1,093 research outputs found

    Impacts of Reforestation on Stabilization of Riverine Water Levels in South Korea

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    We investigate how reforestation contributed to stabilization of riverine water levels in South Korea. For the purpose, we estimate an equation capturing dynamic relationships among rainfall, upstream-area tree stock, and downstream water levels in three river systems of Hongcheon, Mangyeong, and Hyeongsan, using daily observations of precipitation and water levels for the period from 1985 to 2005. Simulation based on estimation results shows that increase in the tree stock in a river basin leads to a significantly suppressed peaking in riverine water levels in response to an abrupt and concentrated rain in the upstream area. For instance, an hour-long concentration of 100mm rain results in 0.7m rise in water level if the volume of growing stock is 1 million m3 , whereas the rise in water level stays below 0.27m with 5 million m3 in the growing-stock volume

    Clinical characteristics and treatment modalities of vulvovaginal atrophy in genitourinary syndrome of menopause

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    Background: Genitourinary syndrome of menopause (GSM) causes symptoms such as vaginal dryness, dysuria, repetitive urinary tract infection and urinary urgency may affect daily activities, sexual relationships, and overall quality of life. The aim of the study was to provide the clinical characteristics of VVA patients in South Korea and the effectiveness as well as complications of the currently used low dose estrogen vaginal suppository.Methods: 52 women who has visited the outpatient gynecology clinic of the National Health Insurance Service Ilsan Hospital from January 2018 to December 2019 were recruited as study subjects. For the analysis of the clinical characteristics, subjective symptoms described by the patient’s own words such as vaginal dryness, pain, dysuria, dyspareunia, or no symptoms at all were included. Objective signs such as thinning of vaginal rugae, mucosal dryness, and mucosal fragility and the presence of petechiae were recorded.Results: Vaginal dryness was the most common complaint (92.3%). Thinning of the vaginal rugae was the most commonly noted objective sign (73.1%). Of the 52 subjects, 31 (59.6%) refrained from using the low dose estrogen vaginal suppository. The most common reason for not being able to use the suppository was the inability to insert the suppository (32.3%).Conclusions: Although patient-reported symptoms and clinical objectivity through physical examination are two components in diagnosing VVA, further study is warranted for a more objective and discriminatory diagnosis criteria for VVA. As the only available treatment modality was low dose vaginal estrogen suppository, comparison with other treatment modalities were not available

    Survival and reproductive outcome of childbearing age ovarian cancer patients taking fertility-sparing surgery

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    Background: Surgical management of ovarian cancer includes total hysterectomy and bilateral salpingo-oophorectomy which results in the loss of fertility. Fertility-sparing surgery in the reproductive aged women with early-stage ovarian cancer with favourable histology has been proposed by American College of Obstetrics and Gynecology and European Society for Medical Oncology. We sought to access the survival and fertility outcome of Korean women in their reproductive age who undertook fertility-sparing surgery.Methods: Based on the Korean National Insurance Claims Data and the National Health Information Database, 328 women with newly developed ovarian cancer in 2010 were followed up for the survival and pregnancy outcome until 2020. Patients who were diagnosed with cancer or underwent hysterectomy before 2010 were excluded. The control group consisted of 552 women matched by age, economic status and place of living.Results: Out of 120, 10 deaths occurred in the fertility-sparing surgery group showing a survival rate of 91.7%. Women undertaking fertility-sparing surgery had a lower chance of delivering a new-born compared to the control group (OR 0.46; 95% CI 0.26-0.81). Diagnosis of infertility, ectopic pregnancy, and abortion appeared higher in the fertility-sparing surgery group, but it did not reach a statistical significance.Conclusions: The pregnancy rate of the ovarian cancer patients with fertility-sparing surgery was lower than that of women without ovarian cancer. Undergoing fertility-sparing surgery per se should not deter women of trying to get pregnant as the pregnancy outcome indicators do not show statistically significant differences compared to the control group

    Refining Historical earthquake Data Through Modeling and Scale Model Tests

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    This study was performed for the reevaluation of historical earthquake records which occurred in Korea through tests and numerical analyses. For the scale model tests, static and cyclic lateral load tests on wooden frames that constitute a Korean ancient commoner’s house were conducted. Full-scale models of two types of frames were used for testing. Two 1:4 scale models were tested for rock and soil foundation conditions. Scaled real earthquake time histories were inputted for the tests. The peak ground acceleration (PGA) at the collapse of the house at the soil site was 0.25g, whereas PGA for moderate damage at the rock site was 0.6g. The intensity of major historical earthquake records related with house collapses was reevaluated based on the results of these scale mode1 tests. The magnitudes of historical earthquake records related with house collapses were estimated considering the magnitude, epicentral distance, soil condition and aging of the house. Eighteen artificial time histories for magnitudes 6-8, epicentral distances 5 km - 350 km and hard and soft soil condition were generated. The aging effects of the house was modeled as the lateral loading capacity of wooden frames represented by hysteretic stiffness decreased linearly with time

    A comparative study on experimental and simulation responses of CR-39 to neutron spectra from a 252Cf source

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    A simulation of the interaction of neutrons emitted from a 252Cf source with a CR-39 detector is presented in this paper. Elastic and inelastic neutron interactions occur with the constituent materials of the CR-39 detector. Inelastic scatterings only consider (n, a) and (n, p) reactions. Fast neutrons tracks are, mainly, produced by recoil particle tracks in the plastic nuclear track detector as a result of the elastic scattering reaction of neutrons with the constituent materials of the solid-state nuclear track detectors, especially hydrogen nuclei. The energy of the neutron, incident position, direction, and type of interaction were sampled by the Monte Carlo method. The energy threshold, critical angle and scattering angle to the detector surface normal were the most important factors considered in our calculations. The energy deposited per neutron mass unit was calculated. The angular response was determined by both Monte Carlo simulation and experimental results. The number of visible proton tracks and energy deposited per neutron per visible track were calculated and simulated. The threshold energy of the recoil proton as a function of the thickness and incident proton angles was measured by the etchable range of protons at scattering angles, along with the shape and diameter of the track. Experimental and simulations result were in good agreement

    A case of anemia caused by combined vitamin B12 and iron deficiency manifesting as short stature and delayed puberty

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    Anemia caused by vitamin B12 deficiency resulting from inadequate dietary intake is rare in children in the modern era because of improvements in nutritional status. However, such anemia can be caused by decreased ingestion or impaired absorption and/or utilization of vitamin B12. We report the case of an 18-year-old man with short stature, prepubertal sexual maturation, exertional dyspnea, and severe anemia with a hemoglobin level of 3.3 g/dL. He had a history of small bowel resection from 50 cm below the Treitz ligament to 5 cm above the ileocecal valve necessitated by midgut volvulus in the neonatal period. Laboratory tests showed deficiencies of both vitamin B12 and iron. A bone marrow examination revealed dyserythropoiesis and low levels of hemosiderin particles, and a cytogenetic study disclosed a normal karyotype. After treatment with parenteral vitamin B12 and elemental iron, both anemia and growth showed gradual improvement. This is a rare case that presented with short stature and delayed puberty caused by nutritional deficiency anemia in Korea

    Impact of Reforestation on Stabilization of Water Level of River in Korea

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    The main objective of this study is to investigate whether and to what extent reforestation contributes on stabilization of water level in river, one of the expected benefits from forest, using both time series and panel data obtained from three rivers in Korea. The time series analysis using daily data collected from each river for the period from 1985 to 2005 show that the impacts of lagged water level and rainfall decrease as the volume of growing stock in adjacent forest increases. However, it is not certain whether that change is contribution of reforestation or contribution of unknown variables with trend. The estimations using panel data of six water level observatories and five rainfall observatories in the three rivers for the same period confirms that the changes in impacts of lagged water level and rainfall cannot be explained by a trend but my reforestation. According to simulations based on the estimation results, when it rains one hundred millimeter per day at time zero, the water level rises by 16.7% on that day, if the volume of growing stock is 1 million m3. In contrast, the water level rises by 10.7%, if the volume of growing stock is 5 million m3. Then, the effects of rainfall gradually vanish

    Impacts of Reforestation on Stabilization of Riverine Water Levels in South Korea

    Get PDF
    We investigate how reforestation contributed to stabilization of riverine water levels in South Korea. For the purpose, we estimate an equation capturing dynamic relationships among rainfall, upstream-area tree stock, and downstream water levels in three river systems of Hongcheon, Mangyeong, and Hyeongsan, using daily observations of precipitation and water levels for the period from 1985 to 2005. Simulation based on estimation results shows that increase in the tree stock in a river basin leads to a significantly suppressed peaking in riverine water levels in response to an abrupt and concentrated rain in the upstream area. For instance, an hour-long concentration of 100mm rain results in 0.7m rise in water level if the volume of growing stock is 1 million m3, whereas the rise in water level stays below 0.27m with 5 million m3in the growingstock volume.2

    Relative Yields and Nutritive Value of Whole Crop Rice Harvested on Four Successive Dates for Forage in Korea

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    About four million tons of forages are fed to ruminants in Korea, but half of them rely on rice straw as roughage and 0.6 million tons of forage was imported. The lack of forage results in increased imports of concentrate feeds and increased production cost. Now, Korea has about 1.1 million ha of rice fields, but as a consequence of world trade negotiation, Korea will open the rice market from next year. It is expected that due to aging farmers and lower rice price, about 0.2 million ha of paddy field will not be cultivated for grain rice. Therefore, we suggest that whole-crop rice cultivation for feeding beef and dairy cattle. The purpose of this study was to investigate relative yield and nutritive value of whole-crop rice grown in paddy fields in Korea
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