31,609 research outputs found
A Synopsis of Bolivian Polyrhaphis Audinet-Serville (Coleoptera, Cerambycidae, Lamiinae) with description of a new species
The Bolivian species of Polyrhaphis Audinet-Serville, 1835, (Coleoptera, Cerambycidae, Lamiinae) are reviewed and illustrated, with P. skillmani new species described. A key is presented to the six species recorded from Bolivia (P. angustata Buquet, 1853; P. argentina Lane, 1978; P. gracilis Bates, 1862; P. pilosa Lane, 1965; P. spinosa (Drury, 1773); and P. skillmani Wappes and Santos-Silva, new species). Their collection localities, based on recently identified specimens examined by the authors, are plotted to show the distribution of species, and displayed next to an ecoregion map of Bolivia to illustrate biogeographical information for Polyrhaphis.Se revisan e ilustran las especies bolivianas de Polyrhaphis Audinet-Serville, 1835, (Coleoptera, Cerambycidae, Lamiinae) con la descripción de P. skillmani especie nueva. Se presenta una clave para las seis especies conocidas de Bolivia (P. angustata Buquet, 1853; P. argentina Lane, 1978; P. gracilis Bates, 1862; P. pilosa Lane, 1965; P. spinosa (Drury, 1773); y P. skillmani Wappes y Santos-Silva especie nueva). Se trazan sobre un mapa las localidades de colecta, basadas en especímenes identificados recientemente y examinados por los autores, y se muestran junto a un mapa de las ecorregiones de Bolivia para ilustrar la información biogeográfica de Polyrhaphis
Descriptions of females of Nothopleurus Lacordaire and Strongylaspis Thomson (Coleoptera: Cerambycidae: Prioninae: Macrotomini) with new distributional records
The female of Nothopleurus subsulcatus (Dalman, 1823) (Coleoptera: Cerambycidae: Prioninae: Macrotomini) is described for the first time, and the female of Strongylaspis bullata Bates, 1872 is redescribed. Color photographs of the habitus of both, and key characters for the former are included. New distributional records within Mexico for N. subsulcatus and Strongylaspis championi Bates, 1884 are given.A fêmea de Nothopleurus subsulcatus (Dalman, 1823) (Coleoptera: Cerambycidae: Prioninae: Macrotomini) é descrita pela primeira vez e a de Strongylaspis bullata Bates, 1872 é redescrita. São adicionadas figuras coloridas para as duas espécies e chave parcial para a N. subsulcatus. São fornecidos novos registros no México para N. subsulcatus e Strongylaspis championi Bates, 1884
The genus Aplagiognathus Thomson, 1861 (Coleoptera, Cerambycidae, Prioninae, Macrotomini)
Aplagiognathus Thomson, 1861 (Coleoptera, Cerambycidae, Prioninae, Macrotomini) and its two species, A. spinosus (Newman, 1840) and A. hybostoma Bates, 1879, are redescribed and figured. As the type of A. spinosus is apparently lost, a neotype for the species is designated herein as is a lectotype for A. hybostoma. Keys to the North and Central American genera of Macrotomini (excluding the West Indies) and to Aplagiognathus species are provided. Details on the numerous changes in the nomenclatural history of the genus are also chronicled
Luttinger liquid superlattices: realization of gapless insulating phases
We investigate Luttinger Liquid superlattices, a periodic structure composed
of two kinds of one-dimensional systems of interacting electrons. We calculate
several properties of the low-energy sector: the effective charge and spin
velocities, the compressibility, various correlation functions, the Landauer
conductance and the Drude weight. The low-energy properties are subsumed into
effective parameters, much like homogeneous one-dimensional systems. A generic
result is the weighted average nature of these parameters, in proportion to the
spatial extent of the underlying subunits, pointing to the possibility of
``engineered'' structures. As a specific realization, we consider a
one-dimensional Hubbard superlattice, which consists of a periodic arrangement
of two long Hubbard chains with different coupling constants and different
hopping amplitudes. This system exhibits a rich phase diagram with several
phases, both metallic and insulating. We have found that gapless insulating
phases are present over a wide range of parameters.Comment: 16 pages, 15 figures, RevTeX
A new genus of Prioninae (Coleoptera, Cerambycidae)
Neoma, a new genus of Cerambycidae (Coleoptera: Cerambycidae: Prioninae: Macrotomini) is described for Mallodonopsis corrosus Bates, 1879, compared to related genera (Aplagiognathus Thomson, 1861; Archodontes Lameere, 1903; and Mallodonopsis Thomson, 1861), and its tribal position discussed. A lectotype for Mallodonopsis corrosus is here designated with the species redescribed and figured
Practice-oriented controversies and borrowed epistemic credibility in current evolutionary biology: phylogeography as a case study
Although there is increasing recognition that theory and practice in science are intimately intertwined, philosophy of science perspectives on scientific controversies have been historically focused on theory rather than practice. As a step in the construction of frameworks for understanding controversies linked to scientific practices, here we introduce the notion of borrowed epistemic credibility (BEC), to describe the situation in which scientists, in order to garner support for their own stances, exploit similarities between tenets in their own field and accepted statements or positions properly developed within other areas of expertise. We illustrate the scope of application of our proposal with the analysis of a heavily methods-grounded, recent controversy in phylogeography, a biological subdiscipline concerned with the study of the historical causes of biogeographical variation through population genetics- and phylogenetics-based computer analyses of diversity in DNA sequences, both within species and between closely related taxa. Toward this end, we briefly summarize the arguments proposed by selected authors representing each side of the controversy: the ‘nested clade analysis’ school versus the ‘statistical phylogeography’ orientation. We claim that whereas both phylogeographic ‘research styles’ borrow epistemic credibility from sources such as formal logic, the familiarity of results from other scientific areas, the authority of prominent scientists, or the presumed superiority of quantitative vs. verbal reasoning, ‘theory’ plays essentially no role as a foundation of the controversy. Besides underscoring the importance of strictly methodological and other non-theoretical aspects of controversies in current evolutionary biology, our analysis suggests a perspective with potential usefulness for the re-examination of more general philosophy of biology issues, such as the nature of historical inference, rationality, justification, and objectivity
Mass-degenerate Higgs bosons at 125 GeV in the Two-Higgs-Doublet Model
The analysis of the Higgs boson data by the ATLAS and CMS Collaborations
appears to exhibit an excess of h --> gamma\gamma events above the Standard
Model (SM) expectations; whereas no significant excess is observed in h --> ZZ*
--> {four lepton} events, albeit with large statistical uncertainty due to the
small data sample. These results (assuming they persist with further data)
could be explained by a pair of nearly mass-degenerate scalars, one of which is
a SM-like Higgs boson and the other is a scalar with suppressed couplings to
W+W- and ZZ. In the two Higgs doublet model, the observed \gamma\gamma and ZZ*
--> {four lepton} data can be reproduced by an approximately degenerate CP-even
(h) and CP-odd (A) Higgs boson for values of \sin(\beta-\alpha) near unity and
0.7 < \tan\beta < 1. An enhanced \gamma\gamma signal can also arise in cases
where m_h ~ m_H, m_H ~ m_A, or m_h ~ m_H ~ m_A. Since the ZZ* --> {four lepton}
signal derives primarily from a SM-like Higgs boson whereas the \gamma\gamma
signal receives contributions from two (or more) nearly mass-degenerate states,
one would expect a slightly different invariant mass peak in the ZZ* --> {four
lepton} and \gamma\gamma channels. The phenomenological consequences of such
models can be tested with additional Higgs data that will be collected at the
LHC in the near future.Comment: 18 pages, 19 pdf figures, v2: references added, v3&v4: added refs and
explanation
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