Notes on Ants of the genus Strumigenys F. Smith, 1860 (Hymenoptera: Formicidae) in the Arabian Peninsula, with a key to species.

The ant genus Strumigenys in the Arabian Peninsula is treated. Three species are recognized, S. arnoldi Forel, S. emmae (Emery) and S. membranifera Emery. The invasive species S. membranifera and the Afrotropical species S. arnoldi are recorded for the first time from Saudi Arabia and the Arabian Peninsula. A key to the Arabian species based on the worker caste is presented. Biological, ecological and distribution notes for each species are given. A regional distribution map for the three species is also presented

Review of the Arabian Crematogaster Lund (Hymenoptera, Formicidae), synoptic list, distribution, and description of two new species from Oman and Saudi Arabia

The genus Crematogaster is one of the most species-rich and widespread groups of ants. Despite their often-high local abundance and important ecological interactions, the taxonomy of the genus is fragmentary and in great need of modern revisionary studies. As a first step towards a revision for the Arabian fauna of Crematogaster, a review of all known species with synoptic species accounts is provided. Seventeen species are recognized and illustrated from the Arabian Peninsula, of which two new species are described: C. jacindae Sharaf & Hita Garcia, sp. nov. from the Dhofar Governorate, Oman, and C. gryllsi Sharaf & Hita Garcia, sp. nov. from the Kingdom of Saudi Arabia (KSA) based on the worker caste. Crematogaster jacindae sp. nov. is easily separated from the remainder of the Arabian Crematogaster fauna due to its complete lack of propodeal spines, slit-shaped propodeal spiracles, and its distinct bicoloration, whereas C. gryllsi sp. nov. is readily distinguished by its unlobed postpetiolar dorsum. Furthermore, new country records are presented: C. acaciae Forel for the KSA and Yemen, and C. delagoensis Forel and C. jehovae Forel for the KSAC. antaris for Qatar, whereas C. luctans Forel is excluded from the Arabian fauna. In addition, on the basis of morphological examination of original type material, C. affabilis Forel is proposed as junior synonym of C. chiarinii Mayr, and C. striaticeps is elevated to species rank stat. nov. Furthermore, a new identification key for the Arabian species is provided, as well as distribution maps for all species

Nullity of a graph with a cut-edge

The nullity of a graph is known to be an analytical tool to predict reactivity and conductivity of molecular π-systems. In this paper we consider the change in nullity when graphs with a cut-edge, and others derived from them, undergo geometrical operations. In particular, we consider the deletion of edges and vertices, the contraction of edges and the insertion of an edge at a coalescence vertex. We also derive three inequalities on the nullity of graphs along the same lines as the consequences of the Interlacing Theorem. These results shed light, in the tight-binding source and sink potential model, on the behaviour of molecular graphs which allow or bar conductivity in the cases when the connections are either distinct or ipso.peer-reviewe

A contribution to the study of the ant fauna (Hymenoptera: Formicidae) of Eastern Iran.

Das faunistische Verzeichnis mehrerer Regionen in Ost-Iran nennt 30 Ameisenarten, die zu 17 Gattungen gehören: Aphaenogaster Mayr 1853, Camponotus Mayr 1861, Cataglyphis Foerster 1850, Crematogaster Lund 1831, Dolichoderus Lund 1831, Formica Linnaeus 1758, Lasius Fabricius 1804, Lepisiota Santschi 1926, Linepithema Mayr 1866, Messor Forel 1890, Monomorium Mayr 1855, Plagiolepis Mayr 1861, Pachycondyla Smith 1858, Pheidole Westwood 1839, Polyrhachis Smith 1857, Solenopsis Westwood 1840, Tapinoma Foerster 1850. Zwei Arten, Crematogaster laestrygon Emery, 1869 und Camponotus adenensis Emery, 1893 werden erstmals für Iran nachgewiesen. Die Mehrzahl der behandelten Taxa ist weit verbreitet. Offensichtlich endemische Arten wurden nicht gesammelt. Weiterhin wird die lokale und weltweite Verbreitung der gesammelten Arten dargestellt.StichwörterPalearctic region, Middle East, distribution, list, new record, Iran.A faunistic inventory of several regions of eastern Iran revealed 30 ant species belonging to 17 genera (Aphaenogaster Mayr 1853, Camponotus Mayr 1861, Cataglyphis Foerster 1850, Crematogaster Lund 1831, Dolichoderus Lund 1831, Formica Linnaeus 1758, Lasius Fabricius 1804, Lepisiota Santschi 1926, Linepithema Mayr 1866, Messor Forel 1890, Monomorium Mayr 1855, Plagiolepis Mayr 1861, Pachycondyla Smith 1858, Pheidole Westwood 1839, Polyrhachis Smith 1857, Solenopsis Westwood 1840, Tapinoma Foerster 1850. Two species, Crematogaster laestrygon Emery, 1869 and Camponotus adenensis Emery, 1893 are recorded for the first time from Iran. The majority of species were widespread taxa. No apparently endemic species were collected. Information on local and world distribution of collected species is presented.KeywordsPalearctic region, Middle East, distribution, list, new record, Iran

Coalescing Fiedler and core vertices

The nullity of a graph G is the multiplicity of zero as an eigenvalue in the spectrum of its adjacency matrix. From the interlacing theorem, derived from Cauchy’s inequalities for matrices, a vertex of a graph can be a core vertex if, on deleting the vertex, the nullity decreases, or a Fiedler vertex, otherwise. We adopt a graph theoretical approach to determine conditions required for the identification of a pair of prescribed types of root vertices of two graphs to form a cut-vertex of unique type in the coalescence. Moreover, the nullity of subgraphs obtained by perturbations of the coalescence G is determined relative to the nullity of G. This has direct applications in spectral graph theory as well as in the construction of certain ipso-connected nano-molecular insulators.peer-reviewe

Progressive Coding and Transmission of Digital Diagnostic Pictures

In radiology, as a result if the increased utilization of digital imaging modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI), over a third of the images produced in a typical radiology department are currently in digital form, and this percentage is steadily increasing, Image compression provides a means for the economical storage and efficient transmission of these diagnostic pictures. The level of coding distortion than can be accepted for clinical diagnosis purposes is not yet well-defined. In this paper we introduce some constraints on the design of existing transform codes in order to achieve progressive image transmission efficiently. The design constraints allow the image quality to be asymptotically improved such that the proper clinical diagnoses are always possible. The modified transform code outperforms simple spatial-domain codes by providing higher quality of the intermediately reconstructed images. The improvement is 10 dB for a compression factor of 256:1. and it is as high as 17.5 dB for a factor of 8:1. A novel progressive quantization scheme is developed for optimal progressive transmission of transformed diagnostic images. Combined with a discrete cosine transform, the new approach delivers intermediately reconstructed images of comparable quality twice as fast as the more usual zig-zag sampled approach. The quantization procedures is suitable for hardware implementation

Edge Degree Weight of Sequential Join of Graphs

Let the weight w of an edge e= uv={u,v} of a graph G be defined by w(e)=deg(u)+deg(v)-2 and the weight of G be defined by w(G)= ∑ e ∈ E(G)w(e), where E(G) is the edge set of G. In this paper the weights of joins, sequential joins, unions, intersections, and products (Cartesian and Tensor) of sets of graphs are obtained. This leads to a variety of open questions and new studies

Review of the ant genus Meranoplus Smith, 1853 (Hymenoptera: Formicidae) in the Arabian Peninsula with description of a new species M. mosalahi sp. n. from Oman

The species of Meranoplus Smith, 1853 of the Arabian Peninsula are reviewed based on the worker caste. Two species are recognized, keyed, and illustrated by Scanning Electron Microscope images (SEM), Meranoplus mosalahi and M. pulcher, Sharaf, 2014. Meranoplus mosalahi sp. n. is described from the Dhofar Governorate, Oman based on the worker caste. The new species belongs to the M. magrettii-group and closely resembles M. pulcher Sharaf, 2014 from the Kingdom of Saudi Arabia (KSA), from which it can be distinguished by the bicolored body, the shallowly concave anterior clypeal margin, the absence of well-developed anterior clypeal teeth, the fewer irregular longitudinal cephalic rugae, and the feeble longitudinal rugae on posterior face of petiolar node