Transcriptome changes and cAMP oscillations in an archaeal cell cycle

Background The cell cycle of all organisms includes mass increase by a factor of two, replication of the genetic material, segregation of the genome to different parts of the cell, and cell division into two daughter cells. It is tightly regulated and typically includes cell cycle-specific oscillations of the levels of transcripts, proteins, protein modifications, and signaling molecules. Until now cell cycle-specific transcriptome changes have been described for four eukaryotic species ranging from yeast to human, but only for two prokaryotic species. Similarly, oscillations of small signaling molecules have been identified in very few eukaryotic species, but not in any prokaryote. Results A synchronization procedure for the archaeon Halobacterium salinarum was optimized, so that nearly 100% of all cells divide in a time interval that is 1/4th of the generation time of exponentially growing cells. The method was used to characterize cell cycle-dependent transcriptome changes using a genome-wide DNA microarray. The transcript levels of 87 genes were found to be cell cycle-regulated, corresponding to 3% of all genes. They could be clustered into seven groups with different transcript level profiles. Cluster-specific sequence motifs were detected around the start of the genes that are predicted to be involved in cell cycle-specific transcriptional regulation. Notably, many cell cycle genes that have oscillating transcript levels in eukaryotes are not regulated on the transcriptional level in H. salinarum. Synchronized cultures were also used to identify putative small signaling molecules. H. salinarum was found to contain a basal cAMP concentration of 200 uM, considerably higher than that of yeast. The cAMP concentration is shortly induced directly prior to and after cell division, and thus cAMP probably is an important signal for cell cycle progression. Conclusions The analysis of cell cycle-specific transcriptome changes of H. salinarum allowed to identify a strategy of transcript level regulation that is different from all previously characterized species. The transcript levels of only 3% of all genes are regulated, a fraction that is considerably lower than has been reported for four eukaryotic species (6% - 28%) and for the bacterium C. crescentus (19%). It was shown that cAMP is present in significant concentrations in an archaeon, and the phylogenetic profile of the adenylate cyclase indicates that this signaling molecule is widely distributed in archaea. The occurrence of cell cycle-dependent oscillations of the cAMP concentration in an archaeon and in several eukaryotic species indicates that cAMP level changes might be a phylogenetically old signal for cell cycle progression

Regional knowledge transfer through public research spin-offs

New ventures stemming from universities and public research institutions have attracted increasing amounts of interest in the field of innovation politics over the last few years. Significant contributions to knowledge and technology transfer is expected from academic spin-offs, who are seen as transfer hubs, quickly creating exceptional products or processes and methods for economic use out of the newest scientific research results. Regions that are sites for research facilities are hoping that the new spin-offs will result in a strengthening of their own venture's innovative capabilities. First and foremost, this paper outlines representative empirical results of the founding of new academic spin-off ventures stemming from universities and public research institutions in germany. The main points of discussion will be the following: 1.) Presentation of the methods used to identify academic spin-offs, whose involvement with significant new research results, led to the establishment of the new venture. 2.) Relevance analysis of the regional proximity of scientific research institutions and their influence in the launch and continued relationship with new ventures. A geographical distance analysis is used. 3.) Identification of spin-off intensities in different industries, regions and categories of incubator institutions. 4.) Econometric analysis of the influence of success factors on spin-offs in comparison to other ventures with a corresponding business segment. This is performed with help of a semi-parametric control-group. 5.) Discussion on the usefulness of technology transfer hubs resulting from new spin-off ventures in the innovative development of regions. The data pool that is being presented here, consists of empirical results from a 1996 to 2000 ZEW survey of about 20,000 new ventures in technology or knowledge based industries and service sectors.

Quantification of ploidy in proteobacteria revealed the existence of monoploid, (mero-)oligoploid and polyploid species

Bacteria are generally assumed to be monoploid (haploid). This assumption is mainly based on generalization of the results obtained with the most intensely studied model bacterium, Escherichia coli (a gamma-proteobacterium), which is monoploid during very slow growth. However, several species of proteobacteria are oligo- or polyploid, respectively. To get a better overview of the distribution of ploidy levels, genome copy numbers were quantified in four species of three different groups of proteobacteria. A recently developed Real Time PCR approach, which had been used to determine the ploidy levels of halophilic archaea, was optimized for the quantification of genome copy numbers of bacteria. Slow-growing (doubling time 103 minutes) and fast-growing (doubling time 25 minutes) E. coli cultures were used as a positive control. The copy numbers of the origin and terminus region of the chromosome were determined and the results were in excellent agreement with published data. The approach was also used to determine the ploidy levels of Caulobacter crescentus (an alpha-proteobacterium) and Wolinella succinogenes (an epsilon-proteobacterium), both of which are monoploid. In contrast, Pseudomonas putida (a gamma-proteobacterium) contains 20 genome copies and is thus polyploid. A survey of the proteobacteria with experimentally-determined genome copy numbers revealed that only three to four of 11 species are monoploid and thus monoploidy is not typical for proteobacteria. The ploidy level is not conserved within the groups of proteobacteria, and there are no obvious correlations between the ploidy levels with other parameters like genome size, optimal growth temperature or mode of life

20% by 2020? Economy-wide impacts of energy efficiency improvement in Germany

The paper presents results of the implementation of an efficiency strategy in Germany until 2020 which is focused on cost-effective measures. The efficiency measures are calculated in bottom-up models and translated into a top-down macro-economic model. The comparison to a business as usual simulation shows some economy-wide rebound effects of about 17% of the overall energy savings. The analysis is limited to 2020. Given that an efficiency strategy is a long-term strategy, this puts the results on the rather conservative side. The results clearly show that improved energy efficiency results in a variety of positive effects on the economy and the environment. These range from reduced greenhouse gas emissions to improved competitiveness of firms and budget savings for consumers to economy wide impacts like additional employment and economic growth. Even the consideration of rebound effects did not change this picture significantly. Thus, exploiting the huge potential stemming from cost-effective efficiency measures should have high priority for the design of energy and climate policies.energy efficiency, bottom up scenario analysis, climate policy

Reifungs- und Strukturbildungsprozesse bei Bindern mit wässrigen Alkalisilikat-Lösungen

Durch Reifungs- und Strukturbildungsprozesse kann es bei silikatischen und alumosilikatischen Bindern zu Rissbildung bei behinderter Verformung, Festigkeitsverlust und somit Verlust der Dauerhaftigkeit kommen. Die Bewertung dieser Prozesse erfolgt an silikatischen Materialien mit einem Ausblick auf die alumosilikatischen Binder

Nonseparability of Shared Intentionality

According to recent studies in developmental psychology and neuroscience, symbolic language is essentially intersubjective. Empathetically relating to others renders possible the acquisition of linguistic constructs. Intersubjectivity develops in early ontogenetic life when interactions between mother and infant mutually shape their relatedness. Empirical findings suggest that the shared attention and intention involved in those interactions is sustained as it becomes internalized and embodied. Symbolic language is derivative and emerges from shared intentionality. In this paper, we present a formalization of shared intentionality based upon a quantum approach. From a phenomenological viewpoint, we investigate the nonseparable, dynamic and sustainable nature of social cognition and evaluate the appropriateness of quantum interaction for modelling intersubjectivity

High-resolution NMR structure of an RNA model system : the 14-mer cUUCGg tetraloop hairpin RNA

We present a high-resolution nuclear magnetic resonance (NMR) solution structure of a 14-mer RNA hairpin capped by cUUCGg tetraloop. This short and very stable RNA presents an important model system for the study of RNA structure and dynamics using NMR spectroscopy, molecular dynamics (MD) simulations and RNA force-field development. The extraordinary high precision of the structure (root mean square deviation of 0.3 Å) could be achieved by measuring and incorporating all currently accessible NMR parameters, including distances derived from nuclear Overhauser effect (NOE) intensities, torsion-angle dependent homonuclear and heteronuclear scalar coupling constants, projection-angle-dependent cross-correlated relaxation rates and residual dipolar couplings. The structure calculations were performed with the program CNS using the ARIA setup and protocols. The structure quality was further improved by a final refinement in explicit water using OPLS force field parameters for non-bonded interactions and charges. In addition, the 2'-hydroxyl groups have been assigned and their conformation has been analyzed based on NOE contacts. The structure currently defines a benchmark for the precision and accuracy amenable to RNA structure determination by NMR spectroscopy. Here, we discuss the impact of various NMR restraints on structure quality and discuss in detail the dynamics of this system as previously determined

Nutzung pflanzengenetischer Ressourcen für den ökologischen Landbau am Beispiel von Wintererbsen

Winter peas were cultivated in Germany in the first half of the 20th century for green manure, green forage or as a threshing crop. So far they are mainly used in field ex-periments, e.g. at the University of Kassel. But winter peas are very interesting for or-ganic farming, because of their high N-fixation rate and their ability to suppress weeds effectively. In the vegetation period 2002/2003 twelve genotypes of winter peas from the German genebank in Gatersleben were examined in field trials. In the long and cold winter of 2002/2003 eight different genotypes from Germany, Hungary and the Balkan survived. The yield of the eight accessions as green forage and as a threshing crop (yield between 3 – 4 t/ha) are promising

Gegenüberstellung der Simulationsfunktionalitäten von Werkzeugen zur Geschäftsprozessmodellierung

Geschäftsprozesse beschreiben, über die Darstellung von Aktivitäten respektive Vorgängen, die Abläufe der Leistungserstellung in einer Unternehmung. Ziel bei der Planung ist es, die Prozesse so effizient und effektiv wie möglich zu gestalten, um mit möglichst wenig eingesetzten Ressourcen ein vordefiniertes Ziel zu erreichen. Effizienz und Effektivität der Prozesse sind dabei entscheidende Faktoren für die Wettbewerbsposition einer Unternehmung, da die realen Kosten der Leistungserstellung aus den Abläufen, die wiederum Ressourcen beanspruchen, resultieren. Um Geschäftsprozesse zu optimieren, können mathematisch-analytische Verfahren angewandt werden. Diese mathematischen Verfahren erlauben es, Geschäftsprozesse und -ketten als geschlossene Ausdrücke zu formulieren und optimal zu lösen. Die analytischen Verfahren scheitern allerdings, so-bald die Geschäftsprozesse eine gewisse Komplexität aufweisen. Gemeint sind hochflexible Geschäftsprozesse, die sich dadurch auszeichnen, dass sie entweder nicht vollständig planbar sind, da prozessrelevante Bezugsgrößen unbekannt oder variabel sind, oder diese nicht losgelöst vom Anwendungskontext betrachtet werden können. Zusätzlich komplexitätssteigernd wirkt sich eine zeit-liche Überlappung zwischen Planung und Ausführung des Prozesses aus. Um diese komplexen Geschäftsprozesse nachvollziehen und untersuchen zu können und somit einen Ansatz für die Optimierung zu schaffen, bietet sich hier eine Simulation dieser Prozesse an. Ein Simulationsmodell besteht aus einer möglichst realitätsnahen Nachbildung eines Ablaufs in einem Modell und dient der Entscheidungsunterstützung. Die Vorteile einer Simulation sind sehr vielschichtig. Das Modell bietet zwar keinerlei Optimalitäts-garantien, liefert aber, im Gegensatz zu analytischen Verfahren, Ergebnisse und unterstützt somit die Erfassung der Systemkomplexität. Das Verhalten des Prozesses kann aus dem Modell abgelesen und nachvollzogen werden, was für ein besseres Systemverständnis sorgt. Ein Simulationsmodell ist einfach anpassbar und erweiterbar und erlaubt das Testen von komplexen Abläufen ohne die Durchführung von Realexperimenten. Zudem sind die Ergebnisse replizierbar und Abläufe lassen sich in kürzester Zeit simulieren, was eine Betrachtung der Prozesse über lange Zeiträume ermöglicht

ORGAP Project – Evaluation toolbox for the evaluation of action plans for organic food and farming

The ORGAP-Project has developed an evaluation toolbox for the evaluation of the European and/or national action plans based on analysis of national action plans and expert/stakeholder consultation