• Korean Journal of Environmental Agriculture
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• v.42 no.2
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• pp.83-92
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• 2023

Excess N and P from the livestock manure applied to farmlands, have entered the water systems and poses a serious threat to the natural environment. Consequently, there has been recent awareness towards the management of livestock manure and its related fields. In this study, piggery wastewater was collected from a piggery in Pohang city, Korea. At 800℃, thermal decomposition of a natural stone, magnesite (MgCO₃), yielded powered MgO with particle sizes ranging between 10 to 100 ㎛. Furthermore, NH₄⁺-N and PO₄^3--P were recovered as struvite precipitates from the piggery wastewater, by adjusting the pH with MgO and H₃PO₄. At pH 10, the recovery efficiencies of NH₄⁺-N and PO₄^3--P were found to be 86.1% and 94.1%, respectively. Using an X-ray Diffractometer (XRD), the struvite in the precipitate was confirmed to be consistent with standard pure struvite. Further, the purity of the struvite precipitate was analyzed using an energy dispersive X-ray (EDX) and thermal gravimetry-differential thermal analysis (TG-DTA), and found to be between 79.2% and 93.0%. Additionally, struvite-containing piggery wastewater and sawdust were mixed in a weight ratio of 2.5:1 and processed into a mature compost. The newly manufactured compost passed all quality standards required for first-class graded livestock composts. Moreover, this compost was sprayed directly onto the soil at the test site, and various parameters of the soil's effluent, such as total organic carbon (TOC), total nitrogen (T-N), total phosphorus (T-P), and dissolved oxygen (DO), were analyzed and measured. Based on these results, it is determined that the newly manufactured compost can more significantly reduce water pollution than commercial compost.

• Parasites, Hosts and Diseases
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• v.61 no.4
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• pp.439-448
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• 2023

Tick infestation causes a significant threat to human and animal health, requiring effective immunological control methods. This study aimed to investigate the potential of recombinant Haemaphysalis longicornis enolase protein for tick vaccine development. The exact mechanism of the recently identified enolase protein from the H. longicornis Jeju strain remains poorly understood. Enolase plays a crucial role in glycolysis, the metabolic process that converts glucose into energy, and is essential for the motility, adhesion, invasion, growth, and differentiation of ticks. In this study, mice were immunized with recombinant enolase, and polyclonal antibodies were generated. Western blot analysis confirmed the specific recognition of enolase by the antiserum. The effects of immunization on tick feeding and attachment were assessed. Adult ticks attached to the recombinant enolase-immunized mice demonstrated longer attachment time, increased bloodsucking abilities, and lower engorgement weight than the controls. The nymphs and larvae had a reduced attachment rate and low engorgement rate compared to the controls. Mice immunized with recombinant enolase expressed in Escherichia coli displayed 90% efficacy in preventing tick infestation. The glycolytic nature of enolase and its involvement in crucial physiological processes makes it an attractive target for disrupting tick survival and disease transmission. Polyclonal antibodies recognize enolase and significantly reduce attachment rates, tick feeding, and engorgement. Our findings indicate that recombinant enolase may be a valuable vaccine candidate for H. longicornis infection in experimental murine model.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.4
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• pp.323-333
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• 2024

Polychlorinated biphenyls (PCBs) were once used throughout various industries; however, because of their persistence in the environment, exposure remains a global threat to the environment and human health. The Kv1.3 and Kv1.5 channels have been implicated in the immunotoxicity and cardiotoxicity of PCBs, respectively. We determined whether 3,3',4,4'-tetrachlorobiphenyl (PCB77), a dioxin-like PCB, alters human Kv1.3 and Kv1.5 currents using the Xenopus oocyte expression system. Exposure to 10 nM PCB77 for 15 min enhanced the Kv1.3 current by approximately 30.6%, whereas PCB77 did not affect the Kv1.5 current at concentrations up to 10 nM. This increase in the Kv1.3 current was associated with slower activation and inactivation kinetics as well as right-shifting of the steady-state activation curve. Pretreatment with PCB77 significantly suppressed tumor necrosis factor-α and interleukin-10 production in lipopolysaccharide-stimulated Raw264.7 macrophages. Overall, these data suggest that acute exposure to trace concentrations of PCB77 impairs immune function, possibly by enhancing Kv1.3 currents.

• Korean Journal of Plant Taxonomy
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• v.46 no.2
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• pp.213-246
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• 2016

Algific talus slopes tend to occur on steep north-facing slopes with bedrock that retains ice and emits cold air throughout the growing season. Algific talus slopes provide a suitable microclimate for disjunct or relict populations of northern plant species at low altitude habitats in temperate zones. The purpose of this study is to suggest a strategy for the comprehensive conservation of the vegetation of algific talus slopes through studies of the floristics and plant species compositions and threat factors at present and in the future of 15 major algific talus slopes in Korea. As a result, the vascular plants surveyed on 15 major algific talus slopes were recorded, with a total of 587 taxa, 109 families, 323 genera, 531 species, 7 subspecies, 47 varieties 1 form and 1 hybrid. Of them, endemic plants numbered 26 taxa, and threatened species according to the IUCN valuation basis numbered 8 taxa. Fourth (IV) and fifth (V) degree indicator species as specified by floristic subregions numbered 31 taxa. Peculiarly, several subalpine-native plant species, in this case Cystopteris fragilis, Gymnocarpium dryopteris, Huperzia selago, Rosa koreana, Vaccinium vitis-idaea and Woodsia hancockii, were distributed on algific talus slopes at 100-600 m above sea level. Numerous and diverse biological resources native to algific talus slopes in Korea have been consistently disturbed or damaged by human activities without some form of protection. An all-taxa biodiversity inventory should be surveyed to provide more information about all biological species living on algific talus slopes. In addition, conservation strategies to ensure biodiversity and effective management of algific talus slopes are discussed in detail.

• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.366-377
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• 2019

Paddy wetlands are a critical habitat for a variety of wild animals, and their rapid development and environmental changes pose a threat to the conservation of agrobiodiversity. The objectives of this study were to evaluate the habitat characteristics of anuran inhabiting paddy wetlands and identify major environmental variables affecting their distributions. The study was conducted in the Daeho reclaimed area in Dangjin, from March to October 2018. In this study, we found three anuran species (Pelophylax nigromaculatus, Hyla japonica and Pelophylax chosenicus). The environmental factors affecting the three species were identified as air temperature, humidity, water-depth, and micro-habitats. H. japonica were affected by water temperature, and P. chosenicus were affected by rice height and types of farming practices. All the three species richness was correlated with air temperature, humidity, and water-depth positively, and the three species used rice transplanted paddy fields the most. It was also found that paddy is the most preferred of the micro-habitats during the breeding season, so the survey area is considered to be used as the major breeding sites for the three species. P. chosenicus were more observed on environmental-friendly paddy fields than conventional paddy fields, which appears to be differences in their surroundings environment caused by predators and weeding. It will be needed to identify their relationship with predators, their preferred food resources and the richness and diversity of wild vegetation around paddy wetlands.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.512-518
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• 2015

Pine wilt disease (PWD) caused by pine wood nematode, Bursaphelenchus xylophilus, has become the most serious threat to pine trees in Korea. This study was subjected to investigate effective biological control agent against PWD. To select nematocidal bacteria against PWD, Bacillus licheniformis MH48 was selected among five bacteria due to its high nematocidal potential. B. licheniformis MH48 was tested for cell growth and protease activity to evaluate its nematicidal potential. In the B. licheniformis MH48, cell numbers were highest three days after incubation, while protease activity was highest after seven days. In the effect of different concentrations of B. licheniformis MH48 culture broth against B. xylophilus, 20% concentration of culture broth showed approximately 80% of pine wood nematode mortality compared to the control. Especially, pine wood nematode's cuticle layers were degraded two days after treatment of B. licheniformis MH48 culture broth. The present study suggests that B. licheniformis MH48 can be one of the potential biocontrol candidates against pine wood nematode due to its ability to produce protease.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.181-189
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• 2018

This study was performed to analyze the dynamics and distributional condition of biological community and to support the basic information about the estuarine ecosystem management by using the intensively surveyed results by each taxon experts around Tamjin river. We analyzed the biological diversity, abundance, correlation among species, and ecological characteristics about 11 taxa groups including vegetation, fish, birds, mammals, etc. in the Tamjin river estuarine ecosystem. We classified vegetation types into 7 physiognomic types and 18 communities according to habitat conditions with the physical environments and salinity. In total, 1125 species including 9 species of endangered species were identified in research area. The species composition and distributional characteristics of each taxon were corresponded to the environmental characteristics of the estuarine ecosystem. Especially, the species diversity and distribution were clearly distinguished in the river according to the difference of the environmental factors such as flow rate, salinity, and soil. Despite the disturbance factors such as barrage and levees, the biodiversity and its distribution were evaluated to be high level under the current environmental conditions. However, loss or reduction of wildlife habitat due to reclamation, embankment, barrage installation and expansion of farmland has been identified as a major threat to the diversity and health of the local ecosystem. The results of this study can be used as a basic data to cope with various development pressure and damage crisis of the whole estuaries including Tamjin river.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.173-178
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• 2011

BACKGROUND: Starfish is one of major sea invertebrates that have become a serious economic threat to aquacultural farms in Korea. Much effort has sacrificed to reduce the economic losses of the farms by predatory starfish, including developing and searching biological resources for medicinal and agricultural purposes. In the present study, we investigated aphicidal activity of the extracts from the starfish Asterina pectinifera against green peach aphid. METHODS AND RESULTS: Fresh starfishes were cut into small pieces, homogenized and soaked in methanol. The methanol extracts were centrifuged and the resulting supernatant was subjected to aphicidal activity assays and a series of silica gel column chromatography. More than 70% mortality of aphids were observed by the extracts at a concentration of 1,000 mg/L, exhibiting dose-dependent mortality. TOF-MS analyses detected polyhydroxysteroid as a main aphicidal compound from the starfish extracts. Transmission electronic microscopy could demonstrate that the extracts with polyhydroxysteroid caused aphids death by affecting their epicuticular membrane. CONCLUSION(s): This is the first report of aphicidal activity of the starfish Asterina pectinifera extracts against green peach aphid. Starfish biological resources may be used as a potential candidate for developing a new type natural insecticide.

• Korean Security Journal
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• no.24
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• pp.91-123
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• 2010

The threat factors available for occurrence given G20 Summit Meeting are expected leader terrorism, hostage terrorism, bomb terrorism, public facilities terrorism, and aircraft terrorism. As for the threat groups, which are expected in Korea, the North Korea, Islam extremist group, and the group such as NGO organization of being opposed to international meeting are regarded as having possibility of causing hazard. Thus, the purpose of this study is to suggest VIP Security-measure plans in the main site in preparation for G20 Summit Meeting. Accordingly, each country in the world is adopting 'the principle of Triple Ring' in common. Thus, it elicited a coping plan by 1st line(inner ring) 2nd line(middle ring) 3rd line(outer ring) based on this principle, and proposed even an opinion together that will need to be reflected in light of policy for the VIP security measures. In conclusion, as for the VIP Security-measure plans in the main site in preparation for G20 Summit Meeting, In the inner ring(safety sector), first, an intercepting measure needs to be devised for a spot of getting into and out of vehicles given the Straight Street. Second, the Walking Formation needs to be reinforced boldly in the exposed area. In the middle ring(security sector), first, the control plan needs to be devised by considering particularity of the main site. Second, there is necessity for adopting the efficient security badge operation plan that is included RFID function within security badge. In the outer ring(aid protective sector), first, there is necessity of preparing for several VIP terrorisms, of collecting information and intelligence, and of reinforcing the information collection system against terrorism under the cooperation with the overseas information agency. Second, the urgent measure training in time of emergency needs to be carried out toward security agent event manpower. Third, to maintain the certain pace in VIP motorcade, the efficient traffic control system needs to be operated. Finally, as for what will need to be reflected in light of policy for VIP security measures, first, there is necessity for allowing VIP residence to be efficiently dispersed to be distributed and controlled. Second, there is necessity for allowing impure element to misjudge or attack to be failed by utilizing diverse deception operations. Third, according to the reorganization in North Korea's Organization of the South Directed Operations, the powerful 'military-support measure' needs to be driven from this G20 Summit Meeting. For this, the necessity was proposed for further reinforcing the front back defense posture under the supervision of the Ministry of National Defense and for positively coping even with detecting and removing poison in preparation for CBR (chemical, biological, and radio-logical) terrorism.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.460-465
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• 2007

In this study, the removal characteristic of ammonia nitrogen and behavior of nitrogen was investigated using Leclercia adecarboxylata, which was derived from the culture contaminated by ammonia nitrogen of high concentration. The method of ammonia nitrogen removal was not biological nitrification and denitrification but elimination of nutrient salt with internal synthesis of microorganisms which use ammonia nitrogen as substrate. L. adecarboxylata(one of ammonia synthesis microorganisms) was highly activated and showed the most high removal efficiency in free salt condition but the removal efficiency decreased badly in salt concentration of more than 4%. About 80 mg/L of $NH_3-N$ was mostly removed within 20 hours and 500 mg/L of $NH_3-N$ showed less then removal efficiency of 50% because carbon source was not enough. However, ammonium nitrogen concentration was decreased again when the carbon source was inserted additionally thus, ammonium nitrogen removal efficiency by L. adecarboxylata, was related to amount of carbon source. pH decreased from 8.0 to 6.36 according to growth of L. adecarboxylata. Concentration of nitrite nitrogen and nitrate nitrogen did not increase and TKN concentration showed no variation while ammonia nitrogen was removed by L. adecarboxylata. In addition to, when content of protein in organic nitrogen was measured, protein was not detected at the beginning of microorganism synthesis but protein of 193.1 mg/L was detected after 48 hours. Hence, ammonium nitrogen was not decomposed as nitrate nitrogen and nitrite nitrogen but synthesized by L. adecarboxylata, which has excellent ability of nitrogen synthesis and can threat ammonia nitrogen of high concentration in wastewater.