Data/hora: 03/06/2024 15:33:43

Biblioteca(s): 	Embrapa Caprinos e Ovinos.	
Data corrente: 	11/10/2002	
Data da última atualização: 	11/10/2002	
Autoria: 	CABARET, J.; HOSTE, H.	
Título: 	Comparative analysis of two methods used to show interspecific associations in naturally acquired parasite nematode communities from the abomasum of ewes.	
Ano de publicação: 	1998	
Fonte/Imprenta: 	Veterinary Parasitology, v. 76, n. 4, p. 275-285, 1998.	
Idioma: 	Inglês	
Conteúdo: 	The aim of our study was to compare a multivariate and a univariate method to evaluate the associations between nematode species in natural infections. We used a data set based on the ear study of the community of abomasal nematodes in ewes of the middle-Atlas region of Morocco. Frequency data (percentage of each species in the individual host community) were processed by principal component ana1ysis. Euclidean distances between species (D2) were calculated from projections of principal component analysis on three axes and compared to a bivariate estimate (I - correlation coefficient R). Low distances were recorded between morphs the same species (Teladorsagia circurncincta and T. trifurcata, for example), which indicates a positive association. Only two species, Trichostrongylus axei and T. circurncincta, were negatively associated having D2 values much over I. The distances D2' i.e., multivariate measure of association intensity were similar in most cases to I - R estimates, indicating probably the absence of strong multispecies association. The D2 fitted a Motomura geometric progression model indicating that associations were arranged in a continuum from low to high values, but they not depart much from what could be expected from random associations for most species. The interest is mostly to relate associations with environmental variables, and comparing with 1 - R, to assess the degree of interaction in the community. 
	
Palavras-Chave: 	Distância multivariada; Nematódeo gastrintestinal.	
Thesagro: 	Ovino; Parasitologia.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Caprinos e Ovinos (CNPC)	
Exemplares: 	CNPC - (14961-1) - ADC - AP - -- -  -  - v.76(4) - DIS