• The Korean Journal of Physiology and Pharmacology
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• 제13권1호
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• pp.1-7
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• 2009

Sodium retention is a hallmark of nephrotic syndrome. We investigated whether sodium retention is associated with changes of natriuretic peptide system at different stages (i.e., a sodium retaining stage and a compensatory stage) of nephrotic syndrome. At day 7 after PAN(puromycin aminonucleoside) injection, the urinary excretion of sodium was decreased, along with the development of ascites and positive sodium balance. The plasma and urinary ANP(atrial natriuretic peptide) immunoreactivities were increased. ANP mRNA expression was increased in the heart and kidney, whereas that of NPR(natriuretic peptide receptor)-A and NPR-C mRNA was decreased in the kidney. The expression of NEP was decreased in the kidney. At day 14, urinary excretion of sodium did not differ from the control. The plasma ANP level and heart ANP mRNA expression returned to their control values. The expression of ANP mRNA in the kidney was increased in association with increased urinary ANP immunoreactivities. The expression of NPR-A in the kidney became normal, whereas that of NPR-C kept decreased. The expression of NEP(neutral endopeptidase) remained decreased. These findings suggest that the increased renal ANP synthesis in association with decreased metabolism via NEP and NPR-C may play a compensatory role against the development of sodium retention in nephrotic syndrome. The decreased of NPR-A expression in the kidney may contribute to the ANP resistance at day 7. The subsequent recovery of NPR-A expression may play a role in promoting sodium excretion in later stage(at day 14).

• 한국물환경학회지
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• 제34권6호
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• pp.579-590
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• 2018

The lakes' metabolism bears important information for the assessment of the carbon budget due to the accumulation or loss of carbon in the lake as well as the dynamics of the food webs through primary production. A lake-scale metabolism is evaluated by Gross Primary Production (GPP), Ecosystem Respiration (R), and Net Ecosystem Production (NEP), which is the difference between the first two values. Methods for estimating GPP and R are based on the levels carbon and oxygen. Estimation of carbon is expensive because of the use of radioactive materials which requires a high degree of proficiency. The purpose of this study was to estimate Lake Daecheong ecosystem metabolism using high frequency water temperature data and DO measurement sensor, widely utilized in the field of water quality monitoring, and to evaluate the possibility of using the application method. High frequency data was collected at intervals of 10 minutes from September to December 2017 by installing a thermistor chain and a DO sensor in downstream of Daechung Dam. The data was then used to estimate GPP, R and NEP using the R public program LakeMetabolizer, and other metabolism models (mle, ols, kalman, bookkeep). Calculations of gas exchange coefficient methods (cole, crusius, heiskanen, macIntyre, read, soloviev, vachon) were compared. According to the result, Lake Daecheong has some deviation based on the application method, but it was generally estimated that the NEP value is negative and acts as a source of atmospheric carbon in a heterotrophic system. Although the high frequency sensor data used in this study had negative and positive GPP and R values during the physical mixing process, they can be used to monitor real-time metabolic changes in the ecosystem if these problems are solved.

• Journal of Ecology and Environment
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• 제46권3호
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• pp.250-258
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• 2022

Background: To assess the carbon sequestration capacity and net ecosystem productivity (NEP) of Quercus glauca forests, we analyzed the net primary productivity (NPP), carbon storage, and carbon emission of soil in a Q. glauca forest on Jeju Island (South Korea) from 2016 to 2018. Results: The average carbon stock in the above- and below-ground plant biomass was 223.7 Mg C ha^-1, while the average amount of organic carbon fixed by photosynthesis was 9.8 Mg C ha^-1 yr^-1, and the average NPP was 9.6 Mg C ha^-1 yr^-1. Stems and branches contributed to the majority of the above- and below-ground standing biomass and NPP. The average heterotrophic carbon emission from the soil was 8.7 Mg C ha^-1 yr^-1, while the average NEP was 1.1 Mg C ha^-1 yr^-1. Although the carbon stock, carbon absorption, and soil respiration values were higher than those reported in other oak forests in the world, the NEP was similar or lower. Conclusions: These results indicator that Q. glauca forests perform the role of a large carbon sink through the CO₂ absorption in the plants in terms of carbon balance. And it is judged to be helpful as data for assessment of carbon storage and flux in the forests and mitigation of elevated CO₂ in the atmosphere.

• 한국산림과학회지
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• 제89권5호
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• pp.598-608
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• 2000

본 연구는 현재 우리나라에 지정된 20개 국립공원 가운데, 설악산, 가야산, 내장산, 북한산, 태안해안, 한려해상국립공원 등 6개 국립공원의 방문객을 대상으로 자연환경태도를 측정하고, 이와 관련 있는 방문객의 사회 경제적 특성 및 방문동기와의 관계를 규명하였다. 자연환경태도의 측정은 Dunlop과 Van Liere(1978)가 개발한 New Environmental Paradigm(NEP) scale올 기초로 Luzar 등(1995)이 6문항으로 축약한 scale을 적용하였으며, 총 2,647명의 방문객을 대상으로 조사되었다. 분석결과 방문객의 자연환경태도는 전반적으로는 친환경적인 경향을 지니고 있는 것으로 나타났으며, 자연환경태도와 관련이 있는 방문객의 사회 경제적 변수로는 교육수준이 양(陽)의 상관관계, 연령의 경우 음(陰)의 상관관계가 통계적으로 존재하는 것으로 나타났다. 다음으로 방문객의 자연환경태도와 방문동기와의 관계에 있어서는 '휴식'과 '건강' 동기요인에 양(陽)의 상관관계가 존재하는 것으로 나타난 반면, '사회성', '가족휴가' 동기요인과는 음(陰)의 상관관계가 있는 것으로 나타났다. 따라서 공원관리적 측면에서 친환경적인 이용객 유도정책을 도입할 경우 교육이 가장 효과적인 수단으로 판단되며, '가족휴가'와 '사회성' 동기가 강한 방문객일수록 자연환경태도 점수가 상대적으로 낮아, 여름 휴가철 가족동반의 방문객이나 가을 단풍철 집단방문객의 경우에서 이용자관리에 보다 세심한 고려가 필요할 것으로 사료된다.

• 천문학회보
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• 제33권1호
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• pp.29.1-29.1
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• 2008

• 천문학회보
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• 제33권1호
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• pp.57.2-57.2
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• 2008

• 천문학회보
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• 제33권1호
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• pp.57.1-57.1
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• 2008

• 월간포장계
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• 통권157호
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• pp.145-153
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• 2006

• 한국전자파학회논문지
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• 제24권11호
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• pp.1027-1033
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• 2013

본 논문에서는 고주파 이미징 시스템에 사용되는 D-band 이미징 검출기(imaging detector)를 65-nm CMOS 공정을 이용하여 설계 및 제작한 결과를 보인다. 검출기 회로 구조는 resistive self-mixing 원리에 기초를 두고 있다. 제작된 검출기는 145 GHz에서 400 V/W의 최대 반응도(responsivity)와 100 $pW/Hz^{1/2}$의 최소 NEP(Noise Equivalent Power)를 보였다. 제작된 회로의 크기는 측정용 패드와 밸룬을 포함하여 $400{\mu}m{\times}450{\mu}m$이며, 중심 회로의 크기는 $150{\mu}m{\times}100{\mu}m$이다.

• 천문학논총
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• 제32권1호
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• pp.327-329
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• 2017

We report a spatial fluctuation analysis of the sky brightness in the near-infrared from observations towards the north ecliptic pole (NEP) by AKARI at 2.4 and $3.2{\mu}m$. As a follow up study of our previous work on the Monitor field of AKARI, we used NEP deep survey data, which covered a circular area of about 0.4 square degrees, in order to extend fluctuation analysis at angular scales up to 1000". After pre-processing, additional correction procedures were done to correct time varying components and instrumental effects such as MUXbleed. To remove resolved objects, we applied $2{\sigma}$ clipping and point spread function (PSF) subtraction. We finally obtained mosaicked images which can be used for the study of various diffuse emissions in the near-infrared sky and found that there are spatial structures in the mosaicked images using a power spectrum analysis.