982 resultados para MORPHOLOGICAL CHARACTERS


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Three classification techniques, namely, K-means Cluster Analysis (KCA), Fuzzy Cluster Analysis (FCA), and Kohonen Neural Networks (KNN) were employed to group 25 microwatersheds of Kherthal watershed, Rajasthan into homogeneous groups for formulating the basis for suitable conservation and management practices. Ten parameters, mainly, morphological, namely, drainage density (D-d), bifurcation ratio (R-b), stream frequency (F-u), length of overland flow (L-o), form factor (R-f), shape factor (B-s), elongation ratio (R-e), circulatory ratio (R-c), compactness coefficient (C-c) and texture ratio (T) are used for the classification. Optimal number of groups is chosen, based on two cluster validation indices Davies-Bouldin and Dunn's. Comparative analysis of various clustering techniques revealed that 13 microwatersheds out of 25 are commonly suggested by KCA, FCA and KNN i.e., 52%; 17 microwatersheds out of 25 i.e., 68% are commonly suggested by KCA and FCA whereas these are 16 out of 25 in FCA and KNN (64%) and 15 out of 25 in KNN and CA (60%). It is observed from KNN sensitivity analysis that effect of various number of epochs (1000, 3000, 5000) and learning rates (0.01, 0.1-0.9) on total squared error values is significant even though no fixed trend is observed. Sensitivity analysis studies revealed that microwatershecls have occupied all the groups even though their number in each group is different in case of further increase in the number of groups from 5 to 6, 7 and 8. (C) 2010 International Association of Hydro-environment Engineering and Research, Asia Pacific Division. Published by Elsevier B.V. All rights reserved.

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The nucleation morphologies of LPE grown GaSb, AlGaSb and AlGaAsSb layers on GaSb substrates are presented. The morphology of the GaSb layers grown from Sb-rich melts showed facets on highly terraced surface, whereas those grown from Ga-rich melts exhibited fine terraces without facets. An optimum temperature in the range of 500 – 550°C was found to be suitable for the growth of mirror smooth layers from Ga-melts. The surface morphology of the AlxGa1-xSb layers degrades drastically with increase in Al content beyond x = 0.5. The surface morphology of AlGaAsSb epilayers has been found to depend strongly on the pre-growth melt dissolution sequence.

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The use of Fourier shape descriptors for morphological studies of vectorcardio-grams (VCGs) is p resented . The FDs can effectively be used as features for classf-fication of VCGs of different clinical categories . In addition , they provide cli-nically significant qualitative shape information for use by the Cardiologist. The initial result sofanalysisof nwrmal and abnormal VCGs areencouraging.

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In most taxa, species boundaries are inferred based on differences in morphology or DNA sequences revealed by taxonomic or phylogenetic analyses. In crickets, acoustic mating signals or calling songs have species-specific structures and provide a third data set to infer species boundaries. We examined the concordance in species boundaries obtained using acoustic, morphological, and molecular data sets in the field cricket genus Itaropsis. This genus is currently described by only one valid species, Itaropsis tenella, with a broad distribution in western peninsular India and Sri Lanka. Calling songs of males sampled from four sites in peninsular India exhibited significant differences in a number of call features, suggesting the existence of multiple species. Cluster analysis of the acoustic data, molecular phylogenetic analyses, and phylogenetic analyses combining all data sets suggested the existence of three clades. Whatever the differences in calling signals, no full congruence was obtained between all the data sets, even though the resultant lineages were largely concordant with the acoustic clusters. The genus Itaropsis could thus be represented by three morphologically cryptic incipient species in peninsular India; their distributions are congruent with usual patterns of endemism in the Western Ghats, India. Song evolution is analysed through the divergence in syllable period, syllable and call duration, and dominant frequency.

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The diamond films were deposited onto a wurtzite gallium nitride (GaN) thin film substrate using hot-filament chemical vapor deposition (HFCVD). During the film deposition a lateral temperature gradient was imposed across the substrate by inclining the substrate. As grown films predominantly showed the hexagonal phase, when no inclination was applied to the substrate. Tilting the substrate with respect to the heating filament by 6 degrees imposed a lateral temperature gradient across the substrate, which induced the formation of a cubic diamond phase. Diamond grains were predominantly oriented in the (100) direction. However, a further increase in the substrate tilt angle to 12 degrees, resulted in grains oriented in the (111) direction. The growth rate and hence the morphology of diamond grains varied along the inclined substrate. The present study focuses on the measurements of dominant phase formation and crystal orientation with varying substrate inclination using orientation-imaging microscopy (OIM). This technique enables direct examination of individual diamond grains and their crystallographic orientation. (C) 2012 Elsevier B.V. All rights reserved.

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The Indian region is presently the second region after the Neotropics in terms of diversity of phalangopsid crickets. Yet their study is impeded by the lack of necessary taxonomic tools for taxon identification. In the present paper, all generic diagnoses are clarified, using morphological and genitalic characters; female genitalia are described and illustrated for all genera with known females. New taxa are described from southern India: Kempiola flavipunctatus Desutter-Grandcolas n. sp., Opiliosina meridionalis Desutter-Grandcolas n. gen., n. sp., Phalangopsina bolivari Desutter-Grandcolas n. sp., P. chopardi Desutter-Grandcolas n. sp., P. gravelyi Desutter-Grandcolas n. sp., and Speluncasina Desutter-Grandcolas n. gen. The list of phalangopsid crickets from the Indian Region is updated, and a key to phalangopsid genera proposed. A lectotype and a paralectotype are designated to fix the name of Phalangopsina dubia (Bolivar, 1900). Opilionacris annandalei Chopard, 1928, previously transferred to the African genus Phaeophilacris Walker, 1871, is transferred to the genus Speluncasina Desutter-Grandcolas n. gen., while Larandopsis jharnae Bhowmik, 1981 and L. newguineae Bhowmik, 1981 described from New Guinea are transferred to the eneopterine genus Lebinthus Stal, 1877. Finally Luzaropsis confusa Chopard, 1969 is removed from its synonymy with L. ferruginea Walker, 1871.

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In this paper, we have carried out thin film characterization of poly(3,4-propylenedioxythiophene)-sultone (PProDOT-S), a derivative of electrochromic poly(3,4-propylenedioxythiophene) (PProDOT). PProDOT-S was deposited onto transparent conducting oxide coated glass substrates by solution casting method. Single wavelength spectrophotometry is used to monitor the switching speed and contrast ratio at maximum wavelength (lambda (max)). The percentage transmittance at the lambda (max) of the neutral polymer is monitored as a function of time when the polymer film is repeatedly switched. This experiment gives a quantitative measure of the speed with which a film is able to switch between the two states i.e. the coloured and the bleached states. PProDOT-S films were switched at a voltage of 1 center dot 9 V with a switching speed of 2 s at lambda (max) of 565 nm and showed a contrast of similar to 37%. Cyclic voltammetry performed at different scan rates have shown the characteristic anodic and cathodic peaks. The structural investigations of PProDOT-S films by IR spectra were in good agreement with previously reported results. Raman spectra of PProDOT-S showed a strong Raman peak at 1509 cm (-aEuro parts per thousand 1) and a weak peak at 1410 cm (-aEuro parts per thousand 1) due to the C = C asymmetric and symmetric stretching vibrations of thiophene rings. The morphological investigations carried out by using scanning electron microscope (SEM) of polymer films have shown that these polymers are found to be arranged in dense packed clusters with non-uniform distribution having an average width and length of 95 nm and 160 nm, respectively.

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We report the variation of glass transition temperature in supported thin films of polymer nanocomposites, consisting of polymer grafted nanoparticles embedded in a homopolymer matrix. We observe a systematic variation of the estimated glass transition temperature T-g, with the volume fraction of added polymer grafted nanoparticles. We have correlated the observed T-g variation with the underlying morphological transitions of the nanoparticle dispersion in the films. Our data also suggest the possibility of formation of a low-mobility glass or gel-like layer of nanoparticles at the interface, which could play a significant role in determining T-g of the films provided. (C) 2013 American Institute of Physics. http://dx.doi.org/10.1063/1.4773442]

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In this paper, we describe a method for feature extraction and classification of characters manually isolated from scene or natural images. Characters in a scene image may be affected by low resolution, uneven illumination or occlusion. We propose a novel method to perform binarization on gray scale images by minimizing energy functional. Discrete Cosine Transform and Angular Radial Transform are used to extract the features from characters after normalization for scale and translation. We have evaluated our method on the complete test set of Chars74k dataset for English and Kannada scripts consisting of handwritten and synthesized characters, as well as characters extracted from camera captured images. We utilize only synthesized and handwritten characters from this dataset as training set. Nearest neighbor classification is used in our experiments.

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Biodegradable composites comprising of modified starch and modified nanoclay have been prepared. Starch has been modified by esterification and subsequently crosslinked. The thermal, mechanical, and biodegradation characteristics of the composites have been investigated. The compressive properties of the composites with the addition of nanoclay were twice that of crosslinked starch phthalate without addition of nanoclay. Predictive theories were used to analyze the obtained experimental results. SEM studies on fracture morphology indicated quasi-brittle fracture. Flexural properties showed considerable improvement due to nanoclay addition. The water uptake increased up to 6% nanoclay, beyond which the uptake decreased. Biodegradation studies showed an initial time lag prior to the onset of degradation.

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Thin films of NiTi were deposited by DC magnetron sputtering from an equiatomic alloy target (Ni/Ti: 50/50 at.%). The films were deposited without intentional heating of the substrates. The thickness of the deposited films was approximately 2 mu m. The structure and morphology of NiTi films annealed at different temperatures were analyzed in order to understand the effect of annealing on physical properties of the films. The compositional investigations of fresh and annealed films were also evaluated by energy dispersive X-ray spectroscopy (EDS) and X-ray photo-electron spectroscopy (XPS) techniques. X-ray diffraction (XRD) studies showed that as-deposited films were amorphous in nature whereas annealed films were found to poly-crystalline with the presence of Austenite phase as the dominant phase. AFM investigations showed higher grain size and surface roughness values in the annealed films. In annealed films, the grain size and film roughness values were increased from 10 to 85 nm and 2-18 nm. Film composition measured by EDS were found to 52.5 atomic percent of Ni and 47.5 atomic percent of Ti. XPS investigations, demonstrated the presence of Ni content on the surface of the films, in fresh films, whereas annealed films did not show any nickel. From HR-XPS investigations, it can be concluded that annealed NiTi films have higher tendency to form metal oxide (titanium dioxide) layer on the surface of the films than fresh NiTi films. (C) 2013 Elsevier B. V. All rights reserved.

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Silver nanoparticles with an average size of 23 nm were chemically synthesized and used to fabricate Zn-Ag composite coatings. The Zn-Ag composite coatings were generated by electrodeposition method using a simple sulfate plating bath dispersed with 0.5, land 1.5 g/l of Ag nanoparticles. Scanning electron microscopy, X-ray diffraction and texture co-efficient calculations revealed that Ag nanoparticles appreciably influenced the morphology, micro-structure and texture of the deposit. It was also noticed that agglomerates of Ag nanopartides, in the case of high bath load conditions, produced defects and dislocations on the deposit surface. Ag nanoparticles altered the corrosion resistance property of Zn-Ag composite coatings as observed from Tafel polarization, electrochemical impedance analysis and an immersion test. Reduction in corrosion rate with increased charge transfer resistance was observed for Zn-Ag composite coatings when compared to a pure Zn coating. However, the particle concentration in the plating bath and their agglomeration state directly influenced the surface morphology and the subsequent corrosion behavior of the deposits. (C) 2013 Elsevier Inc. All rights reserved.

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Zebrafish (Danio rerio) embryos are transparent and advantageous for studying early developmental changes due to ex utero development, making them an appropriate model for studying gene expression changes as a result of molecular targeting. Zebrafish embryos were injected with a previously reported G-quadruplex selective ligand, and the phenotypic changes were recorded. We report marked discrepancies in the development of intersegmental vessels. In silico analysis determined that the putative G-quadruplex motif occur in the upstream promoter region of the Cdh5 (N-cadherin) gene. A real-time polymerase chain reaction-based investigation indicated that in zebrafish, CDH-2 (ZN-cad) was significantly downregulated in the ligand-treated embryos. Biophysical characterization of the interaction of the ligand with the G-quadruplex motif found in this promoter yielded strong binding and stabilization of the G-quadruplex with this ligand. Hence, we report for the first time the phenotypic impact of G-quadruplex targeting with a ligand in a vertebrate organism. This study has unveiled not only G-quadruplex targeting in non-human animal species but also the potential that G-quadruplexes can provide a ready tool for understanding the phenotypic effects of targeting certain important genes involved in differentiation and developmental processes in a living eukaryotic organism.

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Rice landraces are lineages developed by farmers through artificial selection during the long-term domestication process. Despite huge potential for crop improvement, they are largely understudied in India. Here, we analyse a suite of phenotypic characters from large numbers of Indian landraces comprised of both aromatic and non-aromatic varieties. Our primary aim was to investigate the major determinants of diversity, the strength of segregation among aromatic and non-aromatic landraces as well as that within aromatic landraces. Using principal component analysis, we found that grain length, width and weight, panicle weight and leaf length have the most substantial contribution. Discriminant analysis can effectively distinguish the majority of aromatic from non-aromatic landraces. More interestingly, within aromatic landraces long-grain traditional Basmati and short-grain non-Basmati aromatics remain morphologically well differentiated. The present research emphasizes the general patterns of phenotypic diversity and finds out the most important characters. It also confirms the existence of very unique short-grain aromatic landraces, perhaps carrying signatures of independent origin of an additional aroma quantitative trait locus in the indica group, unlike introgression of specific alleles of the BADH2 gene from the japonica group as in Basmati. We presume that this parallel origin and evolution of aroma in short-grain indica landraces are linked to the long history of rice domestication that involved inheritance of several traits from Oryza nivara, in addition to O. rufipogon. We conclude with a note that the insights from the phenotypic analysis essentially comprise the first part, which will likely be validated with subsequent molecular analysis.