252 research outputs found
Early detection of cobweb disease infection on Agaricus bisporus sporocarps using hyperspectral imaging
From the nineteen-nineties, cobweb disease caused serious losses for the mushroom sector in Europe, in the USA, and in Australia (Fletcher & Gaze, 2008), so it is one of the most notable fungal infections of cultivated white button mushroom (Agaricus bisporus). The aim of this study was to identify cobweb disease (Cladobortyum dendroides) caused cap spotting and brownish rot on the mushroom sporocarp, and to find a proper discrimination method in the case of this infection.Fruiting body samples were divided into 4 groups, a control one and three others treated with different chemicals that are tested against fungal infections. The groups were subdivided into 2 portions and the first was infected with cobweb disease. Images of the caps were recorded and their hyperspectral images were acquired in the wavelength range of 900–1700 nm.On the hyperspectral images infected and healthy areas were selected, on these average spectra differences were found around the known water peaks (1200 and 1450 nm). The spatial distribution of the water content can be used for the detection of the spoilage, because the infected areas showed different reflection values at these water absorption peaks.Support Vector Machine method was applied successfully to discriminate between the infected and control groups and Monte Carlo cross-validation was carried out
Outline analysis of the grapevine (Vitis vinifera L.) berry shape by elliptic Fourier descriptors
Grapevine berry morphology is one of the most important features in table grape production. In this study, berry samples of 46 grapevine accessions were investigated for 3 consecutive years with elliptic Fourier descriptors (EFD) to evaluate shape diversity. Ten reference shapes obtained from the OIV descriptor list were involved and principal component (PC) scores summarizing the EFD's were statistically evaluated with Two way ANOVA and discriminant analysis. The cummulative contribution of the five principal components was 96.83 %. Two way ANOVA revealed that berry shape had high variability within the accessions and years. Based on the linear discriminant analysis, reference shapes were compared to those of the accessions and graphic reconstruction was carried out. OIV references were considered as unknown samples and grouped into the accession classes. Overall correct classification of the accessions into their group was 13.88Â %. Our results showed that EFD together with reference shapes are a powerful method to discribe berry shape and possibly give the future basis of uvometric evaluation of grapevine cultivars
Thermodynamic and Kinetic Stabilities of Al(III) Complexes with N2O3 Pentadentate Ligands
: Al(III) complexes have been recently investigated for their potential use in imaging with positron emission tomography (PET) by formation of ternary complexes with the radioisotope fluorine-18 (18F). Although the derivatives of 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) are the most applied chelators for [Al18F]2+ labelling and (pre)clinical PET imaging, non-macrocyclic, semi-rigid pentadentate chelators having two N- and three O-donor atoms such as RESCA1 and AMPDA-HB have been proposed with the aim to allow room temperature labelling of temperature-sensitive biomolecules. The paucity of stability data on Al(III) complexes used for PET imaging instigated a complete thermodynamic and kinetic solution study on Al(III) complexes with aminomethylpiperidine (AMP) derivatives AMPTA and AMPDA-HB and the comparison with a RESCA1-like chelator CD3A-Bn (trans-1,2-diaminocyclohexane-N-benzyl-N,N',N'-triacetic acid). The stability constant of [Al(AMPDA-HB)] is about four orders of magnitude higher than that of [Al(AMPTA)] and [Al(CD3A-Bn)], highlighting the greater affinity of phenolates with respect to acetate O-donors. On the other hand, the kinetic inertness of the complexes, determined by following the Cu2+-mediated transmetallation reactions in the 7.5-10.5 pH range, resulted in a spontaneous and hydroxide-assisted dissociation slightly faster for [Al(AMPTA)] than for the other two complexes (t1/2 = 4.5 h for [Al(AMPTA)], 12.4 h for [Al(AMPDA-HB)], and 24.1 h for [Al(CD3A-Bn)] at pH 7.4 and 25 °C). Finally, the [AlF]2+ ternary complexes were prepared and their stability in reconstituted human serum was determined by 19F NMR experiments
GRA.LE.D. (GRApevine LEaf Digitalization) Software for the Detection and Graphic Reconstruction of Ampelometric Differences Between Vitis Leaves
Raster graphic ampelometric software was not exclusively developed for the estimation of leaf area,but also for the characterization of grapevine (Viti vinifera L.) leaves. The software was written in C++programming language, using the C++ Builder 2007 for Windows 95-XP and Linux operation systems. Ithandles desktop-scanned images. On the image analysed with the GRA.LE.D., the user has to determine11 points. These points are then connected and the distances between them calculated. The GRA.LE.D.software supports standard ampelometric measurements such as leaf area, angles between the veins andlengths of the veins. These measurements are recorded by the software and exported into plain ASCII textfiles for single or multiple samples. Twenty-two biometric data points of each leaf are identified by theGRA.LE.D. It presents the opportunity to statistically analyse experimental data, allows comparison ofcultivars and enables graphic reconstruction of leaves using the Microsoft Excel Chart Wizard. The GRA.LE.D. was thoroughly calibrated and compared to other widely used instruments and methods such asphoto-gravimetry, LiCor Li3100, WinDIAS2.0 and ImageTool. By comparison, the GRA.LE.D. presentedthe most accurate measurements of leaf area, but the LiCor Li3100 and the WinDIAS2.0 were faster, whilethe photo-gravimetric method proved to be the most time-consuming. The WinDIAS2.0 instrument wasthe least reliable. The GRA.LE.D. is uncomplicated, user-friendly, accurate, consistent, reliable and haswide practical application
Stability of Ampelometric Characteristics of Vitis vinifera L. cv. ‘Syrah’ and ‘Sauvignon blanc’ Leaves: Impact of Within-vineyard Variability and Pruning Method/Bud Load
Historically, grapevine (Vitis vinifera L.) leaf characterisation has been a driving force in the identificationof cultivars. In this study, ampelometric (foliometric) analysis was done on leaf samples collected fromhand-pruned, mechanically pruned and minimally pruned ‘Sauvignon blanc’ and ‘Syrah’ vines to estimatethe impact of within-vineyard variability and a change in bud load on the stability of leaf properties.The results showed that within-vineyard variability of ampelometric characteristics was high within acultivar, irrespective of bud load. In terms of the O.I.V. coding system, zero to four class differences wereobserved between minimum and maximum values of each characteristic. The value of variability of eachcharacteristic was different between the three levels of bud load and the two cultivars. With respect to budload, the number of shoots per vine had a significant effect on the characteristics of the leaf laminae. Singleleaf area and lengths of veins changed significantly for both cultivars, irrespective of treatment, while anglebetween veins proved to be a stable characteristic. A large number of biometric data can be recorded on asingle leaf; the data measured on several leaves, however, are not necessarily unique for a specific cultivar.The leaf characteristics analysed in this study can be divided into two groups according to the response toa change in bud load, i.e. stable (angles between the veins, depths of sinuses) and variable (length of theveins, length of the petiole, single leaf area). The variable characteristics are not recommended to be usedin cultivar identification, unless the pruning method/bud load is known
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