Pyrethroid resistance in cockroach populations has been a public health challenge since the 1950s. The pyrethroid resistance in the German cockroach, Blattella germanica, is primarily attributed to knockdown resistance (kdr) mutations (E434K, C764R, and L993F) in the voltage-sensitive sodium channel gene (vssc). In this study, the pyrethroid resistance state of the German cockroach in the Republic of Korea (ROK) was assessed by analyzing the frequencies of kdr mutations using one-step PCR with total RNA. The results revealed that among the 25 populations examined, 14 populations exhibited the L993F kdr mutation, while no other mutations were detected. Since other cockroach species are also commonly found in human dwellings in ROK, the vssc genes were cloned from four other species, including Blattella nipponica, Periplaneta americana, Periplaneta japonica, and Periplaneta fuliginosa. Based on the genomic DNA (gDNA) sequences obtained from the vssc cloning, primer sets were designed to amplify the vssc fragment spanning the L993F mutation for each species and used to monitor the development of pyrethroid resistance in cockroach populations in the ROK. The study will facilitate the implementation of a nationwide monitoring program to assess cockroach resistance and select suitable alternatives.

Salt is crucial for survival, yet excessive intake of sodium chloride can have adverse effects. In the fruit fly, Drosophila melanogaster, internal taste organs located in the pharynx play a pivotal role in determining whether to accept or reject food. However, our understanding of how pharyngeal gustatory receptor neurons (GRNs) perceive high salt levels is still limited. In this study, we discovered that a specific member of the ionotropic receptor family, Ir60b, is selectively expressed in a pair of GRNs that respond to high salt concentrations. Through a two-way choice assay (DrosoX) to measure ingestion volume, we established that IR60b, along with two coreceptors, IR25a and IR76b, is necessary to deter excessive salt consumption. Interestingly, mutants lacking external taste organs but retaining internal taste organs in the pharynx showed significantly higher salt avoidance compared to flies missing all three IRs while still possessing all taste organs. These findings underscore the crucial role of IRs in pharyngeal GRNs in regulating the intake of high salt levels.

단백질의 구조 예측은 생명 과학 및 의약학 분야의 핵심적인 연구 주제 중 하나로, 단백질의 기능 및 상호작용을 이해하기 위한 주요 정보를 제공할 수 있어 다양한 연구가 수행되고 있다. 이러한 연구의 일환으로 최근 Google DeepMind의 AlphaFold2가 등장하였으며, 단백질 구조 예측 성능을 대폭 향상시켜 CASP(Critical Assessment of Protein Structure Prediction)에서 뛰어난 평가점수를 받아 단백질 구조 예측 분야의 최신 기술을 크게 향상시켰다. 이러한 컴퓨터 기반의 단백질의 구조 예측 방법은, 고전적인 방법을 사용하여 직접 단백질 구조를 결정하는 방법 에 비해 매우 정확하고 빠르며 경제적인 비용으로 수행될 수 있어 단백질 구조 예측 및 생리학 연구를 수행하는 연구자들에게 유용한 방법론이 될 것으로 사료된다. 따라서 본 연구소에서는 곤충을 포함한 무척추 자생동물을 연구하는 연구자들을 위해 단백질 구조 예측을 수행할 수 있도록 64Core/128Threads의 CPU, 256GB의 RAM과 6장의 GeForce RTX 3090으로 이루어진 GPU(Graphical Processing Unit) 고성능 컴퓨터 시스템에 AlphaFold2 program을 구축하였다. 최근 인간을 대상으로 한 단백질 구조 예측 연구는 상당한 진전을 보이고 있지만, 곤충을 포함한 자연계의 동물을 대상으로 한 연구는 여전히 미비한 상황이다. 이러한 자생동물자원연구의 확대를 위해 본 연구소에서 구축한 GPU 시스템 및 생물정보학적 분석 방법이 많이 활용되어야 하며, 이를 위해서는 연구자들 의 협력과 참여가 필요하다.

Background: Sperm quality and the number of sperm introduced into the uterus during artificial insemination (AI) are pivotal factors influencing pregnancy outcomes. However, there have been no reports on the relationship between sperm concentration at AI and sperm quality in Hanwoo cattle. In this study, we examined sperm quality and pregnancy rates after AI using sperm inseminated at different concentrations. Methods: We evaluated the motility, viability, and acrosomal membrane integrity of sperm at different concentrations (10, 15, 18, and 20 million sperm/straw) in 0.5-mL straws. Subsequently, we compared the pregnancy rates after AI with different sperm concentrations. Results: After freeze-thawing, sperm at the assessed concentrations showed similar viability and acrosomal membrane integrity. After AI, cattle in the 10 million group had significantly lower pregnancy rates compared to those in the 18 and 20 million groups. Conversely, there were no statistically significant variances observed between cattle in the 10 and 15 million groups. Conclusions: Sperm at concentrations of 10, 15, 18 and 20 million per straw exhibited comparable motility, viability, and acrosomal membrane integrity. However, a concentration of at least 18 million sperm per straw is required to achieve a consistent rate of pregnancy rate in Hanwoo cattle after AI.

글로벌 게임시장의 성장에 따라 국내 게임이용자도 손쉽게 다양한 국가에서 접할 수 있게 되 었다. 그리고 이러한 글로벌 경쟁 속에서 현실의 다양한 문화 창의적으로 반영한 게임이 점증 하고 있다. 대표적인 것이 중국의 호요버스가 개발한 해제 월드 형<원심>으로, 해당 콘텐츠는 캐릭터와 공간디자인에 다양한 국가의 문 것이 특징이다. 이때 의상디자인은 캐릭터의 성격과 매력을 효과적으로 이국적인 특색을 드러내는 기호라는 점에서 특히 중요하다. 이에 이 글은 먼저 캐릭터 의상과 의상 기호에 관한 검토하고, <원심>의 문화 활용 전략을 간단히 살펴보았 다. 이후 퍼스의 기호학을 활용해 중국의 문화적 특색을 반<원신> 캐릭터 ‘운근’을 분석하였다. 분석 결과, <원신>의 캐릭터 디자인전략은 중국의 풍부한 문화적 문맥을 중심 코드를 적극적으 로 빌리는 한편, 캐릭터 성을 부각하는 방향으로 의상 구성요소를 변형 시 나타났다. 이후 분 석 결과를 바탕으로 차후 연구를 위한 발전 방향을 제시하였다..

This study evaluated the risk of single and combined exposure to microplastics in zebrafish (Danio rerio) through biomarkers, such as survival rate, excretion rate, and histological alterations of organ systems. The experimental groups were the control (Cont.), single microplastics exposure group (MPs, 1.83%/fish total weight (g)), the copper group (Cu, 21.6 μg L-1), and a group with combined exposure to MPs and copper (MPs*Cu). The experiment was conducted with individual exposure (7 days) for MP excretion rate analysis and group exposure (14 days) for biomarker analysis. The daily excretion rate of MPs tended to decrease in a time-dependent manner. The copper concentration in the body was not significantly different between single and combined copper exposure. The degeneration of mucous cells in the skin, capillary dilation of the gill lamella, increased intestinal mucous, hepatocyte hypertrophy, and the degeneration of glomeruli and renal tubules were observed in all exposure groups. These histological alterations showed the highest tendency in the MPs*Cu group. In this study, the changes in biomarkers were attributed to the single effect of copper or the combined effect of copper and MPs rather than being solely influenced by MPs.

Molten Salt Reactor (MSR) is one of the 4th generation nuclear power systems which is its verified technology in physically and chemically. Among the various salts used for MSR system, the eutectic composition of NaCl-MgCl2 system maintains the liquid state at around 450°C, in the same time, it has high solubility for nuclear fuel chlorides. This characteristic has high advantage for lowering the operating temperature for the MSR, which could reduce the problem of hightemperature corrosion by salt for structural materials significantly. In particular, since MgCl2 has the similar standard reduction potential with nuclear fuel, is used as a surrogate for, many basic researches have been conducted for verifying characteristic of MgCl2. It is well-known that main short-advantage of MgCl2 is hygroscopic properties. MgCl2 changes to MgCl2-xH2O state easily by absorbing moisture in air condition. The hydrated MgCl2 is producing MgOHCl by thermally decomposing at high temperature, the formed MgOHCl corrodes structural materials, even small amount of MgOHCl gives significant damage. Therefore, the purification of MgCl2 has been required for long-term operation of MSR using MgCl2 as a base salt. In this study, the purification of eutectic composition salt for NaCl-MgCl2 has been mainly performed by considering its thermodynamic properties and electrochemical characteristic, and the experimental results have been discussed.

The effect of various physicochemical processes, such as seawater intrusion, on the performance of the engineered barrier should be closely analyzed to precisely assess the safety of high-level radioactive waste repository. In order to evaluate the impact of such processes on the performance of the engineered barrier, a thermal-hydrological-chemical model was developed by using COMSOL Multiphysics and PHREEQC. The coupling of two software was achieved through the application of a sequential non-iterative approach. Model verification was executed through a comparative analysis between the outcomes derived from the developed model and those obtained in prior investigations. Two data were in a good agreement, demonstrating the model is capable of simulating aqueous speciation, adsorption, precipitation, and dissolution. Using the developed model, the geochemical evolution of bentonite buffer under a general condition was simulated as a base case. The model domain consists of 0.5 m of bentonite and 49.5 m of granite. The uraninite (UO2) was assigned at the canister-bentonite interface as the potential source of uranium. Assuming the lifetime of canister as 1,000 years, the porewater mixing without uranium leakage was simulated for 1,000 years. After then, the uranium leakage through the dissolution of uraninite was initiated and simulated for additional 1,000 years. In the base case model, where the porewater mixing between the bentonite and granite was the only considered process, the gypsum tended to dissolve throughout the bentonite, while it precipitated in the vicinity of bentonite-granite boundary. However, the precipitation and dissolution of gypsum only showed a limited effect on the performance of the bentonite. Due to the low solubility of uraninite in the reduced environment, only infinitesimal amounts of uranium dissolved and transported through the bentonite. Additional cases considering various environmental processes, such as seawater or cement porewater intrusion, will be further investigated.

The WRK (Waste Repository Korea bentonite) compacted bentonite medium has been considered as the appropriate buffer material in the Korean SNF (Spent nuclear fuel) repository site. In this study, hydraulic properties of the WRK compacted bentonite core (4.5 cm in diameter and 1.0 cm in length) as the buffer material were investigated in laboratory experiments. The porosity and the entry pressure of the water saturated core at different confining pressure conditions were measured. The average velocity of water flow in the WRK compacted bentonite core was calculated from results of the breakthrough curves of the CsI aqueous solution and the hydraulic conductivity of the core was also calculated from the continuous flow core experiments. Because various gases could be generated by continuous SNF fission, container corrosion and biochemical reactions in the repository site, the gas migration property in the WRK compacted bentonite core was also investigated in experiments. The gas permeability and the average of gas (H2) in the core at different water saturation conditions were measured. Laboratory experiments with the WRK Compacted bentonite core were performed under conditions simulating the DGR environment (confining pressure: 1.5- 20.0 MPa, injection pressure: 1.0-5.0 MPa, water saturation: 0-100%). The WRK Compacted bentonite core was saturated at various confining pressure conditions and the porosity ranged from 27.5% to 43.75% (average: 36.75%). The calculated hydraulic conductivity (K) of the core using experimental results was 8.69×10-11 cm/s. The gas permeability of the core when the water saturation 0~58 % was ranged of 19.81~3.43×10-16 m2, representing that the gas migration in the buffer depends directly on the water saturation degree of the buffer medium. The average gas velocity in the core at 58% of water saturation was 9.8×10-6 m/s, suggesting that the gas could migrate fast through the buffer medium in the SNF repository site. Identification of the hydraulic property for the buffer medium, acquired through these experimental measurements is very rare and is considered to have high academic values. Experimental results from this study were used as input parameter values for the numerical modeling to simulate the long-term gas migration in the buffer zone and to evaluate the feasibility of the buffer material, controlling the radionuclide-gas migration in the SNF repository site.

In KAERI’s previous phosphate precipitation tests, the dispersed powder of lithium phosphate (Li3PO4) as a precipitation agent reacted with various metal chlorides in a simulated LiCl-KCl molten salt. The reaction of metal chlorides composed of actinides such as uranium and three rare earths (Nd, Ce and La) with lithium phosphate is a solid-liquid reaction. A phosphorylation reaction rate is very fast and the metal phosphates as a reaction product precipitated on the bottom of the molten salt crucible. One of the recovery methods of the metal phosphate precipitates is segregation the lower part (precipitates) of the salt ingot using the various cutting tools. Recently, a new phosphorylation experiment using lithium phosphate ingots carried out in order to collect the metal phosphate precipitates into a small recovering vessel, and the test result of this new method was feasible. However, the reaction rate of test using lithium phosphate ingot is extremely slower than that of test using lithium phosphate powder. In this study, the precipitation reactor design (a tapered crucible with polished inner surface) used for phosphorylation reaction showed that the salt ingot with metal phosphate precipitates could be detached from a tapered stainless steel crucible. We propose that the recovery of precipitates from a salt ingot is possible by introducing a dividing plate structure into a molten salt and by positioning it at the interface between salt and precipitated metal phosphate.

Molten salt reactor (MSR) uses fluoride or chloride based molten salt as a coolant of the system, and fuel materials are dissolved in the molten salt, therefore it can be act as both coolant and nuclear fuel. A few issues have arisen from early-stage research and development program of MSR from Oak Ridge National Laboratory, including corrosion of structural materials and fission product management. For investigating the effect of additives on corrosion of structural materials, Mg(OH)2 and MgCl2*6H2O are added into the NaCl-MgCl2 eutectic salt. Prepared chloride salt is injected into the autoclave in the glove box, as well as corrosion coupons for candidate structural materials for molten chloride salt reactor, SS316, Alloy 600, and C-276 are also prepared. The temperature is set as 700°C. After 500 h corrosion experiment, the samples are taken out from the autoclave, and they are analyzed with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). SS316 samples show weight loss with all salt conditions, while Alloy 600 and C-276 show weight gain after the corrosion experiment.

It has been investigated on the management of Strontium-90 in KAERI. It is needed to separate the solute from the salt solution for the recovery of strontium after the chlorination of the strontium oxide in molten salt. A vacuum distillation technology was used for the separation of strontium from the molten salt in our previous study. Strontium chloride was successfully carbonated by reactive distillation of SrCl2 – K2CO3 – LiCl – KCl system. In this study, it was tried to develop another route to recover strontium from the salt solution by a solid-solid reaction for avoiding the entrainment of product and the salt-K2CO3 reaction. Reactive distillation experiments were carried out for SrCl2 - K2CO3 – LiCl – KCl system. The carbonation temperature and pressure were 520°C and 0.8 bar. After the carbonation reaction, the temperature was elevated to 820°C to remove KCl from the reaction product. SrCO3 and KCl peaks were found in the XRD analysis of the residual product. It could be concluded that SrCl2 can be successfully carbonated after salt removal by the solid-solid reaction.

Hydride reorientation is widely known as one of the major degradation mechanisms in Zirconium cladding during dry storage. Some previous theoretical models for hydride reorientation used assumption of an ideal radial basal pole orientation for HCP structure of Zirconium cladding. Under this assumption, circumferential hydride was considered to precipitate in the basal plane while radial hydride was considered to precipitate in the prismatic plane, thereby giving energetical penalty on thermodynamical precipitation of radial hydrides. However, in reality, reactor-grade Zirconium cladding exhibits average 30° tilted texture, adding complexity to the hydride precipitation mechanism. In this study, reactor-grade Zirconium cladding was charged with hydrogen and hydride reorientation -treated specimens were fabricated. Microstructural characterization of hydrides was conducted via following three methods in terms of interface and stored energy. And this study aimed to compare these characteristics between circumferential and radial hydrides. Using Electron Back Scattered Diffraction (EBSD), the interface was investigated assuming that interface lies parallel to the axial axis of the tube. These were further validated with Transmission Electron Microscope (TEM). In addition, Differential Scanning Calorimetry (DSC) analysis was conducted to calculate the stored energy. This investigation is expected to establish fundamental understanding of how hydrides precipitate in Zirconium cladding with different orientations. And it will also increase the predictability of radial hydride formation and help understanding the mechanical behavior of Zirconium cladding with radial hydrides.

유기농업자재 제조 원료가 되는 주요 식물인 제충국, 고삼, 데리스, 님 등은 대부분 수입에 의존하고 있는 실정 으로 제품수급, 효용성 및 안전성 등에 빈번한 문제가 발생되고 있다. 이러한 문제점을 해결하기 위하여 국내 자생식물을 추출물 원료로 이용하기 위한 연구를 수행하고 있다. 이중 마트린이 함유되어 살충제로 이용되고 있는 고삼에 흰가루병, 총채벌레, 줄붉은들명나방, 담배거세미나방, 거품벌레류가 발생하여 피해를 주었다. 특 히 줄붉은들명나방(Uresiphita prunipennis)은 7월 하순부터 9월 중순까지 발생하여 엽육을 갉아먹고 엽맥만 남기는 피해를 주었고, 피해주율은 11% 였다. 이를 방제하기 위해 18종의 유기농업자재의 살충효과를 조사한 결과 주성분이 마늘추출물 80%, 데리스추출물 70% 등인 자재 6종이 80% 이상의 살충률을 나타내었다.

먹노린재의 방제시기 설정을 위하여 서식지 내 발생 양상을 조사하였다. 전라남도를 중심으로 돌발 대량 발생 한 먹노린재의 발생 조사는 2023년도 벼의 모내기가 완료된 시점부터 전남 곡성군 석곡면과 여수시 화양면 일대 의 친환경단지에서 주 1회 실시하였으며, 벼의 수확이 완료되는 시점까지 진행될 예정이다. 금년도 발생 조사 결과는 지난 2021년도 결과와 비교하여 분석하고자 하였다. 현제까지의 결과, 여수시의 친환경단지 내 먹노린재 의 발생은 모내기가 완료된 이 후 2주 경과 시점에서 발견되었으며, 곡성군은 4주 경과 시점에서 발견되었고, 발생 최고점은 여수시의 경우 모내기 후 6주 경과 시점으로, 곡성군의 경우 5주 경과 시점으로 나타났다. 먹노린재 의 대발생이 지속되던 2021년도의 결과와 비교하였을 때, 2023년도 결과도 유사한 것으로 나타났다. 이에 따라, 먹노린재 친환경제재 살포 시기는 모내기 후 2주 경과 시점이 적절한 것으로 나타났으며, 2차 방제 시점에 대해서 는 추가 조사를 통해서 제안하고자 한다.

The fall armyworm (FAW), Spodoptera frugiperda, is an invasive pest species in Africa and Asia, which is native to the Western hemisphere. Invaded FAW was corn feeding strain. We study the developmental and biology of the corn strain FAW on the rice plants compare the result with corn feeding up to F2- generation. The development periods of F0, F1 and F2 generations of the rice-fed colony were 21.7%, 18.3% and 18.9% longer than corn-fed colony. The rice-fed colony was significantly lower in the body weight of larvae and pupae, and pre-adult survival rate and the fecundity than corn-fed colony. Our results showed that the corn strain FAW can survive and complete its life cycle by feeding rice plants up to several generations under laboratory condition, but their development and fecundity were reduced in comparison to the corn feeding colony. However, this study suggests potential impact of invaded FAW to the infestation of rice fields in Asian countries.

Honey bees are crucial pollinators for agricultural and natural ecosystems, but are experiencing heavy mortality in Korea due to a complex suite of factors. Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. Finding solutions involves knowing the factors associated with high loss rates. To investigate whether loss rates are related to Varroa control and climate condition, we surveyed beekeepers in korea after wintering (2021–2022 to 2022–2023). The results show an average colony loss rate of 46%(2022) and 17%(2023), but over 40% colony loss before wintering at 2022. Beekeepers attempt to manage their honey bee colonies in ways that optimize colony health. Disentangling the impact of management from other variables affecting colony health is complicated by the diversity of practices used and difficulties handling typically complex and incomplete observational datasets. We propose a method to 1) Varroa mite population Control by several methods , and 2) Many nursing bee put in hive before wintering.