1,721,022 research outputs found
Description and evaluation of an high pressure water Venturi injector oxygenator in fish farming
No full textAdvanced imaging tools for plant phenotyping
No full textHigh throughput plant phenotyping, also called plant phenomics, is an emerging and fast growing research field that aims to bridge the existing gap between genomics and plant breeding, by solving the so-called phenotyping bottleneck. Moreover, it can supply highly detailed information and tools for the advancement of both plant physiology and agronomy. Plant phenomics takes advantage from the recent developments in the fields of imaging, computer vision and sensor technologies, allowing the nondestructive detection of phenotypic characters. Plant phenomics ranges from basic science to applications in breeding and precision agriculture, combining studies performed under both controlled environments and in the open fields. Last year, Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria (CREA) joined the Italian Plant Phenotyping Network (ITA-PPN) which gathers the national research centers and universities active in this field. CREA has developed in the last ten years advanced skills for the development of analytical methods for phenotyping, mainly imaging-based. The high-throughput character of our proposed phenotyping methods should help to improve the detection of important plant traits in large field trials as well as help us to reach a better understanding of underlying yield physiological processes and facilitate the genotypephenotype associations. In particular, we developed the following analytic tools for: shape analysis 2d or 3d using landmarks (geometric morphometrics) or outline methods; quantitative color analysis from RGB images (we developed specific algorithms to standardize colors using colorchecker; 3D Thin-Plate Spline); punctual spectrophotometry and hyperspectral imaging; dynamic thermography imaging based; stereovision (multi camera systems for 3d reconstruction). Moreover, we developed an open source conveyor belt prototype multi-sensorized for rapid characterization of experimental wheat field plots. CREA developed advanced analytical approaches based on multivariate methods of prediction and classification (linear approaches and approaches based on artificial neural networks) applied in multi-parametric and multi-sensor metrology for an innovative support in phenomics. All these tools has been developed in Matlab environment, but could be easily exported in open source environments in order to realize highly customizable systems within the phenomics framework
Photonic technologies for non-invasive sexual identification: the case study of Salamandrina perspicillata (Amphibia, Urodela).
No full texthttp://www.cdsarti.org/nova_web/ang/recerca/publi_butlletins.as
Using image analysis on the ventral colour pattern in Salamandrina perspicillata (Amphibia: Salamandridae) to discriminate among populations
No full textThe ventral colour pattern in Salamandrina perspicillata is characteristic of each individual and remains invariant throughout the salamanders' life. The present study aimed to determine, using statistical methods applied to quantitative image analysis, whether the coloration pattern is population-specific. The images of ventral colour pattern of 180 salamanders belonging to five populations were analysed. The images were previously warped by geometric morphometry. To our knowledge, this is the first study to use an approach based on geometric morphometrics to standardize ventral shapes. This technique is useful for eliminating form distortions. The results of an analysis of similarities recognized more coloration similarity among individuals of the same population than among individuals from different populations. Analysis by partial least squares correctly classified the 88.88% of individuals into the correct population. The similarities or differences among individuals of different populations are not related to the geographical distances. The results obtained showed that the coloration of the ventral side of the head of the salamanders can be used for discriminating among populations. (C) 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 35-43
Using image analysis on the ventral colour pattern to discriminate between Salamandrina perspicillata and Salamandrina terdigitata.
No full textEel silvering stage based on PLS classification
Full text linkTo discriminate European eel (Anguilla anguilla, Linnaeus 1758) developmental stages on the basis of body colour, we observed the pigmentation pattern of skin and several biological characteristics of eels collected in the low course of River Tiber (Rome, Italy). A total of 454 individuals have been assigned to a determined stage (Yellow, Intermediate and Silver) and examined to measure five external parameters (total length, weight, pectoral fin length, vertical and horizontal eye diameter). A subsample of 229 eels has been sacrificed in order to collect liver and gut weight and to determine age from otholit observation. A supervised regression technique, Partial Least Squares (PLS) analysis, has been used to develop a model explaining the co-variation between measured parameters, and the three developmental stages. A good discriminant model was obtained for both datasets: the first PLS analysis, using five variables, yields a correct classification of 78 % of the individuals, the second, with eight input variables, yields a correct classification of 79,4 % of the individuals. Yellow and Silver eels are well discriminated by the model, while Intermediate eels don’t constitute an outlined group. The method of staging European eels on the basis of skin colour appeared to be reliable and easy to adopt during field surveys
A multivariate SIMCA index as discriminant in wood pellet quality assessment
Full text linkThe pellet market has experienced a continuous development and increase in recent years due to a number of positive properties of this enhanced biomass. However the supply chain has not been entirely able to follow the same trend, causing some issues, often related to the quality of traded products. These problems can be partially solved by ensuring a continuous and reliable flow of information regarding the quality parameters of wood pellets from the producers to the final users. The aim of this work is to define a metric index for quality parameters that can detect the certifiability of analyzed samples compared with those on the market. The model is built on measured quality parameters of certified and non-certified wood pellet samples taken from products on the market applying a multivariate class modelling methodology (soft independent modelling of class analogy, SIMCA). Results showed that the model can predict the general quality of some test samples and that its precision, already fairly high, can be constantly improved by adding new model samples. The output of the model is also the relative influence (modelling power) of each variable in the prediction of certifiability. The SIMCA model could be easily integrated and implemented on the most common digital platforms where users (private, laboratories, agencies, etc.) could test their samples and verify if the index of their pellet falls within the area defined by the model for certified sample
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
External Shape Differences between Sympatric Populations of Commercial Clams Tapes decussatus and T. philippinarum
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