• Title/Summary/Keyword: POLAR

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Dasania marina gen. nov., sp. nov., of the Order Pseudomonadales, Isolated from Arctic Marine Sediment

  • Lee, Yoo-Kyung;Hong, Soon-Gyu;Cho, Hyun-Hee;Cho, Kyeung-Hee;Lee, Hong-Kum
    • Journal of Microbiology
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    • v.45 no.6
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    • pp.505-509
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    • 2007
  • An obligately aerobic bacterium, strain KOPRI $20902^T$, was isolated from a marine sediment in Ny-${\AA}$lesund, Spitsbergen Islands, Norway. Cells were irregular rods and motile with polar monotrichous flagellum. The optimum growth temperature was $17-22^{\circ}C$. Cells grew best in pH 7.0-10.0 and 3-4% sea salts (corresponding to 2.3-3.1% NaCl). The novel strain required $Ca^{2+}$ or $Mg^{2+}$ in addition to NaCl for growth. Sequence analysis of 16S rRNA gene revealed that the Arctic isolate is distantly related with established species (<92.4% sequence similarity) and formed a monophyletic group with Cellvibrio, which formed a distinct phylogenetic lineage in the order Pseudomonadales. Predominant cellular fatty acids [$C_{16:1}\;{\omega}7c/15:0$ iso 2OH (45.3%), $C_{16:0}$ (18.4%), ECL 11.799 (11.2%), $C_{10:0}$ 3OH (10.4%)]; DNA G+C content (37.0 mol%); nitrate reduction to nitrogen; absence of aesculin hydrolysis, N-acetyl-${\beta}$-glucosaminidase and esterase; no assimilation of arabinose, galactose, glucose, lactose, maltose, and trehalose differentiated the strain from the genus Cellvibrio. Based on the phylogenetic and phenotypic characteristics, Dasania marina gen. nov., sp. nov. is proposed in the order Pseudomonadales. Strain KOPRI $20902^T$ (=KCTC $12566^T$=JCM $13441^T$) is the type strain of Dasania marina.

Preparation and Characterization of a Polar Milk Lipid-enriched Component from Whey Powder

  • Lee, Kwanhyoung;Kim, Ara;Hong, Ki-Bae;Suh, Hyung Joo;Jo, Kyungae
    • Food Science of Animal Resources
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    • v.40 no.2
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    • pp.209-220
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    • 2020
  • Milk fat globule membrane (MFGM) is a lipid carrier in mammals including humans that consists mainly of polar lipids, like phospholipids and glycolipids. In this study, a process to enrich polar lipids in commercial butter and whey powder, including polar lipids of MFGM, was developed. WPC (whey protein concentrate) 60 was selected as the most suitable raw material based on the yield, phospholipid, protein, and lactose content of the polar lipid fraction obtained by ethanol extraction of two WPC (WPC60 and WPC70) and two buttermilk (A and B). After fractionation under optimum conditions, the polar-lipid enriched fraction from WPC60 contained 38.56% phospholipids. The content of glycolipids, cerebroside, lactosylceramide, ganglioside GM3, ganglioside GD3, was 0.97%, 0.55%, 0.09%, and 0.14%, respectively. Rancimat results showed that the oxidation stability of fish oil increased with an increase in the polar-lipid fraction by more than 30 times. In addition, the secretion of IL-6 and TNF-α decreased in a concentration-dependent manner after treatment of RAW 264.7 cells with 0.1 to 100 ppm of the polar lipid fraction. In this study, polar lipid concentrates with antioxidant and anti-inflammatory activity, were prepared from milk processing by-products. The MFGM polar lipid concentrates made from by-products are not only additives for infants, but are also likely to be used as antioxidants in cooking oils and as active ingredients for functional foods.

Affine-Invariant Image normalization for Log-Polar Images using Momentums

  • Son, Young-Ho;You, Bum-Jae;Oh, Sang-Rok;Park, Gwi-Tae
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1140-1145
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    • 2003
  • Image normalization is one of the important areas in pattern recognition. Also, log-polar images are useful in the sense that their image data size is reduced dramatically comparing with conventional images and it is possible to develop faster pattern recognition algorithms. Especially, the log-polar image is very similar with the structure of human eyes. However, there are almost no researches on pattern recognition using the log-polar images while a number of researches on visual tracking have been executed. We propose an image normalization technique of log-polar images using momentums applicable for affine-invariant pattern recognition. We handle basic distortions of an image including translation, rotation, scaling, and skew of a log-polar image. The algorithm is experimented in a PC-based real-time vision system successfully.

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Changes in Endogenous Polyamine Levels during Polar Regeneration from Populus Leaf Segments (Populus 잎절편의 극성분화시 내생 Polyamine의 함량과 Polyamine 생합성 효소의 활성도 변화)

  • 김성호
    • Journal of Plant Biology
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    • v.33 no.4
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    • pp.243-251
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    • 1990
  • Polyamine titers and the activities of arginine decarboxylase(ADC) and ornithine decarboxylase (ODC), enzymes which catalyze rate-limiting steps in polyamine biosynthesis, were investigated during polar regeneration of Populus leaf segments. The polar regeneration occurred at the basal cut end of Populus leaf segments through cell division around the vascular bundle. In the process of polar regeneration, the titers of putrescine and spermidine increased rapidly but the content of spermine remained constant. The leaf segments were then divided into three separte part ; the proximal, middle and distal. Spermidine titers showed an increase mainly in the proximal parts where polar regeneration occurred. On the other hand, putrescine titers showed an increase in the other two parts. In the course of polar regeneration, the activities of ADC and ODC increased, the ADC activities being higher than those of ODC. However, ODC activity was higher in the proximal part. Therefore, the spermidine contents and ODC activities are suggested to be related to polar regeneration in Populus leaf segments.

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Polar Code Design for Nakagami-m Channel

  • Guo, Rui;Wu, Yingjie
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.7
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    • pp.3156-3167
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    • 2020
  • One drawback of polar codes is that they are not universal, that is, to achieve optimal performance, different polar codes are required for different kinds of channel. This paper proposes a polar code construction scheme for Nakagami-m fading channel. The scheme fully considers the characteristics of Nakagami-m fading channel, and uses the optimized Bhattacharyya parameter bounds. The constructed code is applied to an orthogonal frequency division multiplexing (OFDM) system over Nakagami-m fading channel to prove the performance of polar code. Simulation result shows the proposed codes can get excellent bit error rate (BER) performance with successive cancellation list (SCL) decoding. For example, the designed polar code with cyclic redundancy check (CRC) aided SCL (L = 8) decoding achieves 1.1dB of gain over LDPC at average BER about 10-5 under 4-quadrature amplitude modulation (4QAM) while the code length is 1024, rate is 0.5.

Polar Body: Indicator of Oocyte's Maturation, Have Any Function on Oocyte?

  • Dibyendu, Biswas;Hyun, Sang-Hwan
    • Journal of Embryo Transfer
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    • v.24 no.4
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    • pp.249-251
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    • 2009
  • Polar body was usually used as a determinant of oocyte's maturation. Polar body morphology could reflect the embryo quality and implantation competence. This review only focuses on morphology of the first polar body and embryo developmental rate in the presence or absence of polar body. However, it is very difficult to describe whether polar body has any effects on embryo development in vitro or in vivo. Further intensive research is needed to determine its function on embryo development.

Analysis of Polar Region-Related Topics in Domestic and Foreign Textbooks (국내외 교과서에 수록된 극지 관련 내용 분석)

  • Chung, Sueim;Choi, Haneul;Choi, Youngjin;Kang, Hyeonji;Jeon, Jooyoung;Shin, Donghee
    • Journal of the Korean earth science society
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    • v.42 no.2
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    • pp.201-220
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    • 2021
  • The objective of this study is to increase awareness and interest regarding polar science and thereby aid in establishing the concept and future direction of polar literacy. To analyze the current status, textbooks based on the common school curriculum pertaining to polar topics were reviewed. Six countries that actively conduct polar science, namely Korea, France, Japan, Germany, the United States, and the United Kingdom, were chosen. Subsequently, 402 cases in 110 science and social studies (geography) textbooks of these countries were analyzed through both quantitative and qualitative methods. Based on the obtained results, the importance of polar research in geoscience education and the need for spreading awareness regarding polar research as an indicator of global environmental changes were examined. It was found that the primary polar topics described in the textbooks are polar glaciers, polar volcanism, solid geophysics, polar infrastructure, and preservation of geological resources and heritage. This demonstrates that the polar region is a field of research with important clues to Earth's past, present, and future environments and is also a good teaching subject for geological education. However, an educational approach is needed for systematically laying emphasis on polar research. The implications of this study are manifold, such as the establishment of a cooperative system between polar scientists and educators, extraction of core concepts for polar literacy and content reconstruction, discovery of new polar topics associated with the curriculum, diversification of forms of presentation in textbooks, and development of an affective image that is based on correct cognitive understanding. Furthermore, through the continuance of polar topics in textbooks, students can improve their awareness regarding polar literacy and polar science culture, which in turn will serve as the driving force for sustainable polar research in the future.

MIXED VOLUMES OF A CONVEX BODY AND ITS POLAR DUAL

  • Chai, Y. D.;Lee, Young-Soo
    • Bulletin of the Korean Mathematical Society
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    • v.36 no.4
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    • pp.771-778
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    • 1999
  • In this paper, we obtain some geometric inequalities for mixed volumes of a convex body and its polar dual. We also develop a lower bound of the product of quermassintegral of a convex body and its polar dual and give a lower bound for the product of the dual quermassintegral of any index of centrally symmetric convex body and that of its polar dual.

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