The Physics of Star Cluster Formation and Evolution

© 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00689-4.Star clusters form in dense, hierarchically collapsing gas clouds. Bulk kinetic energy is transformed to turbulence with stars forming from cores fed by filaments. In the most compact regions, stellar feedback is least effective in removing the gas and stars may form very efficiently. These are also the regions where, in high-mass clusters, ejecta from some kind of high-mass stars are effectively captured during the formation phase of some of the low mass stars and effectively channeled into the latter to form multiple populations. Star formation epochs in star clusters are generally set by gas flows that determine the abundance of gas in the cluster. We argue that there is likely only one star formation epoch after which clusters remain essentially clear of gas by cluster winds. Collisional dynamics is important in this phase leading to core collapse, expansion and eventual dispersion of every cluster. We review recent developments in the field with a focus on theoretical work.Peer reviewe

Body image and weight loss outcome after bariatric metabolic surgery: a mixed model analysis

Purpose: As in nonsurgical weight loss populations, body image may partly explain differences in weight loss outcomes after surgery. The aim of this study was to determine the prospective association between body image and weight loss in a longitudinal cohort of patients up to 3 years after bariatric metabolic surgery. Materials and Methods: The BODY-Q self-report questionnaire was used to assess body image. Linear mixed models evaluated associations of baseline body image with weight loss in the first year as well as associations of body image at 12 months and first-year change in body image with weight loss 12 to 36 months after surgery. Results: Available body image data included 400 (100%), 371 (93%), 306 (77%), 289 (72%), and 218 (55%) patients at baseline and 4, 12, 24, and 36 months, respectively. Body image scores improved significantly until 12 months, followed by a gradual decline. Scores remained improved in comparison to baseline (β = 31.49, 95% CI [27.8, 35.2], p <.001). Higher baseline body image was associated with less weight loss during the first year, and the effect size was trivial (ß = −0.05, 95% CI [−0.09, −0.01], p =.009). Body image and change in body image were not associated with weight loss 12 to 36 months after surgery. Conclusion: Body image improved after bariatric metabolic surgery. Although no clinically relevant associations of body image with weight loss were demonstrated, the gradual decline in body image scores underlines the importance of long-term follow-up with regular assessment of this aspect of quality of life. Graphical Abstract: [Figure not available: see fulltext.

The Occurrence, Fate and Biological Activities of C-glycosyl Flavonoids in the Human Diet

The human diet contains a wide variety of plant-derived flavonoids, many of which are glycosylated via an O- or less commonly a C-glycosidic linkage. The distribution, quantity, and biological effects of C-glycosyl flavonoids in the human diet have received little attention in the literature in comparison to their O-linked counterparts, however, despite being present in many common foodstuffs. The structural nature, nomenclature, and distribution of C-glycosyl flavonoids in the human diet are, therefore, reviewed. Forty-three dietary flavonoids are revealed to be C-glycosylated, arising from the dihydrochalcone, flavone, and flavan-3-ol backbones, and distributed among edible fruits, cereals, leaves, and stems. C-linked sugar groups are shown to include arabinose, galactose, glucose, rutinose, and xylose, often being present more than once on a single flavonoid backbone and occasionally in tandem with O-linked glucose or rutinose groups. The pharmacokinetic fate of these compounds is discussed with particular reference to their apparent lack of interaction with hydrolytic mechanisms known to influence the fate of O-glycosylated dietary flavonoids, explaining the unusual but potentially important appearance of intact C-glycosylated flavonoid metabolites in human urine following oral administration. Finally, the potential biological significance of these compounds is reviewed, describing mechanisms of antidiabetic, antiinflammatory, anxiolytic, antispasmodic, and hepatoprotective effects