• Title/Summary/Keyword: Natural Crossing

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Merits and Demerits of the Inspection System introduced in Construction of City Planning Road: In Case of Crossing Road of the Aioiyama Green Area in Nagoya

  • Yutaka Okamura
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • no.2
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    • pp.178-184
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    • 2004
  • The Yatomi - Aioiyama line is a city-planning road that was notified in 1957 and subsequently prepared by land readjustments. Currently, approximately 900m of road pass in the inside of the Aioiyama green area has not been constructed. The surveying briefing session for inhabitants was held in July 1992, the project was authorized by the Ministry of Land, Infrastructure and Transport in September 1993, and the project briefing session for inhabitants was held in September 1993. The site purchase has been completed. At the May 2000 briefing session, inhabitants of the area began voicing dissenting demanding the conservation of the natural environment of this green area. The inspector system serves as the third party, independent of both the administration and the inhabitants. Before finalizing the geometric line form of the road to be constructed, some surveys of animals and plants found along the walking trails carried out intensively in the northern area, which is approximately 50 ha, of the Aioiyama green area. The natural environment inspector submitted a plan for changing the geometric line form of the road decided upon by city planning, and it was approved by the city planning council. If the shelter structure or the retaining wall structure is adopted at the location where large slope faces are produced by excavation or landfill, and if the bridge structure is adopted at the place where stream-lines and walking trails intersect, it leads to a reduction of approximately $40\%$ in the areas for which change is planned. Furthermore, approximately $20\%$ of the area to be changed is restored by returning soil to the roof of the shelter.

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Speciation of Viola albida var. takahashii based on both artificial and natural hybridization between V. albida var. albida and V. albida var. chaerophylloides

  • Songhee AHN;Sung Soo WHANG
    • Korean Journal of Plant Taxonomy
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    • v.52 no.4
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    • pp.226-234
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    • 2022
  • The study aims are to examine the characteristics of artificial and natural hybrids between Viola albida var. albida (= albida, from below) and V. albida var. chaerophylloides (= chaerophylloides, from below), and to confirm if hybrids could be fertile and make populations in their native habitats. The 1st filial (= F1, from below) leaf shape produced by artificial crossing between albida and chaerophylloides was the same as that of V. albida var. takahashii (= takahashii, from below), and F1 bore also both chasmogamous and cleistogamous flowers. F1 seed number was 9.6 per cleistogamous pods, which was remarkably less than the average of 38.2 for albida and chaerophylloides, but the germination rate was all similar. The leaf type of self-crossed 2nd offsprings (= F2, from below) showed all leaf types found in the Viola albida complex, but the ratio of chaerophylloides leaf type was relatively low. Individuals whose F2 leaf type was restored to albida produced an average of 31.4 seeds per capsule, meaning that fertility was restored. On the other hand, individuals of F2 takahashii leaf type come to fruition a low average of 10.4 seeds per capsule, which is similar to that of takahashii. The results of crossbreeding experiment, where is their native habitats, were similar to that of laboratory. Both albida and chaerophylloids in Mt. Bulmyeong distribute extensively, but takahashii make a small population only in places where albida and chaerophylloides grow together. Summarizing the above results is suggesting that the speciation of takahashii was done by hybrid between albida and chaerophylloides, and these have been maintained with relatively small population by cleistogamous capsules.

Comparison of Genetic Variation between Pre-practice Mature Trees and Post-practice One-year Old Seedlings in Pinus densiflora Natural Regeneration Stands (소나무 천연갱신림내 성목과 치수의 유전변이 비교)

  • Ahn, Ji Young;Lee, Jei Wan;Lee, Seok Woo;Baek, Seung Hoon;Lim, Hyo In;Kim, Hyun Seop
    • Journal of Korean Society of Forest Science
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    • v.104 no.4
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    • pp.543-548
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    • 2015
  • We studied the genetic impact of natural regeneration practices, such as Single seed tree, Group seed tree, Patch clear cutting and Alternate strip clear cutting systems, by comparing the nuclear microsatellite(nSSR) variation of post-practice natural regeneration one-year old seedlings of Pinus densiflora to that of pre-practice mature trees. The levels of genetic diversity of seedlings (A=13.6, $A_e$=4.3, $H_o$=0.571, $H_e$=0.597) were similar to those of mature trees (A=13.4, $A_e$=4.3, $H_o$=0.596, $H_e$=0.598) and the differences in the level of genetic diversity between seedlings and mature trees for each of the practices were not statistically significant. The degree of genetic differentiation between seedlings and mature trees was very low ($F_{ST}$=0.002) and the pairwise $F_{ST}$ values between seedlings and mature trees for all practices were less than 0.01. Overall, the natural regeneration practices appeared to have only minor impacts on the genetic diversity and the genetic composition in the studied P. densiflora stands. For a better understanding of the genetic effects of natural regeneration practices, subsequent studies such as temporal genetic variation of seedlings formed by crossing among post-practice mature trees should be considered.

CRISPR/CAS9 as a Powerful Tool for Crop Improvement

  • Song, Jae-Young;Nino, Marjohn;Nogoy, Franz Marielle;Jung, Yu-Jin;Kang, Kwon-Kyoo;Cho, Yong-Gu
    • Journal of Plant Biotechnology
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    • v.44 no.2
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    • pp.107-114
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    • 2017
  • Implementation of crop improvement programs relies on genetic diversity. To overcome the limited occurrence of natural mutations, researchers and breeders applied diverse methods, ranging from conventional crossing to classical bio-technologies. Earlier generations of knockout and gain-of-function technologies often result in incomplete gene disruption or random insertions of transgenes into plant genomes. The newly developed editing tool, CRISPR/Cas9 system, not only provides a powerful platform to efficiently modify target traits, but also broadens the scope and prospects of genome editing. Customized Cas9/guide RNA (gRNA) systems suitable for efficient genomic modification of mammalian cells or plants have been reported. Following successful demonstration of this technology in mammalian cells, CRISPR/Cas9 was successfully adapted in plants, and accumulating evidence of its feasibility has been reported in model plants and major crops. Recently, a modified version of CRISPR/Cas9 with added novel functions has been developed that enables programmable direct irreversible conversion of a target DNA base. In this review, we summarized the milestone applications of CRISPR/Cas9 in plants with a focus on major crops. We also present the implications of an improved version of this technology in the current plant breeding programs.

Genetic Structure of the Mulberry Silkworm Population in Sri Lanka: I. Estimation of Combining Ability and Heritability

  • Lea, Ho-Zoo;Alwis, Siriani-M.de
    • Journal of Sericultural and Entomological Science
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    • v.37 no.1
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    • pp.10-15
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    • 1995
  • Genetic characterization of Sri Lankan silkworm bivoltine population has not been at-tempted so far, since its sporadic introduction of bivoltine strains into the island, starting from the 1950's. Genetic structure of Sri Lankan population of mulberry silkworm Bombyx mori was investigated through estimation of general (GCA) and specific combining ability(SCA) and heritability(${h^2}_B$), on the economic quantitative characters from leading 8 inbreds and their 28 F1's in a half diallel cross, in an attempt to utilize the estimates in determination of future breeding methods and to predict the breeding value over the phenotypic value. It was found that the breeding population of the bivoltine silkworm in Sri Lanka has still maintained considerable amounts of additive gene action as well as nonadditive. For some time in the future, both breeding strategies of "selection without inbreeding" and also "inbreeding followed by crossing" should therefore be effective in genetic improvement of economic characters investigated. In addition, superior combiners in general and in specific F1′s were identified for each of 6 economic characters, to be immediately utilized in selection and also in cross breeding programs in Sri Lanka.

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Determinants of Lake Zone Forest Resources' Status: Analyzing the Impact of Implemented Policies in Tanzania

  • Mihayo, Isege Z.;Peng, Daiyan
    • Journal of Forest and Environmental Science
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    • v.36 no.3
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    • pp.233-242
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    • 2020
  • The Lake (Victoria) zone of Tanzania, which has the least forest resources in the country, is a potential economic growth zone in the country. Therefore, this study analyses the impact of implemented forest policies on the status of forest resources in the area, given the unique features. The study identifies the status of forested lands in the area, and then fits binary logistic regression to identify the impact of policies related elements (i.e. type of forest, type of management) on the status; forest area and location (region) are used as control variables. Results show that 63% of the forested land in the area is destructed; main activities being agriculture, residential, firewood, and charcoal burning activities. Logistic results showed natural forests, forests located in Geita region, forests managed by municipal councils are more likely to be destructed; while plantation forests, forests located in Kagera region, privately managed forests are less likely to be destructed. Thus, the study concludes that policies and measures are not enough for the preservation of forest resources in the area; some of the economic activities in the area are occurring at the expenses of the forests; hence recommend more sustainable development plans and incorporating different crossing cutting sectors in the policies.

Modal parameters identification of heavy-haul railway RC bridges - experience acquired

  • Sampaio, Regina;Chan, Tommy H.T.
    • Structural Monitoring and Maintenance
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    • v.2 no.1
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    • pp.1-18
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    • 2015
  • Traditionally, it is not easy to carry out tests to identify modal parameters from existing railway bridges because of the testing conditions and complicated nature of civil structures. A six year (2007-2012) research program was conducted to monitor a group of 25 railway bridges. One of the tasks was to devise guidelines for identifying their modal parameters. This paper presents the experience acquired from such identification. The modal analysis of four representative bridges of this group is reported, which include B5, B15, B20 and B58A, crossing the Caraj$\acute{a}$s railway in northern Brazil using three different excitations sources: drop weight, free vibration after train passage, and ambient conditions. To extract the dynamic parameters from the recorded data, Stochastic Subspace Identification and Frequency Domain Decomposition methods were used. Finite-element models were constructed to facilitate the dynamic measurements. The results show good agreement between the measured and computed natural frequencies and mode shapes. The findings provide some guidelines on methods of excitation, record length of time, methods of modal analysis including the use of projected channel and harmonic detection, helping researchers and maintenance teams obtain good dynamic characteristics from measurement data.

Genetical and Physiological Mechanisms of Adult Diapause in Insects

  • Kim, Yong-Gyun
    • Korean journal of applied entomology
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    • v.34 no.1
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    • pp.20-32
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    • 1995
  • Adult diapause in insects is characterized by suppression of reproductive development. It is induced by environmental cues such as photoperiod, temperature, food availability, and other conditions Diapause-inducing environment is recognized and analyzed by the brain of the insects. The interpreted information is conveyed via endocrine system to target tissues such as ovaries, fat body, and other tissues. From this signal hierarchy of a brain-endocrine-target tissue axis, several factors are involved to express a diapause trait in a quantitative mode, even though the insects show a binomial phenotye between being in diapause or not. Recent works estimated that the number of the factors is relatively small by a series of crossing trials between high and low diapause lines. Heritability of the diapause is quite high (ca. 70%) in some species. Epistasis, sex-linkage, pleiotropism, and other nongenetic components also affect diapause inheritance. Most physiological studies have been focused on control mechanisms of the juvenile hormone (JH) synthesis in corpora allata (CA) because JH level in hemolymph of teneral adults is critical to decide a later developmental mode. Allatostatin, an antagonizer of JH synthesis, has been believed to be a potent brain message to CA for adult diapause induction.

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Direction of Revision of College Scholastic Ability Test Through Literature Review (문헌분석을 통한 대학수학능력시험 수리영역의 개정 방향 탐색)

  • Ko, Ho-Kyoung
    • Journal of the Korean School Mathematics Society
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    • v.11 no.3
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    • pp.467-481
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    • 2008
  • This paper analysed a bulk of theses performed in various perspectives relating to College Scholastic Ability Test since 1994. Further this searched suggestions of revisions of systems about College Scholastic Ability Test along with the revised curriculum throngh this analysis of previous studies, which were categorized into 'correspondence between goal and characteristics', 'impact on education', and 'impact on society'. According to previous studies, they treat crossing application, advantage & disadvantage among optional subjects, difference in subject and content between natural science and cultural science, subjects that have to be included into College Scholastic Ability Test. This research suggests some elements and basic & fundamental information which need to be considered in the process of revising in problem making system of College Scholastic Ability Test.

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Josephson Vortex Dynamics in Tilted Magnetic Fields (경사 자기장 하에서의 조셉슨 볼텍스 동역학)

  • Jin, Yong-Duk;Ki, Dong-Keun;Lee, Hu-Jong
    • Progress in Superconductivity
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    • v.9 no.2
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    • pp.140-145
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    • 2008
  • We report on the Josephson vortex dynamics in $Bi_2Sr_2CaCuO_{8+\delta}$ natural Josephson junctions by c-axis tunneling measurements. Beside the quasiparticle branches in the current-voltage characteristics, a new set of multiple branches, referred to as Josephson-vortex-flow branches (JVFBs), are observed. The JVFBs emerge in an in-plane magnetic field above $H_0\;=\;{\Phi}_0/{\gamma}s^2$ and show highly hysteretic behavior, which can be explained in terms of the recently proposed dynamic-phase-separation model. In this work we examined the effect on the JVFBs by the presence of pancake vortices generated as the external magnetic field was applied slightly tilted from the in-plane direction. JVFBs were found to become larger and prominent with increasing pancake vortex density as the tilt angle increased, which were presumably caused by slowing down of a Josephson vortex lattice in the presence of pancake vortices.

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