Microwave Spectroscopy of a Cooper-Pair Transistor Coupled to a Lumped-Element Resonator

We have studied the microwave response of a single Cooper-pair transistor (CPT) coupled to a lumped-element microwave resonator. The resonance frequency of this circuit, $f_{r}$, was measured as a function of the charge $n_{g}$ induced on the CPT island by the gate electrode, and the phase difference across the CPT, $\phi_{B}$, which was controlled by the magnetic flux in the superconducting loop containing the CPT. The observed $f_{r}(n_{g},\phi_{B})$ dependences reflect the variations of the CPT Josephson inductance with $n_{g}$ and $\phi_{B}$ as well as the CPT excitation when the microwaves induce transitions between different quantum states of the CPT. The results are in excellent agreement with our simulations based on the numerical diagonalization of the circuit Hamiltonian. This agreement over the whole range of $n_{g}$ and $\phi_{B}$ is unexpected, because the relevant energies vary widely, from 0.1K to 3K. The observed strong dependence $f_{r}(n_{g},\phi_{B})$ near the resonance excitation of the CPT provides a tool for sensitive charge measurements.Comment: 10 pages, 6 figure

Taxation

This Article reviews significant recent developments in the laws affecting Virginia state and local taxation. Its Parts cover legislative activity, judicial decisions, and selected opinions and other pronouncements from the Virginia Department of Taxation (the “Tax Department” or “Department of Taxation”) and the Attorney General of Virginia over the past year. Part I of this Article addresses state taxes. Part II covers local taxes, including real and tangible personal property taxes, license taxes, recordation taxes, and administrative local tax procedures. The overall purpose of this Article is to provide Virginia tax and general practitioners with a concise overview of the recent developments in Virginia taxation that are most likely to impact their clients. However, it does not address many of the numerous minor, locality-specific, or technical legislative changes to Title 58.1 of the Virginia Code, which covers taxation

Taxation

This Article reviews significant recent developments in the laws affecting Virginia state and local taxation. Its Parts cover legislative activity, judicial decisions, and selected opinions and other pronouncements from the Virginia Department of Taxation (the “Tax Department”) and the Attorney General of Virginia over the past year. Part I of this Article addresses state taxes. Part II covers local taxes, including real and tangible personal property taxes, license taxes, recordation taxes, and administrative local tax procedures. The overall purpose of this Article is to provide Virginia tax and general practitioners with a concise overview of the recent developments in Virginia taxation that are most likely to impact their clients. However, it does not address many of the numerous minor, locality-specific or technical legislative changes to Title 58.1 of the Virginia Code, which covers taxation

The 67 Hz Feature in the Black Hole Candidate GRS 1915+105 as a Possible ``Diskoseismic'' Mode

The Rossi X-ray Timing Explorer (RXTE) has made feasible for the first time the search for high-frequency (~ 100 Hz) periodic features in black hole candidate (BHC) systems. Such a feature, with a 67 Hz frequency, recently has been discovered in the BHC GRS 1915+105 (Morgan, Remillard, & Greiner). This feature is weak (rms variability ~0.3%-1.6%), stable in frequency (to within ~2 Hz) despite appreciable luminosity fluctuations, and narrow (quality factor Q ~ 20). Several of these properties are what one expects for a ``diskoseismic'' g-mode in an accretion disk about a 10.6 M_sun (nonrotating) - 36.3 M_sun (maximally rotating) black hole (if we are observing the fundamental mode frequency). We explore this possibility by considering the expected luminosity modulation, as well as possible excitation and growth mechanisms---including turbulent excitation, damping, and ``negative'' radiation damping. We conclude that a diskoseismic interpretation of the observations is viable.Comment: 4 Pages, Latex (emulateapj.sty included), to Appear in ApJ Letters, Vol. 477, Final Version with Updated Reference

Phylogeny and biogeography of Morinaceae (Dipsacales) based on nuclear and chloroplast DNA sequences

AbstractThe Morinaceae (Dipsacales) contains 13 species placed in Acanthocalyx, Cryptothladia or Morina, and is distributed from the mountains of southeastern Europe through the Himalayas to the Qinghai-Tibetan Plateau, mainly in alpine habitats. Sequence data from two chloroplast regions (the trnK intron and the trnL-F region) and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA were used to infer phylogenetic relationships of Morinaceae and related Dipsacales. Both the nuclear and chloroplast datasets, as well as the combined data, provide strong support for relationships within the Valerina clade, placing Morinaceae as the sister group of a clade containing Valerianaceae and Dipsacaceae plus Triplostegia. The Morinaceae, Acanthocalyx, Cryptothladia, and a clade containing Morina and Cryptothladia, are all supported as monophyletic. However, Morina was found to be paraphyletic in several of our analyses, with Morina longifolia more closely related to Cryptothladia than to other Morina species. There is some evidence that Morina longifolia produces cleistogamous flowers, as do Cryptothladia species. Dispersal-vicariance analyses support the view that Valerina radiated initially within Asia, with subsequent movement into Europe in Morinaceae, Dipsacaceae, and Valerianaceae, and into the New World in Valerianaceae. For Morinaceae, as for a number of plant groups, the Brahmaputra river drainage marks a significant biogeographic divide, although this has been spanned within Acanthocalyx and the Morina-Cryptothladia lineage

Production of multipartite entanglement for electron spins in quantum dots

We propose how to generate genuine multipartite entanglement of electron spin qubits in a chain of quantum dots using the naturally available single-qubit rotations and two-qubit Heisenberg exchange interaction in the system. We show that the minimum number of required operations to generate entangled states of the GHZ-, cluster and W-type scales linearly with the number of qubits and estimate the fidelities of the generated entangled cluster states. As the required single and two-qubit operations have recently been realized, our proposed scheme opens the way for experimental investigation of multipartite entanglement with electron spin qubits.Comment: 8 pages, 2 Figure

Isolation, via 454 Sequencing, and Characterization of Microsatellites for Vachellia farnesiana (Fabaceae: Mimosoideae)

This work is licensed under a Creative Commons Attribution License (CC-BY-NC-SA) (http://creativecommons.org/licenses/by-nc-sa/4.0).Premise of the study: We isolated 15 polymorphic microsatellite markers from Vachellia farnesiana for use in population genetic studies to determine the native range of the species. Methods and Results: Initially, 454 shotgun sequencing was used to identify and design primers for 68 microsatellite loci. Of these, we trialed 47 loci in the target species, and 42 (89%) amplified a product of expected size. Fifteen of the 47 loci were screened for variation in 21 individuals from the native range of V. farnesiana in southern Mexico and 20 from northwestern Australia. Fourteen loci were polymorphic, with observed heterozygosity ranging from 0.026 to 1.00 (mean = 0.515) and two to 12 alleles per locus (average = 5.2). Cross-amplification was successful in four to 11 loci in three other Vachellia species. Conclusions: The new microsatellite loci will be useful in understanding genetic variation and investigating the role of human-mediated dispersal in the current distribution of V. farnesiana

Modal quantum theory

We present a discrete model theory similar in structure to ordinary quantum mechanics, but based on a finite field instead of complex amplitudes. The interpretation of this theory involves only the "modal" concepts of possibility and necessity rather than quantitative probability measures. Despite its simplicity, our model theory includes entangled states and has versions of both Bell's theorem and the no cloning theorem.Comment: Presented at the 7th Workshop on Quantum Physics and Logic, Oxford University (29-30 May 2010). Revised 1 Aug 2011 in response to referee comment

CN Bimodality at Low Metallicity: The Globular Cluster M53

We present low resolution UV-blue spectroscopic observations of red giant stars in the globular cluster M53 ([Fe/H]=-1.84), obtained to study primordial abundance variations and deep mixing via the CN and CH absorption bands. The metallicity of M53 makes it an attractive target: a bimodal distribution of 3883 angstrom CN bandstrength is common in moderate- and high-metallicity globular clusters ([Fe/H] > -1.6) but unusual in those of lower metallicity ([Fe/H] < -2.0). We find that M53 is an intermediate case, and has a broad but not strongly bimodal distribution of CN bandstrength, with CN and CH bandstrengths anticorrelated in the less-evolved stars. Like many other globular clusters, M53 also exhibits a general decline in CH bandstrength and [C/Fe] abundance with rising luminosity on the red giant branch.Comment: 8 pages including 11 figures and 1 table, accepted by PAS

Establishing Pine Monocultures and Mixed Pine-Hardwood Stands on Reclaimed Surface Mined Land in Eastern Kentucky: Implications for Forest Resilience in a Changing Climate

Surface mining and mine reclamation practices have caused significant forest loss and forest fragmentation in Appalachia. Shortleaf pine (Pinus echinata) is threatened by a variety of stresses, including diseases, pests, poor management, altered fire regimes, and climate change, and the species is the subject of a widescale restoration effort. Surface mines may present opportunity for shortleaf pine restoration; however, the survival and growth of shortleaf pine on these harsh sites has not been critically evaluated. This paper presents first-year survival and growth of native shortleaf pine planted on a reclaimed surface mine, compared to non-native loblolly pine (Pinus taeda), which has been highly successful in previous mined land reclamation plantings. Pine monoculture plots are also compared to pine-hardwood polyculture plots to evaluate effects of planting mix on tree growth and survival, as well as soil health. Initial survival of shortleaf pine is low (42%), but height growth is similar to that of loblolly pine. No differences in survival or growth were observed between monoculture and polyculture treatments. Additional surveys in coming years will address longer-term growth and survival patterns of these species, as well as changes to relevant soil health endpoints, such as soil carbon