1,721,279 research outputs found
Supporting dataset for multi-scale sensorless adaptive optics: application to stimulated emission depletion microscopy
Full text linkMulti-scale sensorless adaptive optics: application to stimulated emission depletion microscopy
Jacopo Antonello, Aurélien Barbotin, Ee Zhuan Chong, Jens Rittscher, and Martin Booth
https://doi.org/10.1364/OE.393363
This folder contains the raw data acquired throughout the experiments. The data is grouped by figure number in the paper.
TIFF files are in OME-TIFF (https://docs.openmicroscopy.org/ome-model/latest/) format and can be opened with FiJi (https://imagej.net/Fiji/Downloads). The legend for the file name is --. So that xy-3dsted-aoon.tif corresponds to an xy scan along the lateral plane, in 3D STED mode, with adaptive optics (AO) correction applied.
AO log files contain the raw data acquired during the aberration correction experiments. These files are in HDF5 (https://www.hdfgroup.org/solutions/hdf5/) format and can be opened with a variety of applications (https://en.wikipedia.org/wiki/Hierarchical_Data_Format) that support HDF5 version 1.10 or later. The legend for the file name is ao---.h5. So that ao4-05-10-zsted.h5 corresponds to the fourth part of the aberration correction, where Zernike modes from 5 to 10 inclusive are corrected in ZSTED mode. The acquired images are stored at the address /stacks/stacks. The first image corresponds to the initial state of the correction. Next, the images necessary for the PN algorithm are collected. In the last image, the correction computed by the PN algorithm is applied. For each image, the corresponding column vector of Zernike coefficients applied by the DM is found at the address /dmlib/control/ZernikeControl/x
Background Reduction in STED-FCS Using a Bivortex Phase Mask: supporting dataset
No full textThis is the research materials used in the paper 'Background Reduction in STED-FCS Using a Bivortex Phase Mask', doi .
Data analysis was performed in Python 3.7.4. Plots generated with matplotlib 3.2.1. Other packages used are listed in requirements.txt. Figure panels were assembled using inkscape (versions 0.92 and 1.0).
Further details can be found in the archive and in the paper, where appropriat
Direct wavefront sensing in adaptive microscopy
Full text linkSpecimen-induced aberrations are frequently encountered in high resolution microscopy, particularly when high numerical aperture lenses are used to image deep into biological specimens. These aberrations distort the focal spot causing reduction in resolution, signal level and contrast. Aberrations arise due to refractive index variations in the specimen. Adaptive optics has been used in microscopes to correct for these effects and restore optimum imaging performance. An adaptive element, such as a deformable mirror, is used to compensate for aberrations by introducing equal but opposite phase distortions to that introduced by the specimen. Most adaptive optics systems in microscopy have employed indirect optimisation schemes that require several exposures of the specimen before the correction phase can be determined. This could lead to photo-toxicity and is sometimes unsuitable for real-time imaging. Direct wavefront sensing can significantly decrease the time required for aberration measurements by using dedicated sensors, but has limitations, particularly when backscattered light is used from thick specimens. While similar research has been undertaken in ophthalmology where the imaged retina is approximately two-dimensional, this report extends that work to three-dimensional specimens in microscopes. Aberration correction has already been demonstrated in single-pass systems for scattering specimens, but have employed either indirect wavefront sensing techniques or fluorescent beads as guide stars. The use of a Shack-Hartmann wavefront sensor for direct wavefront sensing using backscattered light in a dual-pass system is investigated here. Out-of-focus rejection using an axial selectivity pinhole is studied, along with the phase smoothing effect that is dependant on the pinhole size. The effectiveness of using asymmetric illumination and detection paths, and polarisation filtering in the retrieval of phase information are also demonstrated. It is shown that whilst direct quantitative measurements are not possible for scattering specimens, the measurements could be used in closed-loop adaptive optics systems to correct aberrations
Raw data for article 'Laser writing of coherent colour centres in diamond'
No full textSee 00 README.txt in dataset
Continuous wave excitation two-photon fluorescence microscopy exemplified with the 647-nm ArKr laser line.
No full textWe report on efficient two-photon fluorescence imaging in beam scanning microscopy by exciting UV dyes at the 647-nm line of a continuous wave ArKr mixed gas laser. For a numerical aperture of 1.4 (oil), we used an illumination power of up to 210 mW at the sample. High-resolution images were obtained for DAPI-labelled cell nuclei within 4-60 s. Our method is a simple two-photon alternative to UV confocal imaging with the potential of becoming a very useful feature of laser scanning microscopy
Shrinking multiplexed orbital angular momentum to the nanoscale
Full text linkOrbital angular momentum interactions at the nanoscale have remained elusive because the phase structure becomes unresolved. Now researchers have shown how to overcome this with tightly focused beams, demonstrating a record-high six-dimensional encoding in an ultra-dense nanoscale volume
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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