95 research outputs found

    Probabilistic modeling of wavelet coefficients for processing of image and video signals

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    Statistical estimation and detection techniques are widely used in signal processing including wavelet-based image and video processing. The probability density function (PDF) of the wavelet coefficients of image and video signals plays a key role in the development of techniques for such a processing. Due to the fixed number of parameters, the conventional PDFs for the estimators and detectors usually ignore higher-order moments. Consequently, estimators and detectors designed using such PDFs do not provide a satisfactory performance. This thesis is concerned with first developing a probabilistic model that is capable of incorporating an appropriate number of parameters that depend on higher-order moments of the wavelet coefficients. This model is then used as the prior to propose certain estimation and detection techniques for denoising and watermarking of image and video signals. Towards developing the probabilistic model, the Gauss-Hermite series expansion is chosen, since the wavelet coefficients have non-compact support and their empirical density function shows a resemblance to the standard Gaussian function. A modification is introduced in the series expansion so that only a finite number of terms can be used for modeling the wavelet coefficients with rendering the resulting PDF to become negative. The parameters of the resulting PDF, called the modified Gauss-Hermite (NIGH) PDF, are evaluated in terms of the higher-order sample-moments. It is shown that the MGH PDF fits the empirical density function better than the existing PDFs that use a limited number of parameters do. The proposed MGH PDF is used as the prior of image and video signals in designing maximum a posteriori and minimum mean squared error-based estimators for denoising of image and video signals and log-likelihood ratio-based detector for watermarking of image signals. The performance of the estimation and detection techniques are then evaluated in terms of the commonly used metrics. It is shown through extensive experimentations that the estimation and detection techniques developed utilizing the proposed MGH PDF perform substantially better than those that utilize the conventional PDFs. These results confirm that the superior fit of the MGH PDF to the empirical density function resulting from the flexibility of the MGH PDF in choosing the number of parameters, which are functions of higher-order moments of data, leads to the better performance. Thus, the proposed MGH PDF should play a significant role in wavelet-based image and video signal processin

    Corporate Social Responsibility Disclosure: A Comparative Study Between Islamic Banks and Conventional Banks in Bangladesh

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    The purpose of this paper is to compare the Corporate Social Responsibility practices in Islamic and Conventional banking of Bangladesh. Sample selection has been made as per random sampling process. Data are collected from the secondary sources mostly from concerned banks Annual Report, web sites, newsletters and other secondary sources. It has been found that the selected banks are directly engaged in CSR activities mostly in the area of Education, Health, Disaster Relief, Environment, Social welfare and Sport & Culture. The analysis shows that Conventional Banks have emphasized on Educational sector and Islamic Banks have emphasized on Social welfare. On dimensions of Health sector, Disaster relief sector both banks have taken parallel CSR initiatives but Sport & Cultural sector Conventional Banks have taken more CSR activities than Islamic Banks. The study found that both banks have established foundation for operated their CSR activities. The study also found that the dimension of Health care, Conventional banks and Islamic Banks both are taking initiative equally in both rural and urban area. On dimension of Environment, Conventional banks and Islamic Banks both of these banks are trying to preserve environment on their best possible way. Key words: Bangladesh; Corporate social responsibility; Conventional bank; Islamic ban

    Factors associated with compliance and non-compliance by physicians in a large-scale randomized clinical trial

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    BACKGROUND: In order to minimize the amount of incomplete follow-up data, reducing the non-compliance of participating physicians is one of the key issues for the data coordinating center in a multi-center trial. Identifying the physicians' non-compliance in advance is considered to be an important strategy for more efficient conduct of trials. In this study, we identified physicians' characteristics and factors associated with the need for individual visits to institutions to collect data or to complete information during two years of follow-up in a large Japanese investigator-initiated trial related to cardiovascular disease. METHODS: We categorized the physicians into two groups, "complier" and "non-complier". Odds ratios and corresponding 95% confidence intervals were calculated for 11 factors related to the characteristics of and compliance by physicians. Multiple logistic regression analysis was also performed. In addition, we evaluated the incremental cost for obtaining additional information of the non-compliant physicians. RESULTS: Three factors were identified in multiple logistic regression analysis as being significantly associated with compliance status: 1) prior participation in clinical trials (OR = 0.40 95%CI = 0.21–0.74); 2) physician opinion that the support system for case registration and follow-up was well organized (OR = 0.41 95%CI = 0.22–0.75); and 3) number of patients recruited (OR = 2.25 95%CI = 1.01–5.02). The actual incremental cost was about US 112,000(14.4112,000 (14.4% of total routine follow-up costs) for the non-compliant physicians during the 2 years, or about US 570 per patient. CONCLUSION: Investigator-initiated clinical trials have recently attracted great interest, but they often suffer from insufficient funding. If trial networks are to be well organized, it is important that trials are conducted more efficiently. We believe that our findings will be useful for reducing the additional burden associated with incomplete follow-up data and data lost to follow-up when planning future trials

    Psychiatric disorders among the children of 5 to 18 years old of 'SIDR' affected areas

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    Background: Natural disasters give raise a significant amount of physical and mental impairment in human beings. Any sort of disaster acts as a causative and maintaining factor for any psychiatric morbidity. In November 15, 2007, the cyclone "SIDR" intensified to reach peak winds of 215 km/h (135 mph) according to the IMD, a peak of 250 km/h (155 mph) according to the JTWC. "SIDR" officially made landfall around 1700 UTC later that day, with sustained winds of 215 km/h (135 mph). As it intensified to a Category 4-equivalent cyclone and thus coastal districts of Bangladesh faced heavy rainfall as an early impact of the cyclone. The damage in Bangladesh was extensive, including tin shacks flattened, houses and schools blown away and enormous tree damage. The entire cities of Patuakhali, Barguna and Jhalokati District were hit hard by the storm surge of over 5 meters ( 16 ft). The head of the Red Crescent in Bangladesh expects the death toll to reach as high as 10,000. Over 3,000 other fishermen were reported missing on over 500 fishing boats. The "SIDR" left its strong impact on those who survived. Objectives: The Study was aimed to estimate the prevalence of psychiatric disorder among children and adolescents in the "SIDR" affected areas. Method: This was cross sectional, qualitative study done among the children and adolescent groups of 5 to 18 years old to see the effect of natural disaster on the people of southern part of Bangladesh. The whole of the children population who attended in the health camp were included in the study during the study period. Three teams have worked among the four "SIDR" affected districts. Each team consists of Psychiatrists, General Physicians, and Clinical Psychologist.Results: A total of 158 children in four defined areas revealed that the prevalence rate of psychiatric disorder was 48%.Conclusion: This type of study should be done in multi-centers in SIDR affected disti.icts of Bangladesh to find out the actual prevalence rate of child and adolescent psychiatric disorder

    Regional variations in HPV vaccination among 9–17 year old adolescent females from the BRFSS, 2008–2010

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    Human papillomavirus (HPV) vaccine uptake among 18–26 y old women varies by geographic region in the US. However, little is known about regional variations in vaccination among girls who are in the vaccine's targeted age groups. Regional variation in HPV vaccination among female adolescents (9–17 y old) was examined using cross-sectional data from the Behavioral Risk Factor Surveillance System (BRFSS) between 2008 and 2010. Multivariable logistic regression estimated the association of region of residence (10 states included questions about adolescent HPV vaccination) with uptake and completion of the 3-shot HPV vaccine series. Among 7,849 adolescents, 26.9% initiated, and 55.2% of initiators completed the series. Adolescents from Northeast/Midwest/West states were 1.74 (95% CI: 1.45-2.10) times more likely to have initiated HPV vaccination compared to the South/Southwestern states. Among initiators, vaccine series completion did not vary significantly between the South/Southwestern and Northeast/Midwest/West states. Flu vaccination was associated with increased odds of initiation in both regions and completion of the HPV vaccine series in the South/Southwestern states only. Girls 9–10 and 11–12 y old were less likely to have initiated and 11–12 y olds were less likely to have completed the HPV vaccine series compared to 13–17 y olds. The observed regional variations in vaccination could cause rates of cervical cancer to remain higher in the South/Southwest and widen currently observed regional disparities in cervical cancer rates

    Anti-MRSA Activity of Oxysporone and Xylitol from the Endophytic Fungus Pestalotia sp. Growing on the Sundarbans Mangrove Plant Heritiera fomes

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    Heritiera fomes Buch.-Ham., a mangrove plant from the Sundarbans, has adapted to a unique habitat, muddy saline water, anaerobic soil, brackish tidal activities and high microbial competition. Endophytic fungal association protects this plant from adverse environmental conditions. This plant is used in Bangladeshi folk medicine, but it has not been extensively studied phytochemically, and there is hardly any report on investigation on endophytic fungi growing on this plant. In this study, endophytic fungi were isolated from the surface sterilized cladodes and leaves of H. fomes. The antimicrobial activities were evaluated against two Gram-positive and two Gram-negative bacteria and the fungal strain, Candida albicans. Extracts of Pestalotia sp. showed activities against all test bacterial strains, except that the EtOAc extract was inactive against E. coli. The structures of the purified compounds, oxysporone and xylitol, were elucidated by spectroscopic means. The anti-MRSA potential of the isolated compounds were determined against various MRSA strains, i.e., ATCC 25923, SA-1199B, RN4220, XU212, EMRSA-15 and EMRSA-16, with MIC values ranging from 32-128 g/mL. This paper, for the first time, reports on the anti-MRSA property of oxysporone and xylitol, isolation of the endophyte Pestalotia sp. from H. fomes, and isolation of xylitol from a Pestalotia sp
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