2,267 research outputs found

    Originator recognition (OR) path recovery mechanism for load-based routing protocol

    Get PDF
    6LoWPAN has become a new technology to provide the internet connectivity to the traditional WSN. The introduction of 6LoWPAN adaptation layer enables the smooth delivery of packet from network layer to MAC layer. In this paper, the LOAD-based routing protocol with the proposed originator recognition (OR) path recovery mechanism is introduced. The proposed OR path recovery mechanism modifies the IETF conceptual LOAD protocol message by inserting an identity key in the generated RERR message. The identity key is then used by the originator of a failed data packet to initialize path recovery during the link failure. The developed OR-LOAD has examined under the 6LoWPAN environment in Qualnet simulator. Its performance is evaluated and compared to AODV in terms of packet delivery ratio and throughput

    Chemical constituents and antioxidant activity of Cinnamomum microphyllum

    Get PDF
    The extract of Cinnamomum microphyllum showed strong antioxidant activity when it was tested against auto-oxidation of linoleic acid, superoxide, and DPPH radical scavenging activity. Further detailed investigations of the plant constituents and bioactivity studies led to the isolation and identification of known compounds consisting of three lignans, a coumarin, an ester and β-sitosterol. The structures of the compounds were determined using detailed spectroscopic analysis. The lignans were found to possess a significant antioxidant activity when tested against the three assay systems

    Alkaloids and sulphur-containing amides from glycosmis citrifolia and glycosmis elongata

    Get PDF
    Air-dried leaves of both Glycosmis citrifolia and Glycosmis elongata collected from Bogor Botanical Garden, Indonesia were individually extracted with chloroform to give dark viscous extracts after solvent removal. Column chromatographic separation of the extract of G. citrifolia yielded 5(6)-glutene-3α-ol, two sets conformers, (E)-dambullin and (Z)-dambullin, and (E)-methyldambullin and (Z)-methyldambullin. Similar treatment of the extract of G. elongata gave skimmianine and arborinine. The structures of the compounds were elucidated based on spectroscopic data and comparison with published reports

    Developing of emergency evacuation kit in response of Malaysia East Coast flood disaster

    Get PDF
    The flood struck East Coast of Peninsular Malaysia in December 2014 has resulted in huge natural disaster. More than 4.82 million people across four states especially Kelantan were sink flooded, resulted shut down of the area from outside traffic and delaying the rescue forces. Emergency aid has difficulties to reach the evacuation centres and victims were scattered trapped with low life support on water, food, energy and healthcare supply. Therefore, an integrated assessment of flood in the basin is important to seek for effective responses. In response to disaster vulnerability for risk reduction among society who living in flood prone, community contribution is needed in preparation of emergency evacuation kit as a part of preparedness. The survey will be conduct by distribution of questionnaire to the flood disaster victims in order to discover the most important necessities during flood situation. The results of this survey may lead to the preparation of emergency evacuation kit for use in future

    A new cytotoxic carbazole alkaloid from Clausena excavata

    Get PDF
    A new carbazole alkaloid, 3-carbomethoxy-2-hydroxy-7-methoxycarbazole, Clausine-TY (1),together with two known carbazole alkaloid, Clausine-H (2) and Clausine-B (3), were isolated from the ethyl acetate extract of the stem bark of the Malaysian Clausena excavata. The structures of these compounds were elucidated by spectroscopic analyses. The new carbazole alkaloid shows significant cytotoxicity against CEM-SS cell line

    Strain-dependent host transcriptional responses to toxoplasma infection are largely conserved in mammalian and avian hosts

    Get PDF
    Toxoplasma gondii has a remarkable ability to infect an enormous variety of mammalian and avian species. Given this, it is surprising that three strains (Types I/II/III) account for the majority of isolates from Europe/North America. The selective pressures that have driven the emergence of these particular strains, however, remain enigmatic. We hypothesized that strain selection might be partially driven by adaptation of strains for mammalian versus avian hosts. To test this, we examine in vitro, strain-dependent host responses in fibroblasts of a representative avian host, the chicken (Gallus gallus). Using gene expression profiling of infected chicken embryonic fibroblasts and pathway analysis to assess host response, we show here that chicken cells respond with distinct transcriptional profiles upon infection with Type II versus III strains that are reminiscent of profiles observed in mammalian cells. To identify the parasite drivers of these differences, chicken fibroblasts were infected with individual F1 progeny of a Type II x III cross and host gene expression was assessed for each by microarray. QTL mapping of transcriptional differences suggested, and deletion strains confirmed, that, as in mammalian cells, the polymorphic rhoptry kinase ROP16 is the major driver of strain-specific responses. We originally hypothesized that comparing avian versus mammalian host response might reveal an inversion in parasite strain-dependent phenotypes; specifically, for polymorphic effectors like ROP16, we hypothesized that the allele with most activity in mammalian cells might be less active in avian cells. Instead, we found that activity of ROP16 alleles appears to be conserved across host species; moreover, additional parasite loci that were previously mapped for strain-specific effects on mammalian response showed similar strain-specific effects in chicken cells. These results indicate that if different hosts select for different parasite genotypes, the selection operates downstream of the signaling occurring during the beginning of the host's immune response. © 2011 Ong et al

    CMB Telescopes and Optical Systems

    Full text link
    The cosmic microwave background radiation (CMB) is now firmly established as a fundamental and essential probe of the geometry, constituents, and birth of the Universe. The CMB is a potent observable because it can be measured with precision and accuracy. Just as importantly, theoretical models of the Universe can predict the characteristics of the CMB to high accuracy, and those predictions can be directly compared to observations. There are multiple aspects associated with making a precise measurement. In this review, we focus on optical components for the instrumentation used to measure the CMB polarization and temperature anisotropy. We begin with an overview of general considerations for CMB observations and discuss common concepts used in the community. We next consider a variety of alternatives available for a designer of a CMB telescope. Our discussion is guided by the ground and balloon-based instruments that have been implemented over the years. In the same vein, we compare the arc-minute resolution Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). CMB interferometers are presented briefly. We conclude with a comparison of the four CMB satellites, Relikt, COBE, WMAP, and Planck, to demonstrate a remarkable evolution in design, sensitivity, resolution, and complexity over the past thirty years.Comment: To appear in: Planets, Stars and Stellar Systems (PSSS), Volume 1: Telescopes and Instrumentatio

    TRY plant trait database - enhanced coverage and open access

    Get PDF
    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
    corecore