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In order to identify the relevant sources of firms' financing constraints, we ask what financial frictions matter for corporate policies. To that end, we build, solve, and estimate a range of dynamic models of corporate investment and financing, embedding a host of financial frictions. We focus on limited enforcement, moral hazard, and trade-off models. All models share a common technology, but differ in the friction generating financing constraints. Using panel data on Compustat firms for the period 1980-2015 and a more recent dataset on private firms from Orbis, we determine which features of the observed data allow to distinguish among the models, and we assess which model or model combination performs best at rationalizing observed corporate investment and financing policies across various samples. Our tests, based on empirical policy function benchmarks, favor trade-off models for larger Compustat firms, limited commitment models for smaller firms, and moral hazard models for private firms. Our estimates point to significant financing constraints due to agency frictions and highlight the importance of identifying their relevant sources for firm valuation.

We examine the determinants of corporate liquidity management through the lens of an estimated dynamic model of corporate investment and financing. When external finance is costly, firms can absorb shocks and cover liquidity needs by holding cash and by drawing down credit lines. In contrast to cash, we model credit lines as providing liquidity contingent on economic news, but limited by collateral constraints and covenants. The option to draw down credit lines creates value as it allows firms to take advantage of investment opportunities in an effective way, facilitating firm growth. We find that our estimated model matches well the levels and joint dynamics of cash, credit lines, leverage, equity financing and investment when firms can collateralize roughly one third of their assets. In the cross-section, the model provides novel empirical predictions and rationalizes a wide range of stylized facts regarding credit line usage, covenant violations, and cash holdings.

ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗ ΣΤΑ ΕΛΛΗΝΙΚΑ, Avian embryos have been gaining an increasing scientific interest as a valuable model system for the experimental cancer research that could contribute to a significant reduction of the number of laboratory animals. In the present study, the liver lesions induced by N-nitrosodimethylamine and N-nitrosodiethylamine in 15I line, White Leghorn embryos were identified and studied by routine histopathological method s. Foci of altered hepatocytes with basophilic and eosinophilic phenotype, well known as preneoplastic alterations were identified in the avian embryonal livers after in ovo exposure to both N-nitroso compounds. These studies were further extended by histopathological, haematological and biochemical examinations on the effects of N-nitrosodimethylamine in chickens hatched from carcinogen-inoculated eggs. In addition to the preneoplastic lesions observed in the avian livers, proliferations of oval and hepatocellular carcinoma cells, with clearly expressed signs of malignancy were found. The in ovo application of the chemical carcinogen was found to affect both hematological and blood biochemistry parameters measured in experimental birds. The established conditions such as thrombocytopenia and increased levels of liver enzymes, as an essential part of the paraneoplastic syndrome, were associated with the process of hepatocarcinogenesis. The results of this study confirm the preneoplastic nature of the focal lesions in embryonal avian liver and their progression to liver neoplastic alterations after a single in ovo application of known hepatocarcinogens. Moreover, the results indicate that 15I line, White Leghorn embryos are anew, valuable in ovo model for studies on hepatocarcinogenicity of chemical compounds and underline the importance of research on the development of different avian models of carcinogenicity.

Δε διατίθεται περίληψη στα ελληνικά, The aim of this study is to estimate the histopathological changes in visceral organs of naturally infected with the avian influenza virus (AIV) subtype A H5N1 dalmatian pelicans in Bulgaria. The identified gross lesions are: haemorrhagic small intestine, sparse content in gizzard and proventriculus, well defined hyperemia of the tracheal mucosa associated with petechiae, as well as meningeal and brain congestion. The infected birds exhibited the following histopathological changes: edema of the tracheal mucosa with loss of mucosal glands, mild to moderate congestion with focal necrosis and multifocal non suppurative encephalitis and gliosis, mononuclear infiltration in the cecum, and diffuse mononuclear infiltration in the submucosa of the small intestine. The virus was detected by virus isolation (VI) and RT-PCR from tissue samples (lung, trachea, small intestine, brain, proventriculus, cloaca) from the infected birds.

Das Ziel der vorliegenden Arbeit bestand darin, die verletzungsbezogenen Kodes des XIX. Kapitels der ICD-10-GM 2008 in AIS-2005-Schlüsselnummern zu übersetzen. Die inhaltlich am besten passenden Kodes aus den beiden Klassifikationen wurden miteinander verknüpft und in einer Mapping-Tabelle aufgenommen. Deren Funktion sowie die Möglichkeit, Injury Severity Scores (ISS) nach Übersetzung der ICD-10-GM-Kodes in AIS-2005-Schlüsselnummern zu berechnen, wurde mittels 81 Beispielfälle geprüft. Es konnte nachgewiesen werden, dass das XIX. Kapitel der ICD-10-GM 2008 in die AIS 2005 generell übersetzbar ist und dass nach der Übersetzung der verletzungsbezogenen ICD-10-GM-Kodes die entsprechenden ISS berechnet werden können. Mit der Erstellung der Umrechnungstabelle ist es in der Zukunft möglich, von den in der Klinik standardmäßig erhobenen ICD-10-GM Schlüsselnummern, die AIS- und ISS-Kodes zu generieren und damit die behandelten Verletzungsschweren automatisch zu klassifizieren.

Fragestellung: Seit Einführung der ICD 10 ist es nicht mehr möglich ICD 10 Codes in AIS Codes (Abbreviated Injury Scale) ohne größeren manuellen Kodieraufwand umzuwandeln. Da die AIS und der daraus resultierende ISS (Injury Severity Score) für die Dokumentation der Schwere von[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie; 73. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 95. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 50. Tagung des Berufsverbandes der Fachärzte für Orthopädie

Androgens are especially important for the maintenance of spermatogenesis in adulthood and the experimental withdrawal of testosterone (T) production by ethane dimenthanesulfonate (EDS) is a valuable tool for studying androgen-dependent events of spermatogenesis. The aim of the present study was to investigate the specific changes in immunoexpression of androgen receptor (AR) in the testis in relation to degeneration and regeneration of Leydig cell (LC) population and seminiferous epithelium. Immunohistochemistry for AR and 3beta-hydroxysteroid dehydrogenase (3beta-HSD) as well as TUNEL assay for apoptosis were performed on testicular sections of control and EDS-treated rats. Serum LH and T levels were measured by RIA. Our results revealed a total loss of AR immunoexpression from the nuclei of Sertoli (SCs), LCs and peritubular cells during the first week after EDS administration and that coincided with severe drop in T levels. Two weeks after EDS administration, the AR expression was recovered in these cells but normal stage-specificity in SCs was replaced by uniform intensity of AR immunostaining at all the stages of the spermatogenic cycle. The stage-specific pattern of androgen expression in SCs with a maximum at stages VII-VIII appeared 5 weeks after treatment. LC immunoreactivity for 3beta-HSD at different time points after EDS administration correlated with values of T concentration. The maximal germ cell apoptosis on day 7 was followed by total loss of elongated spermatids 2 weeks after EDS treatment. Regeneration of seminiferous epithelium 3 weeks after EDS administration and onwards occurred in tandem with the development of new LC population indicated by the appearance of 3beta-HSD-positive cells and gradual increase in T production. The specific changes in AR after EDS including their loss and recovery in Sertoli cells paralleled with degenerative and regenerative events in Leydig and germ cell populations, confirming close functional relationship between Sertoli, Leydig and germ cells.