• Title/Summary/Keyword: season changes

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Occurrence of Modern Planktonic Foraminiferal Species and their Seasonal Variations around Jeju Island, Korea (제주근해에 출현하는 현생 부유성 유공충 종과 계절변화)

  • Hyun, Sangmin;Kimoto, Katsunori;Cho, Sung-Hwan
    • Ocean and Polar Research
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    • v.35 no.2
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    • pp.181-191
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    • 2013
  • To investigate the occurrence of modern living planktonic foraminiferal species and their seasonal variations around Jeju Island, we conducted planktonic foraminiferal sampling at KIOST's regular sampling sites during 16 months. In total seven genus and 16 modern planktonic foraminiferal species were identified with six dominant species. Dominant species were Gloigerinoides sacculifer, Globigerinoides ruber, Globigerina bulloides, Noegloboquadrina dutertrei, Pulleniatina obliquiloculata, and Globorotalia inflata. Most of the species were characterized as being typical subtropical species and showed seasonal variations and/or intermittent occurrence from season to season. The occurrence of living foraminifera revealed a strong relationship with water temperature, but not with salinity. Species succession seems to occur along with water temperature changes. Some patch distribution and water temperature dependences appear to be significant since there is a high degree of variation in the occurrence patterns of species and standing stock. More detailed quantitative study is necessary to confirm the species diversity and seasonal variations of planktonic foraminifera and related ocean environmental changes.

Effects of Water Level Change on Wetland Vegetation in the Area of Riparian Forest for Dam Construction Period -Focused on the Hantan River Dam- (댐 건설 기간 수위변화가 하반림 일대 습지 식생에 미치는 영향 -한탄강댐을 사례로-)

  • Park, Hyun-Chul;Lee, Jung-Hwan;Lee, Gwan-Gyu
    • Journal of Forest and Environmental Science
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    • v.30 no.1
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    • pp.76-84
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    • 2014
  • This study was performed to monitor the effects of water level change on changes of landscape, vegetation community, and species diversity of riparian forest. Hantan river dam, study area, has been constructed in the area of Chansoo-myeon, Pocheon-si and Yeoncheon-eup, Yeoncheon-gun, Gyeonggi-do, which is a dam for flood control only in flooding season. Landscape changes were notable after the construction of coffer dam, and the changes were caused by water level increase in areas of riparian forests which consisted of mainly withered willow as a dominant species in the flooding season. It changed vegetation communities of riparian forest from Phragmites japonica and Salix koreensis to Phragmites japonica. Species diversity index was lowest in 2010 when the coffer dam was constructed and showed an increasing trend later. Thus, this study is well in agreement with a previous report that plants of the genus Salix wither by muddy water during flooding and also suggests, controlling water level of river and prediction of water level change's effects should be considered when any facilities are planned.

Morphological Changes of the Beach and Foredune by Sand Fences - A Case of Shindu Coastal Dune Area - (사구울타리 설치 후 해빈과 전사구의 지형 변화 - 신두리 해안사구를 사례로 -)

  • SEO, Jong Cheol
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.1
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    • pp.85-93
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    • 2010
  • After the notorious Taean Oil spill in Dec. 2007, a series of sand fences made of fishing net were installed in front of foredune in Shindu dune area. This paper aims to understand the temporal and spatial characteristics of morphological changes of the beach and foredune. About 1m high sand accumulated around sand fences for the last 2 years. While a lot of sand deposited during the winter season (from autumn to spring), small amount of sand eroded and deposited during summer season (from spring to autumn) without big morphological changes. These results mean that sand fences help nature deposit sand near beach and foredune area.

Gametogenic Cycle and the Spawning Season by Quantitative Statistical Analysis and the Biological Minimum Size of Cyclina sinensis in Western Korea

  • Chung, Ee-Yung;Lee, Chang-Hoon;Park, Young-Je;Choi, Moon-Sul;Lee, Ki-Young;Ryu, Dong-Ki
    • The Korean Journal of Malacology
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    • v.27 no.1
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    • pp.43-53
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    • 2011
  • The gametogenic cycle and the spawning season in female and male Cyclina sinensis were investigated by quantitative statistical analysis using an image analyzer system, and the biological minimum size (the size at 50% of sexual maturity) was calculated by combination of quantitative data by size and von Bertalanffy's equation. Compared the gametogenic cycle by quantitative statistical analysis with the previous qualitative results in female and male C. sinensis, monthly changes in female and male gametogenic cycles calculated by quantitative statistical analysis showed similar patterns to the gonadal stages in female and male reproductive cycles by qualitative histological analysis. Comparisons of monthly changes in the portions (%) of each area to eight kinds of areas by quantitative statistical analysis in the gonads in female and male C. sinensis are as follows. Monthly changes in the portions (%) of the ovary areas to total tissue areas in females and also monthly changes in the portions of the testis areas to total tissue areas in males increased in March and reached the maximum in May, and then showed a rapid decrease from June to October. Monthly changes in the portions (%) of oocyte areas to ovarian tissue areas in females and also monthly changes in the portions of the areas of the spermatogenic stages to testis areas in males began to increase in March and reached the maximum in June in females and males, and then rapidly dropped from July to October in females and males when spawnig occurred. From these data, it is apparent that the number of spawning seasons in female and male C. sinensis occurred once per year, from July to October. Monthly changes in the number of the oocytes per mm2 and in the mean diameter of the oocyte in captured image which were calculated for each female slide showed a maximum in May and reached the minimum from December to February. Therefore, C. sinensis in both sexes showed a unimodal gametogenic cycle during the year. The percentage of sexual maturity of female and male clams ranging from 25.1 to 30.0 mm in length was over 50% and 100% for clams over 40.1 mm length. In this study, the biological minimum size (sexually mature shell lengths at 50% of sexual maturity) in females and males were 26.85 and 26.28 mm, respectively.

Study on Compass, Carpenter's square, The Beam of Balance and the Weight of balance[規矩權衡] in "Somun(素問).Maekyojeongmiron(脈要精微論)" ("소문(素問).맥요정미론(脈要精微論)"의 규구충권(規矩衡權)에 대한 연구)

  • Lee, Hye-Yeon;Kang, Jung-Soo
    • Journal of Korean Medical classics
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    • v.23 no.1
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    • pp.101-114
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    • 2010
  • In the perspective of the correspondence of heaven and man[天人相應], people live through Gi of heaven and earth[天地之氣], and the human body which is a small universe[小宇宙] itself receives influence while sympathizing with the Gi and heaven[天氣]. So with unexpected incident of the Eum and Yang, four season[陰陽四時], ups and downs of warmth of cold and chilliness of warm[寒熱溫涼] differs, and the position of Gi of human[人氣] changes, regimen and application of acupuncture, and images[象] of the pulse changes. In "Maekyojeongmiron(脈要精微論)", ups and downs of Eum and Yang changes by four season[四時], and correspondence of ups and downs of pulse law is explained with compass, carpenter's square, the beam of balance and the weight of balance[規矩權衡]. Compass[規] is a measure of instrument that can draw a circle, like regulating the measure and differing the center of the circle and diameter and drawing a circle, compass is a image of Gi of Yang[陽氣] that was staying deep inside the body in winter stretching out by big fault[太過不及] of year and energy[元氣] of human in spring. Carpenter's square[矩] is a instrument that draws direction, which is a image of Gi of Yang flourishing in summer and when it gets highly flourished, again the Gi of Eum[陰氣] comes alive and falls. The beam of balance[衡] is a scale, like a scale that tilts at once when one side is slightly heavy, the beam of balance is a image Gi of yang that is fully flourished in summer and about to descent again, which is just about to fall but not going down yet. The weight of balance [權] is a image of gi of yang which as descent to the bottom and staying in the deepest place. compass, carpenter's square, the beam of balance and the weight of balance is not a direct pulse image[脈象], but standard image of pulse of pulse corresponding to the Gi of human[人氣] that changes by four season, and the explanation includes the pulse image of four season like the taut, full, floating, deeply gather[弦鉤浮營] of "Okgijinjangron(玉機眞藏論)" or taut, full, skip, float, deep [弦鉤代毛石] of "Pyeong-ingisangron(平人氣象論)". So with compass, carpenter's square, the beam of balance and the weight of balance, can judge is human correspond in Eum and Yang, four seasons, this is importantly used in examination of pulse[診脈] with existence and nonexistence, and prognosis of illness.

Relationship between Tobacco Yield and Leaf Dry Weight at Different Growing Season (담배 수량과 생율시기별 건엽중과의 관계)

  • 김정환
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.38 no.5
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    • pp.477-482
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    • 1993
  • The study was conducted to investigate the relationships between tobacco leaf yield and changes of leaf dry matters by tobacco growing season. In flue-cured tobacco, leaf yield was high significantly correlated with leaf dry matters from 50 days to 70 days after transplanting. In Burley tobacco, leaf yield was affected differently by the leaf dry matters according to the different growing season. High significant correlation was noted between yield and leaf dry matters at 70 days after transplanting, and having low significant correlation with leaf dry matters at 55, 60, 65 days after transplanting.

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Analysis of patients transported in ambulances by season and daily temperatures (계절 및 기온에 따른 119 구급대 환자 이송 건수 및 병력의 차이)

  • Lee, Kyoung-Youl;Lee, Jeong-Hyeok
    • The Korean Journal of Emergency Medical Services
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    • v.23 no.3
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    • pp.123-134
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    • 2019
  • Purpose: This study aimed to analyze the number of patients with and without medical history transported to the emergency department due to changes in daily temperature and season. Methods: Data on emergency activity sheet and daily weather were collected from March 2016 to February 2017 in the city of Gyeonggi-do. In total, 13,531 patients were transferred to the emergency department in 119 ambulance. Data were analyzed using the Statistical Package for the Social Sciences (version 21). Results: The daily average number of patients transferred was the highest in August and September, i.e., the summer season. The higher the daily highest and lowest temperatures, higher the daily average number of patients transferred. In contrast, patients with medical history of hypertension, diabetes, heart disease, cerebrovascular disease, and pulmonary disease had a higher incidence of transfers in the winter season and on days with lower temperature. Conclusion: The results indicate that as people become more active during the summer when temperatures are high, the chances of daily emergencies increases, whereas patients with medical history are more likely to experience emergencies when the temperatures were lower. Hence, 119 ambulances will have to be prepared in advance to deal with this trend.

Phytoplankton Community and Surrounding Water Conditions in the Youngsan River Estuary: Weekly Variation in the Saltwater Zone (영산강 하구의 식물플랑크톤 군집 및 수 환경: 해수역의 주별 변동)

  • Sin, Yongsik;Yu, Haengsun
    • Ocean and Polar Research
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    • v.40 no.4
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    • pp.191-202
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    • 2018
  • In this study we conducted a weekly monitoring exercise at a fixed station in the saltwater zone during the dry season (Jan-Mar, 2013) and wet season (Jun-Aug, 2013) to understand the fluctuations in phytoplankton communities and environmental factors in the Youngsan River estuary altered by a dike constructed in the coastal area. Phytoplankton communities displayed seasonality; diatoms were dominant during the dry season whereas dinoflagellates were dominant during the wet season. T-test analysis showed that water temperature was significantly different between the seasons whereas freshwater discharge from the dike was not significantly different. This suggests that seasonal variations of phytoplankton are more likely affected by water temperature than freshwater discharge. However, a short-term fluctuation was also observed in response to freshwater discharge; freshwater species appeared during or after the discharge in the dry and wet seasons and blooms of harmful species developed after the discharge. Phytoplankton communities may be affected by changes in physical factors such as turbidity and salinity and nutrient supply resulting from freshwater discharge. Especially, the nutrient supply may directly contribute to the harmful algal blooms (HABs) composed of dinoflagellates which can adapt to low salinity after freshwater discharge.

Water Quality and Sediment Contamination in the Iksan Stream (익산천 수질시료와 저질토의 오염도 평가)

  • Seo, Young-Seok;Cho, Min;Oh, Byung-Taek
    • Journal of Soil and Groundwater Environment
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    • v.18 no.1
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    • pp.123-128
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    • 2013
  • Water quality and contamination of sediment is a growing concern in the Iksan stream of Korea. Heavy metal contamination and changes in the physicochemical properties of the stream were evaluated. Water and sediment samples were collected from six sites during the dry and rainy seasons; pH, DO, EC, ORP, turbidity, $PO_4$-P, $NO_3$-N and selected heavy metals (Cu, Pb, Ni, As, Zn, Cd, Hg) were measured. Results showed almost no change in pH between seasons. DO was highest at site 2 (~2.63 mg/L) in the dry season; EC (1,540 ms/m) was greatest at site 1 in both seasons. The ORP gradually increased from the dry to rainy season at most of the sites and was highest at site 5. Turbidity was highest at site 1 and gradually decreased from the dry to rainy season at all sites except site 3. $PO_4$-P ranged from a high of 1,193mg/L at site 1 to in the dry season to a low of ~1.2 mg/L at site 4. In contrast, $NO_3$-N was highest at site 3 in the rainy season (12,531 mg/L). Among the heavy metals measured, Cu and Zn concentrations were highest at all sediment sites. Cu and Zn are added to livestock feed to improve reproductive rates and can be carried to the stream with manure. Transport of sediment and heavy metals during the rainy season is the major source of stream contamination and it is important to continue monitoring and take necessary action in these areas.

Supplementation of Dairy Cows with Nitrogen Molasses Mineral Blocks and Molasses Urea Mix during the Dry Season

  • Plaizier, J.C.B.;Nkya, R.;Shem, M.N.;Urio, N.A.;McBride, B.W.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.5
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    • pp.735-741
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    • 1999
  • The effects of supplementation with nitrogen molasses mineral blocks and molasses urea mix during and immediately prior to the dry season on the production of dairy cows were studied on-station and on-farm near Morogoro, Tanzania. Supplementation of blocks to on-station cows also receiving ad libitum grass hay and 6 kg/d of maize bran increased milk production from 6.7 L/d to 11.2 L/d (p<0.05), increased dry matter intake from 10.1 kg/d to 12.0 kg/d (p<0.05), but did not significantly affect milk composition, intake of hay, and live weight changes. This increase in milk yield is mainly explained by increased intakes of energy and nitrogen. Supplementation with the molasses urea mix increased daily milk yield from 6.7 L/d to 8.8 L/d (p<0.05), but did not significantly affect the other measured production parameters. The on-farm supplementation of the blocks increased daily milk yield by 1.5 L/d in the dry season (p<0.05). This supplementation did not increase milk yields prior to the dry season, since quality forage was still available. Taking the production costs into account, supplementation with the blocks and supplementation with mix were cost effective if milk yields increased by 0.7 L/d. Hence supplementation with blocks and supplementation with mix were effective on-station, and supplementation with blocks was cost effective on-farm during the dry season.