4,081 research outputs found

    Sharp weighted estimates for multi-frequency Calder\'on-Zygmund operators

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    In this paper we study weighted estimates for the multi-frequency ω\omega-Calder\'{o}n-Zygmund operators TT associated with the frequency set Θ={ξ1,ξ2,,ξN}\Theta=\{\xi_1,\xi_2,\dots,\xi_N\} and modulus of continuity ω\omega satisfying the usual Dini condition. We use the modern method of domination by sparse operators and obtain bounds TLp(w)Lp(w)N1r12[w]Ap/rmax(1,1pr), 1r<p<,\|T\|_{L^p(w)\rightarrow L^p(w)}\lesssim N^{|\frac{1}{r}-\frac{1}{2}|}[w]_{\mathbb{A}_{p/r}}^{max(1,\frac{1}{p-r})},~1\leq r<p<\infty, for the exponents of NN and Ap/r\mathbb{A}_{p/r} characteristic [w]Ap/r[w]_{\mathbb{A}_{p/r}}

    Quantitative weighted estimates for Rubio de Francia's Littlewood--Paley square function

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    We consider the Rubio de Francia's Littlewood--Paley square function associated with an arbitrary family of intervals in R\mathbb{R} with finite overlapping. Quantitative weighted estimates are obtained for this operator. The linear dependence on the characteristic of the weight [w]Ap/2[w]_{A_{p/2}} turns out to be sharp for 3p<3\le p<\infty, whereas the sharpness in the range 2<p<32<p<3 remains as an open question. Weighted weak-type estimates in the endpoint p=2p=2 are also provided. The results arise as a consequence of a sparse domination shown for these operators, obtained by suitably adapting the ideas coming from Benea (2015) and Culiuc et al. (2016).Comment: 18 pages. Revised versio

    Control-structure interaction in a free beam

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    A simple energy approach to study the problem of control structure interactions in large space structures is presented. For the illustrative case of a free-free beam, the vibrational energy imparted during operation of constant, step, and pulsed thrusters is found in a nondimensional closed form. Then based on a parametric study, suggestions are made on the choice of parameters to minimize the control structure interactions. The study of this simple system provides physical insight and understanding for more complex systems

    Cross-Species Network Analysis Uncovers Conserved Nitrogen-Regulated Network Modules in Rice

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    In this study, we used a cross-species network approach to uncover nitrogen-regulated network modules conserved across a model and a crop species. By translating gene “network knowledge” from the data-rich model Arabidopsis (Arabidopsis thaliana) to a crop (Oryza sativa), we identified evolutionarily conserved N-regulatory modules as targets for translational studies to improve N-use efficiency in transgenic plants. To uncover such conserved N-regulatory network modules, we first generated a N-regulatory network based solely on rice (O. sativa) transcriptome and gene interaction data. Next, we enhanced the “network knowledge” in the rice N-regulatory network using transcriptome and gene interaction data from Arabidopsis and new data from Arabidopsis and rice plants exposed to the same N-treatment conditions. This cross-species network analysis uncovered a set of N-regulated transcription factors (TFs) predicted to target the same genes and network modules in both species. Supernode analysis of the TFs and their targets in these conserved network modules uncovered genes directly related to nitrogen use (e.g. N-assimilation) and to other shared biological processes indirectly related to nitrogen. This cross-species network approach was validated with members of two TF families in the supernode network, bZIP-TGA and HRS1/HHO family, have recently been experimentally validated to mediate the N-response in Arabidopsis.Fil: Obertello, Mariana. University of New York; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular ; ArgentinaFil: Shrivastava, Stuti. University of New York; Estados UnidosFil: Katari, Manpreet S.. University of New York; Estados UnidosFil: Coruzzi, Gloria M.. University of New York; Estados Unido

    Integrating diversity into the medical curriculum

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    In the field of medical education, diversity refers to the presence and representation of persons from a diversified range of personal backgrounds, experiences, and characteristics across the student community, faculty members, and employees in the institution. The scope of diversity in medical education is immense and it plays a vital role in creating an effective learning environment. Once students are exposed to a group of diverse students and patients during their undergraduate training, there is a significant improvement in cultural competence, which becomes crucial in our mission to deliver patient-centered care. Considering the merits of diversity in the medical curriculum for medical students, there is an indispensable need to take specific measures to ensure that diversity is integrated in the curriculum, as it will also ensure the delivery of equitable and culturally competent medical care. As important is to ensure the integration of diversity into medical curriculum, equal importance has to be given to the measurement of various initiatives that have been taken to promote diversity in medical education. In conclusion, diversity in medical education is the need of the hour to create a fruitful learning environment for medical students. This calls for the need to take measures for the integration of diversity into the medical curriculum and subsequently identify strategies and indicators to measure and monitor the progress of diversity initiatives in medical institutions

    Cosmic ray intensity distribution perpendicular to solar equatorial plane at 1 A.U. during 1978-83

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    The distribution of cosmic ray intensity perpendicular to solar equatorial plane, was investigated by using its yearly variation with respect to the heliolatitudinal position of the Earth, for the two intervals 1978 to 1980 and 1981 to 1983. The monthly mean values of two high latitude stations along with the solar and geomagnetic indices are used to derive the cosmic ray intensity distribution free from the changes due to variation in solar activity. The correction is found to be significant only during the interval 1976 to 1980. The results indicate a significant linear increase in cosmic ray intensity from north to south of solar equator, contrary to that observed during 1973 to 1975. No symmetrical gradients are found during the period of study, in agreement with earlier results
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