• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.85-92
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• 2000

The purpose of this study was to identify the controlling factors to construct tidal flat ecosystems having similar characteristics as natural ones. We transplanted the soil in a constructed tidal flat to a natural one and vice versa. Parameters monitored after these transplantations were silt content, organic matter, bacterial population and oxidation-reduction potential. Moreover, the relationship among silt content, organic matter and bacterial population was investigated by laboratory column experiment. The silt content, organic matter, bacterial population and vortical profile of oxidation-reduction potential in the soil transplanted from the constructed tidal flat to the natural one changed to similar values to those In the natural one. On the contrary, all the parameters for the soil transplanted from the natural tidal flat to the constructed one changed to similar values as those in the constructed one. The silt contents in these two transplanted soils were in proportion to the organic carbon contents and bacterial population. Similarly, the bacterial population in laboratory column experiment increased with the increase in silt and organic matter contents. It seemed to be important to select a place to enhance accumulative of silt and/or to maintain the silt content by hydrodynamic control of seawater in order to construct a tidal flat having similar characteristics as natural one.

• Journal of Life Science
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• v.19 no.9
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• pp.1183-1189
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• 2009

85 individual Spiraea prunifolia for. simpliciflora (Rosaceae) were sampled to examine the genetic diversity and population structure of S. prunifolia for. simpliciflora populations. Inter-simple sequence repeats (ISSR) produced 65 polymorphic loci and identified 78 ISSR genotypes. Three multilocus genotypes were shared by more than one plant within a population. Total genetic diversity values ($H_T$) and inter-locus variation in the within-population genetic diversity ($H_S$) were 0.293 and 0.183, respectively. On a per-locus basis, the proportion of total genetic variation due to differences among populations ($G_{ST}$) was 0.373. This indicated that about 37.3% of the total variation was among populations. ISSR markers are very effective in classifying natural population levels of S. prunifolia for. simpliciflora in Korea. In addition, insights into the relative gene diversity among and within populations of S. prunifolia for. simpliciflora would be useful in plant breeding and also for the development of strategies for ex situ conservation of plant genetic resources.

• ALGAE
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• v.27 no.3
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• pp.189-196
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• 2012

Twelve morphological characters and the biochemical composition of Undaria pinnatifida f. distans sporophytes growing on the rocky shores of Jindo and Wando and on cultivation ropes in Kijang were measured to determine whether each population could be characterized by morphological features and biochemical composition. The goal of this study was to compare phenotypic variations between populations as they relate to environmental conditions. The sporophytes of the Kijang population were two times longer and 19 times heavier than those at Jindo. Sporophylls of the Jindo U. pinnatifida population were significantly smaller in length, width, frill number, and weight than those at Wando and Kijang. Kijang Undaria plants showed the highest contents of total protein, crude fiber, total amino acids, the amount of essential amino acids, the proportion of total unsaturated fatty acids, and eicosapentaenoic acid. However, the Jindo population showed the greatest content of carbohydrates, lipids, and minerals (Zn and Ca) of the three U. pinnatifida populations. In particular, Zn content of Jindo plants was 30 times greater than that of Kijang plants. Thus, the proximate composition, mineral composition, amino acids, and fatty acids of Undaria pinnatifida plants were distinguishable among the three representative Undaria populations evaluated. These results suggest that morphological and biochemical differences of the three U. pinnatifida populations can be attributed to differences in environmental conditions of their habitats.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.3105-3112
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• 2014

Purpose: To examine breast cancer (BC) incidence trends in relation to mammographic screening and risk factor prevalence in South Australia (SA). Materials and Methods: Trends in annual BC incidence rates were calculated using direct standardisation and compared with projected incidence derived from Poisson regression analysis of pre-screening rates. Annual percentage change and change time points were estimated using Joinpoint software. Biennial mammography screening participation rates were calculated using data from BreastScreen SA. Trends in overweight/obesity, alcohol use and hormone replacement therapy (HRT) use were examined using 1991-2009 Health Omnibus Survey data. Trends in total fertility were examined using data from the Australian Bureau of Statistics. Results: BC incidence increased around the time BreastScreen commenced and then stabilised in the mid-1990s. However rates have remained higher than projected, even though the proportion and age distribution of first time screening attendees stabilised around 1998. A decrease in BC incidence was observed among women aged 50-59yrs from the late-1990's but not among older women. Obesity and alcohol use have increased steadily in all age groups, while HRT use declined sharply from the late-1990s. Conclusions: BC incidence has remained higher than projected since mammography screening began. The sustained elevation is likely to be due to lead time effects, though over-diagnosis cannot be excluded. Declining HRT use has also impacted incidence trends. Implications: Studies using individual level data, which can account for changes in risk factor prevalence and lead time effects, are required to evaluate 'over-diagnosis' due to screening.

• Journal of Life Science
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• v.16 no.6
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• pp.898-903
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• 2006

The genetic diversity and population structure of fifteen Potentilla discolor Bunge populations in Korea were determined using genetic variations at 19 allozyme loci. Fourteen of the 19 loci (73.7%) showed detectable polymorphism. Genetic diversity at the species level and at the population level was high ($H_{ES}\;=\;0.215$, $H_{EP}\;=\;0.196$, respectively), whereas the extent of the population divergence was relatively low $(G_{ST}\;=\;0.069)$. Total genetic diversity values $(H_T)$ varied between 0.0 and 0.656, giving an average overall polymorphic loci of 0.292. The interlocus variation of genetic diversity within populations $(H_S)$ was high (0.274). On a per locus basis, the proportion of total genetic variation due to differences among populations $(G_{ST})$ ranged from 0.010 for Pgm-2 to 0.261 for Pgd-2 with a mean of 0.069, indicating that about 6.9% of the total allozyme variation was among populations. Wide geographic ranges, perennial herbaceous nature and the persistence of multiple generations are associated with the high level of genetic variation in P. discolor. The estimate of gene flow based on $G_{ST}$ was high among Korean populations of P. discolor (Nm = 3.36).

• Journal of Korean Neurosurgical Society
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• v.62 no.2
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• pp.243-255
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• 2019

Objective : Although traumatic brain injury (TBI) occurs in people of all age groups, the elderly population is at a particular risk. The proportion of elderly population in the society is markedly increasing and Korea is one of the most rapidly aging societies. Here, we analyzed the data from 904 patients older over 65 years who were registered in the Korean Neuro-Trauma Data Bank System (KNTDBS). Methods : The Korean Society of Neurotraumatology recorded data from 20 institutions between September 2010 and March 2014. This retrospective study examined the clinical epidemiology, sex difference, outcome epidemiology, sociodemographic variables, and outcomes in the geriatric population related to TBI based on data from the KNTDBS. Results : The study included 540 men and 364 women. The age distributions in the male and female groups were statistically significantly different. The most common cause of trauma was a fall and diagnosis was acute subdural hematoma. The incidence was the highest in men aged 80-84 years and in women aged 75-79 years. The most common time of arrival to hospital after TBI was within 1 hour and 119 rescue team provided first aid earliest to patients with TBI. The mortality rate stratified according to the cause of trauma was significantly different, with mortality rates of 3.77% in fall and 11.65% in traffic accident. The mortality rates according the severity of brain injury, Glasgow Coma Scale score, and treatment were statistically significant. Conclusion : To our knowledge, this study is the first to focus on elderly patients with TBI in Korea and particularly investigate mortality and characteristics related to TBI-related death based on data from the KNTDBS. Although the study has some limitations, our results may be used to obtain useful information to study targeted prevention and more effective treatment options for older TBI patients and establish novel treatment guidelines and health polish for the geriatric population.

• Journal of agricultural medicine and community health
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• v.35 no.4
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• pp.350-360
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• 2010

Objectives: This study was conducted to identify factors that affect medical service performance in rural health sub-centers and to develop a method to improve health sub-center performance that takes advantage of these insights. Methods: This study included 1,242 South Korean health sub-centers that had been in operation at least since December 31, 2009 as units of analysis. After adjusting for population differences between areas, the performance of medical service among health sub-centers was analyzed according to medical services performed per person. We performed t-tests, ANOVA, Scheffe's tests and multiple regression analyses. Results: The following were significant variables affecting the medical service performance of rural health sub-centers: number of hospitals and clinics, presence of community health practitioner posts, distance from health sub-centers to main public health centers, distance from health sub-centers to the nearest emergency medical facilities, and proportion of the local population aged 65 and over. In contrast, the proportion of the local population between ages 0-4 and the placement of public health doctors that had already completed their internship were not significant variables. Conclusions: The medical service performance of health sub-centers located in rural areas is significantly affected by local population and health care environment characteristics, and therefore, it is imperative to develop strategies to provide differentiated service based on these factors.

• Journal of Ecology and Environment
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• v.44 no.3
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• pp.196-206
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• 2020

Background: The Himalayan forests are of great importance to sustain the nature and community resource demands. These forests are facing pressures both from anthropogenic activities and ongoing global climatic changes. Poor natural regeneration has been considered a major problem in mountainous forests. To understand the population structure and regeneration status of Larix (Larix griffithiana and Larix himalaica), we conducted systematic vegetation surveys in three high-altitude valleys namely Ghunsa (Kanchenjunga Conservation Area, KCA), Langtang (Langtang National Park, LNP), and Tsum (Manaslu Conservation Area, MCA) in Nepal Himalaya. The average values of diameter at breast height (DBH), height, and sapling height were compared for three sites and two species using Kruskal-Wallis test. Population structure was assessed in terms of proportion of seedlings, saplings, and trees. Regeneration was analyzed using graphical representation of frequencies of seedlings, saplings, and trees in histograms. Results: The results showed that the population structure of Larix in terms of the proportion of seedling, sapling, and tree varied greatly in the three study areas. KCA had the highest record of seedling, sapling, and tree compared to other two sites. Seedlings were the least among three forms and many plots were without seedlings. We found no seedling in MCA study plots. The plot level average DBH variation among sites was significant (Kruskal-Wallis χ² = 7.813, df = 2, p = 0.02) as was between species (Kruskal-Wallis χ² = 5.9829, df = 1, p = 0.014). Similarly, the variation in average tree height was significant (Kruskal-Wallis χ² = 134.23, df = 2, p < 0.001) among sites as well as between species (Kruskal-Wallis χ² = 128.01, df = 1, p < 0.001). All the sites showed reverse J-shaped curve but more pronounced for KCA and MCA. In comparing the two species, Larix griffithiana has clear reverse J-shaped diameter distribution but not Larix himalaica. Conclusion: The varied responses of Larix manifested through regeneration status from spatially distinct areas show that regeneration limitations might be more pronounced in the future. In all the three studied valleys, regeneration of Larix is found to be problematic and specifically for Larix griffithiana in MCA and Larix himalaica in LNP. To address the issues of disturbances, especially serious in LNP, management interventions are recommended to sustain the unique Himalayan endemic conifer.

• Korea journal of population studies
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• v.24 no.1
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• pp.149-182
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• 2001

Due to the sustained increase in lifts expectancy, the number and proportion of the aged population has substantially increased, the proportion of the total population aged 65 and over was 7.1% in 2000 and 14.3% in 2022. But All public pension schemes in Korea, including the National Pension scheme, civil servants pension scheme, private school teachers pension scheme and the military pension scheme, are facing valving degree of financial problems at present because of their weak and unstable financial bases. with the result that some of them have recorded deficits for some time and the others are expected to run deficits in the near future. This crisis in financial sustainability in public pension schemes is attributable to the structural weakness of the schemes which can be characterized as high benefits, low contribution. Therefore, this article focuses on alternative of public pension schemes reform in Korea. The results is as follows. First, a basic pension is proposed to be newly established and the earnings related portion of National Pension Scheme will be as national pension. Secondly, the Basic Pension is a universal basic pension covering all nationals over 18 years and older, thereby achieving \"one pension for everybody\" Thirdly, National Pension will be operated as an earnings related pension covering only those participants with assessed income. Fourth1y, the current participants of public occupational pensions will also join the Basic Pension as well as the public occupational pensions whose scope of works will be reduced. And finally, The conversion of Retirement Allocation Scheme into a corporate pension should be left to the discretion of the company concerned.

• Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.59-63
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• 2002

Swim up fry of the Nile tilapia, Oreochromis niloticus, were fed 0 or 60 mg l7-methyltestos­terone (MT) per kg feed for 30 days. Fish that had been fed 0 or 60 ppm MT for the first 30 days were subsequently fed a commercial diet for 56 weeks to evaluate growth, survival, sex ratio, body composition, gonadosomatic index and the total edible portion. Mean body weight of MT treated group and untreated group were 1.7 g and 1.1 g, respectively at the end of the treatment for 30 days $(P<0.05)$. The experiment was terminated after a total of 60 weeks, the mean body weight of the MT treated population was 1,016 g and that of the untreated population was 762g $(P<0.05)$. However, the final mean body weight of untreated males (l, 086g) was not significantly different from treated males (l,016 g), but the mean body weight of the female group was 512 g. Therefore, the reason for the lower mean body weight of the untreated group was entirely due to stunted females. The percentage fillet yield of MT treated fish$(34.6\%)$ was not significantly different from that of the untreated males $(34.4\%)$, but the untreated females were lower than those of both treated and untreated male groups $(32.4\%)$ (P<0.05). There were no significant differences in the percentage of the all edible portion (AP) between MT treated and untreated males, but females were lower than males. Females are smaller fish in size and the gonads are larger in proportion which were discarded along with the intestine this explains the observed difference. Total biomass of the two groups were 134.8kg and 104.5kg per $m^3$, respectively. The proportion of fish reaching a marketable size of over 800 g in body weight within 14 months were $78\%$ in the MT treated group and $41\%$ in the untreated group.