A Multi-center Simulation-Based Emergency Medicine Resident Boot Camp Can Improve Teamwork, Communication, and Clinical Skills.

Boot camps are designed to deliver highly specific education in a short amount of time. Educational boot camps are known to improve confidence in clinical capabilities and medical knowledge and promote teamwork skills. We created an emergency medicine (EM) boot camp with targeted learning objectives based on expected mastery of post-graduate year (PGY)-level educational objectives based on the Accreditation Council for Graduate Medical Education (ACGME) EM milestones. This boot camp included a qualitative assessment, survey-based feedback, and quantitative assessment, which included the team's performance utilizing a validated code team checklist (Cardiac Code Management Assessment Tool). After attending the conference, EM residents felt more confident in achieving the EM ACGME milestones including the ability to provide immediate interventions to a critical patient, effective use of team communication, the ability to switch tasks efficiently, and to provide real-time feedback to their team. Eighty-six percent of residents preferred this teaching modality over other conference-based didactics and would like to see greater incorporation of similar interventions in future conferences.

Sim-Based Home Tracheostomy Care: A Mixed Methods Study on Outcomes and Parental Preparedness.

OBJECTIVES: To assess effects of a Simulation-Based Discharge Education Program (SDP) on long-term caregiver-reported satisfaction and to compare clinical outcomes for children with new tracheostomies whose caregivers completed SDP versus controls. METHODS: The study employed a mixed methods approach: (1) a qualitative analysis of feedback from caregivers who previously completed SDP, and (2) a quantitative retrospective case-control study comparing outcomes between children with new tracheostomies whose caregivers completed SDP versus controls, matched on discharge disposition and age. The primary outcome was emergency department visits for tracheostomy-related issues within 1 year of discharge. RESULTS: Feedback from 18 interviews was coded into 5 themes: knowledge acquisition, active learning, comfort and preparedness, home application of skills, and overall assessment. Caregivers of 27 children (median age 26 months [interquartile range (IQR) 5.5 months-11 years]) underwent SDP training. Clinical outcomes of these children were compared with 27 matched children in the non-SDP group (median age 16 months [IQR 3.5 months-10 years]). There was no significant difference in ED visits for tracheostomy-related complications within 1 year of discharge between the SDP group and non-SDP group (2 [IQR 0-2] vs 1 [IQR 0-2], P = .2). CONCLUSIONS: Caregivers reported overwhelmingly positive experiences with SDP that persisted even 4 years after training. Caregiver participation in SDP did not yield a significant difference in ED visits within 1 year of discharge for tracheostomy-related complications compared with control counterparts. Future steps will identify more effective methods for comparing and analyzing clinical outcomes to further validate impacts of simulation-based programs.

Delivering bad or difficult news. An innovative simulation-based education approach to prepare interdisciplinary fellowships.

BACKGROUND: There is limited data on the effectiveness of training interventions to improve the delivery of bad news. METHODS: This preliminary research included pre-post assessments and an open-ended survey to evaluate the effectiveness and perceived value of training on delivering bad news for 26 first- and second-year fellows from five adult and pediatric fellowship programs. RESULTS: There was a significant increase in faculty assessment scores (34.5 vs. 41.0, respectively, Z = -3.661, p < 0.001) and Standardized Patient (SP) assessment scores (37.5 vs .44.5, respectively, Z = -2.244, p = 0.025). Fellows valued having a standard framework to aid in the delivery of bad news; receiving targeted feedback and having the opportunity to apply their skills in a subsequent case. CONCLUSIONS: A one-hour, four-phase lesson plan that includes an individualized training approach and simulation do-overs can be effective and valuable for preparing fellows to deliver bad news.

Child Death in a Resource-Limited Setting: A Simulation Case for Pediatric Residents to Prepare for Global Health Electives.

Introduction: Pediatric residents are increasingly pursuing global health electives. Differences in cultural norms and management around pediatric deaths in resource-limited settings can be emotionally overwhelming for residents. Educational resources are needed to better equip them for handling these stressful situations. We developed a predeparture simulation child death case to prepare pediatric residents for their global health elective. Methods: The simulation module included a clinical case followed by a multidisciplinary structured debriefing. The case featured a 5-year-old, malnourished child in hypovolemic shock who clinically deteriorates and dies. After obtaining a history and performing a physical examination, residents were expected to diagnose severe malnutrition, treat hypovolemic shock, and decide how far to extend resuscitation with the limited resources. Upon returning from abroad, residents were invited to complete a survey on the utility of the simulation case module in preparing for their elective. Results: Twenty-nine residents participated in the simulation case module, and 18 completed the survey. Seventeen agreed or strongly agreed that the simulation module was a useful tool for preparation (Mdn = 4.5 on a 5-point Likert scale). Residents reflected that the simulation module helped manage expectations and provided them with an understanding of the cross-cultural differences in managing pediatric deaths in a resource-limited setting. Discussion: Pediatric residents trained in resource-rich countries do not encounter death often. Postgraduate training programs could consider simulations like this one to prepare such residents for cross-cultural differences in managing pediatric deaths and build resiliency to operate in resource-limited settings.

Effectiveness of a Simulation Curriculum on Clinical Application: A Randomized Educational Trial.

INTRODUCTION: The use of simulation to develop clinical reasoning and medical decision-making skills for common events is poorly established. Validated head trauma rules help identify children at low risk for clinically important traumatic brain injury and guide the need for neuroimaging. We predicted that interns trained using a high-fidelity, immersive simulation would understand and apply these rules better than those trained using a case-based discussion. Our primary outcomes were to determine the effectiveness of a single targeted intervention on an intern's ability to learn and apply the rules. METHODS: This was a prospective randomized controlled trial. Interns were randomized to participate in either a manikin-based simulation or a case discussion. Knowledge and application of the Pediatric Emergency Care Applied Research Network Head Trauma tool were assessed both under testing conditions using standardized vignettes and in clinical encounters. In both settings, interns completed a validated assessment tool to test their knowledge and application of the Pediatric Emergency Care Applied Research Network Head Trauma tool when assessing patients with head injury. RESULTS: Under testing conditions, both being in the simulation group and shorter time from training were independently associated with higher score under testing conditions using standardized vignettes (P = 0.038 and P < 0.001), but not with clinical encounters. CONCLUSIONS: Interns exposed to manikin-based simulation training demonstrated performance competencies that are better than those in the case discussion group under testing conditions using standardized vignettes, but not in real clinical encounters. This study suggests that information delivery and comprehension may be improved through a single targeted simulation-based education.

Low Concordance Between Pediatric Emergency Attendings and Pediatric Residents for Predictors of Serious Intracranial Injury.

OBJECTIVES: Minor head trauma is a common cause of pediatric emergency room visits. The Pediatric Emergency Care Applied Research Network head trauma clinical decision rules (PECARN-CDR) are designed to assist clinicians in determining which patients require imaging. However, only minimal data are available on the accuracy of residents' assessments using PECARN-CDR. Prior research suggests that trainees often come to erroneous conclusions about pediatric head trauma. The objective of the present study was to assess concordance between pediatric residents' and attending physicians' assessments of children with low-risk head trauma, with the ultimate goal of improving education in pediatric trauma assessment. METHODS: This is a retrospective cohort study analyzing concordance between pediatric residents and pediatric emergency attendings who provided PECARN-CDR-based evaluations of low-risk head injuries. It is a planned subanalysis based on a prospectively collected, multicenter data set tracking pediatric head trauma encounters from July 2014 to June 2019. RESULTS: Data were collected from 436 pediatric residents, who encountered 878 patients. In the case of patients younger than 2 years, low concordance between residents and attendings was observed for the following elements of the PECARN-CDR: severe mechanism (κ = 0.24), palpable skull fracture (κ = 0.23), Glasgow Coma Scale (GCS) score less than 15 (κ = 0.14), and altered mental status (AMS; κ = -0.03). There was moderate to high agreement between residents and attendings for loss of consciousness (κ = 0.71), nonfrontal hematoma (κ = 0.48), and not acting normally per parent (κ = 0.35). In the case of patients older than 2 years, there was low concordance for signs of basilar skull fracture (κ = 0.28) and GCS score less than 15 (κ = 0.10). Concordance was high to moderate for history of vomiting (κ = 0.88), loss of consciousness (κ = 0.67), severe headache (κ = 0.50), severe mechanism (κ = 0.44), and AMS (κ = 0.42). Residents were more conservative, that is, more likely to report a positive finding, in nearly all components of the PECARN-CDR. CONCLUSIONS: Resident assessment of children presenting to the ED with minor head trauma is often poorly concordant with attending assessment on the major predictors of clinically important traumatic brain injury (abnormal GCS, AMS, signs of skull fracture) based on the PECARN-CDR. Future work may explore the reasons for low concordance and seek ways to improve pediatric resident education in the diagnosis and management of trauma.

RISC II is superior to TRISS in predicting 30-day mortality in blunt major trauma patients in Hong Kong.

PURPOSE: Hong Kong (HK) trauma registries have been using the Trauma and Injury Severity Score (TRISS) for audit and benchmarking since their introduction in 2000. We compare the mortality prediction model using TRISS and Revised Injury Severity Classification, version II (RISC II) for trauma centre patients in HK. METHODS: This was a retrospective cohort study with all five trauma centres in HK. Adult trauma patients with Injury Severity Score (ISS) > 15 suffering from blunt injuries from January 2013 to December 2015 were included. TRISS models using the US and local coefficients were compared with the RISC II model. The primary outcome was 30-day mortality and the area under the receiver operating characteristic curve (AUC) for tested models. RESULTS: 1840 patients were included, of whom 1236/1840 (67%) were male. Median age was 59 years and median ISS was 25. Low falls were the most common mechanism of injury. The 30-day mortality was 23%. RISC II yielded a superior AUC of 0.896, compared with the TRISS models (MTOS: 0.848; PATOS: 0.839; HK: 0.858). Prespecified subgroup analyses showed that all the models performed worse for age ≥ 70, ASA ≥ III, and low falls. RISC II had a higher AUC compared with the TRISS models in all subgroups, although not statistically significant. CONCLUSION: RISC II was superior to TRISS in predicting the 30-day mortality for Hong Kong adult blunt major trauma patients. RISC II may be useful when performing future audit or benchmarking exercises for trauma in Hong Kong.

The Acceptability of Avatar Patients for Teaching and Assessing Pediatric Residents in Communicating Medical Ambiguity.

Background: Simulation offers a means to assess resident competence in communication, but pediatric standardized patient simulation has limitations. A novel educational technology, avatar patients (APs), holds promise, but its acceptability to residents, educational relevance, and perception of realism have not been determined. Objective: To determine if APs are acceptable, provide a relevant educational experience, and are realistic for teaching and assessment of a complex communication topic. Methods: Pediatric residents at one academic institution participated in an AP experience from 2019 to 2021 consisting of 2 scenarios representing issues of medical ambiguity. After the experience, residents completed a survey on the emotional relevance, realism, and acceptability of the technology for assessment of their communication competence. Results: AP actor training required approximately 3 hours. Software and training was provided free of charge. Actors were paid $30/hour; the total estimated curricular cost is $50,000. Sixty-five of 89 (73%) pediatric residents participated in the AP experience; 61 (93.8%) completed the survey. Forty-eight (78.7%) were emotionally invested in the scenarios. The most cited emotions evoked were anxiety, uncertainty, concern, and empathy. The conversations were rated by 49 (80.3%) as realistic. APs were rated as beneficial for learning to communicate about medical ambiguity by 40 (65.5%), and 41 (66.7%) felt comfortable having APs used to assess their competence in this area. Conclusions: Pediatric residents were emotionally invested in the AP experience and found it to be realistic. The experience was rated as beneficial for learning and acceptable to be used for assessment of how to communicate medical ambiguity.

Simulation-Based Discharge Education Program for Caregivers of Children With Tracheostomies.

OBJECTIVES: To design, implement, and evaluate a simulation-based education (SBE) program for caregivers of children with tracheostomy. METHODS: Self-reported comfort and confidence in knowledge as well as tracheostomy care skills were assessed before and after a single SBE session for 24 consecutively enrolled caregivers of children with tracheostomies aged <21 years who were hospitalized at an academic medical center from August 2018 to September 2019 by using a survey and checklist, respectively. Mean individual and aggregated scores were compared by using a paired samples t-test, and association between instruments was determined with Spearman correlation. RESULTS: Post-SBE, there was a significant improvement in both self-reported comfort and confidence (P < .001) and checklist assessment of most tracheostomy care skills (P < .001). There were no significant correlations between caregivers' self-reported comfort and confidence and skills pre-SBE (ρ = 0.13) or post-SBE (ρ = 0.14). Cronbach's α coefficients for the survey ranged from 0.93 to 0.95 and for the checklist from 0.58 to 0.67. Seventeen percent of caregivers competently completed the entire checklist post-SBE, with most caregivers missing 1 or 2 critical skills such as obturator removal after tracheostomy insertion. CONCLUSIONS: In this pilot study, we demonstrated successful design and implementation of an SBE program for caregivers of children with tracheostomies, revealing improvements in self-reported comfort and confidence as well as in their performance of tracheostomy care skills. Further optimization is needed, and caregivers may benefit from additional SBE sessions to achieve complete skills competency. Future research on the long-term impact of SBE and the peer-to-peer support element of the program is needed.

Pediatric Emergency Medicine Didactics and Simulation (PEMDAS): Pediatric Diabetic Ketoacidosis.

Introduction: Diabetic ketoacidosis (DKA) is a life-threatening illness which classically presents with polyuria, polydipsia, and polyphagia that can rapidly progress to severe dehydration and altered mental status from cerebral edema. Younger patients may present with subtle or atypical symptoms that are critical to recognize and emergently act upon. Such patients are often cared for by teams in the emergency department (ED) requiring multidisciplinary collaboration. Methods: This simulation case was designed for pediatric emergency medicine fellows and residents. The case was a 14-month-old male who presented to the ED with respiratory distress and dehydration. The team was required to perform an assessment, manage airway, breathing and circulation, and recognize and initiate treatment for DKA including judicious fluid administration and an insulin infusion. The patient developed altered mental status with signs of cerebral edema requiring the initiation of cerebral protection strategies. We created a debriefing guide and a participant evaluation form. Results: Forty-two participants completed this simulation across seven institutions including attendings, residents, fellows, and nurses. The scenario was rated by participants on a 5-point Likert scale and was generally well received (M = 5.0). Participants rated the simulation case as effective in teaching how to recognize (M = 4.8) and manage (M = 4.5) DKA with cerebral edema in a pediatric patient. Discussion: This simulation represents a resource for learners in the pediatric ED in the recognition and management of a toddler with DKA and can be adapted to learners at all levels and tailored to various learning environments.

A prospective randomised simulation trial comparing our novel AIR-BOX to standard airway equipment storage modalities.

Background: There is little evidence guiding equipment handling during emergency endotracheal intubations (EEI). Available evidence and current practice are either outdated, anecdotal or focused on difficult-not emergency-intubation. In this study, we describe and evaluate our equipment handling unit: the AIR-BOX. Methods: This is a proof-of-concept, prospective, randomised simulation trial. A convenience sample of 50 airway course participants voluntarily underwent randomisation: 21 to the AIR-BOX group, 14 to the intubation box group, and 15 to the crash cart group. The volunteers were asked to intubate a manikin using the equipment from the storage unit of their randomisation. Outcome measures included time-to-readiness, time-to-intubation, first-pass success, and subjective operator experience. Results: The mean time-to-readiness was 67.2 s with the AIR-BOX, 84.6 s with the intubation box, and 115 s with the crash cart. The mean time-to-intubation was 105 s with the AIR-BOX, 127 s with the intubation box and 167 s with the crash cart. A statistically significant difference was achieved between the AIR-BOX and the crash cart. No statistically significant difference was found between the three groups with regard to first-pass success or the time between intubation readiness and intubation. Conclusions: This study supports the AIR-BOX as a viable tool that can improve and simplify access to emergency intubating equipment. It also opens doors for multiple future innovations that can positively impact equipment handling practices. Future studies can focus on assessing whether applying the AIR-BOX will yield a clinically significant impact on patient outcomes.

A new FRET-based platform to track substrate ubiquitination by fluorescence.

Post-translational modification of protein by ubiquitin (Ub) alters the stability, subcellular location, or function of the target protein, thereby impacting numerous biological processes and directly contributing to myriad cellular defects or disease states, such as cancer. Tracking substrate ubiquitination by fluorescence provides opportunities for advanced reaction dynamics studies and for translational research including drug discovery. However, fluorescence-based techniques in ubiquitination studies remain underexplored at least partly because of challenges associated with Ub chain complexity and requirement for additional substrate modification. Here we describe a general strategy, FRET diubiquitination, to track substrate ubiquitination by fluorescence. This platform produces a uniform di-Ub product depending on specific interactions between a substrate and its cognate E3 Ub ligase. The diubiquitination creates proximity between the Ub-linked donor and acceptor fluorophores, respectively, enabling energy transfer to yield a distinct fluorescent signal. FRET diubiquitination relies on Ub-substrate fusion, which can be implemented using either one of the two validated strategies. Method 1 is the use of recombinant substrate-Ub fusion, applicable to all substrate peptides that can bind to E3. Method 2 is a chemoenzymatic ligation approach that employs synthetic chemistry to fuse Ub with a substrate peptide containing desired modification. Taken together, our new FRET-based diubiquitination system provides a timely technology of potential to advance both basic research and translation sciences.

Major trauma care in Hong Kong and Germany: a trauma registry data benchmark study.

BACKGROUND: Trauma remains a leading cause of death and effective trauma management within a well-developed trauma system has been shown to reduce morbidity and mortality. A trauma registry, as an integral part of a mature trauma system, can be used to monitor the quality of trauma care and to provide a means to compare local versus international standards. Hong Kong and Germany both have highly developed health care services. We compared the performance of trauma systems including outcomes among major trauma victims (ISS > 15) over a 3-year period (2013-2015) in both settings using trauma registry data. METHODS: This study was a retrospective analysis of prospectively collected data from trauma registries in Hong Kong and Germany. Data from 01/2013 to 12/2015 were extracted from the trauma registries of the five trauma centers in Hong Kong and the TraumaRegister DGU® (TR-DGU). The study cohort included adults (≥ 18 years) with major trauma (ISS > 15). Data related to patient characteristics, nature of the injury, prognostic parameters to calculate the RISC II score, outcomes and clinical management were collected and compared. RESULTS: Datasets from 1,864 Hong Kong and 10,952 German trauma victims were retrieved from respective trauma registries. The unadjusted mortality in Hong Kong (22.4%) was higher compared to Germany (19.2%); the difference between observed and expected mortality was higher in Hong Kong (+ 2.7%) than in Germany (- 0.5%). The standardized mortality ratio (SMR) in Hong Kong and Germany were 1.138 (95% CI 1.033-1.252) and 0.974 (95% CI 0.933-1.016), respectively, and the adjusted death rate in Hong Kong was significantly higher compared to the calculated RISC II data. However, patients in Hong Kong were significantly older, had more pre-trauma co-morbidities, more head injuries, shorter hospital and ICU stays and lower ICU admission rates. CONCLUSION: Hong Kong had a higher mortality rate and a statistically significantly higher standardized mortality ratio (SMR) after RISC II adjustment. However, multiple differences existed between trauma systems and patient characteristics.

Debunking the myth that the majority of medical errors are attributed to communication.

CONTEXT: Many articles, book chapters and presentations begin with a declaration that the majority of medical errors are attributed to communication. However, this statement may not be supported by the research reported in the literature. OBJECTIVES: The purpose of this systematic review is to identify where errors are reported in the research literature. METHODS: A systematised review was conducted of research articles over the last 20 years (1998-2018) indexed in PubMed/MEDLINE and the Cumulative Index to Nursing and Allied Health (CINAHL) using term combinations: medical errors, research and communication. Inclusion was based on reported generalised primary research of medical error and the reported causes. RESULTS: This systematised review resulted in 2881 research articles, which produced 42 that met the inclusion criteria. Although there was some overlap, three categories of errors were dominant in this research: errors of commission (20 articles; 47.6%), errors of omission (six articles; 14.2%) and errors through communication (four articles; 9.5%). There were 12 (28.5%) articles in which all three categories together significantly contributed to error. Of these 12 articles, errors of commission or omission were dominant in nine articles (21.4%) and errors of communication were prevalent in only three articles (7%). CONCLUSIONS: The assertion that the majority of medical errors can be attributed to miscommunication is not supported by this systematic review. Overwhelmingly, most reported errors are attributed to errors of omission or commission. Intentionally or unintentionally providing misinformation may mislead patient safety initiatives, and research and funding agency priorities.

A TeamSTEPPS® implementation plan for recently assigned interns and nurses.

Interns and newly assigned nurses are expected to assimilate rapidly and begin functioning as members of interprofessional teams. This mixed-method pilot research assessed the impact of a Team Strategies and Tools to Enhance Performance and Patient Safety (TeamSTEPPS®) implementation plan in an urban academic teaching hospital that included a cohort of newly assigned pediatric interns and nurses (N = 23). We collected pre- and post-intervention course knowledge and team performance data from two teams in two separate simulation cases. We also surveyed the learners using an open-ended survey to ask about the value of their interprofessional learning experience. TeamSTEPPS® course knowledge improved from pre- to post-intervention (p < 0.001). Team performance scores were tallied and descriptively compared between pre- and post-intervention. Teams performed higher in both post-intervention simulation cases than in the pre-assessments. Post-intervention groups were assessed scores of 4 and 5 in more areas of the team performance checklist. Knowledge scores were compared between pre- and post- intervention by a Wilcoxon rank-sum test. Median scores improved from 17 to 20 following the intervention. Six themes emerged from the coding process that expressed a learned appreciation for contributing to a culture where the expectation is that team members speak up to support patient safety and other team members. As shown by this pilot research, TeamSTEPPS® training approaches that follow the 4-phase brain-based lesson plan for simulation and include interprofessional membership can be promising for integrating newly assigned members into existing clinical teams.

Gibson's theory of affordances and situational awareness occurring in urban departments of pediatrics, medicine, and emergency medicine.

Background: The Team Strategies and Tools to Enhance Performance and Patient Safety (TeamSTEPPS®) program provides a situation-monitoring tool that allows health-care professionals to perform an environmental scan. This process includes scanning the status of the patient, team members, and the environment, to ensure that patient care is progressing toward the goal. It is assumed that health-care professionals will act in a certain way by providing feedback and support based on the scan. However, there is limited research supporting the impact of the clinical environment on behavior among health-care professionals. Methods: This qualitative research used in situ simulation and a theoretical sampling of six day and overnight shift clinical teams (n = 34) from three departments in an urban hospital in New York City: pediatric medicine, emergency medicine, and internal medicine. Notebook entries by the participants at three intervals during the case and a debriefing following the cases captured participant views, observations, and concerns about the immediate clinical environment. Results: In all six cases, and with every shift, there were documented examples of someone in the environment who saw something but did not speak up, possibly making a difference in regard to patient safety and the outcomes in the case. Some of the noted reasons include not wanting to be wrong, not wanting to hurt someone's feelings, or not being sure. Discussion: Our research explored the environmental scan that health-care team members conducted in three unique department settings, including how they perceived affordances, and the reasons why individuals may not speak up when another team member is not performing properly. Each person possesses a unique awareness and deficit of available affordances because of his/her position in the environment. Patient safety is somewhat reliant on the views and observations of each team member. Educators should use these outcomes to justify teamwork and communication training that includes targeted emphasis on providing candid feedback, situation monitoring, and mutual support.

A Saturated Approach to the Four-Phase, Brain-Based Simulation Framework for TeamSTEPPS® in a Pediatric Medicine Unit.

INTRODUCTION: Although many organizations have reported successful outcomes as a result of Team Strategies and Tools to Enhance Performance and Patient Safety (TeamSTEPPS), implementation can be challenging, with its share of administrative obstacles and lack of research that shows observable change in practice. METHODS: This quantitative, pretest/posttest design pilot research used a combination of classroom simulation-based instruction and in situ simulation in a Pediatrics department in an urban academic center. All personnel with direct patient care responsibilities (n = 547) were trained in TeamSTEPPS in an 8-week period. TeamSTEPPS course knowledge scores were compared pretraining to posttraining using the Wilcoxon rank-sum test. The performance of two-day and overnight shift teams, pre- and postintervention was assessed using the TeamSTEPPS Team Performance Observation Tool. RESULTS: TeamSTEPPS course knowledge improved from the beginning of the course to completion with median scores of 16 and 19, respectively (P < 0.001). Both day and evening postintervention groups demonstrated greater team performance scores than their control counterparts. Specifically, postintervention day shift team showed the greatest improvement and demonstrated more TeamSTEPPS behaviors. CONCLUSION: This pilot study involving 1 department in an urban hospital showed that TeamSTEPPS knowledge and performance could be improved to increase patient safety and reduce medical errors. However, teams need to be trained within a shorter period so they can apply a shared-model of teamwork and communication. Leaders and educators throughout the department must also reinforce the behaviors and include them in every education intervention.

Combined Force Ramp and Equilibrium High-Resolution Investigations Reveal Multipath Heterogeneous Unfolding of Protein G.

Over the past two decades, one of the standard models of protein folding has been the "two-state" model, in which a protein only resides in the folded or fully unfolded states with a single pathway between them. Recent advances in spatial and temporal resolution of biophysical measurements have revealed "beyond-two-state" complexity in protein folding, even for small, single-domain proteins. In this work, we used high-resolution optical tweezers to investigate the folding/unfolding kinetics of the B1 domain of immunoglobulin-binding protein G (GB1), a well-studied model system. Experiments were performed for GB1 both in and out of equilibrium using force spectroscopy. When the force was gradually ramped, simple single-peak folding force distributions were observed, while multiple rupture peaks were seen in the unfolding force distributions, consistent with multiple force-dependent parallel unfolding pathways. Force-dependent folding and unfolding rate constants were directly determined by both force-jump and fixed-trap measurements. Monte Carlo modeling using these rate constants was in good agreement with the force ramp data. The unfolding rate constants exhibited two different behaviors at low vs high force. At high force, the unfolding rate constant increased with increasing force, as previously reported by high force, high pulling speed force ramp measurements. However, at low force, the situation reversed and the unfolding rate constant decreased with increasing force. Taken together, these data indicate that this small protein has multiple distinct pathways to the native state on the free energy landscape.

Active and passive transport of cargo in a corrugated channel: A lattice model study.

Inside cells, cargos such as vesicles and organelles are transported by molecular motors to their correct locations via active motion on cytoskeletal tracks and passive, Brownian diffusion. During the transportation of cargos, motor-cargo complexes (MCCs) navigate the confining and crowded environment of the cytoskeletal network and other macromolecules. Motivated by this, we study a minimal two-state model of motor-driven cargo transport in confinement and predict transport properties that can be tested in experiments. We assume that the motion of the MCC is directly affected by the entropic barrier due to confinement if it is in the passive, unbound state but not in the active, bound state where it moves with a constant bound velocity. We construct a lattice model based on a Fokker Planck description of the two-state system, study it using a kinetic Monte Carlo method and compare our numerical results with analytical expressions for a mean field limit. We find that the effect of confinement strongly depends on the bound velocity and the binding kinetics of the MCC. Confinement effectively reduces the effective diffusivity and average velocity, except when it results in an enhanced average binding rate and thereby leads to a larger average velocity than when unconfined.

Mitochondrial disorders.

Primary mitochondrial disorders are a group of clinically variable and heterogeneous inborn errors of metabolism (IEMs), resulting from defects in cellular energy, and can affect every organ system of the body. Clinical presentations vary and may include symptoms of fatigue, skeletal muscle weakness, exercise intolerance, short stature, failure to thrive, blindness, ptosis and ophthalmoplegia, nystagmus, hearing loss, hypoglycemia, diabetes mellitus, learning difficulties, intellectual disability, seizures, stroke-like episodes, spasticity, dystonia, hypotonia, pain, neuropsychiatric symptoms, gastrointestinal reflux, dysmotility, gastrointestinal pseudo-obstruction, cardiomyopathy, cardiac conduction defects, and other endocrine, renal, cardiac, and liver problems. Most phenotypic manifestations are multi-systemic, with presentations varying at different age of onset and may show great variability within members of the same family; making these truly complex IEMs. Most primary mitochondrial diseases are autosomal recessive (AR); but maternally-inherited [from mitochondrial (mt) DNA], autosomal dominant and X-linked inheritance are also known. Mitochondria are unique energy-generating cellular organelles, geared for survival and contain their own unique genetic coding material, a circular piece of mtDNA about 16,000 base pairs in size. Additional nuclear (n)DNA encoded genes maintain mitochondrial biogenesis by supervising mtDNA replication, repair and synthesis, which is modified during increased energy demands or physiological stress. Despite our growing knowledge of the hundreds of genetic etiologies for this group of disorders, diagnosis can also remain elusive due to unique aspects of mitochondrial genetics. Though cure and FDA-approved therapies currently elude these IEMs, and current suggested therapies which include nutritional supplements and vitamins are of questionable efficacy; multi-center, international clinical trials are in progress for primary mitochondrial disorders.