Songkhla, Thailand
Songkhla, Thailand

Prince of Songkla University is the first university in Southern Thailand, established in 1967. The name of the university was granted by His Majesty the King in honor of His Royal Highness Prince Mahidol Adulyadej, Prince of Songkla, the king's father.The university consists of four campuses and one education service area. In 1968, the first permanent campus was established in Pattani. The campus in Hat Yai was opened in 1971 and is now the main campus, with more than 50% of the university's students. Other campuses were established in Phuket and Surat Thani . Additionally, the Trang education service area was founded in 1991. As 2007, the university offers 295 educational programs to its 34,000 students, including 18 international programs and 3 foreign language programs.Prince of Songkla University hosts hundreds of international students. The Phuket campus accommodates the most students from European and North American universities. The International Study Program in Phuket is multidisciplinary, offering courses in Social science, History, Intercultural Communications, Tourism, Human Resources and International Finance and Economics. Wikipedia.

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Ritchie R.J.,Prince of Songkla University
Microbial Ecology | Year: 2013

Ammonia is the preferred nitrogen source for many algae including the cyanobacterium Synechococcus elongatis (Synechococcus R-2; PCC 7942). Modelling ammonia uptake by cells is not straightforward because it exists in solution as NH3 and NH4+. NH3 is readily diffusible not only via the lipid bilayer but also through aquaporins and other more specific porins. On the other hand, NH4+ requires cationic transporters to cross a membrane. Significant intracellular ammonia pools (≈1-10 mol m-3) are essential for the synthesis of amino acids from ammonia. The most common model envisaged for how cells take up ammonia and use it as a nitrogen source is the "pump-leak model" where uptake occurs through a simple diffusion of NH3 or through an energy-driven NH4+ pump balancing a leak of NH3 out of the cell. The flaw in such models is that cells maintain intracellular pools of ammonia much higher than predicted by such models. With caution, [14C]-methylamine can be used as an analogue tracer for ammonia and has been used to test various models of ammonia transport and metabolism. In this study, simple "proton trapping" accumulation by the diffusion of uncharged CH3NH2 has been compared to systems where CH3NH3+ is taken up through channels, driven by the membrane potential (ΔUi,o) or the electrochemical potential for Na+ (ΔμNai,o+). No model can be reconciled with experimental data unless the permeability of CH3NH2 across the cell membrane is asymmetric: permeability into the cell is very high through gated porins, whereas permeability out of the cell is very low (≈40 nm s-1) and independent of the extracellular pH. The best model is a Nain+/CH3NH3+in co-porter driven by ΔμNai,o+ balancing synthesis of methylglutamine and a slow leak governed by Ficks law, and so there is significant futile cycling of methylamine across the cell membrane to maintain intracellular methylamine pools high enough for fixation by glutamine synthetase. The modified pump-leak model with asymmetric permeability of the uncharged form is a viable model for understanding ammonia uptake and retention in plants, free-living microbes and organisms in symbiotic relationships. © 2012 Springer Science+Business Media, LLC.

Chitosan coatings, with and without clove oil, were investigated for effects on quality and shelf life of cooked pork sausages stored at a refrigerated temperature (4 ± 2 °C). The various treatments of cooked pork sausages were: untreated (control), coating with 2% chitosan (CS), and coating with a mixture having 2% chitosan and 1.5% clove oil (CS + CO). Various microbiological, physical, chemical and sensory properties were monitored over 25 days of storage. The total viable count, the psychrotrophic bacteria count, the L* value, peroxide value and the thiobarbituric acid reactive substances increased, while the a* value, the b* value, the pH and the sensory scores decreased with storage time, across all treatments. However, these changes were slowest with the CS + CO treatment. Based on sensory evaluation and microbiological quality, the shelf lives were 14 days for control, 20 days for CS, and 20. days for CS + CO treated samples, under refrigerated storage. © 2015 Published by Elsevier Ltd.

Yeesang C.,Prince of Songkla University | Cheirsilp B.,Prince of Songkla University
Bioresource Technology | Year: 2011

Four green microalgae (TRG, KB, SK, and PSU) identified as Botryococcus spp. by morphological criteria were isolated from lakes and freshwater ponds in southern Thailand. In nitrogen-rich medium the strains achieved a lipid content of 25.8%, 17.8%, 15.8% and 5.7%, respectively. A combination of nitrogen deficiency, moderately high light intensity (82.5μEm -2s -1) and high level of iron (0.74mM) improved lipid accumulation in TRG, KB, SK, and PSU strains up to 35.9%, 30.2%, 28.4% and 14.7%, respectively. The lipid contents and plant oil-like fatty acid composition of the microalgae suggested their potential as biodiesel feedstock. © 2010 Elsevier Ltd.

Choksuchat C.,Prince of Songkla University
Journal of Minimally Invasive Gynecology | Year: 2010

Misoprostol, a prostaglandin E1 derivative, has been widely used in nonpregnant women because of its cervical ripening and uterotonic effects. A large number of studies have demonstrated its effectiveness in enhancing ease of cervical dilation. This review article describes its pharmacokinetic profile and the relationship between prostaglandins and cervical ripening and uterine contraction and provides a review of the clinical use of misoprostol in nonpregnant women including cervical priming before hysteroscopy, before insertion of an intrauterine device, in endometrium biopsy, preoperatively in myomectomy, and before intrauterine insemination to improve pregnancy rates. Adverse effects are also described. © 2010 AAGL.

Cheirsilp B.,Prince of Songkla University | Torpee S.,Prince of Songkla University
Bioresource Technology | Year: 2012

Microalgae capable of accumulating high lipid content were screened in photoautotrophic, heterotrophic and mixotrophic cultures. The biomass and lipid production of all tested strains in mixotrophic culture were notably enhanced in comparison with photoautotrophic and heterotrophic cultures. Among the tested strains, marine Chlorella sp. and Nannochloropsis sp. were ideal candidates for biodiesel production because of their high lipid production. The influence of light intensity and initial glucose concentration on growth and lipid content of both strains were investigated. Although increasing light intensity and initial glucose concentration enhanced the growth of both strains, it reduced their lipid content. To produce a high amount of biomass with high lipid content, a fed-batch cultivation with stepwise increasing light intensity was performed. The lipid production by this strategy was approximately twice that of conventional batch cultivation. The main fatty acid compositions of the two microalgae were C16-C18 (>80%) which are appropriate for biodiesel production. © 2012 Elsevier Ltd.

Ahmad M.,Prince of Songkla University | Benjakul S.,Prince of Songkla University
Food Hydrocolloids | Year: 2011

Gelatins from the skin of unicorn leatherjacket (Aluterus monoceros) pretreated with different acids (0.2M acetic acid or 0.2M phosphoric acid) and extracted with distilled water at 45°C for various times (4 and 8h) were characterized. Yields of 5.23-9.18 or 6.12-11.54% (wet weight basis) were obtained for gelatins extracted from the skin pretreated with 0.2M acetic acid or 0.2M phosphoric acid, respectively. Extracted gelatins contained α1 and α2 chains as the predominant components and some degradation peptides. The absorption bands of gelatins in FTIR spectra were mainly situated in the amide band region (amide I, amide II and amide I{cyrillic, ukrainian}I{cyrillic, ukrainian}I{cyrillic, ukrainian}) and showed the significant loss of molecular order of triple helix. Gelatin samples had a relative solubility greater than 90% in the wide pH ranges (1-10). The gel strength of gelatin from skin pretreated with phosphoric acid (GPA) was higher than that of gelatin from skin pretreated with acetic acid (GAA). Both GPA and GAA had the lower gel strength than that of commercial bovine gelatin (P<0.05). Net charge of GAA and GPA became zero at pHs of 6.64-7.15 and 6.78-7.26, respectively, as determined by zeta potential titration. Emulsifying and foaming properties of GAA and GPA increased with increasing concentrations (1-3%, w/v). Those properties were governed by pretreatments and extraction time. Thus gelatin can be successfully extracted from unicorn leatherjacket skin using the appropriate acid pretreatment and extraction time. © 2010 Elsevier Ltd.

Ritchie R.J.,Prince of Songkla University
International Journal of Plant Sciences | Year: 2012

Water lilies, such as the blue Egyptian water lily (Nymphaea caerulea Savigny), are ubiquitous aquatic plants. Leaves of mature plants normally unfold at the surface and are floating or emergent. Some aquatic vascular plants have a form of CAM (crassulacean acid metabolism) known as submerged aquatic metabolism (SAM). The presence of aerenchyma in water lily leaves and petioles makes it very difficult to measure photosynthesis in water lily plants by gas exchange. Pulse amplitude modulation (PAM) fluorometer techniques provide direct information on the light reactions of plants. PAM technology calculates photosynthesis as the electron transport rate (ETR) through PSII (4 electrons per O2 produced) in mol m -2 s -1. Here, relative ETR (rETR) was based on an assumed leaf absorptance factor of 0.84. Photosynthesis-versus-irradiance (P vs. E) curves were fitted with the waiting-in-line function (rETR =(rETR max ×E/E opt) ×e 1-E=Eopt). Maximum effective quantum yield, maximum relative ETR (rETR max), and quantum efficiency all vary on a diurnal cycle. The nonphotochemical quenching parameters qNmax and NPQmax are highly correlated with each other (r = 0:7476, p << 0:001) but do not show a systematic variation over a diurnal cycle. Nymphaea is a "sun plant" with optimum irradiance (E opt) of 1000 μmol m -2 s -1 PPFD or higher. Titratable acid of leaves varied from~50 to 70 mol H + m -3 (leaf water basis) and was depleted at~0600 and 1800 hours each day, a diel pattern inconsistent with SAM/CAM physiology. The N. caerulea C4 acid pool is too small to support substantial SAM-type metabolism. Gross photosynthesis of Nymphaea leaves had a high value of~5.3 g C m -2 d -1. For a daily irradiance of 56 mol m -2 PPFD, this works out to a 3.3% conversion efficiency in terms of moles of carbon. © 2012 by The University of Chicago. All rights reserved.

Wikaisuksakul S.,Prince of Songkla University
Applied Soft Computing Journal | Year: 2014

This article presents a multi-objective genetic algorithm which considers the problem of data clustering. A given dataset is automatically assigned into a number of groups in appropriate fuzzy partitions through the fuzzy c-means method. This work has tried to exploit the advantage of fuzzy properties which provide capability to handle overlapping clusters. However, most fuzzy methods are based on compactness and/or separation measures which use only centroid information. The calculation from centroid information only may not be sufficient to differentiate the geometric structures of clusters. The overlap-separation measure using an aggregation operation of fuzzy membership degrees is better equipped to handle this drawback. For another key consideration, we need a mechanism to identify appropriate fuzzy clusters without prior knowledge on the number of clusters. From this requirement, an optimization with single criterion may not be feasible for different cluster shapes. A multi-objective genetic algorithm is therefore appropriate to search for fuzzy partitions in this situation. Apart from the overlap-separation measure, the well-known fuzzy Jm index is also optimized through genetic operations. The algorithm simultaneously optimizes the two criteria to search for optimal clustering solutions. A string of real-coded values is encoded to represent cluster centers. A number of strings with different lengths varied over a range correspond to variable numbers of clusters. These real-coded values are optimized and the Pareto solutions corresponding to a tradeoff between the two objectives are finally produced. As shown in the experiments, the approach provides promising solutions in well-separated, hyperspherical and overlapping clusters from synthetic and real-life data sets. This is demonstrated by the comparison with existing single-objective and multi-objective clustering techniques. © 2014 Elsevier B.V. All rights reserved.

Antioxidative activities of different phenolic compounds (catechin, caffeic acid, ferulic acid and tannic acid) at various levels were determined by different assays. Among all the phenolic compounds tested, tannic acid exhibited the highest 2,2-diphenyl-1-picryl hydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities and ferric reducing antioxidant power (FRAP). Nevertheless, catechin showed the highest metal chelating activity (P < 0.05), whereas caffeic acid had the highest lipoxygenase (LOX) inhibitory activity (P < 0.05). The impact of different phenolic compounds at a level of 100 mg/l on lipid oxidation of menhaden oil-in-water emulsion and mackerel mince was investigated. Tannic acid showed the highest efficacy in retardation of lipid oxidation for both model systems as evidenced by the lower peroxide value (PV), conjugated diene (CD) and thiobarbituric acid-reactive substances (TBARS) values. This was also related with the lower non-heme iron content in tannic acid treated samples. Tannic acid was therefore considered as the most potential natural antioxidant for controlling oxidation of fish oil-in-water emulsion and fish mince, whereas ferulic acid seemed to possess the lowest preventive effect on lipid oxidation. © 2009 Elsevier Ltd. All rights reserved.

Piratvisuth T.,Prince of Songkla University
Liver International | Year: 2013

Chronic hepatitis B virus (HBV) infection in pregnancy presents a unique and important challenge. Over 50% of chronic HBV carriers in endemic areas acquire infection vertically from their mothers. More importantly, over 90% of perinatally acquired infections progress to chronic HBV infection. Thus, management of chronic HBV during pregnancy and strategies to prevent mother-to-child transmission is an important step in eradicating or reducing the global burden of chronic hepatitis B. In addition, chronic HBV infection in pregnancy presents a unique clinical challenge because of the complex relationship between the physiological changes of pregnancy and the pathophysiological response to HBV. This review will present the current knowledge and a practical approach to management of HBV in pregnancy. © 2012 John Wiley & Sons A/S.

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