본 연구는 COVID-19로 인한 사회적 거리두기를 경험한 대학생의 사회·정서적 고립감, 우울, 스마트폰 중독 간의 관계를 살펴보고 대학생의 스마트폰 중독에 영향을 주는 요인을 파악하기 위해 시도되 었다. 본 연구에 참여한 대상자는 4개 대학교에 재학 중인 220명이며, 자료수집은 구글 폼으로 설문지를 구성하여 시행하였다. 자료 분석은 SPSS/WIN 28.0 프로그램을 이용하여 변수의 특성에 따라 통계적으로 분석하였다. 본 연구 결과, 대학생의 스마트폰 중독은 사회·정서적 고립감(r=.44, p<.001), 우울(r=.51, p<.001)과 유의한 양의 상관관계를 보였으며, 대학생의 스마트폰 중독에 영향을 주는 요인은 성별(β =.176, p=.001), 주말 스마트폰 사용 시간 7-9시간(β=.387, p=.001), 10-12시간(β=.313, p=.006), 12시 간 이상(β=.299, p=<.001), 우울(β=.302, p<.001), 사회·정서적 고립감(β=.210, p=.004)이었다. 회귀모 형은 통계적으로 유의하였으며 (F=15.81, p<.001) 모형의 설명력은 43% (adj R2=.43, p<.001)였다. 따라 서 대학생의 스마트폰 중독을 예방하기 위해 사회·정서적 고립감과 우울을 감소시킬 수 있는 정신건강 증 진 프로그램을 개발하여 활용할 필요가 있다.

To understand antioxidant enzyme response of two contrasting Arundinella hirta ecotypes to drought stress, drought-tolerant Youngduk and drought-sensitive Jinju-1, were comparatively analyzed changes in the enzymatic activities of peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR). Two ecotypes, drought-tolerant Youngduk and drought-sensitive Jinju-1 were subjected to drought stress by withholding water for 12 days. ROS accumulation level and electrolytic leakage were significantly increased in both A. hirta ecotypes by drought stress treatment but less in Youngduk than Jinju-1. The RWC significantly decreased in both the drought stress-treated ecotypes as compared to control, but less in Youngduk than Jinju-1. Soluble sugar and protein content were increased more in drought stress-treated Youngduk as compared to Jinju-1. The activities of antioxidant enzymes such as SOD, CAT, POD, APX, and GR increased significantly in both the drought stress-treated ecotypes Youngduk and Jinju-1 as compared to control. The increase in antioxidant enzyme activity level was more prominent in drought stress-treated Youngduk as compared to Jinju-1. Taken together, these results suggest that Youngduk was more tolerant to drought stress than Jinju-1, and seem to indicate that tolerance of A. hirta to drought stress is associated with increased activity of antioxidant enzymes.

Expression changes of stress-induced peroxidase (swpa2 and swpa4) and storage root-specific sporamin (spo-A and spo-B) genes were examined using qRT-PCR after treatment with wounding and bacterial pathogens on leaves of sweetpotato (Ipomoea batatas) plants. As a result of examining the expression change in the wounding treatment condition for 48 hours after treatment, which is a representative physical stress, the expression of all genes increased after 12 hours of wounding treatment, but the expression pattern of each gene group showed distinct differences thereafter. Expression levels of swpa2 and swpa4 strongly increased up to 36 or 48 hours after wounding treatment, whereas spo-A and spo-B expression levels strongly decreased after 24 or 36 hours after wounding treatment. Peroxidase and sporamin genes are involved in the early response after wounding treatment and, in particular, the peroxidase swpa2 and swpa4 genes are also involved in the late response after wounding treatment. Gene expression analysis after infection with P. chrysanthemi, which causes softness in sweetpotato, showed that the swpa2 and swpa4 genes were weakly induced after 8 hours and then strongly induced after 20 hours during pathogen infection. Expression of the spo-A gene was weakly induced in the pathogen-treated group after 20 hours, whereas spo-B showed an expression pattern similar to that of the peroxidase genes. The above results indicate that expression of the stress-induced peroxidase gene used in this study is induced not only by abiotic stress but also by biological stress caused by bacterial pathogen invasion and that peroxidase plays an important function in the initial defense response.

본 연구는 간호대학생이 지각한 간호사 이미지와 전공몰입 정도를 파악하고, 이들의 관계를 규명하여 간호대학생의 전공몰입 향상에 필요한 방안을 마련하고자 시도되었다. 본 연구에는 7개 간호대학에 재학 중인 간호대학생 185명이 참여하였으며, 수집된 자료는 SPSS/WIN 24.0 프로그램으로 통계분석하였다. 본연구결과는 다음과 같다. 연구대상자들이 인식한 간호사 이미지는 3.79점. 전공몰입은 3.52점으로 평균 이상의 점수를 보였으며, 대상자가 지각한 간호사 이미지가 긍정적일수록 전공몰입이 높은 것으로 확인 되었다. 또한, 전공몰입에 영향을 미치는 요인에는 전공만족도, 간호에 대한 인식, 간호사 이미지, 간호학과 선택 동기 중 적성과 흥미 순으로 확인되었고 전체 설명력은 42%였다. 이상의 결과를 토대로 볼 때, 간호 대학생이 긍정적인 간호사 이미지를 형성하고 전공에 대해 만족감을 증진할 수 있는 교과 및 비교과 프로그램을 개발하고 적용할 필요가 있다.

최근 급속하게 발전하고 있는 유전자교정기술은 식물이 생산하는 특정 이차 대사산물의 집적을 유도하기 위한 식물대사공학연구에 아주 유용하게 이용되고 있다. 특히 이들 기술 들을 이용하여 만든 유전자교정 작물 중에 일부는 외래 DNA 단편이 잔존 하지 않기 때문에 기존의 유전자변형작물의 안전 관리규정에 적용되지 않을 수 있다는 장점이 있다. 따라서 본 리뷰는 phenylpropanoid 대사과정에 의하여 합성되는 다양한 종류의 이차대사산물을 집적시키기 위한 유전자교정 기술의 적용 연구결과 들을 조사하였다. 먼저, phenylpropanoid 생합성 대사과정에 관여하는 다양한 효소를 암호하는 유전자들을 목표로 하여 식물의 종에 따라 특이하게 집적되는 flavonoids, anthocyanin, 수용성 tannins, 로즈마린산 등의 집적을 유도하거나 화색을 변경하는 등의 성공적인 연구결과들을 검토하였다. 또한, phenylpropanoid 대사과정의 조절에 최종조절 스위치 역할을 하는 수많은 종류의 MYB 전사인자를 암호 하는 유전자를 목표로 하여 CRISPR 유전자교정을 시도한 연구결과들로부터 식물의 이차세포벽 형성에 관여하는 lignin, 물관부, cellulose 등의 생합성 조절 기작을 이해하고 MYB family에 속하는 수많은 종류의 유전자에 대한 개별적인 기능 분석 연구결과들을 조사 분석하여, 문제점 및 향후 연구 방향 등을 검토하였다.

A new WRKY transcription factor gene was isolated by ESTs screening from a cDNA library of suspension cultured cells of Sweet potato (Ipomoea batatas). The 2,285 bp cDNA fragment, IbWRKY, was sequenced, from which a 505 amino acid residue protein was deduced. A search of the protein BLAST database identified significant similarity to other plant WRKY31 protein sequences. RT-PCR analysis showed expression patterns of IbWRKY31 in various intact tissues and suspension cultured cells of Sweet potato, and in leaves exposed to different stresses. The IbWRKY31 gene was highly expressed in suspension cultured cells. In leaf tissues, IbWRKY31 showed strong expression during salicylic acid and methyl jasmonate treatments. Expression of IbWRKY31 was also induced under various abiotic stress and pathogen infection conditions, such as wounding, H2O2, MV, PEG, NaCl, and bacterial pathogen infection. These results suggest that IbWRKY31 is involved in plant responses to various stress conditions, such as abiotic stresses and pathogen infection through a defense signaling pathway.

Arabidopsis nucleoside diphosphate kinase 2 (AtNDPK2) is an upstream signaling molecule that has been shown to induce stress tolerance in plants. In this study, the AtNDPK2 gene, under the control of a stress-inducible SWPA2 promoter, was introduced into the genome of tall fescue (Festuca arundinacea Schreb.) plants. The induction of the transgene expression mediated by methyl viologen (MV) and NaCl treatments were confirmed by RT-PCR and northern blot analysis, respectively. Under salt stress treatment, the transgenic tall fescue plants (SN) exhibited lower level of H2O2 and lipid peroxidation accumulations than the non-transgenic (NT) plants. The transgenic tall fescue plants also showed higher level of NDPK enzyme activity compared to NT plants. The SN plants were survived at 300 mM NaCl treatment, whereas the NT plants were severely affected. These results indicate that stress-inducible overexpression of AtNDPK2 might efficiently confer the salt stress tolerance in tall fescue plants.

뇌와 근육은 상의 하달식 구조로 상지 운동 수행 과정에서 뇌파와 근전도 신호의 변화와 함께 기능적 연결성이 발생한다. 본 논문에서는 사용자가 상지 운동을 수행하였을 때의 뇌파와 근전도 신호에 대해 코히어런스 방법을 적용하 여 운동 의도 여부에 따른 뇌와 근육간의 연결성 차이를 규명하고자 한다. 상지 운동을 수행하는 과정에서 운동 피질 영역의 뇌파는 뮤 리듬(mu rhythm, 8~14 Hz)과 베타 리듬(beta rhythm, 15~30 Hz)에서 활성화 되며, 근전도 신호는 베타 리듬과 파이퍼 리듬(piper rhythm, 30~60 Hz)에서 활성화 된다. 뇌파와 근전도 신호간의 코히어런스 분석 결과 운동 의도를 포함한 능동 운동 수행 시 수동 운동을 수행하였을 때 보다 유의미한 차이로 높은 코히어런스 계수가 확인되었다. 이는 인지적 반응과 근육의 움직임 사이의 코히어런스 관계로 운동 의도가 포함된 상지 운동 수행 과정에서 의 뇌와 근육간의 연결성을 해석할 수 있었다. 운동 의도에 따른 뇌-근육간의 코히어런스 특징을 이용한다면 재활 기기 사용자의 운동 의도에 따라 피드백이 필요한 재활 훈련 시스템 설계에 도움이 될 수 있을 것으로 사료된다.

The objective of this study was to examine the effect of various discontinuous Percoll washing conditions on motile sperm recovery rate and motion kinematics. Frozen semen samples from 3 bulls (0.5 ml plastic straws, 6% glycerol in egg yolk-Tris-glycerol extender) were thawed in 37℃ water bath for 1 min. After thawing, the mixed semen samples were randomly allocated to 12 treatment groups. Briefly, the spermatozoa were centrifuged for three different time lengths (10, 20, and 30 min) at two gravities (300×g and 700×g) through two concentrations of discontinuous Percoll density gradient of 1 ml 90%: 1 ml 45% Percoll and 2 ml 90%: 2 ml 45% Percoll to remove extender, debris, and dead spermatozoa. Motile sperm recovery rate and motion kinematics were evaluated by computer assisted sperm analyzer using Makler counting chamber. Sperm motility (%) and motile sperm recovery rate showed similar pattern in all treatment groups. However, sperm motility (%) and motile sperm recovery rate were highest at 700×g for 30 min through a discontionous Percoll density gradient of 1 ml 90%: 1 ml 45% Percoll. There were no significant differences in motion kinematics after various Percoll washings. These results suggest that force of centrifugation, centrifugation time, and Percoll volume significantly affect motile sperm recovery rate.

The objective of this study was to investigate the effect of storage time on fresh boar semen in Androhep and Beltsville Thawing Solution (BTS). Boar semen samples extended in each extender were stored at 17℃ up to 4 days. Sperm motility kinematics was evaluated by computer assisted sperm analyzer (CASA) and capacitation status by chlortetracycline (CTC)/Hoechst 33258 staining. Sperm motility (%) was not decreased during storage in BTS and Androhep. No significant difference between extenders was observed. Only significant differences in kinematic parameters on linearity during storage were found. The percentage of dead sperm significantly decreased during storage (p<0.05). Also the percentage of noncapacitated, capacitated, and acrosome-reacted sperm significantly modified during storage (p<0.05). However, there was no significant difference between extenders except proportion of capacitated sperm. This finding supported that modification in these parameters was not significantly different between extenders during this short-term storage. Our finding strongly indicated that both Androhep and BTS maintained favorable conditions for motility, motility kinematics, and capacitation status during short-term storage. Despite modifications in some parameters were apparent during sperm storage in extenders, these may not affect the fertilizing capacity of boar semen.

The concerns about potential risks and hazards in children’s playgrounds are increasing and the restrictions for environmental harmful substances in playgrounds have been reinforced in many countries. In this study, the concentrations of heavy metals were analyzed in 142 samples including 105 of sand flooring and 37 playing equipment such as swing, slide, sporting equipment, bench and fence in 18 children’s playgrounds. Heavy metals in sand flooring were investigated and categorized by natural environmental factors such as season, rainfall, post-rainy day, and artificial factors as road, type, and material of nearby play equipment. The concentration of heavy metals such as Pb, Hg, Cu, and Zn were significantly higher in sand flooring near the play equipment than at places away from the playing equipment (p < 0.05). Spearman’s rank correlation analysis showed that play equipment had a positive correlation with the sand flooring with regard to the concentration of Pb (r = 0.42, p < 0.01) and Cu (r = 0.39, p < 0.01). The concentration of heavy metals in the sand flooring showed a statistically significant difference depending on the season, post-rainy day, the distance from a roadway, type of equipment, and the material. The play equipment’s heavy metal concentration and other environmental factors contributed to the heavy metal concentration in the sand flooring’s surface in playgrounds.

This study was performed to investigate the physico-chemical properties and phytoplankton concentration from February to December, 2007 in Gwangju area reservoirs. Water samples from 20 reservoirs were analyzed. As results of the water quality analysis, the average pH was 7.6 and annual pH were 6.3 ～9.6. The higher pH of 8.6 ～ 9.6 were showed from March to August due to eutrophication. Chlorophyll-a concentration ranged from 0.4 to 164.3 mg/㎥. The highest chlorophyll-a concentration was observed in August. BOD was correlated with SS, T-N, and Chlorophyll-a(R=0.82, 0.90 and 0.84) respectively. COD was correlated with BOD, SS and Chlorophyll-a(R= 0.89, 0.77 and 0.76) respectively. The T-N/T-P ratios were 4～281, so phosphorus was considered to be the limiting factor in most of points. The trophic state showed eutrophicate states in Gwangju reservoirs. Therefore it was necessary to monitor continuously. In order to monitor the reservoirs, an algae prediction system must be used.

Plant peroxidases (PODs) have been shown to reduce hydrogen peroxide (H2O2) in the presence of an electron donor. Extracellular POD also induce H2O2 production, and can perform a significant function in responses to environmental stresses. We previously described the isolation of 10 POD cDNA clones from cell cultures of sweetpotato (Ipomoea batatas). Among them, the expression of the swpa4 gene was profoundly induced by a variety of stresses. In this study, transgenic tobacco (Nicotiana tabacum) plants overexpressing the swpa4 gene under the control of the CaMV 35S promoter were generated in order to assess the function of swpa4. Both transient expression analysis with the swpa4-GFP fusion protein and POD activity assays in the apoplastic washing fluid revealed that the swpa4 protein is secreted into the apoplastic space. The transgenic plants also evidenced a significantly enhanced tolerance to a variety of abiotic and biotic stresses. These plants harbored increased lignin and phenolic content, and H2O2 was also generated under normal conditions. Furthermore, they manifested increased expression levels of a variety of apoplastic acidic pathogenesis-related (PR) genes following enhanced H2O2 production. These results suggest that the expression of swpa4 in the apoplastic space functions as a positive defense signal in the H2O2-regulated stress response signaling pathway.