Large Number (large + number)

Distribution by Scientific Domains

Kinds of Large Number

  • very large number


  • Selected Abstracts


    Cervicomental "Turkey Gobbler": A New Source for Full-Thickness Grafts

    DERMATOLOGIC SURGERY, Issue 4 2002
    FIACS, Lawrence M. Field MD
    A LARGE NUMBER of sources for full-thickness grafts have been described. The concepts of adapting liposuction techniques from cosmetic surgery to reconstructive surgery, especially with flap reconstructions, have been well documented by this author and others in many forums over many years.1,7 However, obtaining the excess skin of the lower neck in those patients with "turkey gobbler" deformities utilizing liposuction aspiration and dissection techniques has not been previously documented. This same approach might at times be valuable in very obese necks with excessively redundant skin as well. [source]


    ON THE STRONG LAW OF LARGE NUMBERS UNDER REARRANGEMENTS FOR SEQUENCES OF BLOCKWISE ORTHOGONAL RANDOM ELEMENTS IN BANACH SPACES

    AUSTRALIAN & NEW ZEALAND JOURNAL OF STATISTICS, Issue 4 2007
    Nguyen Van Quang
    Summary The condition of the strong law of large numbers is obtained for sequences of random elements in type p Banach spaces that are blockwise orthogonal. The current work extends a result of Chobanyan & Mandrekar (2000)[On Kolmogorov SLLN under rearrangements for orthogonal random variables in a B -space. J. Theoret. Probab. 13, 135,139.] Special cases of the main results are presented as corollaries, and illustrative examples are provided. [source]


    When and where to fuel before crossing the Sahara desert , extended stopover and migratory fuelling in first-year garden warblers Sylvia borin

    JOURNAL OF AVIAN BIOLOGY, Issue 2 2008
    Thord Fransson
    Large numbers of passerine migrants cross the Sahara desert every year on their way to-and-from wintering areas in tropical Africa. In the desert, hardly any fuelling opportunities exist and most migrants have to prepare in advance. A central question is how inexperienced birds know where to fuel. Inexperienced garden warblers Sylvia borin were studied in Greece just before the desert crossing in autumn. Body mass data collected at two sites indicate that most birds do not fuel for the desert crossing further north. For the first time, detailed information about stopover duration close to the Sahara desert was studied by using light weight radio-transmitters. Results from Crete show that most first-year garden warblers arrive with relatively small fuel loads in relation to lean body mass (<30%), stay for 13,20 d and depart with an average fuel load of about 100%. Radio-tagged birds performed small scale movements initially and took advantage of fig fruits. Birds trapped at fig trees were heavier than birds trapped with tape lures, showing that tape lures can bias the sample of migrants trapped. The precise fuelling pattern found indicates that first-year migrants must also include external spatial cues to make the preparation for crossing the desert in the right area. [source]


    The impact of migration on rural poverty and inequality: a case study in China

    AGRICULTURAL ECONOMICS, Issue 2 2010
    Nong Zhu
    Migration; Poverty; Inequality; China Abstract Large numbers of agricultural labor moved from the countryside to cities after the economic reforms in China. Migration and remittances play an important role in transforming the structure of rural household income. This article examines the impact of rural-to-urban migration on rural poverty and inequality in a mountainous area of Hubei province using the data of a 2002 household survey. Since migration income is a potential substitute for farm income, we present counterfactual scenarios of what rural income, poverty, and inequality would have been in the absence of migration. Our results show that, by providing alternatives to households with lower marginal labor productivity in agriculture, migration leads to an increase in rural income. In contrast to many studies that suggest that the increasing share of nonfarm income in total income widens inequality, this article offers support for the hypothesis that migration tends to have egalitarian effects on rural income for three reasons: (1) migration is rational self-selection,farmers with higher expected return in agricultural activities and/or in local nonfarm activities choose to remain in the countryside while those with higher expected return in urban nonfarm sectors migrate; (2) households facing binding constraints of land supply are more likely to migrate; (3) poorer households benefit disproportionately from migration. [source]


    Ultrastructural study of the precursor to fungiform papillae prior to the arrival of sensory nerves in the fetal rat

    JOURNAL OF MORPHOLOGY, Issue 3 2001
    Shin-ichi Iwasaki
    Abstract The structure of precursors to fungiform papillae without taste buds, prior to the arrival of sensory nerve fibers at the papillae, was examined in the fetal rat on embryonic day 13 (E13) and 16 (E16) by light and transmission electron microscopy in an attempt to clarify the mechanism of morphogenesis of these papillae. At E13, a row of rudiments of fungiform papillae was arranged along both sides of the median sulcus of the lingual dorsal surface, and each row consisted of about 10 rudiments. There was no apparent direct contact between papillae rudiments and sensory nerves at this time. Bilaterally towards the lateral side of the tongue, adjacent to these first rudiments of fungiform papillae, a series of cord-like invaginations of the dorsal epithelium of the tongue into the underlying connective tissue, representing additional papillary primordia parallel to the first row, was observed. The basal end of each invagination was enlarged as a round bulge, indented at its tip by a mound of fibroblasts protruding into the bulge. At E16 there was still no apparent direct contact between rudiments of fungiform papillae and sensory nerves. Each rudiment apically contained a spherical core of aggregating cells, which consisted of a dense assembly of large, oval cells unlike those in other areas of the lingual dorsal epithelium. The differentiation of these aggregated cells was unclear. The basal lamina was clearly recognizable between the epithelium of the rudiment of fungiform papillae and the underlying connective tissue. Spherical structures, which appeared to be sections of the cord-like invaginations of the lingual epithelium that appeared on E13, were observed within the connective tissue separated from the dorsal lingual epithelium. Transverse sections of such structures revealed four concentric layers of cells: a central core, an inner shell, an outer shell, and a layer of large cells. Bundles of fibers were arranged in the central core, and the diameters of bundles varied somewhat depending on the depth of the primordia within the connective tissue and their distance from the median sulcus. Ultrastructural features of cells in the outer shell differed significantly in rudiments close to the lingual epithelium as compared to those in deeper areas of connective tissue. Around the outer shell there was a large-cell layer consisting of one to three layers of radially elongated, oval cells that contained many variously sized, electron-dense, round granules. Large numbers of fibroblasts formed dense aggregates around each spherical rudiment, and were separated by the basal lamina from the large-cell epithelial layer. Progressing from deep-lying levels of the rudiments of the papillae to levels close to the lingual surface epithelium, the central core, inner shell, and outer shell gradually disappeared from the invaginated papillary cords. J. Morphol. 250:225,235, 2001. © 2001 Wiley-Liss, Inc. [source]


    Semaphorin 3A and neurotrophins: a balance between apoptosis and survival signaling in embryonic DRG neurons

    JOURNAL OF NEUROCHEMISTRY, Issue 2 2006
    Ayal Ben-Zvi
    Abstract Large numbers of neurons are eliminated by apoptosis during nervous system development. For instance, in the mouse dorsal root ganglion (DRG), the highest incidence of cell death occurs between embryonic days 12 and 14 (E12,E14). While the cause of cell death and its biological significance in the nervous system is not entirely understood, it is generally believed that limiting quantities of neurotrophins are responsible for neuronal death. Between E12 and E14, developing DRG neurons pass through tissues expressing high levels of axonal guidance molecules such as Semaphorin 3A (Sema3A) while navigating to their targets. Here, we demonstrate that Sema3A acts as a death-inducing molecule in neurotrophin-3 (NT-3)-, brain-derived neurotrophic factor (BDNF)- and nerve growth factor (NGF)-dependent E12 and E13 cultured DRG neurons. We show that Sema3A most probably induces cell death through activation of the c-Jun N-terminal kinase (JNK)/c-Jun signaling pathway, and that this cell death is blocked by a moderate increase in NGF concentration. Interestingly, increasing concentrations of other neurotrophic factors, such as NT-3 or BDNF, do not elicit similar effects. Our data suggest that the number of DRG neurons is determined by a fine balance between neurotrophins and Semaphorin 3A, and not only by neurotrophin levels. [source]


    Glial-guided neuronal migration in P19 embryonal carcinoma stem cell aggregates

    JOURNAL OF NEUROSCIENCE RESEARCH, Issue 1 2005
    Marcelo F. Santiago
    Abstract During development of the nervous system, neuronal precursors that originated in proliferative regions migrate along radial glial fibers to reach their final destination. P19 embryonal carcinoma (EC) stem cells exposed to retinoic acid (RA) differentiate into neurons, glia, and fibroblast-like cells. In this work, we induced P19 aggregates for 4 days with RA and plated them onto tissue culture dishes coated with poly-L-lysine. Several cells migrated out of and/or extended processes from the aggregates after 24 hr. Some cell processes were morphologically similar to radial glial fibers and stained for glial fibrillar acidic protein (GFAP) and nestin. Large numbers of migrating cells showed characteristics similar to those of bipolar migrating neurons and expressed the neuronal marker microtubule-associated protein 2. Furthermore, scanning electron microscopy analysis revealed an intimate association between the radial fibers and the migrating cells. Therefore, the migration of neuron-like cells on radial glia fibers in differentiated P19 aggregates resembled some of the migration models used thus far to study gliophilic neuronal migration. In addition, HPTLC analysis in this system showed the expression of 9-O-acetyl GD3, a ganglioside that has been associated with neuronal migration. Antibody perturbation assays showed that immunoblockage of 9-O-acetyl GD3 arrested neuronal migration in a reversible manner. In summary, we have characterized a new cell culture model for investigation of glial-guided neuronal migration and have shown that 9-O-acetyl GD3 ganglioside has an important role in this phenomenon. © 2005 Wiley-Liss, Inc. [source]


    Frost Injury as a Possible Inciting Factor in Bud and Shoot Necroses of Fraxinus excelsior L.

    JOURNAL OF PHYTOPATHOLOGY, Issue 9 2005
    P. M. Pukacki
    Abstract Large numbers of European ash have died in Poland in all age classes during the last ten years. The characteristic symptom occurring on shoots of planted and self-sown seedlings was bark necroses starting from the shoot apex, necrotic buds, or leaf and twig scars. The results showed that in the bud tissue of cold acclimated European ash extracellular and intracellular ice formation occurred at approximately ,9 and ,32°C, respectively. In deacclimated plants in spring water supercooling is limited by the heterogenous ice nucleation temperature and consequently the cold tolerance is ,9 to ,4°C for bud tissues and ,13 to ,9°C for shoots. Isolations of fungi were performed from dead buds and from necroses occurring on the main stem. Alternaria alternata, Fusarium lateritium and Phomopsis scobina were among the fungi occurring in both these organs at frequencies of more than 7%. Cylindrocarpon heteronemum, Diplodia mutila and Tubercularia vulgaris from necroses were only isolated in frequencies; 3.3, 1.2 and 5.4%, respectively. It seems likely that freezing injury is the inciting factor, which combined with fungal colonization manifests itself as fatal damage to European ash buds and shoots. [source]


    More polymorphic microsatellite markers in the European sea bass (Dicentrarchus labrax L.)

    MOLECULAR ECOLOGY RESOURCES, Issue 4 2002
    Y. Ciftci
    Abstract We provide details of five microsatellite loci screened in 163 individual sea bass. Large numbers of alleles were observed at three loci (20,25) and heterozygosities ranged from 0.52 to 0.86. These loci should prove useful for population genetic studies and for the pedigree analysis and genetic management of this species in aquaculture. [source]


    Dysplastic Nevi of the Scalp and Forehead in Children

    PEDIATRIC DERMATOLOGY, Issue 1 2001
    Martin Fernandez M.D.
    Large numbers of the nevi biopsied from the scalp (13 of 31; 41.93%) and forehead (2 of 10; 20%) were dysplastic. The number of dysplastic nevi from the neck (1 of 58; 1.72%) was not assessed as very different from the incidence found in other regions of the body, where 7 dysplastic nevi (7.36%) from a total of 95 nevi were found. Of the 13 dysplastic nevi from the scalp, 9 showed minimal atypia and 4 showed moderate atypia. No nevi with severe atypia were found. Many pigmented nevi from the scalp and forehead in children in this study were dysplastic. This finding points out the importance of examining the scalp of children for the presence of dysplastic nevi. The majority of nevi from the neck were common nevi. [source]


    Timeline and distribution of melanocyte precursors in the mouse heart

    PIGMENT CELL & MELANOMA RESEARCH, Issue 4 2008
    Flavia Carneiro Brito
    Summary Apart from the well-studied melanocytes of the skin, eye and inner ear, another population has recently been described in the heart. In this study, we tracked cardiac melanoblasts using in situ hybridization with a dopachrome tautomerase (Dct) probe and Dct -LacZ transgenic mice. Large numbers of melanoblasts were found in the atrioventricular (AV) endocardial cushions at embryonic day (E) 14.5 and persisted in the AV valves into adulthood. The earliest time Dct -LacZ-positive cells were observed in the AV endocardial cushions was E12.5. Prior to that, between E10.5 and E11.5, small numbers of melanoblasts traveled between the post-otic area and third somite along the anterior and common cardinal veins and branchial arch arteries with other neural crest cells expressing CRABPI. Cardiac melanocytes were not found in the spotting mutants Ednrbs-l/s-l and Kitw-v/w-v, while large numbers were observed in transgenic mice that overexpress endothelin 3. These results indicate that cardiac melanocytes depend on the same signaling molecules known to be required for proper skin melanocyte development and may originate from the same precursor population. Cardiac melanocytes were not found in zebrafish or frog but were present in quail suggesting an association between cardiac melanocytes and four-chambered hearts. [source]


    Coupling the GAL4 UAS system with alcR for versatile cell type-specific chemically inducible gene expression in Arabidopsis

    PLANT BIOTECHNOLOGY JOURNAL, Issue 4 2007
    Lali Sakvarelidze
    Summary The Aspergillus alc regulon encodes a transcription factor, ALCR, which regulates transcription from cognate promoters such as alcA(p). In the presence of suitable chemical inducers, ALCR activates gene expression from alcA(p). The alc regulon can be transferred to other species and can be used to control the expression of reporter, metabolic and developmental genes in response to low-level ethanol exposure. In this paper, we describe a versatile system for targeting the alc regulon to specific cell types in Arabidopsis by driving ALCR expression from the GAL4 upstream activator sequence (UAS). Large numbers of Arabidopsis lines are available in which GAL4 is expressed in a variety of spatial patterns and, in turn, drives the expression of any gene cloned downstream of the UAS. We have used a previously characterized line that directs gene expression to the endosperm to demonstrate spatially restricted ethanol-inducible gene expression. We also show that the domain of inducible gene expression can easily be altered by crossing the UAS::ALCR cassette into different driver lines. We conclude that this gene switch can be used to drive gene expression in a highly responsive, but spatially restricted, manner. [source]


    A New Approach to the Deposition of Elemental Boron and Boron-Based Coatings by Pulsed Magnetron Sputtering of Loosely Packed Boron Powder Targets

    PLASMA PROCESSES AND POLYMERS, Issue S1 2007
    Martynas Audronis
    Abstract Large numbers of potential application areas for elemental boron and boron-based thin film materials make this subject area a focus of significant scientific and industrial interest. Applications include thermoelectric energy conversion devices, biomedical implants, metalworking tools and automotive components. Boron is however also recognised widely to be a difficult-to-deposit material. Therefore, a new technique to deposit boron (and other boron-based materials) by pulsed magnetron sputtering of loosely packed powder targets has been proposed. Among the benefits of this approach are: improved stability of the deposition process, increased speed and flexibility of target preparation, enhanced time- and cost-effectiveness and the ability to control readily the target and hence the chemical composition of the coating. [source]


    The optimal density of atmospheric sounder observations in the Met Office NWP system

    THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 629 2007
    M. L. Dando
    Abstract Large numbers of satellite observations are discarded from the numerical weather prediction (NWP) process because high-density observations may have a negative impact on the analysis. In current assimilation schemes, the observation error covariance matrix R is usually represented as a diagonal matrix, which assumes there are no correlations in the observation errors and that each observation is an independent piece of information. This is not the case when there are strong error correlations and this can lead to a degraded analysis. The experiments conducted in this study were designed to identify the optimal density and to determine if there were circumstances when exceeding this density might be beneficial to forecast skill. The global optimal separation distance of Advanced TIROS Operational Vertical Sounder (ATOVS) observations was identified by comparing global forecast errors produced using different densities of ATOVS. The global average of the absolute forecast error produced by each different density was found for a 3-week period from December 2004 to January 2005. The results showed that, when using the Met Office NWP system with a horizontal model resolution of ,60 km, the lowest global forecast errors were produced when using separation distances of 115,154 km. However, localized regions of the atmosphere containing large gradients such as frontal regions may benefit from thinning distances as small as 40 km and therefore the global optimal separation distance is not necessarily applicable in these circumstances. Copyright © 2007 Royal Meteorological Society [source]


    Cellular characterization of the gouty tophus: A quantitative analysis

    ARTHRITIS & RHEUMATISM, Issue 5 2010
    Nicola Dalbeth
    Objective To characterize the cellular architecture of the tophus and to determine the presence of cytokines implicated in the initiation and resolution of gouty inflammation. Methods Sixteen fixed, paraffin-embedded, uninfected tophus samples were surgically obtained from 12 patients with microscopically proven gout and were analyzed by quantitative immunohistochemistry. The number of cells present in the corona and fibrovascular zones of the tophus was analyzed by Genmod mixed models analysis. Results Numerous CD68+ mononucleated and multinucleated cells were present within the corona zone. Mast cells were identified in all tophus samples and at similar densities throughout the corona and fibrovascular zones. In contrast, neutrophils were rarely observed. Plasma cells were present in very high numbers within the corona zone. The overall number of CD20+ B cells was much lower. However, in 6 of 12 patients (50%), at least 1 B cell aggregate was present in the fibrovascular zone. Large numbers of cells expressing interleukin-1, (IL-1,) were observed in the corona zone. Transforming growth factor ,1 (TGF,1),expressing mononucleated cells were also identified. The number of CD68+ cells correlated with the number of cells expressing IL-1, (r = 0.691, P = 0.009) and the number expressing TGF,1 (r = 0.518, P = 0.04). Conclusion The tophus represents a complex and organized chronic inflammatory tissue response to monosodium urate monohydrate crystals involving both innate and adaptive immune cells. The coexpression of IL-1, and TGF,1 suggests that both proinflammatory and antiinflammatory factors present within the tophus contribute to a cycle of chronic inflammation, attempted resolution, and tissue remodeling. [source]


    Avian fruit consumption and seed dispersal in a temperate Australian woodland

    AUSTRAL ECOLOGY, Issue 2 2002
    Margaret C. Stanley
    Abstract The effectiveness of avian fruit consumers as seed dispersers of fleshy-fruited plants was studied in a temperate woodland community. As a consequence of the short and overlapping fruiting phenologies of fleshy-fruited plant species in temperate regions of Australia, there are very few avian species that are true specialist frugivores. The relative importance of bird species as fruit consumers was investigated, and how their foraging activities, movements and gut treatment of seeds affected dispersal of viable seeds away from the parent plant was examined. Fruit consumption and consumer seed dispersal capacity were assessed in this study through faecal analyses and by testing the viability of seeds that had passed through the gut of avian consumers. Behavioural observations enabled us to determine the consumption rates of, and quantities of fruit consumed by, various bird species and the amount of time spent feeding. Silvereyes (Zosterops lateralis) were the dominant fruit consumers in the community, although 19 bird species were either observed consuming fruit or provided faecal samples that contained fruit. Silvereyes had a high local abundance at the site and more than 90% of silvereyes'faecal samples contained the seeds of fruiting plants (n = 409). Large numbers of fruit were consumed per visit by silvereyes, particularly for Rhagodia parabolica (fragrant saltbush). Silvereyes consumed an average of four R. parabolica fruit per 5 s and up to a maximum 40 fruit per visit. Viability was high for seeds recovered from silvereyes'faeces (R. parabolica, 94.4% viable; Hymenanthera dentata, 100% viable). However, the number of seeds per faecal sample was high for R. parabolica, which may result in density-dependent seed mortality. Gut passage rate for silvereyes fed R. parabolica fruit in captivity was 31.5 ± 1.9 min. Silvereyes remained at fruiting plants for very short periods (average 50-60 s) and in most cases moved away from the parent plant, primarily toward canopy trees. Given the short visit duration of silvereyes, individuals would have left the parent plant well before seeds passed through the gut. Rhagodia parabolica fruit was consumed by a large number of bird species in the community, including species often thought of as exclusively insectivorous or nectarivorous. These species are likely to disperse viable R. parabolica seeds into microhabitats different from those visited by silvereyes. [source]


    Development of a synthetic plant volatile-based attracticide for female noctuid moths.

    AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2010

    Abstract We investigated the efficacy of insecticides combined with a plant volatile-based attractant for Helicoverpa armigera moths, under laboratory and field conditions. In the laboratory, 16 insecticides were assessed by the level of mortality and time to incapacitate and kill moths. The proboscis extension reflex technique was used for dosing moths. The pyrethroids, bifenthrin (only when synergised by the addition of piperonyl butoxide (PBO) but not without it) and cyfluthrin (with or without PBO), endosulfan, the carbamates methomyl and thiodicarb, and spinosad killed all moths tested at rates equivalent to, or less than, those which would be applied in cover sprays targeting larvae. The shortest time to moth incapacitation and death was observed with methomyl and thiodicarb. Spinosad produced very high mortality but moths took much longer to die. The two pyrethroids gave relatively slow kills, as did endosulfan. In a field trial, four insecticides were combined with the attractant and dead moths were collected daily from 1 to 4 days after application of the attracticide on 50 m rows of cotton. Significantly more dead moths (H. armigera, H. punctigera and other noctuids) were found near the rows treated with attracticide containing methomyl compared with spinosad, fipronil and deltamethrin. For determining the impact of attracticides by recovering dead moths, quick acting insecticides are required to prevent moths flying away from the treated area to locations where they cannot be found. Methomyl and thiodicarb are suitable for this, but other insecticides especially spinosad could be used where quick action is not needed. Large numbers of moths were killed in the field trial, suggesting that attracticides for female Helicoverpa spp. moths could have significant impacts on local populations of these pests. [source]


    Hereditary diffuse gastric cancer: A manifestation of lost cell polarity

    CANCER SCIENCE, Issue 7 2009
    Bostjan Humar
    Hereditary diffuse gastric cancer is a cancer syndrome caused by germline mutations in the gene for the cell adhesion protein E-cadherin (CDH1). E-cadherin plays a central role in the maintenance of cell polarity and its loss during tumorigenesis is associated with poorly differentiated cancers and a poor prognosis. Hereditary diffuse gastric cancer is dominated by diffuse-type gastric adenocarcinoma, often with signet ring cell morphology. Large numbers of stage T1a signet ring cell carcinomas exist in the stomachs of CDH1 mutation carriers from a young age, and these foci sometimes show enrichment to the transition zone between the body and antrum. Generally these signet ring cell carcinomas are hypoproliferative, lack Wnt pathway activation, and are relatively indolent. However, a small proportion of the T1a foci contain cells that are poorly differentiated, display mesenchymal features, and express activated c-Src and its downstream targets. These same features are observed in more advanced stages of hereditary diffuse gastric cancer progression, suggesting that an epithelial,mesenchymal transition is required for tumor invasion beyond the muscularis mucosae. Hereditary diffuse gastric cancer initiation requires somatic down-regulation of the second CDH1 allele, which in most cases is caused by DNA promoter hypermethylation. Subsequent to CDH1 down-regulation, lost polarity in gastric stem or progenitor cells would be predicted to interfere with mitotic spindle orientation and the segregation of cell fate determinants. We predict that this disruption of cell division results in daughter cells being deposited in the lamina propria where their population expands and partially differentiates, resulting in the formation of foci of signet ring cells. (Cancer Sci 2009; 100: 1151,1157) [source]


    Keratoprosthesis surgery: Eastern European and Russian devices

    ACTA OPHTHALMOLOGICA, Issue 2009
    ZF ZAGORSKI
    Purpose To present the development and current status of keratoprosthesis surgery in Eastern Europe. Methods Collection of data from coauthors and other surgeons involved in k-pro surgery. Results Large numbers of surgeries were performed in Filatov's Institute in Odessa (Ukraine), where over 1000 different types of devices developed by Puchkovskaya, Yakimienko and Golubenko were imlanted since 1966. The last model, s.c. "universal separable device" was implanted in over 750 with the best results (extrusion occured in about 2.5% cases). K-pro devices in Russia were mostly developed by S. Fyodorov Z. Moroz, V. Zuyev, ?. Krasnov, V. Volkov, R. Gundorova, N. Ushakov and V. Bedilo. Over 1500 surgeries sine 1969 resulted in the visual aquity improvement in 94% of cases. Haptics were made of titanium, stainless steel and also biocompatible materials (xenopericardium). In Poland about 100 surgeries were performed using mostly Russian and Ukrainian devices. The results were less favorable than in countries of origin. Small numbers were also implanted in other East European states. Conclusion In former Soviet Union keratoprosthesis surgery was well developed in selected centers (Moscow, Odessa). Surgeons in these places have gained extraordinary experience performing hundredes of surgeries. The results presented by the authors were excellent, however they were less favorable in the hands of surgeons from other countries. [source]


    Diagnosis of pemphigus by ELISA: a critical evaluation of two ELISAs for the detection of antibodies to the major pemphigus antigens, desmoglein 1 and 3

    CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 3 2000
    Experimental dermatology, Original article
    Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are characterized by autoantibodies to the desmosomal glycoproteins desmoglein 3 (Dsg 3) and Dsg 1 (Dsg 1), respectively. In this study, two enzyme-linked immunosorbent assays (ELISA) which detect IgG autoantibodies to Dsg 1 and Dsg 3 have been evaluated. A total of 317 normal and disease controls, 82 patients with PV and 25 with PF were studied. The Dsg 3 ELISA was positive in all 34 patients with untreated PV and the Dsg 1 ELISA was positive in all 10 with untreated PF. When patients undergoing treatment were included, the sensitivities fell to 95% and 92%, respectively, but still compared favourably to the sensitivity of indirect immunofluorescence which was 79% in PV and 84% in PF. All PF sera were negative in the Dsg 3 ELISA and the specificity of both assays was 98% or greater. Large numbers of samples could be analysed simultaneously over a relatively short time period. The Dsg 1 and Dsg 3 ELISAs also provided objective, quantitative, reproducible data which allowed differentiation of PV from PF and in view of these advantages, they are likely to become a routine technique in diagnostic laboratories. [source]


    A Constructive Graphical Model Approach for Knowledge-Based Systems: A Vehicle Monitoring Case Study

    COMPUTATIONAL INTELLIGENCE, Issue 3 2003
    Y. Xiang
    Graphical models have been widely applied to uncertain reasoning in knowledge-based systems. For many of the problems tackled, a single graphical model is constructed before individual cases are presented and the model is used to reason about each new case. In this work, we consider a class of problems whose solution requires inference over a very large number of models that are impractical to construct a priori. We conduct a case study in the domain of vehicle monitoring and then generalize the approach taken. We show that the previously held negative belief on the applicability of graphical models to such problems is unjustified. We propose a set of techniques based on domain decomposition, model separation, model approximation, model compilation, and re-analysis to meet the computational challenges imposed by the combinatorial explosion. Experimental results on vehicle monitoring demonstrated good performance at near-real-time. [source]


    Perceptual 3D pose distance estimation by boosting relational geometric features

    COMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 2-3 2009
    Cheng Chen
    Abstract Traditional pose similarity functions based on joint coordinates or rotations often do not conform to human perception. We propose a new perceptual pose distance: Relational Geometric Distance that accumulates the differences over a set of features that reflects the geometric relations between different body parts. An extensive relational geometric feature pool that contains a large number of potential features is defined, and the features effective for pose similarity estimation are selected using a set of labeled data by Adaboost. The extensive feature pool guarantees that a wide diversity of features is considered, and the boosting ensures that the selected features are optimized when used jointly. Finally, the selected features form a pose distance function that can be used for novel poses. Experiments show that our method outperforms others in emulating human perception in pose similarity. Our method can also adapt to specific motion types and capture the features that are important for pose similarity of a certain motion type. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    Computer-based management environment for an assembly language programming laboratory

    COMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 1 2007
    Santiago Rodríguez
    Abstract This article describes the environment used in the Computer Architecture Department of the Technical University of Madrid (UPM) for managing small laboratory work projects and a specific application for an Assembly Language Programming Laboratory. The approach is based on a chain of tools that a small team of teachers can use to efficiently manage a course with a large number of students (400 per year). Students use this tool chain to complete their assignments using an MC88110 CPU simulator also developed by the Department. Students use a Delivery Agent tool to send files containing their implementations. These files are stored in one of the Department servers. Every student laboratory assignment is tested by an Automatic Project Evaluator that executes a set of previously designed and configured tests. These tools are used by teachers to manage mass courses thereby avoiding restrictions on students working on the same assignment. This procedure may encourage students to copy others' laboratory work and we have therefore developed a complementary tool to help teachers find "replicated" laboratory assignment implementations. This tool is a plagiarism detection assistant that completes the tool-chain functionality. Jointly, these tools have demonstrated over the last decade that important benefits can be gained from the exploitation of a global laboratory work management system. Some of the benefits may be transferable to an area of growing importance that we have not directly explored, i.e. distance learning environments for technical subjects. © 2007 Wiley Periodicals, Inc. Comput Appl Eng Educ 15: 41,54, 2007; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20094 [source]


    GraphDice: A System for Exploring Multivariate Social Networks

    COMPUTER GRAPHICS FORUM, Issue 3 2010
    A. Bezerianos
    Abstract Social networks collected by historians or sociologists typically have a large number of actors and edge attributes. Applying social network analysis (SNA) algorithms to these networks produces additional attributes such as degree, centrality, and clustering coefficients. Understanding the effects of this plethora of attributes is one of the main challenges of multivariate SNA. We present the design of GraphDice, a multivariate network visualization system for exploring the attribute space of edges and actors. GraphDice builds upon the ScatterDice system for its main multidimensional navigation paradigm, and extends it with novel mechanisms to support network exploration in general and SNA tasks in particular. Novel mechanisms include visualization of attributes of interval type and projection of numerical edge attributes to node attributes. We show how these extensions to the original ScatterDice system allow to support complex visual analysis tasks on networks with hundreds of actors and up to 30 attributes, while providing a simple and consistent interface for interacting with network data. [source]


    A Data-driven Segmentation for the Shoulder Complex

    COMPUTER GRAPHICS FORUM, Issue 2 2010
    Q Youn Hong
    Abstract The human shoulder complex is perhaps the most complicated joint in the human body being comprised of a set of three bones, muscles, tendons, and ligaments. Despite this anatomical complexity, computer graphics models for motion capture most often represent this joint as a simple ball and socket. In this paper, we present a method to determine a shoulder skeletal model that, when combined with standard skinning algorithms, generates a more visually pleasing animation that is a closer approximation to the actual skin deformations of the human body. We use a data-driven approach and collect ground truth skin deformation data with an optical motion capture system with a large number of markers (200 markers on the shoulder complex alone). We cluster these markers during movement sequences and discover that adding one extra joint around the shoulder improves the resulting animation qualitatively and quantitatively yielding a marker set of approximately 70 markers for the complete skeleton. We demonstrate the effectiveness of our skeletal model by comparing it with ground truth data as well as with recorded video. We show its practicality by integrating it with the conventional rendering/animation pipeline. [source]


    Tactics-Based Behavioural Planning for Goal-Driven Rigid Body Control

    COMPUTER GRAPHICS FORUM, Issue 8 2009
    Stefan Zickler
    Computer Graphics [I.3.7]: Animation-Artificial Intelligence; [I.2.8]: Plan execution, formation, and generation; Computer Graphics [I.3.5]: Physically based modelling Abstract Controlling rigid body dynamic simulations can pose a difficult challenge when constraints exist on the bodies' goal states and the sequence of intermediate states in the resulting animation. Manually adjusting individual rigid body control actions (forces and torques) can become a very labour-intensive and non-trivial task, especially if the domain includes a large number of bodies or if it requires complicated chains of inter-body collisions to achieve the desired goal state. Furthermore, there are some interactive applications that rely on rigid body models where no control guidance by a human animator can be offered at runtime, such as video games. In this work, we present techniques to automatically generate intelligent control actions for rigid body simulations. We introduce sampling-based motion planning methods that allow us to model goal-driven behaviour through the use of non-deterministic,Tactics,that consist of intelligent, sampling-based control-blocks, called,Skills. We introduce and compare two variations of a Tactics-driven planning algorithm, namely behavioural Kinodynamic Rapidly Exploring Random Trees (BK-RRT) and Behavioural Kinodynamic Balanced Growth Trees (BK-BGT). We show how our planner can be applied to automatically compute the control sequences for challenging physics-based domains and that is scalable to solve control problems involving several hundred interacting bodies, each carrying unique goal constraints. [source]


    Fast, Exact, Linear Booleans

    COMPUTER GRAPHICS FORUM, Issue 5 2009
    Gilbert Bernstein
    Abstract We present a new system for robustly performing Boolean operations on linear, 3D polyhedra. Our system is exact, meaning that all internal numeric predicates are exactly decided in the sense of exact geometric computation. Our BSP-tree based system is 16-28× faster at performing iterative computations than CGAL's Nef Polyhedra based system, the current best practice in robust Boolean operations, while being only twice as slow as the non-robust modeler Maya. Meanwhile, we achieve a much smaller substrate of geometric subroutines than previous work, comprised of only 4 predicates, a convex polygon constructor, and a convex polygon splitting routine. The use of a BSP-tree based Boolean algorithm atop this substrate allows us to explicitly handle all geometric degeneracies without treating a large number of cases. [source]


    Space-Time Hierarchical Radiosity with Clustering and Higher-Order Wavelets

    COMPUTER GRAPHICS FORUM, Issue 2 2004
    Cyrille Damez
    Abstract We address in this paper the issue of computing diffuse global illumination solutions for animation sequences. The principal difficulties lie in the computational complexity of global illumination, emphasized by the movement of objects and the large number of frames to compute, as well as the potential for creating temporal discontinuities in the illumination, a particularly noticeable artifact. We demonstrate how space-time hierarchical radiosity, i.e. the application to the time dimension of a hierarchical decomposition algorithm, can be effectively used to obtain smooth animations: first by proposing the integration of spatial clustering in a space-time hierarchy; second, by using a higher-order wavelet basis adapted for the temporal dimension. The resulting algorithm is capable of creating time-dependent radiosity solutions efficiently. [source]


    Investigation of prolonged neonatal jaundice

    ACTA PAEDIATRICA, Issue 6 2000
    S Hannam
    Jaundice persisting beyond 14 d of age (prolonged jaundice) can be a sign of serious underlying liver disease. Protocols for investigating prolonged jaundice vary in complexity and the yield from screening has not been assessed. In order to address these issues, we carried out a prospective study of term infants referred to our neonatal unit with prolonged jaundice over an 18 mo period. Infants were examined by a paediatrician and had the following investigations: a total and conjugated serum bilirubin, liver function tests, full blood count, packed cell volume, group and Coombs' test, thyroid function tests, glucose-6-phosphate dehydrogenase levels and urine for culture. One-hundred-and-fifty-four infants were referred with prolonged jaundice out of 7139 live births during the study period. Nine infants were referred to other paediatric specialties. One infant had a conjugated hyperbilirubinaemia, giving an incidence of conjugated hyperbilirubinaemia of 0.14 per 1000 live births. Diagnoses included: giant cell hepatitis (n= 1), hepatoblastoma (n= 1), trisomy 9p (n= 1), urinary tract infections (n= 2), glucose-6-phosphate dehydrogenase deficiency (n= 3) and failure to regain birthweight (n= 1). Conclusions: In conclusion, a large number of infants referred to hospital for prolonged jaundice screening had detectable problems. The number of investigations may safely be reduced to: a total and conjugated bilirubin, packed cell volume, glucose-6-phosphate dehydrogenase level (where appropriate), a urine for culture and inspection of a recent stool sample for bile pigmentation. Clinical examination by a paediatrician has a vital role in the screening process. [source]


    A flexible content repository to enable a peer-to-peer-based wiki

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 7 2010
    Udo Bartlang
    Abstract Wikis,being major applications of the Web 2.0,are used for a large number of purposes, such as encyclopedias, project documentation, and coordination, both in open communities and in enterprises. At the application level, users are targeted as both consumers and producers of dynamic content. Yet, this kind of peer-to-peer (P2P) principle is not used at the technical level being still dominated by traditional client,server architectures. What lacks is a generic platform that combines the scalability of the P2P approach with, for example, a wiki's requirements for consistent content management in a highly concurrent environment. This paper presents a flexible content repository system that is intended to close the gap by using a hybrid P2P overlay to support scalable, fault-tolerant, consistent, and efficient data operations for the dynamic content of wikis. On the one hand, this paper introduces the generic, overall architecture of the content repository. On the other hand, it describes the major building blocks to enable P2P data management at the system's persistent storage layer, and how these may be used to implement a P2P-based wiki application: (i) a P2P back-end administrates a wiki's actual content resources. (ii) On top, P2P service groups act as indexing groups to implement a wiki's search index. Copyright © 2009 John Wiley & Sons, Ltd. [source]