Home About us Contact
|
Home About us Contact | ||
|
|
||
Mapping Approach (mapping + approach)
Selected AbstractsMapping approach for 3D laminar mixing simulations: application to industrial flowsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 3-4 2002O. S. Galaktionov Abstract The computationally efficient mapping technique is applied to model laminar mixing in the transport section of the co-rotating twin screw extruder. The technique uses coarse grain values to describe the mixture and exploits temporal and spatial periodicity of the flow. The mapping approach yields adequate description of the concentration fields and residence time distributions. Copyright © 2002 John Wiley & Sons, Ltd. [source] Current density mapping approach for design of clinical magnetic resonance imaging magnetsCONCEPTS IN MAGNETIC RESONANCE, Issue 3 2002Stuart Crozier Abstract Novel current density mapping (CDM) schemes are developed for the design of new actively shielded, clinical magnetic resonance imaging (MRI) magnets. This is an extended inverse method in which the entire potential solution space for the superconductors has been considered, rather than single current density layers. The solution provides an insight into the required superconducting coil pattern for a desired magnet configuration. This information is then used as an initial set of parameters for the magnet structure, and a previously developed hybrid numerical optimization technique is used to obtain the final geometry of the magnet. The CDM scheme is applied to the design of compact symmetric, asymmetric, and open architecture 1.0,1.5 T MRI magnet systems of novel geometry and utility. A new symmetric 1.0-T system that is just 1 m in length with a full 50-cm diameter of the active, or sensitive, volume (DSV) is detailed, as well as an asymmetric system in which a 50-cm DSV begins just 14 cm from the end of the coil structure. Finally a 1.0-T open magnet system with a full 50-cm DSV is presented. These new designs provide clinically useful homogeneous regions and have appropriately restricted stray fields but, in some of the designs, the DSV is much closer to the end of the magnet system than in conventional designs. These new designs have the potential to reduce patient claustrophobia and improve physician access to patients undergoing scans. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 208,215, 2002 [source] Pathways to help-seeking in bulimia nervosa and binge eating problems: A concept mapping approachINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 6 2007Natasha Hepworth PhD Abstract Objective: To conduct an in-depth study, using concept mapping, of three factors related to help-seeking for bulimia nervosa and binge eating: problem recognition, barriers to help-seeking, and prompts to help-seeking. Method: Semistructured interviews were conducted to elicit information about help-seeking with 63 women (18,62 years) with past or present bulimic behaviors. Results: Using Leximancer software, factors identified as associated with problem recognition were Changes in Behavior, Interference with Life Roles, Comments about Changes and Psychological Problems. Salient barriers to help-seeking were Fear of Stigma, Low Mental Health Literacy/Perception of Need, Shame, Fear of Change and Cost. Prompts to help-seeking were increased Symptom Severity, Psychological Distress, Interference with Life Roles, Health Problems, and Desire to Get Better. Conclusion: Results highlighted the need for awareness campaigns to reduce both self and perceived stigma by others towards bulimic behaviors, and the need to enhance awareness of available interventions for people ready to engage in treatment, to increase help-seeking. © 2007 by Wiley Periodicals, Inc. [source] Genetic Analysis of ele Mutants and Comparative Mapping of ele1 Locus in the Control of Organ Internal Asymmetry in Garden PeaJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 6 2010Xin Li Previous study has shown that during zygomorphic development in garden pea (Pisum sativum L.), the organ internal (IN) asymmetry of lateral and ventral petals was regulated by a genetic locus, SYMMETRIC PETAL 1 (SYP1), while the dorsoventral (DV) asymmetry was determined by two CYC - like TCP genes or the PsCYC genes, KEELED WINGS (K) and LOBED STANDARD 1 (LST1). In this study, two novel loci, ELEPHANT EAR-LIKE LEAF 1 (ELE1) and ELE2 were characterized. These mutants exhibit a similar defect of IN asymmetry as syp1 in lateral and ventral petals, but also display pleiotropic effects of enlarged organ size. Genetic analysis showed that ELE1 and ELE2 were involved in same genetic pathway and the enlarged size of petals but not compound leaves in ele2 was suppressed by introducing k and lst1, indicating that the enlargement of dorsal petal in ele2 requires the activities of K and LST1. An experimental framework of comparative genomic mapping approach was set up to map and clone LjELE1 locus in Lotus japonicus. Cloning the ELE1 gene will shed light on the underlying molecular mechanism during zygomorphic development and further provide the molecular basis for genetic improvement on legume crops. [source] Erosion modelling approach to simulate the effect of land management options on soil loss by considering catenary soil development and farmers perceptionLAND DEGRADATION AND DEVELOPMENT, Issue 6 2008A. C. Brunner Abstract The prevention of soil erosion is one of the most essential requirements for sustainable agriculture in developing countries. In recent years it is widely recognized that more site-specific approaches are needed to assess variations in erosion susceptibility in order to select the most suitable land management methods for individual hillslope sections. This study quantifies the influence of different land management methods on soil erosion by modelling soil loss for individual soil-landscape units on a hillslope in Southern Uganda. The research combines a soil erosion modelling approach using the physically based Water Erosion Prediction Project (WEPP)-model with catenary soil development along hillslopes. Additionally, farmers' perceptions of soil erosion and sedimentation are considered in a hillslope mapping approach. The detailed soil survey confirmed a well-developed catenary soil sequence along the hillslope and the participatory hillslope mapping exercise proved that farmers can distinguish natural soil property changes using their local knowledge. WEPP-model simulations show that differences in soil properties, related to the topography along the hillslope, have a significant impact on total soil loss. Shoulder and backslope positions with steeper slope gradients were most sensitive to changes in land management. Furthermore, soil conservation techniques such as residue management and contouring could reduce soil erosion by up to 70 percent on erosion-sensitive slope sections compared to that under tillage practices presently used at the study site. The calibrated model may be used as a tool to provide quantitative information to farmers regarding more site-specific land management options. Copyright © 2008 John Wiley & Sons, Ltd. [source] A mutation in NF,B interacting protein 1 causes cardiomyopathy and woolly haircoat syndrome of Poll Hereford cattleANIMAL GENETICS, Issue 1 2009M. A. Simpson Summary Cardiomyopathy and woolly haircoat syndrome (CWH) of Poll Hereford cattle is a lethal, autosomal recessive disorder. Cardiac and haircoat changes are congenital, neonatal ocular keratitis develops in some cases and death usually occurs within the first 12 weeks of life. We undertook a homozygosity mapping approach to identify the chromosomal location of the causative gene. Seven candidate genes were examined for homozygosity in affected animals: desmoplakin and junction plakoglobin (both previously implicated in human cardiocutaneous syndromes), desmocollin 2, desmoglein 2, plakophilin 2, nuclear factor kappa B (NFKB1) and NF,B interacting protein 1 (PPP1R13L, also known as NKIP1). Homozygosity in 13 affected animals was observed at the PPP1R13L locus, located on bovine chromosome 18. Subsequent sequence analysis revealed a 7-bp duplication (c.956_962dup7) in exon 6 of this 13-exon gene. This frameshift variant is predicted to result in the substitution of three amino acids and the introduction of a premature stop codon at position 325 of the protein product (p.Ser322GlnfsX4). PPP1R13L interacts with NF,B, a family of structurally related transcription factors that regulate genes controlling inflammation, immune responses and cell proliferation and survival. CWH represents a large-animal model for cardiocutaneous disorders caused by a mutation in the PPP1R13L gene. The identification of this bovine mutation also indicates that PPP1R13L and other genes affecting NF,B activity may be candidate genes in the study of human cardiovascular disease. [source] Genetic mapping of quantitative trait loci affecting susceptibility in chicken to develop pulmonary hypertension syndromeANIMAL GENETICS, Issue 6 2005T. S. K. M. Rabie Summary Pulmonary hypertension syndrome (PHS), also referred to as ascites syndrome, is a growth-related disorder of chickens frequently observed in fast-growing broilers with insufficient pulmonary vascular capacity at low temperature and/or at high altitude. A cross between two genetically different broiler dam lines that originated from the White Plymouth Rock breed was used to produce a three-generation population. This population was used for the detection and localization of quantitative trait loci (QTL) affecting PHS-related traits. Ten full-sib families consisting of 456 G2 birds were typed with 420 microsatellite markers covering 24 autosomal chromosomes. Phenotypic observations were collected on 4202 G3 birds and a full-sib across family regression interval mapping approach was used to identify QTL. There was statistical evidence for QTL on chicken chromosome 2 (GGA2), GGA4 and GGA6. Suggestive QTL were found on chromosomes 5, 8, 10, 27 and 28. The most significant QTL were located on GGA2 for right and total ventricular weight as percentage of body weight (%RV and %TV respectively). A related trait, the ratio of right ventricular weight as percentage to total ventricular weight (RATIO), reached the suggestive threshold on this chromosome. All three QTL effects identified on GGA2 had their maximum test statistic in the region flanked by markers MCW0185 and MCW0245 (335,421 cM). [source] Putative in silico mapping of DNA sequences to livestock genome maps using SSLP flanking sequencesANIMAL GENETICS, Issue 1 2003C. R. Farber Summary In this study, an in silico approach was developed to identify homologies existing between livestock microsatellite flanking sequences and GenBank nucleotide sequences. Initially, 1955 bovine, 1570 porcine and 1121 chicken microsatellites were downloaded and the flanking sequences were compared with the nr and dbEST databases of GenBank. A total of 74 bovine, 44 porcine and 37 chicken microsatellite flanking sequences passed our criteria and had at least one significant match to human genomic sequence, genes/expressed sequence tags (ESTs) or both. GenBank annotation and BLAT searches of the UCSC human genome assembly revealed that 38 bovine, 13 porcine and 17 chicken microsatellite flanking sequences were highly similar to known human genes. Map locations were available for 67 bovine, 44 porcine and 21 chicken microsatellite flanking sequences, providing useful links in the comparative maps of humans and livestock. In support of our approach, 112 alignments with both microsatellite and match mapping information were located in the expected chromosomal regions based on previously reported syntenic relationships. The development of this in silico mapping approach has significantly increased the number of genes and EST sequences anchored to the bovine, porcine and chicken genome maps and the number of links in various human,livestock comparative maps. [source] Modeling landscape patterns of understory tree regeneration in the Pacific Northwest, USAAPPLIED VEGETATION SCIENCE, Issue 2 2001Michael C. Wimberly Abstract. Vegetation maps serve as the basis for spatial analysis of forest ecosystems and provide initial information for simulations of forest landscape change. Because of the limitations of current remote sensing technology, it is not possible to directly measure forest understory attributes across large spatial extents. Instead we used a predictive vegetation mapping approach to model Tsuga heterophylla and Picea sitchensis seedling patterns in a 3900-ha landscape in the Oregon Coast Range, USA, as a function of Landsat TM imagery, aerial photographs, digital elevation models, and stream maps. Because the models explained only moderate amounts of variability (R2 values of 0.24,0.56), we interpreted the predicted patterns as qualitative spatial trends rather than precise maps. P. sitchensis seedling patterns were tightly linked to the riparian network, with highest densities in coastal riparian areas. T. heterophylla seedlings exhibited complex patterns related to topography and overstory forest cover, and were also spatially clustered around patches of old-growth forest. We hypothesize that the old growth served as refugia for this fire-sensitive species following wildfires in the late 19th and early 20th centuries. Low levels of T. heterophylla regeneration in hardwood-dominated forests suggest that these patches may succeed to shrublands rather than to conifer forest. Predictive models of seedling patterns could be developed for other landscapes where georeferenced inventory plots, remote sensing data, digital elevation models, and climate maps are available. [source] A Self-Consistent Bathymetric Mapping AlgorithmJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 1-2 2007Chris Roman The achievable accuracy of bathymetric mapping in the deep ocean using robotic systems is most often limited by the available guidance or navigation information used to combine the measured sonar ranges during the map making process. This paper presents an algorithm designed to mitigate the affects of poor ground referenced navigation by applying the principles of map registration and pose filtering commonly used in simultaneous localization and mapping (SLAM) algorithms. The goal of the algorithm is to produce a self-consistent point cloud representation of the bottom terrain with errors that are on a scale similar to the sonar range resolution rather than any direct positioning measurement. The presented algorithm operates causally and utilizes sensor data that are common to instrumented underwater robotic vehicles used for mapping and scientific explorations. Real world results are shown for data taken on several expeditions with the JASON remotely operated vehicle (ROV). Comparisons are made between more standard mapping approaches and the proposed method is shown to significantly improve the map quality and reveal scene information that would have otherwise been obscured due to poor direct navigation information. © 2007 Wiley Periodicals, Inc. [source] Development of molecular markers for crown rot resistance in wheat: mapping of QTLs for seedling resistance in a ,2-49' × ,Janz' populationPLANT BREEDING, Issue 6 2005B. C. Y. Collard Abstract Crown rot, caused by Fusarium pseudograminearum, is an important disease of wheat in Australia and elsewhere. In order to identify molecular markers associated with partial seedling resistance to this disease, bulked segregant analysis and quantitative trait loci (QTL) mapping approaches were undertaken using a population of 145 doubled haploid lines constructed from ,2-49' (partially resistant) × ,Janz' (susceptible) parents. Phenotypic data indicated that the trait is quantitatively inherited. The largest QTLs were located on chromosomes 1D and 1A, and explained 21% and 9% of the phenotypic variance, respectively. Using the best markers associated with five QTLs identified by composite interval mapping, the combined effect of the QTLs explained 40.6% of the phenotypic variance. All resistance alleles were inherited from ,2-49' with the exception of a QTL on 2B, which was inherited from ,Janz'. A minor QTL on 4B was loosely linked (19.8 cM) to the Rht1 locus in repulsion. None of the QTLs identified in this study were located in the same region as resistance QTLs identified in other populations segregating for Fusarium head blight, caused by Fusarium graminearum. [source] | ||||||||||||||||