Detection Of Apple Stem Grooving Virus In Dormant Apple Trees With Crude Extracts As Templates For One-Step Rt-Pcr

peer reviewe

Formulation of a 1D finite element of heat exchanger for accurate modelling of the grouting behaviour: Application to cyclic thermal loading

This paper presents a comprehensive formulation of a finite element for the modelling of borehole heat exchangers. This work focuses on the accurate modelling of the grouting and the field of temperature near a single borehole. Therefore the grouting of the BHE is explicitly modelled. The purpose of this work is to provide tools necessary to the further modelling of thermo-mechanical couplings. The finite element discretises the classical governing equation of advection-diffusion of heat within a 1D pipe connected to ground nodes. Petrov-Galerkin weighting functions are used to avoid numerical disturbances. The formulation is able to capture highly transient and steady-state phenomena. The proposed finite element is validated with respect to analytical solutions. An example consisting of a 100 m depth U-pipe is finally simulated. A first continuous heating simulation highlights the nonsymmetric distribution of temperature inside and near the borehole. An estimation of the error on the results as a function of the resolution parameters is also carried out. Finally simulations of cyclic thermal loading exhibit the need to take into account all daily variations if the grouting behaviour must be modelled. This is true especially in case of freeze-thaw damaging risk.Geotherwa

ERNEST: a semantic network system for pattern understanding

Niemann H, Sagerer G, Schröder S, Kummert F. ERNEST: a semantic network system for pattern understanding. IEEE transactions on pattern analysis and machine intelligence. 1990;12(9):883-905

Characterization of a resistance-breaking BaYMV isolate from Belgium

A field near Huccorgne, in the province of Liege, Belgium, sown with the winter barley cultivar Express, has been showing slight mosaic symptoms since 1990. As the symptoms were attributed to an infection by barley yellow mosaic virus, experimental plots for an evaluation of the resistance of barley breeding material were established there from 1991 onwards. Symptoms were scored by visual assessment on a range of cultivars including old French varieties, some resistant Japanese material and breeding material from the Plant Breeding Station, Gembloux. The results were compared with those obtained for the same material sown in a field infected with the common BaYMV and BaMMV isolates. The differences in the behavior of some cultivars or lines in the 2 fields were due to the emergence of a virus strain, which, at present, is limited to this particular field. The use of molecular-based detection techniques and partial sequencing have shown that the new viral agent characterized at Huccorgne is a strain of BaYMV.Caractérisation en Belgique d'un isolat du virus de la mosaïque jaune de l'orge surmontant la résistance de l'hôte. En Belgique, un champ d'orge, situé près de Huccorgne, dans la province de Liège et emblavé avec le cultivar Express, montre des symptômes légers de mosaïque depuis 1990. Comme ces symptômes ont été attribués à une infection de la mosaïque jaune de l'orge, des parcelles expérimentales y ont été mises en place depuis 1991 en vue d'évaluer la résistance des orges sélectionnées vis-à-vis de cet isolat. Les symptômes visuels observés sur les différents cultivars mis en place dans cette parcelle sont notés et les résultats obtenus sont comparés à ceux obtenus pour le même matériel semé dans un champ d'essai où les souches communes de Ba YMV et de BaMMV sont présentes. Les différences de comportement de certains cultivars ou lignées entre ces 2 champs sont dues à l'apparition d'un isolat particulier du virus actuellement limitée à ce seul champ. L'utilisation des techniques de détection basées sur les séquences d'acides nucléiques et le séquençage partiel ont montré que le nouvel agent viral caractérisé à Huccorgne est une souche du BaYMV

Interpolation-based reconstruction methods for tomographic imaging in 3D positron emission tomography

Positron Emission Tomography (PET) is considered a key diagnostic tool in neuroscience, by means of which valuable insight into the metabolism function in vivo may be gained. Due to the underlying physical nature of PET, 3D imaging techniques in terms of a 3D measuring mode are intrinsically demanded to assure satisfying resolutions of the reconstructed images. However, incorporating additional cross-plane measurements, which are specific for the 3D measuring mode, usually imposes an excessive amount of projection data and significantly complicates the reconstruction procedure. For this reason, interpolation-based reconstruction methods deserve a thorough investigation, whose crucial parts are the interpolating processes in the 3D frequency domain. The benefit of such approaches is apparently short reconstruction duration, which can, however, only be achieved at the expense of accepting the inaccuracies associated with the interpolating process. In the present paper, two distinct approaches to the realization of the interpolating procedure are proposed and analyzed. The first one refers to a direct approach based on linear averaging (inverse distance weighting), and the second one refers to an indirect approach based on two-dimensional convolution (gridding method). In particular, attention is paid to two aspects of the gridding method. The first aspect is the choice of the two-dimensional convolution function applied, and the second one is the correct discretization of the underlying continuous convolution. In this respect, the geometrical structure named the Voronoi diagram and its computational construction are considered. At the end, results of performed simulation studies are presented and discussed

Automatically Generated Models For Unknown Words

Especially in recognition of spontaneous speech it is necessary to cope with the occurrence of unknown words. We present an approach to unknown word detection which is integrated into a standard HMM speech recognizer. From the context dependent sub-word units, e.g. triphones, that can be found in the training database a generic word model can be derived automatically using the context restrictions to form valid sequences of sub-word units. This generic word model combines automatically derived knowledge about the phonotactics of the language considered with the modelling quality of context dependent acoustic units. Detection of unknown words is achieved adding this model to the recognizer's lexicon. We present results of experiments carried out on a large German spontaneous speech recognition task. INTRODUCTION In the task of automatic speech recognition one major problem is, that only a certain limited vocabulary in the range of 1000 to 20000 words, is available to the recognizer. If ..

A Hybrid System to Detect Hand Orientation in Stereo Images

this paper is an extension of previous research ([1,2]) where monocular images are used as input. This system is further developed to utilize depth information acquired from stereo images. In the next section, the advantages and disadvantages of both techniques and our approach for their combination in a hybrid system are discussed. Section 3 gives a brief overview of the neural and semantic networks used as the starting point for this work