• Journal of Ecology and Environment
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• 제29권4호
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• pp.353-360
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• 2006

Ecological correlates of flowering times often are examined to infer evolutionary mechanisms for flowering time diversities. We examined ecological characteristic associations such as growth habits and pollination modes with flowering times among 3,037 Korean angiosperms experiencing strong climatic seasonalities. We first examined taxonomic membership effects on flowering times across diverse taxonomic levels. Phylogeny constrained flowering times at all levels down to the genus level. We then analyzed the effects of ecological characteristics using subset data consisting of species randomly selected from each genus to control phylogenetic effects. The commonly observed patterns of early flowering of woody species in temperate regions existed. Spring flowering shrubs and trees, however, both being woody, were involved with biotic and abiotic vectors, respectively. In two herbaceous groups of annuals and perennials, annuals flowered later in the growing season than perennials although both herbs tended to be associated with abiotic vectors when flowering in autumn. These results support our hypothesis that species able to decouple vegetative and reproductive growth flower in spring's dry season, but species with different habits, even when they flower within the same season, are subjected to different selective pressures for efficient pollination.

• Applied Microscopy
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• 제28권4호
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• pp.477-490
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• 1998

Most spiders have four pairs of simple eyes. A few families of the spider have their developed eyes to an extent visual cues make up a significant of information to response from the external stimuli. Most spiders respond to the external stimuli around them. Specially, they are very sensitive to vibrations from the air, the ground, their webs, or even the surface of water. The present study was undertaken to examine the evolutionary development and function of eye with the observation of visual ultrastructure of Atypus coreanus Kim, 1985 using the electron microscopy. They have weak mobility, limited territory and low developed eyes. Atypus coreanus was collected from Mt. Ungil, Namyangju-gun, Kyonggi province. The fine structure of these eyes was examined by electron microscopy, and prepard by teasing method for scanning electron microscopic observation. As a result, the eyes of Atypus coreanus was composed of cornea, lens, vitreous body, retina, and rhabdome.

• 한국균학회지
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• 제23권4호통권75호
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• pp.310-317
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• 1995

담자성 효모와 담자균계의 yeast-like 균류의 총 43개 균류의 18S 리보좀 RNA 부분염기배열을 비교하였다. Fibulobasidium inconspicuum은 Filobasidiella neoformans와 밀접한 유연관계를 보였다. Tremella foliacea, Ustilago rabenhorstiana는 각각 다른 계통지를 형성하여 담자균효모와는 독립적으로 진화해 왔을 가능성을 시사하였다. 담자균효모는 Ustilago rabenhorstiana 보다 Tremella foliacea에 보다 가까운 유연관계를 보였다. 한편, 표현형질 즉 색소, 동포자, 사출포자등은 18S ribosomal RNA의 부분 염기서열 분석 결과 계통학적으로 의미가 없는 것으로 나타났다.

• ALGAE
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• 제24권2호
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• pp.111-120
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• 2009

Choosing an appropriate sample unit is a fundamental decision in the design of ecological studies. While numer-ous methods have been developed to estimate organism abundance, they differ in cost, accuracy and precision.Using both field data and computer simulation modeling, we evaluated the costs and benefits associated with twomethods commonly used to sample benthic organisms in temperatc kelp forests. One of these methods, theTargeted Sampling method, relies on different sample units, each "targeted" for a specific species or group ofspecies while the other method relies on coefficients that represent ranges of bottom cover obtained from visual esti-mates within standardized sample units. Both the field data and the computer simulations suggest that both meth-ods yield remarkably similar estimates of organisnm abundance and among-site variability, although the Coefficientmethod slightly underestimates variability armong sample units when abundances are low. In contrast, the twomethods differ considerably in the effort needed to sample these communities; the Targeted Sampling requiresmore time and twice the persormel to complete. We conclude that the Coeffident Sampling metliod may be bettcrfor environmental monitoring programs where changes in mean abundance are of central conccm and resources arelimiting, but that the Targeted sampling methods may be better for ecological studies where quantitative reIation-ships among species and small-scale variability in abundance are of central concern.

• ALGAE
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• 제33권4호
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• pp.329-340
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• 2018

The present study was to determine the effects of salinity on the growth and nutrient bioextraction abilities of Gracilaria and Ulva species, and to determine if these seaweeds can be used for nutrient bioextraction under hypo- and / or hyperosmotic conditions. Two Gracilaria species, G. chorda and G. vermiculophylla, and two Ulva species, U. prolifera and U. compressa, were cultured at various salinity conditions (5, 10, 15, 20, 30, 40, and 50 psu) for 3 weeks. Results showed that the growth rates, nutrient uptake, tissue nutrient contents and nutrient removal were significantly affected by salinity and species. All four species were euryhaline with the highest growth rates at 20 psu. Among the four species, U. prolifera, U. compressa, and G. vermiculophylla showed potential to be used for nutrient bioextraction in estuaries and / or land-based fish farms due to their rapid growth, high nutrient uptake, high tissue carbon and nitrogen accumulation and removal capacities.

• Animal cells and systems
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• 제5권2호
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• pp.133-137
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• 2001

Long terminal repeats (LTRs) of the human endogenous retrovirus K family (HERV-K) have been found to be coexpressed with sequences of genes closely located nearby. We examined transcribed HERV-K LTR elements in human brain tissue. Using cDNA synthesized from mRNA of the human brain, we performed PCR amplification and identified ten HERV-K LTR elements. These LTR elements showed a high degree of sequence similarity (92.4-99.7%) with the human-specific LTR elements. A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-K LTR elements could be divided into two groups through evolutionary divergence. Some HERV-K LTR elements (HKL-B7, HKL-B8, HKL-B10) belonging to the group II from human brain cDNA were closely related to the human-specific HERV-K LTR elements. Our data suggest that HERV-K LTR element are active in the human brain; they could conceivably play a pathogenic role in human diseases such as psychosis.

• International journal of advanced smart convergence
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• 제8권1호
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• pp.1-8
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• 2019

Coronaviruses are known respiratory pathogens. In the past, most human coronaviruses were thought to cause mild symptoms such as cold. However recently, as seen in the Severe Acute Respiratory Syndrome (SARS) and the Middle East Respiratory Syndrome (MERS), infectious diseases with severe pulmonary disease and respiratory symptoms are caused by coronaviruses, making research on coronaviruses become important. Considering previous studies, we constructed 'HCoV-IMDB (Human Corona Virus Immune Database)' to systematically provide genetic information on human coronavirus and host immune information, which can be used to analyze the interaction between human coronavirus and host immune proteins. The 'HCoV-IMDB' constructed in the study can be used to search for genetic information on human coronavirus and host immune protein and to download data. A BLAST search specific to the human coronavirus, one of the database functions, can be used to infer genetic information and evolutionary relationship about the query sequence.

• 식물분류학회지
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• 제51권4호
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• pp.345-352
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• 2021

Diarthron linifolium Turcz. is an annual herb usually found in sandy soil or limestone areas. Plants in the genus Diarthron are known to have toxic chemicals that may, however, be potentially useful as an anticancer treatment. Diarthron linifolium is a unique species among the species of the genus distributed in Korea. Here, we determine the genetic variation of D. linifolium collected in Korea with a full chloroplast genome and investigate its evolutionary status by means of a phylogenetic analysis. The chloroplast genome of Korean D. linifolium has a total length of 172,644 bp with four subregions; 86,158 bp of large single copy and 2,858 bp of small single copy (SSC) regions are separated by 41,814 bp of inverted repeat (IR) regions. We found that the SSC region of D. linifolium is considerably short but that IRs are relatively long in comparison with other chloroplast genomes. Various simple sequence repeats were identified, and our nucleotide diversity analysis suggested potential marker regions near ndhF. The phylogenetic analysis indicated that D. linifolium from Korea is a sister to the group of Daphne species.

• Fisheries and Aquatic Sciences
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• 제25권10호
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• pp.499-516
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• 2022

Endobiotic microalgae inhabit various groups of organisms, including bivalves. In this group, the association between the giant molluscs Tridacna and Symbiodinium is one of the most recognizable. This consortium allows hydrobionts to survive in oligotrophic waters by regulating their metabolism. The available research has provided an understanding of the interaction and adaptation of these symbionts, but the problem of the beginning of the formation of these relationships remains unresolved. In the case of Tridacninae, symbiosis is essential for the survival of bivalves, in contrast to representatives of the Mytilidae and the Coccomyxa found in them. A few works devoted mainly to the morphological aspects of invasion have shown that endobiont causes inflammation and pathology. Having data to clarify the exact "diagnosis" of the interaction of these organisms is not enough. It is possible that the relationship between bivalves and Coccomyxa is in the early stages of being established, which may lead to mutualism or parasitism in the future. We assume that the analysis of works on the symbiosis of Symbiodinium and bivalves will facilitate the course of research for the less studied Coccomyxa and their hosts. By postulating the Coccomyxa represent a unique evolutionary model for the formation of a symbiotic system, it is possible to use this system to study the interaction of organisms during their initial contact. The identified signalling pathways and mechanisms that allow the photobionts to evade host immunity can be useful for constructing new forms of symbiosystems.

• ALGAE
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• 제37권2호
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• pp.85-103
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• 2022

Korea is one of the most advanced countries in kelp aquaculture. The brown algae, Undaria pinnatifida and Saccharina japonica are major aquaculture species and have been principally utilized for human food and abalone feed in Korea. This review discusses the diversity, population structure and genomics of kelps. In addition, we have introduced new cultivar development efforts considering climate change, and potential carbon sequestration of kelp aquaculture in Korea. U. pinnatifida showed high diversity within the natural populations but reduced genetic diversity in cultivars. However, very few studies of S. japonica have been conducted in terms of population structure. Since studies on cultivar development began in early 2000s, five U. pinnatifida and one S. japonica varieties have been registered to the International Union for the Protection of New Varieties of Plants (UPOV). To meet the demands for seaweed biomass in various industries, more cultivars should be developed with specific traits to meet application demands. Additionally, cultivation technologies should be diversified, such as integrated multi-trophic aquaculture (IMTA) and offshore aquaculture, to achieve environmental and economic sustainability. These kelps are anticipated to be important sources of blue carbon in Korea.