Terrain classification by cluster analisys

The digital terrain modelling can be obtained by different methods belonging to two principal categories: deterministic methods (e.g. polinomial and spline functions interpolation, Fourier spectra) and stochastic methods (e.g. least squares collocation and fractals, i.e. the concept of selfsimilarity in probability). To reach good resul ts, both the fi rst and the second methods need same initial suitable information which can be gained by a preprocessing of data named terrain classification. In fact, the deterministic methods require to know how is the roughness of the terrain, related to the density of the data (elevations, deformations, etc.) used for the i nterpo 1 at ion, and the stochast i c methods ask for the knowledge of the autocorrelation function of the data. Moreover, may be useful or very necessary to sp 1 it up the area under consideration in subareas homogeneous according to some parameters, because of different kinds of reasons (too much large initial set of data, so that they can't be processed togheter; very important discontinuities or singularities; etc.). Last but not least, may be remarkable to test the type of distribution (normal or non-normal) of the subsets obtained by the preceding selection, because the statistical properties of the normal distribution are very important (e.g., least squares linear estimations are the same of maximum likelihood and minimum variance ones)

Photogrammetric determination of discrepancies between actual and planned position of dental implants

The paper describes the design and testing of a photogrammetric measurement protocol set up to determine the discrepancies between the planned and actual position of computer-guided template-based dental implants. Two moulds with the implants positioned in pre- and post- intervention are produced and separately imaged with a highly redundant block of convergent images; the model with the implants is positioned on a steel frame with control points and with suitable targets attached. The theoretical accuracy of the system is better than 20 micrometers and 0.3–0.4° respectively for positions of implants and directions of implant axes. In order to compare positions and angles between the planned and actual position of an implant, coordinates and axes directions are brought to a common reference system with a Helmert transformation. A procedure for comparison of positions and directions to identify out-of-tolerance discrepancies is presented; a numerical simulation study shows the effectiveness of the procedure in identifying the implants with significant discrepancies between pre- and post- intervention

Desulfo-glucosinolate sulfotransferases isolated from several Arabidopsis thaliana ecotypes differ in their sequence and enzyme kinetics

The goal was to investigate whether the diverse glucosinolate (Gl) profiles described for different Arabidopsis thaliana (L.) Heynh. ecotypes are at least partially shaped by the kinetic properties of sulfotransferases (SOTs) (EC 2.8.2.-) catalyzing the final step in Gl core structure biosynthesis. This study focuses on only one of the three SOTs that contribute to Gl biosynthesis. Homologues of AtSOT18 proteins were characterized, which was inspired by earlier findings on SOTs from ecotypes Col-0 and C24 differing in two amino acids (aa) and specific enzyme activities. Could there be a correlation of AtSOT18 enzyme activities and differences in Gl profiles between the ecotypes? SOT18 sequences from eight Arabidopsis ecotypes with highly diverse Gl patterns differed in two aa at various positions in the protein sequence. The SOT18 sequence from Col-0 showed the highest similarity to the largest number of other sequences in the alignment. The small differences in the primary sequence lead to important structural changes in secondary and tertiary structure that might be the key of different kinetic activities towards a broad range of substrates. All recombinant AtSOT18 proteins showed low substrate specificity with an indolic Gl, while the specificity for aliphatic substrates varied. There is no correlation in the kinetic behavior with the major ds-Gl contents or with the ratio of C-3/C-4 ds-Gl in the respective ecotype. Therefore, is it unlikely that ds-Gl AtSOT18 proteins play a major role in shaping the Gl profile in Arabidopsis

A monte carlo simulation study on the dome effect

A dome-shape deformation has been found to affect the photogrammetric surface reconstruction in several real and simulated experiments. Its origin has been recognised in inaccurate estimation of the camera parameters and many papers already concentrated on conditions to avoid its development, especially as far as block design is concerned. This paper presents a Monte Carlo simulation to investigate surface reconstruction elevation errors in UAV (Unmanned Aerial Vehicle) photogrammetric blocks. The simulation tests are designed to find out the effect of block shape, camera axis inclination, side-lap, cross strips addition and block control by GCP or GNSS-assisted on the extent of the deformations. The main findings are: i) that GNSS-assisted blocks are generally more robust compared to GCP-controlled ones; ii) that, in GNSS-assisted blocks, unless a mix of nadiral and inclined strips is present, at least one fixed GCP must be provided; iii) that cross strip can conveniently be slimmed to save flight time and processing time; iv) that the effectiveness of GNSS deteriorate as the block shape slims out

Landslide monitoring by fixed-base terrestrial stereo-photogrammetry

Photogrammetry has been used since long to periodically control the evolution of landslides; however, true monitoring is reserved to robotic total stations and ground based InSAR systems, capable of high frequency, high accurate 24h/day response. This paper presents the first results of a fixed terrestrial stereo photogrammetric system developed to monitor shape changes of the scene. The system is made of two reflex cameras, each contained in a sealed box with a control computer that periodically acquires an image and send it to a host computer; once an image pair is received from the two cameras, the DSM of the scene is generated by image correlation and made available for archiving or analysis. The system has been installed and is being tested on the Mont de la Saxe landslide, where several monitoring system are active. Some instability of the camera attitude has been noticed and is corrected with an automated procedure. First comparisons with InSAR data show a good agreement

Landslide monitoring by fixed-base terrestrial stereo-photogrammetry

Photogrammetry has been used since long to periodically control the evolution of landslides; however, true monitoring is reserved to robotic total stations and ground based InSAR systems, capable of high frequency, high accurate 24h/day response. This paper presents the first results of a fixed terrestrial stereo photogrammetric system developed to monitor shape changes of the scene. The system is made of two reflex cameras, each contained in a sealed box with a control computer that periodically acquires an image and send it to a host computer; once an image pair is received from the two cameras, the DSM of the scene is generated by image correlation and made available for archiving or analysis. The system has been installed and is being tested on the Mont de la Saxe landslide, where several monitoring system are active. Some instability of the camera attitude has been noticed and is corrected with an automated procedure. First comparisons with InSAR data show a good agreement

UAV BLOCK GEOREFERENCING and CONTROL by ON-BOARD GNSS DATA

Unmanned Aerial Vehicles (UAV) are established platforms for photogrammetric surveys in remote areas. They are lightweight, easy to operate and can allow access to remote sites otherwise difficult (or impossible) to be surveyed with other techniques. Very good accuracy can be obtained also with low-cost UAV platforms as far as a reliable ground control is provided. However, placing ground control points (GCP) in these contexts is time consuming and requires accessibility that, in some cases, can be troublesome. RTK-capable UAV platforms are now available at reasonable costs and can overcome most of these problems, requiring just few (or none at all) GCP and still obtaining accurate results. The paper will present a set of experiments performed in cooperation with ARPA VdA (the Environmental Protection Agency of Valle d'Aosta region, Italy) on a test site in the Italian Alps using a Dji Phantom 4 RTK platform. Its goals are: a) compare accuracies obtainable with different calibration procedures (pre- or on-the-job/self-calibration); b) evaluate the accuracy improvements using different number of GCP when the site allows for it; and c) compare alternative positioning modes for camera projection centres determination, (Network RTK, RTK, Post Processing Kinematic and Single Point Positioning)

Genetic relationships among local Vitis vinifera cultivars from Campania (Italy)

A total of 114 accessions putatively corresponding to 69 local grape cultivars from Campania (Southern Italy) were analysed with 8 microsatellite markers (VVS2, VVMD5, VVMD7, VVMD25, VVMD27, VVMD31, VrZAG62 and VrZAG79) in order to evaluate their genetic diversity and relationships. According to their unique genotype at SSR loci finally 56 varieties were found. Interesting cases of synonymy, i.e. Greco di Tufo and Asprinio, Palummina and Piedirosso, and homonymy were disclosed. Pairwise genetic distances were calculated between all cultivars. Clustering of cultivars did not reflect their current distribution and this suggests that grape cultivars of Campania might have been introduced from various and distinct geographic areas

Non-lethal effects of N-acetylcysteine on xylella fastidiosa strain De Donno biofilm formation and detachment

This study investigated in-vitro the non-lethal eects of N-acetylcysteine (NAC) on Xylella fastidiosa subspecies pauca strain De Donno (Xf-DD) biofilm. This strain was isolated fromthe olive trees aected by the olive quick decline syndrome in southern Italy. Xf-DD was first exposed to non-lethal concentrations of NAC from 0.05 to 1000 M. Cell surface adhesion was dramatically reduced at 500 M NAC (47%), hence, this concentration was selected for investigating the eects of pre-, postand co-treatments on biofilm physiology and structural development, oxidative homeostasis, and biofilm detachment. Even though 500 MNAC reduced bacterial attachment to surfaces, compared to the control samples, it promoted Xf-DD biofilm formation by increasing: (i) biofilm biomass by up to 78% in the co-treatment, (ii) matrix polysaccharides production by up to 72% in the pre-treatment, and (iii) reactive oxygen species levels by 3.5-fold in the co-treatment. Xf-DD biofilm detachment without and with NAC was also investigated. The NAC treatment did not increase biofilm detachment, compared to the control samples. All these findings suggested that, at 500 M, NAC diversified the phenotypes in Xf-DD biofilm, promoting biofilm formation (hyper-biofilm-forming phenotype) and discouraging biofilm detachment (hyper-attachment phenotype), while increasing oxidative stress level in the biofilm