Critical Portion Research Articles

Gender Differences in Operative Autonomy Using the Surgical Autonomy Program: A Multicenter Study.

Background The proportion of women surgeons is increasing, but studies show that women in surgical residency are granted less autonomy than men. Objective We utilized the Surgical Autonomy Program (SAP), an educational framework, to evaluate gender differences in self-reported autonomy, attending-reported autonomy, and operative feedback among US neurosurgical residents. Methods The SAP tracks resident progression and guides teaching in neurosurgery. Surgeries are divided into zones of proximal development (opening, exposure, critical portion, and closure). Postoperatively, resident autonomy is rated on a 4-point scale by the resident and the attending for each part of the case, or zone. We utilized data from July 2017 to February 2024 from 8 institutions. Ordinal regression was used to evaluate the odds of self- and attending-evaluated autonomy, accounting for gender, training year, case difficulty, and institution. Differences between attending assessment and self-assessment were calculated across time. Chi-square analyses were used to measure any differences in feedback given to men and women. Results From 128 residents (32 women, 25%), 11894 cases were included. Women were granted less autonomy (OR 0.81; 95% CI 0.74-0.89; P<.001) and self-evaluated as having less autonomy (OR 0.73; 95% CI 0.67-0.80; P<.001). The odds of women operating at higher autonomy were similar to the odds of operating on a hard case compared to average difficulty (OR 0.77; 95% CI 0.71-0.84; P<.001). Men's and women's self-assessment became closer to attending assessment over time, with women improving more quickly for the critical portions of surgeries. Women residents received meaningful postoperative feedback on fewer cases (women: 74.2%, men: 80.5%; X2=31.929; P<.001). Conclusions Women operated with lower autonomy by both attending and self-assessment, but the assessment gap between genders decreased over time. Women also received less feedback from their attendings.

Mathematical Techniques for Enhancing Signal Processing in Electronics

Flag preparing is an critical portion of advanced innovation since it lets us analyze, alter, and progress information for numerous employments, from therapeutic checks to broadcast communications. With the expansion of progressed numerical strategies to information handling, electronic frameworks have gotten to be much more valuable and precise. This paper looks at a few vital numerical procedures that are utilized to move forward flag handling. It centers on calculations and hypothetical models that make flag examination and modifying way better. It is looked at how procedures like Fourier changes, wavelet changes, and measurable flag preparing can offer assistance move forward sifting, commotion diminishment, and determination. The Fourier change can break down signals into their recurrence components. This lets you are doing precise recurrence space investigation and sifting, which is exceptionally imperative for assignments that require high-frequency exactness. Wavelet changes permit for multi-resolution investigation, which makes it simpler to see at signals at diverse sizes and superior distinguish characteristics that alter or do not remain the same. Versatile sifting, expectation hypothesis, and other measurable strategies are talked approximately in terms of how they offer assistance decrease commotion and progress signals in changing settings. Utilizing these logical strategies together not as it were makes electronic frameworks work way better and be more solid, but it too opens the entryway to modern employments in ranges like machine learning and information analytics. This exposition gives an in-depth see at these numerical strategies, centering on their hypothetical establishments, how they are utilized in genuine life, and how they have changed cutting edge flag preparing. This paper looks at these strategies in awesome detail to appear how vital unused scientific thoughts are for progressing electronic flag preparing advances and making a difference to create electronic frameworks that are more brilliant and work superior.

Comparative Analysis of Machine Learning Models for Enhanced Software Fault Detection: Performance and Accuracy Evaluation

Software defect prediction expectation is a critical portion of program designing that tries to discover and anticipate bugs or imperfections in program frameworks some time recently they happen. The objective is to come up with strategies and models that offer assistance program advancement groups choose which testing assignments are most imperative and how to best utilize their assets. A few machine learning (ML) strategies are utilized to do this. To create forecasts, these frameworks utilize a parcel of distinctive information, like code measures, past imperfection information, and data approximately the coder. The reason of this study is to use different machine learning strategies to make a determining demonstrate for finding computer program bugs. The proposed demonstrate is utilized in tests on the KC2 dataset from NASA's Guarantee library as portion of the study. It was attempted and compared how well diverse machine learning strategies worked. This consider utilized the KC2 dataset and found that the Decision Tree strategy got 73.28% accuracy, Naïve Bayes got 85.96%, K-Nearest Neighbour (KNN) got 82.57%, Support Vector Machine (SVM) got 86.74%, and Random Forest got 84.20%. The study about appeared that these different models can precisely anticipate program bugs when the Guarantee dataset KC2 is utilized. These comes about appear that machine learning models can offer assistance anticipate bugs superior, which can offer assistance groups speed up their tests and make way better utilize of their assets. The study appears that employing a run of machine learning models can enormously move forward the precision of foreseeing computer program abandons. This gives us valuable data almost regions of program frameworks that are more likely to have bugs, which helps keep software quality high.

Effect of General Surgery Resident Participation in Thoracic Surgery on Oncologic Outcomes: An Observational Cohort Study.

Background: Despite increasing sub-specialization, general surgeons continue to perform oncologic thoracic surgeries. Our objective was to determine whether general surgery resident participation in thoracic surgery affects surgical quality or oncologic outcomes. We hypothesized that patient outcomes with and without resident participation would be similar. Methods: We retrospectively reviewed the electronic health records of patients with stage 0-IV lung cancer undergoing oncologic pulmonary resection at BLINDED FOR REVIEW during an 11-year period (2012-2022). Patients younger than 18years or older than 85years were excluded, as were those who had incomplete follow-up data or were unregistered in our institutional cancer registry. Patients were divided into groups based on whether residents or staff surgeons completed >50% of the critical portions of the operation. We compared 30-day morbidity outcomes, overall survival (OS), and disease-free survival (DFS). Results: Three hundred thirteen patients met inclusion criteria. Demographic and clinical characteristics were similar between groups, as were types of surgical resection and median operative times. A statistical difference was found in the distribution of surgical approach. The odds of morbidity were 65% higher in the Staff group (OR=1.65; 95% CI, 1.007-2.71). Resident participation was not significantly associated with OS or DFS (P =.32 and P =.54, respectively). Discussion: General surgery resident involvement in lung cancer operations is not associated with longer operative times but is associated with a higher likelihood of a thoracotomy. General surgery resident involvement was associated with decreased postoperative morbidity and did not significantly affect OS or DFS.

Effect of Glenoid Bone Loss and Shoulder Position on Axillary Nerve Anatomy During the Latarjet Procedure.

The Latarjet procedure is increasingly being utilized for the treatment of glenoid bone loss and has a relatively high neurological complication rate. Understanding the position-dependent anatomy of the axillary nerve (AN) is crucial to preventing injuries. To quantify the effects of changes in the shoulder position and degree of glenoid bone loss during the Latarjet procedure on the position of the AN. Controlled laboratory study. A total of 10 cadaveric shoulders were dissected, leaving the tendons of the rotator cuff and deltoid for muscle loading. The 3-dimensional position of the AN was quantified relative to the inferior glenoid under 3 conditions: (1) intact shoulder, (2) Latarjet procedure with 15% bone loss, and (3) Latarjet procedure with 30% bone loss. Measurements were obtained at 0°, 30°, and 60° of glenohumeral abduction (equivalent to 0°, 45°, and 90° of shoulder abduction) and at 0°, 45°, and 90° of humeral external rotation (ER). Abduction of the shoulder to 60° resulted in a posterior (9.5 ± 1.1 mm; P < .001), superior (3.0 ± 1.2 mm; P = .013), and lateral (19.1 ± 2.3 mm; P < .001) shift of the AN, and ER to 90° resulted in anterior translation (10.0 ± 1.2 mm; P < .001). Overall, ER increased the minimum AN-glenoid distance at 30° of abduction (14.9 ± 1.3 mm [0° of ER] vs 17.3 ± 1.5 mm [90° of ER]; P = .045). The Latarjet procedure with both 15 and 30% glenoid bone loss resulted in a superior and medial shift of the AN relative to the intact state. A decreased minimum AN-glenoid distance was seen after the Latarjet procedure with 30% bone loss at 60° abduction and 90° ER (17.7 ± 1.6 mm [intact] vs 13.9 ± 1.6 mm [30% bone loss]; P = .007), but no significant differences were seen after the Latarjet procedure with 15% bone loss. Abduction of the shoulder induced a superior, lateral, and posterior shift of the AN, and ER caused anterior translation. Interestingly, the Latarjet procedure, when performed on shoulders with extensive glenoid bone loss, significantly reduced the minimum AN-glenoid distance during shoulder abduction and ER. These novel findings imply that patients with substantial glenoid bone loss may be at a higher risk of AN injuries during critical portions of the procedure. Consequently, it is imperative that surgeons account for alterations in nerve anatomy during revision procedures. This study attempts to improve understanding of the position-dependent effect of shoulder position and glenoid bone loss after the Latarjet procedure on AN anatomy. Improved knowledge of AN anatomy is crucial to preventing potentially devastating AN injuries during the Latarjet procedure.

Timing of Intraoperative Transitions of Care Among Anesthesiologists Is Not Associated With Postoperative Adverse Outcomes: Retrospective Cohort Study.

The majority of published research suggests that anesthesia handovers during major surgical procedures are associated with unintended harmful consequences. It is still unclear if the number or quality of the transition of care is the main driver of the adverse outcomes. There is even less data if the timing of the anesthesiologist handovers during the critical portion of the anesthetic continuum (induction or emergence versus surgical period) plays a role in patient outcomes. Therefore, we investigated if the anesthesiologist handovers during induction and emergence are associated with adverse patient outcomes. This retrospective investigation included noncardiac surgical procedures occurring between January 1, 2012 and December 31, 2019 that had exactly 1 attending anesthesiologist handover. We categorized transitions of care between attending anesthesiologists as being before incision, between incision and closing, and after closing. Our primary outcome was a composite of 6 categories of surgical complications and in-hospital mortality. We created logistic generalized estimating equation models to estimate the average relative effect odds ratio between each pair of the 3 transition timing groups across the components of the composite outcome. Inverse probability of treatment weights were used to mitigate confounding on a host of baseline variables. We used Bonferroni correction to adjust for multiple comparisons between the transition groups. In total, we studied 36,937 procedures with exactly 1 attending anesthesiologist handover. Of these records, 4370 had the transition during induction, 24,999 between incision and closure, and 7568 during emergence. No differences were found between the transition periods and the composite outcome. The estimated average relative effect odds ratio (98.3% confidence interval [CI]) across the components of the composite outcome was as follows: (1.0002 [0.81-1.24], P = .99) between the induction and surgical period; (1.10 [0.87-1.40], P = .32) between the induction and emergence periods; and (0.91 [0.79-1.04], P = .08) between the emergence and surgical periods. Timing of intraoperative handover among attending anesthesiologists during noncardiac surgery is not associated with adverse patient outcomes.

Outcomes from 871,441 Consecutive Surgical Procedures without Overlap or with Maximally Permissible Non-Concurrent Overlap.

To isolate the impact of subsumed surgery (a shorter procedure completed entirely during overlapping non-critical portions of a longer antecedent procedure) on patient outcomes. The American College of Surgeons recently recommended the elimination of "concurrent surgery" with overlap during a procedure's critical portions. Guidelines for non-concurrent overlap have been established, but the safety of subsumed surgery remains to be examined. All consecutive procedures from 2013 to 2021 within a multihospital academic medical center were included (n=871,441). Simple logistic regression was performed to compare postoperative events between patients undergoing non-overlap surgery (n=533,032) and completely subsumed surgery (n=11,319). Thereafter, coarsened exact matching was used to match patients with non-overlap and subsumed surgery 1:1 on CPT code, 18 demographic features, baseline health characteristics, and procedural variables (n=7,146). Exact-matched cases were subsequently limited to pairs performed by the same surgeon (n=5,028). Primary outcomes included 30-day readmission, ED visits, and reoperations. Univariate analysis suggested that subsumed surgery had a higher 30-day risk of readmission (OR 1.55, P<0.0001), ED evaluation (OR 1.19, P<0.0001), and reoperation (OR 1.98, P<0.0001). When comparison was limited to the exact same procedure and patients were matched on demographics and health characteristics, there were no outcome differences between patients with subsumed surgery and non-overlapping surgery, even when limiting analyses to the same surgeon. Similar surgeries for similar patients result in similar outcomes whether there is completely subsumed or no overlap. Individual surgeons performing a specific procedure have no outcome differences with subsumed and non-overlapping cases.

Critical Portions of a Foot or Ankle Surgical Procedure From Patient and Surgeon Perspectives.

Over the past decade, overlapping procedures in orthopaedic surgery have come under increased public scrutiny. Central to this discussion is what should constitute a "critical portion" of any surgical procedure-a definition which may differ between patients and surgeons. This study therefore aimed to assess which components of three common foot and ankle procedures are considered "critical" from both the patient and surgeon perspectives. For this survey-based study, questionnaires were administered to patients who presented to an orthopaedic foot and ankle clinic and separately administered to foot and ankle surgeons through e-mail. The questionnaires broached all steps involved in three common foot and ankle procedures: open reduction and internal fixation of ankle fracture, Achilles tendon repair, and ankle arthroscopy. Respondents were asked to characterize each step as "always critical," "often critical," sometimes critical," rarely critical," or "never critical." A combined "always critical" and "often critical" response rate of greater than 50% was used to define a step as genuinely critical. Patient and surgeon responses were thereafter compared using Mann-Whitney U and Kruskal-Wallis tests ( P -value <0.05 was considered significant). Notably, both patients and surgeons considered informed consent, preoperative marking of the surgical site, preoperative time-out, surgical soft-tissue dissection, and certain procedure-specific steps (critical portions) of these procedures. By contrast, only patients considered skin incision and wound closure to be critical steps. Patients and surgeons were largely in agreement as to what should comprise the critical portions of several common foot and ankle procedures. Certain discrepancies did exist, however, such as skin incision and closure, and both groups were also in general agreement regarding what was not considered a critical component of these operations. Such findings highlight a potential opportunity for improved preoperative patient education and patient-physician communication. Level IV: Evidence from well-designed case-control or cohort studies.

Overlapping Surgery Verbiage in Informed Consent Documents.

To assess informed consent documents from United States (US) institutions for verbiage regarding overlapping surgery. Overlapping surgery remains a controversial practice. Recent guidance from the Senate Finance Committee and American College of Surgeons emphasizes transparency with patients regarding this practice through the informed consent process, but it remains unclear how many institutions adopted their recommendations. Informed consent documents were collected from a national sample of 104 institutions and assessed for verbiage regarding overlapping surgery and/or attending absence during a surgical case. The verbiage of these forms was further analyzed for inclusion of key terms (e.g., "overlapping surgery," "critical portions") as well as transparency regarding surgeon absence. Thirty (29%) forms included verbiage regarding overlapping surgery and/or surgeon absence during a case. Most of these 30 utilized the terms "overlapping surgery" or "critical portions" (18 [60%] and 25 [83%], respectively), although only 3 (10%) explicitly stated that portions of the procedure that may be performed in the absence of the attending surgeon. Six forms (20%) specifically stated who may perform the procedure without the attending present, and 3 forms (10%) had patients acknowledge this section of the consent form with an additional signature or initial. Only 2 of the forms (7%) fulfilled all of the criteria set forth by the SFC. Detailed information regarding overlapping surgery is infrequently included in hospitals' procedure informed consent documents. Forms that include this information rarely provide explicit statements of attending presence and trainee participation, raising concerns regarding surgeon-patient transparency.

Introducing a novel hybrid educational boot camp to augment medical student training in neurosurgery.

Neurosurgery subinternships are a critical portion of the medical student application to neurosurgery residency programs, allowing programs to assess the student's clinical knowledge, interpersonal skills, work ethic, and character. Despite how critical these auditions are, many students have a poor understanding of expectations prior to beginning these subinternships. Thomas Jefferson University hosted a combined in-person and virtual boot camp session open to all medical students interested in neurosurgery. The authors sought to determine the effectiveness of this inaugural course. A total of 304 registered participants were sent a survey assessing their attitudes toward neurosurgery subinternships, beliefs about their abilities, and their comfort with various neurosurgical skills. All participants were sent a postsession survey composed of the same questions. The mean scores for responses to pre- and postsession survey questions were recorded based on graduating year and by medical school type (US allopathic [US MD], US osteopathic [US DO], or foreign degree/international medical graduate [IMG]). Differences in means between pre- and postsession survey responses were analyzed using the Student t-test, and statistical significance was set at p < 0.05. A total of 112 presession surveys and 64 postsession surveys were completed, yielding a presession survey response rate of 36.8% and a postsession survey response rate of 21.1%. Seventy-five percent of the postsession survey respondents attended virtually, and 25% were in-person. US MD, US DO, and IMG attendees demonstrated a significantly increased understanding of the expectations of a neurosurgery subintern (p < 0.001). All students had significantly increased confidence in their ability to succeed as subinterns (US MD students and IMGs p < 0.001, US DO students p < 0.05). Regarding procedural confidence, US MD students had increased confidence in craniotomies and cranial plating (p < 0.001). When comparing responses by graduation year, students in the classes of 2024 and 2025 (rising 4th-year and rising 3rd-year medical students, respectively) demonstrated significantly increased understanding of expectations and confidence in their ability to succeed (< 0.001). Seventy-five percent of our postsession survey respondents attended virtually, and 25% were in-person. The in-person cohort had greater improvements in comfort with procedures such as craniotomies, cranial plating, and extraventricular drain placement (in-person vs Zoom mean differences: craniotomies and cranial plating, -2.29, extraventricular drain placement, -2.31) (p < 0.05). The boot camp successfully delineated the expectations of neurosurgery subinterns and enhanced the attendees' confidence in their abilities. The authors concluded that a hybrid virtual and in-person format is beneficial and feasible in increasing accessibility to information about neurosurgery subinternships.

Relationships Between Longevity Via Age Difference and Health Age Versus Three Critical Lifestyle Factors, Food Portion, Daily Exercise, and Sleep Hours Using Viscoplastic Energy Model of GH-Method: Math-Physical Medicine (No. 1054, VMT #452)

Moderate food portions, consistent exercise, and sufficient sleep are crucial for health maintenance and potential lifespan extension. Statistical evidence from various epidemiological and clinical studies demonstrates a strong correlation between these three lifestyle factors and increased longevity. The author, who avoids smoking, alcohol, and illicit drugs, and has minimal exposure to environmental hazards, acknowledges the limitations of changing his physical age, genetic makeup, or family history. Consequently, he has chosen to concentrate on modifiable lifestyle factors that can impact his lifespan. Through 15 years of his medical research work, he observed that many deaths are predominantly linked to four chronic diseases, particularly diabetes, with obesity often serving as a precursor. Unhealthy eating habits contribute to weight gain, while regular exercise is essential not only for body weight management but also for diabetes control. Additionally, adequate sleep duration and quality also play a significant role in the management of chronic diseases. Hence, he focused on these three critical factors to explore their effects on longevity. The author developed an estimated “health age" formula: Health Age = Real Biological Age * (1 + ((MI - 0.735)/0.735)/2) Age difference = health age - real age In this article, the author examined two outcomes—age discrepancy (Age Diff) and health age (H. Age) —through separate analyses, each related to three consistent lifestyle factors: food portion (Food P.), daily exercise (Steps), and sleep hours (Sleep H.). To analyze these two scenarios, he employs the space-domain Viscoplastic Medicine Theory (SD-VMT) energy model, facilitating a comprehensive understanding of the effects of these three lifestyle factors on the specified medical symptom of longevity. He also selected three normalization factors, i.e. his targets for these three factors, 0.4 for food portion (40% of his food portion in 2012), 16000 walking steps per day, and 7 hours of night sleep.

Barriers to overlapping complex and general spine surgery at a tertiary academic hospital.

Policy concern and debate surround the concept of overlapping spine surgery. Overlapping surgery specifically refers to nonessential portions of the case or noncutting time overlap. This differs from concurrent surgery, in which critical portions of the procedure overlap. Here the authors explore the barriers for safe and efficient overlapping surgery in academic spinal deformity practice. Over a 24-month period, cases of spinal deformity, degenerative cases, anterior cervical discectomy and fusions (ACDFs), and laminectomy were reviewed for duration in operating room (OR) prior to surgery, duration of cutting time, duration in OR after surgery, turnover duration, and time delay from initial start time. Standard degenerative cases were referenced as 1-2 ACDFs as well as 1- to 2-level laminectomy surgery. The blocks of time between two consecutive cutting periods were investigated to determine the feasibility of overlapping an additional surgery. Specifically, the authors compared the blocks of time that include the postsurgery period, the turnover period, and the presurgery period to cutting periods. One hundred twenty-six complex spinal deformity procedures and 85 degenerative cases (including 49 ACDFs and 36 laminectomies) from one center and one neurosurgeon were reviewed. These procedures were performed between September 2019 and December 2021 with a 3-month gap in military deployment. On average, the procedure's duration for cases of deformity was 236.5 minutes, for cases of ACDFs it was 84 minutes, and for cases of laminectomies it was 105.5 minutes. The block of noncutting time while the patient was in the OR showed no difference from the surgical cut time. The turnover time between cases was 52.35 minutes. Of 100 cases scheduled as the first case of the day, 94 had a delay to the OR averaging 18.2 minutes. The data in this study indicate that estimates for pre- and postsurgical times alone are not sufficient to allow for overlapping surgery. The average cut-time duration of ACDF was 84 minutes; the average presurgical time for deformity was 68 minutes. This highlights the critical analysis for further examination of optimal scheduling, on-time first start, turnover periods, and the orchestration of all members of the providing team to optimize the cutting time for safe and consistent implementation of overlapping spine surgery.

Overlapping otolaryngologic surgery: Safety and efficacy

BackgroundSurgical procedures scheduled staggered between two operating rooms increase efficiency by eliminating turnover time. However, the practice might increase the surgeon's fatigue. Overlapping surgery has been assumed to be safe because no critical portions of procedures are performed simultaneously in two rooms, but there is little evidence in the literature to support that assumption for otolaryngologic surgery, and there is no evidence comparing non-overlapping and overlapping surgical outcomes for a single surgeon with all confounding factors controlled. MethodsRetrospective cohort study that included a consecutive sample of adult subjects who underwent otolaryngologic laryngeal or otologic surgery between June 2013 and March 2016. All procedures were performed by the same surgical team and surgeon who had block time with 2-rooms every other week and 1-room on alternate weeks. The incidence of surgical complications was assessed in the perioperative period. Duration of surgery and time-in-room also were evaluated, as were surgical outcomes. ResultsA total of 496 surgeries were assigned to either overlapping-surgery (n = 346) or non-overlapping-surgery (n = 150) cohorts. Overlapping-surgery was a significant predictor for increased time-in-room on multivariate analysis but was not a significant predictor for surgery duration. Rate of complications, hospital readmission, emergency department visit, reoperation, mortality, and patient satisfaction did not differ significantly between cohorts. ConclusionsOverlapping surgery does not hinder patient safety or functional outcomes in patients undergoing otolaryngologic operations such as voice or ear surgery.

Peak frequency mapping of atypical atrial flutter.

Peak frequency (PF) mapping is a novel method that may identify critical portions of myocardial substrate supporting reentry. The aim of this study was to describe and evaluate PFmapping combined with omnipolar voltage mapping in the identification of critical isthmuses of left atrial (LA) atypical flutters. LA omnipolar voltage and PF maps were generated in flutter using the Advisor HD-Grid catheter (Abbott) and EnSite Precision Mapping System (Abbott) in 12 patients. Normal voltage was defined as ≥0.5 mV, low-voltage as 0.1-0.5 mV, and scar as <0.1 mV. PF distributions were compared with ANOVA and post hoc Tukey analyses. The 1 cm radius from arrhythmia termination was compared to global myocardium with unpaired t-testing. The mean age was 65.8 ± 9.7 years and 50% of patients were female. Overall, 34 312 points were analyzed. Atypical flutters most frequently involved the mitral isthmus (58%) or anterior wall (25%). Mean PF varied significantly by myocardial voltage: normal (335.5 ± 115.0 Hz), low (274.6 ± 144.0 Hz), and scar (71.6 ± 140.5 Hz) (p < .0001 for all pairwise comparisons). All termination sites resided in low-voltage regions containing intermediate or high PF. Overall, mean voltage in the 1 cm radius from termination was significantly lower than the remaining myocardium (0.58vs. 0.95 mV, p < .0001) and PF was significantly higher (326.4vs. 245.1 Hz, p < .0001). Low-voltage, high-PF areas may be critical targets during catheter ablation of atypical atrial flutter.

A Framework for Analyzing System Loadability With Multiple VSCs Using a Hybrid Model

Due to the increasing number of power electronics-based devices in modern power systems, there are concerns about the impact of higher-frequency interactions on system stability. The typically-used algebraic representation of networks fails to capture these newly emergent issues, but dynamically modelling the entire network with differential equations will lead to a prohibitively long simulation time. This paper proposes a computationally-efficient analysis framework to determine the system loadability in power electronics-rich, large networks with the consideration of multiple types of stabilities. The framework developed in this paper identifies the critical network elements based on the eigenvalue sensitivity in order to exploit a hybrid modelling approach. Within the hybrid model, only the critical network portion is modelled dynamically with the rest of the network represented by algebraic equations. Bifurcation theory is used to simultaneously analyze both small-disturbance rotor angle and small-disturbance voltage stability. The results obtained show that the high-frequency interactions are accurately captured with the proposed framework. Additionally, applying this methodology results in a small dimension for the system matrix and a reduction in the computational burden. Two test networks, a three-bus system and the IEEE 39-bus system, are used to illustrate and verify the analysis framework.

Experimental characterization of a Polymer Metal Hybrid (PMH) automotive structure under quasi-static, creep, and impact loading

A feasibility study on a short fibre reinforced Polymer Metal Hybrid (PMH) solution of a car’s suspension control arm has been conducted through a simplified demonstrator, representative of the most critical portion of this component. It was injection moulded in two versions: an all composite one and a PMH version, in which the short fibre reinforced composite was over-moulded on to an aluminium insert. The demonstrator underwent quasi-static, creep and impact tests to simulate most of the loading conditions experienced by a suspension arm during its lifetime. The mechanical behaviours of the two demonstrator versions were compared to highlight the differences introduced by the proposed novel PMH solution. In particular, the ductile metal insert ensured the compliance of the PMH demonstrators with the automotive specific safety requirement of avoiding the complete separation at failure, which was successfully obtained in all testing conditions.

Reflections on Surrogate-Assisted Search-Based Testing: A Taxonomy and Two Replication Studies based on Industrial ADAS and Simulink Models

Surrogate-assisted search-based testing (SA-SBT) aims to reduce the computational time for testing compute-intensive systems. Surrogates enhance testing techniques by improving test case generation focusing the testing budget on the most critical portions of the input domain. In addition, they can serve as approximations of the system under test (SUT) to predict test results instead of executing the tests on compute-intensive SUTs. This article reflects on the existing SA-SBT techniques, particularly those applied to system-level testing and often facilitated using simulators or complex test beds. Recognizing the diversity of heuristic algorithms and evaluation methods employed in existing SA-SBT techniques, our objective is to synthesize these differences and present a comprehensive view of SA-SBT solutions. In addition, by critically reviewing our previous work on SA-SBT, we aim to identify the limitations in our proposed algorithms and evaluation methods and to propose potential improvements. We present a taxonomy that categorizes and contrasts existing SA-SBT solutions and highlights key research gaps. To identify the evaluation challenges, we conduct two replication studies of our past SA-SBT solutions: One study uses industrial advanced driver assistance system (ADAS) and the other relies on a Simulink model benchmark. We compare our results with those of the original studies and identify the difficulties in evaluating SA-SBT techniques, including the impact of different contextual factors on results generalization and the validity of our evaluation metrics. Based on our taxonomy and replication studies, we propose future research directions, including re-considerations in the current evaluation metrics used for SA-SBT solutions, utilizing surrogates for fault localization and repair in addition to testing, and creating frameworks for large-scale experiments by applying SA-SBT to multiple SUTs and simulators.

The Use of Cholangioscopy In the Diagnosis of Indeterminate Biliary Strictures: A Case Report and Review of the Literature

Biliary strictures or narrowing of a portion of the biliary tree can have benign and malignant etiologies. One third of these will originate from iatrogenic injury and these are typically managed endoscopically. We present the case of a 76-year-old man with history of laparoscopic cholecystectomy ten years prior, who presented with one week of jaundice, dark urine, and pruritus. Along with non-invasive biliary imaging, he underwent cholangioscopy during endoscopic retrograde cholangiopancreatography revealing inflammatory-appearing stenosis of the common hepatic duct with embedded suture material. The stenotic area was biopsied using mini forceps and subsequently dilated with a balloon dilator. A plastic biliary stent was placed with improvement in the patient’s hepatic function, with final cytology and pathology being negative for malignancy. Cholangioscopy facilitated detailed visual inspection of strictures and biopsies under direct visualization. The visual impression increased the sensitivity of the biopsy and assisted in ruling out malignancy from the most critical portion of the stricture. While timing of cholangioscopy remains to be determined, its use is a valuable tool in the diagnosis of indeterminate biliary strictures.

Employee engagement in logistics industry: a perspective in Indonesia

Indonesia has a lower employee engagement rate than other nations in Southeast Asia, and this phenomenon applies to all industries, including the logistics sector. The logistics industry generally contributes a critical portion of a nation's economy, so further study of the management effectiveness in logistics companies is essential. Any company requires a reliable workforce to function at its best. This research investigates some variables influencing employee engagement in the Indonesian logistics industry. The first variable is corporate governance; the second variable is internal control; corporate reputation is the third, where all these three are set as independent variables. The research also examines whether leadership style moderates the influences of the three independent variables on employee engagement. This study collected data research by distributing questionnaires to 742 respondents from 353 logistics firms. Statistical results came from the Partial Least Square-Structural Equation Modelling (PLS-SEM) method used in this study. The findings revealed that the three independent variables positively and significantly impacted employee engagement. The leadership style functioned as the moderating role in corporate governance’s impact and the corporate reputation’s effect proven in this research; in contrast, it did not apply to internal control’s impact. These results suggest that logistics companies in Indonesia can improve employee engagement by ensuring exemplary implementation of the three independent variables while adopting a leadership style that supports these efforts.

A surrogate forelimb: Evolution, function and development of the avian cervical spine.

The neck is a critical portion of the avian spine, one that works in tandem with the beak to act as a surrogate forelimb and allows birds to manipulate their surroundings despite the lack of a grasping capable hand. Birds display an incredible amount of diversity in neck morphology across multiple anatomical scales-from varying cervical counts down to intricate adaptations of individual vertebrae. Despite this morphofunctional disparity, little is known about the drivers of this enormous variation, nor how neck evolution has shaped avian macroevolution. To promote interest in this system, I review the development, function and evolution of the avian cervical spine. The musculoskeletal anatomy, basic kinematics and development of the avian neck are all documented, but focus primarily upon commercially available taxa. In addition, recent work has quantified the drivers of extant morphological variation across the avian neck, as well as patterns of integration between the neck and other skeletal elements. However, the evolutionary history of the avian cervical spine, and its contribution to the diversification and success of modern birds is currently unknown. Future work should aim to broaden our understanding of the cervical anatomy, development and kinematics to include a more diverse selection of extant birds, while also considering the macroevolutionary drivers and consequences of this important section of the avian spine.