코로나19는 선원교대를 지연시키면서 선박과 선원의 안전에 위협을 가하고 있다. 선원의 승선환경에 있어 해운기업과 정부가 놓치고 있는 사각지대는 존재하고 있다. 선원의 안전을 위협하는 비상체제 상황에서 인적사고를 유발할 가능성을 제거하기 위해 효과적인 교대방안을 구상해볼 필요가 있다. 본 연구에서는 전직 및 현직 선원을 대상으로 설문조사를 진행한 결과, 승선생활에서 가장 중요하게 생각하는 요인은 안전이었으며 비상체제 상황에서 가장 필요한 것은 임금 및 복지의 향상보다 선원의 원활한 교대방안이 우선적으로 확보되어야 한다고 응답하였다. 국적해운기업의 대륙별 주요 항로를 분석하여 기항 횟수가 많고 항공연계성지수가 높은 항만을 거점항만으로 선정하였다. 또한, 국제해운에 승선하는 국내 선원의 효과적인 교대를 위한 이동경로를 구상하였다. 그를 위해 비상 시 선원의 안전한 본국 귀환 및 이송을 위하여 선박과 항만, 항공을 연계한 이동경로 구축은 다른 나라와의 협의가 필수적이다. 또한, 국제해사기구의 협 력을 통해 선원교대의 어려움에 처해있는 선원들을 위해 함께 노력할 필요가 있다. 이를 시작으로 국적 선원이 승선하는 정기선과 부정 기선의 귀항로 및 불귀항로 정보와 선원 수에 대한 모니터링 체계를 갖추어 상시 확인할 수 있어야 한다. 그러한 체계가 갖추어진다면 비상체제 발생 시 우리나라의 정책 대응방향을 보다 빠르게 결정할 수 있을 것이다. 선원들의 처우를 개선하기 위한 해운기업의 노력과 더 불어 개정이 필요한 국내법을 검토하고 선원에 대한 인식을 개선하기 위한 국민적·사회적 관심이 필요할 것이다.

We present a photometric study of the star cluster system in the merging galaxy NGC 1487, based on the BI photometry obtained from the F450W and F814W images in the HST /WFPC2 archive data. We have found about 560 star cluster candidates in NGC 1487, using the morphological parameters of the objects. We have investigated several photometric characteristics of the clusters: color-magnitude diagrams (CMDs), color distribution, spatial distribution, age, size and luminosity function. The CMD of the bright clusters with 18.5 < B < 24 mag in NGC 1487 shows three major populations of clusters: a blue cluster population with (B-I) ≤ 0.45, an intermediate-color cluster population with 0.45<(B-I) ≤ 1.55, and a red cluster population with (B - I) > 1.55. The intermediate-color population is the most dominant among the three populations. The brightest clusters in the blue and intermediate- color populations are as bright as B ≈18 mag (MB ≈ -12 mag), which are three magnitudes brighter than those in the red population. The blue and intermediate-color clusters are strongly concentrated on the bright condensations, while the red clusters are relatively more scattered over the galaxy. The CMD of these clusters is found to be remarkably similar to that of the clusters in the famous interacting system M51. From this we suggest that the intermediate-color clusters were, probably, formed during the merging process which occurred about 500 Myrs ago.

Rice is one of the most important cereal crops in the world and a model plant for functional genomics of monocotyledon. Recently, rice crop loss is estimated to be approximately 30% of the total yield due to herbivorous pests, mainly insects. Cry1Ac toxin is a protein produced by the bacterium Bacillus thuringiensis and has insecticidal properties. CryBP1 toxin also is an insecticidal protein produced by the bacterium Bacillus popilliae. These two toxic genes derived bacteria, which were inserted into a binary vector, have been introduced into rice plants by Agrobacterium tumefaciens mediated transformation in order to enhance resistance to insects. Here, we utilized anthers to regenerate transgenic rice plants when it has been plated on the callus induction media as a callus-inducing material. Anther culture has a benefit in terms of being apt to produce doubled haploids in short term in plants breeding compared to seed culture. However, anther culture method in generating transgenic rice still has low productivity of plant regeneration in some genotypes of Japonica rice. Therefore, we examined the efficiency of callus induction and transformation with three different cultivars of Japonica rice, Haiami, Ungwang and Dongjin. In this study, our results showed that Haiami is the best genotype among three cultivars of Japonica rice as callus inducing material in anther culture to produce transgenic rice plants conferring resistance to insects.

Drought and salinity are the major abiotic stresses which are being continued to hamper the ecosystem and agriculture of the affected region. Plant species have adaptations to enhance their ability to tolerate stresses through physiological adjustment. Therefore, substantial amount of research are ongoing to provide insights about those mechanisms which enlighten the stress tolerance in plant. In this study, several rice cultivars were collected from the different parts of the world and ion accumulation experiments were conducted to select the best stress tolerant cultivar in drought and salt stress environment. For stress treatment, five rice cultivars were subjected to salt (200 mM NaCl) and drought (200 mM Mannitol) for 72h. Later Na+, Ca++, K+ concentrations in shoot and root samples were examined at different time interval. In both drought and salt stress, rice cultivar C201 (collected for uzbekistan) showed the lowest levels of Na+ ion and Na+: K+ ratio compared to other cultivars. It was significant parallel observation with pokkali (known salt tolerant cultivar). In this preliminary study, it was observed the C201 had more stress tolerant in terms of ion accumulation; however detail physiological studies are required to strengthen the idea regarding the best stress tolerant physiotype.

Physiological properties of Corni fructus extracts were investigated. The DPPH radical scavenging activity of 90% ethanol extracts had shown 97.20% at 25 mL/g, which was highest in the all extracts. Total polyphenol content of 30% ethanol extracts had shown 140.01mg% at 25 mL/g, which was highest in the all extracts. The polyphenol contents increased as extract concentration rose (25 mL/g>50 mL/g>100 mL/g). Tyrosinase inhibitory effects of all samples were 23.96~88.71%, expecially, the highest at 60% ethanol extracts of 25 mL/g. Nitrite-scavenging abilities under acidic conditions (pH 1.2) were the most effective in all extracts. The results would be useful for understanding of the physiological properties of Corni fructus extracts.