Antibody responses in blood and saliva post COVID-19 bivalent booster do not reveal an Omicron BA.4/BA.5- specific response.

Introduction: Current SARS-CoV-2 strains continue to mutate and attempt to evade the antibody response elicited by previous exposures and vaccinations. In September of 2022, the first updated SARS-CoV-2 vaccines, designed to create immune responses specific for the variants circulating in 2022, were approved. These new vaccines, known commonly as the bivalent boost(er), include mRNA that encodes both the original Wuhan-Hu-1 spike protein as well as the spike protein specific to the Omicron BA.4 and BA.5 variants. Methods: We recruited volunteers from University of Massachusetts student, faculty and staff members to provide samples of blood and saliva at four different time points, including pre-boost and three times post boost and analyzed samples for antibody production as well as neutralization of virus. Results: Our data provide a comprehensive analysis of the antibody response following a single dose of the bivalent boost over a 6-month period and support previous findings that the response induced after the bivalent boost does not create a strong BA.4/BA.5-specific antibody response. Conclusion: We found no evidence of a specific anti-BA.4/BA.5 response developing over time, including in a sub-population of individuals who become infected after a single dose of the bivalent booster. Additionally, we present data that support the use of saliva samples as a reliable alternative to blood for antibody detection against specific SARS-CoV-2 antigens.

Webcam-based eye tracking to detect mind wandering and comprehension errors.

Recent advances in computer vision have opened the door for scalable eye tracking using only a webcam. Such solutions are particularly useful for online educational technologies, in which a goal is to respond adaptively to students' ongoing experiences. We used WebGazer, a webcam-based eye-tracker, to automatically detect covert cognitive states during an online reading-comprehension task related to task-unrelated thought and comprehension. We present data from two studies using different populations: (1) a relatively homogenous sample of university students (N = 105), and (2) a more diverse sample from Prolific (N = 173, with < 20% White participants). Across both studies, the webcam-based eye-tracker provided sufficiently accurate and precise gaze measurements to predict both task-unrelated thought and reading comprehension from a single calibration. We also present initial evidence of predictive validity, including a positive correlation between predicted rates of task-unrelated thought and comprehension scores. Finally, we present slicing analyses to determine how performance changed under certain conditions (lighting, glasses, etc.) and generalizability of the results across the two datasets (e.g., training on the data Study 1 and testing on data from Study 2, and vice versa). We conclude by discussing results in the context of remote research and learning technologies.

Modulation of colonic immunometabolic responses during Clostridioides difficile infection ameliorates disease severity and inflammation.

Clostridioides difficile infection (CDI) is the leading cause of antibiotic-associated diarrhea, and its clinical symptoms can span from asymptomatic colonization to pseudomembranous colitis and even death. The current standard of care for CDI is antibiotic treatment to achieve bacterial clearance; however, 15 to 35% of patients experience recurrence after initial response to antibiotics. We have conducted a comprehensive, global colonic transcriptomics analysis of a 10-day study in mice to provide new insights on the local host response during CDI and identify novel host metabolic mechanisms with therapeutic potential. The analysis indicates major alterations of colonic gene expression kinetics at the acute infection stage, that are restored during the recovery phase. At the metabolic level, we observe a biphasic response pattern characterized by upregulated glycolytic metabolism during the peak of inflammation, while mitochondrial metabolism predominates during the recovery/healing stage. Inhibition of glycolysis via 2-Deoxy-D-glucose (2-DG) administration during CDI decreases disease severity, protects from mortality, and ameliorates colitis in vivo. Additionally, 2-DG also protects intestinal epithelial cells from C. difficile toxin damage, preventing loss of barrier integrity and secretion of proinflammatory mediators. These data postulate the pharmacological targeting of host immunometabolic pathways as novel treatment modalities for CDI.

Supporting student success on the practical nurse (PN) licensure exam: The Health Education Systems Incorporated (HESI) PN Exit Exam Study.

BACKGROUND: Practical Nurses or Vocational Nurses (PNs/VNs) complete a 12-month certificate program and must successfully complete the National Council Licensure Exam for Practical Nurses (NCLEX-PN) prior to practice. While the scope of their practice is more circumscribed than the Registered Nurse (RN), they contribute significantly to healthcare throughout the U.S.A. Current research to support their learning and success is needed. Elsevier's Health Education Systems Incorporated (HESI) PN Exit Exam (E2) has been used to determine students' NCLEX-PN readiness for over 20 years. Given regular updates to the NCLEX test plan, ongoing research is needed to assess the E2's continued predictive validity and examine E2 program policies to enhance PN/VN student success. OBJECTIVES: To examine the predictive validity of the E2 on NCLEX-PN first-time pass rates (NCLEX-PN FTPR) and determine which E2-related program policies are related to higher E2 scores and NCLEX-PN FTPR. METHOD: Sixteen PN/VN program directors participated in the study, providing E2 program policy information and NCLEX-FTPR outcomes for 1371 students who took the E2 between 2018 and 2021. RESULTS: Students passed the NCLEX-PN 96-98 % of the time when they scored 900 or higher on the E2 and passed 94 %-96 % of the time when they scored 850 or higher. Out of 16 programs, most required E2 test preparation (n = 13, 81.25 %) and allowed students more than one E2 attempt (n = 11; 68.75 %). Requiring minimum E2 scores and specific E2 test preparation were associated with higher NCLEX-PN pass rates, in each case mediated by higher E2 scores. Requiring remediation for students with low initial E2 scores led to higher E2 scores but not higher NCLEX-PN pass rates. CONCLUSIONS: This study provides evidence for program policies and educational resources to support students' NCLEX-PN success. Setting an expected performance benchmark and requiring PN students to engage in E2 preparation prior to their first attempt are recommended strategies emerging from this study.

Computational modeling of complex bioenergetic mechanisms that modulate CD4+ T cell effector and regulatory functions.

We built a computational model of complex mechanisms at the intersection of immunity and metabolism that regulate CD4+ T cell effector and regulatory functions by using coupled ordinary differential equations. The model provides an improved understanding of how CD4+ T cells are shaping the immune response during Clostridioides difficile infection (CDI), and how they may be targeted pharmacologically to produce a more robust regulatory (Treg) response, which is associated with improved disease outcomes during CDI and other diseases. LANCL2 activation during CDI decreased the effector response, increased regulatory response, and elicited metabolic changes that favored Treg. Interestingly, LANCL2 activation provided greater immune and metabolic modulation compared to the addition of exogenous IL-2. Additionally, we identified gluconeogenesis via PEPCK-M as potentially responsible for increased immunosuppressive behavior in Treg cells. The model can perturb immune signaling and metabolism within a CD4+ T cell and obtain clinically relevant outcomes that help identify novel drug targets for infectious, autoimmune, metabolic, and neurodegenerative diseases.

Durable antibody and effector memory T cell responses in breastmilk from women with SARS-CoV-2.

Background: Given that only 25% of pregnant women elect to receive a COVID-19 vaccine, maternal SARS-CoV-2 infection remains an important route of conferring protective passive immunity to breastfed infants of mothers who are not vaccinated. Methods: We enrolled 30 lactating participants between December 2020 and March 2021 who had a positive PCR-test and their first COVID-19 symptoms within the previous 21 days. Participants were asked to provide serial bilateral milk samples at 12 timepoints (~ every 3 days) over a period of 35 days. A second set of samples was collected at least four months after the beginning of the first set. Participants also were asked to provide their dried blood spots and infant stool samples. All samples were tested for receptor-binding domain (RBD)-specific immunoglobulin (Ig)A, IgG, and IgM. Milk samples were assessed for neutralizing ability against the spike protein and four SARS-CoV-2 variants: D614G, Alpha (B.1.1.7), Beta (B.1.351), and Gamma (P.1). Permeability of the breast epithelium was assessed by measuring the sodium to potassium ions (Na:K) in milk. Using flow cytometry, memory CD4 and CD8 T cells (CD45RO+ and CCR7+/-) and mucosal-homing CD4 and CD8 T cells (CD103+) were determined in cells from milk expressed at 35 days and at least 4 months after their first milk donation. Results: Milk antibodies from SARS-CoV-2 positive participants neutralized the spike complex. Milk from 73, 90, and 53% of participants had binding reactivities to RBD-specific IgA, IgG, and IgM, respectively. In contrast to blood spots, which showed increased levels of IgG, but not IgA or IgM, the COVID-19 response in milk was associated with a robust IgA response. Twenty-seven percent of participants had increased breast-epithelium permeability, as indicated by Na:K ≥ 0.6. The percentage of CD45RO+CCR7- effector-memory T cells in the day ≥120 milk samples was significantly higher than day 35 samples (P< 0.05). Conclusions: Antibodies in milk from participants with recent SARS-CoV-2 infection and those who recovered can neutralize the spike complex. For the first time we show that breastmilk T cells are enriched for mucosal memory T cells, further emphasizing the passive protection against SARS-CoV-2 conferred to infants via breastmilk.

Splenogonadal fusion presenting as a testicular mass, a case report and literature review.

Splenogonadal fusion is a rare, frequently misdiagnosed, congenital anomaly in which the splenic tissue is abnormally attached to the gonadal or mesonephric remnants. It is commonly found as an incidental finding at autopsy, during orchiopexy or hernia repair. However, it can present as a testicular mass or as an acute scrotal pathology such as testicular torsion or epididymoorchitis. It poses as a diagnostic challenge preoperatively and often leads to unnecessary orchiectomy. We present a case of a 15-year-old male who presented with a long-standing left testicular mass thought to be a testicular tumor. Resection of the lesion along with partial left orchiectomy was done and histopathologic evaluation revealed splenogonadal fusion.

NCLEX-RN readiness: HESI Exit Exam validity and nursing program policies.

BACKGROUND: The HESI® Exit Exam (E2) has been used to assess student readiness for the NCLEX-RN® examination for over two decades. PURPOSE: In this study, we examined the relationship between students' average E2 scores and their first time NCLEX-RN pass or fail outcomes to understand the validity of the E2 as a predictor of NCLEX-RN readiness. In addition, we examined the relationship between policies governing E2 use in programs and success on the NCLEX-RN. METHODS: Over 40 programs across the United States participated in the study, providing NCLEX-RN outcome information for 3686 students that took the E2 in 2018-2019 and information about policies. RESULTS: Students who achieved an average E2 score of 850 and above had a NCLEX-RN first-time pass rate (FTPR) of 96.33%. The NCLEX-RN FTPR was 97.29% for students whose average E2 score was 900 and above. Policies such as test preparation requirements and remediation for the E2 were associated with statistically significantly higher student NCLEX-RN FTPR. CONCLUSION: This study builds upon past evidence about the validity of the E2 and extends research in new directions by demonstrating the role of specific E2 policies in supporting students' success on the NCLEX-RN.

Neutralizing Antibodies and Cytokines in Breast Milk After Coronavirus Disease 2019 (COVID-19) mRNA Vaccination.

OBJECTIVE: To evaluate immune responses to coronavirus disease 2019 (COVID-19) mRNA-based vaccines present in breast milk and transfer of the immune responses to breastfeeding infants. METHODS: We enrolled 30 lactating women who received mRNA-based COVID-19 vaccines from January through April 2021 in this cohort study. Women provided serial milk samples, including milk expressed before vaccination, across 2-3 weeks after the first dose, and across 3 weeks after the second dose. Women provided their blood, spotted on cards (dried blood spots), 19 days after the first dose and 21 days after the second dose. Stool samples from the breastfed infants were collected 21 days after mothers' second vaccination. Prepandemic samples of milk, dried blood spots, and infant stool were used as controls. Milk, dried blood spots, and infant stool were tested by enzyme-linked immunosorbent assay for receptor-binding domain (RBD)-specific immunoglobulin (Ig)A and IgG. Milk samples were tested for the presence of neutralizing antibodies against the spike and four variants of concern: D614G, Alpha (B.1.1.7), Beta (B.1.351), and Gamma (P.1). Levels of 10 cytokines were measured in milk samples. RESULTS: Milk from COVID-19-immunized women neutralized the spike and four variants of concern, primarily driven by anti-RBD IgG. The immune response in milk also included significant elevation of interferon-γ. The immune response to maternal vaccination was reflected in breastfed infants: anti-RBD IgG and anti-RBD IgA were detected in 33% and 30% of infant stool samples, respectively. Levels of anti-RBD antibodies in infant stool correlated with maternal vaccine side effects. Median antibody levels against RBD were below the positive cutoffs in prepandemic milk and infant stool samples. CONCLUSION: Humoral and cellular immune responses to mRNA-based COVID-19 vaccination are present in most women's breast milk. The milk anti-RBD antibodies can neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike and variants of concern. Anti-RBD antibodies are transferred to breastfed infants, with the potential to confer passive immunity against SARS-CoV-2.

The impacts of learning analytics and A/B testing research: a case study in differential scientometrics.

BACKGROUND: In recent years, research on online learning platforms has exploded in quantity. More and more researchers are using these platforms to conduct A/B tests on the impact of different designs, and multiple scientific communities have emerged around studying the big data becoming available from these platforms. However, it is not yet fully understood how each type of research influences future scientific discourse within the broader field. To address this gap, this paper presents the first scientometric study on how researchers build on the contributions of these two types of online learning platform research (particularly in STEM education). We selected a pair of papers (one using A/B testing, the other conducting learning analytics (LA), on platform data of an online STEM education platform), published in the same year, by the same research group, at the same conference. We then analyzed each of the papers that cited these two papers, coding from the paper text (with inter-rater reliability checks) the reason for each citation made. RESULTS: After statistically comparing the frequency of each category of citation between papers, we found that the A/B test paper was self-cited more and that citing papers built on its work directly more frequently, whereas the LA paper was more often cited without discussion. CONCLUSIONS: Hence, the A/B test paper appeared to have had a larger impact on future work than the learning analytics (LA) paper, even though the LA paper had a higher count of total citations with a lower degree of self-citation. This paper also established a novel method for understanding how different types of research make different contributions in learning analytics, and the broader online learning research space of STEM education.

Permanent urethral ligation after AUS cuff erosion: Is it ready for prime time?

AIMS: Although artificial urinary sphincter (AUS) has long been the gold standard treatment for severe stress urinary incontinence, poor tissue quality in patients with prior cuff erosions may preclude this option. Formal supravesical diversion and/or bladder neck closure comprise alternative salvage options but are associated with significant morbidity and mortality. We review our experience with permanent urethral ligation (PUL) among patients deemed not to be candidates for AUS replacement following cuff erosion. METHODS: From a single-center database of 396 patients undergoing AUS from 2014 to 2020, 20 men underwent PUL with suprapubic tube (SPT) diversion. Clinical characteristics and outcomes were evaluated. Quality of life (QOL) was assessed using chart review, Michigan Incontinence Symptom Index (M-ISI), and Patient Global Impression of Improvement (PGI-I). RESULTS: PUL resulted in continence in 18 (90%) men; 15 after the initial surgery and three after repeat ligation. Patients were elderly (average age 75) with significant comorbidities. A total of 11 (55.5%) patients experienced complications in the 90-day postoperative period (seven Clavien-Dindo Grade II, four Grade III). Over an average follow-up of 30.3 months (interquartile range: 15.75-48.75), four patients underwent cystectomy and one underwent perineal urethrostomy. In the remaining patients managed by PUL, 13 had satisfactory M-ISI scores and indicated overall improvement on PGI-I. CONCLUSIONS: For men with AUS cuff erosion who are poor candidates for replacement, PUL with chronic SPT drainage represents an acceptable alternative option to restore continence and improve QOL. Though complications are not uncommon, the morbidity profile still compares favorably to more invasive formal urinary diversion.

Urethral atrophy is now a rare cause for artificial urinary sphincter revision surgery in the contemporary 3.5 cm cuff era.

BACKGROUND: Urethral atrophy has long been suggested as the leading cause of artificial urinary sphincter (AUS) revision. Since the introduction of the 3.5 cm AUS cuff in 2010, precise cuff sizing primarily has been suggested to reduce revisions due to urethral atrophy. We evaluated a large contemporary series of reoperative AUS cases to determine reasons for revision surgery. METHODS: We retrospectively reviewed our tertiary referral center database of male AUS procedures performed by a single surgeon from 2007-2019. AUS revision or replacement procedures were included for analysis. Cuff sizes and reasons for reoperation were recorded based on intraoperative findings and evaluated for temporal trends. Patients with cuff erosion or lacking follow-up were excluded. RESULTS: Among 714 AUS cases, 177 revisions or replacements were identified. Of these, 137 met inclusion criteria [mean age 71.7 years, median follow-up 52.7 months (IQR 22.3-94.6 months)]. Urethral atrophy was cited as the cause of AUS failure in 8.0% (11/137) of cases overall, virtually never among those with a 3.5 cm cuff placement (1/51, 2.0%). In those with ≥4.0 cm cuffs, urethral atrophy was the reason for revision in 10/86 (11.6%). Pressure regulating balloon (PRB) failure was the most frequently cited cause of failure (47/137, 34.3%). Cuff-related failure (23/137, 16.8%) and mechanical failure of unspecified device component (16/137, 11.8%) were the next most frequent causes of failure. CONCLUSIONS: Urethral atrophy has become a rare cause of AUS revision surgery since the availability of smaller cuffs. PRB-related failure is now the leading cause of AUS reoperation.

Dutasteride in the long-term management of stuttering priapism.

BACKGROUND: The objective of this study is to review our 12-year experience with the 5-α reductase inhibitor dutasteride as a potential long-term treatment option for stuttering priapism. Dutasteride has a uniquely long half-life of 35 days which offers a theoretical advantage as a chronic therapy for management of stuttering priapism. METHODS: We retrospectively reviewed patients with stuttering priapism in our database from 2006-2018 treated with dutasteride. Men with concurrent use of medications other than dutasteride to treat stuttering priapism were excluded. Patients were started on a dose of 0.5 mg daily and tapered to a more infrequent dosing schedule, ranging from 0.5 mg every other day to once weekly. The frequency of priapism episodes before and after initiation of dutasteride therapy was analyzed. RESULTS: Among 21 cases, 13 patients met our inclusion criteria (mean age 43 years). Median follow-up on daily dutasteride was 79 days, and median follow-up on tapered dutasteride was 607 days. A total of 11/13 (85%) men treated with dutasteride had some degree of improvement-5/13 (38%) had complete resolution of their symptoms and 6/13 (46%) had reduced frequency and/or severity of their episodes. Among 5/13 (38%) men who had >2 emergency room (ER) visits for ischemic priapism prior to therapy, most (3/5, 60%) did not require any ER visits while on dutasteride therapy. Among the five men who received chronic, tapered-dose therapy, all reported continued suppression of priapistic episodes. Among 4 patients with sickle cell disease (SCD), 3/4 (75%) ultimately chose more invasive therapy including androgen deprivation therapy (ADT) and penile prosthesis. Side effects were minimal and included gynecomastia (8%), decreased libido (8%), and fatigue (8%). CONCLUSIONS: In patients with stuttering priapism, daily dutasteride therapy is a promising treatment option to reduce the frequency and severity of priapistic episodes without significant side effects. Therapy can effectively be tapered to once weekly dosing without a reduction in efficacy.

Pressure Regulating Balloon Herniation: A Correctable Cause of Artificial Urinary Sphincter Malfunction.

OBJECTIVE: To report our experience with isolated pressure regulating balloon (PRB) replacement for artificial urinary sphincter (AUS) malfunction in the setting of PRB herniation. METHODS: A retrospective review of our large single-surgeon male AUS database was completed. We analyzed men with herniated PRBs palpable in the groin within an otherwise intact system. Patients with evidence of AUS fluid loss were excluded. PRBs were replaced in a submuscular location through a lower abdominal incision. Continence was defined as requiring ≤1 pad per day. Cystoscopic improvement of sphincter coaptation was confirmed intraoperatively. RESULTS: Of the 725 patients who underwent AUS surgery between 2011 and 2019, we identified 23 (3.2%) with PRB herniation and persistent or bothersome stress urinary incontinence who underwent isolated PRB replacement (median age 72 years, interquartile range 66-80). Four of the 23 patients were excluded from the analysis for subsequent explant unrelated to PRB replacement. At a mean follow-up of 21.7 months (range 2-99 months), 94.7% of patients (18/19) noted significant improvement in their stress urinary incontinence, and 78.9% of patients (15/19) achieved continence. Median time between AUS placement and PRB revision was 13 months (interquartile range 6-34 months). CONCLUSION: PRB replacement appears to be a safe and effective salvage therapy for AUS patients with PRB herniation and persistent incontinence without mechanical failure. Intraoperative cystoscopic confirmation of enhanced sphincter coaptation appears to be a reliable predictor of treatment success.

The effect of habitats and fitness on species coexistence in systems with cyclic dominance.

Cyclic dominance between species may yield spiral waves that are known to provide a mechanism enabling persistent species coexistence. This observation holds true even in presence of spatial heterogeneity in the form of quenched disorder. In this work we study the effects on spatio-temporal patterns and species coexistence of structured spatial heterogeneity in the form of habitats that locally provide one of the species with an advantage. Performing extensive numerical simulations of systems with three and six species we show that these structured habitats destabilize spiral waves. Analyzing extinction events, we find that species extinction probabilities display a succession of maxima as function of time, that indicate a periodically enhanced probability for species extinction. Analysis of the mean extinction time reveals that as a function of the parameter governing the advantage of one of the species a transition between stable coexistence and unstable coexistence takes place. We also investigate how efficiency as a predator or a prey affects species coexistence.

Early Single Sport Specialization in a High-Achieving US Athlete Population: Comparing National Collegiate Athletic Association Student-Athletes and Undergraduate Students.

CONTEXT: Early single-sport specialization and the relative age effect are often cited as improving the chances of sport success. Both concepts suggest that genetics and the environment have little influence on sport success. OBJECTIVE: To compare National Collegiate Athletic Association Division I student-athletes (SAs) with their undergraduate nonathlete peers (NAs) in terms of birth month, age of sport initiation, and age of single-sport specialization. A family history of sport participation was examined as a potential marker for genetic and social influences. DESIGN: Cross-sectional survey. SETTING: Large urban university. PATIENTS OR OTHER PARTICIPANTS: A total of 273 Division I SAs (138 women, 135 men) and 155 NAs (78 women, 77 men) participated. The NAs had been involved in competitive youth sports before entering the university. MAIN OUTCOME MEASURE(S): Participants were asked to complete a questionnaire that addressed the age of sport initiation, birth month, age of single-sport specialization, and parental and sibling sport achievement. MAIN RESULTS: Neither birth month nor the age of sport initiation differed between groups (age of sport initiation = 7.16 ± 2.6 years for the SAs versus 7.71 ± 3.5 for the NAs; P = .176). A larger proportion of SAs began participating before 10 years of age (80% versus 63%; P = .02). The parents of SAs were more likely to have participated in collegiate (32.4% versus 8.4%; P < .0001) and professional (10.9% versus 1.3%; P = .0005) sports. The SAs specialized in a single sport at an older age (15.38 ± 2.7 years versus 14.30 ± 2.6 years; P = .002). Both groups participated in multiple sports in childhood (SAs = 3.9 ± 1.8 sports, NAs = 3.2 ± 1.8 sports; P = .366). CONCLUSIONS: The Division I SAs did not specialize in a single sport at a younger age than the NAs. No evidence of a relative age effect was present. Importantly, higher levels of sport achievement among the parents and siblings of SAs suggest that genetic endowment and family or other environmental dynamics play a large role in athletic performance. Overall, the results are not consistent with deliberate practice theory and point toward an alternative model that includes not only sport-specific skill development but also genetic and social factors as key elements of long-term sport achievement.

Live Imaging and Analysis of Muscle Contractions in Drosophila Embryo.

Coordinated muscle contractions are a form of rhythmic behavior seen early during development in Drosophila embryos. Neuronal sensory feedback circuits are required to control this behavior. Failure to produce the rhythmic pattern of contractions can be indicative of neurological abnormalities. We previously found that defects in protein O-mannosylation, a posttranslational protein modification, affect the axon morphology of sensory neurons and result in abnormal coordinated muscle contractions in embryos. Here, we present a relatively simple method for recording and analyzing the pattern of peristaltic muscle contractions by live imaging of late stage embryos up to the point of hatching, which we used to characterize the muscle contraction phenotype of protein O-mannosyltransferase mutants. Data obtained from these recordings can be used to analyze muscle contraction waves, including frequency, direction of propagation and relative amplitude of muscle contractions at different body segments. We have also examined body posture and taken advantage of a fluorescent marker expressed specifically in muscles to accurately determine the position of the embryo midline. A similar approach can also be utilized to study various other behaviors during development, such as embryo rolling and hatching.

The Loss of ATRX Increases Susceptibility to Pancreatic Injury and Oncogenic KRAS in Female But Not Male Mice.

Background: Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in North America, accounting for >30,000 deaths annually. Although somatic activating mutations in KRAS appear in 97% of PDAC patients, additional factors are required to initiate PDAC. Because mutations in genes encoding chromatin remodelling proteins have been implicated in KRAS-mediated PDAC, we investigated whether loss of chromatin remodeler ɑ-thalassemia, mental-retardation, X-linked (ATRX) affects oncogenic KRAS's ability to promote PDAC. ATRX affects DNA replication, repair, and gene expression and is implicated in other cancers including glioblastomas and pancreatic neuroendocrine tumors. The hypothesis was that deletion of Atrx in pancreatic acinar cells will increase susceptibility to injury and oncogenic KRAS. Methods: Mice allowing conditional loss of Atrx within pancreatic acinar cells were examined after induction of recurrent cerulein-induced pancreatitis or oncogenic KRAS (KRASG12D ). Histologic, biochemical, and molecular analysis examined pancreatic pathologies up to 2 months after induction of Atrx deletion. Results: Mice lacking Atrx showed more progressive damage, inflammation, and acinar-to-duct cell metaplasia in response to injury relative to wild-type mice. In combination with KRASG12D, Atrx-deficient acinar cells showed increased fibrosis, inflammation, progression to acinar-to-duct cell metaplasia, and pre-cancerous lesions relative to mice expressing only KRASG12D. This sensitivity appears only in female mice, mimicking a significant prevalence of ATRX mutations in human female PDAC patients. Conclusions: Our results indicate the absence of ATRX increases sensitivity to injury and oncogenic KRAS only in female mice. This is an instance of a sex-specific mutation that enhances oncogenic KRAS's ability to promote pancreatic intraepithelial lesion formation.

Note-taking and science inquiry in an open-ended learning environment.

Note-taking is important for academic success and has been thoroughly studied in traditional classroom contexts. Recent advancements of technology have led to more students taking notes on computers, and in different situations than are common in traditional instructional contexts. However, research on computer-based note-taking is still an emerging area, and findings from these studies are mixed. In this exploratory study, we conducted multilevel analysis to comprehensively investigate the relationship between note-taking measures and subsequent student success at science inquiry among middle school students, using two scenarios of an open-ended learning environment named Virtual Performance Assessments. Analysis revealed an advantage for content elaborative note-taking over content reproductive note-taking conditional on the source of notes taken, but other measures were less consistent between the two scenarios. Implications of the findings and limitations of this research are also discussed.

Automated high-throughput light-sheet fluorescence microscopy of larval zebrafish.

Light sheet fluorescence microscopy enables fast, minimally phototoxic, three-dimensional imaging of live specimens, but is currently limited by low throughput and tedious sample preparation. Here, we describe an automated high-throughput light sheet fluorescence microscope in which specimens are positioned by and imaged within a fluidic system integrated with the sheet excitation and detection optics. We demonstrate the ability of the instrument to rapidly examine live specimens with minimal manual intervention by imaging fluorescent neutrophils over a nearly 0.3 mm3 volume in dozens of larval zebrafish. In addition to revealing considerable inter-individual variability in neutrophil number, known previously from labor-intensive methods, three-dimensional imaging allows assessment of the correlation between the bulk measure of total cellular fluorescence and the spatially resolved measure of actual neutrophil number per animal. We suggest that our simple experimental design should considerably expand the scope and impact of light sheet imaging in the life sciences.