As contemporary society has become more complicated, specialized, and segmented, people are experiencing more diverse types of stress. In particular, while several factors associated with job stress have been examined among nurses, who belong to a professional group, the existing research has made no quantitative assessments of stress that reflect temporal differences in individuals. Therefore, the aim of this study is to understand the effects of job stress on alpha-amylase with regard to the working hours of nurses, to assess the variations in jobs stress over time, and provide basic data to improve the quality of nursing services. Ninety nurses working in three shifts in general, emergency, and intensive care wards of a university hospital in D City participated in this study. Salivary alpha-amylase (SAA) was extracted and analyzed at two-hour intervals from 07:00 to 15:00 from nurses on the day shift and from 23:00 to 07:00 from those working the night shift. The SAA level was highest between 23:00 and 01:00 for nurses in general wards (mean±S.D. 39.00±14.88) and between 11:00 and 13:00 for those in both intensive care units and emergency wards (mean ± S.D. 67.50 ± 62.93 and mean ± S.D. 39.67±35.96, respectively). The characteristic variation in SAA was significant between 23:00 and 01:00 (p < 0.01) and for those in their fifties or older (p < 0.01). The activation ratio of alpha-amylase, a stress reactant, showed an increase when the sympathetic nervous system was activated by mental stress; in addition, job stress was manifested with the effect of awakening at different time segments and at different ages among the nurses. With the aim of raising the level of service based on the nurses maintaining their mental health, it is necessary to focus sharply on the time segment for critical control and to conduct repetitive studies to determine the divisions of eustress critical values as well as to expand the population.

Preharvest sprouting (PHS) not only causes reduction of grain yield, but also affects the quality of grains, resulting into significant economic losses. PHS is governed by multiple genes. Little is known about the large genetic variation of preharvest sprouting in rice. In the present study, genetic variations of four PHS genes, OsVP1, Osaba1, Alpha-amylase3D and OsGA20ox1 were studied by using whole-genome resequencing data of 84 accessions of rice core set. A total of haplotype groups; 27, 29, 6 and 14, for OsVP1, Osaba1, Alpha-amylase3D and OsGA20ox1, respectively, were detected among the 84 accessions. Some new SNPs and InDels were found in exon part of PHS related genes were expected to result in amino acid changes following analysis of the genetic code variations, and the germplasm or varieties which are resistant to preharvest sprouting were explored. Based on this step, phenotyping for PHS is ongoing, and the association mapping of PHS will be conducted by using SNPs resulted from the haplotyping data. The present results will be ultimately useful to the molecular breeding for the development of PHS resistant rice cultivars.