4,937 research outputs found
Birds of the North Gulf Coast - Prince William Sound Region, Alaska
The North Gulf Coast - Prince William Sound region of Alaska, phytographically, lies at the northern limit of the Sitka Spruce-hemlock coastal/subalpine forests of the Pacific Coast; it includes approximately 178,500 km2 and a shoreline of approximately 8,500 km. Fourteen habitats are utilized by birds: tundra; shrub thickets; hemlock-Sitka Spruce forests; bogs; mixed deciduous-spruce woodlands; marshes; lacustrine waters; fluviatile waters; cliffs, bluffs, and screes; moraines, alluvia, and barrier islands; beaches and tidal flats; rocky shores and reefs; inshore waters; and offshore waters. Two hundred nineteen species of birds have been recorded in the region, 111 of which are primarily water-related. Status, abundance, habitat, and seasonal occurrence are discussed in the annotated list of species. The geographic location and restrictive topography of the region make it a spectacular corridor for millions of migrating birds. In spring millions of Pintails, Dunlins, Western Sandpipers, and Northern Phalaropes move through the region, as do tens of thousands of Whistling Swans, Snow Geese, Knots, and Sanderlings. Fall concentrations of White-fronted Geese and Sandhill Cranes may exceed 100,000's. Species with notably large summering populations include Trumpeter Swans (several hundred breeding pairs), Bald Eagles (1,800-2,000 breeding pairs), Aleutian Terns (150-250 breeding pairs on Copper River Delta), Marbled Murrelets (probably millions), and Kittlitz's Murrelets (probably a few 100,000's). Significant range extensions reported include Yellow-billed Loons (fairly common in winter), Pink-footed and Pale-footed shearwaters, Brandt's Cormorants (breeding), Red-faced Cormorants (breeding), Steller's Eiders (winter), Bristle-thighed Curlews (migrant), Bar-tailed Godwits (migrant), Crested Auklets (winter), and northernmost wintering populations of waterfowl (Canada Geese, Gadwalls, Pintails, Green-winged Teals, American Widgeons) and shorebirds (Surfbirds, Black Trunstones, Dunlins, and Sanderlings). Some unexpected species reported include Skua, Anna's Hummingbird, Purple Marin, Yellowthroat, Common Grackle, and White-throated Sparrow
Schemes of implementation in NMR of quantum processors and Deutsch-Jozsa algorithm by using virtual spin representation
Schemes of experimental realization of the main two qubit processors for
quantum computers and Deutsch-Jozsa algorithm are derived in virtual spin
representation. The results are applicable for every four quantum states
allowing the required properties for quantum processor implementation if for
qubit encoding virtual spin representation is used. Four dimensional Hilbert
space of nuclear spin 3/2 is considered in details for this aimComment: 15 pages, 3 figure
Quantum storage on subradiant states in an extended atomic ensemble
A scheme for coherent manipulation of collective atomic states is developed
such that total subradiant states, in which spontaneous emission is suppressed
into all directions due to destructive interference between neighbor atoms, can
be created in an extended atomic ensemble. The optimal conditions for creation
of such states and suitability of them for quantum storage are discussed. It is
shown that in order to achieve the maximum signal-to-noise ratio the shape of a
light pulse to be stored and reconstructed using a homogeneously broadened
absorbtion line of an atomic system should be a time-reversed regular part of
the response function of the system. In the limit of high optical density, such
pulses allow one to prepare collective subradiant atomic states with near flat
spatial distribution of the atomic excitation in the medium.Comment: V2: considerably revised (title, text). V3: minor changes - final
version as published in PR
Oral History Interview: Ray M. Kessel
This interview is one of series conducted concerning the Oral History of Appalachia. Dr. Ray Kessel was Chairman and Professor of Family Practice at the Medical School of Marshall University. In this interview, he discusses the medical profession, his experience working in a hospital, rural health, the Buffalo Creek accident (a flood), and health in West Virginia.https://mds.marshall.edu/oral_history/1226/thumbnail.jp
Coherent control of collective spontaneous emission in an extended atomic ensemble and quantum storage
Coherent control of collective spontaneous emission in an extended atomic
ensemble resonantly interacting with single-photon wave packets is analyzed. A
scheme for coherent manipulation of collective atomic states is developed such
that superradiant states of the atomic system can be converted into subradiant
ones and vice versa. Possible applications of such a scheme for optical quantum
state storage and single-photon wave packet shaping are discussed. It is shown
that also in the absence of inhomogeneous broadening of the resonant line,
single-photon wave packets with arbitrary pulse shape may be recorded as a
subradiant state and reconstructed even although the duration of the wave
packets is larger than the superradiant life-time. Specifically the
applicability for storing time-bin qubits, which are used in quantum
cryptography is analyzed.Comment: 11 pages, 4 figures, submitted to PR
Murine developmental control genes.
Various strategies have been used to isolate genes that participate in the regulation of mouse development. Gene families that have been identified on the basis of their homology to motifs within Drosophila control genes or human transcription factor genes, namely homeobox (Hox), paired-box (Pax), and POU genes, can be compared with respect to gene organization, structure, and expression patterns. The functions of these genes can be analyzed molecularly in vitro and in vivo with the use of available mouse mutants or transgenic mice. In addition, it has been possible to generate gain- or loss-of-function mutations by random or targeted introduction of transgenes. Models derived from these studies can reveal the successive steps of developmental control on a genetic level
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