6,937 research outputs found

    Spin 3 cubic vertices in a frame-like formalism

    Full text link
    Till now most of the results on interaction vertices for massless higher spin fields were obtained in a metric-like formalism using completely symmetric (spin-)tensors. In this, the Lagrangians turn out to be very complicated and the main reason is that the higher the spin one want to consider the more derivatives one has to introduce. In this paper we show that such investigations can be greatly simplified if one works in a frame-like formalism. As an illustration we consider massless spin 3 particle and reconstruct a number of vertices describing its interactions with lower spin 2, 1 and 0 ones. In all cases considered we give explicit expressions for the Lagrangians and gauge transformations and check that the algebra of gauge transformations is indeed closed.Comment: 17 pades, no figure

    Intelligent spider for Internet searching

    Get PDF
    As World Wide Web (WWW) based Internet services become more popular, information overload also becomes a pressing research problem. Difficulties with searching on the Internet get worse as the amount of information that is available increases. A scalable approach to support Internet search is critical to the success of Internet services and other current or future national information infrastructure (NII) applications. A new approach to build an intelligent personal spider (agent), which is based on automatic textual analysis of Internet documents, is proposed. Best first search and genetic algorithm have been tested to develop the intelligent spider. These personal spiders are able to dynamically and intelligently analyze the contents of the users' selected homepages as the starting point to search for the most relevant homepages based on the links and indexing. An intelligent spider must have the capability to make adjustments according to progress of searching in order to be an intelligent agent. However, the current searching engines do not have communication between the users and the robots. The spider presented in the paper uses Java to develop the user interface such that the users can adjust the control parameters according to the progress and observe the intermediate results. The performances of the genetic algorithm based and best first search based spiders are also reported.published_or_final_versio

    Availability of adequately iodized salt at the household level in Ethiopia: A systematic review and meta-analysis

    Full text link
    BackgroundIodine deficiency disorder (IDD) is a global, regional, and national public health problem that is preventable. Universal salt iodization is a worldwide accepted strategy to prevent IDD. The level of iodine in the salt should be adequate at the household level (≥15ppm). Though there was fragmented evidence on the proportion of adequately iodized salt at the household level in Ethiopia, the national level proportion of adequately iodized salt at the household level was remaining unknown. Therefore, this systematic review and meta-analysis estimated the pooled proportion of adequately iodized salt at the household level in Ethiopia from 2013-2020.MethodWe systematically searched the databases: PubMed/MEDLINE, Google Scholar, and Science Direct for studies conducted in Ethiopia on the availability of adequately iodized salt at the household level since 2013. We have included observational studies, which were published between January first, 2013, and 10 August 2020. The report was compiled according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The quality of included studies was scored based on the Newcastle Ottawa quality assessment scale adapted for cross-sectional studies. The data were extracted in Microsoft excel and analyzed using Stata version 14.1 software. We employed a random-effects model to estimate the pooled proportion of adequately iodized salt at the household level in Ethiopia. The presence of statistical heterogeneity within the included studies was evaluated using the I-squared statistic. We used Egger's regression test to identify evidence of publication bias. The pooled proportion with a 95% confidence interval (CI) was presented using tables and forest plots.ResultsWe screened a total of 195 articles. Of these, 28 studies (with 15561 households) were included in the final systematic review and meta-analysis. In Ethiopia, the pooled proportion of adequately iodized salt at the household level was 37% (95% CI: 28, 46%). The subgroup analyses of 28 studies by residence revealed that the pooled proportion of adequately iodized salt at the household level was 32% (95% CI: 29, 35%) and 48% (95% CI: 31, 66%) in rural and urban areas, respectively. Based on geographic location, the highest proportion was found in Addis Ababa (81%; 95%CI: 78, 83), and the lowest proportion found in Dire Dawa (20%; 95%CI: 17, 22). Besides, the proportion of adequately iodized salt at the household level was significantly increased during 2017-2020 (42%; 95% CI: 30, 53%) as compared with 2013-2016 (27%; 95% CI: 17, 39%).ConclusionsIn Ethiopia, the pooled proportion of adequately iodized salt at the household level was very low as compared to the world health organization's recommendation. Thus, the Federal Ministry of Health of Ethiopia and different stakeholders should give more attention to improve the proportion of adequately iodized salt at the household level

    Parent formulation at the Lagrangian level

    Full text link
    The recently proposed first-order parent formalism at the level of equations of motion is specialized to the case of Lagrangian systems. It is shown that for diffeomorphism-invariant theories the parent formulation takes the form of an AKSZ-type sigma model. The proposed formulation can be also seen as a Lagrangian version of the BV-BRST extension of the Vasiliev unfolded approach. We also discuss its possible interpretation as a multidimensional generalization of the Hamiltonian BFV--BRST formalism. The general construction is illustrated by examples of (parametrized) mechanics, relativistic particle, Yang--Mills theory, and gravity.Comment: 26 pages, discussion of the truncation extended, typos corrected, references adde

    BCR-ABL mutational studies for predicting the response of patients with chronic myeloid leukaemia to second-generation tyrosine kinase inhibitors after imatinib fail

    Get PDF
    Imatinib is the standard treatment for chronic myeloid leukaemia. BCR-ABL kinase domain mutation is the commonest mechanism implicated in imatinib resistance. In in-vitro studies, kinase domain mutations are variably resistant to second-line agents. We performed BCR-ABL kinase domain mutational studies in 25 patients in five institutions who failed imatinib and were treated with either nilotinib or dasatinib, to see if their mutational status would predict their clinical responses. Kinase domain mutations involving 11 amino acid substitutions were found in 12 (48%) patients. Most patients showed single kinase domain mutations. There was some concordance between reported drug sensitivity patterns and patient responses. Discordant responses could be related to drug dosage variations and unknown BCR-ABL independent mechanisms. The response prediction for patients with multiple kinase domain mutations was challenging and their mutational patterns could change after tyrosine kinase inhibitor therapy. Although BCR-ABL kinase domain mutational analysis has limitations as a means of predicting the clinical response to second-line tyrosine kinase inhibitors, it helps inform therapy decisions in the management of chronic myeloid leukaemia after imatinib failure.published_or_final_versio

    Synthesis, characterization and structure of the dimmer complex [ni(tssb)(phen)h2o]·c2h5oh·0.5h2o

    Get PDF
    2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Agrobacterium-mediated genetic transformation of Miscanthus sinensis

    Get PDF
    Miscanthus species are tall perennial rhizomatous grasses with C4 photosynthesis originating from East Asia, and they are considered as important bioenergy crops for biomass production. In this study, Agrobacterium-mediated transformation system for M. sinensis was developed using embryogenic calli derived from mature seeds. In order to establish a stable system, optimum conditions to obtain highly regenerable and transformation-competent embryogenic calli were investigated, and embryogenic calli were efficiently induced with callus induction medium containing 3 mg L-1 2,4-dichlorophenoxyacetic acid and 25 mM l-proline, at pH 5.7 with an induction temperature of 28 A degrees C. In addition, the embryogenic callus induction and regeneration potentials were compared between seven M. sinensis germplasms collected from several sites in Korea, which revealed that the germplasm SNU-M-045 had superior embryogenic callus induction and regeneration potentials. With this germplasm, the genetic transformation of M. sinensis was performed using Agrobacterium tumefaciens EHA105 carrying pCAMBIA1300 with a green fluorescence protein gene as a reporter. After putative transgenic plants were obtained, the genomic integration of transgenes was confirmed by genomic PCR, transgene expression was validated by Northern blot analysis, and the number of transgene integration was confirmed by DNA gel blot analysis. Furthermore, the Agrobacterium-mediated transformation of M. sinensis was also performed with pCAMBIA3301 which contains an herbicide resistance gene (BAR), and we obtained transgenic M. sinensis plants whose herbicide resistance was confirmed by spraying with BASTA(A (R)). Therefore, we have established a stable Agrobacterium-mediated transformation system for M. sinensis, and also successfully produced herbicide-resistant Miscanthus plants by introducing BAR gene via the established method.X111210Ysciescopu

    Ionic high-pressure form of elemental boron

    Full text link
    Boron is an element of fascinating chemical complexity. Controversies have shrouded this element since its discovery was announced in 1808: the new 'element' turned out to be a compound containing less than 60-70 percent of boron, and it was not until 1909 that 99-percent pure boron was obtained. And although we now know of at least 16 polymorphs, the stable phase of boron is not yet experimentally established even at ambient conditions. Boron's complexities arise from frustration: situated between metals and insulators in the periodic table, boron has only three valence electrons, which would favour metallicity, but they are sufficiently localized that insulating states emerge. However, this subtle balance between metallic and insulating states is easily shifted by pressure, temperature and impurities. Here we report the results of high-pressure experiments and ab initio evolutionary crystal structure predictions that explore the structural stability of boron under pressure and, strikingly, reveal a partially ionic high-pressure boron phase. This new phase is stable between 19 and 89 GPa, can be quenched to ambient conditions, and has a hitherto unknown structure (space group Pnnm, 28 atoms in the unit cell) consisting of icosahedral B12 clusters and B2 pairs in a NaCl-type arrangement. We find that the ionicity of the phase affects its electronic bandgap, infrared adsorption and dielectric constants, and that it arises from the different electronic properties of the B2 pairs and B12 clusters and the resultant charge transfer between them.Comment: Published in Nature 453, 863-867 (2009
    corecore