Consulta: subjectFacets:"Multivariate"
Registros recuperados: 12
Data/hora: 01/06/2024 09:28:07

Long-term variability of the Abra alba community in the southern bight of the North Sea
Provedor de dados: 5
Autores: Carpenter, P; Dewarumez, Jm; Lepretre, A.
The Abra alba community from the Gravelines area has been studied since 1976. During this period, sudden and unpredictable variations of the species composition have been observed. These important changes affect a limited number of species without changing the bionomical structure of the community. The species in question are found to be characteristic of this community, and are the more abundant ones. Multivariate statistical methods were used to study quantitative data on the benthic population collected from 1978 to 1992. This analysis was performed in association with air temperature data. Results showed the existence of a six- or seven-year cycle, and this is confirmed by the observation of two complete periods. This cycle, which is found to be...
Tipo: Text
Palavras-chave: Long-term trends; Time series; Multivariate; Methods; Benthos.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00093/20398/18065.pdf

Aires marines protégées et récifs artificiels : méthodes d'évaluation, protocoles expérimentaux et indicateurs
Provedor de dados: 5
Autores: Claudet, Joachim.
Marine Protected Areas' (MPAs) and Artificial Reef's (ARs) management requires complex assessment and monitoring programmes, dealing with different sources of variability. We studied and developed experimental designs and analysis methods suited for the establishment of a monitoring of MPAs and ARs. This methodology is developed from existing data sets in the Northwestern Mediterranean. We build multi-criteria indicators allowing a statistically testable diagnosis of the impact of MPAs and ARs on reef fish assemblages. Using ecological performance indicators permits to monitor and to give an image of the assessed system to managers.  It was possible to show the global response of the fish assemblages to the protection by a MPA. This response was evidenced...
Tipo: Text
Palavras-chave: Management; Northwestern Mediterranean; Statistical Power; Monitoring; Habitat; Multivariate; Indicators; Temperate Fish; Impact Assessment; Artificial Reefs; Marines Protected Areas; Gestion; Méditerranée Nord Occidentale; Puissance Statistique; Suivis; Habitat; Multivarié; Indicateurs; Poissons Tempérés; Evaluation d'Impact; Récifs Artificiels; Aires Marines Protégées.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/these-2132.pdf

Use of Morphometric Variables for Differentiating Spanish Hound Breeds
Provedor de dados: 77
Autores: González,A; Luque,M; Rodero,E; González,C; Aguilera,R; Jiménez,J; Sepúlveda,N; Bravo,S; Herrera,M.
The term Podencos refers to a group of dog breeds from Spain and classification in Group 5 of dog breeds by the Fédération Cynologique Internationale (FCI). The aim of this study was to compare traits morphometric breeds of Podencos; Canario, Ibecenco, Andaluz (small, medium and large) and Orito. Ten morphometric variables were measured in 385 animals (245 females and 140 males), head length, muzzle length, height at withers, rump height, body length, head width, rump width, chest depth, chest girth and the shin circumference. Morphostructural variables were more homogeneous in the Podenco Ibicenco and the Podengo Canario, because for many years there were gradually distinctive trait standards for each breed. The discriminate analysis indicated...
Tipo: Journal article
Palavras-chave: Morphometric; Dog breed; Hound; Multivariate.
Ano: 2011
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022011000400030

Quality Risk and Profitability in Cattle Production: A Multivariate Approach
Provedor de dados: 31
Autores: Belasco,   Eric J.; Schroeder,   Ted C.; Goodwin,   Barry K.
This study evaluates quality, production, and price risk within the context of overall profit variability in fed cattle production. The approach used offers a flexible way to estimate a large system of equations with more than three jointly related censored outcomes. Trade-offs between quality and yield grade levels and production measures, such as average daily gain and feeding efficiency, are evaluated. Simulation procedures are used to assess the impact of quality risk on overall profit variability. Results make an important contribution to existing research by explaining why price signals through grid quality grade premiums may not generate intended producer responses.
Tipo: Journal Article
Palavras-chave: Censoring; Copula; Fed cattle; Grid pricing; Multivariate; Quality risk; Livestock Production/Industries.
Ano: 2010
URL: http://purl.umn.edu/97854

Smallholder Adoption of Soil and Water Conservation Practices in Northern Ghana
Provedor de dados: 31
Autores: Nkegbe,   Paul K.; Shankar,   Bhavani; Ceddia,   M. Graziano.
Both governmental and non-governmental organizations are engaged in the promotion of soil and water conservation practices in northern Ghana, but adoption is believed to be low. This study thus examines the determinants of conservation practices by farming households in the area. Data for the study was collected from 445 households located in 15 communities in northern Ghana. Univariate, bivariate and multivariate probit models were used to analyse the decision to adopt six conservation practices in the area. Results show the major determinants of adoption are plot and cropping characteristics such as location; and socio-economic and institutional variables such as number of contacts with extension officers, membership in farmer association and distance to...
Tipo: Conference Paper or Presentation
Palavras-chave: Conservation practice; Multivariate; Selectivity bias; Ghana; Resource /Energy Economics and Policy.
Ano: 2011
URL: http://purl.umn.edu/114608

Growth, production and yield of common bean under water replacement levels
Provedor de dados: 91
Autores: Magalhães,Ivomberg D.; Lyra,Guilherme B.; Souza,José L. de; Lyra,Gustavo B.; Ferraz,Rener L. de S.; Cavalcante Júnior,Constantino A.
ABSTRACT The bean is a world-class crop and requires adequate water management for higher yield. The objective of this study was to evaluate the growth and the production and to fit multiple regression models to estimate the production components, total biomass accumulation and grain yield of ‘Rosinha’ bean under levels of replacement of evapotranspired water. The experimental design was randomized blocks with four repetitions. Treatments consisted of fractions of crop evapotranspiration (25, 50, 75, 100, 125 and 150% ETc). Growth variables (plant height, number of leaves, leaf area per plant, leaf area index, stem dry mass and leaf dry mass) and production components (number of pods per plant, pod length, pod diameter, pod dry mass, total biomass, pod...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Phaseolus vulgaris; Irrigation; Multivariate.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662019001000754

Cluster evaluation of Brazilian and Moroccan goat populations using physical measurements
Provedor de dados: 96
Autores: Pires,Luanna Chácara; Machado,Théa Mírian Medeiros; Araújo,Adriana Mello de; Silva,João Batista Lopes da; Euclydes,Ricardo Frederico; Costa,Márcio da Silva; Olson,Timothy Aanen.
The aim of this study was to compare the genetic diversity of 12 populations of goats in Brazil and Morocco (n = 796) through the use of physical measurements and different multivariate techniques. Traits measured included wither height (WH), distance from the brisket to the ground (BH) and ear length (EL). The standardized Euclidean distance (D) was adopted. The D values were submitted to clustering analysis using hierarchical methods (from nearest neighbor and UPGMA - Unweighted Pair Group Method with Arithmetic Mean) and the numbers of clusters were analyzed using the Tocher optimization method. The population clustering was different depending on the method of analysis used. Among the hierarchical methods, UPGMA showed the best fit (CCC = 0.82). The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biometry; Divergence genetic; Genetic resources; Multivariate; Zoometric indexes.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013001000004

Microbiological attributes of a cultivated Plinthosol with sugarcane on different levels of straw
Provedor de dados: 109
Autores: Torres-Pórtela,Mirya Grazielle; Carvalho-Leite,Luiz Fernando; Pires-Barbosa,Ranyellson.
Abstract The objective of this work was to evaluate the microbiological attributes of a Plinthossol cropped with sugar cane in straw. The experiment was installed in União (04 ° 51’09”S and 42 ° 53’10 ‘’ W, altitude 52 m), northern region of Piauí state, Brazil. The experimental design was randomized blocks, with four replications, and treatments corresponding to different rates of straw (Mg.ha-1) (0, 4.19, 9.54, 13.04 and 18.38). Microbiological attributes were determined at a depth of 0-10 cm. Data was submitted to analysis of variance, cluster analysis and main components. An increase of straw in the soil influenced the stocks and contents of C, Cmic, Nmic, respiration and microbial and metabolic quotients. Cluster analysis combined the treatments into...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Microorganisms; Multivariate; Biomass; Saccharum offcinarum; Soil organic matter.
Ano: 2020
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122020000400306

Comparison of projection of distance techniques for genetic diversity studies
Provedor de dados: 1
Autores: Sant'Anna, Isabela de Castro; Silva, Gabi Nunes; Carneiro, Vinicius Quintão; Pontes, Daiana Salles; Nascimento, Moyses; Cruz, Cosme Damião.
The objective of this study was to compare different graphical dispersion analysis techniques in two- or three-dimensional planes. In this study, the data from different published works were used in order to determine the best methodology for analyzing the genetic diversity of different species. In this study, efficiency is measured by the amount of original distance absorbed by the projection of distances technique, which in the case of major components is equal to the amount of total variation originally available and retained by the principal components used for dispersion purposes. The projection of dissimilarity measurement technique, principal component analysis (PCA), and principal coordinate analysis (PCoA) were used. Considering the analysis by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Adaptive methods; Dissimilarity; Multivariate; Crops; Statistical.
Ano: 2019
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/42483

Genetic divergence among castor bean lines and parental strains using ward’s method based on morpho-agronomic descriptors
Provedor de dados: 1
Autores: Silva, Adielle Rodrigues da; Silva, Simone Alves; Santos, Laurenice Araújo; Souza, Deoclides Ricardo de; Araújo, Gilmara de Melo; Moreira, Ricardo Franco Cunha.
This study sought to evaluate the genetic divergence among castor lines and parental strains in the germplasm bank at the Federal University of Recôncavo da Bahia (Universidade Federal do Recôncavo da Bahia) using morpho-agronomic descriptors. This experiment was conducted from 2014 to 2015 with 208 treatments represented by bank accessions that were analyzed using a randomized block design, which established homogeneity of the experimental conditions with all treatments repeated in four blocks. The genetic divergence analysis was performed using Ward’s method and Tocher’s method based on Gower’s distance, which are two clustering methods used in studies with castor beans, with the help of the statistical programs R and GENES. The results revealed the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ciências Agrárias Ricinus communis L.; Multivariate; Variability Melhoramento Genético de Plantas.
Ano: 2017
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/32504

Silversides in South Brazil: Morphological and ecological aspects
Provedor de dados: 47
Autores: Bemvenuti,M. A.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Silversides; Odontesthes; Brazil; Morphology; Multivariate.
Ano: 2006
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452006000100013

Statistical methods to study adaptability and stability in breeding lines of food-type soybeans
Provedor de dados: 53
Autores: Freiria,Gustavo Henrique; Gonçalves,Leandro Simões Azeredo; Furlan,Felipe Favoretto; Fonseca Junior,Nelson da Silva; Lima,Wilmar Ferreira; Prete,Cássio Egidio Cavenaghi.
ABSTRACT The grains of food-type soybean cultivars, which are characterized by the absence of lipoxygenases and the presence of high levels of proteins and isoflavones, are regarded as functional foods with high acceptance by consumers. However, few cultivars of food-type soybeans are currently available in the Brazilian market. The aim of this work was to study the adaptability and stability of various genotypes of food-type soybeans and to compare the performance of methods, which are based on analysis of variance, non-parametric, regression, multivariate and mixed models. Ten lines of food-type soybeans obtained from the Breeding Program of Soybeans for Human Consumption of the State University of Londrina (UEL/BPSHC) and two commercial varieties, the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glycine max; Yield; Non-parametric; Regression; Multivariate; Mixed models.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052018000200253