Colossoma macropomum is the second largest scaled fish in the Amazon basin. Reduced harvests in recent decades suggest that populations of this species are already overexploited in some areas. In this study, the population dynamics of C. macropomum was investigated using length and weight data for fish caught in the Manacapuru Lake system, a large ria lake located along the lower reach of the Solimões River. A total of 1270 individuals of C. macropomum with standard lengths varying from 17 to 62 cm and mean length of 31.0 ± 6.7 cm were sampled. Weights varied from 165 to 8195 g, and mean weight was 1148.3 ± 883.8 g. Maximum sustainable yield was estimated at 285.8 g recruit−1, corresponding to a fishing mortality of 0.51 year−1. A scenario analysis based on changes in fishing mortality and age at first capture, two parameters potentially addressed by fishing management strategies, suggested that any improvement in fishing yield depends on increases in age at first capture.

Background Dietary patterns are associated with health outcomes and environment sustainability, having socioeconomic drivers. This ecological study aims to identify dietary patterns in food availability data at the global level using multivariate statistical methodology, to associate the identified dietary patterns with socioeconomic data and to analyze the adequacy of the applied multivariate statistical methods for this purpose. Methods Principal Component Analysis was applied to median values of times series of food availability data of 172 UN registered countries available at FAOSTAT database in Food Balance Sheets section in a sectional manner, after calculating median values of time series for each food group and country. Principal Components were associated with socioeconomic data available from the World Bank database. Sensitivity analyses were realized to verify the stability of dietary patterns through five different times. Results Five principal components were identified in the median values of each time series, each characterizing a possible dietary pattern. The first one, a westernized dietary pattern, was composed of energy-dense and processed foods, foods of animal origin, alcoholic beverages, but also, albeit less, by vegetables, fruits and nuts, being associated with income, urbanization and trade liberalization. This westernized pattern was characterized more animal origin and processed foods, such as vegetable oils, alcoholic beverages and stimulants yet preserving unprocessed and regional foods. The other dietary patterns were three agricultural patterns characterized more by regional foods, especially starchy staples, and one coastal dietary pattern composed of fish and seafoods, being associated with GINI index, poverty, and female labor force. Sensitivity analyses demonstrated the stability of dietary patterns. Conclusions Principal Component Analysis was adequate to identify dietary patterns in food availability data. A westernized dietary pattern was identified, being associated with income, urbanization, and trade liberalization. This association did not occur for the remain of the dietary patterns identified, these being less driven by economic development.

In this brief communication, the authors develop the argument that science by pressrelease and by press conference without the readily available study for scrutiny is outside of the ethos of thescientific enterprise. Additionally, we argue why and how science by press conference and by press release is arecipe for misinformation and poor choices in public health decision-making. Finally, the authors dive into the implications of this emerging phenomenon for publichealth in Brazil in the COVID19 era.

Introduction: Preprints have been increasingly used in biomedical sciences, providing the opportunity for research to be publicly assessed before journal publication. With the increase in attention over preprints during the COVID-19 pandemic, we decided to assess the content of comments left on preprint platforms. Methods: Preprints posted on bioRxiv and medRxiv in 2020 were accessed through each platform's API, and a random sample of preprints that had received between 1 and 20 comments was analyzed. Comments were evaluated in triplicate by independent evaluators using an instrument that assessed their features and general content. Results: 7.3% of preprints received at least 1 comment during a mean follow-up of 7.5 months. Analyzed comments had a median size of 43 words. Criticisms, corrections or suggestions were the most prevalent type of content, followed by compliments or positive appraisals and questions. Most critical comments regarded interpretation, data collection and methodological design, while compliments were usually about relevance and implications. Conclusions: Only a small percentage of preprints posted in 2020 in bioRxiv and medRxiv received comments in these platforms. When present, however, these comments address content that is similar to that analyzed by traditional peer review. A more precise taxonomy of peer review functions would be desirable to describe whether post-publication peer review fulfills these roles.

How a few poorly designed COVID-19 studies may have contributed to misinformation in Brazil: the case for evidencebased communication of science.