16 research outputs found
PENGENALAN DAN PENGAJARAN BERBASIS BAHASA INGGRIS DI SEKOLAH VUTTISATVITTAYANUSON SCHOOL
Bahasa Inggris diintegrasikan ke dalam proses pembelajaran. Bahasa Inggris adalah salah satu bahasa yang paling banyak tersebar dan penting di dunia, dari konferensi akademik internasional hingga laporan berita, dan bahkan lirik musik populer, bahasa Inggris digunakan dalam segala hal. Tidak hanya itu, bahasa Inggris digunakan untuk menyampaikan informasi dan berita, serta menjadi bahasa bisnis, pemerintahan dan pendidikan. Diplomasi membutuhkan bahasa Inggris, dan bahasa Inggris memainkan peran penting dalam profesi ini. Bahasa Inggris adalah bahasa internasional. Program pendidikan berkualitas tinggi juga membutuhkan kefasihan berbahasa Inggris. Belajar bahasa Inggris itu sangat penting. Oleh karena itu, pendidik harus siap mengembangkan bahasa Inggris siswa sebagai kompetensi bahasa internasional melalui kegiatan proses pembelajaran. Dalam proses pengajaran, penulis memberikan materi bahasa Inggris tentang introduction, conversation, dan story telling. Materi ini penulis berikan agar para pelajar di Vuttisatvittayanuson school dapat memahami dan menerapkan proses interaksi dan komunikasi dalam bahasa Inggris dengan baik
Inactivation and sub-lethal injury of salmonella typhi, salmonella typhimurium and vibrio cholerae in copper water storage vessels
Background: This study provides information on the antibacterial effect of copper against the water-borne pathogens Salmonella Typhi, Salmonella Typhimurium and Vibrio cholerae. Methods: Suspensions of each pathogen were kept in water within a traditional copper vessel at 30°C for 24 h. Samples were withdrawn, diluted and plated onto suitable growth media. Conventional enumeration of healthy (uninjured) bacteria was carried out using standard aerobic incubation conditions. Additionally, reactive oxygen species-neutralised (ROS-n) conditions were achieved by adding the peroxide scavenger sodium pyruvate to the medium with anaerobic incubation, to enumerate uninjured (ROS-insensitive) and injured (ROS-sensitive) bacteria. Differences between log-transformed means of conventional (aerobic) and ROS-n counts were statistically evaluated using t tests. Results: Overall, all three pathogens were inactivated by storage in copper vessels for 24 h. However, for shorter-term incubation (4-12 h), higher counts were observed under ROS-n conditions than under aerobic conditions, which demonstrate the presence of substantial numbers of sub-lethally injured cells prior to their complete inactivation. Conclusions: The present study has for the first time confirmed that these bacterial pathogens are inactivated by storage in a copper vessel within 24 h. However, it has also demonstrated that it is necessary to account for short-term sub-lethal injury, manifest as ROS-sensitivity, in order to more fully understand the process. This has important practical implications in terms of the time required to store water within a copper vessel to completely inactivate these bacteria and thereby remove the risk of water-borne disease transmission by this route
Characterisation of solar photo-oxidative disinfection
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Oxygen and photoinactivation of Escherichia in UVA and sunlight
Aims: To establish the influence of oxygen on Escherichia coli before, during and after exposure to UVA orsimulated sunlight. Methods and Results: Bacterial suspensions were exposed either to UVA or simulated sunlight. Conventional aerobic plate counts of illuminated cell suspensions were consistently lower than those obtained under conditions where reactive oxygen species (ROS) were neutralized, either (i) by the addition of the peroxide scavenger sodium pyruvate (0.05% w/v) to the medium with subsequent incubation in an anaerobic jar or (ii) by culturing on a prereduced medium within an anaerobic cabinet, indicating that a substantial proportion of such cells are sublethally injured. While the presence of oxygen during the growth period resulted in a greater resistance of aerobically grown cells to simulated sunlight compared with their anaerobic counterparts, the extent of inactivation during illumination was directly related to the dissolved oxygen content of the water. Conclusions: The results show that, at each stage, oxygen has a marked influence on the observed colony count. Significance and Impact of the Study: Overall, the results indicate that future studies of bacteria exposed to UVA or sunlight should consider the effects of oxygen at every stage in the procedure, and especially during enumeration, where the inhibitory effects of ROS must be neutralized in order to obtain a valid count. An investigation of the effects of ROS neutralization on the counts of faecal bacteria under field conditions in natural waters is now required to establish the significance of these finding to solar water treatment
Oxygen and photoinactivation of Escherichia in UVA and sunlight
Aims: To establish the influence of oxygen on Escherichia coli before, during and after exposure to UVA orsimulated sunlight. Methods and Results: Bacterial suspensions were exposed either to UVA or simulated sunlight. Conventional aerobic plate counts of illuminated cell suspensions were consistently lower than those obtained under conditions where reactive oxygen species (ROS) were neutralized, either (i) by the addition of the peroxide scavenger sodium pyruvate (0.05% w/v) to the medium with subsequent incubation in an anaerobic jar or (ii) by culturing on a prereduced medium within an anaerobic cabinet, indicating that a substantial proportion of such cells are sublethally injured. While the presence of oxygen during the growth period resulted in a greater resistance of aerobically grown cells to simulated sunlight compared with their anaerobic counterparts, the extent of inactivation during illumination was directly related to the dissolved oxygen content of the water. Conclusions: The results show that, at each stage, oxygen has a marked influence on the observed colony count. Significance and Impact of the Study: Overall, the results indicate that future studies of bacteria exposed to UVA or sunlight should consider the effects of oxygen at every stage in the procedure, and especially during enumeration, where the inhibitory effects of ROS must be neutralized in order to obtain a valid count. An investigation of the effects of ROS neutralization on the counts of faecal bacteria under field conditions in natural waters is now required to establish the significance of these finding to solar water treatment