• 제목/요약/키워드: Population dynamics

검색결과 537건 처리시간 0.03초

노년기로의 이행에 따른 소득불평등 변화와 소득이동성 (Changes in Income Inequality and Income Mobility Associated with a Transition to Old Age)

  • 이원진
    • 한국사회복지학
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    • 제64권2호
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    • pp.185-212
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    • 2012
  • 본 연구는 한국노동패널 2차, 7차, 12차 자료를 활용하여 노년기로의 이행에 따른 소득불평등의 변화와 소득이동성을 분석하였다. 분석 결과는 다음과 같이 요약된다. 첫째, 비노년기에서 노년기로 이행할 때 소득불평등 수준이 증가하는 것으로 나타났다. 둘째, 비노년기에서 노년기로 이행하는 시기에 소득순위의 변동이 크게 나타나고, 노년기로의 이행이 이루어진 이후 노년후기로 갈수록 소득순위가 고착화되는 경향이 나타났다. 셋째, 노년기로 이행할 때 소득불평등 수준을 증가시키고 소득순위의 변동을 야기하는 가장 큰 요인은 근로소득의 감소이다. 이러한 분석 결과는 노년기로 이행할 때 근로소득의 감소가 소득불안정성을 야기한다는 사실을 의미한다.

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행위자 기반 공간 모델을 이용한 구제역 확산 시뮬레이션 (Foot-and-mouth disease spread simulation using agent-based spatial model)

  • ;염재홍
    • 한국측량학회지
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    • 제31권3호
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    • pp.209-219
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    • 2013
  • 역학 모델은 질병 확산에 대한 시뮬레이션 및 관련 방역대책을 수립하는데 유용하며, 개체들의 접촉을 통해 전파되는 질병의 공간 확산에 대한 자세한 이해를 가능하게 한다. 이 연구에서는 공간에서 개체 간의 상호작용에 의한 결과로 구제역 전염병의 확산을 시뮬레이션하기 위해 GIS와 통합된 행위자 기반 공간 모델을 제안하고자 한다. 설계된 모델은 모집단, 시간, 공간이라는 세 요소를 고려하여 축산장 간의 간접접촉을 묘사하였다. 모집단의 역학관계는 2010년 경상북도 안동시에서 발생한 구제역 사례를 기준으로 하였으며, 도로를 주행하는 차량에 의한 간접접촉으로 전염병이 전파하는 것으로 설계하였다. 확산 모델은 구제역 전파 확률, 질병에 대한 여러 상태, 질병의 확산 시간, 감염률, 잠복기 및 기타 매개변수 간의 관계를 수식으로 표현하였다. 모델을 이용하여 구제역 발생 상황을 예측하면서 다양한 시나리오를 적용해서 모의실험하였다. 구제역 발생 상황에서 방역 전략을 선정하기 위해 제시된 방법을 이용하여 방역조치를 다양하게 실험하는 것은 구제역 확산을 통제하는 데 중요한 역할을 할 것으로 기대된다.

Oligonucleotide Microarray를 이용한 유류 오염 토양 미생물 군집내 난분해성 화합물 분해 유전자의 검출 (Detection of Biodegradative Genes in Oil Contaminated Soil Microbial Community by Oligonucleotide Microarray)

  • 이종광;김희;이두명;이석재;김무훈
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제11권1호
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    • pp.1-6
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    • 2006
  • 환경 내에서 생물학적 복원을 이해하기 위해서는 미생물 기능성 군집 및 활성을 분석하는 것은 필수적이다. 본 연구에서는 유류오염 토양의 미생물 군집을 모니터링하기 위하여 난분해성 물질의 생물학적 분해에 관여하는 100개의 알려진 대사경로 및 유전자를 기반으로 한 oligonucleotide microarray를 개발하였다. 본 연구에 사용된 microarray는 유류오염 분해 대사에 관련된 유전자를 진단하기 위한 15개의 고유한 probe를 포함하고 있다. 디자인된 probe의 hybridization specificity는 표준 균주, Pseudomonas aeruginosa KCTC1636을 이용하여 확인 하였으며, 유류오염토양 시료의 분석결과 alkane, naphthalene, biphenyl, pyrene(PAH ring-hydroxylating) 분해에 관련된 8개의 유전자 발현을 확인 하였다. 이러한 결과는 DNA microarray가 유류오염토양환경에서 생물학적 분해유전자 진단에 효과적으로 이용될 수 있을 뿐만 아니라 생물학적 복원의 가능성을 진단하기에도 적합한 기법이라는 것을 나타내고 있다.

경포호의 식물플랑크톤과 환경요인의 계절적 변동 (Seasonal Variation of Phytoplankton and Environmental Factors in Kyungpo Lake)

  • 이은주;김형섭;이규송
    • 환경생물
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    • 제18권1호
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    • pp.95-104
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    • 2000
  • In order to elucidate chatracteristics of water quality and seasonal dynamics of phytoplankton community in Kyungpo lake, the weekly variation of algal population and 11 environmental factors were investigated from March 1998 to February 1999. A total 121 species of phytoplankton belonged to 57 genera, 4 genera 7 species of the Euglenophyceae, 1 genera 2 species of the Chrysophyceae, 2 genera 3 species of the Cryptophyceae, 1 genera 1 species of the Dinophyceae, 6 genera 9 species of the Cyanophyceae, 28 genera 78 species of the Bacillario-phyceae and 15 genera 21 species of the Chlorophyceae, was identified. Cryptomonas sp., Chamydomonas sp., Nitzschia frustulum, Oscillatoria sp., Lyngbya sp, and Dictyosphaerium pulchellum occurred successively as dominant phytoplankton species from March 1998 to February 1999. Density of phytoplankton cell number showed the peak in early April when Chlamydomoas sp. was dominated. The diversity index of phytoplankton community showed low values in the dominating period of Cryptomonas sp. and Chlamydomonas sp. The concentration of chlorophyll a fluctuated between 1.09 and 107.7$\mu\textrm{g}$ㆍ1$^{-1}$. Water temperature, salinity, DO, conduc tivity and SS were ranged 0.5-27.8$^{\circ}C$, 2.8-25.2 ppt, 4.62-19.21 mgO$_2$ㆍ1$^{-1}$, 5.33-34.76 mS/cm and 0.017-0.184 mgㆍ1$^{-1}$, respectively. Annual means of Secchi disc transparency was 36cm and thai of pH value was 8.5. The concentrations of PO$_4$-P was ranged 0.0012-0.077 mgㆍ1$^{-1}$ , and showed high value from August to October. The concentrations of NO$_2$-N, NO$_3$-N and NH$_4$-N was ranged 0.0011-0.1 mgㆍ1$^{-1}$, 0.074-3.33mgㆍ1$^{-1}$ and 0.0024-0.259 mgㆍ1$^{-1}$, respectively. Among environmental factors, water temperature was negatively correlated with DO, salinity and conductivity, DO was positively correlated with salinity and conductivity. Chlorophyll a, one of the indicies of eutropication in lake, was negatively correlated with NH$_4$-N. The cell density of Cryptomonas sp., which was the most dominant species in this lake, was negatively correlated with transparency. [Kyoungpo lake, Phytoplankton, Cryptomonas sp. , Chlamydomonas sp., Seasonal variation].

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Survey of American food trends and the growing obesity epidemic

  • Shao, Qin;Chin, Khew-Voon
    • Nutrition Research and Practice
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    • 제5권3호
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    • pp.253-259
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    • 2011
  • The rapid rise in the incidence of obesity has emerged as one of the most pressing global public health issues in recent years. The underlying etiological causes of obesity, whether behavioral, environmental, genetic, or a combination of several of them, have not been completely elucidated. The obesity epidemic has been attributed to the ready availability, abundance, and overconsumption of high-energy content food. We determined here by Pearson's correlation the relationship between food type consumption and rising obesity using the loss-adjusted food availability data from the United States Department of Agriculture (USDA) Economic Research Services (ERS) as well as the obesity prevalence data from the Behavioral Risk Factor Surveillance System (BRFSS) and the National Health and Nutrition Examination Survey (NHANES) at the Centers for Disease Control and Prevention (CDC). Our analysis showed that total calorie intake and consumption of high fructose com syrup (HFCS) did not correlate with rising obesity trends. Intake of other major food types, including chicken, dairy fats, salad and cooking oils, and cheese also did not correlate with obesity trends. However, our results surprisingly revealed that consumption of com products correlated with rising obesity and was independent of gender and race/ethnicity among population dynamics in the U.S. Therefore, we were able to demonstrate a novel link between the consumption of com products and rising obesity trends that has not been previously attributed to the obesity epidemic. This correlation coincides with the introduction of bioengineered corns into the human food chain, thus raising a new hypothesis that should be tested in molecular and animal models of obesity.

새로운 도시빈곤으로서 근로빈곤층의 발생과 대책 (Generation of Working Poor as New Urban Poverty and Its Policy)

  • 노대명;최병두;조명래;류정순
    • 한국지역지리학회지
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    • 제12권6호
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    • pp.671-692
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    • 2006
  • 최근 대도시 내부의 노동인구 가운데 새로운 빈곤, 즉 근로빈곤층이 형성되어, 이에 따른 계층 간 사회공간적 갈등을 심화시킬 징후를 보이고 있다. 이 논문은 노동과 빈곤이 결합하여 나타나는 특수한 문제로서 최근 새롭게 대두되고 있는 근로빈곤층의 문제에 초점을 둔다. 우선 근로빈곤층에 대한 개념정의에서 출발하여, 근로빈곤층이 발생하는 원인을 분석하고 근로빈곤층의 실태를 정태적 및 동태적 관점에서 살펴봄으로써 노동과 빈곤문제가 어떻게 유기적인 관련성을 맺고 있는지 논의하고자 한다. 그리고 기존 근로빈곤층 지원 정책의 한계를 살펴보고 향후 대안적 정책 과제를 제안하고자 한다.

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Diversity of Bacteriophages Infecting Xanthomonas oryzae pv. oryzae in Paddy Fields and Its Potential to Control Bacterial Leaf Blight of Rice

  • Chae, Jong-Chan;Nguyen, Bao Hung;Yu, Sang-Mi;Lee, Ha Kyung;Lee, Yong Hoon
    • Journal of Microbiology and Biotechnology
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    • 제24권6호
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    • pp.740-747
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    • 2014
  • Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a very serious disease in rice-growing regions of the world. In spite of their economic importance, there are no effective ways of protecting rice plants from this disease. Bacteriophages infecting Xoo affect the population dynamics of the pathogen and consequently the occurrence of the disease. In this study, we investigated the diversity, host range, and infectivity of Xoo phages, and their use as a bicontrol agent on BLB was tested. Among the 34 phages that were isolated from floodwater in paddy fields, 29 belonged to the Myoviridae family, which suggests that the dominant phage in the ecosystem was Myoviridae. The isolated phages were classified into two groups based on plaque size produced on the lawn of Xoo. In general, there was a negative relationship between plaque size and host range, and interestingly the phages having a narrow host range had low efficiency of infectivity. The deduced protein sequence analysis of htf genes indicated that the gene was not a determinant of host specificity. Although the difference in host range and infectivity depending on morphotype needs to be addressed, the results revealed deeper understanding of the interaction between the phages and Xoo strains in floodwater and damp soil environments. The phage mixtures reduced the occurrence of BLB when they were treated with skim milk. The results indicate that the Xoo phages could be used as an alternative control method to increase the control efficacy and reduce the use of agrochemicals.

남극 세종기지 주변에 새로이 정착한 현화식물 남극좀새풀 (Deschampsia antarctica)의 개체군 공간분포 (Distribution Pattern of Deschampsia antarctica, a Flowering Plant Newly Colonized around King Sejong Station in Antarctica)

  • 김지희;정호성
    • Ocean and Polar Research
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    • 제26권1호
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    • pp.23-32
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    • 2004
  • As a baseline survey for long-term monitoring on environmental change around the Antarctic King Sejong Station, distribution pattern of Deschampsia antarctica Desv., a flowering plant newly colonized were investigated qualitatively and quantitatively in both austral summer 2002 and 2003. Dispersal of the seeds and vegetative leaves by skuas might lead to the colonization into this area from neighbors in Maxwell Bay. The pioneer populations were observed around ponds and a stream of the Sejong Point in January 2002, and the maximum dispersal area was four times expanded after a year. Most of the populations were formed on the stable and well-drained substrate, which consisted of moss carpet of Sanionia georgico-uncinata (65%) and pebbles (25%), while only a few young individuals were observed on the unstable and watertight silt-sandy area. Especially, S. georgico-uncinata was being effectively utilized as their primary substrate with the soft, coarse and water-contained leaves. Also the perennial mature plants of D. antarctica were mainly formed on the moss carpet rather than pebbles. A few individuals were grown on other mosses of Polytrichastrum alpinum, Bryum pseudotriquetrum, Pohlia cruda, and Conostomum magellanicum and on a liverwort of Cephaloziella varians. We expect that dispersal of D. antarctica and the following succession to grass field will be countinuously and dynamically proceeded in this area, with the characteristics of ecological niche against the initial moss populations, on the similar continuity of environmental conditions. The continuous observations are needed with establishment of database on environmental change of micro-habitats, e.g. the water content and nutrients of soil and the underground temperature and permafrost.

Changes in plant community structure in relation to climate change and restoration plot areas in Mongolia

  • Lkhavgadorj, Khureltsetseg;Iderzorig, Badamnyambuu;Kwon, Ohseok
    • Journal of Ecology and Environment
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    • 제39권1호
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    • pp.119-125
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    • 2016
  • Mongolia has one of the strongest climate warming signals on Earth, and over 40% of the human population depends directly or indirectly on pastoral livestock production for their livelihoods. Thus, climate-driven changes in rangeland production will likely have a major effect on pastoral livelihoods . The loss of species dependent mostly on rainfall has resulted in adverse changes in the botanical composition of the steppes . Summer season in 2015 was completely dry until middle of July and, had not enough vegetation cover as last 15 years. The purpose of this study is to check plant community dynamics in Mongolia in relation to climate change in 2014 and 2015. The study sites were selected in mountain-steppe habitat in central Mongolia. In the 2014, there have been registered 81 plant species of 56 genera of 25 families on the investigated sites and, occurred 57 plant species of 44 genera of 21 families in the 2015. It is concluded that the abundance and richness of plants are directly connected to heavily affect by the climatic factor, i.e. amount of precipitation during growing season. As a same like result of climate change, in Mongolian land is going become desertification, and each spring, soil particles from Mongolia are swept up by a cold air mass into the atmosphere and blasts into south east China, Korea and Japan. The Koreans call this phenomenon the "Fifth season" or "Yellow sand", and the Chinese call it "Yellow dragon".

기후변화에 기인한 연안 수온상승에 따른 연안 어류의 바이러스성 질병 발생 예측 (Changes in Fish Viral Disease Outbreaks in the Coastal Area of Korea Due to Increasing Water Temperature, an Impact of Climate Change)

  • 김위식;김석렬;박명애;이준수;사티샤 에분제;김도형;오명주
    • 한국수산과학회지
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    • 제46권5호
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    • pp.582-588
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    • 2013
  • The impact of global warming on aquatic systems has been a priority research area in the past decade. However, the possibility that increased temperatures will cause shifts in viral disease outbreaks has not been well addressed. In the present study, with increasing water temperature (WT) in the coastal area of Korea, we estimated the possibility of changes in fish viral diseases. From the present time, WT may rise between 0.62 and $1.7^{\circ}C$ by 2050, and the effect on aquaculture could be more adverse than benefitial. Red seabream iridovirus disease (RSIVD) and viral nervous necrosis (VNN) cause high mortality above 22 and $24^{\circ}C$, respectively, and outbreaks could commence earlier and persist for prolonged periods. Nevertheless, the period of occurrence of viral hemorrhagic septicemia (VHS), which outbreaks at a lower WT (< $18^{\circ}C$), could be shorter than the current infectious period. Thermal stress in fish causes reductions in growth and immunocompetence; thus, increases in summer WT can lead to the development of new viral diseases. WT has a strong influence on fish population dynamics; therefore, entry of new viruses and changes in the prevalence of infection can be expected if carrier fishes are introduced or migrate to Korean waters.