Default Risk and Equity Returns: A Comparison of the Bank-Based German and the U.S. Financial System

In this paper, we address the question whether the impact of default risk on equity returns depends on the financial system firms operate in. Using an implementation of Merton's option-pricing model for the value of equity to estimate firms' default risk, we construct a factor that measures the excess return of firms with low default risk over firms with high default risk. We then compare results from asset pricing tests for the German and the U.S. stock markets. Since Germany is the prime example of a bank-based financial system, where debt is supposedly a major instrument of corporate governance, we expect that a systematic default risk effect on equity returns should be more pronounced for German rather than U.S. firms. Our evidence suggests that a higher firm default risk systematically leads to lower returns in both capital markets. This contradicts some previous results for the U.S. by Vassalou/Xing (2004), but we show that their default risk factor looses its explanatory power if one includes a default risk factor measured as a factor mimicking portfolio. It further turns out that the composition of corporate debt affects equity returns in Germany. Firms' default risk sensitivities are attenuated the more a firm depends on bank debt financing

The effect of HIV infection on overdose mortality

Objectives: To quantify the association of HIV infection with overdose mortality and explore the potential mechanisms. Design: A prospective cohort study. Methods: A total of 1927 actively injecting drug users who were HIV seronegative at baseline, of whom 308 later HIV seroconverted, were followed semi-annually for death from 1988 to 2001. Survival analyses using marginal structural and standard Cox models were used to evaluate the effect of HIV infection on the risk of overdose mortality. Results: Overdose death rates were higher in HIV-seropositive than HIV-seronegative drug users: 13.9 and 5.6 per 1000 person-years, respectively (P < 0.01). The hazard ratio (HR) was 2.54 [95% confidence interval (CI) 1.47, 4.38] for the marginal structural model and 2.06 (95% CI 1.25, 3.38) for the standard Cox model, both adjusted for demographics, drug injection characteristics, alcohol abuse, substance abuse treatment, and sexual orientation. Adjusting for possible time-varying mediators (i.e. drug use, medical conditions and healthcare access) in extended marginal structural models reduced the effect of HIV on overdose mortality by 30% (HR 1.82, 95% CI 1.01, 3.30). Abnormal liver function was associated with a higher risk of overdose mortality (HR 2.00, 95% CI 1.05, 3.84); adjustment for this further reduced the effect of HIV on overdose mortality. Conclusion: HIV infection was associated with a higher risk of overdose mortality. Drug use behavior, systematic disease and liver damage associated with HIV infection appeared to account for a substantial portion of this association. The data suggest a group to target with interventions to reduce overdose mortality rates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/40279/2/Wang_The Effect of HIV Infection on Overdose_2005.pd

Vaccination against Bm86 Homologues in Rabbits Does Not Impair Ixodes ricinus Feeding or Oviposition

Human tick-borne diseases that are transmitted by Ixodes ricinus, such as Lyme borreliosis and tick borne encephalitis, are on the rise in Europe. Diminishing I. ricinus populations in nature can reduce tick exposure to humans, and one way to do so is by developing an anti-vector vaccine against tick antigens. Currently, there is only one anti-vector vaccine available against ticks, which is a veterinary vaccine based on the tick antigen Bm86 in the gut of Rhipicephalus microplus. Bm86 vaccine formulations cause a reduction in the number of Rhipicephalus microplus ticks that successfully feed, i.e. lower engorgement weights and a decrease in the number of oviposited eggs. Furthermore, Bm86 vaccines reduce transmission of bovine Babesia spp. Previously two conserved Bm86 homologues in I. ricinus ticks, designated as Ir86-1 and Ir86-2, were described. Here we investigated the effect of a vaccine against recombinant Ir86-1, Ir86-2 or a combination of both on Ixodes ricinus feeding. Recombinant Ixodes ricinus Bm86 homologues were expressed in a Drosophila expression system and rabbits were immunized with rIr86-1, rIr86-2, a combination of both or ovalbumin as a control. Each animal was infested with 50 female adults and 50 male adults Ixodes ricinus and tick mortality, engorgement weights and egg mass were analyzed. Although serum IgG titers against rIr86 proteins were elicited, no effect was found on tick feeding between the rIr86 vaccinated animals and ovalbumin vaccinated animals. We conclude that vaccination against Bm86 homologues in Ixodes ricinus is not an effective approach to control Ixodes ricinus populations, despite the clear effects of Bm86 vaccination against Rhipicephalus microplus

Modelling credit spreads with time volatility, skewness, and kurtosis

This paper seeks to identify the macroeconomic and financial factors that drive credit spreads on bond indices in the US credit market. To overcome the idiosyncratic nature of credit spread data reflected in time varying volatility, skewness and thick tails, it proposes asymmetric GARCH models with alternative probability density functions. The results show that credit spread changes are mainly explained by the interest rate and interest rate volatility, the slope of the yield curve, stock market returns and volatility, the state of liquidity in the corporate bond market and, a heretofore overlooked variable, the foreign exchange rate. They also confirm that the asymmetric GARCH models and Student-t distributions are systematically superior to the conventional GARCH model and the normal distribution in in-sample and out-of-sample testing

Bank ownership structure, regulations and risk-taking : evidence from commercial banks in Pakistan

This paper conducts the first empirical assessment of the theories concerning the influence of ownership structure on bank risk-taking in the presence of regulations in Pakistan. The sample used in this paper comprises a panel data of 26 banks in Pakistan, for the period from 2000 to 2014. The analysis provides evidence that increase in ownership concentration leads to an increase in bank risk-taking. Managerial ownership is associated with high risk-taking at low and high levels of managerial ownership while at intermediate level, managerial ownership has negative impact on bank risk-taking. Different types of ownership of banks in Pakistan have different impact on risk-taking. While government, family and institutional ownership have a positive impact on bank risk-taking, foreign own- ership has a negative impact on bank risk-taking. Furthermore, the results show that capital regulations are important in influencing bank risk-taking with regard to higher ownership concentration. The findings of this paper suggest that the relation between bank risk-taking and capital regulations typically depends on the type of ownership.info:eu-repo/semantics/publishedVersio

Decolorization and partial mineralization of a polyazo dye by Bacillus firmus immobilized within tubular polymeric gel

The degradation of C.I. Direct red 80, a polyazo dye, was investigated using Bacillus firmus immobilized by entrapment in tubular polymeric gel. This bacterial strain was able to completely decolorize 50 mg/L of C.I. Direct red 80 under anoxic conditions within 12 h and also degrade the reaction intermediates (aromatic amines) during the subsequent 12 h under aerobic conditions. The tubular gel harboring the immobilized cells consisted of anoxic and aerobic regions integrated in a single unit which was ideal for azo dye degradation studies. Results obtained show that effective dye decolorization (97.8%), chemical oxygen demand (COD) reduction (91.7%) and total aromatic amines removal were obtained in 15 h with the immobilized bacterial cell system whereas for the free cells, a hydraulic residence time of 24 h was required for an equivalent performance in a sequential anoxic and aerobic process. Repeated-batch experiments indicate the immobilized cells could decolorize C.I. Direct red 80 and reduce medium COD in five successive batch runs with enhanced activity obtained after each consecutive run, thus suggesting its stability and potential for repeated use in wastewater treatment. UV–visible spectrophotometry and HPLC analysis were used to confirm the partial mineralization of the dye. Data from this study could be used as a reference for the development of effective industrial scale biotechnological process for the removal of dyes and their metabolites in textile wastewater

Relations between Financing and Output in the Not-for-Profit Hospital

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68639/2/10.1177_107755878804500204.pd

Transcription-replication conflicts: How they occur and how they are resolved

The frequent occurrence of transcription and DNA replication in cells results in many encounters, and thus conflicts, between the transcription and replication machineries. These conflicts constitute a major intrinsic source of genome instability, which is a hallmark of cancer cells. How the replication machinery progresses along a DNA molecule occupied by an RNA polymerase is an old question. Here we review recent data on the biological relevance of transcription-replication conflicts, and the factors and mechanisms that are involved in either preventing or resolving them, mainly in eukaryotes. On the basis of these data, we provide our current view of how transcription can generate obstacles to replication, including torsional stress and non-B DNA structures, and of the different cellular processes that have evolved to solve them

Bacterial laccases: some recent advances and applications

Laccases belong to the large family of multi-copper oxidases (MCOs) that couple the one-electron oxidation of substrates with the four-electron reduction of molecular oxygen to water. Because of their high relative non-specific oxidation capacity particularly on phenols and aromatic amines as well as the lack of requirement for expensive organic cofactors, they have found application in a large number of biotechnological fields. The vast majority of studies and applications were performed using fungal laccases, but bacterial laccases show interesting properties such as optimal temperature above 50 °C, optimal pH at the neutral to alkaline range, thermal and chemical stability and increased salt tolerance. Additionally, bacterial systems benefit from a wide range of molecular biology tools that facilitates their engineering and achievement of high yields of protein production and set-up of cost-effective bioprocesses. In this review we will provide up-to-date information on the distribution and putative physiological role of bacterial laccases and highlight their distinctive structural and biochemical properties, discuss the key role of copper in the biochemical properties, discuss thermostability determinants and, finally, review biotechnological applications with a focus on catalytic mechanisms on phenolics and aromatic amines.info:eu-repo/semantics/publishedVersio

Rescue of replication failure by Fanconi anaemia proteins

Chromosomal aberrations are often associated with incomplete genome duplication, for instance at common fragile sites, or as a consequence of chemical alterations in the DNA template that block replication forks. Studies of the cancer-prone disease Fanconi anaemia (FA) have provided important insights into the resolution of replication problems. The repair of interstrand DNA crosslinks induced by chemotherapy drugs is coupled with DNA replication and controlled by FA proteins. We discuss here the recent discovery of new FA-associated proteins and the development of new tractable repair systems that have dramatically improved our understanding of crosslink repair. We focus also on how FA proteins protect against replication failure in the context of fragile sites and on the identification of reactive metabolites that account for the development of Fanconi anaemia symptoms