56 research outputs found

    Revisiting On-Line Discussion as Practice for Reflective Thinking in Three Sequential Classes

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    In a previous study, the authors questioned the potential of an on-line environment for increasing productive reflection in three sequential education classes. Of their findings, the issue of consistency stood out as particularly perplexing, namely, why did students exhibit high level reflections sometimes, but not all the time, in an on-line environment? In this follow-up study, the authors question whether in-class reflections coupled with on-line prompts could yield consistently high level pre-service teacher reflections, as measured by individual and class progress over time. This study also examines perceived relationships between the length of a student\u27s reflection and its productivity, as well as a student\u27s depth of focus and productivity. Using the same scoring approach as our previous study, our discussion of the results examines the usefulness of on-line environments for promoting consistently high level pre-service teacher reflection

    A review of zoonotic infection risks associated with the wild meat trade in Malaysia.

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    The overhunting of wildlife for food and commercial gain presents a major threat to biodiversity in tropical forests and poses health risks to humans from contact with wild animals. Using a recent survey of wildlife offered at wild meat markets in Malaysia as a basis, we review the literature to determine the potential zoonotic infection risks from hunting, butchering and consuming the species offered. We also determine which taxa potentially host the highest number of pathogens and discuss the significant disease risks from traded wildlife, considering how cultural practices influence zoonotic transmission. We identify 51 zoonotic pathogens (16 viruses, 19 bacteria and 16 parasites) potentially hosted by wildlife and describe the human health risks. The Suidae and the Cervidae families potentially host the highest number of pathogens. We conclude that there are substantial gaps in our knowledge of zoonotic pathogens and recommend performing microbial food safety risk assessments to assess the hazards of wild meat consumption. Overall, there may be considerable zoonotic risks to people involved in the hunting, butchering or consumption of wild meat in Southeast Asia, and these should be considered in public health strategies

    On the microscopic origins of relaxation processes in aqueous peptide solutions undergoing a glass transition

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    We combine broadband dielectric spectroscopy (BDS) with 1H and 2H nuclear magnetic resonance (NMR) to study molecular dynamics in mixtures of ϵ-polylysine with H2O or D2O. In BDS, four relaxation processes can be attributed to molecular dynamics. While the fastest process P1 obeys the Arrhenius law, the slowest process P4 shows prominent non-Arrhenius behavior typical of structural α relaxation. For the intermediate processes P2 and P3, the temperature dependence changes at the glass transition temperature Tg. The 1H and 2H NMR results yield insights into the molecular origins of these relaxation phenomena. In these NMR analyses, we exploit, in addition to the isotope selectivity of the method, the possibility to distinguish between various types of motion based on their respective line-shape effects and the capability to single out specific molecular moieties based on different spin-lattice relaxation behaviors. In this way, we reveal that process P1 results from the rotation of side and end groups of the peptide, while process P2 is caused by a reorientation of essentially all water molecules, which are quasi-isotropic and survive well below Tg. As for the peptide backbone dynamics, we find evidence that rotational motion of polar groups is involved in process P3 and that nonpolar regions show a dynamical process, which is located between P3 and P4. Thus, the NMR analyses do not yield evidence for coexisting fast peptide-decoupled and slow peptide-coupled water species, which contribute to BDS processes P2 and P3, respectively, but minor bimodality of water motion may remain undetected. Finally, it is demonstrated that the proton/deuteron exchange needs to be considered when interpreting experimental results for molecular dynamics in aqueous peptide solutions.Financial support through the Grant Nos. Vo-905/8-2, PID2019-104650GB-C21, and LINKB20012 is gratefully acknowledge

    Detection of Chlamydia psittaci in free-ranging koalas (Phascolarctos cinereus): DNA hybridization and immuno-slot blot analyses

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    DNA-slot hybridization and immuno-slot blot analyses were compared for the detection of Chlamydia psittact in crude swab material from free-ranging koalas. Immuno-slot blot analysis detected chlamydiae in 43 out of 68 koalas, with the sensitivity of the assay varying from 52 to 73% depending on the site of infection. Gene probe analysis was also used employing a genus-specific probe pCKO-10 isolated from a koala chlamydial gene library (ocular strain) and a plasmid probe pCKU cloned from a urogenital strain. The sensitivity of these two assays was comparable and they were considerably more efficient than the immuno-slot blot method for the detection of chlamydiae. Comparison of these data with a cell-culture method of detection, previously used with the same samples, demonstrated that gene probe analysis detected more positives than observed with cell culture. However, this appears to reflect more on the condition of the swab material rather than the sensitivity of the method

    Detection of B Virus Antibody in Monkey Sera Using Glycoprotein D Expressed in Mammalian Cells

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    The gene encoding glycoprotein D (gD) of the monkey B virus (Cercopithecine herpesvirus 1) was cloned into a mammalian expression vector, pcDNA3.1(−), and the recombinant plasmid DNA was transfected into COS7 cells. The expression of gD in transfected COS7 cells was detected by indirect immunofluorescence assay or radioimmunoprecipitation analysis (RIPA). Although the expressed gD protein was revealed to react well with sera from monkeys naturally infected with B virus by RIPA, some sera showed reduced reactivity when analyzed by the Western blotting (WB) method. Some sera also showed relatively high background when the WB was performed using gD expressed from recombinant plasmid. The mutant gD protein lacking the transmembrane domain (TM) and cytoplasmic tail (CT) was next expressed in COS7 cells. The mutant protein was secreted into culture medium without apparent loss of the antigenicity. Using the secretory form of the gD protein as antigen in dot blot analysis, sera from B virus-infected monkeys were shown to react with the mutant protein without nonspecific reaction. Since the recombinant gD or its derivative lacking TM and CT could be expressed in mammalian cells with proper antigenicity, these antigens appeared to be useful for serological detection of B virus infection in monkeys
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