4,051 research outputs found
Sharp weighted estimates for multi-frequency Calder\'on-Zygmund operators
In this paper we study weighted estimates for the multi-frequency
Calder\'{o}n-Zygmund operators associated with the frequency set
and modulus of continuity
satisfying the usual Dini condition. We use the modern method of domination by
sparse operators and obtain bounds for the exponents of and characteristic
Quantitative weighted estimates for Rubio de Francia's Littlewood--Paley square function
We consider the Rubio de Francia's Littlewood--Paley square function
associated with an arbitrary family of intervals in with finite
overlapping. Quantitative weighted estimates are obtained for this operator.
The linear dependence on the characteristic of the weight turns
out to be sharp for , whereas the sharpness in the range
remains as an open question. Weighted weak-type estimates in the endpoint
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
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
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
Cosmic ray intensity distribution perpendicular to solar equatorial plane at 1 A.U. during 1978-83
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
Symptomatic giant left atrial aneurysm in a child : a rare entity
Isolated left atrial aneurysms are rare entities in clinical practice. Usually the
condition is diagnosed in the second to fourth decades of life. The presence of
such lesions in the pediatric age group is scantily described. We present a 2
year boy who presented with complaints of excessive irritability, respiratory
distress and swelling of the feet. On examination, child was tachypnoeic with
irregularly irregular rhythm. Echo showed a huge aneurysmal LA appendage
with severe left ventricle dysfunction. The child underwent surgical resection
for same. Findings were confirmed intraoperatively but he continued to have
low cardiac output state after the surgery, with frequent arrhythmias and
expired on day 7 of surgery. The case is reviewed and compared with the
available English literature.peer-reviewe
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