Universitätspublikationen
Refine
Year of publication
- 2015 (1742) (remove)
Document Type
- Article (606)
- Doctoral Thesis (187)
- Working Paper (169)
- Contribution to a Periodical (164)
- Book (159)
- Report (157)
- Part of Periodical (124)
- Review (70)
- Preprint (55)
- Conference Proceeding (22)
- Part of a Book (6)
- Master's Thesis (5)
- Periodical (5)
- Bachelor Thesis (4)
- Magister's Thesis (4)
- magisterthesis (4)
- Habilitation (1)
Language
- English (866)
- German (835)
- Spanish (14)
- Italian (11)
- Portuguese (11)
- French (3)
- Multiple languages (1)
- Russian (1)
Is part of the Bibliography
- no (1742)
Keywords
- Islamischer Staat (34)
- IS (25)
- Terrorismus (23)
- Deutschland (16)
- Dschihadismus (13)
- Syrien (12)
- Terror (11)
- Irak (10)
- Islamismus (10)
- Salafismus (10)
Institute
- Präsidium (336)
- Medizin (252)
- Gesellschaftswissenschaften (230)
- Physik (185)
- Wirtschaftswissenschaften (149)
- Exzellenzcluster Die Herausbildung normativer Ordnungen (116)
- Center for Financial Studies (CFS) (115)
- Biowissenschaften (99)
- Frankfurt Institute for Advanced Studies (FIAS) (97)
- Informatik (96)
The endocannabinoids (EC), their synthetizing and metabolizing enzymes, and the cannabinoid (CB) receptors comprise the endocannabinoid system (ECS) that has been detected by Yasuo et al. (2010) in rodent and human brain areas essential for circadian rhythmic control and hormone secretion. The EC are secreted in the pars tuberalis formation (PT) of the pituitary gland and unfold their effect as ligands on cannabinoid receptors type 1 (CB1) in the pars distalis (PD). The CB1 is mostly expressed on folliculo-stellate (fs) cells of the PD. The fs cells execute regulative and supportive functions to adjacent hormone-producing cells (Allaerts and Venkelecom, 2005; Mitsuishi et al., 2013). The lipid and calcium binding protein Annexin A1 (Anx A1) and the cell membrane permeable compound nitric oxide (NO) have been detected in the fs cells (Woods et al., 1990; Devnath and Inoue, 2008). There are published findings indicating strong influence of Anx A1 and NO on hormone production (Taylor et al. 1993; Venkelecom et al, 1997). The hypothesis of this study is that the EC influence hormonal secretion by acting upon CB1 receptors on fs cells and thus activating or inhibiting Anx A1 and NO that directly affect adjacent glandular cells.
Prevalently cell models were used to carry out the experimental work. The TtT/GF and Tpit/F1 cell lines represent the fs cells, the AtT20/D16v stand for the ACTH-producing corticotroph (C) cells, and GH4C1 for the PRL-producing lactotroph (L) cells. Whenever comparison with an integrity model was possible tissue from C3H mice was used. Chemoluminescent and photometrical detection, enzyme-linked immunosorbent assay (ELISA), fluorescence-activated cell sorting (FACS), immunoblot (IB), immunocyto- and immunohisto-chemical analysis (ICC, IHC), in situ hybridization (ISH), and (q) PCR methods were used as assaying tools to investigate CB1, Anx A1, the Anx A1 receptor - Fpr-rs1, NO, ACTH, and PRL.
CB1 was detected on the fs, C, and L cell models. The presence of fatty acid amide hydrolase (FAAH, an EC degrading enzyme) was confirmed in the fs cells. Incubations of the fs cells with CB1 agonists (2-AG, AEA, WIN) and antagonist (otenabant) were performed and resulting increase of Anx A1, and inhibition of NO were detected. Anx A1 binding sites, known as formyl peptide like receptor – related sequence 1 (Fpr-rs1) were identified on the C and L cells. The hormone-producing cells were treated with a 2-AG, Anx A1, and NO and the resulting changes in the levels of ACTH and PRL were detected. Anx A1 acted stimulatory on ACTH in the C AtT20/D16v cell and inhibitory on PRL in the L GH4C1 cell. NO inhibited both ACTH and PRL release. Additional analysis of the levels of expression of mRNA for Anx A1 and Fpr-rs1 in murine PD tissue demonstrated that while the expression of the first was not influenced by time, the expression of the latter was activated during the subjective day.
The here presented study shows that EC influence the ACTH release stimulatory through activating Anx A1 and inhibiting NO. As for PRL, the EC unfold an inhibition through activating Anx A1, and stimulation through inhibiting NO. A clear regulatory linkeage between the EC and ACTH and PRL control is revealed, involving the fs cells with possible time-dependence.
Ausgehend von dem gesellschaftlichen Problem des Übergewichts im Kindesalter wird die besondere Bedeutung und Verantwortung des Sportunterrichts für diese Klientel herausgestellt. Dabei wird die These vertreten, dass der Sportunterricht seinem Auftrag nur dann gerecht werden kann, wenn es gelingt, auch übergewichtigen Kindern positive Erfahrungen in Bezug auf Bewegung, Spiel und Sport zu vermitteln. Im Rahmen dieses sportpädagogischen Problemfeldes wurde zunächst ein Fragebogen konzipiert und validiert, der das Wohlbefinden als Indikator für positive Erfahrungen übergewichtiger Schüler mit dem von normalgewichtigen Kindern vergleicht (n = 336). Eine anschließende qualitative Untersuchung in Form von Leitfadeninterviews (mit acht übergewichtigen/adipösen Kindern) ergänzt und konkretisiert die Ergebnisse.
Als wesentliches Resultat konnte die Erkenntnis gewonnen werden, dass das Wohlbefinden – gemessen durch ein faktorenanalytisch generiertes Modell mit den drei Faktoren „Sportunterricht/Sportlehrer“ (Faktor I), „sportliches Selbstwertgefühl“ (Faktor II) und „Mitschüler/Schulzufriedenheit“ (Faktor III) – keine signifikanten Unterschiede zwischen den Gewichtsklassen zeigt (Faktor I p = .57; Faktor II p = .04; Faktor III p = .23). Übergewichtige Schüler fühlen sich demnach nicht weniger wohl als ihre normalgewichtigen Klassenkameraden, in der Skala sportliches Selbstwertgefühl erzielten sie sogar höhere Werte (Normalgewichtige m = 2,06 ± 0,96; Übergewichtige m = 2,27 ± 0,89). Trotz dieses positiven Befundes verspüren Übergewichtige durchaus so manche Unzufriedenheit. Die Frage nach der Wichtigkeit der bzw. der Zufriedenheit mit den Komponenten Sportunterricht, eigene sportliche Leistung, Zusammenarbeit mit den Mitschülern, Figur und Sportlehrer machte deutlich, dass den Übergewichtigen Figur und sportliche Leistung sehr wichtig sind, sie jedoch nur bedingt damit zufrieden sind. Die Unterschiede in den entsprechenden Skalen erwiesen sich als hoch signifikant (Figur p = .00 d = .28; sportliche Leistung p = .01 d = .29). Die Überprüfung der Frage F1.2 hinsichtlich der geschlechtsspezifischen Unterschiede in den Aussagen zum Wohlbefinden lieferte lediglich ein signifikantes Ergebnis (p = .01) mit mittlerem Effekt (d = .48). Übergewichtige Mädchen gaben im Faktor „Mitschüler/Schulzufriedenheit“ höhere Werte an (m = 3,27 ± 0,66) als übergewichtige Jungen (m = 2,93 ± 0,75). Daraus lässt sich schließen, dass sich die weiblichen Übergewichtigen besser von ihren Mitschülern verstanden und unterstützt fühlen und sie eine allgemein größere Schulzufriedenheit verspüren als die männliche Vergleichsgruppe.
Die Auswertung in Bezug auf die Herkunft der Schüler lieferte keine signifikanten Ergebnisse. Dieser Befund deutet auf eine gelungene Integration der ausländischen Schüler hin, die aber möglicherweise aufgrund des hohen Ausländeranteils im Stadtgebiet Offenbach nicht repräsentativ ist.
Die Auswertung der Interviews zeigte, dass der positive Selbstwert auf ein hohes Maß an sozialer Anerkennung zurückzuführen ist. Entgegen zahlreichen theoretischen Vorannahmen berichtete kein Kind von anhaltenden Diskriminierungen oder Schamgefühlen aufgrund seines Gewichts. Die Bedeutung der eigenen sportlichen Leistung zeichnete sich mehrfach als Schlüsselkriterium im Umgang mit der pädagogischen Herausforderung, dem Erschaffen eines Problembewusstseins, ohne den Selbstwert und die Freude am Sporttreiben zu trüben, ab. Übergewichtige Kinder messen der Leistung einen hohen Stellenwert bei und erkennen in der Hoffnung einer möglichen Verbesserung, dass eine Reduktion des Gewichtes vorteilhaft ist.
Empirical credit demand analysis undertaken at the aggregate level obscures potential behavioral heterogeneity between various borrowing sectors. Looking at disaggregated data and analyzing bank loans to non-financial companies, to financial companies, to households for consumption and for house purchases separately with respect to a common set of macroeconomic determinants may facilitate more accurate empirical relationships and more reliable insights for economic policy. Using quarterly Euro area panel data between 2003 and 2013, empirical evidence for heterogeneity in borrowing behavior across sectors and the credit cycle with respect to interest rates, output and house prices is found. The results motivate sector-specific, counter-cyclical capital requirements.
This paper empirically investigates how organizational hierarchy affects the allocation of credit within a bank. Using an exogenous variation in organizational design, induced by a reorganization plan implemented in roughly 2,000 bank branches in India during 1999-2006, and employing a difference-in-differences research strategy, we find that increased hierarchization of a branch decreases its ability to produce "soft" information on loans, leads to increased standardization of loans and rationing of "soft information" loans. Furthermore, this loss of information brings about a reduction in performance on loans: delinquency rates and returns on similar loans are worse in more hierarchical branches. We also document how hierarchical structures perform better in environments that are characterized by a high degree of corruption, thus highlighting the benefits of hierarchical decision making in restraining rent seeking activities. Finally, we document a channel - managerial interference - through which hierarchy affects loan outcomes.
Our paper evaluates recent regulatory proposals mandating the deferral of bonus payments and claw-back clauses in the financial sector. We study a broadly applicable principal agent setting, in which the agent exerts effort for an immediately observable task (acquisition) and a task for which information is only gradually available over time (diligence). Optimal compensation contracts trade off the cost and benefit of delay resulting from agent impatience and the informational gain. Mandatory deferral may increase or decrease equilibrium diligence depending on the importance of the acquisition task. We provide concrete conditions on economic primitives that make mandatory deferral socially (un)desirable.
In its meeting on 6 September 2012, the Governing Council of the ECB took decisions on a number of technical features regarding the Eurosystem’s outright transactions in secondary sovereign bond markets (OMT). This decision was challenged in the German Federal Constitutional Court (GFCC) by a number of constitutional complaints and other petitions. In its seminal judgment of 14 January 2014, the German court expressed serious doubts on the compatibility of the ECB’s decision with the European Union law.
It admitted the complaints and petitions even though actual purchases had not been executed and the control of acts of an organ of the EU in principle is not the task of the GFCC. As justification for this procedure the court resorted to its judicature on a reserved “ultra vires” control and the defense of the “constitutional identiy” of Germany. In the end, however, the court referred the case pursuant to Article 267 TFEU to the European Court of Justice (ECJ) for preliminary rulings on several questions of EU law. In substance, the German court assessed OMT as an act of economic policy which is not covered by the competences of the ECB. Furthermore, it judged OMT as a – by EU primary law – prohibited monetary financing of sovereign debt. The defense of the ECB (disruption of monetary policy transmission mechanism) was dismissed without closer scrutiny as being “irrelevant”. Finally the court opened, however, a way for a compromise by an interpretation of OMT in conformity with EU law under preconditions, specified in detail.
Procedure and findings of this judgment were harshly criticized by many economists but also by the majority of legal scholars. This criticism is largely convincing in view of the admissibility of the complaints. Even if the “ultra vires” control is in conformity with prior decisions of court it is in this judgment expanded further without compelling reasons. It is also questionable whether the standing of the complaining parties had to be accepted and whether the referral to the ECJ was indicated. The arguments of the court are, however, conclusive in respect of the transgression of competences by the ECB and – to somewhat lesser extent – in respect of the monetary debt financing. The dismissal of the defense as “irrelevant” is absolutey persuasive.
The Treaty of Maastricht imposed the strict obligation on the European Union (EU) to establish an economic and monetary union, now Article 3(4) TEU. This economic and monetary union is, however, not designed as a separate entity but as an integral part of the EU. The single currency was to become the currency of the EU and to be the legal tender in all Member States unless an exemption was explicitly granted in the primary law of the EU, as in the case of the UK and Denmark. The newly admitted Member States are obliged to introduce the euro as their currency as soon as they fulfil the admission criteria. Technically, this has been achieved by transferring the exclusive competence for the monetary policy of the Member States whose currency is the euro on the EU, Article 3(1)(c) TFEU and by bestowing the euro with the quality of legal tender, the only legal tender in the EU, Article 128(1) sentence 3 TFEU.
Savings accounts are owned by most households, but little is known about the performance of households’ investments. We create a unique dataset by matching information on individual savings accounts from the DNB Household Survey with market data on account-specific interest rates and characteristics. We document considerable heterogeneity in returns across households, which can be partly explained by financial sophistication. A one-standard deviation increase in financial literacy is associated with a 13% increase compared to the median interest rate. We isolate the usage of modern technology (online accounts) as one channel through which financial literacy has a positive association with returns.
A theory of the boundaries of banks with implications for financial integration and regulation
(2015)
We offer a theory of the "boundary of the
rm" that is tailored to banking, as it builds on a single ine¢ ciency arising from risk-shifting and as it takes into account both interbank lending as an alternative to integration and the role of possibly insured deposit funding. Amongst others, it explains both why deeper economic integration should cause also greater financial integration through both bank mergers and interbank lending, albeit this typically remains ine¢ ciently incomplete, and why economic disintegration (or "desychronization"), as currently witnessed in the European Union, should cause less interbank exposure. It also suggests that recent policy measures such as the preferential treatment of retail deposits, the extension of deposit insurance, or penalties on "connectedness" could all lead to substantial welfare losses.
In-depth analyses of cancer cell proteomes are needed to elucidate oncogenic pathomechanisms, as well as to identify potential drug targets and diagnostic biomarkers. However, methods for quantitative proteomic characterization of patient-derived tumors and in particular their cellular subpopulations are largely lacking. Here we describe an experimental set-up that allows quantitative analysis of proteomes of cancer cell subpopulations derived from either liquid or solid tumors. This is achieved by combining cellular enrichment strategies with quantitative Super-SILAC-based mass spectrometry followed by bioinformatic data analysis. To enrich specific cellular subsets, liquid tumors are first immunophenotyped by flow cytometry followed by FACS-sorting; for solid tumors, laser-capture microdissection is used to purify specific cellular subpopulations. In a second step, proteins are extracted from the purified cells and subsequently combined with a tumor-specific, SILAC-labeled spike-in standard that enables protein quantification. The resulting protein mixture is subjected to either gel electrophoresis or Filter Aided Sample Preparation (FASP) followed by tryptic digestion. Finally, tryptic peptides are analyzed using a hybrid quadrupole-orbitrap mass spectrometer, and the data obtained are processed with bioinformatic software suites including MaxQuant. By means of the workflow presented here, up to 8,000 proteins can be identified and quantified in patient-derived samples, and the resulting protein expression profiles can be compared among patients to identify diagnostic proteomic signatures or potential drug targets.
In the title compound, C20H24N2O4, both peptide bonds adopt a trans configuration with respect to the —N—H and —C=O groups. The dihedral angle between the aromatic rings is 53.58 (4)°. The molecular conformation is stabilized by an intramolecular N—H⋯O hydrogen bond. The crystal packing is characterized by zigzag chains of N—H⋯O hydrogen-bonded molecules running along the b-axis direction.
Das Hauptziel der vorliegenden Arbeit war es, die energieabhängigen Wirkungsquerschnitte von (γ,n)-Reaktionen für 169Tm, 170Yb, 176Yb und 130Te mittels der Photoaktivierungsmethode zu bestimmen.
Dazu wurden zunächst die Effizienzen der verwendeten Detektoren mithilfe von Simulationen korrigiert, da die verwendeten Targets eine ausgedehnte Geometrie aufweisen im Gegensatz zu den punktförmigen Eichquellen. Es hat sich herausgestellt, dass mit den Simulationen die Effizienzen der MCA-Detektoren energieabhängig korrigiert werden konnten, da die Simulationen die Form der gemessenen Effizienzen gut reproduzieren konnten. Bei den Effizienzen der LEPS-Detektoren hingegen konnte keine energieabhäangige Korrektur vorgenommen werden, da die LEPS-Detektoren aufgrund des geringen Abstandes zu den Detektoren hohe Summeneffekte zeigten. Im Rahmen dieser Arbeit konnten diese Summeneffekte jedoch nicht korrigiert bzw. berücksichtigt werden.
n the EU there are longstanding and ongoing pressures towards a tax that is levied on the EU level to substitute for national contributions. We discuss conditions under which such a transition can make sense, starting from what we call a "decentralization theorem of taxation" that is analogous to Oates (1972) famous result that in the absence of spill-over effects and economies of scale decentralized public good provision weakly dominates central provision. We then drop assumptions that turn out to be unnecessary for this results. While spill-over effects of taxation may call for central rules for taxation, as long as spill-over effects do not depend on the intra-regional distribution of the tax burden, decentralized taxation plus tax coordination is found superior to a union-wide tax.
Do markets correct individual behavioral biases? In an experimental asset market, we compare the outcomes of a standard market economy to those of a an island economy that removed market interactions. We observe asset price bubbles in the market economy while prices are stable in the island economy. We also find that subjects took more risk following larger losses, resulting in larger prices and consistent with a gambling for resurrection motive. This motive can translate into bubbles in the market economy because higher prices increase average losses and thus reinforce the desire to resurrect. By contrast, the absence of such a strategic complementarity in island economies can explain the more stable outcome. These results suggest that markets do not correct behavioral biases, rather the contrary.
This paper analyzes sovereign risk shift-contagion, i.e. positive and significant changes in the propagation mechanisms, using bond yield spreads for the major eurozone countries. By emphasizing the use of two econometric approaches based on quantile regressions (standard quantile regression and Bayesian quantile regression with heteroskedasticity) we find that the propagation of shocks in euro's bond yield spreads shows almost no presence of shift-contagion. All the increases in correlation we have witnessed over the last years come from larger shocks propagated with higher intensity across Europe.
Research on interbank networks and systemic importance is starting to recognise that the web of exposures linking banks balance sheets is more complex than the single-layer-of-exposure paradigm. We use data on exposures between large European banks broken down by both maturity and instrument type to characterise the main features of the multiplex structure of the network of large European banks. This multiplex network presents positive correlated multiplexity and a high similarity between layers, stemming both from standard similarity analyses as well as a core-periphery analyses of the different layers. We propose measures of systemic importance that fit the case in which banks are connected through an arbitrary number of layers (be it by instrument, maturity or a combination of both). Such measures allow for a decomposition of the global systemic importance index for any bank into the contributions of each of the sub-networks, providing a useful tool for banking regulators and supervisors. We use the dataset of exposures between large European banks to illustrate the proposed measures.
Although banks are at the center of systemic risk, there are other institutions that contribute to it. With the publication of the leveraged lending guideline in March 2013, the U.S. regulators show that they are especially worried about the private equity firms with their high-risk deals. Given these risks and the interconnectedness of the banks through the LBO loan syndicates, I shed light on the impact of a bank’s LBO loan exposure on its systemic risk. By using 3,538 observations between 2000 and 2013 from 165 global banks, I show that banks with higher LBO exposure also have a higher level of systemic risk. Other loan purposes do not show this positive relationship. The main drivers influencing this relationship positively are the bank’s interconnectedness to other LBO financing banks and its size. Lending experience with a specific PE sponsor, experience with leading LBO syndicates or a bank’s credit rating, however, lead to a lower impact of the LBO loan exposure on systemic risk.
In the mid-1990s, institutional investors entered the syndicated loan market and started to serve borrowers as lead arrangers. Why are non-banks able to compete for this role against banks? How do the composition of syndicates and loan pricing differ among lead arrangers? By using a dataset of 12,847 leveraged loans between 1997 and 2012, I aim to answer these questions. Non-banks benefit from looser regulatory requirements, have industry expertise which helps them in the screening and monitoring of borrowers and focus on firms that ask for loans only instead of additional cross-selling of other services. I can show that non-banks specialize on more opaque and less experienced borrowers, are more likely than banks to choose participants that help to reduce potentially higher information asymmetries and earn 105 basis points more than banks.