253 research outputs found

    GLCM-based chi-square histogram distance for automatic detection of defects on patterned textures

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    Chi-square histogram distance is one of the distance measures that can be used to find dissimilarity between two histograms. Motivated by the fact that texture discrimination by human vision system is based on second-order statistics, we make use of histogram of gray-level co-occurrence matrix (GLCM) that is based on second-order statistics and propose a new machine vision algorithm for automatic defect detection on patterned textures. Input defective images are split into several periodic blocks and GLCMs are computed after quantizing the gray levels from 0-255 to 0-63 to keep the size of GLCM compact and to reduce computation time. Dissimilarity matrix derived from chi-square distances of the GLCMs is subjected to hierarchical clustering to automatically identify defective and defect-free blocks. Effectiveness of the proposed method is demonstrated through experiments on defective real-fabric images of 2 major wallpaper groups (pmm and p4m groups).Comment: IJCVR, Vol. 2, No. 4, 2011, pp. 302-31

    Similarity Measures for Automatic Defect Detection on Patterned Textures

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    Similarity measures are widely used in various applications such as information retrieval, image and object recognition, text retrieval, and web data search. In this paper, we propose similarity-based methods for defect detection on patterned textures using five different similarity measures, viz., Normalized Histogram Intersection Coefficient, Bhattacharyya Coefficient, Pearson Product-moment Correlation Coefficient, Jaccard Coefficient and Cosine-angle Coefficient. Periodic blocks are extracted from each input defective image and similarity matrix is obtained based on the similarity coefficient of histogram of each periodic block with respect to itself and other all periodic blocks. Each similarity matrix is transformed into dissimilarity matrix containing true-distance metrics and Ward’s hierarchical clustering is performed to discern between defective and defect-free blocks. Performance of the proposed method is evaluated for each similarity measure based on precision, recall and accuracy for various real fabric images with defects such as broken end, hole, thin bar, thick bar, netting multiple, knot, and missing pick

    Effect of immunosuppression on dengue virus infection in mice

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    Mean survival time following intracerebral inoculation of dengue virus was reduced and the titre of the virus in the brain of immunosuppressed mice was markedly increased. A single dose of cyclophosphamide given 24 h after dengue virus i.c. or i.p. substantially reduced the number of antibody forming cells in the spleen. Three doses of dengue virus, each followed by cyclophosphamide 24 h later, produced specific hyporesponsiveness to the dengue virus but not to a heterologous virus (Coxsackie B4), with a reduction in antibody forming cells in the spleen of such animals against dengue virus but not against Coxsackie B4 virus. Adoptive immunity by antiserum was abolished along with increased titres of the virus in the brain of immunosuppressed mice but the protection could be restored by a second dose of antiserum. Pre-treatment of mice with immune or normal spleen cells i.v. or reconstitution of immunosuppressed mice by such cells had no effect. Thus, humoral antibodies play a crucially important role in host defence mechanism in recovery of mice from primary dengue virus infection

    Evidence for latency of Japanese encephalitis virus in T lymphocytes

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    Activation of latent Japanese encephalitis virus (JEV) in the spleen has been studied by co-cultivation with allogeneic or syngeneic cells. Activated virus was isolated by cocultivation from T lymphocytes of spleen, as shown by indirect immunofluorescence or by inoculation into mice. The B lymphocytes and macrophages of latently infected mice did not reactivate the virus. A higher proportion of Lyt 1 cells than Lyt 2 cells were harbouring JEV as shown by indirect immunofluorescence. The spleen cells from latently infected mice elicited the lymphoproliferative response but this was much lower than that observed in the controls. These findings suggest the establishment of latent JEV infection in T lymphocytes

    Effect of dengue virus infection on Fc-receptor functions of mouse macrophages

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    Fc-receptor-mediated attachment and ingestion of opsonized sheep erythrocytes (EA) by the macrophages of spleen and peritoneal cavity were studied during dengue virus type 2 (DV) infection of Swiss albino mice. Following intracerebral inoculation, virus antigen could be demonstrated by immunofluorescence in the splenic macrophages from day 4 and in peritoneal macrophages from day 5 post-infection, with a higher number of positive cells discernible on the 7th and 8th days. The virus could be isolated from spleen tissue from day 5. The total number of cells was markedly reduced from day 4 onwards both in the spleen and peritoneal cavity. A loss in the capacity to attach and ingest EA was noticed, the lowest values of attachment index (AI) and phagocytic index (PI) being reached on day 4. At later periods the AI values increased markedly but continued to be significantly less than those in uninfected control mice. The PI values continued to be lower throughout. The dichotomy between the Fc-mediated attachment and ingestion may be a mechanism for prevention of virus infection of macrophages

    Immune response to Japanese encephalitis virus in mother mice and their congenitally infected offspring

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    The immune response to Japanese encephalitis virus (JEV) was assessed in JEV-infected mice (mothers) and their offspring. The congenitally infected baby mice responded poorly in all assays for cell-mediated immunity. The total number of their splenic cells remained unaltered but the percentage of T cells was significantly reduced; a depressed delayed hypersensitivity response was seen against both homologous (JEV) and heterologous (sheep erythrocytes) antigens. In addition, significantly higher leukocyte migration inhibition (LMI) of spleen cells in the presence of specific antigen was observed. Adult mice infected during pregnancy demonstrated an impaired delayed hypersensitivity response to JEV antigen only. LMI was positive in mothers at 2 weeks post-partum, but not at later periods

    PUPAL EMERGENCE INHIBITION ACTIVITY OF ACALYPHA INDICA LEAF EXTRACT AGAINST DENGUE VECTOR, AEDES ALBOPICTUS MOSQUITO

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    Objective: To investigate the larvicidal activities of six varying extracts of Acalypha indica (A. indica) leaves from family Euphorbiaceae against the dengue mosquito vector, Aedesalbopictus (Ae. albopictus) in laboratory.Methods: Leaves from the study plants were separated, air dried in room temperature, grounded and extracted with different solvents (petroleum ether, chloroform, ethyl acetate, n-butanol, ethanol and aqueous) by solvent apparatus and aqueous extract by maceration method. The extra solvents were evaporated to obtain crude extracts by using rotary evaporator. The crude extracts of six different solvents were dissolved in dimethyl sulphoxide (DMSO) to prepare test dosages of 1000, 2000, 3000, 4000 and 5000 ppm. Third instar larvae of Ae. albopictus were exposed to 1000, 2000, 3000, 4000 and 5000 ppm concentrations of petroleum ether, chloroform, ethyl acetate, n-butanol, ethanol and aqueous extracts of A. indica and compared with control to determine the larvicidal effects. Larval bioassays were carriedout according to World Health Organisation (WHO) procedures. The rate of larval mortality was recorded after 24h and 48 h of time exposure. Three duplicate trials were made for each tested dosage. IC50 and IC90 values were calculated by using probit analysis.Results: Based on probit analysis result the 24h and 48h LC50 and LC90 of petroleum ether extract of A. indica against Ae. albopictus was found to be 2805.43 ppm and 2376.11 ppm, 3825.14 ppm and 3327.8 ppm, respectively. An LC50 and LC90 value of chloroform extracts of A. indicaa gainst third instar larvae was found to be 2276.5 ppm and 4015.8 ppm (24h), 2213.36 ppm and 3430.43 ppm (48h), respectively. An LC50 value of 4472.17 ppm and 2469.61 ppm, and LC90 value of 4215.84 ppm was obtained on ethylacetate extract treatment against Ae. albopictus for 24h and 48h exposure, respectively. The 24h and 48 h LC50 and LC90 values of n-butanol extracts of A. indica was found to be 2777.88 ppm and 3628.19 ppm, 2225.61 ppm and 2518.86 ppm, respectively. In the present study, the larvicidal bioassays demonstrated that the n-butanolextract was most effective with 100% mortality against larvae of Ae. albopictus at 3000, 4000 and 5000 ppm compared to other extracts. All other extracts (petroleum ether, chloroform and ethyl acetate) of A. indica at high concentration (4000 ppm and 5000 ppm) manifested a significant (P<0.01 and 0.05) knock down effect of 100% moratality after 24h and 48h exposure. While the third instar lavae of Ae. albopictus were found to be most susceptabile and produced no mortality to ethanol and aqueous extract at varying parts per million. Conclusion: A. indica leaf extract was tested for the first time against dengue vector Ae. albopictus and the results revealed that A. indica can be used to control dengue vector. Further this extract needs to be evaluated under field conditions for proper exploitation of Ae. albopictus mosquito larvae. Thus, the present study provided a first report on A. indica as a prompting mosquito larvicidal activity and can be considered for further investiagtions such as formulation of bioinsecticides to control Ae. albopictus population

    A study of intrauterine fetal death in a tertiary care hospital

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    Background: Intra uterine fetal death (IUFD) is the most traumatic event for the parents and the treating obstetrician. If the causes of IUFD can be found, an effective strategy for prevention can be formulated. This study was done to study the etiological factors and other determinants of IUFD.Methods: A retrospective observational study was carried out in M. S. Ramaiah medical college and teaching hospital, Bangalore, India between December 2011 to December 2014. 120 cases of IUFD were included in this study.Results: Out of 4103 deliveries that occurred during the study period, there were 120 IUFD (2.9%). 52 cases (43.3%) were referral cases. Majority were multigravida(n=73,60.8%) aged less than 30 years (n=96,80%) with 28 to 36 weeks period of gestation(n=66,55%).91 patients had presented with absent fetal movements(75.8%).In 25% of the cases(n=30) there was preeclampsia and in 21.6% (n=26)of the cases there were no causes determined.99.1%(n=119) delivered by vaginal route.Conclusions: The leading cause of IUFD in our study was preeclampsia. Majority of the cases were referred and they did not have regular antenatal checkups. A bigger impact in reduction of IUFD can be achieved if the importance of antenatal care can be stressed upon at the community level
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