• 제목/요약/키워드: Population dynamics

검색결과 537건 처리시간 0.029초

Feeding by common heterotrophic dinoflagellates and a ciliate on the red-tide ciliate Mesodinium rubrum

  • Lee, Kyung Ha;Jeong, Hae Jin;Yoon, Eun Young;Jang, Se Hyeon;Kim, Hyung Seop;Yih, Wonho
    • ALGAE
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    • 제29권2호
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    • pp.153-163
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    • 2014
  • Mesodinium rubrum is a cosmopolitan ciliate that often causes red tides. Predation by heterotrophic protists is a critical factor that affects the population dynamics of red tide species. However, there have been few studies on protistan predators feeding on M. rubrum. To investigate heterotrophic protists grazing on M. rubrum, we tested whether the heterotrophic dinoflagellates Gyrodiniellum shiwhaense, Gyrodinium dominans, Gyrodinium spirale, Luciella masanensis, Oblea rotunda, Oxyrrhis marina, Pfiesteria piscicida, Polykrikos kofoidii, Protoperidinium bipes, and Stoeckeria algicida, and the ciliate Strombidium sp. preyed on M. rubrum. G. dominans, L. masanensis, O. rotunda, P. kofoidii, and Strombidium sp. preyed on M. rubrum. However, only G. dominans had a positive growth feeding on M. rubrum. The growth and ingestion rates of G. dominans on M. rubrum increased rapidly with increasing mean prey concentration < $321ngCmL^{-1}$, but became saturated or slowly at higher concentrations. The maximum growth rate of G. dominans on M. rubrum was $0.48d^{-1}$, while the maximum ingestion rate was 0.55 ng C $predator^{-1}d^{-1}$. The grazing coefficients by G. dominans on populations of M. rubrum were up to $0.236h^{-1}$. Thus, G. dominans may sometimes have a considerable grazing impact on populations of M. rubrum.

Accessing socio-economic and climate change impacts on surface water availability in Upper Indus Basin, Pakistan with using WEAP model.

  • Mehboob, Muhammad Shafqat;Kim, Yeonjoo
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2019년도 학술발표회
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    • pp.407-407
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    • 2019
  • According to Asian Development Bank report Pakistan is among water scarce countries. Climate scenario on the basis IPCC fifth assessment report (AR5) revealed that annual mean temperature of Pakistan from year 2010-2019 was $17C^o$ which will rise up to $21C^o$ at the end of this century, similarly almost 10% decrease of annual rainfall is expected at the end of the century. It is a changing task in underdeveloped countries like Pakistan to meet the water demands of rapidly increasing population in a changing climate. While many studies have tackled scarcity and stream flow forecasting of the Upper Indus Basin (UIB) Pakistan, very few of them are related to socio-economic and climate change impact on sustainable water management of UIB. This study investigates the pattern of current and future surface water availability for various demand sites (e.g. domestic, agriculture and industrial) under different socio-economic and climate change scenarios in Upper Indus Basin (UIB) Pakistan for a period of 2010 to 2050. A state-of-the-art planning tool Water Evaluation and Planning (WEAP) is used to analyze the dynamics of current and future water demand. The stream flow data of five sub catchment (Astore, Gilgit, Hunza, Shigar and Shoyke) and entire UIB were calibrated and validated for the year of 2006 to 2011 using WEAP. The Nash Sutcliffe coefficient and coefficient of determination is achieved ranging from 0.63 to 0.92. The results indicate that unmet water demand is likely to increase severe threshold and the external driving forces e.g. socio-economic and climate change will create a gap between supply and demand of water.

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한라산 황칠나무 집단의 구조 및 생육동태 (Population Structure and Growth Dynamics of Dendropanax morbifera Lev.(Araliaceae) in Mt. Halla)

  • 김세현;정헌관;장용석;김선창
    • 한국자원식물학회지
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    • 제17권3호
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    • pp.248-256
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    • 2004
  • 천연도료 황칠자원을 보전하고 육성하기 위한 육종계획의 일환으로 한라산 황칠나무 천연집단의 식생구조, 공간분포 및 생육동태 등 생태적 특성을 조사한 결과, 중요치(Ⅳ)가 높은 수종은 구실잣밤나무, 서어나무, 황칠나무, 종가시나무, 가시나무, 동백나무, 당단풍 등인 것으로 조사되었으며 , 모든 조사구에서 공통적으로 출현한 수종은 구실잣밤나무와 서어나무 2종이었다. 층위별 황칠나무의 적산중요치는 상층에서 17.2%, 중층 12.9%, 하층 10.3%로 비교적 높은 우점도를 나타내고 있었으며, 분포형은 상층, 중층, 하층에서 확률분포하는 것으로 나타났다. 황칠나무 임분은 낙엽활엽수인 서어나무를 우점으로 하는 군집에서 종가시나무, 구실잣밤나무 등의 상록활엽수를 우점으로 하는 군집으로 진행되는 천이단계에 있었으며, 황칠나무는 이들 임분에서 주로 상층의 아우점종이거나 중층의 우점종으로 나타났다. Morisita's index를 통한 공간분포는 치수(seedling)와 어린개체 (sapling)들은 대체로 모수로서 추정되는 성숙목으로부터 떨어진 곳에 집중분포하는 경향을 보였으나, 성숙목(Mature tree)은 규칙 분포하는 양상이었다. 결론적으로, 황칠나무는 다른 상록활엽 수들과 동반하여 집단 확산이 일어나며 , 집단의 확산을 위한 치수의 발생과 생장에 있어서 주변의 임분구조에 큰 영향을 미치는 것으로 나타났다. 또한, 개체군의 동태를 예측한 결과, 낮은 직경급의 밀도가 높고 높은 직경 급의 밀도가 낮은 전형적인 역J자형 분포를 보였다.

왕권과 교권의 대립을 통해 본 신대륙의 가톨릭 전파과정 연구 (The study on the diffusion of Catholicism in the New World: focused on the relationship between the king and the pope)

  • 이성훈
    • 비교문화연구
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    • 제37권
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    • pp.7-29
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    • 2014
  • The 'discovery' or 'conquest' of the New World in 1492 was the starting point of world history that irrevocably changed the fate of the Latin American continent. The global stream known as 'Columbian Exchange', which was the widespread inter-continental contacts, inter-civilizational conflicts, or bilateral communication, has rendered multifarious effects throughout many historical periods up to the very contemporary time. The propagation of Catholicism initiated along with this 'discovery' transformed Latin America of nowadays in the region that has the biggest Catholic population in the world. The previous studies in Korea regarding Latin American Catholicism has focused on the spread of Catholicism in relation to the European colonization, rather than analyzing the concrete and detailed ways in which Catholicism exerted tremendous influences in the whole continent. They were less attentive to various historical contexts in which the diffusion of Catholicism differed greatly according to cultural landscapes and political specificities. Thus, this essay attempts to examine the diffusion of Catholicism from the perspective of confrontation between royal authorities and the power of church. The essay points out that the royal communities and institutional authorities which facilitated the intial process of Catholic evangelization maintained antagonistic relationship with ecclesial powers. By delving into the gradual transformation of church systems, it reveals that Catholicism in Latin America became a major field for conquerors in power to attain economic and political dominance. And unlike the initial submission and hospitality, the religious convert of the indigenous people attested to the violent inhumanity and opposition. Therefore, the essay aims to pave a clearer way to the understanding of complicated dynamics and conflicts between Catholicism in Latin America and the establishment of Spanish colonization.

지리산국립공원 세석지역의 아고산 관속식물상 (The Flora of Subalpine Vascular Plants in Seseok Area of Jirisan National Park)

  • 노일;정재민;조민기;김태운;문현식
    • 한국기후변화학회지
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    • 제8권3호
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    • pp.201-211
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    • 2017
  • This study was conducted to investigate the vascular plants which can be an indicator of environmental change in Seseok of Jirisan National Park. The purpose of this study was to find out the basic information for the subalpine species. This study showed that the area had a total 295 taxa including 63 families, 177 genus, 252 species, 2 subspecies, 36 variants 5 forms and Pte-Q was 1.7. Among them, Korea endemic plants were 15 taxa such as Abies koreana. Rare plants were 14 taxa such as Viola diamantiaca. Naturalized plants consisted of 5 taxa such as Rumex crispus. The floristic regional indicator plants found in surveyed area were 72 taxa comprising 3 taxa of grade V, 7 taxa of grade IV and 24 taxa of grade III. In summary, The subalpine plants of the survey region consisted of 37 taxa including Abies koreana and Gymnadenia cucullata. As rare plants distributed in subalpine zone respond sensitively to climate change, accuracy distribution range, environmental characteristics of habitat and population dynamics of rare plants should be evaluated quantitatively.

Effects of Interaction Range on the Behavior of Opinion Consensus

  • Lee, Seungjae;Cho, Young Sul;Hong, Hyunsuk
    • Journal of the Korean Physical Society
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    • 제73권10호
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    • pp.1406-1409
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    • 2018
  • We have frequently encountered the rapid changes that prevalent opinion of the social community is toppled by a new and opposite opinion against the pre-exiting one. To understand this interesting process, mean-field model with infinite-interaction range has been mostly considered in previous studies S. A. Marvel et al., Phys. Rev. Lett. 110, 118702 (2012). However, the mean-field interaction range is lack of reality in the sense that any individual cannot interact with all of the others in the community. Based on it, in the present work, we consider a simple model of opinion consensus so-called basic model on the low-dimensional lattices (d = 1, 2) with finite interaction range. The model consists of four types of subpopulations with different opinions: A, B, AB, and the zealot of A denoted by $A_c$, following the basic model shown in the work by S. A. Marvel et al.. Comparing with their work, we consider the finite range of the interaction, and particularly reconstruct the lattice structure by adding new links when the two individuals have the distance < ${\sigma}$. We explore how the interaction range ${\sigma}$ affects the opinion consensus process on the reconstructed lattice structure. We find that the critical fraction of population for $A_c$ required for the opinion consensus on A shows different behaviors in the small and large interaction ranges. Especially, the critical fraction for $A_c$ increases with the size of ${\sigma}$ in the region of small interaction range, which is counter-intuitive: When the interaction range is increased, not only the number of nodes affected by $A_c$ but also that affected by B grows, which is believed to cause the increasing behavior of the critical fraction for $A_c$. We also present the difference of dynamic process to the opinion consensus between the regions of small and large interaction ranges.

다기간 자료포락분석을 이용한 전기차 충전소 효율성 변화 분석 (Analysis on the Efficiency Change in Electric Vehicle Charging Stations Using Multi-Period Data Envelopment Analysis)

  • 손동훈;강영수;김화중
    • 산업경영시스템학회지
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    • 제44권2호
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    • pp.1-14
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    • 2021
  • It is highly challenging to measure the efficiency of electric vehicle charging stations (EVCSs) because factors affecting operational characteristics of EVCSs are time-varying in practice. For the efficiency measurement, environmental factors around the EVCSs can be considered because such factors affect charging behaviors of electric vehicle drivers, resulting in variations of accessibility and attractiveness for the EVCSs. Considering dynamics of the factors, this paper examines the technical efficiency of 622 electric vehicle charging stations in Seoul using data envelopment analysis (DEA). The DEA is formulated as a multi-period output-oriented constant return to scale model. Five inputs including floating population, number of nearby EVCSs, average distance of nearby EVCSs, traffic volume and traffic congestion are considered and the charging frequency of EVCSs is used as the output. The result of efficiency measurement shows that not many EVCSs has most of charging demand at certain periods of time, while the others are facing with anemic charging demand. Tobit regression analyses show that the traffic congestion negatively affects the efficiency of EVCSs, while the traffic volume and the number of nearby EVCSs are positive factors improving the efficiency around EVCSs. We draw some notable characteristics of efficient EVCSs by comparing means of the inputs related to the groups classified by K-means clustering algorithm. This analysis presents that efficient EVCSs can be generally characterized with the high number of nearby EVCSs and low level of the traffic congestion.

Changes in physicochemical property and lactic acid bacterial community during kimchi fermentation at different temperatures

  • Lee, Hee Yul;Haque, Md. Azizul;Cho, Kye Man
    • Journal of Applied Biological Chemistry
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    • 제63권4호
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    • pp.429-437
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    • 2020
  • This study aimed to investigate the change in physicochemical properties and lactic acid bacterial communities during kimchi fermentation at different temperatures (8, 15, and 25 ℃) using two molecular genetics approaches, multiplex polymerase chain reaction and 16S rRNA gene sequencing. The pH during fermentation at 8, 15, and 25 ℃ decreased from 6.17 on the initial fermentation day to 3.92, 3.79, and 3.48 after 54, 30, and 24 days of fermentation, respectively, while the acidity increased from 0.24% to 1.12, 1.35, and 1.54%, respectively. In particular, the levels of lactic acid increased from 3.74 g/L on the initial day (day 0) to 14.43, 20.60, and 27.69 g/L during the fermentation after 24, 18, and 12 days at 8, 15, and 25 ℃, respectively, after that the lactic acid concentrations decreased slowly. The predominance of lactic acid bacteria (LAB) in the fermented kimchi was dependent on fermentation stage and temperature: Lactobacillus sakei appeared during the initial stage and Leuconsotoc mesenteroides was observed during the optimum-ripening stage at 8, 15, and 25 ℃. Lac. sakei and Lactobacillus plantarum grew rapidly in kimchi produced at 8, 15, and 25 ℃. In addition, Weissella koreensis first appeared at days 12, 9, and 6 at 8, 15, and 25 ℃ of fermentation, respectively. This result suggests that LAB population dynamics are rather sensitive to environmental conditions, such as pH, acidity, salinity, temperature, and chemical factors including free sugar and organic acids.

Comparison of infant mortality and associated factors between Korean and immigrant women in Korea: an 11-year longitudinal study

  • Kim, Kyung Won;Nho, Ju-Hee;Kim, Sooyoung;Park, Byeongje;Park, Sanghee;Kang, Bobae;Kim, Sun-Hee
    • 여성건강간호학회지
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    • 제27권4호
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    • pp.286-296
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    • 2021
  • Purpose: This study compared infant mortality and its associated factors between Korean and immigrant women using vital statistics gathered by Statistics Korea. Methods: Birth and death statistics from the period between 2009 and 2019 were extracted from the census of population dynamics data of the Microdata Integrated Service, Korea. Statistical data were derived from a complete survey and infant mortality was analyzed from mortality statistics data. Descriptive statistics were used for comparison. Results: The average infant mortality rate (IMR) of Korean women was 2.7 in Korea, which did not change significantly between 2009 and 2019; however, the IMR of immigrant women increased significantly in 2018 to 4.2 and subsequently decreased to 2.6 in 2019. Moreover, the age of Korean and immigrant women at the time of infant death gradually increased from 31.1 years and 25.9 years in 2009 to 32.8 years and 30.9 years in 2019, respectively. The gestational age was lower for deceased infants born to immigrant women (mean, 31.04 weeks; standard deviation [SD], 6.42; median, 30.00) compared to infants born to Korean women (mean, 31.71 weeks; SD, 6.48; median, 32.00). Immigrant women (91.7%) received slightly fewer antenatal care visits compared to Korean women (93.1%). Conclusion: It is vital to devise a plan to lower the IMR of immigrant women in Korea. Moreover, it is necessary to explore the factors related to infant mortality among immigrant women within the context of Korean societal situation, culture, and home environment.

Precise control of mitophagy through ubiquitin proteasome system and deubiquitin proteases and their dysfunction in Parkinson's disease

  • Park, Ga Hyun;Park, Joon Hyung;Chung, Kwang Chul
    • BMB Reports
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    • 제54권12호
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    • pp.592-600
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    • 2021
  • Parkinson's disease (PD) is one of the most common neurodegenerative diseases in the elderly population and is caused by the loss of dopaminergic neurons. PD has been predominantly attributed to mitochondrial dysfunction. The structural alteration of α-synuclein triggers toxic oligomer formation in the neurons, which greatly contributes to PD. In this article, we discuss the role of several familial PD-related proteins, such as α-synuclein, DJ-1, LRRK2, PINK1, and parkin in mitophagy, which entails a selective degradation of mitochondria via autophagy. Defective changes in mitochondrial dynamics and their biochemical and functional interaction induce the formation of toxic α-synuclein-containing protein aggregates in PD. In addition, these gene products play an essential role in ubiquitin proteasome system (UPS)-mediated proteolysis as well as mitophagy. Interestingly, a few deubiquitinating enzymes (DUBs) additionally modulate these two pathways negatively or positively. Based on these findings, we summarize the close relationship between several DUBs and the precise modulation of mitophagy. For example, the USP8, USP10, and USP15, among many DUBs are reported to specifically regulate the K48- or K63-linked de-ubiquitination reactions of several target proteins associated with the mitophagic process, in turn upregulating the mitophagy and protecting neuronal cells from α-synuclein-derived toxicity. In contrast, USP30 inhibits mitophagy by opposing parkin-mediated ubiquitination of target proteins. Furthermore, the association between these changes and PD pathogenesis will be discussed. Taken together, although the functional roles of several PD-related genes have yet to be fully understood, they are substantially associated with mitochondrial quality control as well as UPS. Therefore, a better understanding of their relationship provides valuable therapeutic clues for appropriate management strategies.