Search

Experiments were conducted to determine the extent to which listeners can discriminate between different combinations of interaural time and intensity for binaural stimulus configurations which eliminate loudness, lateralization, and image-diffuseness cues. A two-interval forced choice paradigm was used, and the task of the subject was to determine the order of two stimuli, each of which was a slowly gated 500-Hz tone with a combination of interaural time and intensity differences that resulted in a centered primary spatial image. The two stimuli to be discriminated were symmetric in that they differed only in the polarity of their interaural differences. Also, in order to reduce artifacts introduced by variations in the coupling of the earphones to the head, acoustic monitoring and compensation was performed both before and after each experimental run. The performance of the two most highly trained subjects is consistent with previous experimental results that indicate an incomplete trading of interaural time and intensity information. The subjective perceptions of these observers are not consistent with previous studies that describe a ''time image'' and a ''time-intensity traded'' spatial image. [ABSTRACT FROM AUTHOR]

Objective: This study aims to investigate the association between social determinants of health (SDoH) and clinical research recruitment outcomes and recommends evidence-based strategies to enhance equity., Materials and Methods: Data were collected from the internal clinical study manager database, clinical data warehouse, and clinical research registry. Study characteristics (e.g., study phase) and sociodemographic information were extracted. Median neighborhood income, distance from the study location, and Area Deprivation Index (ADI) were calculated. Mixed effect generalized regression was used for clustering effects and false discovery rate adjustment for multiple testing. A stratified analysis was performed to examine the impact in distinct medical departments., Results: The study sample consisted of 3,962 individuals, with a mean age of 61.5 years, 53.6 % male, 54.2 % White, and 49.1 % non-Hispanic or Latino. Study characteristics revealed a variety of protocols across different departments, with cardiology having the highest percentage of participants (46.4 %). Industry funding was the most common (74.5 %), and digital advertising and personal outreach were the main recruitment methods (58.9 % and 90.8 %)., Discussion: The analysis demonstrated significant associations between participant characteristics and research participation, including biological sex, age, ethnicity, and language. The stratified analysis revealed other significant associations for recruitment strategies. SDoH is crucial to clinical research recruitment, and this study presents evidence-based solutions for equity and inclusivity. Researchers can tailor recruitment strategies to overcome barriers and increase participant diversity by identifying participant characteristics and research involvement status., Conclusion: The findings highlight the relevance of clinical research inequities and equitable representation of historically underrepresented populations. We need to improve recruitment strategies to promote diversity and inclusivity in research., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Randomized clinical trials (RCT) are the foundation for medical advances, but participant recruitment remains a persistent barrier to their success. This retrospective data analysis aims to (1) identify clinical trial features associated with successful participant recruitment measured by accrual percentage and (2) compare the characteristics of the RCTs by assessing the most and least successful recruitment, which are indicated by varying thresholds of accrual percentage such as ≥ 90% vs ≤ 10%, ≥ 80% vs ≤ 20%, and ≥ 70% vs ≤ 30%., Methods: Data from the internal research registry at Columbia University Irving Medical Center and Aggregated Analysis of ClinicalTrials.gov were collected for 393 randomized interventional treatment studies closed to further enrollment. We compared two regularized linear regression and six tree-based machine learning models for accrual percentage (i.e., reported accrual to date divided by the target accrual) prediction. The outperforming model and Tree SHapley Additive exPlanations were used for feature importance analysis for participant recruitment. The identified features were compared between the two subgroups., Results: CatBoost regressor outperformed the others. Key features positively associated with recruitment success, as measured by accrual percentage, include government funding and compensation. Meanwhile, cancer research and non-conventional recruitment methods (e.g., websites) are negatively associated with recruitment success. Statistically significant subgroup differences (corrected p -value < .05) were found in 15 of the top 30 most important features., Conclusion: This multi-source retrospective study highlighted key features influencing RCT participant recruitment, offering actionable steps for improvement, including flexible recruitment infrastructure and appropriate participant compensation., Competing Interests: The authors have no conflicts of interest to declare., (© The Author(s) 2023.)

Participant recruitment continues to be a challenge to the success of randomized controlled trials, resulting in increased costs, extended trial timelines and delayed treatment availability. Literature provides evidence that study design features (e.g., trial phase, study site involvement) and trial sponsor are significantly associated with recruitment success. Principal investigators oversee the conduct of clinical trials, including recruitment. Through a cross-sectional survey and a thematic analysis of free-text responses, we assessed the perceptions of sixteen principal investigators regarding success factors for participant recruitment. Study site involvement and funding source do not necessarily make recruitment easier or more challenging from the perspective of the principal investigators. The most commonly used recruitment strategies are also the most effort inefficient (e.g., in-person recruitment, reviewing the electronic medical records for prescreening). Finally, we recommended actionable steps, such as improving staff support and leveraging informatics-driven approaches, to allow clinical researchers to enhance participant recruitment., (©2023 AMIA - All rights reserved.)

Background: The aim of this study is to evaluate whether a dedicated Institutional Review Board (IRB) Liaison Service situated at our Institute's central location could provide additional useful staff support to the investigator community for interactions with the IRB at various levels of protocol submission and review., Materials and Methods: Over a period of 2½ years, from January 2015 to June 2017, a total of 501 in-person consultations were performed during office hours, usually 25-30 per month. Most requests concerned new protocol development, IRB policy questions, and strategies for compliance or assistance in addressing IRB comments on returned protocols. We analyzed the results of a user evaluation survey for in-person consults and performed a focused in-depth analysis of the impact of the IRB Liaison Service., Results: Survey response rate was 43%. Results of 215 completed satisfaction surveys were 100% positive. Users were primarily study coordinators and investigators. Of a randomly selected sample of consultations analyzed in-depth for 67 unique protocols, 73% were subsequently approved within 14 days., Conclusion: National concerns about IRB-related research delays have led to the re-assessment of IRB review processes at institutional levels. Overall, we have found the Liaison Service to be a popular, useful addition to research support for a meaningful number of researchers, enhancing our already research-friendly environment. We plan to continue the service and the evaluation going forward. We will focus in the next phase on exploring whether the Liaison Service can reduce IRB approval times for protocols using its services and on providing support for the use of single IRBs for multi-site studies., The Following Core Competencies Are Addressed in This Article: Practice-based learning and improvement., Competing Interests: Conflicts of interest There are no conflicts of interest.

Intramembrane metalloproteases (IMMPs) are conserved from bacteria to humans and control many important signaling pathways, but little is known about how IMMPs interact with their substrates. SpoIVFB is an IMMP that cleaves Pro-σ(K) during Bacillus subtilis endospore formation. When catalytically inactive SpoIVFB was coexpressed with C-terminally truncated Pro-σ(K)(1-126) (which can be cleaved by active SpoIVFB) in Escherichia coli, the substrate dramatically improved solubilization of the enzyme from membranes with mild detergents. Both the Pro(1-20) and σ(K)(21-126) parts contributed to improving SpoIVFB solubilization from membranes, but only the σ(K) part was needed to form a stable complex with SpoIVFB in a pulldown assay. The last 10 residues of SpoIVFB were required for improved solubilization from membranes by Pro-σ(K)(1-126) and for normal interaction with the substrate. The inactive SpoIVFB·Pro-σ(K)(1-126)-His6 complex was stable during affinity purification and gel filtration chromatography. Disulfide cross-linking of the purified complex indicated that it resembled the complex formed in vivo Ion mobility-mass spectrometry analysis resulted in an observed mass consistent with a 4:2 SpoIVFB·Pro-σ(K)(1-126)-His6 complex. Stepwise photobleaching of SpoIVFB fused to a fluorescent protein supported the notion that the enzyme is tetrameric during B. subtilis sporulation. The results provide the first evidence that an IMMP acts as a tetramer, give new insights into how SpoIVFB interacts with its substrate, and lay the foundation for further biochemical analysis of the enzyme·substrate complex and future structural studies., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

Peptide sequencing by surface-induced dissociation (SID) on a MALDI-ion mobility-orthogonal TOF mass spectrometer is demonstrated. SID of approximately 100-fmol amounts of model peptides HLGLAR (m/z 666.8), gramicidin S (m/z 1142.5), and bovine insulin b chain (m/z 3495.5) was accomplished using hydrocarbon-coated gold grids and approximately 20-eV collision energies. The current version of the instrument achieves a mobility resolution of approximately 20 and TOF mass resolution better than 200. Peptide sequences of four peptides from a tryptic digest of cytochrome c (approximately 1 pmol deposited) were obtained. The advantage of IM-SID-o-TOF-MS is that a single experiment can be used to simultaneously measure the molecular weights of the tryptic peptide fragments (e.g., peptide mass mapping) and partial sequence analysis, (e.g., real-time tandem mass spectrometry.)

A new ion mobility/time-of-flight mass spectrometer employing a high-pressure MALDI source has been designed and tested. The prototype instrument operates at a source/drift cell pressure of 1-10 Torr helium, resulting in a mobility resolution of approximately 25. A small time-of-flight mass spectrometer (20 cm) with a mass resolution of up to 200 has been attached to the drift cell to identify (in terms of mass-to-charge ratio) the separated ions. A simple tripeptide mixture has been separated in the drift tube and mass identified as singly protonated species. The ability to separate peptide mixtures, e.g., tryptic digest of a protein, is illustrated and compared to results obtained on a high-vacuum time-of-flight instrument.