TY  - JOUR
A1  - Muth, Felicitas V.
A1  - Heilig, Michael
A1  - Marquardt, Dorothea
A1  - Mittelberg, Linda
A1  - Sebald, Albrecht
A1  - Kunde, Wilfried
T1  - Lightness perception of structured surfaces
JF  - Color Research and Application
N2  - Visual perception of surfaces is of utmost importance in everyday life. Therefore, it comes naturally, that different surface structures evoke different visual impressions in the viewer even if the material underlying these surface structures is the same. This topic is especially virulent for manufacturing processes in which more than one stakeholder is involved, but where the final product needs to meet certain criteria. A common practice to address such slight but perceivable differences in the visual appearance of structured surfaces is that trained evaluators assess the samples and assign a pass or fail. However, this process is both time consuming and cost intensive. Thus, we conducted two studies to analyze the relationship between physical surface structure parameters and participants visual assessment of the samples. With the first experiment, we aimed at uncovering a relationship between physical roughness parameters and visual lightness perception while the second experiment was designed to test participants' discrimination sensitivity across the range of stimuli. Perceived lightness and the measured surface roughness were nonlinearly related to the surface structure. Additionally, we found a linear relationship between the engraving parameter and physical brightness. Surface structure was an ideal predictor for perceived lightness and participants discriminated equally well across the entire range of surface structures.
KW  - surface structure
KW  - appearance
KW  - color perception
KW  - maximum likelihood difference scaling
KW  - psychophysics
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257314
VL  - 47
IS  - 2
ER  - 
TY  - JOUR
A1  - Trinks, Nora
A1  - Reinhard, Sebastian
A1  - Drobny, Matthias
A1  - Heilig, Linda
A1  - Löffler, Jürgen
A1  - Sauer, Markus
A1  - Terpitz, Ulrich
T1  - Subdiffraction-resolution fluorescence imaging of immunological synapse formation between NK cells and A. fumigatus by expansion microscopy
JF  - Communications Biology
N2  - Expansion microscopy (ExM) enables super-resolution fluorescence imaging on standard microscopes by physical expansion of the sample. However, the investigation of interactions between different organisms such as mammalian and fungal cells by ExM remains challenging because different cell types require different expansion protocols to ensure identical, ideally isotropic expansion of both partners. Here, we introduce an ExM method that enables super-resolved visualization of the interaction between NK cells and Aspergillus fumigatus hyphae. 4-fold expansion in combination with confocal fluorescence imaging allows us to resolve details of cytoskeleton rearrangement as well as NK cells' lytic granules triggered by contact with an RFP-expressing A. fumigatus strain. In particular, subdiffraction-resolution images show polarized degranulation upon contact formation and the presence of LAMP1 surrounding perforin at the NK cell-surface post degranulation. Our data demonstrate that optimized ExM protocols enable the investigation of immunological synapse formation between two different species with so far unmatched spatial resolution.
KW  - biological fluorescence
KW  - fluorescence imaging
KW  - imaging the immune system
KW  - infectious diseases
KW  - super-resolution microscopy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-264996
VL  - 4
IS  - 1
ER  -