313 research outputs found
Writing a thesis on teaching challenges at autism schools- teachers perception
No full textThis thesis is submitted in partial fulfillment of the requirements for the degree of Masters of Science in Early Child Development, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (page 72 - 75).MD Zahir Uddin AkandaM. Early Child Developmen
Simulating yield response of rice to salinity stress with the AquaCrop model
No full textThe FAO AquaCrop model has been widely applied throughout the world to simulate crop responses to deficit water applications. However, its application to saline conditions is not yet reported, though saline soils are common in coastal areas. In this study, we parameterized and tested AquaCrop to simulate rice yield under different salinity regimes. The data and information required in the model were collected through a field experiment at the Bangladesh Agricultural Research Institute, Gazipur. The experiment was conducted with the BRRI Dhan28, a popular boro rice variety in Bangladesh, with five levels of saline water irrigation, three replicates for each level. In addition, field monitoring was carried out at Satkhira in the southwest coastal region of Bangladesh to collect data and information based on farmers' practices and to further validate the model. The results indicated that the AquaCrop model with most of its default parameters could replicate the variation of rice yield with the variation of salinity reasonably well. The root mean square error and mean absolute error of the model yield were only 0.12 t per ha and 0.03 t per ha, respectively. The crop response versus soil salinity stress curve was found to be convex in shape with a lower threshold of 2 dS m?1, an upper threshold of 10 dS m?1 and a shape factor of 2.4. As the crop production system in the coastal belt of Bangladesh has become vulnerable to climate induced sea-level rise and the consequent increase in water and soil salinity, the AquaCrop would be a useful tool in assessing the potential impact of these future changes as well as other climatic parameters on rice yield in the coastal region
Development of solid lipid nanoparticles for sustained release of anticancer agents
No full textA brief introduction to solid lipid nanoparticles (SLN) is provided and the reasoning behind the use of SLN over other colloidal carriers, such as emulsions and liposomes, are discussed. SLN has many advantageous such as controlled drug release, non-biotoxicity of the carrier, increased bioavailability of drug and lower overall cost. Techniques for the production of SLN, drug incorporation, loading capacity and drug release mechanisms are reviewed. The potential of SLN in anti-cancer drug delivery systems is highlighted.
SLN formulations of two different lipids (tristearin, stearic acid), used as carriers for the encapsulation of the anticancer drug substance curcumin (CRC), have been investigated. The physicochemical characteristics of the CRC-SLNs were investigated by particle size, zeta potential and stability measurements. In addition transmission electron microscopy was used to study the morphology of the SLNs and differential scanning calorimetry (DSC) as well as X- ray diffraction (XRD) were used to evaluate the physical state of the drug in the SLN formulations after freeze drying. The release pattern of CRC-SLN showed sustained release over five days, Moreover, encapsulation efficiency at the range of 92-95% indicated the loosely ordered crystal lattice of lipid matrix, which facilitated a higher drug payload.
The anti-cancer effects of CRC encapsulated SLN formulations (both loaded and unloaded) were evaluated using a human prostate cancer cell line (LNCaP). Blank SLN (BL-SLN) did not show any anti-tumour activity; CRC encapsulated SLN (CRC-SLN) displayed anti-tumour activity. Both lipid based CRC loaded SLNs reduced the LNCaP cell viability to almost 0% at a CRC concentration of 100 μg/ml. Cellular uptake studies confirmed the internalisation of CRC-SLN which was found to be localized in the cytoplasm around the nucleus. Flow cytometric studies confirmed the early and late apoptosis inducing ability of CRC-SLNs.
Retinoic acid (RTA) loaded SLN, optimized by tuning the process parameters (pressure and temperature) and using various lipid grades to produce nano-dispersions, displayed enhanced anticancer activity. The RTA-SLN dispersions were produced by high-pressure homogenization and characterized in terms of particle size, zeta potential, drug entrapment efficiency, transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and in vitro drug release. Anticancer efficiency was evaluated by incubating RTA-SLN with LNCaP cells, and demonstrated reduced cell viability with increasing drug concentrations (9.5% at 200 ug/ml) while blank SLN showed negligible cytotoxicity. Cellular uptake studies of SLNs showed localization within the cytoplasm of the cell and flow cytometry analysis showed an increase in the fraction of cells expressing early apoptotic markers, suggesting that the RTA-SLN is able to induce apoptosis in LNCaP cells.
Both empty and loaded (curcumin) nanostructured lipid carriers (NLC) were characterized in relation to their size, zeta potential and polydispersity index. The drug entrapment efficiency and in vitro drug release behaviour of these NLC formulations were also investigated. Analysis of the shape and morphology (using transmission electron microscopy (TEM) and laser diffraction) revealed spherical shaped NLC with a uniform particle size distribution. Cellular uptake studies revealed the internalisation of CRC-NLC, which appear to be localized in the cytoplasm around the nucleus. Flow cytometry studies were performed to evaluate apoptosis inducing abilities of CRC-NLC, as at a CRC concentration of 100 μg/ml, the CRC-NLC treated cells showed 12.2% (early) and 76.9% (late) apoptotic cells. Nude mice bearing prostate cancer xenografts exhibited significant suppression upon administering CRC loaded NLC formulations, with no significant weight loss. The efficacy of CRC-NLC treatment group with CRC only group in comparison with the CRC group showed 40% tumour volume suppression.
Unconjugated SLN were conjugated with transferrin for specific (active) delivery of CRC into LNCaP prostate cancer cells. SLNs prepared by high-pressure homogenization were characterised for particle size, zeta potential and drug loading. The transferrin conjugated to SLN was quantified by the Bradford assay. In vitro and in vivo studies of SLN for passive and active delivery of CRC to LNCaP prostate cancer cells were evaluated. In vivo studies of tumour regression efficiency showed CRC-SLN formulations to be more effective in suppressing tumour growth compared to the free drug. In addition the transferrin conjugated SLN also demonstrated a higher anti-tumour activity in tumour bearing mice compared to the non-conjugated formulation. The tumour mass was significantly suppressed by 61% and 79% for CRC-SLN and Tf-CRC-SLN, respectively, when compared with the control group
Supercritical Carbon Dioxide Extraction Of Mango Seed Kernel Fat Blended With Palm Oil Mid-Fraction And Palm Stearin To Formulate Cocoa Butter Replacers
No full textMango (Mangifera indica L.) is an important annual tropical fruit. Mango seed kernel (MSK) which is industrial by-product contains considerable amount of cocoa butter analogy fats. It is remarkable that no reports on the extraction of the mango seed kernel fat (MSKF) using supercritical carbon dioxide (SC-CO2) have been published. The aim of this work is to blend SC-CO2 extracted MSKF with palm oil mid-fraction (POMF) and palm stearin (PS) to formulate new cocoa butter replacers (CBRs). The physico-chemical properties, thermal properties, solid fat content (SFC) and morphology for the blends of MSKF: POMF and MSKF: PS conducted using different chromatographic and thermal techniques. Optimization of the SC-CO2 extraction parameters of MSKF from MSK were conducted using central composite design (CCD) of response surface methodology (RSM). The variables considered in the study are pressure (20-50 MPa), temperature (40-80 °C), and CO2 flow rate (1-4 ml/min). The optimized fat yield was predicted to be 11.29% at 44.2 MPa, 72.2 ºC and CO2 flow rate of 3.4 ml/min which was close to the fat yield (11.7%) of Soxhlet extraction. The blends containing 70 to 85% of MSKF had physico-chemical properties like fatty acid profiles, iodine value (IV), slip melting point (SMP), saponification value (SPV) and acid value (AV) close to that of commercial CB. Results showed that the major TG ranges in all blends were POP 11-38.8%, SOS 22.1-36.9%, and POS 15.4-16.2%, respectively
Quantitative Nondestructive Evaluation of Crack Depth and Closure Stress of Small Cracks Using Ultrasonics(超音波による微小き裂の深さと閉口圧の定量的非破壊評価)
No full textapplication/pdf博士学位論文の要旨及び審査結果の要旨 (Summary of Thesis(DR))384391 bytesT1H142878othe
Bibliometric Analysis of the E-Journal of Library Philosophy and Practice During the Period of 2014-2018
No full textThe present study is based on the Bibliometrics analysis of the articles published in Library Philosophy and Practice (E-Journal) for the period 2014–2018. During this period, a total of 1046 scholarly papers have been published by LIS researchers around the world. The study analyzes the documents based on various bibliometric aspects like year wise contribution of articles, year wise growth of publication, average publication per author, subject wise distribution of articles, the geographical distribution of articles, authorship pattern, author productivity, degree of collaboration, reference distribution pattern and length of reference distribution. In all with an average 209.2 articles were published each year and the highest numbers (421) of articles were published in 2018. From the 35 of the world contributed countries Nigeria is in top rank with 36.33% contributions. Two authorship is leading authorship trend, and also Multi-Authored has shown the unique number of contribution with the 0. 71 rates of the degree of collaboration
Dietary Exposure Among Adults in Selangor, Malaysia, to Heterocyclic Amines and Polycyclic Aromatic Hydrocarbons in Cooked Meat and Fish
No full textHeterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are possible human carcinogens and potent mutagens which increase the incidence of colon, mammary, prostate, breast and other cancers in rodents. Food containing meat and fish are the most important source of exposure to HCAs and PAHs in the diet and heat-treated foods, especially those which are fried, broiled and grilled. The intake of HCAs and PAHs are influenced by the amount and type of meat and fish ingested, frequency of consumption, cooking methods, cooking temperature and duration of cooking. The aim of the present study was to determine the level of HCAs and PAHs in the most consumed foods in Selangor, Malaysia in order to estimate their exposure to these toxic compounds. The dietary intake of HCAs and PAHs in foods consumed by people in Selangor, Malaysia was determined. Levels of six HCAs, namely: 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3-4-dimethylimidazo[4,5-f] quinoline (MeIQ), 2-amino-3-8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4, 8-DiMeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3,7,8-trimethylimidazo[4,5f] quinoxaline (7,8-DiMeIQx) and three PAHs, fluoranthene, benzo[b]fluoranthene and benzo[a]pyrene were measured. Forty-two samples of meat and fish were included in the study. High-performance liquid chromatography with photodiode array detector and fluorescence detector was used to analyze HCAs and PAHs, respectively. Dietary food consumption data (g/day), including meat type and cooking method were obtained using food frequency questionnaires, which were completed by 600 randomly selected subjects aged above 18 years.
Results of the study showed that the level of total HCAs in food samples studied ranged from 0 to 38.7 ng/g whereas the level of total PAHs was, 0 to 66.28 ng/g. Among the analyzed HCAs and PAHs, PhIP (30.6 ng/g) and fluoranthene (50.96 ng/g) showed the highest level, respectively. The highest level of total HCAs was found in grilled chicken satay (38.7 ng/g) and for PAHs it was in grilled beef satay (66.28 ng/g). The most abundant HCAs such as PhIP and MeIQx, and for PAHs such as fluoranthene were detected in the food products studied. The 4,8-DiMeIQx, 7,8-DiMeIQx (HCAs) for HCAs and benzo[a]pyrene for PAHs were found in 12 and 22% of the meat and fish dishes. The average daily intake level of HCAs was 553.7 ng/capita/day and for PAHs of 297.58 ng/capita/day. The intake of PhIP was the highest, followed by MeIQx and MeIQ, whereas intake of fluoranthene was the highest, followed by benzo[b]fluoranthene and benzo[a]pyrene. The results reveal that grilled and fried meat and fish products were the major contributors to the exposure of HCAs and PAH
A generalized estimating equations approach to capture-recapture closed population models: methods
No full textABSTRACT; Wildlife population parameters, such as capture or detection probabilities, and density or population size, can be estimated from capture-recapture data. These estimates are of particular interest to ecologists and biologists who rely on ac- curate inferences for management and conservation of the population of interest. However, there are many challenges to researchers for making accurate inferences on population parameters. For instance, capture-recapture data can be considered as binary longitudinal observations since repeated measurements are collected on the same individuals across successive points in times, and these observations are often correlated over time. If these correlations are not taken into account when estimating capture probabilities, then parameter estimates will be biased, possibly producing misleading results. Also, an estimator of population size is generally biased under the presence of heterogeneity in capture probabilities. The use of covariates (or auxiliary variables), when available, has been proposed as an alternative way to cope with the problem of heterogeneous capture probabilities. In this dissertation, we are interested in tackling these two main problems, (i) when capture probabilities are dependent among capture occasions in closed population capture-recapture models, and (ii) when capture probabilities are heterogeneous among individuals. Hence, the capture-recapture literature can be improved, if we could propose an approach to jointly account for these problems. In summary, this dissertation proposes: (i) a generalized estimating equations (GEE) approach to model possible effects in capture-recapture closed population studies due to correlation over time and individual heterogeneity; (ii) the corresponding estimating equations for each closed population capture-recapture model; (iii) a comprehensive analysis on various real capture-recapture data sets using classical, GEE and generalized linear mixed models (GLMM); (iv) an evaluation of the effect of ac- counting for correlation structures on capture-recapture model selection based on the ‘Quasi-likelihood Information Criterion (QIC)’; (v) a comparison of the performance of population size estimators using GEE and GLMM approaches in the analysis of capture-recapture data. The performance of these approaches is evaluated by Monte Carlo (MC) simulation studies resembling real capture-recapture data. The proposed GEE approach provides a useful inference procedure for estimating population parameters, particularly when a large proportion of individuals are captured. For a low capture proportion, it is difficult to obtain reliable estimates for all approaches, but the GEE approach outperforms the other methods. Simulation results show that quasi-likelihood GEE provide lower standard error than partial likelihood based on generalized linear modelling (GLM) and GLMM approaches. The estimated population sizes vary on the nature of the existing correlation among capture occasions; RESUMO: Parâmetros populacionais em espécies de vida selvagens, como probabilidade captura ou deteção, e abundância ou densidade da população, podem ser estimados a partir de dados de captura-recaptura. Estas estimativas são de particular interesse para ecologistas e biólogos que dependem de inferências precisas a gestão e conservação das populações. No entanto, há muitos desafios par investigadores fazer inferências precisas de parâmetros populacionais. Por exemplo, os dados de captura-recaptura podem ser considerados como observa longitudinais binárias uma vez que são medições repetidas coletadas nos mesmos indivíduos em pontos sucessivos no tempo, e muitas vezes correlacionadas. Essas correlações não são levadas em conta ao estimar as probabilidades de tura, as estimativas dos parâmetros serão tendenciosas e possivelmente produz resultados enganosos. Também, um estimador do tamanho de uma população geralmente enviesado na presença de heterogeneidade das probabilidades de captura. A utilização de co-variáveis (ou variáveis auxiliares), quando disponível tem sido proposta como uma forma de lidar com o problema de probabilidade captura heterogéneas. Nesta dissertação, estamos interessados em abordar problemas principais em mode1os de captura-recapturar para população fecha (i) quando as probabilidades de captura são dependentes entre ocasiões de captura e (ii) quando as probabilidades de captura são heterogéneas entre os indivíduos Assim, a literatura de captura-recaptura pode ser melhorada, se pudéssemos por uma abordagem conjunta para estes problemas. Em resumo, nesta dissertação propõe-se: (i) uma abordagem de estimação de equações generalizadas (GEE) para modelar possíveis efeitos de correlação temporal e heterogeneidade individual nas probabilidades de captura; (ii) as correspondentes equações de estimação generalizadas para cada modelo de captura-recaptura em população fechadas; (iii) uma análise sobre vários conjuntos de dados reais de captura-recaptura usando a abordagem clássica, GEE e modelos linear generalizados misto (GLMM); (iv) uma avaliação do efeito das estruturas de correlação na seleção de modelos de captura-recaptura com base no ‘critério de informação da Quasi-verossimilhança (QIC); (v) uma comparação da performance das estimativas do tamanho da população usando GEE e GLMM. O desempenho destas abordagens ´e avaliado usando simulações Monte Carlo (MC) que se assemelham a dados de captura- recapture reais. A abordagem GEE proposto ´e um procedimento de inferência útil para estimar parâmetros populacionais, especialmente quando uma grande proporção de indivíduos ´e capturada. Para uma proporção baixa de capturas, ´e difícil obter estimativas fiáveis para todas as abordagens aplicadas, mas GEE supera os outros métodos. Os resultados das simulações mostram que o método da quase-verossimilhança do GEE fornece estimativas do erro padrão menor do que o método da verossimilhança parcial dos modelos lineares generalizados (GLM) e GLMM. As estimativas do tamanho da população variam de acordo com a natureza da correlação existente entre as ocasiões de captura
Architecture and Hardware Design of a Dual-Execution mode Processor Based on Produced Order Queue Execution Model
No full text電気通信大学博士（工学）2007thesi
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