6,391 research outputs found

    Construction and characterization of H5N1-recombinant fowlpox viruses co-expressing host cytokines

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    Possessing a large double stranded DNA genome up to 300 kb, fowlpox virus (FWPV) has been developed to express avian influenza virus (AIV) antigens since the late 1980s. A more advanced approach would be to coexpress host cytokines from such recombinants. This thesis describes the strategy to construct H5N1-recombinant FWPV (rFWPV) coexpressing chicken Interleukin 12 (IL-12) or Interleukin 15 (IL-15), and discusses the immunogenicity of the recombinants following inoculation into specific-pathogen-free (SPF) chickens. Previously cloned and sequenced cDNAs encoding full-length H5 and N1 of influenza strain A/Chicken/Malaysia/5858/2004 genes were amplified by PCR and inserted into plasmid pEFL29, under the control of a copy of the vaccinia virus p7.5 early/late promoter. The expression cassettes were recombined into the genome of the FP9 strain of FWPV at the fpv002 locus. Recombinant viruses were produced by transfection of the plasmid into chicken embryo fibroblasts (CEFs) after infection with FP9, and isolated by six fold plaque purification on CEFs using X-Gal selection. Chicken IL-12 or IL-15 genes, under control of a synthetic/hybrid poxvirus promoter, were inserted into a ‘transient dominant selection’ recombination plasmid, pPC1.X. The cytokine expression cassettes were then recombined, at the fpPC1 (fpv030) locus, into rFWPV already carrying AIV genes. Following three rounds of passage in CEFs in the presence of mycophenolic acid (MPA), recombinant viruses carrying the gpt gene were isolated. These unstable recombinants were plaque-purified in the absence of MPA until they lost the gpt gene spontaneously, verified by their failure to replicate in the presence of MPA. Recombinant proteins were successfully detected using western blotting and indirect immunofluorescence assay (IFAT). Parental and rFWPV (105 PFU) were inoculated subcutaneously into one-day-old SPF chickens. Sera from chickens immunized with rFWPV/H5 and rFWPV/H5/IL-15 demonstrated viral neutralizing activities, based on the haemagglutation inhibition (HI) test, in which reached a peak at Week 3. A competitive enzyme-linked immunosorbent (ELISA) assay detected N1-specific antibodies induced by rFWPV/N1 and rFWPV/N1/IL-12 at Weeks 4 and 5. Non-specific cellular immune responses were assessed by flow cytometric analysis to enumerate CD4+ and CD8+ T-lymphocytes in peripheral blood. Results of Experiment 2 showed chickens vaccinated with rFWPV/H5, rFWPV/H5/IL-15, rFWPV/N1 and rFWPV/N1/IL-12 demonstrated a higher increase in CD8+ than CD4+ T cell population, relative to control and chickens vaccinated with parental FWPV. Weekly weighing showed that chickens vaccinated with rFWPV/H5/IL-15 had the highest body weight compared to other groups, while the rFWPV/N1/IL-12 group showed the significantly lowest body weight. In summary, this study showed diverse immunogenicity of H5N1-rFWPV coexpressing IL-12 or IL-15. It also demonstrated a weight sparing effect of co-expressing IL-15 in rFWPV vaccines. The results provide the basis for future homologous challenge studies, using live H5N1 virus to evaluate the protective efficacy of the rFWPV vaccines

    Mobile health applications digital evidence taxonomy with knowledge sharing approach for digital forensics readiness

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    M-health is the current application that capable to monitor and detect human biological change and used the Internet as a platform to transfer and receive the data from the cloud providers. However, the advancement of Internet of Things (IoT) technology poses a great challenge for digital forensic experts in order to preserve, acquire and analyse digital evidence. Digital evidence taxonomy is one technique in digital forensics that facilitates digital forensics readiness and integration with knowledge sharing approach is necessary to allow digital forensics experts to share their knowledge. Therefore, this research was carried out that consists three phases, namely (1) initial phase, (2) intermediate phase and (3) final phase. In the initial phase, a systematic literature review was conducted to identify any potential gaps from the existing studies. Subsequently, digital evidence taxonomy in the IoT forensics layers was adopted, which consisted of three artefact categories to represent the IoT forensics layers. In the intermediate phase, 34 top rating m-health apps were used as a case study to validate the digital evidence taxonomy. From the analysis of the result, various types of information for forensic investigation were acquired, such as type of outdoor activity, activity timestamp, client IP address and date accessed. In the final phase, the M-Health Digital Evidence Taxonomy System (MDETS) was developed as a proof of concept to demonstrate the integration of digital evidence taxonomy with the knowledge-sharing approach to facilitate digital forensic readiness. Interviews were used as the instrument tool to evaluate knowledge sharing in terms of people, process and technology elements in enabling digital forensic readiness. The results from the interviews support that knowledge sharing facilitates digital forensic readiness in terms of people, process and technology elements. As a conclusion, the integration of digital evidence taxonomy with the knowledge-sharing approach gives the opportunity for the digital forensic community to enhance the existing approach or procedure to increase the findings of a digital forensic investigation and make digital forensic readiness more proactive within the organisation

    Assessment of ecosystem integrity of lowland dipterocarp forest ecosystem using remote sensing

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    Ecosystem Integrity Index (EII) is a concept to determine the quality or the health of an ecosystem. The EII development can assist forest managers and decision makers in the conservation effort and forest management in Malaysia through the development of a simple and easy-to-adopt index. The aim of this study is to assess and evaluate the EII through the development of forest structure empirical models from remotely sensed data for lowland dipterocarp forest in Malaysia. The objectives of this study are: (i) to assess the structure and composition of lowland dipterocarp forest in Malaysia, (ii) to develop empirical model for estimating stand structure from remotely sensed data, and (iii) to derive the ecosystem integrity index for lowland dipterocarp forest. Tree Basal Area (BA), aboveground biomass (AGB) and volume plot from plot data were used as dependent variables, while remote sensing data from Landsat, Pleiades and LiDAR were used as independent variables for model development. Tree plot census was carried out from 17 to 19 May 2016, while remote sensing data acquisition dates for Landsat, Pleiades and LiDAR were 13 March 2016, 24 January 2015 and April 2015 respectively. Forest Structure Modeling was carried out by means of a correlation analysis with the calibration of dependent and independent data to select the most significant and accurate remote sensing variables to derive empiric equation (model), fitting stage to select the best model with the highest coefficient of determination (R2) and the lowest root mean square error ( RMSE) validation of the final selected. The Ecosystem Integrity Index was developed by the average percentage of the predicted BA, AGB and model volume. The EII was categorised at five integrity levels as high (81–100%), medium high (61–80%), moderate (41–60%), medium low (21–40%) and low (0–20%). A total of 1035 trees with diameter at breast height (DBH) of 5.0 cm and above were recorded in 69.115 ha sampling areas. The total trees recorded represented 150 species from 87 genera and 34 families. Shorea macroptera (Dipterocarpaceae), S. leprosula (Dipterocarpaceae) and S. parviflora (Dipterocarpaceae) are three dominant species, with Species Important Value Index (SIVi) of 6.49%, 6.23% and 5.51%, respectively. Dipterocarpaceae is the most dominant with Family Important Value Index (FIVi) of 33.54%. The developed final model is robust and consistent with high R2 with range of 0.84 to 0.87. The final models constructed for AGB, BA and volume value of R2 are 0.85, 0.84 and 0.87 respectively. The RMSE of AGB, BA and volume model are 53.1 Mg/ha, 3.54 m2/ha and 46.4 m3/ha, respectively. The overall stand AGB, BA and volume for Sungai Menyala Forest Reserve is 282.29 Mg/ha, 17.68 m2/ha and 239.51 m3/ha. An Ecosystem Integrity Index (EII) assessment has been successfully demonstrated by this study with production of practical, multi-scaled, flexible, adjustable and policy-relevant index. The overall EII of Sungai Menyala Forest Reserve is in Category 3, which shows that the area is within the medium value

    A Study into the Effect of Loading and Sliding Speed to the Tribological Properties of Brake Pad Material

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    Nowadays, many accidents happen because the failure of the brake to perform effectively. It is because some inferior quality brake pad can not withstand with the loading force and sliding speed between the brake pad and the disc. The friction between the brake pad and rotor are the main factors to stop the vehicle. So we can avoid the accidents if the brake systems can effectively functions. The lack of knowledge about the selection of proper material of brake pad also contributes to the accidents. In this project, a study into the effect of loading and sliding speed to the tribological properties of brake pad material will provide test data and information about the ability of the brake pad to deliver a good braking on such condition. The information obtained from this research study hopefully will provide an insight to the future development of the brake pad material

    Innovative technologies for industrial wastes

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    This article is intended to provide several case studies of successful waste management of a few selected industries in their attempts to become “environmental-conscious” firms. In particular, this article examines the innovative waste-reduction and waste reuse processes undertaken by certain firms in the following industries - asphalt cement and concrete, ferrous metals, Portland cement and concrete, and some other that on the face of it somewhat isolated innovative technologies. For each case, the driver, the waste management technology or processes involved, as well as the associated economic benefits of the adjustments was highlighted. It is hoped that the findings of this article will provide the motivation or continue to motivate engineers and scientists to further explore processes that will help towards better management of industrial wastes

    Factors affecting employee commitment in Molnlycke Health Care Sdn. Bhd. / Nurazlinda Abdul Razak and Mohammad Nazmee Abdul Razak

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    This chapter focuses on the background of this study which is employee commitment in manufacturing industry. It introduces the overall concept of employee commitment, and followed by problem statement, research question, research objectives, scope of study, significant of the study, and the definition of key terms and concepts that is used in this study

    Quantifying 'causality' in complex systems: Understanding Transfer Entropy

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    'Causal' direction is of great importance when dealing with complex systems. Often big volumes of data in the form of time series are available and it is important to develop methods that can inform about possible causal connections between the different observables. Here we investigate the ability of the Transfer Entropy measure to identify causal relations embedded in emergent coherent correlations. We do this by firstly applying Transfer Entropy to an amended Ising model. In addition we use a simple Random Transition model to test the reliability of Transfer Entropy as a measure of `causal' direction in the presence of stochastic fluctuations. In particular we systematically study the effect of the finite size of data sets

    Bioreactor Co-Composting Of Sewage Sludge and Restaurant Waste

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    Composting is an environmental-friendly method to tackle the disposal problem of sewage sludges and municipal solid waste. With appropriate nutrients, porosity, density and moisture content during composting, pathogens such as Salmonella typhi, Escherichia coli etc. will be destroyed and the organic matter will be stabilized producing a compost product that can contribute directly to soil fertility and conditioning. Composting process system has been modernized from the heap or windrow system to the reactor system, which is a comparatively fast process. A 200 liters rotating drum bioreactor/composter was designed, fabricated and used in this cocomposting study. This bioreactor was designed in Universiti Putra Malaysia and was fabricated by Amsea Environment Sdn. Bhd. Three different types of dewatered sewage sludges, i.e. septic tank, oxidation pond and activated sewage sludges were successfully co-composted with municipal solid waste in a two-stage process. The physicochemical and biological characteristics of these municipal solid waste (restaurant waste) and sewage sludges were measured before being used as raw materials for the co-composting process. For the bioreactor composting, the raw materials were fermented for 7 days inside the 200 liters bioreactor before being matured outside the bioreactor in a windrow pile until fully matured and ready to be used. A 2:1 (w/w) ratio of municipal solid waste and sewage sludge was found to give the best initial C/N ratio for the composting process. The carbon content decreased and the nitrogen content increased towards the end of the composting process, which resulted in the reduction of C/N ratio during the composting process to below 20. The low C/N ratio of the final compost product was very important as the indicator of compost maturity and stability. The breakdown of organic materials inside the bioreactor did not increase the temperature to the thermophilic range (50-60°C), where breakdown of organic matter by microorganisms is at the optimum rate. In order to overcome the temperature problem, heated air was supplied to the bioreactor, increasing the temperature of the composting process. Shredded garden waste was added as bulking agent. Bioreactor co-composting took around 40-45 days to produce matured compost. The characteristics of the sewage sludge compost products were almost similar compared to commercial compost available in the local market and also complied with the United States Environmental Protection Agency (USEPA) standard. By using bioreactor system the compost products were improved based on nutrient contents and duration of composting process. The planting out performance of spinach with the research compost showed satisfactory results
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