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The outset of Joyce’s A Portrait of the Artist as a Young Man presents a stage of life and language that is commonly evoked and, at the same time, systematically avoided in autobiographies as well as theoretical approaches to language: infancy. This textual strategy refers back to Augustine’s Confessiones, one of the most canonical autobiographies, reading it as a mainstay for an unconventional hypothesis: Rather that understanding infancy as an early stage of, or even before, language, Joyce expounds that the condition called infancy – the openness for receiving language while being unable to master it – accompanies all speech, be it childlike or eloquent. The article analyses Joyce’s text as one instance of a general paradox of autobiographical writing: initial aphasia. Setting out with birth or infancy, autobiographical texts precede articulate discourse. In Joyce, this paradox appears as starting point for a poetical – rather than theoretical – thinking about language, and language acquisition.
While for centuries Greek tragedies were performed only intermittently (Flashar 1991; Foley 1999; Macintosh et al. 2005; Hall and Macintosh 2005), the 1960s saw an enormous growth internationally in the staging of ancient dramas, and between 1960 and today, more Greek tragedies have been performed than in the entire period from antiquity to 1960.1 The new interest in ancient tragedy corresponded with a fundamental crisis in Western culture, issuing from the Shoah and gradually forcing its way into consciousness. After World War II, and especially since the 1960s, the question of history needed to be reconsidered. With the increasing dissolution of tradition, the interval between antiquity and the present became an unresolved problem. At the same time, a teleological understanding, which sees history as something that can be planned and calculated, had to be considered as failed, since fascism and communism "in the name of history" had erected totalitarian systems. What then appeared in this historical void?
Die Verarbeitung während des Hörprozesses von Säugetieren verläuft von der Kochlea mit den inneren und äußeren Haarsinneszellen (äHZ) über afferente Nervenbahnen bis zum auditorischen Kortex (AK). Die daran beteiligten Schaltstationen und deren Funktion sind überwiegend aufgeklärt. Die Hörbahn ist zudem in besonderer Weise durch efferente Rückkopplungen gekennzeichnet, die interne Modulationen sowie sekundäre Reaktionen auf den Reiz ermöglichen. Anatomisch betrachtet verlaufen efferente Projektionen vom AK zu sämtlichen am Hörprozess beteiligten Kerngebieten. Vom Olivenkomplex erfolgt über mediale und laterale Fasern eine Innervation der äHZ bzw. des Hörnervs. Trotz der gut beschriebenen Anatomie ist die funktionelle Beziehung zwischen dem AK und der Peripherie weitgehend ungeklärt. In der vorliegenden Arbeit wurde der funktionelle Zusammenhang vom AK zu den äHZ in der mongolischen Wüstenrennmaus untersucht. Dafür wurde entweder eine pharmakologische Blockierung der Kortexaktivität durch den Natriumkanalblocker Lidocain erzeugt oder eine Aktivierung der Kortexaktivität durch die Anwendung elektrischer Reize ausgelöst. Der Einfluss der Manipulationen wurde in der Kochlea mittels Messungen von Distorsionsprodukt-otoakustischen Emissionen (DPOAE) erfasst. Diese entstehen durch die nichtlineare Verstärkung leiser Schallsignale durch die äHZ zur Erzielung hoher Sensitivität und Frequenzauflösung. Die DPOAE treten als kubische (z. B. 2f1-f2) und quadratische (z. B. f2-f1) Verzerrungen auf und geben Aufschluss über unterschiedliche Parameter der äHZ-Verstärkungsfunktion.
Die Lidocainversuche wurden entweder kontra- oder ipsilateral zur DPOAE-Messung durchgeführt. In beiden Konstellationen traten nach der Lidocaininjektion Erhöhungen und Verringerungen der DPOAE-Pegel im Vergleich zur Basismessung oder unveränderte DPOAE-Pegel auf. Im Mittel lagen die Pegeländerungen bei ca. 11 dB, in Einzelfällen betrugen sie bis zu 44,8 dB. In den Gesamtdaten waren die Effekte nach kontralateraler Injektion oft signifikant größer als nach ipsilateraler Injektion. Ebenso waren die Effekte in der 2f1-f2 Emission meist signifikant größer als in der f2-f1 Emission. Zudem wurde beobachtet, dass signifikant größere Effekte bei einer Stimulation mit Pegeln von 60/50 dB SPL im Vergleich zu 40/30 dB SPL erreicht wurden. Grundsätzlich trat in allen Datensätzen eine Reversibilität der DPOAE-Pegel mit zunehmender Versuchsdauer auf. Die Effekte waren direkt nach der Injektion am größten und erreichten je nach Stimuluspegel und Emissionstyp nach 28-100 min die Basispegel. In keinem der Datensätze lag eine Abhängigkeit der im Kortex gereizten charakteristischen Frequenz (CF) zum betroffenen Frequenzbereich in der Kochlea vor. Die Effekte waren über den gesamten gemessenen Frequenzbereich von 1-40 kHz nachweisbar. Allerdings waren die Frequenzbereiche von 1-10 kHz und 30,5-40 kHz besonders stark von der Lidocaininjektion betroffen.
Auch nach der elektrischen Reizung wurden die drei oben beschriebenen Effekttypen definiert. Mit 54,6 % war der Prozentsatz unveränderter DPOAE-Pegel allerdings sehr hoch. In den anderen beiden Kategorien konnten zusätzlich Differenzierungen im zeitlichen Verhalten der DPOAE-Pegel vorgenommen werden. In 21,6 % bzw. 16,5 % der Datensätze waren die Verringerungen bzw. Erhöhungen bis zum letzten gemessenen Zeitpunkt nach der elektrischen Reizung irreversibel und nur in jeweils 2,8 % der Datensätze war eine Reversibilität zu verzeichnen. In diesen Fällen war die Effektdauer mit im Mittel 31 bzw. 25 min kürzer als in den Lidocainversuchen. Auch die Effektstärken waren mit maximal 23,9 dB und je nach Effekttyp im Mittel 5,1-13,7 dB geringer als nach der Lidocaininjektion. Die größten Effekte traten in einem mittleren Stimuluspegelbereich von 45-55 dB SPL auf. Wiederum konnte keine Abhängigkeit des betroffenen Frequenzbereichs von der kortikal gereizten CF nachgewiesen werden. In Einzelfällen waren auf DPOAE-Ebene nur die Frequenzen ober- und unterhalb der kortikalen CF beeinflusst, wohingegen bei der CF selbst keine Effekte auftraten.
Durch Kontrollexperimente (Salineinjektion bzw. Einführen der Elektrode ohne elektrische Reizung) konnte nachgewiesen werden, dass die Effekte durch die Manipulation der Kortexaktivität hervorgerufen wurden. Somit liegt eine funktionelle Beziehung zwischen dem AK und der Peripherie vor, die langanhaltende massive Ausmaße annehmen kann. Die Effektrichtung ist vermutlich durch die exzitatorisch oder inhibitorisch wirkenden Neurone vom Colliculus inferior zum Olivenkomplex bedingt. Die größeren Effekte in der kontralateralen Konfiguration lassen sich durch die Diskrepanz in der Anzahl der gekreuzten (2/3) und ungekreuzten (1/3) medialen Efferenzen erklären. Die kubischen Komponenten der äHZ-Verstärkungsfunktion scheinen stärker beeinflusst zu sein als die quadratischen Komponenten, was in größeren Pegeländerungen in der 2f1-f2 Emission resultiert. Die teils großen Effektstärken sowie die nicht vorhandene Frequenzabhängigkeit zwischen AK und Kochlea sind vermutlich auf den großen Kortexbereich zurückzuführen, der von den gewählten Injektionsvolumina bzw. elektrischen Reizstärken betroffen war. Die großen Effekte im mittleren Stimuluspegelbereich lassen sich sowohl mit einer möglichen Schutzfunktion der Efferenzen vor zu lauten Schallereignissen als auch mit einer Verbesserung des Signal-Rausch-Verhältnisses zur erleichterten Detektion akustischer Signale in Einklang bringen. Insgesamt deuten die Ergebnisse darauf hin, dass die Aktivität des AK einen starken Einfluss auf periphere auditorische Mechanismen hat, wodurch die kochleäre Verarbeitung akustischer Signale je nach kortikalem Verarbeitungsstatus massiv modifiziert werden kann.
For the class of balanced, irreducible Pólya urn schemes with two colours, say black and white, limit theorems for the number of black balls after n steps are known. Depending on the ratio of the eigenvalues of the replacement matrix, two regimes of limit laws occur: almost sure convergence to a non-degenerate random variable whose distribution depends on the initial composition of the urn and that is known to be not normally distributed and weak convergence to the normal distribution. In this thesis, upper bounds on the rates of convergence in both the non-normal limit case and the normal limit case are given.
The website Sci-Hub provides access to scholarly literature via full text PDF downloads. The site enables users to access articles that would otherwise be paywalled. Since its creation in 2011, SciHub has grown rapidly in popularity. However, until now, the extent of Sci-Hub’s coverage was unclear. As of March 2017, we find that Sci-Hub’s database contains 68.9% of all 81.6 million scholarly articles, which rises to 85.2% for those published in toll access journals. Coverage varies by discipline, with 92.8% coverage of articles in chemistry journals compared to 76.3% for computer science. Coverage also varies by publisher, with the coverage of the largest publisher, Elsevier, at 97.3%. Our interactive browser at greenelab.github.io/scihub allows users to explore these findings in more detail. We find Sci-Hub preferentially covers popular, paywalled content, containing 96.2% of citations to toll access journals since 2015. For recently requested articles by Unpaywall users, oaDOI provided access to 48.8% whereas Sci-Hub contained 81.5%. Together, oaDOI and Sci-Hub covered 94.1%, demonstrating that gaps in Sci-Hub’s coverage, especially for open access articles, can be filled using licit services. For the first time, nearly all scholarly literature is available gratis to anyone with an Internet connection. Sci-Hub’s scope suggests the subscription publishing model is becoming unsustainable.
The paper provides an overview and an economic analysis of the development of the corporate governance of German banks since the 1950s, highlighting peculiarities – as seen from the meanwhile prevailing standard model perspective – of the German case. These peculiarities refer to the specific German notion and legal-institutional regime of corporate governance in general as well as to the specific three-pillar structure of the German banking system.
The most striking changes in the corporate governance of German banks during the past 50 years occurred in the case of the large shareholder-owned banks. For them, capital markets have become an important element of corporate governance, and their former orientation towards the interests of a broadly defined set of stakeholders has largely been replaced by a one-sided concentration on shareholders’ interests. In contrast, the corporate governance regimes of the smaller local public savings banks and the local cooperative banks have remained virtually unchanged. They acknowledge a broader horizon of stakeholder interests and put an emphasis on monitoring.
The Great Financial Crisis, beginning in 2007, has led to a considerable reassessment in the academic and political debate on bank governance. On an international level, it has revived the older notion that, in view of their high leverage and their innate complexity, banks are “special” and bank corporate governance also – and needs to be seen in this light, not least because research indicates that banks with a strong and one-sided shareholder orientation – and thus with what appears to be the best corporate governance according to the standard model – have suffered most in the crisis. In the German case, the crisis has shown that the smaller local banks have survived the crisis much better than large private and public banks, whose funding strongly depends on wholesale markets. This may point to certain advantages of their governance and ownership regimes. But the differences in the performance during the crisis years may also, or even more so, be a consequence of the business models of large vs small banks than of their different governance regimes.
This study provides a graphic overview on core legislation in the area of economic and financial services. The presentation essentially covers the areas within the responsibility of the Economic and Monetary Affairs Committee (ECON); hence it starts with core ECON areas but also displays neighbouring areas of other Committees' competences which are closely connected to and impacting on ECON's work. It shows legislation in force, proposals and other relevant provisions on banking, securities markets and investment firms, market infrastructure, insurance and occupational pensions, payment services, consumer protection in financial services, the European System of Financial Supervision, European Monetary Union, euro bills and coins and statistics, competition, taxation, commerce and company law, accounting and auditing. Moreover, it notes selected provisions that might become relevant in the upcoming Article 50 TEU negotiations.
The German savings and cooperative banks of the 19th century were precursors of modern microfinance. They provided access to financial services for the majority of the German population, which was formerly excluded from bank funding. Furthermore, they did this at low costs for themselves and affordable prices for their clients. By creating networks of financially viable and stable financial institutions covering the entire country, they contributed significantly to building a sound and “inclusive” financial infrastructure in Germany. A look back at the history of German savings and cooperative banks and combining these experiences with the lessons learned from modern microfinance can guide current policy and be valuable for present and future models of microfinance business.
Effective market discipline incentivizes financial institutions to limit their risk-taking behavior, making it a key element for financial regulation. However, without adequate incentives to monitor and control the risk-taking behavior of financial institutions market discipline erodes. As a consequence, bailing out financial institutions, as happened unprecedentedly during the recent financial crisis, may impose indirect costs to financial stability if bailout expectations of investors change. Analyzing US data covering the period between 2004 and 2014, Hett und Schmidt (2017) find that market participants adjusted their bailout expectations in response to government interventions, undermining market discipline mechanisms. Given these findings, policymakers need to take into account the potential effects on market discipline when deciding about public support to troubled financial institutions in the future. Considering the parallelism of events and public responses during the financial crisis as well as the recent developments of Italian banks, these results not only concern the US, but also have important implications for European financial markets and policy makers.
On 15 August 2017, the Bundesverfassungsgericht (BVerfG) referred the case against the European Central Bank’s policy of Quantitative Easing (QE) to the European Court of Justice (ECJ). The author argues that this event differs in several aspects from the OMT case in 2015 – in content as well as in form. The BVerfG recognizes that it is a legitimate goal of the ECB’s monetary policy to bring inflation up close to 2%, and that the instrument employed for QE is one of monetary policy. However, it doubts whether the sheer volume of QE would not distort the character of the program as one of monetary policy. The ECJ will now have to clarify the extent to which the ECJ’s findings in its OMT judgment are relevant for QE as well as the standard of review applicable to monetary policy. The author raises the questions of whether the principle of democracy under German constitutional law can actually provide the standard by which the ECB is to be measured, and how tight judicial review could be exercised over the ECB without encroaching upon its autonomy in monetary policy matters – and thus upon the very essence of central bank independence.
Crowdfunding is a buzzword that signifies a sub-set in the new forms of finance facilitated by advances in information technology usually categorized as fintech. Concerns for financial stability, investor and consumer protection, or the prevention of money laundering or funding of terrorism hinge incrementally on including the new techniques to initiate financing relationships adequately in the regulatory framework.
This paper analyzes the German regulation of crowdinvesting and finds that it does not fully live up to the regulatory challenges posed by this novel form of digitized matching of supply and demand on capital markets. It should better reflect the key importance of crowdinvesting platforms, which may become critical providers of market infrastructure in the not too distant future. Moreover, platforms can play an important role in investor protection that cannot be performed by traditional disclosure regimes geared towards more seasoned issuers. Against this background, the creation of an exemption from the traditional prospectus regime seems to be a plausible policy choice. However, it needs to be complemented by an adequate regulatory stimulation of platforms’ role as gatekeepers.
Fleckenstein et al. (2014) document that nominal Treasuries trade at higher prices than inflation-swapped indexed bonds, which exactly replicate the nominal cash flows. We study whether this mispricing arises from liquidity premiums in inflation-indexed bonds (TIPS) and inflation swaps. Using US data, we show that the level of liquidity affects TIPS, whereas swap yields include a liquidity risk premium. We also allow for liquidity effects in nominal bonds. These results are based on a model with a systematic liquidity risk factor and asset-specific liquidity characteristics. We show that these liquidity (risk) premiums explain a substantial part of the TIPS underpricing.
This paper studies a consumption-portfolio problem where money enters the agent's utility function. We solve the corresponding Hamilton-Jacobi-Bellman equation and provide closed-form solutions for the optimal consumption and portfolio strategy both in an infinite- and finite-horizon setting. For the infinite-horizon problem, the optimal stock demand is one particular root of a polynomial. In the finite-horizon case, the optimal stock demand is given by the inverse of the solution to an ordinary differential equation that can be solved explicitly. We also prove verification results showing that the solution to the Bellman equation is indeed the value function of the problem. From an economic point of view, we find that in the finite-horizon case the optimal stock demand is typically decreasing in age, which is in line with rules of thumb given by financial advisers and also with recent empirical evidence.
Coming early to the party
(2017)
We examine the strategic behavior of High Frequency Traders (HFTs) during the pre-opening phase and the opening auction of the NYSE-Euronext Paris exchange. HFTs actively participate, and profitably extract information from the order flow. They also post "flash crash" orders, to gain time priority. They make profits on their last-second orders; however, so do others, suggesting that there is no speed advantage. HFTs lead price discovery, and neither harm nor improve liquidity. They "come early to the party", and enjoy it (make profits); however, they also help others enjoy the party (improve market quality) and do not have privileges (their speed advantage is not crucial).
The bail-in tool as implemented in the European bank resolution framework suffers from severe shortcomings. To some extent, the regulatory framework can remedy the impediments to the desirable incentive effect of private sector involvement (PSI) that emanate from a lack of predictability of outcomes, if it compels banks to issue a sufficiently sized minimum of high-quality, easy to bail-in (subordinated) liabilities. Yet, even the limited improvements any prescription of bail-in capital can offer for PSI’s operational effectiveness seem compromised in important respects.
The main problem, echoing the general concerns voiced against the European bail-in regime, is that the specifications for minimum requirements for own funds and eligible liabilities (MREL) are also highly detailed and discretionary and thus alleviate the predicament of investors in bail-in debt, at best, only insufficiently. Quite importantly, given the character of typical MREL instruments as non-runnable long-term debt, even if investors are able to gauge the relevant risk of PSI in a bank’s failure correctly at the time of purchase, subsequent adjustment of MREL-prescriptions by competent or resolution authorities potentially change the risk profile of the pertinent instruments. Therefore, original pricing decisions may prove inadequate and so may market discipline that follows from them.
The pending European legislation aims at an implementation of the already complex specifications of the Financial Stability Board (FSB) for Total Loss Absorbing Capacity (TLAC) by very detailed and case specific amendments to both the regulatory capital and the resolution regime with an exorbitant emphasis on proportionality and technical fine-tuning. What gets lost in this approach, however, is the key policy objective of enhanced market discipline through predictable PSI: it is hardly conceivable that the pricing of MREL-instruments reflects an accurate risk-assessment of investors because of the many discretionary choices a multitude of agencies are supposed to make and revisit in the administration of the new regime. To prove this conclusion, this chapter looks in more detail at the regulatory objectives of the BRRD’s prescriptions for MREL and their implementation in the prospectively amended European supervisory and resolution framework.
This paper studies a consumption-portfolio problem where money enters the agent's utility function. We solve the corresponding Hamilton-Jacobi-Bellman equation and provide closed-form solutions for the optimal consumption and portfolio strategy both in an infinite- and finite-horizon setting. For the infinite-horizon problem, the optimal stock demand is one particular root of a polynomial. In the finite-horizon case, the optimal stock demand is given by the inverse of the solution to an ordinary differential equation that can be solved explicitly. We also prove verification results showing that the solution to the Bellman equation is indeed the value function of the problem. From an economic point of view, we find that in the finite-horizon case the optimal stock demand is typically decreasing in age, which is in line with rules of thumb given by financial advisers and also with recent empirical evidence.
This paper analyzes the bail-in tool under the Bank Recovery and Resolution Directive (BRRD) and predicts that it will not reach its policy objective. To make this argument, this paper first describes the policy rationale that calls for mandatory private sector involvement (PSI). From this analysis, the key features for an effective bail-in tool can be derived.
These insights serve as the background to make the case that the European resolution framework is likely ineffective in establishing adequate market discipline through risk-reflecting prices for bank capital. The main reason for this lies in the avoidable embeddedness of the BRRD’s bail-in tool in the much broader resolution process, which entails ample discretion of the authorities also in forcing private sector involvement. Moreover, the idea that nearly all positions on the liability side of a bank’s balance sheet should be subjected to bail-in is misguided. Instead, a concentration of PSI in instruments that fall under the minimum requirements for own funds and eligible liabilities (MREL) is preferable.
Finally, this paper synthesized the prior analysis by putting forward an alternative regulatory approach that seeks to disentangle private sector involvement as a precondition for effective bank-resolution as much as possible form the resolution process as such.
We analyze the market reaction to the sentiment of the CEO speech at the Annual General Meeting (AGM). As the AGM is typically preceded by several information disclosures, the CEO speech may be expected to contribute only marginally to investors’ decision making. Surprisingly, however, we observe from the transcripts of 338 CEO speeches of German corporates between 2008 and 2016 that their sentiment is significantly related to abnormal stock returns and trading volume around the AGM. By adapting a finance-specific German dictionary based on Loughran and McDonald (2011), we find a negative association of the post-AGM returns with the speeches’ negativity and a positive association with the speeches’ relative positivity (i.e. positivity relative to negativity). Relative positivity moreover corresponds with a lower trading volume around the AGM. Investors hence seem to perceive the sentiment of CEO speeches at AGMs as a valuable indicator of future firm performance. Our results are robust against different weighting schemes and our dictionary appears to be better suited to grasp the sentiment of German business documents compared to general dictionaries.
Since 2014 the ECB has implemented a massive expansion of monetary policy including large-scale asset purchases and negative policy rates. As the euro area economy has improved and inflation has risen, questions concerning the future normalization of monetary policy are starting to dominate the public debate.
The study argues that the ECB should develop a strategy for policy normalization and communicate it very soon to prepare the ground for subsequent steps towards tightening. It provides analysis and makes proposals concerning key aspects of this strategy. The aim is to facilitate the emergence of expectations among market participants that are consistent with a smooth process of policy normalization.
We analyze the market reaction to the sentiment of the CEO speech at the Annual General Meeting (AGM). As the AGM is typically preceded by several information disclosures, the CEO speech may be expected to contribute only marginally to investors’ decision-making. Surprisingly, however, we observe from the transcripts of 338 CEO speeches of German corporates between 2008 and 2016 that their sentiment is significantly related to abnormal stock returns and trading volumes following the AGM. Using a novel business-specific German dictionary based on Loughran and McDonald (2011), we find a negative association of the post-AGM returns with the speeches’ negativity and a positive association with the speeches’ relative positivity (i.e. positivity relative to negativity). Relative positivity moreover corresponds with a lower trading volume in a short time window surrounding the AGM. Investors hence seem to perceive the sentiment of CEO speeches at AGMs as a valuable indicator of future firm performance.
We theoretically and empirically study large-scale portfolio allocation problems when transaction costs are taken into account in the optimization problem. We show that transaction costs act on the one hand as a turnover penalization and on the other hand as a regularization, which shrinks the covariance matrix. As an empirical framework, we propose a flexible econometric setting for portfolio optimization under transaction costs, which incorporates parameter uncertainty and combines predictive distributions of individual models using optimal prediction pooling. We consider predictive distributions resulting from highfrequency based covariance matrix estimates, daily stochastic volatility factor models and regularized rolling window covariance estimates, among others. Using data capturing several hundred Nasdaq stocks over more than 10 years, we illustrate that transaction cost regularization (even to small extent) is crucial in order to produce allocations with positive Sharpe ratios. We moreover show that performance differences between individual models decline when transaction costs are considered. Nevertheless, it turns out that adaptive mixtures based on high-frequency and low-frequency information yield the highest performance. Portfolio bootstrap reveals that naive 1=N-allocations and global minimum variance allocations (with and without short sales constraints) are significantly outperformed in terms of Sharpe ratios and utility gains.
A counterparty credit limit (CCL) is a limit imposed by a financial institution to cap its maximum possible exposure to a specified counterparty. Although CCLs are designed to help institutions mitigate counterparty risk by selective diversification of their exposures, their implementation restricts the liquidity that institutions can access in an otherwise centralized pool. We address the question of how this mechanism impacts trade prices and volatility, both empirically and via a new model of trading with CCLs. We find empirically that CCLs cause little impact on trade. However, our model highlights that in extreme situations, CCLs could serve to destabilize prices and thereby influence systemic risk.
We show an ambivalent role of high-frequency traders (HFTs) in the Eurex Bund Futures market around high-impact macroeconomic announcements and extreme events. Around macroeconomic announcements, HFTs serve as market makers, post competitive spreads, and earn most of their profits through liquidity supply. Right before the announcement, however, HFTs significantly widen spreads and cause a rapid but short-lived drying-out of liquidity. In turbulent periods, such as after the U.K. Brexit announcement, HFTs shift their focus from market making activities to aggressive (but not necessarily profitable) directional strategies. Then, HFT activity becomes dominant and market quality can degrade.
Optimal trend inflation
(2017)
We present a sticky-price model incorporating heterogeneous Firms and systematic firm-level productivity trends. Aggregating the model in closed form, we show that it delivers radically different predictions for the optimal inflation rate than canonical sticky price models featuring homogenous Firms:
(1) the optimal steady-state inflation rate generically differs from zero and,
(2) inflation optimally responds to productivity disturbances.
Using micro data from the US Census Bureau to estimate the inflation-relevant productivity trends at the firm level, we find that the optimal US inflation rate is positive. It was slightly above 2 percent in the year 1986, but continuously declined thereafter, reaching about 1 percent in the year 2013.
Monetary policy communication is particularly important during unconventional times, because high uncertainty about the economy, the introduction of new policy tools and possible limits to the central bank’s toolkit could hamper the predictability of policy actions. We study how monetary policy communication should and has worked under such circumstances. Our main results relate to announcements of asset purchase programmes and the use of forward guidance. We show that announcements of asset purchase programmes have lowered market uncertainty, particularly when accompanied by a contextual release of implementation details such as the envisaged size of the programme. We also show that forward guidance reduces uncertainty more effectively when it is state‐contingent or when it provides guidance about a long horizon than when it is open‐ended or covers only a short horizon, and that the credibility of forward guidance is strengthened if the central bank also has embarked on an asset purchase programme.
Recent work has analyzed the forecasting performance of standard dynamic stochastic general equilibrium (DSGE) models, but little attention has been given to DSGE models that incorporate nonlinearities in exogenous driving processes. Against that background, we explore whether incorporating stochastic volatility improves DSGE forecasts (point, interval, and density). We examine real-time forecast accuracy for key macroeconomic variables including output growth, inflation, and the policy rate. We find that incorporating stochastic volatility in DSGE models of macroeconomic fundamentals markedly improves their density forecasts, just as incorporating stochastic volatility in models of financial asset returns improves their density forecasts.
Commodity connectedness
(2017)
We use variance decompositions from high-dimensional vector autoregressions to characterize connectedness in 19 key commodity return volatilities, 2011-2016. We study both static (full-sample) and dynamic (rolling-sample) connectedness. We summarize and visualize the results using tools from network analysis. The results reveal clear clustering of commodities into groups that match traditional industry groupings, but with some notable differences. The energy sector is most important in terms of sending shocks to others, and energy, industrial metals, and precious metals are themselves tightly connected.
We analyze older individuals’ debt and financial vulnerability using data from the Health and Retirement Study (HRS) and the National Financial Capability Study (NFCS). Specifically, in the HRS we examine three different cohorts (individuals age 56–61) in 1992, 2004, and 2010 to evaluate cross-cohort changes in debt over time. We also use two waves of the NFCS (2012 and 2015) to gain additional insights into debt management and older individuals’ capacity to shield themselves against shocks. We show that recent cohorts have taken on more debt and face more financial insecurity, mostly due to having purchased more expensive homes with smaller down payments.
The growth and popularity of defined contribution pensions, along with the government’s increasing attention to retirement plan costs and investment choices provided, make it important to understand how people select their retirement plan investments. This paper shows how employees in a large firm altered their fund allocations when the employer streamlined its pension fund menu and deleted nearly half of the offered funds. Using administrative data, we examine the changes in plan participant investment choices that resulted from the streamlining and how these changes might affect participants’ eventual retirement wellbeing. We show that streamlined participants’ new allocations exhibited significantly lower within-fund turnover rates and expense ratios, and we estimate this could lead to aggregate savings for these participants over a 20-year period of $20.2M, or in excess of $9,400 per participant. Moreover, after the reform, streamlined participants’ portfolios held significantly less equity and exhibited significantly lower risks by way of reduced exposures to most systematic risk factors, compared to their non-streamlined counterparts.
The long-run consumption risk model provides a theoretically appealing explanation for prominent asset pricing puzzles, but its intricate structure presents a challenge for econometric analysis. This paper proposes a two-step indirect inference approach that disentangles the estimation of the model's macro-economic dynamics and the investor's preference parameters. A Monte Carlo study explores the feasibility and efficiency of the estimation strategy. We apply the method to recent U.S.\data and provide a critical re-assessment of the long-run risk model's ability to reconcile the real economy and financial markets. This two-step indirect inference approach is potentially useful for the econometric analysis of other prominent consumption-based asset pricing models that are equally difficult to estimate.
The long-run consumption risk model provides a theoretically appealing explanation for prominent asset pricing puzzles, but its intricate structure presents a challenge for econometric analysis. This paper proposes a two-step indirect inference approach that disentangles the estimation of the model's macroeconomic dynamics and the investor's preference parameters. A Monte Carlo study explores the feasibility and efficiency of the estimation strategy. We apply the method to recent U.S. data and provide a critical re-assessment of the long-run risk model's ability to reconcile the real economy and financial markets. This two-step indirect inference approach is potentially useful for the econometric analysis of other prominent consumption-based asset pricing models that are equally difficult to estimate.
Die Verknüpfung des Fahrrades mit dem Öffentlichen Verkehr (ÖV) kann den Umweltverbund stärken, den Übergang von einem Verkehrssystem auf das andere erleichtern und eine attraktive Alternative zum motorisierten Individualverkehr schaffen. Die vorliegende Arbeit repräsentiert den ersten umfassenden Projektbericht innerhalb des Forschungsprojektes „Verbesserte Integration des Fahrrads in den öffentlichen Verkehr – Systematische Erschließung von Handlungsoptionen und Bewertung von Best-Practices“. Ziel dieser Publikation ist eine aktuelle Aufarbeitung des Standes der Forschung und der Praxis zu diesem Thema.
Nach einer systematischen Darstellung wichtiger Forschungsstränge, werden zunächst Ergebnisse aus dem „Mobilität in Deutschland“-Datensatz hinsichtlich intermodaler Rad‐ÖV‐Nutzungsmuster präsentiert. Aufbauend darauf werden Datengrundlagen und generelle Erfordernisse an Erhebungsmethoden diskutiert, um die inter- und multimodale Verkehrsmittelnutzung tatsächlich beurteilen zu können. Die Darstellung des aktuellen Standes in der Praxis wird anhand von drei Schwerpunkt-Feldern vorgenommen: Bike and Ride Abstellanlagen an Haltestellen des ÖV, Radmitnahme in den Fahrzeugen des ÖV und Fahrradverleihsysteme. Dabei werden sowohl infrastrukturelle Maßnahmen als auch Betreiberkonzepte und Marketingaspekte behandelt. Ein weiteres Kapitel beschäftigt sich mit den Chancen und Herausforderungen im Zuge der fortschreitenden Digitalisierung und der Verbreitung von mobilen Endgeräten.
Gallery forests (GFs) are floristically and functionally distinct forests along rivers and watercourses. The GFs of the West African savannas form thin stripes with a particular, species-rich flora differing significantly from the surrounding vegetation. Due to their relative isolation in the savannas and their dependence on rivers, GFs are particularly endangered by the expected global climate changes in the 21st century. Despite their high diversity, little is known about the ecology and biogeography of GFs in West Africa. Especially, their response to climate changes and their vegetation dynamics remain largely unknown. This thesis combines floristic, phylo-geographic and ecological data to investigate the biodiversity, historical and recent biogeography and conservation status of GF species in Burkina Faso (BFA) as a model for West Africa.
The topic of this thesis is the investigation of scalar tetraquark candidates from lattice QCD. It is motivated by a previous study originating in the twisted mass collaboration. The initial tetraquark candidate of choice is the $a_0(980)$, an isovector in the nonet of light scalars ($J^P=0^+$). This channel is still poorly understood. It displays an inverted mass hierarchy to what is expected from the conventional quark model and the $a_0(980)$ and $f_0(980)$ feature a surprising mass degeneracy. For this reasons the $a_0(980)$ is a long assumed tetraquark candidate in the literature.
We follow a methodological approach by studying the sensitivity of the scalar spectrum with fully dynamical quarks to a large basis of two-quark and four-quark creation operators. Ultimately, the candidate has to be identified in the direct vicinity of two two-particles states, which is understandably inevitable for a tetraquark candidate. To succeed in this difficult task two-meson creation operators are essential to employ in this channel. By localized four-quark operators we intend to probe the Hamiltonian on eigenstates with a closely bound four-quark structure.
Die Goethe-Universität ernannte 1959 den Frankfurter NS-Schul- und Kulturdezernenten Rudolf Keller sowie den NS-Stadtkämmerer Friedrich Lehmann zu Ehrenbürgern. Vor allem: sie erklärte beide feierlich zu NS-Gegnern. In welche NS-Untaten aber waren beide involviert und worüber waren sie informiert? Das Ergebnis ist die Historiographie: „Schuld und Ehrung. Die Kommunalpolitiker Rudolf Keller und Friedrich Lehmann zwischen 1933 und 1960 - ein Beitrag zur NS-Geschichte in Frankfurt am Main“. Es wird vielfältig und en détail dargelegt, wie beide an NS-Verbrechen und Vergehen beteiligt waren; ihre Rolle im „Dritten Reich“ wird nachgezeichnet. Die Untersuchung fügt sich in aktuelle Forschungen zum erweiterten Täterkreis und zu intellektuellen Unterstützern ein. Die Studie wendet sich an das lokale wie das überregionale Fachpublikum und an die Frankfurter Stadtgesellschaft.
Development of the timing system for the Bunch-to-Bucket transfer between the FAIR accelerators
(2017)
The FAIR project is aiming at providing high-energy beams of ions of all elements from hydrogen to uranium, antiprotons and rare isotopes with high intensities. The existing accelerator facility of GSI and the future FAIR facility employ a variety of circular accelerators like heavy ion synchrotrons (SIS18 and SIS100) and storage rings (ESR, CRYRING, CR and HESR) for the preparation of secondary beams and experiments. Bunches are required to be transferred into rf buckets among GSI and FAIR ring accelerators for different purposes. Without the proper transfer, the beam will be subject to various beam quality deterioration and even to beam losses. Hence, the proper bunch-to-bucket (B2B) transfer between two rings is of great importance for FAIR and is the topic, which has been investigated in this thesis.
These circular accelerators of GSI and FAIR have different ratios in their circumference. For example, the circumference ratio between SIS100 and SIS18 is an integer and between SIS18 and ESR is close to an integer and between CR and HESR is far away from an integer. The ring accelerators are connected via a complicated system of beam transfer lines, targets for the secondary particle production and the high energy separators mentioned above. For FAIR, not only the primary beams are required to be transferred from one ring to another, but also the secondary beams, e.g. the antiproton or rare isotope beams produced by the antiproton (pbar) target, the fragment separator (FRS) or the superconducting fragment separator (Super-FRS). An important topic for this system of accelerators is the proper transfer of beam between the different circular accelerators. Bunches of one ring must be transferred into buckets of another ring within an upper bound time constraint (e.g. 10 ms for most FAIR use cases) and with an acceptable B2B injection center mismatch +-1 degree for most FAIR use cases). Hence, a flexible FAIR B2B transfer system is required to realize the different complex B2B transfers between the FAIR rings in the future. In the focus of the system development and of this thesis is the transfer from SIS18 to SIS100, which can be tested at GSI on the transfer from SIS18 to ESR and from ESR to CRYRING. The system is based on the existing technical basis at GSI, the low-level radio frequency (LLRF) system and the FAIR control system. It coordinates with the Machine Protection System (MPS), which protects SIS100 and subsequent accelerators and experiments from damage caused by high intensity primary beams in case of malfunctioning. Besides, it indicates the beam status and the actual beam injection time for the beam instrumentation and diagnostics.
The conceptual realization of the FAIR B2B transfer system was introduced in this thesis for the first time. It achieves the most FAIR B2B transfers with a tolerable B2B injection center mismatch (e.g. +-1 degree) and within an upper bound time (e.g. 10 ms). It supports two synchronization methods, the phase shift and frequency beating methods. It is flexible to support the beam transfer between two rings with different ratios in their circumference and several B2B transfers running at the same time, e.g. the B2B transfer from SIS18 to SIS100 and at the same time the B2B transfer from ESR to CRYRING. It is capable to transfer beam of different ion species from one machine cycle to another and to transfer beams between two rings via the FRS, the pbar target and the Super-FRS. It allows various complex bucket filling pattern. In addition, it coordinates with the MPS system, which protects the SIS100 and subsequent accelerators or experiments from beam induced damage.
A list of criteria for the preservation of beam qualities during the rf frequency modulation of the phase shift method was analyzed. As an example the beam reaction on three different rf frequency modulation examples were analyzed for SIS18 beams. According to the beam dynamic analysis, there is a maximum value for the rf frequency modulation. The first derivative of the rf frequency modulation must be continuous and small enough and the second derivative must be small enough.
In addition to the analysis from the viewpoint of beam dynamics, two test setups were built. The first test setup was used to characterize the FAIR timing network – white rabbit network for the B2B transfer. In the second test setup, the firmware of the FAIR B2B transfer system was evaluated, which was running on the soft CPU, LatticeMico32, of the Scalable Control Unit - the FAIR standard Front End Controller. Besides, the boundary conditions of the different trigger scenarios of the SIS18 extraction and SIS100 injection kicker magnets were investigated. Finally, the application of the FAIR B2B transfer system for all FAIR use cases was demonstrated.
The dissertation plays a significant important role for the realization of the FAIR B2B transfer system and the further practical application of the system to all FAIR use cases.
Two new genera and species of tiger beetles from Baltic amber (Coleoptera: Carabidae: Cicindelinae)
(2017)
Two fossil tiger beetle species (Coleoptera, Carabidae, Cicindelinae) are described from Eocene Baltic amber using light microscopic and X-ray microscopic techniques. Both species are considered representatives of the subtribe Iresina Rivalier, 1971 due to the shared combination of character states: glabrous head, six labral and four suborbital setae, and glabrous pronotum. Palaeopronyssiformia groehni Wiesner, Will, and Schmidt, new genus, new species, is characterized by a glabrous and furrowed head with six labral setae, large eyes, presence of two supraorbital setae on each side, mandibles with two teeth of the incisor region, and a glabrous and furrowed pronotum. Palaeoiresina cassolai Wiesner, Will, and Schmidt, new genus, new species, is characterized by a unicolored, undentated labrum, mandibles with two teeth of the incisor region, glabrous head with six labral setae, two clypeal setae, two supraorbital setae on each side, and a glabrous pronotum, mesepisternum, mesepimeron, and metepisternum. The species described here represent the only known tiger beetle fossils preserved in Baltic amber.
Redescription of adult and observations of the weevil Revena plaumanni Bondar (Coleoptera: Curculionidae), preying on seeds of the palm tree Butia eriospatha (Mart. ex Drude) Becc. (Arecaceae), as well as oviposition and larval behavior, pupation site, and adult emergence are reported for the fi rst time in Brazil. Photos of host plant, immature forms (egg, larva and pupa) and adult are given. Illustrations of male and female genitalia are also provided.
New Bolivian Rhinotragini (Coleoptera, Cerambycidae, Cerambycinae) are described: three species of Phygopoda Thomson, 1864 (P. longiscopifera sp. nov., P. boliviensis sp. nov. and P. chaquensis sp. nov.); and one species of Phygopoides Peñaherrera-Leiva and Tavakilian, 2007 (P. maxwelli sp. nov.). Two Brazilian species of Neophygopoda Melzer, 1933 are transferred to the genus Phygopoda: P. exilis (Melzer, 1933) comb. nov. and P. agdae (Martins, Galileo and Santos-Silva, 2015) comb. nov. All the species are illustrated, and a key to the Bolivian species of Phygopoda and host flower records are provided.
A primitive subfamily of false click beetles (Coleoptera: Eucnemidae: Phlegoninae) distributed primarily in the Neotropical region is revised. Euryphlegon gen. nov. is described from Belize in Central America. New species include: Phlegon chiriquiensis sp. nov. (Panama), Phlegon panamensis sp. nov. (Panama), Euryphlegon jacqueschassaini sp. nov. (Panama) and Euryphlegon parallelus sp. nov. (Belize). Phlegon herculeanus (Lacordaire) stat. res. is resurrected from synonymy with Phlegon buqueti Laporte. One new combination is proposed: Euryphlegon degallieri (Muona) (Phlegon). Based on a number of observed external character traits, Euryphlegon is placed in Orodotini Muona, 1993 within Macraulacinae Fleutiaux, 1922. Identifi cation keys are provided for species of Phlegon and Euryphlegon in the Neotropical region. The relationships among Phlegon, Euryphlegon, Euryptychus LeConte and other groups within Echthrogasterini Cobos, 1964 and Orodotini are discussed.
Fossile Rohstoffe dienen in unserer heutigen Gesellschaft als Energiequelle und als Rohstofflieferant für Grund-, Feinchemikalien und Pharmazeutika. Sie tragen jedoch zum Klimawandel und Umweltverschmutzung bei. Lignocellulosische Biomasse ist eine erneuerbare und nachhaltige Alternative, die durch biotechnologische Prozesse erschlossen werden kann. Die Bäckerhefe Saccharomyces cerevisiae ist ein sehr gut untersuchter Modellorganismus, für den es zahlreiche genetische Werkzeuge und Analysemethoden gibt. Zudem wird S. cerevisiae häufig in biotechnologischen Prozessen eingesetzt, da diese Hefe robust gegenüber industriellen Bedingungen wie niedrigen pH-Werten, toxischen Chemikalien, osmotischem und mechanischem Stress ist. Die Pentose D-Xylose ist ein wesentlicher Bestandteil von lignocellulosischer Biomasse, die aber nicht natürlicherweise von der Bäckerhefe verwerten werden kann. Für eine kommerzielle Herstellung von Produkten aus lignocellulosischer Biomasse muss S. cerevisiae D-Xylose effektiv verwerten. Für die Bäckerhefe konnten heterologe Stoffwechselwege etabliert werden, damit diese D-Xylose verwerten kann. Für eine effiziente Xyloseverwertung bleiben dennoch zahlreiche Herausforderungen bestehen. Unter anderem nehmen die Zellen D-Xylose über ihre endogenen Hexosetransporter nur langsam auf. Die heterologe Xylose-Isomerase (XI) besitzt in S. cerevisiae eine geringe Aktivität für die Isomerisierung von D-Xylose. Unspezifische Aldosereduktasen konkurrieren mit der Xylose-Isomerase um das gleiche Substrat und produzieren Xylitol, ein starker Inhibitor der Xylose-Isomerase. Eine Möglichkeit die Umsatzrate von Enzymen zu steigern und Substrate vor Nebenreaktionen zu schützen, ist die Anwendung von Substrate Channeling Strategien. Bei Substrate Channeling befinden sich die beteiligten Enzyme in einem Komplex, wodurch die Substrate lokal angereichert werden und von einem aktiven Zentrum zum nächsten weitergeleitet werden, ohne Diffusion in den restlichen Reaktionsraum. In dieser Arbeit wurde untersucht, ob ein Komplex zwischen einem membranständigen Transporter und einem löslichen Enzym konstruiert werden kann, um durch Substrate Channeling eine verbesserte Substrat-Verwertung zu erreichen. Die Xylose-Isomerase aus C. phytofermentans und die endogene Hexose-Permease Gal2 sollten in dieser Arbeit als Modellproteine in S. cerevisiae-Zellen mit Hilfe von Protein-Protein-Interaktionsmodulen (PPIM) in räumliche Nähe zueinander gebracht werden.
Die Expression verschiedener PPIM konnte in S. cerevisiae mittels Western Blot nachgewiesen werden. Auch Fusionsproteine aus unterschiedlichen PPIM wurden in dieser Hefe exprimiert. Die PPIM binden komplementäre PPIM oder kurze Peptidliganden, welche an die Xylose-Isomerase und an den Gal2-Transporter fusioniert wurden. Die Funktionalität beider Proteine wurde mittels in vivo und in vitro Tests untersucht. Die Xylose-Isomerase mit N-terminalen Liganden des WH1-Protein-Protein-Interaktionsmoduls (WH1L-XI) und der Gal2-Transporter mit N-terminalen SYNZIP2-Protein-Protein-Interaktionsmodul (SZ2-Gal2) erwiesen sich als geeignete Kandidaten für weitere Untersuchungen. Mittels indirekter Immunfluoreszenz konnte die Ko-Lokalisierung von SZ2-Gal2 und WH1L-XI, die einander über ein Scaffold-Protein binden, nachgewiesen werden.
Transformanten, in denen ein Komplex aus Transporter, Scaffold-Protein und Xylose-Isomerase gebildet wurde, zeigten bessere Fermentationseigenschaften gegenüber der Scaffold-freien Kontrolle und dem Wildtyp: Sie verwerteten Xylose schneller, bildeten weniger vom unerwünschten Nebenprodukt Xylitol, produzierten mehr Ethanol und wiesen eine höhere Ethanolausbeute auf. Der beobachtete Substrate Channeling Effekt kompensierte die geringere Enzymaktivität der WH1L-XI im Vergleich zum Wildtyp-Protein. Die Wirksamkeit des Substrate Channeling wurde verringert, wenn die Bildung des Komplexes aus Transporter, Scaffold-Protein und Xylose-Isomerase gestört wurde, indem ein getaggtes GFP mit dem Scaffold-Protein um die Bindungsstelle an Gal2 konkurrierte. Dies zeigt, dass die positive Wirkung auf die Komplex-Bildung zwischen XI und Gal2 zurück zu führen ist. Die Fermentationseigenschaften konnten gesteigert werden, indem der zuvor zwischen SZ2-Zipper und Gal2-Transporter verwendete Linker, der aus zehn Aminosäuren von Glycin, Arginin und Prolin (GRP10) bestand, durch einen aus Glycin und Alanin (GA10) ersetzt wurde. Die verbesserten Fermentationseigenschaften beruhten auf einem Substrate Channeling Effekt und einer gesteigerten Aufnahmerate des SZ2-GA10-Gal2-Transporters. Ein Vergleich der Strukturvorhersagen von SZ2-GRP10-Gal2 und SZ2-GA10-Gal2 zeigte, dass der GRP10-Linker einen unstrukturierten, flexiblen Linker ausbildet, während der GA10-Linker eine starre α-Helix ausbildet. Die Struktur und der Transportprozess von Gal2 sind nicht aufgeklärt. Bei verwandten Transportern geht man davon aus, dass Substrate durch Konformationsänderungen ins Innere der Zelle transportiert werden, indem die beiden Domänen gegeneinander klappen. Die α-Helix könnte die Geschwindigkeit der Konformationsänderungen begünstigen.
Durch Kontrollexperimente konnte ausgeschlossen werden, dass die gesteigerten Fermentationseigenschaften eine Folge der Stabilisierung der XI- und Gal2-Fusionsproteine durch das Anfügen des Liganden oder durch Komplexbildung mit dem Scaffold-Protein waren. Substrate Channeling zwischen Gal2 und XI entsteht durch die Komplexbildung mit dem Scaffold-Protein, wodurch sich Gal2 und XI in räumlicher Nähe zueinander befinden. Dieser Effekt beruht möglicherweise zusätzlich aufgrund einer hohen örtlichen Ansammlung dieser Proteine, da die tetramere XI weitere Scaffold-Proteine binden könnte, welche weitere Gal2-Transporter binden könnte. Darüber hinaus sammeln sich Transporter an bestimmten Orten der Membran an und Transporter mit ähnlicher oder gleicher Transmembransequenz tendieren dazu zu ko-lokalisieren. Hierdurch könnten Gal2-XI-Agglomerate entstehen und Xylose wird mit hoher Wahrscheinlichkeit von einer der vielen Xylose-Isomerasen umgesetzt.
HCMV ist ein Pathogen mit einer weltweit sehr hohen Prävalenz und stellt nach wie vor ein großes Problem für Immunsupprimierte (Transplantations- und AIDS-Patienten) und für ungeborene Kinder dar. Seine Pathogenese ist weiterhin nur unzureichend bekannt, eine Impfprophylaxe existiert nicht und es stehen nur wenige, unzureichende Medikamente zur Therapie zur Verfügung. Auch ein verstärkender Einfluss des Virus auf die Tumormalignität ist gezeigt. Aber die der viralen Onkomodulation zugrundeliegenden Mechanismen, insbesondere die Frage, wie und wann Tumorwachstum und -invasion durch HCMV beschleunigt werden, bedürfen weiterer Aufklärung.
Die immediate early-Proteine IE1 und IE2 sind wichtige Regulatorproteine einer HCMV-Infektion – insbesondere IE1, welches einen entscheidenden Einfluss auf die Genexpression der Wirtszelle nimmt. Es wurde a-priori die Hypothese erstellt, dass über einen positiven Einfluss von IE1 auf die Enterokinaseexpression die Trypsin-vermittelte Tumorinvasion gefördert wird.
Im ersten Teil dieser Arbeit wurde ein effizientes, zuverlässiges Protokoll zur Herstellung IE1- und IE2-exprimierender Tumorzelllinien mit Hilfe von lentiviralem Gentransfer ausgearbeitet. Damit verbunden konnten zwei persistent-transduzierte humane Tumorzelllinien, U-251 MGIE1 und U-251 MGIE2, mit hohen Expressionsraten etabliert werden. Weiter konnte im zweiten Teil der Arbeit, sowohl im Akutmodell als auch an persistent-transduzierten Zellen, gezeigt werden, dass die Enterokinaseexpression nicht im Zusammenhang mit der IE1-Expression steht.
Durch die Erarbeitung des Transduktions-Protokolls und die Etablierung der persistent-transduzierten humanen Tumorzelllinien ist es nun möglich, die isolierten Auswirkungen von IE1 und IE2 auf humane Tumorzellen zu untersuchen. Die Widerlegung der Hypothese über die Beeinflussung der Enterokinaseexpression durch IE1 liefert eine Erkenntnis, um die Mechanismen der erhöhten Tumorinvasion besser verstehen zu können. Insgesamt konnte durch diese Arbeit ein Beitrag geliefert werden, die durch HCMV verursachten onkomodulatorischen Effekte noch besser nachvollziehen zu können. Dies wiederum kann künftig dazu dienen therapeutische Strategien, welche der Invasion und Metastasierung entgegen wirken, zu verbessern bzw. zu entwickeln.