Genomic Features Of A Bumble Bee Symbiont Reflect Its Host Environment

Here, we report the genome of one gammaproteobacterial member of the gut microbiota, for which we propose the name >Candidatus Schmidhempelia bombi,> that was inadvertently sequenced alongside the genome of its host, the bumble bee, Bombus impatiens. This symbiont is a member of the recently described bacterial order Orbales, which has been collected from the guts of diverse insect species; however, >Ca. Schmidhempelia> has been identified exclusively with bumble bees. Metabolic reconstruction reveals that >Ca. Schmidhempelia> lacks many genes for a functioning NADH dehydrogenase I, all genes for the high-oxygen cytochrome o, and most genes in the tricarboxylic acid (TCA) cycle. >Ca. Schmidhempelia> has retained NADH dehydrogenase II, the low-oxygen specific cytochrome bd, anaerobic nitrate respiration, mixed-acid fermentation pathways, and citrate fermentation, which may be important for survival in low-oxygen or anaerobic environments found in the bee hindgut. Additionally, a type 6 secretion system, a Flp pilus, and many antibiotic/multidrug transporters suggest complex interactions with its host and other gut commensals or pathogens. This genome has signatures of reduction (2.0 megabase pairs) and rearrangement, as previously observed for genomes of host-associated bacteria. A survey of wild and laboratory B. impatiens revealed that >Ca. Schmidhempelia> is present in 90% of individuals and, therefore, may provide benefits to its host.Center for Insect Science (University of Arizona)National Science Foundation NSF 1046153NIH Director's Pioneer 1DP1OD006416-01NIH R01-HG006677Swiss National Science Foundation 140157, 147881Integrative Biolog

The non-equilibrium solvent response force: What happens if you push a Brownian particle

In this letter we discuss how to add forces to the Langevin equation. We derive the exact generalized Langevin equation for the dynamics of one particle subject to an external force embedded in a system of many interacting particles. The external force may depend on time and/or on the phase-space coordinates of the system. We construct a projection operator such that the drift coefficient, the memory kernel, and the fluctuating force of the generalized Langevin equation are the same as for the system without external driving. We show that the external force then enters the generalized Langevin equation additively. In addition we obtain one term which, to our knowledge, has up to now been overlooked. We analyze this additional term for an exemplary system.Comment: 5 pages, 4 figure

Auftreten von Fusarium spp. und Mykotoxinen im niedersächsischen Spargelanbau : Ertragsrelevanz und determinierende Faktoren

[no abstract

Non-linear frequency response analysis of the kinetics of electrochemical reactions: a case study – ferrocyanide oxidation kinetics

In general, electrochemical (EC) systems are non-linear, which means they respond nonlinearly to a frequency-dependent periodic input perturbation of high amplitude imposed around a steady-state. In addition, the kinetics of EC reactions are quite complex and different rivalling model presentations can be formulated for certain EC reaction. While standard electrochemical methods (steady-state and electrochemical impedance spectroscopy) showed low sensitivity towards the model discrimination, non-linear frequency response analysis (NLFRA) of EC kinetics can appear advantageous for this purpose. In this work, NLFRA is applied in experimental and theoretical study of ferrocyanide oxidation as a model EC reaction.Belgrade, Serbia, June 6-10, 2010Related to the published paper in the Proceedings of the Second Regional Symposium on Electrochemistry South-East Europe, [http://cer.ihtm.bg.ac.rs/handle/123456789/3539

Non-linear frequency response analysis of the kinetics of electrochemical reactions: a case study – ferrocyanide oxidation kinetics

In general, electrochemical (EC) systems are non-linear, which means they respond nonlinearly to a frequency-dependent periodic input perturbation of high amplitude imposed around a steady-state. In addition, the kinetics of EC reactions are quite complex and different rivalling model presentations can be formulated for certain EC reaction. While standard electrochemical methods (steady-state and electrochemical impedance spectroscopy) showed low sensitivity towards the model discrimination, non-linear frequency response analysis (NLFRA) of EC kinetics can appear advantageous for this purpose. In this work, NLFRA is applied in experimental and theoretical study of ferrocyanide oxidation as a model EC reaction.Belgrade, Serbia, June 6-10, 2010Related to the published paper in the Proceedings of the Second Regional Symposium on Electrochemistry South-East Europe, [http://cer.ihtm.bg.ac.rs/handle/123456789/3539

Strategies to control the horse chestnut leafminer (Cameraria ohridella) in urban environments

Von einzelnen Ausnahmen abgesehen befällt die Rosskastanienminiermotte, Cameraria ohridella Deschka & Dimic 1986, die weißblühende Rosskastanie Aesculus hippocastanum L. Die Blütenpracht der Bäume im Frühjahr, die großen schattenspendenden Blätter im Sommer und die als Spielzeug begehrten Früchte im Herbst verhalfen der Rosskastanie zu großer Beliebtheit. Mittlerweile spielen die Bäume in Parks und entlang von Straßen eine ebenso bedeutende Rolle wie in privaten Gärten und sind aus vielen Städten in ganz Europa nicht mehr wegzudenken. Der kontinuierliche Massenbefall der Bäume durch die Kastanienminiermotte und die daraus resultierenden Folgekosten stellen deshalb vor allem im städtischen Siedlungsbereich nicht nur ein ästhetisches, sondern auch ein beträchtliches ökonomisches Problem dar, außerdem verlieren die Bäume bei starken Befall ihre wichtige stadtklimatische Funktion (BALDER, 2002). Im Projekt „BerlinCam“ werden Bekämpfungsmethoden gesucht, die den speziellen Bedürfnissen des Pflanzenschutzes im urbanen Grün gerecht werden sollen. Auf ihre Unbedenklichkeit gegenüber der Bevölkerung wird dabei genauso geachtet wie auf ihre Anwendbarkeit an stark frequentierten oder verkehrsbelasteten öffentlichen Flächen. Nicht zuletzt müssen die Bekämpfungsmaßnahmen auch modernen, hohen Umweltstandards genügen und trotz allem ökonomisch vertretbar sein. Im folgenden wird ein Beispiel aus dem Projekt vorgestellt, das zum jetzigen Zeitpunkt Ansatzpunkte für eine erfolgreiche Bekämpfung von C. ohridella im urbanen Bereich zeigen könnte. Dabei handelt es sich um die Anwendung von systemischen Pflanzenschutzmitteln als Depotverfahren. Diese Methode und die applizierten Produkte sind derzeit noch nicht in Deutschland zur Bekämpfung der Kastanienminiermotte zugelassen.The continuous epidemic infestation of horse chestnuts by C. ohridella is a serious aesthetic and economic problem in urban environments. The project "BerlinCam", therefore, aims to develop control measures which meet the special needs of urban plant protection. Chemical treatments using a recently developed application method achieved a substantial reduction of the infestation level of horse chestnut leaves by the pest insect. Easily practicable and safe depot-applications of systemic insecticides turned out to be effective in killing preimaginal stages of the leafminer on young trees. Questions regarding potential environmental risks and economic practicability of these methods will be answered in the next two years of the project. So far, chemical products are not registered in Germany

Zur Leistungsfähigkeit heimischer Parasitoide bei der Kontrolle der Rosskastanienminiermotte, Cameraria ohridella (Lep., Gracillariidae)

Einzelne Erzwespenarten aus der Familie Eulophidae haben sich mittlerweile als fester Bestandteil des Parasitoidenkomplexes von C. ohridella etabliert. In Berlin wurden im Rahmen eines geförderten Projekts (EFRE- Europäischer Fond für regionale Entwicklung der EU und der Senatsverwaltung für Stadtentwicklung) 21 Schlupfwespen-Arten als natürliche Gegenspieler nachgewiesen (Jäckel & al. 2007). Nach wie vor sind die natürlichen Parasitierungsraten mangelhaft. Dazu wurden während der Projektlaufzeit unterschiedliche Erhebungen mit dem Ziel durchgeführt, Ursachenkomplexe herauszuarbeiten. Die Parasitierungsraten wurden in Abhängigkeit vom Erfassungszeitpunkt, vom Standort der Kastanien in der Stadt, von der Dichte der Kastanien je Flächeneinheit und von der Diversität der Umgebungsvegetation bestimmt. Parallel wurde das Parasitoidenspektrum im Untersuchungszeitraum unter verschiedenen Bedingungen ermittelt. Da keine parasitierungsbegünstigenden Faktoren herausgearbeitet werden konnten, um daraus nützlingsfördende Maßnahmen abzuleiten, wurde eine geeignete Schlupfwespe aus dem natürlichen Parasitoidenkomplex ausgewählt, um die Möglichkeiten eines gezielten Einsatzes zur Dezimierung der Motte im Freiland zu erarbeiten. Die Biologie von P. agraules wurde im Labor und im Freiland untersucht. Weiterhin wurde durch Freilassung markierter Tiere im Freiland deren Verhalten studiert.Among other approaches, biological control measures against Cameraria ohridella (Lep., Gracillariidae) are tested in the project BerlinCam (“Possibilities to control the horse chestnut leafminer in Berlin”, financially supported by the Senate Department of Urban Development Berlin and the EU by means of the EFRE funds). During our investigations, we found 21 parasitoid species on C. ohridella hosts. These species are generalists and known for attacking a broad range of leafminers in Europe. By far the most abundant species is Minotetrastichus frontalis, followed by a second eudominant species, Pnigalio agraules. The structure of the complex and also the parasitism rate is not stable, and we found considerable variations between different generations within one year as well as large variation between the years and the type of habitat in Berlin. Our long-term-monitoring at one location in Berlin shows that parasitism rates are generally very low. The mean parasitism rate of C. ohridella measured over five years was 2,4 % ± 0,88, 3,7 % ± 2,18 and 5,3 % ± 5,43 in generation 1, 2 and 3, respectively. The parasitism rate is not dependent on the specific ecosystem. In the project we investigated several aspects of the biology of P. agraules. Our results show that this native parasitoid meets several of the requirements for successful use as a bioagent in the control of C. ohridella. The parasitoids’ fecundity, longevity and the speed of development by far exceed those of the pest, enabling the parasitoid population to grow faster than that of the host. Future studies on the host preference of this parasitoid species including quantitative aspects regarding release rates will investigate the potential benefits and risks of releases of P. agraules for the control of C. ohridella

The parasitism of the horse chestnut leaf miner (Cameraria ohridella) in the city of Berlin

Als natürliche Gegenspieler der Roßkastanienminiermotte Cameraria ohridella (Lepidoptera, Gracillariidae) haben vor allem Parasitoide Bedeutung. In Berlin wurden bisher im Rahmen eines vom Umweltentlastungsprogramm der Europäischen Gemeinschaft geförderten Forschungsprojektes 16 verschiedene Arten festgestellt. Dabei handelt es sich hauptsächlich um Erzwespen aus der Familie der Eulophidae, die an Larven und Puppen von C. ohridella parasitieren. Es sind polyphage Parasitoide, die auch von anderen Motten, Fliegen und Käfern mit ähnlicher Lebensweise bekannt sind und die unter natürlichen Umständen einen bedeutenden Beitrag zur Kontrolle dieser Minierer leisten. Sowohl die Parasitierungsrate als auch das Artenspektrum einzelner Parasitoidenkomplexe variierte in den Untersuchungsflächen innerhalb Berlins beträchtlich. Der Zeitpunkt der Erfassung der Parasitierung wie auch die unterschiedlichen Standortbedingungen haben dabei großen Einfluss auf das Ergebnis. Im Rahmen der Untersuchungen soll festgestellt werden, ob bestimmte heimische Parasitoidenarten für einen Einsatz oder zur Förderung im Sinne des biologischen Pflanzenschutzes in urbanen Gebieten geeignet sind.The parasitism of the horse chestnut leaf miner (Cameraria ohridella) in the city of Berlin is currently being studied within the project BerlinCam. The project involved intensive field studies at 7 horse chestnut stands in different types of habitats, spanning three vegetative periods, to understand the influence of abiotic and environmental factors on parasitoid complexes and parasitism rates. 16 species of parasitoids have been determined so far, most of them generalistic members of the chalcidoid family Eulophidae. The parasitism rates as well as the numbers of parasitoid species were, on average, lower in 2004 than in 2003, which may be a result of different weather conditions in these two years. Surprisingly, the highest rates of parasitism were measured along streets in the city centre, whereas they were significantly lower at semi-natural stands outside the city. Several environmental factors, like the presence of other leafminers in the surrounding vegetation or the population density of C. ohridella at the locations may be responsible for these esults

Structural annotation of electro- and photochemically generated transformation products of moxidectin using high-resolution mass spectrometry

Moxidectin (MOX) is a widely used anthelmintic drug for the treatment of internal and external parasites in food-producing and companion animals. Transformation products (TPs) of MOX, formed through metabolic degradation or acid hydrolysis, may pose a potential environmental risk, but only few were identified so far. In this study, we therefore systematically characterized electro- and photochemically generated MOX TPs using high-resolution mass spectrometry (HRMS). Oxidative electrochemical (EC) TPs were generated in an electrochemical reactor and photochemical (PC) TPs by irradiation with UV-C light. Subsequent HRMS measurements were performed to identify accurate masses and deduce occurring modification reactions of derived TPs in a suspected target analysis. In total, 26 EC TPs and 59 PC TPs were found. The main modification reactions were hydroxylation, (de-)hydration, and derivative formation with methanol for EC experiments and isomeric changes, (de-)hydration, and changes at the methoxime moiety for PC experiments. In addition, several combinations of different modification reactions were identified. For 17 TPs, we could predict chemical structures through interpretation of acquired MS/MS data. Most modifications could be linked to two specific regions of MOX. Some previously described metabolic reactions like hydroxylation or O-demethylation were confirmed in our EC and PC experiments as reaction type, but the corresponding TPs were not identical to known metabolites or degradation products. The obtained knowledge regarding novel TPs and reactions will aid to elucidate the degradation pathway of MOX which is currently unknown

Detection of Clenbuterol in Urine of Meat Stock and Detection of Sulfamethazine in Pig Meat with the Biosensor Biacore Q

The biosensor-tool BIACORE Q was evaluated and validated to find out if it could be applicated on-site in an abattoir for the detection of veterinary drug residues. The study was focused on the following questions: - Is the biosensor-instrumentation robust enough for the on-site application in an abattoir? - Are reliable results fast enough available? - How many false-negative and false-positive results can be found? This feasibility study was carried out based on the examples clenbuterol and sulfamethazine. A total of 500 urine samples for clenbuterol residues (calf, cattle, pig, and sheep) as well as 160 meat samples for sulfamethazine residues (pig) was randomly taken at two different abattoirs in Switzerland. The samples were analysed with the Biosensor and commercially available Qflex Kits for clenbuterol and sulfamethazine. Positive samples were confirmed using LC-MS. From a technical point of view it is possible to use the biosensor directly at the slaughterhouse for screening of clenbuterol residues in urine samples and sulfamethazine residues in meat samples. Out of 500 urine samples, 3 positive samples were tested negative for clenbuterol using LC-MS. Two samples tested positive for sulfamethazine out of 160 samples were confirmed using LC-MS. The analysis method is rapid and reliable