Browsing by Subject "validation"
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Item A pilot case series for concurrent validation of inertial measurement units to motion capture in individuals who use unilateral lower-limb prostheses(Sage Publications, 2023-07-13) Finco, M. G.; Patterson, Rita M.; Moudy, Sarah C.INTRODUCTION: Inertial measurement units (IMUs) may be viable options to collect gait data in clinics. This study compared IMU to motion capture data in individuals who use unilateral lower-limb prostheses. METHODS: Participants walked with lower-body IMUs and reflective markers in a motion analysis space. Sagittal plane hip, knee, and ankle waveforms were extracted for the entire gait cycle. Discrete points of peak flexion, peak extension, and range of motion were extracted from the waveforms. Stance times were also extracted to assess the IMU software's accuracy at detecting gait events. IMU and motion capture-derived data were compared using absolute differences and root mean square error (RMSE). RESULTS: Five individuals (n = 3 transtibial; n = 2 transfemoral) participated. IMU prosthetic limb data was similar to motion capture (RMSE: waveformItem Developmental and Internal Validation of a Mitochondrial DNA Direct Amplification Kit for Forensic Reference Samples(2015-05-01) Alicea-Centeno, Alessandra; Arthur J. Eisenberg; Rhonda Roby; Dixie L. PetersEvaluation of the control region of the mitochondrial genome is a common practice for forensic casework and research purposes. Since no kit is currently commercially available for the amplification of mitochondrial DNA (mtDNA), its sequencing procedure is time-consuming and laborious. Six steps are generally followed: DNA extraction, quantification and normalization, amplification of two regions (hypervariable regions 1 and 2), cycle sequencing, capillary electrophoresis and data analysis. This project evaluated a mtDNA direct amplification kit by performing developmental and internal validations. The studies performed included sensitivity, stability, reproducibility, case- type samples, mixtures and accuracy. The mtDNA direct amplification kit successfully amplified reference samples used in each study without the need of extraction and quantification steps. In addition, mtDNA profiles were obtained from the sequenced amplification products. Using the validated direct amplification procedure in the laboratory will improve workflow, decrease operational cost and reduce the possibility of error by minimizing sample handling.Item Evaluation of Y-STR Data Using a Duplex Gender Real-Time PCR Assay on an ABI Prism 7000 SDS Followed by Amplification with Applied Biosystems AmpFLSTR Yfiler PCR Amplification Kit(2007-08-01) Miller, Jennifer J.; John Planz; Arthur Eisenberg; Joseph WarrenQuantification is the process of determining the concentration of DNA in a sample and plays an extremely important role in the processes of amplification and STR typing. A method of quantification is mandated for a laboratory conducting forensic DNA analysis by National Standard 9.3 (1). Furthermore, anytime a forensic laboratory chooses to implement a new or novel methodology for any step in DNA analysis, a laboratory must conduct an internal validation to ensure the quality of method and any results generated on the equipment used within that laboratory are reliable, reproducible, and accurate before the method is utilized for casework analysis (1). Prior to an internal validation, the method or technology must undergo a developmental validation by the developer or manufacturer to determine conditions or limitations of the method or technology on DNA analysis of forensic samples (2). A study has shown that Y-STR results can be obtained even when the quantification of samples yields a value of 0.00ng/μl (4). The issue of the absolute lowest limit of detection in the quantification process versus input DNA concentrations of the unknown samples to yield any valuable Y-STR typing data has not been addressed. A duplex gender assay developed by Nicklas and Buel (3) has a reported detection limit of 0.5pg for the Alu probe of the duplex assay and quantification will be evaluated on a different qPCR platform than originally reported and followed by amplification using Applied Biosystems’ AmpFLSTR Yfiler PCR Amplification Kit to assess quantification limits. The goal of this internship project was to complete a preliminary evaluation of the sensitivity of a quantification methodology on a different qPCR platform under different detection parameters utilizing Y-chromosome DNA in correlation to Y-STR typing results and evaluate the data qualitatively.Item Internal Validation of the AmpFlSTR® Identifiler™ PCR Amplification Kit at The Forensic Testing Laboratory, Inc.(2009-08-01) Lowe, Cheryl M.; Warren, Joseph E.Prior to being implemented into forensic casework at a laboratory, a new method or product used in forensic DNA analysis must be validated internally within that laboratory. An internal validation of the AmpFlSTR® Identifiler™ PCR Amplification Kit at The Forensic Testing Laboratory was conducted, and it consisted of a sensitivity study, mixture study, non-probative case sample study, precision study, and a contamination study. The sensitivity study served to determine the target amount of input DNA to be added to each reaction, and the mixture study demonstrated how sensitive this kit is in detecting mixed source samples. The non-probative case sample study simulated various types of samples that may occur in casework. The results of each study are satisfactory for an internal validation, and the AmpFlSTR® Identifiler™ PCR Amplification Kit may now be used in forensic casework, since the kit was proven to be reliable, robust, and reproducible.Item Psychometric Properties of Scales Measuring Resilience in U.S. Latinx Populations: A Systematic Review(Mary Ann Liebert, Inc., 2023-03-11) Cockroft, Joshua D.; Rabin, Julia; Yockey, R. Andrew; Toledo, Isabella; Fain, Susan; Jacquez, Farrah; Vaughn, Lisa M.; Stryker, Shanna D.OBJECTIVES: Instruments used to measure resilience have typically been developed in European or Anglosphere countries and emphasize personal factors of resilience. In addition to being a quickly growing ethnic minority group in the United States, Latinx individuals face unique stressors and protective factors that may contribute to resilience. This review sought to determine the extent to which instruments measuring resilience have been validated in U.S. Latinx populations and what domains of resilience those scales capture. METHODS: A systematic literature review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards and included studies describing psychometric properties of resilience scales for Latinx individuals living in the United States. Articles were assessed for quality of psychometric validation; scales used in the final studies were assessed for representation of domains of the social ecological resilience model. RESULTS: Nine studies were included in the final review examining eight separate resilience measures. The populations of these studies were heterogeneous geographically and demographically; more than half the studies only included Latinx populations as a subgroup. The breadth and quality of psychometric validation were variable across studies. The domains represented by the scales in the review most heavily assessed individual domains of resilience. CONCLUSION: The literature to date on psychometric validation of resilience measures in Latinx populations in the United States is limited and does not robustly capture aspects of resilience that may be particularly meaningful for Latinx populations, such as community or cultural factors. Instruments that are developed with and for Latinx populations are necessary to better understand and measure resilience in this population.Item Validation and Optimization of Automated Instrumentation for Mitochondrial DNA Database Sample Processing(2004-06-01) Crispin, Shelley Jeanine; John Planz; Arthur Eisenberg; Joseph WarrenCrispin, Shelley Jeanine. Validation and Optimization of Automated Instrumentation for Mitochondrial DNA Database Sample Processing. Master of Science (Forensic Genetics), August 2004, 43 pages, 8 figures, 8 tables, 26 references. The validation of Qiagen 9604 BioRobot for DNA extraction and two Corbett CAS-1200 Liquid Precision Handling Systems for mitochondrial DNA database sample processing will alleviate sample backlogs and increase sample throughput. A manual cross-contamination study and an automated cross-contamination study showed that the use of automated instrumentation allowed for quicker and more accurate sample processing. The validation process was completed by processing a 96-well high throughput plate containing AFDIL employee samples. AFDIL loses approximately 10% of samples cycle sequenced using quarter volume BigDye terminator cycle reactions. To validate the use of half volume BigDye terminator cycled sequencing a 96-well high throughput plate containing AFDIL employee samples was used to compare the percentage of samples lost. On average 1.6% of the samples were lost per 96-well high throughput plate utilizing half volume BigDye terminator cycle sequencing reactions. This study has shown that the validation of half volume BigDye terminator cycle sequencing reactions will minimize the number of samples that will have to be reprocessed per 96-well high throughput plate.Item Validation of HemaSpotTM devices for the collection and long-term, room temperature storage of biological fluids from forensic reference samples(2019-05) Gonzalez, Kimberly A.; Warren, Joseph E.; Planz, John V.; Gaydosh-Combs, Laura; Maddux, Scott D.As forensic DNA samples spend more time in storage, collection devices capable of long-term, room temperature preservation provide cost-effective solutions. This project evaluated two different HemaSpot(TM) cartridges for collecting and storing human bodily fluids. Sensitivity was assessed by spotting five different volumes of blood and saliva from two individuals. Stability was examined by storing the sample collection membranes at 100 degrees C to simulate long-term storage. After 24 hours, DNA was extracted from eight 1.2-mm punches, quantified, amplified, and categorized by STR locus. Exposure to elevated temperature resulted in degradation based on quantification quality indicators and electropherogram results. Despite these observations, full STR profiles were obtained for the majority of sensitivity and stability samples. HemaSpotTM devices demonstrate potential in forensic applications for stabilizing reference DNA samples.