• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.22 no.5
• /
• pp.342-350
• /
• 1989

Maturity and spawning of Crangon affinis were studied based on the histological observation. The samples were monthly collected in Nakdong estuary from June, 1988 to May, 1989. The gonad lies on the dorsal side of the thorax. The cavity in which it lies is located below heart and above hepatopancreas. Anterior part of ovary is fused roundly, and the posterior part shows a pair of tubule-like structure. Testis is bilaterally symmetrical; the anterior part shows convoluted tubule, and the posterior part consists of a pair of tubule. Seminal vesicle is connected and opened to the base of the fifth pereiopod. Gametogenesis of ovum and spermatozoon is being repeated in short period without seasonality, and it is formed simultaneously in the whole parts of germinal epithelium. Diameter of a ripe oocyte is ca. $430{\mu}m$. Spermatozoa is oval with distinct nucleoplasm. Reproductive cycle is performed in ca. 40 days. Crangon affinis spawns all year round except November. Incubation period of brooded eggs took $12\~14$ days before hatching in the aquarium at $21^{\circ}C\~24^{\circ}C\;and\;33\%_{\circ}$.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.2 no.1
• /
• pp.9-15
• /
• 2000

The objective of this study is to evaluate the use of RADARSAT and Landsat TM data for the monitoring of rice growth. The relationships between backscatter coefficients($\sigma$$^{0}$ ) of RADARSAT data and digital numbers (DN) of Landsat TM and rice growth parameters were investigated. Radar backscatter coefficients were calculated by calibration process and then compared with rice growth parameters; plant height, leaf area index (LAI), and fresh and dry biomass. When radar backscatter coefficient ($\sigma$$^{0}$ ) of rice was expressed as a function of time, it is shown that the increasing trend ranged from -22--20dB to -9--8dB as growth advances. The temporal variation of backscatter coefficient was significant to interpret rice growth. According to the relationship between leaf area index and backscatter coefficient, backscatter coefficient underestimated leaf area index at the beginning of life history and overestimated, at the reproductive stage. The same increasing trend between biomass and backscatter coefficient was shown. From these results, RADARSAT data appear positive to the monitoring of rice growth. Each band of time-series Landsat TM data had a significant trend as a rice crop grows during its life cycle. Spectral indices, NDVI[(TM4-TM3)/(TM4+TM3)] and RVI(TM4/TM2), derived from Landsat TM equivalent bands had the same trend as leaf area index.

• Korean Journal of Ecology and Environment
• /
• v.50 no.1
• /
• pp.116-125
• /
• 2017

Alpine plants with a scarcity of pollinators in harsh environments have been believed to undergo selfing for reproductive assurance; however, contradictory evidence is also available. Snowmelt regimes in alpine areas function to change life history characteristics of alpine plants such as flowering time and duration; yet the effects of snowmelt regimes have never been tested in alpine plants in Korea. This study was conducted to investigate the dichogamy, mating systems, and flowering characteristics of Megaleranthis saniculifolia populations [early and late snowmelt plots (ESP and LSP, respectively)] in a subalpine area of Sobaeksan Mountain in Korea. M. saniculifolia exhibited incomplete protogyny in that despite early maturation of pistils, maturation times of pistils and stamens within flowers were partly overlapped. Control and hand-outcrossing treatments produced significantly higher number of follicles and seeds per flower than autonomous and hand-selfing treatments. Based on the aggregate fruit set, the auto-fertility index (AI) and self-compatibility index (SI) were 0.33 and 0.50, respectively. Snowmelt occurred 10 days earlier in ESP than in LSP, thereby ESP and LSP showed distinct differences with regard to flower longevity and season, but showing no difference in peak flowering dates. We concluded that M. saniculifolia is an incomplete protogynous and largely outcrossing plant requiring pollinator service. Temporal variation in snowmelt time and subsequent changes in flowering characteristics under climate change may further threaten the population persistence of M. saniculifolia which has already been designated as endangered species in Korea.

• Perspectives in Nursing Science
• /
• v.13 no.2
• /
• pp.88-95
• /
• 2016

Purpose: Gestational weight gain and prepregnancy body weight are important factors of childbirth outcomes, which further cause obesity, metabolic diseases, or psychological problems later in women's lives. Changes in diet, westernized lifestyle, traditional postpartum care, and childbirth at older age are thought to be threats to proper weight management in Korean women of reproductive age. Public health and antenatal care need to focus on the proper body weight management of women by carefully planning pregnancy to postpartum periods. Purpose: This study explored the body weight changes from pregnancy to postpartum and the related characteristics in women within 12 months after childbirth. Methods: A cross-sectional, retrospective study was conducted with 102 Korean women within 12 months after childbirth. Data were collected using an online survey system, and a structured questionnaire available for electronic self-administration was modified to include demographics, obstetrical history, and body weight at 6 time points. The International Physical Activity Questionnaire and Eating Habit Measurement instruments were also used in data collection. A professional survey agency recruited the participants, and data were automatically saved and then analyzed. Results: The average age of the participants was 33.8 years, 48% were housewives and were well-educated. Seventy-two percent of the participants were primiparas and 82% had breastfed their babies. The body mass index (BMI) ranged from 17.3 to 27.8, indicating that 21.5% of the participants were overweight or obese. The mean gestational weight gain was 11.8 kg, and weight loss was apparent during the first 3 months postpartum. The mean decline in weight was 3.4 kg at one year after childbirth. Women wanted to lose 5.6 kg (range: 3~20 kg), however 44% of them reported that they had not engaged in any weight control efforts. Further, 72% of them reported having engaged in a low level of physical activity. Body weight was not associated with women's characteristics, physical activity score, and diet. Conclusion: Women's awareness of gestational weight gain, lifestyle modification, and the risk of prolonged weight retention should be promoted through the antenatal and women's healthcare systems. As pregnancy and childbirth are critical events that affect women's health, integrative education to ensure healthy transition to life after delivery is required.

• Korean journal of applied entomology
• /
• v.61 no.4
• /
• pp.549-554
• /
• 2022

Life table-related studies in insect ecology have been an interesting topic for insect researchers. Two calculation methods are commonly applied to estimate the intrinsic rate of natural increase (r_m) in the life table statistics. The first method is to estimate an approximate r_m by dividing the natural logarithm of the net reproductive rate (R₀) by mean generation time (T) (namely mean generation time-based method). Another approach is to apply the Lotka-Euler equation derived from the population growth equation of Lotka-Volterra to estimate accurate r_m using the maximum likelihood method (Lotka-Euler equation-based method). In the latter case, there is a difference in the estimated r_m value when the initial age class of the target cohort was set to "0" or "1", which confused the application. In this short review, a brief history of the calculation process of the life table was reviewed. It was again confirmed in the Lotka-Euler equation-based method that the form of $\sum\limits_{x=1}^{w}e^{-rx}l_xm_x=1$ should be applied to estimate r_m when the first age class was set to zero, while the form of $\sum\limits_{x=0}^{w}e^{-r(x+1)}l_xm_x=1$ when set to one.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.36 no.4
• /
• pp.78-95
• /
• 2023

Objectives: This study aims to analyze the results of the 2022 Gyeonggi-do Oriental Medicine Fertility Treatment Support Project, review the outcomes and satisfaction of Oriental Medicine fertility support initiatives, and propose progressive fertility treatment support strategies by comparing them with the results of the past three years. Methods: Total of 242 women and 205 spouses participated in the Korean Medicine fertility treatment support project, which encompassed herbal medicine, acupuncture, and counseling treatments over a 3-month period, followed by a 3-month post-treatment follow-up. Data pertaining to patients' general, demographic, and fertility-related characteristics were collected before treatment initiation. During treatment, information regarding the treatments administered by Korean medical doctors was recorded, along with post-treatment outcomes and satisfaction levels. Safety assessments included pre- and post-treatment blood tests and monitoring for adverse events. Results: Among the 242 female subjects, 209 successfully completed the treatment program. Of these, 35 (16.7%) achieved pregnancy, with 30 (15%) attaining pregnancy through herbal monotherapy. Out of the 35 pregnancies, 17 were maintained, while 10 resulted in miscarriage. Notably, 83.8% of patients expressed satisfaction with the treatment outcomes. An analysis spanning three years revealed a continuous increase in the average age of patients, surpassing 38 years in 2022, a critical point in fertility decline age. Additionally, there was a notable rise in the prevalence of patients with a history of gynecological issues, advanced spouse age, and semen abnormalities, which is assumed to have contributed to the decrease in the pregnancy success rate. Conclusions: This study compares the clinical results of the 2022 Gyeonggi-do Korean Medicine Fertility Treatment Support Project with those of the past three years. Based on these findings, recommendations are made to enhance the project, including stricter age criteria for patient selection, enhanced specialized treatment tools for medical doctors, and combining Korean Medicine treatment and medical assisted reproductive technologies, all aimed at increasing pregnancy success rates. These results provide a foundation for the development of fertility support projects and related policies.

• Korean Journal of Psychosomatic Medicine
• /
• v.16 no.2
• /
• pp.112-119
• /
• 2008

Objectives : Premenstrual syndrome(PMS) is known to occur in more than 80% of reproductive women. Since PMS is closely related to changes in sex hormones, biological factors are suspected to be associated with the syndrome, but there have been no consistent reports regarding biological causes. In that sense, it is postulated that the occurrence of PMS is much dependent on the biological aspects, but that the severity or characteristics of the syndrome is more dependent on the psychological factors. Studies focusing on psychological factors are based on the theory that symptoms of PMS and previous psychologically traumatic events are closely related. If the theory is valid, it can be further postulated that symptom severity of PMS is associated with dissociative symptoms, since traumatic events are known to be related to dissociative symptoms. In this study, we tried to find out the association of PMS symptom severity with previous abuse history and dissociative symptoms. Methods : Subjects for the study were 377 nurses working in Seoul, Kyung-gi, and Kyung-book. 183 subjects who submitted valid data entered the study. The presence and the symptom severity of PMS were rated using Daily Records of Severity of Problems(DRSP) and Shortened Premenstrual Assessment Form(SPAF). Dissociative symptoms were evaluated with Dissociation Experience Scale Korean version(DES-K). Previous physical/verbal abuse, sexual abuse, and parental spouse abuse experience were rated with correspondent abuse scales. Results : Subjects were divided into 3 groups as No PMS group, mild to moderate PMS group, and severe PMS group according to SPAF total score. There was a statistically significant difference in DES-K total score among 3 groups($x^2=14.966$, df=2, p=0.001). Physical/verbal abuse scale($x^2=14.397$, df=2, p=0.001), sexual abuse scale($x^2=8.376$, df=2, p=0.015), and parental spouse abuse scale($x^2=9.322$, df=2, p=0.009) also revealed a significant difference among 3 groups. Symptom severity of PMS using SPAF total score showed a positive correlation both with degree of dissociative experience and previous abuse experience. There was a statistically significant difference in both dissociative experience and previous abuse experience among 3 groups. Conclusion : These results show that there can be a possible association among PMS symptoms, dissociative symptoms, and previous psychologically traumatic experience.

• Korean Journal of Psychosomatic Medicine
• /
• v.21 no.1
• /
• pp.44-54
• /
• 2013

Objectives : To investigate the frequency and clinical characteristics of premenstrual syndrome(PMS)/premenstrual dysphoric disorder(PMDD) in high school students, and determine the correlates of PMS/PMDD in association with comorbid depression and anxiety. Methods : A total of 1688 students were recruited from 5 high schools in Seoul, Korea. Subjects completed the questionnaire composed of scales to measure premenstrual symptoms, depression, and anxiety, as well as sociodemographic and reproductive variables. Subjects were categorized into 3 groups by using the Premenstrual Symptom Screening Tool(PSST) to determine the frequency and clinical characteristics of PMS/PMDD. Multivariate logistic regression was used to identify the correlates of PMS/PMDD. Results : The frequency of moderate to severe PMS and PMDD was 20.1% and 6.4%, respectively. Irritability(78.8%), fatigue(76.4%), and emotional sensitivity(69.8%) were common premenstrual symptoms, and functional impairment in academic performance(67.1%) was dominant. Dysmenorrhea[odd ratio(OR)=3.68, 95% confidence interval(CI) 2.45-5.55], family history of PMS(OR=1.91, 95% CI 1.35-2.71), and use of oral contraceptive (OR=1.85, 95% CI 1.16-2.94) were associated with the increased risk of PMS/PMDD after adjustment for depression and anxiety. Negative attitude to menses(OR=15.60, 95% CI 3.61-67.42) was associated with the increased risk of PMS/PMDD, particularly in subjects without depression and anxiety. Conclusions : PMS was common, as the frequency of PMS more than moderate severity including PMDD exceeded 25%, and disrupted daily functioning in adolescents. PMS is associated with various sociodemographic and menstrual characteristics, and these associations are affected by comorbid depression and anxiety.

• Journal of Preventive Medicine and Public Health
• /
• v.9 no.1
• /
• pp.129-138
• /
• 1976

The causes and problems underlying deaths in perinatal period are often similar and might be expected to yield to same type of preventive measures. This is one of the reasons for attempting to develop a reporting of perinatal mortality and its related matters. This study aims at figuring out the biologic risk factors onto the perinatal death. Considering stillbirth and early neonatal mortality separately, considerable associations between stillbirth and reproductive history of women, are observed, ana it is found that prematurity is the the far most important factor in the early neonatal mortality.