16 research outputs found

    Diversity and community composition of fishes in the Pusu River Gombak, Malaysia

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    The Pusu River has been receiving increased pollution loads because of a significant amount of land-clearing activities for development projects. A total of 113 numbers of fishes belonging to six species under six families were recorded from Pusu River throughout the study period (November 2014–March 2015). The most dominant species were Barbonymus schwanenfeldii (38.9%) followed by Oreochromis mossambica (36.28%) under families Cyprinidae and Cichlidae, respectively. Similarly, the species Hypostomus plecostomus (10.62%), Channa striatus (6.19%), Notopterus notopterus (4.42%), Pristolepis fasciata (3.54%) under the family Loricariidae, Channidae, Notopteridae, and Pristolepididae were constituted of the total fish catch, respectively. A greater abundance (56.64%) of fish community was observed at station 3 compared to the other stations. This is a deeper pool area located near the rainforest area with less turbid water compared to the other stations. Second highest abundance (14.16%) was observed at station 2, while station 6 has shown the lowest abundance (2.65%). Overall Shannon diversity value (H0 ¼ 1.399) indicates that Sg. Pusu, Gombak, is not highly diverse with the tropical fish species. The study suggests that a long-term continuous monitoring of water quality and fish diversity is needed to study for sustainable development of fishes in this fascinating tropical river (Sg.) Pusu

    Identifying Recent Cholera Infections Using a Multiplex Bead Serological Assay

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    Estimates of incidence based on medically attended cholera can be severely biased. Vibrio cholerae O1 leaves a lasting antibody signal and recent advances showed that these can be used to estimate infection incidence rates from cross-sectional serologic data. Current laboratory methods are resource intensive and challenging to standardize across laboratories. A multiplex bead assay (MBA) could efficiently expand the breadth of measured antibody responses and improve seroincidence accuracy. We tested 305 serum samples from confirmed cholera cases (4 to 1083 d postinfection) and uninfected contacts in Bangladesh using an MBA (IgG/IgA/IgM for 7 Vibrio cholerae O1-specific antigens) as well as traditional vibriocidal and enzyme-linked immunosorbent assays (2 antigens, IgG, and IgA). While postinfection vibriocidal responses were larger than other markers, several MBA-measured antibodies demonstrated robust responses with similar half-lives. Random forest models combining all MBA antibody measures allowed for accurate identification of recent cholera infections (e.g., past 200 days) including a cross-validated area under the curve (cvAUC200) of 92%, with simpler 3 IgG antibody models having similar accuracy. Across infection windows between 45 and 300 days, the accuracy of models trained on MBA measurements was non-inferior to models based on traditional assays. Our results illustrated a scalable cholera serosurveillance tool that can be incorporated into multipathogen serosurveillance platforms. IMPORTANCE Reliable estimates of cholera incidence are challenged by poor clinical surveillance and health-seeking behavior biases. We showed that cross-sectional serologic profiles measured with a high-throughput multiplex bead assay can lead to accurate identification of those infected with pandemic Vibrio cholerae O1, thus allowing for estimates of seroincidence. This provides a new avenue for understanding the epidemiology of cholera, identifying priority areas for cholera prevention/control investments, and tracking progress in the global fight against this ancient disease

    Asteroseismology of Massive Stars with the TESS Mission: The Runaway β Cep Pulsator PHL 346 = HN Aqr

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    We report an analysis of the first known β Cep pulsator observed by the Transiting Exoplanet Survey Satellite (TESS) mission, the runaway star PHL 346 = HN Aqr. The star, previously known as a singly periodic pulsator, has at least 34 oscillation modes excited, 12 of those in the g-mode domain and 22 p modes. Analysis of archival data implies that the amplitude and frequency of the dominant mode and the stellar radial velocity were variable over time. A binary nature would be inconsistent with the inferred ejection velocity from the Galactic disk of 420 km s -1 , which is too large to be survivable by a runaway binary system. A kinematic analysis of the star results in an age constraint (23 +1 Myr) that can be imposed on asteroseismic modeling and that can be used to remove degeneracies in the modeling process. Our attempts to match the excitation of the observed frequency spectrum resulted in pulsation models that were too young. Hence, asteroseismic studies of runaway pulsators can become vital not only in tracing the evolutionary history of such objects, but to understand the interior structure of massive stars in general. TESS is now opening up these stars for detailed asteroseismic investigation. © 2019. The American Astronomical Society. All rights reserved.

    A review of photochromism in textiles and its measurement

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    Photochromism is a light-induced reversible change in colour defined as: ‘A reversible transformation in a chemical species between two forms having different absorption spectra brought about by photo-irradiation.’ This issue of Textile Progress provides a review of photochromism, the different methods for producing photochromic textiles, their properties, the measurement of kinetic colour changes, and their application in photochromic textiles. Photochromism can be utilised in a variety of textile products from everyday clothing to high-technology applications such as protective textiles, medical textiles, geo-textiles and sports textiles. Although photochromic materials have been used since 1960 to cut down the transmission of light through the lenses in sunglasses, there has been limited further development since that time due to technical difficulties not only in the application of photochromic colourants, but also with the measurement of kinetic colourchanging properties. Renewed interest in photochromic textiles has arisen due to improved commercial potential in particular for applications as photochromic nanofibres, in ‘smart’ textiles and in ‘smart’ clothing
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