32,035 research outputs found
New records, nomenclatural changes, and taxonomic notes for select North American leaf beetles (Coleoptera: Chrysomelidae)
New records, nomenclatural changes and taxonomic notes are presented for select North American leaf beetles (Coleoptera: Chrysomelidae). The following genera are newly recorded from the United States: Nesaecrepida Blake, 1964; Acallepitrix Bechyne, 1959; Margaridisa Bechyne, 1958; Parchicola Bechyne and Springlova de Bechyne, 1975; (all Galerucinae: Alticini); and Demotina Baly, 1874 (Eumolpinae). The following species are newly recorded from the United States: Neolema dorsalis (Olivier, 1791) (Criocerinae); Charidotella bifossulata Boheman, 1855 (Hispinae: Cassidini); Syphrea flauicollis (Jacoby, 1884) (Galerucinae: Alticini); and Promecosoma inflatum Lefevre, 1877, and Demotina modesta Baly, 1874 (Eumolpinae). The following new synonymies are proposed: Deloyala clauata, var. diuersicollis Schaeffer, 1925, transferred from synonymy with Plagiometriona clauata (Fabricius, 1798) to synonymy withP. clauata testudinaria (Boheman, 1855); Chrysomela hybrida Say, 1824, downgraded from subspecies of Calligrapha lunata (Fabricius, 1787) to full synonym of CaZZigrapha lunata (Fabricius); Chrysomela casta Rogers, 1856, downgraded from subspecies of Zygogramma suturalis (Fabricius, 1775) to full synonym of Zygogrammasuturalis (Fabricius); Trirhabdagurneyi Blake, 1951, downgraded to synonym of Trirhabda caduca Horn, 1893; Scelida mimula Wilcox, 1965, downgraded to synonym of Scelida nigricornis (Jacoby, 1888); Exoracalifornica Wilcox, 1953, downgraded to synonym of Pte leon breuicornis (Jacoby, 1887); alaeothonaarizonensis Blake, 1950, downgraded to synonym ofLupraea discrepans (Schaeffer, 1932); Haltica nigritula Linell, 1898, downgraded to synonym of Nesaecrepida asphalt ina (Suffrian, 1868); Cryptocephalus reinhardi Sundman, 1965, downgraded to synonym of Cryptocephalus nwtabilis Melsheimer, 1847. The tribes Chalepini Wiese, 1910, and Uroplatini Weise, 1910 (Hispinae), are synonymized, and both of these family-group names are recognized as nomina protecta. The family-group name Octotomites Chapuis, 1875, is recognized as a nomen oblitum. Coptocycla testudinaria Boheman, 1855, is downgraded from specific status to a subspecies of Plagiometriona clauata (Fabricius, 1798); Cassida bicolor (Fabricius, 1798) is recognized as a valid subspecies of Charidotellasexpunctata (Fabricius). The genus Hemiphrynus Horn, 1889, is removed from synonymy with Phrynocepha and reinstated as a valid genus; Rhabdopterus weisei (Schaeffer, 1920) is removed from synonymy with Rhabdopterus praetextus (Say) and reinstated as a valid species. The following new combinations are proposed: Synetocephalus wallacei (Wilcox, 1965), transferred from Pseudoluperus; Nesaecrepida infuscata (Schaeffer, 1906), transferred from Monomacra; Acallepitrix nitens (Horn, 1889), transferred from Epitrix; Margaridisa atriuentris (Melsheimer, 1847), transferred from Hornaltica; Parchicola iris (Olivier, 1808) and P. tibialis (Olivier, 1808), transferred from Monomacra; and Coleothorpa panochensis (Gilbert, 1981), transferred from Coscinoptera; Promecosoma arizonae (Crotch, 1873), transferred from Metaxyonycha; Tymnes chrysis (Olivier, 1808), T. oregonensis (Crotch, 1873), and T. thaleia (Blake, 1977), transferred from Colaspis. The following new replacement name is proposed: Triarius nigroflaulls, for Luperodes flauoniger Blake, 1942 (not Laboissiere, 1925). The identities of Griburius equestris (Olivier, 1808) and G. laruatlls (Newman, 1840) are discussed
Quantum Sensor Miniaturization
The classical bound on image resolution defined by the Rayleigh limit can be
beaten by exploiting the properties of quantum mechanical entanglement. If
entangled photons are used as signal states, the best possible resolution is
instead given by the Heisenberg limit, an improvement proportional to the
number of entangled photons in the signal. In this paper we present a novel
application of entanglement by showing that the resolution obtained by an
imaging system utilizing separable photons can be achieved by an imaging system
making use of entangled photons, but with the advantage of a smaller aperture,
thus resulting in a smaller and lighter system. This can be especially valuable
in satellite imaging where weight and size play a vital role.Comment: 3 pages, 1 figure. Accepted for publication in Photonics Technology
Letter
Dissociation of Hemoglobin into Subunits II. HUMAN OXYHEMOGLOBIN: GEL FILTRATION STUDIES
Abstract The dissociation of normal human oxyhemoglobin has been studied by gel filtration under conditions of neutral pH and moderate ionic strength, with the use of both integral boundaries, formed between solution and solvent, and finite difference boundaries, formed between solution and solution. The experimental data obtained have been treated by nonlinear least squares procedures to estimate the relevant parameters with their associated standard errors. For this purpose, theoretical equations have been derived for two models, firstly a simple dimer-tetramer reversible equilibrium, and secondly a monomer-dimer-trimer-tetramer reversible equilibrium. In both models the dependence on concentration of the elution volume of the individual species has been taken into account
Densest Subgraph in Dynamic Graph Streams
In this paper, we consider the problem of approximating the densest subgraph
in the dynamic graph stream model. In this model of computation, the input
graph is defined by an arbitrary sequence of edge insertions and deletions and
the goal is to analyze properties of the resulting graph given memory that is
sub-linear in the size of the stream. We present a single-pass algorithm that
returns a approximation of the maximum density with high
probability; the algorithm uses O(\epsilon^{-2} n \polylog n) space,
processes each stream update in \polylog (n) time, and uses \poly(n)
post-processing time where is the number of nodes. The space used by our
algorithm matches the lower bound of Bahmani et al.~(PVLDB 2012) up to a
poly-logarithmic factor for constant . The best existing results for
this problem were established recently by Bhattacharya et al.~(STOC 2015). They
presented a approximation algorithm using similar space and
another algorithm that both processed each update and maintained a
approximation of the current maximum density in \polylog (n)
time per-update.Comment: To appear in MFCS 201
Gilbert damping and spin Coulomb drag in a magnetized electron liquid with spin-orbit interaction
We present a microscopic calculation of the Gilbert damping constant for the
magnetization of a two-dimensional spin-polarized electron liquid in the
presence of intrinsic spin-orbit interaction. First we show that the Gilbert
constant can be expressed in terms of the auto-correlation function of the
spin-orbit induced torque. Then we specialize to the case of the Rashba
spin-orbit interaction and we show that the Gilbert constant in this model is
related to the spin-channel conductivity. This allows us to study the Gilbert
damping constant in different physical regimes, characterized by different
orderings of the relevant energy scales -- spin-orbit coupling, Zeeman
coupling, momentum relaxation rate, spin-momentum relaxation rate, spin
precession frequency -- and to discuss its behavior in various limits.
Particular attention is paid to electron-electron interaction effects,which
enter the spin conductivity and hence the Gilbert damping constant via the spin
Coulomb drag coefficient.Comment: 18 pages, 8 figure
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