"The emperor's new clothes." Manoeuvre warfare and operational art

Wars can be categorised in a number of ways, for example according to the conduct during conflicts, the means used and with regard to the belligerents' strategy, aims and objectives. One reason for categorising is to add precision to the language so we can better develop proper theories and methods, thus aiming at improving our fighting capability. In the wake of these theoretical exercises, new terms and sometimes, old terms used in a new way, are introduced. Since the late 1970s, many lobbyists, military theorists and officers have described warfare in terms of a dichotomy: attrition and manoeuvre warfare. Manoeuvre warfare theory is a hybrid of selected historical examples and military theories developed under different contextual circumstances. The alleged paradigm shift in our approach to war has provided us with, or so we believe, a new methodology for conduct in war and the number of terms suited to describe an unambiguous theory. True manoeuvre warfare is expressed through operational art. This distinct approach to war has now been adopted by military forces throughout the western world. This thesis looks closer at what manoeuvre warfare aspires to be, in the context of its terminology, methodology and its different national expressions. The first part of the thesis is concerned with a comparative analysis of different national manoeuvre warfare doctrines by using general systems theory and non-linear dynamics. The analysis reveals that, what we call manoeuvre warfare theory, has expressions that contradict each other and differ to the extent that the theory exists only in name. The second part of the thesis is concerned with the historical substantiation of manoeuvre warfare. German military conduct, but first and foremost the Blitzkrieg-campaigns are often used to add credibility to the methods prescribed by manoeuvre theory. Some proponents of the theory have chosen General Guderian as the human manifestation of the true manoeuvrist. By using the Clausewitzian term "Centre of Gravity", essential in manoeuvre theory as a departure point, the second part of the thesis analyses German military conduct and thought prior to the Second World War and the campaign in France 1940. Emphasis in the second part is put on German planning prior to the campaign and the conduct of the Wehrmacht's Army Group A during the execution. The analysis reveals that the German military interpreted Clausewitz in a way that is not compatible with strategic thought in modem democratic societies. The German pursuit of military effectiveness led to a tacticisation of strategy. Battles of attrition were fought with the highest degree of mobility. German military thought in the 1930's, manifested in the field manual Truppenfihrung, reveals a pragmatic approach to war, which indicates that there was no Blitzkrieg concept as such. Army Group A's conduct during the campaign in France also contradicts many of the principles and the methodology prescribed by the manoeuvrists. It appears that the ambiguous terms and selective historical examples have been interpreted and distilled to a degree where they eventually conform to the manoeuvrist thought

Precision of field triage in patients brought to a trauma centre after introducing trauma team activation guidelines

<p>Abstract</p> <p>Background</p> <p>Field triage is important for regional trauma systems providing high sensitivity to avoid that severely injured are deprived access to trauma team resuscitation (undertriage), yet high specificity to avoid resource over-utilization (overtriage). Previous informal trauma team activation (TTA) at Ulleval University Hospital (UUH) caused imprecise triage. We have analyzed triage precision after introduction of TTA guidelines.</p> <p>Methods</p> <p>Retrospective analysis of 7 years (2001–07) of prospectively collected trauma registry data for all patients with TTA or severe injury, defined as at least one of the following: Injury Severity Score (ISS) > 15, proximal penetrating injury, admitted ICU > 2 days, transferred intubated to another hospital within 2 days, dead from trauma within 30 days. Interhospital transfers to UUH and patients admitted by non-healthcare personnel were excluded. Overtriage is the fraction of TTA where patients are not severely injured (1-positive predictive value); undertriage is the fraction of severely injured admitted without TTA (1-sensitivity).</p> <p>Results</p> <p>Of the 4 659 patients included in the study, 2 221 (48%) were severely injured. TTA occurred 4 440 times, only 2 002 of which for severely injured (overtriage 55%). Overall undertriage was 10%. Mechanism of injury was TTA criterion in 1 508 cases (34%), of which only 392 were severely injured (overtriage 74%). Paramedic-manned prehospital services provided 66% overtriage and 17% undertriage, anaesthetist-manned services 35% overtriage and 2% undertriage. Falls, high age and admittance by paramedics were significantly associated with undertriage. A Triage-Revised Trauma Score (RTS) < 12 in the emergency department reduced the risk for undertriage compared to RTS = 12 (normal value). Field RTS was documented by anaesthetists in 64% of the patients compared to 33% among paramedics.</p> <p>Patients subject to undertriage had an ISS-adjusted Odds Ratio for 30-day mortality of 2.34 (95% CI 1.6–3.4, p < 0.001) compared to those correctly triaged to TTA.</p> <p>Conclusion</p> <p>Triage precision had not improved after TTA guideline introduction. Anaesthetists perform precise trauma triage, whereas paramedics have potential for improvement. Skewed mission profiles makes comparison of differences in triage precision difficult, but criteria or the use of them may contribute. Massive undertriage among paramedics is of grave concern as patients exposed to undertriage had increased risk of dying.</p

Pre-participation screenings frequently miss occult cardiovascular conditions in apparently healthy male middle-aged first-time marathon runners

INTRODUCTION: The optimal pre-participation screening strategy to identify athletes at risk for exercise-induced cardiovascular events is unknown. We therefore aimed to compare the American College of Sports Medicine (ACSM) and European Society of Cardiology (ESC) pre-participation screening strategies against extensive cardiovascular evaluations in identifying high-risk individuals among 35-50-year-old apparently healthy men. METHODS: We applied ACSM and ESC pre-participation screenings to 25 men participating in a study on first-time marathon running. We compared screening outcomes against medical history, physical examination, electrocardiography, blood tests, echocardiography, cardiopulmonary exercise testing, and magnetic resonance imaging. RESULTS: ACSM screening classified all participants as 'medical clearance not necessary'. ESC screening classified two participants as 'high-risk'. Extensive cardiovascular evaluations revealed ≥1 minor abnormality and/or cardiovascular condition in 17 participants, including three subjects with mitral regurgitation and one with a small atrial septal defect. Eleven participants had dyslipidaemia, six had hypertension, and two had premature atherosclerosis. Ultimately, three (12%) subjects had a serious cardiovascular condition warranting sports restrictions: aortic aneurysm, hypertrophic cardiomyopathy (HCM), and myocardial fibrosis post-myocarditis. Of these three participants, only one had been identified as 'high-risk' by the ESC screening (for dyslipidaemia, not HCM) and none by the ACSM screening. CONCLUSION: Numerous occult cardiovascular conditions are missed when applying current ACSM/ESC screening strategies to apparently healthy middle-aged men engaging in their first high-intensity endurance sports event

Cardiac abnormalities in athletes after SARS-CoV-2 infection: A systematic review

Objectives Quantification of pericardial/myocardial involvement and risks of sudden cardiac arrest/sudden cardiac death (SCA/SCD) after SARS-CoV-2 infection in athletes who return to sports. Design Systematic review on post-SARS-CoV-2 infection pericardial/myocardial manifestations in athletes. Data sources Combinations of key terms in Medline, Embase and Scopus (through 2 June 2021). Eligibility criteria for selecting studies Inclusion: athletes, with cardiovascular magnetic resonance (CMR) or echocardiography after recovery from SARS-CoV-2 infection, including arrhythmia outcomes. Exclusion: study population ≥1 individual comorbidity and mean age 64 years. Quality assessment was performed using Joanna Briggs Institute Critical Appraisal tools checklists. Results In total, 12 manuscripts (1650 papers reviewed) comprising 3131 athletes (2198 college/student athletes, 879 professional athletes and 54 elite athletes) were included. The prevalence of myocarditis on echocardiography and/or CMR was 0%-15%, pericardial effusion 0%-58% and late gadolinium enhancement (LGE) 0%-46%. Weighted means of diagnosed myocarditis were 2.1% in college/student athletes and 0% in elite athletes. The prevalence of LGE was markedly lower in studies with high-quality assessment scores (3%-4%) versus low scores (38%-42%). A single study reported reversibility of myocardial involvement in 40.7%. No important arrhythmias were reported. Ten studies (n=4171) reporting postrecovery troponin T/I found no clear relationship with cardiac abnormalities. Summary/conclusion Athletes have an overall low risk of SARS-CoV-2 pericardial/myocardial involvement, arrhythmias and SCA/SCD. Rates of pericardial/myocardial abnormalities in athletes are highly variable and dependent on study quality. Troponin screenings seem unreliable to identify athletes at risk for myocardial involvement. Prospective athlete studies, with pre-SARS-CoV-2 imaging (CMR), including structured follow-up and arrhythmia monitoring, are urgently needed

ELITE: Rationale and design of a longitudinal elite athlete, extreme cardiovascular phenotyping, prospective cohort study

Introduction The cardiovascular benefits of physical exercise are well-known. However, vigorous exercise has also been associated with adverse cardiac effects. To improve our understanding of cardiovascular adaptation to exercise versus maladaptation and pathology, the limits of adaptation should be firmly established using state-of-the-art diagnostic modalities. We therefore initiated the Evaluation of Lifetime participation in Intensive Top-level sports and Exercise (ELITE) cohort to investigate the longitudinal (beneficial and pathological) cardiovascular effects of intensive elite sports and exercise. Methods and analysis ELITE is a prospective, multicentre, longitudinal cohort study. Elite athletes, from the age of sixteen, are recruited in The Netherlands. The primary objective is to determine the association between elite sports and exercise-induced cardiac remodelling, cardiac pathology, and health benefits over time. Secondary objectives include determining and identifying genetic profiles of elite athletes, and how these are associated with cardiac indices. ELITE will collect data from consultations, electrocardiography, echocardiography and cardiac magnetic resonance imaging, and training- and injury data. ELITE will also collect blood for biobanking and cardiogenetics. Follow-up will take place at intervals of two to five years, and after the elite athletes' professional careers have ended. In addition, a subcohort of ELITE has been established to investigate cardiac sequelae following infections associated with myocardial involvement, including SARS-CoV-2. ELITE is a prospective observational study; therefore, analyses will be primarily explorative. Ethics and dissemination This study has been approved by the Medical Ethics Review Board of the Amsterdam University Medical Centers (NL71682.018.19). The results of the study will be disseminated by publication in peer-reviewed journals (Netherlands Trial Register number: NL9328)

Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution

3C 279 is an archetypal blazar with a prominent radio jet that show broadband flux density variability across the entire electromagnetic spectrum. We use an ultra-high angular resolution technique - global Very Long Baseline Interferometry (VLBI) at 1.3 mm (230 GHz) - to resolve the innermost jet of 3C 279 in order to study its fine-scale morphology close to the jet base where highly variable gamma -ray emission is thought to originate, according to various models. The source was observed during four days in April 2017 with the Event Horizon Telescope at 230 GHz, including the phased Atacama Large Millimeter/submillimeter Array (ALMA), at an angular resolution of similar to 20 mu as (at a redshift of z=0.536 this corresponds to similar to 0.13 pc similar to 1700 Schwarzschild radii with a black hole mass M-BH=8x10(8) M-circle dot). Imaging and model-fitting techniques were applied to the data to parameterize the fine-scale source structure and its variation. We find a multicomponent inner jet morphology with the northernmost component elongated perpendicular to the direction of the jet, as imaged at longer wavelengths. The elongated nuclear structure is consistent on all four observing days and across different imaging methods and model-fitting techniques, and therefore appears robust. Owing to its compactness and brightness, we associate the northern nuclear structure as the VLBI &quot;core&quot;. This morphology can be interpreted as either a broad resolved jet base or a spatially bent jet. We also find significant day-to-day variations in the closure phases, which appear most pronounced on the triangles with the longest baselines. Our analysis shows that this variation is related to a systematic change of the source structure. Two inner jet components move non-radially at apparent speeds of similar to 15 c and similar to 20 c (similar to 1.3 and similar to 1.7 mu as day(-1), respectively), which more strongly supports the scenario of traveling shocks or instabilities in a bent, possibly rotating jet. The observed apparent speeds are also coincident with the 3C 279 large-scale jet kinematics observed at longer (cm) wavelengths, suggesting no significant jet acceleration between the 1.3 mm core and the outer jet. The intrinsic brightness temperature of the jet components are less than or similar to 10(10) K, a magnitude or more lower than typical values seen at &gt;= 7 mm wavelengths. The low brightness temperature and morphological complexity suggest that the core region of 3C 279 becomes optically thin at short (mm) wavelengths

First M87 Event Horizon Telescope Results. II. Array and Instrumentation

The Event Horizon Telescope (EHT) is a very long baseline interferometry (VLBI) array that comprises millimeter- and submillimeter-wavelength telescopes separated by distances comparable to the diameter of the Earth. At a nominal operating wavelength of similar to 1.3 mm, EHT angular resolution (lambda/D) is similar to 25 mu as, which is sufficient to resolve nearby supermassive black hole candidates on spatial and temporal scales that correspond to their event horizons. With this capability, the EHT scientific goals are to probe general relativistic effects in the strong-field regime and to study accretion and relativistic jet formation near the black hole boundary. In this Letter we describe the system design of the EHT, detail the technology and instrumentation that enable observations, and provide measures of its performance. Meeting the EHT science objectives has required several key developments that have facilitated the robust extension of the VLBI technique to EHT observing wavelengths and the production of instrumentation that can be deployed on a heterogeneous array of existing telescopes and facilities. To meet sensitivity requirements, high-bandwidth digital systems were developed that process data at rates of 64. gigabit s(-1), exceeding those of currently operating cm-wavelength VLBI arrays by more than an order of magnitude. Associated improvements include the development of phasing systems at array facilities, new receiver installation at several sites, and the deployment of hydrogen maser frequency standards to ensure coherent data capture across the array. These efforts led to the coordination and execution of the first Global EHT observations in 2017 April, and to event-horizon-scale imaging of the supermassive black hole candidate in M87