The Changing Faces of Leadership in Surgery: Study on Presidents of Major Surgical Organizations.

INTRODUCTION: To gain an understanding of the changing faces of leadership in surgery, we examined trends in the demographics, additional degrees pursued, and scientific publication characteristics of the past presidents of three major surgery organizations. METHODS: We queried the BoardCertifiedDocs and Web of Science databases for the demographics, as well as the quantity and quality of publications, of the past presidents of the Association for Academic Surgery, Society of University Surgeons, and American College of Surgeons from 1970 to 2020. Data were analyzed by decade to identify any trends. RESULTS: We identified a total of 140 presidents from the organizations. The proportion of female presidents significantly increased from the 1990s to the 2010s (10% versus 33%, P < 0.05). The percentage of non-White presidents increased from the 1970s to the 2010s (3.33% versus 21.2%, P = 0.024). The percentage of presidents with additional degrees also increased from the 1970s to the 2010s (10.0% versus 48.8%, P = 0.039). During this same time period, the most common area of expertise of presidents shifted from cardiothoracic surgery to surgical oncology. The ratio of presidents' postinduction to preinduction publications was significantly increased among all three organizations in the 2010s compared to the 1970s (P < 0.05). Co-cluster analysis revealed a research topic change from the 1970s to the 2010s. CONCLUSIONS: The faces of surgical leadership have changed in terms of gender equality, racial diversity, surgical subspecialty, and additional degrees held. Such a transformation mirrors evolving diversity, equity, and inclusion initiatives, and it further highlights the adaptability of surgical leadership to the ever-changing landscape of surgery.

Lower urinary tract injury: is urology consultation necessary?

PURPOSE: There is a paucity of data regarding urology involvement in the management of lower urinary tract injuries (LUTI). We seek to analyze the incidence and epidemiology of LUTI with special attention to trends in urology consultation. METHODS: A retrospective review was conducted of patients presenting to our Level I trauma center with LUTI from 2002 to 2016. Demographics, mechanism of injury, associated injuries, injury severity score (ISS), American Association for the Surgery of Trauma (AAST) injury scales, and clinical hospital course were analyzed. RESULTS: A total of 140 patients (0.47% of all trauma patients) were identified with LUTI, with 72.1% of these presenting with blunt trauma. Bladder injuries were more common than urethral injuries (79% vs. 14%) with 6% of patients having both. In-hospital mortality was 9.2% (13/140). Among patients with LUTI, 115 patients (82%) received urology consultation. There was no significant difference in sex, age, or LOS (hospital and ICU) between the groups. The consult group had a lower mean ISS (21.7 vs 27.9, p = 0.034), but a higher mean AAST bladder injury scale (2.57 vs 2.00, p = 0.016), than the non-consult group. There was a statistically significant difference in the diagnosis methods between the two groups (χ2 test of independence, p = 0.002). CONCLUSION: Urology service is important in the management of LUTI with high AAST injury scale. While further study is needed to look at degree of urology service involvement in the management of LUTI, we recommend a consultation for severe LUTI or when the management of injuries is out of the comfort zone of the trauma surgeons. Whether consultation is obtained or not, there is room for improvement in appropriate work up of lower urinary tract injury.

A seven-center examination of the relationship between monthly volume and mortality in trauma: a hypothesis-generating study.

INTRODUCTION: The relationship between trauma volumes and patient outcomes continues to be controversial, with limited data available regarding the effect of month-to-month trauma volume variability on clinical results. This study examines the relationship between monthly trauma volume variations and patient mortality at seven Level I Trauma Centers located in the Eastern United States. We hypothesized that higher monthly trauma volumes may be associated with lower corresponding mortality. METHODS: Monthly patient volume data were collected from seven Level I Trauma Centers. Additional information retrieved included monthly mortality, demographics, mean monthly injury severity (ISS), and trauma mechanism (blunt versus penetrating). Mortality was utilized as the primary study outcome. Statistical corrections for mean age, gender distribution, ISS, and mechanism of injury were made using analysis of co-variance (ANCOVA). Center-specific, annually-adjusted median monthly volumes (CSAA-MMV) were calculated to standardize patient volume differences across participating institutions. Statistical significance was set at α < 0.05. RESULTS: A total of 604 months of trauma admissions, encompassing 122,197 patients, were analyzed. Controlling for patient age, gender, ISS, and mechanism of injury, aggregate data suggested that monthly trauma volumes < 100 were associated with significantly greater mortality (3.9%) than months with volumes > 400 (mortality 2.9%, p < 0.01). To account for differences in monthly volumes between centers, as well as for temporal bias associated with potential differences over the entire study duration period, data were normalized using CSAA-MMV as a standardized reference point. Monthly volumes ≤ 33% of the CSAA-MMV were associated with adjusted mortality of 5.0% whereas monthly volumes ≥ 134% CSAA-MMV were associated with adjusted mortality of 2.7% (p < 0.01). CONCLUSIONS: This hypothesis-generating study suggests that greater monthly trauma volumes appear to be associated with lower mortality. In addition, our data also suggest that across all participating centers mortality may be a function of relative month-to-month volume variation. When normalized to institution-specific, annually-adjusted "median" monthly trauma contacts, we show that months with patient volumes ≤ 33% median may be associated with subtly but not negligibly (1.4-2.3%) higher mortality than months with patient volumes ≥ 134% median.

Impact of Trauma Hospital Ransomware Attack on Surgical Residency Training.

BACKGROUND: A recent ransomware attack led to the shutdown of the electronic health information system (HIS) at our trauma center for 2 mo. We investigated its impact on residency training during the downtime. MATERIAL AND METHODS: General and orthopedic surgical residents who rotated at the hospital were invited to participate in a survey regarding their patient care and residency training experiences during the downtime. Attending surgeons from both the specialties were invited to participate in a semistructured interview regarding their attitude toward residency training during the downtime. RESULTS: Twenty-nine residents responded to the survey with a response rate of 78.4%. Residents acknowledged significant increases in face-to-face communication and decreases in use of online educational resources during the downtime (P < 0.01). Residents were significantly stressed by the dearth of online resources (P < 0.0001) and by paper-based orders and outpatient clinic (P < 0.05). A multivariate analysis demonstrated an inverse relationship between postgraduate year and stress from paper orders (P = 0.003). Attending surgeon's interviews revealed that they recognized residents' unpreparedness and strove harder to teach more effectively. CONCLUSIONS: Our study demonstrated that an unexpected shutdown of the hospital HIS imposed significant stress upon surgical residents providing trauma patient care and made attending surgeons take greater efforts to be more effective teachers. Residents who are digital natives lack adaptability to handle a paper-based workflow. With cyber security threats increasing in health care, preparedness should be included in the graduate medical education curriculum.

Variation in the Practice of Central Venous Catheter and Chest Tube Insertions among Surgery Residents.

OBJECTIVES: Central venous catheter (CVC) and chest tube (CT) insertions are common bedside procedures frequently performed by surgery residents. Despite published guidelines, variability in the practice exists. We sought to characterize the surgery residents' practice patterns surrounding these two bedside procedures. MATERIALS AND METHODS: Over the last 1½ months of the academic year in 2012 and 2013, surgery residents across the US were surveyed online. Participants reported levels of agreement for 15 questions in a 5-point Likert scale format. RESULTS: A total of 219 residents completed the survey. Majority of residents agreed that they received appropriate education and training. Over half of the respondents reported that they did not have attending staff physician's supervision during the procedures. Junior residents felt less confident in performing CVC or CT insertions. Those younger than 29 years old and of female sex were also less confident in performing CT insertion. Although almost all residents reported using maximal sterile barrier precautions, 7% reported not securing their gowns and another 7% reported inadequate draping of patients. About ⅓ reported no hand cleansing before the procedures. Those from community programs compared to university programs less frequently used antibiotics. Sixty-five percent of residents reported routine use of ultrasound for CVC insertion. CONCLUSION: Surgery residents do not strictly adhere to the guidelines for CVC and CT insertions, and there is substantial variation in the practice of the procedures, which may contribute to complications associated with these procedures. This survey opens new areas for in-service education, feedback, and practices for these procedures to reduce the risk of complications, especially the infectious one.

Timing of venous thromboembolism chemoprophylaxis after traumatic brain injury.

OBJECTIVES: Currently no national standard exists on optimal timing to initiate VTE chemoprophylaxis after traumatic brain injury (TBI). We designed this survey to assess current practice regarding the timing of VTE chemoprophylaxis after TBI. METHODS: All the EAST members were surveyed online. Participants reported demographics, and responses to questions regarding VTE chemoprophylaxis in TBI and timing of chemoprophylaxis in 2 hypothetical clinical scenarios of TBI. RESULTS: Three hundred and ninety-one full responses were collected (response rate 30.9%). Most respondents (75%) reported the decision to initiate VTE chemoprophylaxis with a consensus between the neurosurgery and trauma/critical care services. While 76% of respondents reported experience of seeing pulmonary embolism without chemoprophylaxis, 44% witnessed progression of TBI after VTE chemoprophylaxis. Approximately 50% considered their practice of VTE chemoprophylaxis in TBI patients to be conservative. Almost 50% reported no standardized protocol in their institutions. While 1/3 of the members believed guidelines exist, another 1/3 believed no guidelines available. Responses to two clinical scenarios showed various approaches regarding the timing of VTE chemoprophylaxis. CONCLUSIONS: Currently there is a wide variability in the practice patterns regarding the timing of VTE chemoprophylaxis in TBI patients. This survey reinforces the need for further investigation to guide clinical practice.

Revisiting traumatic cardiac arrest: should CPR be initiated?

OBJECTIVES: Traumatic cardiac arrest (TCA) represents a unique problem, and poses difficult challenges in the care of trauma patients. Although the literature has suggested that attempted resuscitation from TCA in trauma is futile and consumptive of medical and human resources, studies have recently demonstrated that the outcome of TCA is comparable cardiac arrest secondary to non-traumatic events. The objective of this study was to determine the incidence, predictors, and outcomes following TCA. METHODS: We retrospectively reviewed 124 adult patients with TCA over a period of 5 years (July 2010 to June 2014). Cardiopulmonary resuscitation (CPR) occurred either in the field, en route, or in the emergency department at our Level I Trauma Center. Patients' demographics, clinical data, CPR-related variables, and outcomes were extracted from both the electronic and paper medical records. RESULTS: The median age of the group was 37 (IQR 38), and the median ISS was 37 (IQR 50). The most common cardiac rhythm observed was pulseless electrical activity (PEA, 55%). While 31.4% of patients achieved a return of spontaneous circulation (ROSC), only 7.3% survived with a complete neurological recovery (CNR). In blunt injury patients, the mortality rate after CPR was higher in motor-vehicle-related injuries than falls from heights (93.1 vs 72.3%, OR 5.06, 95% CI 0.95-27.0, p < 0.05). In penetrating injuries, the mortality rate after CPR was higher in patients with trauma to the torsos than those suffering injuries to the head, neck, face, and extremities combined (100 vs 81.3%, OR 0.049, 95% CI 0.0024-1.008, p < 0.001). Two variables predicted failure of CPR were prolonged time interval hospital transport (OR 0.42, 95% CI 0.22-0.80, p < 0.01) and high injury severity score (OR 0.97, 95% CI 0.94-1.00, p < 0.05). However, CPR duration/location (out-of-hospital or in-hospital), head injury, and day/night shifts in ED were not associated with the above outcome. When comparing age groups, the mortality was significantly higher in patients < 65 years than those ≥ 65 years (OR 0.2619, 95% CI 0.09485-0.9703, p = 0.0182). CONCLUSION: Although survival after CPR among trauma patients continues to have dismal outcomes, advanced cardiac life support should be initiated regardless of the initial EKG rhythm. Ultimately, both a rapid response time and transport to the ED are of the utmost importance to survival.

Competitive Advantage of MBA for Physician Executives: A Systematic Literature Review.

In response to systemic challenges facing the US healthcare system, many medical students, residents and practicing physicians are pursuing a Master in Business Administration (MBA) degree. The value of such proposition remains poorly defined. The aim of this review is to analyze current literature pertaining to the added value of MBA training for physician executives (PEs). We hypothesized that physicians who supplement their clinical expertise with business education gain a significant competitive advantage. A detailed literature search of four electronic databases (PubMed, SCOPUS, Embase and ERIC) was performed. Included were studies published between Jan 2000 and June 2017, focusing specifically on PEs. Among 1580 non-duplicative titles, we identified 23 relevant articles. Attributes which were found to add value to one's competitiveness as PE were recorded. A quality index score was assigned to each article in order to minimize bias. Results were tabulated by attributes and by publication. We found that competitive domains deemed to be most important for PEs in the context of MBA training were leadership (n = 17), career advancement opportunities (n = 12), understanding of financial aspects of medicine (n = 9) and team-building skills (n = 10). Among other prominent factors associated with the desire to engage in an MBA were higher compensation, awareness of public health issues/strategy, increased negotiation skills and enhanced work-life balance. Of interest, the learning of strategies for reducing malpractice litigation was less important than the other drivers. This comprehensive systemic review supports our hypothesis that a business degree confers a competitive advantage for PEs. Physician executives equipped with an MBA degree appear to be better equipped to face the challenge of the dynamically evolving healthcare landscape. This information may be beneficial to medical schools designing or implementing combined dual-degree curricula.

Surgical management of pancreatic necrosis: A practice management guideline from the Eastern Association for the Surgery of Trauma.

BACKGROUND: Pancreatic or peripancreatic tissue necrosis confers substantial morbidity and mortality. New modalities have created a wide variation in approaches and timing of interventions for necrotizing pancreatitis. As acute care surgery evolves, its practitioners are increasingly being called upon to manage these complex patients. METHODS: A systematic review of the MEDLINE database using PubMed was performed. English language articles regarding pancreatic necrosis from 1980 to 2014 were included. Letters to the editor, case reports, book chapters, and review articles were excluded. Topics of investigation included operative timing, the use of adjuvant therapy and the type of operative repair. Grading of Recommendations, Assessment, Development and Evaluations methodology was applied to question development, outcome prioritization, evidence quality assessments, and recommendation creation. RESULTS: Eighty-eight studies were included and underwent full review. Increasing the time to surgical intervention had an improved outcome in each of the periods evaluated (72 hours, 12-14 days, 30 days) with a significant improvement in outcomes if surgery was delayed 30 days. The use of percutaneous and endoscopic procedures was shown to postpone surgery and potentially be definitive. The use of minimally invasive surgery for debridement and drainage has been shown to be safe and associated with reduced morbidity and mortality. CONCLUSION: Acute Care Surgeons are uniquely trained to care for those with pancreatic necrosis due their training in critical care and complex surgery with ongoing shock. In adult patients with pancreatic necrosis, we recommend that pancreatic necrosectomy be delayed until at least day 12. During the first 30 days of symptoms with infected necrotic collections, we conditionally recommend surgical debridement only if the patients fail to improve after radiologic or endoscopic drainage. Finally, even with documented infected necrosis, we recommend that patients undergo a step-up approach to surgical intervention as the preferred surgical approach. LEVEL OF EVIDENCE: Systematic review/guideline, level III.

A Comprehensive Framework for International Medical Programs: A 2017 consensus statement from the American College of Academic International Medicine.

The American College of Academic International Medicine (ACAIM) represents a group of clinicians who seek to promote clinical, educational, and scientific collaboration in the area of Academic International Medicine (AIM) to address health care disparities and improve patient care and outcomes globally. Significant health care delivery and quality gaps persist between high-income countries (HICs) and low-and-middle-income countries (LMICs). International Medical Programs (IMPs) are an important mechanism for addressing these inequalities. IMPs are international partnerships that primarily use education and training-based interventions to build sustainable clinical capacity. Within this overall context, a comprehensive framework for IMPs (CFIMPs) is needed to assist HICs and LMICs navigate the development of IMPs. The aim of this consensus statement is to highlight best practices and engage the global community in ACAIM's mission. Through this work, we highlight key aspects of IMPs including: (1) the structure; (2) core principles for successful and ethical development; (3) information technology; (4) medical education and training; (5) research and scientific investigation; and (6) program durability. The ultimate goal of current initiatives is to create a foundation upon which ACAIM and other organizations can begin to formalize a truly global network of clinical education/training and care delivery sites, with long-term sustainability as the primary pillar of international inter-institutional collaborations.

Factors influencing US medical students' decision to pursue surgery.

BACKGROUND: Interest and applications to surgery have steadily decreased over recent years in the United States. The goal of this review is to collect the current literature regarding US medical students' experience in surgery and factors influencing their intention to pursue surgery as a career. We hypothesize that multiple factors influence US medical students' career choice in surgery. METHODS: Six electronic databases (PubMed, SCOPUS, Web of Science, Education Resources Information Center, Embase, and PsycINFO) were searched. The inclusion criteria were studies published after the new century related to factors influencing surgical career choice among US medical students. Factors influencing US medical student surgical career decision-making were recorded. A quality index score was given to each article selected to minimize risk of bias. RESULTS: We identified 38 relevant articles of more than 1000 nonduplicated titles. The factors influencing medical student decision for a surgical career were categorized into five domains: mentorship and role model (n = 12), experience (clerkship n = 9, stereotype n = 4), timing of exposure (n = 9), personal (lifestyle n = 8, gender n = 6, finance n = 3), and others (n = 2). CONCLUSIONS: This comprehensive systemic review identifies mentorship, experience in surgery, stereotypes, timing of exposure, and personal factors to be major determinants in medical students' decisions to pursue surgery. These represent areas that can be improved to attract applicants to general surgery residencies. Surgical faculty and residents can have a positive influence on medical students' decisions to pursue surgery as a career. Early introduction to the field of surgery, as well as recruitment strategies during the preclinical and clinical years of medical school can increase students' interest in a surgical career.

Advanced Glycation End Products Induce Obesity and Hepatosteatosis in CD-1 Wild-Type Mice.

AGEs are a heterogeneous group of molecules formed from the nonenzymatic reaction of reducing sugars with free amino groups of proteins, lipids, and/or nucleic acids. AGEs have been shown to play a role in various conditions including cardiovascular disease and diabetes. In this study, we hypothesized that AGEs play a role in the "multiple hit hypothesis" of nonalcoholic fatty liver disease (NAFLD) and contribute to the pathogenesis of hepatosteatosis. We measured the effects of various mouse chows containing high or low AGE in the presence of high or low fat content on mouse weight and epididymal fat pads. We also measured the effects of these chows on the inflammatory response by measuring cytokine levels and myeloperoxidase activity levels on liver supernatants. We observed significant differences in weight gain and epididymal fat pad weights in the high AGE-high fat (HAGE-HF) versus the other groups. Leptin, TNF-α, IL-6, and myeloperoxidase (MPO) levels were significantly higher in the HAGE-HF group. We conclude that a diet containing high AGEs in the presence of high fat induces weight gain and hepatosteatosis in CD-1 mice. This may represent a model to study the role of AGEs in the pathogenesis of hepatosteatosis and steatohepatitis.

Revisiting endotracheal self-extubation in the surgical and trauma intensive care unit: Are they all fine?

OBJECTIVES: Endotracheal self-extubation (ESE) is a serious health care concern. We designed this study to test our hypothesis that not all patients with ESE are successful in spontaneous breathing and reintubation has negative impact on outcomes. METHODS: Data on all 39 patients of ESE in our surgical and trauma intensive care unit (ICU) in 2012 were prospectively collected and retrospectively analyzed. RESULTS: There were 42 episodes of ESE in 39 of 939 intubated patients (frequency, 4.0%), with 54% of events requiring reintubation. Pre-ESE positive end-expiratory pressure was higher and Pao2/fraction of inspired oxygen ratio was lower, and the post-ESE respiration rate was higher in the reintubated group. On univariate analysis, weaning and spontaneous breathing trial before ESE were favorable predictors for nonreintubation. Multivariate regression analysis demonstrated that agitation before ESE was an independent predictor of reintubation. The need for reintubation was associated with increased risk of pulmonary infectious complications, ventilator days, the need for tracheostomy, and ICU and hospital LOS. The financial costs for ventilator days and ICU rooms were significantly higher in patients with reintubation. CONCLUSION: Not all patients were fine after ESE. We have not decreased the frequency of ESE or improved outcomes if the patients were reintubated. The need for reintubation was not only associated with a high pulmonary complication rate but also prolonged duration on mechanical ventilation and hospital/ICU stay and increased the hospital costs.

Correlation of computed tomographic signs of hypoperfusion and clinical hypoperfusion in adult blunt trauma patients.

BACKGROUND: The computed tomographic signs of hypoperfusion (CTSHs) have been reported in radiology literature as preceding the onset of clinical shock in children, but its correlation with tenuous hemodynamic status in adult blunt trauma patients has not been well studied. We hypothesized that these CT findings represent a clinically hypoperfused state and predict patient outcomes. METHODS: We retrospectively reviewed 52 adult blunt trauma patients who presented to our Level I trauma center with an Injury Severity Score (ISS) greater than 15 and a systolic blood pressure less than 90 mm Hg and who underwent torso CT scans during a period of 5.5 years. Patient's demographics and clinical data were recorded. All CT scans were assessed by our radiologist (J.M.) for 25 CTSHs. RESULTS: Seventy-nine percent of the patients studied exhibited CTSH. The mean number of signs identified per patient was 4. Patient with the most common CTSH, that is, free peritoneal fluid, small bowel enhancement, flattened inferior vena cava (IVC), and flattened renal veins, had a significantly higher intensive care unit admission rate than those without (all p < 0.05). Patient with signs of small bowel abnormal enhancement/dilation, flattened IVC/renal vein had worse acidosis (all p < 0.05). A significantly lower admission hemoglobin and an increased need for red blood cell transfusion were found in patient with flattened IVC (p < 0.05), flattened renal vein (p < 0.01), and active contrast extravasation (p < 0.01). Univariate analysis identified small bowel dilatation and splenic injury as factors associated with mortality and laparotomy, respectively. Logistic regression model revealed that splenic injury is a significant independent predictor of laparotomy (odd ratio, 7.50; 95% confidence interval, 1.67-33.71; p < 0.01). CONCLUSION: CTSH correlates with clinical hypoperfusion in blunt trauma patients and has important prognostic and therapeutic implications. The presence of CTSH in blunt trauma patients should draw immediate attention and require prompt intervention. Trauma surgeons should be familiar with these signs and include them in the clinical decision-making paradigms to improve outcomes in blunt trauma. LEVEL OF EVIDENCE: Diagnostic study, level III.

Do we really rely on fast for decision-making in the management of blunt abdominal trauma?

INTRODUCTION: The Focused Assessment with Sonography in Trauma examination (FAST) is currently taught and recommended in the ATLS(®), often as an addendum to the primary survey for patients with blunt abdominal trauma. Although it is non-invasive and rapidly performed at bedside, the utility of FAST in blunt abdominal trauma has been questioned. We designed this study to examine our hypothesis that FAST is not an efficacious screening tool for identifying intra-abdominal injuries. METHODS: We performed a retrospective chart review of all patients with confirmatory diagnosis of blunt abdominal injuries with CT and/or laparotomy for a period of 1.5 years (from 7/2009 to 11/2010). FAST was performed by ED residents and considered positive when free intra-abdominal fluid was visualized. Abdominal CT, or exploratory laparotomy findings were used as confirmation of intra-abdominal injury. RESULTS: A total of 1671 blunt trauma patients were admitted to and evaluated in the Emergency Department during a 1½ year period and 146 patients were confirmed intra-abdominal injuries by CT and/or laparotomy. Intraoperative findings include injuries to the liver, spleen, kidneys, and bowels. In 114 hemodynamically stable patients, FAST was positive in 25 patients, with a sensitivity of 22%. In 32 hemodynamically unstable patients, FAST was positive in 9 patients, with a sensitivity of 28%. A free peritoneal fluid and splenic injury are associated with a positive FAST on univariate analysis, and are the independent predictors for a positive FAST on multiple logistic regression. CONCLUSION: FAST has a very low sensitivity in detecting blunt intraabdominal injury. In hemodynamically stable patients, a negative FAST without a CT may result in missed intra-abdominal injuries. In hemodynamically unstable blunt trauma patients, with clear physical findings on examination, the decision for exploratory laparotomy should not be distracted by a negative FAST.

Complications during intrahospital transport of critically ill patients: Focus on risk identification and prevention.

Intrahospital transportation of critically ill patients is associated with significant complications. In order to reduce overall risk to the patient, such transports should well organized, efficient, and accompanied by the proper monitoring, equipment, and personnel. Protocols and guidelines for patient transfers should be utilized universally across all healthcare facilities. Care delivered during transport and at the site of diagnostic testing or procedure should be equivalent to the level of care provided in the originating environment. Here we review the most common problems encountered during transport in the hospital setting, including various associated adverse outcomes. Our objective is to make medical practitioners, nurses, and ancillary health care personnel more aware of the potential for various complications that may occur during patient movement from the intensive care unit to other locations within a healthcare facility, focusing on risk reduction and preventive strategies.