Predicting the influence of a p2-symmetric substrate on molecular self-organization with an interaction-site model

An interaction-site model can a priori predict molecular selforganisation on a new substrate in Monte Carlo simulations. This is experimentally confirmed with scanning tunnelling microscopy on Fre´chet dendrons of a pentacontane template. Local and global ordering motifs, inclusion molecules and a rotated unit cell are correctly predicted

Life cycle modeling of buildings. Life cycle impact assessement and building specification

The decision to take the building as built as the pivot of product modelling, means that the description of a building has to be process based (building process, operation process) and object based (construction elements). The link to existing catalogues of building specifications as a basis for process description and to existing cost and simple energy calculations is presented and discussed. Keywords: Building specifications, catalogues, database model, ecological impact, life cycle analysi

Phylogenetic diversity, antimicrobial susceptibility and virulence gene profiles of Brachyspira hyodysenteriae isolates from pigs in Germany

Swine dysentery (SD) is an economically important diarrheal disease in pigs caused by different strongly hemolytic Brachyspira (B.) species, such as B. hyodysenteriae, B. suanatina and B. hampsonii. Possible associations of epidemiologic data, such as multilocus sequence types (STs) to virulence gene profiles and antimicrobial susceptibility are rather scarce, particularly for B. hyodysenteriae isolates from Germany. In this study, B. hyodysenteriae (n = 116) isolated from diarrheic pigs between 1990 and 2016 in Germany were investigated for their STs, susceptibility to the major drugs used for treatment of SD (tiamulin and valnemulin) and genes that were previously linked with virulence and encode for hemolysins (tlyA, tlyB, tlyC, hlyA, BHWA1_RS02885, BHWA1_RS09085, BHWA1_RS04705, and BHWA1_RS02195), outer membrane proteins (OMPs) (bhlp16, bhlp17.6, bhlp29.7, bhmp39f, and bhmp39h) as well as iron acquisition factors (ftnA and bitC). Multilocus sequence typing (MLST) revealed that 79.4% of the isolates belonged to only three STs, namely ST52 (41.4%), ST8 (12.1%), and ST112 (25.9%) which have been observed in other European countries before. Another 24 isolates belonged to twelve new STs (ST113-118, ST120-123, ST131, and ST193). The temporal distribution of STs revealed the presence of new STs as well as the regular presence of ST52 over three decades (1990s–2000s). The proportion of strains that showed resistance to both tiamulin und valnemulin (39.1%) varied considerably among the most frequent STs ranging from 0% (0/14 isolates resistant) in ST8 isolates to 46.7% (14/30), 52.1% (25/48), and 85.7% (6/7) in isolates belonging to ST112, ST52, and ST114, respectively. All hemolysin genes as well as the iron-related gene ftnA and the OMP gene bhlp29.7 were regularly present in the isolates, while the OMP genes bhlp17.6 and bhmp39h could not be detected. Sequence analysis of hemolysin genes of selected isolates revealed co-evolution of tlyB, BHWA1_RS02885, BHWA1_RS09085, and BHWA1_RS02195 with the core genome and suggested independent evolution of tlyA, tlyC, and hlyA. Our data indicate that in Germany, swine dysentery might be caused by a limited number of B. hyodysenteriae clonal groups. Major STs (ST8, ST52, and ST112) are shared with other countries in Europe suggesting a possible role of the European intra-Community trade of pigs in the dissemination of certain clones. The identification of several novel STs, some of which are single or double locus variants of ST52, may on the other hand hint towards an ongoing diversification of the pathogen in the studied area. The linkage of pleuromutilin susceptibility and sequence type of an isolate might reflect a clonal expansion of the underlying resistance mechanism, namely mutations in the ribosomal RNA genes. A linkage between single virulence-associated genes (VAGs) or even VAG patterns and the phylogenetic background of the isolates could not be established, since almost all VAGs were regularly present in the isolates

Grüne Gentechnik und ökologische Landwirtschaft

Weltweit findet sich als Rechtsnorm in allen entsprechenden Verbraucherschutzgesetzen die Vorgabe, in der ökologischen Landwirtschaft keine gentechnisch veränderten Organismen einzusetzen. Auf europäischer Ebene enthalten weder die EU-Öko-Verordnung noch die Saatgutverkehrsrichtlinien Regelungen, aufgrund derer Schutzmaßnahmen zur Verhinderung oder Vermeidung von GVO-Einkreuzungen in ökologische Kulturen vorgeschrieben werden können. Eine Prüfung der neuen Freisetzungsrichtlinie ergibt aber, dass bei der Genehmigung zum Inverkehrbringen als „besondere Bedingungen für die Verwendung und Handhabung“ eines GVO auch Maßnahmen zum Schutz vor Sachschäden durch GVO-Einkreuzung vorgeschrieben werden können. Als Maßnahmen zum Schutz vor Sachschäden werden hauptsächlich Sicherheitsabstände zwischen Feldern mit GVO-Pflanzen und ökologisch bewirtschafteten Kulturen sowie zusätzlich gentechnikfreie Gebiete diskutiert. Bei der Analyse der Datenlage zur Definition von Sicherheitsabständen treten viele Lücken in der empirischen Datenbasis zu Tage, sodass sich hier dringender Forschungsbedarf abzeichnet. Es werden pragmatisch Hinweise zu Sicherheitsabständen abgeleitet. Gentechnikfreie Gebiete resp. geschlossene Anbaugebiete werden in Zusammenhang mit der Saatgutproduktion vorgeschlagen. Bisher ermöglicht nur das Zivilrecht in Deutschland einen privaten Ausgleich der Rechts- und Interessensphären der Bio-Bauern und der Nutzer transgener Sorten. § 906 BGB lässt sich hier als zentrale Steuerungsnorm des Umweltprivatrechts heranziehen. Dessen System von Unterlassungs- und Ausgleichsansprüchen ist hochkomplex und wird nur schwer zu einer zufriedenstellenden Koexistenz beitragen können. Eine Lösung wäre daher eine wirksame Selbstorganisation des Wirtschaftszweigs der Saatgutindustrie, die transgene Pflanzen züchtet und das Saatgut in Verkehr bringt. Sollte diese nicht möglich sein, bietet sich eine öffentlich-rechtliche Regelung an. Dazu könnten gehören: Die Einrichtung eines Anbaukatasters, die Einführung einer guten fachlichen Praxis des GVO-Anbaus (GfP), die Festlegung einer Instruktionspflicht auf der Saatgutverpackung sowie der Schutz der ökologischen Saatgutproduktion

Strange Particles in Dense Matter and Kaon Condensates

We discuss the role of strangeness in dense matter and especially in neutron stars. The early (in density) introduction of hyperons found in many calculations is probably delayed by the decrease in vector mean field acting on the neutron. The decrease results from both conventional many-body rescattering effects and from the movement towards asymptotic freedom at high densities. Subthreshold $K^-$-meson production by the KaoS collaboration at GSI shows that the $K^-$-mass must be substantially lowered, by $\gtrsim$ 200 MeV at $\rho\sim 2\rho_0$. It is shown that explicit chiral symmetry breaking through the kaon mass may be responsible for $\Sigma^-$-nucleon and $\Xi^-$-nucleon scalar attraction being weaker than obtained by simple quark scaling. The normal mode of the strangeness minus, charge $e^-$, excitation is constructed as a linear combination of $K^-$-meson and $\Sigma^-$, neutron-hole state. Except for zero momentum, where the terms are unmixed the "kaesobar" is a linear combination of these two components.Comment: 10 pages, 8 postscript figures, Talk given at the International Conference on Hypernuclear and Strange Particle Physics (HYP97), Brookhaven Nat'l Lab., USA, October 13-18, 1997, to be published in Nucl. Phys.

Growing Research Networks on Mycorrhizae for Mutual Benefits

Research on mycorrhizal interactions has traditionally developed into separate disciplines addressing different organizational levels. This separation has led to an incomplete understanding of mycorrhizal functioning. Integration of mycorrhiza research at different scales is needed to understand the mechanisms underlying the context dependency of mycorrhizal associations, and to use mycorrhizae for solving environmental issues. Here, we provide a road map for the integration of mycorrhiza research into a unique framework that spans genes to ecosystems. Using two key topics, we identify parallels in mycorrhiza research at different organizational levels. Based on two current projects, we show how scientific integration creates synergies, and discuss future directions. Only by overcoming disciplinary boundaries, we will achieve a more comprehensive understanding of the functioning of mycorrhizal associations