Optimisation of downy mildew (Plasmopara viticola) control in organic viticulture with low copper doses, new copper formulations and plant strengtheners, results of four years of on farm research

In three different wine growing regions in Germany, due to weather and infection conditions several fungicide (copper formulations) and plant strengtheners (Myco-Sin VIN®, Kendal®, Frutogard ®) applications against downy mildew are required in order to obtain satisfactory disease control. Results of the four years of on farm trials confirmed good efficacy of the copper based substances like copper hydroxide, partly in combination with two or three applications of potassium phosphonate, new copper-hydroxide formulation or copper oxychloride used in a low doses of copper and alternative products like Myco-Sin-VIN® (clay with high aluminium content) in combination with Kendal® ( plant extract)

Fast alternating fitting methods for trigonometric curves for large data sets

This paper discusses and develops new methods for fitting trigonometric curves, such as circles, ellipses, and dumbbells, to data points in the plane. Available methods for fitting circles or ellipses are very sensitive to outliers in the data, and are time consuming when the number of data points is large. The present paper focuses on curve fitting methods that are attractive to use when the number of data points is large. We propose a direct method for fitting circles, and two iterative methods for fitting ellipses and dumbbell curves based on trigonometric polynomials. These methods efficiently minimize the sum of the squared geometric distances between the given data points and the fitted curves. In particular, we are interested in detecting the general shape of an object such as a galaxy or a nebula. Certain nebulae, for instance, the one shown in the experiment section, have a dumbbell shape. Methods for fitting dumbbell curves have not been discussed in the literature. The methods developed are not very sensitive to errors in the data points. The use of random subsampling of the data points to speed up the computations also is discussed. The techniques developed in this paper can be applied to fitting other kinds of curves as well

Design of photonic crystal microcavities for cavity QED

We discuss the optimization of optical microcavity designs based on 2D photonic crystals for the purpose of strong coupling between the cavity field and a single neutral atom trapped within a hole. We present numerical predictions for the quality factors and mode volumes of localized defect modes as a function of geometric parameters, and discuss some experimental challenges related to the coupling of a defect cavity to gas-phase atoms.Comment: 12 pages, 16 figure

Large-scale regression with non-convex loss and penalty

We describe a computational method for parameter estimation in linear regression, that is capable of simultaneously producing sparse estimates and dealing with outliers and heavy-tailed error distributions. The method used is based on the image restoration method proposed in Huang et al. (2017) [13]. It can be applied to problems of arbitrary size. The choice of certain parameters is discussed. Results obtained for simulated and real data are presented

Untersuchungen des BÖL-Verbundprojektes zur Kupferminimierung im ökologischen Weinbau

The development of sustainable and economically feasible strategies to get an effec-tual control of downy mildew on grapes (Plasmopara viticola) with less than 3 kg/(ha*a) of copper to avoid further environmental risks is the intention of this project. Due to harmful effects on the natural environment, copper applications are under considera-tion. Therefore, in this four-year-project first of all test products are screened under greenhouse conditions on potted vines. Thereafter the best test agents are studied in organically managed test vineyards. Finally the selected strategies are tested under practical conditions on organically managed vineyards. Beyond these examinations a close link between wineries and research is given by SME and consultant partners. The results indicate that plant extracts, finely ground stones and new copper formula-tions could probably serve as plant resistance improvers and plant protection prod-ucts, respectively, to prevent attacks of P. viticola. Moreover, it was possible to select prosperous agents and strategies for the growing period 2007. These were agents of the substance categories “new copper formulations”, “plant extracts” and “finely ground stones”. Regarding the results of three growing periods, the project will provide effective and economically feasible alternatives for copper applications in order to deliver sustainable approaches for P. viticola control in practise

Wave function recombination instability in cold atom interferometers

Cold atom interferometers use guiding potentials that split the wave function of the Bose-Einstein condensate and then recombine it. We present theoretical analysis of the wave function recombination instability that is due to the weak nonlinearity of the condensate. It is most pronounced when the accumulated phase difference between the arms of the interferometer is close to an odd multiple of PI and consists in exponential amplification of the weak ground state mode by the strong first excited mode. The instability exists for both trapped-atom and beam interferometers.Comment: 4 pages, 5 figure

Feasibility of detecting single atoms using photonic bandgap cavities

We propose an atom-cavity chip that combines laser cooling and trapping of neutral atoms with magnetic microtraps and waveguides to deliver a cold atom to the mode of a fiber taper coupled photonic bandgap (PBG) cavity. The feasibility of this device for detecting single atoms is analyzed using both a semi-classical treatment and an unconditional master equation approach. Single-atom detection seems achievable in an initial experiment involving the non-deterministic delivery of weakly trapped atoms into the mode of the PBG cavity.Comment: 11 pages, 5 figure

Multi Mode Interferometer for Guided Matter Waves

We describe the fundamental features of an interferometer for guided matter waves based on Y-beam splitters and show that, in a quasi two-dimensional regime, such a device exhibits high contrast fringes even in a multi mode regime and fed from a thermal source.Comment: Final version (accepted to PRL

In vivo imaging and quantitative analysis of leukocyte directional migration and polarization in inflamed tissue

Directional migration of transmigrated leukocytes to the site of injury is a central event in the inflammatory response. Here, we present an in vivo chemotaxis assay enabling the visualization and quantitative analysis of subtype-specific directional motility and polarization of leukocytes in their natural 3D microenvironment. Our technique comprises the combination of i) semi-automated in situ microinjection of chemoattractants or bacteria as local chemotactic stimulus, ii) in vivo near-infrared reflected-light oblique transillumination (RLOT) microscopy for the visualization of leukocyte motility and morphology, and iii) in vivo fluorescence microscopy for the visualization of different leukocyte subpopulations or fluorescence-labeled bacteria. Leukocyte motility parameters are quantified off-line in digitized video sequences using computer-assisted single cell tracking. Here, we show that perivenular microinjection of chemoattractants [macrophage inflammatory protein-1alpha (MIP-1alpha/Ccl3), platelet-activating factor (PAF)] or E. coli into the murine cremaster muscle induces target-oriented intravascular adhesion and transmigration as well as polarization and directional interstitial migration of leukocytes towards the locally administered stimuli. Moreover, we describe a crucial role of Rho kinase for the regulation of directional motility and polarization of transmigrated leukocytes in vivo. Finally, combining in vivo RLOT and fluorescence microscopy in Cx3CR1(gfp/gfp) mice (mice exhibiting green fluorescent protein-labeled monocytes), we are able to demonstrate differences in the migratory behavior of monocytes and neutrophils.Taken together, we propose a novel approach for investigating the mechanisms and spatiotemporal dynamics of subtype-specific motility and polarization of leukocytes during their directional interstitial migration in vivo