• Parasites, Hosts and Diseases
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• v.46 no.4
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• pp.285-288
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• 2008

To examine the infection status of freshwater fish with Gnathostoma spp. larvae in Myanmar, we purchased 15 snakeheads, Channa striatus, from a local market in a suburban area of Naypyidaw, the new capital city. Two larval gnathostomes were collected using an artificial digestion technique, and observed by a light microscope and a scanning electron microscope. The size of an intact larva was 2.65 mm long and 0.32 mm wide. The characteristic morphology of the larvae included the presence of a long esophagus (0.80 mm long), 2 pairs of cervical sacs (0.43 mm long), and a characteristic head bulb with 4 rows of hooklets. The number of hooklets in the 1st, 2nd, 3rd, and 4th row was 45, 48, 50, and 52, respectively. Based on these morphological characters, the larvae were identified as the advanced 3rd-stage larvae of Gnathostoma spinigerum. This is the first report of detection of G. spinigerum 3rd-stage larvae in the central part of Myanmar. Our study suggests that intake of raw meat of snakehead fish in Myanmar may result in human gnathostomiasis.

• Applied Microscopy
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• v.2 no.1
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• pp.7-15
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• 1972

The morphological and fine structural changes during the oogensis of Clonorchis sinensis were studied on the developing ovums in the ovary and ootype with electron microscope. Adult worms were removed from the hepar of the which and previously infected with metacercariae of Clonorchis sinensis. The ovary including the Mehlis' glands and an ootype from adult worm was prefixed for 1-2 hours in 1.25% glutaraldehyde buffered with 0.2M cacodylate at PH 7.2, secondarily fixed for 30 minutes in potassium bicromate and postfixed for an hour in 1% osmic acid buffered with 0.4M cacodylate at PH 7.2. After fixation tissues were dehydrated in an alcohol series, embedded in Epon 812 from propylene oxide and stained with saturated uranyl acetate and $Pn(NO_3)_2$ solution. Material was examined with a Hitachi HS-7S electron microscope. The periphery of the ovary, except for the posterior region, is made up of oogonia. As the oogonia divide they proliferate primary oocytes toward the central part of the ovary. After a period of growth the primary oocyte leaves the ovary and is penetrated by a sperm in the ootype. Sperm penetration immediately activates the primary oocyte to resume its meiotic activity. After the oocytes meiotic activity is completed, the pronuclei fuse to form a single cleavage nucleus which possesses two nucleoli. As the oocytes develop their cytoplamic materials are abundant; small mitochondria are abundant and often their profiles are more unmerous in one part of the cytoplasm than elsewhere; the granular endoplasmic reticulum becomes alveolar-sac form after it leaves the ovary it becomes stratified form. The reticulate Golgi apparatus is apparent in the developed oocyte. A little of cortical granules are distributed inside of the plasma membrane I oogonia and large quantity of cortical granules are arranged just inside of the plasma membrane of the primary oocyte and after fertilization they are disappeared with broken out.

• Journal of Life Science
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• v.14 no.4
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• pp.689-695
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• 2004

This study was investigate the occurrence of bottom rot caused by Rhizoctonia solani at the crisphead lettuce fields in Uiryeong-gun, Gyeongsangnam-do from November to December in 2003. Incidence of bottom rot on crisphead lettuce was up to 5.3% at the six plastic houses. A total of 30 isolates of R. solani were obtained from diseased leaves of plants and were tested by artificial inoculation to the host. Among them, PY-1 isolate was selected showing highly virulent on the whole plant and was identified as R. solani AG1 (IB) based on the anastomosis test, morphological and cultural characteristics. Symptoms of bottom rot by PY-1 isolate produced small dark brown, depressed and elliptical spots on the lower part of leaves in the early stage as same as at the fields, were enlarged onto the upper part of leaves later, and the infected plant wilted and ultimately died in the end. For the pathogenicity test, triturated mycelia-inoculum (A$_{550}$=1.0) of PY-1 isolate was selected the most effective inoculum showing disease incidence of 51.1% for the mycelial inoculation at pot assay. Otherwise, WSRP media-inoculum (wheat brane ： sawdust ： rice brane ： PDB media=30 g ： 10 g ： 10 g ： 100 ml, w/w/w/v) of PY-1 isolate was effectual inoculum showing disease incidence of 61.6% for soil inoculation at the plastic house. Also, in selection of density and amount of inoculum, most suitable density of triturated mycelia-inoculum and amount of WSRP media- inoculum were determined as $A_{550}$=1.0 and 40 ml, respectively. This is the first report on the pathogenicity test using by WSRP media-inoculum of R. solani PY-1 isolate for the bottom rot of crisphead lettuce.

• Korean journal of applied entomology
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• v.43 no.1
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• pp.85-89
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• 2004

Numerical measurements were made for fresh weight, body length and width, head width, and color and length of antenna of Japanese pine sawyer, Monochamus alternatus adults, a primary vector of pine wood nematode, Bursaphelenchus xylophilus in Korea. We measured 563 females and 601 males that emerged out of dead pine logs from 2001 to 2002. General linear model analysis showed that measurements of fresh weight, body length, and body width were significantly higher in females than in males. Head width was not significantly different between sexes. Antennal length of males was significantly longer than that of females. For females and males respectively, average fresh weights were 0.305g and 0.277g, body lengths 20.97mm and 19.93mm, body widths 6.52mm and 6.18mm, head widths 3.78mm and 3.70mm, and antennal lengths 31.19mm and 45.49 mm. Antennal length or ratio of antennal length to body length overlapped in some ranges between 2 sexes. Therefore antennal length itself or ratio of antennal length to body length could not be used as a definite criterion to discriminate sexes. However, check on color of the antennae of 4,033 adults revealed without exception that basal part of every segment of flagellum of female antenna was covered with whitish-grey hairs, while whole part of every segment of male flagellum was covered with brownish-black hairs. This characteristics might be a best way to differentiate sex of this species.

• Ocean Systems Engineering
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• v.6 no.1
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• pp.23-60
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• 2016

The major objective of this study was to develop further understanding of 3D nearshore hydrodynamics under a variety of wave and tidal forcing conditions. The main tool used was a comprehensive 3D numerical model - combining the flow module of Delft3D with the WAVE solver of XBeach - of nearshore hydro- and morphodynamics that can simulate flow, sediment transport, and morphological evolution. Surf-swash zone hydrodynamics were modeled using the 3D Navier-Stokes equations, combined with various turbulence models (${\kappa}-{\varepsilon}$, ${\kappa}-L$, ATM and H-LES). Sediment transport and resulting foreshore profile changes were approximated using different sediment transport relations that consider both bed- and suspended-load transport of non-cohesive sediments. The numerical set-up was tested against field data, with good agreement found. Different numerical experiments under a range of bed characteristics and incident wave and tidal conditions were run to test the model's capability to reproduce 3D flow, wave propagation, sediment transport and morphodynamics in the nearshore at the field scale. The results were interpreted according to existing understanding of surf and swash zone processes. Our numerical experiments confirm that the angle between the crest line of the approaching wave and the shoreline defines the direction and strength of the longshore current, while the longshore current velocity varies across the nearshore zone. The model simulates the undertow, hydraulic cell and rip-current patterns generated by radiation stresses and longshore variability in wave heights. Numerical results show that a non-uniform seabed is crucial for generation of rip currents in the nearshore (when bed slope is uniform, rips are not generated). Increasing the wave height increases the peaks of eddy viscosity and TKE (turbulent kinetic energy), while increasing the tidal amplitude reduces these peaks. Wave and tide interaction has most striking effects on the foreshore profile with the formation of the intertidal bar. High values of eddy viscosity, TKE and wave set-up are spread offshore for coarser grain sizes. Beach profile steepness modifies the nearshore circulation pattern, significantly enhancing the vertical component of the flow. The local recirculation within the longshore current in the inshore region causes a transient offshore shift and strengthening of the longshore current. Overall, the analysis shows that, with reasonable hypotheses, it is possible to simulate the nearshore hydrodynamics subjected to oceanic forcing, consistent with existing understanding of this area. Part II of this work presents 3D nearshore morphodynamics induced by the tides and waves.

• Ocean Systems Engineering
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• v.6 no.1
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• pp.61-97
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• 2016

This is the second of two papers on the 3D numerical modeling of nearshore hydro- and morphodynamics. In Part I, the focus was on surf and swash zone hydrodynamics in the cross-shore and longshore directions. Here, we consider nearshore processes with an emphasis on the effects of oceanic forcing and beach characteristics on sediment transport in the cross- and longshore directions, as well as on foreshore bathymetry changes. The Delft3D and XBeach models were used with four turbulence closures (viz., ${\kappa}-{\varepsilon}$, ${\kappa}-L$, ATM and H-LES) to solve the 3D Navier-Stokes equations for incompressible flow as well as the beach morphology. The sediment transport module simulates both bed load and suspended load transport of non-cohesive sediments. Twenty sets of numerical experiments combining nine control parameters under a range of bed characteristics and incident wave and tidal conditions were simulated. For each case, the general morphological response in shore-normal and shore-parallel directions was presented. Numerical results showed that the ${\kappa}-{\varepsilon}$ and H-LES closure models yield similar results that are in better agreement with existing morphodynamic observations than the results of the other turbulence models. The simulations showed that wave forcing drives a sediment circulation pattern that results in bar and berm formation. However, together with wave forcing, tides modulate the predicted nearshore sediment dynamics. The combination of tides and wave action has a notable effect on longshore suspended sediment transport fluxes, relative to wave action alone. The model's ability to predict sediment transport under propagation of obliquely incident wave conditions underscores its potential for understanding the evolution of beach morphology at field scale. For example, the results of the model confirmed that the wave characteristics have a considerable effect on the cumulative erosion/deposition, cross-shore distribution of longshore sediment transport and transport rate across and along the beach face. In addition, for the same type of oceanic forcing, the beach morphology exhibits different erosive characteristics depending on grain size (e.g., foreshore profile evolution is erosive or accretive on fine or coarse sand beaches, respectively). Decreasing wave height increases the proportion of onshore to offshore fluxes, almost reaching a neutral net balance. The sediment movement increases with wave height, which is the dominant factor controlling the beach face shape.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.4
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• pp.33-40
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• 2021

In this study, the physico-chemical and biological characteristics of anaerobic granular sludge at different heights of a full-scale UASB reactor (UASBr) were investigated. Granular sludge was taken from 1 m, 2 m, and 3 m above the ground level in the UASBr. The morphological analysis showed that the upper part had bigger granules and the lower part had rounder granules. The ANOVA test confirmed that the mean size and the roundness of the granules had statistically significant difference along the height at 95% confidence level, and there was a significant negative linear relationship between the size and roundness (r=-0.40, p<0.05). A SMA test using acetic, propionic and butyric acids showed that granules from 2 m height had the highest specific methanogenic activity. The EPS contents were also unequal to each height, with 2 m showing the highest content. These findings could be helpful to understand the different characteristics of stratified anaerobic granules in full-scale UASBr and maintain the reactor performance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.5
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• pp.449-460
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• 1992

The main purpose of these studies was to obtain the basic informations necessary to develop soybean varieties. Two determinate soybean varieties, Hwangkeumkong and Jangyeobkong, and two indeterminate varieties, Clark and Williams were used to study the differences in growth and yield characters. Indeterminate varieties showed 30 days longer in days from intial flowering to terminal leaf stage and increased 7-8 more nodes on mainstem after initial flowering than determinate varieties. Determinate varieties were greater at middle-upper part, while indeterminate varieties were greater in middle part for the dry weight of the pods and stem at maturity. Total dry weight per unit area was greater in determinate varieties than in indeterminate ones from the early growth to maturity. However, the duration of vegetative growth was longer and the ability to keep leaf area index in the late growth stage was higher in indeterminate varieties. Variations among plants were greater in the order of branch related characters > mainstem, total vegetative, and yield related characters > morphological characters of mains tern and 100 seed weight. In general, variations of vegetative characters formed in the early growth stage were greater than those of yield characters formed in the late growth stage. On the other hand, the variations of those characters were greater in indeterminate varieties than in determinate ones. Variation of a seed weight within a plant was much smaller in determinate varieties than in indeterminate ones : i.e. coefficients of variation of a seed weight within a plant were from 13.6 to 13.8% in determinate varieties and were from 18.5 to 21.1% in indeterminate varieties, respectively.

• The Korean Journal of Mycology
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• v.30 no.2
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• pp.86-94
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• 2002

Recently a serious outbreak of weed mould caused by a species of Hypocrea occurred in oyster mushroom (Pleurotus ostreatus) substrates in Korea. The disease was characterized by a rapid infestation of the oyster mushroom substrates by Hypocrea sp. and subsequent inhibition of fructification of the mushroom. In spite of it's serious losses to the oyster mushroom industry in Korea, etiology and ecology of the disease have not been studied. Morphological characteristics of the fungus were examined and molecular characteristics of the fungus were compared with those of the green moulds (Trichoderma spp.) isolated from oyster mushroom bed. Stromata formed superficially on suface of the substrates were pulvinate to effuse or irreguler, initially white but becoming yellowish brown, measuring $6.0{\sim}13.0{\times}3.0{\sim}11.0mm$. Perithecia were globose to subglobose, immersed in stroma, $223{\sim}263\;(Ave.239.9){\times}167.3{\sim}231\;(Ave.204.1){\mu}m$ in size. Asci were unitunicate, cylindrical, nonamyloid, $82.7{\sim}124.8\;(Ave.103.3){\times}4.1{\sim}5.1\;(Ave.4.9){\mu}m$ in size, 16 part-spored. Ascospores were bullet-shaped or somewhat oblong, hyaline, bicellular, roughened or warted, $5.4{\sim}7.4\;(Ave.6.5){\times}3.6{\sim}5.5\;(Ave.4.7){\mu}m$ in size. This fungus readily form the stroma on PDA. Mycelia on PDA nearly invisible and without cottony aerial mycelium. Optimum temperature for mycelial growth of this fungus was $25^{\circ}C$ on PDA and its growth rate was 15 mm per day. This species did not grow at below 10 and above $35^{\circ}C$. Phialides in culture enlarged in the middle and aggregated to penicillate type. They were very variable, shorted ampulliform and occasionally curved when matured, but cylinderical when young, measuring $11.9{\sim}24.3\;(Ave.\;14.7){\times}2.9{\sim}3.9\;(Ave.\;3.4){\mu}m$ when matured and $7.2{\sim}14.0\;(Ave.\;10.8){\times}2.8{\sim}4.9\;(Ave.\;3.5){\mu}m$ when young. Phialosopres were ovoid to ellipsoid, smooth, measuring $3.5{\sim}7.2\;(Ave.\;4.5){\times}2.6{\sim}3.3\;(Ave.\;2.9){\mu}m$. Nineteen isolates of Hypocrea sp. were analyzed on the basis of molecular characteristics and classified into phenotypic groups. On the basis of RAPD, URP-PCR, the fungus was confirm to monoclonal, and was classified as a different taxon from reported species of Hypocrea and Trichoderma and supposed to be a new species not previously reported in literature.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.543-548
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• 2012

Morphological characters of Baemoochae, xBrassicoraphanus are mostly intermedium of the both parents, Chinese cabbage, Brassica rapa ssp. pekinensis and radish, Raphanus sativus. The upper and lower parts of the leaf resemble the shape of Chinese cabbage and radish, respectively. The midrib of the leaf is round like to that of radish, but very big more than 3 cm in diameter and white in color like that of Chinese cabbage. The root was changed from the swollen type like that of radish to the enlarged taproot like that of the land race of Chinese cabbage after attaining genetical stability. The flower is white. The seed pod is divided into 2 different parts; the upper part is radish and about 4 cm in length and holds 3-4 seeds and the lower part is Chinese cabbage and about 3 cm in length and holds 7-8 seeds. The color of seed is brown, weight per 1.000 seeds is 5.5 g and the number of seeds per mL is 120. The matured plant in the fall season is around 5 kg in weight and outer leaves are very vigorous and stiffly and inner leaves are erect and form a loose head. The leaf and the root contain a high level of sulforaphene which is well known as a functional substance for anti-cancer and anti-super-bacteria. Baemoochae is an amphidiploid and does not have the self incompatibility function. It has a high level of cross compatibility with Chinese cabbage as the female parent, but not the male parent. It is cross incompatible to cabbage, B. oleracea, black mustard, B. nigra and radish. However it is highly compatible to oil seed rape, B. napus, yellow mustard, B. carinata and partial compatible to muatard, B. juncea in the reciprocal cross.