| 1. |
- Behboudi, Afrouz, 1967, et al.
(författare)
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Evolutionary aspects of the genomic organization of rat chromosome 10.
- 2002
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Ingår i: Cytogenetic and genome research. - : S. Karger. - 1424-8581 .- 1424-859X. ; 96:1-4, s. 52-9
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Tidskriftsartikel (refereegranskat)abstract
- Using FISH and RH mapping a chromosomal map of rat chromosome 10 (RNO10) was constructed. Our mapping data were complemented by other published data and the final map was compared to maps of mouse and human chromosomes. RNO10 contained segments homologous to mouse chromosomes (MMU) 11, 16 and 17, with evolutionary breakpoints between the three segments situated in the proximal part of RNO10. Near one of these breakpoints (between MMU17 and 11) we found evidence for an inversion ancestral to the mouse that was not ancestral to the condition in the rat. Within each of the chromosome segments identified, the gene order appeared to be largely conserved. This conservation was particularly clear in the long MMU11-homologous segment. RNO10 also contained segments homologous to three human chromosomes (HSA5, 16, 17). However, within each segment of conserved synteny were signs of more extensive rearrangements. At least 13 different evolutionary breakpoints were indicated in the rat-human comparison. In contrast to what was found between rat and mouse, the rat-human evolutionary breaks were distributed along the entire length of RNO10.
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| 2. |
- Bergman, Annika, et al.
(författare)
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The western Swedish BRCA1 founder mutation 3171ins5; a 3.7 cM conserved haplotype of today is a reminiscence of a 1500-year-old mutation
- 2001
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Ingår i: European Journal of Human Genetics. - : Nature Publishing Group. - 1018-4813 .- 1476-5438. ; 9:10, s. 787-793
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Tidskriftsartikel (refereegranskat)abstract
- The most recurrent BRCA1/BRCA2 mutation in Sweden is the BRCA1 mutation 3171ins5. In the western part of Sweden this mutation accounts for as much as 77% of identified mutations in these two genes. Our aim was to analyse in detail the haplotype and founder effects of the 3171ins5 and furthermore attempt to estimate the time of origin of the mutation. In the study we included eighteen apparently unrelated families with hereditary breast and/or ovarian cancer. At least one individual in each family had previously tested positive for the 3171ins5 mutation. Polymorphic microsatellite markers were used for the haplotype analyses. The markers were located within or flanking the BRCA1 gene spanning a region of 17.3 cΜ. We found several different haplotypes both for disease alleles and for the normal alleles. However, a conserved haplotype of 3.7 cΜ was observed in the 3171ins5 carriers spanning over four markers located within or very close to the BRCA1 gene. As this haplotype was not present in any of the normal controls it is highly likely that this is a mutation identical by descent, i.e. a true founder. The results from the haplotype analyses were used to estimate the age of the mutation. Estimations based on the Pexcess and linkage disequilibrium gives a first appearance of the mutation sometime around the 6th century, approximately 50 generations ago.
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| 3. |
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| 4. |
- El Maroufy, H., et al.
(författare)
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Final Outcome of an Epidemic in Two Interacting Populations
- 2009
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Ingår i: Applied Mathematics & Information Sciences. - 1935-0090 .- 2325-0399. ; 3:2, s. 159-176
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Tidskriftsartikel (refereegranskat)abstract
- we consider a stochastic model for the spread of an epidemic in a closed population consisting of two groups, in which infectives cannot change their group, but are able to infect outside it. Using the matrix-geometric method we obtain a recursive relationship for the Laplace transform of the joint distribution of the number of susceptibles and infectives in the two groups. We also derive the distribution of the total observed size of the epidemic as well as its duration in the case of a general infection mechanism.
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| 5. |
- El Maroufy, H., et al.
(författare)
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Final outcome probabilities for SIR epidemic model
- 2016
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Ingår i: Communications in Statistics - Theory and Methods. - : Informa UK Limited. - 0361-0926 .- 1532-415X. ; 45:8, s. 2426-2437
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Tidskriftsartikel (refereegranskat)abstract
- We consider an SIR stochastic epidemic model in which new infections occur at rate f(x, y), where x and y are, respectively, the number of susceptibles and infectives at the time of infection and f is a positive sequence of real functions. A simple explicit formula for the final size distribution is obtained. Some efficient recursive methods are proved for the exact calculation of this distribution. In addition, we give a Gaussian approximation for the final distribution using a diffusion process approximation.
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| 6. |
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| 7. |
- El Maroufy, H., et al.
(författare)
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On the Qualitative Behaviour of SIR Epidemics with Generalized Infection Rate Functions
- 2010
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Ingår i: Applied Mathematics & Information Sciences. - 1935-0090 .- 2325-0399. ; 4:3, s. 353-363
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Tidskriftsartikel (refereegranskat)abstract
- We consider an SIR stochastic epidemic model in which new infection occurs at rate f(n)(x,y), where x and y are respectively the number of susceptibles and infectives at time of infection and f(n) is a positive sequence of real functions. Threshold theorems analogous to those of Whittle and Williams are fairly proved for this model. Also we examine the shape of the total size distribution for various values of removal rate and suitable values of other important parameters.
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| 8. |
- El Maroufy, H., et al.
(författare)
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TRANSITION PROBABILITIES FOR GENERALIZED SIR EPIDEMIC MODEL
- 2012
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Ingår i: Stochastic Models. - : Informa UK Limited. - 1532-6349 .- 1532-4214. ; 28:1, s. 15-28
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Tidskriftsartikel (refereegranskat)abstract
- Gani and Purdue outlined a matrix-geometric method for determining the total size distribution of an epidemic in a recursive manner. In this article, we explore how this method can be used to study an SIR epidemic model with a generalized mechanism of infection. We are able to obtain an explicit formula for the Laplace transform of the transition probabilities. Using this we derive various other quantities explicitly. Examples of such quantities are the transition probabilities and the expectation of the duration of the epidemic.
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| 9. |
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| 10. |
- Hibbah, El Houcine, et al.
(författare)
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An MCMC computational approach for a continuous time state-dependent regime switching diffusion process
- 2020
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Ingår i: Journal of Applied Statistics. - : Informa UK Limited. - 1360-0532 .- 0266-4763. ; 47:8, s. 1354-1374
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Tidskriftsartikel (refereegranskat)abstract
- State-dependent regime switching diffusion processes or hybrid switching diffusion (HSD) processes are hard to simulate with classical methods which leads us to adopt a Markov chain Monte Carlo (MCMC) Bayesian approach very convenient to estimate complicated models such as the HSD one. In the HSD, the diffusion component is dependent on the switching discrete hidden regimes and the transition rates of the regime switching are dependent on the diffusion observations. Since in reality phenomena are only observed in discrete times, data imputation is called for to create more observations so as to have good approximations for the density of the diffusion process. Three categories of entities will be computed in a Bayesian context: The latent imputed observations, the regime switching states, and the parameters of the models. The latent imputed data is updated at random time intervals in block using a Metropolis Hastings algorithm. The switching states are computed by an adaptation of a forward filtering backward smoothing algorithm to the HSD model. The parameters are estimated after prior specifications and conditional posterior densities formulation using Gibbs sampler or Metropolis Hastings algorithm.
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