Association between telomere length and Plasmodium falciparum malaria endemicity in sub-Saharan Africans.

Leukocyte telomere length (LTL) varies significantly across human populations, with individuals of African ancestry having longer LTL than non-Africans. However, the genetic and environmental drivers of LTL variation in Africans remain largely unknown. We report here on the relationship between LTL, genetics, and a variety of environmental and climatic factors in ethnically diverse African adults (n = 1,818) originating from Botswana, Tanzania, Ethiopia, and Cameroon. We observe significant variation in LTL among populations, finding that the San hunter-gatherers from Botswana have the longest leukocyte telomeres and that the Fulani pastoralists from Cameroon have the shortest telomeres. Genetic factors explain ∼50% of LTL variation among individuals. Moreover, we observe a significant negative association between Plasmodium falciparum malaria endemicity and LTL while adjusting for age, sex, and genetics. Within Africa, adults from populations indigenous to areas with high malaria exposure have shorter LTL than those in populations indigenous to areas with low malaria exposure. Finally, we explore to what degree the genetic architecture underlying LTL in Africa covaries with malaria exposure.

Timing and causes of death to 1 year among children presenting to emergency departments.

BACKGROUND AND OBJECTIVES: A better characterization of deaths in children following emergency care is needed to inform timely interventions. This study aimed to describe the timing, location, and causes of death to 1 year among a cohort of injured and medically ill children. METHODS: We conducted a retrospective cohort study of children <18 years requiring emergency care in six states from January 1, 2012, through December 31, 2017, with follow-up through December 31, 2018, for patients who were not discharged from the emergency department (ED). In this cohort, 1-year mortality, time to death within 1 year, and causes of death were assessed from ED, inpatient, and vital status records. RESULTS: There were 546,044 children during the 6-year period. The 1-year mortality rate was 2.2% (n = 1356) for injured children and 1.4% (n = 6687) for medically ill children. Matched death certificates were available for 861 (63.5%) of 1356 deaths in the injury cohort and for 4712 (70.5%) of 6687 deaths in the medical cohort. Among deaths in the injury cohort, 1274 (94.0%) occurred in the ED or hospital. The most common causes of death were motor vehicle collisions, firearm injuries, and pedestrian injuries. Among the 6687 deaths in the medical cohort, 5081 (76.0%) children died in the ED or hospital (primarily in the ED) and 1606 (24.0%) occurred after hospital discharge. The most common causes of death were sudden infant death syndrome, suffocation and drowning, and congenital conditions. CONCLUSIONS: The 1-year mortality of children presenting to an ED is 2.2% for injured children and 1.4% for medically ill children with most deaths occurring in the ED. Future interventional trials, quality improvement efforts, and health policy focused in the ED could have the potential to improve outcomes of pediatric patients.

Assessment of Protein Binding Using Asymmetric-Flow Field-Flow Fractionation Combined with Multi-angle Light Scattering and Dynamic Light Scattering.

Asymmetric-flow field-flow fractionation (AF4) is a valuable tool to separate and assess different size populations in nanotherapeutics. When coupled with both static light scattering and dynamic light scattering, it can be used to qualitatively assess protein binding to nanoparticles by comparing the shape factors for both non-plasma-incubated samples and plasma-incubated samples. The shape factor is defined as the ratio of the derived root mean square radius (by static light scattering) to the measured hydrodynamic radius (by dynamic light scattering). The shape factor gives an idea of where the center of mass lies in a nanoparticle, and any shift in the shape factor to larger values is indicative of a mass addition to the periphery of the nanoparticle and suggests the presence of protein binding. This protocol will discuss how to set up an experiment to assess protein binding in nanoparticles using AF4, multi-angle light scattering (MALS), and dynamic light scattering (DLS).

Measuring Size and Number Concentration of Metallic Nanoparticles Using spICP-MS.

This protocol describes how to measure the size and concentration of individual metallic nanoparticles using inductively coupled plasma-mass spectrometry (ICP-MS) in single-particle (sp) mode. Accurately determining the size of individual nanoparticles on a per-particle basis, both quickly and accurately, is an ever-increasing need within nanoparticle characterization. ICP-MS is capable of measuring a broad range of metallic nanoparticle sizes with high resolution, thus allowing the measurement of multiple particle populations for the quality assessment of nanoformulations. Additionally, spICP-MS can accurately determine particle concentrations without the need for concentration standards.

Nanoparticle Size Distribution and Stability Assessment Using Asymmetric-Flow Field-Flow Fractionation.

Nanomaterials are inherently polydisperse. Traditional techniques, such as the widely used batch-mode dynamic light-scattering (DLS) analysis, are not ideal nor thoroughly descriptive enough to define the full complexity of these materials. Asymmetric-flow field-flow fractionation (AF4) with various in-line detectors, such as ultraviolet-visible (UV-vis), multi-angle light scattering (MALS), refractive index (RI), and DLS, is an alternative technique that can provide flow-mode analysis of not only size distribution but also shape, drug release/stability, and protein binding.

Rapid color change in a group-hunting pelagic predator attacking schooling prey.

A major challenge for group-hunting predators is coordinating movement at high speed. Billfish - large predators with an elongated rostrum (bill) - include some of the fastest animals in the ocean and often form groups when hunting. This presents a challenge: how do fast-moving predators wielding dangerous weaponry reliably coordinate their attacks to avoid injury? We report a possible solution to this problem through rapid colour change in group-hunting striped marlin (Kajikia audax) as they hunt schools of Pacific sardines (Sardinops sagax). By analysing high-resolution drone footage of marlin attacks, we found that individual marlin intensified the contrast of their body stripes immediately prior to striking prey schools, before rapidly decreasing intensity after their attack. This suggests that color change may be a reliable signal of motivation to attack, potentially deterring conspecifics from attacking.

Adverse Safety Events in Emergency Medical Services Care of Children With Out-of-Hospital Cardiac Arrest.

Importance: Survival for children with out-of-hospital cardiac arrest (OHCA) remains poor despite improvements in adult OHCA survival. Objective: To characterize the frequency of and factors associated with adverse safety events (ASEs) in pediatric OHCA. Design, Setting, and Participants: This population-based retrospective cohort study examined patient care reports from 51 emergency medical services (EMS) agencies in California, Georgia, Oregon, Pennsylvania, Texas, and Wisconsin for children younger than 18 years with an OHCA in which resuscitation was attempted by EMS personnel between 2013 and 2019. Medical record review was conducted from January 2019 to April 2022 and data analysis from October 2022 to February 2023. Main Outcomes and Measure: Severe ASEs during the patient encounter (eg, failure to give an indicated medication, 10-fold medication overdose). Results: A total of 1019 encounters of EMS-treated pediatric OHCA were evaluated; 465 patients (46%) were younger than 12 months. At least 1 severe ASE occurred in 610 patients (60%), and 310 patients (30%) had 2 or more. Neonates had the highest frequency of ASEs. The most common severe ASEs involved epinephrine administration (332 [30%]), vascular access (212 [19%]), and ventilation (160 [14%]). In multivariable logistic regression, the only factor associated with severe ASEs was young age. Neonates with birth-related and non-birth-related OHCA had greater odds of a severe ASE compared with adolescents (birth-related: odds ratio [OR], 7.0; 95% CI, 3.1-16.1; non-birth-related: OR, 3.4; 95% CI, 1.2-9.6). Conclusions and Relevance: In this large geographically diverse cohort of children with EMS-treated OHCA, 60% of all patients experienced at least 1 severe ASE. The odds of a severe ASE were higher for neonates than adolescents and even higher when the cardiac arrest was birth related. Given the national increase in out-of-hospital births and ongoing poor outcomes of OHCA in young children, these findings represent an urgent call to action to improve care delivery and training for this population.

The blobulator: a webtool for identification and visual exploration of hydrophobic modularity in protein sequences.

Motivation: Clusters of hydrophobic residues are known to promote structured protein stability and drive protein aggregation. Recent work has shown that identifying contiguous hydrophobic residue clusters (termed "blobs") has proven useful in both intrinsically disordered protein (IDP) simulation and human genome studies. However, a graphical interface was unavailable. Results: Here, we present the blobulator: an interactive and intuitive web interface to detect intrinsic modularity in any protein sequence based on hydrophobicity. We demonstrate three use cases of the blobulator and show how identifying blobs with biologically relevant parameters provides useful information about a globular protein, two orthologous membrane proteins, and an IDP. Other potential applications are discussed, including: predicting protein segments with critical roles in tertiary interactions, providing a definition of local order and disorder with clear edges, and aiding in predicting protein features from sequence. Availability: The blobulator GUI can be found at www.blobulator.branniganlab.org, and the source code with pip installable command line tool can be found on GitHub at www.GitHub.com/BranniganLab/blobulator.

Integrative functional genomic analyses identify genetic variants influencing skin pigmentation in Africans.

Skin color is highly variable in Africans, yet little is known about the underlying molecular mechanism. Here we applied massively parallel reporter assays to screen 1,157 candidate variants influencing skin pigmentation in Africans and identified 165 single-nucleotide polymorphisms showing differential regulatory activities between alleles. We combine Hi-C, genome editing and melanin assays to identify regulatory elements for MFSD12, HMG20B, OCA2, MITF, LEF1, TRPS1, BLOC1S6 and CYB561A3 that impact melanin levels in vitro and modulate human skin color. We found that independent mutations in an OCA2 enhancer contribute to the evolution of human skin color diversity and detect signals of local adaptation at enhancers of MITF, LEF1 and TRPS1, which may contribute to the light skin color of Khoesan-speaking populations from Southern Africa. Additionally, we identified CYB561A3 as a novel pigmentation regulator that impacts genes involved in oxidative phosphorylation and melanogenesis. These results provide insights into the mechanisms underlying human skin color diversity and adaptive evolution.

The rostral micro-tooth morphology of blue marlin, Makaira nigricans.

Billfish rostra potentially have several functions; however, their role in feeding is unequivocal in some species. Recent work linked morphological variation in rostral micro-teeth to differences in feeding behavior in two billfish species, the striped marlin (Kajikia audax) and the sailfish (Istiophorus platypterus). Here, we present the rostral micro-tooth morphology for a third billfish species, the blue marlin (Makaira nigricans), for which the use of the rostrum in feeding behavior is still undocumented from systematic observations in the wild. We measured the micro-teeth on rostrum tips of blue marlin, striped marlin, and sailfish using a micro-computed tomography approach and compared the tooth morphology among the three species. This was done after an analysis of video-recorded hunting behavior of striped marlin and sailfish revealed that both species strike prey predominantly with the first third of the rostrum, which provided the justification to focus our analysis on the rostrum tips. In blue marlin, intact micro-teeth were longer compared to striped marlin but not to sailfish. Blue marlin had a higher fraction of broken teeth than both striped marlin and sailfish, and broken teeth were distributed more evenly on the rostrum. Micro-tooth regrowth was equally low in both marlin species but higher in sailfish. Based on the differences and similarities in the micro-tooth morphology between the billfish species, we discuss potential feeding-related rostrum use in blue marlin. We put forward the hypothesis that blue marlin might use their rostra in high-speed dashes as observed in striped marlin, rather than in the high-precision rostral strikes described for sailfish, possibly focusing on larger prey organisms.

Diverse African genomes reveal selection on ancient modern human introgressions in Neanderthals.

Comparisons of Neanderthal genomes to anatomically modern human (AMH) genomes show a history of Neanderthal-to-AMH introgression stemming from interbreeding after the migration of AMHs from Africa to Eurasia. All non-sub-Saharan African AMHs have genomic regions genetically similar to Neanderthals that descend from this introgression. Regions of the genome with Neanderthal similarities have also been identified in sub-Saharan African populations, but their origins have been unclear. To better understand how these regions are distributed across sub-Saharan Africa, the source of their origin, and what their distribution within the genome tells us about early AMH and Neanderthal evolution, we analyzed a dataset of high-coverage, whole-genome sequences from 180 individuals from 12 diverse sub-Saharan African populations. In sub-Saharan African populations with non-sub-Saharan African ancestry, as much as 1% of their genomes can be attributed to Neanderthal sequence introduced by recent migration, and subsequent admixture, of AMH populations originating from the Levant and North Africa. However, most Neanderthal homologous regions in sub-Saharan African populations originate from migration of AMH populations from Africa to Eurasia ∼250 kya, and subsequent admixture with Neanderthals, resulting in ∼6% AMH ancestry in Neanderthals. These results indicate that there have been multiple migration events of AMHs out of Africa and that Neanderthal and AMH gene flow has been bi-directional. Observing that genomic regions where AMHs show a depletion of Neanderthal introgression are also regions where Neanderthal genomes show a depletion of AMH introgression points to deleterious interactions between introgressed variants and background genomes in both groups-a hallmark of incipient speciation.

Interferons-Implications in the Immune Response to Respiratory Viruses.

Interferons (IFN) are an assemblage of signaling proteins made and released by various host cells in response to stimuli, including viruses. Respiratory syncytial virus (RSV), influenza virus, and SARS-CoV-2 are major causes of respiratory disease that induce or antagonize IFN responses depending on various factors. In this review, the role and function of type I, II, and III IFN responses to respiratory virus infections are considered. In addition, the role of the viral proteins in modifying anti-viral immunity is noted, as are the specific IFN responses that underly the correlates of immunity and protection from disease.

Emergency Department Pediatric Readiness and Disparities in Mortality Based on Race and Ethnicity.

Importance: Presentation to emergency departments (EDs) with high levels of pediatric readiness is associated with improved pediatric survival. However, it is unclear whether children of all races and ethnicities benefit equitably from increased levels of such readiness. Objective: To evaluate the association of ED pediatric readiness with in-hospital mortality among children of different races and ethnicities with traumatic injuries or acute medical emergencies. Design, Setting, and Participants: This cohort study of children requiring emergency care in 586 EDs across 11 states was conducted from January 1, 2012, through December 31, 2017. Eligible participants included children younger than 18 years who were hospitalized for an acute medical emergency or traumatic injury. Data analysis was conducted between November 2022 and April 2023. Exposure: Hospitalization for acute medical emergency or traumatic injury. Main Outcomes and Measures: The primary outcome was in-hospital mortality. ED pediatric readiness was measured through the weighted Pediatric Readiness Score (wPRS) from the 2013 National Pediatric Readiness Project assessment and categorized by quartile. Multivariable, hierarchical, mixed-effects logistic regression was used to evaluate the association of race and ethnicity with in-hospital mortality. Results: The cohort included 633 536 children (median [IQR] age 4 [0-12] years]). There were 557 537 children (98 504 Black [17.7%], 167 838 Hispanic [30.1%], 311 157 White [55.8%], and 147 876 children of other races or ethnicities [26.5%]) who were hospitalized for acute medical emergencies, of whom 5158 (0.9%) died; 75 999 children (12 727 Black [16.7%], 21 604 Hispanic [28.4%], 44 203 White [58.2%]; and 21 609 of other races and ethnicities [27.7%]) were hospitalized for traumatic injuries, of whom 1339 (1.8%) died. Adjusted mortality of Black children with acute medical emergencies was significantly greater than that of Hispanic children, White children, and of children of other races and ethnicities (odds ratio [OR], 1.69; 95% CI, 1.59-1.79) across all quartile levels of ED pediatric readiness; but there were no racial or ethnic disparities in mortality when comparing Black children with traumatic injuries with Hispanic children, White children, and children of other races and ethnicities with traumatic injuries (OR 1.01; 95% CI, 0.89-1.15). When compared with hospitals in the lowest quartile of ED pediatric readiness, children who were treated at hospitals in the highest quartile had significantly lower mortality in both the acute medical emergency cohort (OR 0.24; 95% CI, 0.16-0.36) and traumatic injury cohort (OR, 0.39; 95% CI, 0.25-0.61). The greatest survival advantage associated with high pediatric readiness was experienced for Black children in the acute medical emergency cohort. Conclusions and Relevance: In this study, racial and ethnic disparities in mortality existed among children treated for acute medical emergencies but not traumatic injuries. Increased ED pediatric readiness was associated with reduced disparities; it was estimated that increasing the ED pediatric readiness levels of hospitals in the 3 lowest quartiles would result in an estimated 3-fold reduction in disparity for pediatric mortality. However, increased pediatric readiness did not eliminate disparities, indicating that organizations and initiatives dedicated to increasing ED pediatric readiness should consider formal integration of health equity into efforts to improve pediatric emergency care.

Emergency department course of patients with asthma receiving initial emergency medical services care-Perspectives From the National Hospital Ambulatory Medical Care Survey.

Objective: Although 911 calls for acute shortness of breath are common, the role of emergency medical services (EMS) in acute asthma care is unclear. We sought to characterize the demographics, course, and outcomes of adult emergency department (ED) patients with asthma in the United States receiving initial EMS care. Methods: We analyzed data from the 2016-2019 National Hospital Ambulatory Medical Care Survey (NHAMCS). We included patients aged ≥18 years with an ED visit diagnosis of asthma, stratifying the cases according to initial EMS care. Accounting for the survey design of NHAMCS, we generated nationalized estimates of the number of EMS and non-EMS asthma visits. Using logistic regression, we determined the associations between initial EMS care and patient demographics (age, sex, race, and insurance type), ED course (initial vital signs, triage category, testing, medications), and outcomes (hospital admission, ED length of stay). Results: Of 435 million adult ED visits during 2016-2019, there were ≈5.3 million related to asthma (1.3 million annually, 1.2%; 95% confidence interval [CI], 1.1%-1.4%). A total of 602,569 (150,642 annually, 11.3%; 95% CI, 8.6%-14.8%) ED patients with asthma received initial EMS care. Compared with non-EMS asthma patients, EMS asthma patients were more likely to present with an "urgent" ED triage category (odds ratio [OR], 22.2; 95% CI, 6.6-74.9) and to undergo laboratory (OR, 2.78; 95% CI, 1.41-5.46) or imaging tests (OR, 2.42; 95% CI, 1.21-4.83). ED patients with asthma receiving initial EMS care were almost 3 times more likely to be admitted to the hospital (OR, 2.81; 95% CI, 1.27-6.25). There were no differences in demographics, ED use of ß-agonists or corticosteroids, or ED length of stay between EMS and non-EMS asthma patients. Conclusions: Approximately 1 in 10 adult ED patients with asthma receive initial care by EMS. EMS asthma patients present to the ED with higher acuity, undergo more diagnostic testing in the ED, and are more likely to be admitted. Although limited in information regarding the prehospital course, these findings highlight the more severe illness of asthma patients transported by EMS and underscore the importance of EMS in emergency asthma care.

Association of Transport Time, Proximity, and Emergency Department Pediatric Readiness With Pediatric Survival at US Trauma Centers.

Importance: Emergency department (ED) pediatric readiness is associated with improved survival among children. However, the association between geographic access to high-readiness EDs in US trauma centers and mortality is unclear. Objective: To evaluate the association between the proximity of injury location to receiving trauma centers, including the level of ED pediatric readiness, and mortality among injured children. Design, Setting, and Participants: This retrospective cohort study used a standardized risk-adjustment model to evaluate the association between trauma center proximity, ED pediatric readiness, and in-hospital survival. There were 765 trauma centers (level I-V, adult and pediatric) that contributed data to the National Trauma Data Bank (January 1, 2012, through December 31, 2017) and completed the 2013 National Pediatric Readiness Assessment (conducted from January 1 through August 31, 2013). The study comprised children aged younger than 18 years who were transported by ground to the included trauma centers. Data analysis was performed between January 1 and March 31, 2022. Exposures: Trauma center proximity within 30 minutes by ground transport and ED pediatric readiness, as measured by weighted pediatric readiness score (wPRS; range, 0-100; quartiles 1 [low readiness] to 4 [high readiness]). Main Outcomes and Measures: In-hospital mortality. We used a patient-level mixed-effects logistic regression model to evaluate the association of transport time, proximity, and ED pediatric readiness on mortality. Results: This study included 212 689 injured children seen at 765 trauma centers. The median patient age was 10 (IQR, 4-15) years, 136 538 (64.2%) were male, and 127 885 (60.1%) were White. A total of 4156 children (2.0%) died during their hospital stay. The median wPRS at these hospitals was 79.1 (IQR, 62.9-92.7). A total of 105 871 children (49.8%) were transported to trauma centers with high-readiness EDs (wPRS quartile 4) and another 36 330 children (33.7%) were injured within 30 minutes of a quartile 4 ED. After adjustment for confounders, proximity, and transport time, high ED pediatric readiness was associated with lower mortality (highest-readiness vs lowest-readiness EDs by wPRS quartiles: adjusted odds ratio, 0.65 [95% CI, 0.47-0.89]). The survival benefit of high-readiness EDs persisted for transport times up to 45 minutes. The findings suggest that matching children to trauma centers with high-readiness EDs within 30 minutes of the injury location may have potentially saved 468 lives (95% CI, 460-476 lives), but increasing all trauma centers to high ED pediatric readiness may have potentially saved 1655 lives (95% CI, 1647-1664 lives). Conclusions and Relevance: These findings suggest that trauma centers with high ED pediatric readiness had lower mortality after considering transport time and proximity. Improving ED pediatric readiness among all trauma centers, rather than selective transport to trauma centers with high ED readiness, had the largest association with pediatric survival. Thus, increased pediatric readiness at all US trauma centers may substantially improve patient outcomes after trauma.

Identifying high cognitive load activities during simulated pediatric cardiac arrest using functional near-infrared spectroscopy.

Aim: To identify specific activities associated with high cognitive load during simulated pediatric out-of-hospital cardiac arrest (POHCA) resuscitation using physiological monitoring with functional near-infrared spectroscopy (fNIRS). Methods: We recruited teams of emergency medical services (EMS) responders from fire departments located throughout the Portland, OR metropolitan area to participate in POHCA simulations. Teams consisted of both paramedics and emergency medical technicians (EMTs), with one paramedic serving as the person in charge (PIC). The PIC was outfitted with the OctaMon to collect fNIRS signals from the prefrontal cortex. Signals reported changes in oxygenated and deoxygenated hemoglobin concentrations, which were used to determine moments of increased cognitive activity. Increased cognitive activity was determined by significant increases in oxygenated hemoglobin and decreases in deoxygenated hemoglobin. Significant changes in fNIRS signals were associated with specific concurrent clinical tasks recorded by two independent researchers using video review. Results: We recorded cognitive activity of EMS providers in 18 POHCA simulations. We found that a proportion of PIC's experienced relatively high cognitive load during medication administration, defibrillation, and rhythm checks compared to other events. Conclusion: EMS providers commonly experienced increased cognitive activity during key resuscitation tasks that were related to safely coordinating team members around calculating and administering medications, defibrillation, and rhythm and pulse checks. Understanding more about activities that require high cognitive demand can inform future interventions that reduce cognitive load.

Evaluation of electronic measurement of capillary refill for Sepsis screening at ED triage.

OBJECTIVE: To evaluate the association between capillary refill time (CRT) measured by a medical device and sepsis among patients presenting to the Emergency Department (ED). METHODS: This prospective observational study enrolled adult and pediatric patients during ED triage when sepsis was considered a potential diagnosis by the triage nurse. Patients were enrolled at an academic medical center between December 2020 and June 2022. CRT was measured by a research assistant using an investigational medical device. The outcomes included sepsis and septic shock defined using sep-3 criteria, septic shock defined as IV antibiotics and a vasopressor requirement, ICU admission, and hospital mortality. Other measures included patient demographics and vital signs at ED triage. We evaluated univariate associations between CRT and sepsis outcomes. RESULTS: We enrolled 563 patients in the study, 48 met Sep-3 criteria, 5 met Sep-3 shock criteria, and 11 met prior septic shock criteria (IV antibiotics and vasopressors to maintain mean arterial pressure of 65). Sixteen patients were admitted to the ICU. The mean age was 49.1 years, and 51% of the cohort was female. The device measured CRT was significantly associated with the diagnosis of sepsis by sep-3 criteria (OR 1.23, 95% CI 1.06-1-43), septic shock by sep-3 criteria (OR 1.57, 95% CI 1.02-2.40), and septic shock defined as receipt of IV antibiotics and a vasopressor requirement (OR 1.37, 95% CI 1.03-1.82). Patients with CRT >3.5 s measured by the DCR device had an odds ratio of 4.67 (95%CI 1.31-16.1) of septic shock (prior definition), and an odds ratio of 3.97 (95% CI 1.99-7.92) of ICU admission, supporting the potential for the 3.5-s cutoff of the DCR measurement. CONCLUSIONS: CRT measured by a medical device at ED triage was associated with the diagnosis of sepsis. Objective CRT measurement using a medical device may be a relatively simple way to improve sepsis diagnosis during ED triage.

Comparison of Resuscitation Quality in Simulated Pediatric and Adult Out-of-Hospital Cardiac Arrest.

Importance: Mortality from pediatric out-of-hospital cardiac arrest (OHCA) is high and has not improved in decades, unlike adult mortality. The low frequency of pediatric OHCA and weight-based medication and equipment needs may lead to lower quality of pediatric resuscitation compared with adults. Objective: To compare the quality of pediatric and adult resuscitation from OHCA in a controlled simulation environment and to evaluate whether teamwork, knowledge, experience, and cognitive load are associated with resuscitation performance. Design, Setting, and Participants: This cross-sectional in-situ simulation study was conducted between September 2020 and August 2021 in the metropolitan area of Portland, Oregon, and included engine companies from fire-based emergency services (EMS) agencies. Exposures: Participating EMS crews completed 4 simulation scenarios presented in random order: (1) adult female with ventricular fibrillation; (2) adult female with pulseless electrical activity; (3) school-aged child with ventricular fibrillation; and (4) infant with pulseless electrical activity. All patients were pulseless on EMS arrival. Data were captured by the research team in real time during the scenarios. Main outcomes and measures: The primary outcome was defect-free care, which included correct cardiopulmonary resuscitation depth, rate, and compression to ventilation ratio, time to bag-mask ventilation, and time to defibrillation, if applicable. Outcomes were determined by direct observation by an experienced physician. Secondary outcomes included additional time-based interventions and the use of correct medication doses and equipment size. We measured teamwork using the clinical teamwork scale, cognitive load with the National Aeronautics and Space Administration task load index (NASA-TLX), and knowledge using advanced life support resuscitation tests. Results: Among the 215 clinicians (39 crews) who participated in 156 simulations, 200 (93%) were male, and the mean (SD) age was 38.7 (0.6) years. No pediatric shockable scenario was defect free and only 5 pediatric nonshockable scenarios (12.8%) were defect free, while 11 (28.2%) adult shockable scenarios and 27 adult nonshockable scenarios (69.2%) were defect free. The mental demand subscale of the NASA-TLX was higher in the pediatric compared with the adult scenarios (mean [SD] pediatric score, 59.1 [20.7]; mean [SD] adult score, 51.4 [21.1]; P = .01). Teamwork scores were not associated with defect-free care. Conclusions and Relevance: In this simulation study of OHCA, resuscitation quality was significantly lower for pediatric than adult resuscitation. Mental demand may have been a contributor.

Mechanisms of group-hunting in vertebrates.

Group-hunting is ubiquitous across animal taxa and has received considerable attention in the context of its functions. By contrast much less is known about the mechanisms by which grouping predators hunt their prey. This is primarily due to a lack of experimental manipulation alongside logistical difficulties quantifying the behaviour of multiple predators at high spatiotemporal resolution as they search, select, and capture wild prey. However, the use of new remote-sensing technologies and a broadening of the focal taxa beyond apex predators provides researchers with a great opportunity to discern accurately how multiple predators hunt together and not just whether doing so provides hunters with a per capita benefit. We incorporate many ideas from collective behaviour and locomotion throughout this review to make testable predictions for future researchers and pay particular attention to the role that computer simulation can play in a feedback loop with empirical data collection. Our review of the literature showed that the breadth of predator:prey size ratios among the taxa that can be considered to hunt as a group is very large (<100 to >102 ). We therefore synthesised the literature with respect to these predator:prey ratios and found that they promoted different hunting mechanisms. Additionally, these different hunting mechanisms are also related to particular stages of the hunt (search, selection, capture) and thus we structure our review in accordance with these two factors (stage of the hunt and predator:prey size ratio). We identify several novel group-hunting mechanisms which are largely untested, particularly under field conditions, and we also highlight a range of potential study organisms that are amenable to experimental testing of these mechanisms in connection with tracking technology. We believe that a combination of new hypotheses, study systems and methodological approaches should help push the field of group-hunting in new directions.