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Nakhon Ratchasima, Thailand

Visutthi M.,Nakhon Ratchasima Rajabhat University
Proceedings 2015 International Conference on Science and Technology, TICST 2015 | Year: 2015

Quorum sensing is an intercellular signaling system in bacteria in response to cell population. Several physiological processes in pathogenesis of medically important bacteria are associated with quorum sensing. As quorum sensing controls bacterial virulences, the inhibition of the system is being considered as a novel approach for antibacterial substance. This research determined the effect of 47 Thai medicinal plant species on bacterial quorum sensing, Chromobacterium violaceum. Anti-quorum sensing activity was indicated by the inhibition of violacein pigment producing of biomonitor strain, C. violaceum DMST 21761. Screening test by disc diffusion assay revealed that five plant extracts exhibited anti-quorum sensing activity including Alpinia galanga Sw., Feronia limonia (L.) Swing, Millingtonia hortensis Linn., Oroxylum indicum (L.) Kurz., and Sesbania grandiflora (L.) Poiret. All extracts, except A. galanga, reduced violacein production. Sixteen extracts produced pronounced inhibitory activity. This result may reveal the mode of action of botanical plants including anti-quorum sensing property and this activity should be further examinations. © 2015 IEEE. Source

Shibata M.,Fukui Prefectural Dinosaur Museum | Jintasakul P.,Nakhon Ratchasima Rajabhat University | Azuma Y.,Fukui Prefectural Dinosaur Museum
Acta Geologica Sinica | Year: 2011

Here we report a new iguanodontian dentary found from the Lower Cretaceous Khok Kruat Formation, Nakhon Ratchasima, northeast Thailand. A unique character, which is an elongated and flat shape of the dentary ramus, makes it possible to assign the specimen to the new genus of non-hadrosaurid iguanodontian, Ratchasimasaurus suranateae gen. etsp. nov. R. suranateae shows both primitive and derived characters, such as a caudally inclined coronoid process and alveolar trough with a primitive crown impression, and a derived buccal shelf between tooth row and coronoid process. The discovery of a new iguanodontian from the Indochina Terrene, considering that the previously reported Probactrosaurus-like iguanodontian, points out a great diversity of this group in the late Early Cretaceous in Thailand, and corresponds to the Asian iguanodontian diversity at that time. Source

Phaiboonnugulkij M.,Nakhon Ratchasima Rajabhat University
International Journal of Applied Linguistics and English Literature | Year: 2016

The objectives of this paper were to compare total and individual metacognitive strategies by four groups of university students from different majors in five different tourism situational lessons. The total of 34 students participated in this study, and they were categorized into four groups based on their major of study and English proficiency level. The research instruments were a web-based speaking test in English for Tourism (WBST-EFT), a strategy coding scheme and the Internet-mediated contextualized English for Domestic Tourism lessons (InConMedt). Mixed methods of quantitative and qualitative approaches were employed in the present study. The quantitative analysis included Kruskal Wallis, Mann-Whitney U test as well as Chi-square, mean rank, frequency and percentages. Qualitative content analysis from the verbal reports in the stimulated recall session on metacognitive strategies was employed in this study. The findings showed that four groups significantly and differently employed total metacognitive strategies in five lessons, 2(3, N = 34) = 10.00, p =.01. The significant difference was evident in the use of individual metacognitive strategies including goal setting and planning of the groups and in a particular lesson. The insights from the verbal report content analysis revealed significant information on how the high proficiency group effectively employed their metacognitive strategy in their speaking performances; whereas the information from the low proficiency group also shed more light in the instructional approach on how to train these students to improve their speaking ability using effective strategies. © 2016, Australian International Academic Centre PTY LTD. All rights reserved. Source

Sata V.,Khon Kaen University | Sathonsaowaphak A.,Nakhon Ratchasima Rajabhat University | Chindaprasirt P.,Khon Kaen University
Cement and Concrete Composites | Year: 2012

This paper presents an investigation of the compressive strength and the durability of lignite bottom ash geopolymer mortars in 3% sulfuric acid and 5% sodium sulfate solutions. Three finenesses of ground bottom ash viz., fine, medium and coarse bottom ash were used to make geopolymer mortars. Sodium silicate, sodium hydroxide and curing temperature of 75°C for 48 h were used to activate the geopolymerization. The results were compared to those of Portland cement and high volume fly ash mortars. It was found that the fine bottom ash was more reactive and gave geopolymer mortars with higher compressive strengths than those of the coarser fly ashes. All bottom ash geopolymer mortars were less susceptible to the attack by sodium sulfate and sulfuric acid solutions than the traditional Portland cement mortars. © 2012 Elsevier Ltd. All rights reserved. Source

Chokchaloemwong D.,Suranaree University of Technology | Prakobsaeng N.,Rajabhat Maha Sarakham University | Sartsoongnoen N.,Nakhon Ratchasima Rajabhat University | Kosonsiriluk S.,University of Minnesota | And 2 more authors.
Hormones and Behavior | Year: 2013

Oxytocin (OT) is known to induce and regulate maternal behaviors in mammals via the supraoptic nucleus and paraventricular nucleus (PVN), whereas the function of mesotocin (MT; the avian homolog of OT) is poorly understood in birds. To elucidate the association of MT and the regulation of maternal behaviors in birds, we studied changes in the number of MT-immunoreactive (ir) neurons in native Thai chickens using immunohistochemistry. We observed that MT-ir neurons and fibers appeared in discrete regions located close to the third ventricle from the level of the preoptic area through the anterior hypothalamus with an abundance observed in the nucleus supraopticus, pars ventralis (SOv), nucleus preopticus medialis (POM), and PVN. The number of MT-ir neurons was low in the SOv, POM, and PVN of non-laying hens, but it increased gradually when the hens entered the laying stage, and peaked in incubating and rearing hens. We compared the number of MT-ir neurons in the SOv, POM, and PVN of native Thai hens rearing chicks (R) with that of non-rearing chicks (NR). The number of MT-ir neurons was high in the R hens, but low in the NR hens in these nuclei. For the first time, these results indicate that the association between the MT neurons and the presence of chicks might, in part, play a role in the neuroendocrine reorganization to establish and maintain maternal behaviors in native Thai chickens. MTergic activity is likely related to the contribution of rearing behavior in this equatorial precocial species. © 2013 Elsevier Inc. Source

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