We argue that long-term debt has a role in controlling management's ability to finance future investments. A company with high (widely-held) debt will find it hard to raise capital. since new security holders will have low priority relative to existing creditors. Conversely for a company with low debt We show there is an optimal debt-equity ratio and mix of senior and junior debt if management undertakes unprofitable as well as profitable investments. We derive conditions under which equity and a single class of senior long-term debt work as well as more complex conuacts for controlling investment behavior.

Air pollutants correlate with CRS symptom severity that may be influenced by exposure levels, with a more pronounced impact on CRSsNP patients. This study is the first to demonstrate the possible role of inhalant pollutants in CRS phenotypes, addressing a critical knowledge gap in environmental risk factors for disease progression.

Background Chronic rhinosinusitis (CRS) is a significant manifestation of cystic fibrosis (CF) with wide‐ranging symptom and disease severity. The goal of the study was to determine clinical variables that correlate with outcome measures of disease severity. Methods A prospective, longitudinal, observational study of 33 adults with symptomatic CRS treated in a CF‐focused otolaryngology clinic was performed. Symptom severity, the presence of rhinosinusitis exacerbations, and endoscopic appearance were assessed, and regression analysis was used to determine clinical predictors of disease outcome. Results Thirty‐three adults with CF‐CRS were included in the study and followed for a mean of 15 months. Rhinosinusitis exacerbations occurred in 61% of participants during the study, and female sex increased the odds of presenting with an exacerbation visit. Sinus disease exacerbations were associated with an odds ratio of 2.07 for presenting with a pulmonary exacerbation at the next visit. CF‐related diabetes was found to be associated with worse symptoms and endoscopic appearance. Infection with Staphylococcus aureus predicted worsening of symptoms, whereas infections with Pseudomonas aeruginosa improved over time. Allergic rhinitis was associated with worse endoscopic appearance, and nasal steroid use was associated with improved endoscopic appearance. Conclusion Sex, CF‐related diabetes, sinonasal infection status, allergic rhinitis, and nasal steroid use may all modulate severity of CF‐CRS in adults. Sinusitis exacerbation may be a precursor to pulmonary exacerbation.

Our results suggest that small inhalant pollutants may contribute to nonallergic symptomatology in patients with and without nasal polyps. Regardless of allergy status, BC may play a role in CRS symptom severity.

's institution has received funding from the National Natural Science Foundation of China. Z. Li and W. Zhang's institution has received funding from the Shanghai Science and Technology Committee. The rest of the authors declare that they have no relevant conflicts of interest.