• Title/Summary/Keyword: population change

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Colonization and Population Changes of a Biocontrol Agent, Paenibacillus polymyxa E681, in Seeds and Roots

  • Park, Okhee;Kim, Jinwoo;Ryu, Choong-Min;Park, Chang-Seuk
    • The Plant Pathology Journal
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    • v.20 no.2
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    • pp.97-102
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    • 2004
  • Paenibacillus polymyxa E681, with its plant growth promotion and root colonization ability, has been proven to be a promising biocontrol agent of cucumber and barley. This study investigated the attributes related to the movement of bacteria from the seed to the radicle and to the whole root system. It also illustrated the existing form and population changes of the bacteria on seed and root using the scanning electron microscope and confocal laser scanning microscopy. The bacteria invaded and colonized the inside of the seed coat while the seeds were soaked in bacterial suspension. Almost the same number of bacteria on seed surface invaded the inside of the seed coat right after seed soaking. The population densities of E681 increased greatly inside as well as on the surface of the seed before the radicle emerged. The bacteria attached on the emerging radicle directly affected the initial population of newly emerg-ing root. The colonized cells on the root were arranged linearly toward the elongation of the root axis. In addition to colonizing the root surface, strain E681 was found inside the roots, where cells colonized the inter-cellular space between certain epidermal and cortical cells. When the cucumber seeds were soaked in bacterial suspension and sown in pot, the bacterial populations attached on both the surface and inside of the root were sustained up to harvesting time. This means that E681 successfully colonized the root of cucumber and sustained its population density up to harvesting time through seed treatment.

Long-Term Estimation of 119 Ambulance Services by Demographic Changes in Korea (인구 변동에 따른 119 구급 서비스의 장기 추계)

  • Kang, Kyunghee
    • Fire Science and Engineering
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    • v.32 no.5
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    • pp.105-111
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    • 2018
  • Based on the Statistical Yearbook of 119 Emergency Medical Services in 2017 (National Fire Agency, 2018) and Population Projection by Province: 2015~2045 (Statistics Korea, 2017), this study analyzed the effects of population changes, such as low fertility and aging on the use of ambulance services in the future. The population of Korea is expected to decline after peaking in 2031, but the number of elderly people aged over 70 is expected to continue to increase. The rates of emergency ambulance transport (REAT, the number of patients transferred per 1,000 inhabitants) are not changed significantly, compared to the recent trends, but the ambulance services for elderly over 70 years of age will increase exponentially. Therefore, the population changes due to low fertility and aging is accompanied by a quantitative and qualitative change in ambulance services, and from the long term perspectives, it is necessary to consider not only the effective response of ambulance services due to aging, but also the adjustment of existing jurisdictions due to population changes and the relocation of manpower and resources.

Study on Fatality Risk of Older Driver and Traffic Accident Cost (고령운전자 연령구간별 사망사고 발생위험도와 사고비용 분석 연구)

  • Choi, Jaesung
    • Journal of the Korean Society of Safety
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    • v.33 no.4
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    • pp.111-118
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    • 2018
  • Korea is facing a surge in the aging population, showing that population aged 65 and above will be accounted for 42.5% of the total population in 2065 with the emphasis on the over-80 population consisting of 19.2%. In response to this abrupt change in population structure, the number of traffic fatality accident referring to older driver as aged 65+ years had been increasing from 605 fatalities in 2011 to 815 fatalities in 2015 resulting in increases in 34.7% in oppose to happening to decreases in 17.2% about non-older driver. With Logit analysis based on Newton-Raphson algorithm utilizing older driver's traffic fatality data for the 2011-2015 years, it was found that the likelihood of an accident resulting in a fatality for super older driver aged 80 years and above considerably increased compared to other older driver with aging classification: 2.24 times for violation of traffic lane, 2.04 times for violation of U-turn, 1.48 times for violation of safety distance, 1.35 times for violation of obstacle of passing; also average annual increase of traffic accident cost related to super older driver was fairly increased rather than other older driver groups. Hence, this study proposes that improving and amending transport safety system and Road Traffic Act for super older driver needs to be urgently in action about license management, safe driving education, etc. when considering the increase of over-80 population in the near future. Also, implementing a social agreement with all ages and social groups to apply with advanced driver assistance system for older driver groups will be able to become a critical factor to enhance safe driving over the face of the country.

A Study on Changes of Korean Mortality Pattern, 1930~1980 (한국인의 사망구조 변화에 대한 고찰)

  • 유임숙;김초강;공세권
    • Korea journal of population studies
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    • v.9 no.2
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    • pp.79-92
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    • 1986
  • Death is one of the population movement phenomena used as an important health index in most society. Especially it is regarded as group phenomenon in a specific group rather than individual one and considered important in public health field because the level and cause of death is related to health of public. The auther examined the changes of the Korean mortality pattern to evaluate the status of the Korean public health by studying mortality indicator using the population census and other materials from 1930 to 1980. The results are as follows: First, the Korean crude death rate was reduced to one third in 1980 compared to that in 1930, but the crude birth rate was constant from 1930 to 1960 causing the increase of population. So the population pattern is changing from the classic pyramic shape to bell shape and the dependency ratio was reduced from 78 in 1930 to 61 in 1980. Second, the infant mortality rate decrease rapidly. In 1980 it was one seventh of that in 1930 which was proved by the change of the age-specific death rate curve from U to J shape. Third, the male mortality reduction after the age of forty was much less than that of female, which explained the specific death pattern of high mortality in Korean middle and oldaged males. Fourth, the main cause of death was changed from infectious, parasitic, respiratory and digestive system disease to circulatory of tumorous diseases. Considering the above results, Korean health problem is now changing from the infant infection to geriatric chronic regressive disease. That naturally the direction of health service should be turned from the infant stage maternal and child health to the health problems of old people.

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Demographic Transition and Population Ageing: A Comparative Study of MDC, LDC, and Korea (인구변천과 인구고령화: 선진국, 개발도상국, 그리고 한국의 비교 연구)

  • Lee, Sung Yong;Lee, Jung Whan
    • International Area Studies Review
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    • v.15 no.1
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    • pp.549-570
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    • 2011
  • The purpose of this article is to review the current states and future trends in the more developed countries(MDC), the less developed countries(LDC), and Korea. In 2009, the percentage of persons ages 65 and older in the world's population is 8%. However, the ratio of elderly to the total population is higher in MDC than LDC (and Korea). In future, population ageing will be a serious social problem in the LDC (and Korea). Population ageing process will occur at a much faster rate in LDC (and Korea). The reason is that the demographic transition in LDC (and Korea) has occurred in much shorter and recent periods. Though the ageing indices such as the old-age dependency ratio, aging index, and the median ages are higher in MDC, they will change rapidly in LDC. In addition, the oldest old population will increase in LDC than MDC. Therefore, when establishing the government policy related to population ageing, we need to consider the different population ageing process between in MDC and in Korea(or LDC).

Change Prediction of Forestland Area in South Korea using Multinomial Logistic Regression Model (다항 로지스틱 회귀모형을 이용한 우리나라 산지면적 변화 추정에 관한 연구)

  • KWAK, Doo-Ahn
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.4
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    • pp.42-51
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    • 2020
  • This study was performed to support the 6th forest basic planning by Korea Forest Service as predicting the change of forestland area by the transition of land use type in the future over 35 years in South Korea. It is very important to analyze upcoming forestland area change for future forest planning because forestland plays a basic role to predict forest resources change for afforestation, production and management in the future. Therefore, the transitional interaction between land use types in future of South Korea was predicted in this study using econometrical models based on past trend data of land use type and related variables. The econometrical model based on maximum discounted profits theory for land use type determination was used to estimate total quantitative change by forestland, agricultural land and urban area at national scale using explanatory variables such as forestry value added, agricultural income and population during over 46 years. In result, it was analyzed that forestland area would decrease continuously at approximately 29,000 ha by 2027 while urban area increases in South Korea. However, it was predicted that the forestland area would be started to increase gradually at 170,000 ha by 2050 because urban area was reduced according to population decrement from 2032 in South Korea. We could find out that the increment of forestland would be attributed to social problems such as urban hollowing and localities extinction phenomenon by steep decrement of population from 2032. The decrement and increment of forestland by unbalanced population immigration to major cities and migration to localities might cause many social and economic problems against national sustainable development, so that future strategies and policies for forestland should be established considering such future change trends of land use type for balanced development and reasonable forestland use and conservation.