Development of a harmonized risk mitigation toolbox dedicated to environmental risks of pesticides in farmland in Europe: outcome of the MAgPIE workshop

Risk mitigation measures are a key component in designing conditions of use of pesticides in crop protection. A 2-step workshop was organized under the auspices of SETAC and the European Commission and gathered risk assessors and risk managers of 21 European countries, industry, academia and agronomical advisors/extension services, in order to provide European regulatory authorities with a toolbox of risk mitigation measures designed to reduce environmental risks of pesticides used in agriculture, and thus contribute to a better harmonization within Europe in the area.The workshop gathered an inventory of the risk mitigation tools for pesticides being implemented or in development in European countries. The inventory was discussed in order to identify the most promising tools for a harmonized toolbox in the European area. The discussions concerned the level of confidence in the technical data on which the tools identified rely, possible regulatory hurdles, expectations as regards the implementation of these tools by farmers and links with risk assessment. Finally, this workshop was a first step towards a network gathering all stakeholders, i.e. experts from national authorities, research sector, industry and farmers, to share information and further develop this toolbox. This paper presents an outline of the content of the toolbox with an emphasis on spray drift reducing techniques, in line with the discussions ongoing in the SPISE workshop

Minimum-Cost Coverage of Point Sets by Disks

We consider a class of geometric facility location problems in which the goal is to determine a set X of disks given by their centers (t_j) and radii (r_j) that cover a given set of demand points Y in the plane at the smallest possible cost. We consider cost functions of the form sum_j f(r_j), where f(r)=r^alpha is the cost of transmission to radius r. Special cases arise for alpha=1 (sum of radii) and alpha=2 (total area); power consumption models in wireless network design often use an exponent alpha>2. Different scenarios arise according to possible restrictions on the transmission centers t_j, which may be constrained to belong to a given discrete set or to lie on a line, etc. We obtain several new results, including (a) exact and approximation algorithms for selecting transmission points t_j on a given line in order to cover demand points Y in the plane; (b) approximation algorithms (and an algebraic intractability result) for selecting an optimal line on which to place transmission points to cover Y; (c) a proof of NP-hardness for a discrete set of transmission points in the plane and any fixed alpha>1; and (d) a polynomial-time approximation scheme for the problem of computing a minimum cost covering tour (MCCT), in which the total cost is a linear combination of the transmission cost for the set of disks and the length of a tour/path that connects the centers of the disks.Comment: 10 pages, 4 figures, Latex, to appear in ACM Symposium on Computational Geometry 200

Cathodoluminescence and TEM investigations of structural and optical properties of AlGaN on epitaxial laterally overgrown AlN/sapphire templates

Surface steps as high as 15 nm on up to 10 μm thick AlN layers grown on patterned AlN/sapphire templates play a major role for the structural and optical properties of AlxGa1−xN layers with x ≥ 0.5 grown subsequently by metalorganic vapour phase epitaxy. The higher the Ga content in these layers is, the stronger is the influence of the surface morphology on their properties. For x = 0.5 not only periodic inhomogeneities in the Al content due to growth of Ga-rich facets are observed by cathodoluminescence, but these facets give rise to additional dislocation formation as discovered by annular dark-field scanning transmission electron microscopy. For AlxGa1−xN layers with x = 0.8 the difference in Al content between facets and surrounding material is much smaller. Therefore, the threading dislocation density (TDD) is only defined by the TDD in the underlying epitaxially laterally overgrown (ELO) AlN layer. This way high quality Al0.8Ga0.2N with a thickness up to 1.5 μm and a TDD ≤ 5x108 cm−2 was obtained

Tularemia - possible increase and new risk factors

Purpose: Tularemia is a zoonotic disease caused by the bacterium Francisella tularensis. In Europe each year approximately 1200 human cases are reported. Four subspecies are currently known: tularensis (the most virulent form), holarctica (the most widespread form), mediasiatic, and novicida. In Austria Francisella tularensis supsp. holarctica is endemic in the eastern part of the country (Lower Austria and Burgenland), and is known to have a 5-year cycle. Zoonotic transmission from pet species in Europe has only been described in Norway due to a cat bite, as well as after an accidental exposure to the disease while spaying a cat. In 2014 first reports of clinically ill dogs were reported from Norway. Methods & Materials: As hunting with dogs has a long tradition in Austria, and as there are endemic areas for the disease a first serological screening of 80 hunting dogs used in the hunt for European brown hares (Lepus europaeus) was conducted. Results: Of these 80 dogs 5 tested positive for tularemia (6.25%, CI 2.1% - 14%). One positive dog had shown some clinical symptoms, however this female dog also tested positive for Brucella canis. Conclusion: This result shows that dogs not only have contact to the pathogen, but also seroconvert. The occurrence of the disease is thought to increase in the next years due to our changing climate, and this year there is a new hotspot of the disease in Austria (i.e. Salzburg). These changes, as well as the result of this study highlight the need to raise the awareness level of the disease, its possible increase and new risk factors

Mimicry technology : a versatile tool for small RNA suppression

A decade ago the discovery of the target mimicry regulatory process on the activity of a mature microRNA (miRNA) enabled for the first time the customized attenuation of miRNA activity in plants. That powerful technology was named MIMIC and was based on engineering the IPS1 long noncoding transcript to become complementary to the miRNA under study. In order to avoid IPS1 degradation, the predicted miRNA-mediated cleavage site was interrupted by three additional nucleotides giving rise to the so-called MIMIC decoy. Since then, MIMIC technology has been used in several plant species and in basic and translational research. We here provide a detailed guide to produce custom-designed MIMIC decoys to facilitate the study of sRNA functions in plants

In situ effects of selected preservatives on total carbon, nitrogen and metals collected in sediment traps

The concentration and chemical composition of preservative or poison to use in sediment trap studies continue to present an important unresolved question. Past laboratory/field experiments designed to answer this question are difficult to interpret, because so-called analogs have been used instead of actual trap materials, which are compositionally complex. This paper presents our results on the in situ effects of formalin, azide and mercuric ion on material collected in MULTITRAPS set at 100 and 300 m for a period of six days in a coastal environment, and at 150 m for a period of 20.6 days in an oligotrophic environment. Effective preservative/poison concentrations used were predetermined from laboratory tests. Parameters tested for relative effects included particulate retention of C, N and selected trace metals, and the effects of the various preservatives/poisons introduced via diffusion chambers or free in solution on in situ microbial growth. In addition, the potential contaminating role of large, nonsinking zooplankton (i.e., “swimmers”) was investigated. Substantial differences between treatments were observed. Effects were not uniform, and appeared to be parameter-specific. For example, during the short-term deployment (six days), no significant differences in C flux were observed at 100 m, regardless of preservative used. Traps treated with azide yielded significantly lower N values. At 300 m (short-term deployment), and 150 m (long-term deployment), the azide treatments produced the lowest mean C and N values. Conversely, the formalin traps gave the highest C and N values relative to all treatments at these depths. In terms of metals, \u3e70% of both Cd and Mn were lost to the trap solutions, regardless of oceanic area or time deployed, while most of the Fe tended to remain in the particulate phase. Zinc, largely in association with the particulate phase over the six-day deployment, was lost to the density solution during the 20.6-day deployment, while Pb results were intermediate between these extremes. Results of the diffusion chamber experiment indicate that the formalin and mercuric ion treatments were equally effective regardless of the mode of introduction (i.e., diffusion chamber or free in solution). Azide did not appear as effective when introduced via diffusion

A Laboratory Investigation of Supersonic Clumpy Flows: Experimental Design and Theoretical Analysis

We present a design for high energy density laboratory experiments studying the interaction of hypersonic shocks with a large number of inhomogeneities. These ``clumpy'' flows are relevant to a wide variety of astrophysical environments including the evolution of molecular clouds, outflows from young stars, Planetary Nebulae and Active Galactic Nuclei. The experiment consists of a strong shock (driven by a pulsed power machine or a high intensity laser) impinging on a region of randomly placed plastic rods. We discuss the goals of the specific design and how they are met by specific choices of target components. An adaptive mesh refinement hydrodynamic code is used to analyze the design and establish a predictive baseline for the experiments. The simulations confirm the effectiveness of the design in terms of articulating the differences between shocks propagating through smooth and clumpy environments. In particular, we find significant differences between the shock propagation speeds in a clumpy medium compared to a smooth one with the same average density. The simulation results are of general interest for foams in both inertial confinement fusion and laboratory astrophysics studies. Our results highlight the danger of using average properties of inhomogeneous astrophysical environments when comparing timescales for critical processes such as shock crossing and gravitational collapse times.Comment: 7 pages, 6 figures. Submitted to the Astrophysical Journal. For additional information, including simulation animations and the pdf and ps files of the paper with embedded high-quality images, see http://pas.rochester.edu/~wm