Optimal capital investment under uncertainty: An extension

This paper develops a model for optimal capital investment in continuous time when both existing and new capital stocks are subject to uncertainty. The model is generalized to allow for large and infrequent changes in the dynamics of the capital stock, which may arise as a result of natural and man-made disasters.

Antibiotic prescription consistent with guidelines in emergency department is associated with 30-day survival in severe community-acquired pneumonia

Background The selection of initial empirical antibiotics is an important issue in the treatment of severe community-acquired pneumonia (CAP). This study aimed to investigate whether empirical antibiotic prescription concordant with guidelines in the emergency department (ED) affects 30-day mortality in patients with severe CAP. Methods We conducted a retrospective analysis of adult patients with severe CAP who were hospitalized in the ED. Severe CAP was defined according to the criteria of the 2007 Infectious Diseases Society of America/American Thoracic Society guidelines. Patients were divided into two groups according to whether they were prescribed empirical antibiotics concordant with guidelines. Multivariable Cox proportional hazard regression analysis was performed to identify the independent association between the prescription of initial empirical antibiotics concordant with the guidelines and 30-day mortality. Propensity score matching was performed to reduce selection bias between groups and Kaplan–Meier survival analysis was performed to analyze the time-to-event of 30-day survival. Results In total, 630 patients were hospitalized in the ED for severe CAP, and 179 (28.4%) died within 30 days. Antibiotics consistent with guidelines were prescribed to 359 (57.0%) patients. The 30-day mortality was significantly higher in the guideline-discordant group (p = 0.003) and multivariable Cox proportional hazard regression analysis revealed that the prescription of antibiotics discordant with the guidelines was independently associated with 30-day mortality (hazard ratio 1.43, 95% CI 1.05–1.93). After propensity score matching, there were 255 patients in each group. The 30-day mortality was lower in the group prescribed guideline-concordant antibiotics than in the group prescribed guideline-discordant antibiotics (23.9% vs. 33.3%, p = 0.024). Kaplan–Meier survival analysis showed that antibiotic prescription concordant with the guidelines resulted in higher survival rates at 30 days (p = 0.002). Conclusions The prevalence of antibiotic prescription consistent with guidelines for severe CAP seemed to be low in the ED, and this variable was independently associated with 30-day survival.This work was supported by the grant no. 02–2014-007 from the SNUBH Research Fund. The funders of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication

Analysis of Porcine Model of Fecal-Induced Peritonitis Reveals the Tropism of Blood Microbiome

Recent studies have suggested the existence of a blood microbiome in the healthy host. However, changes in the blood microbiome upon bloodstream infection are not known. Here, we analyzed the dynamics of the blood microbiome in a porcine model of polymicrobial bacteremia induced by fecal peritonitis. Surprisingly, we detected bacterial populations in the bloodstream even before the infection, and these populations were maintained over time. The native blood microbiome was notably taxonomically different from the fecal microbiome that was used to induce peritonitis, reflecting microbial tropism for the blood. Although the population composition after the infection was similar to that of the native blood microbiome, new bacterial strains entered the bloodstream upon peritonitis induction as clinical symptoms relevant to sepsis developed. This indicates that the bacteria detected in the blood before peritonitis induction were derived from the blood rather than a contamination. Comparison of the functional pathways enriched in the blood and fecal microbiomes revealed that communication and stress management pathways are essential for the survival of the blood microbiome

Portfolio optimization with defaultable securities.

Portfolio optimization with defaultable securities