• 제목/요약/키워드: cell population density

검색결과 78건 처리시간 0.025초

인구격자 셀 버퍼공간 설정에 의한 기반시설부담구역경계 검토방안 연구 (Probing the Impact Fee Zone Boundaries Based on Stepwise Scenarios of the Population Grid Cell Buffer Formation)

  • 최내영
    • 대한공간정보학회지
    • /
    • 제17권4호
    • /
    • pp.53-60
    • /
    • 2009
  • 2008년 9월 기반시설부담구역 지정과 관련한 조항이 국토계획법에 신설되면서 정부는 관련연구를 통해 격자분석에 기초한 인구증가율 기반의 기반시설부담구역 지정기준을 예시한 바 있다. 본 연구는 현재 신도시 조성 등으로 인구증가가 활발한 화성시 동탄동을 사례대상지로 하여 인구증가율에 기초한 격자분석에 의한 구역지정방안에 대해 실무적 차원의 적용방법을 모색해 보았다. 이를 위해 우선 격자 공간분석을 통하여 동 단위의 공간규모에서 법정 인구증가율 상회 격자 셀들을 선별하고 다시 이들에 대한 버퍼공간 중첩의 단계별 시나리오를 통해 인구밀집이 예상되는 구역을 연동 집단화하여 기반시설부담구역 검토경계를 설정하는 방법에 대해 실험해 보았다. 이와 같이 선별한 동탄동 관내 가상 지정구역을 동탄동 토지이용계획도와 중첩하여 검토한 결과 실제 인구집중 구역들이 적절히 연동 집단화된 것으로 판단되었다.

  • PDF

Sprague-dawley(SD) 랫드에서 natural killer cell의 분리 ·동정 및 형태적 특징 (Isolation and morphological characterization of natural killer cell in the sprague-dawley(SD) rats)

  • 강경선;이영순
    • 대한수의학회지
    • /
    • 제32권2호
    • /
    • pp.245-250
    • /
    • 1992
  • This study was performed to demonstrate the presence of large granular lymphocyte(LGL) in Sprague-Dawley(SD) rats and morphologically observe NK cell and also establish the method of isolation of natural killer cell in SD rats. By percoll discontinuous density gradients centrifugation, highly enriched LGL population were shown to fraction 2(border line between 44.2% and 50.8%). LGL were shown to bind selectively to YAC1 mouse lymphoma cell. This fraction expressed very high NK cell cytolysis. Therefore, we thought that LGL have NK activity in SD rats. The Morphology of rat LGL is very similar to that of human LGL. These cells have an eccentric kidney-shaped nucleus. Their most distinctive feature was their cytoplasmic azurophilic granules. Another distinguishing feature of rat LGL was their high cytoplasmic : nuclear ratio. It was concluded that LGL played a role part in mediating natural killer activity in this species.

  • PDF

비선호 시설의 인구분포 관련 입지기준 평가를 위한 GIS-기반 방법론 연구 -원자력 발전소의 경우- (GIS-Based Methods to Assess the Population Distribution Criteria for Undesirable Facilities: The Case of Nuclear Power Plants)

  • 이상일;조대헌
    • 대한지리학회지
    • /
    • 제47권5호
    • /
    • pp.755-774
    • /
    • 2012
  • 본 논문의 주된 연구목적은 비선호 시설, 특히 원자력 발전소의 인구분포 관련 입지기준 평가를 위한 GIS-기반 방법론을 제안하는 것이다. 이 연구목적을 달성하기 위해 우선 IAEA, 미국의 NRC, 그리고 한국원자력안전기술원이 제시하고 있는 입지기준을 살펴보았다. 그 결과 원자력 발전소에 가장 가까이에 위치한 인구중심지까지의 거리를 최대화하는 것이 가장 중요한 입지 평가 원리임이 확인되었다. 이 원리를 실행하기 위한 GIS-기반 방법론은 서로 연관된 두 가지 하위 과제를 수행해야 하는 것으로 판단되었는데, 하나는 인구분포에 대한 정밀한 재현이고, 또 다른 하나는 인구중심지의 확인이다. 본 연구는 전자에 대해서는 대시메트릭 에어리얼 인터폴레이션 기법을, 후자에 대해서는 셀-기반 임계밀도 기법과 구역-기반 임계밀도 기법을 제시한다. 대시메트릭 에어리얼 인터폴레이션을 통해 다양한 공간해상도를 갖는 그리드 셀 단위의 인구밀도 분포의 재현이 이루어진다. 이것에 두 가지 인구중심지 확인 기법을 적용함으로써 특정한 임계밀도와 인구 규모 기준을 만족하는 인구중심지가 확인된다. 이 기법들을 우리나라 고리 원전 1호기의 사례에 적용하여 그 유용성과 한계를 평가하였다. 그 결과 적용된 기법과 투입된 파라미터 값에 따라 입지기준 평가의 결과가 달라질 수 있음이 드러났다. 본 연구는 지리공간분석 및 모델링 분야에서 개발된 기법을 입지 결정과 평가에 적용하는 시도의 활성화에 기여할 것으로 기대된다.

  • PDF

아연환경구배에 의한 녹조류개체군생장의 생태학적 특성 (Ecological Characteristics of Some Algal Populations along Environmental Gradients of Zinc)

  • 송승달
    • Journal of Plant Biology
    • /
    • 제20권3호
    • /
    • pp.119-126
    • /
    • 1977
  • The maximum relative growth rate of algae treated with Zinc was shown as follows: 15, 8, 6, 3 and -5% per day for the rather sensitive Chlorella sp. populations, or 14, 7, 5 and 4% per day for the Pleurococcus sp. populations, and 22, 20, 13, 9 and 7% per day for the more resistant Scenedesmus spinosus populations, respectively for the culture medium with 0, 1, 5, 10 and 20 ppm of Zinc treatment. With mixed cultures of Chlorella sp. and Scenedesmus spinosus populations, the growth of the Chlorella sp. population overcame that of the S. spinomsus population from the cultures treated with relatively low concentration of Zinc. On the contrary, the population growth of the latter resistant species overcame that of the former sensitive species when the concentration of Zinc was above 5 ppm Zn of the medium. This paper describes the results of further investigations of the effects evaluated by direct cell counts method, optical density comparisons, oxygen production and consumption determinations and the measurements of the fate of Zinc treated in the solutions.

  • PDF

세포 재밍 과정의 역학적 상관 관계 가시화 (Visualization of Dynamic Correlations during Cellular Jamming)

  • 정현태;조영빈;신현정
    • 한국가시화정보학회지
    • /
    • 제16권2호
    • /
    • pp.38-44
    • /
    • 2018
  • Cellular jamming phenomenon, defined as a kinetic arrest, is a commonly observed event in dense cell aggregates in epithelial tissues. Cells lose their motility when the density of the cell population becomes too high. Yet, not much is known about how the jamming occurs and how it influences individual cells in the population. In this study, we investigated the mechanisms during the formation of the jammed state by visualizing various dynamic components such as velocity, traction, and intercellular stress. The visualized properties exhibited interrelated features in similar time domains that can be categorized into specific stages, namely migrating, transitional and steady state. During the migrating stage, cells generated spatially correlated tractions and migrations at the collective migration step and lost these properties becoming a transitional stage. These stepwise analyses presented correlative components which are expected to adjust for explaining the detailed mechanisms of cellular jamming.

Acyl-Homoserine lactone Quorum Sensing in Bactreria

  • Greenberg, E.Peter
    • Journal of Microbiology
    • /
    • 제38권3호
    • /
    • pp.117-121
    • /
    • 2000
  • Recent advances in studies of bacterial gene expression and light microscopy show that cell-to cell communication and communication and community behavior are the rule rather than the exception. One type of cell-cell communication, quorum sensing in Gram-negative bacteria involves acyl-homoserine lactone signals. This type of quorum sension represents a dedicated communication system that enables a given species to sense when it has reached a critical population density. and to respond by activating expression of specific genes. The LuxR and LuxI proteins of Vibrio fisheri are the founding members of the acyl-homoserine lactone quorum sensing signal receptor and signal generator families of proteins. Acyl-homeserine lactone signaling in Pseudomonas aeruginosa is one model for the relationship between quorum sensing community behavior, and virulence. In the P. aeruginosa model. quorum sensing is required for normal biofilm maturation and virulence. There are multiple quorum-sensing circuits that control the expression of dozens of specific genes in P. aeruginosa.

  • PDF

남산공원 내 애기나리와 큰애기나리 군락의 동태 및 종간 경쟁의 추정 (On the Population Dynamics and Interspecific Competition of Disporum smilacinum and D. viridescens (Liliaceae) in Mt. Nam Park)

  • 민병미
    • The Korean Journal of Ecology
    • /
    • 제21권5_3호
    • /
    • pp.649-663
    • /
    • 1998
  • The clarify the ecological properties, and to predict change of understory vegetation of mt. Nam Park, population dynamics and interspecific competition of D. smilacinum and D. viridescens, which grow in understory of deciduous broad-leaved forest and pseudo-annuals, were studied from May 20 to May 30 1998. The depth of litter layer, soil moisture content, soil organic matter and soil texture were surveyed in 18 populations (15 D. smilacinum populations and 3 D. viridescens populations). Mean litter layer of d. smilacimum population was thinner than that of D. viridescens populations). Mean litter layer of D. smilacnum population was thinner than that of D. viridescens population. The contents of soil moisture and organic matter of D. smilacinum population were lower than that of D. viridescens population. The D. smilacinum growed in broad range of soil texture but D. viridescens in loamy soil. Because D. smilacinum could tolerate more broad range of soil moisture and soil texture than D. viridescens, the former covered the herb layer in earlier stage and the latter introduced in later stage when rhizome could grow easily. The numbers of individual in two marginal parts were smaller than that in center in same D. smilacinum patch. And the total numbers of individuals grown in (10 ${\times}$ 10)cm were from 0 to 12. The rhizome (subterranean runner) weight, rhizome length, root weight, shoot weight, lea weight and leaf number per subquadrat (cell) increased along the number of individual, that is, increased from marginal part to center. But rhizome weight and rhizome length per individual were vice versa. Therefore, the individuals in marginal part reproduced longer and stronger asexual propagules than that in center. The distribution pattern of D. smilacinum was contageous and that of D. viridescens was random or regular. Therefore, population growth of former was independent on density and that of latter was dependent on density. The distributions of size-class showed normal curves in two population, but the curves based on data of total dry weight showed positive skewness and those of leaf number showed negative skewness The correlation coefficient (CC) values between the properties of each organ were high in two population and significant at 0.1% level. The CC values of D. viridescens were higher of the two. Therefore, the former allocated the energy to each organ stable. The rhizome depth of d. viridescens was 2 times deeper than that of D. smilacinum. And rhizome length and weight of D. viridescens were longer (2 times) or heavier (4 times) than those of D. smilacinum. The patch size of D. viridescens increased 60 cm per year and that of D. smilacinum 30 cm. On this results, the intrinsic increase velocity of d. viridescens patch was 2 times faster than that of d. smilacinum, therefore, on the competition, the former had an advantage over D. smilacinum. The reason why d. viridescens defeated D. smilacinum resulted from that the leaf area of former was 4 times broader than that of latter. in Mt. Nam Park, it was thought that two disporum Population would change with the 3 thpes of environmental change as followings. First, no human impact and increase of soil moisture content resulted in increase of D. viridescens population. Second, mild human impact and similar condition of soil moisture content resulted in slow increase or no changes of D. smilacinum and d. viridescens population. Third, severe human impact and dry condition resulted in decrease or vanishment of two disporum populations.

  • PDF

마산만 식물플랑크톤의 대발생 양상의 변화와 군집 동태 (Change of Blooming Pattern and Population Dynamics of Phytoplankton in Masan Bay, Korea)

  • 이주연;한명수
    • 한국해양학회지:바다
    • /
    • 제12권3호
    • /
    • pp.147-158
    • /
    • 2007
  • 본 연구는 마산만의 적조원인 식물플랑크톤의 천이와 대발생 변화 양상을 밝히고자 이 지역을 대표할 수 있는 1개 정정에서 2003년 11월부터 2004년 10월까지 강우와 연평균 기온차를 포함한 기후학적 요인, 물리 화학적 요인 그리고 식물플랑크톤 군집을 조사하였다. 영양염은 타해역과 비교하였을 때, 암모니아염은 높은 농도를 보였으나, 질산염은 비슷한 농도를 보였다. 그리고 규산염은 타 해역에 비해 낮은 농도를 보였으며, 인산염은 빈영양 수역에 포함될 정도로 낮은 농도를 보여 식물플랑크톤 성장의 제한요소로 작용하였다. 식물플랑크톤 현존량의 탄소량은 2003년 동계와 2004년 하계에, 엽록소-${\alpha}$는 2003년 늦은 추계부터 동계까지 그리고 2004년 하계에 높게 나타나 비슷한 경향을 보였으며, 개체수는 2003년 동계와 2004년 추계에 높았다. 조사기간 동안 출현한 식물플랑크톤은 총 78종으로 동정되었으며, 이 중 우점종은 규조류 Skeletonema costatum, Cylindrotheca closterium, 와편모조류 Heterocapsa triquetra, Prorocentrum minimum, P. triestinum, 침편모조류 Heterosigma akashiwo로 나타났다. 우점종의 계절적 변화 양상을 살펴보면 P. minimum은 늦은 추계부터 동계까지, H. triquetra는 늦은 동계에 우점하였다. P. triestinum은 늦은 춘계부터 이른 하계까지, H. akashiwo는 춘계부터 조금 높은 경향을 보이다가 늦은 하계에 C. closterium이 그리고 S. costatum은 추계에 가장 우점하였다. CCA 분석결과, 개체수로 표현되는 현존량은 규조류와 관계가 있으며, 환경요인 중에서 수온, 질산염과 인산염의 영향을 받는 것으로 나타났다. 탄소량과 엽록소-${\alpha}$로 표현되는 현존량은 규조류 뿐만 아니라 와편모조류와 침편모조류와 관계가 있으며, 염분, 규산염과 인산염의 영향을 받는 것으로 나타났다. 조사기간을 포함한 최근 6년 동안의 기온의 상승에 따른 수온의 상승은 동계 적조를 발생시키는 원인이 되었다. 또한, 동계 적조에 따른 영양염 고갈과 춘계의 강우량 감소에 따른 영양염 공급의 제한은 마산만에서 상습적으로 발생되는 춘계 적조의 발생을 억제하였을 것으로 판단된다. 결과적으로 2004년도의 전형적인 대발생 양상의 변화는 수온의 상승과 강우량의 감소가 중요한 영향을 미쳤을 것으로 추정된다.

Sprague-Dawley 랫트에 자연발생한 고환위축의 병리조직학적 관찰 (Histopathological observation of spontaneous testicular atrophy in Sprague-Dawley rat)

  • 손화영;김용범;하창수;강부현
    • 한국수의병리학회지
    • /
    • 제2권1호
    • /
    • pp.47-52
    • /
    • 1998
  • The incidence of spontaneous testicular atrophy and its morphological changes during stage-specific spermatogenesis were investigated in male Sprague-Dawley rats at 10, 19, and 32 weeks of age. The incidence of testicular atrophy was 0.2%(2/90) 7.9%(9/114) and 10%(4/40) in 4, 13 and 26 weeks respectively. The epididymis with testicular atrophy had low sperm density. In the minimally affected tests scattered tubules showed complete depletion of germ cells without stage specificity. Testes with moderate to severe testicular atrophy showed seminiferous tubules lined with dense Sertoli cell population. While Leydig cells in the interstitium appeared hypertrophy they were immunohistochemically negative for proliferating cell nuclear antigen a marker of cell proliferation.

  • PDF

Effectiveness of Phytogenic Feed Additive as Alternative to Bacitracin Methylene Disalicylate on Hematological Parameters, Intestinal Histomorphology and Microbial Population and Production Performance of Japanese Quails

  • Manafi, M.;Hedayati, M.;Khalaji, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제29권9호
    • /
    • pp.1300-1308
    • /
    • 2016
  • This study was conducted to evaluate the effects of phytogenic additive and antibiotic growth promoter in laying Japanese quails. One hundred and sixty five quails were divided into three groups of 5 replicates and 11 quails (8 females and 3 males) in each replicate. Treatment 1 was fed control diet, treatment 2 was fed control diet supplemented with 0.05% bacitracin methylene disalicylate as antibiotic growth promoter and treatment 3 was fed control diet supplemented with 0.1% phytogenic feed additive (PFA) for two periods of 3 weeks each from 37 to 42 weeks of age. Results showed that egg production, eggshell strength, eggshell weight, villus height and villus height to crypt depth ratio were significantly (p${\leq}$0.05) increased and feed consumption, feed conversion ratio, albumen, Haugh unit, cholesterol, low-density lipoprotein, alanine transaminase, gamma glutamyltransferase, alkaline phosphatase, high-density lipoprotein, triglyceride, number of goblet cell, crypt depth and intestinal bacterial population of Coliforms, Salmonella and E. coli were significantly (p${\leq}$0.05) decreased in PFA fed group. It is concluded that addition of PFA containing phytomolecules and organic acids as main ingredients could significantly improve the production parameters and the general health of laying quails as an alternative to antibiotic growth promoters.