3,830 research outputs found
Caenorhabditis elegans gene unc-25 encodes glutamic acid decarboxylase and is required for synaptic transmission but not synaptic development
Journal ArticleThe neurotransmitter GABA has been proposed to play a role during nervous system development. We show that the Caenorhabditis elegans gene unc-25 encodes glutamic acid decarboxylase (GAD), the GABA biosynthetic enzyme. unc-25 is expressed specifically in GABAergic neurons. Null mutations in unc-25 eliminate the UNC-25 protein or alter amino acids conserved in all known GADs, result in a complete lack of GABA, and cause defects in all GABA-mediated behaviors
Analog hardware for detecting discontinuities in early vision
The detection of discontinuities in motion, intensity, color, and depth is a well-studied but difficult problem in computer vision [6]. We discuss the first hardware circuit that explicitly implements either analog or binary line processes in a deterministic fashion. Specifically, we show that the processes of smoothing (using a first-order or membrane type of stabilizer) and of segmentation can be implemented by a single, two-terminal nonlinear voltage-controlled resistor, the “resistive fuse”; and we derive its current-voltage relationship from a number of deterministic approximations to the underlying stochastic Markov random fields algorthms. The concept that the quadratic variation functionals of early vision can be solved via linear resistive networks minimizing power dissipation [37] can be extended to non-convex variational functionals with analog or binary line processes being solved by nonlinear resistive networks minimizing the electrical co-content.
We have successfully designed, tested, and demonstrated an analog CMOS VLSI circuit that contains a 1D resistive network of fuses implementing piecewise smooth surface interpolation. We furthermore demonstrate the segmenting abilities of these analog and deterministic “line processes” by numerically simulating the nonlinear resistive network computing optical flow in the presence of motion discontinuities. Finally, we discuss various circuit implementations of the optical flow computation using these circuits
Poster: Making Edge-assisted LiDAR Perceptions Robust to Lossy Point Cloud Compression
Real-time light detection and ranging (LiDAR) perceptions, e.g., 3D object
detection and simultaneous localization and mapping are computationally
intensive to mobile devices of limited resources and often offloaded on the
edge. Offloading LiDAR perceptions requires compressing the raw sensor data,
and lossy compression is used for efficiently reducing the data volume. Lossy
compression degrades the quality of LiDAR point clouds, and the perception
performance is decreased consequently. In this work, we present an
interpolation algorithm improving the quality of a LiDAR point cloud to
mitigate the perception performance loss due to lossy compression. The
algorithm targets the range image (RI) representation of a point cloud and
interpolates points at the RI based on depth gradients. Compared to existing
image interpolation algorithms, our algorithm shows a better qualitative result
when the point cloud is reconstructed from the interpolated RI. With the
preliminary results, we also describe the next steps of the current work.Comment: extended abstract of 2 pages, 2 figures, 1 tabl
Investigating the Quality of Life for Children with Autism Spectrum Disorder Scale Using Rasch Methodology
Our purpose in this study was to provide additional psychometric evidence of the Quality of Life for Children with Autism Spectrum Disorder (QOLASD-C) scale. We used Rasch modeling to investigate the QOLASD-C functioning, the characteristics of the items comprising the scale, and the item functioning across subgroups of children with ASD based on gender and race/ethnicity. Results showed that QOLASD-C was unidimensional, met the local independence assumption, and measured quality of life (QOL). The items showed excellent fit to the model and good discriminating ability between low and high QOL. Most items showed a moderate difficulty level. No differential item functioning was observed based on children\u27s gender and race/ethnicity. Implications for research and practice are discussed
Fundamental Limits to Coherent Photon Generation with Solid-State Atomlike Transitions
Coherent generation of indistinguishable single photons is crucial for many
quantum communication and processing protocols. Solid-state realizations of
two-level atomic transitions or three-level spin- systems offer
significant advantages over their atomic counterparts for this purpose, albeit
decoherence can arise due to environmental couplings. One popular approach to
mitigate dephasing is to operate in the weak excitation limit, where excited
state population is minimal and coherently scattered photons dominate over
incoherent emission. Here we probe the coherence of photons produced using
two-level and spin- solid-state systems. We observe that the coupling
of the atomic-like transitions to the vibronic transitions of the crystal
lattice is independent of driving strength and detuning. We apply a polaron
master equation to capture the non-Markovian dynamics of the ground state
vibrational manifolds. These results provide insight into the fundamental
limitations for photon coherence from solid-state quantum emitters, with the
consequence that deterministic single-shot quantum protocols are impossible and
inherently probabilistic approaches must be embraced.Comment: 16 pages [with supplementary information], 8 figure
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