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Integer point sets minimizing average pairwise L1 distance: What is the optimal shape of a town? (2010)

Erik D. Demaine Sándor P. Fekete Günter Rote Nils Schweer Daria Schymura Mariano Zelke

An n-town, n[is an element of]N , is a group of n buildings, each occupying a distinct position on a 2-dimensional integer grid. If we measure the distance between two buildings along the axis-parallel street grid, then an n-town has optimal shape if the sum of all pairwise Manhattan distances is minimized. This problem has been studied for cities, i.e., the limiting case of very large n. For cities, it is known that the optimal shape can be described by a differential equation, for which no closed-form solution is known. We show that optimal n-towns can be computed in O(n[superscript 7.5]) time. This is also practically useful, as it allows us to compute optimal solutions up to n=80.

Analyst behaviour: the geography of social interaction (2012)

Frederik König

An analyst who works in Germany is more likely to publish a high (low) price target regarding a DAX30 stock if other Germany based analysts are also optimistic (pessimistic) about the same stock. This finding is not biased by the fact that DAX30 companies are headquartered in Germany. In times of bull markets, price targets of analysts who regularly exchange their opinion are higher correlated compared to other analysts. This effect vanishes in a bearish market environment. This suggests that communication among analysts indeed plays an important role. However, analysts’ incentives induce them not to deviate too much from the overall average during an economic downturn.

Does social interaction destablise financial markets? (2012)

Frederik König

With this paper, I propose a simple asset pricing model that accounts for the influence from social interaction. Investors are assumed to make up their mind about an asset’s price based on a forecasting strategy and its past profitability as well as on the contemporaneous expectations of other market participants. Empirically analysing stocks of the DAX30 index, I provide evidence that social interaction rather destabilises financial markets. Based on my results, I state that at least, it does not have a stabilising effect.

Fluctuations of social influence: evidence from the behaviour of mutual fund managers during the economic crisis 2008/09 (2012)

Frederik König

In this paper, I analyse the reciprocal social influence on investment decisions within an international group of roughly 2000 mutual fund managers that invested in companies of the DAX30. Using a robust estimation procedure, I provide empirical evidence that in the average a fund manager puts 0.69% more portfolio weight on a particular stock, if other fund managers increase the corresponding position by 1%. The dynamics of this influence on portfolio weights suggest that fund managers adjust their behaviour according to the prevailing market situation and are more strongly influenced by others in times of an economic downturn. Analysing the working locations of the fund managers, I conclude that more than 90% of the magnitude of influence is due to pure observation. While this form of influence varies much in time, the magnitude of influence resulting from the exchange of opinion is more or less constant.

Ultrasound-guided intramural inoculation of orthotopic bladder cancer xenografts: a novel high-precision approach (2013)

Wolfgang Jäger Igor Moskalev Claudia Janssen Tetsutaro Hayashi Shannon Awrey Kilian M. Gust Alan I. So Kaixin Zhang Ladan Fazli Estelle Li Joachim W. Thüroff Dirk Lange Peter C. Black

Orthotopic bladder cancer xenografts are essential for testing novel therapies and molecular manipulations of cell lines in vivo. Current xenografts rely on tumor cell inoculation by intravesical instillation or direct injection into the bladder wall. Instillation is limited by the lack of cell lines that are tumorigenic when delivered in this manner. The invasive model inflicts morbidity on the mice by the need for laparotomy and mobilization of the bladder. Furthermore this procedure is complex and time-consuming. Three bladder cancer cell lines (UM-UC1, UM-UC3, UM-UC13) were inoculated into 50 athymic nude mice by percutaneous injection under ultrasound guidance. PBS was first injected between the muscle wall and the mucosa to separate these layers, and tumor cells were subsequently injected into this space. Bioluminescence and ultrasound were used to monitor tumor growth. Contrast-enhanced ultrasound was used to study changes in tumor perfusion after systemic gemcitabine/cisplatin treatment. To demonstrate proof of principle that therapeutic agents can be injected into established xenografts under ultrasound guidance, oncolytic virus (VSV) was injected into UM-UC3 tumors. Xenograft tissue was harvested for immunohistochemistry after 23–37 days. Percutaneous injection of tumor cells into the bladder wall was performed efficiently (mean time: 5.7 min) and without complications in all 50 animals. Ultrasound and bioluminescence confirmed presence of tumor in the anterior bladder wall in all animals 3 days later. The average tumor volumes increased steadily over the study period. UM-UC13 tumors showed a marked decrease in volume and perfusion after chemotherapy. Immunohistochemical staining for VSV-G demonstrated virus uptake in all UM-UC3 tumors after intratumoral injection. We have developed a novel method for creating orthotopic bladder cancer xenograft in a minimally invasive fashion. In our hands this has replaced the traditional model requiring laparotomy, because this model is more time efficient, more precise and associated with less morbidity for the mice.

Sandrart.net: Eine Online-Edition eines Textes des 17. Jahrhunderts (2010)

Anna Schreurs Carsten Blüm Thorsten Wübbena

Der folgende Text stellt ein Online-Projekt vor, das seit April 2007 mit einer Laufzeit von fünf Jahren auf Initiative des Kunstgeschichtlichen Instituts in Frankfurt und des Kunsthistorischen Instituts in Florenz entwickelt, zusammen mit den Partnerinstitutionen Städel Museum und Historisches Museum in Frankfurt durchgeführt und gemeinsam von der Deutschen Forschungsgemeinschaft und der Max-Planck- Gesellschaft finanziert wird.

Übersetzen : einfangen und frei lassen (2010)

Gerhard Bauer

Wir Philologen haben gut reden. Wir sehen zu, wie andere, die zumeist nicht zu unserer Zunft gehören, die unübersehbare Fülle von Geschriebenem aus seiner jeweiligen Ursprache in alle möglichen Sprachen bringen, und wir verhalten uns dazu als interessierte Zuschauer. Wir haben allen Grund, uns daran zu freuen: Ohne diesen grenzüberschreitenden Waren- und Gedankentausch bliebe das Feld, auf dem wir grasen, enger und parzellierter, als es nach der Intention der Autoren und auch der Sache nach sein müsste. Wir können (sofern wir den nötigen Überblick haben) das loben, was die Übersetzer zu Wege gebracht haben: die Entsprechungen, die sie entdeckt oder erfunden haben, die Kraft, Geschmeidigkeit und Modulationsvielfalt, die sie in ihren Zielsprachen mit Tausenden von einleuchtenden Funden oder mit dem ganzen Ton und Duktus ihrer Übersetzungen erst aktiviert haben. Wenn wir es uns zutrauen, können wir ihnen ins Handwerk pfuschen und einzelne Stellen oder ganze Werke selber übersetzen. Wir können sie kritisieren, wo uns die vorgelegten Übersetzungen zu matt erscheinen oder wo sie sachlich oder stilistisch mehr als nötig ‚hinter dem Original zurückbleiben; wir können Verbesserungsvorschläge machen. Wenn wir Übersetzungen zitieren und es nötig finden, sie abzuwandeln, bewegen wir uns in einer Grauzone zwischen dem Respekt vor dem Übersetzer, der Lust an noch weiteren erkannten Potenzen des Textes und dem Drang, möglichst ‚alles, was wir aus dem Original herausgelesen haben, in der eigenen Sprache den Hörern oder Lesern nahezubringen.

Zwischen Sumpf und Feuer : Literarische Faszination durch Beraubung und Zersetzung (2004)

Gerhard Bauer

„Warnung“, schreibt Ewa Lipska, „Ostrzeżenie“. Natürlich warnt sie, die Poetin der modernen Mobilität und ihrer Komplikationen, nicht vor irgendwelchen Flugzeugabstürzen oder dem Bankrott einer Fluglinie. Sondern: »Ich warne dich vor dir«. Du könntest dir selbst davonlaufen, könntest dich zum Tode verurteilen. [...] Es geht rau zu in ihren Gedichten, wie in vielen Gedichten der 60er, 70er, 80er Jahre. Es kratzt und piekt, wo immer man hinfassen möchte. Faszinierend allerdings sind nur diejenigen Partien darin, die uns anziehen und zugleich im Stich lassen, uns einer unbestimmten, der eigenen Vorstellungskraft überlassenen Gefahr aussetzen. Die Warnung arbeitet dem Zauber entgegen, und einzelne Zauberkunststücke untergraben jedes Sicherheitsdenken.

Über den Widerspruch von religiöser Hoffnung und politischer Analyse in Adam Smith Theorie des freien Marktes (2011)

Burkhard Kühnemund

Die zentrale These des vorliegenden Aufsatzes ist es, dass es ein Adam Smith-Problem im traditionellen Sinne nicht gibt, aber sehr wohl einen Selbstwiderspruch in Adam Smith ökonomischer Theorie. Der Aufsatz behandelt zunächst die enge systematische Verbindung von Smith ökonomischer und ethischer Theorie. Die Verbindung beruht auf der Annahme eines höchsten Wesens und einer daraus gefolgerten prästabilisierenden Harmonie Dem religiösen Vertrauen auf eine natürliche Ordnung korresponiert der Glaube an die Gerechtigkeit des Marktes. Smith weitere politische Analyse produziert allerdings einen Selbstwiderspruch. Smith zeigt auf, dass die unternehmerischen Eigeninteressen dem Allgemeininteresse der Gesellschaft widersprechen und die Unternehmer zudem virtuoser und erfolgreicher beim Durchsetzen ihrer eigenen Interessen agieren als andere Marktakteure. Dennoch hält Smith an der Annahme fest, der Markt entfalte eine harmonisierende und den allseitigen Wohlstand fördernde Wirkung. Diese Annahme mutiert bei seinen Epigonen zu einer ontologischen Gewissheit.

Evidence regarding clinical use of microvolt T-wave alternans (2011)

Stefan H. Hohnloser Takanori Ikeda Richard J. Cohen

Background: Microvolt T-wave alternans (MTWA) testing in many studies has proven to be a highly accurate predictor of ventricular tachyarrhythmic events (VTEs) in patients with risk factors for sudden cardiac death (SCD) but without a prior history of sustained VTEs (primary prevention patients). In some recent studies involving primary prevention patients with prophylactically implanted cardioverter-defibrillators (ICDs), MTWA has not performed as well. Objective: This study examined the hypothesis that MTWA is an accurate predictor of VTEs in primary prevention patients without implanted ICDs, but not of appropriate ICD therapy in such patients with implanted ICDs. Methods: This study identified prospective clinical trials evaluating MTWA measured using the spectral analytic method in primary prevention populations and analyzed studies in which: (1) few patients had implanted ICDs and as a result none or a small fraction (≤15%) of the reported end point VTEs were appropriate ICD therapies (low ICD group), or (2) many of the patients had implanted ICDs and the majority of the reported end point VTEs were appropriate ICD therapies (high ICD group). Results: In the low ICD group comprising 3,682 patients, the hazard ratio associated with a nonnegative versus negative MTWA test was 13.6 (95% confidence interval [CI] 8.5 to 30.4) and the annual event rate among the MTWA-negative patients was 0.3% (95% CI: 0.1% to 0.5%). In contrast, in the high ICD group comprising 2,234 patients, the hazard ratio was only 1.6 (95% CI: 1.2 to 2.1) and the annual event rate among the MTWA-negative patients was elevated to 5.4% (95% CI: 4.1% to 6.7%). In support of these findings, we analyzed published data from the Multicenter Automatic Defibrillator Trial II (MADIT II) and Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) trials and determined that in those trials only 32% of patients who received appropriate ICD therapy averted an SCD. Conclusion: This study found that MTWA testing using the spectral analytic method provides an accurate means of predicting VTEs in primary prevention patients without implanted ICDs; in particular, the event rate is very low among such patients with a negative MTWA test. In prospective trials of ICD therapy, the number of patients receiving appropriate ICD therapy greatly exceeds the number of patients who avert SCD as a result of ICD therapy. In trials involving patients with implanted ICDs, these excess appropriate ICD therapies seem to distribute randomly between MTWA-negative and MTWA-nonnegative patients, obscuring the predictive accuracy of MTWA for SCD. Appropriate ICD therapy is an unreliable surrogate end point for SCD. Key words: Arrhythmia; Sudden cardiac death; Cardiac arrest; ICD; T-wave alternans; Surrogate endpoint; Ventricular tachyarrhythmic event; Primary prevention

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