Consulta: subjectFacets:"Population size"
Registros recuperados: 8
Data/hora: 05/06/2024 17:25:06

Population structure and genetic variability of mainland and insular populations of the Neotropical water rat, Nectomys squamipes (Rodentia, Sigmodontinae)
Provedor de dados: 74
Autores: Almeida,Francisca C.; Maroja,Luana S.; Moreira,Miguel A.M.; Seuánez,Héctor N.; Cerqueira,Rui.
Seven microsatellite loci were used to investigate the genetic variability and structure of six mainland and two island populations of the Neotropical water rat Nectomys squamipes, a South American semi-aquatic rodent species with a wide distribution. High levels of variability were found within mainland populations while island populations were less variable but the more differentiated in respect to allele number and frequency. The time of biological divergence between mainland and island populations coincided with geological data. A significant geographic structure was found in mainland populations (theta = 0.099; rho = 0.086) although the degree of differentiation was relatively low in respect to the distance between surveyed localities (24 to 740 km)....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Microsatellites; Population genetics; Islands; Population expansion; Population size; Divergence time.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500008

A critical evaluation of the effect of population size and phenotypic measurement on QTL detection and localization using a large F2 murine mapping population
Provedor de dados: 74
Autores: Li,Xinmin; Quigg,Richard J; Zhou,Jian; Xu,Shizhong; Masinde,Godfred; Mohan,Subburaman; Baylink,David J.
Population size and phenotypic measurement are two key factors determining the detection power of quantitative trait loci (QTL) mapping. We evaluated how these two controllable factors quantitatively affect the detection of QTL and their localization using a large F2 murine mapping population and found that three main points emerged from this study. One finding was that the sensitivity of QTL detection significantly decreased as the population size decreased. The decrease in the percentage logarithm of the odd score (LOD score, which is a statistical measure of the likelihood of two loci being lied near each other on a chromosome) can be estimated using the formula 1 - n/N, where n is the smaller and N the larger population size. This empirical formula has...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: QTL mapping; Mice; Detection power; Population size; Phenotypic measurement.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000100030

Mating system parameters in a high density population of andirobas in the Amazon forest
Provedor de dados: 86
Autores: Campos,Tatiana de; Cunha,Marcia Oliveira da; Sousa,Adna Cristina Barbosa de; Teixeira,Renata Beltrão; Raposo,Andrea; Sebbenn,Alexandre Magno; Wadt,Lucia Helena de Oliveira.
The objective of this work was to estimate the mating system parameters of a andiroba (Carapa guianensis) population using microsatellite markers and the mixed and correlated mating models. Twelve open‑pollinated progeny arrays of 15 individuals were sampled in an area with C. guianensis estimated density of 25.7 trees per hectare. Overall, the species has a mixed reproductive system, with a predominance of outcrossing. The multilocus outcrossing rate (t m = 0.862) was significantly lower than the unity, indicating that self‑pollination occurred. The rate of biparental inbreeding was substantial (t m ‑ t s = 0.134) and significantly different from zero. The correlation of selfing within progenies was high (r s = 0.635), indicating variation in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carapa guianensis; Allogamy; Conservation; Genetic breeding; Microsatellite; Population size.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2013000500006

A field comparison of two capture-mark-recapture estimators of small mammal populations
Provedor de dados: 104
Autores: Gentile,Rosana; Fernandez,Fernando A.S.
The results obtained by two estimators of population sizes, MNKA and Mh, were compared for four species of small mammmals - Didelphis aurita Wied, 1826, Philander frenata (Olfers, 1818), Nectomys squamipes (Brants, 1827) and Akodon cursor (Winge, 1887) - during a long-term population study. The MNKA estimator consistently underestimated the population sizes in relation to Mh. On the other, the probabilistic estimator Mh, which reduces bias through the jackknife technique, could not be used in all cases as its assumptions were not always met. Correction factors between the estimates obtained by the two methods were calculated for the last three species, for which catchability did not vary significantly in time and that presented positive correlation between...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Capture-recapture; Jackknife estimator; Minimun number known alive; Population size.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751999000400020

Description of the male of Daguerreia inermis Soares &amp;amp; Soares, with biological notes on population size in the Gruta da Lancinha, Paraná, Brazil (Arachnida, Opiliones, Gonyleptidae)
Provedor de dados: 104
Autores: Pinto-da-Rocha,Ricardo.
The male of Daguerreia inermis Soares &amp;amp; Soares, 1947, a troglophilic harvestman, is described. Distribution records are given for caves of the Speleological Province of Vale do Ribeira and two non carbonatic areas (Telêmaco Borba and Arapoti, Paraná), in southeastern Brazil. The population of the Gruta da Lancinha (Paraná, Brazil) was studied from October 1988 to February 1989. The population size was estimated, by Fisher Ford's method, between 158-610 individuals. The sex ratio observed was 1:1.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Arachnida; Opiliones; Daguerreia inermis; Cave fauna; Population size.
Ano: 1996
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751996000400004

Population Structure of Mesoclemmys vanderhaegei (Bour, 1973) (Testudines:Chelidae) in the Cerrado of Chapada dos Guimarães, Mato Grosso, Brazil
Provedor de dados: 49
Autores: Brito,Elizângela Silva de; Strussmann,Christine; Penha,Jerry Magno Ferreira.
Studies on population structure of freshwater turtles belonging to the family Chelidae are scarce in Brazil. Herein we describe the structure of a population of the chelid Mesoclemmys vanderhaegei in a Cerrado area in the municipality of Chapada dos Guimarães, Mato Grosso, Brazil. A total of 80 individuals were captured in five collecting sites, from January to March 2007: 42 adult females, 27 adult males, and 11 juveniles with undetermined sex. Among 80 individuals, 24% were recaptured, at least once. This is the first attempt to estimate the size of a population of Mesoclemmys vanderhaegei. Our results suggest that additional sampling efforts are needed for more accurate estimates of population structure. Nevertheless, they surely provide minimum values...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Chelidae; Neotropics; Sex ratio; Population size; Freshwater turtles.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032009000400024

NOTES ON THE ECOLOGY OF THE COLOMBIAN LEAFTOED GECKO (PHYLLODACTYLUS TRANSVERSALIS), ENDEMIC TO MALPELO ISLAND
Provedor de dados: 50
Autores: López-Victoria,Mateo; Jurczyk,Matthias; Wolters,Volkmar.
The Colombian leaf-toed gecko (Phyllodactylus transversalis) is the least known reptile species of Malpelo Island (Eastern Tropical Pacific). In the 37 years since its original description, no single study strictly dedicated to this species has been conducted. With the goal of providing information on the ecology and population size of this gecko, data collected during two visits to the island are presented. Behavior and reproduction were studied by following individuals during the night and by searching for hidden individuals and eggs during the day. Population's density and habitat preferences were estimated by classifying the island's surfaces into four types and counting geckos inside those habitats within band transects. General morphological...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Phyllodactylus transversalis; Behavior; Reproduction; Habitat preference; Population size.
Ano: 2013
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612013000200006

Estimation of population profiles of two strains of the fly Megaselia scalaris (Diptera: Phoridae) by bootstrap simulation
Provedor de dados: 57
Autores: MANZATO,A. J.; TADEI,W. J.; CORDEIRO,J. A.
Based on experimental population profiles of strains of the fly Megaselia scalaris (Phoridae), the minimal number of sample profiles was determined that should be repeated by bootstrap simulation process in order to obtain a confident estimation of the mean population profile and present estimations of the standard error as a precise measure of the simulations made. The original data are from experimental populations founded with SR and R4 strains, with three replicates, which were kept for 33 weeks by serial transfer technique in a constant temperature room (25 ± 1.0°C). The variable used was population size and the model adopted for each profile was a stationary stochastic process. By these simulations, the three experimental population profiles were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bootstrap; Megaselia; Populations; Simulation; Population size.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000300006