Stability of the magnetic Schr\"odinger operator in a waveguide

The spectrum of the Schr\"odinger operator in a quantum waveguide is known to be unstable in two and three dimensions. Any enlargement of the waveguide produces eigenvalues beneath the continuous spectrum. Also if the waveguide is bent eigenvalues will arise below the continuous spectrum. In this paper a magnetic field is added into the system. The spectrum of the magnetic Schr\"odinger operator is proved to be stable under small local deformations and also under small bending of the waveguide. The proof includes a magnetic Hardy-type inequality in the waveguide, which is interesting in its own

Further review of \u3cem\u3eOrthochirus\u3c/em\u3e Karsch, 1892 (Scorpiones: Buthidae) from Asia: taxonomic position of \u3cem\u3eO. melanurus, O. persa, O. scrobiculosus\u3c/em\u3e, and description of six new species

We describe six new species of Orthochirus: O. birulai sp. n. (Pakistan), O. formozovi sp. n. (Afghanistan, Iran, Tajikistan, Turkmenistan), O. grosseri sp. n. (Uzbekistan), O. kryzhanovskyi sp. n. (Pakistan), O. nordmanni sp. n. (Afghanistan), and O. sejnai sp. n. (Iran). Descriptions are complemented with color photographs of preserved specimens. The identities of Orthochirus melanurus (Kessler, 1874) (Kazakhstan, Uzbekistan), O. persa (Birula, 1900), stat. n. (Afghanistan, Iran), and O. scrobiculosus (Grube, 1873) (Turkmenistan) are reexamined, based on detailed study of the type specimens; lectotypes of all three species are designated. We demonstrate for the first time that the name O. scrobiculosus, previously used as an ‘umbrella’ for various Orthochirus from Central Asia and the Middle East, is currently applicable only to a few confirmed populations from the southwestern Turkmenistan, near the Caspian Sea. New synonymies are proposed at the species level: Paraorthochirus blandini Lourenço & Vachon, 1997 = Orthochirus fuscipes (Pocock, 1900), syn. n. and Afghanorthochirus erardi Lourenço & Vachon, 1997 = Orthochirus persa (Birula, 1900), stat. n., syn. n. We provide a distribution map and a key to all Orthochirus found in ten Asian countries: Afghanistan, India, Iran, Iraq, Kazakhstan, Pakistan, Tajikistan, Turkey, Turkmenistan, and Uzbekistan (41 species)

Scorpions of the Horn of Africa (Arachnida: Scorpiones). Part XXIII. \u3cem\u3eButhus\u3c/em\u3e (Buthidae), with description of two new species

New data are presented on the distribution of the genus Buthus Leach, 1815 in the Horn of Africa, mainly in Somaliland, acquired during expeditions in 2011–2019. Buthus berberensis Pocock, 1900, for which the exact locality was not known, was collected again. B. zeylensis Pocock, 1900 is restored from synonymy and elevated to species rank, based on a study of 75 recently collected specimens. Two new species, B. pococki sp. n. and B. somalilandus sp. n., are described, fully complemented with color photographs of live and preserved specimens, as well as their habitats. In addition to the analyses of external morphology we also described karyotypes of selected species. B. awashensis, B. pococki sp. n. and B. zeylensis have karyotypes with 2n=22. The karyotype of B. berberensis possesses 21 chromosomes, probably as a consequence of heterozygous fusion that is evident as a trivalent during postpachytene in this species. A key and distribution map of Buthus in the Horn of Africa (five species) are included

The first record of \u3ci\u3eOrthochirus glabrifrons\u3c/i\u3e (Kraepelin, 1903) (Scorpiones: Buthidae) from the United Arab Emirates

Orthochirus glabrifrons (Kraepelin, 1903) (Scorpiones: Buthidae) was described from Oman (Muscat). Here, we summarize known localities from Oman as well as records from the United Arab Emirates, which is the new country record for this species. Illustrations of morphology of both sexes are given together with a map of distribution. A lectotype of Orthochirus glabrifrons (Kraepelin, 1903) is designated. Paraorthochirus kaspareki Lourenço & Huber, 2000 and Paraorthochirus kinzelbachi Lourenço & Huber, 2000 are synonymized with Orthochirus glabrifrons (Kraepelin, 1903), syn. n

Scorpions of the Horn of Africa (Arachnida: Scorpiones). Part XXV. Description of \u3cem\u3ePandinurus awalei\u3c/em\u3e sp. n. and the male of \u3cem\u3ePandiborellius somalilandus\u3c/em\u3e (Kovařík, 2012), with remarks on recent synonymies (Scorpionidae: Pandininae)

A new species Pandinurus awalei sp. n. is described from Somaliland. The male of Pandiborellius somalilandus (Kovařík, 2012) is also described for the first time and sexual dimorphism of the species is defined. The habitus, morphology and habitats of both species are illustrated in detail with color and UV fluorescence images, including both live and preserved specimens. The species Pandinurus intermedius (Borelli, 1919) and Pandipalpus lowei (Kovařík, 2012) of Pandininae that were synonymized by Prendini & Loria (2020) are reinstated as valid species

Scorpions of the Horn of Africa (Arachnida: Scorpiones). Part XXX. \u3ci\u3eParabuthus\u3c/i\u3e (Buthidae) (Part III), with description of three new species from Somaliland and occurrence of \u3ci\u3eParabuthus eritreaensis\u3c/i\u3e Kovařík, 2003

A new record of an adult female of Parabuthus eritreaensis Kovařík, 2003 in Somaliland confirms true distribution of this species, already discussed in Kovařík et al. (2016: 19–21). Three new species are described from Somaliland, P. dorisae sp. n., P. evae sp. n., and P. quincyae sp. n.. The hemispermatophore of P. dorisae sp. n. is illustrated and described. In addition to the analyses of external morphology and hemispermatophore, we have provided descriptions of the karyotypes of P. dorisae sp. n. and P. quincyae sp. n. Despite the presence of multivalents (CVIII and CXIV), both species exhibit karyotypes with 2n=16 and chromosomes that gradually decrease in length, with the exception of the first chromosome, which is longer than the following chromosomes. A map of distribution of Parabuthus species in the Horn of Africa is included

Full O(alpha) corrections to e+e- -> sf_i sf_j

We present a complete precision analysis of the sfermion pair production process e+e- -> sf_i sf_j (f = t, b, tau, nu_tau) in the Minimal Supersymmetric Standard Model. Our results extend the previously calculated weak corrections by including all one-loop corrections together with higher order QED corrections. We present the details of the analytical calculation and discuss the renormalization scheme. The numerical analysis shows the results for total cross-sections, forward-backward and left-right asymmetries. It is based on the SPS1a' point from the SPA project. The complete corrections are about 10% and have to be taken into account in a high precision analysis.Comment: 32 pages, 24 figures, RevTeX

Scorpions of the Horn of Africa (Arachnida: Scorpiones). Part XXI. \u3cem\u3eParabuthus\u3c/em\u3e (Buthidae) (Part II), with description of five new species from Somaliland and Ethiopia

The complex of Parabuthus heterurus Pocock, 1897 is split into four species: P. heterurus Pocock, 1897 s. str. whose type locality and real distribution are discussed and corrected, and three herein described species, P. kabateki sp. n., P. robustus sp. n. and P. somalilandus sp. n. In the species complex of Parabuthus liosoma (Ehrenberg, 1828), P. erigavoensis sp. n. from Somaliland is described. Also described are P. mazuchi sp. n., sympatric with P. cimrmani Kovařík, 2004 and P. eritreaensis Kovařík, 2003 from Somaliland. New data are presented on the distribution of the genus Parabuthus Pocock, 1890 in the Horn of Africa, mainly in Somaliland, acquired during expeditions in 2017–2019. Information is provided about Parabuthus species from Somaliland, their taxonomy, distribution, and ecology, fully complemented with color photos of live and preserved specimens, as well as their habitats. The hemispermatophores of P. kabateki sp. n., P. mazuchi sp. n., P. robustus sp. n. and P. somalilandus sp. n. are illustrated and described. In addition to the analyses of external morphology and hemispermatophores, we also described the karyotypes of P. kabateki sp. n., P. robustus sp. n. and P. somalilandus sp. n. All three species have karyotypes with 2n=16 and chromosomes gradually decreasing in length. Included is a key to Parabuthus Pocock, 1890 in the Horn of Africa. Parabuthus terzanii Rossi, 2017 is synonymized with Parabuthus hamar Kovařík et al., 2016 syn. n. as a junior synonym because the description dated July 2016 was in reality published/accessible in March 201

Intragenomic rDNA variation - the product of concerted evolution, mutation, or something in between?

The classical model of concerted evolution states that hundreds to thousands of ribosomal DNA (rDNA) units undergo homogenization, making the multiple copies of the individual units more uniform across the genome than would be expected given mutation frequencies and gene redundancy. While the universality of this over 50-year-old model has been confirmed in a range of organisms, advanced high throughput sequencing techniques have also revealed that rDNA homogenization in many organisms is partial and, in rare cases, even apparently failing. The potential underpinning processes leading to unexpected intragenomic variation have been discussed in a number of studies, but a comprehensive understanding remains to be determined. In this work, we summarize information on variation or polymorphisms in rDNAs across a wide range of taxa amongst animals, fungi, plants, and protists. We discuss the definition and description of concerted evolution and describe whether incomplete concerted evolution of rDNAs predominantly affects coding or non-coding regions of rDNA units and if it leads to the formation of pseudogenes or not. We also discuss the factors contributing to rDNA variation, such as interspecific hybridization, meiotic cycles, rDNA expression status, genome size, and the activity of effector genes involved in genetic recombination, epigenetic modifications, and DNA editing. Finally, we argue that a combination of approaches is needed to target genetic and epigenetic phenomena influencing incomplete concerted evolution, to give a comprehensive understanding of the evolution and functional consequences of intragenomic variation in rDNA

Two dimensional Berezin-Li-Yau inequalities with a correction term

We improve the Berezin-Li-Yau inequality in dimension two by adding a positive correction term to its right-hand side. It is also shown that the asymptotical behaviour of the correction term is almost optimal. This improves a previous result by Melas.Comment: 6 figure