Visualizing High-Order Symmetric Tensor Field Structure with Differential Operators

The challenge of tensor field visualization is to provide simple and comprehensible representations of data which vary both directionally and spatially. We explore the use of differential operators to extract features from tensor fields. These features can be used to generate skeleton representations of the data that accurately characterize the global field structure. Previously, vector field operators such as gradient, divergence, and curl have previously been used to visualize of flow fields. In this paper, we use generalizations of these operators to locate and classify tensor field degenerate points and to partition the field into regions of homogeneous behavior. We describe the implementation of our feature extraction and demonstrate our new techniques on synthetic data sets of order 2, 3 and 4

Spectral Approaches to Natural Mesh Processing

Mesh design is a major bottleneck in the creation of computer games and animation. Therefore simplifying the process of mesh editing is an important problem. Natural mesh processing is generally difficult to perform since natural meshes often have nontrivial surface shapes and high degrees of freedom. In this study I present novel approaches to natural mesh processing utilizing spectral methods based on the manifold harmonic basis.;Geometric scaling transformations do not respect the biological processes which govern the size and shape of living creatures. I describe an approach to scaling which can be related to biological function. Known biological laws of allometry are used which are expressed as power laws to control the mesh deformation in the frequency domain. This approach is motivated by the relation between fractal biological systems and their underlying power-law spectra. I demonstrate my approach to biology-aware character scaling on triangle meshes representing quadrupedal mammals.;Mesh editing is a time-consuming and error-prone process when changes must be manually applied to repeated structures in the mesh. I propose a fast and accurate method for performing region matching which is based on the manifold harmonic transform. Then this matching method is demonstrated in the context of nonlocal mesh editing - propagating mesh editing operations from a single source region to multiple target regions which may be arbitrarily far away. Finally, I show how mesh skeleton generation can be simplified using spectral approaches. These contributions will lead to more efficient methods of mesh editing and character design

Enhanced Optimization Scheme for Parallel PDE Solver of NSL

Authors have been developing a numerical simulation environment NSL [1], which automatically generates parallel PDE (partial differential equations) solver from high-level description of problem. Two of the notable features of NSL are boundary-fitted coordinate system and multi-block method. Physical domain is mapped onto a group of rectangular computational blocks, each of which is partitioned into one or more congruent sub-blocks. Each processor takes charge of a single sub-block. Static load balancing of such system can be modeled as a combinatorial optimization, which can be solved by branch-and-bound method [2][3]. However, in this model, the number of processors (n) is required to be greater than or equal to the number of blocks (m). This restriction can be a major obstacle to handle many blocks on a modestscale parallel computer. This paper presents an enhanced scheme that works regardless of the relationship between m and n, with additional performance improvement. Basic idea i..

Approach

We describe the design and initial implementation of a system for constructing a haptic model of a mathematical function for exploration using a PHANToM. The model is that of a block of balsa wood with the trace of the function carved into its surface. Problem Statement It is difficult to teach some kinds of mathematics without using graphical representations of functions. In this paper we describe the design of a proposed haptic application and the implementation of a prototype using a PHANToM which will allow a blind student to feel the shape of a function being studied. Related Work Some of our previous work has been in constructing PHANToM-based haptic maps for mobility training. [1] Other VE Lab members are constructing haptic models of atoms. [2

Characterization of function and genetic feature of UDP-glucuronosyltransferase in avian species

Birds are exposed to many xenobiotics during their lifetime. For accurate prediction of xenobiotic-induced toxic effects on avian species, it is necessary to understand metabolic capacities in a comprehensive range of bird species. However, there is a lack of information about avian xenobiotic metabolizing enzymes (XMEs), particularly in wild birds. Uridine diphosphate glucuronosyltransferase (UGT) is an XME that plays an important role in phase II metabolism in the livers of mammals and birds. This study was performed to determine the characteristics of UGT1E isoform in avian species, those are related to mammals UGT 1A. To understand the characteristics of avian UGT1E isoforms, in vitro metabolic activity and genetic characteristics were investigated. Furthermore, mRNA expression levels of all chicken UGT1E isoforms were measured. On in vitro enzymatic analysis, the white-tailed eagle, great horned owl, and Humboldt penguin showed lower UGT-dependent activity than domestic birds. In synteny analysis, carnivorous birds were shown to have fewer UGT1E isoforms than herbivorous and omnivorous birds, which may explain why they have lower in vitro UGT activity. These observations suggested that raptors and seabirds, in which UGT activity is low, may be at high risk if exposed to elevated levels of xenobiotics in the environment. Phylogenetic analysis suggested that avian UGT1Es have evolved independently from mammalian UGT1As. We identified the important UGT isoforms, such as UGT1E13, and suspected their substrate specificities in avian xenobiotic metabolism by phylogenetic and quantitative realtime PCR analysis. This is the first report regarding the genetic characteristics and interspecies differences of UGT1Es in avian species

Comparison of xenobiotic metabolism in phase I oxidation and phase II conjugation between rats and bird species

There have been many reports regarding toxic chemicals in birds. Chemicals are mainly metabolized in the liver through phase I oxidation by cytochrome P450 (GYP) and phase II conjugation by conjugated enzymes, such as UDP-glucuronosyltransferase (UGT), sulfotransferase (SULT), glutathione-S-transferase (GST), etc. Xenobiotic metabolism differs among bird species, but little detailed information is available. In the present study, the four ring polycyclic aromatic hydrocarbon (PAH), pyrene, was used as a model xenobiotic to clarify the characteristics of xenobiotic metabolism in birds compared with laboratory animals by in vivo and in vitro studies. Plasma, bile, and excreta (urine and feces) were collected after oral administration of pyrene and analyzed to clarify xenobiotic metabolism ability in chickens and quails. Interestingly, pyrenediol-glucuronide sulfate (PYDOGS) and pyrenediol-diglucuronide (PYDOGG) were present in chickens and quails but not in rats. In addition, the area under the curve (AUC), maximum plasma concentration (C-max), and time to maximum plasma concentration (T-max) of pyrene-1-sulfate (PYOS) were higher than those of the parent molecule, pyrene, while the elimination half-life (t(1/2)) and mean residence time (MRT) were faster than those of the parent pyrene. With regard to sulfation of 1-hydroxypyrene (PYOH), the maximum velocity (V-max) and Michaelis constant (K-m) of rat liver cytosol were greater than those of chicken and quail liver cytosol. Furthermore, V-max/K-m of UGT activity in rat liver microsomes was also greater than those of chicken and quail liver microsomes. Characterization of xenobiotic metabolism revealed species differences between birds and mammals, raising concerns about exposure to various xenobiotics in the environment

Successful treatment with low‐dose oral steroids for contracted bladder after intravesical instillation of Bacillus Calmette–Guérin

Introduction Contracted bladder is a rare adverse effect of intravesical Bacillus Calmette–Guérin instillation, with an incidence of 0.2–3.3%. This report aimed to present a case of contracted bladder successfully treated with a low‐dose oral steroid. Case presentation A 78‐year‐old man underwent a third transurethral resection of a bladder tumor. The pathological diagnosis was urothelial carcinoma in situ. After the fifth instillation of the second‐line induction therapy of Bacillus Calmette–Guérin, the patient discontinued treatment because of increased urinary frequency and a continuous mean voiding volume of 80 mL. The patient was diagnosed with a contracted bladder based on computed tomography findings and a urination chart. After initiating oral prednisolone (20 mg/day), the patient experienced significant recovery within 2 weeks for both urinary frequency and mean voiding volume of 226 mL. Conclusion A patient with a contracted bladder after Bacillus Calmette–Guérin instillation was successfully treated with low‐dose oral steroid therapy