왕피천 수계 내 저서성 대형무척추동물의 군집구조 분석을 위해 총 5개 지점에서 2023년 총 4회(4월, 6월, 8월 11월) 조사를 실시하였다. 조사기간 중 저서성 대형무척추동물은 총 5문 7강 17목 77과 156종 17,179.1개체/㎡가 채집되었다. 수환경 변화에 민감한 E.P.T. 분류군은 전체 156종 중 91종이 출현하여, 전체 출현종의 58.3%를 차지 하였다. 섭식기능군(FFGs) 분석결과, 종 출현 양상은 육식성 포식자(Predator: P)가 51종(32.69%)으로, 개체 출현 양상은 주워먹는 무리(Gathering-collector: GC)가 6,867.2개체/㎡(39.97%)로 높은 비율로 출현하였다. 서식기능 군(FHGs) 분석결과, 붙는 무리(Clinger: CL)가 70종(44.87%), 12,720.6개체/㎡(74.04%)로 가장 높은 비율로 출현 하였다. 군집지수 분석결과, 우점도지수(DI) 0.43, 다양도지수(H′) 3.51, 풍부도지수(R1) 4.59 균등도지수(J′) 0.77 로 나타났다. 생물학적 수질 판정 지수(BMI) 분석결과, 평균 92.36(±0.83)으로 모든 지점에서 “매우 좋음”으로 판정되었다.

A surveillance of chigger mites was performed to monitor the incidence of scrub typhus vectors at four environmental collection points in two locations (Sunchang and Haenam) in the Honam region of Korea from August to December 2023. During the surveillance period, 4,174 chigger mites were collected and the predominant species were Leptotrombidium scutellare (94.3%). The density of chigger mites had the peaked at 44 week (10.26~11.1), while the density of patients peaked at 45 week (11.2~11.8) respectively. A positive correlation (r=0.69) observed between scrub typhus patients and vectors. This result suggests that this vector surveillance method will be useful for alarm system of tsutsugamushi disease. However, the relationship between scrub typhus cases and chigger mite density will be studied through long-term periodic surveillance.

본 연구는 국내에서 실내 관상용으로 많이 활용되는 스킨답 서스의 실내재배 시 적정 인공광원, 수경재배 전기전도도 농 도 및 용토를 선발하기 위하여 수행하였다. 실내재배 시 인공 광원은 형광등, 적청 LED, 백색 LED로 처리하였다. 수경재배 시 양액 농도는 EC 1.2, 1.6, 2.0ds·m-1 수준으로 하였고, 재 배용토는 제올라이트, 코코피트, 펄라이트, 황토볼 4가지로 달리하였다. 스킨답서스의 실내 재배 시 줄기 길이는 형광등 과 적청 LED 처리보다 백색 LED 처리에서 길어졌다. 잎의 크기는 적청 LED 처리에서 형광등과 백색 LED 처리보다 커 지는 경향이었다. 엽록소 지수값은 백색 LED>적청 LED>형광 등 순으로 높았다. 수경재배 시 스킨답서스의 줄기길이는 EC 농도가 높아질수록 길어지는 경향이었고, 용토별로 비교하면 제올라이트와 코코피트에서 높은 경향이었다. 엽록소 지수값 도 EC 농도와 비례하여 높아졌고, 용토별로는 제올라이트와 코코피트에서 높았다. 스킨답서스의 생체중도 EC 농도가 높 을수록 높았고, 제올라이트와 코코피트에 높은 경향이었다. 상기 결과들을 종합할 때, 스킨답서스의 NFT를 이용한 실내 재배 시 적정 인공광원으로는 백색 LED를, 수경재배 양액의 농도는 EC 1.6∼2.0ds·m-1를, 그리고 NFT 용토는 제올라이 트나 코코피트가 적합하다는 것을 알 수 있었다.

KORAD (Korea Radioactive Waste Agency, http://www.korad.or.kr) has stored slightly contaminated ascon (asphalt coated concrete mixture) that was introduced to Gyeongju repository about a decade ago waiting for a final disposal. It is believed to be mainly contaminated by radioisotope 137Cs due to impurities introduced from the outside during the ascon manufacturing process. We studied characteristics of the radioactive waste to see whether this material would be proper enough to be disposed in Gyeongju LILW repository or be other ways to reduce the disposal volume including self-disposal before its final disposal otherwise. KORAD looked into the properness of characteristics of ascon in terms of WAC (Waste Acceptance Criteria) documented by KORAD that includes general chemical and physical properties of asphalt, density, size of grains, content of organic material and possibility of existence of chelate materials that qualitatively limited to be disposed by the criteria. And other associated characteristics such as gas generation and bio degradation were also investigated. Based on the data obtained from the study, we proposed various plausible solutions in associated with operational and disposal safety and economic view points. This study will be used for KORAD’s decision on how to control and safely dispose the spent ascon within a reasonable time period. And also those experiences may be applied for other LILW issues that require treatment or conditioning of radioactive wastes in the future.

This study analyzed the chemical characteristics and physiological activity of five kinds of fresh vegetables produced in trees in early spring and tried to use them as basic data for wild vegetable producers and processed food manufacturers using wild vegetables. The crude protein, minerals, ascorbic acid, folate, total phenol, total flavonoid, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and ACE (angiotensin converting enzyme) inhibitory activity were determined. Five spring wild vegetables contain high protein and phosphorus, indicating that they are useful food ingredients as sources of protein and phosphorus. Vitamin C content was high in R. venicifera and C. sinensis shoots, and in particular, R. venicifera and A. cortex shoots have high folic acid (folate) contents of 1,903.91 ug% and 1,525.35 ug%, respectively, which is considered a good food for folic acid intake in spring. The total phenol content was between 0.52% and 1.27%, and it was the highest in C. sinensis of 1.27%, followed by the order of R. venicifera, A.cortex, K.pictus, and A. elata, which tended to be consistent with the total flavonoid content. As for DPPH radical scavenging ability, C. sinensis (55.93%) showed the highest activity, and ACE inhibitory activity showed the highest activity in A. cortex (88.04%).

To investigate the effect of the catalyst and metal–support interaction on the methane decomposition behavior and physical properties of the produced carbon, catalytic decomposition of methane (CDM) was studied using Ni/SiO2 catalysts with different metal–support interactions (synthesized based on the presence or absence of urea). During catalyst synthesis, the addition of urea led to uniform and stable precipitation of the Ni metal precursor on the SiO2 support to produce Ni-phyllosilicates that enhanced the metal–support interaction. The resulting catalyst upon reduction showed the formation of uniform Ni0 particles (< 10 nm) that were smaller than those of a catalyst prepared using a conventional impregnation method (~ 80 nm). The growth mechanisms of methane-decomposition-derived carbon nanotubes was base growth or tip growth according to the metal–support interaction of the catalysts synthesized with and without urea, respectively. As a result, the catalyst with Ni-phyllosilicates resulting from the addition of urea induced highly dispersed and strongly interacting Ni0 active sites and produced carbon nanotubes with a small and uniform diameter via the base-growth mechanism. Considering the results, such a Ni-phyllosilicate-based catalyst are expected to be suitable for industrial base grown carbon nanotube production and application since as-synthesized carbon nanotubes can be easily harvested and the catalyst can be regenerated without being consumed during carbon nanotube extraction process.

Intermuscular fat is essential for enhancing the flavor and texture of cultured meat. Mesenchymal stem cells derived from intermuscular adipose tissues are a source of intermuscular fat. Therefore, as a step towards developing a platform to derive intermuscular fat from mesenchymal stem cells (MSCs) for insertion between myofibrils in cultured beef, an advanced protocol of intermuscular adipose tissue dissociation effective to the isolation of MSCs from intermuscular adipose tissues was developed in cattle. To accomplish this, physical steps were added to the enzymatic dissociation of intermuscular adipose tissues, and the MSCs were established from primary cells dissociated with physical step-free and step-added enzymatic dissociation protocols. The application of a physical step (intensive shaking up) at 5 minutes intervals during enzymatic dissociation resulted in the greatest number of primary cells derived from intermuscular adipose tissues, showed effective formation of colony forming units-fibroblasts (CFU-Fs) from the retrieved primary cells, and generated MSCs with no increase in doubling time. Thus, this protocol will contribute to the stable supply of good quality adipose-derived mesenchymal stem cells (ADMSCs) as a fat source for the production of marbled cultured beef.

It has been studied on the disposal area reduction for the used nuclear fuel by the management of high decay-heat nuclides, long-lived nuclides, and highly mobile nuclides. It was investigated on the management of the nuclides in KAERI. Strontium-90 is a high heat-generating nuclide in spent nuclear fuel. It is needed to separate the salt from the salt solution for the recovery of strontium after the chlorination of the strontium oxide in molten salt. Vacuum distillation was used for the separation of strontium from the molten salt. Potassium carbonate was chosen as a reactive distillation reagent for SrCl2 – LiCl – KCl system by the thermodynamic calculation. Reactive distillation experiments were carried out. The residual was mainly SrCO3 in the XRD analysis. It could be concluded that K2CO3 could be one of the suitable reagents for the reactive distillation. The salt in the long–lived nuclide powders should be removed to prepare the block for disposal. Experiments were carried out using W powders (surrogate) and U3O8 powders to develop a process for the removal of the residual salt from UOx powders. The salts were successfully removed from the W and U3O8 powders by distillation.

The effect of Li2O addition on precipitation behavior of uranium in LiCl-KCl-UCl3 has been investigated in this study. 99.99% LiCl-KCl eutectic salt is mixed with 10wt% UCl3 chips at 550°C in the Pyrex tube in argon atmosphere glove box, with 10 ppm O2 and 1 ppm H2O. Then, Li2O chunks are added in mixed LiCl-KCl-UCl3 and the system has been cooled down to room temperature for 10 hours to form enough UO2 particles in the salt. The solid salt has been taken out from the glove box, and cut into three sections (top, middle and bottom) by low-speed saw for further microscopic analysis. Three pieces of solid salt are dissolved in deionized water at room temperature and the solution is filtered by a filter paper to collect non-dissolved particles. The filter paper with particles is baked in vacuum oven at 120°C for 6 hours to evaporate remaining moisture from the filter paper. Further analysis was performed for the powder remaining on the filter paper, and periphery of the powder (cake) on the filter paper. Scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), and X-ray powder diffraction (XRD) are adopted to analysis the characteristic of the particles. From SEM analysis, the powders are consisted of small particles which have 5 to 10 m diameter, and EDS analysis shows they are likely UO2 with 23 at. % of uranium and 77 at. % oxygen. Cake is also analyzed by SEM and EDS, and needle like structures are widely observed on the particle. The length of needle is distributed from 5 to 20 m, and it has 6 to 10 at. % of chlorine, which are not fully dissolved into deionized water at room temperature. From XRD analysis, the particles show the peak position of UO2, and the result is well matched with the SEM-EDS results. We are planning to add more Li2O in the system for fully reacting uranium in UCl3, and compare the results to find the effect of Li2O concentration on UO2 precipitation.

Sustainable capacity building of the rice value chain in Africa is essential in achieving the rice self-sufficiency and poverty alleviation. The breeding capacity enhancement has also been at the heart of AfricaRice’s mandate. Therefore, the Korea-Africa Food and Agriculture Cooperation Initiative (KAFACI) has concentrated breeding capacity enhancement for young breeders or breeding technicians of national research institutes in the KAFACI member countries. Four-month trainings have been conducted at the Regional Training Center located in Saint Louis, Senegal. The actual practice training is as follows; First is to learn practical skills and techniques of key aspects of rice breeding which are field preparation and layout, sowing, transplanting, fertilizer application, weed control, water management, hybridization/crossing, selection, yield and yield components determination, and rice palatability testing. Second is to learn some theoretical aspects of plant breeding through lectures including basic principles of breeding, evaluation for biotic and abiotic stresses, and statistical analysis. Third is to learn about the accurate use of field and lab equipment for rice breeding. Forth is to learn about proper scientific reporting and presentation. The courses were organized twice per year following two rice cultivation seasons in Senegal. From 2019, a total of 24 trainees participated in the 4 month courses. We believe they have acquired the basic knowledge and skills to implement rice breeding activities indpendently in their countries.

The Korea-Africa Food and Agriculture Cooperation Initiative (KAFACI) has been cooperating with AfricaRice since 2014 for the eradication of hunger and poverty in Africa through sustainable agriculture and its industrialization. At first, rice breeding activities for staple food production started with KAFACI member countries by sharing high-yielding Tongil-type rice breeding lines and varieties. The Africa Rice Development Partnership project entitled “Enhancement of high-yielding rice germplasm and breeding capacity of rice producing countries in Africa” is implemented for the period from 2016 to 2025 with three phases. The actual rice breeding activities have been conducted by applying anther culture haploid breeding technology in the laboratory and field of AfricaRice Saint-Louis center. The 1,547 elite lines selected through participatory variety selection were distributed to 21 national breeders of KAFACI member countries. These lines derived from the 1,181 cross combination and 34,616 breeding lines on Korea and AfricaRice germplasm crossed. Among them 11 new Tongil-type rice varieties have been selected and registered in the national variety catalogue of Senegal, Mali, Rwanda, Malawi, and Tanzania.

Doublesex and mab-3 related transcription factor (dmrt) play crucial roles in sex determination and sex differentiation in vertebrates and invertebrates. Although dmrt genes have been identified in vertebrates, little is known about aquatic invertebrates. In this study, two dmrt genes, namely, Dc_dmrt93B and Dc_dmrt99B, were identified from brackish water flea, Diaphanosoma celebensis. Transcriptional changes were observed in the dmrt genes when the flea was exposed to bisphenol (BP), an endocrine disruptor. Sequence and phylogenetic analyses showed that both dmrt genes contained two conserved domains, namely, DM and DMA, closely clustered with those of Daphnia spp. Additionally, a significant increase in the Dc_dmrt99B mRNA expression level was observed upon exposure to intermediate concentrations of BP (bisphenol A>bisphenol S=bisphenol F, p<0.05), while the expression of Dc_dmrt93B mRNA was slightly modulated. These findings imply that the two dmrt genes may be involved in sex differentiation of D. celebensis. Furthermore, it was found that the ability of BP to modulate dmrt genes could affect development and reproduction. This study provides a basis for understanding the function of the dmrt genes and the molecular mode of action of BP in small crustaceans.