222 research outputs found

    A noninvasive molecular approach: exploiting species-locus-specific PCR primers in defeating numts and DNA cross-contamination of cercopithecidae

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    The lack of a standardized, noninvasive molecular approach to studying genetic aspects of primates has made it hard for primatologists to decode the evolutionary history of these species. Researchers must optimize their own techniques to fully exploit the available samples. Lack of species-locus-specific primers also contributes to difficulties in using noninvasive genetic samples. Thus, the objectives of this study were to develop a standardized technique to collecting samples noninvasively, propose newly designed species-locus-specific primers, and optimize conditions for polymerase chain reaction (PCR) for Macaca fascicularis, M. nemestrina, Trachypithecus cristatus, and T. obscurus. Nine new species-locus-specific primers for three different loci of mitochondrial DNA, namely D-loop, cytochrome oxidase subunit I (COI), and cytochrome b, were successfully designed. These primers proved to be efficient in amplifying larger datasets (up to ~1,000 bp) of the targeted species in the optimized PCR conditions. The species-locus-specific primers are able to anneal to host DNA alone in highly contaminated feces of highlighted species. They can also offer alternatives measures in avoiding contamination related to nuclear insertion of mitochondrial pseudogenes (numts)

    Spatial variation of physical environment and environmental aspect of selective logging: a case study of tropical hill dipterocarp forests of Peninsular Malaysia.

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    A systematic sampling and survey along the gradient directed transect was conducted within study area to investigate the effects of selective logging on tree species diversity, stand structure and physical environment of tropical hill dipterocarp forest of Peninsular Malaysia. In this study baseline information on environmental aspects of selective logging have been generated and compared with that of pre-logging condition by surveying the same samples. Soil physical parameters and microclimatic variables are mainly included for comparing spatial variation as well as species distribution. However, canopy openness is also discussed to find out its relationship to soil moisture and forest microclimate variation following logging. The variation of species composition in relation to habitat types as identified by numerical methods (Cluster and Principal Component Analysis) has been characterized and described in terms of possible environmental data. The results have been compared with the available studies from Malaysia and overseas. However, for the lack of pre-logging data as well as limited information particularly on microclimate, comparison was compounded. This study shows that the study site, Ulu Muda Forest Reserve, Kedah seems to be largely controlled by local micro-topography and associated microenvironment

    Discharge and flow coefficient analysis in internal combustion engine using computational fluid dynamics simulation

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    Intake system is one of the crucial sub-systems in engine which can inflict significant effect on the air-fuel mixing, combustion, fuel consumption, as well as exhaust gases formation. There are many parameters that will influence engine performances. Good engine breathing is required to get better air flow rate to the engine. One of the methods includes the improvement of intake system by modifying the intake port design. This paper presents the application of Computational Fluid Dynamics analysis on two engines with different intake port shapes. Dimensionless parameters like discharge coefficient and flow coefficient are used to quantify the changes in intake flow at different valve lifts variation. Results show that when valve lift increases, this inflicted the increase in discharge coefficient because of greater mass flow rate of induction air. Both flow and discharge coefficient is dependent on valve lift. Flow analysis proved the relationship by computing the increase of flow coefficient as valve opening increase. The computed analysis shows that different intake port shapes does bring significant effect on discharge coefficient and flow coefficient

    Perception of Subject Matter Experts (SMEs) on various curation and preservation techniques for the development of natural history gallery in Malaysia: a qualitative study

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    Preserving animal’s body or part of the animals have become an important and wellknown conservation medium to ensure that the future generations are still able to enjoy the biodiversity and all the incredible species that live within it. This paper aims to present a qualitative study on perception and preference of subject matter experts (SMEs) on various curation and preservation methods that is suitable for certain animals for the development of Natural History Gallery. Interview with the SMEs were done by using semi-structured questionnaire and prior to this, permission were gained from the respondents by signing the Informed Consent Form (ICF). The findings suggest that the preservation methods of specimens ultimately depend on the purpose of specimens collected, either to be preserved as research specimens or exhibition specimens. The information gained form this study will be valuable as directive for the development of natural history gallery in Malaysia

    3D Numerical modelling on the thermal performance of reinforced concrete encased wide-flanged steel column

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    This paper presents the development and verification of a three-dimensional (3D) numerical modelling to predict the thermal performance of reinforced concrete encased wideflanged steel (RCEWFS) column. The numerical model was developed using finite element software, ABAQUS. Then, the verified model was used to determine the suitable value for heat transfer conductance, time step and mesh size that provide the most reliable prediction against the experimental results. The parametric studies were also conducted to study the effect of rising time of fire exposure, section size, and flange width of I-section on the thermal performance of the RCEWFS column. From this study, it can be concluded that the predictions by the 3D numerical model are reliable and accurate. The study on the contour of the model shows that the thermal behaviour of concrete is non-linear

    Adaptive FEC error control scheme for wireless video transmission

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    Transmission errors have detrimental impact on video quality in wireless network. Hence, this requires highly efficient error correction scheme to significantly improve the quality of the media content. Deploying error correction technique alone would not strategically eradicate the problem unless some adaptation mechanism has been included in order to make efficient decision while adding more redundant information base on the channel condition. Adapting with channel condition can significantly enhance the network performance and video quality as well. In this paper, we paper presents an approach using forward error correction and cross layer mechanism which dynamically adapts with the channel condition to recover the loss packets in order to enhance the perceived video quality. The scheme has been developed and tested on NS-2 simulator and it shows more dramatic improvement in video quality

    A training monitoring system for cyclist based on wireless sensor networks

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    This paper presents a training monitoring system for cyclist that is based on the technology of wireless sensor networks (WSNs). A stable and reliable wireless cyclist monitoring system is vital to establish a smart and efficient sports management program. A training monitoring system has been developed and tested in a real cyclist training environment in a velodrome. The system is designed is such a way that the packet loss rate is minimum. Using TelG mote as the basis, customized sensor nodes that function as a forwarder node and the relay nodes are developed to form the WSN. This WSN is linked to the cloud network on the Internet. The cloud network is then established and end users application for data accessing is designed. Several experiments have been conducted in a real scenario in a velodrome to measure the reliability of the system architecture. It is shown from the experiments that the proposed system is reliable even when the cyclist is moving at a high speed. The packet loss is less than 2% which does not give a huge impact to the data transmission

    Characterization of End-to-end Path Selection for Cognitive Radio Wireless Mesh Networks

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    Abstract: The Cognitive Radio (CR) can delivers the environment to Secondary Users (SUs) of Wireless Mesh Network (WMN) to utilize unused spectrum of Primary Users (PUs) opportunistically. The CR can improve the spectrum usage of the WMN. However, this rises the some additional complexities for the SUs such as spectrum heterogeneity, unpredictable PU activity and interference constraints. In this paper an analytical model has been developed to analyse these complexities for each SU node and link characteristics for end-to-end optimal Path and channel assignment. Numerical results show that the analytical model is an effective tool to investigate the effects of the PU activities and channel heterogeneity on the network performance

    Investigation on microstructure and hardness of nickel-alumina functionally graded material

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    In this research study, six-layered nickel-alumina (Ni-Al2O3) functionally graded material (FGM) was prepared using powder metallurgy (PM) method. The objectives of this study were to investigate the microstructure and hardness of the graded composite layer by layer. Using a cylindrical steel die, the six-layered nickel-alumina graded structure was fabricated considering 0%, 20%, 40%, 60%, 80% and 100% weight percentage of ceramic concentration for different layers. A hydraulic press was used for fabrication of the FGM layered structure and 30 ton compaction load was applied. Considering two-step sintering cycle, sintering was carried out at sintering temperature 1200 °C and sintering time 4 h. The sintered specimens were characterized using optical microscopy (OM), scanning electron microscopy (SEM) and hardness testing. It was observed that uniform particle distribution within the graded layers and smooth microstructural transition occurred between adjacent layers. It was also observed that the interface lines are obvious, less wavy, straight and parallel which confirms proper layer stacking process. On the other hand, from the SEM micrographs, the existence of microcracks and voids are identified in the alumina-rich layer and mostly around alumina particles

    Iot-based intelligent irrigation management and monitoring system using arduino

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    Plants, flowers and crops are living things around us that makes our earth more productive and beautiful. In order to growth healthy, they need water, light and nutrition from the soil in order to effect cleaning air naturally and produce oxygen to the world. Therefore, a technology that manage to brilliantly control plants watering rate according to its soil moisture and user requirement is proposed in this paper. The developed system included an Internet of Things (IoT) in Wireless Sensor Network (WSN) environment where it manages and monitors the irrigation system either manually or automatically, depending on the user requirement. This proposed system applied Arduino technology and NRF24L01 as the microprocessor and transceiver for the communication channel, respectively. Smart agriculture and smart lifestyle can be developed by implementing this technology for the future work. It will save the budget for hiring employees and prevent from water wastage in daily necessities
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