Miller's 1950s experiments used, besides the apparatus known in textbooks, one that generated a hot water mist in the spark flask, simulating a water vapor-rich volcanic eruption. We found the original extracts of this experiment in Miller's material and reanalyzed them. The volcanic apparatus produced a wider variety of amino acids than the classic one. Release of reduced gases in volcanic eruptions accompanied by lightning could have been common on the early Earth. Prebiotic compounds synthesized in these environments could have locally accumulated, where they could have undergone further processing.

Limb ischemia complications from ECMO may be decreased by prophylactic placement of an antegrade DPC. Without DPC, continuous monitoring using NIRS may identify limb ischemia, which can be treated subsequently with DPC and or fasciotomy.

Introduction The coronavirus disease 2019 (COVID-19) pandemic has led to widespread postponement and cancelation of elective surgeries in the United States. We designed and administered a global survey to examine the impact of COVID-19 on vascular surgeons. We describe the impact of the pandemic on the practices of Vascular Surgeons in the United States. Methods The Pandemic Practice, Anxiety, Coping, and Support Survey for Vascular Surgeons is an anonymous cross-sectional survey sponsored by the Society for Vascular Surgery Wellness Task Force disseminated April 14-24, 2020. This analysis focuses on pattern changes in vascular surgery practices in the United States including the inpatient setting, ambulatory, and vascular laboratory setting. Specific questions regarding occupational exposure to COVID-19, adequacy of personal protective equipment (PPE), elective surgical practice, changes in call schedule, and redeployment to non-vascular surgery duties were also included in the survey. Regional variation was assessed. The survey data were collected using REDCap and analyzed using descriptive statistics. Results A total of 535 vascular surgeons responded to the survey from 45 states. Most of the respondents were male (73.1%), White (70.7%), practiced in urban settings (81.7%), and in teaching hospitals (66.8%). Almost half were in hospitals with greater than 400 beds (46.4%). There was no regional variation in the presence of pre-operative COVID-19 testing, COVID-19 OR protocols, adherence to national surgical standards, and the presence of PPE. The overwhelming majority of respondents (91.7%) noted elective surgery cancellation, with the Northeast and Southeast regions having the most case cancellations 94.2% and 95.8% respectively %). The Northeast region reported the highest percentage of operations/procedures on patients with COVID-19, which was either identified at the time of the surgery or later in the hospital course (82.7%). Ambulatory visits were performed via telehealth (81.3%), with 71.1% having restricted hours. Over half of OBLs were closed, although there was regional variation with over 80% in the Midwest being closed. Cases performed in OBLs focused on critical limb ischemia (42.9%) and dialysis access maintenance (39.9%). Call schedules modifications were common, although the number of call days remained the same (45.8%). Conclusions Vascular surgeons in the United States report substantial impact on their practices during the COVID-19 pandemic, and regional variations are demonstrated - particularly in OBL utilization, ICU bed availability, and COVID-19 exposure at work.

Chemical contamination and disease outbreaks have increased in many ecosystems. However, connecting pollution to disease spread remains difficult, in part, because contaminants can simultaneously exert direct and multi-generational effects on several host and parasite traits. To address these challenges, we parametrized a model using a zooplankton-fungus-copper system. In individual-level assays, we considered three sublethal contamination scenarios: no contamination, single-generation contamination (hosts and parasites exposed only during the assays) and multi-generational contamination (hosts and parasites exposed for several generations prior to and during the assays). Contamination boosted transmission by increasing contact of hosts with parasites. However, it diminished parasite reproduction by reducing the size and lifespan of infected hosts. Multi-generational contamination further reduced parasite reproduction. The parametrized model predicted that a single generation of contamination would enhance disease spread (via enhanced transmission), whereas multi-generational contamination would inhibit epidemics relative to unpolluted conditions (through greatly depressed parasite reproduction). In a population-level experiment, multi-generational contamination reduced the size of experimental epidemics but did not affect Daphnia populations without disease. This result highlights the importance of multi-generational effects for disease dynamics. Such integration of models with experiments can provide predictive power for disease problems in contaminated environments.