998 resultados para map generalisation axioms


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Detection and perception of ecological relationships between biota and their surrounding habitats is sensitive to analysis scale and resolution of habitat data. We measured strength of univariate linear correlations between reef fish and seascape variables at multiple spatial scales (25 to 800 m). Correlation strength was used to identify the scale that best associates fish to their surrounding habitat. To evaluate the influence of map resolution, seascape variables were calculated based on 4 separate benthic maps produced using 2 levels of spatial and thematic resolution, respectively. Individual seascape variables explained only 25% of the variability in fish distributions. Length of reef edge was correlated with more aspects of the fish assemblage than other features. Area of seagrass and bare sand correlated with distribution of many fish, not just obligate users. No fish variables correlated with habitat diversity. Individual fish species achieved a wider range of correlations than mobility guilds or the entire fish assemblage. Scales of peak correlation were the same for juveniles and adults in a majority of comparisons. Highly mobile species exhibited broader scales of peak correlation than either resident or moderately mobile fish. Use of different input maps changed perception of the strength and even the scale of peak correlations for many comparisons involving hard bottom edge length and area of sand, whereas results were consistent regardless of map type for comparisons involving area of seagrass and habitat diversity.

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We have made a complete set of painting probes for the domestic horse by degenerate oligonucleotide-primed PCR amplification of flow-sorted horse chromosomes. The horse probes, together with a full set of those available for human, were hybridized onto metaphase chromosomes of human, horse and mule. Based on the hybridization results, we have generated genome-wide comparative chromosome maps involving the domestic horse, donkey and human. These maps define the overall distribution and boundaries of evolutionarily conserved chromosomal segments in the three genomes. Our results shed further light on the karyotypic relationships among these species and, in particular, the chromosomal rearrangements that underlie hybrid sterility and the occasional fertility of mules.

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Cross-species chromosome painting with probes derived from flow-sorted dog and human chromosomes was used to construct a high-resolution comparative map for the pig. In total 98 conserved autosomal segments between pig and dog were detected by probes specific for the 38 autosomes and X Chromosome of the dog. Further integration of our results with the published human-dog and cat-dog comparative maps, and with data from comparative gene mapping, increases the resolution of the current pig-human comparative map. It allows for the conserved syntenies detected in the pig, human, and cat to be aligned against the putative ancestral karyotype of eutherian mammals and for the history of karyotype evolution of the pig lineage to be reconstructed. Fifteen fusions, 17 fissions, and 23 inversions are required to convert the ancestral mammalian karyotype into the extant karyotype of the pig.

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Density modeling is notoriously difficult for high dimensional data. One approach to the problem is to search for a lower dimensional manifold which captures the main characteristics of the data. Recently, the Gaussian Process Latent Variable Model (GPLVM) has successfully been used to find low dimensional manifolds in a variety of complex data. The GPLVM consists of a set of points in a low dimensional latent space, and a stochastic map to the observed space. We show how it can be interpreted as a density model in the observed space. However, the GPLVM is not trained as a density model and therefore yields bad density estimates. We propose a new training strategy and obtain improved generalisation performance and better density estimates in comparative evaluations on several benchmark data sets. © 2010 Springer-Verlag.

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Epigenetic regulation in insects may have effects on diverse biological processes. Here we survey the methylome of a model insect, the silkworm Bombyx mori, at single-base resolution using Illumina high-throughput bisulfite sequencing (MethylC-Seq). We conservatively estimate that 0.11% of genomic cytosines are methylcytosines, all of which probably occur in CG dinucleotides. CG methylation is substantially enriched in gene bodies and is positively correlated with gene expression levels, suggesting it has a positive role in gene transcription. We find that transposable elements, promoters and ribosomal DNAs are hypomethylated, but in contrast, genomic loci matching small RNAs in gene bodies are densely methylated. This work contributes to our understanding of epigenetics in insects, and in contrast to previous studies of the highly methylated genomes of Arabidopsis(1) and human(2), demonstrates a strategy for sequencing the epigenomes of organisms such as insects that have low levels of methylation.

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Nisin is a widely used naturally occurring antimicrobial effective against many pathogenic and spoilage microorganisms. It has been proposed that reduced efficacy of nisin in foods can be improved by technologies such as encapsulation to protect it from interferences by food matrix components. The aim of this study was using of spray dried encapsulated nisin with zein in concentration of (0.15 and 0.25 g/kg) and sodium citrate (1.5 and 2.5%) and treatments with both of them to extent the shelf life of filleted trouts packaged by Modified Atmosphere Packaging (45% CO2, 50% N2 ,5% O2) and stored at 4±1 °C for 20 days. Furthermore, to evaluate the antimicrobial efficiency of encapsulated nisin and soudium citrate the trouts fillets was inoculated with Staphylococcus aureus as an index pathogenic bacteria. Assessment of chemical spoilage indexes such as (Proxide value, Thiobarbituric acid, total volatile base nitrogen and pH) , microbial parameters (Total Plate Count, Psychrotrophic count, Lactic acid bacteria count), Staphylococcus aureus cont in treatments which were inoculated with 5 logcfu/g of this bacteria and sensory evaluation of fillets including (smell, color, texture and total acceptability) was carried out in days of 0, 4, 8, 12, 16 and 20. The results revealed that treatment with both exposure of nisin and sodium citrate showed significantly lower chemical spoilage indexes in comparison with controls (vaccum packed and MAP) (P<0.05). Furthermore, (nisin 0.25 g/kg sodium citrate 2.5%) treatment which was exposed to the maximal level used of both materials was significantly the lowest treatment with (Proxide value, Thiobarbituric acid, total volatile base nitrogen and pH) of 9.95 (meq O2/kg) , 1.55 (mgMA/kg), 29.65 (mgN/100g) and 6.65 , respectively and according to the maximal recommended level of this indices , shelf life of fillets in this treatment was esstimated 20 days.The control (vaccum packed) treatment was significantly the highest treatment with (Proxide value, Thiobarbituric acid, total volatile base nitrogen and pH) of 15.17 (meq O2/kg), 3.03 (mgMA/kg), 38.4 (mgN/100g) and 6.95 , respectively and according to the maximal recommended level of this indices , shelf life of fillets in this treatment was estimated 11 days. Also, in microbial point of view (nisin 0.25 g/kg- sodium citrate 2.5%) treatment was the lowest treatment with Total Plate Count, Psychrotrophic count, Lactic acid bacteria count and Staphylococcus aureus count of 6.7, 6.83, 5.25 and 6.04 logcfu/g respectively, and conrol (vaccum packed) treatment was the highest treatment with 9.15, 9.41, 7.7 and 9.01 logcfu/g respectively. According to the lower results of chemical and microbial indices and higher sensory evaluated scores assessed in this research for encapsulated nisin in comparison with free nisin , it was concluded that encapsulation of nisin with zein capsules may improve the efficiency of nisin. The measuremented values of Mass yield, Total solids content of capsules, Encapsulation efficiency, In vitro release kinetics in 200 hour for encapsulated nisin in this study was 49.89, 62, 98.31 and 69% respectively and Encapsulated particle size was lower than 674.21 μm for 90% of particles. As a consequence, nisin , in particular encapsulated nisin, and sodium citrate alone or together with and Modified Atmosphere packaging might be considered as effective tools in preventing the quality degradation of the fillets, resulting in an extension of their shelf life.

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Male and female heroin-dependent patients (HDPs) matched with "normal" people were tested on 4 topographical orientation tasks: schematic map-following, map-memory, schematic picture-following, and picture-memory tasks. The results showed that, in general

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Introducing a "Cheaper, Faster, Better" product in today's highly competitive market is a challenging target. Therefore, for organizations to improve their performance in this area, they need to adopt methods such as process modelling, risk mitigation and lean principles. Recently, several industries and researchers focused efforts on transferring the value orientation concept to other phases of the Product Life Cycle (PLC) such as Product Development (PD), after its evident success in manufacturing. In PD, value maximization, which is the main objective of lean theory, has been of particular interest as an improvement concept that can enhance process flow logistics and support decision-making. This paper presents an ongoing study of the current understanding of value thinking in PD (VPD) with a focus on value dimensions and implementation benefits. The purpose of this study is to consider the current state of knowledge regarding value thinking in PD, and to propose a definition of value and a framework for analyzing value delivery. The framework-named the Value Cycle Map (VCM)- intends to facilitate understanding of value and its delivery mechanism in the context of the PLC. We suggest the VCM could be used as a foundation for future research in value modelling and measurement in PD.

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Three-dimensional (3-D) spatial data of a transportation infrastructure contain useful information for civil engineering applications, including as-built documentation, on-site safety enhancements, and progress monitoring. Several techniques have been developed for acquiring 3-D point coordinates of infrastructure, such as laser scanning. Although the method yields accurate results, the high device costs and human effort required render the process infeasible for generic applications in the construction industry. A quick and reliable approach, which is based on the principles of stereo vision, is proposed for generating a depth map of an infrastructure. Initially, two images are captured by two similar stereo cameras at the scene of the infrastructure. A Harris feature detector is used to extract feature points from the first view, and an innovative adaptive window-matching technique is used to compute feature point correspondences in the second view. A robust algorithm computes the nonfeature point correspondences. Thus, the correspondences of all the points in the scene are obtained. After all correspondences have been obtained, the geometric principles of stereo vision are used to generate a dense depth map of the scene. The proposed algorithm has been tested on several data sets, and results illustrate its potential for stereo correspondence and depth map generation.

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Three-dimensional (3-D) spatial data of a transportation infrastructure contain useful information for civil engineering applications, including as-built documentation, on-site safety enhancements, and progress monitoring. Several techniques have been developed for acquiring 3-D point coordinates of infrastructure, such as laser scanning. Although the method yields accurate results, the high device costs and human effort required render the process infeasible for generic applications in the construction industry. A quick and reliable approach, which is based on the principles of stereo vision, is proposed for generating a depth map of an infrastructure. Initially, two images are captured by two similar stereo cameras at the scene of the infrastructure. A Harris feature detector is used to extract feature points from the first view, and an innovative adaptive window-matching technique is used to compute feature point correspondences in the second view. A robust algorithm computes the nonfeature point correspondences. Thus, the correspondences of all the points in the scene are obtained. After all correspondences have been obtained, the geometric principles of stereo vision are used to generate a dense depth map of the scene. The proposed algorithm has been tested on several data sets, and results illustrate its potential for stereo correspondence and depth map generation.