Generic rank-k Perturbations of Structured Matrices

System of generic groups in mealybugs (Homoptera: Coccinea: Pseudococcidae)

Zoosystematica Rossica ◽

10.31610/zsr/2015.24.2.236 ◽

2015 ◽

Vol 24 (2) ◽

pp. 236-259 ◽

Cited By ~ 10

Author(s):

I.A. Gavrilov-Zimin

Keyword(s):

Taxonomic Revision ◽

Generic Rank ◽

The World ◽

Generic Groups ◽

World Fauna

The paper provides a brief conspectus of the system of morphological generic groups, elaborated earlier by the author basing on the total taxonomic revision of Palaearctic mealybugs. Here the system is complemented by the analysis of all 249 genera of the world fauna. Borders of two generic groups are reconsidered and two else groups (with mainly Oriental and Australasian genera) are included in the system. Main taxonomic characters of generic rank are discussed and illustrated.

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Aspidisca beringiana sp. nov. and Simbiodisca subgen. nov. (Ciliophora, Euplotida), a symbiont of terebellid polychaetes in the Bering Sea

Zoosystematica Rossica ◽

10.31610/zsr/2009.18.2.184 ◽

2009 ◽

Vol 18 (2) ◽

pp. 184-190

Author(s):

A.W. Jankowski

Keyword(s):

Bering Sea ◽

Tidal Zone ◽

Generic Rank ◽

New Subgenus ◽

Bering Island ◽

The Bering Sea

Terebellids in tidal zone of the Bering Island bear three new symbionts - rhabdophryid suctorians, peritrichs with small rosette-like colonies and aspidiscid hypotrich with a long peristome parallel to left body margin. This is the main feature of a new subgenus of the genus Aspidisca, named Simbiodisca. It may deserve the full generic rank if the use of protargol silvering method will not reveal any upper left rudiment of the peristomal membranelles.

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The larva of Psychoda (Philosepedon) humeralis Meigen (Diptera, Psychodidae)

Parasitology ◽

10.1017/s0031182000072620 ◽

1963 ◽

Vol 53 (1-2) ◽

pp. 155-156

Author(s):

Kenneth G. V. Smith ◽

L. W. Grensted

Keyword(s):

Larval Stage ◽

Sensu Stricto ◽

Present Account ◽

Generic Rank ◽

Detailed Treatment

Satchell (1947) described and keyed the larvae of 14 of the 19 British species of Psychoda, but this study did not include P. humeralis Mg., presumably because the author accorded generic rank to Philosepedon and Threticus which would put them outside his study of Psychoda sensu stricto. The larva of P. humeralis has been briefly described by Spärck (1920), but his figures are rather crude. A detailed treatment of the larval head is given by Anthon (1943). The present account is offered to facilitate identification of this species in the larval stage when used in conjunction with Satchell's comprehensive paper.

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Preserving spectral properties of structured matrices under structured perturbations

Linear Algebra and its Applications ◽

10.1016/j.laa.2021.07.017 ◽

2021 ◽

Author(s):

Tinku Ganai ◽

Bibhas Adhikari

Keyword(s):

Spectral Properties ◽

Structured Matrices ◽

Structured Perturbations

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Global Properties of Eigenvalues of Parametric Rank One Perturbations for Unstructured and Structured Matrices

Complex Analysis and Operator Theory ◽

10.1007/s11785-021-01094-7 ◽

2021 ◽

Vol 15 (3) ◽

Author(s):

André C. M. Ran ◽

Michał Wojtylak

Keyword(s):

Unit Circle ◽

Structured Matrices ◽

Additional Structure ◽

General Properties ◽

Global Properties ◽

Classes Of Matrices ◽

Rank One

AbstractGeneral properties of eigenvalues of $$A+\tau uv^*$$ A + τ u v ∗ as functions of $$\tau \in {\mathbb {C} }$$ τ ∈ C or $$\tau \in {\mathbb {R} }$$ τ ∈ R or $$\tau ={{\,\mathrm{{e}}\,}}^{{{\,\mathrm{{i}}\,}}\theta }$$ τ = e i θ on the unit circle are considered. In particular, the problem of existence of global analytic formulas for eigenvalues is addressed. Furthermore, the limits of eigenvalues with $$\tau \rightarrow \infty $$ τ → ∞ are discussed in detail. The following classes of matrices are considered: complex (without additional structure), real (without additional structure), complex H-selfadjoint and real J-Hamiltonian.

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Revision of European and North African Folsomides Stach with special emphasis on the Canarian fauna (Collembola: Isotomidae)

Insect Systematics & Evolution ◽

10.1163/187631292x00245 ◽

1992 ◽

Vol 23 (4) ◽

pp. 453-473 ◽

Cited By ~ 6

Author(s):

Arne Fjellberg

Keyword(s):

New Species ◽

Canary Islands ◽

Morphological Characters ◽

Maxillary Palp ◽

North African ◽

African Species ◽

Mouth Region ◽

Generic Rank ◽

Number Of Species ◽

Narrow Definition

AbstractThe genus Folsomides Stach, 1922 is redefined and given a narrow definition based on a limited set of consistent morphological characters: Position and distribution of tergal macrosensilla, chaetotaxy of mouth region, tibiotarsi, ventral tube and furca. Eighteen new species are described from the Canary Islands: semiparvulus sp. n., xerophilus sp. n., vinosus sp. n., cumbrosus sp. n., unicus sp. n., terrus sp. n., pocosensillatus sp. n., nigrocellatus sp. n., teno sp. n., oromii sp. n., ononicolus sp. n., graminis sp. n., famarensis sp. n., pinicolus sp. n., intermedius sp. n., tonellus sp. n., supranubius sp. n. and analuisae sp. n. The following European/African species are redescribed: parvulus Stach, portucalensis Gama, angularis (Axelson), cf. petiti Delamare, lawrencei Gers & Deharveng, cf. zairensis Martynova, nanus Ellis and centralis (Denis). Highly discriminate species characters are found in maxillary palp, tibiotarsal chaetotaxy and distribution of tergal microsensilla. A number of species are removed from Folsomides, and Subisotoma Stach, 1947 is given generic rank.

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