• 제목/요약/키워드: MP4

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MP3Player의 변화에서 나타나는 재매개적 특성 I : 계보적 변화와 재매개성 (Remediation Characteristics that Appear in the Change of MP3Player I : Re-mediation and Genealogical Change)

  • 이진혁;이영천;구윤희
    • 한국콘텐츠학회논문지
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    • 제13권11호
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    • pp.59-68
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    • 2013
  • iPod Touch는 초기의 음악 재생기능을 무색하게 할 만큼 다양한 응용소프트웨어가 제공되고, UI를 UX의 차원으로 한층 높임으로써 혁신적이라는 평을 받기도 하였다. 또한 인터넷을 통한 다양한 영상의 제공이 이루어 졌음에도 불구하고 일부에서는 여전히 MP3Player의 상품분류가 음향기기로 인식되고 있다. 어떻게 음향기기가 하루아침에 영상 장치가 되었는지, 그러기까지 어떠한 요인들이 작용했는지는 매체의 본질적 변화 외에도 사회적, 문화적, 그리고 기술적 변화의 요일들이 존재할 것이다. 이 연구는 MP3Player의 매체적 특성에 관한 연구이다. 즉 MP3Player의 계보적 변화를 4개의 지점으로 분류할 수 있었다. 그리고 분류에 따른 각 지점별 특성을 분석하였다. 그 결과 MP3Player의 계보적 변화에는 기술적 변화와 사회적 맥락성이 함께 관계하고 있음을 알 수 있었다. 하나의 장치가 변화하는 데에는 다양한 요소들이 존재하지만, MP3Player의 계보적 변화의 요인에는 사회적 요구와 맥락, 그리고 기술적 변화의 총체성을 보이고 있다고 하겠다.

폐 미세플라스틱(PET)의 물벼룩 만성독성 연구 (Effect of Chronic Toxicity by Waste Microplastics (PET) on Daphnia magna)

  • 한보미;박건우;유승우;김창해;정진호;나주림
    • Ecology and Resilient Infrastructure
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    • 제8권4호
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    • pp.281-289
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    • 2021
  • 상업에서 사용되는 일회용 컵은 환경으로 유입되어 파편화되어 미세플라스틱 (MP)이 될 수 있다. 또한 MP는 수생 생물에게 섭식 될 수 있으며, 다양한 부작용을 미칠 수 있다. 본 연구는 일회용 컵에서 유래된 MP 조각이 물벼룩에게 미치는 급성 및 만성 독성을 평가했다. MP 조각은 33.18 ±7.76 ㎛ 크기의 PET (Polyethylene terephthalate) MP 조각으로 확인되었으며, 3종류의 첨가제 (1- Propanone. 1-phenyl-3-[2-(phenylmethoxy)phenyl]-, p-Xylene and ethylbenzene)가 함유되어 있는 것을 확인하였다. 48시간 급성 독성은 최고 농도의 PET MP (200 mg L-1)에 노출된 물벼룩에서 20%의 유영저해 및 사망을 발견하였다. 21일 만성 독성은 5 mg L-1의 PET MP 조각에 노출된 D. magna에서 대조군과 비교하여 줄어든 생존율 (31%)과 번식 (52%)을 보여주었다. 더욱이 PET MP는 태어난 개체의 발달 이상을 (3.5%) 대조군 (0.3%)과 비교하여 유의하게 (p < 0.05) 증가시켰다. 이러한 결과는 MP 조각의 섭취에 의한 장 막힘과 더 긴 체류 시간 때문일 수 있다. 본 연구의 결과는 일회용 컵 (PET 폴리머)이 작은 크기의 MP 조각으로 단편화되면 수생 생물에 심각한 생태학적 위험을 제기할 수 있음을 시사하고 있다. 또한 MP 독성 및 첨가제에 대한 근본적인 독성 메커니즘을 확인하기 위해 추가 연구가 수행되어야 한다.

Inactivation of the genes involved in histone H3-lysine 4 methylation abates the biosynthesis of pigment azaphilone in Monascus purpureus

  • Balakrishnan, Bijinu;Lim, Yoon Ji;Suh, Jae-Won;Kwon, Hyung-Jin
    • Journal of Applied Biological Chemistry
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    • 제62권2호
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    • pp.157-165
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    • 2019
  • Di- and tri-methylation of lysine 4 on histone H3 (H3K4me2 and H3K4me3, respectively) are epigenetic markers of active genes. Complex associated with Set1 (COMPASS) mediates these H3K4 methylations. The involvement of COMPASS activity in secondary metabolite (SM) biosynthesis was first demonstrated with an Aspergillus nidulans cclA knockout mutant. The cclA knockout induced the transcription of two cryptic SM biosynthetic gene clusters, leading to the production of the cognate SM. Monascus spp. are filamentous fungi that have been used for food fermentation in eastern Asia, and the pigment Monascus azaphione (MAz) is their main SM. Monascus highly produces MAz, implying that the cognate biosynthetic genes are highly active in transcription. In the present study, we examined how COMPASS activity modulates MAz biosynthesis by inactivating Monascus purpureus cclA (Mp-cclA) and swd1 (Mp-swd1). For both ${\Delta}Mp-cclA$ and ${\Delta}Mp-swd1$, a reduction in MAz production, accompanied by an abated cell growth, was observed. Suppression of MAz production was more effective in an agar culture than in the submerged liquid culture. The fidelity of the ${\Delta}Mp-swd1$ phenotypes was verified by restoring the WT-like phenotypes in a reversion recombinant mutant, namely, trpCp: Mp-swd1, that was generated from the ${\Delta}Mp-swd1$ mutant. Real-time quantitative Polymerase chain reaction analysis indicated that the transcription of MAz biosynthetic genes was repressed in the ${\Delta}Mp-swd1$ mutant. This study demonstrated that MAz biosynthesis is under the control of COMPASS activity and that the extent of this regulation is dependent on growth conditions.

IP망을 통한 MP4 파일 스트리밍 시스템의 설계 및 구현 (Design and Implementation of An MP4 File Streaming System over IP Networks)

  • 김현철;민승홍;서덕영;김규헌;김진웅
    • 방송공학회논문지
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    • 제6권3호
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    • pp.205-214
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    • 2001
  • 본 논문에서는 IP 망을 통한 MP4 파일 스트리밍 시스템을 소개한다. 사용자는 제안된 스트리밍 시스템을 이용하여 IF망을 통해 서버측의 MF4 컨텐츠를 엑세스할 수 있으며, 스트리밍되는 컨텐츠와 상호 작용도 가능하다. MP4 파일 형식은 MPEG-4 미디어 정보를 저장할 수 있도록 설계되었으며, 객체 지향적 구조를 이루고 있다 본 논문에서 제시한 스트리밍 서버 시스템은 GUL, Session Manager, Splitter, SL Packetizer; Transmitter 등으로 구성되어 있으며, 클라이언트 시스템은 MPEG-4 참조 소프트웨어인 IMI-2D 플레이어를 기반으로 구현되었다. 또한 본 스트리밍 시스템은 실시간 전송이 필요한 미디어 데이터와 QoS 관리를 위해 RTP와 RTCP를 각각 사용하도록 설계되었으며, 초기객체기술자(IOD), 객체기술자(OD), BIFS와 같은, 스트리밍을 위해서 반드시 전송되어져야 할 데이터와 정지영상 및 텍스트 등과 같이 하나의 패킷으로 전송이 완료되는 미디어 데이터를 위해서는 TCP를 사용하도록 설계되었다.

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자작나무 엽(葉)의 Triterpenoid 성분연구(成分硏究) -Triterpenoid의 분리(分離) 및 동정(同定)- (Triterpenoid Components of Betula latifolia $K_{OMAROV}$ -Isolation and Characterization of Triterpenoids-)

  • 한병훈;지형준;한용남
    • 생약학회지
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    • 제4권4호
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    • pp.167-172
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    • 1973
  • Five crystalline substances, which are positive to$L_{IEBERMAN}-B_{URCHARD}$ reaction, were isolated from the unsaponifiable fraction of the fresh leaves of Betula latifolia $K_{OMAROV}$ (Betulaceae)by silica gel column chromatographic purification. Compound $A\;(C_{29}H_{50}O,\;mp\;136^{\circ}), \;B\;(C_{30}H_{52}O_3,\;mp\;165^{\circ}), \;C\;(C_{30}H_{52}O_4,\;mp\;237^{\circ}), \;D\;(C_{30}H_{52}O_3,\;mp\;196^{\circ})\;and\; E\;(C_{30}H_{52}O_4,\;mp\;121^{\circ})$ were isolated. Compound B was characterized as a new tetracyclic triterpenoid. Compounds A, C and D were identified as ${\beta}-sitosterol$, betulatriterpene C, and betulafolienetriol, respectively.

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Studies of Tertiary Structures of Mastoparan B and Alanine Analogues by NMR Spectroscopy

  • Kyeunghee Yu;Kang, Shin-Won;Park, Nam-Gyu;Kim, Yangmee
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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    • pp.33-33
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    • 1999
  • Mastoparan B (MP-B), an antimicrobial cationic tetradecapeptide amide isolated from the venom of the hornet Vespa basalis, is an amphiphilic ${\alpha}$-helical peptide. In order to study the relationship between the structure and biological activity, we used the three analogues by replacing amino acids with alanine (4LysAla: 4MP-B, 12-LYsAla: 12MP-B, 9TrpAla: 9Mp-B).(omitted)

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A study on the development of the OMS/MP based on the Fundamentals of Systems Engineering

  • Jeong, Yeonhwan
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제10권4호
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    • pp.468-476
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    • 2018
  • The Systems Engineering method is increasingly recognized as a central in the Acquisition of Weapon Systems in South Korea. Because of these trends, issues concerned with improving weapon system design are increasingly raised. This paper presents a development of Operational Mode Summary/Mission Profile (OMS/MP) in terms of Weapon Systems Acquisition for application to Systems Engineering method. For a systematic approach, a precise concept of OMS/MP is derived by analyzing the concept of conventional OMS/MP. This paper reviews the results of a series of previously reported examples aiming to develop the OMS/MP of a weapon system. Based on this, the limitations of the conventional OSM/MP applications are investigated. And these limitations can be resolved by the Fundamentals of Systems Engineering. Finally, the OMS/MP framework based on the Fundamentals of Systems Engineering has been proposed and is successfully implemented for the Harbor Underwater Surveillance System.

Localization of Barley yellow dwarf virus Movement Protein Modulating Programmed Cell Death in Nicotiana benthamiana

  • Ju, Jiwon;Kim, Kangmin;Lee, Kui-Jae;Lee, Wang Hu;Ju, Ho-Jong
    • The Plant Pathology Journal
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    • 제33권1호
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    • pp.53-65
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    • 2017
  • Barley yellow dwarf virus (BYDV) belongs to Luteovirus and is limited only at phloem related tissues. An open reading frame (ORF) 4 of BYDV codes for the movement protein (MP) of BYDV gating plasmodesmata (PD) to facilitate virus movement. Like other Luteoviruses, ORF 4 of BYDV is embedded in the ORF3 but expressed from the different reading frame in leaky scanning manner. Although MP is a very important protein for systemic infection of BYDV, there was a little information. In this study, MP was characterized in terms of subcellular localization and programmed cell death (PCD). Gene of MP or its mutant (ΔMP) was expressed by Agroinfiltration method. MP was clearly localized at the nucleus and the PD, but ΔMP which was deleted distal N-terminus of MP showed no localization to PD exhibited the different target with original MP. In addition to PD localization, MP appeared associated with small granules in cytoplasm whereas ΔMP did not. MP associated with PD and small granules induced PCD, but ΔMP showed no association with PD and small granules did not exhibit PCD. Based on this study, the distal N-terminal region within MP is seemingly responsible for the localization of PD and the induction small granules and PCD induction. These results suggest that subcellular localization of BYDV MP may modulate the PCD in Nicotiana benthamiana.

한국산 Thalictrum속 식물의 성분연구(II) 자주꿩의 다리 뿌리의 성분 (Isolation and Identification of Phenolic Tertiary and Quaternary Alkaloids from Thalictrum uchiyamai)

  • 이인란
    • 약학회지
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    • 제28권3호
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    • pp.185-190
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    • 1984
  • Protothalipine colorless needle crystal, mp $195-6^{\circ}$, $C_{21}H_{25}NO_{5}$) and jatrorrhizine chloride (Base A, orange needle crystal, mp $198^{\circ}$) are identified by chemical, spectral analysis, and comparison with authentic sample. Base B (reddish crystal, mp $192-4^{\circ}$) might be a artifact substance, which was changed from the jatrorrhizine chloride. Base C (yellowish needle crystal, mp $228~230^{\circ}$) and Base D (reddish needle crystal, mp $211~213^{\circ}$) were assumed to be thalifendine chloride, desoxythalidastine chloride by phytochemical and spectral analysis respectively.

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Calcium permeability of transient receptor potential canonical (TRPC) 4 channels measured by TRPC4-GCaMP6s

  • Ko, Juyeon;Myeong, Jongyun;Yang, Dongki;So, Insuk
    • The Korean Journal of Physiology and Pharmacology
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    • 제21권1호
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    • pp.133-140
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    • 2017
  • Conflicting evidence has been obtained regarding whether transient receptor potential cation channels (TRPC) are store-operated channels (SOCs) or receptor-operated channels (ROCs). Moreover, the Ca/Na permeability ratio differs depending on whether the current-voltage (I-V) curve has a doubly rectifying shape or inward rectifying shape. To investigate the calcium permeability of TRPC4 channels, we attached GCaMP6s to TRPC4 and simultaneously measured the current and calcium signals. A TRPC4 specific activator, (-)-englerin A, induced both current and calcium fluorescence with the similar time course. Muscarinic receptor stimulator, carbachol, also induced both current and calcium fluorescence with the similar time course. By forming heteromers with TRPC4, TRPC1 significantly reduced the inward current with outward rectifying I-V curve, which also caused the decrease of calcium fluorescence intensity. These results suggest that GCaMP6s attached to TRPC4 can detect slight calcium changes near TRPC4 channels. Consequently, TRPC4-GCaMP6s can be a useful tool for testing the calcium permeability of TRPC4 channels.