• Title/Summary/Keyword: Population Density

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Spatial Heterogeneity and Long-term Changes in Bivalve Anadara broughtoni Population: Influence of River Run-off and Fishery

  • Silina, Alla V.
    • Ocean Science Journal
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    • v.41 no.4
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    • pp.211-219
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    • 2006
  • A comparison was made of population of the economically important cockle Anadara (=Scapharca) broughtoni (Bivalvia, Arcidae) inhabiting different areas of the Razdolnaya River estuary at the head of Amurskii Bay (Peter the Great Gulf, East Sea). Also, changes in cockle population density and structure, as well as in cockle growth rates during the last 20 years were studied. In all years of investigation, the morphometrical parameters and growth rates of cockles were smaller at the sites located close to the River mouth than farther down-estuary. The differences can be attributed to higher concentration of suspended particulate matter, decreased salinity and water temperature, as well as a longer exposure to these unfavorable environmental factors at sites located close to the River mouth, compared to farther sites. For two decades, cockle population density had decreased by almost 30 times at some sites in the River estuary. The main reason for this population decline is commercial over-fishing of the cockle. Besides, for the last 20 years, linear parameters of the cockles in the population decreased approximately by 30% and weight parameters, almost two times. Cockle growth rates also decreased for this period. Evidently, these facts are due to the damaging effect of dredging.

Imputation Accuracy from Low to Moderate Density Single Nucleotide Polymorphism Chips in a Thai Multibreed Dairy Cattle Population

  • Jattawa, Danai;Elzo, Mauricio A.;Koonawootrittriron, Skorn;Suwanasopee, Thanathip
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.4
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    • pp.464-470
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    • 2016
  • The objective of this study was to investigate the accuracy of imputation from low density (LDC) to moderate density SNP chips (MDC) in a Thai Holstein-Other multibreed dairy cattle population. Dairy cattle with complete pedigree information (n = 1,244) from 145 dairy farms were genotyped with GeneSeek GGP20K (n = 570), GGP26K (n = 540) and GGP80K (n = 134) chips. After checking for single nucleotide polymorphism (SNP) quality, 17,779 SNP markers in common between the GGP20K, GGP26K, and GGP80K were used to represent MDC. Animals were divided into two groups, a reference group (n = 912) and a test group (n = 332). The SNP markers chosen for the test group were those located in positions corresponding to GeneSeek GGP9K (n = 7,652). The LDC to MDC genotype imputation was carried out using three different software packages, namely Beagle 3.3 (population-based algorithm), FImpute 2.2 (combined family- and population-based algorithms) and Findhap 4 (combined family- and population-based algorithms). Imputation accuracies within and across chromosomes were calculated as ratios of correctly imputed SNP markers to overall imputed SNP markers. Imputation accuracy for the three software packages ranged from 76.79% to 93.94%. FImpute had higher imputation accuracy (93.94%) than Findhap (84.64%) and Beagle (76.79%). Imputation accuracies were similar and consistent across chromosomes for FImpute, but not for Findhap and Beagle. Most chromosomes that showed either high (73%) or low (80%) imputation accuracies were the same chromosomes that had above and below average linkage disequilibrium (LD; defined here as the correlation between pairs of adjacent SNP within chromosomes less than or equal to 1 Mb apart). Results indicated that FImpute was more suitable than Findhap and Beagle for genotype imputation in this Thai multibreed population. Perhaps additional increments in imputation accuracy could be achieved by increasing the completeness of pedigree information.

Method of Determining Future Facility Location with Maintaining Present Accessibility

  • Takahagi, Wataru;Sumitani, Yasushi;Takahashi, Hirotaka;Omae, Yuto;Sakai, Kazuki
    • Industrial Engineering and Management Systems
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    • v.15 no.3
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    • pp.197-205
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    • 2016
  • The public services closely related to the daily lives of the Japanese people, such as firefighting, police or primary school education, are largely financed by the local governments. As the population as a whole in Japan declines, the population in local regions are forecasted to experience particularly rapid decline in the future, and it is inevitable to reduce the cost of public services provided by the local governments to keep their financial basis sustainable. In order to provide public services to the people properly and fairly, the local governments own and utilize their public facilities, such as fire stations, police stations or primary schools. On the other hand, we have to secure the accessibility, which is the condition of accessing a facility easily in a whole local city including the high population density area and low population density area. In this paper, we propose a method of determining the number of future facilities and its facility locations in which we maintain the present accessibility. In our proposed method, we determine them comparing the accessibility measurement calculated by facility location model using the present and future population. We adopted k-centdian model as the facility location model, which can secure the accessibility in a whole local city determining the weights of both areas. We applied our proposed method to fire station in Iwaki city, Japan. The results suggested that 7 facilities would be reduced in 2064, after 50 years from 2014. Additionally, we confirmed that the future facility location had secured accessibility in both high and low population density area.

Small-scale spatial genetic structure of Asarum sieboldii metapopulation in a valley

  • Jeong, Hyeon Jin;Kim, Jae Geun
    • Journal of Ecology and Environment
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    • v.45 no.3
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    • pp.97-104
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    • 2021
  • Background: Asarum sieboldii Miq., a species of forest understory vegetation, is an herbaceous perennial belonging to the family Aristolochiaceae. The metapopulation of A. sieboldii is distributed sparsely and has a short seed dispersal distance by ants as their seed distributor. It is known that many flowers of A. sieboldii depend on self-fertilization. Because these characteristics can affect negatively in genetic structure, investigating habitat structure and assessment of genetic structure is needed. A total of 27 individuals in a valley were sampled for measuring genetic diversity, genetic distance, and genetic differentiation by RAPDPCR. Results: The habitat areas of A. sieboldii metapopulation were relatively small (3.78~33.60 m2) and population density was very low (five to seven individuals in 20×20 m quadrat). The habitat of A. sieboldii was a very shady (relative light intensity = 0.9%) and mature forest with a high evenness value (J = 0.81~0.99) and a low dominance value (D = 0.19~0.28). The total genetic diversity of A. sieboldii was quite high (h = 0.338, I = 0.506). A total of 33 band loci were observed in five selected primers, and 31 band loci (94%) were polymorphic. However, genetic differentiation along the valley was highly progressed (Gst = 0.548, Nm = 0.412). The average genetic distance between subpopulations was 0.387. The results of AMOVA showed 52.77% of variance occurs among populations, which is evidence of population structuring. Conclusions: It is expected that a small-scale founder effect had occurred, an individual spread far from the original subpopulation formed a new subpopulation. However, geographical distance between individuals would have been far and genetic flow occurred only within each subpopulation because of the low density of population. This made significant genetic distance between the original and new population by distance. Although genetic diversity of A. sieboldii metapopulation is not as low as concerned, the subpopulation of A. sieboldii can disappear by stochastic events due to small subpopulation size and low density of population. To prevent genetic isolation and to enhance the stable population size, conservative efforts such as increasing the size of each subpopulation or the connection between subpopulations are needed.

Planning of low-rise high-density small-scaled urban housing complex (국내 도시지역에 적용가능한 저층고밀 소형 공동주택 계획안)

  • An, Jae-Min;Mo, Jeong-Hyun
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.11a
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    • pp.263-267
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    • 2009
  • Recently, we have seen the change of population and family structure, population growth has slowed and family differentiation was constantly done. A rapidly increase of single and couple household. So small-scaled house demand will be increased. Therefore this study planned to solve recent collective housing problem and to satisfy new housing demand. The purpose of planning was that low-rise high-density small-scaled of urban housing complex. This study used for two methods. First methods were literature analysis for domestic collective houses's present conditions and issues. Other purpose was to confirm change of household. Second method is case studies. It went through two phases to select the cases. The cases selected domestic and foreign each eight, total sixteen. The cases analyzed to twelve elements characteristic of housing complex, unit and community facilities. This study applied one area of Seoul to the low-rise high-density small-scaled housing complex.

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A Study on the Change of the Housing Supply and the Residential Density in Daegu (대구시의 주택보급과 주거밀도변화에 관한 연구)

  • 권용일
    • Journal of the Korean housing association
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    • v.12 no.2
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    • pp.151-160
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    • 2001
  • The purpose of this study is for investigating characteristics of changing residential density and relations between housing supply and redistribution of population in Daegu. As a result, the following conclusions could be made. First, land development and housing supply have important effect on distribution of population and changing residential density in Daegu. Second, according to massive site development to meet the housing demand in suburban area, the suburbanization has begun and build-up-area grows faster, so centre of gravity of residential density increasing rate has moved to the suburban. Third, the inner district and the district near urban centre will need remodelling or redevelopment project in the near future.

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Effects of Wet Cupping (Al-Hijamah) on Cholesterol in a Sudanese Population

  • Amna Mohammed Alamin Abbshar;Hafsa Ahmed Elrheima Ahmed
    • Journal of Acupuncture Research
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    • v.40 no.4
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    • pp.351-355
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    • 2023
  • Background: Wet cupping (WC) is an efficient and cost-effective technique for removing metabolic waste from the bloodstream via the skin. The study aimed to examine the effect of WC on cholesterol levels including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in a Sudanese population. Methods: In this prospective cross-sectional study, 30 participants undergoing regular WC therapy were enrolled. Blood samples collected twice: pre-WC therapy (case group) and 10-14 days afterward (controls). Results: Of the participants, 56.67% were male and 43.33% were female, aged 24-69. Pre-WC TC and LDL-C levels were significantly higher than the post-WC control group (p = 0.001). Conversely, HDL-C levels decreased significantly in the pre-WC cases compared to controls (p = 0.001). No significant sex-based difference in mean cholesterol levels (p > 0.05). Conclusions: After WC, males and females experienced significant reductions in TC and LDL-C, and significant increase in HDL-C.

Effect of the Amount of Fertilizer, Plant Density, and Halvesting Time on the Production of Tobacco leaf Protein (시비량, 재식밀도, 수확시기가 담배 잎단백질 생산에 미치는 영향)

  • 우억구;이학수
    • Journal of the Korean Society of Tobacco Science
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    • v.15 no.1
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    • pp.75-89
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    • 1993
  • Effect of the amount of fertilizer, plant density, and harvesting time on the production of tobacco leaf protein and fresh biomass was investigated. Flue-cured tobacco(M tabacum, L., cv. NC 82) seedlings were transplanted in the field dressed 200kg N per ha at 1$\times$105, 3$\times$105, 5$\times$105, 7$\times$105 plants per ha, and were harvested at the time when 6 and 10 weeks after transplanting, respectively. Harvest at 10 weeks after transplanting increased greatly number of leaves per plant and fresh weight of a plant, Precentage of senescent leaf weight, but significantly decreased fresh weight of a leaf and total protein contents g-1 fresh weight of leaf and stalk over the amount obtained from the harvest at 6 weeks after transplanting. Also, fresh leaf numbers of a plant, fresh weight of a leaf and of a plant, and total protein contents g-1 fresh weight of biomass were more decreased, but percentage of senescent leaf weight were remarkably increased under higher plant density. Therefore, it was seemed that harvesting at 6 weeks after transplanting under 1$\times$105 plant density per ha is more effective for producing higher yield of biomass and protein per plant than 10 weeks harvesting with 7$\times$105 population per ha. A trend was observed that biomass and protein yields per ha are positively correlated with plant population. Biomass yield per ha was the greatest at 7$\times$105 density(80.5t), but the peak of protein yield was at the near of 5$\times$105 population(2454kg as total protein) per ha on the regression curve. It was assumed that if tobacco plants are transplanted under 5$\times$105 plant density at the mid of May, and thereafter harvest at 6 weeks repeatedly during the growing season, it is possible to harvest 2~3 times per year, and to yield more 6.024kg of protein and over 140me1ric tons of fresh biomass ha 1 year 1 statistically in the korea tobacco growing regions.

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Effects of Light Intensity and Quality on the Growth and Quality of Korean Ginseng (Panax ginseng C.A. Meyer) II. Relationship between Light Intensity and Planting Density (광량 및 광질이 고려인삼의 생육과 품질에 미치는 영향 II. 광량과 재식밀도와의 관계)

  • Cheon, Seong-Gi;Mok, Seong-Gyun;Lee, Seong-Sik
    • Journal of Ginseng Research
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    • v.15 no.1
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    • pp.31-35
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    • 1991
  • In order to know the optimum planting density under shading structures at different light intensity, We investigated the growth status, distribution of ginseng leaf area, correlation between planting density and root weight per plant and yield, correlation between leaf area index and root weight per plant and yield. According to the increase of planting density the leaf area per plant was decreased, but leaf area index (L.A.I) was increased. Ginseng leaf population at different lines under common straw shading were distributed mainly in frost lines but polyethylene net shading at 10fo light intensity were distributed equally in all lines. Optimum planting density in common straw shading at 5% light intensity was 55 plant per tan (90 cmX180 cm) and polyethylene net shading 81 10% light intensity was 60 plant per tan, in consideration of root weight and yield. Optimum leaf area index was 2.4 under common straw shading at 5% light intensity but was 2.7 under polyethylene net shading at 10% light intensity.

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Estimating Population Density of Leopards in Semi-Arid habitat, Western India

  • Randeep Singh;Puneet Pandey;Qamar Qureshi;Kalyanasundaram Sankar;Paul R. Krausman;Surendra Prakash Goyal
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.4 no.2
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    • pp.72-78
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    • 2023
  • The leopard (Panthera pardus) is one of the most widespread felids worldwide. Despite their wide distribution, reliable data on leopard population densities are still inadequate for conservation and management strategies in different landscapes. In the present study, we estimated leopard density using camera traps in the Ranthambhore Tiger Reserve (RTR), Rajasthan, India, between December 2010 and February 2011, where leopards coexist alongside a high density of tigers (Panthera tigris), a larger predator (RTR). A sampling effort of 4,450 trap days was made from 178 camera trapping stations over 75 days, resulting in 46 suitable photo captures (25 right flanks and 21 left flanks). In total, 18 individuals (7 males, 8 females, and 3 unknown sexes) were identified using the right flanks, and the estimated leopard density was 8.8 (standard error=2.8) individuals/100 km2. Leopard density appeared to respond to small prey (<50 kg weight) richness. As this is the first systematic study to provide baseline information on leopard density in RTR, it could form a baseline for comparison in future investigations.