University of Konstanz

About: University of Konstanz is a education organization based out in Konstanz, Baden-Württemberg, Germany. It is known for research contribution in the topics: Population & Membrane. The organization has 12115 authors who have published 27401 publications receiving 951162 citations. The organization is also known as: University of Constance & Universität Konstanz.

VIVID is a flavoprotein and serves as a fungal blue light photoreceptor for photoadaptation

Abstract: Blue light regulates many physiological and developmental processes in fungi. Most of the blue light responses in the ascomycete Neurospora crassa are dependent on the two blue light regulatory proteins White Collar (WC)-1 and -2. WC-1 has recently been shown to be the first fungal blue light photoreceptor. In the present study, we characterize the Neurospora protein VIVID. VIVID shows a partial sequence similarity with plant blue light photoreceptors. In addition, we found that VIVID non-covalently binds a flavin chromophore. Upon illumination with blue light, VIVID undergoes a photocycle indicative of the formation of a flavin-cysteinyl adduct. VVD is localized in the cytoplasm and is only present after light induction. A loss-of-function vvd mutant was insensitive to increases in light intensities. Furthermore, mutational analysis of the photoactive cysteine indicated that the formation of a flavin-cysteinyl adduct is essential for VIVID functions in vivo. Our results show that VIVID is a second fungal blue light photoreceptor which enables Neurospora to perceive and respond to daily changes in light intensity.

Alpha rhythms in audition : cognitive and clinical perspectives

Abstract: Like the visual and the sensorimotor systems, the auditory system exhibits pronounced alpha-like resting oscillatory activity. Due to the relatively small spatial extent of auditory cortical areas, this rhythmic activity is less obvious and frequently masked by non-auditory alpha-generators when recording noninvasively using MEG or EEG. Following stimulation with sounds, marked desynchronizations can be observed between 6-12 Hz, which can be localized to the auditory cortex. However knowledge about the functional relevance of the auditory alpha rhythm has remained scarce so far. Results from the visual and sensorimotor system have fueled the hypothesis of alpha activity reflecting a state of functional inhibition. The current article pursues several intentions: 1) Firstly we review and present own evidence (MEG, EEG, sEEG) for the existence of an auditory alpha-like rhythm independent of visual or motor generators, something that is occasionally met with scepticism. 2) In a second part we will discuss tinnitus and how this audiological symptom may relate to reduced background alpha. The clinical part will give an introduction into a method which aims to modulate neurophysiological activity hypothesized to underlie this distressing disorder. Using neurofeedback, one is able to directly target relevant oscillatory activity. Preliminary data point to a high potential of this approach for treating tinnitus. 3) Finally, in a cognitive neuroscientific part we will show that auditory alpha is modulated by anticipation / expectations with and without auditory stimulation. We will also introduce ideas and initial evidence that alpha oscillations are involved in the most complex capability of the auditory system, namely speech perception. The evidence presented in this article corroborates findings from other modalities, indicating that alpha-like activity functionally has an universal inhibitory role across sensory modalities.

Aerobic respiration in sulfate‐reducing bacteria*

Abstract: Cultures of Disulfovibrio desulfuricans strain CSN (incubated in a sulfide- and sulfate-free medium) reduced up to 5 mM O2 with H2 as electron donor. Aerobic respiration was not coupled with growth, but resulted in ATP formation. Washed cells incubated in H2-saturated phosphate buffer revealed respiration rates of up to 250 nmol O2 min−1 mg protein−1. The uncoupler carbonyl-cyanide m -chlorophenylhydrazone (CCCP) stimulated the respiration rate and abolished ATP formation. The terminal oxidase has not yet been identified. Respiration was microaerophilic, insensitive to cyanide and azide, but inhibited after heat treatment of the cells (80°C for 10 min). The ph optimum was at pH 6 with less than 50% activity at pH 4.5 and pH 9. Besides H2, organic eletron donors (formate, ethanol, lactate or pyruvate) and inorganic sulfur compounds (H2S, thiosulfate, sulfite) were used as electron donors for aerobic respiration. Sulfite and thiosulfate were oxidized completely to sulfate. The capability of aerobic respiration was also detected in Desulfovibrio vulgaris, D. sulfidismutans, Desulfobacterium autotrophim, Desulfobulbus propionicus , and Desulfococcus multivorans .