Mechano-Dependent Phosphorylation of the PDZ-Binding Motif of CD97/ADGRE5 Modulates Cellular Detachment

Summary Cells respond to mechanical stimuli with altered signaling networks. Here, we show that mechanical forces rapidly induce phosphorylation of CD97/ADGRE5 (pCD97) at its intracellular C-terminal PDZ-binding motif (PBM). Biochemically, this phosphorylation disrupts CD97 binding to PDZ domains of the scaffold protein DLG1. In shear-stressed cells, pCD97 appears not only in junctions, retracting fibers, and the attachment area but also in lost membrane patches, demonstrating (intra)cellular detachment at the CD97 PBM. This motif is critical for the CD97-dependent mechanoresponse. Cells expressing CD97 without the PBM are more deformable, and under shear stress, these cells lose cell contacts faster and show changes in the actin cytoskeleton when compared with cells expressing full-length CD97. Our data indicate CD97 linkage to the cytoskeleton. Consistently, CD97 knockout phenocopies CD97 without the PBM, and membranous CD97 is organized in an F-actin-dependent manner. In summary, CD97 shapes the cellular mechanoresponse through signaling modulation via its PBM

CUBES : the Cassegrain U-band Efficient Spectrograph

In the era of Extremely Large Telescopes, the current generation of 8-10m facilities are likely to remain competitive at ground-UV wavelengths for the foreseeable future. The Cassegrain U-Band Efficient Spectrograph (CUBES) has been designed to provide high-efficiency (> 40%) observations in the near UV (305-400 nm requirement, 300-420 nm goal) at a spectral resolving power of R >20, 000 (with a lower-resolution, sky-limited mode of R ~7, 000). With the design focusing on maximizing the instrument throughput (ensuring a Signal to Noise Ratio (SNR) ~20 per high-resolution element at 313 nm for U ~18.5 mag objects in 1h of observations), it will offer new possibilities in many fields of astrophysics, providing access to key lines of stellar spectra: a tremendous diversity of iron-peak and heavy elements, lighter elements (in particular Beryllium) and light-element molecules (CO, CN, OH), as well as Balmer lines and the Balmer jump (particularly important for young stellar objects). The UV range is also critical in extragalactic studies: the circumgalactic medium of distant galaxies, the contribution of different types of sources to the cosmic UV background, the measurement of H2 and primordial Deuterium in a regime of relatively transparent intergalactic medium, and follow-up of explosive transients. The CUBES project completed a Phase A conceptual design in June 2021 and has now entered the detailed design and construction phase. First science operations are planned for 2028

Surface plasmon resonance based detection of human serum albumin as a marker for hepatocytes activity

Techniques for monitoring cell cultures and fermentation processes not only enable prompt feedback to variations in critical parameters (e.g., media composition and metabolites) but further improve our understanding of the processes themselves. In this context, surface plasmon resonance (SPR) spectroscopy is one of the methods of choice. This technique exploits angle shifting to follow molecular interactions in real-time. Therefore, it allows samples to be characterized without additional molecular labels and time-consuming sample preparation. The immobilization of receptors onto the chip surface is one of the most challenging requirements in SPR. Especially for measurements in crude samples, it is crucial to achieve a sufficient immobilization level and block the remaining sensitive area to prevent nonspecific binding. In this article, we present a SPR-based detection system for human serum albumin (HSA). As HSA is exclusively synthesized in the liver, it can be used to characterize the specific activity of in vitro cultivated human hepatocytes. These can be cultivated in so-called multi-organ-chips, which have been developed by groups at the TU Berlin and Fraunhofer IWS for predictive preclinical substance evaluation

Designing e-learning courses for classroom and distance learning in physics: The role of learning tasks

Digital learning technologies have grown increasingly important in physics education, partly enforced through the COVID-19 pandemic. During the pandemic, digital technologies allowed for continued teaching and learning of students even when schools were closed. While research in psychology and educational technology has yielded many insights into the effectiveness of e-learning courses, fewer studies have examined the design of e-learning courses. Few studies have empirically investigated the design of learning tasks as a central element of e-learning courses. The present study analyzes how the design of tasks in e-learning courses, specifically with respect to their degree of openness as well as the relevance of their contexts, influences students’ behavioral engagement, learning outcomes, and situational interest. Due to the importance of e-learning courses during the COVID-19 pandemic, we also analyzed the extent to which specific learning settings (classroom learning, distance learning) influence the effects of e-learning course design on students’ behavioral engagement, learning outcomes, and situational interest. To investigate the research questions, we analyzed a total of N=1060 datasets for 12 different e-learning courses (3 to 5 lessons, middle school physics), of which n=557 were completed before and n=503 during the COVID-19 pandemic. The results suggest that e-learning courses with a high proportion of learning tasks that relate to meaningful real-world contexts appear to be more conducive to behavioral engagement, learning outcomes, and situational interest. Regarding the consideration of open-ended tasks, the results suggest that these appear to be more useful for classroom learning but should be used in a limited way when designing e-learning courses for distance education

Conflicts as aversive signals: Conflict priming increases negative judgments for neutral stimuli

Botvinick, Cognitive, Affective, & Behavioral Neuroscience 7:356–366 (2007) recently suggested that competing theories of the monitoring function of the anterior cingulate cortex (ACC) for cognitive control might converge on the detection of aversive signals in general, implying that response conflicts, a known trigger of ACC activation, are aversive, too. Recent evidence showing conflict priming (i.e., faster responses to negative targets after conflict primes) directly supports this notion but remains inconclusive with regard to possible confounds with processing fluency. To this end, two experiments were conducted to offer more compelling evidence for the negative valence of conflicts. Participants were primed by (conflict and nonconflict) Stroop stimuli and subsequently had to judge the valence of neutral German words (Experiment 1a) or Chinese pictographs (Experiment 1b). Results showed that conflict, as compared with nonconflict, primes led to more negative judgments of subsequently presented neutral target stimuli. The findings will be discussed in the light of existing theories of action control highlighting the role of aversive signals for sequential processing adjustments

CUBES, the Cassegrain U-Band Efficient Spectrograph

In the era of Extremely Large Telescopes, the current generation of 8-10m facilities are likely to remain competitive at ground-UV wavelengths for the foreseeable future. The Cassegrain U-Band Efficient Spectrograph (CUBES) has been designed to provide high-efficiency (>40%) observations in the near UV (305-400 nm requirement, 300-420 nm goal) at a spectral resolving power of R>20,000 (with a lower-resolution, sky-limited mode of R ~ 7,000). With the design focusing on maximizing the instrument throughput (ensuring a Signal to Noise Ratio (SNR) ~20 per high-resolution element at 313 nm for U ~18.5 mag objects in 1h of observations), it will offer new possibilities in many fields of astrophysics, providing access to key lines of stellar spectra: a tremendous diversity of iron-peak and heavy elements, lighter elements (in particular Beryllium) and light-element molecules (CO, CN, OH), as well as Balmer lines and the Balmer jump (particularly important for young stellar objects). The UV range is also critical in extragalactic studies: the circumgalactic medium of distant galaxies, the contribution of different types of sources to the cosmic UV background, the measurement of H2 and primordial Deuterium in a regime of relatively transparent intergalactic medium, and follow-up of explosive transients. The CUBES project completed a Phase A conceptual design in June 2021 and has now entered the detailed design and construction phase. First science operations are planned for 2028