Effect of Chapter 11 Bankruptcy Protection on Airfares in the U.S. Domestic Airline Industry

I empirically examine the effects of bankruptcy protection (Chapter 11) on airfares in the U.S. domestic airline industry using cross sectional air tickets data from 2001:Q1 through 2012:Q4. A hedonic price model was developed to identify the determinants of airfares. The results indicate that, airfares charged by a bankrupt airline are approximately 4% lower than airfares of other airlines that are not in bankruptcy, ceteris paribus. Individually, bankrupt airlines lower their airfares as much as 16-19% during bankruptcy protection. Furthermore, it is evident that low cost carriers (LCCs) have significantly lower airfares than legacy carriers. This confirms the high degree of price competition in the industry.Upper Great Plains Transportation Institut

Three Essays on Urban Public Transit Systems in the U.S.

Public transportation is a critical component of urban communities and plays an important role in facilitating mobility which is integral to economic development and the quality of life of urban residents. In recent years, urban transportation has evolved rapidly with the emergence of transportation network companies (TNCs) and e-commerce that drastically transformed urban living. The availability of TNCs has given consumers more transportation options. However, the implications of TNCs on public transit ridership are unknown. In addition, the rising online shopping trend has drastically reduced the businesses of brick-and-mortar retailers, but does the shift in consumer shopping behavior reduce the demand for public transit? The objective of this dissertation is to address the following three research questions: (1) How is U.S. public transit ridership impacted by the rise of TNCs? (2) How have transit subcontracting (or purchased transportation) and TNC partnership affected transit productivity in recent years? (3) Has increased online shopping reduced the demand for public transit service? The key findings of my study are: (1) transit effectiveness of both bus and rail transits declined over the study period; (2) TNC availability increased rail transit ridership in 2015; (3) transit effectiveness was highly significant for public transit, and when examining its effect year-by-year, rail transit effectiveness trumped TNC availability; (4) TNCs are neither a complement nor a substitute of bus transit; (5) for bus transit agencies, outsourcing or purchased transportation is associated with negative efficiency and productivity changes; (6) although purchased transportation has a positive effect on technological change for bus transit, the effect is not significant; (7) TNC partnerships also have a negative effect on efficiency and productivity changes in bus transit; (8) there is a positive significant relationship between shopping mall visits and public transit use; (9) however, the effect of mall visits on transit use is small relative to the effects of car ownership; (10) taken together, the marginal effect of car ownership is 9 times larger than the effect of mall visits on transit use

Hardware Context Switch-based Cryptographic Accelerator for Handling Multiple Streams

International audienceThe confidentiality and integrity of a stream has become one of the biggest issues in telecommunication. The best available algorithm handling the confidentiality of a data stream is the symmetric key block cipher combined with a chaining mode of operation such as cipher block chaining (CBC) or counter mode (CTR). This scheme is difficult to accelerate using hardware when multiple streams coexist. This is caused by the computation time requirement and mainly by management of the streams. In most accelerators, computation is treated at the block-level rather than as a stream, making the management of multiple streams complex.&lt;br&gt;&lt;br&gt;This article presents a solution combining CBC and CTR modes of operation with a hardware context switching. The hardware context switching allows the accelerator to treat the data as a stream. Each stream can have different parameters: key, initialization value, state of counter. Stream switching was managed by the hardware context switching mechanism. A high-level synthesis tool was used to generate the context switching circuit. The scheme was tested on three cryptographic algorithms: AES, DES, and BC3. The hardware context switching allowed the software to manage multiple streams easily, efficiently, and rapidly. The software was freed of the task of managing the stream state. Compared to the original algorithm, about 18%&ndash;38% additional logic elements were required to implement the CBC or CTR mode and the additional circuits to support context switching. Using this method, the performance overhead when treating multiple streams was low, and the performance was comparable to that of existing hardware accelerators not supporting multiple streams.</p

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Not AvailableAn experiment was designed to delineate the efficacy of a dietary mixture of selenium nanoparticles (Se-NPs) and riboflavin (RF) on the thermal efficiency/tolerance of Pangasianodon hypophthalmus reared under arsenic (2.8 mg/L) and high-temperature (34 °C) stress. A green synthesis method was employed for the synthesis of Se- NPs using fish gills, which are normally discarded as by-products. Four isocaloric and iso-nitrogenous experimental diets were used, namely, a control diet (Se-NPs and RF @ 0 mg/kg diet) and diets containing RF @ 5, 10 or 15 mg/kg diet and Se-NPs @ 0.5 mg/kg diet, and feeding was performed for 95 days. At the end of the feeding trial, the thermal tolerance was evaluated by determination of the following parameters: critical thermal minimum (CTMin), lethal thermal minimum (LTMin), critical thermal maximum (CTMax), and lethal thermal maximum (LTMax). The anti-oxidative status in the form of catalase (CAT), glutathione-s-transferase (GST) and glutathione peroxidase (GPx) activities was significantly (p < 0.01) enhanced upon concurrent exposure to arsenic and high temperature at LTMin and LTMax, whereas a non-significant (p > 0.05) change in superoxide dismutase (SOD) activity was observed in the brain at LTMin and brain, gill and kidney at LTMax. Supplementation with Se-NPs @ 0.5 mg/kg diet and RF @ 5, 10 or 15 mg/kg diet significantly (p < 0.01) improved the anti-oxidative status with or without stressors. AChE activity in the brain was significantly (p < 0.01) inhibited upon concurrent exposure to arsenic and high temperature and improved in the treatment group supplemented with Se-NPs and RF. The arsenic concentration in muscle and experimental water and Se concentration in muscle and experimental feed were analysed. Overall, the results indicated that supplementation with RF @ 5 mg/kg diet and Se-NPs @ 0.5 mg/kg diet could confer protection to the fish against arsenic and thermal stress and led to enhanced thermal efficiency/tolerance of P. hypophthalmusNot Availabl

Synthesis, molecular docking and anti-mycobacterial evaluation of new imidazo1,2-a]pyridine-2-carboxamide derivatives

New anti-tubercular agents, imidazo1,2-a]pyridine-2-carboxamide derivatives (5a-q) have been designed and synthesized. The structural considerations of the designed molecules were further supported by the docking study with a long-chain enoyl-acyl carrier protein reductase (InhA). The chemical structures of the new compounds were characterized by IR, H-1 NMR, C-13 NMR, HRMS and elemental analysis. In addition, single crystal X-ray diffraction has also been recorded for compound 5f. Compounds were evaluated in vitro against Mycobacterium tuberculosis H37Rv, and cytotoxicity against HEK-293T cell line. Amongst the tested compounds 5j, 5l and 5q were emerged as good anti-tubercular agents with low cytotoxicity. The structure-anti TB activity relationship of these derivatives was explained by molecular docking. (C) 2014 Elsevier Masson SAS. All rights reserved