scholarly journals The phylodynamic of H1a genotype measles virus in Jiangsu province, China, 2005-2017

2019 ◽  
Author(s):  
Peishan Lu ◽  
Ying Hu ◽  
Xiuying Deng ◽  
Xiang Sun ◽  
Hongxiong Guo
Keyword(s):  
Measles Virus ◽  
Bayesian Skyline Plot ◽  
Jiangsu Province ◽  
Monte Carlo Algorithm ◽  
Gene Sequences ◽  
Effective Population ◽  
Helpful Tool ◽  
Nucleoprotein Gene ◽  
Multiple Origins ◽  
The Mean

Abstract Background: The change on the pressures during viruses evolving will cause changes in phylodynamic. To know phylodynamic characteristic of measles virus in high vaccination coverage era, the phylodynamic characteristic was analyzed using nucleoprotein gene sequences of measles viruses isolated from Jiangsu province of China from 2005 to 2017. Methods: Nucleoprotein gene sequences of measles viruses were used to analyze gene distance and construct phylogenetic tree with Markov chain Monte Carlo algorithm. The mean gene distance within each group was computed with MEGA7.0 software. The phylodynamic of measles virus circulating in Jiangsu province was constructed using Bayesian skyline plot analyses. Results: Our results showed that the decline trend is observed in the gene distance of nucleoprotein gene and effective population size of measles virus with time. Two clusters of H1a genotype shows multiple origins and the extinction of variants with time. Conclusion: These findings highlight that phylodynamic of measles viruses is a helpful tool to assess the effectiveness of epidemic control.

Phylogenetic analysis of the nucleoprotein gene of measles viruses prevalent in Nantong, Jiangsu Province, China, during 2010

2011 ◽  
Vol 140 (9) ◽  
pp. 1607-1611
Author(s):  
H. LI ◽  
S. D. SPENCER ◽  
L. LIAN ◽  
Z. ZHANG ◽  
P. LU
Keyword(s):  
Phylogenetic Analysis ◽  
Nucleotide Sequence ◽  
Measles Virus ◽  
Genetic Characterization ◽  
Jiangsu Province ◽  
Wild Type ◽  
City Region ◽  
Rt Pcr ◽  
Nucleoprotein Gene ◽  
Endemic Transmission

SUMMARYMeasles control in China is monitored in part by surveillance of circulating wild-type viruses. The objective of this study was genetic characterization and phylogenetic analysis of measles strains in the Nantong City region of Jiangsu province, China, during 2010. Sera from suspected cases were tested for IgM antibodies and measles virus isolated by inoculation of transport medium onto Vero/SLAM cells. Isolated strains were phylogenetically analysed according to the nucleotide sequence of the C-terminal region of the nucleoprotein gene amplified by RT–PCR. The results revealed 34 cases confirmed by positive IgM, for an incidence of 0·45/100 000. Six isolates identified were all clustered within genotype H1. The findings reported here support continued endemic transmission of measles virus in China.

scholarly journals Effective population size: the effects of sex, genotype, and density on the mean and variance of offspring numbers in the flour beetle, Tribolium castaneum

1980 ◽  
Vol 36 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Michael J. Wade
Keyword(s):  
Population Size ◽  
Effective Population Size ◽  
Tribolium Castaneum ◽  
Black Body ◽  
Body Colour ◽  
Effective Population ◽  
Flour Beetle ◽  
Colour Mutant ◽  
Mean And Variance ◽  
The Mean

SUMMARYIn this paper I present the results of an experimental study of the effects of genotype and density on the mean and variance of offspring numbers in both sexes of the flour beetle, Tribolium castaneum. From the observed variance in offspring numbers the effective population size at several different densities is estimated using the methods of Crow & Morton (1955).I found that both the mean and variance of offspring numbers varied with genotype and density. In general, males were more variable in offspring numbers than females and this variability increased with density. Individuals homozygous for the black body colour mutant, b/b, were less variable in offspring numbers than + / + individuals, but the latter produced more offspring at most densities. As density increased, + / + individuals became more variable in offspring numbers whereas b/b individuals were less sensitive in this regard. These findings are discussed in relation to the ecology of selection at the black and closely linked loci.

scholarly journals GENETIC VARIABILITY MAINTAINED BY MUTATION AND OVERDOMINANT SELECTION IN FINITE POPULATIONS

Genetics ◽  
1981 ◽  
Vol 98 (2) ◽  
pp. 441-459 ◽  
Author(s):  
Takeo Maruyama ◽  
Masatoshi Nei
Keyword(s):  
Mutation Rate ◽  
Allozyme Polymorphism ◽  
Random Genetic Drift ◽  
Effective Population ◽  
Mathematical Properties ◽  
Overdominant Selection ◽  
Mean And Variance ◽  
The Mean ◽  
Neutral Mutations ◽  
The Relationship

ABSTRACT Mathematical properties of the overdominance model with mutation and random genetic drift are studied by using the method of stochastic differential equations (Itô and McKean 1974). It is shown that overdominant selection is very powerful in increasing the mean heterozygosity as compared with neutral mutations, and if 2Ns (N = effective population size; s = selective disadvantage for homozygotes) is larger than 10, a very low mutation rate is sufficient to explain the observed level of allozyme polymorphism. The distribution of heterozygosity for overdominant genes is considerably different from that of neutral mutations, and if the ratio of selection coefficient (s) to mutation rate (ν) is large and the mean heterozygosity (h) is lower than 0.2, single-locus heterozygosity is either approximately 0 or 0.5. If h increases further, however, heterozygosity shows a multiple-peak distribution. Reflecting this type of distribution, the relationship between the mean and variance of heterozygosity is considerably different from that for neutral genes. When s/v is large, the proportion of polymorphic loci increases approximately linearly with mean heterozygosity. The distribution of allele frequencies is also drastically different from that of neutral genes, and generally shows a peak at the intermediate gene frequency. Implications of these results on the maintenance of allozyme polymorphism are discussed.

scholarly journals IDENTITY COEFFICIENTS IN FINITE POPULATIONS. I. EVOLUTION OF IDENTITY COEFFICIENTS IN A RANDOM MATING DIPLOID DIOECIOUS POPULATION

Genetics ◽  
1977 ◽  
Vol 86 (3) ◽  
pp. 697-713
Author(s):  
C Chevalet ◽  
M Gillois ◽  
R F Nassar
Keyword(s):  
Genetic Variability ◽  
Population Size ◽  
Effective Population Size ◽  
Random Mating ◽  
Matrix Multiplication ◽  
Inbred Lines ◽  
Inbreeding Coefficient ◽  
Effective Population ◽  
The Mean ◽  
Over Time

ABSTRACT Properties of identity relation between genes are discussed, and a derivation of recurrent equations of identity coefficients in a random mating, diploid dioecious population is presented. Computations are run by repeated matrix multiplication. Results show that for effective population size (Ne) larger than 16 and no mutation, a given identity coefficient at any time t can be expressed approximately as a function of (1—f), (1—f)3 and (1—f)6, where f is the mean inbreeding coefficient at time t. Tables are presented, for small Ne values and extreme sex ratios, showing the pattern of change in the identity coefficients over time. The pattern of evolution of identity coefficients is also presented and discussed with respect to N eu, where u is the mutation rate. Applications of these results to the evolution of genetic variability within and between inbred lines are discussed.

scholarly journals Volume and surface changes in vero cell and its nucleus after infection with measles virus: a stereological study

2011 ◽  
Vol 2 (1) ◽  
pp. 18
Author(s):  
Ali Noorafshan ◽  
Mohammad Motamedifar ◽  
Saied Karbalay-Doust
Keyword(s):  
Vero Cell ◽  
Post Infection ◽  
Measles Virus ◽  
Plaque Assay ◽  
Vero Cells ◽  
Uninfected Control ◽  
Mean Cell Volume ◽  
Significant Difference ◽  
Infected Cells ◽  
The Mean

Measles virus has no or indistinctive cytopathic effects (CPE) in cell couture system. Employment of some detecting methods like plaque assay or stereologic experiments, as a method of detecting of viral infection in the cells would be applicable. The aim of this study was investigating the early changes in quantitative parameters of measles virus infected Vero cells. Stereological methods using invariator, were applied for the first time to estimate cell and nucleus volume and cell surface of the infected Vero cell line with the measles virus.This method can be applied on other cultured cells.Vero cells grown in tissue culture plates for 48 hours at 36˚C were infected with 100TCID50 of AiK strain of measles virus. Volume and surface of the infected Vero cells were studied at 4, 9 and 25 hours post infection along with uninfected control cells. The mean cell volume and surface of the cells infected with measles virus, increased ~87% and ~50%, respectively, 4 hours post-infection, as compared with the uninfected control. The nuclei did not show any differences. The mean parameters of infected cells in other time intervals showed no significant difference comparing with the control cells. Although there are other specific methods, stereology may be used as an integrated protocol to detect cytophatic changes of the measles virus infected cells early in the permissive cell culture system.

Population structure of the Sahiwal breed in Pakistan

1995 ◽  
Vol 60 (2) ◽  
pp. 163-168 ◽  
Author(s):  
A. Dahlin ◽  
U. N. Khan ◽  
A. H. Zafar ◽  
M. Saleem ◽  
M. A. Chaudhry ◽  
...  
Keyword(s):  
Population Structure ◽  
Population Size ◽  
Effective Population Size ◽  
Breeding Population ◽  
Effective Population ◽  
Data Set ◽  
Inbreeding Coefficients ◽  
Sahiwal Cows ◽  
The Mean ◽  
Average Population Size

AbstractThe present study was undertaken to assist conservation and improvement schemes in the Sahiwal breed of cattle in Pakistan. A data set, consisting of records of 244 pure Sahiwal breeding bulls and 5247 cows, the latter representing about 80% of all recorded Sahiwal cows in Pakistan born during a period covering about 20 years, was analysed with regard to inbreeding, additive relationships, effective population size and generation intervals. Average inbreeding coefficients of 1224 cows and 49 bulls, for which at least the grandparents and great-grandsires were known, were 0·043 and 0·046, respectively. About two-thirds of the inbreeding was due to matings between animals with parents or grandparents in common. The mean additive relationship among the cows was 0·062, with within-herd averages ranging from 0·087 to 0·358. The average population size in a subdata set of recorded Sahiwal cattle from 1980 to 1984 was 1612, whereas the most likely estimate of the effective population size was about 30 animals for the same active breeding population. The study indicated the immediate need for an active conservation programme whereby the Sahiwal subpopulations of India and Kenya also should be involved.

scholarly journals HIDDEN GENETIC VARIABILITY WITHIN ELECTROMORPHS IN FINITE POPULATIONS

Genetics ◽  
1976 ◽  
Vol 84 (2) ◽  
pp. 385-393
Author(s):  
Ranajit Chakraborty ◽  
Masatoshi Nei
Keyword(s):  
Genetic Variability ◽  
Probability Generating Function ◽  
Effective Population ◽  
Finite Populations ◽  
Site Model ◽  
Stepwise Mutation ◽  
Mean And Variance ◽  
The Mean ◽  
Bivariate Probability ◽  
Two Populations

ABSTRACT The amount of hidden genetic variability within electromorphs in finite populations is studied by using the infinite site model and stepwise mutation model simultaneously. A formula is developed for the bivariate probability generating function for the number of codon differences and the number of electromorph state differences between two randomly chosen cistrons. Using this formula, the distribution as well as the mean and variance of the number of codon differences between two identical or nonidentical electromorphs are studied. The distribution of the number of codon differences between two randomly chosen identical electromorphs is similar to the geometric distribution but more leptokurtic. Studies are also made on the number of codon differences between two electromorphs chosen at random one from each of two populations which have been separated for an arbitrary number of generations. It is shown that the amount of hidden genetic variability is very large if the product of effective population size and mutation rate is large.

scholarly journals Ongoing African measles virus genotype outbreak in Tel Aviv district since April, Israel, 2012

2012 ◽  
Vol 17 (37) ◽  
Author(s):  
E Kopel ◽  
Z Amitai ◽  
M Savion ◽  
Y Aboudy ◽  
E Mendelson ◽  
...  
Keyword(s):  
World Health Organization ◽  
Measles Virus ◽  
World Health ◽  
European Region ◽  
Virus Genotype ◽  
Tel Aviv ◽  
Measles Outbreak ◽  
The World ◽  
The Mean ◽  
Health Organization

A measles outbreak is affecting the Tel Aviv district, Israel, since April 2012. As of 10 September, 99 cases were confirmed, including 63 (64%) migrants of Eritrean and Sudanese origin. All genotyped cases had the African B3 genotype*. The mean age of migrant and non-migrant cases was 6.0±9.6 and 30.2±24.2 years, respectively (p<0.001). The majority of both migrant and non-migrant cases was unvaccinated. This is the second African measles B3 genotype outbreak within the World Health Organization European region in 2012.

scholarly journals KINETIC EVOLUTION OF A 3D SPHERICAL CRYSTAL WITH MOBILE PARTICLES USING MONTE CARLO

Anales AFA ◽  
2019 ◽  
Vol Vol.30 (Vol.30 N.2) ◽  
pp. 25-30
Author(s):  
P. I. Achával ◽  
C. A. Rodríguez Luca ◽  
C. L. Di Prinzio
Keyword(s):  
Monte Carlo ◽  
Grain Boundary ◽  
Boundary Migration ◽  
The Other ◽  
Monte Carlo Algorithm ◽  
Grain Boundary Migration ◽  
Initial Radius ◽  
The Mean ◽  
Spherical Crystal ◽  
The Law

In this work, the evolution of a tridimensional (3D) spherical crystal with mobile particles using a Monte Carlo algorithm is presented. The mean radius R of spherical crystal without particles changes according to the law: R2 = -4kt + Ro2, where Ro is the initial radius and k is a crystal constant. However, this law is modified when mobile particles are included. The effect of two types of mobile particles on the grain boundary migration of a spherical grain was also studied. One type of particle remained located in the middle of the grain boundary once it was incorporated (CT), and the other type of particle remained at the grain boundary without having any particular location (NC). It could be seen that the CT particle slowed down more the grain boundary migration than the NC particles. It was also found that the rate of reduction of the grain area is inversely proportional to the concentration of CT particles in the grain boundary for all the CT particles concentrations. Finally, it was established that the grain reaches a limit radius for CT particles which is related to the amount of particles that can be accommodated in the grain boundary.

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