Rapid and reliable identification of multivariate geochemical anomalies is critical for delineating prospective mineralized zones and reducing uncertainty in mineral exploration targeting. Extended isolation forest (EIF) is a powerful unsupervised ensemble learning algorithm that efficiently isolates anomalies from high-dimensional geochemical datasets using randomly oriented hyperplane partitions. Previous studies have demonstrated the effectiveness of EIF in multivariate geochemical anomaly detection and mineral potential modeling. However, its performance can be significantly affected by stochastic variability arising from random partitioning and random subsampling during isolation tree construction, which may result in unstable anomaly patterns and inconsistent exploration targets in complex geological environments. To mitigate this limitation, we developed a robust unsupervised framework for the identification of multivariate geochemical anomalies associated with gold mineralization in the Southwestern Yilgarn Craton, Australia. The proposed framework integrates robust factor analysis (RFA), a Jaccard-based stability index and EIF to enhance the reliability and reproducibility of anomaly detection. RFA was first applied to compositional soil geochemical data to identify the most significant pathfinder elements associated with gold mineralization, which were subsequently used as input variables for the EIF model. The model was then optimized using a Jaccard-based stability criterion to ensure consistent anomaly detection across repeated independent runs. Model performance was assessed using area under the receiver operating characteristic curve (AUC). The obtained AUC value of 0.82 indicates strong predictive capacity, confirming that the generated anomaly map effectively delineates mineralization-related geochemical patterns and provides a reliable proxy for mineral prospectivity mapping. Overall, the proposed framework offers a robust and reproducible unsupervised approach for multivariate geochemical anomaly detection with strong applicability in both greenfield and brownfield mineral exploration settings.
Background: Lyon Consensus 2.0 revised the criteria for conclusive GERD by including grade B esophagitis and requiring abnormal acid exposure on at least 2 monitoring days for physiologic confirmation. Whether these criteria improve selection of patients for antireflux surgery (ARS) remains uncertain. We compared Lyon 2.0 with conventional surgical criteria for their association with favorable postoperative outcomes. Study Design: Patients undergoing ARS after preoperative endoscopy and 48-hour wireless pH monitoring were classified according to Lyon 2.0 criteria and conventional surgical criteria, defined as grade C/D esophagitis or an abnormal DeMeester score on ≥1 monitoring day. Favorable outcome was defined as patient satisfaction and freedom from proton pump inhibitor use at 1 year. Associations were evaluated using multivariable logistic regression, receiver operating characteristic analysis, and decision curve analysis. Results: Among 1,068 patients, 76.7% achieved a favorable outcome. Conventional surgical criteria were associated with favorable outcomes (adjusted odds ratio 1.93; p=0.006). Patients meeting both frameworks had the highest favorable outcome rate (79.7%). However, 26.1% met conventional surgical criteria but not Lyon 2.0 criteria, and 73.1% of these patients achieved a favorable outcome. Discrimination did not differ significantly between Lyon 2.0 and conventional criteria (area under the curve 0.571 vs 0.558; p=0.469). Conclusions: Lyon 2.0 and conventional surgical criteria identify overlapping but distinct ARS populations. Nearly three-quarters of patients meeting conventional criteria but not Lyon 2.0 achieved a favorable outcome. Failure to meet Lyon 2.0 criteria alone should not be used to exclude patients from operative consideration.
BACKGROUND:Hospital closures are increasing because of consolidation, acquisition, and rising operating costs, yet their effects on surgical workload redistribution within regional health systems remain poorly defined. We evaluated the impact of an urban hospital closure on operative volume, essential surgical procedures, payer mix, and timing of presentation at a neighboring community hospital (NCH) and a state trauma center (TC). STUDY DESIGN:A retrospective review compared surgical activity before (2015-2017) and after (2018-2024) closure of an urban hospital. Patient demographics, insurance status, operative volume, and presentation timing were analyzed at the NCH and TC. Essential operations were defined as laparoscopic cholecystectomy, laparoscopic appendectomy, and incision and drainage. Analyses were stratified by zip codes previously served by the closed hospital. RESULTS:Following hospital closure, total operative volume increased by 2.9% at the NCH and decreased by 3.5% at the TC. Essential operations increased by 20.2% at the NCH but decreased by 11.6% at the TC. Both hospitals experienced increases in holiday/weekend operations (NCH, 15.8%; TC, 10.3%). Patients from zip codes previously served by the closed hospital disproportionately contributed to growth in off-hours surgical care and were more likely to be publicly insured. Private insurance coverage did not differ before versus after closure at either hospital. CONCLUSIONS:Closure of an urban hospital was associated with redistribution of urgent surgical care toward neighboring hospitals, particularly increases in off-hours essential operations among publicly insured patients. These findings may inform operating room capacity planning, workforce allocation, and resource deployment across surgical systems serving vulnerable populations.
BACKGROUND:Chest tubes for traumatic pneumothorax are commonly managed with initial suction before transition to water seal, despite limited evidence supporting this practice. We hypothesized that initial water seal would reduce chest tube duration without increasing complications. STUDY DESIGN:We conducted a single-center, pragmatic, month-based cluster-randomized study of adult trauma patients with pneumothorax requiring chest tube placement from October 2024 to May 2025. Patients with a hemothorax component >300 mL or chest tube placement before computed tomography were excluded. Patients were assigned by alternating calendar month to initial suction or water seal; subsequent management was at clinician discretion. The primary outcome was initial chest tube duration. The trial was registered at ClinicalTrials.gov (NCT06688734). RESULTS:Among 3,372 trauma admissions, 133 patients required chest tubes for pneumothorax and 72 met inclusion criteria (37 suction, 35 water seal). Four patients died before chest tube removal and were excluded from the primary outcome analysis. Initial water seal was associated with shorter median initial chest tube duration compared with suction (41 vs 51 hours, p = 0.001) and shorter total chest tube duration (44 vs 60 hours, p = 0.011). Complications, secondary interventions, and mortality were similar between groups (all p > 0.05). CONCLUSIONS:Initial water seal management was associated with shorter chest tube duration without an observed increase in complications. These findings challenge routine initial suction for selected patients with traumatic pneumothorax and support evaluation of an initial water seal strategy in larger multicenter studies.
BACKGROUND:The Advanced Trauma Life Support (ATLS) course is the global standard for trauma education, delivered primarily in a traditional multi-day in-person format requiring trained faculty and resources that may limit access in low-resource settings. Hybrid delivery has expanded availability, but comparative effectiveness data are lacking. We sought to determine whether hybrid ATLS courses were noninferior to traditional ATLS by comparing pass rate and learner satisfaction rate at the course level. STUDY DESIGN:We analyzed 7,387 ATLS courses (April 2022-June 2025) from the ACS COT learning management system with complete pass rate and learner survey data: 4,808 traditional (65%) 2,579 hybrid (35%). Primary outcome was course pass rate and co-primary outcome was participant satisfaction with educational format. Mixed-effects regression clustered courses within course sites, adjusting for year, class size, physician composition, instructor-to-student ratio, and region. Non-inferiority (NI) was pre-specified at a 5 percentage-point (pp) margin (distribution-based MCID). RESULTS:Hybrid courses are non-inferior to traditional courses on both outcomes. Adjusted pass rates were 92.9% (traditional) vs 93.3% (hybrid); the 95% CI for the difference (-0.6 to +1.3pp) excluded the ±5pp NI margin. Composite satisfaction with course format was 95.9% vs. 94.9%); the 95% CI for the difference (-1.7 to -0.4pp) likewise excluded NI margin. Effect sizes were small across all analyses (Cohen's d < 0.25). Findings were robust across multiple pre-specified sensitivity analyses. CONCLUSIONS:Hybrid ATLS delivery is non-inferior to traditional formats for both pass rate and learner satisfaction and may expand access to high-quality trauma education without compromising effectiveness.
Water conservancy and hydropower projects enhance regional climate resilience and watershed water security yet inevitably trigger large-scale involuntary reservoir resettlement. As representative involuntarily displaced populations, reservoir resettlees' social identity directly impacts local social stability and regional sustainable socioeconomic development. Based on a ten-year longitudinal qualitative investigation including in-depth interviews and participant observation in Village Y of Wuxikou Reservoir, Jiangxi Province, this paper divides the entire resettlement process into three stages: relocation, stabilization and development. From the dual perspectives of host community identity and out-groups identity, this study explores the dynamic evolutionary rules of resettlees' social identity. The results indicate that resettlees sequentially develop alienated identity, superficial adaptive identity and segregated identity across different phases. On this basis, the core concept of differential identity is proposed, which features a dual structure of vertical temporal differentiation and horizontal spatial differentiation. This paper expands the applicable scope and explanatory power of the “differential mode of association” and social identity theory in involuntary resettlement contexts. Grounding on the differential identity framework, this paper puts forward targeted integrated governance solutions to break intergroup segregation, facilitate cross-group integration and build resilient resettlement communities consistent with Sustainable Development Goals (SDGs) 11 and 13.
The discrimination of ore deposit types is primarily based on geological, geochemical, and isotopic characteristics. Conventionally, these types are identified using specific element diagrams. However, traditional geochemical methods often fail to determine scheelite deposit types of the complex Xuefengshan Sb-Au-W metallogenic belt in China, where mineralization resulted from the superposition of multiphase geological events. Machine learning (ML) methods, have been increasingly applied to identify deposit genesis by establishing relationships between deposit characteristics and genetic types using extensive datasets. However, inaccurate data labels, the limitations of single models, and poor model interpretability lead to decreased accuracy. This study proposes a ML framework based on interpretable ensemble learning. We collects geochemical element data from typical orogenic and magmatic-hydrothermal scheelite deposits globally. Deep clustering is used to filter data and overcome the subjectivity of original data labels. An ensemble learning model is used to construct a classifier to improve the model's robustness and generalization ability. An interpretable model is introduced to analyze the contribution of individual feature elements, revealing the metallogenic genesis. This method demonstrates high accuracy on the test set. According to this method, the scheelite deposit type of the Xuefengshan metallogenic belt is primarily magmatic-hydrothermal in origin, with orogenic superposition. This helps resolve a long-standing controversy in the region and establishes a repeatable and interpretable new paradigm for ML-based discrimination of ore deposit genetic types.
Though volcanogenic massive sulfide (VMS) deposits are major global sources of indium (In), the physicochemical mechanisms and key factors controlling its significant enrichment remain poorly understood. To address the issue, this study investigates the Tiemurt VMS Pb-Zn-Cu deposit, utilizing detailed petrography, in-situ LA-ICP-MS analysis, and thermodynamic modeling to reveal the In enrichment mechanisms in VMS deposits. Petrographic observations identified two distinct generations of sphalerite corresponding to different mineralization stages. The early-stage sphalerite (Sp1) is euhedral-subhedral, associated with pyrite, and displays darker colors (red to brown), whereas the late-stage sphalerite (Sp2) is anhedral, intimately intergrown with chalcopyrite, and shows lighter colors (mainly yellow). The trace element results demonstrate that Sp1 has a significantly higher In content (average 317 ppm) than Sp2 (average 220 ppm). Additionally, In concentrations positively correlate with Fe contents. Because Fe is the primary chromophore that darkens sphalerite, this strong coupled enrichment mechanism allows macroscopic sphalerite color (red > brown > yellow) to serve as a reliable indicator for In concentration. Crystallization temperatures calculated using the GGIMFis thermometer range from 344 to 382 °C for Sp1 and 312 to 355 °C for Sp2, indicating a cooling trend during fluid evolution. Thermodynamic modeling data showed that in the early-stage hydrothermal fluids (≥360 °C), Zn2+ preferentially complexes with Cl−, leaving InCl2+ or In3+ as unstable species, and In efficiently precipitates into Sp1 under the environment of log fO2 = −32 to −26 and pH = 6–8. As the fluids cool at ~340 °C, weakened Zn2+ competition allows In3+ to form stable InCl3, and In precipitates into Sp2 under the conditions of log fO2 = −42 to −32 and pH = 5.5–11. We therefore conclude that the key factor controlling the difference in In content between Sp1 and Sp2 is the precipitation mechanism rather than migration capacity. This may be different from the In enrichment mechanism associated with magmatic hydrothermal systems, where In is mainly present as InCl3 complexes with strong migration capacity. These new findings enable us to understand how the physicochemical conditions of fluids control the enrichment of In in VMS deposits, and also highlight that the color of sphalerite can be used to target potential In resources in PbZn deposits.
Since the National Highway Traffic Safety Administration (NHTSA) started the Automatic Collision Notification project in 1995, basic Automatic Crash Notifications (ACN) and Advanced Automatic Crash Notification (AACN) systems were integrated into cars to notify emergency medical services (EMS) by contacting 911, the national emergency number. However, despite technological advances, these systems are not standard in all vehicles. Additionally, the available vehicle telematic data is not easily transferred to public safety answering points (PSAP), where public safety telecommunicators (PST) take 911 calls and coordinate the emergency response with law enforcement, fire, and medical services and transport to a trauma center. The purpose of this paper is to review the existing literature of how ACN and AACN benefit patient outcomes and describe challenges and opportunities to implementation.
BACKGROUND:Early hemorrhage control remains the cornerstone of trauma resuscitation, yet traditional ground emergency medical services (EMS) resuscitation relies predominantly on crystalloid fluids. We compared outcomes after prehospital crystalloid, packed red blood cells (pRBC), and whole blood (WB) resuscitation and quantified absolute risk reduction (ARR) and number needed to treat (NNT) for survival. STUDY DESIGN:Trauma patients with hemorrhagic shock (evidence of hemorrhage and shock index >1.0) enrolled in a prospective multicenter ground EMS registry who received crystalloid alone, pRBC, or WB during transport were evaluated. The primary outcome was in-hospital mortality. Secondary outcomes included change in shock index from the prehospital setting to emergency department arrival. ARR and NNT were calculated with 95% confidence intervals. RESULTS:Among 299 patients, mortality was highest after crystalloid resuscitation (13/84, 15.5%) compared with pRBC (9/168, 5.4%) and WB (2/47, 4.3%). Shock index improved in all groups, with the greatest reduction after pRBC (Δ-0.32 vs crystalloid Δ-0.14; p<0.001). Compared with crystalloid, ARR was 10.1% (95% CI, 2.5-19.7%) for pRBC (NNT≈10; p=0.02), 11.2% (95% CI, 1.5-20.9%) for WB (NNT≈9; p=0.03), and 10.4% (95% CI, 2.7-18.0%) for combined blood products (NNT≈10; p=0.006). Contextual comparison demonstrated favorable NNT estimates relative to established trauma interventions. CONCLUSIONS:In this prospective multicenter observational cohort, prehospital blood resuscitation was associated with lower in-hospital mortality than crystalloid alone, with a NNT of approximately 9-10. These findings support implementation research and systems-level evaluation of ground EMS prehospital blood programs for hemorrhagic shock.
BACKGROUND:Morel-Lavallée lesions (MLLs) are closed degloving injuries that occur throughout the body and present treatment challenges due to their rarity and variability in management. We aimed to compare characteristics and outcomes for MLL patients undergoing early (less than 48 hours) vs late (more than 48 hours) surgical intervention, hypothesizing decreased length of stay (LOS) with early intervention. STUDY DESIGN:Fifteen centers participated in this prospective observational study, including all adult patients who sustained a MLL and underwent surgery. No patients were excluded. Bivariate comparisons for early vs late intervention cohorts were performed. RESULTS:Of 150 MLL patients, 101 (67.3%) underwent early intervention. Both cohorts had comparable ages, BMI, vitals, Charlson Comorbidity Index, and injury severity scores (all p > 0.05). However, early intervention patients more commonly had abdominal (37% vs 6.3%, p < 0.001) MLLs, whereas late intervention patients more often had hip (16.7% vs 3.0%, p = 0.01) and thigh (41.7% vs 22%, p = 0.03) MLLs. Early patients had shorter ICU LOS (2 vs 5, p = 0.003) but statistically similar hospital LOS (12 vs 20, p = 0.06). There was no difference in wound-related complications (19.8% vs 24.5%, p = 0.51) or mean number of additional surgeries (p = 0.41) between cohorts. CONCLUSIONS:Over two-thirds of MLL patients underwent early operation. These patients had decreased ICU LOS and a statistically similar albeit clinically shorter overall LOS, despite similar demographics, comorbidities, injury severity, and number of additional surgeries. Therefore, early operation appears beneficial and should be pursued in MLL patients when clinically indicated and feasible.
BACKGROUND:Relationships within the surgeon-anesthesiologist dyad may influence perioperative teamwork, safety, and efficiency, yet little is known about the perceptions and expectations these physicians hold of one another. STUDY DESIGN:We conducted a qualitative, phenomenological study using semi-structured, one-on-one virtual interviews with 20 surgeons (7 women) and 20 anesthesiologists (13 women), ages 31 to 81 years, representing 24 US states. Interviews were audio-recorded, transcribed, and coded using Dedoose version 9.2.22. After stabilization of a codebook, working in teams, investigators applied consensus coding with 100% interrater agreement and performed thematic analysis focused on perceptions and expectations. RESULTS:Surgeons frequently described anesthesiologists with whom they had difficulty as lacking dedication, continuity of care, and equal ownership of patients. Anesthesiologists frequently described surgeons with whom they had difficulty as not recognizing anesthesiologist expertise, not demonstrating expected professional respect, prioritizing operative goals over patient physiology, and exhibiting problematic personality traits. Despite these negative generalizations, both groups articulated some positive perceptions of their colleagues and shared expectations of what can be characterized as operating room professionalism, including engagement, respect, effective communication, competence, flexibility, efficiency, and prioritization of patient care. Differences emerged in emphasis: surgeons highlighted conscientiousness and engagement, whereas anesthesiologists emphasized respect for their professional expertise. CONCLUSIONS:Surgeons and anesthesiologists hold unexpressed negative perceptions and unmet expectations of one another that may influence collaboration and perioperative care delivery. Increasing awareness of these attitudes may represent a first step toward improving relational coordination, teamwork, and patient safety.
