5,814 research outputs found
Historical Research and the case for a Fifth Component of SMS
Abstract
Three tragic events from aviation history were examined using a Historical Research and Case Study Method. The events explored were the disasters of the Airship R101 (1930), the Space Shuttle Challenger (1986) and the Boeing 737 Max 8 (2018). From the research, several closely related commonalities, or themes, were discovered across the three events. In each case, fatal decisions were made by upper-level managers, who allowed non-safety related motivations to influence their decision making. Each case also involved employees who discovered safety concerns and reported those concerns within their organizations, only to have those alerts be ignored, downplayed, rationalized or overruled. Analysis of these themes lead to recommendations that are aimed at preventing the circumstances that surrounded these three events from ever evolving again. Specifically, a recommendation is made to add a fifth component to the FAA’s current Safety Management System
Lessons from my Undergraduate Research Students
From very early on, my personal/professional life has been shaped by teachers in many different settings. Teaching and learning form a two-way street. In the process of teaching undergraduate students, particularly in the research lab, I have learned some profound lessons about the importance of listening to them, challenging them, giving them autonomy, and allowing them to enjoy success and to risk failure. I am now working with a team of faculty members to implement these lessons in a course-based undergraduate research experience in the biochemistry teaching laboratory. Our goal is to seek answers to the question “How do students become scientists?” and to implement those answers with our future students
A Content Analysis of Three Works of Aviation Literature
Using the qualitative research method of Content Analysis, a comprehensive exploration was conducted into three acclaimed works of aviation literature: Wind, Sand and Stars, by Antoine de Saint-Exupery; West with the Night, by Beryl Markham; and Fate is the Hunter, by Ernest K. Gann. Using the precise elements of the methodology, codes were identified, categories were combined and emerging themes were discovered. These discoveries led to a greater understanding of the works and their contribution to the knowledge base of aviation
No evidence for a culturable bacterial tetrodotoxin producer in Pleurobranchaea maculata (Gastropoda: Pleurobranchidae) and Stylochoplana sp. (Platyhelminthes: Polycladida)
Tetrodotoxin (TTX) is a potent neurotoxin found in the tissues of many taxonomically diverse organisms. Its origin has been the topic of much debate, with suggestions including endogenous production, acquisition through diet, and symbiotic bacterial synthesis. Bacterial production of TTX has been reported in isolates from marine biota, but at lower than expected concentrations. In this study, 102 strains were isolated from Pleurobranchaea maculata (Opisthobranchia) and Stylochoplana sp. (Platyhelminthes). Tetrodotoxin production was tested utilizing a recently developed sensitive method to detect the C9 base of TTX via liquid chromatography—mass spectrometry. Bacterial strains were characterized by sequencing a region of the 16S ribosomal RNA gene. To account for the possibility that TTX is produced by a consortium of bacteria, a series of experiments using marine broth spiked with various P. maculata tissues were undertaken. Sixteen unique strains from P. maculata and one from Stylochoplana sp. were isolated, representing eight different genera; Pseudomonadales, Actinomycetales, Oceanospirillales, Thiotrichales, Rhodobacterales, Sphingomonadales, Bacillales, and Vibrionales. Molecular fingerprinting of bacterial communities from broth experiments showed little change over the first four days. No C9 base or TTX was detected in isolates or broth experiments (past day 0), suggesting a culturable microbial source of TTX in P. maculata and Stylochoplana sp. is unlikely
The Relation Between Managed Care Market Share and the Treatment of Elderly Fee-For-Service Patients with Myocardial Infarction
Managed care may affect medical treatments for non-managed-care patients if it alters local market structure or physician behavior. We investigate whether higher levels of overall managed care market share are associated with greater use of recommended therapies for fee-for-service patients with acute myocardial infarction using data on 112,900 fee-for-service Medicare beneficiaries residing in one of 320 metropolitan statistical areas, with age >= 65 years, and admitted with an acute myocardial infarction between February 1994 and July 1995 from the Cooperative Cardiovascular Project. After adjustment for patient characteristics, severity of illness, characteristics of the hospital of admission, specialty of treating physicians, and other area characteristics, patients treated in areas with high levels of managed care had greater relative use of beta-blockers during hospitalization and at discharge and aspirin during hospitalization and at discharge, consistent with more appropriate care. Patients in high HMO areas may be less likely to receive angiography when compared to areas with low levels of managed care, although this result was only marginally significant. In unadjusted comparisons, patients in high HMO market share areas had lower 30 day mortality, but there were no differences in 30 day mortality when all of the control variables were included in the model. We conclude that managed care can have widespread effects on the treatment of patients and the quality of care they receive, even for patients not enrolled in managed care organizations.
Oxidation processes in magneto-optic and related materials
The surface oxidation processes of thin films of magneto-optic materials, such as the rare-earth transition metal alloys have been studied, starting in ultrahigh vacuum environments, using surface analysis techniques, as a way of modeling the oxidation processes which occur at the base of a defect in an overcoated material, at the instant of exposure to ambient environments. Materials examined have included FeTbCo alloys, as well as those same materials with low percentages of added elements, such a Ta, and their reactivities to both O2 and H2O compared with materials such as thin Fe films coated with ultrathin adlayers of Ti. The surface oxidation pathways for these materials is reviewed, and XPS data presented which indicates the type of oxides formed, and a critical region of Ta concentration which provides optimum protection
The Platte as a Prairie River: A Response to Johnson and Boettcher
Johnson and Boettcher (2000) question the status of the presettlement Platte River as a prairie river, and they argue that it was a wooded river traversing a prairie landscape. Here we review evidence in support of the prairie river concept, suggesting the channels of the Platte were predominantly open and largely absent of trees. Direct support for a prairie river is found in the detailed map drawn by Lieutenant Woodbury in locating the site for Fort Kearny in 1847. Woodbury showed a thin strip of timber, located in an area that appeared to be elevated above the influence of active river flows. Woodbury also illustrated the main channel as having vegetated islands only in one location, with only a scattering [of] trees along the banks. Historical accounts, an examination of historical perspectives, the distribution of land survey witness trees, a lack of regeneration of trees following supposed deforestation, and population changes in bird distributions over the past 100 years also support the prairie river concept. We argue woodland development is not true restoration in this area. Given current conditions, we suggest that long term management should be for a mosaic of habitats for migratory birds and other species including 10% open river channel in the Big Bend reach of the Platte River in central Nebraska
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