Current Search: Forensic (x)
Pages
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Title
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THE DEVELOPMENT OF A "GENETIC EYEWITNESS" PROFILING SYSTEM FOR LOW TEMPLATE FORENSIC SPECIMENS: IDENTIFICATION OF NOVEL PROTEIN, RNA, DNA BIOMARKERS.
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Creator
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Hanson, Erin, Ballantyne, Jack, University of Central Florida
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Abstract / Description
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In many criminal investigations, valuable information regarding the physical appearance of suspected perpetrators or the time and order of events that transpired are provided by eyewitness accounts. However, the information obtained from eyewitnesses is often constrained by human recollection or subjective accounts and provides a biased description of the perpetrator's appearance or an inaccurate time line of events. Additionally, in numerous situations eyewitness accounts may not be...
Show moreIn many criminal investigations, valuable information regarding the physical appearance of suspected perpetrators or the time and order of events that transpired are provided by eyewitness accounts. However, the information obtained from eyewitnesses is often constrained by human recollection or subjective accounts and provides a biased description of the perpetrator's appearance or an inaccurate time line of events. Additionally, in numerous situations eyewitness accounts may not be available. An increasing reliance therefore is placed on the biological evidence recovered during criminal investigations to act as a silent witness, providing unbiased and scientific information that may aid in the resolution of criminal investigations. While the current capabilities of operational forensic crime laboratories include analytical methods to allow for a determination of the origin of a biological stain and for the recovery of a genetic profile of the donor, the sensitivity of such methods is not always sufficient to accommodate the limited amounts of biological material often recovered in forensic casework, Therefore, it is critical that continual advancements in the analysis of low template samples be made. In this report, we have sought to identify novel protein, RNA and DNA biomarkers that, in combination with enhanced profiling strategies, would allow for a determination of the time since deposition, the body fluid of origin and the genetic profile of the donor ("genetic eyewitness") of forensic low template specimens. First, we have developed a novel strategy for the determination of the time since deposition of dried bloodstains using spectrophotometric analysis of hemoglobin. An examination of the Soret band (lambda max = 414nm) in aged bloodstains has revealed a previously unidentified hypsochromic shift as the age of the stain increases. The extent of this shift permits a distinction to be made between stains that differ in age by only minutes, hours, days and months thus providing the highest resolution of any previously developed method. We also demonstrate that it may be possible to utilize a decline in enzyme activity to determine the age of a forensic biological stain. Second, we demonstrate that the differential expression of a panel of nine miRNAs allows for the identification of the body fluid origin of forensic biological stains using as little as 50pg of total RNA. This is the highest reported sensitivity of any RNA-based approach and this assay has demonstrated a high degree of specificity for each body fluid tested. The final task of this work was to identify novel DNA biomarkers and to develop enhanced profiling strategies to allow for greater sensitivity and reliability in the genetic profiling of low template samples. We demonstrate that the use of laser capture micro-dissection and enhanced amplification strategies resulted in the ability to obtain genetic profiles from as few as 2-5 epithelial cells and 5-10 sperm cells with greater reproducibility than previously reported studies. The use of a novel whole genome amplification method provided the ability to not only increase the quantity of genetic material obtained from micro-dissected cells but also the ability to recover additional genetic information from individual samples using novel DNA biomarkers. The novel biomarkers and profiling strategies described in this report provide the basis for the establishment of a molecular "genetic eyewitness" from low template forensic samples and demonstrate the future potential for routine and reliable analysis of trace amounts of genetic material recovered from low template biological evidence.
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Date Issued
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2008
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Identifier
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CFE0002373, ucf:47785
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0002373
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Title
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THE FORENSIC ANALYSIS OF TRIACETONE TRIPEROXIDE (TATP) PRECURSORS AND SYNTHETIC BY-PRODUCTS.
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Creator
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Painter, Kimberly, Sigman, Michael, University of Central Florida
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Abstract / Description
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Triacetone Triperoxide (TATP) is a primary high explosive that can be synthesized using commercially available starting materials and has grown in use among terrorists over the past several years. Additives present in the precursors were investigated to see if they carry through the TATP synthesis and can be detected in the final product potentially aiding in the identification of the source. Additives identified in the acetones were also identified in pre-blast and in some post-blast samples...
Show moreTriacetone Triperoxide (TATP) is a primary high explosive that can be synthesized using commercially available starting materials and has grown in use among terrorists over the past several years. Additives present in the precursors were investigated to see if they carry through the TATP synthesis and can be detected in the final product potentially aiding in the identification of the source. Additives identified in the acetones were also identified in pre-blast and in some post-blast samples. However, these additives are present in trace quantities relative to the TATP, which coupled with the volatility and short lifetimes of some of the additives in TATP samples limit their detection in pre-blast and post-blast material. TATP prepared with different acids in the laboratory could generally be discriminated by observing the change in composition of the headspace of the samples upon heating and by IMS analysis of the crystals. The analysis of TATP synthesized on a larger scale was compared to the laboratory results of pre-blast material and post-blast debris. As in the laboratory samples, organic additives were also detected in the large-scale pre-blast samples and the identification of the additives in post-blast debris was consistent with the results obtained in the laboratory detonations.
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Date Issued
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2009
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Identifier
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CFE0002942, ucf:47983
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0002942
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Title
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Vulture Scavenging of Child-sized Pig Carcasses in Central Florida: Utilizing GIS to Analyze Site Variables Affecting Skeletal Dispersal.
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Creator
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Mitchell, Alexander, Schultz, John, Williams, Lana, Dupras, Tosha, University of Central Florida
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Abstract / Description
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Scavengers can significantly alter a forensic scene and consume, modify, disarticulate, and disperse bodies. However, little research exists regarding scavenging in Central Florida, specifically scavenging involving Black and Turkey Vultures (Coragyps atratus, Cathartes aura respectively). The purpose of this study is to examine the effects of vulture scavenging on consumption, disarticulation, and dispersal of child-sized carcasses in the Central Florida region. The research sample consisted...
Show moreScavengers can significantly alter a forensic scene and consume, modify, disarticulate, and disperse bodies. However, little research exists regarding scavenging in Central Florida, specifically scavenging involving Black and Turkey Vultures (Coragyps atratus, Cathartes aura respectively). The purpose of this study is to examine the effects of vulture scavenging on consumption, disarticulation, and dispersal of child-sized carcasses in the Central Florida region. The research sample consisted of four pig (Sus scrofa) carcasses weighing approximately 25kgs that were deposited in two distinct sites (shaded and unshaded) at the Deep Foundations Geotechnical Research Site located on the UCF campus. Two field cameras were placed at each site to record the scavenging, decomposition, and dispersal. The dispersal data was mapped and analyzed using ArcGIS v. 10.2.2 spatial analyst tools. Additionally, the scavengers recorded during the research period were noted, and their effect on disarticulation, consumption and dispersal were analyzed. Overall, while the canopy at the shaded sites did not impact vulture scavenging, grass height, the site perimeter fence, and the ground surface foliage density impacted vulture dispersal patterns. The majority of elements were dispersed within 6m of the initial carcass deposition. Through analysis of recorded video it was determined that vultures were able to completely skeletonize a child-sized carcass in approximately 8 hours of feeding time. In addition to vulture activity, opossums were recorded further dispersing and modifying skeletal remains after vulture activity had ceased.
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Date Issued
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2016
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Identifier
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CFE0006358, ucf:51498
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0006358
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Title
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"An Examination of the Progression of Fracture Propagation in Long Bones During the Postmortem Period in Central Florida".
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Creator
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Green, Ashley, Schultz, John, Dupras, Tosha, Williams, Lana, University of Central Florida
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Abstract / Description
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The forensic anthropologist is often tasked with analyzing skeletal trauma and determining time since death. Differentiating between perimortem and postmortem fractures can be difficult when bone retains fresh characteristics in the postmortem interval. As a result, it is important to conduct research that investigates timing of injury in the postmortem period by observing fracture characteristics created at known postmortem intervals. Investigation into the timing of injury was undertaken in...
Show moreThe forensic anthropologist is often tasked with analyzing skeletal trauma and determining time since death. Differentiating between perimortem and postmortem fractures can be difficult when bone retains fresh characteristics in the postmortem interval. As a result, it is important to conduct research that investigates timing of injury in the postmortem period by observing fracture characteristics created at known postmortem intervals. Investigation into the timing of injury was undertaken in this study over a four month time period. By fracturing bones using a custom impact device, specific morphological characteristics that are typically used in trauma analysis were created for analysis. Long bones of pigs (Sus scrofa) (N=140) were placed in two separate outdoor environments: full sun and full shade. Five bones were collected from each environment weekly and subsequently fractured. A control group consisting of 5 fresh bones was fractured to simulate perimortem trauma. Analysis of fracture characteristics was completed using a standardized protocol that was modified from previous studies, evaluating the fracture angle, fracture surface, and fracture outline. Statistical analyses were performed to investigate the relationships between and among these variables. The results of this study denote a discernable relationship between fracture characteristics and the postmortem interval, indicating a significant shift in the occurrence of these variables as the postmortem interval increases. As the postmortem interval increases, there is a trend toward primarily dry fracture characteristics. Additionally, statistical analysis indicates that the environment in which the bones are deposited has a significant effect on the fracture surface and outline as the postmortem interval increases. This study found that intrinsic dry fracture characteristics were observed as early as two weeks postmortem. These results suggest that it is possible to distinguish wet from dry fracture characteristics earlier in the Central Florida region than previously reported in the literature. These findings support the use of taphonomic models developed according to geographic region. Environmental factors are regionally specific, potentially complicating reconstruction of post-depositional history. The use of taphonomic models and standardized protocols for analysis provides increased accuracy in taphonomic analyses and estimation of the post-mortem interval in forensic casework.
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Date Issued
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2015
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Identifier
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CFE0006219, ucf:51062
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0006219
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Title
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CONTROLLED RESEARCH UTILIZING GEOPHYSICAL TECHNOLOGIES IN THE SEARCH FOR BURIED FIREARMS AND MISCELLANEOUS WEAPONS.
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Creator
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Rezos, Mary, Schultz, John, University of Central Florida
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Abstract / Description
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Incorporating geophysical technologies into forensic investigations has become a growing practice. Oftentimes, forensic professionals rely on basic metal detectors to assist their efforts during buried weapons searches, perhaps being used by someone with negligible or limited training, in turn slowing down investigation time and destroying the scene. This has created a need for research in the area of weapons searches, specifically to formulate guidelines for advanced geophysical methods that...
Show moreIncorporating geophysical technologies into forensic investigations has become a growing practice. Oftentimes, forensic professionals rely on basic metal detectors to assist their efforts during buried weapons searches, perhaps being used by someone with negligible or limited training, in turn slowing down investigation time and destroying the scene. This has created a need for research in the area of weapons searches, specifically to formulate guidelines for advanced geophysical methods that may be appropriate for locating weapons that have been discarded or buried by criminals attempting to conceal their involvement in a crime. This research project was the first to demonstrate the utility of geophysical technologies at a crime scene or a suspected weapon burial site by detecting and identifying specific types of buried metal targets, including an array of firearms. Controlled testing of 32 buried targets (including sixteen decommissioned street-level firearms, six pieces of assorted scrap metals, and ten blunt or bladed weapons) was conducted using a basic all-metal detector, an advanced metal detector, and a magnetic locator. Overall, a number of important conclusions were drawn from the research project. All forensic targets included in the project were detected with the basic all-metal detector, but only down to the shallower depths. The magnetic locator provided the deepest detection for the largest firearms, scrap metals, and miscellaneous weapons. However, not all forensic targets included in the project were detected due to the detection capabilities inherent to the magnetic locator (i.e. only detecting ferromagnetic items). The advanced metal detector was best suited for detecting the handguns and was able to detect most of the targets, excluding a number of items comprised of iron, down to deeper depths using the factory presets.
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Date Issued
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2009
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Identifier
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CFE0002624, ucf:48222
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0002624
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Title
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MongoDB Incidence Response.
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Creator
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Morales, Cory, Lang, Sheau-Dong, Zou, Changchun, Guha, Ratan, University of Central Florida
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Abstract / Description
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NoSQL (Not only SQL) databases have been gaining some popularity over the last few years. Such big companies as Expedia, Shutterfly, MetLife, and Forbes use NoSQL databases to manage data on different projects. These databases can contain a variety of information ranging from nonproprietary data to personally identifiable information like social security numbers. Databases run the risk of cyber intrusion at all times. This paper gives a brief explanation of NoSQL and thoroughly explains a...
Show moreNoSQL (Not only SQL) databases have been gaining some popularity over the last few years. Such big companies as Expedia, Shutterfly, MetLife, and Forbes use NoSQL databases to manage data on different projects. These databases can contain a variety of information ranging from nonproprietary data to personally identifiable information like social security numbers. Databases run the risk of cyber intrusion at all times. This paper gives a brief explanation of NoSQL and thoroughly explains a method of Incidence Response with MongoDB, a NoSQL database provider. This method involves an automated process with a new self-built software tool that analyzing MongoDB audit log's and generates an html page with indicators to show possible intrusions and activities on the instance of MongoDB. When dealing with NoSQL databases there is a lot more to consider than with the traditional RDMS's, and since there is not a lot of out of the box support forensics tools can be very helpful.
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Date Issued
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2016
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Identifier
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CFE0006538, ucf:51356
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0006538
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Title
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DISCRIMINATION OF AUTOMOBILE CARPET FIBERS USING MULTIPLE ANALYTICAL TECHNIQUES AND THE SUBSEQUENT CREATION OF A SEARCHABLE DATABASE.
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Creator
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Dorrien, Derek, Sigman, Michael, University of Central Florida
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Abstract / Description
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Forensic fiber examination is an important part of trace evidence analysis. Fibers may be recovered from a crime scene that could link a particular suspect to the scene. Clothing fibers are most frequently encountered but automobile carpeting fibers may also be recovered. An understanding of the frequency of occurrence and the discrimination power of different analytical techniques is needed in order to better establish the evidentiary value of automobile carpet fiber evidence. Seventy-five...
Show moreForensic fiber examination is an important part of trace evidence analysis. Fibers may be recovered from a crime scene that could link a particular suspect to the scene. Clothing fibers are most frequently encountered but automobile carpeting fibers may also be recovered. An understanding of the frequency of occurrence and the discrimination power of different analytical techniques is needed in order to better establish the evidentiary value of automobile carpet fiber evidence. Seventy-five automobile carpet fiber samples were analyzed using a series of techniques ranging from nondestructive to destructive. These techniques included polarized light microscopy, fluorescence microscopy, microspectrophotometry, Fourier-transform infrared spectroscopy, microtomy (cross section analysis), dye extraction and liquid chromatography-mass spectrometry. Based on the information obtained from these techniques an overall discrimination of 98.02% was calculated. Only 55 of 2775 pairwise comparisons were indistinguishable. The information was subsequently entered into a searchable database for general public use.
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Date Issued
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2006
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Identifier
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CFE0001483, ucf:47103
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0001483
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Title
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MONITORING LONG-TERM CONTROLLED GRAVE SCENARIOS USING GROUND PENETRATING RADAR.
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Creator
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Hawkins, William, Schultz, John, University of Central Florida
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Abstract / Description
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Geophysical techniques, such as ground-penetrating radar (GPR), have been successfully used by law enforcement agencies to locate graves and forensic evidence. However, more controlled research is needed to better understand the potential and limitations of this technology in the forensic context. The goal of this study was to determine the potential of GPR using both a 250 MHz and 500 MHz antennae to monitor eight controlled graves with six different burial scenarios using pig carcasses as...
Show moreGeophysical techniques, such as ground-penetrating radar (GPR), have been successfully used by law enforcement agencies to locate graves and forensic evidence. However, more controlled research is needed to better understand the potential and limitations of this technology in the forensic context. The goal of this study was to determine the potential of GPR using both a 250 MHz and 500 MHz antennae to monitor eight controlled graves with six different burial scenarios using pig carcasses as human proxy cadavers. In addition, a conductivity meter was employed to determine the applicability of using this technology to locate unmarked graves. For the conductivity meter, the data was processed using an EM38 program in conjunction with the SURFER program to display a conductivity contour map of the grid. For the GPR imagery, reflection profile data was processed using the program REFLEXW while horizontal slices were processed using the GPR-SLICE program. Results indicate that the conductivity meter is not a viable option in the detection of clandestine graves when other geophysical tools are available. For the GPR, results indicate that while graves can still be detected after a two-year period, there is a marked decrease in the response, or resolution, of the burial scenarios. Furthermore, burials with grave goods interred along with the carcasses were far more likely to be detected than burials that were interred with no accompanying grave goods. When comparing the performance of the two antennae, the 250 MHz antenna provided increased resolution for large cadavers buried in deep graves.
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Date Issued
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2011
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Identifier
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CFE0003601, ucf:48859
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0003601
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Title
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Diagenetic Changes in Long Bones in Central Florida: A Preliminary Macro- and Microscopic Comparison of Sun and Shade Microenvironments.
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Creator
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Overholtzer, Mikayla, Schultz, John, Dupras, Tosha, Williams, Lana, University of Central Florida
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Abstract / Description
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In forensic investigations, the estimation of time since death is of utmost importance when examining decomposing bodies and skeletal remains. Current methodology typically focuses on the gross and macroscopic changes to human remains. Surprisingly, microscopic analysis of diagenetic change has not been fully researched in regards to time since death. The current study involved the analysis of diagenetic change in 15 pig (Sus scrofa) long bones from two microenvironments (sun and shade) in...
Show moreIn forensic investigations, the estimation of time since death is of utmost importance when examining decomposing bodies and skeletal remains. Current methodology typically focuses on the gross and macroscopic changes to human remains. Surprisingly, microscopic analysis of diagenetic change has not been fully researched in regards to time since death. The current study involved the analysis of diagenetic change in 15 pig (Sus scrofa) long bones from two microenvironments (sun and shade) in the subtropical environment of Central Florida. While the control bone was not placed in the field, seven bones were placed in the sun microenvironment and seven in the shade microenvironment. One bone was collected from each micro environment every other week for a duration of 14 weeks. The samples were then analyzed for gross and macroscopic taphonomic changes, which included soil staining, hemolysis staining, loss of bone grease, and penetration of hemolysis staining into the bone cortex. Microscope slides were then prepared using thin sections of the 15 long bones. Slides were then stained with Periodic Acid Schiffer's stain and Hemotoxylin and Eosin stain and analyzed for Non-Wedl microscopic focal destruction (MFD), Wedl tunneling, and Haversian canal inclusions using standard light microscopy. While gross and macroscopic changes were not significant due to the short time interval studied, microscopic diagenetic changes that were observed included MFD and Wedl tunneling as early as four and six weeks, respectively. Group A (sun) demonstrated a greater occurrence of diagenetic change and greater diameter of MFD. Additionally, the maximum diameter of MFD steadily increased over time, suggesting a correlation between size of MFD and time since death. This pilot study demonstrates the possibility for future research to establish standards for estimating time since death using microscopic analysis. For example,further research should consider implementing a larger sample size, a longer postmortem interval, additional environments, comparative human samples, and a standardized methodology for preparing and analyzing the histological samples.
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Date Issued
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2015
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Identifier
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CFE0006366, ucf:51516
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0006366
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Title
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Multidimensional Room-Temperature Fluorescence Microscopy for the Nondestructive Analysis of Forensic Trace Textile Fibers.
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Creator
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Mujumdar, Nirvani, Campiglia, Andres, Sigman, Michael, Harper, James, Rex, Matthew, Peale, Robert, University of Central Florida
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Abstract / Description
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The purpose of this dissertation is to advance nondestructive methodology for forensic fiber examination. Non-destructive techniques that can either discriminate between similar fibers or match a known to a questioned fiber (-) and still preserve the physical integrity of the fibers for further court examination - are highly valuable in forensic science. A challenging aspect of forensic fiber examinations involves the comparison of fibers colored with visually indistinguishable dyestuffs....
Show moreThe purpose of this dissertation is to advance nondestructive methodology for forensic fiber examination. Non-destructive techniques that can either discriminate between similar fibers or match a known to a questioned fiber (-) and still preserve the physical integrity of the fibers for further court examination - are highly valuable in forensic science. A challenging aspect of forensic fiber examinations involves the comparison of fibers colored with visually indistinguishable dyestuffs. This is not an uncommon situation, as there are numerous indistinguishable fibers pre-dyed with commercial dyes of virtually identical colors. Minimal chemical structural variations are actually encouraged by the dye patent process and commercial competition.The common denominator to forensic methodology is the fact that fiber analysis primarily focuses on the dyes used to color the fibers and do not investigate other potential discriminating components present in the fiber. This dissertation explores a different aspect of fiber analysis as it focuses on the total fluorescence emission of fibers. In addition to the contribution of the textile dye (or dyes) to the fluorescence spectrum of the fiber, we consider the contribution of intrinsic fluorescence impurities (-) i.e. impurities imbedded into the fibers during fabrication of garments - as a reproducible source of fiber comparison. Although fluorescence microscopy is used in forensic labs for single fiber examination, measurements are made with the aid of band-pass filters that provide very limited information on the spectral profiles of fibers. We take the non-destructive nature of fluorescence microscopy to a higher level of selectivity with the collection of room-temperature fluorescence excitation emission matrices (RTF-EEMs). The information contained in the EEMs was first used to select the best excitation wavelength for recording first order data, i.e. two-dimensional fluorescence spectra. Pairwise comparisons involved the following visually indistinguishable fibers: nylon 361 pre-dyed with acid yellow (AY) 17 and AY 23, acrylic 864 pre-dyed with basic green (BG) 1 and BG 4, acetate satin 105B pre-dyed with disperse blue (DB) 3 and DB 14, and polyester 777 pre-dyed with disperse red (DR) 1 and DR 19. With the exception of acrylic 864 fibers dyed with BG1 and BG4, the comparison of two-dimensional spectra via principal component analysis (PCA) provided accurate fiber identification for all the analyzed fibers. The same approach was later applied to the investigation of laundering effects on the comparison of textile fibers. The presence of brighteners and other detergent components adsorbed in the fibers provided spectral fingerprints that enhanced the fiber identification process.The full dimensionality of EEMs was then explored with the aid of parallel factor analysis (PARAFAC), a second order algorithm capable to determine the number of fluorescence components that contribute to an EEM along with their individual excitation and emission profiles. The application of PARAFAC was carried out unsupervised and supervised by linear discrimination analysis (LDA). The classification performances of PARAFAC and LDA-supervised PARAFAC were compared to the one obtained with supervised discriminant unfolded partial least squares (DU-PLS). The best discrimination was obtained with the supervised DU-PLS, which allowed the pairwise differentiation of the four pairs of investigated fibers.DU-PLS was then used to investigate weathering effects on the spectral features of cotton 400 pre-dyed with DB1, nylon 361 pre-dyed with AY17 and acrylic 864 pre-dyed with BG4. The investigated fibers were exposed to humid (Florida) and dry (Arizona) weathering conditions for three, six, nine and twelve months. In all cases, this algorithm was unable to differentiate non-exposed acrylic fibers from exposed acrylic fibers. DU-PLS was able to differentiate non-exposed cotton and nylon fibers from exposed fibers to Florida and Arizona weathering conditions. It was possible to determine the period of exposure to either Florida or Arizona conditions. It was also possible to discriminate between fibers exposed to Florida or Arizona weathering conditions for the same period of time. These results provide the foundation for future studies towards a non-destructive approach capable to provide information on the history of the fiber.
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Date Issued
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2016
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Identifier
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CFE0006838, ucf:51773
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0006838
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Title
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Forensic Application of Chemometric Analysis to Visible Absorption Spectra Collected from Dyed Textile Fibers.
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Creator
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Flores, Alejandra, Sigman, Michael, Yestrebsky, Cherie, Campiglia, Andres, Chumbimuni Torres, Karin, Ni, Liqiang, University of Central Florida
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Abstract / Description
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Forensic analysis of evidence consists of the comparison of physical, spectroscopic, or chemical characteristics of a questioned sample to a set of knowns. Currently, decisions as to whether or not the questioned sample can be associated or grouped with the knowns are left up to the discretion of the forensic analyst. The implications of these outcomes are presented as evidence to a jury in a court of law to determine if a defendant is guilty of committing a crime or not. Leading up to, and...
Show moreForensic analysis of evidence consists of the comparison of physical, spectroscopic, or chemical characteristics of a questioned sample to a set of knowns. Currently, decisions as to whether or not the questioned sample can be associated or grouped with the knowns are left up to the discretion of the forensic analyst. The implications of these outcomes are presented as evidence to a jury in a court of law to determine if a defendant is guilty of committing a crime or not. Leading up to, and since, the publication of the National Academy of Sciences (NAS) report entitled (")Strengthening Forensic Science in the United States: A Path Forward,(") the inadequacies of allowing potentially biased forensic opinion to carry such weight in the courtroom have been unmasked. This report exposed numerous shortcomings in many areas of forensic science, but also made recommendations on how to fortify the discipline. The main suggestions directed towards disciplines that analyze trace evidence include developing error rates for commonly employed practices and evaluating method reliability and validity.This research focuses on developing a statistical method of analysis for comparing visible absorption profiles collected from highly similarly colored textile fibers via microspectrophotometry (MSP). Several chemometric techniques were applied to spectral data and utilized to help discriminate fibers beyond the point where traditional methods of microscopical examination may fail. Because a dye's chemical structure dictates the shape of the absorption profile, two fibers dyed with chemically similar dyes can be very difficult to distinguish from one another using traditional fiber examination techniques. The application of chemometrics to multivariate spectral data may help elicit latent characteristics that may aid in fiber discrimination.The three sample sets analyzed include dyed fabric swatches (three pairs of fabrics were dyed with chemically similar dye pairs), commercially available blue yarns (100% acrylic), and denims fabrics (100% cotton). Custom dyed swatches were each dyed uniformly with a single dye whereas the dye formulation for both the yarns and denims is unknown. As a point for study, spectral comparisons were performed according to the guidelines published by the Standard Working Group for Materials Analysis (SWGMAT) Fiber Subgroup based on visual analysis only. In the next set of tests, principal components analysis (PCA) was utilized to reduce the dimensionality of the large multivariate data sets and to visualize the natural groupings of samples. Comparisons were performed using the resulting PCA scores where group membership of the questioned object was evaluated against the known objects using the score value as the distance metric. Score value is calculated using the score and orthogonal distances, the respective cutoff values based on a quantile percentage, and an optimization parameter, ?. Lastly, likelihood ratios (LR) were generated from density functions modelled from similarity values assessing comparisons between sample population data. R code was written in-house to execute all method of fiber comparisons described here. The SWGMAT method performed with 62.7% accuracy, the optimal accuracy rate for the score value method was 75.9%, and the accuracy rates for swatch-yarn and denim comparisons, respectively, are 97.7% and 67.1% when the LR method was applied.
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Date Issued
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2015
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Identifier
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CFE0005613, ucf:50212
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0005613
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Title
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Detecting Submerged Remains: Controlled Research Using Side-Scan Sonar to Detect Proxy Cadavers.
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Creator
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Healy, Carrie, Schultz, John, Dupras, Tosha, Walker, John, University of Central Florida
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Abstract / Description
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While side-scan sonar has become a valuable geophysical tool for forensic water searches, controlled research is paramount to determine the best practices for searches in aquatic environments as it provides a structured environment in which to investigate variables that influence the effectiveness of the technology and provides valuable experience for sonar operators. The purpose of this research is to conduct controlled research in order to evaluate the applicability of side-scan sonar to...
Show moreWhile side-scan sonar has become a valuable geophysical tool for forensic water searches, controlled research is paramount to determine the best practices for searches in aquatic environments as it provides a structured environment in which to investigate variables that influence the effectiveness of the technology and provides valuable experience for sonar operators. The purpose of this research is to conduct controlled research in order to evaluate the applicability of side-scan sonar to searches involving submerged firearms and proxy cadavers. In addition, the best practices for employing this technology in forensic searches in freshwater ponds and lakes in a humid, subtropical environment in Central Florida would be developed. Five street-level firearms were submerged in a pond, and two sets of three pig carcasses (Sus scrofa), utilized as proxies for human bodies, were staked to the bottom of a pond for this research. Transects were conducted over the firearms and the pig carcasses utilizing side-scan sonar. The first set of pig carcasses represented a child size (30-32 kg) and the second set a small adult size (51-54 kg). Results show that firearms were not detected due to the terrain and small size. However, this technology successfully located small to medium-sized proxy carcasses on a flat, sandy lake bottom when experienced operators were conducting the search. Conversely, vegetation obscured submerged bodies. While the smaller carcasses were difficult to detect throughout the data collection, medium-sized carcasses were easily discerned. Moreover, the medium-sized carcasses decomposed at the same rate as previous studies and were visible throughout each stage of decomposition. Finally, employing a 900 kHz frequency with a 20 m swath-width provided the best search parameters. Therefore, in the appropriate conditions,side-scan sonar is an effective tool for locating submerged bodies in freshwater lakes and ponds in a humid, subtropical environment.
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Date Issued
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2012
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Identifier
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CFE0004544, ucf:49257
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004544
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Title
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Providing Context to the Clues: Recovery and Reliability of Location Data from Android Devices.
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Creator
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Bell, Connie, Lang, Sheau-Dong, Guha, Ratan, Zou, Changchun, University of Central Florida
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Abstract / Description
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Mobile device data continues to increase in significance in both civil and criminal investigations. Location data is often of particular interest. To date, research has established that the devices are location aware, incorporate a variety of resources to obtain location information, and cache the information in various ways. However, a review of the existing research suggests varying degrees of reliability of any such recovered location data. In an effort to clarify the issue, this project...
Show moreMobile device data continues to increase in significance in both civil and criminal investigations. Location data is often of particular interest. To date, research has established that the devices are location aware, incorporate a variety of resources to obtain location information, and cache the information in various ways. However, a review of the existing research suggests varying degrees of reliability of any such recovered location data. In an effort to clarify the issue, this project offers case studies of multiple Android mobile devices utilized in controlled conditions with known settings and applications in documented locations. The study uses data recovered from test devices to corroborate previously identified accuracy trends noted in research involving live-tracked devices, and it further offers detailed analysis strategies for the recovery of location data from devices themselves. A methodology for reviewing device data for possible artifacts that may allow an examiner to evaluate location data reliability is also presented. This paper also addresses emerging trends in device security and cloud storage, which may have significant implications for future mobile device location data recovery and analysis. Discussion of recovered cloud data introduces a distinct and potentially significant resource for investigators, and the paper addresses the cloud resources' advantages and limitations.
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Date Issued
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2015
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Identifier
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CFE0005924, ucf:50837
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0005924
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Title
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MITOCHONDRIAL DNA ANALYSIS BY PYROSEQUENCING.
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Creator
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Hastings, Patsy-Ann Susan, Ballantyne, Jack, University of Central Florida
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Abstract / Description
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Mitochondrial DNA (deoxyribo nucleic acid) is typically used in forensic casework when small quantities of high molecular weight quality DNA is not expected to be present thus negating the chances of obtaining usable nuclear DNA. Typical samples that utilized mitochondrial DNA analysis are: hair, bones, teeth, ancient remains (samples or remains that are at least 100 years old) or very old samples (samples that are less than 100 but greater than 10 years old). The current method used to...
Show moreMitochondrial DNA (deoxyribo nucleic acid) is typically used in forensic casework when small quantities of high molecular weight quality DNA is not expected to be present thus negating the chances of obtaining usable nuclear DNA. Typical samples that utilized mitochondrial DNA analysis are: hair, bones, teeth, ancient remains (samples or remains that are at least 100 years old) or very old samples (samples that are less than 100 but greater than 10 years old). The current method used to evaluate mitochondrial DNA is Sanger sequencing. Although robust, it is also time consuming and labor intensive, on the other hand pyrosequencing is a nonelectrophoretic, rapid, reliable, and sensitive sequencing method which can be easily automated. Therefore pyrosequencing could enable the widespread use of mitochondrial DNA in forensic casework and reduce the amount of time spent on each sample without compromising quality.The aim of this study is to evaluate the efficacy of pyrosequencing for forensic DNA applications, in particular mitochondrial DNA. Two dispensation orders, cyclic and directed, were examined to determine if there is any effect on the sequence generated. The accuracy of pyrosequencing was evaluated by sequencing samples of known sequence provided by the FBI. The sensitivity of pyrosequencing was evaluated by sequencing samples at different DNA concentrations and inputs. Experiments were conducted to determine the ability of pyrosequencing to detect mixtures and heteroplasmy. Additionally, the ability of pyrosequencing to sequence damaged/degraded DNA was evaluated using blood, semen, and saliva samples that were subjected to three different environmental conditions. A blind study will be conducted to confirm the accuracy of pyrosequencing. Finally, a comparison study will be conducted in which pyrosequencing will be compared to Sanger sequencing.
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Date Issued
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2004
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Identifier
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CFE0000098, ucf:46116
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0000098
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Title
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FORENSIC ANALYSIS OF C-4 AND COMMERCIAL BLASTING AGENTS FOR POSSIBLE DISCRIMINATION.
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Creator
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Steele, Katie, Sigman, Michael, University of Central Florida
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Abstract / Description
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The criminal use of explosives has increased in recent years. Political instability and the wide spread access to the internet, filled with "homemade recipes," are two conjectures for the increase. C-4 is a plastic bonded explosive (PBX) comprised of 91% of the high explosive RDX, 1.6% processing oils, 5.3% plasticizer, and 2.1% polyisobutylene (PIB). C-4 is most commonly used for military purposes, but also has found use in commercial industry as well. Current methods for the forensic...
Show moreThe criminal use of explosives has increased in recent years. Political instability and the wide spread access to the internet, filled with "homemade recipes," are two conjectures for the increase. C-4 is a plastic bonded explosive (PBX) comprised of 91% of the high explosive RDX, 1.6% processing oils, 5.3% plasticizer, and 2.1% polyisobutylene (PIB). C-4 is most commonly used for military purposes, but also has found use in commercial industry as well. Current methods for the forensic analysis of C-4 are limited to identification of the explosive; however, recent publications have suggested the plausibility of discrimination between C-4 samples based upon the processing oils and stable isotope ratios. This research focuses on the discrimination of C-4 samples based on ratios of RDX to HMX, a common impurity resulting from RDX synthesis. The relative amounts of HMX are a function of the RDX synthetic route and conditions. RDX was extracted from different C-4 samples and was analyzed by ESI-MS-SIM as the chloride adduct, EI-GC-MS-SIM, and NICI-GC-MS. Ratios (RDX/HMX) were calculated for each method. An analysis of variance (ANOVA) followed by a Tukey HSD allowed for an overall discriminating power to be assessed for each analytical method. The C-4 processing oils were also extracted, and analyzed by direct exposure probe mass spectrometry (DEP-MS) with electron ionization, a technique that requires less than two minutes for analysis. The overall discriminating power of the processing oils was calculated by conducting a series of t tests. Lastly, a set of heterogeneous commercial blasting agents were analyzed by laser induced breakdown spectroscopy (LIBS). The data was analyzed by principal components analysis (PCA), and the possibility of creating a searchable library was explored.
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Date Issued
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2007
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Identifier
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CFE0001805, ucf:47358
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0001805
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Title
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SECONDARY VICTIMIZATION OF YOUNG ADULT FEMALE SEXUAL ASSAULT VICTIMS.
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Creator
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Hunter, Kristin M, Covelli, Maureen, Ricci, Susan, University of Central Florida
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Abstract / Description
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The response of community members and public institutions to the crimes of rape and sexual assault have been, historically, disappointing. Victims have felt forced into silence, ashamed to speak out about their experiences. More recently, with the rise of social media use and the #me-too movement, attention and interest has been garnered for this unique class of crimes and victims. It has been discovered that victims of sexual assault who report their assault to community members, police...
Show moreThe response of community members and public institutions to the crimes of rape and sexual assault have been, historically, disappointing. Victims have felt forced into silence, ashamed to speak out about their experiences. More recently, with the rise of social media use and the #me-too movement, attention and interest has been garnered for this unique class of crimes and victims. It has been discovered that victims of sexual assault who report their assault to community members, police investigators, and health care workers are at risk of secondary victimization. This is a series of attitudes, behaviors, and practices that retraumatizes, shames, and blames victims of sexual assault. These behaviors contribute to increased levels of Post-Traumatic Stress Disorder (PTSD), depression, anxiety, shame, self-blame, lack of perpetrator prosecution, and more. The purpose of this thesis was to evaluate the causes and effects of secondary victimization, its extent and prevalence, specifically how young adult females were affected by this issue, and any potential programs or solutions that may reduce or limit secondary victimization. This aim was achieved by reviewing and synthesizing thirty-two research articles related to issues of women's health, secondary victimization, and sexual assault or rape. Several programs were found to show promise for reducing this phenomenon, including sexual assault nurse examiner programs, victim advocates, professional counseling, and improving the education of police investigators and others involved in interactions with sexual assault victims.
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Date Issued
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2019
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Identifier
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CFH2000473, ucf:45902
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFH2000473
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Title
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ROOM TEMPERATURE FLUORESCENCE SPECTROSCOPY AS A TOOL FOR THE FORENSIC TRACE ANALYSIS OF TEXTILE FIBERS.
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Creator
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Rex, Matthew, Campiglia, Andres, University of Central Florida
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Abstract / Description
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ABSTRACT Trace textile fiber evidence is found at numerous crime scenes and plays an important role in linking a suspect to the respective scene. Several methods currently exist for the analysis of trace fiber evidence. Microscopy provides information regarding the fibers material, color and weave. For more detailed chemical analysis chromatographic methods are employed and for discrimination between dyes, liquid chromatography coupled with mass spectrometry (LC-MS) is currently the method...
Show moreABSTRACT Trace textile fiber evidence is found at numerous crime scenes and plays an important role in linking a suspect to the respective scene. Several methods currently exist for the analysis of trace fiber evidence. Microscopy provides information regarding the fibers material, color and weave. For more detailed chemical analysis chromatographic methods are employed and for discrimination between dyes, liquid chromatography coupled with mass spectrometry (LC-MS) is currently the method providing the most discrimination. These methods have primarily focused on the dyes used to color the fibers and have not investigated other components that can potentially discriminate among fibers. This dissertation deals with investigations into the fluorescence of the fiber dyes, (contaminants?) and the fibers themselves, as well as methodology for discriminating between fibers using fluorescence. Initial systematic analysis was conducted on dye standards and extracts taken from fibers colored with the respective dyes of interest. Absorbance, excitation and fluorescence spectra were compared between standards and extracts to determine the optimal area of the fiber to investigate: dyes, fluorescent impurities or the whole fiber. High performance liquid chromatography investigations were performed to give detailed information on the number of dye and fluorescent components present in extracts. Our investigations then focused on the best room-temperature fluorescence (RTF) data format for analysis and discrimination of fiber samples. An excitation emission matrix (EEM) was found to give the greatest amount of spectral information and provide the highest level of discrimination. Successful discrimination between non similar and similar fibers was achieved with the aid of Chemometric analysis. The level of discrimination obtained via RTF-EEM spectroscopy was sufficient to differentiate among fibers obtained from two separate cloths of the same material and colored with the same dye reagent. Final studies deal with examining exposure of the fiber to various environmental contaminants. Clothing fibers are typically exposed to myriad numbers of contaminants, from food stains to cigarette smoke. The challenge then becomes detecting fluorescence signals from trace amounts of these environmental contaminants. We demonstrate the detection and classification of polycyclic aromatic hyrdrocarbons (PAH) present on fibers after exposure to cigarette smoke. This dissertation also investigates the change in fluorescence emission after laundering fibers numerous times. The main drawback of chemical analysis of fibers is the destructive nature of the methods. To extract a dye or contaminant from a fiber essentially destroys the evidence. This leaves the investigator without their original sample in the courtroom. This also provides a finite amount of sample for testing and analysis. This is true of chromatographic methods and for the method detailed in this dissertation which makes use of extracts taken from fiber samples. Lastly, we propose an instrumental setup coupling a microscope to a spectrofluorimeter for the purpose of taking EEM directly from a fiber sample. This setup makes use of the superior optics of the microscope for focusing excitation light onto the fiber sample. Initial studies have been performed on extracts from a single textile fiber and EEM collected from said fiber.
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Date Issued
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2009
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Identifier
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CFE0002833, ucf:48084
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0002833
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Title
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THE IMPLICATIONS OF VIRTUAL ENVIRONMENTS IN DIGITAL FORENSIC INVESTIGATIONS.
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Creator
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Patterson, Farrah, Lang, Sheau-Dong, Guha, Ratan, Zou, Changchun, University of Central Florida
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Abstract / Description
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This research paper discusses the role of virtual environments in digital forensic investigations. With virtual environments becoming more prevalent as an analysis tool in digital forensic investigations, it's becoming more important for digital forensic investigators to understand the limitation and strengths of virtual machines. The study aims to expose limitations within commercial closed source virtual machines and open source virtual machines. The study provides a brief overview of...
Show moreThis research paper discusses the role of virtual environments in digital forensic investigations. With virtual environments becoming more prevalent as an analysis tool in digital forensic investigations, it's becoming more important for digital forensic investigators to understand the limitation and strengths of virtual machines. The study aims to expose limitations within commercial closed source virtual machines and open source virtual machines. The study provides a brief overview of history digital forensic investigations and virtual environments, and concludes with an experiment with four common open and closed source virtual machines; the effects of the virtual machines on the host machine as well as the performance of the virtual machine itself. My findings discovered that while the open source tools provided more control and freedom to the operator, the closed source tools were more stable and consistent in their operation. The significance of these findings can be further researched by applying them in the context of exemplifying reliability of forensic techniques when presented as analysis tool used in litigation.
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Date Issued
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2011
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Identifier
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CFE0004152, ucf:49050
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004152
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Title
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INFLUENCE OF THE CSI EFFECT ON EDUCATION AND MASS MEDIA.
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Creator
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McManus, Sarah, Schultz, John, University of Central Florida
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Abstract / Description
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Forensic science television shows, especially CSI: Crime Scene Investigation, have been said to influence the public's perception of how forensic science is used and create interest in studying forensic science and pursuing jobs in the field. This study investigates this claim through a variety of methods. First, definitions of the CSI effect are discussed, including how it was first used and mentioned in the media. Second, survey data from students in a forensic anthropology course regarding...
Show moreForensic science television shows, especially CSI: Crime Scene Investigation, have been said to influence the public's perception of how forensic science is used and create interest in studying forensic science and pursuing jobs in the field. This study investigates this claim through a variety of methods. First, definitions of the CSI effect are discussed, including how it was first used and mentioned in the media. Second, survey data from students in a forensic anthropology course regarding interest in forensic science media and educational and career choices are analyzed. Third, the number and debut dates of forensic science non-fiction books, novels, non-fiction television shows, and television dramas are investigated. Finally, a content analysis of the television show Bones is undertaken in order to understand how the forensic anthropology presented in this show differs from the actual practice of forensic anthropology. Results of this study indicate that, overall, students who wanted to pursue forensic science careers and graduate study did not watch more forensic science television shows and read more forensic science novels than those who did not want to pursue forensic science careers and graduate study. Also, based on the decreased interest in a number of forensic careers, it appears that respondents may have started the course with false perceptions regarding the actual job descriptions of these careers. Regarding the number and debut dates of forensic science media, this study found that the majority of non-fiction forensic anthropology books, non-fiction television shows, television dramas debuted after CSI appeared, corroborating the claim that CSI led to an increase in interest in forensic anthropology. In addition, this study found that while much of Bones is fictionalized for entertainment purposes, many of the techniques and analyses presented on the show have a peripheral basis in scientific methods.
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Date Issued
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2010
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Identifier
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CFE0003184, ucf:48596
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0003184
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Title
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Testing the Capability of Close-Range Photogrammetry to Document Outdoor Forensic Scenes With Skeletal Remains Using Mock Scenarios.
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Creator
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Gidusko, Kevin, Schultz, John, Branting, Scott, Walker, John, University of Central Florida
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Abstract / Description
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More rigorous methodological protocols are needed to document outdoor forensic scenes containing skeletal remains. However, law enforcement protocols rarely provide specific guidelines for processing these scenes. Regardless, the need to preserve contextual information at crime scenes is of paramount importance and it is worth exploring new technological applications that will allow for better documentation. Close-range photogrammetry (CRP) is one option for outdoor scene documentation, more...
Show moreMore rigorous methodological protocols are needed to document outdoor forensic scenes containing skeletal remains. However, law enforcement protocols rarely provide specific guidelines for processing these scenes. Regardless, the need to preserve contextual information at crime scenes is of paramount importance and it is worth exploring new technological applications that will allow for better documentation. Close-range photogrammetry (CRP) is one option for outdoor scene documentation, more prominently utilized in archaeological contexts, that may provide forensic archaeologists with a tool to better document these scenarios via 3D modeling. To test the efficacy of CRP as documentation tool three mock scenarios representing common outdoor scenes were created using faux osteological material: a close scatter of osteological remains in a pine flatwood setting, a wide scatter of osteological remains in the same setting, and the partial excavation of skeletonized remains. Images were collected using a digital camera and processed using Agisoft Photoscan Professional. A series of variables were tested in successive iterations of data capture for each scenario to determine best practices for overall accuracy: camera images captured by hand versus fixed to a tripod, scale bar positioning, and number of images captured. Accuracy was determined via final root mean square error values and through a comparison between real-world to virtual measurements. Results show that CRP is a cost and time-effective method of documenting contextual data at a scene via the creation of 3D models and scaled orthomosaic images. This method is most useful for the documentation of excavations owing to the controlled and contrasted sub-surface in comparison to the subject material. The two scatter scenarios offered additional challenges due to the complexity of the ground covering, however models nonetheless provided accurate contextual detail and errors may be mitigated through proper data capture. There was little difference in the variables for image capture, scale bar placement, or number of images. Instead, the quality of images, image capture method, and post-processing operations proved to be more important. Due to the ease of use and the ability to convey best practices for data capture, the utilization of CRP for outdoor scene documentation is recommended as a valuable addition to current forensic documentation protocols. Future research should focus on the utilization of actual osteological material as a proxy for forensic scenarios as well as study the applicability of CRP to assist in documenting taphonomic modifications.
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Date Issued
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2018
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Identifier
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CFE0007182, ucf:52261
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007182
Pages