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Meiosis and Postmeiotic Mitosis in Boletus rubinellus (Boletus rubinellus에서 감수분열 및 감수분열후 유사분열)

  • 윤권상
    • Journal of Plant Biology
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    • v.30 no.4
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    • pp.225-247
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    • 1987
  • Meiosis and postmeiotic mitosis in Boletus rubinellus were examined ultrastructurally. Meriosis occurred at the apex of the basidium. A sausage-shaped spindle pole body(SPB) was observed along with the presence of synaptonemal complexes during pachytene and a diglobular SPB was present on late pachytene or diplotene nuclei. During metaphase I, the monoglobular SPB at the spindle pole was surrounded bya membrane and the nuclear enveloope was discontinuous. At anaphase I, the chromosomes became better defined and formed a central spindle. The nucleolus was extruded from the nucleus. During anaphase I, the SPB was excluded from the chromosomal region by a membrane and both poles were fully separated to opposite sides of the basidial wall. In meiosis II, the two nuclei divided synchronously and the spindles were parallel. The spindles were smaller than in meiosis I, while the SPB was approximately the same size as that of the similar stage in meiosis I. During anaphasetelophase II, the SPB was surrounded by a cap of endoplasmic reticulum (ER) that delimited it from the spindle. The postmeiotic interphase nuclei migrated to the mid-region of the basidium before migration to the spores. The SPB at this stage was diglobular. A postmeiotic mitosis occurred within the basidiospore, and the plane of the spindle was obique to the long axis of the spore. The spindle and SPB were smaller than at meiosis I and there were fewer nonchromosomal microtubules. At anaphase, the nucleolus was present inside the nuclear envelope but lateral to the spindle.

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Fringe-Order Determination Method in White-Light Phase-Shifting Interferometry for the Compensation of the Phase Delay and the Suppression of Excessive Phase Unwrapping

  • Kim, SeongRyong;Kim, JungHwan;Pahk, HeuiJae
    • Journal of the Optical Society of Korea
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    • v.17 no.5
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    • pp.415-422
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    • 2013
  • White-light phase-shifting interferometry (WLPSI) is widely recognized as a standard method to measure shapes with high resolution over a long distance. In practical applications, WLPSI, however, is associated with some degree of ambiguity of its phase, which occurs due to a phase delay, which is the offset between the phase of the fringes and the fringe envelope peak position. In this paper, a new algorithm is proposed for the determination of a fringe order suitable for samples in which the phase delay mainly occurs due to noise, diffraction and a steep angle. The concepts of the decouple factor and the connectivity are introduced and a method for calculating the decouple factor and the connectivity is developed. With the phase-unwrapping procedure which considers these values, it is demonstrated that our algorithm determines the correct fringe order. To verify the performance of the algorithm, a simulation was performed with the virtual step height under noise. Some specimens such as step height standard and a column spacer with a steep angle are also measured with a Mirau interference microscope, after which the algorithm is shown to be effective and robust.

Research on PAE of CMOS Class-E Power Amplifier For Multiple Antenna System (다중 안테나 시스템을 위한 CMOS Class-E 전력증폭기의 효율 개선에 관한 연구)

  • Kim, Hyoung-Jun;Joo, Jin-Hee;Seo, Chul-Hun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.12
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    • pp.1-6
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    • 2008
  • In this paper, bias control circuit structure have been employed to improve the power added efficiency of the CMOS class-E power amplifier on low input power level. The gate and drain bias voltage has been controlled with the envelope of the input RF signal. The proposed CMOS class-E power amplifier using bias controlled circuit has been improved the PAE on low output power level. The operating frequency is 2.14GHz and the output power is 22dBm to 25dBm. In addition to, it has been evident that the designed the structure has showed more than a 80% increase in PAE for flatness over all input power level, respectively.

Characterization of Binding Mode of the Heterobiaryl gp120 Inhibitor in HIV-1 Entry: A Molecular Docking and Dynamics Simulation Study

  • Gadhe, Changdev G.;Kothandan, Gugan;Cho, Seung Joo
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2466-2472
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    • 2013
  • Human immunodeficiency virus type-1 (HIV-1) is a causative agent of Acquired immunodeficiency syndrome (AIDS), which has affected a large population of the world. Viral envelope glycoprotein (gp120) is an intrinsic protein for HIV-1 to enter into human host cells. Molecular docking guided molecular dynamics (MD) simulation was performed to explore the interaction mechanism of heterobiaryl derivative with gp120. MD simulation result of inhibitor-gp120 complex demonstrated stability. Our MD simulation results are consistent with most of the previous mutational and modeling studies. Inhibitor has an interaction with the CD4 binding region. Van der Waals interaction between inhibitor and Val255, Thr257, Asn425, Met426 and Trp427 were important. This preliminary MD model could be useful in exploiting heterobiaryl-gp120 interaction in greater detail, and will likely to shed lights for further utilization in the development of more potent inhibitors.

Statistical Characteristics of Bottom Backscattering by a Moving Source at a Shallow Water Site (천해에서 이동음원으로 측정한 해저면 후방산란의 통계적 특성)

  • Park, J.S.;Jurng, M.S.;Chang, D.H.;Choi, J.Y.;Shim, Tae-Bo
    • The Journal of the Acoustical Society of Korea
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    • v.15 no.4
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    • pp.18-23
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    • 1996
  • Fluctuation statistics of scattering strength are not only important because they impact the performance of active sonar systems, but also because they may provide insight into the major scattering process. In this article, analysis of the statistical characteristics of bottom backscattering, measured in shallow water, are presented. The slowly moving experimental sonar was operated at 30kHz to gather data over the bottom. Spatial and temporal correlation functions of the signal amplitudes were measured. The distribution function and probability of false alarm function of the detected envelope of widebeam and narrowbeam signals were measured. An attempt was made to compare the results with existing theoretical models. The result suggests that the statistical characteristics of bottom backscattering fluctuation of moving source is differ from that of fixed source.

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A Normal Pregnancy and Delivery by Assisted Activation Following Roundheaded Spermatozoa (Globozoospermia) Injected into Oocytcs (구형정자의 난자내 미세주입 후 보조활성화술에 의한 임신과 분만 1례)

  • Joo, Jae-Hong;Lee, Yong-Chan;Yun, San-Hyun;Im, Jin-Ho;Park, Heum-Dai
    • Clinical and Experimental Reproductive Medicine
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    • v.27 no.3
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    • pp.301-305
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    • 2000
  • Globozoospermia is a rare type of teratozoospermia. It occurs in 0.1% of all andrological patient's and used to be considered sterile. Globozoospermic patient has 100% round headed spermatozoa, but the spermiogram is normal. The spermatozoa show oval-shape head, the lack of a nuclear envelope, acrosome, and post acrosomal sheath. Objective: To report that a couple with infertility secondary to globozoospermia received ICSI treatment. Material and Method: Case report Results: In the first trial, fertilization was failed. In the second trial, 40% of oocytes were fertilized and all of these embryos were cleaved, but pregnancy did not achieved. In the third trial, sperm injected oocytes were exposed to 10 ${\mu}M$ calcium ionophore for 15 min. All of the injected oocytes were fertilized and proceeded to develop. Triplet pregnancy was achieved after the transfer of six embryos in their third cycle. One embryo vanished and the remaining twins (female) were delivered at 33 weeks of gestation by Caesarean section. Conclusion: This result shows that assisted activation following ICSI may overcome infertility associated with globozoospermia.

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Wind tunnel model studies to predict the action of wind on the projected 558 m Jakarta Tower

  • Isyumov, N.;Case, P.C.;Ho, T.C.E.;Soegiarso, R.
    • Wind and Structures
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    • v.4 no.4
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    • pp.299-314
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    • 2001
  • A study of wind effects was carried out at the Boundary Layer Wind Tunnel Laboratory (BLWTL) for the projected 558-m high free-standing telecommunication and observation tower for Jakarta, Indonesia. The objectives were to assist the designers with various aspects of wind action, including the overall structural loads and responses of the Tower shaft and the antenna superstructure, the local wind pressures on components of the exterior envelope, and winds in pedestrian areas. The designers of the Tower are the East China Architectural Design Institute (ECADI) and PT Menara Jakarta, Indonesia. Unfortunately, the project is halted due to the financial uncertainties in Indonesia. At the time of the stoppage, pile driving had been completed and slip forming of the concrete shaft of the Tower had begun. When completed, the Tower will exceed the height of the CN-Tower in Toronto, Canada by some 5 m.

Experimental and numerical analysis of RC structure with two leaf cavity wall subjected to shake table

  • Onat, Onur;Lourenco, Paulo B.;Kocak, Ali
    • Structural Engineering and Mechanics
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    • v.55 no.5
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    • pp.1037-1053
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    • 2015
  • This paper presents finite element (FE) based pushover analysis of a reinforced concrete structure with a two-leaf cavity wall (TLCW) to estimate the performance level of this structure. In addition to this, an unreinforced masonry (URM) model was selected for comparison. Simulations and analyses of these structures were performed using the DIANA FE program. The mentioned structures were selected as two storeys and two bays. The dimensions of the structures were scaled 1:1.5 according to the Cauchy Froude similitude law. A shake table experiment was implemented on the reinforced concrete structure with the two-leaf cavity wall (TLCW) at the National Civil Engineering Laboratory (LNEC) in Lisbon, Portugal. The model that simulates URM was not experimentally studied. This structure was modelled in the same manner as the TLCW. The purpose of this virtual model is to compare the respective performances. Two nonlinear analyses were performed and compared with the experimental test results. These analyses were carried out in two phases. The research addresses first the analysis of a structure with only reinforced concrete elements, and secondly the analysis of the same structure with reinforced concrete elements and infill walls. Both researches consider static loading and pushover analysis. The experimental pushover curve was plotted by the envelope of the experimental curve obtained on the basis of the shake table records. Crack patterns, failure modes and performance curves were plotted for both models. Finally, results were evaluated on the basis of the current regulation ASCE/SEI 41-06.

Laboratory study on the modulation evolution of nonlinear wave trains

  • Dong, G.H.;Ma, Y.X.;Zhang, W.;Ma, X.Z.
    • Ocean Systems Engineering
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    • v.2 no.3
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    • pp.189-203
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    • 2012
  • New experiments focusing on the evolution characteristics of nonlinear wave trains were conducted in a large wave flume. A series of wave trains with added sidebands, varying initial steepness, perturbed amplitudes and frequencies, were physically generated in a long wave flume. The experimental results show that the increasing wave steepness, increases the speed of sidebands growth. To study the frequency and phase modulation, the Morlet wavelet transform is adopted to extract the instantaneous frequency of wave trains and the phase functions of each wave component. From the instantaneous frequency, there are local frequency downshifts, even an effective frequency downshift was not observed. The frequency modulation increases with an increase in amplitude modulation, and abrupt changes of instantaneous frequencies occur at the peak modulation. The wrapped phase functions show that in the early stage of the modulation, the phase of the upper sideband first diverges from that of the carrier waves. However, at the later stage, the discrepancy phase from the carrier wave transformed to the lower sideband. The phase deviations appear in the front of the envelope's peaks. Furthermore, the evolution of the instantaneous frequency exhibits an approximate recurrence-type for the experiment with large imposed sidebands, even when the corresponding recurrence is not observed in the Fourier spectrum.

Theoretical Review and Experiment on Applicability of Double Skin Facade Ventilated by Fans (팬을 부착한 이중외피의 이론적 검토 및 적용성에 대한 실험 연구)

  • Lim, Ji-Hye;Sohn, Jang-Yeul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.9
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    • pp.605-613
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    • 2010
  • Double skin facade(DSF) ventilated by fans consists of a normal external and an internal envelope. In this glass layer, the installed fan replaces an air inlet for the control of air flow through the cavity. The purpose of this paper is to investigate physical theory and to analyze the applicability of fans installed in a DSF. The experiment was conducted in 2 rooms. One room has a DSF with installed fans and the other one has a typical window. The room ventilated through a DSF which fans are installed was always kept warmer than the other room, ventilated directly from the outdoors. The average increase of the supplied air temperature through the DSF ventilated by fans was $6.54^{\circ}C$ at 78CMH, $6.2^{\circ}C$ at 95CMH, and $3.7^{\circ}C$ at 120CMH. As a result, the DSF with installed fans was appropriate for installation in rooms. It supplies outdoor fresh air heated through a cavity and ventilates a constant air volume.