CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 5-6 2008
Wei-Wei Xu
SUMMARY 1High-density lipoprotein (HDL) is widely accepted as a lipoprotein that protects against coronary artery and other atherosclerotic diseases. Recently, a new apolipoprotein encoded by the APOM gene, which plays an important role in affecting the intrinsic properties of HDL, has been reported. Genetic variations exist in the APOM gene, but their significance is presently unclear. The aim of the present study was to elucidate whether the APOM T-855C mutant allele is implicated in coronary artery disease (CAD). 2In the present study, 418 patients with CAD and 372 controls were studied, all of whom were Han Chinese from Jiangsu Province, China. Plasma levels of triglycerides (TG), total cholesterol (TC), HDL,cholesterol (HDL-C) and low-density lipoprotein,cholesterol (LDL-C) were evaluated. Genomic DNA from the whole blood from these subjects was subjected to polymerase chain reaction amplification and restriction enzyme digestion to determine genotype with respect to the APOM T-855C polymorphism. 3The allelic frequencies were in Hardy,Weinberg equilibrium. Plasma HDL levels were significantly lower in subjects with CAD than in control subjects (1.08 ± 0.31 vs 1.25 ± 0.32, respectively; P < 0.001) and the distribution of genotypes and allelic frequencies was significantly different in the two groups (P = 0.013 and 0.005, respectively). Multiple logistic regression analysis after adjustment for age, gender, smoking, body mass index, hypertension and serum glucose showed that, compared with the wild-type TT genotype, carriers of the C allele had an increased risk of CAD (odds ratio = 1.819, 95% confidence interval 1.142,2.898; P = 0.012). 4In conclusion, the results of the present study suggest that the APOM T-855C polymorphism carries an increased risk for CAD in this Chinese population. [source]

Nevus Lipomatosus Cutaneous Superficialis: A Rare Giant Variant in an Unusual Location

DERMATOLOGIC SURGERY, Issue 12 2008
NAMBI G. ILANGO MS
No abstract is available for this article. [source]

A Putative Alternatively Spliced Variant of the P2X1 Purinoreceptor in Human Bladder

EXPERIMENTAL PHYSIOLOGY, Issue 4 2000
L. A. Hardy
Activation of purinergic P2X receptors, putatively P2X1, may be important in the initiation of contraction in human detrusor. Purinergic transmission may be more important in muscle taken from patients with bladder instability. In this study the presence of the P2X1 receptor subtype was confirmed using RT-PCR. In addition, the results indicate, at the mRNA level, the presence of a splice variant of P2X1 that is lacking part of the second transmembrane domain. It is therefore possible that human bladder expresses multiple isoforms of the P2X1 receptor which may be potential sites for modifying or regulating putative purinergic activation of the human bladder. [source]

Variant of estimation method of aboveground plant biomass in grassland with the gamma model.

GRASSLAND SCIENCE, Issue 2 2006

Abstract A modified method with visual observation for estimating biomass distribution on grasslands is proposed. This labor-saving technique facilitates surveys for estimating herbaceous biomass distribution for grasslands. It is based on the principle of Shiyomi's visual observation method. The procedure is performed as follows. (i) Set two points with biomass of c1 g and c2 g used as criteria in a pasture (c1 < c2). (ii) In the first visual observation, divide herbaceous biomass in the pasture into two classes that are more or less than c1 g. (iii) In the second visual observation, divide herbaceous biomass in the same pasture into two classes that are more or less than c2 g. Then, match the trial numbers obtained in the first and second observations. (iv) Measure the biomass weights of c1 and c2 with cutting. (v) From the data obtained above, infer the herbaceous biomass distribution using the gamma model. The procedure was conducted in a Zoysia grazed pasture. The following are discussed: advantages and regulations of the current method with a gamma model; some problems of the cutting method, as viewed from the shape of herbaceous biomass distribution; and the influence of grazing pressure on herbaceous biomass distribution. [source]

Heterozygous SOX9 Mutations Allowing for Residual DNA-binding and Transcriptional Activation Lead to the Acampomelic Variant of Campomelic Dysplasia,

HUMAN MUTATION, Issue 6 2010
Alex Staffler
Abstract Campomelic dysplasia is a malformation syndrome with multiple symptoms including characteristic shortness and bowing of the long bones (campomelia). CD, often lethal due to airway malformations, is caused by heterozygous mutations in SOX9, an SRY-related gene regulating testis and chondrocyte development including expression of many cartilage genes such as type II collagen. Male to female sex reversal occurs in the majority of affected individuals with an XY karyotype. A mild form without campomelia exists, in which sex-reversal may be also absent. We report here two novel SOX9 missense mutations in a male (c.495C>G; p.His165Gln) and a female (c.337A>G; p.Met113Val) within the DNA-binding domain leading to non-lethal acampomelic CD. Functional analyses of mutant proteins demonstrate residual DNA-binding and transactivation of SOX9-regulated genes. Combining our data and reports from the literature we postulate a genotype-phenotype correlation: SOX9 mutations allowing for residual function lead to a mild form of CD in which campomelia and sex reversal may be absent. © 2010 Wiley-Liss, Inc. [source]

Is That a Pathogenic Mutation, a Rare Non-pathogenic Variant, or Don't You Know?

HUMAN MUTATION, Issue 5 2009
Hamish S. Scott
No abstract is available for this article. [source]

The Effects of a Variant of the Program for All-inclusive Care of the Elderly on Hospital Utilization and Outcomes

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2 2006
Robert L. Kane MD
OBJECTIVES: To compare the effects of the Wisconsin Partnership Program (WPP) on hospital, emergency department (ED), and nursing home utilization with those of traditional care. DESIGN: Quasi-experimental longitudinal cohort design. SETTING: Selected counties in Wisconsin. PARTICIPANTS: WPP elderly enrollees and two matched control groups consisting of frail older people enrolled in fee-for-service insurance plans, Medicare, and Medicaid and receiving home- and community-based waiver services, one from the same geographic area as the WPP and another from a location in the state where the WPP was not offered. MEASUREMENTS: Data came from administrative records. Regression and survival analyses were adjusted for case-mix variables. RESULTS: No significant differences in hospital utilization, ED visits, preventable hospitalizations, risk of entry into nursing homes, or mortality were found. WPP enrollees had more contact with care providers than did controls. CONCLUSION: WPP did not dramatically alter the pattern of care. Part of the weak effect may be attributable to the small numbers of WPP cases per participating physician. [source]

Characterization of a New Pulmonary Vein Variant Using Magnetic Resonance Angiography:

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2004
Imaging, Incidence, Interventional Implications of the "Right Top Pulmonary Vein"
Introduction: Catheter ablation of the pulmonary veins (PVs) for prevention of recurrent atrial fibrillation requires precise anatomic information. We describe the characteristics of a new anatomic variant of PV anatomy using magnetic resonance angiography. Methods and Results: A 1.5-T magnetic resonance imaging system with a body coil or a torso phased-array coil was used before and after gadolinium injection. Magnetic resonance angiograms were acquired with a breath-hold three-dimensional fast spoiled gradient-echo imaging sequence in the coronal plane. Three-dimensional reconstruction with maximum intensity projections and multiplanar reformations was performed. A newly described variant PV ascending from the roof of the left atrium was found in 3 of 91 subjects. The mean ostial diameter of the roof PV was 7 ± 2 mm, the mean distance from the ostium to the first branching point was 22 ± 8.5 mm, and the mean distance to the right superior PV was 3.3 ± 0.6 mm. Conclusion: We refer to the newly described variant of PV anatomy as the "right top pulmonary vein." It is important to be aware of this anatomic pattern to avoid inadvertent catheter intubation, which can result in misleading mapping results and PV stenosis. (J Cardiovasc Electrophysiol, Vol. 15, pp. 538-543, May 2004) [source]

Febrile Ulceronecrotic Mucha-habermann Disease: a Rare, Severe Variant

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2006
Michele M. Thompson
A 56 year old Hispanic man presented with extensive ulcerative skin lesions, involving his lower trunk, groin and upper legs, severe pain and a temperature of 38.7 degrees Celsius. He was admitted to the Medical Intensive Care Unit for empiric intravenous antibiotics. Several biopsies were performed. In the following days his condition worsened and ulcerative lesions involved nearly all of his skin. Previous biopsies were consistent with pityriasis lichenoides et varioliformis acuta (PLEVA), however, neither this, nor others in the histological differential diagnosis, fit his severe and worsening clinical picture. Histology revealed vacuolar alteration with dyskeratotic keratinocytes and a superficial perivascular mixed infiltrate of lymphocytes and eosinophils. There was confluent parakeratosis containing neutrophils, and a diminished granular layer with pallor in the upper portion of the spinous layer. Immunofluorescence studies were negative. These findings were consistent with PLEVA. A clinical diagnosis of febrile ulceronecrotic Mucha-Habermann disease was made. Febrile ulceronecrotic Mucha-Habermann disease is a rare and severe variant of PLEVA characterised by high fever and papulonecrotic skin lesions. Twenty-five cases have been previously reported. We present the clinical and histological findings in this unusual clinical presentation. [source]

Voxel-Based Morphometry and Voxel-Based Relaxometry in Parkinsonian Variant of Multiple System Atrophy

JOURNAL OF NEUROIMAGING, Issue 3 2010
Loukia C. Tzarouchi MD
ABSTRACT BACKGROUND AND PURPOSE Multiple system atrophy (MSA) is a progressive neurodegenerative disorder divided into a parkinsonian (MSA-P) and a cerebellar variant. The purpose of this study was to assess regional brain atrophy and iron content using Voxel-based morphometry (VBM) and Voxel-based relaxometry (VBR) respectively, in MSA-P. METHODS Using biological parametric mapping the effect of brain atrophy was evaluated in T2 relaxation time (T2) measurements by applying analysis of covariance (ANCOVA) and correlation analysis to the VBM and VBR data. Eleven patients with MSA-P (aged 61.9 ± 11.7 years, disease duration 5.42 ± 2.5 years) and 11 controls were studied. RESULTS In comparison to the controls the patients showed decreased gray matter in the putamen, the caudate nuclei, the thalami, the anterior cerebellar lobes, and the cerebral cortex, and white matter atrophy in the pons, midbrain, and peduncles. VBR analysis showed prolonged T2 in various cortical regions. On ANCOVA, when controlling for gray and white matter volume, these regions of prolonged T2 were shrunk. Negative correlation was demonstrated between T2 and gray and white matter volume. CONCLUSIONS Diffuse brain atrophy, mainly in the motor circuitry is observed in MSA-P. Normalization for atrophy should always be performed in T2 measurements. [source]

Gene Coding Variant in Cas1 Between the C57BL/6J and DBA/2J Inbred Mouse Strains: Linkage to a QTL for Ethanol-Induced Locomotor Activation

ALCOHOLISM, Issue 1 2002
Yan Xu
Background: Among some (e.g., DBA/2J or D2) but not all (C57BL/6J or B6) inbred strains of mice, ethanol has a marked psychostimulant effect. Intercrosses formed from the D2 and B6 strains have been used to detect quantitative trait loci (QTLs) for this phenotype. The major QTL is found at the mid-region of chromosome 2 (Demarest et al., 1999). This QTL has also been detected in heterogeneous stock mice (Demarest et al., 2001). A potential candidate gene in this region is Cas1, which codes for catalase. The current studies were conducted to determine (a) if there was difference in the open reading frame (ORF) of Cas1 between the D2 and B6 strains; (b) if a difference was found, was it likely that the difference had functional effects; and (c) if it could be established that Cas1 meets the criteria for QTL to gene. Methods: The open reading frame (ORF) of Cas1 was sequenced in both the D2 and B6 mouse strains. A single polymorphism was found between the strains (see below); the strain distribution pattern for this polymorphism was determined in the 36 strains of the B6XD2 (BXD) recombinant inbred (RI) series. These data were used to map the position of Cas1 as described by Cudmore et al. (1999). Results: The only difference between the D2 and B6 strains in the coding region was found at #349, G,>A. This will result in a difference in the amino acid sequence between the strains at amino acid #117,alanine is found in the D2 strain while threonine is found in the B6 strain. The RI strain distribution pattern for this polymorphism was used to determine the relative placement of Cas1. The estimate suggests that Cas1 is flanked by D2Mit12 and D2Mit43 and relative to D2Mit94 (which was set at 47 cM), Cas1 is located at approximately 57 cM, confirming previous estimates (see http://www.jax.org). Conclusions: Pharmacological data (Correa et al., 2001) strongly support the idea that Cas1 meets the criteria for QTL to gene. However, based on the mapping data, Cas1 is clearly not included in the QTL for heterogeneous stock mice. Finally, other genetic data suggest that the polymorphism is not sufficient to generate the QTL. [source]

A Variant of Des-,-Carboxy Prothrombin Was Increased in Alcoholic Liver Disease Without Hepatocellular Carcinoma

ALCOHOLISM, Issue 2001
Motoyuki Ohhira
Serum variants of des-,-carboxy prothrombin (DCP) recognized by two different monoclonal antibodies, 19B7 and MU-3, were measured in patients with alcoholic liver disease (ALD), and the values were compared with those of viral liver disease (VLD) and hepatocellular carcinoma (HCC). In the assay that used 19B7 antibody, DCP levels in ALD and HCC were significantly higher than that of VLD, although there was no significant difference in the values between ALD and HCC. In the assay that used MU-3 antibody, DCP level of HCC was significantly higher than those of ALD and VLD, although there was no significant difference in values between ALD and VLD. The ratio of 19B7/MU-3 assay values was significantly higher for ALD than the ratios for VLD and HCC. It is suggested that ALD has a different DCP variant pattern compared with VLD and HCC, which suggests that ALD has a different mechanism of DCP production. [source]

Some Remarks on the Origin and Chronology of Halberds in Europe

OXFORD JOURNAL OF ARCHAEOLOGY, Issue 3 2002
Thomas X. Schuhmacher
The present article examines the chronology of the various types of halberd in Europe with particular attention to those from the Iberian Peninsula. An older substrate of halberds is identified which originates in Ireland and Great Britain. From there the design of the Breaghwy type was distributed to the Continent, where the idea and the design were soon imitated in the form of the Rouans, Carrapatas and Variant 6 Continental types. The success of the idea of the halberd is explained by its high prestige character. [source]

CD5-Negative, CD10-Negative small B-cell leukemia: Variant of chronic lymphocytic leukemia or a distinct entity?,

AMERICAN JOURNAL OF HEMATOLOGY, Issue 4 2002
Salwa S. Sheikh
Abstract CD5- and CD10-negative chronic lymphocytic leukemias are quite uncommon as compared to the CD5-positive CLL. We reviewed 250 sequential cases of peripheral blood lymphocytosis to characterize cases of small B-cell lymphoproliferative disorders, submitted with a clinical diagnosis of chronic lymphocytic leukemia exhibiting a non-classic immunophenotypic profile. Six cases of CD5-, CD10-negative chronic lymphocytic leukemias and no tissue involvement were identified that revealed high-density surface-membrane immunoglobulin and CD20 expression, with variable expression of CD11c, CD23, and CD25. Most had a profound leukocytosis (mean WBC 180 × 109/L) with proliferation of mature-appearing lymphocytes. Subsequent bone marrow biopsies showed diffuse infiltration by neoplastic cells in all evaluated patients. The clinical course appeared indolent, with follow-up revealing three patients alive (survival time 38,68 months), while two died of unrelated causes and one was lost to follow-up soon after diagnosis. These cases may represent somewhat unusual chronic lymphoproliferative disorders, with morphologic features and immunophenotypic profile not readily classifiable, but which are certainly atypical for classic chronic lymphocytic leukemia. Some of these features are reminiscent of those seen in marginal-zone lymphoma. However, it is most unusual for this known to be tissue-based disease to present primarily as leukemia rather than lymphoma. Am. J. Hematol. 71:306,310, 2002. © 2002 Wiley-Liss, Inc. [source]

Cutaneous Manifestations from the Follicular Variant of Papillary Carcinoma of the Thyroid: A Case Report and Literature Review

THE LARYNGOSCOPE, Issue S1 2009
Yoon-Soo Bae BS
No abstract is available for this article. [source]

Limited Distribution of a Cardiomyopathy-Associated Variant in India

ANNALS OF HUMAN GENETICS, Issue 2 2010
Tatum S. Simonson
Summary Heart failure is a leading cause of death of people in South Asia, and cardiomyopathy is a major cause of heart failure. Myosin binding protein C (MYBPC3) is expressed in the heart muscle, where it regulates the cardiac response to adrenergic stimulation and is important for the structural integrity of the sarcomere. Mutations in the MYBPC3 gene are associated with hypertrophic or dilated cardiomyopathies. A 25-base-pair deletion in intron 32 causes skipping of the downstream exon and is associated with familial cardiomyopathy. To date, this deletion is found primarily in India and South Asia, although it is also found at low frequency in Southeast Asia. In order to better characterise the distribution of this variant, we determined its frequency in 447 individuals from 19 populations, including 10 populations from India and neighbouring populations from Pakistan and Nepal. The deletion frequency is over 8% in some of our Indian samples, and it is not present in any of the populations we sampled outside of India. The differences in the deletion frequencies among populations in India are consistent with patterns of variation previously reported and with patterns we observed among Indian populations based on high-density SNP chip data. Our results indicate that the MYBPC3 deletion is primarily found among Indian populations and that its distribution is consistent with genome-wide patterns of variation in India. [source]

Refined Geographic Distribution of the Oriental ALDH2*504Lys (nee 487Lys) Variant

ANNALS OF HUMAN GENETICS, Issue 3 2009
Hui Li
Summary Mitochondrial aldehyde dehydrogenase (ALDH2) is one of the most important enzymes in human alcohol metabolism. The oriental ALDH2*504Lys variant functions as a dominant negative, greatly reducing activity in heterozygotes and abolishing activity in homozygotes. This allele is associated with serious disorders such as alcohol liver disease, late onset Alzheimer disease, colorectal cancer, and esophageal cancer, and is best known for protection against alcoholism. Many hundreds of papers in various languages have been published on this variant, providing allele frequency data for many different populations. To develop a highly refined global geographic distribution of ALDH2*504Lys, we have collected new data on 4,091 individuals from 86 population samples and assembled published data on a total of 80,691 individuals from 366 population samples. The allele is essentially absent in all parts of the world except East Asia. The ALDH2*504Lys allele has its highest frequency in Southeast China, and occurs in most areas of China, Japan, Korea, Mongolia, and Indochina with frequencies gradually declining radially from Southeast China. As the indigenous populations in South China have much lower frequencies than the southern Han migrants from Central China, we conclude that ALDH2*504Lys was carried by Han Chinese as they spread throughout East Asia. Esophageal cancer, with its highest incidence in East Asia, may be associated with ALDH2*504Lys because of a toxic effect of increased acetaldehyde in the tissue where ingested ethanol has its highest concentration. While the distributions of esophageal cancer and ALDH2*504Lys do not precisely correlate, that does not disprove the hypothesis. In general the study of fine scale geographic distributions of ALDH2*504Lys and diseases may help in understanding the multiple relationships among genes, diseases, environments, and cultures. [source]

A Novel Point Variant in NTRK3, R645C, Suggests a Role of this Gene in the Pathogenesis of Hirschsprung Disease

ANNALS OF HUMAN GENETICS, Issue 1 2009
R. M. Fernández
Summary Hirschsprung disease (HSCR) is a developmental disorder characterized by the absence of ganglion cells in the myenteric and submucosal plexuses due to a defect in the migration process of neural crest neuroblasts. Manifestation of the disease has been linked to the dysfunction of two principal signalling pathways involved in the enteric nervous system (ENS) formation: the RET-GDNF and the EDN3-EDNRB receptor systems. However, the NTF3/NTRK3 signalling pathway plays an essential role in the development of the ENS suggesting a potential role for those genes in the pathogenesis of HSCR. We have sought to evaluate the candidature of the NTRK3 gene, which encodes the TrkC receptor, as a susceptibility gene for Hirschsprung disease. Using dHPLC technology we have screened the NTRK3 coding region in 143 Spanish HSCR patients. A total of four previously described polymorphisms and 12 novel sequence variants were detected. Of note, the novel R645C mutation was detected in 2 affected siblings of a HSCR family also carrying a RET splicing mutation. Using bioinformatics tools we observed that the presence of an additional cysteine residue might implicate structural alterations in the mutated protein. We propose haploinsufficiency as the most probable mechanism for the NTRK3 R645C mutation. NTRK3 and RET mutations in this family only appear together in the HSCR patients, suggesting that they per se are necessary but not sufficient to produce the phenotype. In addition, it is quite probable that the contribution of other still unidentified modifier genes, may be responsible for the different phenotypes (length of aganglionosis) in the two affected members. [source]

ChemInform Abstract: A New Variant of Reformatsky,Claisen Rearrangement Mediated by Indium Chloride.

CHEMINFORM, Issue 4 2010
Jun Ishihara
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

ChemInform Abstract: Cd13-xInySb10 (x , 2.7, y , 1.5): An Interstitial-Free Variant of Thermoelectric ,-Zn4Sb3.

CHEMINFORM, Issue 38 2009
Andreas Tengaa
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

ChemInform Abstract: New Scandium Platinum Silicides: ScPt2Si with "Inverse" MgCuAl2 Structure and Sc5Pt9Si7, a Variant of the Zr2Fe12P7 -Type.

CHEMINFORM, Issue 32 2009
Peter Lorenz
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

ChemInform Abstract: Infinite Gold Zig-Zag Chains as Structural Motif in Ca3Au3In , A Ternary Ordered Variant of the Ni4B3 Type.

CHEMINFORM, Issue 11 2008
Ihor R. Muts
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

The New Silver(I)thioantimonate(III) [C4N2H14] [Ag3Sb3S7] and a New Structural Variant of the Silver(I)thioantimonate(III) [C2N2H9]2 [Ag5Sb3S8] Both Synthesized under Solvothermal Conditions.

CHEMINFORM, Issue 2 2007
V. Spetzler
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

Primary male infertility in Kuwait: a cytogenetic and molecular study of 289 infertile Kuwaiti patients

ANDROLOGIA, Issue 3 2007
F. Mohammed
Summary Infertility is one of the major public health problems, affecting 15% of couples who attempt pregnancy; in 50% of these, the male partner is responsible. Chromosomal abnormalities and Y microdeletions in the azoospermia factor (AZF) region are known to be associated with spermatogenetic failure. In the present study, 289 patients with primary male infertility because of spermatogenetic failure were studied in order to highlight the molecular background of male infertility in Kuwait, and to avoid the possibility of transmission of any microdeletions/chromosomal aberrations to offspring via intracytoplasmic sperm injection (ICSI). Of the 289 infertile men, 23 patients (8%) had chromosomal aberration in the form of Klinefelter syndrome/variant (16/23; 69.6%), XYY syndrome (3/23; 13%), XX male syndrome (2/23; 8.7%), 45,X/46X, i(Yp)(1/23; 4.4%) and 45,XY, t(9;22) (1/23;4.4%). Y-chromosome microdeletion in the AZFb and AZFc regions were detected in 7/266 cases (2.6%). Testicular biopsy was carried out in 31 azoospermic patients, of whom five men had Sertoli-cell only syndrome, while 26 patients had spermatogenic arrest. In conclusion, this study showed that the frequency of both chromosomal anomalies and Y microdeletions were found in 10.4% of the infertile men. The potential risk of transmitting these genetic disorders to offspring provides a rationale for screening infertile men prior to ICSI. [source]

Generalized minimum-norm perspective shadow maps

COMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 5 2008
Fan Zhang
Abstract Shadow mapping has been extensively used for real-time shadow rendering in 3D computer games, though it suffers from the inherent aliasing problems due to its image-based nature. This paper presents an enhanced variant of light space perspective shadow maps to optimize perspective aliasing distribution in possible general cases where the light and view directions are not orthogonal. To be mathematically sound, the generalized representation of perspective aliasing errors has been derived in detail. Our experiments have shown the enhanced shadow quality using our algorithm in dynamic scenes. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Hierarchical Image-Space Radiosity for Interactive Global Illumination

COMPUTER GRAPHICS FORUM, Issue 4 2009
Greg Nichols
Abstract We introduce image-space radiosity and a hierarchical variant as a method for interactively approximating diffuse indirect illumination in fully dynamic scenes. As oft observed, diffuse indirect illumination contains mainly low-frequency details that do not require independent computations at every pixel. Prior work leverages this to reduce computation costs by clustering and caching samples in world or object space. This often involves scene preprocessing, complex data structures for caching, or wasted computations outside the view frustum. We instead propose clustering computations in image space, allowing the use of cheap hardware mipmapping and implicit quadtrees to allow coarser illumination computations. We build on a recently introduced multiresolution splatting technique combined with an image-space lightcut algorithm to intelligently choose virtual point lights for an interactive, one-bounce instant radiosity solution. Intelligently selecting point lights from our reflective shadow map enables temporally coherent illumination similar to results using more than 4096 regularly-sampled VPLs. [source]

LazyBrush: Flexible Painting Tool for Hand-drawn Cartoons

COMPUTER GRAPHICS FORUM, Issue 2 2009
Daniel Sýkora
Abstract In this paper we present LazyBrush, a novel interactive tool for painting hand-made cartoon drawings and animations. Its key advantage is simplicity and flexibility. As opposed to previous custom tailored approaches [SBv05, QWH06] LazyBrush does not rely on style specific features such as homogenous regions or pattern continuity yet still offers comparable or even less manual effort for a broad class of drawing styles. In addition to this, it is not sensitive to imprecise placement of color strokes which makes painting less tedious and brings significant time savings in the context cartoon animation. LazyBrush originally stems from requirements analysis carried out with professional ink-and-paint illustrators who established a list of useful features for an ideal painting tool. We incorporate this list into an optimization framework leading to a variant of Potts energy with several interesting theoretical properties. We show how to minimize it efficiently and demonstrate its usefulness in various practical scenarios including the ink-and-paint production pipeline. [source]

Provably Good 2D Shape Reconstruction from Unorganized Cross-Sections

COMPUTER GRAPHICS FORUM, Issue 5 2008
Pooran Memari
Abstract This paper deals with the reconstruction of 2-dimensional geometric shapes from unorganized 1-dimensional cross-sections. We study the problem in its full generality following the approach of Boissonnat and Memari [BM07] for the analogous 3D problem. We propose a new variant of this method and provide sampling conditions to guarantee that the output of the algorithm has the same topology as the original object and is close to it (for the Hausdorff distance). [source]

Optimal integrated code generation for VLIW architectures

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 11 2006
Christoph Kessler
Abstract We present a dynamic programming method for optimal integrated code generation for basic blocks that minimizes execution time. It can be applied to single-issue pipelined processors, in-order-issue superscalar processors, VLIW architectures with a single homogeneous register set, and clustered VLIW architectures with multiple register sets. For the case of a single register set, our method simultaneously copes with instruction selection, instruction scheduling, and register allocation. For clustered VLIW architectures, we also integrate the optimal partitioning of instructions, allocation of registers for temporary variables, and scheduling of data transfer operations between clusters. Our method is implemented in the prototype of a retargetable code generation framework for digital signal processors (DSPs), called OPTIMIST. We present results for the processors ARM9E, TI C62x, and a single-cluster variant of C62x. Our results show that the method can produce optimal solutions for small and (in the case of a single register set) medium-sized problem instances with a reasonable amount of time and space. For larger problem instances, our method can be seamlessly changed into a heuristic. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Diagnosing PNH with FLAER and multiparameter flow cytometry

CYTOMETRY, Issue 3 2007
D. Robert Sutherland
Abstract Background: PNH is an acquired hematopoietic stem cell disorder leading to a partial or absolute deficiency of all glycophosphatidyl-inositol (GPI)-linked proteins. The classical approach to diagnosis of PNH by cytometry involves the loss of at least two GPI-linked antigens on RBCs and neutrophils. While flow assays are more sensitive and specific than complement-mediated lysis or the Hams test, they suffer from several drawbacks. Bacterial aerolysin binds to the GPI moiety of cell surface GPI-linked molecules and causes lysis of normal but not GPI-deficient PNH cells. FLAER is an Alexa488-labeled inactive variant of aerolysin that does not cause lysis of cells. Our goals were to develop a FLAER-based assay to diagnose and monitor patients with PNH and to improve detection of minor populations of PNH clones in other hematologic disorders. Methods: In a single tube assay, we combined FLAER with CD45, CD33, and CD14 allowing the simultaneous analysis of FLAER and the GPI-linked CD14 structure on neutrophil and monocyte lineages. Results: Comparison to standard CD55 and CD59 analysis showed excellent agreement. Because of the higher signal to noise ratio, the method shows increased sensitivity in our hands over single (CD55 or CD59) parameter analysis. Using this assay, we were able to detect as few as 1% PNH monocytes and neutrophils in aplastic anemia, that were otherwise undetectable using CD55 and CD59 on RBC's. We also observed abnormal FLAER staining of blast populations in acute leukemia. In these cases, the neutrophils stained normally with FLAER, while the gated CD33bright cells failed to express normal levels of CD14 and additionally showed aberrant CD45 staining and bound lower levels of FLAER. Conclusion: FLAER combined with multiparameter flow cytometry offers an improved assay for diagnosis and monitoring of PNH clones and may have utility in detection of unsuspected myeloproliferative disorders. © 2007 Clinical Cytometry Society [source]