Review of the genus Chrysolina Motschulsky, 1860 (Coleoptera: Chrysomelidae) from Nepal Himalaya with description of a new species

11 species and subspecies of Chrysolina hitherto known from Nepal are reviewed. From them only 4 species and 1 subspecies not attributed to exact subgenus can be treated as Himalayan typical alpine species. One more new species Chrysolina romandudkoi Mikhailov sp.n. is described from alpine zone of Eastern Nepal. Short aedeagus with broad anchor- shaped apex distinguishes it from all known Nepalese Chrysolina. Elytra with regular rows of punctures place the new species closer to Ch. dhaulagirica and Ch. hartmanni, but from both species having margins of elytra red fulvous it differs in uniformly dark bronze colour and lateral callus of pronotum not separated from disc. From Ch. nagaja and Ch. daccordii having uniformly bronze body and similar habitus it differs by regular punctures on elytra. The key to high mountain Chrysolina from Nepal Himalaya is provided. © RUSSIAN ENTOMOLOGICAL JOURNAL, 2019

Large negative and positive delay of optical pulses in coherently prepared dense Rb vapor with buffer gas

We experimentally study the group time delay for a light pulse propagating through hot Rb vapor in the presence of a strong coupling field in a $\Lambda$ configuration. We demonstrate that the ultra-slow pulse propagation is transformed into superluminal propagation as the one-photon detuning of the light increases due to the change in the transmission resonance lineshape. Negative group velocity as low as -c/10^6=-80 m/s is recorded. We also find that the advance time in the regime of the superluminal propagation grows linearly with increasing laser field power.Comment: 5 pages, 6 figure

Utility investigation of artificial time delay in displacement-noise-free interferometers

Laser interferometer gravitational wave detectors are usually limited by displacement noise in their lower frequency band. Recently, theoretical proposals have been put forward to construct schemes of interferometry that are insusceptible to displacement noise as well as classical laser noise. These so-called displacement-noise-free interferometry (DFI) schemes take advantage of the difference between gravitational waves and displacement noise in their effects on light propagation. However, since this difference diminishes in lower frequencies (i.e., Omega>[script L]D/c) into the interferometry scheme, with the hope of improving low-frequency sensitivity. We found that sensitivity can only be improved by schemes in which fluctuations in the artificial time delays are not canceled

Unexpected finding of rare and little known leaf beetle chrysolina levi (Coleoptera, chrysomelidae) in West Siberia

The first record of rare and little known leaf beetle Chrysolina levi Okhrimenko, 1990 was registered in the Omsk region (West Siberia). Redescription of male is given because holotype was collected dead and damaged, lacking legs, antennae, head and pronotum. Position of Chrysolina levi inside subgenus Chalcoidea is discussed, its distribution area in Scythian steppe region is now considered as Taman’–Irtysh instead of Pontic. Copyright Yuri E. Mikhailov

Genus Apterocuris Jacobson, 1901 (Coleoptera: Chrysomelidae) in the Subfamily Chrysomelinae with Description of a New Species and Remarks on Significance of Preimaginal Characters

For Apterocuris Jacobson, 1901, formerly considered a monotypic genus endemic to South Siberia, a second congener is described from the Central Sikhote-Alin' Mountains in the Far East of Russia. Apterocuris brinevi sp. n. differs from A. sibirica Jacobson, 1901 in the rather convex body, shining smooth dorsum, absence of rectangular projecting basilateral angles of elytra, and only two or three distinct striae of elytral punctures. For Apterocuris sibirica, the pupa is first described, imago redescribed, and the revised distribution is mapped. The place of Apterocuris in the tribe Chrysomelini is discussed and its similarity to the genus Sclerophaedon Weise, 1882 considered. Both genera have pupae with two urogomphi that should place them into the subtribe Entomoscelina, but their adults with open anterior coxal cavities do not fit the subtribe diagnosis. Therefore, re-establishment of the subtribe Sclerophaedonina Steinhausen, 1996 is proposed to place the genera Sclerophaedon, Apterocuris, Colaphellus Weise, 1916 and Colaspidema Laporte, 1833. A triple key to the genera of the tribe Chrysomelini based on the combination of larval, pupal and imaginal characters is presented

Unexpected finding of rare and little known leaf beetle chrysolina levi (Coleoptera, chrysomelidae) in West Siberia

The first record of rare and little known leaf beetle Chrysolina levi Okhrimenko, 1990 was registered in the Omsk region (West Siberia). Redescription of male is given because holotype was collected dead and damaged, lacking legs, antennae, head and pronotum. Position of Chrysolina levi inside subgenus Chalcoidea is discussed, its distribution area in Scythian steppe region is now considered as Taman’–Irtysh instead of Pontic. Copyright Yuri E. Mikhailov

Representations of sl(2,?) in category O and master symmetries

We show that the indecomposable sl(2,?)-modules in the Bernstein-Gelfand-Gelfand category O naturally arise for homogeneous integrable nonlinear evolution systems. We then develop a new approach called the O scheme to construct master symmetries for such integrable systems. This method naturally allows computing the hierarchy of time-dependent symmetries. We finally illustrate the method using both classical and new examples. We compare our approach to the known existing methods used to construct master symmetries. For new integrable equations such as a Benjamin-Ono-type equation, a new integrable Davey-Stewartson-type equation, and two different versions of (2+1)-dimensional generalized Volterra chains, we generate their conserved densities using their master symmetries

Numerical realization of spatial model of system building-base-ground

For example, a typical brick building is considered in the process of modeling and calculation of loaded deformed condition of the space system building-base-ground. The numerical implementation of the nonlinear problem in view of the structural destruction of materials by finite element method is in accordance with the developed algorithm. Crack propagation is presented in pattern and contour plots of stress and displacement, resulting from the calculation

Entrainment of randomly coupled oscillator networks by a pacemaker

Entrainment by a pacemaker, representing an element with a higher frequency, is numerically investigated for several classes of random networks which consist of identical phase oscillators. We find that the entrainment frequency window of a network decreases exponentially with its depth, defined as the mean forward distance of the elements from the pacemaker. Effectively, only shallow networks can thus exhibit frequency-locking to the pacemaker. The exponential dependence is also derived analytically as an approximation for large random asymmetric networks.Comment: 4 pages, 3 figures, revtex 4, submitted to Phys. Rev. Let