Orbital stability of periodic waves for the nonlinear Schroedinger equation

The nonlinear Schroedinger equation has several families of quasi-periodic travelling waves, each of which can be parametrized up to symmetries by two real numbers: the period of the modulus of the wave profile, and the variation of its phase over a period (Floquet exponent). In the defocusing case, we show that these travelling waves are orbitally stable within the class of solutions having the same period and the same Floquet exponent. This generalizes a previous work where only small amplitude solutions were considered. A similar result is obtained in the focusing case, under a non-degeneracy condition which can be checked numerically. The proof relies on the general approach to orbital stability as developed by Grillakis, Shatah, and Strauss, and requires a detailed analysis of the Hamiltonian system satisfied by the wave profile.Comment: 34 pages, 7 figure

Effects of high temperature on survival, symbiotic performance and genomic modifications of bean nodulating Rhizobium strains.

High temperatures can affect the survival, establishment and symbiotic properties of Rhizobium strains. Bean nodulating Rhizobium strains are considered particularly sensitive because on this strains genetic recombinations and/or deletions occur frequently, thus compromising the use of these bacteria as inoculants. Rhizobium tropici and R. leguminosarum bv. phaseoli strains isolated from cerrado soils were exposed to thermal stress and the strains' growth, survival and symbiotic relationships as well as alterations in their genotypic and phenotypic characteristics were analysed. After successive thermal shocks at 45 degrees C for four hours, survival capacity appeared to be strain-specific, independent of thermo-tolerance and was more apparent in R. tropici strains. Certain R. leguminosarum bv. phaseoli strains had significant alterations in plant dry weight and DNA patterns obtained by AP-PCR method. Rhizobium tropici strains (with the exception of FJ2.21) were more stable than R. leguminosarum bv. phaseoli strains because no significant phenotypic alterations were observed following thermal treatments and they maintained their original genotypic pattern after inoculation in plants.

Lenguaje y conflicto: ¿imperativo necesario?

The language constitutes a true evidence of human evolution. Through the years, it has participated in the changes of mankind and in some way, it has influenced existing conflicts and their solutions. In this article, we want to raise some ideas that allow us to see how the language, as well as the human being, has been co-evolving to the point that it has been slowly positioning it in the decisions affecting the development of the individual. We also want to show how through the language it can be possible not only to understand the conflict, but to learn and build up with it.El lenguaje se constituye en una evidencia cierta de la evolución de la humanidad. A lo largo de los años ha participado en los cambios de la humanidad y de una u otra forma ha influido en los conflictos existentes, así como en sus soluciones. En este artículo de reflexión queremos plantear algunas ideas que permiten ver cómo el lenguaje, al igual que el hombre, ha ido evolucionando hasta tal punto que se ha ido posicionando cada vez más en las decisiones que afectan el desarrollo del individuo. También queremos mostrar, cómo a través del lenguaje se puede, no sólo entender el conflicto, sino aprender y construir con él

Computational identification of disease models through cross-species phenotype comparison.

The use of standardised phenotyping screens to identify abnormal phenotypes in mouse knockouts, together with the use of ontologies to describe such phenotypic features, allows the implementation of an automated and unbiased pipeline to identify new models of disease by performing phenotype comparisons across species. Using data from the International Mouse Phenotyping Consortium (IMPC), approximately half of mouse mutants are able to mimic, at least partially, the human ortholog disease phenotypes as computed by the PhenoDigm algorithm. We found the number of phenotypic abnormalities in the mouse and the corresponding Mendelian disorder, the pleiotropy and severity of the disease, and the viability and zygosity status of the mouse knockout to be associated with the ability of mouse models to recapitulate the human disorder. An analysis of the IMPC impact on disease gene discovery through a publication-tracking system revealed that the resource has been implicated in at least 109 validated rare disease-gene associations over the last decade

Homoclinic standing waves in focussing DNLS equations --Variational approach via constrained optimization

We study focussing discrete nonlinear Schr\"{o}dinger equations and present a new variational existence proof for homoclinic standing waves (bright solitons). Our approach relies on the constrained maximization of an energy functional and provides the existence of two one-parameter families of waves with unimodal and even profile function for a wide class of nonlinearities. Finally, we illustrate our results by numerical simulations.Comment: new version with revised introduction and improved condition (A3); 16 pages, several figure

Capítulo IV: caracterización morfo-agronómica de especies y variedades botánicas del genero Lycopersicon

En condiciones de invernadero se renovó la semilla de 58 introducciones del género Lycopersicon. En condiciones de campo se evaluaron cerca de 30 plantas de cada una de las introducciones viables. Además, se realizaron 5 cruzamientos, incluyendo los recíprocos, entre cada una de las introducciones viables y las variedades experimentales Chonto-109 y Napoli-1457. De 58 introducciones solo 16 produjeron semilla viable (L. hirsutum-1408, L. glandulusum   1403 y 1404, L. peruvianum-613 y 1409, L. pimpinellifolium-615, L. esculentum-633, L. pennelli- 632, L. esculentum var. ceraciforme- 183, 616. 923, 1140, 1506 Y 1508, L. esculentum varo grandifolium -1217, L. esculentum validum- 1110). Hubo gran variabilidad en emergencia, precocidad, duración de cosecha, cuajamiento de flores, rendimiento y sus componentes, análisis físico-químico de frutos entre las diferentes introducciones. L. peruvianum- 613 y 1409, L. glandulosum- 1403 y 1404 y L. pimpinellifolium 615 presentaron poco ataque de Scrobipalpula absoluta. Las variedades botánicas de L. esculentum presentaron mayores eficiencias de cruzamiento (84.3 %) que las especies de Lycopersicon (27.7 %), cuyas eficiencias fueron: L. esculentum (75%), L. pimpinellifolium (50%), L. hirsutum (40%), L. glandulosum (5%) y L. peruvianum (2.5%).The seeds from 58 introductions of the genus Lycopersicon were multiplied in the glasshouse. Thirty seeding of each introductions producing germinated seed were planted for to observe the characteristics of agronomical interest. Five reciprocal crosses were made with two experimental varieties (Chonto-1091 and Napoli-1457) with the purpose of to study the crossing efficiency of the introductions. From 58 introductions planted on1y 16 produced germinated seeds (L. hirsutum- 1408, L. g1andulosum- 1403 y 1404, L. peruvianum-613 y 1409 L. pimpinellifolium- 615, L. esculentum-633 S. pennelli- 632 L. esculentum var. ceraciforme- 183, 616. 923, 1140, 1506 y 1508 L. esculentum grandifolium -1217 L. esculentum validum- 1110). The was great variability in emergence, precocity, harvest  interval, fruit flower relationsphip, yield, and in the chemical and physical anaIisys of the fruits. L. peruvianum- 613 and 1409, L. glandulosum- 1403 and 1404; L. pimpinellifolium 615 did not show a severe attack of Scrobipalpula absoluta. The varieties of L. esculentum had higher crossing efficiency (84.3 %) then the species of Lycopersicon (27.7%). In Lycopersicon species the efficiencies were: L. esculentum (75%); L. pimpinellifolium (50%); L. hirsutum (40%), L. glandulosum (5%) and L. peruvianum (2.5%)

Análisis de la tecnología local de producción de frijol soya en zonas potenciales del Meta y Casanare

sumarios (En, Es)El documento presenta las Características principales de cada uno de los municipios y hace énfasis en la tecnología local para el cultivo del fríjol soya- El trabajo se inició con una recopilación de información secundaria acerca de las características biofísicas de los municipios y mediante entrevistas con funciona ríos de las entidades departamentales del sector agropecuario. En una segunda etapa se procedió a reunir información de los profesionales de las UMATA, asistentes técnicos, distribuidores de insumos, agentes comercializadores y productores agrícolas. El ejercicio se realizó durante los tres últimos meses del año 2000 y el primer mes del año 2001 v se adelantó por parte de un equipo interdisciplinario. constituidos por profesionales de la oficina de planeación y del programa regional de transferencia de tecnología de la regional ochoSoya-Soja- Glycine ma

Metastatic melanoma in an esophagus demonstrating Barrett esophagus with high grade dysplasia

BACKGROUND: Metastatic melanoma involving the esophagus is rare; the occurrence of metastatic melanoma in a background of Barrett esophagus is rarer still. We report a case of an 80 year-old male who presented to our institution for workup of Barrett esophagus with high-grade dysplasia and who proved to have metastatic melanoma occurring in the background of Barrett esophagus, the first report of this kind, to our knowledge, in the English literature. CASE PRESENTATION: An 80 year-old Caucasian male was diagnosed at an outside institution with Barrett’s esophagus with high grade dysplasia and presented to our institution for therapy. The patient underwent endoscopic mucosal resection using a band ligation technique of an area of nodularity within the Barrett esophagus. Microscopic examination demonstrated extensive Barrett esophagus with high-grade dysplasia as well as a second tumor which was morphologically different from the surrounding high-grade dysplasia and which was positive for S-100, HMB 45 and Melan-A on immunohistochemistry, consistent with melanoma. Further workup of the patient demonstrated multiple radiologic lesions consistent with metastases. Molecular studies demonstrated that the melanoma was positive for the 1799T>A (V600E) mutation in the BRAF gene. The overall features of the tumor were most consistent with metastatic melanoma occurring in a background of Barrett esophagus with high-grade dysplasia. CONCLUSION: This case demonstrates a unique intersection between a premalignant condition (Barrett esophagus with high grade dysplasia) and a separate malignancy (melanoma). This report also shows the utility of molecular testing to support the hypothesis of primary versus metastatic disease in melanoma

Co-periodic stability of periodic waves in some Hamiltonian PDEs

International audienceThe stability theory of periodic traveling waves is much less advanced than for solitary waves, which were first studied by Boussinesq and have received a lot of attention in the last decades. In particular, despite recent breakthroughs regarding periodic waves in reaction-diffusion equations and viscous systems of conservation laws [Johnson–Noble–Rodrigues–Zumbrun, Invent math (2014)], the stability of periodic traveling wave solutions to dispersive PDEs with respect to 'arbitrary' perturbations is still widely open in the absence of a dissipation mechanism. The focus is put here on co-periodic stability of periodic waves, that is, stability with respect to perturbations of the same period as the wave, for KdV-like systems of one-dimensional Hamiltonian PDEs. Fairly general nonlinearities are allowed in these systems, so as to include various models of mathematical physics, and this precludes complete integrability techniques. Stability criteria are derived and investigated first in a general abstract framework, and then applied to three basic examples that are very closely related, and ubiquitous in mathematical physics, namely, a quasilinear version of the generalized Korteweg–de Vries equation (qKdV), and the Euler–Korteweg system in both Eulerian coordinates (EKE) and in mass Lagrangian coordinates (EKL). Those criteria consist of a necessary condition for spectral stability , and of a sufficient condition for orbital stability. Both are expressed in terms of a single function, the abbreviated action integral along the orbits of waves in the phase plane, which is the counterpart of the solitary waves moment of instability introduced by Boussinesq. However, the resulting criteria are more complicated for periodic waves because they have more degrees of freedom than solitary waves, so that the action is a function of N + 2 variables for a system of N PDEs, while the moment of instability is a function of the wave speed only once the endstate of the 1 solitary wave is fixed. Regarding solitary waves, the celebrated Grillakis–Shatah– Strauss stability criteria amount to looking for the sign of the second derivative of the moment of instability with respect to the wave speed. For periodic waves, stability criteria involve all the second order, partial derivatives of the action. This had already been pointed out by various authors for some specific equations, in particular the generalized Korteweg–de Vries equation — which is special case of (qKdV) — but not from a general point of view, up to the authors' knowledge. The most striking results obtained here can be summarized as: an odd value for the difference between N and the negative signature of the Hessian of the action implies spectral instability, whereas a negative signature of the same Hessian being equal to N implies orbital stability. Furthermore, it is shown that, when applied to the Euler–Korteweg system, this approach yields several interesting connexions between (EKE), (EKL), and (qKdV). More precisely, (EKE) and (EKL) share the same abbreviated action integral, which is related to that of (qKdV) in a simple way. This basically proves simultaneous stability in both formulations (EKE) and (EKL) — as one may reasonably expect from the physical point view —, which is interesting to know when these models are used for different phenomena — e.g. shallow water waves or nonlinear optics. In addition, stability in (EKE) and (EKL) is found to be linked to stability in the scalar equation (qKdV). Since the relevant stability criteria are merely encoded by the negative signature of (N + 2) × (N + 2) matrices, they can at least be checked numerically. In practice, when N = 1 or 2, this can be done without even requiring an ODE solver. Various numerical experiments are presented, which clearly discriminate between stable cases and unstable cases for (qKdV), (EKE) and (EKL), thus confirming some known results for the generalized KdV equation and the Nonlinear Schrödinger equation, and pointing out some new results for more general (systems of) PDEs

Caracterización de los sistemas de producción agropecuarios en los municipios de Granada y Cumaral - Meta.

Informe técnico elaborado con la participación directa de productores, gremios y entidades, en el que se presenta un conocimiento detallado de las condiciones biofísicas y aspectos socioeconómicos de dos municipios del departamento del Meta. A partir de información general del área de estudio, se analizan los componentes: socioeconómico, físico y biótico, se establecen las jerarquías de caracterización de los sistemas de producción agropecuarios, de determinan los resultados en términos de las unidades biofísicas de tierra, de los arreglos agropecuarios y de los sistemas tipo o modales, se analizan las circunstancias y aspectos de comercialización de las actividades agrícola y pecuaria, se detalla la capacidad de uso de los suelos, se describen los conflictos de usos y se definen los limitantes edáficos a la producción agropecuaria. Finalmente se consignan las recomendaciones pertinente