Spider communities as indicators of the development (succession) of afforested coal mining sites

On the basis of a space-for-time-substitution the succession of the spider coenosis of a Lusatian lignite mining area (pine afforestation) was investigated. Spiders were chosen because of their high abundance in both species and individuals and as representatives of a high trophic level. By comparing pine afforestations of different ages which additionally are located far away from each other we could detect a typical succession pattern in the spider coenosis. The pioneer Oedothorax apicatus (Linyphiidae) is characteristic of the initial state. Ten years after afforestation this species has disappeared and the locality shows a mixed population of spiders including species which prefer open habitats as well as species occurring in forests. After 30 years the typical species community of open, dry pine forests has established

Influence of mulching treatment on epigeic spiders in vineyards of the Kaiserstuhl area (SW-Germany)

Grünmulchen in den Rebflächen des Kaiserstuhls bewirkt, daß die Arten- und Individuenzahlen der Spinnen zunehmen. Das Artenspektrum verschiebt sich in Richtung trockenheitsliebender Arten - die Spinnenfauna wird "kaiserstuhltypischer". Die begrünten Rebflachen sind damit nicht nur Produktionsflächen, sondern auch Lebensraum für eine vielfaltige Fauna. Es gibt keine "Hackfrucht-Spinnengemeinschaft", vergleichbar der Hackfruchtflora in bodenbearbeiteten Rebflächen. Es gibt auf Rebflächen nur eine typische Spinnengemeinschaft, die je nach Intensität der Bearbeitung mehr oder weniger in Arten- und Individuenzahl reduziert ist.The spider fauna found in vineyards treated either by mulching or soil tilling was investigated and compared. Mulching treatment results in a spider community that is richer in species and in numbers. Many species found are typical for dry habitats and represent characteristic species of the Kaiserstuhl area

The disstribution of syntopic Atypus affinis and Atypus piceus (Araneae, Atypidae) in a succession area of vineyard slopes in the Kaiserstuhl (south-western Germany)

Eines der gut belegten syntopen Vorkommen der beiden in Morphologie und Lebensweise sehr ähnlichen Atypus- Arten A. affinis und A. piceus befindet sich im Kaiserstuhl (Südwestdeutschland). Dies konnte im Rahmen einer seit 1979 kontinuierlich laufenden Langzeitstudie über die Wiederbesiedlung von Weinbergsböschungen nach großflächiger Flurbereinigung gezeigt werden. Die Männchen der beiden Arten sind zu unterschiedlichen Jahreszeiten an der Oberfläche aktiv, sie sind auch in der Größe klar verschieden. Für beide Arten konnte die Besiedlungsgeschichte nachvollzogen werden: Wie für einen typischen K-Strategen zu erwarten, erfolgt der Populationsaufbau langsam und ist heute noch nicht abgeschlossen. Die Atypus-Arten werden als geeignet angesehen, beispielhaft für Fragestellungen des Naturschutzes zu dienen. Auf Grund ihres langen Entwicklungszyklus sind diese Arten durch drastische Biotopveränderungen besonders gefährdet, am Kaiserstuhl wäre dies das neuerdings wieder erlaubte Flämmen zur Böschungspflege

Reverse engineering of gene regulatory networks governing cell-cell communication in the microenvironment of pancreatic cancer

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer death, with a five-year survival rate of <5% and a median survival of 6 months. Extensive desmoplastic reaction is a characteristic feature and a prognostic factor of PDAC, which conveys its resistance. Desmoplastic stroma accounts for approx. 90% of tumor volume and consists predominantly of non-malignant fibroblasts (pancreatic stellate cells, PSC). Previous studies have revealed the PSC mesenchymal origins, capacity to switch between quiescent and activated states, proinflammatory features, expression of soluble factors, ability to migrate, and phagocytize. State of the art: Abundance of stroma has sparked previous attempts to dissect the interactions between PSC and tumor cells (TC) producing a common picture of a microenvironment supporting PDAC development. Unfortunately, focus on snapshot-like analysis has proven difficult to translate into therapeutical advances, as it discards the dynamic interactions in the microenvironment, as well as the temporal dynamics of gene expression itself. Gene regulatory networks (GRN) adapt to environmental cues by rewiring connections between genes, those induced modulations effectively lead to state-transitions e.g. PSC activation, or produce mutually exclusive cell-fate decisions e.g. differentiation, senescence, or death. We recognize that cell-specific assignment of stimuli, identification of genes forming the GRNs, as well as the identification of cellular state-changes remain undiscovered. We hypothesize that at an early stage, the quiescent → activated PSC transition yields a steady state PSC gene regulatory network (GRN), but the subsequent succession of impulse responses along TC→PSC→TC interaction axis drives both cell types into unstable states maintained only for the duration of the direct TC-PSC contact. Aims: Through the application of a high-throughput complexity reduction approach and in silico modeling I aim to reconstruct the GRNs underlying the cell-cell communication, and identify key soluble factors shaping the double-paracrine interactions. I aim to use the models to gain a mechanistic and functional insight into how the cues are integrated and how they affect GRN maintenance. I hope to capture cell-fate decisions and identify key dynamic changes with the ultimate goal of finding genetic markers to aid development of novel therapeutic options for this deadly malignancy. Results: We have individually stimulated PSC and TC with conditioned supernatant from the respective other cell type and recorded a time-series (1-24h) from which genome-wide microarray expression data has been generated. In this dissertation I used the time-resolved expression profiles to identify significant gene kinetics through an approach-involving gene ranking, filtering, and clustering followed by gene ontology and pathway analysis. I identified key gene interactions using a genetic algorithm embedded in a continuous time recurrent neural network (CTRNN) modeling scheme. Then I used the derived GRN’s to produce a picture of unique intercellular interactions. Through in silico simulations with the created models, and subsequent data analysis and interpretation I delivered targets for experimental testing on the inter- as well as intra-cellular levels. Experimental validation of the selected gene targets using gene silencing and qRT-PCR confirmed the in silico predicted TC network behavior; validation of the intercellular connections confirmed their dependence on the identified networks

The effect of pro-ecological procedures and insect foraging on the total content of phenol compounds in winter wheat

In laboratory conditions, the effect of pro-ecological procedures (application of effective microorganisms and Asahi SL biostimulator) and foraging by insects [cereal leaf beetle (Oulema melanopa L.) and bird cherry-oat aphid (Rhopalosiphum padi (L.)] on the total content of phenolic compounds in winter wheat, was studied. Correlations between the total content of phenolic compounds (determined by the Folin-Ciocalteau colorimetric method) expressed as the amount of pyrogallol in wheat plants: undamaged, damaged by O. melanopa, damaged by R. padi, the length of feeding scar left by cereal leaf beetle and the number of pricks made by actively feeding insects of bird cherry-oat aphid were analysed. The wheat was treated by EM inoculant and a biostimulator. The mode of application of the preparations used had a significant effect on level the total phenolic compounds in the undamaged wheat and the wheat exposed to foraging by the above-mentioned insects. The plants not exposed to insects foraging contained greater amounts of phenolic compounds than those exposed to the insects. The correlation between the total content of phenols in the wheat damaged by the insects in the ‘no-choice’ conditions, proved insignificant

Der Färberwaid (Isatis tinctoria L.) - ein Beitrag zur Vegetationsökologie und Biozönologie

In the southern Upper Rhine region 3 mass proliferations of Isatis tinctoria L. were observed since 1978, the last in 2005. Long-term observations in the Kaiserstuhl revealed that such “waves” followed a drought period and collapsed after 2 - 3 years. Because dyer's woad (also called German indigo) has been an important crop plant culture-historically and today is known as a troublesome pest in North America, in 2005 it was investigated phytosociologically and with regard to its monophagous beetles, documented nearly 3 decades by trap captures. A semiquantitative detailed mapping in the Kaiserstuhl showed dominance in the most xerothermic southwestern and central part, and absence in the somewhat moister northeastern part. The qualitative analysis of stands revealed high demands on soil aeration and temperature, as well as for light intensity, thereby indicating weak competition. Moreover, it evidently shows poor dispersal ability. The coincidence with the mass increase of monophagous beetles, especially Psylliodes isatidis, explains the rapid decline of the population of Isatis. In a literature comparison Isatis tinctoria turned out to be, at least in southern Germany, a weak character species of the Convolvulo-Agropyrion repentis, the only alliance of the Agropyretea intermedio-repentis present here

Effects of mechanical injury and insect feeding on volatiles emitted by wheat plants

We report on changes in the volatiles emitted by wheat plants of the cultivar ‘Tonacja’ after the plants were scraped, pierced or damaged by adults of Oulema melanopus (Linnaeus). The blend of volatiles was dominated by typical green leaf volatiles and in addition contained linalool and B-caryophyllene, but the latter two were released in large amounts only after more than one day of insect feeding. Overall, the plants that had been damaged by the insect released more odors than the plants that were subjected to mechanical damage. Moreover, control plants released significantly lower amounts of volatiles. Scraping of leaves induced higher volatile emission than puncturing the leaves. A Y-tube bioassay was used to evaluate upwind orientation ofadult cereal leafbeetles. Greater number of female 0. melanopus was attracted to (Z)-3-hexenal and (Z)-3 -hexenyl acetate at low concentrations. Higher concentration of these compounds and linalool significantly repelled both females and males

"Workshop zur Taxonomie mitteleuropäischer Spinnen" in Erlangen (8. - 10.01.1993): Taxonomie und Faunistik der kleinen Euophrys-Arten und der Gattungen Neaetha und Pellenes (Salticidae)

Da innerhalb der Araneae Mitteleuropas immer noch taxonomische Probleme bestehen, haben wir begonnen, systematisch schwierige Gattungen im Teamwork zu bearbeiten