We discuss theoretical properties and estimation of continuous-time ARMA (CARMA) processes, which are driven by a stable Lévy process. Such processes are very useful in a continuous-time linear stationary setup: they have a similar structure as the widely used ARMA models, and provide all advantages of a continuous-time model. As an application we consider data from a deregulated electricity market. Here we t a CARMA(2,1) model to spot prices from the Singapore New Electricity Market. The quality of the estimates is assessed in a simulation study. The continuous-time modelling aims at a new pricing methodology for energy derivatives.

We investigate the large-sample behavior of change-point tests based on weighted two-sample U-statistics, in the case of short-range dependent data. Under some mild mixing conditions, we establish convergence of the test statistic to an extreme value distribution. A simulation study shows that the weighted tests are superior to the nonweighted versions when the change-point occurs near the boundary of the time interval, while they loose power in the center.

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Subcutaneous abscesses occur frequently in the pediatric population, yet there is great variability in the approach to diagnosis and management, partly due to opposing recommendations in the current literature and the lack of a standardized protocol for diagnosis and management among pediatric medical centers. This has led to inconsistencies by the providers, as well as the hospital clinical pathways, with regards to the appropriate management of subcutaneous abscesses. We hypothesize that the current variability in diagnostic work-up and management contributes to the wide use of unnecessary imaging and therapeutics without altering the overall outcomes. We performed a retrospective chart review that compared 200 encounters for patients < 18 years of age with a diagnosis of subcutaneous abscess at a single large tertiary pediatric institution. Our results showed that only 13.6% of wound cultures obtained led to a change in the antibiotic regimen and that blood cultures were positive in only 2.1% of cases. There was no difference in the incision and drainage performed based on ultrasound findings in the presence of fluctuance on physical exam. Patients presenting with fever were more likely to be admitted to the hospital for further care than those without fever. Our results showed no difference in outcome after incision and drainage for abscesses packed with gauze versus those left to drain via a vessel loop drain. There was no difference in recurrence in patients discharged with oral antibiotics versus without oral antibiotic treatment. Our data indicate that many of the diagnostic studies used for the management of a subcutaneous abscess have little to no effect on the outcome. Subcutaneous abscesses are a common pediatric complaint, and this study could help healthcare providers utilize more effective and efficient management strategies for skin and soft tissue infections.

(1) Background: Significant racial and ethnic disparities affect access to pediatric Emergency Department (ED) and surgical care across the United States. The present study sought to assess the role of racial and ethnic disparities in the management of pediatric subcutaneous abscesses. (2) Methods: A retrospective chart review was performed including ED visits for subcutaneous abscesses in patients < 18 years of age, over a 12-month period. The effects of self-reported ethnicity (Hispanic versus non-Hispanic) and race (Hispanic, Black, Caucasian and Asian) on the diagnosis and management of subcutaneous abscesses were analyzed. (3) Results: 192 patients were identified with an average age of 4.7 ± 5.3 years and 43.8% identified as Hispanic. Non-Hispanic patients were significantly more likely to receive treatment of their SSTI prior to the ED and to be admitted, compared to Hispanic patients. There was no difference in bedside versus operating room incision and drainage (I&D); however, significantly more non-Hispanic patients received procedural sedation for bedside I&D compared to Hispanic patients. There were no differences in outcomes such as recurrence or re-admission based on ethnicity or race. (4) Conclusions: Ethnic and racial disparities exist in the management of subcutaneous abscesses in the United States. Further studies are needed to address the systemic causes of these disparities such as access to tertiary healthcare facilities and systems-based analyses of unconscious bias in healthcare.