134 research outputs found
The Founders Go On-Line: An Original Intent Solution to a Jurisdictional Dilemma
The Internet has created a blossoming cyber-economy and a new way of conducting business. Unfortunately for those looking for jurisdictional certainty, however, cyberspace also effectively eliminates geographic boundaries. The unprecedented circumstances set by this new frontier have put federal courts in the unenviable position of deciding whether Internet-based cases meet diversity jurisdiction requirements. Examining the constitutional history and recent use of diversity, this Note argues that the Founders did not foresee an era where every contract or sales case would end up in federal court; rather, they intended diversity jurisdiction to be a rare and perhaps temporary proposition. The author argues that the potential of Internet-based contacts to throw a large number of cases into federal court could overburden the federal system. This Note suggests that the solution to this problem lies in courts following the Founder\u27s intent
Quantifying Graft Detachment after Descemet's Membrane Endothelial Keratoplasty with Deep Convolutional Neural Networks
Purpose: We developed a method to automatically locate and quantify graft
detachment after Descemet's Membrane Endothelial Keratoplasty (DMEK) in
Anterior Segment Optical Coherence Tomography (AS-OCT) scans. Methods: 1280
AS-OCT B-scans were annotated by a DMEK expert. Using the annotations, a deep
learning pipeline was developed to localize scleral spur, center the AS-OCT
B-scans and segment the detached graft sections. Detachment segmentation model
performance was evaluated per B-scan by comparing (1) length of detachment and
(2) horizontal projection of the detached sections with the expert annotations.
Horizontal projections were used to construct graft detachment maps. All final
evaluations were done on a test set that was set apart during training of the
models. A second DMEK expert annotated the test set to determine inter-rater
performance. Results: Mean scleral spur localization error was 0.155 mm,
whereas the inter-rater difference was 0.090 mm. The estimated graft detachment
lengths were in 69% of the cases within a 10-pixel (~150{\mu}m) difference from
the ground truth (77% for the second DMEK expert). Dice scores for the
horizontal projections of all B-scans with detachments were 0.896 and 0.880 for
our model and the second DMEK expert respectively. Conclusion: Our deep
learning model can be used to automatically and instantly localize graft
detachment in AS-OCT B-scans. Horizontal detachment projections can be
determined with the same accuracy as a human DMEK expert, allowing for the
construction of accurate graft detachment maps. Translational Relevance:
Automated localization and quantification of graft detachment can support DMEK
research and standardize clinical decision making.Comment: To be published in Translational Vision Science & Technolog
Giant Josephson current through a single bound state in a superconducting tunnel junction
We study the microscopic structure of the Josephson current in a single-mode
tunnel junction with a wide quasiclassical tunnel barrier. In such a junction
each Andreev bound state carries a current of magnitude proportional to the
{\em amplitude} of the normal electron transmission through the junction.
Tremendous enhancement of the bound state current is caused by the resonance
coupling of superconducting bound states at both superconductor-insulator
interfaces of the junction. The possibility of experimental observation of the
single bound state current is discussed.Comment: 11 pages, [aps,preprint]{revtex
Corneal Pachymetry by AS-OCT after Descemet's Membrane Endothelial Keratoplasty
Corneal thickness (pachymetry) maps can be used to monitor restoration of
corneal endothelial function, for example after Descemet's membrane endothelial
keratoplasty (DMEK). Automated delineation of the corneal interfaces in
anterior segment optical coherence tomography (AS-OCT) can be challenging for
corneas that are irregularly shaped due to pathology, or as a consequence of
surgery, leading to incorrect thickness measurements. In this research, deep
learning is used to automatically delineate the corneal interfaces and measure
corneal thickness with high accuracy in post-DMEK AS-OCT B-scans. Three
different deep learning strategies were developed based on 960 B-scans from 50
patients. On an independent test set of 320 B-scans, corneal thickness could be
measured with an error of 13.98 to 15.50 micrometer for the central 9 mm range,
which is less than 3% of the average corneal thickness. The accurate thickness
measurements were used to construct detailed pachymetry maps. Moreover,
follow-up scans could be registered based on anatomical landmarks to obtain
differential pachymetry maps. These maps may enable a more comprehensive
understanding of the restoration of the endothelial function after DMEK, where
thickness often varies throughout different regions of the cornea, and
subsequently contribute to a standardized postoperative regime.Comment: Fixed typo in abstract: The development set consists of 960 B-scans
from 50 patients (instead of 68). The B-scans from the other 18 patients were
used for testing onl
Spin-Imbalance and Magnetoresistance in Ferromagnet/Superconductor/Ferromagnet Double Tunnel Junctions
We theoretically study the spin-dependent transport in a ferromagnet/super-
conductor/ferromagnet double tunnel junction. The tunneling current in the
antiferromagnetic alignment of the magnetizations gives rise to a spin
imbalance in the superconductor. The resulting nonequilibrium spin density
strongly suppresses the superconductivity with increase of bias voltage and
destroys it at a critical voltage Vc. The results provide a new method not only
for measuring the spin polarization of ferromagnets but also for controlling
superconductivity and tunnel magnetoresistance (TMR) by applying the bias
voltage.Comment: 4pages, to be published in Phys. Rev. Let
Current and Spin-Torque in Double Tunnel Barrier Ferromagnet - Superconductor - Ferromagnet Systems
We calculate the current and the spin-torque in small symmetric double tunnel
barrier ferromagnet - superconductor - ferromagnet (F-S-F) systems.
Spin-accumulation on the superconductor governs the transport properties when
the spin-flip relaxation time is longer than the transport dwell time. In the
elastic transport regime, it is demonstrated that the relative change in the
current (spin-torque) for F-S-F systems equals the relative change in the
current (spin-torque) for F-N-F systems upon changing the relative
magnetization direction of the two ferromagnets. This differs from the results
in the inelastic transport regime where spin-accumulation suppresses the
superconducting gap and dramatically changes the magnetoresistance [S.
Takahashi, H. Imamura, and S. Maekawa, Phys. Rev. Lett. 82, 3911 (1999)]. The
experimental relevance of the elastic and inelastic transport regimes,
respectively, as well as the reasons for the change in the transport properties
are discussed.Comment: 7 page
Self-consistent scattering description of transport in normal-superconductor structures
We present a scattering description of transport in several
normal-superconductor structures. We show that the related requirements of
self-consistency and current conservation introduce qualitative changes in the
transport behavior when the current in the superconductor is not negligible.
The energy thresholds for quasiparticle propagation in the superconductor are
sensitive to the existence of condensate flow (). This dependence is
responsible for a rich variety of transport regimes, including a voltage range
in which only Andreev transmission is possible at the interfaces, and a state
of gapless superconductivity which may survive up to high voltages if
temperature is low. The two main effects of current conservation are a shift
towards lower voltages of the first peak in the differential conductance and an
enhancement of current caused by the greater availability of charge
transmitting scattering channels.Comment: 31 pages, 10 PS figures, Latex file, psfig.sty file is added. To
appear in Phys. Rev. B (Jan 97
First-principles study of nucleation, growth, and interface structure of Fe/GaAs
We use density-functional theory to describe the initial stages of Fe film
growth on GaAs(001), focusing on the interplay between chemistry and magnetism
at the interface. Four features appear to be generic: (1) At submonolayer
coverages, a strong chemical interaction between Fe and substrate atoms leads
to substitutional adsorption and intermixing. (2) For films of several
monolayers and more, atomically abrupt interfaces are energetically favored.
(3) For Fe films over a range of thicknesses, both Ga- and As-adlayers
dramatically reduce the formation energies of the films, suggesting a
surfactant-like action. (4) During the first few monolayers of growth, Ga or As
atoms are likely to be liberated from the interface and diffuse to the Fe film
surface. Magnetism plays an important auxiliary role for these processes, even
in the dilute limit of atomic adsorption. Most of the films exhibit
ferromagnetic order even at half-monolayer coverage, while certain
adlayer-capped films show a slight preference for antiferromagnetic order.Comment: 11 two-column pages, 12 figures, to appear in Phys. Rev.
Direct Classification of Type 2 Diabetes From Retinal Fundus Images in a Population-based Sample From The Maastricht Study
Type 2 Diabetes (T2D) is a chronic metabolic disorder that can lead to
blindness and cardiovascular disease. Information about early stage T2D might
be present in retinal fundus images, but to what extent these images can be
used for a screening setting is still unknown. In this study, deep neural
networks were employed to differentiate between fundus images from individuals
with and without T2D. We investigated three methods to achieve high
classification performance, measured by the area under the receiver operating
curve (ROC-AUC). A multi-target learning approach to simultaneously output
retinal biomarkers as well as T2D works best (AUC = 0.746 [0.001]).
Furthermore, the classification performance can be improved when images with
high prediction uncertainty are referred to a specialist. We also show that the
combination of images of the left and right eye per individual can further
improve the classification performance (AUC = 0.758 [0.003]), using a
simple averaging approach. The results are promising, suggesting the
feasibility of screening for T2D from retinal fundus images.Comment: to be published in the proceeding of SPIE - Medical Imaging 2020, 6
pages, 1 figur
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