Browsing by Author "Pibulsongkram Rajabhat University"
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Publication Metadata only A cluster-randomized trial of insecticide-treated curtains for dengue vector control in Thailand(2013-02-01) Audrey Lenhart; Yuwadee Trongtokit; Neal Alexander; Chamnarn Apiwathnasorn; Wichai Satimai; Veerle Vanlerberghe; Patrick Van Der Stuyft; Philip J. McCall; Centers for Disease Control and Prevention; Pibulsongkram Rajabhat University; London School of Hygiene & Tropical Medicine; Mahidol University; Thailand Ministry of Public Health; Prins Leopold Instituut voor Tropische Geneeskunde; Liverpool School of Tropical MedicineThe efficacy of insecticide-treated window curtains (ITCs) for dengue vector control was evaluated in Thailand in a cluster-randomized controlled trial. A total of 2,037 houses in 26 clusters was randomized to receive the intervention or act as control (no treatment). Entomological surveys measured Aedes infestations (Breteau index, house index, container index, and pupae per person index) and oviposition indices (mean numbers of eggs laid in oviposition traps) immediately before and after intervention, and at 3-month intervals over 12 months. There were no consistent statistically significant differences in entomological indices between intervention and control clusters, although oviposition indices were lower (P < 0.01) in ITC clusters during the wet season. It is possible that the open housing structures in the study reduced the likelihood of mosquitoes making contact with ITCs. ITCs deployed in a region where this house design is common may be unsuitable for dengue vector control. Copyright © 2013 by The American Society of Tropical Medicine and Hygiene.Publication Metadata only Comparative stages of atretic oocyte between sesarmid crabs episesarma singaporense and E. Versicolor from Thailand: Implications on reproductive success(2021-01-01) Chanyut Sudtongkong; Sinlapachai Senarat; Supparat Kong-Oh; Pisit Poolprasert; Koraon Wongkamhaeng; Wannee Jiraungkoorskul; Rajamangala University of Technology Srivijaya; Pibulsongkram Rajabhat University; Kasetsart University; Mahidol UniversityThe oocyte atresia is the primary mechanism responsible for the degeneration and resorptive process as a common groundwork for aquatic animals, but it has rarely been reported in crabs. The present study focused on the characteristics and stages of the atretic oocyte from two important female sesarmid crabs (Singapore vinegar crab, Episesarma singaporense and violet vinegar crab, E. versicolor) during ovarian maturation. A total of 30 female samples from each crab species was collected from the Palian mangrove area of Trang Province, Thailand. The results shared among those crab samples from the primary growth (PG) and secondary growth (SG) phases underwent a degenerative atresia process. The latter atresia stage during SG was also divided into five stages (I, II, III, IV, and V). The degeneration of follicular cell and yolk architecture identified in the SG was highlighted. The number of atresias was compared between E. singaporense and E. versicolor, indicating that there were no significant differences. Observations suggested that the low number of atresia could be associated with the increased reproductive success of two female sesarmid crabs living in natural habitats.Publication Metadata only Development of a one-step immunochromatographic strip test using gold nanoparticles for the rapid detection of Salmonella typhi in human serum(2012-01-15) Pattarachaya Preechakasedkit; Kulwadee Pinwattana; Wijitar Dungchai; Weena Siangproh; Wanpen Chaicumpa; Pongsri Tongtawe; Orawon Chailapakul; Chulalongkorn University; Pibulsongkram Rajabhat University; King Mongkuts University of Technology Thonburi; Srinakharinwirot University; Mahidol University; Thammasat UniversityAn immunochromatographic strip test using gold nanoparticles was developed for the rapid detection of Salmonella typhi (S. typhi) in human serum. The strip test based on the principle of sandwich immunoassay by the specific binding of antigens from S. typhi O901 and antibody of S. typhi O901 on a nitrocellulose membrane. Antibody-gold nanoparticle conjugate was used as the label and was coated onto a glass fiber membrane, which was used as a conjugate pad. To create a test and control zone, antibody of S. typhi O901 and an anti-IgG were dotted on the nitrocellulose membrane, respectively. Positive samples were displayed as red dots at the test and control zones of the nitrocellulose membrane, while negative samples resulted in a red dot only in the control zone. The limit of detection (LOD) was found to be 1.14×10 5 cfumL -1 , which could be visually detected by the naked eye within 15min. This strip test provided a lower detection limit and analysis time than a dot blot immunoassay (8.88×10 6 cfumL -1 for LOD and 110min for reaction time). In addition, our immunochromatographic strip test was employed to detect S. typhi in human serum effectively, with high accuracy. This strip test offers great promise for a rapid, simple and low-cost analysis of S. typhi. © 2011 Elsevier B.V.Publication Metadata only Diarylheptanoids of curcuma comosa with inhibitory effects on nitric oxide production in macrophage RAW 264.7 Cells(2015-01-01) Nilubon Sornkaew; Yuan Lin; Fei Wang; Guolin Zhang; Ratchanaporn Chokchaisiri; Ailian Zhang; Kanjana Wongkrajang; Parichat Suebsakwong; Pawinee Piyachaturawat; Apichart Suksamrarn; Ramkhamhaeng University; Chengdu Institute of Biology Chinese Academy of Sciences; University of Phayao; Zhejiang Agriculture and Forestry University; Pibulsongkram Rajabhat University; Mahidol UniversityEight new diarylheptanoids, a 1.2:1 mixture of (3S)-And (3R)-1-(4-hydroxyphenyl)-7-phenyl-(4E,6E)-4,6-heptadien-3-ol (1a and 1b), a racemic mixture of (3S)-And (3R)-1-(4-hydroxyphenyl)-3-methoxy-7-phenyl-(4E,6E)-4,6-heptadiene (2a and 2b), a ca. 1:1 mixture of (3S)-And (3R)-1-(4-hydroxy-3-methoxyphenyl)-3-methoxy-7-phenyl)-(4E,6E)-4,6-heptadiene (3a and 3b), 3-Acetoxy-1-(3,4-dihydroxyphenyl)-7-phenylheptan-5-ol (4), (3R)-1-(4,5-dihydroxyphenyl)-7-phenyl-(6E)-6-hepten-3,2-epoxide (5), and thirteen known diarylheptanoids, 6-12, a 3:1 mixture of 13a and 13b, and 14-17, were isolated from the rhizomes of Curcuma comosa from Sakon Nakhon, northeastern part of Thailand. The isolated compounds were evaluated for their antiinflammatory activities on the inhibition of lipopolysaccharide-induced nitric oxide production in macrophage RAW 264.7 cells and the diarylheptanoids 1a and 1b mixture and 14 exhibited potent inhibitory activity.Publication Metadata only Effects of extraction methods on phytochemicals of rice bran oils produced from colored rice(2018-01-01) Sukanya Mingyai; Khongsak Srikaeo; Aikkarach Kettawan; Riantong Singanusong; Kiyotaka Nakagawa; Fumiko Kimura; Junya Ito; Pibulsongkram Rajabhat University; Naresuan University; Mahidol University; Tohoku University; Shokei Gakuin University© 2018 by Japan Oil Chemists’ Society. Rice bran oil (RBO) especially from colored rice is rich in phytochemicals and has become popular in food, cosmetic, nutraceutical and pharmaceutical applications owing to its offering health benefits. This study determined the contents of phytochemicals including oryzanols, phytosterols, tocopherols (Toc) and tocotrienols (T3) in RBOs extracted using different methods namely cold-press extraction (CPE), solvent extraction (SE) and supercritical CO2 extraction (SC-CO2). Two colored rice, Red Jasmine rice (RJM, red rice) and Hom-nin rice (HN, black rice), were studied in comparison with the popular Thai fragrant rice Khao Dawk Mali 105 (KDML 105, white rice). RBOs were found to be the rich source of oryzanols, phytosterols, Toc and T3. Rice varieties had a greater effect on the phytochemicals concentrations than extraction methods. HN rice showed the significantly highest concentration of all phytochemicals, followed by RJM and KDML 105 rice, indicating that colored rice contained high concentration of phytochemicals in the oil than non-colored rice. The RBO samples extracted by the CPE method had a greater concentration of the phytochemicals than those extracted by the SC-CO2 and SE methods, respectively. In terms of phytochemical contents, HN rice extracted using CPE method was found to be the best.Publication Metadata only Equilibriums and periodic solutions of related systems of piecewise linear difference equations(2013-05-28) Wirot Tikjha; Yongwimon Lenbury; Evelina Giusti Lapierre; Pibulsongkram Rajabhat University; Mahidol University; Centre of Excellence in Mathematics; Johnson and Wales UniversityIn this paper we consider three systems of piecewise linear difference equations where the initial condition for each system is an arbitrary point on the real plane. For one system we show that there exists exactly two prime period-6 solutions, and that every solution of the system is eventually one of the two prime period-6 solutions except for equilibrium point. For the remaining two systems we show that every solution of each system is the unique equilibrium solution.Publication Metadata only Esophagogastric region and liver tissue in dog-faced water snake Cerberus rynchops: Histology and histochemistry(2017-12-01) Piyakorn Boonyoung; Sinlapachai Senarat; Jes Kettratad; Wannee Jiraungkoorskul; Pisit Poolprasert; Sansareeya Wangkulangkul; Theerakamol Pengsakul; Watiporn Yenchum; Yassir Sulieman; Prince of Songkla University; Chulalongkorn University; Mahidol University; Pibulsongkram Rajabhat University; National Institute of Metrology (Thailand); University of Shendi© 2018 Observation of the esophagogastric region and liver tissue of the dog-faced water snake, Cerberus rynchops, living in Thailand was evaluated using standard histological techniques. The results revealed that the digestive tract of this snake consists of three parts: the oesophagus, stomach and intestine, respectively. From the histological analysis, the longitudinal folds of the oesophagus were lined by pseudostratified columnar epithelia with goblet cells. The goblet cells stained positively with periodic acid-Schiff (PAS) and alcian blue (AB) methods. In the stomach, gastric glands extended into the lamina propria. Each gastric gland had a greater cell size than other regions and also a branched tubular gland was visible in the histological images. The mucous neck cell was positive to PAS and AB reactions, whereas, the oxynticopeptic cells slightly reacted to both PAS and AB staining and were preferentially located in this gland. The liver parenchyma of C. rynchops was composed of hepatic sinusoids and hepatocytes. In conclusion, this was the first study on digestive tract and liver tissue in C. rynchops from the Paknam Pranburi Estuary, Thailand.Publication Metadata only Eye structure and chemical details of the retinal layer of juvenile Queen danio Devario regina (Fowler, 1934)(2015-12-01) Piyakorn Boonyoung; Sinlapachai Senarat; Jes Kettratad; Pisit Poolprasert; Watiporn Yenchum; Wannee Jiraungkoorskul; Prince of Songkla University; Chulalongkorn University; Pibulsongkram Rajabhat University; National Institute of Metrology (Thailand); Mahidol University© 2015, Kasetsart University. All rights reserved. The eye structures and chemical details of the retinal layer in juvenile Queen Danio—Devario regina, an ornamental fish—were histologically investigated under a light microscope. Sample fish were collected from the Tapee River, Nakhon Si Thammarat province, Thailand and their heads were exclusively prepared using a standard histological technique. The results revealed that the eye of D. regina was composed of three layers—inner, middle and external—based on histological organization and cell types. The inner layer was composed of 10 layers; 1) pigment epithelium, 2) photoreceptor layer, 3) outer liming membrane, 4) outer nuclear layer, 5) outer plexiform layer, 6) inner nuclear layer, 7) inner plexiform layer, 8) ganglion cell layer, 9) optic nerve layer and 10) inner limiting membrane, respectively. The localization and chemical details showed that a periodic acid-Schiff reaction for the detection of glycoprotein was intensive in the pigment epithelial layer whereas the inner plexifrom layer had only a slight reaction. Reaction of aniline blue was employed for the detection of mucopolysaccharide which was slightly positive for three layers—the outer limiting membrane, outer plexiform and inner plexiform.Publication Metadata only Feeding response of Aedes aegypti and Anopheles dirus (Diptera: Culicidae) using out-of-date human blood in a membrane feeding apparatus(2010-06-01) Jinrapa Pothikasikorn; Rapee Boonplueang; Chalermchai Suebsaeng; Rungpetch Khaengraeng; Theeraphap Chareonviriyaphap; Mahidol University; Pibulsongkram Rajabhat University; Kasetsart UniversityThe colonization of Aedes aegypti and Anopheles dirus was performed using out-of-date human blood from a blood bank as a nutritional supply dispensed from a common artificial feeder. Preserved human blood was collected and used for feeding on days 5, 15, and 25 after date of expiration and dispensed from a common artificial feeder to rear the mosquitoes. Ae. aegypti had a feeding rate of 78.7, 62, and 18% at the respective intervals while An. dirus had a rate of 80, 56.8, and 7.3% on the same respective days. Direct feeding on live hamsters resulted in a rate of 96 and 90% for Ae. aegypti and An. dirus, respectively. Although egg production rates decreased from the day 5 feeding to the day 25 feeding, all of the developmental stages resulting from An. dirus fed at day 5 and 15 showed insignificant differences when compared with direct feeding on the blood of a hamster.Publication Metadata only Gastrointestinal tract and accessory organs in the spotted bent-toed gecko, cyrtodactylus peguensis (boulenger, 1893): A histological and histochemical study(2019-01-01) Lamai Thongboon; Sinlapachai Senarat; Jes Kettratad; Wannee Jiraungkoorskul; Sansareeya Wangkulangkul; Pisit Poolprasert; Chamnan Para; Gen Kaneko; Theerakamol Pengsakul; University of Houston-Victoria; Pibulsongkram Rajabhat University; Chulalongkorn University; Mahidol University; Prince of Songkla University; Mahasarakham University© 2019 by Thieme Revinter. The spotted bent-toed gecko Cyrtodactylus peguensis is one of the exploited reptiles in Thailand. In order to provide basic information for the digestive system of this species, we have examined histologically the gastrointestinal and accessory organs of C. peguensis using routine methods. The gastrointestinal region of this reptile started from the stomach and the intestine. The stomach was separated into fundic and pyloric regions. In both regions, the stomach wall was formed by four distinct tissue layers, including mucosa, submucosa, muscularis, and serosa layers. Mucous neck cells and oxynticopeptic cells were identified as glycoprotein-producing cells in the stomach by Periodic acid-Schiff (PAS) staining. The small and large intestines shared many histological characteristics, but the former contained more intestinal folds, while the latter had more PAS-positive goblet cells. Histological characteristics of accessory organs, liver and pancreas, were also provided. Overall, the gastrointestinal and accessory organs of C. peguensis were largely similar to those from other reptiles, but fine structural information will open up considerable opportunities to further studies related to the endocrinology, the physiology, and the conservation of this species.Publication Metadata only Health status in wild and captive short mackerel, Rastrelliger brachysoma from Thailand: Histopathology(2018-09-01) Sinlapachai Senarat; Jes Kettratad; Sasipong Tipdomrongpong; F. Gerald Plumley; Wannee Jiraungkoorskul; Pisit Poolprasert; Pibulsongkram Rajabhat University; Chulalongkorn University; Mahidol University; Samut Songkhram Marine Fisheries Research and Development Station© 2018, Prince of Songkla University. All rights reserved. Information regarding the health status of wild and captive Rastrelliger brachysoma (Bleeker, 1851) is scanty. This is an economically/ ecologically important fish species in Thailand which has experienced recent dramatic declines in population numbers. Therefore, the aim of this research was to assess the health status of this fish using histopathology as biomarker. The results revealed previously the gill lesions including lamellae disorganization, fusion and edema with lifting of lamellar epithelium in the secondary lamellae. The skin histopathology included epidermal hyperplasia and the proliferation of the Malpighian cells. Pyknotic nuclei and vacuolar degeneration of exocrine acinar cells were detected in the pancreas tissue. Degeneration of the renal parenchyma and tubules as well as the melanomacrophage center (MMC) was observed in kidney tissue. In captive fish, the most common histopathology of gill tissue, primary lamellae disorganization and degeneration of secondary gills, was observed in all samples. In some areas of the kidney tissues, renal degeneration and damage to the glomeruli throughout the majority of the macrophage aggregates (MMC) were also found. Important histopathological observations of liver tissue were hepatic degeneration, focal coagulation necrosis and increased frequency of MMC. Interestingly, a gastric tumor was observed in only one male specimen. Additionally, it must be emphasized that histopathological alterations are an effective biomarker used to evaluate potential effects of the environmental pollution on fish health and marine biota.Publication Metadata only The identification and distribution of the mucous secreting cells in the integument of the schaap’s dragonet, Callionymus schaapii, Bleeker, 1852(2020-01-01) Sinlapachai Senarat; Piyakorn Boonyoung; Jes Kettratad; Wannee Jiraungkoorskul; Pisit Poolprasert; Shuaiqin Huang; Theerakamol Pengsakul; Ezra Mongkolchaichana; Chamnan Para; Pibulsongkram Rajabhat University; Chulalongkorn University; Xiamen University; Mahidol University; Prince of Songkla University; Mahasarakham University; Navamindrahiraj University© 2020, Chiang Mai University - Faculty of Veterinary Medicine. All rights reserved. The microanatomical structure of mucous secreting cells (Ms) in fish has been widely found; however, there is a lack of research on the Schaap’s dragonet, Callionymus schaapii, which is regarded as an important benthic fish. The identification and distribution of Ms in different areas along the integumentary system of Callionymus schaapii were therefore demon-strated and compared using histochemical techniques. The integument system of this fish consists of two layers: an outer epidermis and an underlying dermis. In particular, the Ms can be classified because they were positively stained with periodic acid-schiff and alcian blue methods. As a result, the distribution of Ms could be observed in all areas (lateral head, pectoral – pelvic, middle trunk and caudal areas) and along with the integumentary system, respectively. The observation confirmed that the highest number of Ms was found in the pectoral-pelvic area. The caudal area had the lowest number of this cell. The localization and abundance of Ms in the integument may support the behavior and enhance swimming to the area under the estuarine conditions.Publication Metadata only Identification of sbGnRH-GTHs system and estrogen receptor α (ER α) immunoreactivities in the mature testicular tissue in rastrelliger brachysoma (Bleeker, 1851)(2018-08-01) Sinlapachai Senarat; Jes Kettratad; Wannee Jiraungkoorskul; F. Gerald Plumley; Kanda Tongmit; Pisit Poolprasert; Niwat Kangwanrangsan; Masafumi Amano; Akio Shimizu; Piyakorn Boonyoung; Pibulsongkram Rajabhat University; Chulalongkorn University; Faculty of Medicine, Prince of Songkia University; National Research Institute of Fisheries Science, FRA; Mahidol University; Kitasato University; Prince of Songkla University© 2018 Senarat et al. Background: Comprehensive information of reproductive physiology in the testis of Rastrilliger brachysoma is not well known. In this study, the distributions of sbGnRH-GTHs system and estrogen receptor-α (ERα)–immunoreactivities (–ir) in the mature testicular tissue of male Rastrelliger brachysoma were described. Material and Methods: Sexually mature Rastrelliger brachysoma, 17-18 cm with average 17.4 cm in standard length (n = 10 individual fish) were used and investigated using immunohistochemistry and immunofluorescence. Results: Immunolocalization confirmed that the intense staining of sbGnRH, GTHs and ERα, in the mature testicular tissues of R. brachysoma were co-located and prominently observed in the Leydig cells and fibroblasts in the interstial compartment. Strong immunostaining of Sertoli cell was also observed, whereas intermediate/moderate immunoreactivity of the spermatogonia in the stromal compartment was seen. Conclusion: This data is reported for the first time and indicated that the testicular tissue and spermatogenesis of the R. brachysoma may locally produce sbGnRH, GTHs and ERα, which all are probably concerned with reproductive activity.Publication Metadata only Mature gonadal histology and gametogenesis of the tortoise beetle Aspidimorpha sanctaecrucis (Fabricius, 1792) (coleoptera: Cassidinae: Chrysomelidae): Histological observation(2020-01-01) Piyakorn Boonyoung; Sinlapachai Senarat; Jes Kettratad; Wannee Jiraungkoorskul; Narit Thaochan; Kong Wah Sing; Theerakamol Pengsakul; Pisit Poolprasert; Rajamangala University of Technology Srivijaya; Pibulsongkram Rajabhat University; Chulalongkorn University; Kunming Institute of Zoology Chinese Academy of Sciences; Mahidol University; Prince of Songkla University© 2020, Prince of Songkla University. All rights reserved. The gonadal structure of insects has been well reported but there is a lack of such information from tortoise beetles that are an economically important insect. In this study, the gonadal structure and differentiating stage of gametogenesis of tortoise beetles Aspidomorpha sanctaecrucis are examined using the histological technique. At the level of light microscopy, our results revealed that the A. sanctaecrucis male reproductive system has a pair of testicular structures that consist of six seminiferous tubules. All zones contained various stages of spermatogenesis and could be divided into five stages depending on the shape and histological organization, particularly chromatin organization, which was divided into spermatogonia, primary spermatocytes with 8 sub-steps (leptotene, zygotene, pachytene, diplotene, diakinesis, metaphase, anaphase, and telophase), secondary spermatocytes, spermatids (two sub-steps), and spermatozoa. A pair of ovaries was observed in the female A. sanctaecrucis. Each ovary is considered to be a meroistic ovariole that exists with nurse cells. The differentiating oogenic stages including previtellogenic and vitellogenic stages were observed. Our study provides baseline data that will be useful for future work involved in the ultrastructure and physiology of the reproductive tissue in tortoise beetles, especially the differential characterizations of the seminiferous tubule and ovarian type in beetles.Publication Metadata only Microarchitectural study of the olfactory organ of Devario Regina (Fowler,1934) using pas technique(2014-01-01) Piyakorn Boonyoung; Sinlapachai Senarat; Jes Kettratad; Watiporn Yenchum; Pisit Poolprasert; Wannee Jiraungkoorskul; Prince of Songkla University; Chulalongkorn University; National Institute of Metrology (Thailand); Pibulsongkram Rajabhat University; Mahidol University© 2014,Institute of Biological Science. All rights reserved. Context: Microarchitectural observation of the olfactory organ in Devario regina (Fowler,1934) is still unknown. Objectives: The normal histology and chemical detailed of glycoprotein in D. regina olfactory organ were investigated using histochemical analysis. Materials and Methods: Fishes were collected from the Tapee River,Nakhon Si Thammarat Province,Thailand and were processed by the standard histological technique. Results: Microarchitecture of olfactory organ revealed that it was a paired olfactory sac. Each sac was composed of the olfactory chamber and many lamellae surrounding by olfactory epithelium. This epithelium contained the differential cell types in both sensory (sensory ciliated cells) and non-sensory olfactory epithelium. The special localization of glycoprotein was intensively detected on the mucous cells. Conclusion: This study provided the basic histology of the fish olfactory organ that will support the investigation regarding the physiological and ultrastructural analysis.Publication Metadata only Microscopic organization of the eye of Stoliczkae's barb Puntius stoliczkanus (day, 1871)(2013-01-01) Sinlapachai Senarat; Jes Kettratad; Watiporn Yenchum; Pisit Poolprasert; Niwat Kangwanrangsan; Chulalongkorn University; National Institute of Metrology (Thailand); Pibulsongkram Rajabhat University; Mahidol UniversityThe histology of the organization of the eye in the Stoliczkae's barb Puntius stoliczkanus was investigated using a light microscope. It was found that the eye in P. stoliczkanus comprised three layers-external, middle uveal and inner. The external layer consisted of the cornea and sclera. The cornea showed three layers: 1) corneal epithelium, 2) corneal stroma and 3) corneal endothelium, while the sclera exhibited a thick connective fiber and an external sheath of hyaline cartilage supporting the sclera. The middle uveal layer showed only the lens and choroid. The lens protruded into the aqueous chamber. The choroid was subdivided into two distinct layers: 1) a connective layer adjacent to the sclera and 2) the lamina vasculosa and choriocapillaris. The inner layer or retinal tunica was composed of 10 distinct layers: 1) pigment epithelium, 2) photoreceptor layer, 3) outer liming membrane, 4) outer nuclear layer, 5) outer plexiform layer, 6) inner nuclear layer, 7) inner plexiform layer, 8) ganglion cell layer, 9) optic nerve layer and 10) inner limiting membrane, respectively, from the outside inward. These results provided data for other investigations in aquaculture, reproductive biology and histopathology.Publication Metadata only Oocyte Differentiation and Reproductive Health of Solitary Tunicate (Styela plicata) from Eastern Coast of Thailand(2021-01-01) S. Senarat; J. Kettratad; P. Boonyoung; W. Jiraungkoorskul; F. Kato; E. Mongkolchaichana; G. Kaneko; P. Poolprasert; Navamindradhiraj University; University of Houston-Victoria; Rajamangala University of Technology Srivijaya; Pibulsongkram Rajabhat University; Chulalongkorn University; Mahidol University; Kyushu University; Prince of Songkla UniversityHistopathological examination is a widely acknowledged technique to assess the reproductive health of aquatic organisms, but it has never been applied to the tunicate Styela plicata, a potential indicator species of water quality. In this study, we examined the oocyte differentiation of S. plicata obtained from the eastern coast of the Gulf of Thailand in order to provide basic information for future assessment of its reproductive health. The mature gonad of S. plicata comprised several ovo-testicular convoluted tubes, in which each tube was divided into apical and terminal portions. The ovarian tissue is located in the apical part of the tunicate body and contained oocytes of various differentiation stages (asynchronous development type) consisting of the four phases namely oogonial proliferation phase, primary growth phase, secondary growth phase (secondary growth and full-growth stages), and post-ovulatory phase. Changes in the morphology of oocytes and follicular cells were described for each differentiation stage. In addition, we unexpectedly observed a high prevalence of atretic follicles (24.5%), which might indicate the oocyte damage by environmental stresses. These findings would be useful for future assessment of reproductive histology of S. plicata and other tunicate species from environmental perspectives.Publication Metadata only Periodic behavior of solutions of a certain piecewise linear system of difference equations(2015-01-01) Wirot Tikjha; Somsri Jintanasonti; Yongwimon Lenbury; Pibulsongkram Rajabhat University; Mahidol University; South Carolina Commission on Higher Education© 2015 by the Mathematical Association of Thailand. All rights reserved. In this paper, we study the behavior of solutions of piecewise linear system of difference equations xn+1= |xn| − yn− 2 and yn+1= xn+ |yn| with initial condition that (x0, y0) is in R2− {(x, y): x < 0 and y < 0}. After we observe via a computer program and some direct computations, we found that the system has an equilibrium point and periodic solutions. We also show that the solution of the system is eventually periodic with prime period 3 by finding the pattern of solutions and formulating the statements that involve the natural numbers and then proving by mathematical induction.Publication Metadata only Periodic solutions of a generalized system of piecewise linear difference equations(2015-12-12) Wirot Tikjha; Evelina Lapierre; Yongwimon Lenbury; Pibulsongkram Rajabhat University; Thailand Ministry of Education; Johnson and Wales University; Mahidol University© 2015, Tikjha et al. In this article we consider the global behavior of the following system of piecewise linear difference equations: (Formula presented.) where b is any positive real number and the initial condition (Formula presented.) is an element of R2. By mathematical induction and direct computations we show that the solution to the system is eventually one of two particular prime period 3 solutions or the unique equilibrium solution.Publication Metadata only Systemic organization of tetraponera rufonigra (Jerdon, 1851) hymenoptera: Formicidae): Histological observation(2020-01-01) Naphat Somala; Sinlapachai Senarat; Chamnan Para; Wannee Jiraungkoorskul; Gen Kaneko; Thitiya Poonpet; Pisit Poolprasert; University of Houston-Victoria; Pibulsongkram Rajabhat University; King Mongkut's Institute of Technology Ladkrabang; Mahidol University; Mahasarakham University; Bang Khrok; Rajamankala University of Technology Srivijaya© 2020, Universiti Kebangsaan Malaysia Press. All rights reserved. Tetraponera rufonigra Jerdon, 1851, is one of the most dangerous ants, whose apex of gaster region contains a sting structure with a complex venom gland. Here, we describe the systemic organ system of T. rufonigra using histological techniques. The venom gland of T. rufonigra was located above the mesentero-proctodeal region, which could be histologically classified into two parts; the venom gland reservoir and the venom gland tubes. The venom gland tubes were lined by a simple cuboidal epithelium, whereas the venom gland reservoir was enclosed with simple squamous epithelium. The pygidial gland was localized near the cuticle as clusters, and each of the oval shape pygidial gland cells contained a spherical nucleus surrounded by acidophilic cytoplasm. High magnification observation showed that the integumentary system consists of three layers; epicuticle, exocuticle, and endocuticle. The digestive system was a single narrow tube consisting of the foregut, midgut, and hindgut. Five to six rectal papillae were found in the hindgut. The urinary system was made up of Malpighian tubules, which lined with simple cuboidal epithelium and tracheal embedded in the adipose tissue. The respiratory system was composed of spiracles and trachea adjacent to the integument, all of which were surrounded by a simple squamous epithelium. In the nervous system, several ganglia were found in this study. There were two layers in each ganglion: Outer cortex and inner medullar layers. Several cell types were observed in the cortex layer including the neurosecretory cells, the neuroglia, and neurons. The outcomes of this study could provide a useful basis for future research on the family Formicidae.