmetro do caule. Foi usado o delineamento experimental em blocos casualizados, com quatro repetições. Os dados foram submetidos à análise de variância multivariada, análise discriminante canônica, contrastes multivariados e univariados. A primeira função linear discriminante canônica captou 81% da variação total contida nos dados. O teste de Scott-Knott formou dois grupos de linhas puras na média dos escores da primeira função linear discriminante canônica. Considera-se que testar as hipóteses com os escores canônicos pode causar perda de informações valiosas obtidas pelos dados originais. Os contrastes multivariados evidenciaram diferenças dentro do grupo formado pelo teste de Scott-Knott. A análise discriminante canônica e os contrastes multivariados são técnicas excelentes para serem combinadas na avaliação multivariada, sendo efetuadas para explorar e testar hipóteses, respectivamente.(AU)

A comparison of fresh, pasta filata, and aged Hispanic cheeses using sensory, chemical, functional, and microbiological assessments.

Anecdotal information suggests that some Hispanic consumers may consider US-made Hispanic cheeses as having a general lack of authenticity compared with those made in their countries of origin. To characterize the potential differences, samples of fresh, pasta filata, and aged Hispanic cheeses were acquired from both the United States (total n=39) and countries of origin (total n=30) purchased from Mexico, Central America (Costa Rica and El Salvador), and the Caribbean (Puerto Rico). The proximate composition, microbial counts, melt profile, and sensory characteristics were evaluated and compared in country-of-origin cheeses and the US-made counterparts. The presence of Listeria spp. was confirmed for 1 Mexican aged cheese sample and 6 cheese samples from Central America (3 fresh, 2 pasta filata, and 1 aged). The chemical composition, melt profile, and sensory characteristics of fresh and pasta filata US Hispanic cheeses were not significantly different from their Mexican counterparts. Likewise, the chemical composition and melt profile of US aged Hispanic cheeses was not significantly different from the aged Mexican cheeses, but sensory characteristics varied among all aged cheeses. These results demonstrate the similarities and differences among US fresh, pasta filata, and aged Hispanic cheeses relative to their counterparts made in the countries of origin.

Soil physical properties in Royal Gala apple orchards under conventional and organic production systems / Atributos físicos do solo em pomares de maçãs Royal Gala em sistemas convencional e orgânico de produção

The management of apple orchards is conditioned by the form of cultivation adopted, which influences on plant yield, profitability and longevity of the area. This study aimed to evaluate the effects of management systems for conventional and organic apple production on soil physical properties and identify the variables that discriminate between the two production systems, using canonical discriminant analysis (CDA). The experiment was carried out in São Joaquim, SC, in two orchards, one under conventional system (CS) and the other under organic system (OS), both established in 2001, using Royal Gala cultivar, on M9 rootstock, in a Humic Cambisol. Soil samples were collected during 2008-2009 season in the layers 0-10 cm and 10-20 cm. The soil physical properties evaluated were particle size distribution, aggregate stability, represented by the mean geometric diameter (MGD), bulk density (BD), total porosity (TP) and degree of flocculation (DF). The results were tested for comparison of means and CDA. The OS had higher values of MGD and BD in the two layers. In the 10-20 cm layer, macroporosity was greater in the CS. The MGD in the layer 0-10 cm and microporosity in the layer 10-20 cm showed the highest values of parallel discrimination rate coefficient (PDRC), revealing that these properties were good indicators of soil physical quality and can be used to study changes in apple

O manejo dos pomares de maçãs é condicionado pela forma de cultivo adotado, o qual influencia na sua produtividade, lucratividade e longevidade. O presente estudo teve como objetivo avaliar os efeitos dos sistemas de manejo convencional e orgânico de produção de maçãs sobre atributos físicos do solo e identifi car os parâmetros que discriminam os dois sistemas de produção, por meio da utilização da análise canônica discriminante (ACD). O experimento foi realizado no município de São Joaquim, SC, em dois pomares, um no sistema convencional (PC) e o outro no sistema orgânico (PO), ambos implantados em 2001, com a cultivar Royal Gala, sobre porta-enxerto M-9, em um Cambissolo Húmico. As amostras de solo foram coletadas na safra 2008-2009, nas camadas de 0-10 cm e 10-20 cm. Os atributos físicos do solo avaliados foram granulometria, estabilidade de agregados, representada pelo diâmetro médio geométrico (DMG), densidade do solo (Ds), macro, micro e porosidade total (PT) e grau de floculação (GF). Os resultados obtidos foram submetidos ao teste de Tukey para comparação de médias e à ACD. O PO apresentou menores valores de DMG e macroporosidade na camada de 0-10 cm. Na camada de 10-20 cm, a macroporosidade e PT foram maiores no PC. O DMG na camada de 0-10 cm e a microporosidade na camada de 10-20 cm apresentaram os maiores valores de coeficientes de taxa de discriminação paralela (TDP

Soil physical properties in Royal Gala apple orchards under conventional and organic production systems / Atributos físicos do solo em pomares de maçãs Royal Gala em sistemas convencional e orgânico de produção

The management of apple orchards is conditioned by the form of cultivation adopted, which influences on plant yield, profitability and longevity of the area. This study aimed to evaluate the effects of management systems for conventional and organic apple production on soil physical properties and identify the variables that discriminate between the two production systems, using canonical discriminant analysis (CDA). The experiment was carried out in São Joaquim, SC, in two orchards, one under conventional system (CS) and the other under organic system (OS), both established in 2001, using Royal Gala cultivar, on M9 rootstock, in a Humic Cambisol. Soil samples were collected during 2008-2009 season in the layers 0-10 cm and 10-20 cm. The soil physical properties evaluated were particle size distribution, aggregate stability, represented by the mean geometric diameter (MGD), bulk density (BD), total porosity (TP) and degree of flocculation (DF). The results were tested for comparison of means and CDA. The OS had higher values of MGD and BD in the two layers. In the 10-20 cm layer, macroporosity was greater in the CS. The MGD in the layer 0-10 cm and microporosity in the layer 10-20 cm showed the highest values of parallel discrimination rate coefficient (PDRC), revealing that these properties were good indicators of soil physical quality and can be used to study changes in apple

O manejo dos pomares de maçãs é condicionado pela forma de cultivo adotado, o qual influencia na sua produtividade, lucratividade e longevidade. O presente estudo teve como objetivo avaliar os efeitos dos sistemas de manejo convencional e orgânico de produção de maçãs sobre atributos físicos do solo e identifi car os parâmetros que discriminam os dois sistemas de produção, por meio da utilização da análise canônica discriminante (ACD). O experimento foi realizado no município de São Joaquim, SC, em dois pomares, um no sistema convencional (PC) e o outro no sistema orgânico (PO), ambos implantados em 2001, com a cultivar Royal Gala, sobre porta-enxerto M-9, em um Cambissolo Húmico. As amostras de solo foram coletadas na safra 2008-2009, nas camadas de 0-10 cm e 10-20 cm. Os atributos físicos do solo avaliados foram granulometria, estabilidade de agregados, representada pelo diâmetro médio geométrico (DMG), densidade do solo (Ds), macro, micro e porosidade total (PT) e grau de floculação (GF). Os resultados obtidos foram submetidos ao teste de Tukey para comparação de médias e à ACD. O PO apresentou menores valores de DMG e macroporosidade na camada de 0-10 cm. Na camada de 10-20 cm, a macroporosidade e PT foram maiores no PC. O DMG na camada de 0-10 cm e a microporosidade na camada de 10-20 cm apresentaram os maiores valores de coeficientes de taxa de discriminação paralela (TDP

The differences in body volume and skinfold thickness between basketball players and footballers / Diferencias en el volumen corporal y el grosor de los pliegues cutáneos entre los jugadores de baloncesto y jugadores de fútbol

The human body is composed of lean tissues that are metabolically active, and fat tissue that is not metabolically active, but is an essential part of human body. Training is a significant factor affecting body composition, performance, as well and physiological parameters. The aim of this study was through changeable of 13 measured anthropometrical variables, to research the influence of different sports in body composition. The anthropometrical tests were done on 90 basketball players and 512 footballers from Kosova. The gained results were analyzed in terms of basic statistical parameters, T-test, and Canonical Discriminant Analysis. T-test shows that basketballers and footballers have realized significant differences in almost all measured variables. Canonical Discriminative Analysis indicates the characteristics of tested sportsmen: The basketballers are taller and heavier than footballers, as well they have the greater bodily volume, and more skinfold thickness, compared with footballers. It seems that the bodily volume of the tested basketballers has been influenced by the elements of basketball, than the bodily volume of footballers by the elements of football. As for subcutaneous adipose tissue that is less disperse on the footballers body compared with basketballers, could be explained with different ratio between aerobic and anaerobic demands of different sports.

El cuerpo humano se compone de tejido blando que es metabólicamente activo y tejido graso que no es metabólicamente activo, pero es una parte esencial del cuerpo. El entrenamiento es un factor significativo que afecta la composición corporal, el rendimiento y los parámetros fisiológicos. El objetivo de este estudio fue investigar la influencia de los diferentes deportes en la composición corporal, a través de la medición de 13 variables antropométricas. Las pruebas antropométricas fueron realizadas en 90 jugadores de baloncesto y 512 jugadores de fútbol de la ciudad de Kosovo. Los resultados obtenidos fueron analizados estadísticamente utilizándose el T-test y el análisis discriminante canónico. El T-test mostró que los jugadores de baloncesto y los futbolistas poseen diferencias significativas en casi todas las variables estudiadas. El análisis discriminante canónico de las características de los deportistas evaluados mostraron que: los jugadores de baloncesto son más altos y de mayor peso que los futbolistas y tenían mayor volumen corporal y pliegues cutáneos en comparación con los futbolistas. El volumen corporal de los jugadores de baloncesto han sido más influenciados por los elementos del baloncesto, que el volumen corporal de los futbolistas por los elementos del fútbol. En cuanto a tejido adiposo subcutáneo, es menos disperso en el cuerpo de los futbolistas comparado con jugadores de baloncesto, lo que podría explicarse por una relación diferente entre las demandas aeróbica y anaeróbica exigidas en los diferentes deportes.

Geographic pattern of morphological variation of the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), using multivariate morphometry / Padrão geográfico de variação morfológica do ácaro do coqueiro, Aceria guerreronis Keifer (Acari: Eriophyidae), utilizando morfometria multivariada

The coconut mite, Aceria guerreronis Keifer, has become one of the most important pests of coconut in the Americas and Africa and recently in Southeast Asia. Despite the great economic importance of this mite, there is a lack of information on its origin and invasion history that are important to guide the search of biological control agents as well as the adoption of quarantine procedures. This study evaluates morphometric variation among A. guerreronis populations throughout its occurrence area, relates this variation with historical sequence of records, looking for information on its biogeography. Samples of 27 populations from the Americas, Africa and Asia were analysed using Principal Component Analysis and Canonical Discriminant Analysis. Results showed significant morphometric variability of A. uerreronis throughout its distribution area, with a high variability among American populations and otherwise a high similarity among African and Asian populations. The geographic pattern of variation of mite populations observed supports the hypothesis that A. guerreronis originated in the Americas and was introduced into Africa and Asia. Some inferences related to taxonomy of Eriophyoidea mites were included.

O ácaro do coqueiro, Aceria guerreronis Keifer, se tornou uma das pragas mais importantes do coqueiro nas Américas e África e, recentemente, no sudeste da Ásia. Apesar da importância econômica deste ácaro, faltam informações sobre sua origem e seu histórico de invasão, o que é importante para orientar a busca de agentes de controle biológico assim como a adoção de medidas quarentenárias. Este estudo teve como objetivo avaliar a variação morfométrica entre populações de A. guerreronis ao longo de sua área de ocorrência, relacionar esta variação com a sequência histórica de registros, buscando informações sobre sua biogeografia. Amostras de 27 populações das Américas, África e Ásia foram analisadas utilizando-se Análise dos Componentes Principais e Análise Discriminante Canônica. Os resultados mostraram uma significante variabilidade de A. guerreronis ao longo de sua área de distribuição, com uma alta variabilidade entre as populações americanas e, por outro lado, uma alta similaridade entre populações africanas e asiáticas. O padrão geográfico de variação de populações do ácaro observado suporta a hipótese de que A. guerreronis é originário da América e foi introduzido na África e Ásia. Algumas inferências relacionadas à taxonomia de ácaros Eriophyoidea foram incluídas.

Geographic pattern of morphological variation of the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), using multivariate morphometry

The coconut mite, Aceria guerreronis Keifer, has become one of the most important pests of coconut in the Americas and Africa and recently in Southeast Asia. Despite the great economic importance of this mite, there is a lack of information on its origin and invasion history that are important to guide the search of biological control agents as well as the adoption of quarantine procedures. This study evaluates morphometric variation among A. guerreronis populations throughout its occurrence area, relates this variation with historical sequence of records, looking for information on its biogeography. Samples of 27 populations from the Americas, Africa and Asia were analysed using Principal Component Analysis and Canonical Discriminant Analysis. Results showed significant morphometric variability of A. uerreronis throughout its distribution area, with a high variability among American populations and otherwise a high similarity among African and Asian populations. The geographic pattern of variation of mite populations observed supports the hypothesis that A. guerreronis originated in the Americas and was introduced into Africa and Asia. Some inferences related to taxonomy of Eriophyoidea mites were included.

O ácaro do coqueiro, Aceria guerreronis Keifer, se tornou uma das pragas mais importantes do coqueiro nas Américas e África e, recentemente, no sudeste da Ásia. Apesar da importância econômica deste ácaro, faltam informações sobre sua origem e seu histórico de invasão, o que é importante para orientar a busca de agentes de controle biológico assim como a adoção de medidas quarentenárias. Este estudo teve como objetivo avaliar a variação morfométrica entre populações de A. guerreronis ao longo de sua área de ocorrência, relacionar esta variação com a sequência histórica de registros, buscando informações sobre sua biogeografia. Amostras de 27 populações das Américas, África e Ásia foram analisadas utilizando-se Análise dos Componentes Principais e Análise Discriminante Canônica. Os resultados mostraram uma significante variabilidade de A. guerreronis ao longo de sua área de distribuição, com uma alta variabilidade entre as populações americanas e, por outro lado, uma alta similaridade entre populações africanas e asiáticas. O padrão geográfico de variação de populações do ácaro observado suporta a hipótese de que A. guerreronis é originário da América e foi introduzido na África e Ásia. Algumas inferências relacionadas à taxonomia de ácaros Eriophyoidea foram incluídas.