• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11a
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• pp.98-98
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• 2002

In higher dicotyledonous plants, the floral organs are arranged in four different whorls, containing sepals, stamens and carpels. petals, stamens and carpels. The specification of floral organ identity is explained by the ABC model (Weigel and Meyerowitz 1994). expression of an A-function gene specifies sepal formation in whorl 1. the combination of A-and B-function genes specifies the formation of petals in whorl 2, B-and C-function genes spesify stamen formation in whorl 3, and expression of the C-function alone determines the formation of carpels in whorl 1. A-, B-, C-function genes have been isolated from many plant species and most of them belong to the family of MADS-box genes encoding transcription factor. In contrast to the flower of higher dicots, the perianths of genseng plants have three whorls of almost identical petaloid organs. van Tunen et al. (1993) proposed a modified ABC model, exemplified with tulip. In this model, B-function genes are expressed in whorl 1 as well as whorl 2 and 3, theefore the organs of whorl 1 and whorl 2 have the same petaloid structure. They proposed this model with the molphological data of wild type and mutant flowers of tulip, however, there are no molecular data. To date, B-function genes were isolated several grass plants, rice, wheat and maize. However, grass plants have highly derived flowers, without well-developed perianths. To find out how the ABC model has to be modified for the Genseng plants, we have cloned and characterized orthologs of A-, B-, C-function genes from genseng.

• Journal of Science Education
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• v.36 no.1
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• pp.35-48
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• 2012

The purpose of this study was to analyze inquiry activities in the middle school science textbooks focused on the unit 'Nutrition of Plants' of the 2007 revision curriculum and the corresponding unit 'The Structure and Function of Plants' of the 7th curriculum in terms of content, process and contexts of inquiries. The average number of the inquiry activities in the unit 'Nutrition of Plants' was 9.2, which was a 3.8 decrease than in the unit 'Structure and Function of Plants'. In the respective of process of the inquiry activities, 'observation' was most prevailing in the basic inquiry process and 'data interpretation' was most prevailing in the integrated inquiry process in both of the units. In the respective of the types and contexts of the inquiry activities, 'experiment/observation' was most prevailing and the percentage of the natural scientific contexts was larger in both of the units. In the unit 'Nutrition of Plants', the components of the integrated inquiry process and the percentage of personal contexts were larger than in the unit 'Structure and Function of Plants'. And simulation activities were newly presented and technical contexts and natural environmental contexts were included in the unit 'Nutrition of Plants'. This study makes a suggestion that a wider variety of inquiry activities should be included when new science textbooks are developed.

• The Plant Pathology Journal
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• v.38 no.6
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• pp.583-592
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• 2022

Root-knot nematode disease is a widespread and catastrophic disease of tobacco. However, little is known about the relationship between rhizosphere bacterial community and root-knot nematode disease. This study used 16S rRNA gene sequencing and PICRUSt to assess bacterial community structure and function changes in rhizosphere soil from Meloidogyne incognita-infected tobacco plants. We studied the rhizosphere bacterial community structure of M. incognita-infected and uninfected tobacco plants through a paired comparison design in two regions of tobacco planting area, Yuxi and Jiuxiang of Yunnan Province, southwest China. According to the findings, M. incognita infection can alter the bacterial population in the soil. Uninfested soil has more operational taxonomic unit numbers and richness than infested soil. Principal Coordinate Analysis revealed clear separations between bacterial communities from infested and uninfested soil, indicating that different infection conditions resulted in significantly different bacterial community structures in soils. Firmicutes was prevalent in infested soil, but Chloroflexi and Acidobacteria were prevalent in uninfested soil. Sphingomonas, Streptomyces, and Bradyrhizobium were the dominant bacteria genera, and their abundance were higher in infested soil. By PICRUSt analysis, some metabolism-related functions and signal transduction functions of the rhizosphere bacterial community in the M. incognita infection-tobacco plants had a higher relative abundance than those uninfected. As a result, rhizosphere soils from tobacco plants infected with M. incognita showed considerable bacterial community structure and function alterations.

• Journal of Korean Elementary Science Education
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• v.21 no.1
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• pp.13-24
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• 2002

This study examined the knowledge structure constructed by children before formal instruction, and successive changes in the structural complexity of knowledge during the learning of the 'Structure and Function of Plants' unit. The researchers let the 5th graders draw the first draft of their concept maps in order to examine the pre-existing knowledge structure concerned with the unit and also four concept maps after completing every fourth lesson. Each concept map drawn by children on the basis of the previous one showed the degree of their current understanding on the structure and function of plants. The results revealed that only two levels of hierarchy and five relationships among the components of the first concept map(relationship, hierarchy, cross link and example) were proven to be valid in terms of conceptual relevance. According to the standard map, there was no change in hierarchy from the 2nd to the 3rd map, and in example from the 2nd to the 4th map. However, the gradual and successive increases of the scores in all components appeared in the children's maps throughout the unit. Knowledge restructuring occurred strongly in the early periods from the 1st to the 6th lesson, and the significant stable changes in tuning and accretion appeared throughout the whole lessons. The results also showed that there were no significant gender differences on the 5th grader's knowledge structuring.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.127-134
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• 2015

In this note, a continuous sliding surface transformed variable structure systems by the saturation function is presented for MIMO uncertain linear plants. A discontinuous sliding surface transformed VSS is proposed theoretically. The closed loop exponential stability together with the MIMO existence condition of the sliding mode on the predetermined sliding surface is investigated. For practical applications, a continuous approximation of the discontinuous VSS is made by means of the saturation function. The discontinuity of the control input as the inherent property of the VSS is much improved in view of the practical aspects. Through a design example and simulation studies, the usefulness of the proposed continuous transformed VSS controller is verified.

• BMB Reports
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• v.33 no.3
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• pp.195-201
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• 2000

A human gene has been reported that may encode the enzyme acetohydroxyacid synthase. Previously this enzyme was thought to be absent from animals although it is present in plants and many microorganisms. In plants, this enzyme is the target of a number of commercial herbicides and the use of these compounds may need to be reassessed if the human enzyme exists and proves to be susceptible to inhibition. Here we report the construction of several plasmid vectors containing the cDNA sequence for this protein, and their expression in Escherichia coli. High levels of expression were observed, but most of the protein proved to be insoluble. The small amounts of soluble protein contained little or no acetohydroxyacid synthase activity. Attempts to refold the insoluble protein were successful insofar as the protein became soluble. However, the refolded protein did not gain any acetohydroxyacid synthase activity. In vivo complementation tests of an E. coli mutant produced no evidence that the protein is active. Incorrect folding, or the lack of another subunit, may explain the data but we favor the interpretation that this gene does not encode an acetohydroxyacid synthase.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.115-122
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• 2012

We present here a new class of activation functions for neural networks, which herein will be called CosGauss function. This function is a cosine-modulated gaussian function. In contrast to the sigmoidal-, hyperbolic tangent- and gaussian activation functions, more ridges can be obtained by the CosGauss function. It will be proven that this function can be used to aproximate polynomials and step functions. The CosGauss function was tested with a Cascade-Correlation-Network of the multilayer structure on the Tic-Tac-Toe game and iris plants problems, and results are compared with those obtained with other activation functions.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.2 s.109
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• pp.48-59
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• 2005

The purpose of this study was to examine the ecological characteristics of herbaceous communities by systematic and scientific analysis of their structure and diversity in the Midongsan Arboretum and to offer raw data for a long-tenn monitoring study. The importance value and diversity index of species appearing in twenty plots from July to September, 2004 were analyzed and a management plan for these communities is presented. Vascular plants were represented by 60 taxa of 23 families, 51 genera, 50 species and 10 varieties. Based on the results of importance value analysis, the most dominant species was Artemisia princeps var. orientalis, followed by Setaria viridis and Erigeron canadensis. The diversity index analysis showed that plot no. 5 had the highest H' and H'_{max}$(2.0135 and 2.6391). It's species composition was comparatively more diverse and it's structure more stable than other plots. Artemisia montana and Dactylis glomerata showed the highest correlation between species. Because herbaceous communities are important biological habitats and provide important function in environmental conservation, it is important to properly preserve these communities. At the same time, in order to preserve genetic resources and improve spatial function, it may be necessary to consider removing herbaceous communities in certain areas. In the future, the relations between physicochemical soil properties and herbaceous communities should be examined and community movement should be studied.

• ALGAE
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• v.18 no.4
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• pp.295-299
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• 2003

The population dynamics of Ecklonia stolonifera was investigated at Tongyeong coastal area in the South Sea of Korea. The blade length and width, stipe length and diameter, mean total length and mean weight were measured from randomly collected fifty individuals in every month. The plants in Tongyeong population were relatively bigger than those of Busan Korea and Aomori Japan in terms of their blade length and width. The population biomass was low in winter and high in spring and summer. The sporangial sori were found from August to December but prominent in September and October. About 90 % of the Tongyeong population was consisted of one- and two-year old plants and the zoosporangial sori were observed mostly in two-year old plants. It was different from the results of Busan and Aomori population in which the zoosporangial sori were observed from the plants older than three years. The new populations were developed from the zoospores of two-year old plants and their generation time was relatively shorter than those of Busan and Aomori.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.1
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• pp.93-119
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• 2014

Tropical tasar silkworm, Antheraea mylitta (Lepidoptera: Saturniidae) is a polyphagous silk producing forest silkworm of commercial importance in India. Forest dependent people rear its larvae on different forestry host plants twice or thrice in a year for small household income. Larvae of A. mylitta feeds on many forest tree species, but always show a great degree of selectivity as a function of its behavioural responses to physical structure and chemical features of the host plants. Cocoon crop of A. mylitta is influenced by heterogeneity of tasar food plants and climatic conditions of the habitat. The role of host plants, temperature, humidity, rainfall, photoperiod and climatic variables on the growth and development of insects have clearly been demonstrated. This article entails an in-depth analysis on ecological and nutritional aspects of A. mylitta, which may provide selective information to researcher and forest managers, who are particularly associated with livelihood improvement of the poor people in forested area through location specific forest insect industry.