| 1. |
- A.O., Tillmar, et al.
(författare)
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Using X-chromosomal markers in relationship testing: Calculation of likelihood ratios taking both linkage and linkage disequilibrium into account
- 2011
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Ingår i: Forensic Science International: Genetics. - : Elsevier BV. - 1872-4973 .- 1878-0326. ; 5:5, s. 506-511
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Tidskriftsartikel (refereegranskat)abstract
- X-chromosomal markers in forensic genetics have become more widely used during recent years, particularly for relationship testing. Linkage and linkage disequilibrium (LD) must typically be accounted for when using close X-chromosomal markers. Thus, when producing the weight-of-evidence, given by a DNA-analysis with markers that are linked, the normally used product rule is invalid. Here we present an implementation of an efficient model for calculating likelihood ratios (LRs) with markers on the X-chromosome which are linked and in LD. Furthermore, the model was applied on several cases based on data from the eight X-chromosomal loci included in the Mentype® Argus X-8 (Biotype). Using a simulation approach we showed that the use of X-chromosome data can offer valuable information for choosing between the alternatives in each of the cases we studied, and that the LR can be high in several cases. We demonstrated that when linkage and LD were disregarded, as opposed to taken into account, the difference in calculated LRs could be considerable. When these differences were large, the estimated haplotype frequencies often had a strong impact and we present a method to estimate haplotype frequencies. Our conclusion is that linkage and LD should be accounted for when using the tested set of markers, and the used model is an efficient way of doing so.
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| 2. |
- Bartoszek, Krzysztof, 1984, et al.
(författare)
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A phylogenetic comparative method for studying multivariate adaptation
- 2012
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Ingår i: Journal of Theoretical Biology. - : Elsevier BV. - 0022-5193 .- 1095-8541. ; 314, s. 204-215
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Tidskriftsartikel (refereegranskat)abstract
- Phylogenetic comparative methods have been limited in the way they model adaptation. Although some progress has been made, there are still no methods that can fully account for coadaptation between traits. Based on Ornstein–Uhlenbeck (OU) models of adaptive evolution, we present a method, with R implementation, in which multiple traits evolve both in response to each other and, as in previous OU models, to fixed or randomly evolving predictor variables. We present the interpretation of the model parameters in terms of evolutionary and optimal regressions enabling the study of allometric and adaptive relationships between traits. To illustrate the method we reanalyze a data set of antler and body-size evolution in deer (Cervidae).
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| 3. |
- Benson, Mikael, 1954, et al.
(författare)
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DNA microarray analysis of transforming growth factor-β and related transcripts in nasal biopsies from patients with allergic rhinitis
- 2002
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Ingår i: Cytokine. ; 18:1, s. 20-25
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Tidskriftsartikel (refereegranskat)abstract
- Decreased activity of anti-inflammatory cytokines like transforming growth factor (TGF)-β may contribute to allergic inflammation. In vivo effects of TGF-β-effects are difficult to infer from local concentrations, since TGF-β-effects depend on a complex system of regulatory proteins and receptors. Instead the effects of TGF-β might be inferred by examining TGF-β-inducible transcripts. In this study DNA microarrays were used to examine local expression of TGF-β, TGF-β-regulatory and -inducible transcripts in nasal biopsies from patients with symptomatic allergic rhinitis and healthy controls. In addition, nasal fluids were analysed with cytological and immunological methods. Nasal fluid eosinophils, albumin, eosinophil granulae proteins and IgE, but not TGF-β, were higher in patients than in controls. DNA microarray analysis of nasal mucosa showed expression of transcripts encoding TGF-β, TGF-β-regulatory proteins and -receptors at variable levels in patients and controls. By comparison, analysis of 28 TGF-β-inducible transcripts indicated that 23 of these had lower measurement values in patients than in controls, while one was higher, and the remaining four were absent in both patients and controls. In summary, TGF-β and a complex system of regulatory genes and receptors are expressed in the nasal mucosa. Low expression of TGF-β-inducible transcripts may indicate decreased TGF-β activity in allergic rhinitis. DNA microarray analysis may be a way to study cytokine effects in vivo.
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| 4. |
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| 5. |
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| 6. |
- Egeland, Thore, et al.
(författare)
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Estimating the number of contributors to a DNA profile
- 2003
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Ingår i: International Journal of Legal Medicine. ; 117:5, s. 271-275
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Tidskriftsartikel (refereegranskat)abstract
- The broad topic of this paper is the evaluation of DNA evidence in criminal cases. More specifically, we deal with mixture evidence which refers to cases where there are, or could be, several contributors to a biological stain based on, e.g., blood or semen. The present paper adresses DNA mixtures based on single nucleotide polymorphism (SNP) markers, i.e., diallelic markers. Based on STR analysis, it is in most cases easy to identify the presence of a mixture since three or four bands will show up with a high probability for at least one locus. Obviously, this will not be the case for diallelic markers and interpreting mixtures will be a great challenge. We address this problem by first approaching the more general problem of estimating the number of contributors to a stain. In addition we discuss how the markers should be selected and how many are required.
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| 7. |
- Egeland, Thore, et al.
(författare)
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Response to: DNA identification by pedigree likelihood ratio accommodating population substructure and mutations
- 2011
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Ingår i: Investigative Genetics. - : Springer Science and Business Media LLC. - 2041-2223. ; 2:7
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Tidskriftsartikel (refereegranskat)abstract
- Mutation models are important in many areas of genetics including forensics. This letter criticizes the model of the paper 'DNA identification by pedigree likelihood ratio accommodating population substructure and mutations' by Ge et al. (2010). Furthermore, we argue that the paper in some cases misrepresents previously published papers. Please see related letter: http://www.investigativegenetics.com/content/2/1/8.
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| 8. |
- Egeland, Thore, et al.
(författare)
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Statistical Genetics and Genetical Statistics: a Forensic Perspective
- 2002
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Ingår i: Scandinavian Journal of Statistics. ; 29:2, s. 297-307
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Tidskriftsartikel (refereegranskat)abstract
- This review paper focuses on forensic aspects of the relation between statistics and genetics. Some of the scientific achievements of the Swedish psychiatrist and geneticist Erik Essen-Möller may be viewed in the above interdisciplinary context. In a number of situations the correct familial relation between a group of individuals is required. We discuss recent work done to relax some assumptions involved in the classical calculations in Essen-Möller (1938). Moreover, we extend the discussion to identification problems. In a given case there may be a large number of possible family constellations or pedigrees. A prior probability distribution is established. The posterior model accounts for the combinatorial complexities of the pedigrees, mutations, kinship, and uncertainty in allele frequencies. Examples are based on the shareware program FAMILIAS, see http://www.nr.no/familias. A main message of the present paper is that the Bayesian approach is a convenient framework to down-weight unreasonable (e.g. incestuous) pedigrees that may always appear likely if only DNA-measurements are used.
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| 9. |
- He, L, et al.
(författare)
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Glomerulus-specific mRNA transcripts and proteins identified through kidney expressed sequence tag database analysis
- 2007
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Ingår i: Kidney International. - 1523-1755 .- 0085-2538. ; 71:9, s. 889-900
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Tidskriftsartikel (refereegranskat)abstract
- The kidney glomerulus plays a crucial role in blood filtration but the molecular composition and physiology of the glomerulus is not well understood. We previously constructed and large-scale sequenced four mouse glomerular expressed sequence tag (EST) libraries from newborn and adult mouse glomeruli. Here, we compared glomerular EST profiles with whole kidney EST profiles, thereby identifying 497 transcripts corresponding to UniGene clusters that were glomerulus-enriched, that is expressed more abundantly in glomeruli than in whole kidney. These include several known protein-coding glomerulus-specific transcripts critical for glomerulus development and function, but also a large number of gene transcripts, which have not previously been shown to be expressed in the glomerulus, or implicated in glomerular functions. We used in situ hybridization to demonstrate glomerulus-specific RNA expression for six novel glomerular genes and the public Human Protein Atlas to verify glomerular protein expression for another two. The higher mRNA abundance for the eight genes in glomeruli compared with whole kidney was also verified by Taqman quantitative polymerase chain reaction. We surmise that the further characterization of these genes and proteins will increase our understanding of glomerular development and physiology.
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| 10. |
- Hedell, Ronny, 1985, et al.
(författare)
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Detection probability models for bacteria, and how to obtain them from heterogeneous spiking data. An application to Bacillus anthracis
- 2017
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Ingår i: International Journal of Food Microbiology. - : Elsevier BV. - 1879-3460 .- 0168-1605. ; 241, s. 78-88
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Tidskriftsartikel (refereegranskat)abstract
- © 2016 Elsevier B.V.Efficient and correct evaluation of sampling results with respect to hypotheses about the concentration or distribution of bacteria generally requires knowledge about the performance of the detection method. To assess the sensitivity of the detection method an experiment is usually performed where the target matrix is spiked (i.e. artificially contaminated) with different concentrations of the bacteria, followed by analyses of the samples using the pre-enrichment method and the analytical detection method of interest. For safety reasons or because of economic or time limits it is not always possible to perform exactly such an experiment, with the desired number of samples. In this paper, we show how heterogeneous data from diverse sources may be combined within a single model to obtain not only estimates of detection probabilities, but also, crucially, uncertainty estimates. We indicate how such results can then be used to obtain optimal conclusions about presence of bacteria, and illustrate how strongly the sampling results speak in favour of or against contamination. In our example, we consider the case when B. cereus is used as surrogate for B. anthracis, for safety reasons. The statistical modelling of the detection probabilities and of the growth characteristics of the bacteria types is based on data from four experiments where different matrices of food were spiked with B. anthracis or B. cereus and analysed using plate counts and qPCR. We show how flexible and complex Bayesian models, together with inference tools such as OpenBUGS, can be used to merge information about detection probability curves. Two different modelling approaches, differing in whether the pre-enrichment step and the PCR detection step are modelled separately or together, are applied. The relative importance on the detection curves for various existing data sets are evaluated and illustrated.
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