UK and EU policy for approval of pesticides suitable for organic systems: Implications for Wales

This study was commissioned by the Welsh Assembly Government (WAG) to review the pesticide approval system in the UK and Europe as far as it affects the use of substances and techniques for crop protection by organic producers in Wales. WAG considers it important that the UK pesticide approval system does not present unnecessary barriers to the development of organic production in Wales. Key Recommendations and scope for further work · WAG should work with the Pesticides Safety Directorate to ensure that the development of pesticide regulatory policy at both National and European level takes full account of the needs of both conventional and organic agriculture and horticulture in the UK. · There is scope for WAG to support the development of a National Pesticide Policy so that regulatory and commercial barriers impeding the development of organic pesticides are minimised. Not only could greater availability of ‘organic pesticides’ have a significant impact on organic production in Wales but there could be important implications for conventional horticulture systems and the use of alternatives to conventional pesticides. · One important regulatory barrier to the registration of ‘organic pesticides’ is the MRL requirement(s) for their approval and this needs to be resolved. Suitable analytical techniques are required to determine firstly whether these substances result in residues, and secondly to identify the breakdown and residue pathways. So far, this issue has not received the attention of any EU Member State. · According to the proposed framework for the 4th Stage Review of EU Pesticides Directive 91/414, notifiers are required to produce a dossier, at their own expense, covering characterisation, human toxicity, ecotoxicity efficacy and other relevant data. The Review includes specific provision for companies notifying the same substance to submit a shared dossier. This will help those businesses (many of which are relatively small companies) to save on the high cost of producing the dossiers. It will also aid the Commission since it will reduce the number of dossiers that have to be considered, and ensure that all the available data is included. WAG should encourage and support the production of collective dossiers; although as yet there is no indication of how this will be done in practice, and further details from the Commission are awaited. · This study has concluded that access to a wider range of ‘organically acceptable pesticides’ would not have a dramatic impact on organic production in Wales. However, in developing an integrated organic policy, WAG should continue to address the pesticides issue. Some of the methods of pest & disease control in organic systems are either physical or multi-cellular e.g. micro-organisms used as biocontrol agents. WAG agri environment policy may provide a vehicle to promote these techniques much more actively. Further, it is important to recognise that while Wales alone is too small to have a major impact on commercial and regulatory pressures, WAG can have an impact by working pro-actively with others to make progress. · There are no published EU or national Member State criteria that can be used to evaluate the acceptability of pesticide substances for organic production. Identifying such criteria and promoting their acceptance at EU level and nationally would allow more active substances to be made available. WAG should work with PSD and others to identify appropriate criteria. · The specific provisions of Article 7 in Annex 2(b) of the Organic Regulation (2092/91) place potential barriers to the adoption of organically acceptable substances for crop protection. There are a number of potentially useful substances currently not included in the Organic Regulation e.g. potassium bicarbonate. WAG should work with PSD and others to identify such substances and support the production of appropriate dossiers. WAG could also encourage further dialogue between the organic sector and Defra to identify amendments in the Organic Regulations to facilitate the inclusion of new pesticides. · Organic pest and disease management is not just a question of inputs but it also relies crucially on advice and extension through initiatives such as Farming Connect and the work of Organic Centre Wales. Long-term commitment to supporting on going advice and extension activities is vital to promote and disseminate best practice in Welsh agriculture and horticulture. · Organic horticulture, vegetable and fruit production systems are particularly sensitive to pest and disease management. Successful control of pests, diseases (and weeds) in these sectors can be critical to the business, and is not assured even when all husbandry and management methods have been effectively applied. Consequently, the use of organically acceptable crop protection methods resulting from future developments (e.g. biopesticides, biological control agents) could have an important role in pest and disease management in these sectors. Both organic and conventional producers in Wales could benefit from having these options available to them and WAG could encourage the adoption of these approaches through appropriate Technology Transfer activities. · The way in which such substances will be regulated at a European level in future is evolving as the review of the Pesticide Directive 91/414 EEC enters the 4th Stage. This stage of the review includes (amongst others) those substances permitted for use in organic production. The guidance documents for the evaluation of applications on plant protection products made from plants or plant extracts and from chemical substances are currently at the draft stage. The response of the Pesticide Safety Directorate and Defra to these developments is not yet clear but this provides an excellent opportunity for WAG to have an input at an early stage in the review process

Release of Ca2+ and Mg2+ from yeast mitochondria is stimulated by increased ionic strength

BACKGROUND: Divalent cations are required for many essential functions of mitochondrial metabolism. Yet the transporters that mediate the flux of these molecules into and out of the mitochondrion remain largely unknown. Previous studies in yeast have led to the molecular identification of a component of the major mitochondrial electrophoretic Mg(2+ )uptake system in this organism as well as a functional mammalian homolog. Other yeast mitochondrial studies have led to the characterization of an equilibrative fatty acid-stimulated Ca(2+ )transport activity. To gain a deeper understanding of the regulation of mitochondrial divalent cation levels we further characterized the efflux of Ca(2+ )and Mg(2+ )from yeast mitochondria. RESULTS: When isolated mitochondria from the yeast Saccharomyces cerevisiae were suspended in a salt-based suspension medium, Ca(2+ )and Mg(2+ )were released from the matrix space. Release did not spontaneously occur in a non-ionic mannitol media. When energized mitochondria were suspended in a mannitol medium in the presence of Ca(2+ )they were able to accumulate Ca(2+ )by the addition of the electrogenic Ca(2+ )ionophore ETH-129. However, in a KCl or choline Cl medium under the same conditions, they were unable to retain the Ca(2+ )that was taken up due to the activation of the Ca(2+ )efflux pathway, although a substantial membrane potential driving Ca(2+ )uptake was maintained. This Ca(2+ )efflux was independent of fatty acids, which have previously been shown to activate Ca(2+ )transport. Endogenous mitochondrial Mg(2+ )was also released when mitochondria were suspended in an ionic medium, but was retained in mitochondria upon fatty acid addition. When suspended in a mannitol medium, metal chelators released mitochondrial Mg(2+), supporting the existence of an external divalent cation-binding site regulating release. Matrix space Mg(2+ )was also slowly released from mitochondria by the addition of Ca(2+), respiratory substrates, increasing pH, or the nucleotides ATP, ADP, GTP, and ATP-gamma-S. CONCLUSION: In isolated yeast mitochondria Ca(2+ )and Mg(2+ )release was activated by increased ionic strength. Free nucleotides, metal ion chelators, and increased pH also stimulated release. In yeast cells this release is likely an important mechanism in the regulation of mitochondrial matrix space divalent cation concentrations

Loss of NAD(H) from swollen yeast mitochondria

BACKGROUND: The mitochondrial electron transport chain oxidizes matrix space NADH as part of the process of oxidative phosphorylation. Mitochondria contain shuttles for the transport of cytoplasmic NADH reducing equivalents into the mitochondrial matrix. Therefore for a long time it was believed that NAD(H) itself was not transported into mitochondria. However evidence has been obtained for the transport of NAD(H) into and out of plant and mammalian mitochondria. Since Saccharomyces cerevisiae mitochondria can directly oxidize cytoplasmic NADH, it remained questionable if mitochondrial NAD(H) transport occurs in this organism. RESULTS: NAD(H) was lost more extensively from the matrix space of swollen than normal, condensed isolated yeast mitochondria from Saccharomyces cerevisiae. The loss of NAD(H) in swollen organelles caused a greatly decreased respiratory rate when ethanol or other matrix space NAD-linked substrates were oxidized. Adding NAD back to the medium, even in the presence of a membrane-impermeant NADH dehydrogenase inhibitor, restored the respiratory rate of swollen mitochondria oxidizing ethanol, suggesting that NAD is transported into the matrix space. NAD addition did not restore the decreased respiratory rate of swollen mitochondria oxidizing the combination of malate, glutamate, and pyruvate. Therefore the loss of matrix space metabolites is not entirely specific for NAD(H). However, during NAD(H) loss the mitochondrial levels of most other nucleotides were maintained. Either hypotonic swelling or colloid-osmotic swelling due to opening of the yeast mitochondrial unspecific channel (YMUC) in a mannitol medium resulted in decreased NAD-linked respiration. However, the loss of NAD(H) from the matrix space was not mediated by the YMUC, because YMUC inhibitors did not prevent decreased NAD-linked respiration during swelling and YMUC opening without swelling did not cause decreased NAD-linked respiration. CONCLUSION: Loss of endogenous NAD(H) from isolated yeast mitochondria is greatly stimulated by matrix space expansion. NAD(H) loss greatly limits NAD-linked respiration in swollen mitochondria without decreasing the NAD-linked respiratory rate in normal, condensed organelles. NAD addition can totally restore the decreased respiration in swollen mitochondria. In live yeast cells mitochondrial swelling has been observed prior to mitochondrial degradation and cell death. Therefore mitochondrial swelling may stimulate NAD(H) transport to regulate metabolism during these conditions

Technical Reference: Using Lightning Location in the Wildland Fire Assessment System

Location of the ground position of lightning discharges has been possible for several years. A technique for using ignition probability calculations together with lightning location data results in maps that are useful to fire managers in making decisions on timescales from historical to real-time. These maps, part of the Wildland Fire Assessment System, will aid fire managers in assessing the potential that lightning will result in reportable fires. The maps are generated using ignition probability based on duff depth, fuel moisture, and fuel type. To match fire potential classes, ignition probabilities are classified into ignition potential classes of low. medium, high, very high, and extreme. Possible benefits are savings in time, fire suppression costs, and perhaps even lives

Foraging ecology of a generalist predator the female New Zealand fur seal

Copyright © 2002 Inter-Research.Abstract: This study examined how diet, foraging location and diving behaviour of female New Zealand fur seals Arctocephalus forsteri at Otago Peninsula, New Zealand (45°52¹S, 170°44¹E), varied in relation to prey abundance among seasons in 1994 and 1995. Time-depth recorders measured the diving behaviour of 24 lactating female fur seals, during summer, autumn or winter of 1994 and summer and autumn of 1995. Foraging locations were obtained by deploying satellite transmitters in summer, autumn and winter of 1994 only. Estimated biomass of prey items was determined from 690 scats and 166 regurgitates collected over summer, autumn and winter of both years, and compared with abundance data from research trawls in the same area. Foraging trip duration increased during the cooler seasons. Female fur seals showed a clear bout structure in dive behaviour, with the relative proportion of 3 main bout types (Long, Shallow, Deep) varying with season. Time between bouts (IBI) and bout duration varied with season, suggesting that prey distribution and prey encounter rate also varied. Linear discriminant analysis of the dive and foraging trip characteristics of individual females demonstrated clear seasonal differences. Females foraged on or near the continental slope in summer and farther offshore in autumn. Satellite telemetry locations and diet suggest principally inshore foraging during winter. Fur seals ate predominantly arrow squid Nototodarus sloanii during summer and autumn of both years, although fish, particularly myctophids, were persistent in the diet. Arrow squid were less common in winter when diet was more varied, and an inshore, benthic fish, ahuru Auchenoceros punctatus was dominant. There was no relationship between the annual changes in abundance of major prey species as measured by research trawls and their occurrence in seal diet. Overall, changes in dive behaviour may reflect changes in prey selection as prey abundance and availability change among seasons.Robert G. Harcourt, Corey J. A. Bradshaw, Kate Dickson, Lloyd S. Davi

Sensitivity Analysis of a Comprehensive Model for a Miniature-Scale Linear Compressor for Electronics Cooling

A comprehensive model of a linear compressor for electronics cooling was previously presented by Bradshaw et al. (2011). The current study expands upon this work by first developing methods for predicting the resonant frequency of a linear compressor and for controlling its piston stroke. Key parameters governing compressor performance – leakage gap, eccentricity, and piston geometry – are explored using a sensitivity analysis. It is demonstrated that for optimum performance, the leakage gap and frictional parameters should be minimized. In addition, the ratio of piston stroke to diameter should not exceed a value of one to minimize friction and leakage losses, but should be large enough to preclude the need for an oversized motor. An improved linear compressor design is proposed for an electronics cooling application, with a predicted cooling capacity of 200 W a cylindrical compressor package size of diameter 50.3 mm and length 102 mm

Laser-controlled fluorescence in two-level systems

The ability to modify the character of fluorescent emission by a laser-controlled, optically nonlinear process has recently been shown theoretically feasible, and several possible applications have already been identified. In operation, a pulse of off-resonant probe laser beam, of sufficient intensity, is applied to a system exhibiting fluorescence, during the interval of excited- state decay following the initial excitation. The result is a rate of decay that can be controllably modified, the associated changes in fluorescence behavior affording new, chemically specific information. In this paper, a two-level emission model is employed in the further analysis of this all-optical process; the results should prove especially relevant to the analysis and imaging of physical systems employing fluorescent markers, these ranging from quantum dots to green fluorescence protein. Expressions are presented for the laser-controlled fluorescence anisotropy exhibited by samples in which the fluorophores are randomly oriented. It is also shown that, in systems with suitably configured electronic levels and symmetry properties, fluorescence emission can be produced from energy levels that would normally decay nonradiatively. © 2010 American Chemical Society