Reproductive ecology of Bombina variegata: aspects of life history

Individual reproductive behaviour and survival of Bombina variegata was studied in a dynamic habitat with a variety of rain-filled ponds from 1990 to 1992. Most animals reached sexual maturity at the age of two years. Annual adult survival was at least 62%. Individual females, on average, laid between 40 and 70 eggs per "clutch". While about 12% of the breeding females spawned a second time within the season, a similar proportion did not seem to spawn every possible year, probably depending on climatic conditions. The results are consistent with ultimate predictions from life history theory, but the proximate mechanisms of ovulation and spawning in response to environmental conditions remain to be investigated

A Conserved Ribosomal Protein Has Entirely Dissimilar Structures in Different Organisms

\ua9 The Author(s) 2023. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution. Ribosomes from different species can markedly differ in their composition by including dozens of ribosomal proteins that are unique to specific lineages but absent in others. However, it remains unknown how ribosomes acquire new proteins throughout evolution. Here, to help answer this question, we describe the evolution of the ribosomal protein msL1/msL2 that was recently found in ribosomes from the parasitic microorganism clade, microsporidia. We show that this protein has a conserved location in the ribosome but entirely dissimilar structures in different organisms: in each of the analyzed species, msL1/msL2 exhibits an altered secondary structure, an inverted orientation of the N-termini and C-termini on the ribosomal binding surface, and a completely transformed 3D fold. We then show that this fold switching is likely caused by changes in the ribosomal msL1/msL2-binding site, specifically, by variations in rRNA. These observations allow us to infer an evolutionary scenario in which a small, positively charged, de novo-born unfolded protein was first captured by rRNA to become part of the ribosome and subsequently underwent complete fold switching to optimize its binding to its evolving ribosomal binding site. Overall, our work provides a striking example of how a protein can switch its fold in the context of a complex biological assembly, while retaining its specificity for its molecular partner. This finding will help us better understand the origin and evolution of new protein components of complex molecular assemblies-thereby enhancing our ability to engineer biological molecules, identify protein homologs, and peer into the history of life on Earth

Monolithic solder-on nanoporous Si-Cu contacts for stretchable silicone composite sensors

We report a method of creating solderable, mechanically robust, electrical contacts to interface (soft) silicone-based strain sensors with conventional (hard) solid-state electronics using a nanoporous Si-Cu composite. The Si-based solder-on electrical contact consists of a copper-plated nanoporous Si top surface formed through metal-assisted chemical etching and electroplating, and a smooth Si bottom surface which can be covalently bonded onto silicone-based strain sensors through plasma bonding. We investigated the mechanical and electrical properties of the contacts proposed under relevant ranges of mechanical stress for applications in physiological monitoring and rehabilitation. We also produced a series of proof-of-concept devices, including a wearable respiration monitor, leg band for exercise monitoring and Squeeze-ball for monitoring rehabilitation of patients with hand injuries or neurological disorders, to demonstrate the mechanical robustness and versatility of the technology developed, in real-world applications

Global glacier mass changes and their contributions to sea-level rise from 1961 to 2016

International audienc

Viral Hepatitis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65791/1/j.1365-4362.1981.tb00836.x.pd

Reproductive ecology of Bombina variegata: characterisation of spawning ponds

The use of spawning sites by Bombina variegata was analysed in a dynamic habitat containing a variety of different ponds. Cool or shadowy as well as permanent ponds were not used for spawning at all. Among the ephemeral ponds that were used, egg numbers increased with water temperature, both when compared among ponds and between different areas within ponds. Egg numbers were also higher in ponds of intermediate duration than in those persisting for shorter or longer periods. Ponds of intermediate duration with moderate predator densities and with larvae of competing anuran species (Hyla arborea, Bufo calamita) were used more often than short-lived ponds with no predators and competitors. This pattern of spawn deposition can be interpreted as an attempt to select sites allowing rapid larval development (warm water) and to avoid sites with high numbers of newts and invertebrate predators (permanent ponds). The selection critera seem to be adaptive, because pond duration and desiccation are more importent for larval survival than predators and competitors. Yet, optimal reproductive conditions remain highly unpredictable for Bombina variegata, as the characteristics and dynamics of spawning ponds are mainly determined by climatic conditions. Consequently, survival chances of tadpoles can change within a few days or weeks, depending on rainfall and evaporation