Insect and mollusc communities in wildflower strips: effects of plant diversity and surrounding landscape in an agro-ecosystem

Agricultural land covers approximately 38% of the world's land area, so its contribution to biodiversity is critical for successful conservation in the future. Managed in the right way, agriculture can contribute to the conservation of high-diversity systems, which may provide important ecosystem services such as pollination and biological control. The identification of environmental factors that structure biodiversity is central to the assessment of the impact of land use and climate changes and the planning of conservation strategies. The quality, proportion and spatial arrangement of semi-natural habitats and overall habitat heterogeneity in intensively-used agricultural landscapes are thought to play major roles. Aiming to better understand community organization in spatially-structured ecosystems, we made use of sown wildflower strips. Over the last decade, these ecological compensation zones have been established in the matrix of our intensive agriculture to conserve biodiversity. We conducted a semi-natural experiment in wildflower strips, manipulating trophic structure (reduction of herbivorous molluscs and of major predators) and plant diversity (2, 6, 12, 20 and 24 sown species) to assess the effect of plant diversity, biomass and composition on different functional groups of invertebrates that are of specific importance for agriculture. First we experimentally assessed the effect of plant diversity, biomass and composition on molluscs, and vice versa, the effect of mollusc abundance on vegetation. We showed that plant diversity, structure and composition can have substantial effects on mollusc abundance and composition. The agricultural pest species Arion lusitanicus was less abundant in more diverse habitats. Species rich communities thus appear to be more resistant against generalist herbivores. Plant species composition was the most important determinant of the gastropod community. Thus selective feeding and active habitat choice in molluscs might be the reason for lower abundances in diverse habitat patches. An optimization of the species composition of wildflower strips could thus reduce their attractiveness to slugs. We also provide evidence for a significant decrease in plant species richness caused by molluscs after three years of the experiment, resulting in a compositional change of the vegetation. Our results demonstrate the protective role of plant biodiversity against generalist herbivores, which would otherwise negatively impact plant diversity on a longer term, driving the system along a "low plant diversity – high mollusc abundance" trajectory. Second, we focused on hymenopteran-based food webs in standardized trap nests that allowed us to study species richness, abundance, and quantitative interactions of aboveground nesting bees and wasps that act as pollinators and biological control agents, and their natural enemies. We simultaneously analyzed the effects of plant species richness, vegetation structure and plant composition on these trap-nesting communities at a small spatial scale. Decreasing plant species richness resulted in lower wasp species richness and fewer brood cells of spider-predating wasps. However, for some functional groups, namely bees, aphidand herbivore-predating wasps, we found no effects of vegetation. Spider abundances in the wildflower strips were regulated by top-down and bottom-up control by spider-predating wasps and herbivores, respectively. Our results indicate that plant diversity loss has strong effects on mobile hymenopterans that are limited by the load of their prey. We conclude that preserving even small biodiversity hotspots with a particular rich plant composition can benefit the conservation of biodiversity in agricultural landscapes. Third, we assessed the diversity and abundance of the trap-nesting communities at the landscape scale, and compared the importance of landscape composition and heterogeneity, of spatial arrangement, and of vegetation diversity, composition and structure on the complexity and the organisation of the hymenopteran food web. The proportion of forest cover close to wildflower strips stood out as the most influential landscape element, resulting in a richer trap nest community with more links between species in the food webs and a higher diversity of interactions. Forest close to wildflower strips increased the quantitative food-web metrics vulnerability and generality, while plant species richness was positively related to compartmentalization. Our study revealed the necessity to restore a dense network of flower-rich habitat patches in agricultural landscapes and also to conserve a diverse landscape mosaic with high proportions of woody habitat, in order to 1) ensure long-term sustainability of ecosystem services such as pollination and biological control, and 2) attract fewer, and maintain a low impact of potentially problematic herbivores.Fast 38% der Landfläche unserer Erde wird landwirtschaftlich genutzt. Ihr Beitrag zur Biodiversität ist deshalb wichtig für den Umweltschutz. Wenn landwirtschaftliche Flächen nachhaltig genutzt werden, können sie zu einer hohen Diversität beitragen, was sich positiv auf sogenannte Ökosystemleistungen wie Bestäubung und biologische Schädlingsbekämpfung auswirkt. Die Identifizierung von Umweltfaktoren, welche die Biodiversität erhöhen, ist wichtig für die Einschätzung des Einflusses der Landnutzung und der Planung von Umweltschutzstrategien. Die Qualität, Fläche, räumliche Verteilung und Heterogenität von naturnahen Habitaten spielen eine wichtige Rolle in intensiv genutzter landwirtschaftlicher Fläche. Mit dem Ziel Lebensgemeinschaften in räumlich-strukturierten Ökosystemen besser zu verstehen und damit schützen zu können, führten wir eine Studie in Buntbrachen durch. Im letzten Jahrzehnt wurden diese ökologischen Ausgleichsflächen innerhalb von landwirtschaftlichen Flächen etabliert, um die Biodiversität zu erhöhen. Für unsere Studien etablierten wir 12 Buntbrachen in intensiv genutzter Landwirtschaft und manipulierten die Abundanz von Herbivoren (Schnecken und Kleinsäugern) und ihren natürlich vorkommenden Feinden (Igeln, Raubvögel und Füchsen), sowie die Artenvielfalt von Pflanzen (2, 6, 12, 20 und 24 gesäte Arten). Somit konnte der Effekt der Vegetation auf verschiedene landwirtschaftlich relevante Invertebraten Gruppen gemessen werden. Im ersten Experiment untersuchten wir den Effekt der Pflanzenmischung, Diversität und Struktur auf Schnecken, und vice versa, den Effekt der Schnecken auf die Vegetation. Unsere Ergebnisse zeigten, dass alle drei Vegetationsmerkmale einen wesentlichen Einfluss auf die Schneckenanzahl und Zusammensetzung haben. Vor allem die Art, die den grössten landwirtschaftlichen Schaden hervorruft, Arion lusitanicus, die Spanische Wegschnecke war viel weniger häufig in einem Habitat mit hohem Pflanzenartenreichtum. Wir schliessen daraus, dass artenreiche Flächen resistenter gegen generalistische Pflanzenfresser sind. Die Artenzusammensetzung der Pflanzen hatte bei weitem, den größten Einfluss auf die Schneckengemeinschaft. Der selektive Fraß und aktive Habitatswahl sind Gründe für eine geringere Anzahl an Schnecken in artenreichen Flächen. Eine Optimierung der Pflanzenartenmischung in Buntbrachen könnte somit ihre Attraktivität für Schnecken reduzieren. Der Pflanzenartenreichtum wurde drastisch durch den Schneckenfraß reduziert, was zu einer Veränderung der Pflanzenmischung führte. Unsere Ergebnisse zeigten somit eine Schutzfunktion der Pflanzendiversität gegen generalistische Herbivoren, welche wiederum einen negativen Einfluss auf die Pflanzendiversität haben können, was längerfristig zu „niedriger Pflanzendiversität bei hoher Herbivorenzahl“ führen könnte. Im zweiten Experiment analysieren wir Gemeinschaften und Nahrungsnetzte basierend auf solitären Bienen und Wespen in standardisierten Nisthilfen. Diese ermöglichten uns den Artenreichtum und die Abundanz dieser Bestäuber, und natürlichen Feinden von landwirtschaftlichen Schädlingen, ihren eigenen Feinden und ihrer Beute zu bestimmen. In unserer ersten Studie an diesem System untersuchten wir klein-räumliche Effekte der Pflanzenmischung, Diversität und Struktur auf diese Lebensgemeinschaften. Unsere Ergebnisse zeigten einen starken Rückgang der Wespendiversität mit sinkendem Pflanzenartenreichtum und eine geringere Abundanz an spinnenfressenden Wespen. Für andere trophische Gruppen, wie bienen- und herbivorenfressenden Wespen fanden wir entgegen unserer Erwartung keinen Einfluss. Desweiteren zeigte sich, dass die Spinnengesellschaft wahrscheinlich durch die spinnenfressenden Wespen von oben und gleichzeitig durch die Abundanz ihrer Beute von unten reguliert wird. Anhand unserer Studie konnten wir zeigen, dass ein Pflanzenartenrückgang einen Einfluss auf mobile Insekten haben kann, wenn diese stark von Grösse und Gewicht ihrer Beutetiere limitiert werden. Wir schlussfolgern, dass die Etablierung und Erhaltung von selbst kleinen Biodiversitäts- „Hotspots“ in der Landwirtschaft von grossem ökologischem Nutzen sein kann. Im dritten Experiment untersuchten wir wieder die Diversität und Abundanz der Bienen- und Wespengemeinschaften, aber diesmal auf der Landschaftsebene. Hierzu studierten wir den Einfluss der Landschaftszusammensetzung, der räumlichen Verteilung der Buntbrachen und der Vegetation auf die Artenzusammensetzung in Nisthilfen und die Struktur der Nahrungsnetze. Waldflächen in der Nähe von Buntbrachen hatten den stärksten Einfluss, was sich in einem größeren Artenreichtum der Nisthilfenbewohner und einer größeren Diversität an Interaktionen wiederspiegelte. Waldflächen in der Umgebung von Buntbrachen beeinflussten auch die quantitativen Messwerte und die Struktur der Nahrungsnetze, was theoretisch zu einer höheren Stabilität der Gemeinschaften führt. Unsere Studie zeigte, dass in intensiv genutzter Agrarlandschaft ein dichtes Netz von artenreichen Ausgleichsflächen mit einem hohen Anteil an Waldflächen wichtig ist, um 1) Ökosystemleistungen wie Bestäubung und biologische Schädlingsbekämpfung langfristig zu erhalten, sowie 2) die Anzahl und den Einfluss von problematischen Herbivoren zu reduzieren

Use of cardiovascular and antidiabetic drugs before and after starting with clozapine versus other antipsychotic drugs:a Dutch database study

Reports of decreased mortality among patients with schizophrenia who use clozapine may be biased if clozapine is prescribed to relatively healthy patients and if intensive monitoring during its use prevents (under-treatment of) somatic disorder. We aimed to assess whether there is a difference in: (1) somatic comorbidity between patients who start with clozapine and those who start with other antipsychotics and (2) prescribed somatic medication, between patients using clozapine and those using olanzapine. Cohort study based on insurance claims (2010-2015). After selecting new users of antipsychotics and those who subsequently switched to clozapine (N = 158), aripiprazole (N = 295), olanzapine (N = 204) or first-generation antipsychotics (N = 295), we compared the clozapine starters to others on cardiovascular or diabetic comorbidity. Those using clozapine and olanzapine were compared on new prescriptions for cardiovascular or antidiabetic drugs. The OR(adj)of cardiovascular or diabetic comorbidity among other starters compared with clozapine starters was 0.77 [95% confidence interval (CI): 0.43-1.39], that is, a nonsignificantly increased prevalence associated with clozapine was found. Users of clozapine received significantly more new prescriptions for cardiovascular or antidiabetic medication (ORadj: 2.70, 95% CI: 1.43-5.08). Starters with clozapine were not cardiovascular/metabolic healthier than starters with other antipsychotics. During its use, they received more somatic treatment

Einfluss von Biodiversität und Landnutzung auf pflanzenverfügbaren Phosphor im Boden

Phosphor (P) ist ein essentieller Pflanzennährstoff, der wie Stickstoff das Pflanzenwachstum limitieren kann. Unser Ziel ist die Trennung der Effekte von Landnutzung und Biodiversität auf den pflanzenverfügbaren P im Boden. Hierzu haben wir in Bodenproben von Grünlandstandorten der Schwäbischen Alb die P-Fraktionen nach der Methode von Hedley et al. (1982) bestimmt. Unsere Ergebnisse zeigen, dass über den Landnutzungseffekt hinaus die Gehalte an pflanzenverfügbarem P im Boden maßgeblich von der Pflanzenartenzahl beeinflusst werden. Es besteht ein negativer Zusammenhang zwischen Pflanzenartenzahl und den NaHCO3-löslichen anorganischen P-Gehalten im Boden, der nicht auf unterschiedliche Ausgangsbedingungen der Standorte in Bezug auf pH-Werte und P-Gehalte des Ausgangssubstrates beruht oder auf den Einfluss von Leguminosen zurückzuführen ist. Eine hohe Artenzahl auf Grünlandstandorten führt folglich zur effektiveren Nutzung von pflanzenverfügbarem P im Boden

Production of a fusogenic oncolytic rVSV-NDV virus: Cell-line screening and process development in small-scale suspension cultures

Fusogenic oncolytic viruses represent a novel class of immunotherapeutics, which offer hope for the treatment of otherwise incurable cancers. Their enhanced intratumoral spread through syncytia formation allows for a potent mechanism of tumor cell death and induction of antitumor immune responses [1]. While the ability of these viruses to induce cell-cell fusion reactions offers numerous beneficial properties, it also presents unique challenges for large-scale clinical-grade manufacturing. Infected cells rapidly fuse with surrounding cells, resulting in large multinucleated syncytia, which quickly die before high titers of the virus can be produced or released [2]. Here, we evaluated the production of a novel hyper-fusogenic hybrid of vesicular stomatitis virus and Newcastle disease virus (rVSV-NDV) in four different suspension cell lines. Cell growth, metabolism, and virus productivity were characterized for each candidate respectively. Permissiveness was evaluated based on extracellular infectious virus titer and cell-specific virus yields (CSVY). For the purpose of process intensification, virus adaptation, and multiplicity of infection (MOI) screenings were conducted in small-scale and confirmed in a 1 L bioreactor. BHK-21 and HEK293SF were identified as promising candidates for rVSV-NDV production, yielding infectious titers at infection cell concentrations of 2.0 E06 cells/mL of up to 3.0 E08 TCID50/mL and 7.5 E07 TCID50/mL, and CSVYs of 153 and 9, respectively. Oncolytic potency was not affected by production in suspension cultures compared to the reference stock produced in adherent AGE1.CR.pIX cultures. Overall, promising suspension cell substrates were identified for a highly efficient and scalable production process of this fusogenic rVSV-NDV. This paves the way for an efficient large-scale manufacturing process, which can be further intensified towards high cell density production in order to provide sufficient virus material for conducting a phase I clinical trial of oncolytic VSV-NDV in cancer patients. 1. Krabbe, T. and J. Altomonte, Fusogenic Viruses in Oncolytic Immunotherapy. Cancers (Basel), 2018. 10(7). 2. Abdullahi, S., et al., A Novel Chimeric Oncolytic Virus Vector for Improved Safety and Efficacy as a Platform for the Treatment of Hepatocellular Carcinoma. J Virol, 2018. 92(23)

Including community composition in biodiversity–productivity models

Studies on biodiversity and ecosystem functioning (BEF) have elicited debate over the interpretation of the positive relationship between species richness and plant productivity. Manipulating richness cannot be achieved without affecting composition; it is thus essential to consider the latter in statistical models.We firstly review existing approaches that use species richness as an explanatory variable and propose modifications to improve their performance. We use an original data set to illustrate the analyses. The classical method where composition is coded as a factor with a level for each different species mixture can be improved by defining the levels using clustering. Methods based on ordinations reduce the dimensionality of plant composition and use the new coordinates as fixed effects; they provide a much better fit to our observations.Secondly, we develop a new method where composition is included as a similarity matrix affecting the residual variance–covariance. Similarity in composition between plots is treated in the same way as shared evolutionary history between species in phylogenetic regression. We find that it outperforms the other models.We discuss the different approaches and suggest that our method is particularly suited for observational studies or for manipulative studies where plant diversity is not kept constant by weeding. By treating species composition in an intuitive and sensible way, it offers a valuable and powerful complement to existing models

A virtual reality paradigm to assess episodic memory: Validation-dataset for six parallel versions and a structured behavioral assessment

In the epilepsy monitoring unit of the Department of Neurology at the University Clinic of Salzburg 20 adult patients were recruited to participate in a validation of 6 parallel versions of the virtual reality test for episodic memory. Patients were tested up to 7 times, i.e. twice a day, in the morning and evening, beginning on Monday evening. Each session consisted of learning a new town and immediate recall for this town. All sessions but the first one included also delayed recall of the previously learned town and a recognition test. Recall included the sub-scales what, details, when, egocentric where and allocentric where. Recognition memory was tested by presenting the patients 30 sentences of which 15 were true and 15 were false. While not all patients completed the full testing schedule, at immediate recall for 9 patients a full data set (7 sessions) is available. All patients were free of antiepileptic medication (N = 19) or medication was kept constant across the week (N = 1). This data can be used to demonstrate the feasibility to use the virtual reality test in the epilepsy monitoring unit e.g. to monitor effects of seizures or medication on episodic memory.Yvonne Höller's research was funded by the Austrian Science Fund (FWF) : T 798-B27 and by the Research Fund of the Paracelsus Medical University : A-16/02/021-HÖL .Peer reviewe

Bis(stearoyl) Sulfide: A Stable, Odor-Free Sulfur Precursor for High-Efficiency Metal Sulfide Quantum Dot Photovoltaics

The synthesis of metal sulfide nanocrystals is a crucial step in the fabrication of quantum dot (QD) photovoltaics. Control over the QD size during synthesis allows for precise tuning of their optical and electronic properties, making them an appealing choice for electronic applications. This flexibility has led to the implementation of QDs in both highly-efficient single junction solar cells and other optoelectronic devices including photodetectors and transistors. Most commonly, metal sulfide QDs are synthesized using the hot-injection method utilizing a toxic, and air- and moisture-sensitive sulfur source: bis(trimethylsilyl) sulfide ((TMS)2S). Here, bis(stearoyl) sulfide (St2S) is presented as a new type of air-stable sulfur precursor for the synthesis of sulfide-based QDs, which yields uniform, pure, and stable nanocrystals. Photovoltaic devices based on these QDs are equally efficient as those fabricated by (TMS)2S but exhibit enhanced operational stability. These results highlight that St2S can be widely adopted for the synthesis of metal sulfide QDs for a range of optoelectronic applications