14 research outputs found
Artificial intelligence-based classification of motor unit action potentials in real-world needle EMG recordings
ObjectiveTo develop an artificial neural network (ANN) for classification of motor unit action potential (MUAP) duration in real-word, unselected and uncleaned needle electromyography (n-EMG) recordings.MethodsTwo nested ANN models were trained, the first discerning muscle rest, contraction and artifacts in n-EMG recordings from 2674 individual muscles from 326 patients obtained as part of daily care. The second ANN model subsequently used segments labeled as contraction for prediction of prolonged, normal and shortened MUAPs. Model performance was assessed in one internal and two external validation datasets of 184, 30 and 50 muscles, respectively.ResultsThe first model discerned rest, contraction and artifacts with an accuracy of 96%. The second model predicted prolonged, normal and shortened MUAPs with an accuracy of 67%, 83% and 68% in the different validation sets.ConclusionsWe developed a two-step ANN that classifies rest, muscle contraction and artifacts from real-world n-EMG recordings with very high accuracy. MUAP duration classification had moderate accuracy.SignificanceThis is the first study to show that an ANN can classify MUAPs in real-world n-EMG recordings highlighting the potential for AI assisted MUAP classification as a clinical tool.Neurological Motor Disorder
A dual-side fabrication method for silicon plate springs with high out-of-plane stiffness
The MUSE Hubble Ultra Deep Field Survey:II. Spectroscopic redshifts and comparisons to color selections of high-redshift galaxies
We have conducted a two-layered spectroscopic survey (1'x1' ultra deep and
3'x3' deep regions) in the Hubble Ultra Deep Field (HUDF) with the Multi Unit
Spectroscopic Explorer (MUSE). The combination of a large field of view, high
sensitivity, and wide wavelength coverage provides an order of magnitude
improvement in spectroscopically confirmed redshifts in the HUDF; i.e., 1206
secure spectroscopic redshifts for HST continuum selected objects, which
corresponds to 15% of the total (7904). The redshift distribution extends well
beyond z>3 and to HST/F775W magnitudes as faint as ~30 mag (AB, 1-sigma). In
addition, 132 secure redshifts were obtained for sources with no HST
counterparts that were discovered in the MUSE data cubes by a blind search for
emission-line features. In total, we present 1338 high quality redshifts, which
is a factor of eight increase compared with the previously known spectroscopic
redshifts in the same field. We assessed redshifts mainly with the spectral
features [OII] at z<1.5 (473 objects) and Lya at 2.9<z<6.7 (692 objects). With
respect to F775W magnitude, a 50% completeness is reached at 26.5 mag for ultra
deep and 25.5 mag for deep fields, and the completeness remains >~20% up to
28-29 mag and ~27 mag, respectively. We used the determined redshifts to test
continuum color selection (dropout) diagrams of high-z galaxies. The selection
condition for F336W dropouts successfully captures ~80% of the targeted z~2.7
galaxies. However, for higher redshift selections (F435W, F606W, and F775W
dropouts), the success rates decrease to ~20-40%. We empirically redefine the
selection boundaries to make an attempt to improve them to ~60%. The revised
boundaries allow bluer colors that capture Lya emitters with high Lya
equivalent widths falling in the broadbands used for the color-color selection.
Along with this paper, we release the redshift and line flux catalog.Comment: 26 pages, 26 figures, 4 tables, accepted for publication in A&A (MUSE
UDF Series Paper II), the redshift catalogs will be available at the CD
OcorrĂȘncia e recrutamento larval de Teredinidae (Mollusca, Bivalvia) na regiĂŁo do Sistema Costeiro CananĂ©ia-Iguape, SĂŁo Paulo, Brasil
Optimization of five ultra-high vacuum compatible voice coil actuator topologies
ABSTRACT In this paper, a coupled electro-thermal optimization of five ultra-high vacuum compatible voice coil actuators (VCAs) is performed. Based on the resulting force range and steady state coil temperature, a prototype VCA is manufactured. Its performance is measured on a test setup
Properties and redshift evolution of star-forming galaxies with high [OâŻ
We present a study of the [OâŻII
The MUSE Hubble Ultra Deep Field Survey: XI. Constraining the low-mass end of the stellar mass - Star formation rate relation at z < 1
Star-forming galaxies have been found to follow a relatively tight relation between stellar mass (M*) and star formation rate (SFR), dubbed the âstar formation sequenceâ. A turnover in the sequence has been observed, where galaxies with M*â< â1010âMâ follow a steeper relation than their higher mass counterparts, suggesting that the low-mass slope is (nearly) linear. In this paper, we characterise the properties of the low-mass end of the star formation sequence between 7ââ€âlogâM*[Mâ]âââ€ââ10.5 at redshift 0.11â< âzââ< ââ0.91. We use the deepest MUSE observations of the Hubble Ultra Deep Field and the Hubble Deep Field South to construct a sample of 179 star-forming galaxies with high signal-to-noise emission lines. Dust-corrected SFRs are determined from HÎČâλ4861 and Hαâλ6563. We model the star formation sequence with a Gaussian distribution around a hyperplane between logM*, logSFR, and log(1â
+â
z), to simultaneously constrain the slope, redshift evolution, and intrinsic scatter. We find a sub-linear slope for the low-mass regime where log SFR [Mâyrâ1] = 0.83+0.07â0.06 log M*[Mâ]+1.74+0.66â0.68 log(1 + z), increasing with redshift. We recover an intrinsic scatter in the relation of Ïintr = 0.44+0.05â0.04, dex, larger than typically found at higher masses. As both hydrodynamical simulations and (semi-)analytical models typically favour a steeper slope in the low-mass regime, our results provide new constraints on the feedback processes which operate preferentially in low-mass halos.</jats:p