Short-term storage and cryopreservation of Urechis unicinctus (Echiura: Urechidae) sperm   总被引：2，自引：0，他引：2  

Kyoung Ho Kang  Ming Yu Shao  Kang Hee Kho  & Zhi Feng Zhang 《Aquaculture Research》2004,35(13):1195-1201

In the present study, attempts were made to preserve Urechis unicinctus sperm at 4°C. Cryopreservation procedures were optimized for various cryoprotectants and freezing rates, equilibration times and dilution ratios. During short‐term storage, the motility of undiluted sperm was extended for 6 days of cold storage,and in 70% and 100% artificial seawater only persisted for 2 and 4 days respectively. The survival rate of undiluted sperm was maintained at a high level accordingly. After cryopreservation, the highest motility and survival rate (41.5±2.2%) were obtained in 15% dimethyl sulphoxide (Me₂SO) using a freezing rate of 30°C min^?1. After thawing the sperm cryopreserved in glycerol lost almost all motility. The motility and survival rate of post‐thawing sperm did not show significant differences after 8 and 15 min equilibration using 15% Me₂SO as cryoprotectant; the values were significantly higher than those of 2 min equilibration. Comparisons of motility and survival rate between treatments pooled by dilution ratio showed that the effect of 1:1 ratio (sperm volume to cryoprotectant volume) was best. There was no difference between 1:3 and 1:5, and other ratioswere significantly worse.  相似文献   

Development of a multiplex PCR assay to detect Edwardsiella tarda,Streptococcus parauberis,and Streptococcus iniae in olive flounder (Paralichthys olivaceus)     

Seong Bin Park  Kyoung Kwon  In Seok Cha  Ho Bin Jang  Seong Won Nho  Fernand F. Fagutao  Young Kyu Kim  Jong Earn Yu  Tae Sung Jung 《Journal of veterinary science (Suw?n-si, Korea)》2014,15(1):163-166

A multiplex PCR protocol was established to simultaneously detect major bacterial pathogens in olive flounder (Paralichthys olivaceus) including Edwardsiella (E.) tarda, Streptococcus (S.) parauberis, and S. iniae. The PCR assay was able to detect 0.01 ng of E. tarda, 0.1 ng of S. parauberis, and 1 ng of S. iniae genomic DNA. Furthermore, this technique was found to have high specificity when tested with related bacterial species. This method represents a cheaper, faster, and reliable alternative for identifying major bacterial pathogens in olive flounder, the most important farmed fish in Korea.  相似文献   

Characterization of the DNA nucleotide sequences in the genome of red sea bream iridoviruses isolated in Korea     

Joon Bum Jeong  Lyu Jin Jun  Min Ho Yoo  Myong Sug Kim  Jack L. Komisar  Hyun Do Jeong   《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):119-133

The nucleotide sequences of DNA fragments amplified by polymerase chain reaction (PCR) from four different genomic regions of nine red sea bream iridoviruses (RSIVs) isolated from different species of fish, different areas and in different years in Korea were compared with the reported reference sequences. One isolate, RSIV Namhae, showed 100% homology to the reference sequences, while the other eight isolates, which appeared to contain identical nucleotide sequences, showed 96.6–98.9% homology with reference sequences depending upon the target regions of PCR gene amplification. However, differences in nucleotide sequences were not apparent between the RSIVs isolated in different locations, in different years or in different host species. We also cloned and sequenced the 3′ end flanking region (K1) of the DNA polymerase (DPOL) gene using the cassette ligation-mediated PCR method. This sequence was 4436-bp long and possessed two open reading frames (ORF-1 and ORF-2) oriented in opposite directions. The putative proteins encoded by these two ORFs could not be characterized by comparison with the proteins of other species in the data banks. The presence of the ribonucleotide reductase small subunit (RNRS) gene at the 3′ end of the K1 region allowed us to determine that these two genes, RNRS and DPOL, are separated 5508 bp and oriented in the same direction in the genome of RSIV. Moreover, it is of interest that a PstI-restriction fragment, of which the sequence but not the location within the RSIV genome had previously been reported, is located at nucleotide positions from 1096 to 2054, extending from within the ORF-1 region, spanning the intervening sequence between ORF-1 and ORF-2, and extending into the ORF-2 region. Various repeating sequences up to 86 bp were present at the 3′ ends of ORFs, especially within the nucleotide sequences at the 3′ terminus of ORF-2. No similarities were detected when the DNA sequences of the K1 region were compared to the DNA sequences of a repetitive element in the genome of other iridoviruses.  相似文献   

A concept to define a quantitative measure of mixture state     

Hyung Bum Kim  Jung Ho Lim  You Huh 《Fibers and Polymers》2014,15(9):2001-2012

Mixing is a mechanical operation to distribute components evenly in a plane or a space. Composite molding and textile manufacturing industries are routinely taking advantage of mixing operations in order to distribute raw materials uniformly or in a specific way during composite molding or textile producing processes. Key issues to identify any mixed state are (1) the time needed to accomplish through mixing (the time scale) and (2) the extent of the homogeneity of the mixture in a plane (the length scale). In this paper, a new concept of mixture status is focused on the length scale. The goal to derive a new concept of mixture status is to establish a measure to describe the mixed extent of a mixture consisting of two components, derived from clump size and clump distribution. To verify the usefulness of the newly conceived “Mixedness Index”, the suggested definition was compared with the existing coefficient of variation (CV) method based on simulation and experiments. Results showed a reasonable relationship between the Mixedness Index and observation, demonstrating the feasibility of the proposed Mixedness Index for industrial applications.  相似文献   

Synthesis and properties of Nylon 4/5 copolymers for hydrophilic fibers     

Kyeong-Suk Kang  Yu-Kyoung Hong  Young Jun Kim  Joon Ho Kim 《Fibers and Polymers》2014,15(7):1343-1348

Nylon 4, which can be synthesized by anionic ring-opening polymerization, has good mechanical properties and a very high affinity for water owing to its high polarity. On the other hand, despite its high melting temperature, the polymer has not been commercialized because of its low thermal stability. In this study, copolymerization of 2-pyrrolidone (C4) with 2-piperidone (C5) was performed to reduce the melting temperature of Nylon 4 homopolymer. The copolymerization reaction was controlled by changing the comonomer content, catalyst content, temperature, initiator content, and reaction time. The Nylon copolymers were characterized by ¹H-nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The hydrophilic properties of Nylon 4 and its copolymers were evaluated by surface free energy analysis and moisture regain measurement. The intrinsic viscosity and polymerization yield of Nylon 4 increased with increasing catalyst concentration until 5 mole% and decreased with further increases in catalyst loading. The proton NMR spectrum revealed the composition of the Nylon 4/5 copolymer to be 62.5 % C4 moiety at a 5:5 comonomer feed ratio. The melting temperature of the Nylon 4/5 copolymers decreased considerably according to the composition. The moisture regain of the Nylon 4/5 copolymer was higher than 6.4 % even at 77.3 % C4 in composition.  相似文献   

Genetic evidence of stable northward extension of Pinus thunbergii Parl. forests in the Democratic People’s Republic of Korea     

Ho  Un-Hyang  Song  Sam-Rang  Pak  Hak-Song  Kim  Kang  Ho  Tong-Su  Ju  Il-Yop 《Genetic Resources and Crop Evolution》2022,69(6):2105-2114

Genetic Resources and Crop Evolution - Japanese black pine (Pinus thunbergii Parl.) with high salt tolerance may be an important constitutive element sustaining terrestrial ecosystem by playing a...  相似文献   

Flowering estimation in apple orchards by image analysis     

Marko Hočevar  Brane Širok  Tone Godeša  Matej Stopar 《Precision Agriculture》2014,15(4):466-478

Tree-specific management practice related to individual tree physiological condition is necessary for higher quality and quantity in apple fruit production. Detection of apple flowering abundance based on analysis of HSL (hue, saturation, luminance) images was used to estimate the number of flower clusters (FC) of individual trees in a high density apple orchard. The image acquisition was performed with a still camera and an industrial color camera during the day and night. The FC estimation algorithm included HSL thresholding with parameter optimization. Three hypothetical, tree-specific management practices (sprayings) were assumed, using >25, >50 and >100 FC thresholds to carry out the practice. When an industrial camera was used for image acquisition during the daytime and hypothetical spraying was done by on/off criterion >100 FC per tree, 10 % incorrect executions were identified. Comparable FC counting performance was achieved by using a still camera or an industrial camera.  相似文献   

Cryopreservation of filefish (Thamnaconus septentrionalis Gunther, 1877) sperm     

Kyoung Ho Kang  Kang Hee Kho  Zong Tao Chen  Jae Min Kim  Young Hun Kim  & Zhi Feng Zhang 《Aquaculture Research》2004,35(15):1429-1433

The present study examined the possibility of long‐term storage, by cryopreservation in liquid nitrogen, of the sperm of filefish (Thamnaconus septentrionalis). Changes in motility, survival rate, ultrastructure and fertilization rate of the sperm after freezing and thawing were tested. For selection of the immobilizing solution, artificial seawater (ASW) of 250, 350 and 450 mOsmol kg^?1 were tested. Sperm motility was significantly inhibited in 350 mOsmol kg^?1 ASW, and restored entirely after 100% ASW (1200 mOsmol kg^?1) was added. Two cryoprotectants, dimethyl sulphoxide and glycerol, were employed. The sperm was diluted at the ratio of 1:6 with the extenders, and frozen at a freezing rate of ?40°C min^?1 to ?100°C after equilibration for 10 min at room temperature, followed by plunging into liquid nitrogen. The highest post‐thawed sperm motility and survival rate were obtained with 5% glycerol. Afterwards, the effect of different freezing rates was examined using 5% glycerol as a cryoprotectant, and the rate of ?30°C min^?1 to ?100°C showed the best result.  相似文献   

Ciguatoxin in moray eels raising the risk for seafood safety in Viet Nam     

Dao  Ha Viet  Le  Hy Ho Khanh  Le  Thao Thi Thu  Pham  Ky Xuan  Bui  Minh Quang  Chan  Leo Lai 《Fisheries Science》2022,88(6):821-830

Fisheries Science - Recently, suspected ciguatera fish poisoning (CFP) cases caused by the consumption of moray eels, popular seafood for locals and tourists, have been reported in Viet Nam....  相似文献   

Association between basal stem rot disease and simple sequence repeat markers in oil palm,Elaeis guineensis Jacq.     

Emad Omer Hama-Ali  Jothi Malar Panandam  Soon Guan Tan  Sharifah Shahrul Rabiah Syed Alwee  Tan Joon Sheong  Ho Chai Ling  Parameswari Namasivayam  Hoh Boon Peng 《Euphytica》2015,202(2):199-206

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