| 1. |
- Andréasson, Hanna, et al.
(författare)
-
Forensic mitochondrial coding region analysis for increased discrimination using pyrosequencing technology
- 2007
-
Ingår i: Forensic Science International. - : Elsevier BV. - 1872-4973 .- 1878-0326. ; 1:1, s. 35-43
-
Tidskriftsartikel (refereegranskat)abstract
- Analysis of mitochondrial DNA (mtDNA) is very useful when nuclear DNA analysis fails due to degradation or insufficient amounts of DNA in forensic analysis. However, mtDNA analysis has a lower discrimination power compared to what can be obtained by nuclear DNA (nDNA) analysis, potentially resulting in multiple individuals showing identical mtDNA types in the HVI/HVII region. In this study, the increase in discrimination by analysis of mitochondrial coding regions has been evaluated for identical or similar HVI/HVII sequences. A pyrosequencing-based system for coding region analysis, comprising 17 pyrosequencing reactions performed on 15 PCR fragments, was utilised. This assay was evaluated in 135 samples, resulting in an average read length of 81 nucleotides in the pyrosequencing analysis. In the sample set, a total of 52 coding region SNPs were identified, of which 18 were singletons. In a group of 60 samples with 0 or 1 control region difference from the revised Cambridge reference sequence (rCRS), only 12 samples could not be resolved by at least two differences using the pyrosequencing assay. Thus, the use of this pyrosequencing-based coding region assay has the potential to substantially increase the discriminatory power of mtDNA analysis.
|
|
| 2. |
- Andréasson, Hanna, et al.
(författare)
-
Mitochondrial sequence analysis for forensic identification using Pyrosequencing technology
- 2002
-
Ingår i: BioTechniques. - 0736-6205 .- 1940-9818. ; 32:1, s. 124-6, 128, 130-3
-
Tidskriftsartikel (refereegranskat)abstract
- Over recent years, requests for mtDNA analysis in the field of forensic medicine have notably increased, and the results of such analyses have proved to be very useful in forensic cases where nuclear DNA analysis cannot be performed. Traditionally, mtDNA has been analyzed by DNA sequencing of the two hypervariable regions, HVI and HVII, in the D-loop. DNA sequence analysis using the conventional Sanger sequencing is very robust but time consuming and labor intensive. By contrast, mtDNA analysis based on the pyrosequencing technology provides fast and accurate results from the human mtDNA present in many types of evidence materials in forensic casework. The assay has been developed to determine polymorphic sites in the mitochondrial D-loop as well as the coding region to further increase the discrimination power of mtDNA analysis. The pyrosequencing technology for analysis of mtDNA polymorphisms has been tested with regard to sensitivity, reproducibility, and success rate when applied to control samples and actual casework materials. The results show that the method is very accurate and sensitive; the results are easily interpreted and provide a high success rate on casework samples. The panel of pyrosequencing reactions for the mtDNA polymorphisms were chosen to result in an optimal discrimination power in relation to the number of bases determined.
|
|
| 3. |
- Andréasson, H., et al.
(författare)
-
Real-Time DNA Quantification of Nuclear and Mitochondrial DNA in Forensic Analysis
- 2002
-
Ingår i: BioTechniques. - 0736-6205 .- 1940-9818. ; 33:2, s. 402-411
-
Tidskriftsartikel (refereegranskat)abstract
- The rapid development of molecular genetic analysis tools has made it possible to analyze most biological materialfound at the scene of a crime. Evidence materials containing DNA quantities too low to be analyzed using nuclear markers can be analyzed using the highly abundant mtDNA. However, there is a shortage of sensitive nDNA and mtDNA quantification assays. In this study, an assay for the quantification of very small amounts of DNA, based on the real-time Taq-Man assay, has been developed. This analysis will provide an estimate of the total number of nDNA copies and the total number of mtDNA molecules in a particular evidence material. The quantification is easy to perform, fast, and requires a minimum of the valuable DNA extracted from the evidence materiaL The results will aid in the evaluation of whether the specific sample is suitable for nDNA or mtDNA analysis. Furthermore, the optimal amount of DNA to be used in further analysis can be estimated ensuring that the analysis is successful and that the DNA is retained for future independent analysis. This assay has significant advantages over existing techniques because of its high sensitivity, accuracy, and the combined analysis of nDNA and mtDNA. Moreover, it has the potential to provide additional information about the presence of inhibitors in forensic samples. Subsequent mitochondrial and nuclear analysis of quantified samples illustrated the potential to predict the number of DNA copies required for a successful analysis in a certain typing assay.
|
|
| 4. |
- Andréasson, Hanna, 1975-
(författare)
-
Sensitive Forensic DNA Analysis : Application of Pyrosequencing and Real-time PCR Quantification
- 2005
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The field of forensic genetics is growing fast and the development and optimisation of more sensitive, faster and more discriminating forensic DNA analysis methods is highly important. In this thesis, an evaluation of the use of novel DNA technologies and the development of specific applications for use in forensic casework investigations are presented.In order to maximise the use of valuable limited DNA samples, a fast and user-friendly Real-time PCR quantification assay, of nuclear and mitochondrial DNA copies, was developed. The system is based on the 5’ exonuclease detection assay and was evaluated and successfully used for quantification of a number of different evidence material types commonly found on crime scenes. Furthermore, a system is described that allows both nuclear DNA quantification and sex determination in limited samples, based on intercalation of the SYBR Green dye to double stranded DNA. To enable highly sensitive DNA analysis, Pyrosequencing of short stretches of mitochondrial DNA was developed. The system covers both control region and coding region variation, thus providing increased discrimination power for mitochondrial DNA analysis. Finally, due to the lack of optimal assays for quantification of mitochondrial DNA mixture, an alternative use of the Pyrosequencing system was developed. This assay allows precise ratio quantification of mitochondrial DNA in samples showing contribution from more than one individual.In conclusion, the development of optimised forensic DNA analysis methods in this thesis provides several novel quantification assays and increased knowledge of typical DNA amounts in various forensic samples. The new, fast and sensitive mitochondrial DNA Pyrosequencing assay was developed and has the potential for increased discrimination power.
|
|
| 5. |
- Andréasson, Per, et al.
(författare)
-
Emotional Empathy and Facial Feedback
- 2008
-
Ingår i: Journal of nonverbal behavior. - : Springer Science and Business Media LLC. - 0191-5886 .- 1573-3653. ; 32:4, s. 215-224
-
Tidskriftsartikel (refereegranskat)abstract
- We studied if emotional empathy is related to sensitivity to facial feedback. The participants, 112 students, rated themselves on the questionnaire measure of emotional empathy (QMEE) and were divided into one high and one low empathic group. Facial expressions were manipulated to produce a happy or a sulky expression. During the manipulation, participants rated humorous films with respect to funniness. These ratings were the dependent variable. No main effect of facial expression was found. However, a significant interaction between empathy and condition indicated that the high as compared to the low empathic group rated the films as being funnier in a happy condition and a tendency to be less funny in a sulky condition. On the basis of the present results we suggest emotional empathy to be one important and previously ignored factor to explain individual differences in effects of facial feedback.
|
|
| 6. |
- Andréasson, Per, et al.
(författare)
-
Emotional empathy, facial manipulations and facial feedback
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- People with a low but not people with a high degree of emotional empathy have been found to rate humorous films as funnier in a sulky versus a happy facial manipulation, in contrast to what the facial feedback hypothesis predicts (Andréasson & Dimberg, 2008). Experiment 1 replicated this finding with people with extra ordinary high or low degree of emotional empathy. Interestingly, when the facial manipulations were a smile versus a frown, as in experiment 2, people with low as well as high emotional empathy reacted as predicted by the facial feedback hypothesis. In conclusion, emotional empathy is suggested to be related to effects of facial feedback in some facial manipulations but not in others.
|
|
| 7. |
- Andréasson, Per, 1963-
(författare)
-
Emotional Empathy, Facial Reactions, and Facial Feedback
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The human face has a fascinating capability to express emotions. The facial feedback hypothesis suggests that the human face not only expresses emotions but is also able to send feedback to the brain and modulate the ongoing emotional experience. It has furthermore been suggested that this feedback from the facial muscles could be involved in empathic reactions. This thesis explores the concept of emotional empathy and relates it to two aspects concerning activity in the facial muscles. First, do people high versus low in emotional empathy differ in regard to in what degree they spontaneously mimic emotional facial expressions? Second, is there any difference between people with high as compared to low emotional empathy in respect to how sensitive they are to feedback from their own facial muscles? Regarding the first question, people with high emotional empathy were found to spontaneously mimic pictures of emotional facial expressions while people with low emotional empathy were lacking this mimicking reaction. The answer to the second question is a bit more complicated. People with low emotional empathy were found to rate humorous films as funnier in a manipulated sulky facial expression than in a manipulated happy facial expression, whereas people with high emotional empathy did not react significantly. On the other hand, when the facial manipulations were a smile and a frown, people with low as well as high emotional empathy reacted in line with the facial feedback hypothesis. In conclusion, the experiments in the present thesis indicate that mimicking and feedback from the facial muscles may be involved in emotional contagion and thereby influence emotional empathic reactions. Thus, differences in emotional empathy may in part be accounted for by different degree of mimicking reactions and different emotional effects of feedback from the facial muscles.
|
|
| 8. |
- Bridel, Claire, et al.
(författare)
-
Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology : A Systematic Review and Meta-analysis
- 2019
-
Ingår i: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149 .- 2168-6157. ; 76:9, s. 1035-1048
-
Forskningsöversikt (refereegranskat)abstract
- Importance Neurofilament light protein (NfL) is elevated in cerebrospinal fluid (CSF) of a number of neurological conditions compared with healthy controls (HC) and is a candidate biomarker for neuroaxonal damage. The influence of age and sex is largely unknown, and levels across neurological disorders have not been compared systematically to date.Objectives To assess the associations of age, sex, and diagnosis with NfL in CSF (cNfL) and to evaluate its potential in discriminating clinically similar conditions.Data Sources PubMed was searched for studies published between January 1, 2006, and January 1, 2016, reporting cNfL levels (using the search terms neurofilament light and cerebrospinal fluid) in neurological or psychiatric conditions and/or in HC.Study Selection Studies reporting NfL levels measured in lumbar CSF using a commercially available immunoassay, as well as age and sex.Data Extraction and Synthesis Individual-level data were requested from study authors. Generalized linear mixed-effects models were used to estimate the fixed effects of age, sex, and diagnosis on log-transformed NfL levels, with cohort of origin modeled as a random intercept.Main Outcome and Measure The cNfL levels adjusted for age and sex across diagnoses.Results Data were collected for 10 059 individuals (mean [SD] age, 59.7 [18.8] years; 54.1% female). Thirty-five diagnoses were identified, including inflammatory diseases of the central nervous system (n = 2795), dementias and predementia stages (n = 4284), parkinsonian disorders (n = 984), and HC (n = 1332). The cNfL was elevated compared with HC in a majority of neurological conditions studied. Highest levels were observed in cognitively impaired HIV-positive individuals (iHIV), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), and Huntington disease. In 33.3% of diagnoses, including HC, multiple sclerosis, Alzheimer disease (AD), and Parkinson disease (PD), cNfL was higher in men than women. The cNfL increased with age in HC and a majority of neurological conditions, although the association was strongest in HC. The cNfL overlapped in most clinically similar diagnoses except for FTD and iHIV, which segregated from other dementias, and PD, which segregated from atypical parkinsonian syndromes.Conclusions and Relevance These data support the use of cNfL as a biomarker of neuroaxonal damage and indicate that age-specific and sex-specific (and in some cases disease-specific) reference values may be needed. The cNfL has potential to assist the differentiation of FTD from AD and PD from atypical parkinsonian syndromes.
|
|
| 9. |
- Dimberg, Ulf, et al.
(författare)
-
Emotional empathy and facial reactions to facial expressions
- 2011
-
Ingår i: Journal of Psychophysiology. - : Hogrefe Publishing Group. - 0269-8803 .- 2151-2124. ; 25:1, s. 26-31
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigates whether people High in emotional empathy are more facially reactive than are people Low in emotional empathy when exposed to pictures of angry and happy facial expressions. Facial electromyographic activity was measured from the corrugator and the zygomatic muscle regions. In accordance with the predictions, the High empathic group reacted with larger corrugator activity to angry as compared to happy faces and with larger zygomatic activity to happy faces. However, the Low empathic group did not differentiate between the angry and happy stimuli at all. The High empathic group, as compared to the Low empathic group, also rated the angry faces as expressing more anger and the happy faces as being happier. It is concluded that high empathic people are particularly sensitive in reacting with facial reactions to facial expressions and that this ability is accompanied by a higher level of empathic accuracy.
|
|
| 10. |
|
|
