University of Vienna

About: University of Vienna is a education organization based out in Vienna, Austria. It is known for research contribution in the topics: Population & Context (language use). The organization has 44686 authors who have published 95840 publications receiving 2907492 citations.

Bioorganometallic chemistry—from teaching paradigms to medicinal applications

Abstract: In undergraduate level organometallic chemistry courses students are usually taught that organometallic compounds are toxic and unstable in air and water. While this is true of many complexes, some are also non-toxic and stable in air and water. Indeed, bioorganometallic chemistry, the study of biomolecules or biologically active molecules that contain at least one carbon directly bound to a metal, is a thriving subject, and air and water stability is a general pre-requisite. This interdisciplinary field is located at the borderline between chemistry, biochemistry, biology and medicine. In this tutorial review, various aspects of bioorganometallic chemistry are introduced, with the main emphasis on medicinal organometallic compounds. Organometallic therapeutics for cancer, HIV and malaria and other medicinal applications are described. It is also shown how rational ligand design has led to new improved therapies much in the same way that an organometallic chemist working in catalysis will design new ligands for improved activities.

The Geography of Equity Listing: Why Do Companies List Abroad?

Abstract: This paper documents aggregate trends in the foreign listings of companies, and analyzes their distinctive prelisting characteristics and postlisting performance. In 1986‐1997, many European companies listed abroad, mainly on U.S. exchanges, while the number of U.S. companies listed in Europe decreased. European companies that cross-list tend to be large and recently privatized firms, and expand their foreign sales after listing abroad. They differ sharply depending on where they cross-list: The U.S. exchanges attract high-tech and export-oriented companies that expand rapidly without significant leveraging. Companies cross-listing within Europe do not grow unusually fast, and increase their leverage after cross-listing. FOREIGN LISTINGS ARE BECOMING an increasingly important strategic issue for companies and stock exchanges alike. As companies become global in their product market and investment strategies, direct access to foreign capital markets via an equity listing can yield important benefits. At the same time, the international integration of capital markets has led to unprecedented levels of competition among stock exchanges. In this competitive struggle, the winners are the exchanges that manage to attract more foreign listings and the attendant trading volume and business opportunities. Despite the importance of these issues, still little is known about which exchanges succeed in capturing more listings from abroad and why. This question is intimately related to a second issue, namely which advantages companies expect to get from a foreign listing: securing cheap equity capital for new investment, allowing controlling shareholders to divest on a liquid market, preparing for foreign acquisitions, or simply enhancing the compa

TRY plant trait database : Enhanced coverage and open access

Abstract: Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.

A new rank based version of the ant system: a computational study

Abstract: The ant system is a new meta-heuristic for hard combinatorial optimization problems. It is a population-based approach that uses exploitation of positive feedback as well as greedy search. It was first proposed for tackling the well known Traveling Salesman Problem (TSP), but has been also successfully applied to problems such as quadratic assignment, job-shop scheduling, vehicle routing and graph coloring.In this paper we introduce a new rank based version of the ant system and present results of a computational study, where we compare the ant system with simulated annealing and a genetic algorithm on several TSP instances. It turns out that our rank based ant system can compete with the other methods in terms of average behavior, and shows even better worst case behavior. (author's abstract)