3,412 research outputs found
Have the Major U.S. Air Carriers Finally Turned the Corner? A Financial Condition Assessment
Rare prior to the deregulation of the airline industry, air carrier bankruptcies became rather endemic in the period 1982-2005. Since 1982, over 175 airlines have filed under the bankruptcy codes. This number includes eight of the carriers that were formerly referred to as “trunk carriers,” now known as “Majors.” Major carriers are defined as those with annual revenues exceeding $1.0 billion. The purpose of this paper is to analyze the recent performance of these carriers using a statistical model specifically designed to predict the likelihood of financial stress for airlines. The paper will also update past research in this important industry to demonstrate the very precarious nature of profitability. The major reasons for the improvement of the industry’s profitability will be briefly discussed. The analysis will show that the current financial condition of the industry has improved significantly due to increased concentration and the market domination of some carriers, very low fuel costs facing the carriers, and the record low interest rates resulting from the Federal Reserve’s easy monetary policy. the industry may still be fragile or vulnerable to changes in these input factors
The evaluation of partial binocular overlap on car maneuverability: A pilot study
An engineering approach to enlarge the helmet mounted display (HMD) field of view (FOV) and maintain resolution and weight by partially overlapping the binocular FOV has received renewed interest among human factors scientists. It is evident, based on the brief literature review, that any panoramic display with a binocular overlap, less than a minimum amount, annoys the viewer, degrades performance, and elicits undesirable behavior. The major finding is that across the 60 deg conditions, subjects moved their heads a greater distance (by about 5 degs on each side) than in the 180 deg condition, presumably to compensate for the lack of FOV. It is quite clear that the study, based on simple car maneuverability and two subjects, reveals differences in FOV, but nothing significant between binocular overlap levels and configurations. This tentatively indicates that some tradeoffs of binocular vision for a larger overall display FOV are acceptable
Using multiple Mendelian randomization approaches and genetic correlations to understand obesity, urate, and gout
Observational studies suggest relationships between obesity, urate, and gout but are possibly confounded. We assessed whether genetically determined obesity, higher urate (and related traits), and gout were causal using multiple Mendelian randomization (MR) approaches and linkage disequilibrium score regression for genetic correlations (rg). For data, we used genome-wide association study summary statistics available through MR-Base. We observed that obesity increased urate (beta = 0.127; 95% CI = 0.098, 0.157; P-value = 1.2E−17; rg = 0.25 [P-value = 0.001]) and triglycerides (beta = 0.082; 95% CI = 0.065, 0.099; P-value = 1.2E−21; rg = 0.23 [P-value = 8.8E−12]) and decreased high-density lipoprotein cholesterol (HDL) (beta = − 0.083; 95% CI = − 0.101, − 0.065; P-value = 2.5E−19; rg = − 0.28; [P-value = 5.2E−24]). Higher triglycerides increased urate (beta = 0.198; 95% CI = 0.146, 0.251; P-value = 8.9E−14; rg = 0.29 [P-value = 0.001]) and higher HDL decreased urate (beta = − 0.109; 95% CI = − 0.148, − 0.071; P-value = 2.7E− 08; rg = − 0.21 [P-value = 9.8E−05]). Higher urate (OR = 1.030; 95% CI = 1.028, 1.032; P-value = 1.1E−130; rg = 0.89 [P-value = 1.7E−55]) and obesity caused gout (OR = 1.003; 95% CI = 1.001, 1.004; P-value = 1.3E−04; rg = 0.23 [P-value = 2.7E−05]). Obesity on gout with urate as a mediator revealed all the effect of obesity on gout occurred through urate. Obesity on low-density lipoprotein cholesterol (LDL) was null (beta = −0.011; 95% CI = −0.030, 0.008; P-value = 2.6E−01; rg = 0.03 [P-value = 0.369]). A multivariable MR of obesity, HDL, and triglycerides on urate showed obesity influenced urate when accounting for HDL and triglycerides. Obesity’s impact on urate was exacerbated by it decreasing HDL
Can increasing years of schooling reduce type 2 diabetes (T2D)?: Evidence from a Mendelian randomization of T2D and 10 of its risk factors
© 2020, The Author(s). A focus in recent decades has involved examining the potential causal impact of educational attainment (schooling years) on a variety of disease and life-expectancy outcomes. Numerous studies have broadly revealed a link suggesting that as years of formal schooling increase so too does health and wellbeing; however, it is unclear whether the associations are causal. Here we use Mendelian randomization, an instrumental variables technique, with a two-sample design, to probe whether more years of schooling are causally linked to type 2 diabetes (T2D) and 10 of its attendant risk factors. The results revealed a protective effect of more schooling years against T2D (odds ratio = 0.39; 95% confidence interval: 0.26, 0.58; P = 3.89 × 10–06), which in turn might be partly mediated by more years of schooling being protective against the following: having a father with T2D, being overweight, having higher blood pressure and higher levels of circulating triglycerides, and having lower levels of HDL cholesterol. More schooling years had no effect on risk for gestational diabetes or polycystic ovarian syndrome and was associated with a decreased likelihood of moderate physical activity. These findings imply that strategies to retain adults in higher education may help reduce the risk for a major source of metabolic morbidity and mortality
A Mendelian randomization study of telomere length and blood-cell traits
© 2020, The Author(s). Whether telomere attrition reducing proliferative reserve in blood-cell progenitors is causal has important public-health implications. Mendelian randomization (MR) is an analytic technique using germline genetic variants as instrumental variables. If certain assumptions are met, estimates from MR should be free from most environmental sources of confounding and reverse causation. Here, two-sample MR is performed to test whether longer telomeres cause changes to hematological traits. Summary statistics for genetic variants strongly associated with telomere length were extracted from a genome-wide association (GWA) study for telomere length in individuals of European ancestry (n = 9190) and from GWA studies of blood-cell traits, also in those of European ancestry (n ~ 173,000 participants). A standard deviation increase in genetically influenced telomere length increased red blood cell and white blood cell counts, decreased mean corpuscular hemoglobinand mean cell volume, and had no observable impact on mean corpuscular hemoglobin concentration, red cell distribution width, hematocrit, or hemoglobin. Sensitivity tests for pleiotropic distortion were mostly inconsistent with glaring violations to the MR assumptions. Similar to germline mutations in telomere biology genes leading to bone-marrow failure, these data provide evidence that genetically influenced common variation in telomere length impacts hematologic traits in the population
The Case for a Reparations Clinic: A Proposal for Investigation, Documentation, and Remediation of Historic Housing Discrimination Through the Law School Clinic Model
Article published in the Michigan State Law Review
Storytime Can Be Social Justice Time
Library storytimes are resources through which children can learn literacy skills, but they also have the potential for even greater impact. Families also use storytimes to gain valuable social interactions.
Libraries currently offer storytimes in response to community needs and values, and looking at storytime through a social justice lens gives library staff an opportunity to share and model valuable lessons in acceptance, inclusion, kindness, and empathy.
Resources exist to help storytime providers re-evaluate their storytimes and make incremental changes that can reap big benefits for attendees
Operating, Financial and Total Leverage and the Effects on U.S. Carrier Returns, 1990-2003
The U.S. airline industry has always been highly cyclical and somewhat fixed cost driven. The carriers are thus high in what financial analysts refer to as operating leverage. In addition, the majority of the airlines have followed aggressive debt strategies; that is, they have chosen to use large amounts of long-term debt finance to purchase assets. This results in a high degree of financial leverage. In the past, the resulting combined leverage has created severe financial problems for many in the industry. This paper will examine these different levels of leverage using elasticity measures borrowed from economic theory. The purpose is to examine the effects of this leverage during the years in which the carriers saw unprecedented growth and a return to profitability. It will also compare and contrast several carriers (such as Southwest) which have avoided the "boom and bust" cycle of this industry as well as the effects of 9/11. The sample will consist of the major U.S airlines and several of the group referred to as "nationals.
Synthesis and study of palladium-containing nanomaterials for hydrogen technologies
We are currently facing a climate change and global warming effect due to the emission of greenhouse gases from our existing energy sources. A hydrogen-based economy is one solution to uphold our standard of living while lowering our carbon emissions. Palladium has the potential to play a major role in many aspects of the hydrogen-based economy, from purifying hydrogen to harnessing the energy via fuel cells and storing hydrogen as PdH x . In my M.Sc. study, Pd-based nanomaterials have been synthesized and examined for their applications in various hydrogen technologies. Surface properties of the synthesized Pd-based nanomaterials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and N 2 gas adsorption/desorption. Electrochemical analysis of the fabricated materials was performed using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and chronoamperometry (CA). Other characterization methods were also applied such as inductively-coupled plasma atomic emission spectroscopy (ICP-AES), density functional theory (OFT) calculations, and hydrogen gas adsorption/absorption. The adsorption of the catalytically poisoning species, carbon monoxide, was also examined on Pd, PdPt, and PdAu nanostructures. The relative quantities of CO molecules adsorbed to surface of the catalysts decrease in the order of: PdPt > Pd > PdAu. It was found that the possible adsorption sites of CO can be tuned by alloying Pd with metals to which CO has different binding strengths. The work done in this thesis shows that by alloying Pd with other metals, both geometric and electronic properties are changed drastically. This has a major influence on the applications of Pd for hydrogen technologies
Shared genomic architectures of COVID-19 and antisocial behavior
Little is known about the genetics of norm violation and aggression in relation to coronavirus disease 2019 (COVID-19). To investigate this, we used summary statistics from genome-wide association studies and linkage disequilibrium score regression to calculate a matrix of genetic correlations (rgs) for antisocial behavior (ASB), COVID-19, and various health and behavioral traits. After false-discovery rate correction, ASB was genetically correlated with COVID-19 (rg = 0.51; P = 1.54E-02) and 19 other traits. ASB and COVID-19 were both positively genetically correlated with having a noisy workplace, doing heavy manual labor, chronic obstructive pulmonary disease, and genitourinary diseases. ASB and COVID-19 were both inversely genetically correlated with average income, education years, healthspan, verbal reasoning, lifespan, cheese intake, and being breastfed as a baby. But keep in mind that rgs are not necessarily causal. And, if causal, their prevailing directions of effect (which causes which) are indiscernible from rgs alone. Moreover, the SNP-heritability (hg2) estimates for two measures of COVID-19 were very small, restricting the overlap of genetic variance in absolute terms between ASB and COVID-19. Nonetheless, our findings suggest that those with antisocial tendencies possibly have a higher risk of exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) than those without antisocial tendencies. This may have been especially true early in the pandemic before vaccines against SARS-CoV-2 were available and before the emergence of the highly transmissible Omicron variant
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