185 research outputs found
On Global Solutions of a Zakharov type System
We consider a class of wave-Schroedinger systems with a Zakharov-Schulman
type coupling. This class of systems is indexed by a parameter gamma which
measures the strength of the null form in the nonlinearity of the wave
equation. The case gamma = 1 corresponds to the well-known Zakharov system,
while the case gamma = -1 corresponds to the Yukawa system. Here we show that
sufficiently smooth and localized Cauchy data lead to pointwise decaying global
solutions which scatter, for any gamma in (0,1].Comment: 19 pages. Minor changes, including titl
An unusual S-adenosylmethionine synthetase gene from dinoflagellate is methylated
Background: S-Adenosylmethionine synthetase (AdoMetS) catalyzes the formation of S-Adenosylmethionine (AdoMet), the major methyl group donor in cells. AdoMet-mediated methylation of DNA is known to have regulatory effects on DNA transcription and chromosome structure. Transcription of environmental-responsive genes was demonstrated to be mediated via DNA methylation in dinoflagellates. Results: A full-length cDNA encoding AdoMetS was cloned from the dinoflagellate Crypthecodinium cohnii. Phylogenetic analysis suggests that the CcAdoMetS gene, is associated with the clade of higher plant orthrologues, and not to the clade of the animal orthrologues. Surprisingly, three extra stretches of residues ( 8 to 19 amino acids) were found on CcAdoMetS, when compared to other members of this usually conserved protein family. Modeled on the bacterial AdeMetS, two of the extra loops are located close to the methionine binding site. Despite this, the CcAdoMetS was able to rescue the corresponding mutant of budding yeast. Southern analysis, coupled with methylation-sensitive and insensitive enzyme digestion of C. cohnii genomic DNA, demonstrated that the AdoMetS gene is itself methylated. The increase in digestibility of methylation-sensitive enzymes on AdoMet synthetase gene observed following the addition of DNA methylation inhibitors L-ethionine and 5-azacytidine suggests the presence of cytosine methylation sites within CcAdoMetS gene. During the cell cycle, both the transcript and protein levels of CcAdoMetS peaked at the G1 phase. L- ethionine was able to delay the cell cycle at the entry of S phase. A cell cycle delay at the exit of G2/M phase was induced by 5-azacytidine. Conclusion: The present study demonstrates a major role of AdoMet-mediated DNA methylation in the regulation of cell proliferation and that the CcAdoMetS gene is itself methylated
Duchon-Robert solutions for the Rayleigh-Taylor and Muskat problems
We construct analytic solutions to the Euler equations with an interface
between two fluids, extending work of Duchon and Robert. We also show that the
estimates of Duchon and Robert yield global analytic solutions to the Muskat
problem with small initial data.Comment: 18 pages. To appear, J. Diff. Eqn
Global wellposedness for a certain class of large initial data for the 3D Navier-Stokes Equations
In this article, we consider a special class of initial data to the 3D
Navier-Stokes equations on the torus, in which there is a certain degree of
orthogonality in the components of the initial data. We showed that, under such
conditions, the Navier-Stokes equations are globally wellposed. We also showed
that there exists large initial data, in the sense of the critical norm
that satisfies the conditions that we considered.Comment: 13 pages, updated references for v
Impacto de las presunciones tributarias en la determinación del impuesto a la renta e IGV en la empresa Modior Confecciones S.A.C. - PerÃodo 2017 (Art. 65º del Código Tributario)
Actualmente en nuestro paÃs, la industria textil se encuentra en un proceso de adaptación respecto al sinceramiento tributario, actualmente estas empresas omiten declarar ingresos a fin de evadir las obligaciones tributarias, en tal sentido la Administración Tributaria (SUNAT), viene desarrollando acciones de fiscalización con el objetivo de encontrar inconsistencias por las operaciones realizadas en el ejercicio 2017.
MODIOR CONFECCIONES S.A.C, ubicado en el Emporio Comercial de Gamarra, en el distrito de La Victoria, departamento de Lima, ante esta problemática y teniendo conocimiento de las posibles contingencias en las que puede incurrir, ha tomado la decisión de encargar al área contable realice una auditorÃa tributaria interna a fin de evitar que la SUNAT califique el incumplimiento como una defraudación tributaria.
La presente trata de identificar, de acuerdo a lo establecido en el artÃculo 65º de Código Tributario, el impacto de las presunciones tributarias, en la determinación del Impuesto a la Renta e Impuesto General a las Ventas - IGV, de la empresa por el perÃodo 2017, asà como también el cálculo de las multas e intereses y la gradualidad por subsanación voluntaria por la infracción tipificada en el numeral 1 de artÃculo 178 de Código Tributario.Trabajo de suficiencia profesionalCampus Lima Centr
Comercialización de tableta de chocolate hipocalórico libre de azúcar incluyendo insumos autóctonos del Perú
El trabajo que presentamos, se desarrolló como modelo de Plan de Negocios, con el propósito de lanzar un nuevo producto a base de cacao, el chocolate, solo que el concepto a usarse es diferente a lo tradicional ya existente en el Perú: un chocolate hipocalórico libre de azúcar. Para ello, se trabajará con productos autóctonos como el aguaymanto, el manà y las almendras (Anexo N° 11).
El presente Plan de Negocios tiene como objetivo ofrecer un chocolate a base de cacao, hipocalórico libre de azúcar, apto para las personas entre los 23 y 36 años, de los segmentos NSE A, B y C, afines al consumo saludable de los distritos de Santiago de Surco, San Miguel y Jesús MarÃa (Anexo N° 11). Asimismo, tiene como objetivo, desarrollar y posicionar KAMARI, como marca, en la mentalidad del consumidor dentro de las categorÃas de chocolate, de acuerdo con la Norma Técnica Peruana (Codex stan 87:2013). Los resultados de la investigación se han obtenido a través de la técnica de la encuesta, cuyo resultado determinó el comportamiento del consumidor.
El Plan de Negocio está estructurado en tres etapas: en la primera, se maquila el chocolate y se comercializa a través de los canales modernos (tiendas por conveniencia y especialidad) al público objetivo mencionado en el párrafo anterior. En la segunda etapa, se comercializa el chocolate en Lima Metropolitana a través de los canales modernos. Finalmente, en la tercera etapa se distribuye y comercializa en todo el PaÃs.Trabajo de investigaciónCampus Lima Centr
Local semicircle law at the spectral edge for Gaussian -ensembles
We study the local semicircle law for Gaussian -ensembles at the edge
of the spectrum. We prove that at the almost optimal level of
, the local semicircle law holds for all at
the edge. The proof of the main theorem relies on the calculation of the
moments of the tridiagonal model of Gaussian -ensembles up to the
-moment where . The result is the analogous to
the result of Sinai and Soshnikov for Wigner matrices, but the combinatorics
involved in the calculations are different.Comment: 16 pages, 2 figure
The road to deterministic matrices with the restricted isometry property
The restricted isometry property (RIP) is a well-known matrix condition that
provides state-of-the-art reconstruction guarantees for compressed sensing.
While random matrices are known to satisfy this property with high probability,
deterministic constructions have found less success. In this paper, we consider
various techniques for demonstrating RIP deterministically, some popular and
some novel, and we evaluate their performance. In evaluating some techniques,
we apply random matrix theory and inadvertently find a simple alternative proof
that certain random matrices are RIP. Later, we propose a particular class of
matrices as candidates for being RIP, namely, equiangular tight frames (ETFs).
Using the known correspondence between real ETFs and strongly regular graphs,
we investigate certain combinatorial implications of a real ETF being RIP.
Specifically, we give probabilistic intuition for a new bound on the clique
number of Paley graphs of prime order, and we conjecture that the corresponding
ETFs are RIP in a manner similar to random matrices.Comment: 24 page
- …