216 research outputs found
Criminal Law: Customer’s Permanent Exclusion From Retail Store Due to Prior Shoplifting Arrests Held Enforceable Under Criminal Trespass Statute
In interpretive research, trustworthiness has developed to become an important alternative for measuring the value of research and its effects, as well as leading the way of providing for rigour in the research process. The article develops the argument that trustworthiness plays an important role in not only effecting change in a research project’s original setting, but also that trustworthy research contributes toward building a body of knowledge that can play an important role in societal change. An essential aspect in the development of this trustworthiness is its relationship to context. To deal with the multiplicity of meanings of context, we distinguish between contexts at different levels of the research project: the domains of the researcher, the collective, and the individual participant. Furthermore, we argue that depending on the primary purpose associated with the collective learning potential, critical potential, or performative potential of phenomenographic research, developing trustworthiness may take different forms and is related to aspects of pedagogical legitimacy, social legitimacy, and epistemological legitimacy. Trustworthiness in phenomenographic research is further analysed by distinguishing between the internal horizon – the constitution of trustworthiness as it takes place within the research project – and the external horizon, which points to the impact of the phenomenographic project in the world mediated by trustworthiness
Proximity Effect and Multiple Andreev Reflections in Chaotic Josephson junctions
We study the dc-current transport in a voltage biased superconductor-chaotic
dot-superconductor junction with an induced proximity effect(PE) in the dot. It
is found that for a Thouless energy of the dot smaller than the
superconducting energy gap , the PE is manifested as peaks in the
differential conductance at voltages of order away from the even
subharmonic gap structures . These peaks are
insensitive to temperatures but are suppressed by a weak
magnetic field. The current for suppressed PE is independent of and
magnetic field and is shown to be given by the Octavio-Tinkham-Blonder-Klapwijk
theory.Comment: 4 pages, 3 figure
Coherent electronic transport through a superconducting film
We study coherent quantum transport through a superconducting film connected
to normal-metal electrodes. Simple expressions for the differential conductance
and the local density of states are obtained in the clean limit and for
transparent interfaces. Quasiparticle interference causes periodic vanishing of
the Andreev reflection at the energies of geometrical resonances, subgap
transport, and gapless superconductivity near the interfaces. Application of
the results to spectroscopic measurements of the superconducting gap and the
Fermi velocity is analyzed.Comment: 5 pages, 4 figure
Coherent current transport in wide ballistic Josephson junctions
We present an experimental and theoretical investigation of coherent current
transport in wide ballistic superconductor-two dimensional electron
gas-superconductor junctions. It is found experimentally that upon increasing
the junction length, the subharmonic gap structure in the current-voltage
characteristics is shifted to lower voltages, and the excess current at
voltages much larger than the superconducting gap decreases. Applying a theory
of coherent multiple Andreev reflection, we show that these observations can be
explained in terms of transport through Andreev resonances.Comment: 4 pages, 4 figure
DC current through a superconducting two-barrier system
We analyze the influence of the structure within a SNS junction on the
multiple Andreev resonances in the subgap I-V characteristics. Coherent
interference processes and incoherent propagation in the normal region are
considered. The detailed geometry of the normal region where the voltage drops
in superconducting contacts can lead to observable effects in the conductance
at low voltages.Comment: 11 pages, including 7 postscript file
Chiral Logs in Quenched QCD
The quenched chiral logs are examined on a lattice with
Iwasaki gauge action and overlap fermions. The pion decay constant is
used to set the lattice spacing, . With pion mass as low
as , we see the quenched chiral logs clearly in
and , the pseudoscalar decay constant. We analyze the data
to determine how low the pion mass needs to be in order for the quenched
one-loop chiral perturbation theory (PT) to apply. With the constrained
curve-fitting method, we are able to extract the quenched chiral log parameter
together with other low-energy parameters. Only for do we obtain a consistent and stable fit with a constant
which we determine to be 0.24(3)(4) (at the chiral scale ). By comparing to the lattice, we estimate the
finite volume effect to be about 2.7% for the smallest pion mass. We also
fitted the pion mass to the form for the re-summed cactus diagrams and found
that its applicable region is extended farther than the range for the one-loop
formula, perhaps up to MeV. The scale independent
is determined to be 0.20(3) in this case. We study the quenched
non-analytic terms in the nucleon mass and find that the coefficient
in the nucleon mass is consistent with the prediction of one-loop PT\@.
We also obtain the low energy constant from . We conclude from
this study that it is imperative to cover only the range of data with the pion
mass less than in order to examine the chiral behavior of
the hadron masses and decay constants in quenched QCD and match them with
quenched one-loop PT\@.Comment: 37 pages and 24 figures, pion masses are fitted to the form for the
re-summed cactus diagrams, figures added, to appear in PR
BtubA-BtubB Heterodimer Is an Essential Intermediate in Protofilament Assembly
BACKGROUND:BtubA and BtubB are two tubulin-like genes found in the bacterium Prosthecobacter. Our work and a previous crystal structure suggest that BtubB corresponds to alpha-tubulin and BtubA to beta-tubulin. A 1:1 mixture of the two proteins assembles into tubulin-like protofilaments, which further aggregate into pairs and bundles. The proteins also form a BtubA/B heterodimer, which appears to be a repeating subunit in the protofilament. METHODOLOGY/PRINCIPAL FINDINGS:We have designed point mutations to disrupt the longitudinal interfaces bonding subunits into protofilaments. The mutants are in two classes, within dimers and between dimers. We have characterized one mutant of each class for BtubA and BtubB. When mixed 1:1 with a wild type partner, none of the mutants were capable of assembly. An excess of between-dimer mutants could depolymerize preformed wild type polymers, while within-dimer mutants had no activity. CONCLUSIONS:An essential first step in assembly of BtubA + BtubB is formation of a heterodimer. An excess of between-dimer mutants depolymerize wild type BtubA/B by sequestering the partner wild type subunit into inactive dimers. Within-dimer mutants cannot form dimers and have no activity
Josephson effect in double-barrier superconductor-ferromagnet junctions
We study the Josephson effect in ballistic double-barrier SIFIS planar
junctions, consisting of bulk superconductors (S), a clean metallic ferromagnet
(F), and insulating interfaces (I). We solve the scattering problem based on
the Bogoliubov--de Gennes equations and derive a general expression for the dc
Josephson current, valid for arbitrary interfacial transparency and Fermi wave
vectors mismatch (FWVM). We consider the coherent regime in which quasiparticle
transmission resonances contribute significantly to the Andreev process. The
Josephson current is calculated for various parameters of the junction, and the
influence of both interfacial transparency and FWVM is analyzed. For thin
layers of strong ferromagnet and finite interfacial transparency, we find that
coherent (geometrical) oscillations of the maximum Josephson current are
superimposed on the oscillations related to the crossover between 0 and
states. For the same case we find that the temperature-induced
transition occurs if the junction is very close to the crossovers at zero
temperature.Comment: 13 pages, 6 figure
Evaluation of very high- and very low-dose intravitreal aflibercept in patients with neovascular age-related macular degeneration.
PURPOSE: To determine bioactivity and duration of effect of intravitreal aflibercept injection (also known as vascular endothelial growth factor Trap-Eye) for neovascular age-related macular degeneration (AMD).
METHODS: In this double-masked, phase 1 study, 28 patients with lesions ≤12 disc areas, ≥50% active choroidal neovascularization (CNV), and best corrected visual acuity (BCVA) ≤20/40 were randomized 1:1 to a single intravitreal injection of aflibercept 0.15 or 4 mg. The primary end point was the change from baseline in central retinal/lesion thickness (CR/LT) at week-8. Secondary outcomes were the change from baseline BCVA, the change in CNV lesion size and area of leakage, and proportion of patients requiring repeat injection at 8 weeks.
RESULTS: Mean percent decrease in CR/LT for the 4-mg and 0.15-mg groups was, respectively, 34.2 versus 13.3 at week 4 (P=0.0065), 23.8 versus 5.9 at week 6 (P=0.0380), and 25.2% versus 11.3% at week 8 (P=0.150). The 4-mg group gained a mean of 4.5 letters in BCVA (6/14 patients gaining ≥10 letters) versus 1.1 letters in 0.15-mg group (1/14 gaining ≥10 letters) at week 8. Fewer patients needed retreatment in the 4-mg group at week 8. No serious adverse event or ocular inflammation was reported in either group.
CONCLUSIONS: Intravitreal aflibercept 4 mg had a safety profile similar to that of the very low dose 0.15 mg, and was well-tolerated. The 4-mg dose significantly reduced foveal thickening at weeks 4 and 6, significantly improved BCVA at weeks 6, and reduced the need for repeat injection after 8 weeks compared with intravitreal aflibercept 0.15 mg in neovascular AMD patients
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