2,637 research outputs found
Imaging diagnosis-computed tomography of traction bronchiectasis secondary to pulmonary fibrosis in a Patterdale Terrier
An 8-year-old, Patterdale terrier was referred for evaluation of tachypnoea, exercise intolerance, and weight loss. Computed tomographic images showed pneumomediastinum, diffuse pulmonary ground glass opacity, and marked dilatation of peripheral bronchi, but no evidence of thickened bronchial walls. The histopathologic diagnosis was diffuse pulmonary interstitial fibrosis, type II pneumocyte hyperplasia, and bronchiectasis. The lack of evidence of primary bronchitis supported a diagnosis of traction bronchiectasis. Traction bronchiectasis can occur as a sequela to pulmonary fibrosis in dogs. (C) 2016 American College of Veterinary Radiology
Time Protection: the Missing OS Abstraction
Timing channels enable data leakage that threatens the security of computer
systems, from cloud platforms to smartphones and browsers executing untrusted
third-party code. Preventing unauthorised information flow is a core duty of
the operating system, however, present OSes are unable to prevent timing
channels. We argue that OSes must provide time protection in addition to the
established memory protection. We examine the requirements of time protection,
present a design and its implementation in the seL4 microkernel, and evaluate
its efficacy as well as performance overhead on Arm and x86 processors
Synthesizing Functional Reactive Programs
Functional Reactive Programming (FRP) is a paradigm that has simplified the
construction of reactive programs. There are many libraries that implement
incarnations of FRP, using abstractions such as Applicative, Monads, and
Arrows. However, finding a good control flow, that correctly manages state and
switches behaviors at the right times, still poses a major challenge to
developers. An attractive alternative is specifying the behavior instead of
programming it, as made possible by the recently developed logic: Temporal
Stream Logic (TSL). However, it has not been explored so far how Control Flow
Models (CFMs), as synthesized from TSL specifications, can be turned into
executable code that is compatible with libraries building on FRP. We bridge
this gap, by showing that CFMs are indeed a suitable formalism to be turned
into Applicative, Monadic, and Arrowized FRP. We demonstrate the effectiveness
of our translations on a real-world kitchen timer application, which we
translate to a desktop application using the Arrowized FRP library Yampa, a web
application using the Monadic threepenny-gui library, and to hardware using the
Applicative hardware description language ClaSH.Comment: arXiv admin note: text overlap with arXiv:1712.0024
Assessment and Evaluation of Sand Control Methods for a North Sea Field
Imperial Users onl
Joining refractory/austenitic bimetal tubing Supplemental report
Joining bimetal tubing consisting of austenitic stainless steel with inner lining of niobium or tantalu
Learning Bayes-optimal dendritic opinion pooling
In functional network models, neurons are commonly conceptualized as linearly
summing presynaptic inputs before applying a non-linear gain function to
produce output activity. In contrast, synaptic coupling between neurons in the
central nervous system is regulated by dynamic permeabilities of ion channels.
So far, the computational role of these membrane conductances remains unclear
and is often considered an artifact of the biological substrate. Here we
demonstrate that conductance-based synaptic coupling allow neurons to
represent, process and learn uncertainties. We suggest that membrane potentials
and conductances on dendritic branches code opinions with associated
reliabilities. The biophysics of the membrane combines these opinions by taking
account their reliabilities, and the soma thus acts as a decision maker. We
derive a gradient-based plasticity rule, allowing neurons to learn desired
target distributions and weight synaptic inputs by their relative
reliabilities. Our theory explains various experimental findings on the system
and single-cell level related to multi-sensory integration, and makes testable
predictions on dendritic integration and synaptic plasticity.Comment: 36 pages, 10 figures; Mihai A. Petrovici and Walter Senn share senior
authorshi
Exact computation of the Maximum Entropy Potential of spiking neural networks models
Understanding how stimuli and synaptic connectivity in uence the statistics
of spike patterns in neural networks is a central question in computational
neuroscience. Maximum Entropy approach has been successfully used to
characterize the statistical response of simultaneously recorded spiking
neurons responding to stimuli. But, in spite of good performance in terms of
prediction, the fitting parameters do not explain the underlying mechanistic
causes of the observed correlations. On the other hand, mathematical models of
spiking neurons (neuro-mimetic models) provide a probabilistic mapping between
stimulus, network architecture and spike patterns in terms of conditional
proba- bilities. In this paper we build an exact analytical mapping between
neuro-mimetic and Maximum Entropy models.Comment: arXiv admin note: text overlap with arXiv:1309.587
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