(-)-Prezizanol

Understanding why various organisms evolve alternative ways of living requires information on both the fitness advantages of phenotypic modifications and the costs of constructing and operating cellular features. Although the former has been the subject of a myriad of ecological studies, almost no attention has been given to how organisms allocate resources to alternative structures and functions. We address these matters by capitalizing on an array of observations on diverse ciliate species and from the emerging field of evolutionary bioenergetics. A relatively robust and general estimator for the total cost of a cell per cell cycle (in units of ATP equivalents) is provided, and this is then used to understand how the magnitudes of various investments scale with cell size. Among other things, we examine the costs associated with the large macronuclear genomes of ciliates, as well as ribosomes, various internal membranes, osmoregulation, cilia, and swimming activities. Although a number of uncertainties remain, the general approach taken may serve as blueprint for expanding this line of work to additional traits and phylogenetic lineages.

Background Pediatric inpatient admissions for viral respiratory infections decreased worldwide during the early part of the coronavirus disease 2019 (COVID-19) pandemic. This was likely due to social distancing measures and mask mandates leading to a decreased spread of viruses. We question if there was an increase in respiratory admissions during the winter of 2020-2021 due to the overlap of seasonal respiratory viruses and COVID-19 and the severity of those admissions. Methods We performed a single-center retrospective chart review of all respiratory admissions to our pediatric intensive care unit (PICU) from October to April during the years 2018-2019, 2019-2020, and 2020-2021. We compared the total number of respiratory admissions from different viruses and respiratory admissions by diagnoses among those time periods. Second, we compared the PICU length of stay and duration of mechanical ventilation (both invasive and non-invasive) for these respiratory admissions during those years. Results We saw a drastic decrease in the total respiratory admissions to the PICU in 2020-2021 compared to the same period of time in the last two years. The greatest contributor to this decrease was admissions secondary to bronchiolitis. We noticed a statistically significant decrease in both asthma (p<0.001) and chronic respiratory failure admissions (p=0.0029) during the pandemic winter compared to previous winters. Although, the total number of all respiratory viral admissions is not significant, admissions specific to the respiratory syncytial virus (RSV) (p<0.0001), rhino-enterovirus (p<0.0001), and multi-virus (p=0.0016), achieved statistical significance. There was no statistical difference between the PICU length of stay and duration of mechanical ventilation during the three years. Conclusion Despite a decrease in pediatric respiratory admissions during the COVID-19 pandemic, the severity of illness based on length of stay in the PICU and length of time on respiratory support remains unchanged compared to the previous two years.

Introduction: Headache has been cited as both a primary symptom and a sequela of infection with the novel coronavirus. Cases of long coronavirus disease (COVID) headache have already been documented in adults, but literature on similar cases in children and adolescents is scant. Case report: We present three cases of persistent headache after infection with COVID-19 in pediatric patients presenting to a tertiary headache center. Conclusion: Infection has been suggested as a trigger for chronic headaches, specifically those of the new daily persistent headache type. Although the association between new daily persistent headache and COVID-19 remains unclear, these cases highlight the importance of awareness of the neurological sequelae of novel coronavirus infection in children and adolescents.