On geometric ideas which lie at the foundation of quantum theory

AbstractPart I advances the hypothesis that between any two events on the world-line of a particle there can be at most finitely many intermediate events. From this it draws the conclusion that the space-time coordinates of events do not have precise meanings. Part II modifies the Feynman integral in a way which is analogous to the replacement of white noise by Gaussian noise. It thereby obtains a version of the quantum mechanics for a nonrelativistic particle in a potential. In the new discrete quantum theory, space coordinates have probabilistic rather than precise meanings; the energy of a free particle is a bounded operator; and the potential energy is a compact operator. It is argued that the differential scattering cross section for elastic scattering is unchanged when taken in the Born approximation

Association of operative approach with postoperative outcomes in neonates undergoing surgical repair of esophageal atresia and tracheoesophageal fistula

Introduction: Minimally invasive surgery (MIS) is gaining traction as a first-line approach to repair congenital anomalies. This study aims to evaluate outcomes for neonates undergoing open versus MIS repairs for esophageal atresia/tracheoesophageal fistula (EA/TEF). Methods: Neonates undergoing EA/TEF repair from 2013-2020 were identified using the National Surgical Quality Improvement Program-Pediatric database. Proportions of operative approach (open vs. MIS) over time were analyzed. A propensity score-matched analysis using preoperative characteristics was performed and outcomes were compared including composite morbidity and reintervention rates (overall, major [thoracoscopy, thoracotomy], and minor [chest/feeding tube placement, endoscopy]) between operative approaches. Pearson’s chi-square or Fisher’s exact test were used as appropriate. Results: We identified 1738 neonates who underwent EA/TEF repair. MIS utilization increased over time (p=0.019). Pre-match, neonates undergoing open repair were more likely premature, lower weight, and higher ASA class. Post-match, the groups were similar and included 183 neonates per group. MIS repair was associated with longer median operative time (206 vs. 180 minutes, p\u3c0.001), increased overall reintervention rates (MIS 9.8% vs. open 3.3%, p=0.011), and increased minor reintervention rates (MIS 7.7% vs. open 2.2%, p=0.016). There were no differences in composite morbidity (MIS 20.2% vs. open 26.8%, p=0.14) or major reinterventions (MIS 2.2% vs. open 1.1%, p=0.41). Discussion: MIS is gaining traction as a first-line approach for neonates with EA/TEF but appears to be associated with a higher rate of reinterventions. Further studies evaluating MIS approaches for the repair of EA/TEF are needed to better define short and long-term outcomes to optimize patient selection

Small representations of finite classical groups

Finite group theorists have established many formulas that express interesting properties of a finite group in terms of sums of characters of the group. An obstacle to applying these formulas is lack of control over the dimensions of representations of the group. In particular, the representations of small dimensions tend to contribute the largest terms to these sums, so a systematic knowledge of these small representations could lead to proofs of important conjectures which are currently out of reach. Despite the classification by Lusztig of the irreducible representations of finite groups of Lie type, it seems that this aspect remains obscure. In this note we develop a language which seems to be adequate for the description of the "small" representations of finite classical groups and puts in the forefront the notion of rank of a representation. We describe a method, the "eta correspondence", to construct small representations, and we conjecture that our construction is exhaustive. We also give a strong estimate on the dimension of small representations in terms of their rank. For the sake of clarity, in this note we describe in detail only the case of the finite symplectic groups.Comment: 18 pages, 9 figures, accepted for publications in the proceedings of the conference on the occasion of Roger Howe's 70th birthday (1-5 June 2015, Yale University, New Haven, CT

Traumatic injury in the United States: In-patient epidemiology 2000–2011

Background Trauma is a leading cause of death and disability in the United States (US). This analysis describes trends and annual changes in in-hospital trauma morbidity and mortality; evaluates changes in age and gender specific outcomes, diagnoses, causes of injury, injury severity and surgical procedures performed; and examines the role of teaching hospitals and Level 1 trauma centres in the care of severely injured patients. Methods We conducted a retrospective descriptive and analytic epidemiologic study of an inpatient database representing 20,659,684 traumatic injury discharges from US hospitals between 2000 and 2011. The main outcomes and measures were survey-adjusted counts, proportions, means, standard errors, and 95% confidence intervals. We plotted time series of yearly data with overlying loess smoothing, created tables of proportions of common injuries and surgical procedures, and conducted survey-adjusted logistic regression analysis for the effect of year on the odds of in-hospital death with control variables for age, gender, weekday vs. weekend admission, trauma-centre status, teaching-hospital status, injury severity and Charlson index score. Results The mean age of a person discharged from a US hospital with a trauma diagnosis increased from 54.08 (s.e. = 0.71) in 2000 to 59.58 (s.e. = 0.79) in 2011. Persons age 45–64 were the only age group to experience increasing rates of hospital discharges for trauma. The proportion of trauma discharges with a Charlson Comorbidity Index score greater than or equal to 3 nearly tripled from 0.048 (s.e. = 0.0015) of all traumatic injury discharges in 2000 to 0.139 (s.e. = 0.005) in 2011. The proportion of patients with traumatic injury classified as severe increased from 22% of all trauma discharges in 2000 (95% CI 21, 24) to 28% in 2011 (95% CI 26, 30). Level 1 trauma centres accounted for approximately 3.3% of hospitals. The proportion of severely injured trauma discharges from Level 1 trauma centres was 39.4% (95% CI 36.8, 42.1). Falls, followed by motor-vehicle crashes, were the most common causes of all injuries. The total cost of trauma-related inpatient care between 2001 and 2011 in the US was $240.7 billion (95$12.0 billion (95% CI 10.5, 13.4) in 2001 to 29.1 billion (95% CI 25.2, 32.9) in 2011. Conclusions Trauma, which has traditionally been viewed as a predicament of the young, is increasingly a disease of the old. The strain of managing the progressively complex and costly care associated with this shift rests with a small number of trauma centres. Optimal care of injured patients requires a reappraisal of the resources required to effectively provide it given a mounting burden

International Bottom Trawl Survey Working Group (IBTSWG). ICES Scientific Reports, 04:65

The International Bottom Trawl Survey Working Group (IBTSWG) coordinates fishery-independent bottom trawl surveys in the ICES area in the Northeast Atlantic and the North Sea. These long-term monitoring surveys provide data for stock assessments and facilitate examina-tion of changes in fish distribution and relative abundance. The group also promotes the stand-ardization of fishing gears and methods as well as survey coordination. This report summarizes the national contributions in 2021–2022 and plans for the 2022–2023 surveys coordinated by IBTSWG

Policy mixes for incumbency: the destructive recreation of renewable energy, shale gas 'fracking,' and nuclear power in the United Kingdom

The notion of a ‘policy mix’ can describe interactions across a wide range of innovation policies, including ‘motors for creation’ as well as for ‘destruction’. This paper focuses on the United Kingdom’s (UK) ‘new policy direction’ that has weakened support for renewables and energy efficiency schemes while strengthening promotion of nuclear power and hydraulic fracturing for natural gas (‘fracking’). The paper argues that a ‘policy apparatus for incumbency’ is emerging which strengthens key regimebased technologies while arguably damaging emerging niche innovations. Basing the discussion around the three technology-based cases of renewable energy and efficiency, fracking, and nuclear power, this paper refers to this process as “destructive recreation”. Our study raises questions over the extent to which policymaking in the energy field is not so much driven by stated aims around sustainability transitions, as by other policy drivers. It investigates different ‘strategies of incumbency’ including ‘securitization’, ‘masking’, ‘reinvention’, and ‘capture.’ It suggests that analytical frameworks should extend beyond the particular sectors in focus, with notions of what counts as a relevant ‘policy maker’ correspondingly also expanded, in order to explore a wider range of nodes and critical junctures as entry points for understanding how relations of incumbency are forged and reproduced