Esthetics

Over 30 years, the Gram-positive bacterium Priestia megaterium (previously known as Bacillus megaterium) was systematically developed for biotechnological applications ranging from the production of small molecules like vitamin B12, over polymers like polyhydroxybutyrate (PHB) up to the in vivo and in vitro synthesis of multiple proteins and finally whole-cell applications. Here we describe the use of the natural vitamin B12 (cobalamin) producer P. megaterium for the elucidation of the biosynthetic pathway and the subsequent systematic knowledge-based development for production purposes. The formation of PHB, a natural product of P. megaterium and potential petro-plastic substitute, is covered and discussed. Further important biotechnological characteristics of P. megaterium for recombinant protein production including high protein secretion capacity and simple cultivation on value-added carbon sources are outlined. This includes the advanced system with almost 30 commercially available expression vectors for the intracellular and extracellular production of recombinant proteins at the g/L scale. We also revealed a novel P. megaterium transcription-translation system as a complementary and versatile biotechnological tool kit. As an impressive biotechnology application, the formation of various cytochrome P450 is also critically highlighted. Finally, whole cellular applications in plant protection are completing the overall picture of P. megaterium as a versatile giant cell factory. KEY POINTS: • The use of Priestia megaterium for the biosynthesis of small molecules and recombinant proteins through to whole-cell applications is reviewed. • P. megaterium can act as a promising alternative host in biotechnological production processes.

Facial appearance expresses numerous cues about physical qualities as well as psychosocial and personality traits. Attractive faces are recognized clearly when seen and are often viewed advantageously in professional, social and romantic relationships. On the other hand, self-perceived attractiveness is not well understood and has been mainly attributed to psychological and cognitive factors. Here we use 3-dimensional facial surface data of a large young adult population (n = 601) to thoroughly assess the effect of facial shape on self-perceived facial attractiveness. Our results show that facial shape had a measurable effect on self-perception of facial attractiveness in both sexes. In females, self-perceived facial attractiveness was linked to decreased facial width, fuller anterior part of the lower facial third and more pronounced middle forehead and root of the nose. Males favored a well-defined chin, flatter cheeks and zygomas, and more pronounced eyebrow ridges, nose and middle forehead. The findings of this study support the notion that self-perceived facial attractiveness is not only motivated by psychological traits, but objectively measured phenotypic traits also contribute significantly. The role of social stereotypes for facial attractiveness in modern society is also inferred and discussed.

The sanitary-mask effect (Miyazaki and Kawahara in Jpn Psychol Res 58(3):261-272, 2016) is the finding that medical face masks prompt an image of disease and thus result in lower ratings of facial attractiveness of the wearer. However, during the COVID-19 pandemic, medical masks have been found to increase attractiveness (Patel et al. in Plast Reconstruct Surg Glob Open 8(8), 2020) although this could have been a general effect of occlusion. To further explore this issue, female participants were presented with a series of male faces of low or high attractiveness that were occluded with a medical mask, cloth mask, book or not occluded and asked to rate them on attractiveness. The results show that faces were considered as most attractive when covered by medical masks and significantly more attractive when occluded with cloth masks than when not occluded. Contrary to expectation, base attractiveness did not interact with the type of occlusion, suggesting that this is not simply due to occlusion of negative features. The present findings are contrary to the sanitary-mask effect and explanations in terms of social desirability, and the association of medical masks with caregiving professions is explored.

BackgroundFacial attractiveness is shaped by multiple visual cues, yet the influence of image resolution on attractiveness judgments remains underexplored. Advances in display and imaging technology now allow for image presentation at resolutions approaching the limits of human spatial vision, enabling investigations under higher-fidelity spatial sampling conditions that more closely approximate retina-like detail at typical viewing distances.ObjectivesThis study aimed to determine whether facial image resolution, specifically matched to the spatial resolving power of the human visual system, affects perceived facial attractiveness.MethodsHigh-resolution facial images of 180 Japanese female models were captured using an 8K imaging system (7680 × 4320 pixels; 283.2 ppi). Low-resolution versions (35.3 ppi) were created by downsampling the originals using pixelation. Both high- and low-resolution images were presented on an 8K display in a within-subjects design. Participants rated the attractiveness of each face using a standardized 6-point scale.ResultsFacial images presented at higher resolution received slightly higher attractiveness ratings than their low-resolution counterparts, as confirmed by linear mixed-effects models accounting for crossed observer and identity effects. The effect was especially pronounced for faces with higher baseline attractiveness. Age-related declines in attractiveness ratings were observed in both conditions.ConclusionsUltra-high image resolution yields a small but reliable increase in perceived facial attractiveness, particularly for faces with higher baseline attractiveness. These findings suggest that increased spatial detail may amplify attractiveness-related cues that are otherwise diminished in conventional-resolution displays.