• 제목/요약/키워드: Disturbance model

검색결과 1,121건 처리시간 0.03초

제천시 농업용저수지의 어류상 및 생태건강성평가 (Freshwater Fish Fauna and Ecological Health Assessment of the Agricultural Reservoirs in Jecheon City, Korea)

  • 한정호;김재환;이상보;백운기
    • 환경영향평가
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    • 제27권3호
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    • pp.307-321
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    • 2018
  • 2017년 5월부터 9월까지 제천시에 위치한 2개의 저수지인 의림지(Ur)와 솔방죽(Sr)을 대상으로 어류상 조사 및 호수생태건강성평가를 실시하였다. 조사기간 동안 채집된 어류는 7과 16속 21종이 출현하였다. 그 중 잉어과 어류가 11종(52.4%), 318개체(46.2%)가 출현하여 우점하는 것으로 나타났고, 검정우럭과(2종, 264개체, 38.4%)가 아우점하는 것으로 나타났다. 전체 출현종 중 참몰개(RA 22.7%, 156개체)가 우점종으로 나타났으며, 아우점종은 파랑볼우럭(19.5%, 134개체), 큰입배스(18.9%, 130개체)로 외래종이 차지하는 것으로 나타났다. 화학적산소요구량(COD), 총인(TP)과 엽록소-a(CHL)를 이용한 부영양화지수($TSI_{KO}$) 분석결과, 두 저수지는 중영양상태를 보이는 것으로 분석되었다. 두 저수지의 수환경영향평가를 위해 LEHA(Lentic Ecosystem Health Assessment) 다변수 모델을 적용하였고, 생태 건강도 모델 값을 산정하였다. 생태건강성평가 결과, 내성종이 각각 56.8%(Ur), 98.3%(Sr)로 나타났으며, 잡식종이 43.9%(Ur), 65.6%(Sr)로 나타나 섭식구조의 단순화로 인하여 내성종과 잡식종의 우점현상을 보였으며, 특히 큰입배스의 상대풍부도가 16.3%(Ur), 31.1%(Sr)로 나타나 생태계가 교란되어 생태건강성이 크게 악화된 것으로 나타났다. 상기 LEHA 다변수 모델을 이용한 의림지(Ur)와 솔방죽(Sr)의 생태건강성 지수 값은 각각 22(의림지), 12(솔방죽)으로서 환경부(2014)의 등급에 의거하였을 때 "악화상태(의림지)", "최악상태(솔방죽)"인 것으로 평가되었다.

하천식생 이입현상의 원인 별 유형화 및 연구 방향 (Cause-based Categorization of the Riparian Vegetative Recruitment and Corresponding Research Direction)

  • 우효섭;박문형
    • Ecology and Resilient Infrastructure
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    • 제3권3호
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    • pp.207-211
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    • 2016
  • 본 연구는 충적하천의 식생이입 현상, 즉 경관생태적으로 하천이 화이트리버에서 그린리버로 변하는 현상을 원인 별로 구분하고, 구분된 각각의 유형을 설명하고, 앞으로의 연구방향을 제시하는 것이다. 문헌연구와 과거 필자들이 제한된 범위에서 시행한 관련 국내 연구성과에 의하면 사주 상 하천식생 이입과 퇴행의 필요/충분 조건은 기계적 교란 (하상소류력), 토양습윤(지하수위, 지형, 하상재료 구성, 강수 등), 침수기간, 극단적 기후, 그리고 영양염류의 유입 등이다. 본 연구에서 사주 상 하천식생 이입과 퇴행의 원인 별 유형으로서 부분적으로 입증된 가설인 봄철 강우양상 변화로 인한 비조절하천에서 홍수 저감과 하천에 영양물질 유입증가 유형을 추가하였다. 하천식생 이입과 퇴행 현상을 과학적으로 더 규명하고 실제 이용가능한 하천식생모형의 개발을 위해서는 화이트리버가 그린리버로 바뀌는 현상의 전국적인 현황조사, 가설의 검증과 세분화를 통한 원인 별 유형 정립, 동적 하천식생 모델링 기법 개발, 변화에 따른 적응관리 등에 대해 연구가 필요하다.

가토 하악골 골신장 후 맥동전자기장이 조기 골경화에 미치는 효과에 대한 연구 (EFFECT OF PULSED ELECTROMAGNETIC FIELD STIMULATION ON THE EARLY BONE CONSOLIDATION AFTER DISTRACTION OSTEOGENESIS IN RABBIT MANDIBLE MODEL)

  • 황경균;조태형;송윤미;김도균;한성희;김인숙;황순정
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제29권2호
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    • pp.123-131
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    • 2007
  • Introduction: Distraction osteogenesis is widely used as for bone lengthening in patients with maxillofacial deformity and alveolar bone atrophy. One of the major problems in distraction osteogenesis is long consolidation period for 2-3 months, in which the devices have to be fixed on the bone to prevent relapse. It results in scar formation on the face, disturbance of mastication and speech. This study was performed to evaluate the stimulating effect of pulsed electromagnetic field on the early bone consolidation in distraction osteogenesis. Materials and methods: Total 10 rabbit were used (5 for control group, 5 for experimental group). A vertical osteotomy in the mandibular body was performed and the distraction device was fixed. After 5 days distraction was done 1mm per a day for 7 days. A pulsed electromagnetic field (38 Gauss, 60 Hz) was applied for 8 hours per day and it continued for 5 days immediately after distraction in the experimental group. Both groups were sacrificed after 2 weeks. Histological specimens with H&E and Masson Trichrome staining were made and histomorphometrically analysed with image analyser. Results: The device for distraction osteogenesis was displaced in one animal for each group, therefore, only four animals in both groups were evaluated. In both groups, a new bone formation was observed in the distracted area after 2 weeks. The bone formation was enhanced in the experimental groups ($31.76{\pm}8.68%$) compared with control group ($9.94{\pm}3.23%$), its difference was statistically significant (p<0.001). Conclusion: This study suggests that electrical stimulation with electromagnectic field may be effective in the early bone formation after distraction osteogenesis. Further studies with large number of animals are needed before clinical application.

노인들이 지각하고 있는 건강수준에 관한 연구 (A Study on the Health as Perceived by the Aged)

  • 양경희;장혜숙;김영희
    • 지역사회간호학회지
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    • 제7권2호
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    • pp.229-243
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    • 1996
  • The purpose of this study was to develop a nursing model for the aged. This study was conducted to measure the physical, psychological and mental health status of the aged and to identify relationships between these health levels and various variables. The data were collected from 172 aged(over 60 years old) by interviews. The tools used for this study was a structured questionnaire which was developed and revised by the researchers. The tool consisted of 22 items on physical health assessment, 7 items on psychological health assessment, 9 items on mental health assessment and 10 items on an ADL evaluation. The major results of the study were as follows ; 1. In physical health, the aged complained of visual disturbance(60.5%), incontinence of urine (55.2%), back or muscle pain(73.3%), dizziness(70.3%) and diarrhea or constipation(44.2%). In psychological health, most aged people felt anger when they got some order from an other person(80.2%). Also, they had depression (69.8%) and felt like dying(64.0%). The ADL level was mostly normal for daily life. 2. The aged man was more healthy than the aged woman in physical and mental health especially the 60-64 year old group. The physical, mental health and ADL level had a positive correlation with age(p>.004), but psychological health had a negative correlation with age. 3. The physical, psychological, mental health and ADL level was positively interrelated with each other. 4. The physical, mental health, & ADL level lowered with inceasing age. Physical & psychological health worsened rapidly from 65-69 years, but for 10-15 years, their health level was preserved. Psychological health level was high in 80-84. 5. The physical health was affected by edu cational level, sex and pocket money (R=.4029, 16.24%). The psychological health was affected by the supportive style and pocket money (R=.5128, 26.30%). And the mental health was affected by education level, age, support ive style, sex and job(R=.4377, 19.16%). As seen above, we suggest the intervention of the young for the old to cope with their life and to maintain their healthy late adulthood. Also, if they have received psychological support in the institution, they will maintain healthy life condition. For further studies should be a search for variables that affect aged health, and should contribut to a nursing program better suited for the aged.

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도심지 물다짐 공법의 적정 시공방법에 관한 연구 (Study on the Optimal Construction Method for the Compaction Method of Hydraulic Filling in Metropolitan Areas)

  • 정달영;장종환;정진혁
    • 한국산학기술학회논문지
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    • 제21권2호
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    • pp.175-181
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    • 2020
  • 본 연구는 도심지에서 좁은 폭 구간에 실시하는 물다짐 공법의 적정 시공방법 제안을 연구목적으로 한다. 도심지 차도나 보도의 도로함몰로 차량의 파손, 인명의 손실 등이 발생할 수 있다. 공사장 인근에서 발생하는 도로함몰의 주요 원인은 부실시공이다. 원인조사 결과 약 25~49%가 굴착복구 미흡으로 발생하는 것으로 발표되었다. 굴착복구 시공은 장비 혹은 인력으로 실시하며, 다짐장비나 인력으로 다짐이 어려운 소폭의 관로 되메우기, 흙막이가시설과 구조물 사이 협소 공간 되메우기 등을 수행할 때는 통상적으로 물다짐 공법을 사용하고 있다. 그러나 물다짐에 관한 다짐원리와 시공 조건 관련 표준시방 및 품질관리 기준은 미흡한 상태이다. 이에 본 연구에서는 물다짐 공법에 대해서 다짐원리 및 적정 되메우기 재료와 다짐효율에 관한 실내모형시험을 수행하고, 현장시공 현황 및 문제점을 조사·분석하여 물다짐 공법의 가이드라인을 제시하였다. 결론적으로 물다짐 공법의 원리를 분석한 결과 투기하는 되메우기 재료는 입도분포와 투수성이 주요 인자로 입도 및 투수계수의 세부기준을 제시하였고, 시공방법은 다짐효율을 높이기 위해 하부 배수층을 확보한 상태로 0.3m 단위로 층별 물다짐을 수행하여 상대다짐도 90%이상의 다짐품질을 확보해야 한다. 또한 물다짐이 완료된 상태에서 엄지말뚝을 인발한 경우 교란범위인 H-pile 단면기준으로 폭(B)의 1.5배, 높이(H)의 1.0배 주변 지반에 추가 물다짐을 수행하여야 한다.

Recovery Effects from Oxidative Cell Damage by So-Hap-Hyang-Won on Bovine Aortic Endothelial Cells (BAEC)

  • Lee, Mi-Hwa;Kim, Ji-Young;Ju, Hyun-Yang;Lee, Ju-Young;Roh, Sang-Keun;Gu, Bon-Seong;Kim, Min-Ho;Han, Sang-Min;Kim, Hong-Sik;Choi, Won-Chul
    • 대한한의학회지
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    • 제24권4호
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    • pp.71-81
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    • 2003
  • So-Hap-Hyang-Won, a traditional oriental medicine used in the treatment of stroke patients, was examined for its ability to reverse the cell damage caused by lipid peroxidation products and oxidative stress in bovine aortic endothelial cells (BAEC). The effects of herbal medicine on cell proliferation and recovery of oxidative damaged situation were studied in BAEC, which was considered an appropriate in vitro model for stroke resulting from various vascular diseases prevalent in advanced age. In a clinical study of stroke patients, So-Hap-Hyang-Won appeared to improve considerably arm and leg movements as well as consciousness disturbance condition, compared with other traditional medicines used for stroke. When BAEC were treated with extracts of the lyophilized herbal medicines, only that of So-Hap-Hyang-Won stimulated cell proliferation and showed no toxicity even at high concentrations. In studies of BAEC treated with extracts of the lyophilized material of the 14 components of So-Hap-Hyang-Won, only the extract of Foeniculi Fructus stimulated cell growth at all concentrations tested. Moreover, when cells were treated with Foeniculi Fructus (10 and 100 mg/ml) extract after prior exposure to t-BHP ($l0\mu\textrm{M}$) or HNE ($0.2\mu\textrm{M}$), lipid peroxidation products which are known to be involved in aging and vascular diseases, or after the exposure to SIN-l ($500\mu\textrm{M}$), which generates nitric oxide (NO) and other reactive oxygen species, there was substantial recovery from the oxidative damage, presumably due to the radical-scavenging effect of Foeniculi Fructus extract. Foeniculi Fructus not only showed stimulatory effects on cell growth and cell damage repair in BAEC, but also appeared to show the most anti-aging activity among all the herbal components of So-Hap-Hyang-Won.

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Systematic influence of different building spacing, height and layout on mean wind and turbulent characteristics within and over urban building arrays

  • Jiang, Dehai;Jiang, Weimei;Liu, Hongnian;Sun, Jianning
    • Wind and Structures
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    • 제11권4호
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    • pp.275-289
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    • 2008
  • Large eddy simulations have been performed within and over different types of urban building arrays. This paper adopted three dimensionless parameters, building frontal area density (${\lambda}_f$) the variation degree of building height (${\sigma}_h$), and the staggered degree of building range ($r_s$), to study the systematic influence of building spacing, height and layout on wind and turbulent characteristics. The following results have been achieved: (1) As ${\lambda}_f$ decrease from 0.25 to 0.18, the mean flow patterns transfer from "skimming" flow to "wake interference" flow, and as ${\lambda}_f$ decrease from 0.06 to 0.04, the mean flow patterns transfer from "wake interference" flow to "isolated roughness" flow. With increasing ${\lambda}_f$, wind velocity within arrays increases, and the vortexes in front of low buildings would break, even disappear, whereas the vortexes in front of tall buildings would strengthen and expand. Tall buildings have greater disturbance on wind than low buildings do. (2) All the wind velocity profiles and the upstream profile converge at the height of 2.5H approximately. The decay of wind velocity within the building canopy was in positive correlation with ${\lambda}_f$ and $r_s$. If the height of building arrays is variable, Macdonald's wind velocity model should be modified through introducing ${\sigma}_h$, because wind velocity decreases at the upper layers of the canopy and increases at the lower layers of the canopy. (3) The maximum of turbulence kinetic energy (TKE) always locates at 1.2 times as high as the buildings. TKE within the canopy decreases with increasing ${\lambda}_f$ and $r_s$ but the maximum of TKE are very close though ${\sigma}_h$ varies. (4) Wind velocity profile follows the logarithmic law approximately above the building canopy. The Zero-plane displacement $z_d$ heighten with increasing ${\lambda}_f$, whereas the maximum of and Roughness length $z_0$ occurs when ${\lambda}_f$ is about 0.14. $z_d$ and $z_0$ heighten linearly with ${\sigma}_h$ and $r_s$, If ${\sigma}_h$ is large enough, $z_d$ may become higher than the average height of buildings.

성장호르몬분비 뇌하수체 선종 80예의 수술성적 및 예후 인자의 분석 (Surgical Results of 80 Patients with Growth Hormone-Producing Pituitary Adenomas : Analysis of Outcome and Prognostic Factors)

  • 김정은;정희원;곽호신;백선하;김동규;최길수
    • Journal of Korean Neurosurgical Society
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    • 제29권6호
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    • pp.754-762
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    • 2000
  • Objectives : The surgical results of 80 patients with growth hormone(GH)-producing pituitary adenoma were analyzed retrospectively to evaluate the clinical manifestations and to determine which preoperative factors significantly influenced the surgical outcome. Patients and Methods : The patients consisted of 39 men and 41 women and the age of patients at the time of initial operation ranged from 17 to 67 years(mean age, 40.5 years) Between January 1990 and June 1996, 77 patients underwent transsphenoidal surgery and 3 patients underwent craniotomy for GH-producing pituitary adenoma at our institution. Preoperative administration of octreotide was performed in 18 patients. Surgical control was defined as a postoperative serum basal level of GH less than 5ng/ml. A logistic regression model was used for univariate and multivariate analysis. Probability value of less than 0.05 was considered as statistically significant. Results : The most common presenting symptom was acromegaly, followed by headache, visual disturbance, and fatigability. Visual symptoms were present in 39% of the patients. Diabetes mellitus was associated in 24 patients and hypertension in 12. Preoperative mean basal level of GH was 93.2ng/ml(range 72-500ng/ml) which was closely related with tumor size(p<0.05). Grade II by Hardy's classification was the most common radiological type. Preoperative octreotide treatment significantly reduced the level of GH(p<0.05), but not enough to induce endocrinological remission. One patient died of cerebral infarction after craniotomy. The most common surgical complication was transient diabetes insipidus. The symptom of the earliest improvement after surgery was paresthesia and tightness of the hand and foot, followed by headache and easy fatigability. The preoperative visual symptom was improved in all patients. The patients who had hypertension or DM experienced alleviated symptoms in 67% and 92%, respectively. The overall rate of endocrinological remission was 44%. By multivariate logistic regression analysis, the size of tumor, extrasellar extension, and extent of removal were significant prognostic factors for endocrinologial remission. Conclusion : Early detection of a small tumor without extrasellar extension followed by a complete resection is highly recommended in order to achieve endocrinological cure of GH-producing pituitary adenomas.

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"한국형 기억 및 행동문제 개정점검표(Korean Version of the Revised Memory and Behavioral Problems Checklist: K-RMBPC)"의 타당화를 위한 탐색적 연구 (A Cross-Validation of the Korean Version of the Revised Memory and Behavioral Problems Checklist(K-RMBPC): Exploratory and Confirmatory Analyses)

  • 이민홍;윤은경
    • 한국사회복지학
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    • 제59권2호
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    • pp.65-88
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    • 2007
  • 본 연구의 목표는 서양에서 가족수발자가 돌보는 노인의 인지적 기능을 평가하기 위해 개발된 기억 및 행동문제 개정점검표를 우리나라 요보호노인의 가족수발자에게 맞게 수정하여 한국형 기억 및 행동 문제 개정점검표를 제시하는 것이다. 연구에 참여한 가족수발자 387명을 무작위로 두 집단으로 나눠서, 연구 1에서는 기억 및 행동문제 개정점검표의 신뢰도, 탐색적 요인, 수렴 및 기준 타당도 분석을 실시하였고, 연구 2는 연구 1에서 제시한 한국형 기억 및 행동문제 개정점검표의 신뢰도 분석, 확증적 요인분석, 수렴 및 기준 타당도를 검증하였다. 본 연구결과는 수정된 척도(K-RMBPC)가 노인의 기억 및 행동문제를 측정하기 위한 도구로서 적절함을 통계적으로 보여주고 있다. 이는 사회복지 연구와 실천현장에서 노인의 인지적 기능을 더욱 정확하게 측정할 수 있는 틀로 사용될 것으로 기대한다.

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Methyl Donor Status Influences DNMT Expression and Global DNA Methylation in Cervical Cancer Cells

  • Poomipark, Natwadee;Flatley, Janet E;Hill, Marilyn H;Mangnall, Barbara;Azar, Elnaz;Grabowski, Peter;Powers, Hilary J
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권7호
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    • pp.3213-3222
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    • 2016
  • Background: Methyl donor status influences DNA stability and DNA methylation although little is known about effects on DNA methyltransferases. The aim of this study was to determine whether methyl-donor status influences DNA methyltransferase (Dnmt) gene expression in cervical cancer cells, and if so, whether there are associated effects on global DNA methylation. Materials and Methods: The human cervical cancer cell line, C4-II, was grown in complete medium and medium depleted of folate (F-M+) and folate and methionine (F-M-). Growth rate, intracellular folate, intracellular methionine and homocysteine in the extracellular medium were measured to validate the cancer cell model of methyl donor depletion. Dnmt expression was measured by qRT-PCR using relative quantification and global DNA methylation was measured using a flow cytometric method. Results: Intracellular folate and methionine concentrations were significantly reduced after growth in depleted media. Growth rate was also reduced in response to methyl donor depletion. Extracellular homocysteine was raised compared with controls, indicating disturbance to the methyl cycle. Combined folate and methionine depletion led to a significant down-regulation of Dnmt3a and Dnmt3b; this was associated with an 18% reduction in global DNA methylation compared with controls. Effects of folate and methionine depletion on Dnmt3a and 3b expression were reversed by transferring depleted cells to complete medium. Conclusions: Methyl donor status can evidently influence expression of Dnmts in cervical cancer cells, which is associated with DNA global hypomethylation. Effects on Dnmt expression are reversible, suggesting reversible modulating effects of dietary methyl donor intake on gene expression, which may be relevant for cancer progression.