Plant-aphid interactions: molecular and ecological perspectives.

Plant lectins as defense proteins against phytophagous insects

The Carroll group was originally introduced by Levy-Leblond (1965 Ann. Inst. Henri Poincare 3 1) by considering the contraction of the Poincare group as c → 0. In this paper an alternative definition, based on the geometric properties of a non-Minkowskian, non-Galilean but nevertheless boost-invariant, spacetime structure is proposed. A 'duality' with the Galilean limit c → ∞ is established. Our theory is illustrated by Carrollian electromagnetism.

Carroll versus Newton and Galilei: two dual non-Einsteinian concepts of time

The paper provides an introduction and survey of conservative discretization methods for Hamiltonian partial differential equations. The emphasis is on variational, symplectic and multi-symplectic methods. The derivation of methods as well as some of their fundamental geometric properties are discussed. Basic principles are illustrated by means of examples from wave and fluid dynamics.

https://iopscience.iop.org/article/10.1088/0305-4470/39/19/S02/pdf

Numerical methods for Hamiltonian PDEs

Conformal extensions of Levy–Leblondʼs Carroll group, based on geometric properties analogous to those of Newton–Cartan space-time are proposed. The extensions are labeled by an integer k. This framework includes and extends our recent study of the Bondi–Metzner–Sachs (BMS) and Newman–Unti (NU) groups. The relation to conformal Galilei groups is clarified. Conformal Carroll symmetry is illustrated by ‘Carrollian photons’. Motion both in the Newton–Cartan and Carroll spaces may be related to that of strings in the Bargmann space.

https://iopscience.iop.org/article/10.1088/1751-8113/47/33/335204/pdf

Conformal Carroll groups

On special relativity with cosmological constant

Based on some important properties of dS space, we present a Beltrami model BA that may shed light on the observable puzzle of dS space and the paradox between the special relativity principle and cosmological principle. In BA, there are inertial-type coordinates and inertial-type observers. Thus, the classical observables can be defined for test particles and light signals. In addition, by choosing the definition of simultaneity the Beltrami metric is transformed to the Robertson-Walker-like metric. It is of positive spatial curvature of order A. This has already been shown by the CMB power spectrum from WMAP and should be further confirmed by its data in large scale.

On Beltrami model of de Sitter spacetime

To evaluate the possible antiaphid function of Amaranthus caudatus agglutinin (ACA) in allogenetic plants, transgenic cotton plants expressing the ACA gene under the control of a phloem-specific promoter were generated via Agrobacterium-mediated gene transformation. Based on the results of Southern blot analyses, six plants with single or lower copy transgene and favourable agronomic traits were selected for further studies. ACA expression levels ranged from 0.02% to 0.45% of total soluble protein as determined by Western blot analysis in the six selected transgenic plants. Insect bioassays using nymphs of cotton aphid (Aphis gossypii Glover) showed that five of the six transgenic plants significantly inhibited the population growth of cotton aphid, with the highest inhibition rate of 64.5%. These results shed some new light on the antiaphid function of the ACA gene as well as the promising application of the gene for obtaining aphid-resistant transgenic cotton plants to reduce the yield loss and honeydew contamination of fibre by aphids.

Transgenic cotton, expressing Amaranthus caudatus agglutinin, confers enhanced resistance to aphids

It is found that there is no period in the imaginary Beltrami time of the de Sitter spacetime with Beltrami metric and that the "surface-gravity" in view of inertial observers in de Sitter spacetime is zero! They show that the horizon might be at zero temperature in de Sitter spacetime and that the thermal property of the horizon in the de Sitter spacetime with a static metric should be analogous to that of the Rindler horizon in Minkowski spacetime.

https://iopscience.iop.org/article/10.1209/epl/i2005-10327-4/pdf

Temperature at horizon in de Sitter spacetime

Based on the relativistic principle and the postulate of universal invariant constants (c, l), all kinematic symmetries can be set up as the subsets of the Umov-Weyl-Fock-Hua transformations for the inertial motions. These symmetries are connected to each other via combinations rather than via contractions and deformations.

Han-Ying Guo

Papers

On special relativity with cosmological constant

On Beltrami model of de Sitter spacetime

Transgenic cotton, expressing Amaranthus caudatus agglutinin, confers enhanced resistance to aphids

Temperature at horizon in de Sitter spacetime

The principle of relativity, kinematics and algebraic relations