• 제목/요약/키워드: second

검색결과 63,186건 처리시간 0.058초

SECOND MAIN THEOREM FOR MEROMORPHIC MAPPINGS ON p-PARABOLIC MANIFOLDS INTERSECTING HYPERSURFACES IN SUBGENERAL POSITION

  • Yuehuan Zhu
    • 대한수학회보
    • /
    • 제60권6호
    • /
    • pp.1621-1639
    • /
    • 2023
  • In this paper, we give an improvement for the second main theorems of algebraically non-degenerate meromorphic maps from generalized p-parabolic manifolds into projective varieties intersecting hypersurfaces in subgeneral position with some index, which extends the results of Han [6] and Chen-Thin [3].

β-elemene Induces Caspase-dependent Apoptosis in Human Glioma Cells in vitro through the Upregulation of Bax and Fas/FasL and Downregulation of Bcl-2

  • Li, Chen-Long;Chang, Liang;Guo, Lin;Zhao, Dan;Liu, Hui-Bin;Wang, Qiu-Shi;Zhang, Ping;Du, Wen-Zhong;Liu, Xing;Zhang, Hai-Tao;Liu, Yang;Zhang, Yao;Xie, Jing-Hong;Ming, Jian-Guang;Cui, Yu-Qiong;Sun, Ying;Zhang, Zhi-Ren;Jiang, Chuan-Lu
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권23호
    • /
    • pp.10407-10412
    • /
    • 2015
  • Background: ${\beta}$-elemene, extracted from herb medicine Curcuma wenyujin has potent anti-tumor effects in various cancer cell lines. However, the activity of ${\beta}$-elemene against glioma cells remains unclear. In the present study, we assessed effects of ${\beta}$-elemene on human glioma cells and explored the underlying mechanism. Materials and Methods: Human glioma U87 cells were used. Cell proliferation was determined with MTT assay and colony formation assay to detect the effect of ${\beta}$-elemene at different doses and times. Fluorescence microscopy was used to observe cell apoptosis with Hoechst 33258 staining and change of glioma apoptosis and cell cycling were analyzed by flow cytometry. Real-time quantitative PCR and Western-blotting assay were performed to investigated the influence of ${\beta}$-elemene on expression levels of Fas/FasL, caspase-3, Bcl-2 and Bax. The experiment was divided into two groups: the blank control group and ${\beta}$-elemne treatment group. Results: With increase in the concentration of ${\beta}$-elemene, cytotoxic effects were enhanced in the glioma cell line and the concentration of inhibited cell viability ($IC_{50}$) was $48.5{\mu}g/mL$ for 24h. ${\beta}$-elemene could induce cell cycle arrest in the G0/G1 phase. With Hoechst 33258 staining, apoptotic nuclear morphological changes were observed. Activation of caspase-3,-8 and -9 was increased and the pro-apoptotic factors Fas/FasL and Bax were upregulated, while the anti-apoptotic Bcl-2 was downregulated after treatment with ${\beta}$-elemene at both mRNA and protein levels. Furthermore, proliferation and colony formation by U87 cells were inhibited by ${\beta}$-elemene in a time and does-dependent manner. Conclusions: Our results indicate that ${\beta}$-elemene inhibits growth and induces apoptosis of human glioma cells in vitro. The induction of apoptosis appears to be related with the upregulation of Fas/FasL and Bax, activation of caspase-3,-8 and -9 and downregulation of Bcl-2, which then trigger major apoptotic cascades.

Unified Parametric Approaches for Observer Design in Matrix Second-order Linear Systems

  • Wu Yun-Li;Duan Guang-Ren
    • International Journal of Control, Automation, and Systems
    • /
    • 제3권2호
    • /
    • pp.159-165
    • /
    • 2005
  • This paper designs observers for matrix second-order linear systems on the basis of generalized eigenstructure assignment via unified parametric approach. It is shown that the problem is closely related with a type of so-called generalized matrix second-order Sylvester matrix equations. Through establishing two general parametric solutions to this type of matrix equations, two unified complete parametric methods for the proposed observer design problem are presented. Both methods give simple complete parametric expressions for the observer gain matrices. The first one mainly depends on a series of singular value decompositions, and is thus numerically simple and reliable; the second one utilizes the right factorization of the system, and allows eigenvalues of the error system to be set undetermined and sought via certain optimization procedures. A spring-mass system is utilized to show the effect of the proposed approaches.

Estimation using response probability when missing data happen on the second occasion

  • Park, Hyeonah;Na, Seongryong
    • Journal of the Korean Data and Information Science Society
    • /
    • 제25권1호
    • /
    • pp.263-269
    • /
    • 2014
  • When the loss of samples appears under repeated surveys, new samples can often replace missing values. Estimators using response probability can be considered under repeated surveys on two occasions where new samples are selected instead of missing data on the second occasion. We propose a new estimator that uses both respondents and new samples on the second occasion. It is considered for the simulation setting that missing values can happen at the second occasion and are replaced by new samples. We can see that the proposed estimator is more efficient than that using a weighting adjustment method for respondents at the second occasion.

제2언어습득에서 부정적 피드백이 갖는 역할에 대한 비판적 고찰: 재조정 입력의 역할을 중심으로 (The role of negative feedback in second language acquisition with a focus on recasts)

  • 김현진
    • 영어어문교육
    • /
    • 제9권2호
    • /
    • pp.151-171
    • /
    • 2003
  • This paper critically reviewed the role of negative feedback in second language acquisition with a focus on recasts based on the findings of recent research investigating the effects of recasts on second language acquisition. First, recasts as negative feedbacks or negative evidence were reviewed in terms of Pinker's four criteria: the evidence of existence, availability, use, and necessity of recasts in second language acquisition. Second, the issue of the nature of recasts, whether they have benefits in SLA as a negative or positive evidence, was discussed with reference to Leeman(2003)'s research findings. Then, in relation to availability and use of recasts, the issue of the extent that they are noticed by learners was reviewed based on the findings from Philp(2003)'s study. Finally, the limitations of these two studies and the research orientation of future study were mentioned.

  • PDF

ON SOME GEOMETRIC PROPERTIES OF QUADRIC SURFACES IN EUCLIDEAN SPACE

  • Ali, Ahmad T.;Aziz, H.S. Abdel;Sorour, Adel H.
    • 호남수학학술지
    • /
    • 제38권3호
    • /
    • pp.593-611
    • /
    • 2016
  • This paper is concerned with the classifications of quadric surfaces of first and second kinds in Euclidean 3-space satisfying the Jacobi condition with respect to their curvatures, the Gaussian curvature K, the mean curvature H, second mean curvature $H_{II}$ and second Gaussian curvature $K_{II}$. Also, we study the zero and non-zero constant curvatures of these surfaces. Furthermore, we investigated the (A, B)-Weingarten, (A, B)-linear Weingarten as well as some special ($C^2$, K) and $(C^2,\;K{\sqrt{K}})$-nonlinear Weingarten quadric surfaces in $E^3$, where $A{\neq}B$, A, $B{\in}{K,H,H_{II},K_{II}}$ and $C{\in}{H,H_{II},K_{II}}$. Finally, some important new lemmas are presented.

모델식의 2차 근사에 의한 정량적인 초음파 단층 촬영 알고리즘 (A Quantitative Ultrasound Tomography Algorithm Via the Second Order Approximation of the Model Equation)

  • 김환우;김영길
    • 전자공학회논문지B
    • /
    • 제29B권11호
    • /
    • pp.16-21
    • /
    • 1992
  • The validity of the application of the second-order Born equation to the ultrasound tomography algorithm is studied by comparing the scattered fields computed using the first-order Born equation, the first-order Rytove equation, and the second-order Born equation. The second-order Born equation turns out to provide more desirable results than the other two equations for a certain group of test objects. Phantom images with resolutions upto 1 pixel$\times$1 pixel are satisfactorily reconstructed using the second-order Born equation. It is shown that when the view angle is limited, good resonstruction results are also obtained using multi-frequency incident fields.

  • PDF

Practical (Second) Preimage Attacks on the TCS_SHA-3 Family of Cryptographic Hash Functions

  • Sekar, Gautham;Bhattacharya, Soumyadeep
    • Journal of Information Processing Systems
    • /
    • 제12권2호
    • /
    • pp.310-321
    • /
    • 2016
  • TCS_SHA-3 is a family of four cryptographic hash functions that are covered by a United States patent (US 2009/0262925). The digest sizes are 224, 256, 384 and 512 bits. The hash functions use bijective functions in place of the standard compression functions. In this paper we describe first and second preimage attacks on the full hash functions. The second preimage attack requires negligible time and the first preimage attack requires $O(2^{36})$ time. In addition to these attacks, we also present a negligible time second preimage attack on a strengthened variant of the TCS_SHA-3. All the attacks have negligible memory requirements. To the best of our knowledge, there is no prior cryptanalysis of any member of the TCS_SHA-3 family in the literature.

맥동관냉동기의 2차속도와 온도 (Second-order velocity and temperature in pulse tube refrigerators)

  • 이호진;채왕병;정은수
    • 설비공학논문집
    • /
    • 제9권2호
    • /
    • pp.239-248
    • /
    • 1997
  • Steady components and unsteady components of second-order velocity and temperature within pulse tube refrigerators were obtained. Second-order solutions were obtained from the first-order solutions of continuity, momentum and energy equations, assuming that the amplitude of the piston motion is small. The axial temperature gradient was considered in the analysis. The flow direction of the streaming was consistent with previous experimental observations. Effects of axial temperature gradient on secondary flow and second-order temperature were shown.

  • PDF