Neonicotinoid seed treatment products – Occurrence and relevance of guttation for honeybee colonies

Background: Guttation is a natural botanical phenomenon and describes the active excretion of liquid water (guttation fluid) by some vascular plants in form of droplets on the tips of leaves or on leaf edges. Guttation fluid may contain neonicotinoid residues after plant uptake from seed treatments. To clarify the relevance of the guttation fluid as a water source for honey bee colonies and to assess potential associated risks under conditions of agronomic practice, various studies were performed in key broad acre crops such as maize, sugar beet, potato (in-furrow application), winter barley and oilseed rape by placing honeybee colonies adjacent to freshly emerged fields for several weeks and by following up potential lethal and sub-lethal effects, as well as potential effects on colony performance.Results: Guttation droplets contained peak residue levels theoretically capable of harming individual honeybees (i.e. several hundred ppm). Residue levels, however, generally decreased with time, as expected based on the physiological process involved. The temporal coincidence of honeybee flight activity and the presence of guttation droplets were generally limited to early morning hours and to a much lesser extent to evening hours. Spatially, honeybees were found to predominately collect water, if any, in the direct vicinity of the hives. Water collection generally ceased within a couple of metres distance to the hives, which renders distance to the crop to be a significant exposure factor, and in turn renders dew and guttation from off-crop vegetation to be more relevant to water collecting honeybees than guttation from the crop. Mortality events, if any, were scarce and generally matched in treatments and in controls. The absolute numbers of dead bees involved in these rare cases were so low that they did not translate into any colony level effects or impacts on bee health or overwintering success, nor on adverse effects on honey production of the involved colonies.Conclusions: Given the overall body of data, the associated intensity of the assessments in each study as well as the worst-case exposure conditions employed, it can be concluded that exposure of honeybee colonies to guttation fluid, excreted from neonicotinoid seed-treated crop plants, did not pose an unacceptable acute or chronic risk to honeybee colony development or survival, and does not adversely interfere with bee keeping practices. Overall, guttation water from seedtreated crop plants was found not to be a significant exposure route for honeybees.Keywords: pesticide, honey bee, guttatio

Weeds in the treated field - a realistic scenario for pollinator risk assessment?

In July 2013 the European Food Safety Authority (EFSA) released its final guidance on the risk assessment of plant protection products (PPPs) to bees1. One objective of the guidance was to produce a simple and cost effective first tier risk assessment scheme to ensure that the appropriate level of protection is achieved. However, recent impact analyses have indicated that the first tier of this risk assessment does not act effectively as a screen for compounds of low risk to bees. For example substances showing no toxicity to bees often fail the tier 1 risk assessment based on a worst-case exposure to flowering weeds inside the treated field. If realistic farming practices (e.g. tillage and herbicide applications) are considered, weeds are not usually prevalent in arable fields. It is therefore suggested that the scenarios in the guidance could be considered overly conservative and in some instances unrealistic. The EFSA guidance states that if <10% of the area of use is flowering weeds then the exposure route is not relevant in the 90th %ile case, and thus does not need to be considered. However, despite this, the option to generate data or refine assessments based on available data is questioned as no guidance for the assessment of the abundance of weeds is available. As part of an industry-led initiative we present and discuss the use of empirical evidence (i.e. occurrence and growth stage of weeds in control plots from herbicide efficacy field trials conducted for regulatory submission) to illustrate that the scenarios in the guidance document could be modified using currently available data to create a more effective tier 1 risk assessment and still ensure that the appropriate level of protection is achieved. We have demonstrated here that less than 2% of all weeds recorded in arable crop trials (represented here by wheat, oilseed rape, sugar beet, sunflower, potatoes, maize, peas and beans) are at a flowering growth stage; therefore in arable crops the flowering weeds scenario is not applicable for the 90th %ile exposure. For permanent crop trials (represented here by orchards and vines) 37% of weeds were recorded at a flowering growth stage. When the attractiveness and density data are considered, the percentage of attractive, flowering weeds which cover >10% of the ground area is only 12.3%, indicating that for permanent crops further investigation may be required as to whether this scenario is relevant

Das Soziale lernen Ergebnisse eines landesweiten Modellprojekts

Soziales Lernen muss gezielt und systematisch gefoerdert werden. Es wird untersucht, wie entsprechende Lernarrangements und Konzepte aussehen koennen und wie sie sich gesellschaftlich organisieren lassen. Gemeinsam mit Schulen, Jugendorganisationen und sozialen Einrichtungen aus dem staedtischen und laendlichen Raum Baden-Wuerttembergs werden unterschiedliche Projekt- und Kooperationsformen entwickelt und erprobt. Dabei handelt es sich um drei- bis fuenftaegige Veranstaltungen in Blockform oder zeitlich verteilt. Von den 21 Projekten aus dem Zeitraum November 1996 bis Juni 1998 werden 408 Frageboegen der 13- bis 24jaehrigen Teilnehmer ausgewertet, daneben auch Tagebuecher der Praxistage und Praktikumsberichte. Die Lernerfahrungen der Teilnehmer und die Erfahrungen mit der Projektorganisation werden wiedergegeben. Sie betreffen 'soziales Wissen', Selbsterkenntnis, Verhaltenssicherheit usw. und erweisen sich als gewinnbringend fuer alle Beteiligten. Neben diesem Beitrag zu einer 'Neuen Kultur des Sozialen' werden noch weitere aehnliche Projekte angefuehrt. (prf)Available from UuStB Koeln(38)-990106137 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Transcriptional Regulation of Renal Cytoprotective Genes by Nrf2 and Its Potential Use as a Therapeutic Target to Mitigate Cisplatin-Induced Nephrotoxicity

The use of the chemotherapeutic drug cisplatin is limited in part by nephrotoxicity. Cisplatin causes renal DNA adducts and oxidative stress in rodents. The transcription factor Nrf2 (nuclear factor E2-related factor 2) induces expression of cytoprotective genes, including Nqo1 (NADPH:quinone oxidoreductase 1), Ho-1 (heme oxygenase-1), and Gclc (glutamate cysteine ligase catalytic subunit), in response to electrophilic and oxidative stress. In the present study, plasma and kidneys from wild-type and Nrf2-null mice were collected after receiving cisplatin for evaluation of renal injury, inflammation, mRNA, and protein expression. Compared with wild types, more extensive nephrotoxicity was observed in Nrf2-null mice after cisplatin treatment. Kidneys from Nrf2-null mice treated with cisplatin had more neutrophil infiltration accompanied by increased p65 nuclear factor κB binding and elevated inflammatory mediator mRNA levels. Cisplatin increased renal mRNA and protein expression of cytoprotective genes (Nqo1, Ho-1, Gclc) and transporters Mrp2 and Mrp4 in wild-type but not in Nrf2-null mice. Lastly, the Nrf2 activator, CDDO-Im [2-cyano-3,12-dioxooleana-1,9-dien-28-oic imidazolide], increased Nrf2 signaling in kidneys from wild-type mice and protected them from cisplatin toxicity. Collectively, these data indicate that the absence of Nrf2 exacerbates cisplatin renal damage and that pharmacological activation of Nrf2 may represent a novel therapy to prevent kidney injury. Coordinated regulation of detoxification enzymes and drug transporters and suppression of inflammation by Nrf2 during cisplatin nephrotoxicity are probable defense mechanisms to eliminate toxic mediators and promote proximal tubule recovery

QUAREP-LiMi: A community-driven initiative to establish guidelines for quality assessment and reproducibility for instruments and images in light microscopy

A modern day light microscope has evolved from a tool devoted to making primarily empirical observations to what is now a sophisticated , quantitative device that is an integral part of both physical and life science research. Nowadays, microscopes are found in nearly every experimental laboratory. However, despite their prevalent use in capturing and quantifying scientific phenomena, neither a thorough understanding of the principles underlying quantitative imaging techniques nor appropriate knowledge of how to calibrate, operate and maintain microscopes can be taken for granted. This is clearly demonstrated by the well-documented and widespread difficulties that are routinely encountered in evaluating acquired data and reproducing scientific experiments. Indeed, studies have shown that more than 70% of researchers have tried and failed to repeat another scientist's experiments, while more than half have even failed to reproduce their own experiments. One factor behind the reproducibility crisis of experiments published in scientific journals is the frequent underreporting of imaging methods caused by a lack of awareness and/or a lack of knowledge of the applied technique. Whereas quality control procedures for some methods used in biomedical research, such as genomics (e.g. DNA sequencing, RNA-seq) or cytometry, have been introduced (e.g. ENCODE), this issue has not been tackled for optical microscopy instrumentation and images. Although many calibration standards and protocols have been published, there is a lack of awareness and agreement on common standards and guidelines for quality assessment and reproducibility. In April 2020, the QUality Assessment and REProducibility for instruments and images in Light Microscopy (QUAREP-LiMi) initiative was formed. This initiative comprises imaging scientists from academia and industry who share a common interest in achieving a better understanding of the performance and limitations of microscopes and improved quality control (QC) in light microscopy. The ultimate goal of the QUAREP-LiMi initiative is to establish a set of common QC standards, guidelines, metadata models and tools, including detailed protocols, with the ultimate aim of improving reproducible advances in scientific research. This White Paper (1) summarizes the major obstacles identified in the field that motivated the launch of the QUAREP-LiMi initiative; (2) identifies the urgent need to address these obstacles in a grassroots manner, through a community of stakeholders including, researchers, imaging scientists, bioimage analysts, bioimage informatics developers, corporate partners, funding agencies, standards organizations, scientific publishers and observers of such; (3) outlines the current actions of the QUAREP-LiMi initiative and (4) proposes future steps that can be taken to improve the dissemination and acceptance of the proposed guidelines to manage QC. To summarize, the principal goal of the QUAREP-LiMi initiative is to improve the overall quality and reproducibility of light microscope image data by introducing broadly accepted standard practices and accurately captured image data metrics