Italian ryegrass (Lolium multiflorum Lam.) is one of the most widely grown winter forage crops in Korea, but its yields are known to be greatly affected by drought that occur frequently in spring. This study aimed to compare the growth and tolerance response characteristics to drought stress in several Italian ryegrass varieties cultivated in Korea. Twenty-day-old Italian ryegrass was subjected to drought treatment for 4 days, and then the growth and physiological responses of the plants were compared. Drought stress reduced leaf length, fresh weight, and dry weight in all Italian ryegrass varieties compared to the control. In addition, chlorophyll content was significantly decreased in all varieties treated with drought stress, but Fv/Fm was significantly decreased only in Winter hawk. For H2O2 and malondialdehyde (MDA) contents, Winter hawk showed the highest increase and New dawn showed the least increase. In terms of relative water content (RWC), New dawn showed the least decrease and Winter hawk showed the greatest decrease. These results indicate that New dawn is relatively drought-tolerant and Winter hawk is a drought-sensitive variety, indicating that each variety of Italian ryegrass has different drought tolerance mechanisms, which may provide basic insight for the development of tolerant varieties in the future.

Drought stress is one of the major factors that reduce plant growth and productivity. This study was conducted to investigate the effect of exogenous acetic acid pretreatment on drought stress tolerance response in plants. Fourteen-day-old alfalfa plants were pretreated with 15 mM acetic acid, and then subsequently subjected to drought stress for 6 days. The fresh weight and relative water content in the leaves of acetic acid pretreated alfalfa plants were increased compared to the control group. The chlorophyll and carotenoid contents were slightly decreased in the acetic acid treatment. The H2O2 and proline contents were also significantly decreased in the acetic acid treatment. These results suggest that the scavenging mechanism of reactive oxygen species in alfalfa activated by acetic acid pretreatment is involved in conferring tolerance to drought stress.

The present study was conducted to analyze agronomic characteristics of 8 ecotypes of Arundinella hirta (A. hirta) and the correlation among them. Changes in phenotypic characteristics of 8 ecotypes were measured at equal intervals of time from May to September. Among ecotypes, Jangsoo-1 has the highest plant height (172.33 cm), number of leaves (9.00) and leaf length (55 cm) while the ecotype Youngduk has the highest leaf width (1.57 cm), fresh mass (26.63 g), dry mass (7.06 g), number of spikelets per spike (53.33), amount of seeds per spike (0.74 g) and amount of seeds per 10 spikes (7.23 g). The ecotype Jinju-1 has the shortest plant height (119 cm) and leaf number (6.33), while Okgye-2 has shortest leaf length (30.67 cm), leaf width (0.93 cm), fresh mass (12.60 g), dry mass (3.30 g), spike length (30.33 cm), spikelet per spike (39.67), amount of seeds per spike (0.61 g) and amount of seeds per 10 spikes (6.00 g). Correlation coefficients were estimated among the studied agronomic characteristics which showed positive and significant association with each other. In the present study, the agronomic data collected would be useful to understand the potential of A. hirta as a forage resource and helpful in selecting the high-yielding genetic resource for future forage improvement.

From the standpoint of developing a transformative service to create improvements in collective wellbeing (Anderson & Ostrom, 2015), evidence of a sport–resilience relationship is gradually accumulating in the literature (Kim et al., 2022). Sport management and social science scholars are making considerable efforts to understand how sport entities with transformative services can contribute to consumer resilience—an intervention through a sport consumption experience that affects people’s abilities to cope with adversity (Inoue et al., 2022; MacIntosh et al., 2020). However, little is known about the sport industry and spatial consumer behavior in terms of consumer resilience. Although previous researchers have identified a macro-level association between sport industry and community resilience from a bird's eye view (Kim et al., 2021), it could not determine how and where sport industry at a macro level can be related to individual-level resilience through metaphors of Consumer Desire. Specifically, the spatial patterns of sport consumption (i.e., consumer spatial behavior) can be a result of sport consumer behavior affected by spatial context upon heterogeneous features of sport industry across regions (Kim et al., 2021) in the environment–behavior paradigm (Olsson & Gale, 1968). The macrolevel clustering of the sport industry in a region (environment) can be a community resource to provide individuals with the opportunity for sport consumption (behavior), which promotes the micro-level psychosocial factors for sport consumer resilience (Inoue et al., 2022). Furthermore, recent work illustrates heterogeneous spatial interaction at the regional level of the sport industry and individual-level sport consumption (Kim et al., 2022), suggesting the elaboration of cross-level spatial interaction models (Kim et al., 2021). Accordingly, in this study we aim to not only (a) determine spatially heterogeneous interactions in the association between sport industry and consumer spatial behavior in affecting consumer resilience, but also (b) identify what effect spatial interaction has on cross-level relationships. Using data focused on a multiscale-based nested geographic structure (e.g., individual-level consumption by zip code, county, state, and nation) that could elucidate the sport consumer spatial behavior, We collected multiple types of data from Florida, including the location quotient of the main seven sport industries (e.g., sport facilities) and socioeconomic factors (e.g., social vulnerability) at the county level from secondary sources. In addition, we acquired individual-level data from Qualtrics panels (1,107 Florida residents) to measure sport consumer spatial behavior (e.g., location-based sport consumption experience) and consumer resilience using the Connor-Davidson Resilience Scale. To address spatial interaction and heterogeneity, we used a comprehensive analytical model for global and local spatial analysis, including a spatial multilevel mediation (SMM) model and multiscale geographically weighted regression (MGWR) model. As a result of the SMM model, the county-level cluster of sport facilities affected individual-level participatory sport consumption, which enhanced consumer resilience (cross-level interaction effect). However, considerable spatial non-stationarity appeared in the spatial interaction, indicating interregional interactions in the cross-level effects within a county. The results of MGWR indicated significant spatially heterogeneous patterns in the association between the cluster of sport facilities and participatory sport consumption. That is, it was clarified that the spatial heterogeneous effects of the clustering of sport facilities on sport consumer spatial behavior are associated with consumer resilience. This empirical interdisciplinary work, including sport management, geography, and consumer psychology, advances knowledge of consumer spatial behavior and resilience by demonstrating heterogeneous spatial interactions. Practically, the current study calls for spatial management planning and strategy in sport industry for enhancing consumer resilience through spatial sport consumption, considering spatially varying patterns.

This study was conducted to investigate the effect of waterlogging stress on the physiological response and growth characteristics of the five Italian ryegrass varieties. For all varieties, the germination rate of seed decreased by 10-15% as the waterlogging period increased, but the waterlogging stress treatment after the early seedling stage increased the growth of shoot and root length. Photosynthetic activity (Fv/Fm) according to waterlogging stress treatment decreased in all vareity, and Florida 80 showed the least decrease with 1.5%. Waterlogging stress treatment was found to reduce the accumulation of reactive oxygen species (malondialdehyde, MDA) and the activities of antioxidant enzymes. These results suggest that other mechanisms may be involved in the defense mechanism of Italian ryegrass against waterlogging stress, such as promoting root growth to escape from waterlogging stress, in addition to the antioxidant enzyme system.

Because Cnidium officinale is susceptible to viral infection, this study investigated the proportion of virus elimination and plant growth after treatments with thermotherapy and chemotherapy. In the thermotherapy group, Apple stem grooving virus (ASGV) and Cnidium vein yellowing virus–2 (CnVYV-2) were significantly reduced in 33℃ treatment. However, Cnidium vein yellowing virus–1 (CnVYV-1) was not affected by any of the four temperature treatments, and Cucumber mosaic virus (CMV) did not show the tendency to eliminate viruses according to temperature treatment. In the investigation of in vitro growth characteristics, plants were not significantly affected by temperature treatments. In the chemotherapy group, 40 mg･L-1 ribavirin treatment was the most effective in eliminating viruses. Different ribavirin concentrations (0 to 40 mg･L-1) did not significantly influence the in vitro plant survival rate. ASGV was completely eliminated with combined thermotherapy and chemotherapy (T29R20 and T29R40). Although the combined thermotherapy and chemotherapy treatment did not affect in vitro plant growth, it significantly influenced root development. The results indicate that thermotherapy, chemotherapy, and the combined treatment effectively eliminated these four viruses (ASGV, CnVYV-1, CnVYV-2, and CMV) without producing any major problems in C. officinale.

The underground environment has an advantage to minimize the external influences because it is isolated space with surrounded rock medium. Therefore, underground rock has been used recently as the target for a disposal system of spent fuel with high-level radioactive. The disposal system mainly consists of natural barrier (i.e., surrounded rock medium) and engineered barrier (i.e., concrete lining, plug, backfill, canister, and buffer). In particular, the engineered barrier is important for long-term storage because it has to preferentially block the leakage of radioactive nuclide. Non-destructive technologies (NDT) have been utilized to monitor the state of disposal system for considering the limitation in deep depth conditions such as limited environment for direct damage inspection. Acoustic emission (AE) monitoring technique is an effective method to monitor the damage (crack) magnitude, history (i.e., crack evolution), and location using high-frequency elastic waves. To apply the AE monitoring method in the disposal system, the characteristics of damaged materials should be considered. The concrete lining has multi-failure behavior (i.e., brittle and ductile) resulted from composition as cement and reinforcing steel bar. Therefore, it important to investigate the AE characteristics according to the failure level of reinforced concrete for damage monitoring of the disposal systems. In this study, the four-point bending tests were carried out to measure the AE signals from the cracking of reinforce concrete specimens in laboratory. The test specimens were prepared with different strength. After the experiment, the AE characteristics were analyzed using the AE parameters with loading and failure state in the curve of time-stress. This study will be helpful for damage monitoring using AE technique in the field of high-level radioactive disposal system.

본 연구는 초등학생의 골연령에 따라 군집화 시켜 각 군집 그룹의 체격, 체력 및 골성숙도를 분석하고 자료 분석을 통해 초등학생들의 균형적인 발달을 위한 기초자료를 제공하는 데 있다. 연구대상은 8세∼13세에 해당하는 2243명을 대상으로 하였으며 골성숙도 산출을 위해 X-ray필름을 촬영한 후 TW3 방법 점수 환산표에 적용시켜 골성숙도를 산출했다. 신장계(Hanebio, Korea, 2021)와 Inbody 270 (Biospace, Korea, 2019)를 사용하여 총 2개의 체격 요소를 측정하였으며, 체력은 근력(악력), 평형성(외발 서기), 민첩성(플랫테핑), 순발력(제자리멀리뛰기), 유연성(좌전굴), 근지구력(윗몸일으키기), 심폐지구력(셔 틀런)으로 총 7개 체력 요소의 종목을 측정하였다. 자료처리 방법은 SPSS PC/Program(Version 26.0)과 Britics Studio Tool을 이용하여 K-Means 클러스터링 기법, 교차분석, 일원변량분석(One-Way ANOVA) 을 실시하였으며, p< .05 수준에서 유의한 것으로 간주하였다. 본 연구의 결과는 다음과 같다. 첫째, 미숙, 보통, 조숙의 3가지 골성숙도를 사용하여 군집화한 결과, 군집 1(미숙)은 근력, 평형성, 민첩성에서 높게 나 타났다. 군집 2(보통)는 유연성에서 낮게 나타났으며, 군집 3(조숙)은 근력에서 높게 나타났다. 둘째, 초등 학생의 개인특성별 군집화에 따른 체격 차이를 분석한 결과, 신장, 체중, 체지방률 모두 군집 3(조숙)이 높 게 나타났다. 셋째, 초등학생의 개인특성별 군집화에 따른 체력 차이를 분석한 결과, 악력검사(좌, 우)는 군 집 3(조숙)이 높게 나타났고 외발서기의 경우 군집 1(미숙)이 높게 나타났으며, 제자리멀리뛰기의 경우 군 집 3(조숙)이 높게 나타났다.

본 연구는 유소년의 골연령에 따른 체력을 평가하는 데 있으며, 골연령에 따른 체력 표준지표 를 통해 유소년들의 균형적인 발달을 위한 기초자료를 제공하는 데 있다. 연구 대상은 골연령 11세∼13세 및 역연령 11세∼13세에 해당하는 730명을 대상으로 하였으며 골연령 산출을 위해 X-ray 필름을 촬영한 후 TW3 방법으로 평가하였다. 체격은 신장, 체중을 신장계(Hanebio, Korea, 2021), Inbody 270(Biospace, Korea, 2019)를 사용하여 총 2개의 체격 요소를 측정하였으며, 체력은 근력(악력), 평형성 (외발서기), 민첩성(플랫테핑), 순발력(제자리멀리뛰기), 유연성(좌전굴), 근지구력(윗몸일으키기), 심폐지구 력(셔틀런)으로 총 7개 체력 요소의 종목을 측정하였다. 자료처리 방법은 SPSS PC/Program(Version 26.0) 을 이용하여 기술통계, 독립표본 t-test 검정을 실시하였으며, p< .05수준에서 유의한 것으로 간주하였다. 본 연구의 결과는 다음과 같다. 첫째, 11세∼13세 골연령과 역연령을 비교한 결과, 체력에서 남자는 근력, 순발력, 근지구력, 심폐지구력에서 유의한 차이가 나타났다. 여자는 근력, 평형성, 민첩성, 순발력, 유연성, 근지구력, 심폐지구력에서 유의한 차이가 나타났다. 둘째, 골연령에 따른 유소년의 성별과 연령(11∼13세) 별로 체력평가의 기초 자료인 골연령 체력 표준지표를 개발하였다.

The increase in temperature due to climate warming is predicted to affect crop yields in the future. Until now, various types of OTC (open top chamber) that simulate the future climate condition have been developed and used to study the effect of temperature increase due to global warming on maize growth. However, in most OTCs, high equipment and maintenance costs were required to artificially increase the temperature. This study was carried to develop a cost-effective and simple OTC suitable for climate warming experiments for forage maize. Three octagonal OTCs with a height of 3.5 m × a diameter of 4.08 m and a partially covered top were constructed. The lower part of OTC covered film was opened at a height of 26 cm (OTC-26), 12 cm (OTC-12) from the ground surface, or not opened (0 cm, OTC-0). Mean air temperatures during the daytime on a sunny day in OTC-0, OTC-12 and OTC-26 increased to 3.23℃, 1.33℃, and 0.89℃, respectively, compared to the ambient control plot. For a pilot test, forage maize, ‘Gwangpyeongok’ was grown at OTCs and ambient control plots. As a result, in the late maize vegetative growth phase (July 30), the plant height was increased more than 45% higher than the ambient control plot in all OTC plots, and the stem diameter also increased in all OTC plots. These results indicate that it is possible to set the temperature inside the OTC by adjusting the opening height of the lower end of the OTC, and it can be applied to study the response of forage maize to elevated temperature. An OTC, with its advantages of energy free, low maintenance cost, and simple temperature setting, will be helpful in studying maize growth responsiveness to climate warming in the future.

Aluminum (Al) stress in acidic pH is known to decrease the growth and productivity of alfalfa. However, not much is known about how the application of silicon (Si) affects the Al stress response in alfalfa. This study was conducted to evaluate the effect of exogenous application of Si on the growth of alfalfa seedlings exposed to Al stress in pots. Alfalfa seedlings grown in pots for 2 weeks were treated either Al stress (pH 4.0, 0.2 mM Al) or Al stress + Si (1 mM) for 5 days, lengths and biomass of shoot and root, and chlorophyll and carotenoid contents in leaf tissues were analyzed respectively. Al stress treatment inhibited shoot and root growth, and decreased fresh and dry weights, and chlorophyll content in leaves, but increased carotenoid content. In contrast, when alfalfa seedlings treated with Al stress combined with Si, delayed growth caused by Al stress of shoot and root of alfalfa seedlings was restored, dry weight was increased and chlorophyll content of leaf tissue was increased, but carotenoid content was decreased. These results suggest that Si has a function of alleviating Al toxicity in alfalfa, of which it exhibits a mitigating effect by a function that overlaps with some of the intracellular functions of carotenoids.

This experiment evaluated the efficiency of mechanical ventilation, one of the measures to reduce indoor radon concentration in residential spaces. In the most popular ventilation rates of the air conditioning system, the most efficient air conditioning system was confirmed by checking the time when the radon concentration reached the lowest level, the radon reduction rate, and the radon concentration that could be lowered as much as possible. The results showed a reduction rate of up to 80% or more as a result of conducting the experiment by blocking the inflow of outside air. It was confirmed that the time to reach the lowest concentration after starting the mechanical ventilation was about 6 hours to a maximum of 7 hours. Therefore, this study verified that indoor radon concentrations can be efficiently reduced by using a mechanical ventilation system.

Charcoal canisters are broadly used for radon detection because of their handiness and short sampling period. Radon detection using charcoal canisters are known to be susceptible to surrounding conditions such as temperature and humidity. Public radon inspectors cannot handle extreme temperature, and the relative humidity can differ in districts due to the use of different types of construction. Thus, if relative humidity can be controlled at the entrance of a charcoal canister, radon inspectors will be able to procure more reliable data. The purpose of this study was to assess the efficiency of existing filters in a charcoal canister and to apply a new type of filter (Super Absorbent Polymers, SAP) that can control the moisture penetrating into the charcoal canister. Based on adequate case studies using the new filter, radon data have shown over 98% close to the reference data irrespective of varying moisture levels. Meanwhile, basic filters showed 88% similarity compared to the reference data, which means that charcoal canisters were affected by moisture. The SAP filter is reasonably inexpensive and once it turns into its gel shape (which, in turn, is saturated by moisture), it can be easily replaced. This filter will not only be able to provide more accurate radon data, but also apply to other gas phase material detections that are sensitive to moisture in the air.

In this study, a system was developed that can evaluate the radon gas removal efficiency of air cleaner filters. The system has three acrylic chambers connected in series;: the 1st chamber, the filter chamber and the 2nd chamber. In the 1st chamber, a radon source and an air pump were installed to create an environment with a constant radon concentration. Radon concentration in the two chambers was continuously monitored by ionization chamber detectors(RD-200, FRD1600, FTLab, Korea) and, in the 2nd chamber, the radon concentration increase of air filtrated by each filter was inter-compared. HEPA filters and two honeycomb type filters were evaluated. Results of HEPA filter, GAC 1 and GAC 2 were 1142 Bq, 7016 Bq and 12053 Bq, respectively. HEPA filter showed a significantly lower capacity for radon removal than the GAC filters. Also, the GAC 2 filter showed a more than 70 % better result compared to GAC 1 due to the difference in filter materials. Therefore, this system can be used to evaluate the radon removal ability of air cleaner filters, by filter type and filter material.

In Korea, six mealybug species have been reported on pears. This study investigated the occurrence of mealybugs in 19 pear orchards from 2013 to 2014. Two species, Crisicoccus matsumotoi (Siraiwa) (Hemiptera: Pseudococcidae) and Pseudococcus comstocki (Kuwana) were mainly found. The dominant species was C. matsumotoi identified on 73% of infested fruit. Toxicities of 14 registered insecticides (7 single formulations and 7 mixed formulations) commonly used to control P. comstocki were evaluated to C. matsumotoi nymphs and adults at the recommended concentration. As a results, all insecticides exhibited strong insecticidal activity with 100% mortality of both nymphs and adults. These results indicate that the 14 insecticides can be used in control for C. matsumotoi in field.

Many forest pests present a problem during wood quarantine. The effectiveness of phosphine (PH3), which is an altered form of MB, was examined in Monochamus saltuaris and M. alternatus. After 24 h, the larvae and the adults of both insects were susceptible to PH3 at 3 mg/L at 20°C. However, the larvae of both pests were rather than dead, seem to have been quiescent condition. PH3 showed increasing insecticidal activity in a time-dependent manner in the larva stage of both pests. We investigated the fumigants at all stages of M. saltuaris and M. alternatus, as well as the synergistic effects of PH3 in controlled atmospheres of 50% and 80% oxygen. The atmospheric oxidation of PH3 fumigation slightly increased the toxicity of the fumigant to larva stages in 125 L container at 4 mg/L. These results indicate that highly concentrated atmospheric oxidation of PH3 could be useful as a fumigant agent against M. saltuaris and M. alternatus.