Survival study and factors associated with mortality in Chilean patients on peritoneal dialysis infected with SARS-CoV-2.

The Covid-19 pandemic has been responsible for millions of deaths worldwide. Patients with comorbidities- such as those on peritoneal dialysis (PD)- present higher morbidity and mortality than the general population. We prospectively evaluated all Chilean patients on PD (48 centres) and followed those who had Covid-19 from the beginning of the Covid-19 pandemic in Chile (March 2020) to January 2021 (start of vaccination campaign). We described demographic history, comorbidities, factors related to infection, need for hospitalisation and death due to Covid-19. During the study period, 106 adults on PD were infected by SARS-CoV-2, with a mean age of 53.1 (±16.3) and of which 53.9% were female. From that group, 54.8% required hospitalisation and 24.5% (n = 26) died due to Covid-19. Most of the patients (63.4%) were infected at home and 22.8% during hospitalisation for other reasons. There was a significant association for Covid-19 mortality with: being ≥60 years old, diabetes, time on PD ≥5 years, need for hospitalisation and hospital-acquired infection. At 90 days of follow-up, all deaths associated to Covid-19 occurred before 40 days. We conclude that patients on PD without Covid-19 vaccination have a high mortality and need for hospitalisation associated to Covid-19. To avoid this negative outcome, it is necessary to intensify strategies to avoid contagion, especially in those ≥60 years old, with diabetes and/or ≥5 years spent on PD.

A mobile lab for ancient DNA extraction in Perug.

We report the use of a mobile laboratory set up to extract ancient DNA (aDNA) from 34 human coprolites (fossilized faeces) samples. Our approach enabled the rapid genetic characterization of 5,000 years old archeological samples. It is useful for the on-site screening of museums and freshly excavated samples for DNA. This approach is accessible to other investigators as the mobile laboratory was set up using commercially available instruments.

Tackling Real-World Environmental Paper Pollution: A Problem-Based Microbiology Lesson About Carbon Assimilation.

Governmental and educational organizations advocate for the adoption of inquiry-based, student-centered educational strategies in undergraduate STEM curricula. These strategies are known to benefit students by increasing performance, enhancing mastery of class content, and augmenting affect, particularly in underrepresented racial/ethnic minority students. Among these strategies, case study and project-based learning allow students to master course content while collectively tackling relevant, real-world societal problems. In particular, environmental pollution with paper-based products provide a current problem by which microbiology students learn about the role of microorganisms in paper waste management as well as the microbiological and biochemical processes involved in protein secretion, nutrient uptake, and energy metabolism. Delivered in a flipped, hybrid class in a Technology-Enabled Active Learning (TEAL) laboratory, this lesson taught students about exoenzyme secretion, biopolymer hydrolysis, intracellular transport of sugars, and sugar catabolic reactions. Students demonstrated increased comprehension of exoenzyme function and secretion, as well as how cells uptake the products of exoenzyme hydrolysis. However, students had challenges in placing the transported exoenzyme products within metabolic processes. Our results show increased perceived learning from the students as well as an understanding of the societal implications of these microbiological concepts. Our lesson deviated from knowledge silos in which students learn information in discrete topics. While departing from employing traditional, compartmentalized learning approaches, this student-centered guided lesson frames the systemic nature of the microbiological and biochemical processes underlying the decomposition of organic matter in a real-world context.

Environmental change and economic development in coastal Peru between 5,800 and 3,600 years ago.

Between approximately 5,800 and 3,600 cal B.P. the biggest architectural monuments and largest settlements in the Western Hemisphere flourished in the Supe Valley and adjacent desert drainages of the arid Peruvian coast. Intensive net fishing, irrigated orchards, and fields of cotton with scant comestibles successfully sustained centuries of increasingly complex societies that did not use ceramics or loom-based weaving. This unique socioeconomic adaptation was abruptly abandoned and gradually replaced by societies more reliant on food crops, pottery, and weaving. Here, we review evidence and arguments for a severe cycle of natural disasters-earthquakes, El Niño flooding, beach ridge formation, and sand dune incursion-at approximately 3,800 B.P. and hypothesize that ensuing physical changes to marine and terrestrial environments contributed to the demise of early Supe settlements.