The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform
Maurice C G Aalders - One of the best experts on this subject based on the ideXlab platform.
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practical implementation of Blood Stain age estimation using spectroscopy
IEEE Journal of Selected Topics in Quantum Electronics, 2016Co-Authors: Gerda Edelman, Martin Roos, Annabel Bolck, Maurice C G AaldersAbstract:Blood is one of the most often encountered and valuable traces found at a crime scene. It not only contains information about what happened, but the chemical composition can also lead to the identification of the donor and even to the time of deposition, an important objective in forensic science. Many techniques have been explored for determination of the time of deposition, but none have made it into forensic practice. We have earlier used optical reflection spectroscopy for the age estimation of Blood Stains on white cotton, and to make this method suitable for forensic practice, we have adapted it to correct for the influence of the optical properties of the various substrates where Blood may be found by extending a one-dimensional light-transport model to a two-layered model. With this model, we are able to calculate the relative amounts of OxyHemoglobin, MetHemoglobin, and Hemichrome in Blood Stains on colored surfaces, based on their reflectance spectra. We describe here a statistical method to calculate the 95% confidence interval around the calculated age. We demonstrate the applicability to field work and the potential value for crime investigations in a case study of a shooting incident. The absolute and relative ages of different groups of Blood Stains were measured using our new method. The measured age of Blood Stains can lead to a more realistic reconstruction of the timeline of events. To our knowledge, this paper presents the world's first implementation in practice of a method for determining the age of Blood Stains.
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Age estimation of Blood Stains by hemoglobin derivative determination using reflectance spectroscopy.
Forensic science international, 2010Co-Authors: Rolf H Bremmer, Annemarie Nadort, Ton G Van Leeuwen, Martin J C Van Gemert, Maurice C G AaldersAbstract:Blood Stains can be crucial in reconstructing crime events. However, no reliable methods are currently available to establish the age of a Blood Stain on the crime scene. We show that determining the fractions of three hemoglobin derivatives in a Blood Stain at various ages enables relating these time varying fractions to the age of the Blood Stain. Application of light transport theory allows addressing the spectroscopic changes in ageing Blood Stains to changes in chemical composition, i.e. the transition of oxy-hemoglobin into met-hemoglobin and hemichrome. We have found in 20 Blood Stains that the chemical composition of the Blood Stain with age, called hemoglobin reaction kinetics, under controlled circumstances, shows a distinct time-dependent behavior, with a unique combination of the three hemoglobin derivatives at all moments in time. Finally, we employed the hemoglobin reaction kinetics inversely to assess the age of 20 other Blood Stains studied, again over a time period of 0-60 days. We estimated an age of e.g. 55 days correct within an uncertainty margin of 14 days. In conclusion, we propose that the results obtained under controlled conditions demand further evaluation of their possible value for age determination of Blood Stains on crime scenes.
A Nimnual - One of the best experts on this subject based on the ideXlab platform.
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forensic Blood Stain aging using reverse transcription real time pcr
Forensic Science International: Reports, 2021Co-Authors: C Manasatienkij, A NimnualAbstract:Abstract BloodStains are among the most important biological types of forensic evidence collected from crime scenes. This study aimed to evaluate the effectiveness of age estimation of Blood Stains on cotton cloth using the Real-time PCR technique combined with a multidimensional prediction model. A tissue-specific mRNA (HBB) and 2 Housekeeping genes (GAPDH and B2M) were analyzed over a 150-day period. The combined correlation equation for estimating the age of a Blood Stain was identified as: Age (Day) = −1.205+4.794(2 −(ΔCT GAPDH − 2.14))+50.293(2 −(ΔCT HBB + 8.117))−5.778(2 −(ΔCT HBB + 8.117)) 2.
Tomas Marquesbonet - One of the best experts on this subject based on the ideXlab platform.
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metagenomic analysis of a Blood Stain from the french revolutionary jean paul marat 1743 1793
Infection Genetics and Evolution, 2020Co-Authors: Toni Dedios, Lucy Van Dorp, Philippe Charlier, Sofia Morfopoulou, Esther Lizano, Celine Bon, Corinne Le Bitouze, Marina Alvarezestape, Tomas MarquesbonetAbstract:Abstract The French revolutionary Jean-Paul Marat (1743–1793) was assassinated in 1793 in his bathtub, where he was trying to find relief from the debilitating skin disease he was suffering from. At the time of his death, Marat was annotating newspapers, which got Stained with his Blood and were subsequently preserved by his sister. We extracted and sequenced DNA from the Blood Stain and also from another section of the newspaper, which we used for comparison. Results from the human DNA sequence analyses were compatible with a heterogeneous ancestry of Marat, with his mother being of French origin and his father born in Sardinia. Metagenomic analyses of the non-human reads uncovered the presence of fungal, bacterial and low levels of viral DNA. Relying on the presence/absence of microbial species in the samples, we could cast doubt on several putative infectious agents that have been previously hypothesised as the cause of his condition but for which we detect not a single sequencing read. Conversely, some of the species we detect are uncommon as environmental contaminants and may represent plausible infective agents. Based on all the available evidence, we hypothesize that Marat may have suffered from a fungal infection (seborrheic dermatitis), possibly superinfected with bacterial opportunistic pathogens.
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metagenomic analysis of a Blood Stain from the french revolutionary jean paul marat 1743 1793
bioRxiv, 2019Co-Authors: Toni Dedios, Lucy Van Dorp, Philippe Charlier, Sofia Morfopoulou, Esther Lizano, Celine Bon, Corinne Le Bitouze, Marina Alvarezestape, Tomas Marquesbonet, Francois BallouxAbstract:Abstract The French revolutionary Jean-Paul Marat was assassinated in 1793 in his bathtub, where he was trying to find relief from the debilitating skin disease he was suffering from. At the time of his death, Marat was annotating newspapers, which got Stained with his Blood and were subsequently preserved by his sister. We extracted and sequenced DNA from the Blood Stain and also from another section of the newspaper, which we used for comparison. Analysis of human DNA sequences supported the heterogeneous ancestry of Marat, with his mother being of French origin and his father born in Sardinia, although bearing more affinities to mainland Italy or Spain. Metagenomic analyses of the non-human reads uncovered the presence of fungal, bacterial and low levels of viral DNA. Relying on the presence/absence of microbial species in the samples, we could confidently rule out several putative infectious agents that had been previously hypothesised as the cause of his condition. Conversely, some of the detected species are uncommon as environmental contaminants and may represent plausible infective agents. Based on all the available evidence, we hypothesize that Marat may have suffered from a primary fungal infection (seborrheic dermatitis), superinfected with bacterial opportunistic pathogens. Significance The advent of second-generation sequencing technologies allows for the retrieval of ancient genomes from long-dead people and, using non-human sequencing reads, of the pathogens that infected them. In this work we combined both approaches to gain insights into the ancestry and health of the controversial French revolutionary leader and physicist Jean-Paul Marat (1743-1793). Specifically, we investigate the pathogens, which may have been the cause of the debilitating skin condition that was affecting him, by analysing DNA obtained from a paper Stained with his Blood at the time of his death. This allowed us to confidently rule out several conditions that have been put forward. To our knowledge, this represents the oldest successful retrieval of genetic material from cellulose paper.
Philippe Charlier - One of the best experts on this subject based on the ideXlab platform.
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metagenomic analysis of a Blood Stain from the french revolutionary jean paul marat 1743 1793
Infection Genetics and Evolution, 2020Co-Authors: Toni Dedios, Lucy Van Dorp, Philippe Charlier, Sofia Morfopoulou, Esther Lizano, Celine Bon, Corinne Le Bitouze, Marina Alvarezestape, Tomas MarquesbonetAbstract:Abstract The French revolutionary Jean-Paul Marat (1743–1793) was assassinated in 1793 in his bathtub, where he was trying to find relief from the debilitating skin disease he was suffering from. At the time of his death, Marat was annotating newspapers, which got Stained with his Blood and were subsequently preserved by his sister. We extracted and sequenced DNA from the Blood Stain and also from another section of the newspaper, which we used for comparison. Results from the human DNA sequence analyses were compatible with a heterogeneous ancestry of Marat, with his mother being of French origin and his father born in Sardinia. Metagenomic analyses of the non-human reads uncovered the presence of fungal, bacterial and low levels of viral DNA. Relying on the presence/absence of microbial species in the samples, we could cast doubt on several putative infectious agents that have been previously hypothesised as the cause of his condition but for which we detect not a single sequencing read. Conversely, some of the species we detect are uncommon as environmental contaminants and may represent plausible infective agents. Based on all the available evidence, we hypothesize that Marat may have suffered from a fungal infection (seborrheic dermatitis), possibly superinfected with bacterial opportunistic pathogens.
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metagenomic analysis of a Blood Stain from the french revolutionary jean paul marat 1743 1793
bioRxiv, 2019Co-Authors: Toni Dedios, Lucy Van Dorp, Philippe Charlier, Sofia Morfopoulou, Esther Lizano, Celine Bon, Corinne Le Bitouze, Marina Alvarezestape, Tomas Marquesbonet, Francois BallouxAbstract:Abstract The French revolutionary Jean-Paul Marat was assassinated in 1793 in his bathtub, where he was trying to find relief from the debilitating skin disease he was suffering from. At the time of his death, Marat was annotating newspapers, which got Stained with his Blood and were subsequently preserved by his sister. We extracted and sequenced DNA from the Blood Stain and also from another section of the newspaper, which we used for comparison. Analysis of human DNA sequences supported the heterogeneous ancestry of Marat, with his mother being of French origin and his father born in Sardinia, although bearing more affinities to mainland Italy or Spain. Metagenomic analyses of the non-human reads uncovered the presence of fungal, bacterial and low levels of viral DNA. Relying on the presence/absence of microbial species in the samples, we could confidently rule out several putative infectious agents that had been previously hypothesised as the cause of his condition. Conversely, some of the detected species are uncommon as environmental contaminants and may represent plausible infective agents. Based on all the available evidence, we hypothesize that Marat may have suffered from a primary fungal infection (seborrheic dermatitis), superinfected with bacterial opportunistic pathogens. Significance The advent of second-generation sequencing technologies allows for the retrieval of ancient genomes from long-dead people and, using non-human sequencing reads, of the pathogens that infected them. In this work we combined both approaches to gain insights into the ancestry and health of the controversial French revolutionary leader and physicist Jean-Paul Marat (1743-1793). Specifically, we investigate the pathogens, which may have been the cause of the debilitating skin condition that was affecting him, by analysing DNA obtained from a paper Stained with his Blood at the time of his death. This allowed us to confidently rule out several conditions that have been put forward. To our knowledge, this represents the oldest successful retrieval of genetic material from cellulose paper.
Fathiah A Zubaidi - One of the best experts on this subject based on the ideXlab platform.
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a novel liquid chromatography tandem mass spectrometry technique using multi period multi experiment of mrm epi mrm3 with library matching for simultaneous determination of amphetamine type stimulants related drugs in whole Blood urine and dried bloo
Journal of Analytical Toxicology, 2019Co-Authors: Fathiah A Zubaidi, Yeunmun Choo, Guan Huat Tan, Hamimah Abd Hamid, Yap Ken ChoyAbstract:A novel mass spectrometry detection technique based on a multi-period and multi- experiment (MRM-EPI-MRM3) with library matching in a single run for fast and rapid screening and identification of amphetamine type stimulants (ATS) related drugs in whole Blood, urine and dried Blood Stain was developed and validated. The ATS-related drugs analyzed in this study include ephedrine, pseudoephedrine, amphetamine, methamphetamine, MDMA (3,4-Methylenedioxymethamphetamine), MDA (3,4-Methylenedioxyamphetamine), MDEA (3,4-Methylenedioxy-N-ethylamphetamine) and phentermine. The relative standard deviation for inter and intraday was less than 15% while recoveries ranged from 80% to 120% for all three matrices, i.e., whole Blood, urine and dried Blood Stain. All compounds gave library matching percentage of more than 85% based on the purity. This method was proven to be simple and robust, and provide high confident results complemented with library matching confirmation.
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bland altman statistical analysis and mean concentration ratio for the determination of amphetamine type stimulants related drugs in dried Blood Stain dbs versus whole Blood sample wbs by liquid chromatography tandem mass spectrometry lc ms ms applic
Journal of Forensic Research, 2019Co-Authors: Fathiah A Zubaidi, Yeunmun Choo, Syaiful Izwan Ismail, Guan Huat TanAbstract:The performance of dried Blood Stain (DBS) versus whole Blood sample (WBS) methods were evaluated using Bland-Altman analysis and mean concentration ratio for forensic toxicology cases in Malaysia. Common amphetamine-type stimulants related drugs of ephedrine, pseudoephedrine, amphetamine, methamphetamine, MDMA (3,4- Methylenedioxymethamphetamine), MDA (3,4-Methylenedioxyamphetamine), MDEA (3,4- Methylenedioxy-N-ethylamphetamine) and phentermine were investigated using DBS and WBS methods. The analysis was performed utilizing novel protocol consists of mass spectrometry detection technique based on a multiperiod and multi-experiment (MRM-EPI- MRM3) with library matching post liquid-liquid extraction of whole Blood and corresponding DBS samples from spiked samples. The analysis was applied to 20 whole Blood samples submitted for forensic and medico-legal analysis which were reported positive for the presence of the drugs. Results for both DBS and WBS were compared using Bland-Altman mean difference plots and mean concentration ratio for degree of agreement. The results showed good degree of agreements indicating no significant differences in results obtaining from DBS and WBS methods, allowing both methods to be used interchangeably. The study also demonstrated the advantage of the DBS method as an inexpensive alternative to WBS in the forensic toxicology field.