Rounds Of Testing Research Articles

High-frequency first syllables facilitate name-face association learning.

It is harder to learn a proper name than a common noun in association with a new face, and low-frequency (LF) or rare surnames are harder to learn than high-frequency (HF) or common surnames. A separate body of research has shown that words containing HF phonological components can be easier to retrieve and produce than words with LF phonological components. This study tested for a "downstream" benefit of increased syllable frequency (independent of name frequency) on name-face association learning: surnames with HF first syllables were predicted to be learned more easily than those with LF first syllables. Participants were tasked with learning 5 names with HF first syllables and 5 names with LF first syllables in association with 10 unfamiliar faces over repeated testing rounds with feedback. People learned more names containing HF than LF first syllables, demonstrating a benefit of increased phonological frequency to name learning. Findings support an interactive activation model that accounts for name-face association learning as well as phonological frequency effects on production, along with many other aspects of memory and language.

Cumulative Incidence of SARS-CoV-2 in Healthcare Workers at a General Hospital in Germany during the Pandemic-A Longitudinal Analysis.

Health workers (HW) are at increased risk for SARS-CoV-2 infection. In order to monitor the infection dynamic on the basis of contact with patients, HW at the St. Antonius Hospital (SAH) were tested four times in one year by PCR and serology. The cumulative incidence of infection in HW was calculated. Swab and blood tests were simultaneously performed between April 2020 and April 2021. Risk factors and demographic information were assessed at the beginning of the study. The response rate was above 75% in all rounds of testing. The study comprised 1506 HW, 165 (10.6%) of which tested positive for SARS-CoV-2 infection. Working in an ICU or on wards with patient contact were risk factors (OR 4.4, 95% CI 1.73–13.6 and OR 2.9, 95% CI 1.27–8.49). At the end of the study, the majority of HW (810 of 1363 (59.4%)) had been vaccinated at least once. A total of 29.1% of unvaccinated HW and 5.3% of vaccinated HW showed an immune response typical for natural SARS-CoV-2 infection. Of the 73 HW who provided information on the course of the disease, 31.5% reported that their quality of life continued to be impaired. The cumulative incidence of infection was low in these HW, which may be attributed to vaccination and good hygiene. Nevertheless, a work-related infection risk was identified, highlighting the need to improve protection against infection. A high risk of developing long COVID was found after the infection has subsided. Special rehabilitation programs should be provided and HW should be compensated for reduced work capacity in the case that rehabilitation fails or takes a long time.

The impact of three-dimensional reconstruction and standardised CT interpretation (AMIGO) on the anatomical understanding of mesenteric vascular anatomy for planning complete mesocolic excision surgery: A randomised crossover study.

Preoperative planning is a crucial aspect of safe complete mesocolic excision (CME) surgery. 3D models derived from imaging may help improve anatomical understanding of the complex vascular anatomy. Here, we assessed the effect of 3D models on surgeons' anatomical understanding in comparison to a systematic approach for CT scan interpretation (AMIGO). Fifteen cases were included in the study. Two GI radiology consultants reviewed each scan to ascertain the vascular anatomy. Virtual 3D models were produced and displayed on a web-based platform (https://skfb.ly/6OZUZ). A total of 13 surgical trainees were recruited. Candidates were assessed after baseline anatomical training and subsequently using the AMIGO method and 3D models. Five cases were randomly allocated in each round of testing for each participant. The primary outcome measure was an objective vascular anatomy knowledge score. The secondary outcome measure was subjective feedback from participants. Both 3D and AMIGO significantly improved anatomical understanding in comparison to baseline testing. However, 3D was superior to AMIGO (3D [n=65; median score 8/14] vs. AMIGO [n=65; median score 6/14; p<0.0001]. For 13/15 patient cases examined, 3D was superior to the AMIGO method. Eleven participants demonstrated better anatomical understanding using 3D models versus AMIGO. Ten participants preferred 3D models in comparison to standard CT imaging. 3D models improve anatomical understanding of mesenteric vascular anatomy in a group of colorectal surgical trainees in comparison to a formal CT interpretation method. 3D models may be a useful planning adjunct to 2D imaging for CME surgery.

Development of a psychosocial functioning questionnaire for patients with major depressive disorder

BackgroundThe importance of psychosocial functioning in the assessment, diagnosis and treatment of major depressive disorder (MDD) is widely recognised. However, there is a lack of effective scales to assess psychosocial...

Impact of Covid-19 on Residency Training in Tertiary Health Institutions in Nigeria: A National Survey.

The emergence of COVID-19 had a massive impact on the health system globally. While there are many kinds of literature reporting the impact on postgraduate medical training in other parts of the world, this cannot be said about Nigeria. This was a national cross-sectional study among Resident doctors via an online google form survey for 8-months. Stratified cluster design where the entire country was stratified into the six geopolitical zones, and Tertiary Health Institutions (THI) were randomly selected from each of these zones. Data from the 47-item google form were analysed with Statistical Package for Social Science (SPSS) version 23, and internal consistency reliability was measured by Cronbach's alpha coefficient. Categorical variables were compared using chi-square, and the p-value was <0.05. A total of 239 residents from THI in all six geopolitical zones completed the survey. The mean± standard deviation of the age of respondents, years in practice, and years in residency were 36.3±4.4); 10.2±7.6 years, and 4.2±2.6 years, respectively. The Cronbach's alpha coefficient was 0.95. Less than half had delayed the progression of residency (44.4%). The least strongly positive impacts were related to recruitments (4.2%), laboratory testing (4.2%), and ward rounds (4.2%); and the more strongly positive disruptive impact was on postgraduate seminars (9.2%), research (8.4%), professional examinations (8.0%) and residents' clinical schedules (8.0%). COVID-19 has caused a considerable delay in residents' training programs, and resident doctors have great concerns regarding the pandemic. This impact is perceived by them in almost all aspects of the training.

The Avon Longitudinal Study of Parents and Children - A resource for COVID-19 research: Antibody testing results, April - June 2021.

The Avon Longitudinal Study of Parents and Children (ALSPAC) is a prospective population-based cohort which recruited pregnant women in 1990-1992 and has followed these women, their partners (Generation 0; G0) and their offspring (Generation 1; G1) ever since. The study reacted rapidly and repeatedly to the coronavirus disease 2019 (COVID-19) pandemic, deploying multiple online questionnaires and a previous home-based antibody test in October 2020. A second antibody test, in collaboration with ten other longitudinal population studies, was completed by 4,622 ALSPAC participants between April and June 2021. Of 4,241 participants with a valid spike protein antibody test result (8.2% were void), indicating antibody response to either COVID-19 vaccination or natural infection, 3,172 were positive (74.8%). Generational differences were substantial, with 2,463/2,555 G0 participants classified positive (96.4%) compared to 709/1,686 G1 participants (42.1%). Of 4,199 participants with a valid nucleocapsid antibody test result (9.2% were void), suggesting potential and recent natural infection, 493 were positive (11.7%); 248/2,526 G0 participants (9.8%) and 245/1,673 G1 participants (14.6%) tested positive, respectively. We also compare results for this round of testing to that undertaken in October 2020. Future work will combine these test results with additional sources of data to identify participants' COVID-19 infection and vaccination status. These ALSPAC COVID-19 serology data are being complemented with linkage to health records and Public Health England pillar testing results as they become available, in addition to four previous questionnaire waves and a prior antibody test. Data have been released as an update to the previous COVID-19 datasets. These comprise: 1) a standard dataset containing all participant responses to all four previous questionnaires with key sociodemographic factors; and 2) individual participant-specific release files enabling bespoke research across all areas supported by the study. This data note describes the second ALSPAC antibody test and the data obtained from it.

Reviewing the User-Centered Design Process for a Comprehensive Gastroesophageal Reflux Disease (GERD) App.

The objective of this study was to design a user-centered mobile health (mHealth) application for individuals with gastroesophageal reflux disease (GERD) and evaluate its design features and effectiveness for use by doctors. Prior to designing, our team undertook a discovery process that involved creating personas, conducting a competitor analysis and heuristic evaluation of existing apps, along with interviews with acid reflux patients. Then, we created a low-fidelity prototype, which was revised on the basis of several rounds of user testing. During the design phase, each round of user testing included a mix of surveys, concurrent think-alouds, and interviews to gather user feedback on the prototypes. Lastly, an evaluation phase consisting of gathering feedback on the user-centered design approach from user experience experts and medical doctors specialized in GERD was conducted. Overall, the final GERD app includes important features for tracking symptoms and triggers, analytics, data export, and community information, while promoting individualization, accessibility, and usability. The documentation of the design process of this app serves as a reference point for future medical app developers as it followed an empirically supported user-centered design strategy and resulted in an app which received positive feedback from users and human factors experts. We also intend to share some of the limitations due to the constrained resources, as well as potential ways to strengthen the design process for mHealth applications.

Developing a User-Centered Digital Clinical Decision Support App for Evidence-Based Medication Recommendations for Type 2 Diabetes Mellitus: Prototype User Testing and Validation Study.

BackgroundClosing the gap between care recommended by evidence-based guidelines and care delivered in practice is an ongoing challenge across systems and delivery models. Clinical decision support systems (CDSSs) are widely deployed to augment clinicians in their complex decision-making processes. Despite published success stories, the poor usability of many CDSSs has contributed to fragmented workflows and alert fatigue.ObjectiveThis study aimed to validate the application of a user-centered design (UCD) process in the development of a standards-based medication recommender for type 2 diabetes mellitus in a simulated setting. The prototype app was evaluated for effectiveness, efficiency, and user satisfaction.MethodsWe conducted interviews with 8 clinical leaders with 8 rounds of iterative user testing with 2-8 prescribers in each round to inform app development. With the resulting prototype app, we conducted a validation study with 43 participants. The participants were assigned to one of two groups and completed a 2-hour remote user testing session. Both groups reviewed mock patient facts and ordered diabetes medications for the patients. The Traditional group used a mock electronic health record (EHR) for the review in Period 1 and used the prototype app in Period 2, while the Tool group used the prototype app during both time periods. The perceived cognitive load associated with task performance during each period was assessed with the National Aeronautics and Space Administration Task Load Index. Participants also completed the System Usability Scale (SUS) questionnaire and Kano Survey.ResultsAverage SUS scores from the questionnaire, taken at the end of 5 of the 8 user testing sessions, ranged from 68-86. The results of the validation study are as follows: percent adherence to evidence-based guidelines was greater with the use of the prototype app than with the EHR across time periods with the Traditional group (prototype app mean 96.2 vs EHR mean 72.0, P<.001) and between groups during Period 1 (Tool group mean 92.6 vs Traditional group mean 72.0, P<.001). Task completion times did not differ between groups (P=.23), but the Tool group completed medication ordering more quickly in Period 2 (Period 1 mean 130.7 seconds vs Period 2 mean 107.7 seconds, P<.001). Based on an adjusted α level owing to violation of the assumption of homogeneity of variance (Ps>.03), there was no effect on screens viewed and on perceived cognitive load (all Ps>.14).ConclusionsThrough deployment of the UCD process, a point-of-care medication recommender app holds promise of improving adherence to evidence-based guidelines; in this case, those from the American Diabetes Association. Task-time performance suggests that with practice the T2DM app may support a more efficient ordering process for providers, and SUS scores indicate provider satisfaction with the app.

Development of decision aid on health help-seeking for medical students.

Rates of mental health problems are increasing among medical students, who have added pressures compared with non-medical students. Medical student populations exhibit low rates of help-seeking and often struggle with disclosing health conditions due to the barriers experienced and concerns over negative repercussions. This study aimed to create and test the feasibility and potential efficacy of an online decision aid (DA) tool that provides medical students with resources for disclosing and help-seeking for their health concerns. The research used mixed methods, comprising two rounds of testing, the first used the Think-Aloud method to identify modifications needed, and both of which measured feasibility and assessed decision making outcomes pre and post use of the DA utilizing O'Connor's Decisional Conflict Scale (DCS) (2010) and Stage of Decision Making (SDM) (2003) measures. Results showed good feasibility of the DA. The mean DCS total score decreased from 32 to 16.75, (Wilcoxon signed-rank tests Z = -3.06, P < 0.05). There was no significant change in the SDM. The results suggest that the DA may reduce decisional conflict, improving their certainty and confidence in decision making, but had no immediate impact on their SDM, consistent with some other DAs. Further longitudinal research would be beneficial.

Transmission Dynamics of Large Coronavirus Disease Outbreak in Homeless Shelter, Chicago, Illinois, USA, 2020.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has the potential for rapid transmission in congregate settings. We describe the multidisciplinary response to an outbreak of coronavirus disease (COVID-19) in a large homeless shelter in Chicago, Illinois, USA. The response to the outbreak included 4 rounds of mass PCR testing of all staff and residents and subsequent isolation of persons who tested positive for SARS-CoV-2. We further describe the dynamics of the shelter outbreak by fitting a modified susceptible-exposed-infectious-recovered compartmental model incorporating the widespread SARS-CoV-2 testing and isolation measures implemented in this shelter. Our model demonstrates that rapid transmission of COVID-19 in the shelter occurred before the outbreak was detected; rates of transmission declined after widespread testing and isolation measures were put in place. Overall, we demonstrate the feasibility of mass PCR testing and isolation in congregate settings and suggest the necessity of prompt response to suspected COVID-19 outbreaks in homeless shelters.

Follow-up for a Preterm Infant with Beckwith-Wiedemann Syndrome.

Follow-up for a Preterm Infant with Beckwith-Wiedemann Syndrome.

Identification of propagated defects to reduce software testing cost via mutation testing.

In software engineering, testing has long been a research area of software maintenance. Testing is extremely expensive, and there is no guarantee that all defects will be found within a single round of testing. Therefore, fixing defects that are not discovered by a single round of testing is important for reducing the test costs. During the software maintenance process, testing is conducted within the scope of a set of test cases called a test suite. Mutation testing is a method that uses mutants to evaluate whether the test cases of the test suite are appropriate. In this paper, an approach is proposed that uses the mutants of a mutation test to identify defects that are not discovered through a single round of testing. The proposed method simultaneously applies two or more mutants to a single program to define and record the relationships between different lines of code. In turn, these relationships are examined using the defects that were discovered by a single round of testing, and possible defects are recommended from among the recorded candidates. To evaluate the proposed method, a comparative study was conducted using the fault localization method, which is commonly employed in defect prediction, as well as the Defects4J defect prediction dataset, which is widely used in software defect prediction. The results of the evaluation showed that the proposed method achieves a better performance than seven other fault localization methods (Tarantula, Ochiai, Opt2, Barinel, Dstar2, Muse, and Jaccard).

Planning, design and logistics of a decision analysis study: The FBI/Ames study involving forensic firearms examiners

This paper describes design and logistical aspects of a decision analysis study to assess the performance of qualified firearms examiners working in accredited laboratories in the United States in terms of accuracy (error rate), repeatability, and reproducibility of decisions involving comparisons of fired bullets and cartridge cases. The purpose of the study was to validate current practice of the forensic discipline of firearms/toolmarks (F/T) examination. It elicited error rate data by counting the number of false positive and false negative conclusions. Preceded by the experimental design, decisions, and logistics described herein, testing was ultimately administered 173 qualified, practicing F/T examiners in public and private crime laboratories. The first round of testing evaluated accuracy, while two subsequent rounds evaluated repeatability and reproducibility of examiner conclusions. This project expands on previous studies by involving many F/T examiners in challenging comparisons and by executing the study in the recommended double-blind format.

Toward a Behavior Theory-Informed and User-Centered Mobile App for Parents to Prevent Infant Falls: Development and Usability Study.

BackgroundFalls account for approximately 50% of infant injury hospitalizations, and caretaker behavior is central to preventing infant falls. Behavior theory–informed interventions for injury prevention have been suggested, but to date, few have been reported. The potential of using smartphones for injury prevention intervention delivery is also underexploited.ObjectiveThis study aims to develop a behavior theory– and evidence-based as well as user-centered digital intervention as a mobile app for parents to prevent infant falls following agile development practices.MethodsInfant falls while feeding was selected as the fall mechanism to demonstrate the approach being taken to develop this intervention. In phase 1, the Behaviour Change Wheel was used as a theoretical framework supported by a literature review to define intervention components that were then implemented as a mobile app. In phase 2, after the person-based approach, user testing through think-aloud interviews and comprehension assessments were used to refine the content and implementation of the intervention.ResultsThe target behaviors identified in phase 1 were adequate rest for the newborn’s mother and safe feeding practices defined as prepare, position, and place. From behavioral determinants and the Behaviour Change Wheel, the behavior change functions selected to achieve these target behaviors were psychological capability, social opportunity, and reflective motivation. The selected behavior change techniques aligned with these functions were providing information on health consequences, using a credible source, instruction on performing each behavior, and social support. The defined intervention was implemented in a draft Android app. In phase 2, 4 rounds of user testing were required to achieve the predefined target comprehension level. The results from the think-aloud interviews were used to refine the intervention content and app features. Overall, the results from phase 2 revealed that users found the information provided to be helpful. Features such as self-tracking and inclusion of the social and environmental aspects of falls prevention were liked by the participants. Important feedback for the successful implementation of the digital intervention was also obtained from the user testing.ConclusionsTo our knowledge, this is the first study to apply the Behaviour Change Wheel to develop a digital intervention for child injury prevention. This study provides a detailed example of evidence-based development of a behavior theory–informed mobile intervention for injury prevention refined using the person-based approach.

Round-Robin Tests with Relocatable Coverslips Improve Asbestos Fibre Counting.

Asbestos fibre counting by phase-contrast microscope is subject to many sources of variation, including those dependent on the analyst. In this study, asbestos sample slides prepared with relocatable coverslips have been used for fibre counting among voluntary analysts to evaluate their proficiency. One slide of amosite and one of chrysotile were distributed to all the analysts, and three proficiency testing rounds were conducted for amosite and four for chrysotile. Each relocatable coverslip has a report in which are reported for each viewing field both the number of certified fibres (Verified Fibres) and a drawing representing the shape and position of the individual fibres. In the first round, the analysts were asked to report only the number of fibres counted in each of the predesignated fields of view. In the other rounds, subsequently developed, the analysts had to report the number and the position of the fibres for each field. The reported number of fibres and their position in each of the designed fields were evaluated against their respective verified fibres, to identify types of error. Discrepancies between reported fibres and verified fibres in each field of view have been used to evaluate the proficiency of the analysts. The discrepancies can be positive (D+) or negative (D-) depending on whether the analyst counts, for a specific field of view, more or less fibres compared to the verified fibres. The score is calculated using the following equation: Score = (1 - ∑D+ + ∑│D-│/VF) × 100. An analyst obtaining a score of ≥60, which corresponds to (∑D+ + ∑│D-│)/VF ≤ 0.40, is proficient. The number of laboratories that participating in this study varied from 13 to 17 depending on the rounds. For amosite fibre counts, the results were generally good compared to a proficiency score of 60. The major error made by analysts was the counting of fibres shorter than 5 µm, where this error was of 62% of extra fibres and accounted for 8% over-estimation of amosite fibres. For chrysotile, a score of ≥50 has been used to consider an analyst as proficient. The results of chrysotile fibres showed that in the first round all analysts counted less than fifty per cent of the verified fibres. In the second round 10 analysts out of 13 reached a score of ≥50, 8 of 16 in the third and 10 of 12 in the fourth. For chrysotile fibres, the error relating to the counting of fibres shorter than 5 µm was of 56% of extra fibres, but the error that most influenced the results was the number of oversight-missing fibres. This type of error accounted for 97% of the missing fibres and for the 29% under-estimation of the chrysotile fibres. For amosite fibre counting, results of this study show an improvement of the analyst's performance. For the chrysotile fibre count, although there is a significant improvement in the comparison between some rounds, this is not continuous over time.

Identifying and Minimizing Errors in the Measurement of Early Childhood Development: Lessons Learned from the Cognitive Testing of the ECDI2030.

Challenges in measuring early childhood development (ECD) at scale have been documented, yet little is known about the specific difficulties related to questionnaire design and question interpretation. The purpose of this paper is to discuss the challenges of measuring ECD at scale in the context of household surveys and to show how to overcome them. The paper uses examples from the cognitive interviewing exercises that were conducted as part of the methodological work to develop a measure of ECD outcomes, the ECDI2030. It describes the methodological work carried out to inform the selection and improvement of question items and survey implementation tools as a fundamental step to reduce and mitigate systematic measurement error and improve data quality. The project consisted of a total of five rounds of testing, comprising 191 one-on-one, in-depth cognitive interviews across six countries (Bulgaria, India, Jamaica, Mexico, Uganda, and the USA). Qualitative data analysis methods were used to determine matches and mismatches between intention of items and false positives or false negative answers among subgroups of respondents. Key themes emerged that could potentially lead to systematic measurement error in population-based surveys on ECD: (1) willingness of child to perform task versus ability of child to perform task; (2) performing task versus performing task correctly; (3) identifying letters or numbers versus recognizing letters or numbers; (4) consistently performing task versus correctly performing task; (5) applicability of skills being asked versus observability of skills being asked; and (6) language production versus language comprehension. Through an iterative process of testing and subsequent revision, improvements were made to item wording, response options, and interviewer training instructions. Given the difficulties inherent in population-level data collection in the context of global monitoring, this study’s findings confirm the importance of cognitive testing as a crucial step in careful, culturally relevant, and sensitive questionnaire design and as a means to reduce response bias in cross-cultural contexts.

Assessment of Entrustable Professional Activities Using a Web-Based Simulation Platform During Transition to Emergency Medicine Residency: Mixed Methods Pilot Study.

BackgroundThe 13 core entrustable professional activities (EPAs) are key competency-based learning outcomes in the transition from undergraduate to graduate medical education in the United States. Five of these EPAs (EPA2: prioritizing differentials, EPA3: recommending and interpreting tests, EPA4: entering orders and prescriptions, EPA5: documenting clinical encounters, and EPA10: recognizing urgent and emergent conditions) are uniquely suited for web-based assessment.ObjectiveIn this pilot study, we created cases on a web-based simulation platform for the diagnostic assessment of these EPAs and examined the feasibility and acceptability of the platform.MethodsFour simulation cases underwent 3 rounds of consensus panels and pilot testing. Incoming emergency medicine interns (N=15) completed all cases. A maximum of 4 “look for” statements, which encompassed specific EPAs, were generated for each participant: (1) performing harmful or missing actions, (2) narrowing differential or wrong final diagnosis, (3) errors in documentation, and (4) lack of recognition and stabilization of urgent diagnoses. Finally, we interviewed a sample of interns (n=5) and residency leadership (n=5) and analyzed the responses using thematic analysis.ResultsAll participants had at least one missing critical action, and 40% (6/15) of the participants performed at least one harmful action across all 4 cases. The final diagnosis was not included in the differential diagnosis in more than half of the assessments (8/15, 54%). Other errors included selecting incorrect documentation passages (6/15, 40%) and indiscriminately applying oxygen (9/15, 60%). The interview themes included psychological safety of the interface, ability to assess learning, and fidelity of cases. The most valuable feature cited was the ability to place orders in a realistic electronic medical record interface.ConclusionsThis study demonstrates the feasibility and acceptability of a web-based platform for diagnostic assessment of specific EPAs. The approach rapidly identifies potential areas of concern for incoming interns using an asynchronous format, provides feedback in a manner appreciated by residency leadership, and informs individualized learning plans.

Evolution of SARS-CoV-2 seroprevalence and clusters in school children from June 2020 to April 2021: prospective cohort study Ciao Corona.

Few studies have explored the spread of SARS-CoV-2 in schools in 2021, with the advent of variants of concern. We aimed to examine the evolution of the proportion of seropositive children at schools from June-July 2020 to March-April 2021. We also examined symptoms, under-detection of infections, potential preventive effect of face masks, and reasons for non-participation in the study. Children in lower (7–10 years), middle (8–13 years) and upper (12–17 years) school levels in randomly selected schools and classes in the canton of Zurich, Switzerland, were invited to participate in the prospective cohort study Ciao Corona. Three testing rounds were completed in June-July 2020, October-November 2020 and March-April 2021. From 5230 invited, 2974 children from 275 classes in in 55 schools participated in at least one testing round. We measured SARS-CoV-2 serology in venous blood, and parents filled in questionnaires on sociodemographic information and symptoms. The proportion of children seropositive for SARS-CoV-2 increased from 1.5% (95% credible interval [CrI] 0.6–2.6%) by June-July 2020, to 6.6% (4.0–8.9%) by October-November, and to 16.4% (12.1–19.5%) by March-April 2021. By March-April 2021, children in upper school level (12.4%; 7.3–16.7%) were less likely to be seropositive than those in middle (19.5%; 14.2–24.4%) or lower school levels (16.0%; 11.0–20.4%). The ratio of PCR-diagnosed to all seropositive children changed from one to 21.7 (by June-July 2020) to one to 3.5 (by March-April 2021). Potential clusters of three or more newly seropositive children were detected in 24 of 119 (20%) classes, 17 from which could be expected by chance. Clustering was not higher than expected by chance in middle and upper school levels. Children in the upper school level, who were wearing face masks at school from November 2020, had a 5.1% (95% confidence interval 9.4% to 0.7%) lower than expected seroprevalence by March-April 2021 than those in middle school level, based on difference-in-differences analysis. Symptoms were reported by 37% of newly seropositive and 16% seronegative children. Fear of blood sampling (64%) was the most frequently reported reason for non-participation. Although the proportion of seropositive children increased from 1.5% in June-July 2020 to 16.4% in March-April 2021, few infections were likely associated with potential spread within schools. In March-April 2021, significant clustering of seropositive children within classes was observed only in the lower school level.

Heregulin Activity Assays for Residual Testing of Cell Therapy Products

BackgroundHeregulin is a ligand for the protooncogene product ErbB/HER that acts as a key mitogenic factor for human Schwann cells (hSCs). Heregulin is required for sustained hSC growth in vitro but must be thoroughly removed before cell collection for transplantation due to potential safety concerns. The goal of this study was to develop simple cell-based assays to assess the effectiveness of heregulin addition to and removal from aliquots of hSC culture medium. These bioassays were based on the capacity of a β1-heregulin peptide to elicit ErbB/HER receptor signaling in adherent ErbB2+/ErbB3+ cells.ResultsWestern blotting was used to measure the activity of three different β1-heregulin/ErbB-activated kinases (ErbB3/HER3, ERK/MAPK and Akt/PKB) using phospho-specific antibodies against key activating residues. The duration, dose-dependency and specificity of β1-heregulin-initiated kinase phosphorylation were investigated, and controls were implemented for assay optimization and reproducibility to detect β1-heregulin activity in the nanomolar range. Results from these assays showed that the culture medium from transplantable hSCs elicited no detectable activation of the aforementioned kinases in independent rounds of testing, indicating that the implemented measures can ensure that the final hSC product is devoid of bioactive β1-heregulin molecules prior to transplantation.ConclusionsThese assays may be valuable to detect impurities such as undefined soluble factors or factors for which other biochemical or biological assays are not yet available. Our workflow can be modified as necessary to determine the presence of ErbB/HER, ERK, and Akt activators other than β1-heregulin using native samples, such as fresh isolates from cell- or tissue extracts in addition to culture medium.

Compatibility of Alumina-Forming Austenitic Steels in Static and Flowing Pb

Alumina-forming austenitic (AFA) steels were evaluated for the lead fast reactor application in static and flowing high-purity Pb. Two AFA composition ranges with different Ni, Mn, Al, Cr and Nb contents were targeted, and Zr foil was used in an attempt to getter O in some capsules. Based on two rounds of capsule testing at 500–800°C, two AFA compositions were selected for evaluation in flowing Pb with a peak temperature of 650°C in a thermal convection loop made of pre-oxidized FeCrAlMo tubing. After exposure for 1000 h, the mass losses for both AFA alloys were generally low, suggesting good compatibility under these conditions without preoxidation.