130 research outputs found
Automatic Probe Movement Guidance for Freehand Obstetric Ultrasound
We present the first system that provides real-time probe movement guidance
for acquiring standard planes in routine freehand obstetric ultrasound
scanning. Such a system can contribute to the worldwide deployment of obstetric
ultrasound scanning by lowering the required level of operator expertise. The
system employs an artificial neural network that receives the ultrasound video
signal and the motion signal of an inertial measurement unit (IMU) that is
attached to the probe, and predicts a guidance signal. The network termed
US-GuideNet predicts either the movement towards the standard plane position
(goal prediction), or the next movement that an expert sonographer would
perform (action prediction). While existing models for other ultrasound
applications are trained with simulations or phantoms, we train our model with
real-world ultrasound video and probe motion data from 464 routine clinical
scans by 17 accredited sonographers. Evaluations for 3 standard plane types
show that the model provides a useful guidance signal with an accuracy of 88.8%
for goal prediction and 90.9% for action prediction.Comment: Accepted at the 23rd International Conference on Medical Image
Computing and Computer Assisted Intervention (MICCAI 2020
Green abalone, Haliotis fulgens infected with the agent of withering syndrome do not express disease signs under a temperature regime permissive for red abalone, Haliotis rufescens
The Effects of NMDA Subunit Composition on Calcium Influx and Spike Timing-Dependent Plasticity in Striatal Medium Spiny Neurons
Calcium through NMDA receptors (NMDARs) is necessary for the long-term potentiation (LTP) of synaptic strength; however, NMDARs differ in several properties that can influence the amount of calcium influx into the spine. These properties, such as sensitivity to magnesium block and conductance decay kinetics, change the receptor's response to spike timing dependent plasticity (STDP) protocols, and thereby shape synaptic integration and information processing. This study investigates the role of GluN2 subunit differences on spine calcium concentration during several STDP protocols in a model of a striatal medium spiny projection neuron (MSPN). The multi-compartment, multi-channel model exhibits firing frequency, spike width, and latency to first spike similar to current clamp data from mouse dorsal striatum MSPN. We find that NMDAR-mediated calcium is dependent on GluN2 subunit type, action potential timing, duration of somatic depolarization, and number of action potentials. Furthermore, the model demonstrates that in MSPNs, GluN2A and GluN2B control which STDP intervals allow for substantial calcium elevation in spines. The model predicts that blocking GluN2B subunits would modulate the range of intervals that cause long term potentiation. We confirmed this prediction experimentally, demonstrating that blocking GluN2B in the striatum, narrows the range of STDP intervals that cause long term potentiation. This ability of the GluN2 subunit to modulate the shape of the STDP curve could underlie the role that GluN2 subunits play in learning and development
Multi-Scale Sampling to Evaluate Assemblage Dynamics in an Oceanic Marine Reserve
To resolve the capacity of Marine Protected Areas (MPA) to enhance fish productivity it is first necessary to understand how environmental conditions affect the distribution and abundance of fishes independent of potential reserve effects. Baseline fish production was examined from 2002–2004 through ichthyoplankton sampling in a large (10,878 km2) Southern Californian oceanic marine reserve, the Cowcod Conservation Area (CCA) that was established in 2001, and the Southern California Bight as a whole (238,000 km2 CalCOFI sampling domain). The CCA assemblage changed through time as the importance of oceanic-pelagic species decreased between 2002 (La Niña) and 2003 (El Niño) and then increased in 2004 (El Niño), while oceanic species and rockfishes displayed the opposite pattern. By contrast, the CalCOFI assemblage was relatively stable through time. Depth, temperature, and zooplankton explained more of the variability in assemblage structure at the CalCOFI scale than they did at the CCA scale. CalCOFI sampling revealed that oceanic species impinged upon the CCA between 2002 and 2003 in association with warmer offshore waters, thus explaining the increased influence of these species in the CCA during the El Nino years. Multi-scale, spatially explicit sampling and analysis was necessary to interpret assemblage dynamics in the CCA and likely will be needed to evaluate other focal oceanic marine reserves throughout the world
Plant-Mediated Synthesis of Silver Nanoparticles: Their Characteristic Properties and Therapeutic Applications
Rapid detection of Cr(VI) by AgNPs probe produced by Anacardium occidentale fresh leaf extracts
Dietary factors associated with metabolic syndrome and its components in overweight and obese Brazilian schoolchildren: a cross-sectional study
SRD5A2 gene mutations and polymorphisms in Spanish 46,XY patients with a disorder of sex differentiation
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