1. |
- Antonsson, Helena, et al.
(author)
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Caregivers' reflections on their interactions with adult people with learning disabilities
- 2008
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In: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 15:6, s. 484-91
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Journal article (peer-reviewed)abstract
- People with learning disabilities and their professional carers often have difficulty interacting. The aim of this study was to illuminate carers' reflections on their interactions with adult people with learning disabilities. In a previous study, interactions between 16 carers and 11 residents with learning disabilities were recorded on video. In this study, stimulated recall interviews about the interactions were carried out with all the carers. The text was analysed using qualitative content analysis. The findings indicate that the carers reflected on both successful and unsuccessful interaction. Examples of successful interaction included understanding cues, satisfying needs, and managing challenging behaviours, and the carers reflected on the influences that successful interaction had on security, confidence, and satisfaction among the residents. Examples of unsuccessful interaction included failing to understand cues, failing to satisfy needs and failing to manage challenging behaviours, and the carers reflected on the consequences of such interaction, which included irritation, aggression and violence among the residents. Our findings have implications for interventions aimed at strengthening the competence of carers and developing strategies for managing challenging behaviour, in order to ensure high-quality care and a good working climate. © 2008 The Authors.
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2. |
- Degerman, Johan, 1976, et al.
(author)
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An automatic system for in vitro cell migration studies
- 2009
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In: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 233:1, s. 178-191
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Journal article (peer-reviewed)abstract
- This paper describes a system for in vitro cell migration analysis. Adult neural stem/progenitor cells are studied using time-lapse bright-field microscopy and thereafter stained immunohistochemically to find and distinguish undifferentiated glial progenitor cells and cells having differentiated into type-1 or type-2 astrocytes. The cells are automatically segmented and tracked through the time-lapse sequence. An extension to the Chan-Vese Level Set segmentation algorithm, including two new terms for specialized growing and pruning, made it possible to resolve clustered cells, and reduced the tracking error by 65%. We used a custom-built manual correction module to form a ground truth used as a reference for tracked cells that could be identified from the fluorescence staining. On average, the tracks were correct 95% of the time, using our new segmentation. The tracking, or association of segmented cells, was performed using a 2-state Hidden Markov Model describing the random behaviour of the cells. By re-estimating the motion model to conform with the segmented data we managed to reduce the number of tracking parameters to essentially only one. Upon characterization of the cell migration by the HMM state occupation function, it was found that glial progenitor cells were moving randomly 2/3 of the time, while the type-2 astrocytes showed a directed movement 2/3 of the time. This finding indicates possibilities for cell-type specific identification and cell sorting of live cells based on specific movement patterns in individual cell populations, which would have valuable applications in neurobiological research.
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3. |
- Gustafsson, Anders
(author)
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Cathodoluminescence studies of nanostructured semiconductors
- 2006
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In: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 224:1, s. 72-78
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Journal article (peer-reviewed)abstract
- Spatially and spectrally resolved cathodoluminescence in the scanning electron microscope is a very powerful technique for studying the optical properties of semiconductor structures, especially low-dimensional structures (structures with nanometre-sized features). The technique is generally nondestructive and can be combined with the normal imaging capabilities and analysis possibilities of the scanning electron microscope. This article gives an introduction to the technique and a number of examples of the possibilities of the technique.
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4. |
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5. |
- Jonasson, Jenny, 1976, et al.
(author)
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A pixel-based likelihood framework for analysis of fluorescence recovery after photobleaching data
- 2008
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In: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 232:2, s. 260-269
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Journal article (peer-reviewed)abstract
- A new framework for the estimation of diffusion coefficients from data on fluorescence recovery after photobleaching (FRAP) with confocal laser scanning microscopy (CLSM) is presented. It is a pixel-based statistical methodology that efficiently utilizes all information about the diffusion process in the available set of images. The likelihood function for a series of images is maximized which gives both an estimate of the diffusion coefficient and a corresponding error. This framework opens up possibilities (1) to obtain localized diffusion coefficient estimates in both homogeneous and heterogeneous materials, (2) to account for time differences between the registrations at the pixels within each image, and (3) to plan experiments optimized with respect to the number of replications, the number of bleached regions for each replicate, pixel size, the number of pixels, the number of images in each series etc. To demonstrate the use of the new framework, we have applied it to a simple system with polyethylene glycol (PEG) and water where we find good agreement with diffusion coefficient estimates from NMR diffusometry. In this experiment, it is also shown that the effect of the point spread function is negligible, and we find fluorochrome-concentration levels that give a linear response function for the fluorescence intensity. © 2008 The Authors.
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6. |
- Mölder, Anna, et al.
(author)
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Non-invasive, label-free cell counting and quantitative analysis of adherent cells using digital holography
- 2008
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In: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 232:2, s. 240-247
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Journal article (peer-reviewed)abstract
- Manual cell counting is time consuming and requires a high degree of skill on behalf of the person performing the count. Here we use a technique that utilizes digital holography, allowing label-free and completely non-invasive cell counting directly in cell culture vessels with adherent viable cells. The images produced can provide both quantitative and qualitative phase information from a single hologram. The recently constructed microscope HolomonitorTM (Phase Holographic Imaging AB, Lund, Sweden) combines the commonly used phase contrast microscope with digital holography, the latter giving us the possibility of achieving quantitative information on cellular shape, area, confluence and optical thickness. This project aimed at determining the accuracy and repeatability of cell counting measurements using digital holography compared to the conventional manual cell counting method using a haemocytometer. The collected datawere also used to determine cell size and cellular optical thickness.Theresults showthat digital holography can be used for non-invasive automatic cell counting as precisely as conventional manual cell counting
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7. |
- Yao, Yiming, 1957, et al.
(author)
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Cross sectional TEM investigation of Ni-catalysed carbon nanotube films grown by plasma enhanced CVD
- 2005
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In: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 219, s. 69-75
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Journal article (other academic/artistic)abstract
- Nickel-catalysed multiwall carbon nanotubes synthesized by plasma-enhanced chemical vapour deposition on a silicon substrate with acetylene and ammonia at 700 °C have been characterized by high-resolution and analytical transmission electron microscopy. The nucleation of the carbon nanotubes occurs as a consequence of the carburization and dusting of supported preformed nickel- and silicon-rich particles. This process yields disintegrated silicon-containing nickel particles dispersed in dome-shaped carbon islands adherent to the substrate. The particles act as catalysts for tube growth, resulting in aligned multiwall carbon nanotubes with a bamboo-like structure anchored to the dome-shaped carbon islands. The bottom part of the carbon islands contains bundles of graphene sheets orientated parallel to the substrate. The nanotubes are capped with fcc nickel particles containing dissolved silicon. Most of these particles have a conical shape orientated with a <110> direction along the tube growth axis, and with {110} and {111} planes as exposed faces.
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8. |
- Stollberg, Heide, et al.
(author)
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A vacuum-compatible wet-specimen chamber for compact x-ray microscopy
- 2007
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In: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 226:1, s. 71-73
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Journal article (peer-reviewed)abstract
- Soft X-ray microscopy is a powerful tool for investigations of, for example, polymers or soils in their natural liquid environment. This requires a wet-specimen chamber. Compact X-ray microscopy allows the horizontal mounting of such samples, thereby reducing the influence of gravitational forces. We have developed a wet-specimen chamber for such compact X-ray microscope. The chamber is vacuum compatible, which reduces the exposure time. The vacuum sealing is achieved by a combination of mechanical sealing and sealing by bio-compatible glue. With the wet-specimen chamber the specimens can be kept in an aqueous environment in a vacuum of 10(-4) mbar for several hours. Imaging of lipid droplets in water demonstrates the function of the wet-specimen chamber.
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9. |
- Stollberg, Heide, et al.
(author)
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Size-selective colloidal-gold localization in transmission x-ray microscopy
- 2007
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In: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 225:1, s. 80-87
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Journal article (peer-reviewed)abstract
- Colloidal gold is a useful marker for functional-imaging experiments in transmission X-ray microscopy. Due to the low contrast of gold particles with small diameters it is necessary to develop a powerful algorithm to localize the single gold particles. The presented image-analysis algorithm for identifying colloidal gold particles is based on the combination of a threshold with respect to the local absorption and shape discrimination, realized by fitting a Gaussian profile to the identified regions of interest. The shape discrimination provides the possibility of size-selective identification and localization of single colloidal gold particles down to a diameter of 50 nm. The image-analysis algorithm, therefore, has potential for localization studies of several proteins simultaneously and for localization of fiducial markers in X-ray tomography.
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10. |
- Adler, Jeremy
(author)
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The unitary scale bar : human and machine readable
- 2008
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In: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 230:1, s. 163-166
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Journal article (peer-reviewed)abstract
- A format is described for a scale bar that encodes the length represented within the structure of the bar itself, thereby removing the need for any supporting text. Although the 'unitary' scale bar has a conventional appearance it is also machine readable and therefore retains information about the scale even when the file format is changed. The format is based on the metre and is suitable for all terrestrial applications.
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