• Title/Summary/Keyword: Sexual Maturity

Search Result 232, Processing Time 0.022 seconds

Regeneration and Maturation Induction of Free-Living Gametophytes of Undariopsis peterseniana for their Mass Production (넓미역(Undariopsis peterseniana)의 대량생산을 위한 유리배우체의 재생 및 성숙 유도)

  • Hwang, Eun-Kyoung;Shim, Cheol-Hong;Ha, Dong-Soo;Gong, Yong-Gun;Park, Chan-Sun
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.44 no.2
    • /
    • pp.155-161
    • /
    • 2011
  • Induction of regeneration and maturation of the free-living gametophytes of Undariopsis peterseniana (Kjellman) Miyabe et Okamura was studied at four temperatures (5, 10, 15, and $20^{\circ}C$), four levels of irradiance (5, 10, 20, and 40 ${\mu}mol$ $m^{-2}\;s^{-1}$) and three photoperiods (14:10, 12:12, and 10:14 h L:D). Female gametophyte fragments were maintained in active regeneration without reaching sexual maturity under conditions of $15^{\circ}C$, 20 ${\mu}mol\;m^{-2}\;s^{-1}$, 10:14 h (L:D), whereas the conditions for male gametophytes were slightly different at $15^{\circ}C$, 20 ${\mu}mol\;m^{-2}\;s^{-1}$, 14:10 h (L:D). The sexual maturation of female and male gametophytes took place under $15^{\circ}C$, 20 ${\mu}mol\;m^{-2}\;s^{-1}$, 14:10 h (L:D) and $10^{\circ}C$, 10 ${\mu}mol\;m^{-2}\;s^{-1}$, 10:14 h (L:D), respectively. These results provide basic information for controlling the regeneration and maturation of free-living gametophytes for artificial seed production of U. peterseniana.

Adult Eclosion and Emergence of the Black Pine Bast Scale, Matsucoccus thunbergianae (Homoptera: Coccoidae: Margarodidae) (솔껍질깍지벌레 성충의 우화습성)

  • ;Law
    • Korean journal of applied entomology
    • /
    • v.30 no.1
    • /
    • pp.86-93
    • /
    • 1991
  • Adult eclosion and emergence behavior of the black pine base scale, Matsucoccus thunbergianae Miller and Park, was studied in a laboratory. Adult eclosion in males did not appear to be limited to a specific time of the day. Newly molted male adults, at room temperatures, usually remained in the cocoons as pre-emergence adults for 0.5-20. days before emerging; most males emerged within one hour after the onset of photophase, and emergence was faster at higher light intensity. Most females molted into adults within three hours after the onset of photophase, and they were active immediately after molting. Quiescence in males appears to help the scales concentrate their sexual activity within a particular period of the day as well as to protect newly molted adults until sexual and locomotive maturity.

  • PDF

A Study on Beliefs and Experiences Related to Dual Relationships among Social Workers (이중관계에 대한 사회복지사들의 신념과 경험에 관한 연구)

  • Park, Mi-Eun;Seo, Mi-Kyung;Kim, Young-Ran
    • Korean Journal of Social Welfare
    • /
    • v.47
    • /
    • pp.178-205
    • /
    • 2001
  • This article investigates 295 social workers in order to find out how much they believe that each behavior related to dual relationships is ethical and with how many clients they engaged in these behaviors. This article, based on the literature, explores three areas of dual relationships which are sexual, bartering, and private dual relationships. The results from the research were 1) The social workers tend to believe that while sexual and bartering dual relationships are less ethical, private dual relationships are more ethical. Meanwhile, they have little experience to engage in all areas of dual relationships; 2) Compared to beliefs and experiences, the social workers believe that each behavior is ethical, but they have less experienced the same behavior. However, the result of strong correlations between beliefs and experiences shows that the more the social workers believe that the behaviors are ethical, the more they tend to engage in the behaviors; 3) Based on socio-demographic characteristics, male social workers tend to accept dual relationships as ethical behavior than their female counterparts do. And those who are practicing in health settings tend to believe that the behaviors related to dual relationships are less ethical than those who are practicing in the other areas of the profession do. Finally, the research recommends that enhancing social worker's self-awareness and professional maturity is needed in order to prevent the occurrence of dual relationship engagement. Also, social work professional associations and agencies should provide education, training, and institutional restrictive devices for dealing with unethical dual relationships.

  • PDF

Nutrition-induced Changes of Growth from Birth to First Calving and Its Impact on Mammary Development and First-lactation Milk Yield in Dairy Heifers: A Review

  • Lohakare, J.D.;Sudekum, K.H.;Pattanaik, A.K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.25 no.9
    • /
    • pp.1338-1350
    • /
    • 2012
  • This review focuses on the nutritional effects from birth until age at first calving on growth, mammary developmental changes, and first-lactation milk yield in heifer calves. The advancement in the genetic potential and the nutritional requirements of the animals has hastened the growth rate. Genetic selection for high milk yield has suggested higher growth capacity and hence increasing nutritional inputs are required. Rapid rearing by feeding high energy or high concentrate diets not only reduces the age of sexual maturity but also lowers the time period of attaining the age of first calving. However, high energy diets may cause undesirable fat deposition thereby affecting future milk yield potential. Discrepancies exist whether overfed or overweight heifers at puberty can influence the mammary development and future milk yield potential and performance. The data on post-pubertal nutritional management suggested that body weight at calving and post-pubertal growth rate is important in first lactation milk yield. There is a continuous research need for strategic feeding that accelerates growth of dairy heifers without reduction in subsequent production. Nutritional management from birth, across puberty and during pregnancy is critical for mammary growth and for producing a successful cow. This review will mostly highlight studies carried out on dairy breeds and possible available opportunities to manipulate nutritional status from birth until age at first calving.

Asymmetries in Chickens from Lines Selected and Relaxed for High or Low Antibody Titers to Sheep Red Blood Cells

  • Tu, Yunjie;Siegel, P.B.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.28 no.3
    • /
    • pp.323-327
    • /
    • 2015
  • Wattle length, width, and area were measured to classify bilateral asymmetries in four lines of chickens. The lines were the S26 generation of White Leghorns selected for high (HAS) or low (LAS) response to sheep red blood cells and sublines in which selection had been relaxed for three generations (high antibody relaxed [HAR] and low antibody relaxed [LAR]). Antibody titers (AB) were greater for HAS than for HAR with both greater than for LAS and LAR which while different for males did not differ for females. The low antibody lines were heavier and reached sexual maturity at younger age than the high antibody lines. In general, wattle length, width, and area were greater in the low than high antibody lines. In 24 comparisons for bilaterality 18 exhibited fluctuating asymmetry and 6 exhibited directional asymmetry with 5 of the 6 being for wattle length. There was not a clear pattern for changes in degree of asymmetry when selection was relaxed for 3 generations. For females, the relative asymmetry (RA) of wattle area was larger ($p{\leq}0.05$) for HAR than for LAR and not different from the selected lines and relaxed lines. There were no differences among lines for RA of wattle length and width of females and wattle length, width, and area of males.

Reproduction of the Shotted halibut in the southern Korean waters (한국 남해에 서식하는 물가자미, Eopsetta grigorjewi (Herzenstein)의 재생산 연구)

  • Cha, Hyung-Kee;Kang, Su-Kyung;Choi, Jung-Hwa;Oh, Taeg-Yun;Seo, Young-Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.47 no.3
    • /
    • pp.194-202
    • /
    • 2011
  • Maturation and spawning of the Shotted halibut, Eopsetta grigorjewi was investigated based on the samples captured in South Korean waters from January 2008 to December 2009. Gonadosomatic index began to increase in December, and reached maximum between January to March. After spawning it began to decrease from May. Reproductive season was estimated to January-April, with peak in February. Fecundity was proportional to the size of the female, with the clutch size varying from 170,000 eggs in the smallest female (total length, 28.9cm) to 1,300,000 eggs in the largest (total length, 41.5cm). Size at 50% sexual maturity (TL50), determined from mature females, was 28.8cm. Annual reproductive cycles of this species could be divided into six successive stages; immature stage (May-October), nucleolus stage (November-January), yolk vesicle stage (January-February), vitellogenic and ripe stage (January-April) and spent stage (April-May).

Reproduction characteristics of hagfish Eptatretus burgeri in the South Sea of Korea (한국 남해에 출현하는 먹장어 Eptatretus burgeri의 재생산 특성)

  • KIM, Doo-Nam;HWANG, Kang-Seok;CHA, Hyung-Kee;PARK, Jun-Su;KIM, Jung-Nyun;MOON, Seong-Yong;LEE, Jeong-Hoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.54 no.2
    • /
    • pp.188-192
    • /
    • 2018
  • The reproduction characteristics of hagfish Eptatretus burgeri were examined using individuals caught in the South Sea of Korea. The spawning season and size at minimum sexual maturity of this species were characterized based on a gonad-somatic index (GSI) and monthly variation egg size (long axis). From monthly variation of GSI, the spawning season was estimated to be from August to September. Developing eggs larger than 10 mm were found in March, and the largest egg size was found in July. The first spawning length was 34.2 cm TL. Batch fecundity ranged from 13 to 117 eggs for hagfish sized from 34.2 cm TL to 77.0 cm TL, respectively, and increased linearly with total length.

Role Expectation on Spouse of Married Women in Korea (기성여성의 배우자에 대한 역할 기대)

  • Chang, Soon-Bok;Tak, Young-Ran
    • Women's Health Nursing
    • /
    • v.2 no.1
    • /
    • pp.40-52
    • /
    • 1996
  • This study sought to investigate the spousal role expectation of married childbearing women in the social milieu. The purpose of this study was to determine the spouse's role expectation which influences marital quality and marital satisfaction, thereby contributing to married women's psychological well-being and family health. Data collection was done in the prenatal care center of 212 early adult, married, middle class women living in the urban area by interview. Using content analysis, 701 answers were recoded by 12 categories of role expectation as family integration, health maintenance, father role taking, personal maturity, communication and respect, social confidence, division of domestic labor, relationship with extended family, recreation and hobby, social support for wife's self actualization, faith in sexual relationship, and security in economic status. The influence of the altered gender role in modern society, women's expectation is derived from somewhat masculinity and feminity in role expectation. The results are discussed in relation to prototype of gender role and relationships. These finding will assist nurse in the understanding and intervening the marital problem and women's health.

  • PDF

DEVELOPMENT OF THE EPIDIDYMIS IN MEISHAN BOARS

  • Harayama, H.;Nanjo, I.;Kanda, S.;Kato, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.5 no.1
    • /
    • pp.165-171
    • /
    • 1992
  • The developmental process of the epididymis was investigated in Meishan boars from 1 to 364 days of age. Epididymal weight increased rapidly between 45 and 150-180 days of age. The diameter and epithelial area of the epididymal ducts greatly increased up to 105-120 days of age. At 1 day of age, the central and distal cauda already had a pseudostratified epithelium surrounded by smooth muscle. At 60-75 days of age, the central and distal caput, corpus, and proximal cauda revealed a well-developed structure of the epithelium. The proximal caput showed a tall, irregular and vacuolar epithelium at 105-120 days of age. PAS-positive contents in the lumen of the caput, corpus and cauda epididymides were first detected at 60-75, 45-60 and 1-30 days of age, respectively. Moreover, in the central and distal caput, PAS-positive granules appeared at 60-75 days of age, and increased until 105-120 days. These results suggest that the epididymis develops completely by approximately 120 days of age, though its weight increases rapidly up to 150-180 days. Thus, it appears that development of the epididymis occurs at an earlier age in Meishan boars than in European and American breeds.

Development and Effects of Nocturnal Emission and Menstruation Education Program using CAI for Korean Elementary School Children (CAI (컴퓨터 이용학습)를 활용한 후기 학령기 아동의 몽정과 월경 교육 프로그램 개발 및 효과)

  • Lee, Yong Hwa
    • Korean Parent-Child Health Journal
    • /
    • v.16 no.1
    • /
    • pp.27-36
    • /
    • 2013
  • Purpose: The purpose of this study was to develop a nocturnal emission and menstruation education program using CAI for Korean elementary school children. Methods: The research design was methodological study a ISD model 4 fields into sub contents in each field of the nocturnal emission and menstruation by CD titles. And to verify the effect of the education program, performance evaluation of the educational program for structured questionnaire was conducted on 120 late school-age children on June, 2010. Results: The results of this study were as follows; Through this, developed program was proved its effectiveness in enhancing knowledge level on nocturnal emission and menstruation in late school-age children(t=14.03, p<.001, t=11.52, p<.001). Conclusion : Accordingly, this program is expected to be an educational program to be used in various educational institutes, communities, and home as well as self-study that allows children themselves to study repeatedly, choosing the contents they want, whenever they hope as an educational program on nocturnal emission and menstruation in school-age children. In addition, it is suggested that various fields of programs should develop in consideration of early sexual maturity.

  • PDF