Active regions for colour texture segmentation integrating region and boundary information

In this paper a colour texture segmentation method, which unifies region and boundary information, is proposed. The algorithm uses a coarse detection of the perceptual (colour and texture) edges of the image to adequately place and initialise a set of active regions. Colour texture of regions is modelled by the conjunction of non-parametric techniques of kernel density estimation (which allow to estimate the colour behaviour) and classical co-occurrence matrix based texture features. Therefore, region information is defined and accurate boundary information can be extracted to guide the segmentation process. Regions concurrently compete for the image pixels in order to segment the whole image taking both information sources into account. Furthermore, experimental results are shown which prove the performance of the proposed method

Unsupervised active regions for multiresolution image segmentation

An unsupervised approach to image segmentation which fuses region and boundary information is presented. The proposed approach takes advantage of the combined use of 3 different strategies: the guidance of seed placement, the control of decision criterion, and the boundary refinement. The new algorithm uses the boundary information to initialize a set of active regions which compete for the pixels in order to segment the whole image. The method is implemented on a multiresolution representation which ensures noise robustness as well as computation efficiency. The accuracy of the segmentation results has been proven through an objective comparative evaluation of the method

Does social capital reinforce technological inputs in the creation of knowledge? Evidence from the Spanish regions

In this paper we seek to verify the hypothesis that trust and cooperation between individuals, and between them and public institutions, can encourage technological innovation and the adoption of knowledge. Additionally, we test the extent to which the interaction of social capital with human capital and R&D expenditures improve their effect on a region’s ability to innovate. Our empirical evidence is taken from the Spanish regions and employs a knowledge production function and longitudinal count data models. Our results suggest that social capital correlates positively with innovation. Further, our analysis reveals a powerful interaction between human and social capital in the production of knowledge, whilst the complementarity with R&D efforts would seem less clear.

Panel Data Stochastic Convergence Analysis of the Mexican Regions

The stochastic convergence amongst Mexican Federal entities is analyzed in panel data framework. The joint consideration of cross-section dependence and multiple structural breaks is required to ensure that the statistical inference is based on statistics with good statistical properties. Once these features are accounted for, evidence in favour of stochastic convergence is found. Since stochastic convergence is a necessary, yet insufficient condition for convergence as predicted by economic growth models, the paper also investigates whether-convergence process has taken place. We found that the Mexican states have followed either heterogeneous convergence patterns or divergence process throughout the analyzed period.

Avantatges i inconvenients de la metodologia INE per a elaborar indicadors de la producció industrial per a les regions espanyoles

Conèixer l'evolució conjuntural del sector industrial, tant a nivell nacional com regional, és de gran importància. En aquest sentit, el retard en la publicació de les xifres de les Comptabilitats Nacionals/Regionals, fa necessària l'elaboració d'indicadors que permetin dur a terme un seguiment a curt termini de l'activitat industrial. Així, l'INE elabora un IPI mensual obtingut pel mètode directe pel conjunt de l'Estat. D'altra banda, al llarg dels darrers anys, a algunes comunitats autònomes espanyoles, s'han engegat projectes centrats en l'elaboració d'indicadors de l'activitat industrial regional, tot i que a partir de metodologies no homogènies. Per corregir aquesta situació, d'un temps ençà, a diferents fòrums s'ha proposat emprar la metodologia emprada per l'IDESCAT per elaborar l'indicador de la comunitat catalana com a alternativa per construir indicadors de l'activitat industrial regional, atès el seu bon comportament per Catalunya. Així, l'INE recentment ha publicat uns IPIs per les CA espanyoles d'acord amb dita metodologia. A aquest treball s'estudia la idoneïtat d'estendre l'esmentada metodologia a totes les regions espanyoles. Per això, es duu a terme una anàlisi comparativa centrada en (tres de) les quatre regions que disposen d'un IPI elaborat pel mètode directe: Andalusia, Astúries i el País Basc.

Local human capital and productivity: An analysis for Spanish regions

In this paper, we examine the relationship between the stock of human capital and productivity in the Spanish regions (NUTS III), and assess whether the transmission channel involves external economies. The empirical evidence points to a positive relationship between the two variables, although it cannot be explained in terms of the impact of exogenous local human capital external economies, but rather in terms of other demand factors.

Chemical characterization by GC-MS and phytotoxic potential of non-polar and polar fractions of seeds of Dioteryx odorata (Aubl.) Willd. from Venezuelan regions

Dipteryx odorata (Aubl.) Willd. is a tall arboreal species native to Central and Northern South America. This paper describes the chemical characterization and phytotoxic potential of polar and non-polar extracts from D. odorata seeds. Structural determinations were accomplished by chemical derivatization and analyzed by GC/MS. The chemical composition of the non-polar fraction (hexane and dichloromethane) presented fatty acids as major constituent. Medium polar and polar fractions (ethyl acetate and ethanol: water) contained carboxylic acid and high 6,7-Dyhidroxycoumarin-β-D-glucopyranoside content, not previously reported for seeds of D. odorata. Extracts showed a significant level of phytotoxic activity, correlated to the content of coumarin derivatives, predominantly in the polar fraction.

Chemical composition of volatiles from male and female specimens of Baccharis trimera collected in two distant regions of southern brazil: a comparative study using chemometrics

GC/MS/FID analyses of volatile compounds from cladodes and inflorescences from male and female specimens of Baccharis trimera (Less.) DC. collected in the states of Paraná and Santa Catarina, Brazil, showed that carquejyl acetate was the primary volatile component (38% to 73%), while carquejol and ledol were identified in lower concentrations. Data were subjected to hierarchical cluster analysis and principal component analysis, which confirmed that the chemical compositions of all samples were similar. The results presented here highlight the occurrence of the same chemotype of B. trimera in three southern states of Brazil.

Variability in ribosomal DNA genic and spacer regions in Verticillium dahliae isolates from different hosts

Using PCR-based assays with specific primers for amplification of the ribosomal DNA intergenic spacer region (IGS) and a portion of the mitochondrial DNA small subunit ribosomal RNA gene (mtDNA SSU rRNA), the genetic variability among Verticillium dahliae isolates from olive (Olea europaea) and other host species from Argentina and Brazil was estimated. The derived UPGMA-generated phenograms based upon the restriction fingerprinting data of rDNA IGS products revealed genetic differences, correlating with the host of origin. Isolates infecting olive genetically distinct from those from cocoa (Theobroma cacao) and sunflower (Helianthus annuus). Digestion of mitochondrial DNA SSU rRNA PCR products revealed less variability, distinguishing only one isolate from sunflower. Ribosomal DNA ITS restriction patterns were identical for all isolates of V. dahliae, irrespective of host of origin. These preliminary results may have relevance for Verticillium wilt control practices, possibly reflecting a different evolutionary origin, or reproductive isolation of the pathogen in olive, distinct from populations of other hosts.

Low-flow estimates in regions of extrapolation of the regionalization equations: a new concept

ABSTRACT Knowledge of natural water availability, which is characterized by low flows, is essential for planning and management of water resources. One of the most widely used hydrological techniques to determine streamflow is regionalization, but the extrapolation of regionalization equations beyond the limits of sample data is not recommended. This paper proposes a new method for reducing overestimation errors associated with the extrapolation of regionalization equations for low flows. The method is based on the use of a threshold value for the maximum specific low flow discharge estimated at the gauging sites that are used in the regionalization. When a specific low flow, which has been estimated using the regionalization equation, exceeds the threshold value, the low flow can be obtained by multiplying the drainage area by the threshold value. This restriction imposes a physical limit to the low flow, which reduces the error of overestimating flows in regions of extrapolation. A case study was done in the Urucuia river basin, in Brazil, and the results showed the regionalization equation to perform positively in reducing the risk of extrapolation.

Thermal efficiency of individual shelters for girolando calves in brazilian semi-arid regions

ABSTRACT The objective of this research was to evaluate the thermal efficiency of roofs used on individual shelters during milk-feeding stage of Girolando calves. The research was conducted at a farm located in a dry region of Pernambuco state, Brazil. The experimental design was completely randomized, with 27 Holstein × Gir dairy crossbred calves housed in shelters with three roofing materials (fibre cement tile, recycled tile, and thatched roofs). The recycled tiles and thatched roofs provided reductions of 18.7 and 14.6% in radiant thermal load, respectively. Regardless the roofing material, all animals increased their respiratory rate to maintain thermal equilibrium.

Genetic and antigenic analysis of Babesia bigemina isolates from five geographical regions of Brazil

A molecular epidemiological study was performed with Babesia bigemina isolates from five geographical regions of Brazil. The genetic analysis was done with random amplification of polymorphic DNA (RAPD), repetitive extragenic palindromic elements-polymerase chain reaction (REP-PCR) and enterobacterial repetitive intergenic consensus sequences-polymerase chain reaction (ERIC-PCR) that showed genetic polymorphism between these isolates and generated fingerprinting. In RAPD, ILO872 and ILO876 primers were able to detect at least one fingerprinting for each B. bigemina isolate. The amplification of B. bigemina DNA fragments by REP-PCR and ERIC-PCR gave evidence for the presence in this haemoprotozoan of the sequences described previously in microorganisms of the bacterial kingdom. For the first time it was demonstrated that both techniques can be used for genetic analysis of a protozoan parasite, although the ERIC-PCR was more discriminatory than REP-PCR. The dendogram with similarity coefficient among isolates showed two clusters and one subcluster. The Northeastern and Mid-Western isolates showed the greatest genetic diversity, while the Southeastern and Southern isolates were the closest. The antigenic analysis was done through indirect fluorescent antibody technique and Western blotting using a panel of monoclonal antibodies directed against epitopes on the merozoite membrane surface, rhoptries and membrane of infected erythrocytes. As expected, the merozoite variable surface antigens, major surface antigen (MSA)-1 and MSA-2 showed antigenic diversity. However, B cell epitopes on rhoptries and infected erythrocytes were conserved among all isolates studied. In this study it was possible to identify variable and conserved antigens, which had already been described as potential immunogens. Considering that an attenuated Babesia clone used as immunogen selected populations capable of evading the immunity induced by this vaccine, it is necessary to evaluate more deeply the cross-protection conferred by genetically more distant Brazilian B. bigemina isolates and make an evaluation of the polymorphism degree of variable antigens such as MSA-1 and MSA-2.

Genotype characterization of Haematobia irritans from different Brazilian geographic regions based on randomly amplified polymorphic DNA (RAPD) analysis

Blood-sucking diptera are important parasites in bovine production systems, especially regarding confinement conditions. Haematobia irritans, the horn fly, is one of the most troublesome species within bovine production systems, due to the intense stress imposed to the animals. An important aspect while studying the variability within a species is the study of the geographic structure of its populations and, attempting to find out the genetic flow of Brazilian populations of horn fly, the RAPD technique, which is suited for this purpose, has been used. The use of molecular markers generated from RAPD made it possible to identify the geographic origin of samples from different Brazilian geographic regions, as well as to estimate the genotypic flow among the different Brazilian populations of the horn fly.

Clonal study of avian Escherichia coli strains by fliC conserved-DNA-sequence regions analysis

The clonal relationship among avian Escherichia coli strains and their genetic proximity with human pathogenic E. coli, Salmonela enterica, Yersinia enterocolitica and Proteus mirabilis, was determined by the DNA sequencing of the conserved 5' and 3'regions fliC gene (flagellin encoded gene). Among 30 commensal avian E. coli strains and 49 pathogenic avian E. coli strains (APEC), 24 commensal and 39 APEC strains harbored fliC gene with fragments size varying from 670bp to 1,900bp. The comparative analysis of these regions allowed the construction of a dendrogram of similarity possessing two main clusters: one compounded mainly by APEC strains and by H-antigens from human E. coli, and another one compounded by commensal avian E. coli strains, S. enterica, and by other H-antigens from human E. coli. Overall, this work demonstrated that fliC conserved regions may be associated with pathogenic clones of APEC strains, and also shows a great similarity among APEC and H-antigens of E. coli strains isolated from humans. These data, can add evidence that APEC strains can exhibit a zoonotic risk.