962 research outputs found
Media Literacy Definitions
This thesis conducts a critical discourse analysis on definitions of the term āmedia literacyā used by researchers in media literacy educational interventions. These definitions are compared to the skills developed in participants of media literacy interventions. This comparison reveals if and how researchers are operationalizing their stated definition of media literacy. Over half of researchers are using the definition proffered by the National Association for Media Literacy Education. However the disagreement in the field around a definition of the term āmedia literacyā has created confusion. This confusion has left educators falling back on practices scaffolded by the previous educational paradigm. This research finds that the definition of media literacy put forth by NAMLE addresses the paradigm shift that has taken place in the field
Improving the Coherence Time of Superconducting Coplanar Resonators
The quality factor and energy decay time of superconducting resonators have
been measured as a function of material, geometry, and magnetic field. Once the
dissipation of trapped magnetic vortices is minimized, we identify surface
two-level states (TLS) as an important decay mechanism. A wide gap between the
center conductor and the ground plane, as well as use of the superconductor Re
instead of Al, are shown to decrease loss. We also demonstrate that classical
measurements of resonator quality factor at low excitation power are consistent
with single-photon decay time measured using qubit-resonator swap experiments.Comment: 3 pages, 4 figures for the main paper; total 5 pages, 6 figures
including supplementary material. Submitted to Applied Physics Letter
Compressed sensing quantum process tomography for superconducting quantum gates
We apply the method of compressed sensing (CS) quantum process tomography
(QPT) to characterize quantum gates based on superconducting Xmon and phase
qubits. Using experimental data for a two-qubit controlled-Z gate, we obtain an
estimate for the process matrix with reasonably high fidelity compared
to full QPT, but using a significantly reduced set of initial states and
measurement configurations. We show that the CS method still works when the
amount of used data is so small that the standard QPT would have an
underdetermined system of equations. We also apply the CS method to the
analysis of the three-qubit Toffoli gate with numerically added noise, and
similarly show that the method works well for a substantially reduced set of
data. For the CS calculations we use two different bases in which the process
matrix is approximately sparse, and show that the resulting estimates of
the process matrices match each ther with reasonably high fidelity. For both
two-qubit and three-qubit gates, we characterize the quantum process by not
only its process matrix and fidelity, but also by the corresponding standard
deviation, defined via variation of the state fidelity for different initial
states.Comment: 16 pages, 11 figure
A temporal and spatial study of invertebrate communities associated with hard-bottom habitats in the South Atlantic Bight
Species composition, biomass, density, and diversity of benthic invertebrates from six bard-bottom areas were evaluated. Seasonal collections using a dredge, trawl, and suction and grab samplers yielded 432, 525, and 845 taxa, respectively. Based on collections wltb the different gear types, species composition of invertebrates was found to change bathymetrically. Inner- and mlddle-shelf sites were more similar to each other in terms of invertebrate species composition than they were to outer-shelf sites, regardless of season. Sites on the inner and outer shelf were grouped according to latitude; however, results suggest that depth is apparently a more important determinant of invertebrate species composition than either season or latitude. Sponges generally dominated dredge and trawl collections in terms of biomass. Generally, cnidarians, bryozoans, and sponges
dominated at sites In terms of number of taxa collected.
The most abundant smaller macrofauna collected in suction and grab samples were polychaetes, amphipods, and mollusks. Densities of the numerically dominant species changed botb seasonally and bathymetrically, with very few of these species restricted to a specific bathymetrlc zone.
The high diversity of invertebrates from hard-bottom sites is attributed to the large number of rare species. No consistent seasonal changes in diversity or number of species were noted for individual stations or depth zones. In addition, H and its components showed no definite patterns related to depth or latitude. However, more species were collected at middle-shelf sites than at inner- or outer-shelf sites, which may be related to more
stable bottom temperature or greater habitat complexity in that area. (PDF file contains 110 pages.
Denaturation transition of stretched DNA
We generalize the Poland-Scheraga model to consider DNA denaturation in the
presence of an external stretching force. We demonstrate the existence of a
force-induced DNA denaturation transition and obtain the temperature-force
phase diagram. The transition is determined by the loop exponent for which
we find the new value such that the transition is second order
with in . We show that a finite stretching force
destabilizes DNA, corresponding to a lower melting temperature , in
agreement with single-molecule DNA stretching experiments.Comment: 5 pages, 3 figure
Quantum process tomography of two-qubit controlled-Z and controlled-NOT gates using superconducting phase qubits
We experimentally demonstrate quantum process tomography of controlled-Z and
controlled-NOT gates using capacitively-coupled superconducting phase qubits.
These gates are realized by using the state of the phase qubit. We
obtain a process fidelity of 0.70 for the controlled-phase and 0.56 for the
controlled-NOT gate, with the loss of fidelity mostly due to single-qubit
decoherence. The controlled-Z gate is also used to demonstrate a two-qubit
Deutsch-Jozsa algorithm with a single function query.Comment: 10 pages, 8 figures, including supplementary informatio
Multiplexed dispersive readout of superconducting phase qubits
We introduce a frequency-multiplexed readout scheme for superconducting phase
qubits. Using a quantum circuit with four phase qubits, we couple each qubit to
a separate lumped-element superconducting readout resonator, with the readout
resonators connected in parallel to a single measurement line. The readout
resonators and control electronics are designed so that all four qubits can be
read out simultaneously using frequency multiplexing on the one measurement
line. This technology provides a highly efficient and compact means for reading
out multiple qubits, a significant advantage for scaling up to larger numbers
of qubits.Comment: 4 pages, 4 figure
Inferring the effective thickness of polyelectrolytes from stretching measurements at various ionic strengths: applications to DNA and RNA
By resorting to the thick-chain model we discuss how the stretching response
of a polymer is influenced by the self-avoidance entailed by its finite
thickness. The characterization of the force versus extension curve for a thick
chain is carried out through extensive stochastic simulations. The
computational results are captured by an analytic expression that is used to
fit experimental stretching measurements carried out on DNA and single-stranded
RNA (poly-U) in various solutions. This strategy allows us to infer the
apparent diameter of two biologically-relevant polyelectrolytes, namely DNA and
poly-U, for different ionic strengths. Due to the very different degree of
flexibility of the two molecules, the results provide insight into how the
apparent diameter is influenced by the interplay between the
(solution-dependent) Debye screening length and the polymers' ``bare''
thickness. For DNA, the electrostatic contribution to the effective radius,
, is found to be about 5 times larger than the Debye screening length,
consistently with previous theoretical predictions for highly-charged stiff
rods. For the more flexible poly-U chains the electrostatic contribution to
is found to be significantly smaller than the Debye screening length.Comment: iopart, 14 pages, 13 figures, to appear in J. Phys.: Condens. Matte
- ā¦