Platformisation

Este artigo contextualiza, define e operacionaliza o conceito de plataformização. A partir de insights vindos de diferentes perspectivas acadêmicas sobre plataformas – estudos de software, economia política crítica, estudos de negócios e estudos culturais – desenvolvemos uma abordagem compreensiva em relação a esse processo. A plataformização é definida como a penetração de infraestruturas, processos econômicos e estruturas governamentais das plataformas digitais em diferentes setores econômicos e esferas da vida. Ela também envolve a reorganização de práticas e imaginários culturais em torno dessas plataformas. A partir do exemplo de app stores, mostramos como essa definição pode ser empregada em pesquisas empíricas.Palavras-chave: Plataformas. Plataformização. Dataficação. Mercados multilaterais. Economia política. Governança.This article contextualises, defines, and operationalises the concept of platformisation. Drawing insights from different scholarly perspectives on platforms—software studies, critical political economy, business studies, and cultural studies—it develops a comprehensive approach to this process. Platformisation is defined as the penetration of infrastructures, economic processes and governmental frameworks of digital platforms in different economic sectors and spheres of life, as well as the reorganisation of cultural practices and imaginations around these platforms. Using app stores as an example, we show how this definition can be employed in research.Keywords: Platforms. Platformisation. Datafication. Multi-sided markets. Political Economy. Governance

Trehalose is required for the acquisition of tolerance to a variety of stresses in the filamentous fungus Aspergillus nidulans

Trehalose is a non-reducing disaccharide found at high concentrations in Aspergillus nidulans conidia and rapidly degraded upon induction of conidial germination. Furthermore, trehalose is accumulated in response to a heat shock or to an oxidative shock. The authors have characterized the A. nidulans tpsA gene encoding trehalose-6-phosphate synthase, which catalyses the first step in trehalose biosynthesis. Expression of tpsA in a Saccharomyces cerevisiae tps1 mutant revealed that the tpsA gene product is a functional equivalent of the yeast Tps1 trehalose-6-phosphate synthase. The A. nidulans tpsA-null mutant does not produce trehalose during conidiation or in response to various stress conditions. While germlings of the tpsA mutant show an increased sensitivity to moderate stress conditions (growth at 45 °C or in the presence of 2 mM H2O2), they display a response to severe stress (60 min at 50 °C or in the presence of 100 mM H2O2) similar to that of wild-type germlings. Furthermore, conidia of the tpsA mutant show a rapid loss of viability upon storage. These results are consistent with a role of trehalose in the acquisition of stress tolerance. Inactivation of the tpsA gene also results in increased steady-state levels of sugar phosphates but does not prevent growth on rapidly metabolizable carbon sources (glucose, fructose) as seen in Saccharomyces cerevisiae. This suggests that trehalose 6-phosphate is a physiological inhibitor of hexokinase but that this control is not essential for proper glycolytic flux in A. nidulans. Interestingly, tpsA transcription is not induced in response to heat shock or during conidiation, indicating that trehalose accumulation is probably due to a post-translational activation process of the trehalose 6-phosphate synthase

Social Media and trust in scientific expertise: Debating the Covid-19 Pandemic in The Netherlands

This article examines the role of social media dynamics in the public exchange of information between scientists (experts), government (policy-makers), mass media (journalists), and citizens (nonexperts) during the first 4 months after the Covid-19 outbreak in the Netherlands. Over the past decade, the institutional model of science communication, based on linear vectors of information flows between institutions, has gradually converted into a networked model where social media propel information flows circulating between all actors involved. The question driving our research is, “How are social media deployed to both undermine and enhance public trust in scientific expertise during a health crisis?” Analyzing the public debate during the period of the corona outbreak in the Netherlands, we investigate two stages: the emergency response phase and the “smart exit strategy” phase, discussing how scientific experts, policy-makers, journalists, and citizens appropriate social media logic to steer information and to control the debate. We conclude by outlining the potential risks and benefits of adopting social media dynamics in institutional contexts of science communication

Influence of daily 10-85 mu g vitamin D supplements during pregnancy and lactation on maternal vitamin D status and mature milk antirachitic activity

Pregnant and lactating women and breastfed infants are at risk of vitamin D deficiency. The supplemental vitamin D dose that optimises maternal vitamin D status and breast milk antirachitic activity (ARA) is unclear. Healthy pregnant women were randomised to 10 (n 10), 35 (n 11), 60 (n 11) and 85 (n 11) mu g vitamin D-3/d from 20 gestational weeks (GW) to 4 weeks postpartum (PP). The participants also received increasing dosages of fish oil supplements and a multivitamin. Treatment allocation was not blinded. Parent vitamin D and 25-hydroxyvitamin D (25(OH)D) were measured in maternal plasma at 20 GW, 36 GW and 4 weeks PP, and in milk at 4 weeks PP. Median 25(OH)D and parent vitamin D at 20 GW were 85 (range 25-131) nmol/l and 'not detectable (nd)' (range nd-40) nmol/l. Both increased, seemingly dose dependent, from 20 to 36 GW and decreased from 36 GW to 4 weeks PP. In all, 35 mu g vitamin D/d was needed to increase 25(OH)D to adequacy (80-249 nmol/l) in >97 center dot 5 % of participants at 36 GW, while >85 mu g/d was needed to reach this criterion at 4 weeks PP. The 25(OH)D increments from 20 to 36 GW and from 20 GW to 4 weeks PP diminished with supplemental dose and related inversely to 25(OH)D at 20 GW. Milk ARA related to vitamin D-3 dose, but the infant adequate intake of 513 IU/l was not reached. Vitamin D-3 dosages of 35 and >85 mu g/d were needed to reach adequate maternal vitamin D status at 36 GW and 4 weeks PP, respectively

The popular music heritage of the Dutch pirates: illegal radio and cultural identity

This article explores how cultural identities are negotiated in relation to the heritage of illegal radio in the Netherlands. The term ‘pirate radio’ commonly refers to the offshore radio stations that were broadcasting during the 1960s. These stations introduced commercial radio and popular music genres like beat music, which were not played by public broadcasters at the time. In their wake, land-based pirates began broadcasting for local audiences. This study examines the identities that are constituted by the narrative of pirate radio. Drawing on in-depth interviews with archivists, fans and broadcasters, this article explores the connection between pirate radio, popular music heritage and cultural identity. Moreover, it considers how new technologies such as internet radio provide platforms to engage with this heritage and thus to maintain these local identities. To examine how the memories of pirate radio live on in the present a narrative approach to identity will be used

Folate reference interval estimation in the Dutch general population

Background: Folate functions as an enzyme co-factor within the one-carbon metabolic pathway, providing key metabolites required for DNA synthesis and methylation. Hence, insufficient intake of folate can negatively affect health. As correct interpretation of folate status is dependent on a well-established reference interval, we set out to perform a new estimation following the restandardization of the Roche folate assay against the international folate standard. Materials and methods: The folate reference interval was estimated using samples obtained from the Dutch population-based Lifelines cohort. The reference interval was estimated using two methods: a nonparametric estimation combined with bootstrap resampling and by fitting the data to a gamma distribution. The lower reference limit was verified in a patient cohort by combined measurement of folate and homocysteine. Results: Dependent on the method used for estimation and in- or exclusion of individuals younger than 21 years of age, the lower reference limit ranged from 6.8 to 7.3 nmol/L and the upper reference limit ranged from 26 to 38.5 nmol/L. Applying a lower reference limit of 7.3 nmol/L resulted in the following percentage of folate deficiencies over a period of 12 months: general practitioner 15.5% (IQR 4.0%), general hospital 12.8% (IQR 5.3%), academic hospital 9.6% (IQR 4.3%). Conclusions: We estimated the folate reference interval in the Dutch general population which is not affected by a folic acid fortification program and verified the obtained lower reference limit by homocysteine measurements. Based on our results, we propose a folate reference interval independent of age of 7.3-38.5 nmol/