Improvement of the quality of propagation material for organic farming system

The use of organic propagation material is obligatory according to the current EU regulations for organic production. However, frequently difficulties are en-countered regarding the availability, the costs or the quality. In the Netherlands a national research program aims at developing solutions, needed for improving the production of high quality organic propagation material. The main emphasis in the pro-gram is on the model crops cabbage, onion, wheat and potato. Individual projects within the program include epidemiological studies of seed borne dis-eases to develop disease prevention strategies, meth-ods to improve resistance of seeds and seedlings towards pathogens and methods to control silver scurf in seed potatoes, development of multi-spectral analysis and sorting techniques and methods for analysis and improvement of seed vigour. Active involvement of producers and users of the seeds or seed potatoes ensures that the results will be imple-mented in practice. The program also aims at strengthening the international collaboration, amongst others through involvement in international research projects

How well do CMIP5 Earth System Models simulate present climate conditions in Europe and Africa?

This study provides a comprehensive evaluation of seven Earth System Models (ESMs) from the Coupled Model Intercomparison Project Phase 5 in present climate conditions from a downscaling perspective, taking into account the requirements of both statistical and dynamical approaches. ECMWF's ERA-Interim reanalysis is used as reference for an evaluation of circulation, temperature and humidity variables on daily timescale, which is based on distributional similarity scores. To additionally obtain an estimate of reanalysis uncertainty, ERA-Interim's deviation from the Japanese Meteorological Agency JRA-25 reanalysis is calculated. Areas with considerable differences between both reanalyses do not allow for a proper assessment, since ESM performance is sensitive to the choice of reanalysis. For use in statistical downscaling studies, ESM performance is computed on the grid-box scale and mapped over a large spatial domain covering Europe and Africa, additionally highlighting those regions where significant distributional differences remain even for the centered/zero-mean time series. For use in dynamical downscaling studies, performance is specifically assessed along the lateral boundaries of the three CORDEX domains defined for Europe, the Mediterranean Basin and Africa.S.B. would like to thank the CSIC JAE-PREDOC programme for financial support. J.F. and J.M.G. acknowledge financial support from the Spanish R&D&I programme through grants CGL2010-22158-C02 (CORWES project) and CGL2010-21869 (EXTREMBLES project) and from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 243888 (FUME Project).Peer Reviewe

Comments on "global and regional comparison of daily 2-m and 1000-hPa maximum and minimum temperatures in three global reanalyses"

Pitman and Perkins claimed that instantaneous 2-m air temperatures from different reanalysis products largely disagree over widespread regions of the globe and that, because of their much smaller differences, temperatures at 1000 hPa should be preferably used. This comment shows that this claim is based on erroneous results. © 2012 American Meteorological Society.S.B. would like to thank the 'Consejo Superior de Investigaciones Científicas' (CSIC) pre- doctoral program 'JAE-PREDOC' for funding.Peer Reviewe

Beheersing van zilverschurft

Zilverschurftvrij uitgangsmateriaal en een werkelijk schone bewaarplaats zijn dè preventieve maatregelen om uitbreiding van de ziekte tegen te gaan. Daarnaast gaan koel (3°C) en droog bewaren heel effectief uitbreiding tegen. In de praktijk is er vaak wel wat infectie op het geoogste materiaal, waarna de schimmel zich tijdens de bewaring snel kan uitbreiden. Gebruik van natuurlijke middelen zoals etherische oliën kan helpen uitbreiding tegen te gaan. Onderzoek heeft laten zien dat als het uitgangsmateriaal toch besmet is, het juist zinvol is om volledig met zilverschurft overgroeid pootgoed te gebruiken. Dit blijkt minder besmetting te geven in de nateelt

Energetics and mechanism of drug transport mediated by the lactococcal multidrug transporter LmrP

The gene encoding the secondary multidrug transporter LmrP of Lactococcus lactis was heterologously expressed in Escherichia coli. The energetics and mechanism of drug extrusion mediated by LmrP were studied in membrane vesicles of E. coli, LmrP-mediated extrusion of tetraphenyl phosphonium (TPP+) from right-side-out membrane vesicles and uptake of the fluorescent membrane probe 1-[4-(trimethylamino)phenyl]-6-phenylhexa-1,3,5-triene (TMA-DPH) into inside-out membrane vesicles are driven by the membrane potential (Delta psi) and the transmembrane proton gradient (Delta pH), pointing to an electrogenic drug/proton antiport mechanism, Ethidium bromide, a substrate for LmrP, inhibited the LmrP-mediated TPP+ extrusion from right-side-out membrane vesicles, showing that LmrP is capable of transporting structurally unrelated drugs. Kinetic analysis of LmrP-mediated TMA-DPH transport revealed a direct relation between the transport rate and the amount of TMA-DPH associated with the cytoplasmic leaflet of the lipid bilayer. This observation indicates that drugs are extruded from the inner leaflet of the cytoplasmic membrane into the external medium. This is the first report that shows that drug extrusion by a secondary multidrug resistance (MDR) transporter occurs by a ''hydrophobic vacuum cleaner'' mechanism in a similar way as was proposed for the primary lactococcal MDR transporter, LmrA