Primary Productivity of Phytoplankton at the Eutrophic down Reach of a Regulated River (the Han River, Korea)

Namkung, Hyun,Hwang, Gil Son,Kim, Bom Chul,Kim, Kap Soo 한국육수학회 2001 생태와 환경 Vol.34 No.4

수도권의 중심부를 가로지르는 한강의 하류수역은 조수의 영향을 받을 수 있는 하구의 상단부에 위치해 있다. 한강 하류수역은 한강 종합개발사업의 일환으로 이루어진 준설과 수중보 건설에 의해서 강물이 정체되었으며, 또한 지천으로부터 유입되는 많은 오염물질에 의해서 식물플랑크톤의 대량 발생을 촉진할 수 있는 환경으로 변화되었다. 본 연구에서는 부영양한 한강 하류수역에서 식물플랑크톤의 1차생산을 측정하였으며, 더불어 내부생성유기물과 외부기원유기물을 산정하였다. 1차생산력은 C-14 uptake법과 P-I 모델법으로 측정하였다. 1차생산력의 범위는 140∼4,890 mgC m^-2 day^-1(중앙값 1,865 mgC m^-2 day^-1)이었으며, 국내의 부영양한 호수와 유사한 수준이었다. 식물플랑크톤의 생물량 변동은 봄철에 최대치를 보였으며, 유량의 변화와 관련이 있는 것으로 나타났다. 외부기원유기물은 여름철 홍수기를 제외한 연중 내내 지천을 통하여 유입되는 오염물질에 의해서 좌우되었다. 총 유기물 부하량에 대하여 식물플랑크톤의 1차생산이 차지하는 기여도는 40.9%로서, 유수 생태계로서는 높은 수준이었다. The downstream reach of the Han River adjoining Seoul in Korea was the upper boundary of an estuary where tidal effect on the flow rate could be exerted. According to the comprehensive river regulation project, the river was channelized and impounded by two overflow dams, which provided favorable condition for algal growth in this sewage polluted eutrophic reach. In this study primary productivity of phytoplankton was measured in the down reach and the autochthonous and allochthonous organic carbon loadings were estimated. Primary production of phytoplankton measured by C-14 uptake and P-I model method ranged from 140 to 4,890 mgC m^-2 d^-1 (median value 1,865 mgC m^-2 d^-1) showing the level of eutrophic lakes. Phytoplankton density that varied according to water flow rate was highest in spring. Allochthonous organic carbon loading was dominated by sewage input through tributaries in most of days except flood flow period. The average proportion of autochthonous carbon generation by phytoplankton was 40.9%, which is very high proportion for a lotic habitat.

Revision of the Fauna of Korean Spiders (Arachnida: Araneae)

Namkung, Joon,Kim, Seung-Tae,Lee, Joon-Ho 한국응용곤충학회 2000 Insecta Koreana Vol.17 No.4

A list of Korean spiders was revised, including 46 families 225 genera 622 species which were reported by December 1999. Of these 61 added species and 37 alterated scientific names were supplemented, and 3 species, which have been reported since June 1994, were newly synonymized. The spider fauna of Korea is composed of 12 Cosmopolitan, 34 Holarctic, 66 Palearctic and 136 Korean endemic species. The spider fauna of Korea has much more similarity with Japanese spider fauna than with those of other countries.

New evaluation measures for multifactor dimensionality reduction classifiers in gene-gene interaction analysis.

Namkung, Junghyun,Kim, Kyunga,Yi, Sungon,Chung, Wonil,Kwon, Min-Seok,Park, Taesung Oxford University Press 2009 Bioinformatics Vol.25 No.3

<P>Gene-gene interactions are important contributors to complex biological traits. Multifactor dimensionality reduction (MDR) is a method to analyze gene-gene interactions and has been applied to many genetics studies of complex diseases. In order to identify the best interaction model associated with disease susceptibility, MDR classifiers corresponding to interaction models has been constructed and evaluated as a predictor of disease status via a certain measure such as balanced accuracy (BA). It has been shown that the performance of MDR tends to depend on the choice of the evaluation measures.</P>

Characteristics of novel synthetic fuels using coal and sewage sludge impregnated bioliquid applying for a coal combustion system

Namkung, Hueon,Park, Ju-Hyoung,Lee, Young-Joo,Song, Gyu-Seob,Choi, Jong Won,Kim, Joeng-Geun,Park, Jun-Su,Um, Byung Hwan,Song, Kwang Ho,Park, Se-Joon,Choi, Young-Chan Elsevier 2017 Fuel processing technology Vol.167 No.-

<P><B>Abstract</B></P> <P>The application of biomass resources and sewage sludge is currently the most important issue in the field of coal combustion systems. The main drawback for operating a boiler system is its varied firing characteristics and low heating value. In this study, we have developed new synthetic fuels, namely hybrid sludge fuel (HSF), using coal and sewage sludge impregnated bioliquid (molasses) and evaluated their properties by comparison with conventional fuels. To prepare the HSF, it was treated in a carbonization system at 250°C. Depending on the van Krevelen diagram, the fuel quality of HSF was superior to that of raw bioliquid and sewage sludge. In addition, its fuel characteristic was similar to sub-bituminous and bituminous coal. Thermogravimetric analysis (TGA) indicated only a single-stage combustion pattern for HSF during non-isothermal heating. To clarify the unburned carbon (UBC) content, an ultimate analysis was conducted. The amount of UBC of the HSF was much more than that of sewage sludge, but less than that of coal. To investigate the surface hydrophobicity of HSF, Fourier transform infrared spectroscopy (FT-IR) analysis and a moisture re-adsorption test were carried out. The HSF possessed high hydrophobicity and presented a low moisture re-adsorption rate compared to conventional fuels.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The new synthetic fuel (HSF) using coal and sewage sludge impregnated bioliquid was investigated. </LI> <LI> HSF properties were similar to sub-bituminous and bituminous coal on the van Krevelen diagram. </LI> <LI> HSF showed single-stage combustion characteristics from the thermogravimetric analysis. </LI> <LI> HSF presented higher fuel reactivity in comparison with low reactivity coal. </LI> <LI> HSF had a higher hydrophobicity on the surface. </LI> </UL> </P>

Revision of the Fauna of Korean Spiders (Arachnida: Araneae)

Namkung, Joon,Kim, Seung-Tae,Lee, Joon-Ho Korean Society of Applied Entomology 2000 INSECTA KOREANA Vol.17 No.4

A list of Korean spiders was revised, including 46 families 225 genera 622 species which were reported by December 1999. Of these 61 added species and 37 alterated scientific names were supplemented, and 3 species, which have been reported since June 1994, were newly synonymized. The spider fauna of Korea is composed of 12 Cosmopolitan, 34 Holarctic, 66 Palearctic and 136 Korean endemic species. The spider fauna of Korea has much more similarity with Japanese spider fauna than with those of other countries.

The Spider Fauna of Gyeongju National Park, Korea

NamKung, Joon,Choi, Yong-Gun,Shin, Hee-Kwan,Yoo, Sea-Hee national science museum of korea 2008 Journal of Korean nature Vol.1 No.1

The authors has investigated spider fauna of Gyeongju National Park in Gyeongsangbuk-do of Korea from Apr. 2007 to Aug. 2007. The results are as follows: (1) In this report, 192 species of 105 genera belonging to 29 families of spiders have been collected at Gyeongju, National Park, Korea. (2) 178 (92.7%) species are newly added to the fauna of Gyeongju, National Park, Korea. (3) The spider fauna of Gyeongju National Park are composed of 32 northern species (16.7%), 6 southern species (3.1%), 4 Cosmopolitan species (2.1%), 19 Palaearctic temperate speies (9.9%) and 6 Korea endemic species (3.1%). (4) The predominant species of Gyeongju National Park area are known to Araneidae (16.1%), Salticidae (13.5%), Theridiidae (9.4%), Linyphiidae (8.9%), Thomisidae (7.8%) in number. (5) The dominant species of Gyeongju National Park area are showed as Achaearnea tepidariorum, Pholcus extumidus, Neriene nigripectoris, Pardosa astrigera, Pirata procurvus. (6) The common species to comparative with foreign countries are as follows: Gyeongju National Park / China 170 species (88.5%) Gyeongju National Park / Japan 168 species (87.5%) Gyeongju National Park / Russia 116 species (60.4%) Gyeongju National Park / Europe 29 species (15.1%) Gyeongju National Park / America 10 species (5.2%).

Who Buys Our Brand? The Influence of Consumption Values and the Congruity with Brand Benefits on Brand Identification, Trust and Loyalty

Namkung, Sol,Park, Seong-Yeon Korean Marketing Association 2021 ASIA MARKETING JOURNAL Vol.22 No.4

This paper explores how the positive effect achieved when consumption value matches brand benefit can increase brand loyalty. Prior research on consumption value mainly focused on perceived value; these studies omit consumers' views of consumption value. Therefore, this study examines the effect of congruence between consumption values (functional, emotional, social, and ethical value) and perceived brand benefits (enabling, enticing, symbolic, and socially responsible benefits) on consumers' brand identification, trust, and loyalty. We find a positive effect on brand identification and brand trust when a consumer's value is similar to a brand benefit, particularly between functional value and enabling benefit, and ethical value and socially responsible benefit. However, congruence between consumption value and perceived brand benefit only had an indirect effect on brand loyalty by mediating brand identification and trust. This study provides a basis for implementing a marketing strategy to build brand assets and increase brand loyalty by providing consumers with the value they want in a diversified market.

Regulation of Systemic Energy Homeostasis by Peripheral Serotonin

Namkung, Jun,Oh, Chang-Myung,Park, Sangkyu,Kim, Hail Association for Research of MPS and Rare Diseases 2016 Journal of mucopolysaccharidosis and rare disease Vol.2 No.2

Whole body energy balance is achieved through the coordinated regulation of energy intake and energy expenditure in various tissues including liver, muscle and adipose tissues. A positive energy imbalance by excessive energy intake or insufficient energy expenditure results in obesity and related metabolic diseases. Although there have been many obesity treatment trials aimed at the reduction of energy intake, these strategies have achieved only limited success because of their associated adverse effects. Serotonin is among those traditional pharmacological targets for anti-obesity treatment because central 5-HT functions as an anorexigenic neurotransmitter in the brain. Thus, there have been many trials aimed at increasing the activity of 5-HT in the central nervous system, and some of the developed methods are already used in the clinical setting as anti-obesity drugs. However, recent studies suggest the new functions of peripheral serotonin in energy homeostasis ranging from the endocrine regulation by gut-derived serotonin to the autocrine/paracrine regulation by adipocyte-derived serotonin. Pharmacological inhibition of 5-HT synthesis leads to inhibition of lipogenesis in epididymal white adipose tissue (WAT), induction of browning in inguinal WAT and activation of adaptive thermogenesis in brown adipose tissue (BAT). Fat specific Tph1 knock-out (Tph1 FKO) mice exhibit similar phenotypes as mice with pharmacological inhibition of 5-HT synthesis, suggesting the localized effects of 5-HT in adipose tissues. In addition, Htr3a KO mice exhibit increased energy expenditure in BAT and Htr2a KO mice exhibit the decreased lipid accumulation in WAT. These data suggest the clinical significance of the peripheral serotonergic system as a new therapeutic target for anti-obesity treatment.

INTERNATIONAL DETERMINANTS OF JAPANESE TRUST RATINGS OF FOREIGN NATIONS

Namkung, Gon The Institute for Far Eastern Studies, Kyungnam Un 1999 ASIAN PERSPECTIVE Vol.23 No.1

The study employs a multiregression model to test a hypothesis on international determinants of Japanese trust ratings of 32 foreign nations. I divide explanatory determinants into the following three categories: first, national characteristics of the 32 nation-objects (regime type, economic standard of living, and national power), second, economic interdependence between Japan and the 32 nation-obejcts, and third, inherent cultural similarity to Japan of the 32 nation-objects. I found that both the "political democracy" and "economic interdependence" variables have substantial impacts on Japanese trust ratings of the 32 foreign nation-objects. Based on these findings, it is basically argued that that the promotion of democracy for each nation and multi-level economic interdependence among nations apparently leads to good interpersonal relationship among their peoples as seen in high levels of trust. However, national power and cultural similarity are not good indicators for measuring Japanse turst ratings of foreign nations. Even if national power for a nation is colinear with its economic achievement, I could not find any statistically significant association between national power of a foreign nation-object and Japanese trust rating of that nation. An analysis of a dummy variable (cultural similarity) does not prove that the Japanese give higher trust ratings to East Asian nations than culturally dissimilar and geographically distant nations.

Identification of gene-gene interactions in the presence of missing data using the multifactor dimensionality reduction method

Namkung, Junghyun,Elston, Robert C.,Yang, Jun-Mo,Park, Taesung Wiley Subscription Services, Inc., A Wiley Company 2009 Genetic epidemiology Vol.33 No.7

<P>Gene-gene interaction is believed to play an important role in understanding complex traits. Multifactor dimensionality reduction (MDR) was proposed by Ritchie et al. [2001. Am J Hum Genet 69:138–147] to identify multiple loci that simultaneously affect disease susceptibility. Although the MDR method has been widely used to detect gene-gene interactions, few studies have been reported on MDR analysis when there are missing data. Currently, there are four approaches available in MDR analysis to handle missing data. The first approach uses only complete observations that have no missing data, which can cause a severe loss of data. The second approach is to treat missing values as an additional genotype category, but interpretation of the results may then be not clear and the conclusions may be misleading. Furthermore, it performs poorly when the missing rates are unbalanced between the case and control groups. The third approach is a simple imputation method that imputes missing genotypes as the most frequent genotype, which may also produce biased results. The fourth approach, Available, uses all data available for the given loci to increase power. In any real data analysis, it is not clear which MDR approach one should use when there are missing data. In this article, we consider a new EM Impute approach to handle missing data more appropriately. Through simulation studies, we compared the performance of the proposed EM Impute approach with the current approaches. Our results showed that Available and EM Impute approaches perform better than the three other current approaches in terms of power and precision. Genet. Epidemiol. 33:646–656, 2009. © 2009 Wiley-Liss, Inc.</P>