• Title/Summary/Keyword: natural mortality

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Secular chang of density, litterfall, phytomass and primary productivity in mongolian oak(quercus mongolica)forest (신갈나무 숲의 林木密度, 落葉量, 植物量 및 1次 純生産量의 經年 變化)

  • Kwak, Toung-Se;Kim, Joon-Ho
    • The Korean Journal of Ecology
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    • v.15 no.1
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    • pp.19-33
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    • 1992
  • The density, litterfall, phytomass, and primary productivity for 7 years in quercus mongolian forest locasted at mt. nambyengsan, pyeongchang-gun, gangwon provance in central part of korean peninsula were estimated quantitatively. at the first year in 1984, a stand had 1, 450 trees/ha in tree density, which was 0.67 of skewness and 0.54 of kurtosis in frequency distribution, however, at the 7th year in 1990, the stand had 1, 133 trees/ha in the density with 22%(or 316 tree/ha)in mortality, which was 1.16 of skewness and 1.89 of kurtosis in the frequency. annual mean litterfall was 5 ton DM/ha, which was composed of 68% of leaves, 17% of branches, 3% of bud scales, 9% of arcons and cups, 0.7% of flowers and others. the phytomass of tree layer for 7 years was gradually increased from 149.7 ton DM/ha at the first year to 188.5 ton DM/ha at the 7th year.annual net productivity for the tree layer studied ranged from 8.76 ton DM/ha.yr-1 to 11.62 ton DM/ha. yr-1 with heavy fluctuation year by year. average annual productivity of the stand of trunk, branches, leaves and roots for 7 years were 4.42, 0.67, 3.85 and 1.29 ton DM/ha.yr-1, respectively. turnover rate of the stand was 6.9% at the first year and 5.6% at the 7th year. such fluctuation of the productivity was caused by the chang of density, mortality, mortality and turnover rate.

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Population Dynamics of Corbicula ( Corbicula) japonica Prime from Namdae Stream in Yangyang, Korea (강원도 양양 남대천에서 채집된 일본재첩, Corbicula (Corbicula) japonica Prime의 수산자원학적 연구)

  • Kwon Dae Hyeon;Kang Yong Joo;Kim Wan Ki;Lee Chae Sung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.6
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    • pp.686-695
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    • 2002
  • Samples of Corbicula ( Corbicula) japonica Prime of Namdae Stream in Gangnung were collected from November 2000 to October 2001. Age of C. (C.) japonica was determined from the rings on the shell, The shell length of the samples ranged from 8 mm to 38 mm. The ring on the shell was formed once a year in March. Von Bertalanffy's growth parameters were estimated using a nonlinear regression method, asyinptotie shell length ($L_{\omega}$) was 48,98 mm, K was 0.20421year, theoretical age at 0 shell length $(t_0)$ was 0.3169 year, and asymptotic total weight ($W_{\omega}$) was 41.37 g. The formula of allomeky between shell length (L, mm) and total weight (W, g) of the brackish water clam was W=3.42$\times$10^{-4}L^{3}. The annual survival rate was estimated at 0.3799, instantaneous coefficient of natural mortality was 0.5007/year, and instantaneous coefficient of fishing mortality was 0.46721year. The age at first capture was estimated at 2.1593 year using shell length compositions of the brackish water clam, The current yield-per-recruit at 0.4672/year of fishing mortality was 0.6595 g. F_0.1 was estimated at 0.1865/year, Acceptable biological catch was estimated at 14.4 metric ton.

Efficacy of live NNV immersion vaccination in three grouper species (Seven band grouper Hyporthodus septemfasciatus, Red spotted grouper Epinephelus akaara, Long tooth grouper Epinephelus bruneus) (바리과 어류 3종(능성어 Hyporthodus septemfasciatus, 붉바리 Epinephelus akaara, 자바리 Epinephelus bruneus)에 대한 신경괴사증바이러스(Nervous Necrosis Virus, NNV)의 생백신 처리 효과)

  • Kim, Si-Woo;Park, Jung-Jun;Hong, Chang-Gi;Oh, Myung-Joo
    • Journal of fish pathology
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    • v.34 no.1
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    • pp.99-104
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    • 2021
  • In this study, we investigated safety and efficacy of a low temperature immunization protocol with NNV in red spotted grouper, Epinephelus akaara and long tooth grouper, Epinephelus bruneus and seven band grouper, Hyporthodus septemfasciatus. Further, growth rate between immunized and naïve fish was evaluated during the experiment to check side effect of immunization. Three grouper species were immunized by immersion method with live NNV at 105.0 TCID50/mL at 16.5℃ for 30 min and reared for 120 days at natural sea water temperature. To evaluate growth rate, total length and wet weight was measured 7 times after immunization. Immunized three grouper species were challenged by intramuscular inoculation with NNV at 104.2 TCID50/100 µL/fish. Immunization at low temperature with live NNV did not show any clinical symptoms of infection, mortality and inhibition of growth. After challenge, cumulative mortality of naïve seven band grouper, red spotted grouper, long tooth grouper were 45, 10, 20 %, respectively. However no mortality was observed at immunized groupers. Thus, it was demonstrated that immunization at low temperature with live NNV are able to protect three different species of groupers without inhibition of growth.

Ecological Characteristics and Biomass of White Croaker Pennahia argentata Population in the South Sea of Korean Peninsula (한국 남해안 보구치(Pennahia argentata)의 자원생태학적 특성치 및 자원량 추정)

  • Jeon, Bok Soon;Lee, Hae Won;Kang, Sukyung;Lee, Seung Jong;Oh, Chul-Woong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.5
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    • pp.721-729
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    • 2022
  • We investigated the ecological characteristics and biomass of white croaker Pennahia argentata population in the South Sea of Korea using catch data from Danish seins fishery and biological data from 2018 to 2020. Survival rate (S), which was estimated using Pauly method (1984) was 0.361 per year, and the instantaneous coefficient of total mortality (Z) was 1.019 per year. The instantaneous coefficient of natural mortality (M) and that of fishing mortality (F) were estimated as 0.351 and 0.668 per year, respectively. At first capture, age was estimated to be 1.19 years and length at this age was 18.7cm. The annual biomass was estimated with a biomass-based cohort analysis using annual catch data between 1997-2020 in Korean water. The biomass of the white croaker declined sharply from 4,000 tons in 1999 to the lowest level of approximately 1,000 tons in 2004. Post 2004, the biomass started to increase gradually and reached approximately 7,000 tons. The amount of resources was 35.7%, 34.8%, and 16.5% at age one, two, and three years, respectively, and 86.9% of all captured white croaker individuals belonged to the age group of 1-3 years.

In Silico Docking Studies of Selected Flavonoids - Natural Healing Agents against Breast Cancer

  • Suganya, Jeyabaskar;Radha, Mahendran;Naorem, Devi Leimarembi;Nishandhini, Marimuthu
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.19
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    • pp.8155-8159
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    • 2014
  • Background: Breast cancer is the serious health concern in India causing the highest mortality rate in females, which occurs due to uncontrolled cell division and can be metastasize to other parts of the human body. Interactions with estrogen receptor (ER) alpha are mainly responsible for the malignant tumors with regulation of the transcription of various genes as a transcription factor. Most of the drugs currently used for the breast cancer treatment produce various side effects and hence we focused on natural compounds which do not exhibit any toxic effect against normal human cells. Materials and Methods: Structure of human ER was retrieved from the Protein Data Bank and the structures of flavonoid compounds have been collected from PubChem database. Molecular docking and drug likeness studies were performed for those natural compounds to evaluate and analyze the anti-breast cancer activity. Results: Finally two compounds satisfying the Lipinski's rule of five were reported. The two compounds also exhibited highest binding affinity with human ER greater than 10.5 Kcal/mol. Conclusions: The results of this study can be implemented in the drug designing pipeline.

Natural History of Early Gastric Cancer: a Case Report and Literature Review

  • Iwai, Tomohiro;Yoshida, Masao;Ono, Hiroyuki;Kakushima, Naomi;Takizawa, Kohei;Tanaka, Masaki;Kawata, Noboru;Ito, Sayo;Imai, Kenichiro;Hotta, Kinichi;Ishiwatari, Hirotoshi;Matsubayashi, Hiroyuki
    • Journal of Gastric Cancer
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    • v.17 no.1
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    • pp.88-92
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    • 2017
  • Early detection and treatment decrease the mortality rate associated with gastric cancer (GC). However, the natural history of GC remains unclear. An 85-year-old woman was referred to our hospital for evaluation of a gastric tumor. Esophagogastroduodenoscopy identified a 6 mm, flat-elevated lesion at the lesser curvature of the antrum. A biopsy specimen showed a well-differentiated tubular adenocarcinoma. The depth of the lesion was estimated to be intramucosal. Although the lesion met the indications for endoscopic resection, periodic endoscopic follow-up was performed due to the patient's advanced age and comorbidities. The mucosal GC invaded into the submucosa 3 years later, and finally progressed to advanced cancer 5 years after the initial examination. The patient died of tumor hemorrhage 6.4 years after the initial examination. In this case, mucosal GC progressed to advanced GC, eventually leading to the patient's death from GC. Early and appropriate treatment is required to prevent GC-related death.

A Detection Kit for Aeromonas hydrophila Using Antibody Sensitized Latex

  • Shin, En-Joo;Lee, Soon-Deuk;Lee, Kyung-Won;Lee, Yeon-Hee
    • Journal of Microbiology and Biotechnology
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    • v.10 no.5
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    • pp.595-598
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    • 2000
  • Aeromonas hydrophila is a pathogen to fish as well as human. It is a food-borne disease, and causes severe mortality in fish, and sometimes severe septicemia in human. In this study, a rapid detection method using latex agglutination has been developed for A. hydrophila. Polyclonal antibodies were raised against membrane and whole cells of three isolates from rainbow trout. Among these, latex particles coated with antibodies raised against whole cells of isolate No. 2 showed the best sensitivity. With latex particles coated with this antibody, we could detect $5{\times}10^4$ CFU of A. hydrophila in 5 min. The cross-reactivity with bacteria constituting the normal intestinal microflora and other pathogens for rainbow trout was insignificant. This latex agglutination assay method produced positive reaction with all clinical isolates of A. hydrophila which were identified by species-specific PCR for 16S rRNA in A. hydrophila.

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Tschimganidine reduces lipid accumulation through AMPK activation and alleviates high-fat diet-induced metabolic diseases

  • Min-Seon Hwang;Jung-Hwan Baek;Jun-Kyu Song;In Hye Lee;Kyung-Hee Chun
    • BMB Reports
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    • v.56 no.4
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    • pp.246-251
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    • 2023
  • Obesity increases the risk of mortality and morbidity because it results in hypertension, heart disease, and type 2 diabetes. Therefore, there is an urgent need for pharmacotherapeutic drugs to treat obesity. We performed a screening assay using natural products with anti-adipogenic properties in 3T3-L1 cells and determined that tschimganidine, a terpenoid from the Umbelliferae family, inhibited adipogenesis. To evaluate the anti-obesity effects of tschimganidine in vivo. Mice were fed either a normal chow diet (NFD) or a high-fat chow diet (HFD) with or without tschimganidine for 12 weeks. Treatment with tschimganidine decreased lipid accumulation and adipogenesis, accompanied by reduced expression of adipogenesis and lipid accumulation-related factors. Tschimganidine significantly increased the phosphorylation of AMP-activated protein kinase (AMPK) and decreased that of AKT. Depletion of AMPK relieved the reduction in lipid accumulation resulting from tschimganidine treatment. Moreover, tschimganidine administration drastically reduced the weight and size of both gonadal white adipose tissue (WAT) and blood glucose levels in high-fat diet-induced obese mice. We suggest that tschimganidine is a potent anti-obesity agent, which impedes adipogenesis and improves glucose homeostasis. Tschimganidine can then be evaluated for clinical application as a therapeutic agent.

Inhibitory effects of herbal medicine on coccidiosis (한약재의 첨가 급여에 따른 콕시듐 억제 효과)

  • Park, Young-Suk;Kim, Jeong-Rak;Kang, Byeong-Kwon;Choe, Yeong-Ho;Kim, Byeong-Soo
    • Korean Journal of Veterinary Service
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    • v.35 no.1
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    • pp.25-31
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    • 2012
  • This study examined the efficacy of natural ingredient formulated herbal medicine as feed additives against coccidiosis in broiler chicken. Medicinal herbs used in this study were Artemisia annua, Pulsatilla chinensis, Clematis chinensis and Scutellaria baicalensis. Two week old chicks were administered with 1% ingredient formulated herbal medicine. Observations of the efficacy were confirmed by examining the lesion score, histopathological appearance of cecum, shedding of fecal oocyst and production index in farm. S. baicalensis of the most effective substance were analyzed by UPLC. The results are as follows; among various types of Chinese medicine, the most efficacious ingredient was found to be pure bicalein. The major index substance is bicalein and $13{\mu}g/ml$ per gram was found. Feeding of chickens with S. baicalensis induced the coccidiostat effect and reduced the fecal shedding of E. tenella oocyst by 14%. Experimental results on a farm, feed conversion ratio and weight gain and production rate in the group with natural ingredient formulated additives than in control group increased. The rate of weight gain (%) in each experimental group showed 108% and 126% increase while the mortality rate was 1.4% lower than the control group. The investigation showed that the most efficacious ingredient was found to be S. baicalensis among herbal medicine products for coccidiostats. However, as it was found in the farm experiment that pure S. baicalensis alone is economically unviable. The additives with cocktailed of efficacious ingredient are suggested to be implemented for effective protection against coccidiosis.

STUDIES ON THE MORTALITY OF THE YOUNG BIVALVES, MERETRIX LUSORIA (1) Boring Rates of Drills on the Young Bivalve, Meretrix lusoria (대합 Meretrix lusoria 치패의 폐사에 관한 연구 (1) 대합치패의 천공복족류 Neverita didyma, Natica severa에 의한 천공률에 관하여)

  • LEE Jung Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.2 no.1
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    • pp.63-70
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    • 1969
  • 1. This paper deals with the natural mortality of the early young bivalve, Meretrix lusoria, (less than 13mm in shell length) and the perforations bored in the bivalve by bering snails, Neverita didyma and Natica severa. The investigation was carried out in the Kunsan area and in the laboratory from May to October of 1968. 2. The natural mortality of the field population during this period was $12.1\%$ and among this number $38.1\%$ were drilled by boring snails. 3. The common species of the Naticid gastropods, boring snails-Neverite didyma and Natice severa - are encountered in the habitat of M. lusoria. The perforations drilled by these species were broadly bevelled. 4. The location of the holes on the valves varied widely, while most of holes on the valves were located at a relatively definite umbo position. 5. The inner and outer diameters of the holes varied in proportion to the shell length of the clam; each ranging in shell length from 1 to 3mm, 3 to 6mm, and 6 to 13mm, and the outer diameters were 0.4-0.5mm, 0.7-0.9mm and 0.9-1.2mm. On the other hand, the ratio of the inner and outer diameters differed in proportion to the shell length of the clam. 6. Predation rates of Neverita didyma was much greater at night than during the day at room temperature. An average of 1.7 young clams was drilled and consumed, per snail, per day. This rate was greater than that of the Natica severa. 7 Predation rates varied in proportion to the shell length of the clam and the shell height of the snails.

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