• Title/Summary/Keyword: reproduction period

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Development and Reproduction of Eucyclops serrulatus(Copepoda: Cyclopoida) in the Laboratory Culture (실험실에서 배양한 Eucyclops serrulatus(검물벼룩목 요각류)의 생식과 성장에 관한 연구)

  • Yoon, Kyong-A;Kim, Won
    • Korean Journal of Ecology and Environment
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    • v.33 no.1 s.89
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    • pp.1-8
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    • 2000
  • Four cyclopoids were tested for laboratory culture. Among these animals, only Eucyclops serrulatus was successfully cultured in the laboratory. Under the laboratory culture condition, nine kinds of diets were tested for the suitability of nauplius development. Development and reproduction of E. serrulatus were also investigated. Chlamydomonas reinhardii was the only one which could induce complete development from nauplii to adults. It was found that E. serrulatus had relatively short generation time, could produce lots of progenies, and could be handled easily, allowing to obtain many individuals during a short period. With these characteristics, this species may be a candidate for a good test organism for evaluating freshwater pollution.

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Ultradian Rhythms in the Hypothalamic Arcuate Nucleus Kisspeptin Neurons and Developmental Processes

  • Kim, Doyeon;Choe, Han Kyoung;Kim, Kyungjin
    • Molecules and Cells
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    • v.43 no.7
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    • pp.600-606
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    • 2020
  • Numerous physiological processes in nature have multiple oscillations within 24 h, that is, ultradian rhythms. Compared to the circadian rhythm, which has a period of approximately one day, these short oscillations range from seconds to hours, and the mechanisms underlying ultradian rhythms remain largely unknown. This review aims to explore and emphasize the implications of ultradian rhythms and their underlying regulations. Reproduction and developmental processes show ultradian rhythms, and these physiological systems can be regulated by short biological rhythms. Specifically, we recently uncovered synchronized calcium oscillations in the organotypic culture of hypothalamic arcuate nucleus (ARN) kisspeptin neurons that regulate reproduction. Synchronized calcium oscillations were dependent on voltage-gated ion channel-mediated action potentials and were repressed by chemogenetic inhibition, suggesting that the network within the ARN and between the kisspeptin population mediates the oscillation. This minireview describes that ultradian rhythms are a general theme that underlies biological features, with special reference to calcium oscillations in the hypothalamic ARN from a developmental perspective. We expect that more attention to these oscillations might provide insight into physiological or developmental mechanisms, since many oscillatory features in nature still remain to be explored.

Epidemiological Characteristics of COVID-19 in Chungju City from 2021 July to 2021 December (2021년 7월 - 2021년 12월 충주시 COVID-19의 역학적 특성)

  • Cheon-Hoo Jeon;Jungtae Leem
    • The Journal of Korean Medicine
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    • v.44 no.3
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    • pp.47-58
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    • 2023
  • Objectives: This study aimed to investigate the epidemiological characteristics of COVID-19 in Chungju City from July to December 2021. Methods: The authors processed and analyzed the epidemiological analysis report written by researcher. The estimated reproduction rate was analyzed using web-based software that calculates time-varying reproduction numbers. The results were analyzed through univariate multiple regression analysis, with a maximum significance level set at 0.05. Results: During the study period, a total of 1,188 patients were identified, with 7.9% of them progressing to a severe status. The maximum reproduction rate recorded was 3.48. Factors associated with the transition to a severe status included the presence of symptoms at the time of diagnosis, lack of vaccination, and belonging to the age group over 40. Conclusion: Based on the findings of this study, it can be strongly supported that the measures implemented in Chungju City, such as social distancing, vaccination, and preemptive diagnostic tests, were appropriate. Furthermore, it demonstrates that Chungju City effectively managed the impact of COVID-19. Korean Medicine Doctors made significant contributions to the epidemiological investigations of COVID-19. To comprehensively manage infectious diseases, it is crucial to provide administrative and legal support and encourage active research to expand the role of Korean Medicine Doctors in this area.

Suggestion of experimental model on the innate kidney essence insufficiency syndrome for the development of humanitas traditional medicine

  • Lee, Byongjoo;Go, Jihyun;Lee, Duckgue
    • CELLMED
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    • v.3 no.3
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    • pp.23.1-23.3
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    • 2013
  • According to the traditional Korean medicine (TKM), kidney has been recognized as the roof of innate endowment because it plays an important role in the birth, growth, sexual reproduction, and aging. Kidney essence insufficiency syndrome (KEIS) is caused when kidney is impaired. KEIS is characterized by retarded development, decreased reproduction, tinnitus, loosening of teeth, and loss of hair and forgetfulness. In traditional Chinese medicine, KEIS mouse model was established by use of threatinjuring the kidney combined with over-fatigue. However, the TKM theory-based KEIS experiment model has not been described correctly. In the present study, we suggest a new KEIS experiment model including following cases; 1) weakness of father essence and mother blood, 2) life nurturing during pregnancy, 3) full-term gestation period.

The study on the reproductive rate of retained fetal membrane in Korean native cattles (한우의 후산정체가 수태율에 미치는 영향에 관한 연구)

  • 최경문;김병기
    • Korean Journal of Animal Reproduction
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    • v.12 no.1
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    • pp.20-23
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    • 1988
  • The 3211 Korean native cows raised in Muan, Milyang were investigated for the purpose of finding reproductive rate of cows that retained fetal membrane for two years from April, 1981 to March, 1983. The results obtained were summarized as follows ; 1. The incidence of retained fetal membrane was found in 64 cows(1.98%). 2. The day to first estrus was similar to normal postpartum period unless concurrent genital infection occured. 3. Conception rate of cows that retained fetal membrane was 32.7%, 10.9%, 5.2% and 3.6% at the first, second, third and forth service, respectively and non pregnant cow was 47.6%. 4. Reproductive disorder of non pregnant cows was the highest in repeat breeder and the effect of treatment was very low.

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A Study on the Restoration of Gable Headdress (게이블 헤드드레스의 제작에 관한 연구)

  • 김경희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.3_4
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    • pp.333-342
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    • 2003
  • The purpose of the study is to understand the newer and more direct design techniques, and to provide information to exert creativity in designing. The headdress, one of dress items, was selected so that the change might be investigated in designs and production methods. A headdress was manufactured on the basis of literature review and portrait analysis. The target period of the study was limited to Henry Ⅶ and Henry Ⅷl(1485∼l547) when gable headdress was put on. The details and the patterns of gable headdress were identified for the selected gable hood to be manufactured. It was not possible to get the same dress material, so a similar one was made as in the pictures. The same was done to the color. Putting the focus of the study on the reproduction of the figure in the portrait, some dimension were measured in bodily proportion and patterns were made by three-dimensional cutting. As results, some dimensions used in the manufacture had some limits.

Effects of Castration and Administration of Testosterone Propionate on the Thyroid Gland, Adrenal Gland and Testis in Immature Male Rats (미성숙 수흰쥐에 있어서 생식선척출 및 propionate testosterone 투여가 갑상선, 부신 및 정소조직에 미치는 영향)

  • 김종호;정영채;김창근
    • Korean Journal of Animal Reproduction
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    • v.4 no.1
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    • pp.35-45
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    • 1980
  • The purpose of this experiment was to investigate the effects of castration and administration of testosterone propionate(TP) on the development of the thyroid, adrenal glands and the testis in immature male rats, 25 days immatured, weighing 64.1${\pm}$2g, were divided into two groups of control and castrated, each sub-divided into 30 rats again, treated and untreated with TP respectivity. Each rat was given 20$m\ell$ of TP subcutaneously at two weeks interval. Six rats among each group were randomly sacrificed at 7, 21, 35, 49, and 63 days after treatment, of which their thyroid, adrenal glands and testis were collected for cytometric observation. The results obtained were as follows. 1. The size of the follicle of thyroid glands had a tendency to increase proportionally to the treatment period in every group. However, in castration group, the follicular size of the untreated with TP were significantly increased from 49 days (p<0.05) after treatment than that of the treated with TP, while in control group, the treated with TP were not increased during the treatment period. Regarding the height of the follicular epithelial cell in thyroid gland, the treated with TP had a tendency to increase than the untreated with TP in both castration and control group. 2. Regarding the size of the follicle of thyroid gland in relation with the increment period, the untreated with TP in control group were slightly increased from 49 days after treatment, but the treated with TP were not changed significantly. Castration group had a tendency to increase significantly than the control group, especially the untreated with TP in castration group were significantly increased. 3. As for the change of the relative height of thyroidal follicular epithelial cell in relation with the increment of treatment period, the untreated, A and C group, in both castration and control group were increased at 35 days 63 days after treatment while the treated, B and D group had tendency to increase from 21 days after treatment. 4. Regarding the thickness fo adrenal cortex, the castration group had a tendency to increase than the control group until 21 days after treatment. But, at 35 days, the change of the thickness was reversed; Mean while at 49 days and 63 days, especially C group in castration were significantly increased than any other groups although there were no significant differences among the every group during the whole treatment period. Regarding the thickness of adrenal cortex in relation with the increment of treatment period, A, B and C group had a tendency to increase until 21 days after treatment. After that period, there was no significant increment in all groups. Especially, in D group, there were no significant changes from 7 days to 63 days after treatment. 5. As for the tickness of adrenal medulla, there were no significant changes in every group of castration and TP treatment, except that the castration group had a tendency to increase continually than the control throughout the whole treament period. 6. In terms of the number, diameter and thickness of seminiferous tubule in testis of control group, the treated group with TP were distinctly reduced than those of the untreated group from 49 days after treatment respectively.

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Heterosis and Percent Improvement in Survivability, Reproduction and Production Performance of Various Genetic Groups of Temperate x Zebu Crosses in Tropics

  • Singh, Kuldeep;Khanna, A.S.;Sangwan, M.L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.6
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    • pp.794-799
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    • 2003
  • A study was conducted on 2102 records of 808 crossbred cows of various genetic groups maintained under 'All India Coordinated Research Project on Cattle' at C C S Haryana Agricultural University, Hisar, over 25 years period (1968-1993) with an objective to assess and compare the amount of percent improvement and heterotic effect for different performance traits in various genetic groups produced under this programme. Survivability sharply and significantly declined from 1/2 to $3/4^th$ bred and further from $3/4^th$ to inter-se bred. This may be due to periodic and management differences in addition to the higher level of exotic inheritance and decreased heterotic effect over the filial generations. Jersey and Holstein Friesian crosses among 1/2 breds and their 50% inheritance among $3/4^th$ and inter-se breds had highest improvement and heterosis in reproduction and production traits respectively. Among inter se bred genetic groups, BFH (I) had no recombination loss in SP and CI, while FJH (I), JFH (I) and FBH (I) had on recombination loss in AFC, LY, LL and PE. The crossbreeding of zebu cows with exotic breeds brings about spectacular improvement in comparison to the performance of zebu breed, while conventional selection over several generation would lead to only modest improvement. In addition to additive effect, there was sufficient heterosis in Jersey crosses for reproduction and Holstein Friesian crosses for production performance. Three breed crosses with exotic inheritance between 50 and 75 percent incorporating genes (25 to 50%) from both of these breeds is the best combination for stabilization.

Design and Implementation of Digital Contents Protection System using Triple DES Algorithm (Triple DES 알고리즘을 이용한 디지털 콘텐츠 보호 시스템 설계 및 구현)

  • 권도윤;이경원;김정호
    • Proceedings of the Korea Contents Association Conference
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    • 2003.05a
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    • pp.160-164
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    • 2003
  • Broadcasting environment of present our country is greeting period of transition that undergo a change to digital broadcasting system in analog broadcasting system continued for last several decades. With change of these broadcasting environment interest about various digital broadcasting contents industry that fill to digital broadcasting infra and unlawfulness reproduction prevention technology far digital broadcasting contents of high added value is rising. According as is converted to digital broadcasting environment interest about reproduction prevention is well-founded to be risen sensitively. First analog broadcasting environment can not remove perfectly error at transmission in receiver, but can reconstruct contents such as original by error correction function in receiver in the case of digital broadcasting environment. Secondarily, although quality of copy is dwindled than original repeat reproduction in case of analog, many copies are available innumerably regardless of number of times of copy keeping quality such as original in the case of digital And third element is possible easily to anyone to on-line along with development of internet in case of digital contents unlike analog. Under these background, this thesis wish to design and implement digital contents protection system to prevent unlawfulness reproduction and distribution of digital contents using Triple DES algorithm.

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Effect of Season and Age on the Ovarian Size and Activity of One-Humped Camel (Camelus dromedarius)

  • Ali, Shujait;Ahmad, Nazir;Akhtar, Nafees;Rahman, Zia-ur;Sarwar, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.9
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    • pp.1361-1366
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    • 2007
  • In this project, ovarian size and activity during the peak (November-April) and the low (May-October) breeding seasons in young and adult camels were studied. Ovaries of 92 camels (Camelus dromedarius), with clinically normal reproductive tracts, aged 3-15 years and slaughtered at Faisalabad or Lahore abattoirs over a period of 24 months, were collected. Jugular blood was collected from each animal before slaughter; the serum was separated and analyzed for oestradiol concentration. The size (length, width and thickness) and weight of each ovary were measured. Grossly observable Graafian follicles were counted and their diameter was measured using Vernier Calipers. The camels having ovaries presenting follicles more than 5 mm in diameter were taken as having active ovaries. The results showed that ovarian length, width and weight were significantly higher (p<0.05) during the peak than the low breeding season. The percentage of active ovaries was also significantly higher (p<0.01) during the peak than the low breeding season. However, the effect of season on ovarian thickness was non-significant. Similarly, the ovarian length, width, thickness, weight and activity did not vary significantly between young (3-7 years old) and adult (8-15 years old) animals. Serum oestradiol concentrations were significantly higher (p<0.05) during the peak ($67.70{\pm}1.36$ pg/ml) than the low breeding season ($15.25{\pm}1.54$ pg/ml). It was concluded that in Pakistani camels ovarian size and activity were higher during the peak than the low breeding season. However, age of the camel (from 3 to 15 years) had no effect on these parameters.