Long-Term Evolution in Transit Duration of Extrasolar Planets from Magnetic Activity in their Parent Stars

Existing upper limits on variations in the photospheric radius of the Sun during the solar magnetic activity cycle are at a fractional amplitude of 2x10^{-4}. At that level, the transit duration of a close-in planet around a Sun-like star could change by a fraction of a second per year. This magnitude of variation is larger than that caused by other studied effects (owing to proper motion or general-relativistic effects), and should be included in the analysis of constraints on multi-planet systems from transit timing. A temporal correlation between the transit duration and spectroscopic measures of stellar activity can be used to separate the stellar radius change from other effects. The magnetic activity effect could be significantly larger for late-type stars, such as M-dwarfs, which are more variable than the Sun. In general, precision transit measurements provide a new tool for measuring long-term variations of stellar radii.Comment: 5 pages, accepted for publication in New Astronom

C60+_{60}^+ and the Diffuse Interstellar Bands: An Independent Laboratory Check

In 2015, Campbell et al. (Nature 523, 322) presented spectroscopic laboratory gas phase data for the fullerene cation, C$_{60}^+$, that coincide with reported astronomical spectra of two diffuse interstellar band (DIB) features at 9633 and 9578 \AA. In the following year additional laboratory spectra were linked to three other and weaker DIBs at 9428, 9366, and 9349 \AA. The laboratory data were obtained using wavelength-dependent photodissociation spectroscopy of small (up to three) He-tagged C$_{60}^+-$He$_n$ ion complexes, yielding rest wavelengths for the bare C$_{60}^+$ cation by correcting for the He-induced wavelength shifts. Here we present an alternative approach to derive the rest wavelengths of the four most prominent C$_{60}^+$ absorption features, using high resolution laser dissociation spectroscopy of C$_{60}^+$ embedded in ultracold He droplets. Accurate wavelengths of the bare fullerene cation are derived based on linear wavelength shifts recorded for He$_n$C$_{60}^+$ species with $n$ up to 32. A careful analysis of all available data results in precise rest wavelengths (in air) for the four most prominent C$_{60}^+$ bands: 9631.9(1) \AA, 9576.7(1) \AA, 9427.5(1) \AA, and 9364.9(1) \AA. The corresponding band widths have been derived and the relative band intensity ratios are discussed

Harnessing Large Language Models to Enhance Self-Regulated Learning via Formative Feedback

Effectively supporting students in mastering all facets of self-regulated learning is a central aim of teachers and educational researchers. Prior research could demonstrate that formative feedback is an effective way to support students during self-regulated learning (SRL). However, for formative feedback to be effective, it needs to be tailored to the learners, requiring information about their learning progress. In this work, we introduce LEAP, a novel platform that utilizes advanced large language models (LLMs), such as ChatGPT, to provide formative feedback to students. LEAP empowers teachers with the ability to effectively pre-prompt and assign tasks to the LLM, thereby stimulating students' cognitive and metacognitive processes and promoting self-regulated learning. We demonstrate that a systematic prompt design based on theoretical principles can provide a wide range of types of scaffolds to students, including sense-making, elaboration, self-explanation, partial task-solution scaffolds, as well as metacognitive and motivational scaffolds. In this way, we emphasize the critical importance of synchronizing educational technological advances with empirical research and theoretical frameworks.Comment: 9 pages, 3 Figures, 1 Tabl

Search for production of strangelets in quark matter using particle correlations

We present a new technique for observing the strangelet production in quark matter based on unlike particle correlations. A simulation is presented with a two-phase thermodynamical model

Building blocks for automated elucidation of metabolites: Machine learning methods for NMR prediction

BACKGROUND: Current efforts in Metabolomics, such as the Human Metabolome Project, collect structures of biological metabolites as well as data for their characterisation, such as spectra for identification of substances and measurements of their concentration. Still, only a fraction of existing metabolites and their spectral fingerprints are known. Computer-Assisted Structure Elucidation (CASE) of biological metabolites will be an important tool to leverage this lack of knowledge. Indispensable for CASE are modules to predict spectra for hypothetical structures. This paper evaluates different statistical and machine learning methods to perform predictions of proton NMR spectra based on data from our open database NMRShiftDB. RESULTS: A mean absolute error of 0.18 ppm was achieved for the prediction of proton NMR shifts ranging from 0 to 11 ppm. Random forest, J48 decision tree and support vector machines achieved similar overall errors. HOSE codes being a notably simple method achieved a comparatively good result of 0.17 ppm mean absolute error. CONCLUSION: NMR prediction methods applied in the course of this work delivered precise predictions which can serve as a building block for Computer-Assisted Structure Elucidation for biological metabolites

The Influence of Load and Speed on the Initial Breakdown of Rolling Bearings Exposed to Electrical Currents

The reason for the failure of electric vehicle drives is increasingly current-induced damage to rolling bearings. Studies show that rolling bearings are more susceptible to current pass-through after the first occurrence of unwanted bearing currents. To investigate this effect, a test plan is introduced with variations in axial and radial loads, as well as rotational speeds. A new bearing is mechanically run-in for each test point and then subjected to a realistic voltage signal of gradually increasing amplitude. After the initial breakdown, the different voltage amplitudes are applied again to investigate the behavior after the initial breakdown. During the whole test, the maximum current, the duration and the dissipated energy of each breakdown are measured. The results provide insights into the processes after the initial breakdown and the stochastic nature of the breakdown behavior

Striatins as plaque molecules of zonulae adhaerentes in simple epithelia, of tessellate junctions in stratified epithelia, of cardiac composite junctions and of various size classes of lateral adherens junctions in cultures of epithelia- and carcinoma-derived cells

Proteins of the striatin family (striatins 1–4; sizes ranging from 90 to 110 kDa on SDS-polyacrylamide gel electrophoresis) are highly homologous in their amino acid sequences but can differ in their cell-type-specific gene expression patterns and biological functions. In various cell types, we have found one, two or three polypeptides of this evolutionarily old and nearly ubiquitous family of proteins known to serve as scaffold proteins for diverse protein complexes. Light and electron microscopic immunolocalization methods have revealed striatins in mammalian cell-cell adherens junctions (AJs). In simple epithelia, we have localized striatins as constitutive components of the plaques of the subapical zonulae adhaerentes of cells, including intestinal, glandular, ductal and urothelial cells and hepatocytes. Striatins colocalize with E-cadherin or E–N-cadherin heterodimers and with the plaque proteins α- and β-catenin, p120 and p0071. In some epithelia and carcinomas and in cultured cells derived therefrom, striatins are also seen in lateral AJs. In stratified epithelia and in corresponding squamous cell carcinomas, striatins can be found in plaques of some forms of tessellate junctions. Moreover, striatins are major plaque proteins of composite junctions (CJs; areae compositae) in the intercalated disks connecting cardiomyocytes, colocalizing with other CJ molecules, including plectin and ankyrin-G. We discuss the “multimodulator” scaffold roles of striatins in the initiation and regulation of the formation of various complex particles and structures. We propose that striatins are included in the diagnostic candidate list of proteins that, in the CJs of human hearts, can occur in mutated forms in the pathogeneses of hereditary cardiomyopathies, as seen in some types of genetically determined heart damage in boxer dogs.German-Israeli Foundation for Scientific Research and Development (GIF grant I-1098-43.11/2010