Acquisition and retention of lung ultrasound skills by respiratory therapists: A curriculum for respiratory therapists.

Purpose: Lung point-of-care ultrasound (POCUS) is a versatile bedside tool. The utility of POCUS has grown during the coronavirus disease 2019 pandemic, as it allows clinicians to obtain real-time images without requiring transport of the patient outside the intensive care unit. As respiratory therapists (RTs) are involved in caring for those with respiratory failure, there is a good rationale for their adoption of lung ultrasound. However, no training standards have been defined. Our objective was to develop and implement a training programme for RTs to achieve and sustain competence in lung ultrasound. Methods: This was a single-centre, prospective, single-cohort observational study. A total of 10 RTs completed our curriculum and were tasked with independently completing and interpreting 10 initial lung ultrasound exams and 3 subsequent exams after a 6-week interim period. All exams were blindly overread by a local expert in lung ultrasound. Results: After completing the curriculum, RTs were able to acquire and accurately interpret their images over 85% of the time. They were more successful in the upper lung zone image acquisition and interpretation compared with the lower lung zones. After 6 weeks, the RTs' lung POCUS skills remained stable, and their lower lung zone image interpretation improved. The RTs reported that their confidence improved throughout the study. Conclusion: The RTs in our study have demonstrated competence in acquisition and interpretation of upper lung zone images. They have also reported confidence in acquiring and interpreting upper lung zone images. More experience appears to be required to gain competence and confidence in lower lung zone ultrasound. Next steps would be to repeat the present study with a higher number of RTs completing at least 20 lung POCUS studies.

Genome-wide analysis of aberrant position and sequence of plasma DNA fragment ends in patients with cancer.

Genome-wide fragmentation patterns in cell-free DNA (cfDNA) in plasma are strongly influenced by cellular origin due to variation in chromatin accessibility across cell types. Such differences between healthy and cancer cells provide the opportunity for development of novel cancer diagnostics. Here, we investigated whether analysis of cfDNA fragment end positions and their surrounding DNA sequences reveals the presence of tumor-derived DNA in blood. We performed genome-wide analysis of cfDNA from 521 samples and analyzed sequencing data from an additional 2147 samples, including healthy individuals and patients with 11 different cancer types. We developed a metric based on genome-wide differences in fragment positioning, weighted by fragment length and GC content [information-weighted fraction of aberrant fragments (iwFAF)]. We observed that iwFAF strongly correlated with tumor fraction, was higher for DNA fragments carrying somatic mutations, and was higher within genomic regions affected by copy number amplifications. We also calculated sample-level means of nucleotide frequencies observed at genomic positions spanning fragment ends. Using a combination of iwFAF and nine nucleotide frequencies from three positions surrounding fragment ends, we developed a machine learning model to differentiate healthy individuals from patients with cancer. We observed an area under the receiver operative characteristic curve (AUC) of 0.91 for detection of cancer at any stage and an AUC of 0.87 for detection of stage I cancer. Our findings remained robust with as few as 1 million fragments analyzed per sample, demonstrating that analysis of fragment ends can become a cost-effective and accessible approach for cancer detection and monitoring.

Micro-DRIFTS for small area hyper-black spectroscopy.

We have developed a low-cost micro-diffuse reflectance infrared Fourier transform spectroscopic (micro-DRIFTS) setup for measuring the reflectance of small area diffuse samples. The system performance is characterized and then demonstrated on small area vertically aligned carbon nanotube (VACNT) samples. We find that our system can measure samples with a spatial resolution of approximately 140 µm with sensitivities of 10s of ppm in the 2 µm - 18 µm spectral window. Our uncertainty budget is presented along with how our measured reflectance can be equated to directional-hemispherical reflectance.

We Have Never Been White: Afropessimism, Black Rage, and What The Pandemic Helped me Learn About Race (and Psychoanalysis).

Amidst a pandemic and the events following George Floyd's murder in 2020, discussions of race have escalated in the psychoanalytic community. One theoretical formulation, Afropessimism, has served as a lightning rod across both psychoanalytic and academic circles. Another, Black Rage, offers a psychoanalytic theory of the psychic effect of racial oppression on traumatized subjects. Using both as catalysts, this essay explores the historicity of the questions raised by the racial unrest of the pandemic--the deep embedding of questions of race and Blackness in unconscious prehistories of modernity, the human, and our understanding of our social worlds.

High-accuracy room temperature planar absolute radiometer based on vertically aligned carbon nanotubes.

We have developed a planar absolute radiometer for room temperature (PARRoT) that will replace the legacy C-series calorimeter as the free-space continuous-wave laser power detector standard at the National Institute of Standards and Technology (NIST). This instrument will lower the combined relative expanded measurement uncertainty (k = 2) from 0.84 % to 0.13 %. PARRoT's performance was validated by comparing its response against a transfer standard silicon trap detector traceable to NIST's primary standard laser optimized cryogenic radiometer (LOCR) and against the C-series calorimeter. On average, these comparisons agreed to better than 0.008 % and 0.05 %, respectively.

Analysis of recurrently protected genomic regions in cell-free DNA found in urine.

Cell-free DNA (cfDNA) in urine is a promising analyte for noninvasive diagnostics. However, urine cfDNA is highly fragmented. Whether characteristics of these fragments reflect underlying genomic architecture is unknown. Here, we characterized fragmentation patterns in urine cfDNA using whole-genome sequencing. Size distribution of urine cfDNA fragments showed multiple strong peaks between 40 and 120 base pairs (bp) with a modal size of 81- and sharp 10-bp periodicity, suggesting transient protection from complete degradation. These properties were robust to preanalytical perturbations, such as at-home collection and delay in processing. Genome-wide sequencing coverage of urine cfDNA fragments revealed recurrently protected regions (RPRs) conserved across individuals, with partial overlap with nucleosome positioning maps inferred from plasma cfDNA. The ends of cfDNA fragments clustered upstream and downstream of RPRs, and nucleotide frequencies of fragment ends indicated enzymatic digestion of urine cfDNA. Compared to plasma, fragmentation patterns in urine cfDNA showed greater correlation with gene expression and chromatin accessibility in epithelial cells of the urinary tract. We determined that tumor-derived urine cfDNA exhibits a higher frequency of aberrant fragments that end within RPRs. By comparing the fraction of aberrant fragments and nucleotide frequencies of fragment ends, we identified urine samples from cancer patients with an area under the curve of 0.89. Our results revealed nonrandom genomic positioning of urine cfDNA fragments and suggested that analysis of fragmentation patterns across recurrently protected genomic loci may serve as a cancer diagnostic.

Call on me! Undergraduates' perceptions of voluntarily asking and answering questions in front of large-enrollment science classes.

Allowing students to voluntarily ask and answer questions in front of the whole class are common teaching practices used in college science courses. However, few studies have examined college science students' perceptions of these practices, the extent to which students choose to engage in these practices, and what discourages students from participating. In this study, we surveyed 417 undergraduates at a research-intensive institution about their experiences asking and answering questions in large-enrollment college science courses. Specifically, students answered questions about to what extent they perceive voluntarily asking and answering questions in large-enrollment science courses is helpful to them and why. They also answered questions about to what extent they engage in asking and answering questions in large-enrollment college science courses and what factors could discourage them from participating. Using binary logistic regression, we examined whether there were differences among students of different demographic groups regarding their opinions about asking and answering questions. We found that overwhelmingly students reported that other students voluntarily asking and answering instructor questions is helpful to them. Notably, compared to continuing generation students, first-generation students were more likely to perceive other students asking questions to be helpful. Despite perceiving asking and answering questions to be helpful, over half of students reported that they never ask or answer questions in large-enrollment college science courses during a semester, and women were more likely than men to report never asking questions. We identified fear of negative evaluation, or students' sense of dread associated with being unfavorably evaluated, as a primary factor influencing their decision to answer instructor questions. This work adds to a growing body of literature on student participation in large-enrollment college science courses and begins to uncover underlying factors influencing student participation.

Culture and stress biology in immigrant youth from the prenatal period to adolescence: A systematic review.

Immigration patterns over the last two decades have changed the demographic composition of the United States; children are growing up in an increasingly multicultural environment. Immigrant youth may face culture-related stressors and leverage culture-related strengths across development that may influence their mental and physical health. Responses to early life stressors may differ across children at the level of stress biology, which can affect how they handle cultural challenges. However, there is limited research on culture and stress biology, which may be a mediator or moderator of culture's effects on immigrant youth. The aim of the present article is to systematically review research that examines the roles of both culture and stress biology from the prenatal period to adolescence in immigrant youth. Specifically, we review articles that examine how stress-sensitive biological systems (hypothalamic pituitary adrenal axis and the autonomic nervous system) and culture-related constructs have been modeled together in immigrant youth. Based on these findings, we note remaining questions and recommendations for future research in integrating measures of cultural processes and stress biology in children.

Distribution, Stability, and Continuity of Autonomic Nervous System Responsivity at 18- and 36-Months of Age.

OBJECTIVE: Cardiac autonomic nervous system (ANS) measures, respiratory sinus arrhythmia (RSA) and preejection period (PEP), are valid and reliable indicators of children's sensitivity to their environment; however, there are few studies of ANS measures in children less than three years of age. This study's aim was to summarize the distributions, stability, and continuity of RSA and PEP measures during resting, challenge, and reactivity for children at 18- and 36-months. METHODS: This was a cohort study of racially- and ethnically-diverse, low-income children who completed a developmentally challenging protocol while we simultaneously assessed their RSA and PEP at 18-months (N = 134) and 36-months (N = 102). RESULTS: The ANS resting, challenge, and reactivity measures at 18- and 36-months of age were normally distributed. The RSA resting (r = 0.29), RSA challenge (r = 0.44), PEP resting (r = 0.55) and PEP challenge (r = 0.58) measures were moderately stable but RSA (r = 0.01) and PEP reactivity (r = 0.02) were not stable from 18- to 36-months of age. There was no continuity in the ANS measures from 18- to 36-months of age with statistically significant changes in sample means for all of the ANS measures. DISCUSSION: These developmental changes in ANS are shown at the sample level but there are individual differences in ANS responses from 18- to 36-months that may be affected by adversity or protective factors experienced early in life.

Feedback Control of a Nonlinear Electrostatic Force Transducer.

We document a feedback controller design for a nonlinear electrostatic transducer that exhibits a strong unloaded resonance. Challenging features of this type of transducer include the presence of multiple fixed points (some of which are unstable), nonlinear force-to-deflection transfer, effective spring-constant softening due to electrostatic loading and associated resonance frequency shift. Furthermore, due to the utilization of lowpass filters in the electronic readout circuitry, a significant amount of transport delay is introduced in the feedback loop. To stabilize this electro-mechanical system, we employ an active disturbance-rejecting controller with nonlinear force mapping and delay synchronization. As demonstrated by numerical simulations, the combination of these three control techniques stabilizes the system over a wide range of electrode deflections. The proposed controller shows good setpoint tracking and disturbance rejection, and improved settling time, compared to the sensor alone.

To be funny or not to be funny: Gender differences in student perceptions of instructor humor in college science courses.

For over 50 years instructor humor has been recognized as a way to positively impact student cognitive and affective learning. However, no study has explored humor exclusively in the context of college science courses, which have the reputation of being difficult and boring. The majority of studies that explore humor have assumed that students perceive instructor humor to be funny, yet students likely perceive some instructor humor as unfunny or offensive. Further, evidence suggests that women perceive certain subjects to be more offensive than men, yet we do not know what impact this may have on the experience of women in the classroom. To address these gaps in the literature, we surveyed students across 25 different college science courses about their perceptions of instructor humor in college science classes, which yielded 1637 student responses. Open-coding methods were used to analyze student responses to a question about why students appreciate humor. Multinomial regression was used to identify whether there are gender differences in the extent to which funny, unfunny, and offensive humor influenced student attention to course content, instructor relatability, and student sense of belonging. Logistic regression was used to examine gender differences in what subjects students find funny and offensive when joked about by college science instructors. Nearly 99% of students reported that they appreciate instructor humor and reported that it positively changes the classroom atmosphere, improves student experiences during class, and enhances the student-instructor relationship. We found that funny humor tends to increase student attention to course content, instructor relatability, and student sense of belonging. Conversely, offensive humor tends to decrease instructor relatability and student sense of belonging. Lastly, we identified subjects that males were more likely to find funny and females were more likely to find offensive if a college science instructor were to joke about them.

Building and Breaking the Cell Wall in Four Acts: A Kinesthetic and Tactile Role-Playing Exercise for Teaching Beta-Lactam Antibiotic Mechanism of Action and Resistance.

"Building and breaking the cell wall" is designed to review the bacterial cell envelope, previously learned in lower-division biology classes, while introducing new topics such as antibiotics and bacterial antibiotic resistance mechanisms. We developed a kinesthetic and tactile modeling activity where students act as cellular components and construct the cell wall. In the first two acts, students model a portion of the gram-positive bacterial cell envelope and then demonstrate in detail how the peptidoglycan is formed. Act III involves student demonstration of the addition of ß-lactam antibiotics to the environment and how they inhibit the formation of peptidoglycan, thereby preventing bacterial replication. Using Staphylococcus aureus as a model for gram-positive bacteria, students finish the activity (Act IV) by acting out how S. aureus often becomes resistant to ß-lactam antibiotics. A high level of student engagement was observed, and the activity received positive feedback. In an assessment administered prior to and two months after the activity, significant improvements in scores were observed (p < 0.0001), demonstrating increased understanding and retention. This activity allows students to (i) visualize, role play, and kinesthetically "build" the cell envelope and form the peptidoglycan layer, (ii) understand the mechanism of action for ß-lactam antibiotics, as well as how gene acquisition and protein changes result in resistance, and (iii) work cooperatively and actively to promote long-term retention of the subject material.

A Course-Embedded Comparison of Instructor-Generated Videos of Either an Instructor Alone or an Instructor and a Student.

Instructor-generated videos have become a popular way to engage students with material before a class, yet this is a relatively unexplored area of research. There is support for the use of videos in which instructors tutor students, but few studies have been conducted within the context of a classroom. In this study, conducted in a large-enrollment college physiology course, we used a randomized crossover design to compare the impact of two types of instructor-generated videos that students watched as part of their preclass assignments. We compared videos featuring only an instructor (instructor-only videos) with videos featuring an instructor tutoring a student (instructor-tutee videos). We analyzed student survey responses and weekly physiology quiz scores and found that students preferred, enjoyed, and valued the instructor-only videos significantly more than the instructor-tutee videos. In contrast to prior literature, students with a grade point average (GPA) below the median (3.49) performed significantly better on physiology quizzes after watching instructor-only videos compared with instructor-tutee videos. Students with a GPA at or above the median performed equivalently on physiology quizzes after watching instructor-only or instructor-tutee videos. We present this study as an example of bringing cognitive science studies into the context of a real physiology classroom.

An Integrated Pest Management Intervention Improves Knowledge, Pest Control, and Practices in Family Child Care Homes.

To reduce young children's exposure to pesticides when attending family child care homes (FCCHs), we developed an integrated pest management (IPM) intervention for FCCH directors. First, we developed IPM educational materials and resources to provide the foundation for an IPM educational intervention for FCCHs. Next, we conducted and evaluated a six-month nurse child care health consultant (CCHC)-led education and consultation IPM intervention to increase IPM knowledge, IPM practices, IPM policies, and decrease the presence or evidence of pests. The pilot intervention study was conducted by three CCHCs in 20 FCCHs in three counties in California. Pre- and post-intervention measures were completed by the FCCH directors and observation measures were completed by the CCHCs. Results indicated significant increases in IPM knowledge, (t-statistic (degrees of freedom), (t(df) = 2.55(10), p < 0.05), increases in IPM practices (t(df) = -6.47(17), p < 0.05), and a 90% reduction in the prevalence of pests. There were no significant differences in changes in IPM practices based on director education, FCCH county, or IPM intervention intensity or duration. A nurse-led IPM education and consultation intervention can reduce exposures of young children attending family child care homes to harmful chemicals.

Portable, high-accuracy, non-absorbing laser power measurement at kilowatt levels by means of radiation pressure.

We describe a non-traditional optical power meter which measures radiation pressure to accurately determine a laser's optical power output. This approach traces its calibration of the optical watt to the kilogram. Our power meter is designed for high-accuracy and portability with the capability of multi-kilowatt measurements whose upper power limit is constrained only by the mirror quality. We provide detailed uncertainty evaluation and validate experimentally an average expanded relative uncertainty of 0.016 from 1 kW to 10 kW. Radiation pressure as a power measurement tool is unique to the extent that it does not rely on absorption of the light to produce a high-accuracy result. This permits fast measurements, simplifies power scalability, and allows high-accuracy measurements to be made during use of the laser for other applications.

Noise characteristics of thermistors: Measurement methods and results of selected devices.

As part of the development of a spectrally uniform room-temperature absolute radiometer, we have studied the electrical noise of several bulk chip thermistors in order to estimate the noise floor and optical dynamic range. Understanding the fundamental limits of the temperature sensitivity leads inevitably to studying the noise background of the complex electro-thermal system. To this end, we employ a measurement technique based on alternating current synchronous demodulation. Results of our analysis show that the combination of a low-current noise Junction Field Effect Transistor (JFET) preamplifier together with chip thermistors is optimal for our purpose, yielding a root mean square noise temperature of 2.8 µK in the frequency range of 0.01 Hz to 1 Hz.

Planar hyperblack absolute radiometer.

The absolute responsivity of a planar cryogenic radiometer fabricated from micromachined silicon and having carbon nanotubes, as the absorber and thermistor were measured in the visible and far infrared (free-field terahertz) wavelength range by means of detector-based radiometry. The temperature coefficient of the thermistor near 4.8 K and noise equivalent power were evaluated along with independent characterization of the window transmittance and specular reflectance of the nanotube absorber. Measurements of absolute power by means of electrical substitution are compared to the German national standard and the uncertainty of the radiometer responsivity as a function of wavelength is summarized.

Integrated Pest Management Intervention in Child Care Centers Improves Knowledge, Pest Control, and Practices.

INTRODUCTION: To reduce young children's exposure to pests and pesticides, an integrated pest management (IPM) intervention was provided for child care center staff. METHODS: The 7-month IPM education and consultation intervention was conducted by trained nurse child care health consultants in 44 child care centers in California. IPM knowledge surveys were completed by child care staff, objective IPM assessments were completed by research assistants pre- and postintervention, and activity logs were completed by the nurses. RESULTS: There were significant increases in IPM knowledge for the child care staff who attended workshops. There were reductions in the prevalence of pests and increases in IPM practices at the postintervention compared with the preintervention time point. The nurses consulted an average of 5.4 hours per center. DISCUSSION: A nurse-led IPM intervention in child care centers can reduce exposure to harmful substances for young children attending child care centers.

Tonic glutamate in CA1 of aging rats correlates with phasic glutamate dysregulation during seizure.

OBJECTIVE: Characterize glutamate neurotransmission in the hippocampus of awake-behaving rodents during focal seizures in a model of aging. METHODS: We used enzyme-based ceramic microelectrode array technology to measure in vivo extracellular tonic glutamate levels and real-time phasic glutamate release and clearance events in the hippocampus of awake Fischer 344 rats. Local application of 4-aminopyridine (4-AP) into the CA1 region was used to induce focal motor seizures in different animal age groups representing young, late-middle aged and elderly humans. RESULTS: Rats with the highest preseizure tonic glutamate levels (all in late-middle aged or elderly groups) experienced the most persistent 4-AP-induced focal seizure motor activity (wet dog shakes) and greatest degree of acute seizure-associated disruption of glutamate neurotransmission measured as rapid transient changes in extracellular glutamate levels. SIGNIFICANCE: Increased seizure susceptibility was demonstrated in the rats with the highest baseline hippocampal extracellular glutamate levels, all of which were late-middle aged or aged animals. The manifestation of seizures behaviorally was associated with dynamic changes in glutamate neurotransmission. To our knowledge, this is the first report of a relationship between seizure susceptibility and alterations in both baseline tonic and phasic glutamate neurotransmission.