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Christian, Syndney Donald. "Factors affecting the life threat to aged persons in domestic dwelling fires." Thesis, London South Bank University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357170.
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Musiyandaka, Fungisai Lorraine. "Assessment of the suitability of blood samples collected for toxicological analysis for subsequent genetic analysis: A follow-up study one year later." Master's thesis, Faculty of Health Sciences, 2018. http://hdl.handle.net/11427/30930.
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Drug usage, both of a recreational or pharmaceutical nature, is common, however the abuse of such substances is an international problem. In the Western cape, South Africa, the burden of drug-related fatalities is high compared to the rest of the country. The provincial Forensic Pathology Service may encounter cases where drug-related fatalities are unclear whether death was accidental or suicidal, or drug toxicity is inconsistent with the medical/social history. This may be due to genetic alterations with drug metabolism and it has been suggested that genetic analyses may be the next step in these cases. However, toxicology results from the National Forensic Chemistry Laboratory in the Western Cape may be delayed by months to years, meaning that upon interpretation of toxicology results, there is no chance to obtain another blood sample from the deceased individual for genetic analysis. It was therefore important to determine the suitability of blood samples collected and handled in toxicology environments for subsequent genetic tests. Previously, blood samples from 30 post-mortem cases were collected into two red-top (no additives), two grey-top (sodium fluoride/potassium oxalate) and one purple-top (EDTA) tubes. Samples from one red-top and one grey-top tube underwent toxicological analysis, followed by DNA analysis, while the remaining tubes (controls) underwent DNA analysis immediately. All samples were then stored for approximately one year, prior to this study. The DNA analysis was repeated on all blood samples (n = 150) and results were assessed in terms of storage time and tube type. DNA was not significantly degraded in any of the samples; however, DNA from red-top tubes had significantly lower concentrations compared to that from grey-top tubes (p < 0.001), regardless of whether the sample had undergone toxicological analysis. The very low yields of DNA from red-top tubes posed substantial challenges for PCR-based analysis, resulting in poor quality Sanger sequencing results. Some DNA from grey-top tubes, passed the quality assessments and hence further work is required to provide an informed decision on which tube type is better suited for genetic analyses.
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Yang, Chi-ting, and 楊志婷. "Pharmacokinetics of alcohol using breath measures and some statisticalaspects in forensic science." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46506159.
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Smith, Fiona. "Wetting and evaporation of human blood in relation to forensic analysis." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0479.
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La physique de mouillage et de séchage de sang n’est pas encore bien connue. Dans le cadre d’un travail collaboratif, une étude est réalisée afin d’apporter de nouveaux outils aux équipes d’investigations criminelles. L’objectif est de comprendre les dynamiques qui entrent en jeu dans la formation de traces de sang, un fluide complexe. Nous nous intéressons aux traces dites passives telles que l’égouttement ou l’accumulation, qui résultent de l’action de la pesanteur. Nous considérons d’abord les gouttes passives. Le comportement d’impact de gouttes de fluides complexes est un sujet qui a été largement étudié mais suscite encore de vifs débats. Bien que le séchage d’une goutte déposée ait déjà été étudié, ceci n’est pas le cas pour des gouttes qui viennent impacter perpendiculairement une surface, tombant depuis une certaine hauteur. Parallèlement nous étudions le séchage de flaques de sang car leur dynamique de séchage n’a pas été étudiée jusqu’à présent. Différents paramètres tels que la nature des substrats, l’humidité et la température sont pris en compte afin de comprendre le lien entre la typologie des motifs séchés et les phénomènes observés en vue de répondre à des applications criminelles. Enfin des relations empiriques sont établies. Grace à des méthodes inverses, ces relations permettent, par la suite, d’obtenir une estimation de la vitesse d’impact de gouttes séchéesThe physics behind wetting and drying of blood is not yet completely understood. In the context of a collaborative project, new techniques have been developed to provide evidence for investigators in crime solving. Given that blood is a complex fluid, the major aim has been to investigate the dynamics involved in the patterns of stain formation. Interest is focused on passive stains, which result from the action of gravity in dripping or blood flow accumulation. In the case of drip stains, the impact behaviour of complex fluid droplets, despite many studies, raises much debate. Although the drying dynamics of a deposited drop of blood were already studied, this is not the case for drops of blood impacting perpendicularly a surface, falling from a certain height. Beside this, until the present work, little attention has been paid to the dynamics controlling the drying of blood pools. In both situations, the influence of different parameters such as substrates, humidity and temperature are examined. Empirical relations are established between final dried blood patterns and the generating mechanism, yielding possible application in blood pattern analysis for forensic investigations. Finally, using inverse methods, the empirical relations allow estimating an impact velocity, for dried drip stains
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Dama, Tavisha. "Development of a method for the utilization of a single sample for presumptive, confirmatory and DNA analysis of blood." Thesis, Boston University, 2013. https://hdl.handle.net/2144/21144.
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Thesis (M.S.F.S) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.In any forensic investigation it is important to consider sample preservation. Oftentimes trace quantities of biological materials are found at crime scenes. The usual practice among forensic analysts is to take one sample of a suspected biological stain for presumptive testing, another for confirmatory testing and if both these results are positive, take a third portion for DNA analysis. This works well when sufficient sample is available, however, when trace quantities of sample are present at crime scenes, sample preservation becomes of importance. Thus, this study attempts to develop a procedure where presumptive, confirmatory and DNA analysis could be carried out on a single portion of the sample. In this study four different presumptive reagents – phenolphthalein, o-tolidine, 3, 3’, 5, 5’- tetramethylbenzidine (TMB) and luminol – were used and their effects on the ABAcard® Hematrace® immunochromatographic membrane test and subsequent DNA analysis were studied. In order to develop the method for one-sample analysis, the lowest volume of blood that gave sufficient quantity of DNA was determined by extracting different volumes (20, 10, 5, 2.5 and 1.25 μL) of whole blood. Additionally, different volumes of blood mixed with ABAcard® Hematrace® buffer were extracted. From this preliminary work it was determined that 1.25 μL of whole blood yielded sufficient DNA quantity even when mixed with the ABAcard® Hematrace® buffer. Bloodstains of 1.25 μL were then prepared and the one-sample analysis was carried out. The method developed was most successful when luminol was used as the presumptive reagent. For the bloodstains treated with the other three presumptive reagents (phenolphthalein, o-tolidine and TMB), a decrease in DNA yield was detected. This decrease was attributed to the inability of the Qiagen® QIAmp® column to adsorb the DNA after exposure to the chemical reagents and to the insolubility of the bloodstain in ABAcard® Hematrace® buffer following the addition of presumptive blood test reagents. Extraction of DNA from the ABAcard® Hematrace® immunochromatographic membrane was also carried out using the Qiagen® QIAmp® DNA investigator kit; no DNA was obtained from the membranes on which 150 μL of a dilute blood sample had been applied. This suggests that either the extraction method used was not capable of extracting the minute quantities of DNA that might be present on the membrane or there were insufficient white blood cells deposited on the membrane during the testing process. Thus, a one-sample procedure was successfully developed for bloodstains treated with luminol. A loss/reduction of DNA was observed for the samples previously exposed to phenolphthalein, o-tolidine and TMB due to the incapability of the reagents to work with silicon-based extraction chemistries. Further experimentation is needed to develop a similar procedure to be used with such presumptive testing reagents. Alternatively, a procedure can be developed that utilizes two samples: one for presumptive testing and another for confirmatory and subsequent DNA analysis, since it was observed that only the presumptive reagents, and not the ABAcard® Hematrace® buffer, interfered with DNA analysis.
2031-01-01
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Vuko, Loyiso Abongile Marvin. "Post-mortem toxicogenetics: determining the suitable of blood samples collected for routine toxicological analyses for use in subsequent genetic analyses." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29525.
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South Africa has one of the highest prevalences of drug misuse and abuse in Africa. Salt River Mortuary (Cape Town, South Africa), along with other national Forensic Pathology Service providers, receives many cases of suspected drug-related deaths. In some cases, the traditional autopsy – when viewed together with the decedent's history – is not able to indicate whether a drug-related death is accidental or suicidal in relation to altered drug metabolism. Literature has shown that this can be investigated by sequencing gene(s) encoding the implicated metabolising enzyme(s) in a postmortem genetic analysis. However, as such an analysis would normally be performed following the obtainment of postmortem toxicological results, it is imperative to investigate whether blood samples retrieved back from a toxicology laboratory would be sufficient for the said genetic analysis, despite the handling involved in the process of toxicological investigation. To this end, blood samples from 30 deceased individuals in which drug use/abuse may have contributed to death, were collected into two red-top tubes (plain), two grey-top tubes (containing sodium fluoride and potassium oxalate) and one EDTAcontaining purple-top tube (control). DNA was immediately extracted from one of each colour tube, while the duplicate red-top and grey-top tubes first underwent a process of toxicological analyses, and then underwent DNA extraction. The concentration, degradation, purity, contamination, and quality of DNA were assessed using real-time PCR, spectrophotometry, forensic DNA profiling, and Sanger sequencing. In contrast to the grey-top tubes, the results showed that the red-top tubes were most suitable for the aforementioned genetic analysis. Overall, the study not only demonstrated that postmortem genetic analysis using samples retrieved from a toxicology laboratory is possible in the local context, but also provided guidelines around the pre-analytical phase of the analysis. These results illustrate the opportunity to investigate these toxicogenetic avenues further, particularly in future expansion of services currently provided at Salt River Mortuary, which may provide families more information about circumstances of their relative’s death.
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Miranda, Geraldo Elias 1978. "Analysis of the fluorescence of body fluids on different surfaces based on the age of the sample = Análise da fluorescência de fluidos corporais em diferentes superfícies de acordo com a idade da amostra." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/290736.
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Orientador: Eduardo Daruge JuniorDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
Made available in DSpace on 2018-08-25T14:52:09Z (GMT). No. of bitstreams: 1 Miranda_GeraldoElias_M.pdf: 1300905 bytes, checksum: 727847fefeb94b489d815161f789fc98 (MD5) Previous issue date: 2014
Resumo: A utilização de técnicas de triagem como a alternate light source (ALS) é importante para encontrar evidências biológicas em uma cena de crime. O objetivo deste trabalho foi avaliar se a fluorescência do fluido biológico (sangue, sêmen, saliva e urina) depositado em diferentes superfícies sofre variação em função da idade da amostra. A mancha foi iluminada com uma ALS da marca Megamaxx¿ System e fotografada com o auxílio do Canon EOS Utility¿. A análise das imagens foi feita por meio de uma combinação dos programas Adobe Photoshop¿ e ImageJ¿. O Adobe Photoshop¿ foi utilizado para preparar as fotografias para as análises e o ImageJ¿ para registrar o valor do brilho do pixel da imagem. Os dados obtidos foram submetidos na técnica de análise de variância por meio do ajuste de um modelo linear generalizado misto com dois fatores fixos e um terceiro fator, o tempo, analisado como medidas repetidas no formato de efeito aleatório com matriz de covariância do tipo autorregressivo de primeira ordem. Efeitos significativos tiveram suas médias comparadas duas a duas por meio do teste de Tukey. Pode-se concluir que a fluorescência dos fluidos biológicos analisados variaram em função do tempo em que foram expostos. A fluorescência foi menor quando as amostras estavam úmidas e permaneceram constantes quando estavam secas até o tempo máximo analisado (60 dias), independentemente do substrato em que o fluido foi depositado. Portanto, o perito forense pode detectar fluidos biológicos no local do crime usando uma ALS mesmo após vários dias da ocorrência do crime
Abstract: The use of screening techniques, such as an alternative light source (ALS), is important for finding biological evidence at a crime scene. The objective of this study was to evaluate whether biological fluid (blood, semen, saliva, and urine) deposited on different surfaces changes as a function of the age of the sample. Stains were illuminated with a Megamaxx¿ ALS System and photographed with a Canon¿ camera. Adobe Photoshop¿ was utilized to prepare photographs for analysis, and then ImageJ¿ was used to record the brightness values of pixels in the images. Data were submitted to analysis of variance using a generalized linear mixed model with two fixed effects (surface and fluid). Time was treated as a random effect (through repeated measures) with a first-order autoregressive covariance structure. Means of significant effects were compared by the Tukey test. In all tests, a 5% level of significance was established. The fluorescence of the analyzed biological material varied depending on the age of the sample. Fluorescence was lower when the samples were moist. Fluorescence remained constant when the sample was dry, up to the maximum period analyzed (60 days), independent of the substrate on which the fluid was deposited. Therefore, the forensic expert can detect biological fluids at the crime scene using an ALS even several days after a crime has occurred
Mestrado
Odontologia Legal e Deontologia
Mestre em Biologia Buco-Dental
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Wells, Joanna Kathleen. "Investigation of factors affecting the region of origin estimate in bloodstain pattern analysis." Thesis, University of Canterbury. Physics and Astronomy, 2006. http://hdl.handle.net/10092/1419.
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The causes of errors in the angle of impact calculation were investigated including the surface type, falling velocity and the method used to fit an ellipse to a bloodstain. As had been cited previously the angle of impact was generally underestimated, especially at acute angles and the reason for this was determined to be due to an overestimation of the length of a bloodstain. The surface type was found to significantly affect the accuracy of an angle of impact calculation and as the falling velocity increased, the angle of impact calculation became more accurate. High-speed photography was used to further investigate the formation of bloodstains on surfaces. It was found that the formation of the bloodstain varied depending on the surface type and the angle of the surface. Bloodstain pattern analysis involves the application of scientific techniques to reconstruct events that resulted in a bloodstain pattern. The position of the blood source in three-dimensional space is a fundamental element of this application. Currently little is known about the methods used by bloodstain pattern analysts to select bloodstains when determining the region of origin. Fourteen analysts worldwide were surveyed in order to ascertain this information. It was found that the methods used were variable and were often not based on scientific research. Research was therefore undertaken into bloodstain selection and in particular, which bloodstains should be selected for a region of origin analysis. As a result of these experiments, two sets of selection criteria were established, one for use when the region of origin is being calculated manually and one for when directional analysis is being used.
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Hussain, Munir. "Endogenous cardioactive substances in blood : effects on the isolated guinea-pig atria." Thesis, University of Central Lancashire, 1991. http://clok.uclan.ac.uk/20393/.
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Investigations were made into the role of blood-borne substances affecting myocardial contractility. Isolated left and right guinea-pig au -ia were used as bioassay for the detection of endogenous cardiotonic substances in bovine serum. Results show that serum that had been buffer exchanged to Krebs-Henseleit by dialysis or Sephadex G-25, produced positive inotropic and positive chronotropic effects on the isolated guinea-pig au-ia. The hypodynamic state was not a prerequisite for the detection of cardioactivity. The cardioactive effectswere not blocked by the combined presence of propranolol and methysergide (both 10 6M) and were also dissimilar in time course from other known cardiotonic agents such as noradrénaline, isoprenaline, 5-hydroxytryptamine and cardiac glycosides. After ultrafiltration on Amicon diaflo membranes (XM100A and PM30A) activity was found solely in the retentate fractions. The ultrafiltrates were devoid of positive inotropic and chronotropic actions. Since the molecular weight cut-off of the XM100A membranes was 100 Kilodaltons, it is probable that the active principle is greater than 100 kilodaltons. Alternatively, a smaller active substance may be bound to a large protein. The cardioaciive factor in whole bovine serum was heat labile and lost after 30 minutes incubation at 70 0C or boiling for 10 minutes. Activity of whole bovine serum was not cold labile during a 30 minute incubation at 0°C. Activity was also present after dialysis at 4-8 °C for up to 48 hours. Cardioactivity of whole serum was lost following acidification to pH 5.0 at 4-8 0C for 24 hours. This experiment was extended to include a wider range of pH values between 4.5 and 75. The positive inotropic and chronotropic activities of serum were markedly reduced at acidic pH values. The cardioactive factor was also lost after equilibration of serum to physiological buffers of a low ionic strength. The loss of activity was independent of the nature of the buffer and was prevented by raising the ionic strength with the addition of NaCl. The cardiotonic principle was also sensitive to the addition of KBr but not equimolar (or higher) concentrations of KCI or NaCl. The above results taken together would be consistent with a proteinaceous nature of the active substance. The major purification methods therefore employed included precipitation techniques involving (NH4)2SO4 and polyethyleneglycol-8000, ion exchange, hydrophobic interaction chromatography and gel filtration. Attempts to isolate and purify the cardiotonic agent were largely unsuccessful due, particularly, to the labile nature of the active molecule when exposed to non-physiological experimental conditions. Investigations in to the cellular mechanism of action of the cardioactive factor in buffer exchanged serum suggested that the effects may perhaps be mediated by increases in the level of endogenous cyclic AMP and not via inhibition of the N a+,Kt ATPase. In conclusion, the present study has demonstrated the existence of a factor in bovine serum that produced positive inotropic and chronotropic effects on the isolated guinea-pig au-ia. Properties of the cardioactive factor suggest the existence of a novel proteinaceous substance with some previously unidentified characteristics.
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Counsil, Tyler I. "Real-time RNA-based amplification allows for sensitive forensic blood evidence analysis." Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1391475.
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The purpose of this experiment was to determine if nucleic acid sequence based amplification (NASBA) is a suitable application for the differentiation of body fluids that might comprise a forensic evidence sample. NASBA is a sensitive RNA transcription based amplification system. NASBA could theorhetically be used for bodily fluid identification based upon amplification of tissue-specific mRNA transcripts present in a given forensic sample.Amplification of both Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and Matrix Metalloproteinase 1 1 (MMPmRNA transcripts were used to determine that NASBA could amplify body fluid transcripts and whether it could distinguish between menstrual and non-menstrual blood, respectively. GAPDH is a housekeeping gene that is constituently expressed and its mRNA transcripts could therefore be used to determine whether non-menstrual blood could be amplified using the NASBA procedure. MMP 11 is a menstrual cycle-specific gene associated with endometrial breakdown. Using the mRNA transcripts from MMP 11, NASBA could be utilized for menstrual blood identification. In this study, non-menstrual and menstrual blood samples were analyzed with NASBA both in the presence and absence of chemical contamination. Contaminants utilized ranged from commercial automotive wax, transmission fluid, brake fluid, artificial tears, hand soap, 10% bleach, and the luminol blood detecting reagent. Non-menstrual blood was aliquoted onto a 1 cm x 1 cm cotton cloth for contamination, while menstrual blood was provided on a 1 cm x 1 cm area of sterile menstrual pad. All samples underwent Tri reagent extraction to obtain RNA samples for NASBA amplification.With respect to NASBA amplification data, non-menstrual blood data (from extracted RNA and unextracted blood samples) revealed the highest levels of amplification as shown in relative fluorescence units (RFU). Uncontaminated menstrual blood revealed the second highest amplification data. In the presence of chemical contamination, high levels of amplification were observed when samples were contaminated with brake fluid and commercial hand soap. Moderately low amplification was observed with samples contaminated with transmission fluid, 10% bleach, and artificial tears. NASBA amplification was completely inhibited in the presence of automotive wax and luminol. Cycle threshold (CO values for each amplification result were also obtained from each reaction. Smaller Ct values correspond to a higher NASBAreaction efficiency and therefore larger amplification values. The Ct values obtained for each amplified sample correlate strongly with the amount of amplification observed from reaction. Based upon the results of this experiment, NASBA should be considered as a novel tool for forensic evidence analysis.Department of Biology
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Reidy, Lisa Jayne. "Stable isotope analysis : a new forensic science tool." Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479310.
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Chow, W. M. L. "Capilliary column gas chromatography in forensic science." Thesis, University of Strathclyde, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371945.
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Sheehan, C. P. "The application of the enzyme-linked immunosorbent assay (ELISA) to ABH grouping in forensic science." Thesis, University of Surrey, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381661.
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Rinke, Caitlin. "Selective Multivariate Applications in Forensic Science." Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5459.
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A 2009 report published by the National Research Council addressed the need for improvements in the field of forensic science. In the report emphasis was placed on the need for more rigorous scientific analysis within many forensic science disciplines and for established limitations and determination of error rates from statistical analysis. This research focused on multivariate statistical techniques for the analysis of spectral data obtained for multiple forensic applications which include samples from: automobile float glasses and paints, bones, metal transfers, ignitable liquids and fire debris, and organic compounds including explosives. The statistical techniques were used for two types of data analysis: classification and discrimination. Statistical methods including linear discriminant analysis and a novel soft classification method were used to provide classification of forensic samples based on a compiled library. The novel soft classification method combined three statistical steps: Principal Component Analysis (PCA), Target Factor Analysis (TFA), and Bayesian Decision Theory (BDT) to provide classification based on posterior probabilities of class membership. The posterior probabilities provide a statistical probability of classification which can aid a forensic analyst in reaching a conclusion. The second analytical approach applied nonparametric methods to provide the means for discrimination between samples. Nonparametric methods are performed as hypothesis test and do not assume normal distribution of the analytical figures of merit. The nonparametric permutation test was applied to forensic applications to determine the similarity between two samples and provide discrimination rates. Both the classification method and discrimination method were applied to data acquired from multiple instrumental methods. The instrumental methods included: Laser Induced-Breakdown Spectroscopy (LIBS), Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy, and Gas Chromatography-Mass Spectrometry (GC-MS). Some of these instrumental methods are currently applied to forensic applications, such as GC-MS for the analysis of ignitable liquid and fire debris samples; while others provide new instrumental methods to areas within forensic science which currently lack instrumental analysis techniques, such as LIBS for the analysis of metal transfers. The combination of the instrumental techniques and multivariate statistical techniques is investigated in new approaches to forensic applications in this research to assist in improving the field of forensic science.Ph.D.
Doctorate
Chemistry
Sciences
Chemistry
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Nelson, Alexander J. "Software signature derivation from sequential digital forensic analysis." Thesis, University of California, Santa Cruz, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10140317.
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Hierarchical storage system namespaces are notorious for their immense size, which is a significant hindrance for any computer inspection. File systems for computers start with tens of thousands of files, and the Registries of Windows computers start with hundreds of thousands of cells. An analysis of a storage system, whether for digital forensics or locating old data, depends on being able to reduce the namespaces down to the features of interest. Typically, having such large volumes to analyze is seen as a challenge to identifying relevant content. However, if the origins of files can be identified—particularly dividing between software and human origins—large counts of files become a boon to profiling how a computer has been used. It becomes possible to identify software that has influenced the computer's state, which gives an important overview of storage system contents not available to date.
In this work, I apply document search to observed changes in a class of forensic artifact, cell names of the Windows Registry, to identify effects of software on storage systems. Using the search model, a system's Registry becomes a query for matching software signatures. To derive signatures, file system differential analysis is extended from between two storage system states to many sequences of states. The workflow that creates these signatures is an example of analytics on data lineage, from branching data histories. The signatures independently indicate past presence or usage of software, based on consistent creation of measurably distinct artifacts. A signature search engine is demonstrated against a machine with a selected set of applications installed and executed. The optimal search engine according to that machine is then turned against a separate corpus of machines with a set of present applications identified by several non-Registry forensic artifact sources, including the file systems, memory, and network captures. The signature search engine corroborates those findings, using only the Windows Registry.
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Pieters, Janke. "Development and partial validation of a method for the quantification of benzodiazepines and antidepressants in whole blood, serum and urine by liquid chromotography - Tandem mass spectrometry." Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/15750.
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The aim of this project is to develop a single quantification method for certain benzodiazepines, opiates and antidepressants in whole blood, serum and urine by LC-MS/M5 and to consequently validate the analytical method for official use in the Division of Pharmacology at the University of Cape Town.
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Tse, Wai-hin Kenneth, and 謝維軒. "Forensic analysis using FAT32 file cluster allocation patterns." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46605733.
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Zahra, Nathalie. "The development of PCR internal controls (PICs) for forensic DNA analysis." Thesis, University of Central Lancashire, 2009. http://clok.uclan.ac.uk/20515/.
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Proper interpretation of DNA profiles depends on the quality of the DNA samples, the amplification efficiency and the success of post-PCR processing. Chemicals associated with forensic samples can affect the amplification process while random errors occurring during pipetting and electrokinetic injection can cause variability. This can lead to either a reduced signal or lack of DNA profiles. As recommended by the SWGDAM, laboratories carrying out DNA profiling have to adopt standardise and validate procedures, which lead to high levels of quality assurance and control. During amplification, monitoring is restricted to the use of exogenous controls, which are unable to identify issues associated with individual samples. To address this limitation, four PCR Internal Controls (PJC5) i.e. two Internal Amplification Controls (IACs) and two Internal Non-Amplifiable Control (INAC5), to be used with the AmpFtSTR® SGM Plus® kit were developed. The IACs (90 bp and 410 bp) and INACs (80 bp and 380 bp) fragments were generated from the plasmid pBR322 and added along with human DNA in a 12.5 gl PCR volume. During the reaction the IAC% and 1AC 41 0 are amplified non-competitively with ROX labelled primers, while the pre-labelled INAC80 and 1NAC 380 were not involved with the amplification process. Both sets of fragments were detected as red peaks on the electropherogram flanking the human DNA profile. To study the behaviour of the markers within the system and their effect on the performance and sensitivity of the assay, the PICs were used during the amplification of human DNA of different quantity and quality and with the addition of three common inhibitors. Initial experiments involving the individual development of the fragments showed that both the INACs and IACs can be successfully applied to the amplification of human DNA with SGM Plus® reaction under optimised conditions, without significantly impacting the quality of human DNA profile. As the INACs fragments are designed not to amplify during the reaction, they gave a stable signal that can be used to monitor the post-PCR sample processing. The peak height ratios (PHRs) of human DNA with that of the LNAC8 0 or 1NAC380 can also be used to normalise the signal and assess the amplification efficiency of human DNA samples within replicates of the same sample run under the same conditions. The JACs on the other hand gave more information on the process of the PCR. They were able to monitor changes in the amplification efficiency and detect presence of inhibitors with a minimum inhibitory concentration closer to the SGM Plus® as compared to the Quantifiler® WC system. The IAC90 and 1AC410 ratios were also used to distinguish between partial profiles obtained from degraded DNA and those resulting from partial inhibition. Combining the two sets of fragments together with the amplification of human DNA needed further reaction optimisation, involving the addition of dNTPs and MgCl2. The presence of PICs provided information on the amplification performance and post-PCR processing and can assist with the interpretation of human DNA profiles. The position of the fragments also allowed PICs to be used as sizing standard. Compared to the GSTh 500 ROXTM size standard, PICs showed a slightly lower sizing precision, with standard deviations lower than 0.3 bp. Even though this resulted in allelic bins higher than 1 bp limit for 99.7% confidence, all samples sized with PICs were correctly genotyped. The addition of PICs would be a valuable tool, in particular, for the analysis of compromised DNA. In particular it would be useful when analysing DNA recovered from skeletal remains, which are prone to accumulation of PCR inhibitors and DNA degradation.
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Soobhany, Ahmad Ryad. "Image source identification and characterisation for forensic analysis." Thesis, Keele University, 2013. http://eprints.keele.ac.uk/2301/.
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Digital imaging devices, such as digital cameras or mobile phones, are prevalent in society. The images created by these devices can be used in the commission of crime. Source device identification is an emerging research area and involves the identification of artefacts that are left behind in an image by the camera pipeline. These artefacts can be used as digital signatures to identify the source device forensically. The type of digital signature considered in this thesis is the Sensor Pattern Noise (SPN), which consists mainly of the PRNU (Photo Response Non-Uniformity) of the imaging device. The PRNU is unique to each individual sensor, which can be extracted traditionally with a wavelet denoising filter and enhanced to attenuate unwanted artefacts. This thesis proposes a novel method to extract the PRNU of a digital image by using Singular Value Decomposition (SVD) to extract the digital signature. The extraction of the PRNU is performed using the homomorphic filtering technique, where the inherently nonlinear PRNU is transformed into an additive noise. The range of the energy of the PRNU is estimated, which makes it easier to separate from other polluting components to obtain a cleaner signature, as compared to extracting all the high frequency signals from an image. The image is decomposed by using SVD, which separates the image into ranks of descending order of energies. The estimated energy range of the PRNU is used to obtain the interesting ranks that are utilised to form part of the digital signature. A case study of an existing image analyser platform was performed by investigating its identification and classification results. The SVD based extraction method was tested by extracting image signatures from camera phones. The results of the experiments show that it is possible to determine the source device of digital images.
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Schultz, John S. "Offline forensic analysis of Microsoft Windows XP physical memory." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Sep%5FSchultz.pdf.
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Thesis (M.S. in Computer Science)--Naval Postgraduate School, September 2006.Thesis Advisor(s): Chris Eagle. "September 2006." Includes bibliographical references (p. 73-74). Also available in print.
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Van, Winkle Carolyn. "Forensic DNA Extraction Strategies for PCR Analysis." Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc278269/.
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There is a transition nationwide on the analysis of forensic evidentiary stains containing biological material from traditional serology to Polymerase Chain Reaction (PCR) methodologies. The increased sensitivity of PCR, the limited number of alleles at each locus, and the necessity of producing unambiguous data for entry into the FBI's Combined DNA Index System make this study of extraction procedures of utmost importance. A "single tube" extraction procedure for blood stains collected onto FTA™ paper and a modified differential nonorganic extraction method from spermatozoa containing
mixed stains were analyzed and compared. The extraction success was evaluated by amplification and typing of the amplified fragment length polymorphism, D1S80. These modifications of the nonorganic method utilized gave an improved separation of the spermatozoa-containing mixed stains.
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Alshamaileh, M. Y. "Novel strategies for the analysis of drugs of abuse." Thesis, University of Lincoln, 2016. http://eprints.lincoln.ac.uk/23695/.
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The data presented in this thesis has been organized in three parts: First part included the development and validation of a quantitative HPLC-DAD analytical method of mephedrone after extraction from spiked whole blood and serum samples, alone and with methcathinone. The second part included in vitro metabolism of mephedrone and other NPS, which are methoxetamine and methcathinone, using an in-house prepared in vitro metabolic system, namely liver microsomes, followed by performing analysis for the drugs and their proposed metabolites utilizing LC-MS. Third part included in vitro studies of selected NPS using purchased HepaRG and hepatocytes. In vitro study included in vitro cytotoxicity studies of 4-fluoromethamphetamine, mephedrone, methoxetamine and methcathinone, and analytical studies of these drugs of abuse and their potentially produced metabolites using GC-MS. In the first part of this thesis, a HPLC method for the analysis of mephedrone after LLE from blood matrix was developed and validated and shown to be linear with R2> 0.995, precise with intraday and interday RSD values of 4.36 and 4.77% respectively and LOD and LOQ of 0.025 and 0.082 μg/mL respectively. Recovery percentages were low and ranged between 28-37%. Emulsion formation was the major problem effaced which negatively affected recovery and precision values. The previously developed method was optimised and fully validated for the simultaneous analysis of mephedrone and methcathinone after liquid-liquid extraction (LLE) from whole blood and serum samples. The LLE method was optimised through selection of extraction solvent and adjustment of pH values achieving the best validation parameters and minimal emulsion formation. The LLE protocol involved extraction with a mixture of dichloromethane: n-butanol (80:20 v: v) after buffering the sample with borate buffer pH=9.2 and using aniline as internal standard. The HPLC-DAD method was optimized, using reverse mode chromatography and buffered mobile phase of (acetate buffer pH 4.1: ACN – 85:15) for qualitative and quantitative analysis of these drugs in less than 10 minutes under isocratic elution and ambient temperature. The method was fully validated for both drugs and showed to be linear over the specified range of 0.1-10 μg/mL with R2 > 0.99 for both drugs. The accuracy was assessed by calculating percentage recovery at different concentrations for xii both drugs, and retained recovery percent between 84-110%. For repeatability and intermediate precision tests, RSD values were ≤ 6.73%. Specificity was assessed by good resolution between the peaks and by checking peak purities. Limit of detection and limit of quantification, calculated mathematically for both drugs either extracted from whole blood or serum samples, were 0.010- 0.013 μg/ml and 0.032 - 0.043 μg/mL, respectively. In the second part, in vitro studies on the metabolism of the selected NPS using pig liver microsomes and liquid chromatography-mass spectrometry (LC-MS) analysis were performed. Microsomes were prepared by a conventional ultracentrifugation method. In brief, pig liver was brought freshly from local abattoir, sliced into small pieces, homogenised and ultra-centrifuged to produce microsomes and S9 fractions. Produced microsomes were incubated with the drugs of interest under optimised conditions and followed by analysis utilizing LC-MS for the detection of the drugs and the potentially produced metabolites. It was possible to detect two metabolites of the drug mephedrone, hydroxytolyl-mephedrone and nor-dihydro mephedrone. For MXE, one metabolite produced by the O-demethylation was detected and it identity confirmed by MS/MS study to be o-desmethyl-MXE. Another metabolite was detected is suggestively produced by the reduction of the ketone moiety to produce dihydro-MXE or by two steps of O-demethylation and hydroxylation to produce O-desmethyl –hydroxy-MXE. However, due to low intensity signal recorded, MS/MS study was not conclusive for the identity of the molecule In the third part, two types of hepatocytes were used for the study of the metabolism and cytotoxicity of the selected NPS - Mephedrone, Methoxetamine, Methcathinone and 4-Fluoromethamphetamine. Studying the metabolism of selected NPS followed utilizing HepaRG™ followed by GC-MS analysis, it was possible to detect new peaks in the chromatograms of mephedrone and methcathinone which is suggestively the product of N-demethylation. However, it was not possible to detect any new peaks in the chromatograms of methoxetamine nor 4-flouromethamphetamine. The cytotoxicity study utilizing HepaRG cell line showed that these drugs have cytotoxic effects causing in vitro cell death, within the specified range of 4.0x10-2-1.6x101 mM. These drugs were able to cause 43-83% ii cell death, and EC50 values were 0.2323-0.6297 mM. The most potent drug was 4-fluoromethamphetamine, while mephedrone showed the least biological effect to produce.
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Daman, O. A. "Quantitative analysis of amphiphilic properties of membrane interactive proteins." Thesis, University of Central Lancashire, 2003. http://clok.uclan.ac.uk/20542/.
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Integral membrane proteins often possess lipophilic a-helical regions of approximately 21 amino acid residues that are able to traverse the bilayer. These may either be amphiphilic or predominantly hydrophobic (such as those found in the photoreaction centres). Such helices are distinguished by low charge densities and large mean hydrophobicities. Several hydrophobicity measures (scales) and algorithms for identification of these segments have been developed. Here, a survey of currently available hydrophobicity scales and prediction techniques has been conducted and a brief description of each of the techniques is reported. The hydrophobic moment methodology, even after twenty years of existence, appears to be the most widely used technique for amphiphilic helical structure prediction. The reliability of this methodology at predicting structure and function relationship in membrane proteins was tested using proteins and peptides from different but known classes. In predicting structure, the hydrophobic moment appears to make predictions consistent with those from other researchers using other prediction techniques based on other alternative properties. However, the predictions for function were not consistent with the role of proteins in some cases. Scatterplots of mean hydrophobicity and mean hydrophobic moment for different window sizes revealed that there is a negative association between the two variates and, that mean hydrophobic moment decreases as window size increases. It was also deduced from 99% bootstrap confidence intervals for the correlation coefficients, that short window sizes (7-15) are more discriminative than tong ones (16-20). Angular frequencies between 95° and 107 0 were also investigated for all window sizes and it was observed that different window lengths have different optimum angular frequencies. Variation in both window size and angular frequency were seen to affect prediction with window sizes 7-15 residues giving better prediction. A data set of 403 transmembrane segments was assembled. The compositionat and distributional properties of constituent amino acids were investigated. It was observed that transmembrane segments tend to posses high occurrence of charged amino acid residues at the interface, large planar molecules just within the membrane interior and smalt hydrophobic residues in the central region. When the amino acid residue compositions of the boundaries of transmembrane a-helices were compared statisticatly, it was observed that at the 5% significant level there is no difference between the boundaries within, or between classes of transmembrane spans. It was also observed that the assumed length of twenty-one residues is, on average, reasonable for uncleaved sequences but that twenty-two may be appropriate for stop transfer sequences. When the presence of a hydrophobicity gradient in transmembrane a-hetices was examined, 25% of the sequences in the data set showed the distribution of hydrophobicity which is observed in typical transmembrane spans (tow-high-low). However, 13% showed the distribution of hydrophobicity which is similar to that seen in tilted peptides. It would appear that some transmembrane a-helices do have a hydrophobicity gradient, but this has not been related to any biological role. A new measure of amphiphilicity, which takes into account the third dimension of a helix, was also developed and compared to the conventional hydrophobic moment using bootstrap and regression modelling with a categoricat predictor. From the 95% bootstrap confidence intervals for estimates of model parameters, it was concluded though that there is no difference between the two measures, implying that the loss of spatial information in the conventional hydrophobic moment model, is not significant.
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Lockard, Michael. "The fluid dynamics of droplet impacts on inclined surfaces with application to forensic blood-spatter analysis." Thesis, Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53920.
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Bloodstain pattern analysis is used in the investigation of a crime scene to infer the impact velocity and size of an impacting droplet and from these, the droplet’s point and cause of origin. The final pattern is the result of complex fluid dynamic processes involved in the impact and spreading of a blood drop on a surface with variable surface properties such as wettability and porosity. An experiment has been designed to study these processes and the resulting patterns for the case of a single Newtonian droplet impacting an inclined surface with variable roughness and wetting properties. An experimental apparatus, including a droplet generator, has been designed to produce droplets on-demand, and that impact an interchangeable surface. In addition, a blood-simulant liquid has been developed as a replacement for performing tests with real blood. With this apparatus and blood simulant, fluid dynamics concepts, such as contact line motion and wetting behavior are examined in the context of parameters of interest to the forensics community. These include eccentricity, spread factor and the number of spines formed on impact. The effect of varying dimensionless parameters including Reynolds number, Weber number and Laplace number, the angle of impact and surface properties is examined. Correlations are developed for predicting conditions at the point of impact from those observed later, as would be available to a forensics examiner, and the accuracy of the predictions developed in this thesis are evaluated.
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Bexon, Kimerley Jane. "Forensic microRNA analysis of body fluids relating to sexual assaults." Thesis, University of Huddersfield, 2017. http://eprints.hud.ac.uk/id/eprint/34347/.
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DNA profiling has become a universal technique for identifying individuals for evidential use in courts of law. In more complex cases such as sexual assaults, identifying the origin of a stain or sample offers valuable information as to the events that occurred. Currently, many ‘in service’ body fluid identification (BFID) techniques are presumptive, require significant sample volumes and generate false positives. As such, the development of a highly specific and reliable BFID technique would be highly beneficial to forensic scientists in provide more informative and reliable evidence. MicroRNAs (miRNA) are short, stable, non-coding RNA’s which modulate gene expression. Expression of some of these miRNA are body fluid specific, making them a potentially robust tool for BFID. The possibility for the integration of a robust, miRNA based BFID technology for forensic casework employing stem-loop reverse transcription and qPCR analysis was the theme of the research presented here. To be incorporated into the workflow of current forensic laboratories, the protocol must be able to be carried out alongside current techniques with limited addition of cost, equipment, analysts and time. A range of custom designed miRNA markers were analysed on vaginal material, menstrual blood, saliva, venous blood, semen, seminal fluid and skin. Screening indicated specificity of hsa mir-124 to vaginal material, hsa-mir-10a, 135a and 888 to semen, hsa-mir-412 and 507 to menstrual blood, hsa-mir-144-3, 144-5, 142 and 451 to blood and although highly expressed in saliva, hsa-mir-205 was also observed in vaginal material. Universal expression was observed in hsa-mir-93, 508, 1260b and SNORD 47 providing a means of normalisation through the designation of these markers as endogenous controls. A combined panel of markers are presented which were capable of identifying all body fluids, excluding skin from single stains. The panel was successful at identifying certain mixtures such as semen within vaginal material but was unable to confirm saliva presence within vaginal material. Screening of hsa-mir 205 within vaginal material uncovered the observation that hsa-mir-205 was impacted by the use of female contraception. Once a full BFID panel was generated the robustness of the markers was further analysed across the menstrual cycle. No significant difference (p > 0.001) was seen in markers highly expressed in vaginal material during screening (hsa-mir-124, 203a, 205). Expression of non specific markers highlighted the importance of the optimisation of input miRNA. Differential extraction of genetic material was found to be detrimental to miRNA sample integrity. As such, total DNA extraction was employed for vaginal swabs obtained from volunteers following unprotected sexual intercourse, markers hsa mir-10a, 135a and 888 were able to successfully detect semen presence for up to 96 hours. The data generated to date has highlighted a number of miRNA markers that provide a platform for BFID. The developed protocol is reliable and robust; requiring minimal optimisation and is capable of integration with current laboratory workflow with minimum implications to time and cost. The markers identified for BFID have been implemented within studies that are representative of real case scenarios, and have demonstrated their ability to be stable, specific and successful in the identification of certain body fluids. Overall, this research showcases a reliable and body fluid specific protocol capable of being performed alongside DNA profiling.
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Churinsky, Candace Renee. "Characterization of carbon electrode surfaces development of biosensors for forensic DNA applications." Thesis, Boston University, 2013. https://hdl.handle.net/2144/21139.
Full textAbstract:
Thesis (M.S.F.S) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.Quantitative polymerase chain reaction (qPCR) techniques are currently used to quantify samples containing deoxyribonucleic acid (DNA) in forensic analyses. This technology can provide valuable information to an analyst regarding the amount of DNA present but lacks the ability to determine the quality of the sample. Electrochemistry-based biosensors that utilize screen-printed electrodes may provide a method to determine the number of DNA molecules and the length of those molecules in a single assay. This work aimed to create a biosensor by electrostatically loading TPOX oligonucleotides onto a carbon screen-printed electrode for the purpose of quantifying genomic DNA. Electrochemical signal was obtained via the indicating molecule bis-benzimide H33258, which preferentially interacts with double-stranded DNA and would indicate a hybridization event. Cyclic voltammetry was chosen to measure the current signal; peaks obtained using this technique can be analyzed with the Randles-Sevčik equation, which relates current signal with concentration of the target species. A large amount of signal variation and background charging current was observed when H33258 was used as the redox probe. This led to a study of the surface characteristics of the carbon electrodes themselves (i.e. effective surface area) by utilizing the reversible and well-characterized redox couple hexaammine ruthenium. The effect of electrode activation at high anodic potentials was also studied. Though highly recommended in the literature, activation of the carbon surface caused effective surface area and charging current to increase. While a larger electro-active surface is often desirable, the high background current generated when activation is used within the protocol can mask the signal of interest. Due to the low signal-to-noise ratio and inability to reuse the carbon electrode, it was concluded that carbon screen printed electrodes are not optimal forensic DNA biosensors.
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Thakur, Neha S. "Forensic Analysis of WhatsApp on Android Smartphones." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1706.
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Android forensics has evolved over time offering significant opportunities and exciting challenges. On one hand, being an open source platform Android is giving developers the freedom to contribute to the rapid growth of the Android market whereas on the other hand Android users may not be aware of the security and privacy implications of installing these applications on their phones. Users may assume that a password-locked device protects their personal information, but applications may retain private information on devices, in ways that users might not anticipate. In this thesis we will be concentrating on one such application called 'WhatsApp', a popular social networking application. We will be forming an outline on how forensic investigators can extract useful information from WhatsApp and from similar applications installed on an Android platform. Our area of focus is extraction and analysis of application user data from non-volatile external storage and the volatile memory (RAM) of an Android device.
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Williamson, Claire Louise. "The analysis of ballpoint inks with APCI-MS after fading with light, hydrogen peroxide and sodium hypochlorite bleach." Thesis, University of Central Lancashire, 2015. http://clok.uclan.ac.uk/16735/.
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The ability to discriminate between different inks and to determine the length of time an ink has been on a substrate can provide important scientific evidence, especially in cases involving document fraud. Many techniques have been used to analyse inks for ink dating including chromatography and spectroscopy, but the results are unreliable as a result of factors affecting the aging process such as light. This study utilises established techniques in Forensic Document Examination, including filtered light examination but also novel techniques for ink analysis; Atmospheric Pressure Chemical Ionisation (APCI) to analyse inks and dyes with the aim of discriminating between samples based on their degradation products. APCI-MS was used for the first time to study nineteen ballpoint pens from a range of manufacturers by investigating the chemical processes that occur and the products that are formed following the deposition of ink onto a substrate and in solution. Monitoring the degradation process as an ink ages and fades enables the identification of components present in the inks. Using molecular mass data, accurate ink component identifications could be made over a period of two years on samples subjected to a range of external influences. Light, hydrogen peroxide and sodium hypochlorite bleach were used to simulate natural and deliberate fading of inks and dye solutions. Benzophenone and phenol molecules were identified as degradation products but their presence differed for each of the different conditions tested such as no phenol products when bleach was used. This novel approach to ink analysis utilises existing equipment commonly used by document examiner to analyse inks that are old or faded in some way, in order to discriminate between the inks or determine method of alteration.
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Thompson, Marcus A. "An exploratory forensic acquisition and analysis of digital evidence on the Amazon Kindle." Thesis, Purdue University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1565358.
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The Amazon Kindle is becoming a popular e-book reader. This popularity will lead criminals to use the Kindle as an accessory to their crime. Very few Kindle publications in the digital forensics domain exist at the time of this writing. Various blogs on the Internet currently provide some of the foundation for Kindle forensics. For this research each fifth generation Kindle was populated with various types of files a typical user may introduce using one method, the USB interface. The Kindle was forensically imaged with AccessData's Forensic Toolkit Imager before and after each Kindle was populated. Each file was deleted through the USB interface. Files were retrieved and recovered through the USB interface before and after file deletion. These two sets of files were compared to the original set of files. All files retrieved before deletion matched their original counterpart. Not all files recovered after deletion matched their original counterpart. These steps and procedures followed a similar methodology developed by Leshney (2008) for virtual machines.
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Nik, Mohamed Nik Elena. "Investigation of blood dynamics : surface flow and droplet stain morphology on fabrics." University of Western Australia. Centre for Forensic Science, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0112.
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This thesis is divided into two parts, each of which examines aspects of bloodstain analysis where gravity is the main force applied to blood. Part I is a preliminary study on the dynamics of blood flow on various inclined surfaces and examines the use of blood analogs for easy test replication. The flow of uncoagulated human blood at different volumes and temperatures was examined on wood at a set angle of 1.5°, and on glass at varying incline angles. Glycerol solutions of 59% and 42% were used to represent blood at 23°C and 37°C respectively. Glycerol flow trials of similar volumes were conducted on wood, PVC and glass. Fluid flow plots of distance versus time exhibited double exponential curve behaviour, although a power-law relationship derived by H. E. Huppert's (1982) flow expression was obtained for blood flowing on inclined wood. Blood flow exhibited several observable characteristics; a decreasing width of the leading edge over time, and streaking and component separation of the leading region at very low speeds. On a glass surface, the width of the initial flow region decreased and initial speed increased with increasing angles. The glycerol analogs used in this study did not represent their blood counterparts well due to differences in physical properties of the fluids. Part II of this study focuses on the forensic value of passive bloodstains on three fabrics; 100% cotton drill, 65/35 polyester cotton, and 100% Shantung silk. 26 µL drops of 37°C human blood were deposited onto the three fabrics and paper from a height of 14 cm at various impact angles. The stains were photographed and analysed qualitatively and quantitatively using computational methods. 100% cotton drill, 65/35 polyester cotton and ironed 100% Shantung silk provided useful forensic values such as direction of travel and angle of impact. Overall, this study has provided useful preliminary data for further research work.
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Gallo, Jenny M. "Elemental analysis of cotton fiber evidence for use in the field of forensic science." FIU Digital Commons, 2009. http://digitalcommons.fiu.edu/etd/3440.
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The purpose of this research is to introduce a method for the forensic elemental analysis of cotton fibers for the purpose of increasing the discrimination between otherwise similar cotton evidence using microwave digestion Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Laser Ablation- Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS). A quadrupole ICP-MS and UV laser ablation (266nm) instruments were used for the analysis. A cotton standard reference material (IAEA V-9) was used to validate the developed methods producing good accuracy with typically 10 % bias and good precision (typically 5% RSD) for the element list: 25Mg, 27Al, 55Mn, 57Fe, 88Sr and 137Ba. It was found that the LA-ICP-MS method resulted in improved precision over the solution ICP-MS method. Twenty four (24) raw cotton samples and five white cotton T-Shirts were analyzed with the developed methods. It was also found that all the raw cotton samples from different sources were distinguishable from each other, as were all the cotton T-shirts resulting in zero type I errors and zero type II errors for the pairwise comparisons.
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Majero, T. A. Tiffany. "Retrospective analysis of blunt force trauma associated with fatal road traffic accidents in Cape Town (South Africa) over a two-year period." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29580.
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Road transportation systems are a global developmental achievement. However, with them comes increased morbidity and mortality rates in the form of road traffic accidents. In South Africa, there is a need to characterize road traffic accidents and the injuries associated with them, to determine the preventative mechanisms required to reduce their morbidity and mortality rates. A brief review of fatal road traffic accidents from a global perspective is presented, highlighting the current literature surrounding the prevalence, demographics and blunt force trauma injuries associated with road traffic accidents in South Africa. There is limited research regarding the prevalence and characteristics of road traffic accidents. The objective of this study was to determine the prevalence of fatal road traffic accidents, necessitating the need for research, particularly at the regional level. A retrospective analysis was therefore conducted of all fatal road traffic accident related deaths autopsied at Salt River Mortuary (which services the West Metropole region of Cape Town, South Africa) from January 1st , 2013 to December 31st , 2014. The mean prevalence of road traffic accidents for the reviewed period was 15.9 / 100 000 population. The majority of road traffic accident victims were males who fell in the age group of 30 – 49 years. Over the two-year period, the majority of road traffic accident victims were pedestrians with elevated blood alcohol concentration levels. The head and facial regions of victims commonly exhibited external injuries, while the majority of fractures and organ injury were seen in the head and chest regions. There are limited studies which have investigated the blunt force trauma injuries associated with road traffic accidents in South Africa, and there is a need for further research. Interventions are of paramount importance to decrease fatal road traffic accidents, particularly amongst pedestrians as a road user. This study presents recent data on road traffic accidents for the West Metropole region of Cape Town (South Africa).
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Catterson, Sandra Lynne. "Complementary and alternate medicines: a forensic analysis of the potential adulteration of over-the-counter anorectics and "lifestyle" medicines in South Africa." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/27059.
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Background: Complementary and Alternate Medicines (CAMs) in South Africa are not yet subjected to the same rigorous testing required for allopathic (prescription) medication, yet they are freely available as over-the-counter medicines. Past research has shown the presence of a banned drug, sibutramine in natural anorectics and a schedule 6 prescription drug, sildenafil, found in natural erectile dysfunction preparations. Methods: Initially, 26 exhibits (18 erectile dysfunction medicines and 8 anorectics) were screened for active pharmaceutical ingredients using high performance liquid chromatography tandem mass spectrometry. An AB SCIEX 3200 TRAP® linear ion-trap quadrupole mass spectrometer was used to detect and subsequently quantitate these active pharmaceutical ingredients using a targeted multiple reaction monitoring mode. Samples were extracted with 50% v/v methanol in water. A method for the quantitation of sildenafil was subsequently partially validated. The intra- and inter-assay precisions were evaluated and the linearity of the method was investigated in the range of 20 ng/mL to 2000 ng/mL. The method was then successfully applied to a random selection of CAMs. A random sample (n=61) of erectile dysfunction CAMs were selected for quantitation from two different clusters. Cluster 1 comprised of supermarkets and cluster 2 of pharmacies. Results: The validation method for sildenafil showed that the limit of detection was 1.09 ng/mL and the limit of quantitation was 20 ng/mL. The correlation co-efficient and bias were less than 20%. Initial screening of the 26 exhibits indicated that sildenafil was present in 12 of the 18 samples tested and sibutramine in 6 of the 8 anorectics. Of the later 61 exhibits tested, 43 tested positive for sildenafil. The mass of sildenafil per sample ranged from 1.09 ng/mL to 123.7 mg/sample. Conclusion: The lack of label content, regulation and legislation exposes the consumer to the risk of consuming an active pharmaceutical ingredient which may very likely have an adverse effect on their health. There is a need to raise public awareness to the potential dangers of unregulated CAMs, encourage doctors to become more aware of their patients' consumption of CAMs and to motivate the Medicines Control Council to follow through with their deadlines for the regulation of CAMs.
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Woods, Kathleen Nichole. "Analysis of entheseal changes and cross-sectional bone properties of the humerus: implications for bioarchaeology." Thesis, Boston University, 2013. https://hdl.handle.net/2144/21278.
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Thesis (M.S.F.S.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.Bioarchaeologists work to reconstruct the past using skeletal remains inside a framework influenced by archaeological data. One area, into which bioarchaeologists have sought to provide insight, is the reconstruction of physical activities through skeletal indicators. These indicators of activity include looking at skeletal changes such as development of osteoarthritis, osteon remodeling, dental modifications, cross-sectional bone geometry (CSBG) and changes to muscle attachment sites, also known as entheseal changes. The study of entheseal changes has received much attention as researchers have hypothesized that a direct correlation between muscle use and entheseal size exists. Researchers sought to interpret specific movements such as spear-throwing or kayaking by examining the muscle attachment sites involved in those movements and analyzing the robusticity of the entheses. CSBG has also been used to analyze activity levels and interpret the degree of manual labor an individual was involved in. These analyses are based on the biomechanical interpretation of bone as structure that reacts to mechanical stress by increasing bone thickness. This research tested the hypothesis that changes to entheseal size in the humerus would correlate to changes in CSBG. Entheseal changes were analyzed using two methods, the Hawkey and Merbs (1995) and Mariotti et al. (2007) methods. Both methods were analyzed in terms of their ease of use and intraobserver error rates. The Mariotti et al. (2007) method of scoring entheseal changes was found to have more instances of a significant intraobserver error rate than the Hawkey and Merbs (1995) method despite the improved photographs and more detailed descriptions provided by the authors. Both entheseal scoring methods were used to analyze the correlation between entheseal changes and CSBG in the form of the polar moment of area (J) as standardized for size (J'). CSBG has been found to have stronger correlations with mechanical use and this research sought to identify relationships between entheseal development and J' in the humerus. Entheses scored using the Mariotti et al. (2007) method were more frequently found to have a significant correlation with CSBG, while only one enthesis scored using the Hawkey and Merbs (1995) method was found to have a significant correlation (p <.05) with CSBG. This implies that the method used greatly affects the identifiable correlations between entheseal changes and CSBG. Refined methods and more research are necessary before entheseal changes can be accurately used in activity reconstruction.
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Patience, Meryl. "Retrospective analysis of suspected pesticide-related fatalities admitted to Salt River Mortuary in the West Metropole of Cape Town, Republic of South Africa." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29351.
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Introduction: Pesticides offer great benefits in the agricultural sector, but exposure may pose both acute and chronic health risks to humans. In developing countries, morbidity and mortality rates related to pesticide exposure are high and in certain areas (such as in rural, lower socioeconomic and/or agricultural-dependent communities), pesticides may be stored in and around homes, which may increase the risk of accidental exposure as well as intentional poisoning. In Cape Town, South Africa, this public health issue is exacerbated by the informal selling of street pesticides. These are pesticides that usually comprise of a mixture of these chemicals, sold unregistered as liquids or granules in bottles or packages without clear identification labels, for domestic use. While cheap and widely available in informal settlements; these pesticide formulations are not regulated and extremely toxic. Data illustrating the extent and nature of fatalities related to acute and chronic pesticide exposure in Cape Town, particularly as related to street pesticides, is limited. This dissertation provides an overview of the literature associated with pesticide toxicity and related mortality, paying particular attention to available South African research. This is followed by a study investigating pesticide deaths at Salt-River Mortuary over a period of five years.
Aim: The aim of this study was to determine the prevalence and characteristics of deaths associated with suspected acute pesticide toxicity, to broaden the spectrum of knowledge concerning pesticide-related deaths in Cape Town, South Africa.
Methods: A retrospective analysis of cases admitted to Salt River Mortuary (SRM) from 2011 to 2015 (inclusive) was conducted. Demographic, autopsy, investigative and toxicological data (where available) were collected from post-mortem and other investigative reports.
Results: Of the total of 16,453 cases admitted to SRM over a five-year period from January 2011 until December 2015, 104 (0.63%) were deemed to be acutely pesticide-related based on available autopsy data. There was an equal number of male (n=52; 50%) and female (n=52; 50%) victims. Most deaths (n=74; 71%) occurred at medical centres following exposure, and Terbufos was found to be the common pesticide detected analytically (n=42, 61%) in toxicology reports available (76%). Results revealed that (60%) of acute pesticide toxicity cases were suspected suicides, while (6%) of cases were suspected accidents and (3%) cases were suspected homicides, while the remainder were still undetermined pending toxicological investigations.
Conclusion: A history of ingestion, autopsy findings and toxicological results (if available) assisted in identification of these cases, most of which came from lower socio-economic communities. While the number of overall cases is low, it is evident that these deaths are a public health burden, and may be preventable through improved notification and policy development. Challenges with this study involved the inability to distinguish mortality associated with chronic pesticide exposure, the lack of toxicological results available, limited scene investigation information to identify street pesticide contributions, and that the study was limited to one mortuary in Western Cape. An extension of this research to other mortuaries in Western Cape as well as collaborative work with community and public health sectors on availability and toxicity of street pesticides will assist in strategic intervention methods and policy reform to reduce accidental and suicidal mortality associated with acute pesticide exposure.
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McAvoy, Yvonne. "The analysis of amphetamines and explosives by supercritical fluid chromatography : an evaluation." Thesis, Staffordshire University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287282.
Full text
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Charles, Brianne E. "A geometric morphometric analysis of the human ossa coxae for sex determination." Thesis, Boston University, 2013. https://hdl.handle.net/2144/21133.
Full textAbstract:
Thesis (M.S.F.S) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.This study compares sexual variation of the human skeletal pelvis through geometric morphometric analyses. Digitization of the skeletal elements provides the framework for a multi-faceted examination of shape. The sample used in the study consists of individuals from the Bass Donated Skeletal Collection, located at the University of Tennessee-Knoxville. Landmarks digitized for the study are derived from the 36 points implemented in Joan Bytheway and Anne Ross’s geometric morphometric study of human innominates (2010). The author hypothesizes that morphological variation between males and females will be visible to varying degrees throughout the pelvis, with structures to be compared consisting of the ilium, ischium, pubis, obturator foramen, and acetabulum. Particular attention will be paid to the pelvic canal, as this area seems to carry the most sex-specific function of the bone. It is hypothesized that structures directly contributing to the pelvic canal will be more sexually dimorphic than peripheral structures. Data points plotted throughout the pelvis will allow for comparison of various regions. Results indicate that the innominate can be divided into modules with relatively low levels of covariation between them. Greatest amounts of sexual dimorphism are located at the pubis and ischium. The shape of the acetabulum and obturator foramen display little variation between the two sexes. Areas that have the potential for sex determination could be investigated more thoroughly in the future and may be of use in forensic cases in which remains are incomplete.
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Torres, Garcia Christine. "Comparison of 500 Solid Copper Bullets and an Analysis of their Influence on the Individual Rifling Characteristics of Firearms." Thesis, University of California, Davis, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10974211.
Full textAbstract:
This study examines whether 500 solid copper bullets fired from a 9mm firearm would have a significant effect on the individual rifling characteristics of the barrels of a Glock Model 17, a Beretta Model M9, and a Taurus Model PT 92 AF. Five silicone casts of each barrel bore were prepared over the course of this study. The casts were used to compare and evaluate the wear on the rifling of each barrel and note any changes that may have occurred during the progression of the study. The bullets were purchased as reloading components and were tested for hardness in addition to Energy Dispersive Spectroscopy (EDS) analysis. The bullets used for examination were collected at the start, throughout the experiment, and after the firearm had been cleaned following the 500 firings. The bullets, as well as barrel casts, were analyzed using a Leica FS C comparison microscope. Results from the analysis indicate the bullets do not obturate and they do not engage with the grooves of each barrel. Analysis of land impressions show striations that deteriorate or disappear completely; while others appear over the course of firing the 500 copper bullets. Regarding the influence of the bullet wear on the individual rifling characteristics, the striations of each firearm barrel were permanently changed to the point where bullet identification no longer was possible.
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Connon, Catherine Cupples. "Improving Processing Efficiency for Forensic DNA Samples." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc799515/.
Full textAbstract:
The goal of this project was to reduce processing time for forensic DNA testing without incurring significant added costs and/or the need for new instrumentation, while still generating high quality profiles. This was accomplished by: 1) extraction normalization using the ChargeSwitch® Forensic DNA Purification Kit such that a small range of DNA concentrations was consistently obtained, eliminating the need for sample quantification and dilution; 2) developing fast PCR protocols for STR primer sets using shorter amplification methods, low volume reactions and non-fast thermal cyclers; and 3) developing a quicker 3130xl Genetic Analyzer detection method using an alternative polymer/array length combination. Extraction normalization was achieved through a reduction in bead quantity, thereby forcing an increase in bead binding efficiency. Four products (AmpliTaq Gold® Fast PCR Master Mix, KAPA2G™ Fast Multiplex PCR Kit, SpeedSTAR™ HS DNA Polymerase and Type-it Microsatellite PCR Kit) were evaluated for low volume (3μl) fast PCR on a 384-well Veriti® thermal cycler with the Identifiler primer set. KAPA2G™ was selected for 3μl fast PCR protocols using PowerPlex 16 HS and Identifiler Plus primer sets (42-51min), as well as 5μl and 6μl Identifiler fast reactions on a 9700 thermal cycler (51-60min). Alternative detection (POP-6™/22cm) achieved 24-28min run times, but with decreased resolution as compared to traditional POP-4®/36cm detection for alleles >200bp; however, 1bp resolution was still obtainable for alleles <300bp. These modifications resulted in robust databasing processes with up to a 37% reduction in processing time for buccal swabs and Buccal DNA Collectors™ using the three primer sets evaluated (3μl fast PCR reactions) and generated high quality STR profiles with ≥90% pass rates.
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Schober, Cassandra C. (Cassandra Carolyn). "The Evolution, Applications, and Statistical Interpretations of DNA Typing in Forensic Science." Thesis, University of North Texas, 1997. https://digital.library.unt.edu/ark:/67531/metadc332776/.
Full textAbstract:
This thesis examines the evolution, applications, and statistical interpretations of DNA typing as a tool in the field of forensic science as well as in our criminal justice system. The most controversial aspect of DNA typing involves the determination of how likely it is that two people share the same DNA profile. This involves the use of population genetics and databases of allelic frequencies as well as some assumptions about population structuring.
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Conner, Laura. "Evaluation of field sampling and analysis methods for fire investigation including electronic noses and adsorption sampling/gas chromatography mass spectrometry." FIU Digital Commons, 2005. http://digitalcommons.fiu.edu/etd/2422.
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This study evaluates the use of commercially available instruments for locating and collecting accelerants in the field. Electronic noses can be used to scan a fire scene for the possible presence of an accelerant. The TLV Sniffer® was found to be able to detect accelerants at low levels but did alert to some burned matrix alone. When subjected to a proficiency test designed for canines, the TLV Sniffer® was able to locate accelerants in two of the three tests. The tpi®Pocket was found not to be sensitive or selective enough to be useful in locating accelerants. Once the location of possible accelerants has been determined, they can be collected by dynamic headspace sampling in the field with the Portable Arson Sampler (PAS). The PAS was found to be able to collect a broad range of compounds from ignitable liquids and had comparable efficiency to a conventional method.
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Benson, Andrew James. "High-performance liquid chromatography (HPLC) and high-performance liquid chromatography mass spectrometry (HPLC/MS) for the analysis of date rape drugs." FIU Digital Commons, 2002. http://digitalcommons.fiu.edu/etd/1602.
Full textAbstract:
The drugs studied in this work have been reportedly used to commit drug-facilitated sexual assault (DFSA), commonly known as "date rape". Detection of the drugs was performed using high-performance liquid chromatography with ultraviolet detection (HPLC/UV) and identified with high performance-liquid chromatography mass spectrometry (HPLC/MS) using selected ion monitoring (SIM). The objective of this study was to develop a single HPLC method for the simultaneous detection, identification and quantitation of these drugs.
The following drugs were simultaneously analyzed: Gamma-hydroxybutyrate (GHB), scopolamine, lysergic acid diethylamide, ketamine, flunitrazepam, and diphenhydramine. The results showed increased sensitivity with electrospray (ES) ionization versus atmospheric pressure chemical ionization (APCI) using HPLC/MS. HPLC/ES/MS was approximately six times more sensitive than HPLC/APCI/MS and about fifty times more sensitive than HPLC/UV. A limit of detection (LOD) of 100 ppb was achieved for drug analysis using this method. The average linear regression coefficient of correlation squared (r2) was 0.933 for HPLC/UV and 0.998 for HPLC/ES/MS.
The detection limits achieved by this method allowed for the detection of drug dosages used in beverage tampering. This method can be used to screen beverages suspected of drug tampering.
The results of this study demonstrated that solid phase microextraction (SPME) did not improve sensitivity as an extraction technique when compared to direct injections of the drug standards.
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Wang, Mengmeng, and 王萌萌. "Temporal analysis on HFS+ and across file systems in digital forensic investigation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B50900122.
Full textAbstract:
In computer forensics, digital evidence related to time is both important and complex. The rules of changes in time associated with digital evidence, such as files or folders, can be used to analyze certain user behaviors like data access, modification or transfer. However, the format and the rules in time information for user actions are quite different for different file systems, even for different versions of operating systems with the same file system.
Some research on temporal analysis has already been done on NTFS and FAT file systems, while there are few resources that describe temporal analysis on the Hierarchical File System Plus (HFS+), the default file system in Apple computer. Moreover, removable devices like USB disks are used frequently; transferring files and folders between different devices with different file systems and operating systems happens more and more frequently, so the changes of times across different file systems are also crucial in digital forensics and investigations.
In this research, the changes in time attributes of files and folders resulting from user actions on the HFS+ file system and across file systems are analyzed, and the rules of time are generated by inductive reasoning to help reconstruct crime scenes in the digital forensic investigation. Since inductive reasoning is not definitely true compared with deductive reasoning, experiments are performed to validate the rules. The usage of the rules is demonstrated by analyzing a case in details. The methods proposed here are efficient, practical and easy to put into practice in real scenarios.published_or_final_version
Computer Science
Master
Master of Philosophy
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Carreras, Annette Rodriguez. "Biodistance analysis of Hispanic skeletons." Thesis, Boston University, 2013. https://hdl.handle.net/2144/21130.
Full textAbstract:
Thesis (M.S.F.S.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.The morphoscopic traits used to assign the term Hispanic to a skeleton constitute mainly a mixture of characteristics that have been assigned by anthropologists to Asian and Caucasian ancestry groups. Therefore, the morphological characteristics for the population termed Hispanic are not well defined. The aim of this study is to conduct a biodistance analysis of skeletons of Hispanic ancestry from Puerto Rico. The purpose of this is to assess how similar their morphoscopic characteristics are to other populations termed Hispanic as well as populations termed Asian. The analysis will be conducted by taking craniometric measurements. Pre-Colombian as well as modern skeletons from Puerto Rico will be examined and compared to other Hispanic as well as Asian populations that form part of the Forensic Anthropology Data Bank (FDB). Results from this study will help characterize Hispanic skeletal variation. In addition, this study will discuss the complexities of Hispanic classification in forensic anthropological contexts.
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Kaeser, Jasmin Christine. "Investigating the origin of stochastic effects in low-template DNA samples by developing a single-tube extraction protocol." Thesis, Boston University, 2013. https://hdl.handle.net/2144/21183.
Full textAbstract:
Thesis (M.S.F.S.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.The use of polymerase chain reaction (PCR) has revolutionized DNA typing in forensic laboratories. Producing a deoxyribonucleic acid (DNA) profile now requires less time and less DNA than before. However, not all evidence samples can be reliably profiled, particularly those with low masses of DNA. These samples often exhibit stochastic effects such as allele dropout, elevated stutter and peak height imbalance, which are challenging to separate from true donor alleles. Several scholarly articles have documented these difficulties and suggest that these stochastic effects are due to uneven amplification of heterozygous alleles in early PCR. However, in early PCR all reaction components are at their maximum concentrations and should be able to amplify all alleles in a sample proportionate to their original concentrations. If both alleles are present in the sample at equal concentrations prior to PCR, both alleles should theoretically be amplified with the same efficiency; the fact that this is not the case suggests that there may already be variation within the sample. One possible reason is that pre-PCR sampling error from pipetting and sample transfers results in an uneven number of allele copies in the sample prior to amplification. Thus, it may not be PCR chemistry alone that contributes to stochastic effects, but also sampling error, which creates unequal allele concentrations prior to PCR. In order to separate and study these possibilities, a single-tube DNA extraction method was developed. The forensicGEM™ Saliva kit developed by ZyGEM provides an extraction method that utilizes a thermostable proteinase found in a proprietary Bacillus species to lyse the cell and destroy nucleases without inhibiting downstream amplification. Combining this extraction protocol with the McCrone and Associates, Inc. cell transfer method allowed for the addition of cells directly to the PCR tube, giving an approximate DNA mass without quantitation. These samples should show the effects of PCR chemistry alone, with pipetting and tube transfer steps prior to amplification removed. For comparison, samples of bulk DNA extracted with forensicGEM™ Saliva were diluted down to a comparable concentration and subjected to multiple transfer steps in an effort to identify both pre-PCR sampling error and any error due to PCR chemistry. Results show that the single-tube extraction method gives reliable results, with forensicGEM™ Saliva showing comparable peak heights (PH) and peak height ratios (PHR) to the Qiagen QIAmp DNA Investigator kit and the cell transfer method providing accurate DNA concentrations with minimal PCR inhibition. Comparison of the cell transfer-generated samples to the diluted bulk DNA samples showed that the cell transfer samples had higher average PHRs at 0.0625 ng of target DNA when amplified with Identifiler® Plus, but showed no significant difference between the sample types at 0.125 ng of target DNA. The cell transfer samples were also shown to have lower overall PHs at both concentrations and a higher occurrence of allelic dropout, but only when amplified with the Identifiler® kit; when amplified with Identifiler® Plus, the occurrence of dropout was low for cell transfer and bulk DNA samples at both concentrations. These results suggest that as DNA mass decreases, pre-PCR sampling error may contribute to the development of stochastic effects; however, the vast majority of stochastic effects are due to the PCR chemistry itself. As the PCR chemistry improves and the prevalence of stochastic effects decreases, the importance of pre-PCR sampling error may increase.
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Thompson, Alex Frances. "Forensic Analysis of the psychoactive alkaloids harmine and harmaline in peganum harmala seeds." Thesis, Boston University, 2013. https://hdl.handle.net/2144/21262.
Full textAbstract:
Thesis (M.S.F.S.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.The Peganum harmala plant is a flowering shrub that produces small, dark brown seeds in pods. These seeds contain the hallucinogenic alkaloids harmine and harmaline. As such, they have been historically used for shamanic rites and folk medicine. Presently, P. harmala seeds are commercially available and subject to no legal restrictions in the United States. This has allowed for the recreational use and abuse of these hallucinogenic seeds or seed extracts made with household chemicals. Overdose cases from excessive consumption of seeds or seed extracts have been reported. Overdose patients present with hallucinations, tremors, agitation, tachycardia, and gastric distress. Severe overdose cases have resulted in hospitalization for respiratory depression and coma. The goal of this research was to develop a protocol for forensic analysis of suspected P. harmala seeds. Physical examination was selected as a quick, cost-effective preliminary method to screen seeds. P. harmala seeds are, on average, approximately 2.3 ± 0.3 mm long and 1.0 ± 0.2 mm thick, with an average Feret’s diameter of 2.8 ± 0.3 mm. The mean mass of one seed is 2.5 ± 0.2 mg. The seeds are dark brown, irregularly shaped, and have a pitted surface. Seeds matching these descriptors can be further analyzed to detect harmine and harmaline. Direct analysis in real time (DART) allows for very rapid mass spectral analysis of P. harmala seeds. Ions corresponding to harmine and harmaline can be detected when an intact seed is placed in front of the DART ion source, and higher levels of harmine and harmaline are observed when a seed cut in half to reveal interior surfaces is analyzed. Solvent extraction of crushed seeds using ethanol followed by gas chromatography – mass spectrometry allows for confirmation of the presence of harmine and harmaline in suspected seeds. When selected ion monitoring is used, this method is able to detect harmine and harmaline in a sample consisting of a single seed. Infrared spectra of harmine and harmaline standards, crushed P. harmala seeds, and solid material obtained from evaporating off the solvent from an extraction of crushed seeds were obtained. Infrared spectroscopy can be used to distinguish between pure harmine and harmaline, but is a poor choice for analysis of samples containing a mixture of harmine and harmaline, such as P. harmala seeds. In conclusion, physical characterization, direct analysis in real time, solvent extraction, and gas chromatography – mass spectrometry are recommended techniques for the forensic analysis of P. harmala seeds.
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Bow, Hansen Chang. "Microfluidic devices for analysis of red blood cell mechanical properties." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/60139.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged PDF version of thesis.
Includes bibliographical references (p. 118-126).
Decreased deformability of human red blood cells (RBCs) is both a cause of disease and biomarker for disease (1). To traverse blood capillaries, the biconcave disk-shaped RBC must deform dramatically, since the diameter of the unconstrained RBC is larger than that of the capillaries. If the RBC becomes immobilized in a capillary, hypoxia and tissue injury may result, potentially leading to death. Changes in RBC deformability may be attributable to genetics (e.g. sickle cell anemia (2) and spherocytosis (3)), drug exposure (e.g. pentoxifylline (4)), and disease (e.g. diabetes (5) and malaria (6)). Within the past 15 years, microfabrication techniques have enabled the creation of pores comparable in size and shape to the smallest human capillaries (7) and slits in the spleen (8). We use this microfabrication ability to create devices that analyze and separate RBCs of different deformability. The first device we create is an automated 'deformability cytometer' that measures dynamic mechanical responses of 103~104 individual cells in a cell population. Fluorescence measurements of each cell are simultaneously acquired, resulting in a population-based correlation between biochemical properties (e.g. cell surface markers) and dynamic mechanical deformability. This device is especially applicable to heterogeneous cell populations, and we demonstrate its ability to mechanically characterize a small number of ring-stage malaria-infected RBCs in a large population of healthy RBCs. Next we present a device whose design is based on the architecture of the human spleen. This device is able to continuously separate more deformable from less deformable RBCs. We demonstrate the ability of this device to separate schizont-stage malaria-infected RBCs from healthy RBCs. Together, these devices enable the analysis and separation of single-RBCs based on deformability.
by Hansen Chang Bow.
Ph.D.
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Swift, Benjamin. "The use of radio-isotopes in forensic science : the development of the isotope fingerprint analysis." Thesis, University of Leicester, 2004. http://hdl.handle.net/2381/29475.
Full textAbstract:
It is generally accepted that remains should be no more than 75 years old to warrant police interest. Therefore any reliable dating method should distinguish bones from within this interval accurately from those lying outside of it. Although archaeologists have reliable tools for dating material, pathologists have been unable to devise a method that caters for their specific needs. Previous work has focused upon the physiochemical properties of bone or its organic constituents, though the results have failed to produce a workable calibration system. The first hypothesis of this thesis has confirmed the existence of a predictable and measurable relationship between specific radioisotope concentrations in human bone and the post-mortem interval (PMI). It is predicted that the relationship is such that, once a calibration system has been created, it is possible to accurately estimate the PMI in a set of remains of unknown antiquity. Though concentrating upon 210Pb activities, the study also evaluated additional commonly occurring nuclides, both natural and man-made, the latter being subsequent to nuclear experimentation. The second confirmed hypothesis is that the geographical region an individual lived within becomes imprinted within their skeletal system, such that recognisable relationships between isotopes exist, creating a radio-isotope fingerprint. Examination of these relationships allows identification of the country in which a decedent lived.
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Ballantine, Lucy Elizabeth. "Transcriptomic analysis of peripheral blood monocytes and synovial macrophages in inflammatory arthritis." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2825/.
Full textAbstract:
Background: Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) are two distinct forms of chronic auto-immunity; understanding the transcriptomic profiles of key leukocyte subsets implicated in these arthritides could improve the diagnosis and treatment of patients. Current microarray analyses of samples derived from RA and PsA patients have examined the genetic profiles of whole blood or diseased tissue which, although informative, can mask the genetic contributions of individual cell types. Monocytes and macrophages are a cellular subset known to play a major role in PsA and RA through the production of pro-inflammatory chemokines, cytokines and destructive proteinases. Aim: To define the transcriptome in CD14+ cells separated from the blood and synovial fluid of PsA and RA patients, and to then compare and contrast that signature in health and disease. Thereafter to define the relevant activities of selected novel moieties described in the foregoing analysis. Methods & Results: The transcriptomic profiles of healthy, RA and PsA CD14+ blood cells were remarkably similar - few genes could distinguish diseased from healthy CD14+ cells. Comparison of the genetic signature of the RA and PsA synovial fluid CD14+ cells revealed that just over 50% of the differentially expressed genes were shared between the two disease groups. Furthermore, analysing the canonical pathways in the synovial fluid cells compared to the matched peripheral blood of both patient groups surprisingly revealed Liver X receptor (LXR) activation pathway as the most significantly upregulated pathway: this pathway has been previously shown by our group to play a pro-inflammatory role in arthritis. Examination of specific upregulated mRNAs in the synovial fluid CD14+ cells from both disease types revealed two novel genes that had not previously been associated with arthritis, the lysosomal enzyme legumain and the cell surface molecule plexin A1. Legumain was demonstrated to be present in RA and PsA CD14+ cells by RNA and protein analysis and was physiologically active. Incubation of CD14+ cells with patient synovial fluid under hypoxic conditions also potentiated legumain expression. Plexin A1 was confirmed to be expressed at the mRNA level within RA synovium. siRNA knockdown of plexin A1 suggested that it may play a pro-inflammatory role within macrophages since subsequent treatment of these macrophages with LPS resulted in decreased TNFα production. However, investigations into the identity of the specific ligands for plexin A1 in arthritis, known as semaphorins, were inconclusive. I finally generated microarray data to evaluate the transcriptome of macrophages activated via cel contact with activated T cells. Such cells shared only a small percentage of genes with those dysregulated in the RA and PsA synovial fluid derived CD14+ cells suggesting that this model at the time points chosen may not be an appropriate in vitro representation of articular macrophages. An imaging system of this in vitro model was also established to visualise the dynamic nature of the T cell – macrophage interactions and demonstrated that variables such as duration or method of T cell activation could alter the number and duration of interactions between the two cell types. Conclusions: These studies demonstrate that the CD14+ cells isolated from the blood are similar transcriptomically between healthy controls and RA and PsA patients. The synovial fluid CD14+ cells from RA and PsA patients exhibit substantial overlap in terms of their genetic profile. Two novel molecules expressed by diseased patients namely plexin A1 and legumain have been identified and their preliminary characteristics in the context of synovitis have been defined.
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Parker, Kyle Robert Carl. "Analysis of Mitochondrial DNA Coding Region SNPs by Pyrosequencing." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2579.
Full textAbstract:
To date, the use of mitochondrial DNA in forensic analysis has relied on the presence of variations in the control region to differentiate between samples. One problem that this analysis has shown is the occurrence of common Haplogroup H haplotypes or identical sequences. Thus, there is a need to enhance the distinguishing power of this type of analysis. One option has been to investigate the mitochondrial coding region for polymorphisms that could differentiate between samples with identical control region haplotypes. The goal of this study has been to identify polymorphic coding region sites for development in a Pyrosequencing assay that would effectively enhance the discriminatory power of mitochondrial DNA analysis. With this goal in mind, five duplexes have been successfully developed and tested, utilizing the ten polymorphic sites that had been selected, with most sites being specific to Caucasians. Validation studies were performed to test the durability of the assay. The specificity of the assay to primate and non-primate species was determined to be limited to primate species only. Sample variations, including mixtures, dilutions and environmental exposure, were utilized to assess the sensitivity of the Pyrosequencing method. It was found that a minimum initial DNA input of 10fg was necessary for reliable results. The Pyrosequencing assay was able to detect mixtures at a 1:1 ratio and environmental samples exposed to the elements from up to 1 week for blood and 6 weeks for semen. Samples designed to simulate typical casework materials were analyzed and found to provide for consistent results, including trace fingerprints and digested hair shafts. These validation results provide the conclusion that this assay is suitable for use in forensic casework and demonstrate that the mitochondrial coding region provides a viable alternative to hypervariable region analysis.M.S.
Department of Chemistry
Sciences
Forensic Science MS