• Title/Summary/Keyword: APA

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Vertical Profiles of Alkaline Phosphatase Activity in Dam Reservoirs and its Relation with Microbial Parameters (댐 저수지에서 alkaline phosphatase 활성의 수직변화와 미생물 요인들과의 상관관계)

  • Nakagawa, Ayumi;Kagawa, Hisanori;Hiroshi, Hirotani
    • Korean Journal of Ecology and Environment
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    • v.37 no.4 s.109
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    • pp.406-410
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    • 2004
  • The alkaline phosphatase activity (APA) of two dam reservoirs and inflowing streams were measured monthly in 2000. During summer months in 2001, the vertical profiles of APA and related parameters were also examined in one of the reservoirs. The APA was relatively high during the summer season in the epilimnion while it was almost invariable in the hypolimnion. A small increase in APA was observed at just above the bottom. The APA fluctuation was independent of the concentration of soluble reactive phosphorus. It was assumed that APA is not indicative of the phosphorus availability status. An examination of size-fractionated samples suggested that APA in reservoirs was attached to particles larger than $0.4{\mu}m$, whereas in streams it existed in a dissolved form. There was a positive significant correlation between chlorophyll a concentration and APA in the photic zone. In the aphotic zone, APA correlated positively with the colony count of heterotrophic bacteria, but not with microscopic total bacterial counts.

Sequential Polyadenylation to Enable Alternative mRNA 3' End Formation

  • Yajing Hao;Ting Cai;Chang Liu;Xuan Zhang;Xiang-Dong Fu
    • Molecules and Cells
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    • v.46 no.1
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    • pp.57-64
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    • 2023
  • In eukaryotic cells, a key RNA processing step to generate mature mRNA is the coupled reaction for cleavage and polyadenylation (CPA) at the 3' end of individual transcripts. Many transcripts are alternatively polyadenylated (APA) to produce mRNAs with different 3' ends that may either alter protein coding sequence (CDS-APA) or create different lengths of 3'UTR (tandem-APA). As the CPA reaction is intimately associated with transcriptional termination, it has been widely assumed that APA is regulated cotranscriptionally. Isoforms terminated at different regions may have distinct RNA stability under different conditions, thus altering the ratio of APA isoforms. Such differential impacts on different isoforms have been considered as post-transcriptional APA, but strictly speaking, this can only be considered "apparent" APA, as the choice is not made during the CPA reaction. Interestingly, a recent study reveals sequential APA as a new mechanism for post-transcriptional APA. This minireview will focus on this new mechanism to provide insights into various documented regulatory paradigms.

Comparison of shear bond strength according to various surface treatment methods of zirconia and resin cement types (지르코니아의 다양한 표면처리 방법과 레진시멘트 종류에 따른 전단결합강도 비교)

  • Bae, Ji-Hyeon;Bae, Gang-Ho;Park, Taeseok;Huh, Jung-Bo;Choi, Jae-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.59 no.2
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    • pp.153-163
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    • 2021
  • Purpose: The aim of this study was to evaluate the effects of four surface treatment methods to improve zirconia roughness and three types of resin cement on the shear bond strength (SBS). Materials and methods: A total of 120 zirconia blocks were randomly divided into four surface treatments: non-treatment (Control), airborne-particle abrasion (APA) with 50 ㎛ Al2O3 (APA50), APA with 125 ㎛ Al2O3 (APA125), and ZrO2 slurry (ZA). Three resin cements (Panavia F 2.0, Superbond C&B, and Variolink N) were applied to the surface-treated zirconia specimens. All specimens were subjected to SBS testing using a universal testing machine. The surface of the representative specimens of each group was observed by scanning electron microscope (SEM). SBS data were analyzed with oneway ANOVA, two-way ANOVA test and post-hoc Tukey HSD Test (α=.05). Results: In the surface treatment method, APA125, APA50, ZA, and Control showed high shear bond strength in order, but there was no significant difference between APA125 and APA50 (P>.05). Also, ZA showed significantly higher shear bond strength than Control (P<.05). In the resin cement type, Panavia F 2.0, Superbond C&B, and Variolink N showed significantly higher shear bond strength in order (P<.05). In SEM images, the zirconia surfaces of the APA50 and APA125 showed quite rough and irregular shapes, and the zirconia surface of the ZA was observed small irregular porosity and rough surfaces. Conclusion: APA and ZrO2 slurry were enhanced the surface roughness of zirconia, and Panavia F 2.0 containing MDP showed the highest shear bond strength with zirconia.

An Adaptive Decision-Directed Equalizer using Iterative Hyperplane Projection for SIMO systems (IHP 알고리즘을 이용한 SIMO 시스템용 적응 직접 결정 등화기 연구)

  • Lee Won-Cheol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.1C
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    • pp.82-91
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    • 2005
  • This paper introduces an efficient affine projection algorithm(APA) using iterative hyperplane projection. Among various fast converging adaptation algorithms, APA has been preferred to be employed for various applications due to its inherent effectiveness against the rank deficient problem. However, the amount of complexity of the conventional APA could not be negligible because of the accomplishment of sample matrix inversion(SMI). Moreover, the 'shifting invariance property' usually exploited in single channel case does not hold for the application of space-time decision-directed equalizer(STDE) deployed in single-input-multi-output(SIMO) systems. Thus, it is impossible to utilize the fast adaptation schemes such as fast transversal filter(FlF) having low-complexity. To accomplish such tasks, this paper introduces the low-complexity APA by employing hyperplane projection algorithm, which shows the excellent tracking capability as well as the fast convergence. In order to confirm th validity of the proposed method, its performance is evaluated under wireless SIMO channel in respect to bit error rate(BER) behavior and computational complexity.

Enhancement of Immune Response by New Herb Mixture, APA-01, in Mice (한방혼합액 APA-01의 면역 증강 효과)

  • Lee Young Sun;Han Ok Kyung;Park Chan Woo;Jeon Tae Won;Lee Eun Sil;Shin Sang Woo;Kim Kwang Joong;Kim Hyo Jung
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.3
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    • pp.483-489
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    • 2002
  • APA-01, which is an aqueous extract of five Chinese herbs, is a modified formula of Huoxiang-Zhengqi-San. The effect of new herb extract on immune response was investigated. The parameter examined to assess apparent immune response of APA-01 in mice included changes of body weight, relative weight of immune organs, cell proliferation and cytokine gene expression. The body weight and relative weight of immune organs were not significantly changed among the tested groups. In the spleen cell prolijeration assay, APA-01 increased the cell proliferation in a dose-dependent manner. Methotrexate (MTX), an agent of immune suppression, inhibited the spleen cell proliferation (IC/sub 50/: 800㎍/㎖). However, APA-01 significantly inhibited the suppression of mouse spleen cell proliferation. Therefore, it seems that APA-01 has a reducing effect of immune suppression. Immunomodulatory effect of APA-01 was further investigated using reverse transcription polymerase chain reaction (RT-PCR) in mouse spleen cells. In RT-PCR test, APA-01 enhanced the expression of cyclooxygenase-2 (COX-2) mRNA in a dose-dependent manner. In spite of immune suppression by MTX, COX-2 mRNA was induced by co-treatment with APA-01. These results suggest that APA-01 stimulates the proliferation of spleen cells, regulates the expression of COX-2 mRNA, and accelerates the recovery of inhibition of spleen cell proliferation induced by MTX, thus providing the immunological basis for clinical benefit of APA-01.

The Validity of Activity Participation Assessment for School-Age Children (학령기 아동을 위한 활동 참여 평가도구(Activity Participation Assessment)의 타당도 연구)

  • Kim, Se-Yun
    • The Journal of Korean Academy of Sensory Integration
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    • v.17 no.1
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    • pp.19-29
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    • 2019
  • Objective : The aim of this study was to verify validity of the Activity Participation Assessment for school-age children. Methods : A questionnaire consisting of 30 items from the APA, 75 items from the PACS, and 55 items from the CAPE was administered to elementary school students. A total of 207 questionnaires were analyzed. Confirmatory factor analysis was performed to confirm the construct validity of the APA. Convergence validity and discriminant validity were verified with the average variance extracted (AVE) and the square of the correlation coefficient. The discriminant validity was the Pearson correlation coefficient of the APA, PACS, and CAPE. Results : The results of the analysis were as follows: 1) For construct validity, the goodness of fit of the modified hierarchical second-order factor model was found to be appropriate (p < .001), 2) For convergent validity, the AVE was higher than .50 for all latent variables, 3) For discriminant validity, the AVE of the latent variable was greater than the square of the correlation coefficient (0.239), 4) For concurrent validity, the correlation between the total sum of the APA and PACS scores showed a positive correlation in all domains, and the correlation coefficient ranged from .303 to .647 at a statistically significant level (p < .01), 5) The correlation coefficient between the total sum of the APA and CAPE scores was .490 for recreational activities, .329 for physical activities, .571 for social activities, .401 for skill-based activities, and .390 for self-improvement activities. All domains showed a positive correlation, and were statistically significant (p < .01). Conclusion : APA can be used as a valid assessment tool to measure the participation of school aged children.

Online Parameter Estimation of SPMSM using Affine Projection Algorithm (Affine Projection 알고리즘을 이용한 표면 부착형 영구자석 전동기의 온라인 파라미터 추정)

  • Moon, Byung-Hun;Kim, Hyoung-Woo;Choi, Joon-Young
    • The Transactions of the Korean Institute of Power Electronics
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    • v.23 no.1
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    • pp.66-71
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    • 2018
  • We propose an online parameter estimation method for surface-mounted permanent-magnet synchronous motor (SPMSM) using an affine projection algorithm (APA). The proposed method estimates parameters with two APAs based on the discrete-time model equation of SPMSM during motor operation. The first APA is designed to estimate inductance, and the second APA is designed to estimate resistance and flux linkage. However, in case when the d-axis current is controlled to 0A, the second APA cannot estimate resistance and flux linkage simultaneously because the matrix rank in APA becomes deficient. To overcome this problem, we temporarily inject a negative reference current input to the d-axis control loop, and the matrix in the APA then becomes full rank, which enables the simultaneous estimation of resistance and flux linkage. The proposed method is verified by PSIM simulation and an actual experiment, and the results reveal that SPMSM parameters can be estimated online during motor operation.

Suggestion for Determination of Minimum $S_D$ for Rut-Resistable Asphalt Concretes (고온 내변형 아스팔트혼합물 선정을 위한 변형강도 임계치 결정 방안)

  • Kim, Kwang-W.;Cho, Byung-J.;Lee, Soon-Jae;Doh, Young-S.
    • International Journal of Highway Engineering
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    • v.9 no.4
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    • pp.193-204
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    • 2007
  • Deformation strength($S_D$) is a property which shows relatively good correlation with rut resistance of asphalt mixtures at high temperature. The Asphalt Pavement Analyzer (APA) is widely used as an equipment for estimating rut resistance of asphalt mixtures. The APA was used as corresponding property of the $S_D$ to estimate rutting resistance of asphalt mixtures. Many data were collected to establish the correlation of $S_D$ with APA. For $S_D$ test, the specimen is submerged into the $60^{\circ}C$ water for 30 minutes before applying a vertical load at the speed of 50mm/min to obtain peak load (P) and deformation (y) for $S_D$ calculation. For the same materials, APA test was performed. Relation of the $S_D$ with APA rut depth was evaluated using regression analysis. The $R^2$ value was 0.76, indicating this simple test procedure being a possible method for predicting deformation resistance of asphalt concretes at high temperature. It was also shown that, using the regression model, minimum value(s) of $S_D$ of surface course asphalt mixture or binder course for a particular road level can be determined. The limit values may be possible to use as cut-off value(s) of asphalt mixtures for the layer after further elaborated studies.

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Variable Dimension Affine Projection Algorithm (가변 차원 인접투사 알고리즘)

  • Choi, Hun;Kim, Dae-Sung;Bae, Hyeon-Deok
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.5
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    • pp.410-416
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    • 2003
  • In the affine projection algorithm(APA), the projection dimension depends on a number of projection basis and of elements of input vector used for updating of coefficients of the adaptive filter. The projection dimension is closely related to a convergence speed of the APA, and it determines computational complexity. As the adaptive filter approaches to steady state, convergence speed is decreased. Therefore it is possible to reduce projection dimension that determines convergence speed. In this paper, we proposed the variable dimension affine projection algorithm (VDAPA) that controls the projection dimension and uses the relation between variations of coefficients of the adaptive filter and convergence speed of the APA. The proposed method reduces computational complexity of the APA by modifying the number of projection basis on convergence state. For demonstrating the good performances of the proposed method, simulation results are compared with the APA and normalized LMS algorithm in convergence speed and computational quantity.

Concentration of 6-Amonopenicillanic Acid from Penicillin Bioconversion Solution and Its Mother Liquor by Nanofiltration Membrane

  • Xuejun Cao;Wu, Xing-Yan;Tong Wu;Keming Jin;Hur, Byung-Ki
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.6 no.3
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    • pp.200-204
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    • 2001
  • In this study, nanofiltration was applied to the concentration of the 6-aminopenicillinic acid (6-APA) from bioconverted penicillin solution and also to its mother liquor. The 6-APA in the solution was concentrated from 0.211 mol/L to 0.746 mol/L by nanofiltration. The final maximum concentration was 3.6 times higher than the initial concentration an the recovery yield was 97% to 99% of the original 6-APA. The concentrated solution was crystallized with the yields of 88.9-90.2% and the purity of the crystallized product was about 98%. The concentration of 6-APA in the mother liquor after crystallization was 0.014 mol/L and thus was concentrated 20-30 fold by nanofiltration and crystallization. The recovery of 6-APA was over 98%. The salts contained in the mother liquor, such as NH$_4$Cl and KCl, could be removed by allowing them to permeate through the membrane.

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