Structural and functional analysis of SAM-dependent N-methyltransferases involved in ovoselenol and ovothiol biosynthesis.

Thio/selenoimidazole Nπ-methyltransferases are an emerging family of enzymes catalyzing the final step in the production of the S/Se-containing histidine-derived antioxidants ovothiol and ovoselenol. These enzymes, prevalent in prokaryotes, show minimal sequence similarity to other methyltransferases, and the structural determinants of their reactivities remain poorly understood. Herein, we report ligand-bound crystal structures of OvsM from the ovoselenol pathway as well as a member of a previously unknown clade of standalone ovothiol-biosynthetic Nπ-methyltransferases, which we have designated OvoM.

Enhanced mercury deposition in Arctic Alaskan lake sediments coincides with early Holocene hydroclimate shift.

Substantial amounts of mercury (Hg) are projected to be released into Arctic watersheds as permafrost thaws amid warmer and wetter conditions. This may have far-reaching consequences because the highly toxic methylated form of Hg biomagnifies rapidly in ecosystems. However, understanding how climate change affects Hg dynamics in permafrost regions is limited due to the lack of long-term Arctic Hg records.

Intertwined people-nature relations are central to nature-based adaptation to climate change.

Adaptation to climate change is a social-ecological process: it is not solely a result of natural processes or human decisions but emerges from multiple relations within social systems, within ecological systems and between them. We propose a novel analytical framework to evaluate social-ecological relations in nature-based adaptation, encompassing social (people-people), ecological (nature-nature) and social-ecological (people-nature) relations. Applying this framework to 25 case studies, we analyse the associations among these relations and identify archetypes of social-ecological adaptation.

A core beliefs model of disordered eating: processes and pathways to eating disorder symptomatology.

Objective: At present there is no clear, cohesive, and comprehensive theoretical understanding of the role of core beliefs in the development of disordered eating. The present study aimed to develop and test a theoretical model outlining important processes and pathways from core beliefs to eating disorder (ED) behaviours. It also aimed to explore potential differences (or similarities) in contributions of four core belief dimensions to the development and maintenance of ED symptomatology.

Quantification of Internal Disc Strain Under Dynamic Loading Via High-Frequency Ultrasound.

Measurement of internal intervertebral disc strain is paramount for understanding the underlying mechanisms of injury and validating computational models. Although advancements in noninvasive imaging and image processing have made it possible to quantify strain, they often rely on visual markers that alter tissue mechanics and are limited to static testing that is not reflective of physiologic loading conditions. The purpose of this study was to integrate high-frequency ultrasound and texture correlation to quantify disc strain during dynamic loading.