20 research outputs found
Two Decades of Progress for Minorities in Aviation
Diversity within the science, technology, engineering, and mathematics (STEM) fields has historically lagged behind that which is found in other vocational paths. Aviation has also suffered poor diversity with virtually no participation among professional pilots. With both the literature specifying the benefits of diversity in the aviation workplace and potential shortages of pilots looming, it is in the interest of aerospace stakeholders to have access to the most comprehensively diverse employee pool possible. The purpose of this research was to evaluate the trends in participation by minorities who completed professional pilot education programs in the United States. Data concerning the number of students who completed degrees at the associate’s, bachelor’s, and master’s levels were collected via the Integrated Postsecondary Education Data System (IPEDS). Participation rates were compared to those found within the aviation industry. In general, the participation rates by non-White minorities in collegiate aviation (27.3%) exceeds that reported in the professional pilot vocation (18.4%). Detailed trends over the past 10 years were evaluated. Between 2004 and 2014, minority (including women) participation increased from 17.1% to 22.2%, which was deemed to be statistically significant (z = 3.7, p \u3c 0.001). The greatest gains were exhibited among Hispanics (p \u3c 0.001), specifically Hispanic men (p \u3c 0.001), with marginal gains by Asians (p = 0.06). Decreases were noted in Native American participation (p = 0.03) as well as among women, albeit not significantly (p = 0.31). When extending the analysis back another seven years, minority (including women) participation showed significant change from 1997 (16.5%) to 2014 (22.2%), z = 3.7, p \u3c 0.001. Minority participation in professional pilot education has shown steady gains over the past two decades; however, it appears that this trend is leveling, especially among women. Further study is recommended with particular interest in promotion and recruitment of a diverse aviation student population
Identification of Air Traffic Management Principles Influential in the Development of an Airport Arrival Delay Prediction Model
Since the September 11, 2001 attacks, worldwide air traffic has steadily been increasing towards peak levels reported from 2000 to 2001 (Federal Aviation Administration [FAA], 2011). Although U.S. system-wide traffic is still around 10% less than the highest volumes, congestion at particular airports prone to delays, such as Newark, Philadelphia, New York LaGuardia, and New York Kennedy, is up nearly 10% from 2000 metrics. Other airports, such as Chicago O’Hare and Atlanta in the U.S. and London Heathrow, Madrid, and Istanbul in Europe, are seemingly continually plagued with flight delays regardless of variations in traffic (FAA, 2012). According to the Bureau of Transportation Statistics (2013), the best flight punctuality rate among the 29 largest primary U.S. airports in January 2012 was 89.7% with the worst being 77.2%. In Europe, 14 major airports reported arrival delays in excess of 15 minutes for more than 25% of flights (FAA, 2012). Air traffic forecasts through 2031 indicate that both the passenger volume and the number of transport aircraft will be double that of 2012 levels. Considering many of the aforementioned airports are operating near or beyond capacity, it is likely that air traffic delays will only get worse (Airbus, 2012). The importance of delay management is critical to a variety of stakeholders from passengers to air carrier operations management to air traffic control personnel. Reliable delay prediction can mitigate the snowball effects delays can have on the air traffic management system and air carrier structures (Xu, Sherry, & Laskey, 2008). A variety of studies have been implemented to study air traffic delays but generally focus on a system-wide approach that includes arrival, enroute, and departure delays (Brooker, 2009; Coy, 2006; Santos & Robin, 2011; Xu, Sherry, & Laskey, 2008). Alternatively, others have focused on individual airports and their potential influence on the whole air traffic management system (Nayak & Zhang, 2011). More research on the factors associated with and prediction of airport-related delays have been advocated (Brooker, 2009; Coy, 2006; Nayak & Zhang, 2011; Santos & Robin, 2011; Xu, Sherry, & Laskey, 2008). Ideally, an improved model with predictive capabilities would assist in planning for and potentially mitigating negative effects of airport-based arrival congestion. The goal of this pilot study is to begin the construction of an improved airport delay prediction model by exploring potentially influential air traffic management principles. Utilizing expert panel-based model and procedural improvement techniques similar to those used in medical and technical fields, this study aims to bolster existing airport arrival delay prediction models (Deason & Jefferson, 2010; Estes, 2008; Gisev, Bell, O’Reilly, Rosen, & Chen, 2010). In this Phase I pilot study, a purposeful sample of air traffic control instructors, college faculty, and air traffic controllers will be asked to generate a list of air traffic management principles that influence airport arrival efficiency. This data will be utilized to create subsequent phases which will include a Delphi Panel to rank the identified principles, confirmatory analysis, statistical modeling, and model testing
Airborne Isocyanate Exposures in the Collision Repair Industry and a Comparison to Occupational Exposure Limits
Isocyanate exposure was evaluated in 33 spray painters from 25 Washington State autobody shops. Personal breathing zone samples (n = 228) were analyzed for isophorone diisocyanate (IPDI) monomer, 1,6-hexamethylene diisocyanate (HDI) monomer, IPDI polyisocyanate, and three polyisocyanate forms of HDI. The objective was to describe exposures to isocyanates while spray painting, compare them with short-term exposure limits (STELs), and describe the isocyanate composition in the samples. The composition of polyisocyanates (IPDI and HDI) in the samples varied greatly, with maximum amounts ranging from up to 58% for HDI biuret to 96% for HDI isocyanurate. There was a significant inverse relationship between the percentage composition of HDI isocyanurate to IPDI and to HDI uretdione. Two 15-min STELs were compared: (1) Oregon's Occupational Safety and Health Administration (OR-OSHA) STEL of 1000 μg/m3 for HDI polyisocyanate, and (2) the United Kingdom's Health and Safety Executive (UK-HSE) STEL of 70 μg NCO/m3 for all isocyanates. Eighty percent of samples containing HDI polyisocyanate exceeded the OR-OSHA STEL while 98% of samples exceeded the UKHSE STEL. The majority of painters (67%) wore half-face air-purifying respirators while spray painting. Using the OROSHA and the UK-HSE STELs as benchmarks, 21% and 67% of painters, respectively, had at least one exposure that exceeded the respirator's OSHA-assigned protection factor. A critical review of the STELs revealed the following limitations: (1) the OR-OSHA STEL does not include all polyisocyanates, and (2) the UK-HSE STEL is derived from monomeric isocyanates, whereas the species present in typical spray coatings are polyisocyanates. In conclusion, the variable mixtures of isocyanates used by autobody painters suggest that an occupational exposure limit is required that includes all polyisocyanates. Despite the limitations of the STELs, we determined that a respirator with an assigned protection factor of 25 or greater is required to protect against isocyanate exposures during spray painting. Consequently, half-face air-purifying respirators, which are most commonly used and have an assigned protection factor of 10, do not afford adequate respiratory protection
Rationale and design of the participant, investigator, observer, and data-analyst-blinded randomized AGENDA trial on associations between gene-polymorphisms, endophenotypes for depression and antidepressive intervention: the effect of escitalopram versus placebo on the combined dexamethasone-corticotrophine releasing hormone test and other potential endophenotypes in healthy first-degree relatives of persons with depression
<p>Abstract</p> <p>Background</p> <p>Endophenotypes are heritable markers, which are more prevalent in patients and their healthy relatives than in the general population. Recent studies point at disturbed regulation of the hypothalamic-pituitary-adrenocortical axis as a possible endophenotype for depression. We hypothesize that potential endophenotypes for depression may be affected by selective serotonin re-uptake inhibitor antidepressants in healthy first-degree relatives of depressed patients. The primary outcome measure is the change in plasma cortisol in the dexamethasone-corticotrophin releasing hormone test from baseline to the end of intervention.</p> <p>Methods</p> <p>The AGENDA trial is designed as a participant, investigator, observer, and data-analyst-blinded randomized trial. Participants are 80 healthy first-degree relatives of patients with depression. Participants are randomized to escitalopram 10 mg per day versus placebo for four weeks. Randomization is stratified by gender and age. The primary outcome measure is the change in plasma cortisol in the dexamethasone-corticotrophin releasing hormone test at entry before intervention to after four weeks of intervention. With the inclusion of 80 participants, a 60% power is obtained to detect a clinically relevant difference in the primary outcome between the intervention and the placebo group. Secondary outcome measures are changes from baseline to four weeks in scores of: 1) cognition and 2) neuroticism. Tertiary outcomes measures are changes from baseline to four weeks in scores of: 1) depression and anxiety symptoms; 2) subjective evaluations of depressive symptoms, perceived stress, quality of life, aggression, sleep, and pain; and 3) salivary cortisol at eight different timepoints during an ordinary day. Assessments are undertaken by assessors blinded to the randomization group.</p> <p>Trial registration</p> <p>Local Ethics Committee: H-KF 307413</p> <p>Danish Medicines Agency: 2612-3162.</p> <p>EudraCT: 2006-001750-28.</p> <p>Danish Data Agency: 2006-41-6737.</p> <p>ClinicalTrials.gov: NCT 00386841</p
Clinical evaluation of intranasal medetomidine-ketamine and medetomidine-S(+)-ketamine for induction of anaesthesia in rabbits in two centres with two different administration techniques
OBJECTIVE: The aim was to compare efficacy and side effects of induction with medetomidine-ketamine or medetomidine-S(+)-ketamine by intranasal (IN) instillation in rabbits and to evaluate both protocols during subsequent isoflurane anaesthesia. STUDY DESIGN: Prospective, blinded, randomized experimental study in two centres. ANIMALS: Eighty-three healthy New Zealand White rabbits undergoing tibial or ulnar osteotomy. METHODS: Medetomidine (0.2 mg kg-1 ) with 10 mg kg-1 ketamine (MK) or 5 mg kg-1 S(+)-ketamine (MS) was administered IN to each rabbit in a randomized fashion. In Centre 1 (n = 42) rabbits were held in sternal recumbency, and in Centre 2 (n = 41) in dorsal recumbency, during drug instillation. Adverse reactions were recorded. If a rabbit swallowed during endotracheal intubation, half of the initial IN dose was repeated and intubation was re-attempted after 5 minutes. Anaesthesia was maintained with isoflurane. Heart rate, blood pressure, end-tidal carbon dioxide concentration and blood gases were recorded. Data were analysed using Student's t-test, Mann-Whitney test and Fisher's exact test. RESULTS: In all, 39 animals were assigned to the MK group and 44 to the MS group. Two rabbits in the MS group held in dorsal recumbency died after instillation of the drug. Eight (MK) and 11 rabbits (MS) were insufficiently anaesthetized and received a second IN dose. One rabbit in MK and three in MS required an isoflurane mask induction after the second IN dose. There were no significant differences between treatments for induction, intraoperative data, blood gas values and recovery data. CONCLUSION AND CLINICAL RELEVANCE: This study indicated that medetomidine-ketamine and medetomidine-S(+)-ketamine were effective shortly after IN delivery, but in dorsal recumbency IN administration of S(+)-ketamine led to two fatalities. Nasal haemorrhage was noted in both cases; however, the factors leading to death have not been fully elucidated
Clinical evaluation of intranasal medetomidine–ketamine and medetomidine–S(+)-ketamine for induction of anaesthesia in rabbits in two centres with two different administration techniques
Airborne Isocyanate Exposures in the Collision Repair Industry and a Comparison to Occupational Exposure Limits
Isocyanate exposure was evaluated in 33 spray painters from 25 Washington State autobody shops. Personal breathing zone samples (n = 228) were analyzed for isophorone diisocyanate (IPDI) monomer, 1,6-hexamethylene diisocyanate (HDI) monomer, IPDI polyisocyanate, and three polyisocyanate forms of HDI. The objective was to describe exposures to isocyanates while spray painting, compare them with short-term exposure limits (STELs), and describe the isocyanate composition in the samples. The composition of polyisocyanates (IPDI and HDI) in the samples varied greatly, with maximum amounts ranging from up to 58% for HDI biuret to 96% for HDI isocyanurate. There was a significant inverse relationship between the percentage composition of HDI isocyanurate to IPDI and to HDI uretdione. Two 15-min STELs were compared: (1) Oregon's Occupational Safety and Health Administration (OR-OSHA) STEL of 1000 μg/m(3) for HDI polyisocyanate, and (2) the United Kingdom's Health and Safety Executive (UK-HSE) STEL of 70 μg NCO/m(3) for all isocyanates. Eighty percent of samples containing HDI polyisocyanate exceeded the OR-OSHA STEL while 98% of samples exceeded the UKHSE STEL. The majority of painters (67%) wore half-face air-purifying respirators while spray painting. Using the OROSHA and the UK-HSE STELs as benchmarks, 21% and 67% of painters, respectively, had at least one exposure that exceeded the respirator's OSHA-assigned protection factor. A critical review of the STELs revealed the following limitations: (1) the OR-OSHA STEL does not include all polyisocyanates, and (2) the UK-HSE STEL is derived from monomeric isocyanates, whereas the species present in typical spray coatings are polyisocyanates. In conclusion, the variable mixtures of isocyanates used by autobody painters suggest that an occupational exposure limit is required that includes all polyisocyanates. Despite the limitations of the STELs, we determined that a respirator with an assigned protection factor of 25 or greater is required to protect against isocyanate exposures during spray painting. Consequently, half-face air-purifying respirators, which are most commonly used and have an assigned protection factor of 10, do not afford adequate respiratory protection