Quantum critical phase of FeO spans conditions of Earth's lower mantle.

Seismic and mineralogical studies have suggested regions at Earth's core-mantle boundary may be highly enriched in FeO, reported to exhibit metallic behavior at extreme pressure-temperature (P-T) conditions. However, underlying electronic processes in FeO remain poorly understood. Here we explore the electronic structure of B1-FeO at extreme conditions with large-scale theoretical modeling using state-of-the-art embedded dynamical mean field theory (eDMFT). Fine sampling of the phase diagram reveals that, instead of sharp metallization, compression of FeO at high temperatures induces a gradual orbitally selective insulator-metal transition. Specifically, at P-T conditions of the lower mantle, FeO exists in an intermediate quantum critical state, characteristic of strongly correlated electronic matter. Transport in this regime, distinct from insulating or metallic behavior, is marked by incoherent diffusion of electrons in the conducting t2g orbital and a band gap in the eg orbital, resulting in moderate electrical conductivity (~105 S/m) with modest P-T dependence as observed in experiments. Enrichment of solid FeO can thus provide a unifying explanation for independent observations of low seismic velocities and elevated electrical conductivities in heterogeneities at Earth's mantle base.

Minding the gap: towards a shared clinical reasoning lexicon across the pre-clerkship/clerkship transition.

Teaching and learning of clinical reasoning are core principles of medical education. However, little guidance exists for faculty leaders to navigate curricular transitions between pre-clerkship and clerkship curricular phases. This study compares how educational leaders in these two phases understand clinical reasoning instruction. Previously reported cross-sectional surveys of pre-clerkship clinical skills course directors, and clerkship leaders were compared. Comparisons focused on perceived importance of a number of core clinical reasoning concepts, barriers to clinical reasoning instruction, level of familiarity across the undergraduate medical curriculum, and inclusion of clinical reasoning instruction in each area of the curriculum. Analyses were performed using the Mann Whitney U test. Both sets of leaders rated lack of curricular time as the largest barrier to teaching clinical reasoning. Clerkship leaders also noted a lack of faculty with skills to teach clinical reasoning concepts as a significant barrier (p < 0.02), while pre-clerkship leaders were more likely to perceive that these concepts were too advanced for their students (p < 0.001). Pre-clerkship leaders reported a higher level of familiarity with the clerkship curriculum than clerkship leaders reported of the pre-clerkship curriculum (p < 0.001). As faculty transition students from the pre-clerkship to the clerkship phase, a shared understanding of what is taught and when, accompanied by successful faculty development, may aid the development of longitudinal, milestone-based clinical reasoning instruction.

Melting and defect transitions in FeO up to pressures of Earth's core-mantle boundary.

The high-pressure melting curve of FeO controls key aspects of Earth's deep interior and the evolution of rocky planets more broadly. However, existing melting studies on wüstite were conducted across a limited pressure range and exhibit substantial disagreement. Here we use an in-situ dual-technique approach that combines a suite of >1000 x-ray diffraction and synchrotron Mössbauer measurements to report the melting curve for Fe1-xO wüstite to pressures of Earth's lowermost mantle. We further observe features in the data suggesting an order-disorder transition in the iron defect structure several hundred kelvin below melting. This solid-solid transition, suggested by decades of ambient pressure research, is detected across the full pressure range of the study (30 to 140 GPa). At 136 GPa, our results constrain a relatively high melting temperature of 4140 ± 110 K, which falls above recent temperature estimates for Earth's present-day core-mantle boundary and supports the viability of solid FeO-rich structures at the roots of mantle plumes. The coincidence of the defect order-disorder transition with pressure-temperature conditions of Earth's mantle base raises broad questions about its possible influence on key physical properties of the region, including rheology and conductivity.

Examining undergraduate student perceptions and engagement during the second year of the COVID-19 pandemic.

The objectives of this study were to understand undergraduate students' overall experiences with the transition to remote learning and understand students' level of involvement with online and in-person campus programs at the start of the COVID-19 pandemic. This paper presents the findings from a series of library focus groups conducted with undergraduate students in the summer 2021. Findings showed that students experienced parallel benefits and challenges to that of remote learning when attending online campus programs. Based on these findings this paper provides student-driven recommendations for library programming. Understanding the levels of student involvement across different types of engagement and different campus stakeholders allows for articulation of the greater implications for developing library student engagement efforts.

Periclase deforms more slowly than bridgmanite under mantle conditions.

Transport of heat from the interior of the Earth drives convection in the mantle, which involves the deformation of solid rocks over billions of years. The lower mantle of the Earth is mostly composed of iron-bearing bridgmanite MgSiO3 and approximately 25% volume periclase MgO (also with some iron). It is commonly accepted that ferropericlase is weaker than bridgmanite1. Considerable progress has been made in recent years to study assemblages representative of the lower mantle under the relevant pressure and temperature conditions2,3. However, the natural strain rates are 8 to 10 orders of magnitude lower than in the laboratory, and are still inaccessible to us. Once the deformation mechanisms of rocks and their constituent minerals have been identified, it is possible to overcome this limitation thanks to multiscale numerical modelling, and to determine rheological properties for inaccessible strain rates. In this work we use 2.5-dimensional dislocation dynamics to model the low-stress creep of MgO periclase at lower mantle pressures and temperatures. We show that periclase deforms very slowly under these conditions, in particular, much more slowly than bridgmanite deforming by pure climb creep. This is due to slow diffusion of oxygen in periclase under pressure. In the assemblage, this secondary phase hardly participates in the deformation, so that the rheology of the lower mantle is very well described by that of bridgmanite. Our results show that drastic changes in deformation mechanisms can occur as a function of the strain rate.

The magmatic web beneath Hawai'i.

The deep magmatic architecture of the Hawaiian volcanic system is central to understanding the transport of magma from the upper mantle to the individual volcanoes. We leverage advances in earthquake monitoring with deep learning algorithms to image the structures underlying a major mantle earthquake swarm of nearly 200,000 events that rapidly accelerated after the 2018 Kilauea caldera collapse. At depths of 36 to 43 kilometers, we resolve a 15-kilometers-long collection of near-horizontal sheeted structures that we identify as a sill complex. These sills connect to the lower depths of Kilauea's plumbing by a 25-kilometers-long belt of seismicity. Additionally, a column of seismicity links the sill complex to a shallow décollement near Mauna Loa. These findings implicate the mantle sill complex as a nexus for magma transport beneath Hawai'i and furthermore indicate widespread magmatic connectivity in the volcanic system.

Application of a Screening-Level Pollinator Risk Assessment Framework to Trisiloxane Polyether Surfactants.

Regulatory requirements exist to assess the potential impacts of pesticides on insect pollinators, but "inert," coformulants to pesticide formulations are not included in standard regulatory risk assessments. Some publications in the open literature have suggested that the agricultural uses of "inert" ingredients, including trisiloxane polyether surfactants, may result in adverse effects on pollinators. We conducted a screening-level risk assessment to evaluate the potential risk to insect pollinators, using honey bees (Apis mellifera) as a surrogate, from exposure to three trisiloxane polyether surfactants based on agricultural application scenarios following the current US Environmental Protection Agency (USEPA) guidance. The exposure assessment included data from two sources: (1) use data reported in California's (USA) Pesticide Use Registry (PUR) database for all crops, and (2) an almond orchard residue study conducted using the three trisiloxane polyether surfactants. Honey bee laboratory studies with each of the trisiloxane polyether surfactants reported 50% lethal doses (LD50s) or no adverse effect levels, which were used as the effects inputs to BeeREX. The exposure and toxicity data were combined to estimate potential honey bee risk based on the determination of acute and chronic risk quotients (RQs) for larval and adult life stages. The RQs calculated using both the PUR use rates as well as the application rates and peak measured residues from the almond orchard residue study were below the USEPA acute and chronic levels of concern (acute, 0.4; chronic, 1.0). Based on these results, the use of these three trisiloxane polyether surfactants in agricultural use settings can be considered minimal risk to insect pollinators, and higher tier assessment is unnecessary for the characterization of risk. Environ Toxicol Chem 2022;41:3084-3094. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Antiviral Pharmacology: A Standardized Patient Case for Preclinical Medical Students.

Introduction: Pharmacology is an important learning topic in preclinical medical education. Simulated patient encounters allow students to apply basic science knowledge in a clinical setting and have been useful in previous studies of pharmacology education. We developed a standardized patient (SP) encounter to reinforce antiviral pharmacology content for first-year medical students. Methods: Students were instructed to recommend a medication for shingles during an SP encounter and to answer questions from the SP on mechanism of action and adverse effects. Students then attended a large-group debrief session. Following the activity, students evaluated the exercise through a voluntary survey. For knowledge assessment, students were randomized into two groups to complete three multiple-choice questions either before or after the learning activity. Results: In 2020 and 2021, 144 and 145 students, respectively, participated. In 2020, there was no significant difference in the proportion of correct answers between the pre- and postsimulation groups (p > .05). In 2021, the postsimulation group significantly outperformed the presimulation group in knowledge of mechanism of action (p < .01) and adverse effects (p < .01), but no difference was seen between the groups regarding medication selection (p = .27). Most learners assessed the instructional design as effective for the tasks assigned. Discussion: This SP activity provided an opportunity for early medical students to practice integrating antiviral pharmacology knowledge into a patient encounter and was well received by learners. The instructional method offers a clinically relevant approach for reinforcing pharmacology knowledge for preclinical medical students.

Integrating the Electronic Health Record Into Patient Encounters: An Introductory Standardized Patient Exercise for Preclinical Medical Students.

INTRODUCTION: Increasingly, use of the electronic health record (EHR) is interwoven into even the most basic patient care tasks. Accordingly, learning how to utilize the EHR during patient encounters is important for medical students as they develop their clinical skills. Existing EHR curricula have focused primarily on doctor-patient relationship skills. We developed a session for our preclinical students on EHR-related doctor-patient relationship skills as well as on using the EHR to verify data and focus one's history taking. METHODS: We developed student notes, three training videos, four standardized patient (SP) cases, and a simplified, simulated EHR based on these cases. Students reviewed the notes and videos prior to class. During class, students practiced EHR-related communication and data-collection strategies by interviewing an SP while interacting with the simulated EHR. Following each encounter, students received feedback from a small group of peers and faculty. RESULTS: Two-hundred eighty-nine second-year medical students participated this session in 2019 and 2020, and 27 (19%, 2019) and 40 (28%, 2020) students, respectively, completed the postsession evaluation. Most respondents rated the SP activity as extremely or quite effective for practicing doctor-patient relationship strategies while interacting with the EHR (89%, 2019; 83%, 2020) and for practicing verification of EHR data during a patient encounter (81%, 2019; 86%, 2020). DISCUSSION: This training session was effective for introducing preclinical medical students to fundamental concepts and skills related to incorporating the EHR into patient encounters and offers a low-cost approach to teaching early medical students these important skills.

Kawasaki Disease and Multisystem Inflammatory Syndrome in Children: An Overview and Comparison.

Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) are inflammatory conditions that present diagnostic and therapeutic challenges to the physician. Although many of their features overlap, they are two distinct conditions. KD is a febrile illness most commonly affecting children younger than five years. It manifests with prolonged fever and at least four of the following features: bilateral bulbar conjunctivitis, mucositis, diffuse maculopapular rash, extremity changes, and cervical lymphadenopathy of 1.5 cm or more in diameter. Patients with MIS-C may have many of the same manifestations but tend to have higher rates of gastrointestinal and neurocognitive symptoms and signs of shock on presentation. Both conditions are associated with cardiac sequelae, including coronary artery aneurysms, although children with MIS-C are at high risk of developing ventricular dysfunction and depressed cardiac output. Lymphocytopenia, thrombocytopenia, elevated troponin, and elevated B-type natriuretic peptide are key laboratory findings of MIS-C that can help distinguish it from KD. The use of intravenous immune globulin is well established in KD and also appears to have a role in the treatment of MIS-C. Aspirin has been used in KD for an anti-inflammatory effect, and low-dose aspirin is recommended for MIS-C to reduce the risk of thrombosis. In addition to supportive care, patients with MIS-C may benefit from immunomodulatory medications, although data on this topic are evolving.

Simulation: an Innovative Approach to Engaging Preclinical Medical Students with Bioethics.

BACKGROUND: Integrating bioethical concepts into preclinical medical school curriculum and engaging early medical learners in bioethics are a challenge. ACTIVITY: A total of 140 medical students participated in a 2-h simulation activity consisting of a series of standardized patient (SP) encounters. RESULTS: A total of 41 of 140 students (29%) completed the learner evaluation survey. Ninety-one percent thought that the SP encounter was relevant to their role as a future physician. Ninety-three percent of students rated the exercise as highly effective. CONCLUSIONS: SP encounters enhance preclinical medical students' engagement with bioethics and provide learners practice applying these concepts to clinically relevant scenarios.

The First Detection of an Earthquake From a Balloon Using Its Acoustic Signature.

Extreme temperature and pressure conditions on the surface of Venus present formidable technological challenges against performing ground-based seismology. Efficient coupling between the Venusian atmosphere and the solid planet theoretically allows the study of seismically generated acoustic waves using balloons in the upper atmosphere, where conditions are far more clement. However, earthquake detection from a balloon has never been demonstrated. We present the first detection of an earthquake from a balloon-borne microbarometer near Ridgecrest, CA in July 2019 and include a detailed analysis of the dependence of seismic infrasound, as measured from a balloon on earthquake source parameters, topography, and crustal and atmospheric structure. Our comprehensive analysis of seismo-acoustic phenomenology demonstrates that seismic activity is detectable from a high-altitude platform on Earth, and that Rayleigh wave-induced infrasound can be used to constrain subsurface velocities, paving the way for the detection and characterization of such signals on Venus.

Perspectives on the current state of pre-clerkship clinical reasoning instruction in United States medical schools: a survey of clinical skills course directors.

OBJECTIVES: Clinical reasoning skills are essential for sound medical decision-making. Though many have suggested that clinical reasoning instruction should begin in pre-clerkship curricula, neither pre-clerkship clinical skills director perspectives nor extent of instruction is known. This survey study serves as part of a needs assessment for United States medical school pre-clerkship clinical reasoning curricula. METHODS: United States medical school pre-clerkship clinical skills course directors were surveyed about perceived importance of formal instruction on clinical reasoning concepts, inclusion of these concepts in the curricula, barriers to instruction, and familiarity with clerkship curricula. Results were analyzed using descriptive and analytic statistics. Narrative comments were analyzed qualitatively for themes. RESULTS: Of 148 directors surveyed, 102 (69%) participated and 89 (60%) completed all closed-ended items. Each clinical reasoning concept was identified as somewhat to extremely important to include in pre-clerkship curricula by 90-99% of respondents. Pre-clerkship curricula included variable degrees of formal instruction for concepts, though most respondents rated their inclusion as moderate or extensive. Perceived importance of teaching most concepts moderately correlated with the degree of inclusion in the curriculum (Spearman's rho 0.39-0.44). Curricular time constraints and lack of faculty with skills to teach these concepts were the most frequently cited barriers to instruction. Respondents indicated being somewhat 57% (n=54) to extremely 29% (n=27) familiar with clerkship curricula at their institutions. CONCLUSIONS: This study is the first to examine pre-clerkship clinical skills course director perspectives about clinical reasoning instruction and extent of its inclusion in their curricula.

The influence of δ-(Al,Fe)OOH on seismic heterogeneities in Earth's lower mantle.

The high-pressure phases of oxyhydroxides (δ-AlOOH, ε-FeOOH, and their solid solution), candidate components of subducted slabs, have wide stability fields, thus potentially influencing volatile circulation and dynamics in the Earth's lower mantle. Here, we report the elastic wave velocities of δ-(Al,Fe)OOH (Fe/(Al + Fe) = 0.13, δ-Fe13) to 79 GPa, determined by nuclear resonant inelastic X-ray scattering. At pressures below 20 GPa, a softening of the phonon spectra is observed. With increasing pressure up to the Fe3+ spin crossover (~ 45 GPa), the Debye sound velocity (vD) increases. At higher pressures, the low spin δ-Fe13 is characterized by a pressure-invariant vD. Using the equation of state for the same sample, the shear-, compressional-, and bulk-velocities (vS, vP, and vΦ) are calculated and extrapolated to deep mantle conditions. The obtained velocity data show that δ-(Al,Fe)OOH may cause low-vΦ and low-vP anomalies in the shallow lower mantle. At deeper depths, we find that this hydrous phase reproduces the anti-correlation between vS and vΦ reported for the large low seismic velocity provinces, thus serving as a potential seismic signature of hydrous circulation in the lower mantle.

The Simulated Cardiology Clinic: A Standardized Patient Exercise Supporting Medical Students' Biomedical Knowledge and Clinical Skills Integration.

Introduction: Development of cardiac disease-related diagnostic skills-including hypothesis-driven data gathering, heart sound interpretation, and ECG interpretation-is an important component of medical student training. Prior studies indicate trainees' performance of these skills is limited. Simulation provides students with opportunities to practice integrating their developing knowledge in a relevant clinical context. We developed a simulated clinic activity for second-year medical students consisting of standardized patient (SP) cases representing cardiovascular (CV) diseases. Methods: Student small groups rotated through four SP encounters. For each case, one student performed the history, after which the whole small group listened to audio files of heart sounds, interpreted an ECG, and collaboratively developed a prioritized differential diagnosis. The CV course director met with students for a large-group debrief, highlighting key learning points. We collected learners' evaluations of the event through an online survey. Results: Of students, 276 participated in this activity over the course of 2 years. Nearly all students assessed the activity as extremely or quite effective for applying learning content from the CV course (97%, 2018; 93%, 2019), and for practicing how to approach chest pain, shortness of breath, palpitations, and fatigue (100%, 2018; 95%, 2019). The most helpful aspects were reinforcement of CV disease illness scripts, hypothesis-driven data gathering practice, ECG interpretation, and applying knowledge and skills in a realistic context. Discussion: SP encounters representing CV conditions can effectively provide opportunities for students to integrate basic science knowledge and clinical skills. Students assessed the activity as helpful and engaging.

The Zombie Virus Pandemic: An Innovative Simulation Integrating Virology, Population Health, and Bioethics for Preclinical Medical Students.

Introduction: Understanding population health in the context of infectious disease outbreaks is an important physician competency. However, identifying effective ways to engage early medical students in this content remains a challenge. We designed an innovative pandemic simulation for first-year medical students utilizing the pop culture theme of zombies. Methods: This 2.5-hour simulation was conducted in 2018 and 2020 during students' virology course. Student teams collected and analyzed data to formulate hypotheses for the source pathogen. The teams completed reports explaining their diagnostic hypotheses, infection containment recommendations, and resource allocation recommendations. Learners completed an evaluation of the simulation through an online survey. Responses were analyzed using descriptive statistics; narrative responses were analyzed qualitatively for themes. A content analysis was performed on students' reports. Results: Two hundred eighty-four medical students participated in this activity. Nearly all respondents agreed that the small-group format (98%, 2018 and 2020) and pace and duration (92%, 2018; 94%, 2020) were appropriate and that the activity was intellectually stimulating (97%, 2018; 96%, 2020). Learner engagement measures were high (90%-97%, 2018; 83%-96%, 2020). Analysis of students' reports revealed evidence of cognitive integration of virology, population health, and bioethics concepts, including integration of new learning content. Discussion: Collaborative problem-solving during a simulated zombie-themed pandemic provided preclinical medical students with an engaging opportunity to integrate virology, population health, and bioethics concepts. Implementing this event required advanced planning, use of multiple spaces, learning materials preparation, and recruitment of several faculty, staff, and actors.

The Simulated Virology Clinic: A Standardized Patient Exercise for Preclinical Medical Students Supporting Basic and Clinical Science Integration.

Introduction: Virology is inherently challenging due to the sheer volume of information medical students are responsible for learning. Cognitive integration of this content is critical for early medical students to practice applying this knowledge to diagnostic problem-solving. Simulation offers learners engaging opportunities to practice cognitive integration. We developed a simulated clinic activity for first-year medical students consisting of standardized patient (SP) encounters representing viral infections. Methods: Student small groups rotated through eight SP encounters during which they collected patient histories, reviewed physical exam findings, and developed a differential diagnosis and diagnostic plan for each case. The instructor debriefed students on the cases afterward. We assessed students' evaluation of the activity through online surveys. Results: Two hundred seventy-eight students participated in the simulated clinic in 2018 and 2019. Students rated the activity as very effective for learning about the infections represented and for providing opportunities to integrate clinical skills. Students agreed that the event's instructional design was appropriate for its objectives and that the problem-solving aspect was intellectually stimulating. They indicated that the most effective aspects were solidifying illness scripts for the infections represented, integrating knowledge and skills to diagnose patients in a realistic clinical context, and working collaboratively to problem-solve. Discussion: The simulated virology clinic is an effective method for providing students opportunities to integrate microbiology and clinical skills and has been positively received by students. This instructional method offers learners an opportunity to solidify illness scripts for viral infections using an interactive, collaborative approach.

The GI Simulated Clinic: A Clinical Reasoning Exercise Supporting Medical Students' Basic and Clinical Science Integration.

Introduction: Cognitive integration is required to perform clinical decision-making tasks, even in the preclinical curriculum of medical school. Simulation supports students' cognitive integration by providing practical application of basic science knowledge in a relevant clinical context. To address the need for integrative activities in our curriculum, we implemented a simulated clinic exercise with cases representing gastrointestinal diseases for first-year medical students. Methods: Basic science and clinical skills course directors collaborated to design this simulated clinic event, during which student small groups rotated through a series of standardized patient encounters. During each encounter, one student performed the history and physical exam, following which the small group collaboratively developed a prioritized differential diagnosis. Afterwards, the gastroenterology course director debriefed students to highlight key learning points. We collected learner evaluation data following the event. Results: Two hundred eighty first-year medical students participated in the simulated clinic in 2018 and 2019. Students rated these events as effective for learning about clinical features of the diseases presented and for reinforcing skills learned in the clinical skills course. Students agreed that the small-group format, pace, and duration were appropriate and that the problem-solving aspect was intellectually stimulating. The most effective aspects were opportunities to solidify illness scripts, apply knowledge to solve a problem, and encounter diseases in a realistic clinical context. Discussion: This simulated clinic model effectively supported preclinical students' basic and clinical science integration to complete diagnostic reasoning tasks for gastrointestinal gastrointestinal conditions and was evaluated favorably by learners.

Chasing Fevers: An Interactive Exercise for Pediatrics Residents on Triaging and Assessing Inpatients With Fever.

Introduction: Pediatrics residents are frequently tasked with triaging fevers in pediatric inpatients. The variety of clinical scenarios in the inpatient setting-patients with a multitude of diseases and a spectrum of risk for invasive infection-makes this task challenging. To enhance our residents' training on this topic, we developed an activity providing explicit instruction on how to approach these patient scenarios. Methods: The 45-minute activity began with an interactive discussion on approaching pediatric inpatient fevers, followed by a case-based exercise where small groups were assigned one of six clinical scenarios involving inpatients with fever. Learners discovered new information about their patient by drawing paper slips out of a container. Each slip could take their patient's story in a different direction. Small groups discussed decision-making options for their assigned case at each step. Among the potential events were rapid response calls-acute issues requiring immediate assessment-in which learners competed for limited seats to determine who would respond to the call. The activity concluded with a discussion about treatment of inpatient fevers. Results: Respondents to the postevent evaluation rated the activity as highly engaging, effective in helping them achieve its learning objectives, highly relevant to their career, and effective in simulating real-life clinical decision-making situations. Discussion: This instructional technique offers a unique, engaging, case-based approach to teaching about inpatient fever management in which instructors facilitate and support learners' articulation of clinical reasoning. Future directions include using this technique for other common clinical problems and with other learner groups.

Medical Students' Clinical Reasoning During a Simulated Viral Pandemic: Evidence of Cognitive Integration and Insights on Novices' Approach to Diagnostic Reasoning.

INTRODUCTION: Cognitive integration from multiple disciplines is essential to clinical problem-solving. Because it is not directly observable, demonstrating evidence of learners' cognitive integration remains a challenge. In addition, little is known about preclinical medical students' approach to diagnostic reasoning despite widespread implementation of clinical reasoning curricula for these early learners. The objectives of this study were to characterize how first-year medical students integrated knowledge to problem-solve during a simulated viral pandemic and to characterize students' diagnostic reasoning approach to this clinical scenario. MATERIALS AND METHODS: Student teams analyzed clinical data to formulate hypotheses for the pandemic's source and submitted reports justifying their hypotheses and treatment recommendations. A content analysis on students' reports identified codes and themes characterizing the learning content integrated and students' approaches to diagnostic reasoning tasks. RESULTS: Sixteen problem-solving codes were identified, demonstrating integration of new and previously encountered content from multiple disciplines. A compare-contrast analytical approach was the most commonly employed diagnostic reasoning approach (100%), with a smaller subset of teams also using a causal approach (20%). DISCUSSION: Content analysis of preclinical students' diagnostic justification tasks provided insights into their approach to diagnostic reasoning, which was most consistent with the search-inference framework rather than a causal approach, likely due to limited pathophysiological knowledge at that point in training. CONCLUSIONS: Evidence of cognitive integration can be made explicit through learners' narrative justification of diagnostic reasoning tasks. Preclinical students' diagnostic reasoning development has implications for curricular design and implementation for this learner group.