• BMB Reports
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• v.56 no.3
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• pp.172-177
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• 2023

BEST family is a class of Ca²⁺-activated Cl- channels evolutionary well conserved from bacteria to human. The human BEST paralogs (BEST1-BEST4) share significant amino acid sequence homology in the N-terminal region, which forms the transmembrane helicases and contains the direct calcium-binding site, Ca²⁺-clasp. But the cytosolic C-terminal region is less conserved in the paralogs. Interestingly, this domain-specific sequence conservation is also found in the BEST1 orthologs. However, the functional role of the C-terminal region in the BEST channels is still poorly understood. Thus, we aimed to understand the functional role of the C-terminal region in the human and mouse BEST1 channels by using electrophysiological recordings. We found that the calcium-dependent activation of BEST1 channels can be modulated by the C-terminal region. The C-terminal deletion hBEST1 reduced the Ca²⁺-dependent current activation and the hBEST1-mBEST1 chimera showed a significantly reduced calcium sensitivity to hBEST1 in the HEK293 cells. And the C-terminal domain could regulate cellular expression and plasma membrane targeting of BEST1 channels. Our results can provide a basis for understanding the C-terminal roles in the structure-function of BEST family proteins.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.11
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• pp.1149-1155
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• 2003

OFDM/SFH(orthogonal frequency division multiplexing/slow frequency hopping) system is the combination of OFDM communication system with frequency hopping(FH) method and OFDM/DS(orthogonal frequency division multiplexing/direct sequence) system combines the OFDM communication system with direct sequence(DS) method in terms of PN(pseudo noise) sequence. These two systems are also can be used for anti-jamming. In this study we analyze performances of OFDM/SFH system and OFDM/DS system with the equal information rate in partial band jamming and tone jamming channel. We find BER(bit error rate) in the variation of JFR(jamming fractional ratio) and JSR(jamming to signal power ratio) of the partial band jamming. Also, BER is found in the several JSR of the single tone or multi tone jamming. OFDM/DS system shows better performance than OFDM/SFH system in partial band jamming environment. OFDM/DS system has about 2.5 ㏈ SNR(signal to noise power ratio) gains than OFDM/SFH system when JFR=4/16 and JSR=0 ㏈ to meet BER=10$\^$-3/. However, OFDM/SFH system has about 3 ㏈ SNR gains than OFDM/DS system at single tone jamming of JSR=5 ㏈. In multi tone jamming, performance of OFDM/SFH system is considerably degraded than OFDM/DS system.

• Parasites, Hosts and Diseases
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• v.56 no.1
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• pp.87-91
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• 2018

Morphological and molecular characteristics of spirometrid tapeworms, Spirometra decipiens, were studied, which were recovered from a heavily infected stray cat road-killed in Eumseong-gun, Chungcheongbuk-do (Province), the Republic of Korea (=Korea). A total of 134 scolices and many broken immature and mature proglottids of Spirometra tapeworms were collected from the small intestine of the cat. Morphological observations were based on 116 specimens. The scolex was 22.8-32.6 mm (27.4 mm in average) in length and small spoon-shape with 2 distinct bothria. The uterus was coiled 3-4 times, the end of the uterus was ball-shaped, and the vaginal aperture shaped as a crescent moon was closer to the cirrus aperture than to the uterine aperture. PCR amplification and direct sequencing of the cox1 target fragment (377 bp in length and corresponding to positions 769-1,146 bp of the cox1 gene) were performed using total genomic DNA extracted from 134 specimens. The cox1 sequences (377 bp) of the specimens showed 99.0% similarity to the reference sequence of S. decipiens and 89.3% similarity to the reference sequence of S. erinaceieuropaei. In the present study, we report a stray cat heavily infected with S. decipiens identified by mitochondrial cox1 sequence analysis and morphological examinations of the adult worms.

• Journal of the Mineralogical Society of Korea
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• v.16 no.2
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• pp.161-169
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• 2003

A phase transformation study on a synthetic amorphous diopside, $(Ca,Mg)SiO_3$has been carried out up to ∼30 GPa, and ∼$1000^{\circ}C$ using a diamond anvil cell and YAG laser heating system, respectively. A starting amorphous material shows a direct transition to cubic $(Ca,Mg)SiO_3$perovskite at high pressure, which contradicts to the crystalline diopside phase transformation sequence disproportionating into mixtures of the orthorhombic$ MgSiO_3$perovskite and the cubic $CaSiO_3$perovskite phases. This discrepancy might be due to the different starting materials as well as the temperature variations at each specific experiment performed. The present phase transfor mation sequence would modify the mineralogical assemblage in the Earth transition region and the lower mantle depending upon the pressure, temperature and the oxygen partial pressure.

• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.196-200
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• 1999

A recombinant human $\alpha_{s1}$-casein was expressed as a secretory product in the yeast Saccharomyces cerevisiae. Three different leader sequences derived from the mating factor $\alpha$l (MF$\alpha$l), inulinase, and human $\alpha_{s1}$-casein were used to direct the secretion of human $\alpha_{s1}$-casein into the extracellular medium. Among the three leader sequences tested, the native leader sequence of human $\alpha_{s1}$-casein was found to be the most efficient in the secretory expression of human $\alpha_{s1}$-casein, which implies that the native leader sequence of human $\alpha_{s1}$-casein might be used very efficiently for the secretory production of other heterologous proteins in yeast. The recombinant human $\alpha_{s1}$-casein was proteolytically cleaved as the culture proceeded. Therefore, an attempt was made to produce human $\alpha_{s1}$-casein using a S. cerevisiae mutant in which the YAP3 gene encoding yeast aspartic protease 3 (YAP3) was disrupted. After 72 h of culture, most of the human $\alpha_{s1}$-casein secreted by the wild type was cleaved, whereas more than 70% of the human $\alpha_{s1}$-casein secreted by yap3-disruptant remained intact. The results suggest that YAP3 might be involved in the internal cleavage of human $\alpha_{s1}$-casein expressed in yeast

• Journal of Communications and Networks
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• v.17 no.6
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• pp.622-633
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• 2015

The coexistence among different systems is a major problem in communications. Mutual interference between different systems should be analyzed and mitigated before their deployment. The paper focuses on two aspects that have an impact on the system performance. First, the coexistence analysis, i.e. evaluating the mutual interference. Second aspect is the coexistence techniques, i.e. appropriate system modifications that guarantee the simultaneous use of the spectrum by different technologies. In particular, the coexistence problem is analyzed between ultra-wide bandwidth (UWB) and narrow bandwidth (NB) systems emphasizing the role of spectrum sensing to identify and classify the NB interferers that mostly affect the performance of UWB system. A direct sequence (DS)-time hopping (TH) code design technique is used to mitigate the identified NB interference. Due to the severe effect of Narrowband Interference on UWB communications, we propose an UWB transceiver that utilizes spectrum-sensing techniques together with mitigation techniques. The proposed transceiver improves both the UWB and NB systems performance by adaptively reducing the mutual interference. Detection and avoidance method is used where spectrum is sensed every time duration to detect the NB interferer's frequency location and power avoiding it's effect by using the appropriate mitigation technique. Two scenarios are presented to identify, classify, and mitigate NB interferers.

• Journal of Broadcast Engineering
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• v.27 no.2
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• pp.207-215
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• 2022

The latest volumetric technology's high geometrical accuracy and realism ensure a high degree of correspondence between the real object and the captured 3D model. Nevertheless, since the 3D model obtained in this way constitutes a sequence as a completely independent 3D model between frames, the consistency of the model surface structure (geometry) is not guaranteed for every frame, and the density of vertices is very high. It can be seen that the interconnection node (Edge) becomes very complicated. 3D models created using this technology are inherently different from models created in movie or video game production pipelines and are not suitable for direct use in applications such as real-time rendering, animation and simulation, and compression. In contrast, our method achieves consistency in the quality of the volumetric 3D model sequence by linking re-meshing, which ensures high consistency of the 3D model surface structure between frames and the gradual deformation and texture transfer through correspondence and matching of non-rigid surfaces. And It maintains the consistency of volumetric 3D model sequence quality and provides post-processing automation.

• IMMUNE NETWORK
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• v.2 no.2
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• pp.79-85
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• 2002

Background: In contrast to evidences of Ig H chain receptor editing in transformed cell lines and transgenic mouse models, there has been no direct evidence that this phenomenon occurs in human developing B cells. Methods: $V_HDJ_H$ rearrangements were obtained from genomic DNA of individual $IgM^-$ B cells from liver and $IgM^+B$ cells from bone marrow of 18 wk of gestation human fetus by PCR amplification and direct sequencing. Results: We found three examples of H chain receptor editing from $IgM^+$ and $IgM^-human$ fetal B cells. Two types of $V_H$ replacements were identified. The first involved $V_H$ hybrid formation, in which part of a $V_H$ gene from the initial VDJ rearrangement is replaced by part of an upstream $V_H$ gene at the site of cryptic RSS. The second involved a gene conversion like replacement of CDR2, in which another $V_H$ gene donated a portion of its CDR2 sequence to the initial VDJ rearrangement. Conclusion: These data provide evidence of receptor editing at the H chain loci in developing human B cells, and also the first evidence of a gene conversion event in human Ig genes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8A
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• pp.1238-1244
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• 1999

In this paper, a new design of a triple-erroe-correcting (TEC) Reed-Solomon decoder is presented based on direct decoding method which is more efficient for the case of relatively small error correction capability. The proposed decoder requires only 9 GF(2m) multipliers in obtaining the error-locator polynomial and the error-evaluator polynomial, whereas other decoders needs 24 multipliers. Thus, the attractive feature of this decoder is its remarkable simplicity from the point of view of implementation. Futhermore, the proposed TEC Reed-Solomon decoder has very simple control circuit and short decoding delay. Therefore this decoder can be implemented by simple hardware and also save buffer memory which stores received sequence.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.3
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• pp.35-46
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• 1999

A derotator VLSI which compensates for the frequency and phase errors of a received signal in digital communication systems was developed employing a CORDIC algorithm. The CORDIC circuit directly rotates the input signal according to the phase error information, thus is much simpler than the conventional derotator architecture which consists of a DDFS (Direct Digital Frequency Synthesizer) and a complex multiplier. Since a derotator needs only small phase error accumulation, a fast direction sequence generation method which exploits the linearity of the arctangent function in small angles is utilized in order to enhance the operating speed. The chip was designed and implemented using a $0.6\mu\textrm{m}$ triple metal CMOS process by the full custom layout method. The whole chip size is $6.8\textrm{mm}^2$ and the maximum operating frequency is 25 MHz.