53 research outputs found

    Analysis and application of minimum variance discrete time system identification

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    An on-line minimum variance parameter identifier is developed which embodies both accuracy and computational efficiency. The formulation results in a linear estimation problem with both additive and multiplicative noise. The resulting filter which utilizes both the covariance of the parameter vector itself and the covariance of the error in identification is proven to be mean square convergent and mean square consistent. The MV parameter identification scheme is then used to construct a stable state and parameter estimation algorithm

    Analysis and application of minimum variance discrete time system identification

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    An on-line minimum variance parameter identifier was developed which embodies both accuracy and computational efficiency. The new formulation resulted in a linear estimation problem with both additive and multiplicative noise. The resulting filter is shown to utilize both the covariance of the parameter vector itself and the covariance of the error in identification. It is proven that the identification filter is mean square covergent and mean square consistent. The MV parameter identification scheme is then used to construct a stable state and parameter estimation algorithm

    Digital adaptive flight controller development

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    A design study of adaptive control logic suitable for implementation in modern airborne digital flight computers was conducted. Two designs are described for an example aircraft. Each of these designs uses a weighted least squares procedure to identify parameters defining the dynamics of the aircraft. The two designs differ in the way in which control law parameters are determined. One uses the solution of an optimal linear regulator problem to determine these parameters while the other uses a procedure called single stage optimization. Extensive simulation results and analysis leading to the designs are presented

    Mycobacterium shottsii sp nov., a slowly growing species isolated from Chesapeake Bay striped bass (Morone saxatilis)

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    Slowly growing, non-pigmented mycobacteria were isolated from striped bass (Morone saxatilis) during an epizootic of mycobacteriosis in the Chesapeake Bay. Growth characteristics, acid-fastness and results of 16S rRNA gene sequencing were consistent with those of the genus Mycobacterium. A unique profile of biochemical reactions was observed among the 21 isolates. A single cluster of eight peaks identified by analysis of mycolic acids (HPLC) resembled those of reference patterns but differed in peak elution times from profiles of reference species of the Mycobacterium tuberculosis complex. One isolate (M175(T)) was placed within the slowly growing mycobacteria by analysis of aligned 16S rRNA gene sequences and was proximate in phylogeny to Mycobacterium ulcerans and Mycobacterium marinum. However, distinct nucleoticle differences were detected in the 16S rRNA gene sequence among M175(T), M. ulcerans and M. marinum (99-2% similarity). Isolate IM175(T) could be differentiated from other slowly growing, nonpigmented mycobacteria by its inability to grow at 37degreesC, production of niacin and urease, absence of nitrate reductase and resistance to isoniazid (1 mug ml(-1)), thiacetazone and thiophene-2-carboxylic hydrazide. Based upon these genetic and phenotypic differences, isolate IM175T (= ATCC 700981(T) = NCTC 13215(T)) is proposed as the type strain of a novel species, Mycobacterium shottsii sp. nov

    Biochemical and histological evidences for the antitumor potential of Teucrium Oliverianum and Rhazya stricta in chemically-induced hepatocellular carcinoma

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    Background: Teucrium oliverianum and Rhazya stricta are medicinal plants used in traditional and herbal medicine for the treatment of diabetes, liver diseases and inflammatory conditions. The present study was planned to investigate the antitumor efficacy of Teucrium oliverianum and Rhazya stricta in chemically-induced hepatocellular carcinoma (HCC) in rats.Materials and Methods: Forty adult male rats weighing 170-200 g were divided into four groups; each group was comprised of ten rats: (1): Normal healthy animals served as negative control group, (2):  Hepatocellular carcinoma (HCC) group in which the rats were orally administered Nnitrosodiethylamine (dissolved in 0.9% normal saline), in a dose of 20 mg/kg b.wt. five times a week for six weeks, (3): HCC group treated with Teucrium oliverianum extract in a dose of 600 mg/kg b.wt for two months and (4): HCC group treated with Rhazya stricta extract in a dose of 750 mg/kg b.wt for two months. Serum alanine  aminotransferase (ALT), asparatate aminotransferase (AST), alkaline phosphatase (ALP) and  gammaglutamyl transferase (γ-GT) activities were estimated. Serum  carcinoembyronic antigen (CEA), alpha-fetoprotein (AFP), alpha-L-fucosidase (AFU), glypican-3 (GPC-3), golgi protein 73 (Gp-73) and vascular endothelial growth factor (VEGF) levels were determined. Histopathological examination of liver tissue sections was also carried out.Results: The HCC group showed significant elevation in serum AST, ALT, ALP and γ-GT activities as well  as CEA, AFP, AFU, Gpc-3, Gp 73 and VEGF levels versus the negative control group. Photomicrograph of liver tissue sections of rats in HCC revealed hepatic parenchyma with foci of anaplastic hepatocellular carcinoma as well as other foci of cystic cholangio carcinoma associated with areas of telangictasis with haemorrhage as well as individual hepatocellular necrosis.Conclusion: Treatment of HCC groups with Teucrium oliverianum or Rhazya stricta extract experienced significant improvement in the measured biochemical parameters as well as in the structural  organization of the liver. In conclusion, the current study provided experimental evidences for the antitumor efficacy of Teucrium oliverianum and Rhazya stricta against hepatocellular carcinoma. Such effect could be attributed to hepatoprotective properties, antiproliferative activity and antiangiogenic potential.Keywords: Hepatocellular carcinoma, Teucrium oliverianum, Rhazya stricta, rat

    BIOCHEMICAL AND HISTOLOGICAL EVIDENCES FOR THE ANTITUMOR POTENTIAL OF TEUCRIUM OLIVERIANUM AND RHAZYA STRICTA IN CHEMICALLY-INDUCED HEPATOCELLULAR CARCINOMA

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    Background: Teucrium oliverianum and Rhazya stricta are medicinal plants used in traditional and herbal medicine for the treatment of diabetes, liver diseases and inflammatory conditions. The present study was planned to investigate the antitumor efficacy of Teucrium oliverianum and Rhazya stricta in chemically-induced hepatocellular carcinoma (HCC) in rats. Materials and Methods: Forty adult male rats weighing 170-200 g were divided into four groups; each group was comprised of ten rats: (1): Normal healthy animals served as negative control group, (2): Hepatocellular carcinoma (HCC) group in which the rats were orally administered Nnitrosodiethylamine (dissolved in 0.9% normal saline), in a dose of 20 mg/kg b.wt. five times a week for six weeks, (3): HCC group treated with Teucrium oliverianum extract in a dose of 600 mg/kg b.wt for two months and (4): HCC group treated with Rhazya stricta extract in a dose of 750 mg/kg b.wt for two months. Serum alanine aminotransferase (ALT), asparatate aminotransferase (AST), alkaline phosphatase (ALP) and gammaglutamyl transferase (γ-GT) activities were estimated. Serum carcinoembyronic antigen (CEA), alpha-fetoprotein (AFP), alpha-L-fucosidase (AFU), glypican-3 (GPC-3), golgi protein 73 (Gp-73) and vascular endothelial growth factor (VEGF) levels were determined. Histopathological examination of liver tissue sections was also carried out. Results: The HCC group showed significant elevation in serum AST, ALT, ALP and γ-GT activities as well as CEA, AFP, AFU, Gpc-3, Gp 73 and VEGF levels versus the negative control group. Photomicrograph of liver tissue sections of rats in HCC revealed hepatic parenchyma with foci of anaplastic hepatocellular carcinoma as well as other foci of cystic cholangio carcinoma associated with areas of telangictasis with haemorrhage as well as individual hepatocellular necrosis. Conclusion: Treatment of HCC groups with Teucrium oliverianum or Rhazya stricta extract experienced significant improvement in the measured biochemical parameters as well as in the structural organization of the liver. In conclusion, the current study provided experimental evidences for the antitumor efficacy of Teucrium oliverianum and Rhazya stricta against hepatocellular carcinoma. Such effect could be attributed to hepatoprotective properties, antiproliferative activity and antiangiogenic potential

    Canadian 24-hour movement guidelines for adults aged 18-64 years and adults aged 65 years or older: an integration of physical activity, sedentary behaviour, and sleep

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    The Canadian Society for Exercise Physiology assembled a Consensus Panel representing national organizations, content experts, methodologists, stakeholders, and end-users and followed an established guideline development procedure to create the Canadian 24-Hour Movement Guidelines for Adults aged 18-64 years and Adults aged 65 years or older: An Integration of Physical Activity, Sedentary Behaviour, and Sleep. These guidelines underscore the importance of movement behaviours across the whole 24-h day. The development process followed the strategy outlined in the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument. A large body of evidence was used to inform the guidelines including 2 de novo systematic reviews and 4 overviews of reviews examining the relationships among movement behaviours (physical activity, sedentary behaviour, sleep, and all behaviours together) and several health outcomes. Draft guideline recommendations were discussed at a 4-day in-person Consensus Panel meeting. Feedback from stakeholders was obtained by survey (n = 877) and the draft guidelines were revised accordingly. The final guidelines provide evidence-based recommendations for a healthy day (24-h), comprising a combination of sleep, sedentary behaviours, and light-intensity and moderate-to-vigorous-intensity physical activity. Dissemination and implementation efforts with corresponding evaluation plans are in place to help ensure that guideline awareness and use are optimized. Novelty First ever 24-Hour Movement Guidelines for Adults aged 18-64 years and Adults aged 65 years or older with consideration of a balanced approach to physical activity, sedentary behaviour, and sleep Finalizes the suite of 24-Hour Movement Guidelines for Canadians across the lifespa

    Association between Multimorbidity and COVID-19 Mortality in Qatar: A Cross-Sectional Study

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    This study assessed the association between multimorbidity and mortality from COVID-19 in the Middle East and North Africa region, where such data are scarce. We conducted a cross-sectional study using data of all cases with COVID-19 reported to the Ministry of Public Health of Qatar from March to September 2020. Data on pre-existing comorbidities were collected using a questionnaire and multimorbidity was defined as having at least two comorbidities. Proportions of deaths were compared by comorbidity and multimorbidity status and multivariable logistic regression analyses were carried out. A total of 92,426 participants with a mean age of 37.0 years (SD 11.0) were included. Mortality due to COVID-19 was associated with gastrointestinal diseases (aOR 3.1, 95% CI 1.16–8.30), respiratory diseases (aOR 2.9, 95% CI 1.57–5.26), neurological diseases (aOR 2.6, 95% CI 1.19–5.54), diabetes (aOR 1.8, 95% CI 1.24–2.61), and CVD (aOR 1.5, 95% CI 1.03–2.22). COVID-19 mortality was strongly associated with increasing multimorbidity; one comorbidity (aOR 2.0, 95% CI 1.28–3.12), two comorbidities (aOR 2.8, 95% CI 1.79–4.38), three comorbidities (aOR 6.0, 95% 3.34–10.86) and four or more comorbidities (aOR 4.15, 95% 1.3–12.88). This study demonstrates a strong association between COVID-19 mortality and multimorbidity in Qatar
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