527 research outputs found
Grapevine cultivar Müller-Thurgau and its true to type descent
Ampelographic investigations supported by molecular marker analysis were used to reevaluate the progenitors of the grapevine cv. Muller-Thurgau. From these studies we conclude Muller-Thurgau to be a descent of the offspring of a Riesling and Madeleine Royale (syn. Konigliche Magdalenentraube) hybridisation. The results reveal the importance of true to typeness of the grapevine varieties used for genotyping, parentage analyses, etc
Powdery mildew responsive genes of resistant grapevine cultivar 'Regent'
The ascomycete Erysiphe necator causes powdery mildew disease of grapevine, a disastrous infection which is commonly defeated with multiple fungicide applications in viticulture. Breeding for natural resistance of quality grapes (Vitis vinifera) is thus a major aim of current efforts. The cultivar 'Regent' is resistant to powdery mildew due to an introgression from an American Vitis sp. resistance donor. To identify key regulatory elements in defense responses of 'Regent' we performed transcript analyses after challenging with E. necator inoculation in comparison with a susceptible grapevine. A set of genes selected from preliminary microarray hybridization results were investigated by RT-qPCR. The data indicate an important role of transcription factors MYB15, WRKY75, WRKY33, WRKY7, ethylene responsive transcription factors ERF2 and ERF5 as well as a CZF1/ZFAR transcripton factor in regulating the early defense when the fungus starts the interaction with its host by the formation of haustoria
BAT (Berry Analysis Tool): A high-throughput image interpretation tool to acquire the number, diameter, and volume of grapevine berries
QTL-analysis (quantitative trait loci) and marker development rely on efficient phenotyping techniques. Objectivity and precision of a phenotypic data evaluation is crucial but time consuming. In the present study a high-throughput image interpretation tool was developed to acquire automatically number, size, and volume of grape berries from RGB (red-green-blue) images. Individual berries of one cluster were placed on a black construction (300 x 300 mm) to take a RGB image from the top. The image interpretation of one dataset with an arbitrary number of images runs automatically using the BAT (Berry-Analysis-Tool) developed in MATLAB. For validation of results, the number of berries was counted and their size was measured using a digital calliper. A measuring cylinder was used to determine reliably the berry volume by displacement of water. All placed berries could be counted by BAT 100 % correctly. Manual ratings compared with BAT ratings showed strong correlation of r = 0.96 for mean berry diameter/image and r = 0.98 for cluster volume.
Initial steps for high-throughput phenotyping in vineyards
The evaluation of phenotypic characters of grapevines is required directly in vineyards and is strongly limited by time, costs and the subjectivity of person in charge. Sensor-based techniques are prerequisite in order to allow non-invasive phenotyping of individual plant traits, to increase the quantity of object records and to reduce error variation. Thus, a Prototype-Image-Acquisition-System (PIAS) was developed for semi-automated capture of geo-referenced images in an experimental vineyard. Different strategies were tested for image interpretation using MATLAB®. The interpretation of images from the vineyard with real background is more practice-oriented but requires the calculation of depth maps. Different image analysis tools were verified in order to enable contactless and non-invasive detection of bud burst and quantification of shoots at an early developmental stage (BBCH 10) and enable fast and accurate determination of the grapevine berry size at BBCH 89. Depending on the time of image acquisition at BBCH 10 up to 94 % of green shoots were visible in images. The mean berry size (BBCH 89) was recorded non-invasively with a precision of 1 mm.
Effects of canopy architecture and microclimate on grapevine health in two training systems
Semi minimal pruned hedge (SMPH) is a time and cost saving grapevine training system, which is becoming more and more popular in German viticulture. In this study we compared the canopy architecture and its effect on the microclimate of SMPH trained grapevines with those of plants trained in vertical shoot positioning (VSP). We detected a 3 % points higher humidity and a 0.9 °C lower mean temperature within the complex canopy architecture of SMPH trained vines compared to VSP. Moreover, we investigated the influence of the differing microclimate, canopy and bunch architecture, as well as berry skin characteristics of the two training systems on the incidence of the major fungal grapevine diseases Downy Mildew, Powdery Mildew and Botrytis Bunch Rot, as well as on the occurrence and damage of the invasive insect pest Drosophila suzukii. We demonstrate that SMPH trained vines can be more susceptible to Downy Mildew and Powdery Mildew than VSP trained vines. The incidence of Botrytis Bunch Rot can be higher in the latter system, even if berry skin characteristics are the same in both training systems. We trapped a higher number of D. suzukii in SMPH canopies, however no increased berry damage was observed. Based on our results we recommend a more adapted plant protection regime for SMPH trained vines due to their higher susceptibility to the major fungal diseases. Furthermore, we propose a combination of SMPH and fungal resistant grapevine cultivars, e.g. 'Reberger', to achieve a more competitive, environmentally friendly and high quality grapevine production
Inferring the Scale of OpenStreetMap Features
International audienceTraditionally, national mapping agencies produced datasets and map products for a low number of specified and internally consistent scales, i.e. at a common level of detail (LoD). With the advent of projects like OpenStreetMap, data users are increasingly confronted with the task of dealing with heterogeneously detailed and scaled geodata. Knowing the scale of geodata is very important for mapping processes such as for generalization of label placement or land-cover studies for instance. In the following chapter, we review and compare two concurrent approaches at automatically assigning scale to OSM objects. The first approach is based on a multi-criteria decision making model, with a rationalist approach for defining and parameterizing the respective criteria, yielding five broad LoD classes. The second approach attempts to identify a single metric from an analysis process, which is then used to interpolate a scale equivalence. Both approaches are combined and tested against well-known Corine data, resulting in an improvement of the scale inference process. The chapter closes with a presentation of the most pressing open problem
Antiferromagnetic Ising model in a triangular vortex lattice of quantum fluids of light
[EN] Vortices are topologically distinctive objects appearing as phase twists in coherent fields of optical beams and Bose-Einstein condensates. Structured networks and artificial lattices of coupled vortices could offer a powerful platform to study and simulate interaction mechanisms between constituents of condensed matter systems, such as antiferromagnetic interactions, by replacement of spin angular momentum with orbital angular momentum. Here, we realize such a platform using a macroscopic quantum fluid of light based on exciton-polariton condensates. We imprint all-optical hexagonal lattice that results into a triangular vortex lattice, with each cell having a vortex of charge l = +/- 1. We reveal that pairs of coupled condensates spontaneously arrange their orbital angular momentum antiparallel, implying a form of artificial orbital "antiferromagnetism." We discover that correlation exists between the emergent vortex patterns in triangular condensate lattices and the low-energy solutions of the corresponding antiferromagnetic Ising system. Our study offers a path toward spontaneously ordered vortex arrays with nearly arbitrary configurations and controlled couplings.This work was supported by Russian Science Foundation (RSF) grant no. 21- 72- 00088. H.S. acknowledges Icelandic Research Fund (Rannis) grant no. 239552- 051. C.M. acknowledges support from the Spanish government via grant PID2021- 124618NB- C21 by MCIN/AEI/10.13039/501100011033 and "ERDF: a way of making Europe" of the European Union and the Generalitat Valenciana PROMETEO/2021/082. Y.V.K. acknowledges funding by the research project FFUU- 2024- 0003 of the Institute of Spectroscopy of the Russian Academy of Sciences.Alyatkin, S.; Milián Enrique, C.; Kartashov, YV.; Sitnik, KA.; Gnusov, I.; Töpfer, JD.; Sigurosson, H.... (2024). Antiferromagnetic Ising model in a triangular vortex lattice of quantum fluids of light. Science Advances. 10(34). https://doi.org/10.1126/sciadv.adj1589103
Inductive localization accuracy of a passive 3-D coil in an Industry 4.0 environment
In this paper a localization system of a passive 3-D coil is
proposed and signal uncertainties due to the 3-D coil's arbitrary orientation
are analyzed. The 3-D coil is excited by an alternating primary magnetic
field. Geometrically distributed pick-up coils measure the 3-D coil's
secondary field. By means of a simulated look-up table that assigns expected
voltages from the pick-up coils to the positions of the 3-D coil, the
position of the 3-D coil is deduced by a least-squares approach. A basic
assumption is that the secondary field is invariant to the orientation of the
3-D coil. This allows a reduction of the computational effort for the look-up
table generation and the table search during the localization phase since for
each position the field distribution for only one orientation has to be
calculated. However, the assumption of invariance to rotation is only valid
for a dipole model. In this paper we investigate the localization error
introduced by this assumption when using 3-D coils with a geometric extent in
an inhomogeneous primary field. Optimized localization methods that decrease
the statistical error are proposed. The theoretical results are verified with
measurements conducted on a laboratory system.</p
Experimental analysis on image resolution of quantum imaging with undetected light through position correlations
Image resolution of quantum imaging with undetected photons is governed by
the spatial correlations existing between the photons of a photon pair that has
been generated in a nonlinear process. These correlations allow for obtaining
an image of an object with light that never interacted with that object.
Depending on the imaging configuration, either position or momentum
correlations are exploited. We hereby experimentally analyse how the crystal
length and pump waist affect the image resolution when using position
correlations of photons that have been generated via spontaneous parametric
down conversion in a nonlinear interferometer. Our results support existing
theoretical models for the dependency of the resolution on the crystal length.
In addition, we probe the resolution of our quantum imaging scheme for varying
pump waists over one order of magnitude. This analysis reveals the intricate
dependency of the resolution on the strength of the correlations within the
biphoton states for parameter combinations in which the crystal lengths are
much larger than the involved photon wavelengths. We extend the existing models
in this parameter regime to properly take nontrivial effects of finite pump
waists into account and demonstrate that they match the experimental results.Comment: 28 pages, 9 figure
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