scispace - formally typeset
Search or ask a question
Institution

University of Konstanz

EducationKonstanz, Baden-Württemberg, Germany
About: University of Konstanz is a education organization based out in Konstanz, Baden-Württemberg, Germany. It is known for research contribution in the topics: Population & Visualization. The organization has 12115 authors who have published 27401 publications receiving 951162 citations. The organization is also known as: University of Constance & Universität Konstanz.


Papers
More filters
Journal ArticleDOI
TL;DR: These data provide the first evidence that Rb and Rb-related proteins can directly regulate DNA replication and that components of licensing factor are targets of the products of tumor suppressor genes.
Abstract: A yeast two-hybrid screen was employed to identify human proteins that specifically bind the amino-terminal 400 amino acids of the retinoblastoma (Rb) protein. Two independent cDNAs resulting from this screen were found to encode the carboxy-terminal 137 amino acids of MCM7, a member of a family of proteins that comprise replication licensing factor. Full-length Rb and MCM7 form protein complexes in vitro, and the amino termini of two Rb-related proteins, p107 and p130, also bind MCM7. Protein complexes between Rb and MCM7 were also detected in anti-Rb immunoprecipitates prepared from human cells. The amino-termini of Rb and p130 strongly inhibited DNA replication in an MCM7-dependent fashion in a Xenopus in vitro DNA replication assay system. These data provide the first evidence that Rb and Rb-related proteins can directly regulate DNA replication and that components of licensing factor are targets of the products of tumor suppressor genes.

196 citations

Journal ArticleDOI
TL;DR: An increase in evolutionary rate in about half of the duplicated genes seems to suggest that either positive Darwinian selection has occurred or that functional constraints have been relaxed at one point in time during functional divergence.
Abstract: The duplication of genes and even complete genomes may be a prerequisite for major evolutionary transitions and the origin of evolutionary novelties. However, the evolutionary mechanisms of gene evolution and the origin of novel gene functions after gene duplication have been a subject of many debates. Recently, we compiled 26 groups of orthologous genes, which included one gene from human, mouse, and chicken, one or two genes from the tetraploid Xenopus and two genes from zebrafish. Comparative analysis and mapping data showed that these pairs of zebrafish genes were probably produced during a fish-specific genome duplication that occurred between 300 and 450 Mya, before the teleost radiation (Taylor et al. 2001). As discussed here, many of these retained duplicated genes code for DNA binding proteins. Different models have been developed to explain the retention of duplicated genes and in particular the subfunctionalization model of Force et al. (1999) could explain why so many developmental control genes have been retained. Other models are harder to reconcile with this particular set of duplicated genes. Most genes seem to have been subjected to strong purifying selection, keeping properties such as charge and polarity the same in both duplicates, although some evidence was found for positive Darwinian selection, in particular for Hox genes. However, since only the cumulative pattern of nucleotide substitutions can be studied, clear indications of positive Darwinian selection or neutrality may be hard to find for such anciently duplicated genes. Nevertheless, an increase in evolutionary rate in about half of the duplicated genes seems to suggest that either positive Darwinian selection has occurred or that functional constraints have been relaxed at one point in time during functional divergence.

196 citations

Book ChapterDOI
TL;DR: This chapter describes the technique for cryofixation, which implies the maintenance of the statistical distribution of all solute components in the solvent and the preservation of the size and shape of the macromolecules in the hydrated state.
Abstract: Publisher Summary This chapter describes the technique for cryofixation. The goal of ultrastructural fixation methods is to preserve the momentary distribution of all components in a system. For molecular systems, this implies the maintenance of the statistical distribution of all solute components in the solvent and the preservation of the size and shape of the macromolecules in the hydrated state. Cryofixation and freeze-storage of biological materials are important problems in many regards: for the storage of living materials, for the storage and processing of proteins, and for the preservation of structural details. The main problem of cryofixation is that the “fixed” structures are thermodynamically unstable at low temperatures. It is important to have several different cryofixation techniques at hand, if the variety of biological materials and the broad spectrum of secondary techniques are considered, whereby each has its requirements.

196 citations

Journal ArticleDOI
TL;DR: In this article, the authors present a quantitative assessment of reporting bias in a micro-level analysis of media-based event reports and those from military sources, showing that the purported violence-increasing effect of cellphone coverage is partly due to higher reporting rates of violence in cellphone-covered areas.
Abstract: Recent data collections about political violence are frequently based on media reports, which can lead to reporting bias. This is an issue in particular for the emergent literature on communication technology and conflict, since this technology may not only affect violence, but also the reporting about it. Using the effect of cellphones on violence as an example, this article presents a quantitative assessment of reporting bias in a micro-level analysis. Comparing media-based event reports and those from military sources, the results show that the purported violence-increasing effect of cellphone coverage is partly due to higher reporting rates of violence in cellphone-covered areas. A simple diagnostic procedure for this problem is implemented. Applied to the analysis of cellphones and violence in Africa, it produces a pattern that is consistent with reporting bias driving much of the effect found in the Pierskalla and Hollenbach (2013) study about this topic.

196 citations

Journal ArticleDOI
TL;DR: It is demonstrated for the first time that inducible transcription factors such as c‐Fos and JunB are an essential part of fundamental biological processes in the adult mammalian nervous system, e.g. of light‐induced phase shifts of the circadian pacemaker.
Abstract: Light-induced phase shifts of circadian rhythmic locomotor activity are associated with the expression of c-Jun, JunB, c-Fos and FosB transcription factors in the rat suprachiasmatic nucleus, as shown in the present study. In order to explore the importance of c-Fos and JunB, the predominantly expressed AP-1 proteins for the phase-shifting effects of light, we blocked the expression of c-Fos and JunB in the suprachiasmatic nucleus of male rats, housed under constant darkness, by intracerebroventricular application of 2 microliters of 1 mM antisense phosphorothioate oligodeoxynucleotides (ASO) specifically directed against c-fos and junB mRNA. A light pulse (300 lux for 1 h) at circadian time 15 induced a significant phase shift (by 125 +/- 15 min) of the circadian locomotor activity rhythm, whereas application of ASO 6 h before the light pulse completely prevented this phase shift. Application of control nonsense oligodeoxynucleotides had no effect. ASO strongly reduced the light-induced expression of c-Fos and JunB proteins. In contrast, light pulses with or without the control nonsense oligodeoxynucleotides evoked strong nuclear c-Fos and JunB immunoreactivity in the rat suprachiasmatic nucleus. These results demonstrate for the first time that inducible transcription factors such as c-Fos and JunB are an essential part of fundamental biological processes in the adult mammalian nervous system, e.g. of light-induced phase shifts of the circadian pacemaker.

196 citations


Authors

Showing all 12272 results

NameH-indexPapersCitations
Robert E. W. Hancock15277588481
Lloyd J. Old152775101377
Andrew White1491494113874
Stefanie Dimmeler14757481658
Rudolf Amann14345985525
Niels Birbaumer14283577853
Thomas P. Russell141101280055
Emmanuelle Perez138155099016
Shlomo Havlin131101383347
Bruno S. Frey11990065368
Roald Hoffmann11687059470
Michael G. Fehlings116118957003
Yves Van de Peer11549461479
Axel Meyer11251151195
Manuela Campanelli11167548563
Network Information
Related Institutions (5)
ETH Zurich
122.4K papers, 5.1M citations

93% related

University of California, Irvine
113.6K papers, 5.5M citations

91% related

Arizona State University
109.6K papers, 4.4M citations

91% related

University of California, Santa Barbara
80.8K papers, 4.6M citations

91% related

Max Planck Society
406.2K papers, 19.5M citations

91% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202360
2022202
20211,361
20201,299
20191,166
20181,082