30 research outputs found
Visual attention to and perception of undamaged and damaged versions of natural and colored female hair
No full textFemale hair color is thought to influence physical attractiveness, and although there is some evidence for this assertion, research has yet not addressed the question if and how physical damaging affects the perception of female hair color. Here we investigate whether people are sensitive (in terms of visual attention and age, health and attractiveness perception) to subtle differences in hair images of natural and colored hair before and after physical damaging. We tracked the eye-gaze of 50 men and 50 women aged 3150years whilst they viewed randomized pairs of images of 20 natural and 20 colored hair tresses, each pair displaying the same tress before and after controlled cuticle damage. The hair images were then rated for perceived health, attractiveness, and age. Undamaged versions of natural and colored hair were perceived as significantly younger, healthier, and more attractive than corresponding damaged versions. Visual attention to images of undamaged colored hair was significantly higher compared with their damaged counterparts, while in natural hair, the opposite pattern was found. We argue that the divergence in visual attention to undamaged colored female hair and damaged natural female hair and associated ratings is due to differences in social perception and discuss the source of apparent visual difference between undamaged and damaged hair
Enzymatische Bildung aromaaktiver [alpha]-Hydroxyketone mit der Wildhefe Zygosaccharomyces bisporus
No full text[no abstract
Enzymatische Bildung aromaaktiver a-Hydroxyketonealpha-Hydroxyketone mit der Wildhefe Zygosaccharomyces bisporus
No full textFormation of Aliphatic and Aromatic α-Hydroxy Ketones by Zygosaccharomyces bisporus
No full textThe wild-type yeast strain Zygosaccharomyces bisporus CBS 702 produced a-hydroxy-ketones (acyloins) from amino acid precursors after transamination to the corresponding 2-oxo acids. The key enzyme of the subsequent decarboxylation and C-C bond forming reaction, pyruvate decarboxylase (PDC), was examined for its substrate- and stereo-specific-ity. A wide variety of saturated and unsaturated aliphatic and aromatic aldehydes was successfully converted to acyloins. 19 of the biotransformation products identified had not been reported as natural substances before. Product yields were strongly affected by substrate structure. © 2000, Verlag der Zeitschrift für Naturforschung. All rights reserved
Response of solvent-based self-healing smart materials under fatigue
No full textSelf-healing of epoxy matrix could prove essential in increasing the reliability and service life of fiber-reinforced polymers. The principle of encapsulated liquid healing agents dispersed in the matrix has been demonstrated successfully using different chemistries and different testing setups. In addition, progress has been made in the field of smart composites regarding crack detection and closure, using for example fiber optics and shape memory alloy fibers. An active response is given to a detected and localized damage event by the combined action of crack closure and local heating. We report here on encapsulated EPA solvent based epoxy materials with embedded SMA fibers tested in fatigue loading of TDCB sample geometries. Healing in solventbased capsule systems occurs through solvent diffusion, swelling of the polymer on the crack faces thus enabling further reaction of residual monomer and bonding crack faces which are in contact. Epoxy samples loaded with EPA microcapsules fared substantially better than samples without capsules or samples with inactive control solvent microcapsules. This behavior is attributed to a crack blunting effect: as the EPA diffuses into the matrix, the modulus decreases while the epoxy becomes more ductile. As a result, complete crack arrest at relatively high stress intensities KIc was observed. TDCB samples containing capsules and embedded SMA wires were tested statically until complete fracture, activated through the SMA wires for healing and finally tested in fatigue after healing. Such healed samples exceeded the virgin properties in fatigue response. Secondly, samples with or without SMA wires were tested in fatigue for 20\u92000 cycles at high stress intensities, followed by a rest period (with SMA wire activation, if applicable) for different durations and further tested in fatigue. Sample response was improved by SMA wire activation and longer healing rest periods. Overall, EPA solvent capsules are beneficial to the fatigue life of an epoxy matrix, by combined effects of crack blunting during loading and crack healing at rest periods
Purification, characterisation and cDNA sequencing of pyruvate decarboxylase from Zygosaccharomyces bisporus
No full textCells of the wild-type yeast strain Zygosaccharomyces bisporus CBS 702 form alpha-hydroxy ketones from aromatic amino acid precursors during fermentation, Pyruvate decarboxylase (PDC, E.C. 4.1.1.1), the key enzyme of this biotransformation catalysing the nonoxidative decarboxylation of pyruvate and other 2-oxo-acids, was purified and characterised. The active enzyme is homotetrameric (alpha(4)) with a molecular mass of about 244 kDa, Activation of PDC by its substrate pyruvate results in a sigmoidal dependence of the reaction rate from substrate concentration (apparent K-m value 1.73 mM; Hill coefficient 2.10). A cDNA library was screened using a PCR-based procedure, and a 1856 bp cDNA of PDC was identified and sequenced. The cDNA encodes a polypeptide of 563 amino acid residues (monomeric unit), Sequence alignments demonstrate high homologies (> 80%) to PDC genes from Saccharomyces cerevisiae, Kluyveromyces lactis and Kluyveromyces marxianus
A new inventory for assessing worry in managers: Correlates with job involvement and self-reliance
No full textThis work introduces the "Worry Inventory for Managers" (WIM), a 24-item measure of jobrelated worries in managers. A sample of 138 managers responded to the WIM and to measures of pathological worry, job involvement, and self-reliance. Factor analysis of the WIM revealed two facets of job-related worry, namely worry about (1) organizational processes and about (2) work overload. Results indicate that job-related worry shows differential correlations from pathological worry with the three factors of self-reliance (counterdependence, overdependence, and interdependence)
New Aspects of Thromboangiitis obliterans (von Winiwarter-Buerger's Disease)
No full textThe existence of thromboangiitis obliterans as a clinical entity has been a matter of debate for many years. In contrast to other immunovasculitides there is no organ involvement while peripheral vessels are affected. Heavy smokers under 40 years of age have a high predisposition for the disease. The cerebral form shows relapsing brain infarctions which can be visualized in CCT while panarteriography remains negative. Apart from unspecific inflammatory signs in blood and CSF there are distinctive laboratory findings proving the autoimmunological character of von Winiwarter-Buerger's disease. In the serum anti-elastin antibodies, IgE and anticollagen antibody activity are detectable. In 3 patients the authors detected specific immunohistochemical findings in a biopsy specimen of the temporal artery. In addition to platelet-inhibiting substances corticoids in acute and azathioprine in chronic treatment becomes necessary
