Traditional craftspeople are not copycats: Potter idiosyncrasies in vessel morphogenesis

Ceramics are quintessential indicators of human culture and its evolution across generations of social learners. Cultural transmission and evolution theory frequently emphasizes apprentices' need for accurate imitation (high-fidelity copying) of their mentors' actions. However, the ensuing prediction of standardized fashioning patterns within communities of practice has not been directly addressed in handicraft traditions such as pottery throwing. To fill this gap, we analysed variation in vessel morphogenesis amongst and within traditional potters from culturally different workshops producing for the same market. We demonstrate that, for each vessel type studied, individual potters reliably followed distinctive routes through morphological space towards a much-less-variable common final shape. Our results indicate that mastering the pottery handicraft does not result from accurately reproducing a particular model behaviour specific to the community's cultural tradition. We provide evidence that, at the level of the elementary clay-deforming gestures, individual learning rather than simple imitation is required for the acquisition of a complex motor skill such as throwing pottery

When Handicraft Experts Face Novelty: Effects of Shape and Wheel Familiarity on Individual and Community Standardization of Ceramic Vessels

Indian Prajapati and Multani Kumhar potting communities use different wheels in throwing their vessels. Highly-experienced potters from these communities threw assemblages of (i) familiar shapes using their familiar wheels, (ii) unfamiliar shapes using their familiar wheels and (iii) unfamiliar shapes using unfamiliar wheels. We analyzed how the potters dealt with the novelty provided by the unfamiliar shapes and wheels by assessing their effects on the degree of assemblage standardization. When throwing familiar shapes with familiar wheels, potters demonstrated a high degree of standardization, both at the level of the individual potter and at the level of their respective communities. Throwing unfamiliar shapes considerably affected standardization, especially for the more difficult shapes. Hence, novelty may be detected in archaeological assemblages by the coexistence of (large quantities of) highly standardized artifacts of one type and (smaller quantities of) less standardized artifacts of another type. However, throwing the unfamiliar shapes on unfamiliar wheels (“borrowed” from the other community) did not give rise to additional markers of novelty in the assemblages produced. Thus, at least part of the expert potters’ skill can be transferred from their usual conditions of practice to new, unfamiliar conditions without leaving observable traces in the artifacts produced

Transient eco-evolutionary dynamics early in a phage epidemic have strong and lasting impact on the long-term evolution of bacterial defences

This is the final version. Available on open access from Public Library of Science (PLoS) via the DOI in this recordData Availability: Data and code are available online https://doi.org/10.5281/zenodo.8193506Organisms have evolved a range of constitutive (always active) and inducible (elicited by parasites) defence mechanisms, but we have limited understanding of what drives the evolution of these orthogonal defence strategies. Bacteria and their phages offer a tractable system to study this: Bacteria can acquire constitutive resistance by mutation of the phage receptor (surface mutation, sm) or induced resistance through their CRISPR-Cas adaptive immune system. Using a combination of theory and experiments, we demonstrate that the mechanism that establishes first has a strong advantage because it weakens selection for the alternative resistance mechanism. As a consequence, ecological factors that alter the relative frequencies at which the different resistances are acquired have a strong and lasting impact: High growth conditions promote the evolution of sm resistance by increasing the influx of receptor mutation events during the early stages of the epidemic, whereas a high infection risk during this stage of the epidemic promotes the evolution of CRISPR immunity, since it fuels the (infection-dependent) acquisition of CRISPR immunity. This work highlights the strong and lasting impact of the transient evolutionary dynamics during the early stages of an epidemic on the long-term evolution of constitutive and induced defences, which may be leveraged to manipulate phage resistance evolution in clinical and applied settings.Natural Environment Research Council (NERC)European Research Council (ERC)Biotechnology and Biological Sciences Research Council (BBSRC

Web Futures: Inclusive, Intelligent, Sustainable The 2020 Manifesto for Web Science

International audienceThis Manifesto was produced from the Perspectives Workshop 18262 entitled "10 Years of Web Science" that took place at Schloss Dagstuhl from June 24-29, 2018. At the Workshop, we revisited the origins of Web Science, explored the challenges and opportunities of the Web, and looked ahead to potential futures for both the Web and Web Science. We explain issues that society faces in the Web by the ambivalences that are inherent in the Web. All the enormous benefits that the Web offers-for information sharing, collective organization and distributed activity, social inclusion and economic growth-will always carry along negative consequences, too, and 30 years after its creation negative consequences of the Web are only too apparent. The Web continues to evolve and its next major step will involve Artificial Intelligence (AI) at large. AI has the potential to amplify positive and negative outcomes, and we explore these possibilities, situating them within the wider debate about the future of regulation and governance for the Web. Finally, we outline the need to extend Web Science as the science that is devoted to the analysis and engineering of the Web, to strengthen our role in shaping the future of the Web and present five key directions for capacity building that are necessary to achieve this: (i), supporting interdisciplinarity, (ii), supporting collaboration, (iii), supporting the sustainable Web, (iv), supporting the Intelligent Web, and (v), supporting the Inclusive Web. Our writing reflects our background in several disciplines of the social and technical sciences and that these disciplines emphasize topics to various extents. We are acutely aware that our observations occupy a particular point in time and are skewed towards our experience as Western scholars-a limitation that Web Science will need to overcome

Predictors of functional decline in elderly patients undergoing transcatheter aortic valve implantation (TAVI)

Aims This study aimed to assess functional course in elderly patients undergoing transcatheter aortic valve implantation (TAVI) and to find predictors of functional decline. Methods and results In this prospective cohort, functional course was assessed in patients ≥70 years using basic activities of daily living (BADL) before and 6 months after TAVI. Baseline EuroSCORE, STS score, and a frailty index (based on assessment of cognition, mobility, nutrition, instrumental and basic activities of daily living) were evaluated to predict functional decline (deterioration in BADL) using logistic regression models. Functional decline was observed in 22 (20.8%) of 106 surviving patients. EuroSCORE (OR per 10% increase 1.18, 95% CI: 0.83-1.68, P = 0.35) and STS score (OR per 5% increase 1.64, 95% CI: 0.87-3.09, P = 0.13) weakly predicted functional decline. In contrast, the frailty index strongly predicted functional decline in univariable (OR per 1 point increase 1.57, 95% CI: 1.20-2.05, P = 0.001) and bivariable analyses (OR: 1.56, 95% CI: 1.20-2.04, P = 0.001 controlled for EuroSCORE; OR: 1.53, 95% CI: 1.17-2.02, P = 0.002 controlled for STS score). Overall predictive performance was best for the frailty index [Nagelkerke's R2 (NR2) 0.135] and low for the EuroSCORE (NR2 0.015) and STS score (NR2 0.034). In univariable analyses, all components of the frailty index contributed to the prediction of functional decline. Conclusion Over a 6-month period, functional status worsened only in a minority of patients surviving TAVI. The frailty index, but not established risk scores, was predictive of functional decline. Refinement of this index might help to identify patients who potentially benefit from additional geriatric interventions after TAV

Darwin’s wind hypothesis: does it work for plant dispersal in fragmented habitats?

Using the wind-dispersed plant Mycelis muralis, we examined how landscape fragmentation affects variation in seed traits contributing to dispersal. Inverse terminal velocity (Vt−1) of field-collected achenes was used as a proxy for individual seed dispersal ability. We related this measure to different metrics of landscape connectivity, at two spatial scales: in a detailed analysis of eight landscapes in Spain and along a latitudinal gradient using 29 landscapes across three European regions. In the highly patchy Spanish landscapes, seed Vt−1 increased significantly with increasing connectivity. A common garden experiment suggested that differences in Vt−1 may be in part genetically based. The Vt−1 was also found to increase with landscape occupancy, a coarser measure of connectivity, on a much broader (European) scale. Finally, Vt−1 was found to increase along a south–north latitudinal gradient. Our results for M. muralis are consistent with ‘Darwin’s wind dispersal hypothesis’ that high cost of dispersal may select for lower dispersal ability in fragmented landscapes, as well as with the ‘leading edge hypothesis’ that most recently colonized populations harbour more dispersive phenotypes.

Phage gene expression and host responses lead to infection-dependent costs of CRISPR immunity

This is the final version. Available on open access from Springer Nature via the DOI in this recordCRISPR-Cas immune systems are widespread in bacteria and archaea, but not ubiquitous. Previous work has demonstrated that CRISPR immunity is associated with an infection-induced fitness cost, which may help explain the patchy distribution observed. However, the mechanistic basis of this cost has remained unclear. Using Pseudomonas aeruginosa PA14 and its phage DMS3vir as a model, we perform a 30-day evolution experiment under phage mediated selection. We demonstrate that although CRISPR is initially selected for, bacteria carrying mutations in the phage receptor rapidly invade the population following subsequent reinfections. We then test three potential mechanisms for the observed cost of CRISPR: (1) autoimmunity from the acquisition of self-targeting spacers, (2) immunopathology or energetic costs from increased cas gene expression and (3) toxicity caused by phage gene expression prior to CRISPR-mediated cleavage. We find that phages can express genes before the immune system clears the infection and that expression of these genes can have a negative effect on host fitness. While infection does not lead to increased expression of cas genes, it does cause differential expression of multiple other host processes that may further contribute to the cost of CRISPR immunity. In contrast, we found little support for infection-induced autoimmunological and immunopathological effects. Phage gene expression prior to cleavage of the genome by the CRISPR-Cas immune system is therefore the most parsimonious explanation for the observed phage-induced fitness cost.Natural Environment Research Council (NERC)Biotechnology & Biological Sciences Research Council (BBSRC)Wellcome TrustEuropean Research Council (ERC

Evolutionary Epidemiology of Drug-Resistance in Space

The spread of drug-resistant parasites erodes the efficacy of therapeutic treatments against many infectious diseases and is a major threat of the 21st century. The evolution of drug-resistance depends, among other things, on how the treatments are administered at the population level. “Resistance management” consists of finding optimal treatment strategies that both reduce the consequence of an infection at the individual host level, and limit the spread of drug-resistance in the pathogen population. Several studies have focused on the effect of mixing different treatments, or of alternating them in time. Here, we analyze another strategy, where the use of the drug varies spatially: there are places where no one receives any treatment. We find that such a spatial heterogeneity can totally prevent the rise of drug-resistance, provided that the size of treated patches is below a critical threshold. The range of parasite dispersal, the relative costs and benefits of being drug-resistant compared to being drug-sensitive, and the duration of an infection with drug-resistant parasites are the main factors determining the value of this threshold. Our analysis thus provides some general guidance regarding the optimal spatial use of drugs to prevent or limit the evolution of drug-resistance