The SO(N) principal chiral field on a half-line

We investigate the integrability of the SO(N) principal chiral model on a half-line, and find that mixed Dirichlet/Neumann boundary conditions (as well as pure Dirichlet or Neumann) lead to infinitely many conserved charges classically in involution. We use an anomaly-counting method to show that at least one non-trivial example survives quantization, compare our results with the proposed reflection matrices, and, based on these, make some preliminary remarks about expected boundary bound-states.Comment: 7 pages, Late

Wheat lines, suffering structural rearrangements between wheat-1BS and rye-1RS chromosomes, display differential patterns of magnesium accumulation

Poster no. 238Two near isogenic lines, designated as 1RS and 1RW, resulting from the recombination of the rye (Secale cereale) chromosome 1RS with chromosome 1BS of bread wheat (Triticum aestivum), differ in a relatively small region of that short chromosome arm. We have recently reported that chromosome rearrangements in this region imply modifications in the dosage of some genes (including OPRIII codifying an enzyme involved in jasmonic acid (JA) biosynthesis pathway). This dosage difference confer differential drought resistance in a way primarily associated to the capacity of roots for soil exploration. An emerging question is whether or not those rearrangements also differentially influence plant mineral nutrition. In the present study we analyzed the ionome of 1RS and 1RW, which unveiled the existence of relevant differences in the distribution of magnesium (Mg) between the shoot and the root of these lines. Following this observation, we explored the physiological and molecular determinants of differential magnesium accumulation observed.Instituto de Recursos BiológicosFil: Gualano, L.D. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Moriconi, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Tranquilli, Gabriela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Santa-María, Guillermo E. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; Argentin

Physiological and genetic characterization of wheat lines sharply differing in sodium accumulation

Poster no. 129Improving nutrient use efficiency is an important objective in modern breeding programs. Our group attempts to elucidate the components that contribute to greater efficiencies of potassium (K) acquisition and utilization in wheat (Triticum aestivum), and its nexus with sodium (Na) dynamics.Instituto de Recursos BiológicosFil: Silva, Martha M. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Moriconi, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Gualano, L.D. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Tranquilli, Gabriela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Santa-María, Guillermo E. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; Argentin

Noncommutative Integrable Field Theories in 2d

We study the noncommutative generalization of (euclidean) integrable models in two-dimensions, specifically the sine- and sinh-Gordon and the U(N) principal chiral models. By looking at tree-level amplitudes for the sinh-Gordon model we show that its na\"\i ve noncommutative generalization is {\em not} integrable. On the other hand, the addition of extra constraints, obtained through the generalization of the zero-curvature method, renders the model integrable. We construct explicit non-local non-trivial conserved charges for the U(N) principal chiral model using the Brezin-Itzykson-Zinn-Justin-Zuber method.Comment: 18 pages, 1 figure; v2: references adde

Vortex Reconnection as the Dissipative Scattering of Dipoles

We propose a phenomenological model of vortex tube reconnection at high Reynolds numbers. The basic picture is that squeezed vortex lines, formed by stretching in the region of closest approach between filaments, interact like dipoles (monopole-antimonopole pairs) of a confining electrostatic theory. The probability of dipole creation is found from a canonical ensemble spanned by foldings of the vortex tubes, with temperature parameter estimated from the typical energy variation taking place in the reconnection process. Vortex line reshuffling by viscous diffusion is described in terms of directional transitions of the dipoles. The model is used to fit with reasonable accuracy experimental data established long ago on the symmetric collision of vortex rings. We also study along similar lines the asymmetric case, related to the reconnection of non-parallel vortex tubes.Comment: 8 pages, 3 postscript figure

A wheat/rye polymorphism affects seminal root length and yield across different irrigation regimes

The introgression of a small segment of wheat (Triticumaestivum L.) chromosome arm 1BS in the distal region of rye (Secalecereale L.) 1RS.1BL arm translocation in wheat (henceforth 1RSRW) was previously associated with reduced grain yield, carbon isotope discrimination and stomatal conductance, suggesting reduced access to soil moisture. Here we show that lines with the normal 1RS arm have longer roots than lines with the 1RSRW arm in both field and hydroponic experiments. In the 1RSRW lines, differences in seminal root length were associated with a developmentally regulated arrest of the root apical meristem (RAM). Approximately 10 days after germination, the seminal roots of the 1RSRW plants showed a gradual reduction in elongation rate, and stopped growing a week later. Seventeen days after germination, the roots of the 1RSRW plants showed altered gradients of reactive oxygen species and emergence of lateral roots close to the RAM, suggesting changes in the root meristem. The 1RSRW lines also showed reduced biomass (estimated by Normalized Differences Vegetation Index) and grain yield relative to the 1RS lines, with larger differences under reduced or excessive irrigation than under normal irrigation. These results suggest that this genetic variation could be useful to modulate root architecture.Fil: Howell, Tyson. University of California; Estados UnidosFil: Moriconi, Jorge Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Zhao, Xueqiang. Chinese Academy of Sciences; República de ChinaFil: Joshua Hegarty. University of California; Estados UnidosFil: Fahima, Tzion. University of Haifa; IsraelFil: Santa Maria, Guillermo Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin

The boundary supersymmetric sine-Gordon model revisited

We argue that, contrary to previous claims, the supersymmetric sine-Gordon model with boundary has a two-parameter family of boundary interactions which preserves both integrability and supersymmetry. We also propose the corresponding boundary S matrix for the first supermultiplet of breathers.Comment: 9 pages, LaTeX; amssymb, no figures; v2: one equation and one reference added; v3: more references and a "note added

Circulation Statistics in Three-Dimensional Turbulent Flows

We study the large $\lambda$ limit of the loop-dependent characteristic functional $Z(\lambda)=$, related to the probability density function (PDF) of the circulation around a closed contour $c$. The analysis is carried out in the framework of the Martin-Siggia-Rose field theory formulation of the turbulence problem, by means of the saddle-point technique. Axisymmetric instantons, labelled by the component $\sigma_{zz}$ of the strain field -- a partially annealed variable in our formalism -- are obtained for a circular loop in the $xy$ plane, with radius defined in the inertial range. Fluctuations of the velocity field around the saddle-point solutions are relevant, leading to the lorentzian asymptotic behavior $Z(\lambda) \sim 1/{\lambda^2}$. The ${\cal O}(1 / {\lambda^4})$ subleading correction and the asymmetry between right and left PDF tails due to parity breaking mechanisms are also investigated.Comment: Computations are discussed in a more detailed way; accepted for publication in Physical Review

Two-year observations of the Jupiter polar regions by JIRAM on board Juno

We observed the evolution of Jupiter's polar cyclonic structures over two years between February 2017 and February 2019, using polar observations by the Jovian InfraRed Auroral Mapper, JIRAM, on the Juno mission. Images and spectra were collected by the instrument in the 5‐μm wavelength range. The images were used to monitor the development of the cyclonic and anticyclonic structures at latitudes higher than 80° both in the northern and the southern hemispheres. Spectroscopic measurements were then used to monitor the abundances of the minor atmospheric constituents water vapor, ammonia, phosphine and germane in the polar regions, where the atmospheric optical depth is less than 1. Finally, we performed a comparative analysis with oceanic cyclones on Earth in an attempt to explain the spectral characteristics of the cyclonic structures we observe in Jupiter's polar atmosphere