Another Approach to Enhance Airline Safety: Using Management Safety Tools

The ultimate goal of conducting an accident investigation is to prevent similar accidents from happening again and to make operations safer system-wide. Based on the findings extracted from the investigation, the "lesson learned" becomes a genuine part of the safety database making risk management available to safety analysts. The airline industry is no exception. In the US, the FAA has advocated the usage of the System Safety concept in enhancing safety since 2000. Yet, in today s usage of System Safety, the airline industry mainly focuses on risk management, which is a reactive process of the System Safety discipline. In order to extend the merit of System Safety and to prevent accidents beforehand, a specific System Safety tool needs to be applied; so a model of hazard prediction can be formed. To do so, the authors initiated this study by reviewing 189 final accident reports from the National Transportation Safety Board (NTSB) covering FAR Part 121 scheduled operations. The discovered accident causes (direct hazards) were categorized into 10 groups Flight Operations, Ground Crew, Turbulence, Maintenance, Foreign Object Damage (FOD), Flight Attendant, Air Traffic Control, Manufacturer, Passenger, and Federal Aviation Administration. These direct hazards were associated with 36 root factors prepared for an error-elimination model using Fault Tree Analysis (FTA), a leading tool for System Safety experts. An FTA block-diagram model was created, followed by a probability simulation of accidents. Five case studies and reports were provided in order to fully demonstrate the usefulness of System Safety tools in promoting airline safety

The role of TonEBP in regulation of AAD expression and dopamine production in renal proximal tubule cells upon hypertonic challenge

a b s t r a c t Renal proximal tubule cells overexpress aromatic L-amino acid decarboxylase (AAD) to produce dopamine, which inhibits salt absorption in the hypertonic environment. We examined the effect of TonEBP on AAD expression in human proximal tubule epithelial cells, HK-2 cell line. Confocal microscopy showed that after 2 h of exposure to the hypertonic medium, TonEBP accumulation in nuclei increased as compared to the isotonic control. The activated TonEBP enhanced the mRNA expression of the representative downstream genes (i.e., SMIT and TauT). Meanwhile, AAD protein abundance also increased with TonEBP activation. EMSA and luciferase reporter assay showed that TonEBP was involved in transcriptional regulation of AAD upon hypertonic stress. Inactivation of TonEBP by the p38 inhibitor SB203580, or TonEBP shRNA significantly reduced AAD expression, which was rescued by re-expressing Myc-tagged TonEBP. Up-regulation of AAD increased dopamine synthesis, and dopamine inhibited NKA activity in hypertonic condition. These results suggested that TonEBP played an important role in the epithelial cells of renal proximal tubule upon hypertonic stress by enhancing AAD expression, which could promote dopamine secretion to negative regulate NKA activity. The elucidation of a new mechanism described in this study combined with previous findings provides more insights into this issue