5,254 research outputs found

    Analysis of volatile compounds of Malaysian Tualang (Koompassia excelsa) honey using gas chromatography mass spectrometry

    Get PDF
    The constituents of honey’s volatile compounds depend on the nectar source and differ depending on the place of origin. To date, the volatile constituents of Tualang honey have never been investigated. The objective of this study was to analyze the volatile compounds in local Malaysian Tualang honey. A continuous extraction of Tualang honey using five organic solvents was carried out starting from non-polar to polar solvents and the extracted samples were analysed using gas chromatography-massspectrometry (GC-MS). Overall, 35 volatile compounds were detected. Hydrocarbons constitute 58.5% of the composition of Tualang honey. Other classes of chemical compounds detected included acids, aldehydes, alcohols, ketones, terpenes, furans and a miscellaneous group. Methanol yielded the highest number of extracted compounds such as acids and 5-(Hydroxymethyl) furfural (HMF). This is the first study to describe the volatile compounds in Tualang honey. The use of a simple one tube, stepwise, non-thermal liquid-liquid extraction of honey is a advantageous as it prevents sample loss. Further research to test the clinical benefits of these volatile compounds is recommended

    Discovery and Application of Genetic Determinants of Cardiovascular Disease Risk Factors

    Get PDF
    The focus of my PhD has been two-­‐fold: First, to improve the understanding of the biology behind a well-­‐known cardiovascular disease (CVD) risk factor -­‐ left ventricular mass, by identifying novel genetic loci associated with this risk factor. A large-­‐scale association meta-­‐analysis in over 10,000 individuals identified four novel loci associated with electrocardiographically-­‐determined left ventricular mass. Second, to explore the application of known genetic determinants of the main blood lipid fractions, the latter being well-­‐known CVD risk factors and therapeutic targets. I assess the use of genetic variants associated with total cholesterol, low-­‐ density lipoprotein-­‐cholesterol (LDL-­‐C), high-­‐density lipoprotein-­‐cholesterol (HDL-­‐C) and triglycerides for discriminating healthy individuals from those that have a high absolute risk of CVD, those that require lipid-­‐lowering medication, and those that have a coronary event. The lipid genetic variants showed poor discriminatory ability for all three outcomes and provided no improvement over the widely-­‐used, non-­‐ genetic Framingham 10 year CVD risk score. Lipid-­‐associated genetic variants were also used to generate genetic risk score instruments for LDL-­‐C, HDL-­‐C and triglycerides, which were applied in a Mendelian randomisation analysis to determine their causal relationship with carotid-­‐intima media thickness (CIMT). CIMT has been a widely used surrogate outcome measure in clinical trials of CVD drugs. LDL-­‐C-­‐lowering drugs have shown to reduce CIMT progression and CHD risk in clinical trials. However, the extent of any causal association between HDL-­‐C or triglycerides and CIMT is unclear. The results from this MR analysis support a casual relationship with LDL-­‐C, but not with HDL-­‐C and triglycerides, which may indicate that CIMT is a less useful surrogate end point in clinical trials of primarily HDL-­‐C or triglyceride modifying therapie

    Co adaptation of LiCl tolerant Solanum tuberosum L. callus cultures to NaCl stress

    Get PDF
    In this research, co-adaptation of the Calli of Solanum tuberosum, raised from petioles, to the presence of lithium (LiCl) and sodium chloride (NaCl) was studied. The cultures were adapted with LiCl in the absence of an osmotic stress and the response of adapted and unadapted calli to salinity was investigated. Undifferentiated callus growth was induced in S. tuberosum by the addition of 2 mg/l 2,4 dichlorophenoxy acetic acid (2,4-D), 0.25 mg/l kinetin to Murashige and Skoog medium. Subcultures were subjected to an incremental increase in LiCl to obtain adapted lines. Adapted and undapted calli were grown with LiCl and NaCl and the tissue content of Na+, K+, Ca2+, Mg2+ and proline levels were determined. Either 40 mM LiCl or 100 mM NaCl inhibited unadapted calli by more than 50%, while adapted calli grew normally under these conditions. The adapted calli exhibited a lower K+ content with or without salt and showed a lower accumulation of Na+ at 100 mM NaCl. The tissue K+ and Mg2+ contents decreased and their proline levels increased with salinity. A co-adaptation phenomenon is induced by LiCl that involves a regulation of K+ and Na+ contents and an accumulation of proline, which also brings about tolerance to osmotic effects of salt. This data is highly useful for devising breeding and molecular modification strategies for stress tolerance.Key words: Cations, proline, osmotic adjustment, salt tolerance, Solanum tuberosum

    Nurturing Environmental Stewards through Preschool Physical Design

    Get PDF
    Environmental stewardship starts with education. This paper aims to discuss how preschools can be used to nurture environmental stewards among Malaysian children. In summary, elements of preschool physical environments can be manipulated to enhance environmental education while landscape elements such as vegetation and topography can be manipulated to maximize interaction with nature. Effective interaction with nature is the most important factor to ensure environmental awareness. Findings are useful for Malaysian designers and policy makers to ensure that preschool’s physical settings support environmental education to respond to climate change and preserve the planet for future generations.© 2016. The Authors. Published for AMER ABRA by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.Keywords: Malaysian preschool ; Green preschool design ; Children environmental behaviour ; Environmental educatio

    Off-Street Vehicular Fog for Catering Applications in 5G/B5G: A Trust-based Task Mapping Solution and Open Research Issues

    Get PDF
    One of the key enablers in serving the applications requiring stringent latency in 5G networks is fog computing as it is situated closer to the end users. With the technological advancement of vehicles’ on-board units, their computing capabilities are becoming robust, and considering the underutilization of the off-street vehicles, we envision that the off-street vehicles can be an enormously useful computational source for the fog computing. Additionally, clustering the vehicles would be advantageous in order to improve the service availability. As the vehicles become highly connected, trust is needed especially in distributed environments. However, vehicles are made from different manufacturers, and have different platforms, security mechanisms, and varying parking duration. These lead to the unpredictable behavior of the vehicles where quantifying trust value of vehicles would be difficult. A trust-based solution is necessary for task mapping as a task has a set of properties including expected time to complete, and trust requirements that need to be met. However, the existing metrics used for trust evaluation in the vehicular fog computing such as velocity and direction are not applicable in the off-street vehicle fog environments. In this paper, we propose a framework for quantifying the trust value of off-street vehicle fog computing facilities in 5G networks and forming logical clusters of vehicles based on the trust values. This allows tasks to be shared with multiple vehicles in the same cluster that meets the tasks’ trust requirements. Further, we propose a novel task mapping algorithm to increase the vehicle resource utilization and meet the desired trust requirements while maintaining imposed latency requirements of 5G applications. Results obtained using iFogSim simulator demonstrate that the proposed solution increases vehicle resource utilization and reduces task drop noticeably. This paper presents open research issues pertaining to the study to lead..

    Characterization of wide cross derivatives in rice Oryza sativa L. using genomic in situ hybridization (GISH)

    Get PDF
    Interspecific crosses provide a bridge by which the gene pool of rice can be increased. Introduction of alien genes requires hybridization followed by meiotic pairing and recombination between the chromosomes of cultivated and wild species. Attempts have been made to visualize the genomic constitution of wide-cross derivatives. Genomic in situ hybridization was used to detect Oryza australiensis chromosomes and introgressed segment from O. australiensis into the Oryza sativa background. Genomic DNA from O. australiensis was labeled with biotin-14-dATP and hybridized to the homologous chromosomes in hybrids, back cross progenies, monosomic alien addition line (MAAL) and introgression line. The probe hybridization fluoresced green and non-labeled O. sativa chromosomes appeared red due to counterstaining with propidium iodide (PI). This differential painting of chromosomes unequivocally detected the O. australiensis chromatin introgressed into the O. sativa genome. The probe produced uniform labeling pattern over the entire length of all the O. australiensis chromosomes. Genomic in situ hybridization (GISH) detected 12 O. australiensis chromosomes in the hybrid, O. sativa x O. australiensis in BC1 progenies, and a single chromosome in MAAL. Small segment of O. australiensis was localized on the chromosome 12 of the introgression line. However, results showed that GISH is a powerful technique to be used as an aid in selecting segregating progenies.Key words: Genomic in situ hybridization, wide hybrid, localizing introgression

    Localizing introgression on the chromosome of rice by genomic in situ hybridization (GISH)

    Get PDF
    Genomic in situ hybridization was used to detect introgressed segment from Oryza australinesis onto the chromosomes of introgression line derived from the hybrid O. sativa x O. australinesis. Genomic DNA from Oryza australinesis was labeled with biotin and hybridized to the homologous sequences on the O. sativa chromosomes. The probe hybridization fluoresced green and non labeled O. sativa chromosomes appeared red or blue due to counterstaining with propidium iodide (PI) or 4,6-diamidino-2-phenylindole (DAPI). This differential painting of chromosomes unequivocally detected the introgressedsegment. Among the 200 cells analyzed, 6.5% of the cells showed  hybridization signal. Signal appeared on one chromosome in 5%, on two homologous chromosomes in 1% and on sister chromatids in 0.5%of the cells. Hybridization was seen on the short arm of the chromosome 12 of the introgression line

    An Efficient Resource Management Mechanism for Network Slicing in LTE Network

    Get PDF
    The proliferation of mobile devices and user applications has continued to contribute to the humongous volume of data traffic in cellular networks. To surmount this challenge, service and resource providers are looking for alternative mechanisms that can successfully facilitate managing network resources in a more dynamic, predictive and distributed manner. New concepts of network architectures such as Software Defined Network (SDN) and Network Function Virtualization (NFV) have paved the way to move from static to flexible networks. They make networks more flexible (i.e. network providers capable of on-demand provisioning), easily customizable and cost effective. In this regard, network slicing is emerging as a new technology built on the concepts of SDN and NFV. It splits a network infrastructure into isolated virtual networks and allows them to manage resources allocation individually based on their requirements and characteristics. Most of the existing solutions for network slicing are computationally expensive because of the length of time they require to estimate the resources required for each isolated slice. In addition, there is no guarantee that the resource allocation is fairly shared among users in a slice. In this paper, we propose a Network Slicing Resource Management (NSRM) mechanism to assign the required resources for each slice in an LTE network, taking into consideration resources isolation between different slices. In addition, NSRM aims to ensure isolation and fair sharing of distributed bandwidths between users belonging to the same slice. In NSRM, depending on requirements, each slice can be customized (e.g. each can have a different scheduling policy)
    corecore