적정 국적 선원 수의 유지는 우리나라의 해운산업 경쟁력 확보와 국가안보를 위해 필수적이다. 그러나, 우리나라 국적 선원 수 는 최근 지속적으로 감소하고 있다. 우리나라 정부도 이와 같은 국적 선원의 중요성과 문제점을 인식하고, 원인 및 대응 방안을 모색하려 노력하고 있다. 이러한 과정 중에서 정부는 20~30세대의 해기사 선호도 감소로 인한 높은 초기 이직을 국적 선원 급감의 주요 원인 중 하 나로 추정하였다. 이를 해결하기 위해 정부는 청년층이 장기승선을 선택할 수 있는 환경을 조성하는 다양한 정책 마련을 이미 하였거나 앞으로 하고자 한다. 이에 따라 본 연구는 ‘M’대학교 해사대학에 재학 중인 학생을 대상으로 장기승선 여부를 결정하는 결정 요인을 분석 하고, 희망 승선기간과의 관계를 확인하였다. 본 연구를 통해 예비 해기사들이 인식하는 장기승선 결정 요인으로 선원 구성 요인(CC), 장 기계획 요인(LP), 근무 환경 요인(WE), 가정 환경 요인(FE)이 도출되었다. 이중, 장기계획 요인(LP)과 근무환경 요인(WE)이 희망 승선기간 에 유의한 영향을 미치는 것으로 분석되어 장기계획에 대한 인식이 강하고, 근무환경에 무감각할수록 희망 승선기간은 증가하는 것으로 추정되었다. 장기승선에 대한 그룹별 인식차이에서는 성별차이에 따라 일부 장기승선 결정 요인을 다르게 인식한 것으로 분석되었다. 본 연구를 통해 예비 해기사의 장기승선 유도를 위한 요인 및 그룹별 정책 방안 마련에 도움이 될 수 있을 것으로 기대된다.
Construction industry is considered as one of the most high-risk industries for work-related injuries and fatalities, accounting for more than half of fatalities in Korea. Advanced countries have recognized the critical role of designers in preventing construction accidents and have established regulations on design for safety. In line with this, the Korean government have also implemented regulations that require owners and designers to review the safety of design outcomes. However, it has been observed that designers face challenges in identifying hazards and integrating design solutions at the design stage mainly due to their shortage of required knowledge and skills. This study aimed to examine design solutions that can be applied to prevent fall accidents in the construction industry, and to establish a relationship between these solutions and fatal fall accidents occurred over the past three years in Korea. This study also analyzed the relationships of four variables (construction type, cost, work type, and fall location) with design solutions. The results indicated that all four variables have significant relationships with design solutions, with fall location showing the strongest relationship. The design solutions and their relationships with fatal fall accidents identified in this study can be utilized in identifying hazard and integrating design solutions to ensure design for safety.
The Severe Disaster Punishment Act had recently been established in order to promote safety and health (OSH) management system for severe accident prevention. OSH management system is primarily designed based on risk assessments; however, companies in industries have been experiencing difficulties in hazard identification and selecting proper measures for risk assessments and accident prevention. This study intended to introduce an accident analysis method based on epidemiological model in finding hazard and preventive measures. The accident analysis method employed in this study was proposed by the U.S. Department of Energy. To demonstrate the effectiveness of the accident analysis method, this study applied it to two accident cases occurred in construction and manufacturing industries. The application process and results of this study can be utilized in improving OSH management system and preventing severe accidents.
선박으로부터 발생하는 온실가스 배출을 저감하기 위한 규제가 점차 강화되고 있다. 현존선에서도 EEXI(Energy Efficiency Existing Index)가 도입되었으며 이와 같은 온실가스 배출 감축목표를 달성하기 위해 다양한 연구가 진행되고 있다. 본 연구에서는 국제항 해에 종사하는 현존선 중 자동차운반선에 태양광 발전시스템을 적용하여 연료유 사용량을 줄임으로써 온실가스 배출이 저감될 수 있는 시스템을 제안하였다. 제안된 태양광 발전시스템은 태양광 모듈, 에너지저장시스템, 전력변환장치 등으로 구성되었으며, 본 시스템의 적 용 가능성을 확인하기 위해 전력전자프로그램을 통해 시스템을 모델링하였으며, 시뮬레이션을 실시하였다. 또한, 실제 선박에 적용하기 위한 타당성 검증을 위해 경제성 분석을 실시하였으며, 약 11년 이후 경제성 부분에서도 유의미한 결과가 도출됨을 확인할 수 있었다.
Haemaphysalis longicornis (H. longicornis) is the most dominant species that accounts for more than 90% of domestic ticks in Korea. It is also a main mediator and propagator of Severe Fever with Thrombocytopenia Syndrome virus. In order to efficient control of H. longicornis, it is essential to obtain the genetic information of pesticide target genes and determine the mutations putatively involved in insecticide resistance. Acetylcholinesterase (Ace) is a target gene of organophosphorus and carbamate insecticides, but no sequence information of Ace is available to date in H. longicornis. Therefore, in this study, we analyzed the transcriptome of H. longicornis and obtained the sequence information of three Ace genes (HlAce1, HlAce2 and HlAce3). Based on the comparison analysis with sequences of multiple ace genes from other hard ticks, mites and insects, three HlAces were grouped in Acari Ace1, Ace2 and Ace3 clade, respectively. Among three HlAces, HlAce1 seems to be major enzyme because of its conserved amino acids involved in catalytic function.
Honey bee has been widely used as a model insect for biological sciences because of its sociality and specialized labor division. For the investigation of the seasonal and labor-dependent expression patterns of genes putatively involved in its sociality, quantitative real-time PCR (qRT-PCR) can be applied to quantify gene expression level and selection of reliable reference gene(s) for normalization is an accurate step. In this study, using three softwares (geNorm, NormFinder and BestKeeper), we evaluated seasonal expression stabilities of four reference genes that have been widely used for qRT-PCR in forager and nurse heads. Among four candidates, two genes, rpS18 and gapdh, were suggested to be the optimal reference genes for qRT-PCR.
Ras activates a series of downstream effectors, including the mitogen-activated protein kinase pathway and the Rac/Rho pathway after insulin stimulation. Mutations in Ras are found in approximately 30% of all human cancers and are critical factors in tumor initiation and maintenance. There are four Ras proteins with 80-90% amino acid sequence homology with major differences in the carboxyl termini. Ras proteins undergo farnesylation on their carboxyl termini catalyzed by the enzyme protein farnesyltransferase (FTase), which facilitates localization of Ras proteins to the inner surface of the plasma membrane. Because inhibition of FTase would prevent Ras from processing into its active form, FTase is viewed as a potential therapeutic target. A variety of FTase inhibitors have showed great potency against tumor cells in preclinical studies. Although many farnesyltransferase inhibitors have been developed, their adverse effects on the mitogenic and metabolic actions of insulin are not completely understood. Here we show that YH3096, a farnesyltransferase inhibitor, inhibits insulin-mediated DNA synthesis in HIRc-B cells without affecting c-Jun expression and membrane ruffling in HIRc-B cells. Moreover, YH3096 and its derivatives did not affect insulin-induced glucose uptake in 3T3-L1 adipocytes. Our results provide a laboratory evaluation of the effects of Ras inhibitors on insulin functions.
Probiotic strain is known to regulate the immune system by colonizing in the intestine and interact with intestinal cell receptors of lymphoid tissue. In this study, safety of Streptococcus thermophilus KCTC14471BP and silk fibroin coating effects was evaluated with respect to mucin binding abilities and immune system modulation. S. thermophilus KCTC14471BP was coated with silk fibroin by adding 1% water-soluble calcium and 0.1% silk fibroin. S. thermophilus KCTC14471BP showed the high activities of leucine arylamidase and β-galactosidase. Regarding the antibiotic resistance tests, S. thermophilus KCTC14471BP was susceptible to ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, and chloramphenicol. S. thermophilus KCTC14471BP coated with silk fibroin showed the improved mucin binding ability from 16.1% to 71.3% and was confirmed to have no cytotoxicity against RAW 264.7 macrophage. S. thermophilus KCTC14471BP coated with silk fibroin showed dose-dependently significant increases in pro-inflammatory cytokines IL-1β, IL-6, and TNF-α. These results suggested that S. thermophilus KCTC14471BP can be expected as a promising probiotic bacteria for applications to food industries such as fermentation or functional foods.