Western drywood termite, Incisitermes minor, is distributed southwestern USA and northern Mexico. Invasions had been reported to Canada, China, Hawaii and Japan. Incisitermes minor may be introduced through wooden structures. In California and Arizona, it caused economic damage of about $250 million. In September 2023, it was discovered in a house in Changwon-city, Korea and a joint investigation was conducted by APQA and other government agencies. The 16S rRNA sequence was used in the molecular epidemiological investigation to trace the origin of the invasion. Five individuals found in Changwon and 18 foreign sequences collected by NCBI were compared. A total of 462bp of base sequences were compared, and the genetic distance was observed to range from a minimum of 0.000 to a maximum of 0.1791. They were most genetically similar to the California individual in the United States.

Drywood termite (Cryptotermes domesticus), native to South East Asia, is distributed in India, China, Taiwan, Australia and so on. In China, it is considered an economically important pest causing damage to wood. It lives in dry wood environments such as furniture, buildings, and structural timber. It is difficult to find drywood termite within a structure but it can be detected by the presence of alate flight and small egg-like pellets of excreta. It was found in a house in Seoul, Korea in July 2023 and was investigated joint by APQA, National Institute of Ecology, National Institute Biological Resources, National Institute of Forest Science, Cultural Heritage Administration and Gyeongsang National University. The COII barcode region was analized with PCR method and compared with the sequences of all C. domesticus registered in NCBI 557bp of base sequence. Genetic difference ranged from a minimum of 0.0072 to a maximum of 0.0557. Among these, the individual with the minimum genetic distance was from Guangdong Province, China.

To overcome the challenges in tracking insects underground, a detection method consisting of a metal detector and aluminum tag was developed for tracking a dung beetle, Copris ochus (Coleoptera: Scarabaeidae). First, detection rate was evaluated for varying volumes of aluminum tags varying orientations of the tags under soil. Then, the detection efficacy was evaluated in the field at varying depths of hidden tags in two types of vegetation. Finally, the effect of aluminum-tagging on the survivorship, burrowing depth, and horizontal movement of C. ochus adults were assessed. Generally, an increase in tag volume resulted in a greater detection depth with maximum depth of 17 cm. Orientation, however, did not affect detection rate except when tag was placed perpendicular to the soil surface. In the field, metal detectors could detect aluminum-tagged models with success rates ≥85% up to 10 cm and 45−60% at 20 cm under soil. Finally, no significant effect of tagging on survivorship and behaviors of C. ochus was observed.

Riptortus pedestris is known to acquire their symbiotic bacteria, Caballeronia insecticola, from soil environments in every generation. The symbionts have been demonstrated to affect behavioral and physiological traits of the host insect such as the enhancement of development. In particular, symbiotic effects on female adults could directly entail changes in their population growth. Therefore, we investigated a suite of symbiotic effects of C. insecticola on behaviors and fitness-related parameters of female R. pedestris. Overall, symbiotic females showed an behavioral enhancement in both feeding efficacy and movement capacity including walking and flight. In addition, the survival rates under exposure to overwintering conditions and insecticide resistance level were significantly higher in symbiotic females than the aposymbiotic. Finally, although symbiotic females exhibited shorter longevity, their fecundity was found higher compared to the apo-symbiotic.

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.

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.

최근 정원에 대한 관심이 증가함에 따라 자생 식물을 활용 하기 위한 연구가 진행되고 있다. 참식나무(Neolitsea sericea (Blume) Koidz).는 관상용뿐만 아니라 목재로도 이용할 수 있 다. 따라서 이 연구는 참식나무를 정원 식물 소재로 활용하기 위한 대량 증식 기술 개발을 위하여 종자의 발아 특성과 저장 특성에 대해 알아보고자 진행하였다. 2022년 11월 2일 제주 지역에서 채집한 종자를 실험에 사용하였다. 종자의 내·외부 형태 관찰을 한 결과, 종자가 탈리되는 시점에 배가 완전히 발 달한 형태를 가지고 있기 때문에 형태적휴면(morphological dormancy, MD)이 없음을 확인할 수 있었다. 수분흡수 실험 을 통하여 참식나무 종자는 72시간 이후 40% 정도의 수분흡수 율을 보여 내과피의 불투성에 의한 물리적휴면(PY, physical dormancy)이 없는 것으로 판단하였다. 채종 후 곧바로 무가 온 온실에 파종하면 이듬해 5월에 약 60%가 발아하였다. 저 온습윤처리 0, 2, 4, 8, 12주 후 25/15°C에 배양한 결과 최 종 발아율은 각각 0%, 0%, 21.1%, 32.6%, 34.7%였다. GA3 를 0, 10, 100, 1000mg·L-1 농도로 처리한 후 25/15°C에서 배양한 결과, 최종 발아율은 각각 0, 14.5, 22.7, 42.2%였다. 따라서 본 실험의 결과 8주 이상의 저온 처리 또는 GA3 처리 를 통하여 어느 정도 휴면을 타파시킬 수 있었다. 이러한 결과 를 통하여 종자는 intermediate PD를 가지는 것으로 판단 된다. 일부 발아하지 않은 종자는 deep PD를 가지고 있는 것 으로 판단하였다. 후숙 처리 실험의 결과 4주 만에 수분 함량 이 2% 이하로 감소하였고 종자는 전혀 발아하지 않았다. 따라 서 종자의 저장 특성 중 recalcittrant 특성을 지닌 난저장성 종자로 보인다.

Most of the C-14 produced is in the organic form, generated as methane (14CH4), methanol (14CH3OH), formaldehyde (14CH2O), and formic acid (14CO2H2). When analyzing C-14, it is transformed into the form of 14CO2, and its concentration is determined using LSC. Typical examples include the wet oxidation method, the combustion or Pyrolysis. The wet oxidation method uses strong acids and involves repeated operations, which generates large amounts of acid waste and secondary radioactive waste. The combustion method uses high temperatures, which requires an oxygen device. Pyrolysis also requires high temperature in a vacuum and catalysts. Catalysts are expensive because they are platinum-based. To compensate for these shortcomings, a C-14 analysis method using UV irradiation was developed. In this study, 100 mL of distilled water mixed with formic acid (CO2H2), potassium persulfate (K2S2O8), and silver nitrate (AgNO3) was irradiated with a 320-390 nm UV lamp to conduct a CO2 production reaction experiment. The UV range was measured using a photometer (UV Power puck II). The beaker was made of quartz in 150 mL size with three inlets : a temperature measurement, a sample inlet, and a collection tube connector. We changed the UV lamp used from a 450 W halogen lamp to a 100 W LED, which has a lower temperature and is safer. As a result of the experiment, CO2 bubbles were generated in the collection tube, due to the UV irradiation react, which uses oxidizer and catalysts. The maximum temperature of the solution irradiated with the LED UV lamp was less than 56°C. It confirmed the rate of bubble generation changed depending on the lamp distance, the amount of sample, oxidizer, and catalyst. In an experiment to confirm the reaction caused by heat, it was found that although a reaction occurred due to heat, the reaction was significantly lower than when using a UV lamp. The reproducibility experiment was conducted three times in total under the same conditions. It showed the same pattern. In the future, we plan to select mock samples, collect 14CO2 in Carbo- Sorb, and analyze them using LSC. The results of this research will be used as a technology to recover C-14 more safely and efficiently and will also be used to expand its application to the treatment of other wastes such as waste liquid and waste resin through simulated samples.

In the decommissioning process of nuclear power plants, Ni-59, Ni-63 and Fe-55 present in radioactive waste are crucial radionuclides used as fundamental indicators in determining waste treatment methods. However, due to their low-energy emissions, the chemical separation of these two radionuclides is essential compared to others. Therefore, this study aims to evaluate the suitability of various pre-treatment methods for decommissioning waste materials by conducting characteristic assessments at each chemical separation stage. The goal is to find the most optimized pre-treatment method for the analysis of Ni-59, Ni-63 and Fe-55 in decommissioning waste. The comparative evaluation results confirm that the chemical separation procedures for Fe and Ni are very stable in terms of stepwise recovery rates and the removal of interfering radionuclides. However, decommissioning waste materials, which mainly consist of concrete, metals, etc., possess unique properties, and a significant portion may be low-radioactivity waste suitable for on-site disposal. Considering that the chemical behavior and reaction characteristics may vary at each chemical separation stage depending on the matrix properties of the materials, it is considered necessary to apply cascading chemical separation or develop and apply individual chemical separation methods. This should be done by verifying and validating their effectiveness on actual decommissioning waste materials.

The inorganic scintillator used in gamma spectroscopy must have good efficiency in converting the kinetic energy of charged particles into light as well as high light output and high light detection efficiency. Accordingly, various studies have been conducted to enhance the net-efficiency. One way to improve the light yield has been studied by coating scintillators with various nanoparticles, so that the scintillation light can undergo resonance on surface between scintillators and nanoparticles resulting in higher light yield. In this study, an inorganic scintillator coated with CsPbBr3 perovskite nanocrystals using dip coating technique was proposed to improve scintillation light yield. The experiment was carried out by measuring scintillation light output, as the result of interaction between inorganic scintillator coated with CsPbBr3 perovskite nanocrystals and gamma-ray emitted from Cs-137 gamma source. The experimental results show that the channel corresponding to 662 keV full energy peak in the Cs-137 spectrum shifted to the right by 14.37%. Further study will be conducted to investigate the detailed relationships between the scintillation light yield and the characteristics of coated perovskite nanoparticles, such as diameter of nanoparticles, coated area ratio and width of coated region.

Tc-99 is considered as one of the major fission products in the context of disposal of spent nuclear fuel, due to the long half-life and chemical stability. In the atmospheric aqueous solutions, Tc is expected to exist in the form of TcO4 ‒ and thus is considered as an environmental concern according to its high solubility and mobility. Therefore, the development of an effective and economically viable adsorbent for aqueous Tc(VII) is imperative from the perspective of decontamination and remediation of contaminated environments. In this work, the adsorption behaviors of Re(VII), as a chemical surrogate of Tc(VII), onto the bentonites modified with two different organic cations such as hexadecyl pyridinium (HDPy) and hexadecyl trimethylammonium (HDTMA) were quantitatively analyzed and compared with each other. For the sorption experiment, adsorbents were prepared by surface modification of bentonite. Before the modification, the initial bentonite was pre-treated with 1 M NaClO4 and then reacted with HDPy or HDTMA. The modification process was performed at room temperature for 24 hours with various concentrations of organic cations, which were set to a range of 50-400% compared to the cation exchange capacity (CEC) of bentonite. After the reaction, the dried and crushed modified bentonites were filtered with the sieve with a mesh size of 63 μm. Aqueous Re(VII) solutions were prepared by dissolution of NH4ReO4 (Sigma-Aldrich) in deionized water with three different Re(VII) concentrations of 10-4M, 10-5M, and 10-6M. After that, the modified bentonite and the aqueous Re(VII) solutions were mixed at a liquid-to-solid ratio of 1 g/L. Aliquots of the samples were extracted for quantification analysis with ICP-MS after syringe filtration (pore size: 45 μm) at reaction times of 10, 50, 100, and 500 minutes. According to the results, a considerably fast adsorption reaction of Re(VII) onto all modified bentonites was observed, revealing exceptional sorption affinity of HDPy- and HDTMA-modified bentonites. For both organic cations, bentonites modified with the concentrations of organic cations ranging from 200 to 400% relative to the CEC of bentonite showed almost complete removal of aqueous Re(VII). For bentonites modified with lower concentrations of organic cations, the HDTMA presented a relatively larger sorption capacity than the HDPy. The result obtained through this study is expected to be referred to as a case study for the synthesis of cost-efficient and highly effective adsorbent material for highly mobile anionic radionuclides such as I‒ and TcO4 ‒.