• Title/Summary/Keyword: Patch formation

검색결과 58건 처리시간 0.034초

제주해협에서의 이료생물 분포에 따른 갈치어장의 변동특성 (The Fluctuation of Fishing Grounds of Hairtail, Trichiurus lepturus in the Cheju Strait by the Distribution of Feeding Biomass)

  • 김상현;노홍길
    • 수산해양기술연구
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    • 제38권1호
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    • pp.1-10
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    • 2002
  • 1. 제주해협에서는 6월에 가장 낮은 생물량 분포를 나타내었고, 가을철(11월)에 가장 높은 생물량 분포를 보이면서 높은 2차 생산력을 보이는 것으로 사료된다. 2. 해황 및 습중량과의 관계에서 가장 높은 분포를 나타내는 정점은 각각 정점 14와 11로 그 출현위치는 해협의 중앙부분이고, 한국남해연안역 및 제주도 북부연안역에는 다소 낮은 생물량분포를 보이고 있으며, 생물량 분포가 높게 나타나는 해역의 특징은 patch의 형태로 분포하였다 반면 한국남해연안역에 비하여 제주도 북부연안역에높은 생물량 분포를 나타냄으로써 제주해협에서의 갈치어장 형성위치와 생물량 분포와의 관계가 밀접하게 나타날 것으로 판단된다. 그리고, 가을 의 해황 특성인 서로 다른 이질수괴의 경계역인 안상부 해황의 중심에 높은 생물량을 나타냈다. 3. 제주해협에서 patch의 형태로 생물량 분포가 높게 나타나는 해역의 외측에 좋은 갈치어장이 형성되었다.

자연형 수로 내 식생흐름 분석을 위한 실험적 연구 (Experimental Study of Vegetated Flows in the Stream-scale Natural Channel)

  • 류용욱;김지현;지운;강준구
    • 대한토목학회논문집
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    • 제39권5호
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    • pp.587-594
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    • 2019
  • 하천 내 흐름에 대한 식생 밀도의 영향을 조사하기 위해 버드나무가 활착된 하천 규모의 자연형 수로에서 유동 측정 실험을 수행하였다. 식생 내 흐름에 대한 하천 규모 실험은 식생의 반 잠김 조건에 대해 수행되었다. 수로 내 식생대(vegetation patch)는 교차로 형성된 사주의 형상으로 배열되었고 식생 구간과 비식생 구간에서의 흐름을 비교하였다. 3차원 유동 구조는 초음파 유속계(Acoustic Doppler Velocimeter)에 의해 측정되었고 종방향 속도의 연직 분포는 다양한 지점에서의 측정값으로부터 분석되었다. 유속은 식생대의 밀도에 따라 다른 양상을 보여 주는데, 식생 구간와 비식생 구간에서의 흐름 속도의 차이는 밀집된 식생대 주변에서 크게 나타나며 흐름 분포의 형태는 식생대의 하류방향 하단에서 복잡한 모습을 나타낸다. 하류에 위치한 식생대 주변의 흐름은 상류에 설치된 식생대에 의해 교란된 흐름에도 불구하고 유사한 분포를 보여준다.

외상성 심실중격결손 및 승모판막 역류증의 일차 완전정복 (One Stage Repair of Traumatic Ventricular Septal Defect and Mitral Regurgitation)

  • 이재원;송태승;제형곤;송명근
    • Journal of Chest Surgery
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    • 제32권12호
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    • pp.1131-1134
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    • 1999
  • After a penetrating thoracic injury early detection of intracardiac injury and early surgical repair when indicated are essential. A case presenting severe respiratory distress two weeks after a penetrating thoracic injury is reported. Transesophageal echocardiography showed massive pericardial effusion ventricular septal defect and mirtal regurgitation, The infundibular ventricular septal perforation was repaired using a Dacron patch the anterior mitral leaflet by interrupted sutures and the ruptured chordae of the posterior leaflet by a new chordae formation.

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Modulation of Neural Circuit Actvity by Ethanol in Basolateral Amygdala

  • Chung, Leeyup
    • 한국발생생물학회지:발생과생식
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    • 제16권4호
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    • pp.265-270
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    • 2012
  • Ethanol actions in the amygdala formation may underlie in part the reinforcing effects of ethanol consumption. Previously a physiological phenomenon in the basolateral amygdala (BLA) that is dependent on neuronal network activity, compound postsynaptic potentials (cPSPs) were characterized. Effects of acute ethanol application on the frequency of cPSPs were subsequently investigated. Whole cell patch clamp recordings were performed from identified projection neurons in a rat brain slice preparation containing the amygdala formation. Acute ethanol exposure had complex effects on cPSP frequency, with both increases and decreases dependent on concentration, duration of exposure and age of the animal. Ethanol produces complex biphasic effects on synaptically-driven network activity in the BLA. These findings may relate to subjective effects of ethanol on arousal and anxiolysis in humans.

The impact of ram pressure on the multi-phase ISM probed by the TIGRESS simulation

  • Choi, Woorak;Kim, Chang-Goo;Chung, Aeree
    • 천문학회보
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    • 제43권1호
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    • pp.62.1-62.1
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    • 2018
  • Galaxies in the cluster environment interact with the intracluster medium (ICM), losing the interstellar medium (ISM) and alternating their evolution. Observational evidences of the extraplanar ISM stripped by the ICM's ram pressure are prevalent in HI imaging studies of cluster galaxies. However, current theoretical understanding of the ram pressure stripping (or ICM-ISM interaction in general) is still limited mainly due to the lack of numerical resolution at ISM scales in large-scale simulations. Especially, self-consistent modeling of the turbulent, multiphase ISM is critical to understand star formation in galaxies interacting with the ICM. To achieve this goal, we utilize the TIGRESS simulation suite, simulating a local patch of galactic disks with high resolution to resolve key physical processes in the ISM, including cooling/heating, self-gravity, MHD, star formation, and supernova feedback. We then expose the ISM disk to ICM flows and investigate the evolution of star formation rate and the properties of the ISM. By exploring ICM parameter space, we discuss an implication of the simple ram pressure stripping condition (so called the Gunn-Gott condition) to the realistic ISM.

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소나무 천연갱신지의 목재수확 유형별 종자 유입 특성 (Seed Inflow Characteristics of the Korean Red Pine according to Harvest Type in Natural Regeneration Forests)

  • 정준모;이상태;김현섭;정상훈
    • 한국산림과학회지
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    • 제112권3호
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    • pp.331-339
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    • 2023
  • 본 연구는 목재수확 유형에 따른 종자 유입 특성을 구명하여 천연갱신에 의한 소나무 후계림 조성 기술의 기초자료를 제공하고자 수행되었다. 이를 위해 모수작업(단목모수, 군상모수) 및 개벌작업(대상개벌 10 mㆍ20 mㆍ40 m, 군상개 벌 20 mㆍ30 mㆍ40 m)을 실시하여 시험지를 조성하고, 2014년부터 6년간 천연갱신지의 종자 유입 특성을 분석하였다. 소나무 종자는 대부분 10~11월 갱신상에 유입되었으며, 종자 결실이 좋은 해에는 80% 이상이 10월에 유입되었다. 목재수확 유형별 연평균 종자 유입량은 군상 모수작업지(296천립/ha/yr), 20 m 군상 개벌작업지(291천립/ha/yr), 10 m 대상 개벌 작업지(281천립/ha/yr) 순으로 많았다. 유입 종자 분포 균일성은 20 m 대상 개벌작업지(52.2), 20 m 군상 개벌작업지(52.9), 10 m 대상 개벌작업지(56.1) 순으로 분석되어 벌채 면적이 상대적으로 좁은 10 m 대상 개벌작업지와 20 m 군상 개벌작업지가 종자 유입량 및 분포 균일성이 높은 것으로 나타났다.

Functional Cardiomyocytes Formation Derived from Mouse Embryonic Stem Cells

  • Shin, Hyun-Ah;Lee, Keum-Sil;Cho, Hwang-Yoon;Park, Sae-Young;Kim, Eun-Young;Lee, Young-Jae;Park, Se-Pill;Lim, Jin-Ho
    • 한국발생생물학회:학술대회논문집
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    • 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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    • pp.100-100
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    • 2003
  • Pluripotent embryonic stem (ES) cells differentiate spontaneously into beating cardiomyocytes via embryo-like aggregates. We describe the use of mouse embryonic stem (mES03) cells as a reproducible differentiation system for cardiomyocyte. To induce cardiomyocytic differentiation, mES03 cells were dissociated and allowed to aggregate (EB formation) at the presence of 0 75% dimethyl sulfoxide (DMSO) for 4 days and then another 4 days without DMSO (4+/4-). Thus treated EBs were plated onto gelatin-coated dish for differentiation. Spontaneously contracting colonies which appeared in approximately 4-5 days upon differentiation. Expression of cardiac-specific genes were determined by RT-PCR. Rebust expression of myosin light chain (MLC-2V), cardiac myosin heavy chain $\alpha$, cardiac muscle heavy polypeptide 7 $\beta(\beta$-MHC), cardiac transcription factor GATA4 and skeletal muscle-specific ${\alpha}_1$-subunit of the L-type calcium channel (${\alpha}_1 CaCh_{sm}$) were detected as early as 8 days after EB formation, but message of cardiac muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel (${\alpha}_1$CaCh) were revealed at a low level. Strikingly, the expression of atrial natriuretic factor (ANF) was not detected. When spontaneous contracting cell masses were examined their electrophysiological features by patch-clamp technique, it showed ventricle-like action potential 17 days after the EB formation. This study indicates that mES03 cell-derived cardiomyocytes displayed biochemical and electrophysiological properties of cardiomyocytes and DMSO enhanced development of cardiomyocytes in 4+/4- method.

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Formation, Breakage and Reformation of Humic Flocs by Inorganic and Organic Coagulants

  • Kam, Sang-Kyu;Lee, Min-Gyu;Kang, Kyung-Ho;Xu, Mei-Lan
    • 한국환경과학회지
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    • 제17권3호
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    • pp.275-285
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    • 2008
  • The floc formation, breakage and reformation of humic acid by inorganic (alum and PAC) and organic coagulants (cationic polyelectrolytes) at several conditions (pH, ionic strength and floc breakage time) were examined and compared among the coagulants at different conditions using a continuous optical monitoring method, with controlled mixing and stirring conditions. For alum, the shapes of formation, breakage and reformation curves at different pH (5 and 7) were different, but the shapes and the sizes of initial floc and reformed floc were nearly the same in the absence and presence of electrolytes at pH 7. For PAC, similar shapes of the curves were obtained at different pH and ionic strength, but the sizes were different, except for those of reformed flocs at different pH. However, for these coagulants, reformed flocs after floc breakage, occurred irreversibly for all the conditions used in this study. For organic coagulants, the time to attain the initial plateau floc size, the extent of floc strength at high shear rate and reversibility of reformed floes were different, depending floc formation mechanism. Especially, for the cationic polyelectrolyte forming humic flocs by charge neutralization or electrostatic patch effect mechanism, reformed flocs occurred reversibly, regardless of pH and floc breakage time, but occurred irreversibly in the presence of electrolytes.

Cytotoxicity of Vibrio vulnificus Cytolysin on Rat Neutrophils

  • Park, Kwang-Hyun;Rho, In-Whan;Park, Byung-Hyun;Kim, Jong-Suk;Kim, Hyung-Rho
    • BMB Reports
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    • 제32권3호
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    • pp.273-278
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    • 1999
  • Cytolysin produced by Vibrio vulnificus has been known to be lethal to mice by increasing vascular permeability and neutrophil sequestration in the lung. In the present study, a cytotoxic mechanism of V. vulnificus cytolysin on the neutrophil was investigated. Cytolysin rapidly bound to neutrophils and induced cell death, as determined by the trypan blue exclusion test. V. vulnificus cytolysin caused the depletion of cellular ATP without the release of ATP or lactate dehydrogenase. Formation of transmembrane pores was evidenced by the rapid efflux of potassium and 2-deoxy-D-[$^3H$]glucose from cytolysin-treated neutrophils. It was further confirmed by the rapid flow of monovalent ions in the patch clamp of cytolysin-treated neutrophil membrane. The pore formation was accompanied by the oligomerization of cytolysin monomers on the neutrophil membrane as demonstrated by immunoblot, which exhibited a 210 kDa band corresponding to a tetramer of the native cytolysin of $M_r$ 51,000. These findings indicate that V. vulnificus cytolysin rapidly binds to the neutrophil membrane and oligomerizes to form small transmembrane pores, which induce the efflux of potassium and the depletion of cellular ATP leading to cell death without cytolysis.

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단면 윤곽선을 기반으로 한 두부표변의 재구성 (Reconstruction of Head Surface based on Cross Sectional Contours)

  • 한영환;성현경;홍승홍
    • 대한의용생체공학회:의공학회지
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    • 제18권4호
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    • pp.365-373
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    • 1997
  • 본 논문에는 표면 형태만을 고려한 방법으로 다수의 단면 영상 데이터로부터, 관심있는 기관의 외부 표면을 패치(patch)에 의한 방법으로 재구성하여 삼차원적으로 표시하는 것을 목적으로 한다. 이를 위해 본 논문에서는 표면을 형성하기 위한 특징점을 추출하기 위하여 제거법에 의한 특징점 추출이라는 알고리즘을 제안하여 사용하였으며, 표면을 재구성하기 윟나 과정에서 두 단면의 영상의 특징점 사이의 최소 거리를 비용 함수로 사용하는 방법을 제안하였다. 제안한 알고리즘의 효용성을 확인하기 위하여 두부에 대한 이차원 CT 영상을 사용하여 실험을 실시하고 다른 방법과 비교하여 보았다.

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