• Environmental Engineering Research
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• v.11 no.4
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• pp.194-200
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• 2006

Recently, the population growth, industrial and agricultural development are rapidly undergoing in the Lower Rio Grande Valley (LRGV) in Texas. The Lower Rio Grande Valley (LRGV) composed of the 4 counties and three of them are interesting for Non-point and point source pollutant modeling: Starr, Cameron, and Hidalgo. Especially, the LRGV is an intensively irrigation region, and Texas A&M University Agriculture Program and the New Mexico State University College of Agriculture applied irrigation district program, projects in GIS and Hydrology based agricultural water management systems and assessment of prioritized protecting stream network, water quality and rehabilitation based on water saving potential in Rio Grande River. In the LRGV region, where point and non-point sources of pollution may be a big concern, because increasing fertilizers and pesticides use and population cause. This project objective seeks to determine the accumulation of non-point and point source and discuss the main impacts of agriculture and environmental concern with water quality related to pesticides, fertilizer, and nutrients within LRGV region. The GIS technique is widely used and developed for the assessment of non-point source pollution in LRGV region. This project shows the losses in $kg/km^2/yr$ of BOD (Biological Oxygen Demand), TN (total Nitrogen) and TP (total phosphorus) in the runoff from the surface of LRGV. Especially, farmers in Cameron County consume a lot of fertilizer and pesticide to improve crop yield net profit. Then, this region can be created as larger nonpoint source area for nutrients and the intensity of runoff by excess irrigation water. And many sediment and used irrigation water with including high nutrients can be discharged into Rio Grade River.

• Environmental Analysis Health and Toxicology
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• v.13 no.3_4
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• pp.105-115
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• 1998

Reactive oxygen species (ROS) are highly reactive molecules due to their unpaired electron. They have been suspected as one of the major tissue damage inducers in biological metabolic systems. Antioxidant enzymes, such as catalase and superoxide dismutase, could not repair all the oxidative damages resulting from those excessive toxic ROS. It is, therefore, urgent to develop effective antioxidants to relieve from the oxidatire damages. In this study antioxidative effects were investigated by using two flavonoids such as quercetin and naringenin and a flavonoid-rich extract, Ginkgo biloba extract in combination with paraquat that is known as a strong generator of oxygen radicals. The results are summeringed as follows: 1. To assess radical scavenging ability reduction concentrations (IC$_{50}$) of 1,1-diphenyl-2-picrylhydrazine (DPPH) within 15 minutes were measured. The values of the IC$_{50}$ of quercetin and Ginkgo biloba extract were 15.4 $\mu$M and 13.2$\mu$g/ml, respectively. Their radical removing activities showed concentration-dependent manners. 2. In the hydrogen peroxide assay by using PMS-NADH system, quercetin, naringenin and Ginkgo biloba extract led to removing hydrogen peroxide in concentrationdependent manner whose removing abilities at 100$\mu$M or 100 $\mu$g/ml were 75.6, 25.8 and 26.0%, respectively. 3. In the hydrogen peroxide-induced rat blood hemolysis assay all three compounds led to similar effects whose hemolysis inhibition ratios at 100$\mu$M or 100$\mu$g/ml were 68.0, 5.14 and 55.8%, respectively. 4. In the xanthinee oxidase assay by measuring degree of NADH oxidation in the presence of hypoxanthine and xanthinee oxidase, both quercetin and Ginkgo biloba extract showed excellent activities showing 42.8 and 24.2% inhibiting xanthine oxidase activity at 100$\mu$M or 100$\mu$g/ml concentrations, respectively.

• Journal of Plant Biotechnology
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• v.33 no.3
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• pp.161-169
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• 2006

Plant metabolomics is a plant biology field for identifying all of the metabolites found in a certain plant cell, tissue, organ, or whole plant in a given time and conditions and for studying changes in metabolic profiling as time goes or conditions change. Metabolomics is one of the most recently developed omics for holistic approach to biology and is a kind of systems biology. For holistic approach, metabolomics frequently uses chemometrics or multivariate statistical analysis of metabolic profillings. In plant biology, metabolomics is useful to determine functions of genes often in combination with DHA microarrays by analyzing tagged mutants of the model plants Arabidopsis and rice. This review paper attempted to introduce basic concepts of metabolomics and practical uses of multivariate statistical analysis of metabolic profiling obtained by $^1$H HMR and Fourier transform infrared spectrometry.

• Korean Journal of Plant Taxonomy
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• v.37 no.3
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• pp.309-321
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• 2007

Korea national arboretum has worked with the plant taxonomic society of Korea to make the first fully electronic floristic checklist in Korea. The result is an ever-expanding online plant name index containing scientifically authorative, up-to-date information on the approximately 7,000 taxa including cultivars. With 37 contributing taxonomists, KPNI is the largest collaborative research projects ever assembled in Korea. A comprehensive database model for the taxonomic data from literature and other sources is presented, which was devised for the Korea National Plant Index database project (KPNI). Gwangreung database model is based on an approach using entity-relationsip diagram. It encompasses taxa of all ranks, nothotaxa and hybrid formulae, cultivars, full synonymy, basionyms, Korean name, and other nomenclatural information. Ths paper presents an analysis of KPNI work processes and an overview how we are approaching the construction of Gwangreung databaese model. It can help the system engineers of other biological information systems to develop their database based on the accurate and integrative taxonomic database.

• Journal of Forest and Environmental Science
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• v.25 no.3
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• pp.177-185
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• 2009

Dryland species and ecosystems have developed unique strategies to cope with low and sporadic rainfall. They are highly resilient and recover quickly from prevailing disturbances such as fires, herbivore pressure and drought. Dryland people have engineered pastoral and farming systems, which are adapted to these conditions and have sustained the livelihoods of dryland people for centuries. In this article, we present the status of potentials and threats to dryland biodiversity and explore options for its conservation and sustainable use. Findings of the research can be summarized as follows: (i) The ecosystem goods and services are highly valued by the community but mechanism for wise use of the resources has disappeared, (ii) forests are under the ownership of the government but the local community is the realistic custodian of the forests through village leaderships and environmental committees; (iii) the immediate major threat to dryland biodiversity held in the forests appears to be the degradation of ecosystems and habitats caused by new and powerful forces of environmental degradation such as large scale irrigation of rice farms, poverty-induced overexploitation of natural resources, and disappearance and ignorance of traditional institutions for management of dryland biodiversity. These new forms of disturbances often overpower the legendary resilience of dryland ecosystems and constitute potentially serious threats to dryland biodiversity. Forests, wetlands and oases all of which are micro hot spots of dryland biodiversity, appear to be particularly vulnerable hence the need to set up some rules and regulations for sustainable utilization of these resources.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.376-395
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• 1996

The neuropeptide substance P(SP) has been recognized to modulate immune systems, with close proximity between peptidergic sensory nerve endings and immune cells. These include the macrophage and neutrophil activation, IL-2 production in T cell, augmentation of Ig synthesis, mast cell degranulation, $PGE_2$ and collagenase secretion in synoviocytes. In this study I examined SP-induced various biological activities such as antimicrobial action, cytokine production, and mast cell degranulation in the presence or absence of other inflammatory cell activators. Antimicrobial studies showed that undifferentiated HL-60 cells were not affected by SP. However, SP significantly enhanced antimicrobial action of TPA-treated or dbcAMP-treated HL-60 cells which had been differentiated into PMN or macrophage/monocyte. I could not find synergistic relationship between SP and LPS in parallel experiments of the above. SP did not induce IL-l production from murine macrophage cell line RAW264.7 whether costimulated with LPS or not. Mast cell degranulation was occured only when stimulated with high dose ($10^{-5}M$) of SP and the degree of this activation was slightly reduced by simultaneous application of $MIP-1{\alpha}$. In addition, CGRP which is known to be a common coexisting neuropeptide with SP within specific fibers did not augment the function of SP on mast cell degranulation. These results suggest that immunoregulatory activities of SP could be mediated through direct upregulation of various functions of immune cells and also upregulation of responsiveness of immune cells to other immune activators.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1555-1560
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• 2010

Quantum dots (QDs) are extensively employed for biomedical research as a fluorescence reporter and their use for various labeling applications will continue to increase as they are preferred over conventional labeling methods for various reasons. However, concerns have been raised over the toxicity of these particles in the biological system. Till date no thorough investigation has been carried out to identify the molecular signatures of QD mediated toxicity. In this study we evaluated the toxicity of CdSe, $Cd_{1-x}Zn_xS$/ZnS and CdSe/ZnS quantum dots having different spectral properties (red, blue, green) using human embryonic kidney fibroblast cells (HEK293). Cell viability assay for both short and long duration exposure show concentration material dependent toxicity, in the order of CdSe > $Cd_{1-x}Zn_xS$/ZnS > CdSe/ZnS. Genome wide changes in the expression of genes upon QD exposure was also analyzed by wholegenome microarray. All the three QDs show increase in the expression of genes related to apoptosis, inflammation and response towards stress and wounding. Further comparison of coated versus uncoated CdSe QD-mediated cell death and molecular changes suggests that ZnS coating could reduce QD mediated cytotoxicity to some extent only.

• Journal of Environmental Health Sciences
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• v.40 no.3
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• pp.187-203
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• 2014

Objectives: As the demand to deal with pathogens in domestic research institutions has expanded and biological accidents have increased, the need for systematic biosafety management in infectious disease laboratories has grown. According to international standards, risk assessment (RA) is required for biosafety management. However, RA criteria have not been clearly established in Korea, so to this end I have attempted to determine RA criteria meeting international levels Methods: In order to provide RA criteria for application, I analyzed the RA criteria in use in the U.S., Europe and at international organizations. In order to ensure the public nature of the RA criteria, I constructed the research model through modified management consulting methodology reflecting the model of Radnor and O'Mahoney. Results: According to the results of the study, existing laboratory biosafety regulations were comparable to domestic laboratory safety laws. Existing laboratory biosafety standards that are designed around risk factors were found to be insufficient. An RA case to be carried out in infectious disease laboratories at the National Institute of Health of KCDC was identified. Conclusion: To establish a systematic risk management system meeting international standards, it was necessary first to harmonize the systems of national and international standards. In addition, in order to provide specific biosafety management on-site, I recognized a need for methodology and planning strategies to discover biosafety management so that it can be carried out as required through the RA of individual laboratories.

• Korean Journal of Agricultural Science
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• v.44 no.1
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• pp.40-49
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• 2017

Cultural practices for adzuki bean and the distribution of weed species in the south-west regions of Korea were surveyed to provide information on effective weed management. Approximately 27.5% of the farm households were growing adzuki bean in an area larger than 1 ha while the rest grew the crop in an area smaller than 1 ha. Of all adzuki bean growers, 17.1% seeded in early June, 8.6% in mid June, 34.3% in late June, 17.1% in early July, 20.0% in mid July, and 2.9% in late July. The average planting distance was $71.0{\times}29.5cm$. From the 40 surveys in adzuki bean fields, 35 weed species in 17 families were identified. According to the occurrence frequency, the dominant weed species were Digitaria sanguinalis, Acalypha australis, Cyperus amuricus, Echinochloa crus-galli, and Amaranthus nangostanus in decreasing order of dominance. However, based on dry weight, Chenopodium album (34.4%) was the most dominant followed by Acalypha australis (21.9%), Amaranthus nangostanus (19.1%), Digitaria sanguinalis (7.5%), and Portulaca oleracea (6.1%). The exotic weeds found in the field of adzuki were Ipomoea hederacea, Abutilon avicennae, and Celosia argentea. The plant heights of I. hederacea, A. avicennae, and C. argentea were 259 cm, 98 cm, and 76 cm, respectively, while the fresh weights were 850 g, 66 g, and 101 g, respectively. Integrated weed management systems utilizing mechanical, chemical, and biological control techniques need to be developed for effective weed management in adzuki bean production.

• Advances in environmental research
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• v.1 no.1
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• pp.15-35
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• 2012

Mercury (Hg) is a global environmental pollutant that has been the cause of many public concerns. One particular concern about Hg in aquatic systems is its trophic transfer and biomagnification in food chains. For example, the Hg concentration increases with the increase of food chain level. Fish at the top of food chain can accumulate high concentrations of Hg (especially the toxic form, methylmercury, MeHg), which is then transferred to humans through seafood consumption. Various biological and physiochemical conditions can significantly affect the bioaccumulation of Hg-including both its inorganic (Hg(II)) and organic (MeHg) forms-in fish. There have been numerous measurements of Hg concentrations in marine and freshwater fish worldwide. Many of these studies have attempted to identify the processes leading to variations of Hg concentrations in fish species from different habitats. The development of a biokinetic model over the past decade has helped improve our understanding of the mechanisms underlying the bioaccumulation processes of Hg in aquatic animals. In this review, I will discuss how the biokinetic modeling approach can be used to reveal the interesting biodynamics of Hg in fish, such as the trophic transfer and exposure route of Hg(II) and MeHg, as well as growth enrichment (the increases in Hg concentration with fish size) and biomass dilution (the decreases in Hg concentration with increasing phytoplankton biomass). I will also discuss the relevance of studying the subcellular fates of Hg to predict the Hg bioaccessibility and detoxification in fish. Future challenges will be to understand the inter- and intra-species differences in Hg accumulation and the management/mitigation of Hg pollution in both marine and freshwater fish based on our knowledge of Hg biodynamics.