EELS: Autonomous snake-like robot with task and motion planning capabilities for ice world exploration.

Ice worlds are at the forefront of astrobiological interest because of the evidence of subsurface oceans. Enceladus in particular is unique among the icy moons because there are known vent systems that are likely connected to a subsurface ocean, through which the ocean water is ejected to space. An existing study has shown that sending small robots into the vents and directly sampling the ocean water is likely possible. To enable such a mission, NASA's Jet Propulsion Laboratory is developing a snake-like robot called Exobiology Extant Life Surveyor (EELS) that can navigate Enceladus' extreme surface and descend an erupting vent to capture unaltered liquid samples and potentially reach the ocean. However, navigating to and through Enceladus' environment is challenging: Because of the limitations of existing orbital reconnaissance, there is substantial uncertainty with respect to its geometry and the physical properties of the surface/vents; communication is limited, which requires highly autonomous robots to execute the mission with limited human supervision. Here, we provide an overview of the EELS project and its development effort to create a risk-aware autonomous robot to navigate these extreme ice terrains/environments. We describe the robot's architecture and the technical challenges to navigate and sense the icy environment safely and effectively. We focus on the challenges related to surface mobility, task and motion planning under uncertainty, and risk quantification. We provide initial results on mobility and risk-aware task and motion planning from field tests and simulated scenarios.

Plant size, latitude, and phylogeny explain within-population variability in herbivory.

Interactions between plants and herbivores are central in most ecosystems, but their strength is highly variable. The amount of variability within a system is thought to influence most aspects of plant-herbivore biology, from ecological stability to plant defense evolution. Our understanding of what influences variability, however, is limited by sparse data. We collected standardized surveys of herbivory for 503 plant species at 790 sites across 116° of latitude. With these data, we show that within-population variability in herbivory increases with latitude, decreases with plant size, and is phylogenetically structured. Differences in the magnitude of variability are thus central to how plant-herbivore biology varies across macroscale gradients. We argue that increased focus on interaction variability will advance understanding of patterns of life on Earth.

The carbon footprint of surgical operations: a systematic review update.

INTRODUCTION: Sustainability in healthcare is a rapidly developing area of research with recent formal recognition from institutions around the world. We completed an update of a systematic review published in 2020. The aims of this review were to determine the reported carbon footprints of surgical operations in hospitals worldwide, identify variations in reported carbon footprints and highlight carbon hotspots associated with surgery. METHODS: A systematic review was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. The MEDLINE®, Embase® and Cochrane Library databases were searched, and eligibility criteria applied. The study characteristics, scope of product inventory and results were extracted and synthesised. A quality assessment of each study was completed to inform the reliability of the research. RESULTS: 1,308 articles were identified and 7 met the inclusion criteria for the review. The carbon footprint ranged from 28.49kg to 505.1kg carbon dioxide equivalents (CO2e). Medical devices and consumables were the greatest contributor to emissions, with material production and manufacture representing the majority of this carbon hotspot. There were significant methodological limitations and a lack of consistency in carbon footprint calculations between studies. CONCLUSIONS: This systematic review identifies medical devices and consumables as the largest carbon hotspot where healthcare providers should target their sustainability initiatives. Nevertheless, the number of studies was limited and the quality of the evidence was weak. We recommend that researchers in healthcare sustainability develop international standards for conducting and reporting such studies. This would allow for comparison of individual studies and facilitate meta-analysis of cumulative evidence. A reliable evidence base is a prerequisite for identifying optimal interventions to ensure societal benefits.

Bloodstream infections in neonates with central venous catheters in three tertiary neonatal intensive care units in Pune, India.

BACKGROUND: Neonates admitted to the neonatal intensive care unit (NICU) are at risk for healthcare-associated infections, including central line-associated bloodstream infections. We aimed to characterize the epidemiology of bloodstream infections among neonates with central venous catheters admitted to three Indian NICUs. METHODS: We conducted a prospective cohort study in three tertiary NICUs, from May 1, 2017 until July 31, 2019. All neonates admitted to the NICU were enrolled and followed until discharge, transfer, or death. Cases were defined as positive blood cultures in neonates with a central venous catheter in place for greater than 2 days or within 2 days of catheter removal. RESULTS: During the study period, 140 bloodstream infections were identified in 131 neonates with a central venous catheter. The bloodstream infection rate was 11.9 per 1000 central line-days. Gram-negative organisms predominated, with 38.6% of cases caused by Klebsiella spp. and 14.9% by Acinetobacter spp. Antimicrobial resistance was prevalent among Gram-negative isolates, with 86.9% resistant to third- or fourth-generation cephalosporins, 63.1% to aminoglycosides, 61.9% to fluoroquinolones, and 42.0% to carbapenems. Mortality and length of stay were greater in neonates with bloodstream infection than in neonates without bloodstream infection (unadjusted analysis, p < 0.001). CONCLUSIONS: We report a high bloodstream infection rate among neonates with central venous catheters admitted to three tertiary care NICUs in India. Action to improve infection prevention and control practices in the NICU is needed to reduce the morbidity and mortality associated with BSI in this high-risk population.

Zigzag persistence for coral reef resilience using a stochastic spatial model.

A complex interplay between species governs the evolution of spatial patterns in ecology. An open problem in the biological sciences is characterizing spatio-temporal data and understanding how changes at the local scale affect global dynamics/behaviour. Here, we extend a well-studied temporal mathematical model of coral reef dynamics to include stochastic and spatial interactions and generate data to study different ecological scenarios. We present descriptors to characterize patterns in heterogeneous spatio-temporal data surpassing spatially averaged measures. We apply these descriptors to simulated coral data and demonstrate the utility of two topological data analysis techniques-persistent homology and zigzag persistence-for characterizing mechanisms of reef resilience. We show that the introduction of local competition between species leads to the appearance of coral clusters in the reef. We use our analyses to distinguish temporal dynamics stemming from different initial configurations of coral, showing that the neighbourhood composition of coral sites determines their long-term survival. Using zigzag persistence, we determine which spatial configurations protect coral from extinction in different environments. Finally, we apply this toolkit of multi-scale methods to empirical coral reef data, which distinguish spatio-temporal reef dynamics in different locations, and demonstrate the applicability to a range of datasets.

Regulation of antigen-specific T cell infiltration and spatial architecture in multiple myeloma and premalignancy.

Entry of antigen-specific T cells into human tumors is critical for immunotherapy, but the underlying mechanisms are poorly understood. Here, we combined high-dimensional spatial analyses with in vitro and in vivo modeling to study the mechanisms underlying immune infiltration in human multiple myeloma (MM) and its precursor monoclonal gammopathy of undetermined significance (MGUS). Clustered tumor growth was a feature of MM but not MGUS biopsies, and this growth pattern was reproduced in humanized mouse models. MM biopsies exhibited intralesional as well as spatial heterogeneity, with coexistence of T cell-rich and T cell-sparse regions and the presence of areas of T cell exclusion. In vitro studies demonstrated that T cell entry into MM clusters was regulated by agonistic signals and CD2-CD58 interactions. Upon adoptive transfer, antigen-specific T cells localized to the tumor site but required in situ DC-mediated antigen presentation for tumor entry. C-type lectin domain family 9 member A-positive (CLEC9A+) DCs appeared to mark portals of entry for gradients of T cell infiltration in MM biopsies, and their proximity to T cell factor 1-positive (TCF1+) T cells correlated with disease state and risk status. These data illustrate a role for tumor-associated DCs and in situ activation in promoting the infiltration of antigen-specific T cells in MM and provide insights into spatial alterations in tumor/immune cells with malignant evolution.

Differential Response of Pelvic Bone Marrow Fluorodeoxyglucose Uptake in Patients Receiving Concurrent Chemoradiotherapy.

AIMS: Irradiation of pelvic bone marrow (PBM) at the level of the typical low dose bath of intensity-modulated radiotherapy delivery (10-20 Gy) is associated with an increased risk of haematological toxicity, particularly when combined with concurrent chemotherapy. Although sparing of the whole of the PBM at a 10-20 Gy dose level is unachievable, it is known that PBM is divided into haematopoietically active and inactive regions that are identifiable based on the threshold uptake of [18F]-fluorodeoxyglucose (FDG) seen on positron emission tomography-computed tomography (PET-CT). In published studies to date, the definition of active PBM widely used is that of a standardised uptake value (SUV) greater than the mean SUV of the whole PBM prior to the start of chemoradiation. These studies include those looking at developing an atlas-based approach to contouring active PBM. Using baseline and mid-treatment FDG PET scans acquired as part of a prospective clinical trial we sought to determine the suitability of the current definition of active bone marrow as representative of differential underlying cell physiology. MATERIALS AND METHODS: Active and inactive PBM were contoured on baseline PET-CT and using deformable registration mapped onto mid-treatment PET-CT. Volumes were cropped to exclude definitive bone, voxel SUV extracted and the change between scans calculated. Change was compared using Mann-Whitney U testing. RESULTS: Active and inactive PBM were shown to respond differentially to concurrent chemoradiotherapy. The median absolute response of active PBM for all patients was -0.25 g/ml, whereas the median inactive PBM response was -0.02 g/ml. Significantly, the inactive PBM median absolute response was shown to be near zero with a relatively unskewed distribution (0.12). CONCLUSIONS: These results would support the definition of active PBM as FDG uptake greater than the mean of the whole structure as being representative of underlying cell physiology. This work would support the development of atlas-based approaches published in the literature to contour active PBM based on the current definition as being suitable.

Biomarkers of biological aging in recipients of solid organ transplantation and clinical outcomes: A scoping review.

INTRODUCTION: Biological aging is the accumulation of cellular and molecular damage within an individual over time. The biological age of a donor organ is known to influence clinical outcomes of solid organ transplantation, including delayed graft function and frequency of rejection episodes. While much research has focused on the biological age of donor organs, the recipient's biological age may also influence transplantation outcomes. The aim of this scoping review was to identify and provide an overview of the existing evidence regarding biological aging in solid organ transplant recipients and the impact on patient outcomes post-transplant. METHODS: Literature searches were carried out on PubMed, Web of Science, Google Scholar, Embase and TRIP using the phrases 'solid organ transplant', 'cell senescence', 'cell aging' and 'outcomes', using boolean 'and/or' phrases and MeSH terms. Duplicates were removed and abstracts were reviewed by two independent reviewers. Full papers were then screened for inclusion by two reviewers. Data extraction was carried out using a standardised proforma agreed on prior to starting. RESULTS: 32 studies, including data on a total of 7760 patients, were identified for inclusion in this review; 23 relating to kidney transplant recipients, three to liver transplant, five to lung transplant and one to heart transplantation. A wide range of biomarkers of biological aging have been assessed in kidney transplant recipients, whereas studies of liver, lung and heart transplant have predominantly assessed recipient telomere length. The most robust associations with clinical outcomes are observed in kidney transplant recipients, possibly influenced by the larger number of studies and the use of a wider range of biomarkers of biological aging. In kidney transplant recipients reduced thymic function and accumulation of terminally differentiated T cell populations was associated with reduced risk of acute rejection but increased risk of infection and mortality. CONCLUSION: Studies to date on biological aging in transplant recipients have been heavily biased to kidney transplant recipients. The results from these studies suggest recipient biological age can influence clinical outcomes and future research is needed to prioritise robust biomarkers of biological aging in transplant recipients.

Gamification of POCUS: Are Students Learning?

INTRODUCTION: While gamification of point-of-care ultrasound (POCUS) is well received by learners, little is known about the knowledge gained from material taught during these events. We set out to determine whether a POCUS gamification event improved knowledge of interpretation and clinical integration of POCUS. METHODS: This was a prospective observational study of fourth-year medical students who participated in a 2.5-hour POCUS gamification event consisting of eight objective-oriented stations. Each station had one to three learning objectives associated with the content taught. Students completed a pre-assessment; they then participated in the gamification event in groups of three to five per station and subsequently completed a post-assessment. Differences between pre- and post-session responses were matched and analyzed using Wilcoxon signed-rank test and Fisher's exact test. RESULTS: We analyzed data from 265 students with matched pre- and post-event responses; 217 (82%) students reported no to little prior POCUS experience. Most students were going into internal medicine (16%) and pediatrics (11%). Knowledge assessment scores significantly improved from pre- to post-workshop, 68% vs 78% (P=0.04). Self-reported comfort with image acquisition, interpretation, and clinical integration all significantly improved from pre- to post-gamification event (P<0.001). CONCLUSION: In this study we found that gamification of POCUS, with clear learning objectives, led to improved student knowledge of POCUS interpretation, clinical integration, and self-reported comfort with POCUS.

Recruitment of Older African Americans in Alzheimer's Disease Clinical Trials Using a Community Education Approach.

Alzheimer's disease and related dementias (ADRD) is two times more prevalent among compared to non-Hispanic Whites. Despite the higher prevalence of ADRD among older African Americans, recent estimates suggest research enrollment by those who identify as African American remains limited. The purpose of the study is to 1) explore how a culturally tailored community education program impacts clinical trial interest and enrollment in ADRD research studies and to 2) identify how applicable the African American community perceived the culturally tailored curriculum. Using a community-engaged research approach, we collaborated with predominately African American serving community-based organizations to support content development and delivery of Aging with Grace (AWG), a culturally tailored ADRD educational curriculum. A total of five AWG presentations were given to 66 attendees. Most attendees (67%) expressed interest in participating in clinical trials after attending AWG. Enrollment increased within an observational study (84%) and lifestyle prevention clinical trials (52%) from 2018 to 2019. Attendees (32%) also perceived an increase in ADRD knowledge from attending AWG and 89.1% believed more African Americans should participate in research. Our work demonstrates the effectiveness of a culturally tailored community education program to enhance knowledge, clinical trial interest, and recruitment into observational studies and lifestyle ADRD clinical trials among older African Americans. Education programs developed in partnership with the community can serve as bridge to research participation for underrepresented minorities in clinical research. Future studies should assess long-term retention of knowledge and research readiness.

Assessment of Medical Students' Ability to Integrate Point-of-Care Cardiac Ultrasound Into a Case-Based Simulation After a Short Intervention.

INTRODUCTION: While a large amount of point-of-care ultrasound (POCUS) undergraduate medical education research exists, very little assesses the effectiveness of teaching on the student's ability to utilize POCUS within a clinical context. We set out to assess the ability of pre-clinical (second year) medical students to perform and interpret a parasternal long axis (PSLA) cardiac ultrasound view, and to diagnose a pericardial effusion on POCUS in a simulated patient with hypotension. METHODS: This was a prospective study assessing second-year medical students before and after focused cardiac POCUS instruction. Pre-instruction, students completed a pre-assessment and test. They then watched a short video on cardiac ultrasound technique, anatomy, and pathology. Students then participated in 10 minutes of one-on-one hands-on instruction using a simulated patient. Immediately after didactics and hands-on instruction, students in groups of two to four completed a case simulation where they performed a PSLA view, identified pathology, and made a diagnosis. Differences between pre- and post-workshop responses were analyzed using the Chi-square test. RESULTS: We analyzed data on 132 pre-clinical second-year medical students; 126 (95%) had limited to no POCUS experience prior to the workshop. Comparing pre- to post-workshop responses, we found significant improvement in students' ability to identify a pericardial effusion (46% to 69%) (p=0.002) on a PSLA cardiac view. Of the 57 student groups (132 students), 41 (72%) groups were able to adequately obtain a PSLA view on a mannequin using an ultrasound simulator without needing guidance with probe placement or maneuvering. Thirty-five (61%) student groups were able to identify a pericardial effusion and diagnose cardiac tamponade in a simulated patient with hypotension. CONCLUSION: After short, structured training, pre-clinical medical students, novice to cardiac POCUS, showed improved knowledge with identifying a pericardial effusion on an ultrasound image. The majority of students were able to obtain a PSLA view and diagnose cardiac tamponade in a hypotensive patient during a during a case-based simulation.

The Forefront of Dentistry-Promising Tech-Innovations and New Treatments.

KNOWLEDGE TRANSFER STATEMENT: This article discusses innovations in technology and treatments that have enormous potential to revolutionize our dental care, including novel concepts in electronic health records, communication between dentists and patients, biologics around diagnosis and treatment, digital dentistry, and, finally, the real-time optimization of information technology. The early implementation and validation of these innovations can drive down their costs and provide better dental and medical services to all members of our society.

Mental health and behavioural problems in adolescents conceived after ART.

STUDY QUESTION: Does mental health and behaviour differ between those conceived with and those conceived without ART? SUMMARY ANSWER: Our study observed less externalizing behaviour (delinquent/aggressive), and more parent-reported internalizing behaviour, as well as more (clinical) depression at age 14 years, in adolescents conceived after ART compared to their non-ART counterparts. WHAT IS KNOWN ALREADY: Health outcomes of ART-conceived offspring may differ from those conceived without ART, and previous studies have reported differences in behaviour and mental health, particularly in childhood. STUDY DESIGN, SIZE, DURATION: The Growing Up Healthy Study (GUHS) is a prospective cohort study, investigating the long-term health of offspring conceived after ART (aged 14, 17 and 20 years), in the two operational fertility clinics in Western Australia 1991-2001 (n = 303). Their long-term health outcomes were compared to those of offspring conceived without ART from the Raine Study Generation 2 (Gen2) born 1989-1991 (n = 2868). Both cohorts are representative of the local adolescent population. PARTICIPANTS/MATERIALS, SETTING, METHODS: Mental health parameters and behaviour were assessed at ages 14 and 17 years, through the parent completed 'Child Behaviour Checklist' (CBCL; ART versus non-ART: age 14 years: N = 150 versus N = 1781, age 17 years: N = 160 versus N = 1351), and the adolescent completed equivalent 'Youth Self-Report' (YSR; age 14 years: by N = 151 versus N = 1557, age 17 years: N = 161 and N = 1232). Both tools generate a T-score (standardized for age and sex) for internalizing (withdrawn, somatic complaints, anxious/depressed), externalizing (delinquent/aggressive behaviour) and total behaviour. Adolescents also completed the 'Beck Depression Inventory for Youth' (BDI-Y; age 14 years: N = 151 versus N = 1563, age 17 years: N = 161 versus N = 1219). Higher scores indicate poorer mental health and behaviour on all the above tools. Parent-reported doctor-diagnosed conditions (anxiety, behavioural problems, attention problems and depression) were also univariately compared between the cohorts. In addition, univariate comparisons were conducted between the GUHS adolescents and Gen2 adolescents born to subfertile parents (time to pregnancy >12 months), as well as between offspring born to subfertile versus fertile parents within the Gen2 cohort. A subgroup analysis excluding offspring born preterm (<37 weeks' gestation) or at low birthweight (<2500 g) was also performed. Generalized estimating equations that account for correlated familial data were adjusted for the following covariates: non-singleton, primiparity, primary caregiver smoking, family financial problems, socio-economic status and both maternal and paternal ages at conception. MAIN RESULTS AND THE ROLE OF CHANCE: At both 14 and 17 years of age, ART versus non-ART-conceived adolescents reported lower mean T-scores for externalizing problems (age 14 years: 49 versus 51, P = 0.045, age 17 years: 49 versus 52, P < 0.001). A similar effect was reported by parents, although not significant (age 14 years: P = 0.293, age 17 years: P = 0.148). Fewer ART-conceived adolescents reported a T-score above the clinical cut-off for externalizing behaviour (≥60; age 14 years: 7.3% versus 16.3%, P = 0.003, age 17 years: 8.1% versus 19.7%, P < 0.001). At both ages, no differences in internalizing behaviour were reported by adolescents (age 14 years: P = 0.218, age 17 years: P = 0.717); however, higher mean scores were reported by parents of the ART-conceived adolescents than by parents of the non-ART conceived adolescents (age 14 years: 51 versus 48, P = 0.027, age 17 years: 50 versus 46, P < 0.001). No differences in internalizing behaviour above the clinical cut-off (T-score ≥ 60) were observed. At age 17 years, parents who conceived through ART reported higher total behaviour scores than those parents who conceived without ART (48 versus 45, P = 0.002). At age 14 years, ART versus non-ART-conceived adolescents reported significantly higher mean scores on the BDI-Y (9 versus 6, P = 0.005); a higher percentage of adolescents with a score indicating clinical depression (≥17; 12.6% versus 8.5%, aOR 2.37 (1.18-4.77), P = 0.016), as well as more moderate/severe depression (≥21; 9.3% versus 4.0%, P = 0.009). At age 17 years, no differences were reported on the BDI-Y. There was also a higher percentage of parent-reported doctor-diagnosed anxiety in the ART cohort (age 14 years: 8.6% versus 3.5%, P = 0.002, at age 17 years: 12.0% versus 4.5%, P < 0.001). Removing adolescents born preterm or at low birthweight did not alter the above results. Comparing outcomes between GUHS adolescents and Gen2 adolescents born to subfertile parents, as well as between those born to subfertile versus fertile parents within Gen2, did not alter results for CBCL and YSR outcomes. Those born to subfertile parents showed higher rates of clinical depression than those born to fertile parents at age 14 years (13.7% versus 6.9%, P = 0.035). LIMITATIONS, REASONS FOR CAUTION: The main limitation of the study is the time difference between the GUHS and Gen2 assessments. Even though we have adjusted for covariates, additional socio-economic and lifestyle factors affecting behaviour and mental well-being could have changed. We were unable to differentiate between different types of ART (e.g. IVF versus ICSI), owing to the low number of ICSI cycles at the time of study. Fertility sub-analyses need to be replicated in larger cohorts to increase power, potentially using siblingship designs. Lastly, selection bias may be present. WIDER IMPLICATIONS OF THE FINDINGS: The reported lower prevalence of externalizing behaviour (delinquent/aggressive), and higher prevalence of internalizing behaviour, as well as more (clinical) depression at age 14 years, in ART versus non-ART-conceived adolescents, is in line with some previous studies, mostly conducted in childhood. It is reassuring that differences in the rates of depression were not observed at age 17 years, however, these findings require replication. As the use of ART is common, and mental health disorders are increasing, knowledge about a potential association is important for parents and healthcare providers alike. STUDY FUNDING/COMPETING INTEREST(S): This project was funded by an NHMRC Grant (Hart et al., ID 1042269). R.J.H. is the Medical Director of Fertility Specialists of Western Australia and a shareholder in Western IVF. He has received educational sponsorship from MSD, Merck-Serono and Ferring Pharmaceuticals. P.B. is the Scientific Director of Concept Fertility Centre, Subiaco, Western Australia. J.L.Y. is the Medical Director of PIVET Medical Centre, Perth, Western Australia. TRIAL REGISTRATION NUMBER: N/A.

Effect of rumen fluke on feed digestibility and methane emissions in sheep.

Thirty-six ewes aged 18 months were assigned to one of three groups (n = 12) on the basis of faecal egg count (FEC) for rumen fluke; C: control (FEC = 0-5 epg), T: affected (FEC ≥ 6 epg) and treated, NT: affected (FEC ≥ 6 epg) and not treated. T ewes were treated with oxyclozanide 14 days prior to the trial commencing. Ewes were fed grass silage ad libitum. Digestibility crates and respiration chambers were used to measure feed digestibility and methane production. Dry matter intake (DMI), feed digestibility and CH4/DMI did not differ (P > 0.05) between treatments. However, CH4/live weight (LW) was significantly greater (P < 0.001) for NT ewes, while that of C and T ewes were similar. This study indicates that a high rumen fluke burden can increase methane emissions but only when expressed on a body weight basis (per kg LW). As the link between rumen fluke infection and methane production has not previously been investigated within the literature, these findings demonstrate the need for further research to better understand these relationships.

Piloting a Graduate Medical Education Point-of-Care Ultrasound Curriculum.

Objective As point-of-care ultrasound (POCUS) use grows, training in graduate medical education (GME) is increasingly needed. We piloted a multispecialty GME POCUS curriculum and assessed feasibility, knowledge, and comfort with performing POCUS exams. Methods Residents were selected from the following residency programs: internal medicine, family medicine, emergency medicine, and a combined internal medicine/pediatrics program. Didactics occurred through an online curriculum that consisted of five modules: physics and machine operation, cardiac, lung, soft tissue, and extended focused sonography in trauma applications. Residents completed a pre- and post-curriculum questionnaire, as well as knowledge assessments before and after each module. One-hour hands-on training sessions were held for each module. Differences between pre- and post-participation questionnaire responses were analyzed using the Wilcoxon rank sum. Results Of the 24 residents selected, 21 (86%) were post-graduate year two or three, and 16 (65%) were from the internal medicine program. Eighteen (67%) residents reported limited prior POCUS experience. All pre- to post-knowledge assessment scores increased (p<0.05). Statistically significant increases pre- to post-curriculum were found for frequency of POCUS use (p = 0.003), comfort in using POCUS for assessing for abdominal aortic aneurysm, soft tissue abscess detection, undifferentiated hypotension and dyspnea, cardiac arrest and heart failure (p<0.025); and competency in machine use, acquiring and interpreting images and incorporating POCUS into clinical practice (p<0.001). All participants felt the skills learned during this curriculum were essential to their future practice. Conclusions In this pilot, we found using a combination of online and hands-on training to be feasible, with improvement in residents' knowledge, comfort, and use of POCUS.

Heterogeneity in the onwards transmission risk between local and imported cases affects practical estimates of the time-dependent reproduction number.

During infectious disease outbreaks, inference of summary statistics characterizing transmission is essential for planning interventions. An important metric is the time-dependent reproduction number (Rt), which represents the expected number of secondary cases generated by each infected individual over the course of their infectious period. The value of Rt varies during an outbreak due to factors such as varying population immunity and changes to interventions, including those that affect individuals' contact networks. While it is possible to estimate a single population-wide Rt, this may belie differences in transmission between subgroups within the population. Here, we explore the effects of this heterogeneity on Rt estimates. Specifically, we consider two groups of infected hosts: those infected outside the local population (imported cases), and those infected locally (local cases). We use a Bayesian approach to estimate Rt, made available for others to use via an online tool, that accounts for differences in the onwards transmission risk from individuals in these groups. Using COVID-19 data from different regions worldwide, we show that different assumptions about the relative transmission risk between imported and local cases affect Rt estimates significantly, with implications for interventions. This highlights the need to collect data during outbreaks describing heterogeneities in transmission between different infected hosts, and to account for these heterogeneities in methods used to estimate Rt. This article is part of the theme issue 'Technical challenges of modelling real-life epidemics and examples of overcoming these'.

Sickle cell bone disease and response to intravenous bisphosphonates in children.

Children with sickle cell disease (SCD) have the potential for extensive and early-onset bone morbidity. This study reports on the diversity of bone morbidity seen in children with SCD followed at three tertiary centers. IV bisphosphonates were effective for bone pain analgesia and did not trigger sickle cell complications. INTRODUCTION: To evaluate bone morbidity and the response to intravenous (IV) bisphosphonate therapy in children with SCD. METHODS: We conducted a retrospective review of patient records from 2003 to 2019 at three Canadian pediatric tertiary care centers. Radiographs, magnetic resonance images, and computed tomography scans were reviewed for the presence of avascular necrosis (AVN), bone infarcts, and myositis. IV bisphosphonates were offered for bone pain management. Bone mineral density was assessed by dual-energy X-ray absorptiometry (DXA). RESULTS: Forty-six children (20 girls, 43%) had bone morbidity at a mean age of 11.8 years (SD 3.9) including AVN of the femoral (17/46, 37%) and humeral (8/46, 17%) heads, H-shaped vertebral body deformities due to endplate infarcts (35/46, 76%), and non-vertebral body skeletal infarcts (15/46, 32%). Five children (5/26, 19%) had myositis overlying areas of AVN or bone infarcts visualized on magnetic resonance imaging. Twenty-three children (8/23 girls) received IV bisphosphonate therapy. They all reported significant or complete resolution of bone pain. There were no reports of sickle cell hemolytic crises, pain crises, or stroke attributed to IV bisphosphonate therapy. CONCLUSION: Children with SCD have the potential for extensive and early-onset bone morbidity. In this series, IV bisphosphonates were effective for bone pain analgesia and did not trigger sickle cell complications.

Point-of-Care Ultrasound Education During a Pandemic: From Webinar to Progressive Dinner-Style Bedside Learning.

OBJECTIVE: Point-of-care ultrasound (POCUS), traditionally, requires the proximity of learners and educators, making POCUS education challenging during the COVID-19 pandemic. We set out to evaluate three alternate approaches to teaching POCUS in UME. Sessions progressed from an online seminar to a remote, interactive simulation to a "progressive dinner" style session, as precautions evolved throughout the pandemic. METHODS: This prospective study details a series of three POCUS workshops that were designed to align with prevailing social distancing precautions during the COVID-19 pandemic. Overall, 656 medical students were included. The first and second workshops used web-based conferencing technology with real-time ultrasound imaging, with the second workshop focusing on clinical integration through simulation. As distancing precautions were updated, a novel "progressive dinner" technique was used for the third workshop. Surveys were conducted after each session to obtain feedback on students' attitudes toward alternative teaching techniques and quantitative and qualitative analyses were used. RESULTS: The initial, remote POCUS workshop was performed for 180 medical students. Ninety-nine (177) percent of students felt the session was "intellectually challenging" and "stimulating." Ninety-nine percent of students (340/344), after the second workshop, indicated the session was intellectually challenging, stimulating, and a positive learning experience. Students' ability to correctly identify pathologic images increased post-session evaluation from in-session polling. For workshop three, 99% (107/108) of students indicated that the session was "informative." There was a significant improvement in pre- to post-workshop knowledge regarding image acquisition, interpretation, and clinical integration. CONCLUSION: While image acquisition skills are best conveyed at the bedside, these modified POCUS teaching techniques developed and delivered in alignment with COVID-19 pandemic restrictions during a series of three workshops were shown to be effective surrogates for traditional teaching approaches when social distancing requirements, a large learner pool, or lack of local expertise exist.

Success of implementation of a systemwide point-of-care ultrasound privileging program for emergency medicine faculty.

Objectives: Point-of-care ultrasound (POCUS) is widely used in the emergency department (ED). Not all practicing emergency physicians received POCUS training during residency, leaving a training gap that is reflected in POCUS privileging. The purpose of this study was to evaluate the success of meeting privileging criteria as well as associated factors, following implementation of a basic POCUS training and privileging program within a large emergency medicine department. Methods: We implemented a POCUS training and privileging program, based on national guidelines, for faculty physicians who worked at one of the following EDs staffed by the same emergency medicine department: a pediatric tertiary site, two tertiary academic sites, and seven community sites. POCUS examinations included aorta, cardiac, first-trimester obstetrics (OB), and extended focused assessment with sonography in trauma. Pediatric emergency medicine faculty were taught soft tissue and thoracic US instead of aorta and OB. Completion of the program required 16 h of didactics, ≥25 quality-assured US examinations by examination type, and passing a series of knowledge-based examinations. Descriptive statistics were calculated. Associations between physician characteristics and successfully becoming privileged in POCUS were modeled using Firth's logistic regression. Results: A total of 176 faculty physicians were eligible. A total of 145 (82.4%) achieved basic POCUS privileging during the study period. Different pathways were used including 86 (48.9%) practice-based, nine (5.1%) fellowship-based, and 82 (46.9%) residency-based. POCUS privileging was lower for those working in a community versus academic setting (odds ratio 0.3, 95% confidence interval 0.1-0.9). A greater number of scans completed prior to the privileging program was associated with greater success. Conclusions: Implementation of a POCUS training and privileging program can be successful in a large emergency medicine department that staffs hospitals in a large-scale health care system composed of both academic and community sites. Faculty physicians with at least some prior exposure to POCUS were more successful.