The Timing of Climate Agreements under Multiple Externalities

We study the potential of cooperation in global emission abatements with multiple externalities. Using a two-country model without side-payments, we identify the strategic effects under different timing regimes of cooperation. We obtain a positive complementarity effect of long-term cooperation in abatement on R&D levels that boosts potential bene?t of long-term cooperation and a redistributive effect that destabilizes long-term cooperation when countries are asymmetric. We show that whether and what type of cooperation is sustainable, depends crucially on the kind rather than on the magnitude of asymmetries

Perceiving animacy from shape

Superordinate visual classification—for example, identifying an image as “animal,” “plant,” or “mineral”—is computationally challenging because radically different items (e.g., “octopus,” “dog”) must be grouped into a common class (“animal”). It is plausible that learning superordinate categories teaches us not only the membership of particular (familiar) items, but also general features that are shared across class members, aiding us in classifying novel (unfamiliar) items. Here, we investigated visual shape features associated with animate and inanimate classes. One group of participants viewed images of 75 unfamiliar and atypical items and provided separate ratings of how much each image looked like an animal, plant, and mineral. Results show systematic tradeoffs between the ratings, indicating a class-like organization of items. A second group rated each image in terms of 22 midlevel shape features (e.g., “symmetrical,” “curved”). The results confirm that superordinate classes are associated with particular shape features (e.g., “animals” generally have high “symmetry” ratings). Moreover, linear discriminant analysis based on the 22-D feature vectors predicts the perceived classes approximately as well as the ground truth classification. This suggests that a generic set of midlevel visual shape features forms the basis for superordinate classification of novel objects along the animacy continuum

On the Antiquity of Man

Man is now lord of the earth and of the beasts and flowers, but he took millions of years to achieve his dominion. Two events more than others made man capable of his exercise of power. 1) A slowly achieved adaptation of man himself increased his potentialities far beyond those of other animals. The first step was man\u27s gradual assumption of the erect posture. This put him on his peculiarly successful evolutionary path. It freed his hands and opened the way for the development of the central nervous system which made man unique in his capabilities. 2) A late revolution in man\u27s control of his environment gave him the opportunity to exploit his special capabilities. This was the domestication of plants and animals, the food-producing revolution. It freed man from day-by-day hunting and gathering and permitted the development of civilized communities

Zum Gedenken an Günter Tiede

Am 9. April 2011 verstarb im Alter von 80 Jahren Günter Tiede, Ehrenmitglied des Ornithologischen Vereins Dessau (OVD). Geboren wurde Günter Tiede am 26.10.1930 in Wörlitz. Nach dem Besuch der Knaben-und Mittelschule ging er bei seinem Vater, einem Tischlermeister, in die Lehre. Den väterlichen Betrieb konnte er nach Abschluss der Meisterprüfung noch bis 1969 weiter führen. Danach nahm er eine Tätigkeit in einer Produktionsgenossenschaft (PGH) des holzverarbeitenden Handwerks an

Topical delivery of alpha1-Antichymotrypsin for wound healing

The work is introduced by reviews of wound healing and protein delivery using hydrogel carriers. In the following, the formulation studies of alpha1-Antichymotrypsin (ACT) are outlined starting with solution carriers. The latter are followed by formulation studies in hydrogels and dry gel forms, i.e. xerogels prepared by freeze-drying and films gained from air drying of hydrogels. All carriers are investigated upon their stabilizing activity on the protein drug also for mid term shelf life, their suitability for the use as wound dressings mainly from mechanical point of view, and their release behaviour especially for ACT. As a result, xerogel and film formulations are presented that match all requirements for such a product

DOUBLE TAXATION - TREATMENT OF CORPORATE EARNINGS UNDER AMERICAN AND GERMAN LAW

This thesis is going to describe the different ways the United States and Germany deal with the problem of double taxation in the legal context of corporate distributions to its shareholders in the form of dividends. Tax law is particularly one of the areas of laws that are subject to frequent and often substantial changes. This is true for the German as well as for the U.S. tax laws. Since some of the issues being discussed in the United States today in connection with the corporate tax law are similar if not identical to the issues discussed in Germany before the tax reform, the purpose of this thesis is to describe the impact and effects the tax reform had on the corporate tax law in Germany After stating the results of the tax reform, the thesis determines whether or not the suggestions raised by the legal literature to improve the U.S. tax system with regard to the policy principles of equity and efficiency are likely to be successful. The second chapter of the thesis introduces the reader to the tax principles of equity and efficiency since these principles set the standards for the evaluation of the tax provisions The third chapter describes in its first part the history and the present state of the U.S. tax law with regard to the distribution of dividends. The second part of the chapter explains the corresponding issues under the German tax law The fourth chapter describes first the adverse and supporting criticism that is expressed in the ongoing discussion about double taxation in the United States. Afterward, the thesis addresses whether the results of the German tax reform met its original objectives

Pinched Gluon Vertex Operator in Super-Worldline Formalism

We reformulate, using super worldline formalism, the pinched gluon vertex operator proposed by Strassler. The pinched vertex operator turns out to be the product of two gluon vertex operators with the insertion of $\delta$-function which makes the super distances between them zero. Thus the pinch procedures turn out to be nothing but the insertions of $\delta$-function. Applying our formulation to two-loop diagrams which are the QED correction to gluon scatterings via a single spinor loop, with the QED charge e being replaced by the strong coupling g, we show various formulae on pinched N-point functions.Comment: Latex 23 pages, no figure, with some clarifications. Version to appear in Nucl. Phys.

Inflation Forecasting with Inflation Sentiment Indicators

In this paper we argue that future inflation in an economy depends on the way people perceive current inflation, their inflation sentiment.We construct some simple measures of inflation sentiment which capture whether price acceleration is shared by many components of the CPI basket. In a comparative analysis of the forecasting power of the different inflation indicators for the US and Germany, we demonstrate that our inflation sentiment indicators improve forecast accuracy in comparison to a standard Phillips curve approach. Because the forecast performance is particularly good for longer horizons, we also compare our indicators to traditional measures of core inflation.Here, the sentiment indicators outperform the weighted median and show a similar forecasting power as a trimmed mean. Thus, they offer a convincing alternative to traditional core inflation measures.Inflation forecasting, monetary policy

An ultrasensitive sorting mechanism for EGF receptor endocytosis

Background The EGF receptor has been shown to internalize via clathrin-independent endocytosis (CIE) in a ligand concentration dependent manner. From a modeling point of view, this resembles an ultrasensitive response, which is the ability of signaling networks to suppress a response for low input values and to increase to a pre-defined level for inputs exceeding a certain threshold. Several mechanisms to generate this behaviour have been described theoretically, the underlying assumptions of which, however, have not been experimentally demonstrated for the EGF receptor internalization network. Results Here, we present a mathematical model of receptor sorting into alternative pathways that explains the EGF-concentration dependent response of CIE. The described mechanism involves a saturation effect of the dominant clathrin-dependent endocytosis pathway and implies distinct steady-states into which the system is forced for low vs high EGF stimulations. The model is minimal since no experimentally unjustified reactions or parameter assumptions are imposed. We demonstrate the robustness of the sorting effect for large parameter variations and give an analytic derivation for alternative steady-states that are reached. Further, we describe extensibility of the model to more than two pathways which might play a role in contexts other than receptor internalization. Conclusions Our main result is that a scenario where different endocytosis routes consume the same form of receptor corroborates the observation of a clear-cut, stimulus dependent sorting. This is especially important since a receptor modification discriminating between the pathways has not been found. The model is not restricted to EGF receptor internalization and might account for ultrasensitivity in other cellular contexts