5,026 research outputs found
Species boundaries of Pardosa concinna and P. lapponica (Araneae: Lycosidae) in the northern Nearctic: morphology and DNA barcodes
No full textSim, Kathrin A., Buddle, Christopher M., Wheeler, Terry A. (2014): Species boundaries of Pardosa concinna and P. lapponica (Araneae: Lycosidae) in the northern Nearctic: morphology and DNA barcodes. Zootaxa 3884 (2): 169-178, DOI: http://dx.doi.org/10.11646/zootaxa.3884.2.
High-speed 3D structured illumination microscopy (SIM)
No full textSuper-resolution Structured Illumination Microscopy (SIM) is a microscopy technique which provides a two-fold enhancement in resolution over traditional microscopy, beyond the diffraction limit of light. In this thesis, I investigate the patiotemporal limits of SIM and explore new strategies to increase speed and throughput. I describe a new method, developed to assess the spatiotemporal resolution limits of SIM in silico. This method is based on tracking the magnitude of different spatial frequencies in the reconstructed SIM images while modulating the intensity of the illumination with different temporal frequencies. Notably, it was applied to determine the temporal resolution limits of a recent SIM reconstruction approach termed interleaving reconstruction. It was demonstrated that the latter does not provide the increase in temporal resolution that it claims over traditional SIM reconstruction approaches.
After identifying the factors limiting the performance of current SIM systems through a thorough study of the literature, a simple and robust optical design for SIM is proposed, which features a high power efficiency, imaging versatility and theoretically capable of live-cell imaging at speeds up to 800 two-dimensional SIM stacks/second and 740 three-dimensional SIM stacks/second. The potential enhancement in imaging speed provided by this new system relies on the use of a single moving part (galvo) to perform the rotations and phase shifts of the striped illumination with minimum switching delays, bringing the pattern switching speed to 2,600 frames/second. The first laboratory prototype was built successfully, and preliminary tests and characterisations were performed. Results show that the striped illumination pattern can be generated with high temporal stability. While the modulation contrast is yet not sufficient to obtain good-quality SIM images, strategies to reach the required contrast and improve the overall performance of the system in the future are proposed. Biological applications that will benefit from the microscope are explored.Open Acces
Efficient Jacobian-Based Inverse Kinematics With Sim-to-Real Transfer of Soft Robots by Learning
No full textThis article presents an efficient learning-based method to solve the <italic>inverse kinematic</italic> (IK) problem on soft robots with highly nonlinear deformation. The major challenge of efficiently computing IK for such robots is due to the lack of analytical formulation for either forward or inverse kinematics. To address this challenge, we employ neural networks to learn both the mapping function of forward kinematics and also the Jacobian of this function. As a result, Jacobian-based iteration can be applied to solve the IK problem. A sim-to-real training transfer strategy is conducted to make this approach more practical. We first generate a large number of samples in a simulation environment for learning both the kinematic and the Jacobian networks of a soft robot design. Thereafter, a sim-to-real layer of differentiable neurons is employed to map the results of simulation to the physical hardware, where this sim-to-real layer can be learned from a very limited number of training samples generated on the hardware.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Materials and ManufacturingMechatronic Desig
Gut bacteria and necrotizing enterocolitis: cause or effect?
No full textDevelopment of necrotising enterocolitis (NEC) is considered to be dependent on the bacterial colonisation of the gut. With little concordance between published data and a recent study failing to detect a common strain in infants with NEC, more questions than answers are arising about our understanding of this complex disease
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VSA Dating Sim
No full textThe VSA Dating Sim is a small dating simulator about a new freshman getting to know people in the Vietnamese Student Association at UCSC. Although this game is not as expansive and long as real dating simulators players make decisions that can affect the outcome of who the player ends up with
Alpha particle spectroscopy using FNTD and SIM super-resolution microscopy
No full textStructured illumination microscopy (SIM) for the imaging of alpha particle tracks in fluorescent nuclear track detectors (FNTD) was evaluated and compared to confocal laser scanning microscopy (CLSM). FNTDs were irradiated with an external alpha source and imaged using both methodologies. SIM imaging resulted in improved resolution, without increase in scan time. Alpha particle energy estimation based on the track length, direction and intensity produced results in good agreement with the expected alpha particle energy distribution. A pronounced difference was seen in the spatial scattering of alpha particles in the detectors, where SIM showed an almost 50% reduction compared to CLSM. The improved resolution of SIM allows for more detailed studies of the tracks induced by ionising particles. The combination of SIM and FNTDs for alpha radiation paves the way for affordable and fast alpha spectroscopy and dosimetry. Journal compilatio
FIGURE 2 in Species boundaries of Pardosa concinna and P. lapponica (Araneae: Lycosidae) in the northern Nearctic: morphology and DNA barcodes
No full textFIGURE 2. Box plots (heavy line = median; box = quartiles; dashed line = range) of genitalic characters of Nearctic Pardosa lapponica and P. concinna. The mean size of all characters is significantly larger in P. concinna (grey boxes), but the size range overlaps between the two species. l.—length; M.—median; w.—width.Published as part of Sim, Kathrin A., Buddle, Christopher M. & Wheeler, Terry A., 2014, Species boundaries of Pardosa concinna and P. lapponica (Araneae: Lycosidae) in the northern Nearctic: morphology and DNA barcodes, pp. 169-178 in Zootaxa 3884 (2) on page 173, DOI: 10.11646/zootaxa.3884.2.5, http://zenodo.org/record/495160
FIGURE 2 in Species boundaries of Pardosa concinna and P. lapponica (Araneae: Lycosidae) in the northern Nearctic: morphology and DNA barcodes
No full textFIGURE 2. Box plots (heavy line = median; box = quartiles; dashed line = range) of genitalic characters of Nearctic Pardosa lapponica and P. concinna. The mean size of all characters is significantly larger in P. concinna (grey boxes), but the size range overlaps between the two species. l.—length; M.—median; w.—width.Published as part of Sim, Kathrin A., Buddle, Christopher M. & Wheeler, Terry A., 2014, Species boundaries of Pardosa concinna and P. lapponica (Araneae: Lycosidae) in the northern Nearctic: morphology and DNA barcodes, pp. 169-178 in Zootaxa 3884 (2) on page 173, DOI: 10.11646/zootaxa.3884.2.5, http://zenodo.org/record/495160
A simple disc wind model for broad absorption line quasars
No full textApproximately 20 per cent of quasi-stellar objects (QSOs) exhibit broad, blue-shifted absorption lines in their ultraviolet spectra. Such features provide clear evidence for significant outflows from these systems, most likely in the form of accretion disc winds. These winds may represent the ‘quasar’ mode of feedback that is often invoked in galaxy formation/evolution models, and they are also key to unification scenarios for active galactic nuclei (AGN) and QSOs. To test these ideas, we construct a simple benchmark model of an equatorial, biconical accretion disc wind in a QSO and use a Monte Carlo ionization/radiative transfer code to calculate the ultraviolet spectra as a function of viewing angle. We find that for plausible outflow parameters, sightlines looking directly into the wind cone do produce broad, blue-shifted absorption features in the transitions typically seen in broad absorption line (BAL) QSOs. However, our benchmark model is intrinsically X-ray weak in order to prevent overionization of the outflow, and the wind does not yet produce collisionally excited line emission at the level observed in non-BAL QSOs. As a first step towards addressing these shortcomings, we discuss the sensitivity of our results to changes in the assumed X-ray luminosity and mass-loss rate, Ṁwind. In the context of our adopted geometry, Ṁwind ∼ Ṁacc is required in order to produce significant BAL features. The kinetic luminosity and momentum carried by such outflows would be sufficient to provide significant feedback
Connecticut State Innovation Model (SIM); Proposed framework--revised 4/30/19
No full text1 online resource (32 pages) : color illustrationsFinal version; "This report was prepared by Health Management Associates (HMA), a leading independent national research and consulting firm"--Page 3; "The project described was supported by Funding Opportunity Number CMS-1G1CMS331630-02-00 from the U.S. Department of Health & Human Services, Centers for Medicare & Medicaid Services."; "Approved June 2019."; Includes bibliographical reference
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