563 research outputs found

    Integral mean estimates for the polar derivative of a polynomial

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    Let P(z) P(z) be a polynomial of degree n n having all zeros in ∣z∣≤k|z|\leq k where k≤1,k\leq 1, then it was proved by Dewan \textit{et al} that for every real or complex number α\alpha with ∣α∣≥k|\alpha|\geq k and each r≥0r\geq 0 n(∣α∣−k){∫02π∣P(eiθ)∣rdθ}1r≤{∫02π∣1+keiθ∣rdθ}1rMax∣z∣=1∣DαP(z)∣. n(|\alpha|-k)\left\{\int\limits_{0}^{2\pi}\left|P\left(e^{i\theta}\right)\right|^r d\theta\right\}^{\frac{1}{r}}\leq\left\{\int\limits_{0}^{2\pi}\left|1+ke^{i\theta}\right|^r d\theta\right\}^{\frac{1}{r}}\underset{|z|=1}{Max}|D_\alpha P(z)|. \indent In this paper, we shall present a refinement and generalization of above result and also extend it to the class of polynomials P(z)=anzn+∑ν=μnan−νzn−ν,P(z)=a_nz^n+\sum_{\nu=\mu}^{n}a_{n-\nu}z^{n-\nu}, 1≤μ≤n,1\leq\mu\leq n, having all its zeros in ∣z∣≤k|z|\leq k where k≤1k\leq 1 and thereby obtain certain generalizations of above and many other known results.Comment: 8 page

    Do Campaign Contribution Limits Curb the Influence of Money in Politics?

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    Over 40% of countries around the world have adopted limits on campaign contributions to curb the influence of money in politics. Yet, we have limited knowledge on whether and how these limits achieve this goal. With a regression discontinuity design that uses institutional rules on contribution limits in Colombian municipalities, we show that looser limits increase the number and value of public contracts assigned to the winning candidate’s donors. The evidence suggests that this is explained by looser limits concentrating influence over the elected candidate among top donors and not by a reduction in electoral competition or changes in who runs for office. We further show that looser limits worsen the performance of donor-managed contracts: they are more likely to run over costs and require time extensions. Overall, this paper demonstrates a direct link between campaign contribution limits, donor kickbacks, and worse government contract performance

    Lp mean estimates for an operator preserving inequalities between polynomials

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    If P(z)P(z) be a polynomial of degree at most nn which does not vanish in ∣z∣<1|z| < 1, it was recently formulated by Shah and Liman \cite[\textit{Integral estimates for the family of BB-operators, Operators and Matrices,} \textbf{5}(2011), 79 - 87]{wl} that for every R≥1R\geq 1, p≥1p\geq 1, ∥B[P∘σ](z)∥p≤Rn∣Λn∣+∣λ0∣∥1+z∥p∥P(z)∥p,\left\|B[P\circ\sigma](z)\right\|_p \leq\frac{R^{n}|\Lambda_n|+|\lambda_{0}|}{\left\|1+z\right\|_p}\left\|P(z)\right\|_p, where BB is a Bn \mathcal{B}_{n}-operator with parameters λ0,λ1,λ2\lambda_{0}, \lambda_{1}, \lambda_{2} in the sense of Rahman \cite{qir}, σ(z)=Rz\sigma(z)=Rz and Λn=λ0+λ1n22+λ2n3(n−1)8\Lambda_n=\lambda_{0}+\lambda_{1}\frac{n^{2}}{2} +\lambda_{2}\frac{n^{3}(n-1)}{8}. Unfortunately the proof of this result is not correct. In this paper, we present a more general sharp LpL_p-inequalities for Bn\mathcal{B}_{n}-operators which not only provide a correct proof of the above inequality as a special case but also extend them for 0≤p<1 0 \leq p <1 as well.Comment: 16 Page

    Evaluation of allelopathic effect of Eclipta alba (L.) Hassk on biochemical activity of Amaranthus spinosus L., Cassia tora L. and Cassia sophera L.

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    A study was conducted to assess the magnitude of suppressing ability of Eclipta alba (L.) Hassk. on some selected weeds of Aligarh namely, Amaranthus spinosus L., Cassia tora L. and Cassia sophera L. The research finding was conducted to evaluate the effect of aqueous leaf leachate and organic fractions of donor plant on biochemical activities (carbohydrate content, chlorophyll content and protein content). The result shows that aqueous leachate and organic fractions reduced the level of biochemical activities. Carbohydrate content was increased in treated plants as compared to control while chlorophyll content and protein content were reduced as compared to the control. Aqueous leachate showed maximum toxicity on weeds than organic fractions. The reduction may be due to the allelochemicals present in E. alba leaves.Key words: Allelochemicals, aqueous leachate, organic fractions, chlorophyll content, carbohydrate content, Eclipta alba
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