Implementation of a Blind Quality Control Program in Blood Alcohol Analysis

Declared proficiency tests are limited in their use for testing the performance of the entire system, because analysts are aware that they are being tested. A blind quality control (BQC) is intended to appear as a real case to the analyst to remove any intentional or subconscious bias. A BQC program allows a real-time assessment of the laboratory’s policies and procedures and monitors reliability of casework. In September 2015, the Houston Forensic Science Center (HFSC) began a BQC program in blood alcohol analysis. Between September 2015 and July 2018, HFSC submitted 317 blind cases: 89 negative samples and 228 positive samples at five target concentrations (0.08, 0.15, 0.16, 0.20 and 0.25 g/100 mL; theoretical targets). These blood samples were analyzed by a headspace gas chromatograph interfaced with dual-flame ionization detectors (HS-GC-FID). All negative samples produced `no ethanol detected’ results. The mean (range) of reported blood alcohol concentrations (BACs) for the aforementioned target concentrations was 0.075 (0.073–0.078), 0.144 (0.140–0.148), 0.157 (0.155–0.160), 0.195 (0.192–0.200) and 0.249 (0.242–0.258) g/100 mL, respectively. The average BAC percent differences from the target for the positive blind cases ranged from −0.4 to −6.3%, within our uncertainty of measurement (8.95–9.18%). The rate of alcohol evaporation/degradation was determined negligible. A multiple linear regression analysis was performed to compare the % difference in BAC among five target concentrations, eight analysts, three HS-GC-FID instruments and two pipettes. The variables other than target concentrations showed no significant difference (P \u3e 0.2). While the 0.08 g/100 mL target showed a significantly larger % difference than higher target concentrations (0.15–0.25 g/100 mL), the % differences among the higher targets were not concentration-dependent. Despite difficulties like gaining buy-in from stakeholders and mimicking evidence samples, the implementation of a BQC program has improved processes, shown methods are reliable and added confidence to staff’s testimony in court

Changes in quality of life, cognition and functional status following catheter ablation of atrial fibrillation

Objective To investigate changes in quality of life (QoL), cognition and functional status according to arrhythmia recurrence after atrial fibrillation (AF) ablation. Methods We compared QoL, cognition and functional status in patients with recurrent atrial tachycardia (AT)/AF versus those without recurrent AT/AF in the AXAFA-AFNET 5 clinical trial. We also sought to identify factors associated with improvement in QoL and functional status following AF ablation by overall change scores with and without analysis of covariance (ANCOVA). Results Among 518 patients who underwent AF ablation, 154 (29.7%) experienced recurrent AT/AF at 3 months. Patients with recurrent AT/AF had higher mean CHA(2)DS(2)-VASc scores (2.8 vs 2.3, p Conclusions Patients without recurrent AT/AF appear to experience greater improvement in functional status but similar QoL as those with recurrent AT/AF after AF ablation

Blind Testing and Blind Verification in Firearms

This workshop provides a summary of the Houston Forensic Science Center's blind quality control program, focusing on blind quality control and blind verification in the Firearms section. The presenters will share their experiences- successes and failures- to best inform other laboratories that are interested in starting similar programs. Participants will have the opportunity to process map their case workflow, identify challenges that might arise when implementing blind verifications or blind testing, and discuss options for making the program viable for different laboratories.The following was presented at the Association of Firearm and Tool Mark Examiners (AFTE) 2023, Austin, Texas, May 21-26, 2023. Posted with permission of CSAFE

Blind testing in firearms: Preliminary results from a blind quality control program

Open proficiency tests meet accreditation requirements and measure examiner competence but may not represent actual casework. In December 2015, the Houston Forensic Science Center began a blind quality control program in firearms examination. Mock cases are created to mimic routine casework so that examiners are unaware they are being tested. Once the blind case is assigned to an examiner, the evidence undergoes microscopic examination and comparison to determine whether the fired evidence submitted was fired in the same firearm. Fifty-one firearms blind cases resulting in 570 analysis and comparison determinations were reported between December 2015 and June 2021. No unsatisfactory results were obtained; however, 40.3% of comparisons in which the ground truth was either elimination or identification resulted in inconclusive conclusions. Due to the quality of some of the evidence submitted, inconclusive results were not unexpected. A ground truth of elimination and comparison result of inconclusive was observed at a rate of 74%, while a ground truth of identification and comparison result of inconclusive was observed at a rate of 31%. Bullets (61.8%) were the main contributors to inconclusive conclusions; variables such as the assigned examiners, training program, examiner experience, and the intended complexity of the case did not significantly contribute to the results. The program demonstrates that the quality management system and firearms section procedures can obtain accurate and reliable results and provides examiners added confidence in court. Additionally, the program can be tailored to target specific research questions and provide opportunities for collaboration with other laboratories and researchers.This article is published as Neuman M, Hundl C, Grimaldi A, Eudaley D, Stein D, Stout P. Blind testing in firearms: Preliminary results from a blind quality control program. J Forensic Sci. 2022;67:964–974. https://doi.org/10.1111/1556-4029.15031. Presented at the 74th Annual Scientific Conference of the American Academy of Forensic Sciences, February 21-26, 2022, in Seattle, WA. Posted with permission of CSAFE. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited

Blind Testing in Firearms: Preliminary Results from a Blind Quality Control Program

Learning Objective: This presentation will inform attendees on preliminary findings from a blind testing program in the Firearms section at the Houston Forensic Science Center. Additionally, this presentation will detail trends in the data and discuss the benefits, limitations, and future directions of the blind testing program. Impact Statement: The intent of this presentation is to evaluate a blind testing program in firearms examination and demonstrate how such a program can be a useful tool for assessing examiner and workflow processes. Audience members will be encouraged to consider the feasibility of incorporating similar blind testing programs into their laboratories’ workflows. Open proficiency tests created by external vendors meet accreditation requirements and help demonstrate examiner competence; however, the tests are limited in the ability to test the entire quality management system from evidence submission to reporting of results. Blind proficiency testing has been considered a more precise testing an individual’s accuracy1. In December 2015, the Houston Forensic Science Center implemented a blind quality control (blind QC) program in firearms examination. The intent of the blind QC program is to supplement open proficiency tests by creating mock cases that mimic routine casework, so examiners are unaware that they are being tested. Blind QC cases are created by Firearms section management but submitted by members of the Quality Division, which is organizationally separate from the analytical sections. This study examined the results of blind QCs submitted to the Firearms section for analysis. Firearms section management evaluates the created evidence prior to submission to determine the expected results and reviews the results of the completed blind QCs to determine satisfactory completion. A satisfactory result may include: 1) a result that conforms to the known ground truth, or 2) a result that does not necessarily conform to the known ground truth but is technically sound (i.e., a known elimination/identification that is reported as inconclusive based on the applicable standards in the field)2. A firearms examiner can choose to conclude inconclusive if the item does not contain the quality or quantity of information needed to include or exclude from another item. Fragments, bullet cores, and poor-quality items are expected to be reported as unsuitable or insufficient regardless of ground truth based on availability of microscopic characteristics. Fifty-one blind QC cases were reported between December 2015 and June 2021 resulting in 570 sufficiency and comparison conclusions. In 40.3% (n=225) of the comparisons, the ground truth result was either elimination or identification, but the examiner made an inconclusive conclusion. Variables such as the examiners assigned to the case, the training program, the examiner experience level, and the intended complexity of the case did not significantly contribute to the inconclusive results. The main factor contributing to the inconclusive conclusions was the type of evidence compared (e.g., bullets vs. cartridge cases). While a blind QC program can be challenging to implement, the program has demonstrated great value. The program demonstrates that the quality management system and procedures used by the Firearms section can obtain accurate and reliable results and provides examiners added confidence in court. Additionally, the blind QC program can be tailored to target specific research questions and provide opportunities for collaboration with other laboratories and researchers. References: 1. Committee on Identifying the Needs of the Forensic Sciences Community, National Research Council. Strengthening forensic science in the United States: A path forward. Washington, DC, 2009. https://www.ncjrs.gov/pdffiles1/nij/grants/228091.pdf.The following was presented at the 74th Annual Scientific Conference of the American Academy of Forensic Sciences (AAFS), Seattle, Washington, February 21-25, 2022. Posted with permission of CSAFE

Implementation of a Blind Quality Control Program in Blood Alcohol Analysis

Declared proficiency tests are limited in their use for testing the performance of the entire system, because analysts are aware that they are being tested. A blind quality control (BQC) is intended to appear as a real case to the analyst to remove any intentional or subconscious bias. A BQC program allows a real-time assessment of the laboratory’s policies and procedures and monitors reliability of casework. In September 2015, the Houston Forensic Science Center (HFSC) began a BQC program in blood alcohol analysis. Between September 2015 and July 2018, HFSC submitted 317 blind cases: 89 negative samples and 228 positive samples at five target concentrations (0.08, 0.15, 0.16, 0.20 and 0.25 g/100 mL; theoretical targets). These blood samples were analyzed by a headspace gas chromatograph interfaced with dual-flame ionization detectors (HS-GC-FID). All negative samples produced `no ethanol detected’ results. The mean (range) of reported blood alcohol concentrations (BACs) for the aforementioned target concentrations was 0.075 (0.073–0.078), 0.144 (0.140–0.148), 0.157 (0.155–0.160), 0.195 (0.192–0.200) and 0.249 (0.242–0.258) g/100 mL, respectively. The average BAC percent differences from the target for the positive blind cases ranged from −0.4 to −6.3%, within our uncertainty of measurement (8.95–9.18%). The rate of alcohol evaporation/degradation was determined negligible. A multiple linear regression analysis was performed to compare the % difference in BAC among five target concentrations, eight analysts, three HS-GC-FID instruments and two pipettes. The variables other than target concentrations showed no significant difference (P > 0.2). While the 0.08 g/100 mL target showed a significantly larger % difference than higher target concentrations (0.15–0.25 g/100 mL), the % differences among the higher targets were not concentration-dependent. Despite difficulties like gaining buy-in from stakeholders and mimicking evidence samples, the implementation of a BQC program has improved processes, shown methods are reliable and added confidence to staff’s testimony in court.This is a manuscript of an article published as Moral, Jackeline, Callan Hundl, Dayong Lee, Maddisen Neuman, Aimee Grimaldi, Maria Cuellar, and Peter Stout. "Implementation of a blind quality control program in blood alcohol analysis." Journal of analytical toxicology 43, no. 8 (2019): 630-636. Posted with permission of CSAFE.</p

Germinal center exclusion of autoreactive B cells is defective in human systemic lupus erythematosus

Breach of B cell tolerance is central to the pathogenesis of systemic lupus erythematosus (SLE). However, how B cell tolerance is subverted in human SLE is poorly understood due to difficulties in identifying relevant autoreactive B cells and in obtaining lymphoid tissue. We have circumvented these limitations by using tonsil biopsies to study autoreactive B cells (9G4 B cells), whose regulation is abnormal in SLE. Here we show that 9G4 B cells are physiologically excluded during the early stages of the GC reaction before acquiring a centroblast phenotype. Furthermore, we provide evidence to indicate that an anergic response to B cell receptor stimulation may be responsible for such behavior. In contrast, in SLE, 9G4 B cells progressed unimpeded through this checkpoint, successfully participated in GC reactions, and expanded within the post-GC IgG memory and plasma cell compartments. The faulty regulation of 9G4 B cells was not shared by RA patients. To our knowledge, this work represents the first comparative analysis of the fate of a specific autoreactive human B cell population. The results identify a defective tolerance checkpoint that appears to be specific for human SLE

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

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