1,411 research outputs found

    2′,3,4,4′-Tetra­meth­oxy­chalcone

    Get PDF
    In the title compound [systematic name: 1-(2,4-dimethoxyphenyl)-3-(3,4-dimethoxyphenyl)prop-2-en-1-one], C19H20O5, the dihedral angle between the benzene rings is 26.88 (5)°. One of the meth­oxy groups is twisted slightly away from the plane [C—O—C—C torsion angle = −12.8 (3)°] while the others are almost co-planer [C—O—C—C torsion angles = −3.2 (3), 2.6 (3) and −3.6 (3)°]. The crystal packing is stabilized by inter­molecular C—H⋯O inter­actions. A weak intra­molecular C—H⋯O inter­action occurs

    Patterns of RAPD markers and heavy metal concentrations in Perna viridis (L.), collected from metal-contaminated and uncontaminated coastal waters: Are they correlated with each other?

    Get PDF
    Genetic variation due to heavy metal contamination has always been an interesting topic of study. Because of the numerous contaminants being found in coastal and intertidal waters, there is always much discussion and argument as to which contaminant(s) caused the variations in the genetic structures of biomonitors. This study used a Single Primer Amplification Reaction (SPAR) technique, namely Random Amplified Polymorphic DNA (RAPD), to determine the genetic diversity of the populations of the green-lipped mussel Perna viridis collected from a metal-contaminated site at Kg. Pasir Puteh and those from four relatively uncontaminated sites (reference sites). Heavy metal levels (Cd, Cu, Pb, and Zn) were also measured in the soft tissues and byssus of the mussels from all the sites. Cluster analyses employing UPGMA based on the RAPD markers grouped the populations into two major clusters; the Bagan Tiang, Pantai Lido, Pontian, and Kg. Pasir Puteh populations were in one cluster, while the Sg. Belungkor population clustered by itself. This indicated that the genetic diversity based on bands resulting from the use of all four RAPD primers on P. viridis did not indicate its potential use as a biomarker of heavy metal pollution in coastal waters. However, based on a correlation analysis between a particular metal and a band resulting from a specific RAPD primer revealed some significant (P < 0.01) correlations between the primers and the heavy metal concentrations in the byssus and soft tissues. Thus, the correlation between a particular metal and the bands resulting from the use of a specific RAPD primer on P. viridis could be used as biomonitoring tool of heavy metal pollution

    Overcoming data scarcity of Twitter: using tweets as bootstrap with application to autism-related topic content analysis

    Full text link
    Notwithstanding recent work which has demonstrated the potential of using Twitter messages for content-specific data mining and analysis, the depth of such analysis is inherently limited by the scarcity of data imposed by the 140 character tweet limit. In this paper we describe a novel approach for targeted knowledge exploration which uses tweet content analysis as a preliminary step. This step is used to bootstrap more sophisticated data collection from directly related but much richer content sources. In particular we demonstrate that valuable information can be collected by following URLs included in tweets. We automatically extract content from the corresponding web pages and treating each web page as a document linked to the original tweet show how a temporal topic model based on a hierarchical Dirichlet process can be used to track the evolution of a complex topic structure of a Twitter community. Using autism-related tweets we demonstrate that our method is capable of capturing a much more meaningful picture of information exchange than user-chosen hashtags.Comment: IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining, 201

    Crystallization and preliminary X-ray diffraction studies of FHA domains of Dun1 and Rad53 protein kinases

    Get PDF
    Forkhead-associated (FHA) domains are modular protein–protein interaction domains of ~130 amino acids present in numerous signalling proteins. FHA-domain-dependent protein interactions are regulated by phosphorylation of target proteins and FHA domains may be multifunctional phosphopeptide-recognition modules. FHA domains of the budding yeast cell-cycle checkpoint protein kinases Dun1p and Rad53p have been crystallized. Crystals of the Dun1-FHA domain exhibit the symmetry of the space group P6122 or P6522, with unit-cell parameters a = b = 127.3, c = 386.3 Å; diffraction data have been collected to 3.1 Å resolution on a synchrotron source. Crystals of the N-terminal FHA domain (FHA1) of Rad53p diffract to 4.0 Å resolution on a laboratory X-ray source and have Laue-group symmetry 4/mmm, with unit-cell parameters a = b = 61.7, c = 104.3 Å

    (2E)-1-(2-Bromo­phen­yl)-3-(4-bromo­phen­yl)prop-2-en-1-one

    Get PDF
    The title compound, C15H10Br2O, is a chalcone with 2-bromo­phenyl and 4-bromo­phenyl rings bonded to opposite sides of a propenone group. The dihedral angle between mean planes of the benzene rings is 71.3 (1)°. The angle between the mean plane of the prop-2-ene-1-one group and the mean planes of the 2-bromo­phenyl and 4-bromo­phenyl rings are 64.2 (9) and 71.3 (1)°, respectively. A weak inter­molecular C—H⋯O inter­action and two weak C—Br⋯π inter­actions are observed, which contribute to the stability of the crystal packing

    Predictive biometrics: A review and analysis of predicting personal characteristics from biometric data

    Get PDF
    Interest in the exploitation of soft biometrics information has continued to develop over the last decade or so. In comparison with traditional biometrics, which focuses principally on person identification, the idea of soft biometrics processing is to study the utilisation of more general information regarding a system user, which is not necessarily unique. There are increasing indications that this type of data will have great value in providing complementary information for user authentication. However, the authors have also seen a growing interest in broadening the predictive capabilities of biometric data, encompassing both easily definable characteristics such as subject age and, most recently, `higher level' characteristics such as emotional or mental states. This study will present a selective review of the predictive capabilities, in the widest sense, of biometric data processing, providing an analysis of the key issues still adequately to be addressed if this concept of predictive biometrics is to be fully exploited in the future

    The covid-19 pandemic situation in Malaysia: lessons learned from the perspective of population density

    Get PDF
    This paper attempts to ascertain the impacts of population density on the spread and severity of COVID-19 in Malaysia. Besides describing the spatio-temporal contagion risk of the virus, ultimately, it seeks to test the hypothesis that higher population density results in exacerbated COVID-19 virulence in the community. The population density of 143 districts in Malaysia, as per data from Malaysia’s 2010 population census, was plotted against cumulative COVID-19 cases and infection rates of COVID-19 cases, which were obtained from Malaysia’s Ministry of Health official website. The data of these three variables were collected between 19 January 2020 and 31 December 2020. Based on the observations, districts that have high population densities and are highly inter-connected with neighbouring districts, whether geographically, socio-economically, or infrastructurally, tend to experience spikes in COVID-19 cases within weeks of each other. Using a parametric approach of the Pearson correlation, population density was found to have a moderately strong relationship to cumulative COVID-19 cases (p-value of 0.000 and R2 of 0.415) and a weak relationship to COVID-19 infection rates (p-value of 0.005 and R2 of 0.047). Consequently, we provide several non-pharmaceutical lessons, including urban planning strategies, as passive containment measures that may better support disease interventions against future contagious diseases

    3-(3-Bromo-4-methoxy­phen­yl)-1,5-diphenyl­pentane-1,5-dione

    Get PDF
    In the title compound, C24H21BrO3, the central bromo­methoxy­benzene ring forms dihedral angles of 63.6 (1) and 60.3 (1)° with the terminal phenyl rings, while the angle between the two phenyl rings is 25.8 (1)°. The crystal structure is stabilized by weak C—H⋯Br and C—H⋯O hydrogen bonds, and C—H⋯π and π–π stacking [centroid–centroid distance = 3.910 (3) Å] inter­actions

    (2E)-1-(2-Bromo­phen­yl)-3-(4-chloro­phen­yl)prop-2-en-1-one

    Get PDF
    In the title compound, C15H10BrClO, the dihedral angle between the mean planes of the benzene rings in the ortho-bromo- and para-chloro-substituted rings is 70.5 (6)°. The dihedral angles between the mean plane of the prop-2-en-1-one group and the mean planes of the benzene rings in the 4-chloro­phenyl and 2-bromo­phenyl rings are 14.9 (3) and 63.3 (8)°, respectively. In the crystal, inversion dimers linked by pairs of weak C—H⋯O interactions are observed as well as aromatic π–π stacking inter­actions
    corecore