The Best of PLOS ONE

The homogeneity of Aluminium-26 (Al-26) isotope distribution in the accreting solar nebula is debated. Here, the authors show that the age determination of meteorite Erg Chech 002, compared with other igneous meteorites, indicates that Al-26 was heterogeneously distributed in the early Solar System.

Background Mobile health clinics provide an alternative portal into the healthcare system for the medically disenfranchised, that is, people who are underinsured, uninsured or who are otherwise outside of mainstream healthcare due to issues of trust, language, immigration status or simply location. Mobile health clinics as providers of last resort are an essential component of the healthcare safety net providing prevention, screening, and appropriate triage into mainstream services. Despite the face value of providing services to underserved populations, a focused analysis of the relative value of the mobile health clinic model has not been elucidated. The question that the return on investment algorithm has been designed to answer is: can the value of the services provided by mobile health programs be quantified in terms of quality adjusted life years saved and estimated emergency department expenditures avoided? Methods Using a sample mobile health clinic and published research that quantifies health outcomes, we developed and tested an algorithm to calculate the return on investment of a typical broad-service mobile health clinic: the relative value of mobile health clinic services = annual projected emergency department costs avoided + value of potential life years saved from the services provided. Return on investment ratio = the relative value of the mobile health clinic services/annual cost to run the mobile health clinic. Results Based on service data provided by The Family Van for 2008 we calculated the annual cost savings from preventing emergency room visits, $3,125,668 plus the relative value of providing 7 of the top 25 priority prevention services during the same period, US$17,780,000 for a total annual value of $20,339,968. Given that the annual cost to run the program was $567,700, the calculated return on investment of The Family Van was 36:1. Conclusion By using published data that quantify the value of prevention practices and the value of preventing unnecessary use of emergency departments, an empirical method was developed to determine the value of a typical mobile health clinic. The Family Van, a mobile health clinic that has been serving the medically disenfranchised of Boston for 16 years, was evaluated accordingly and found to have return on investment of $36 for every $1 invested in the program.

Background Zoological gardens contain unique configurations of exotic and endemic animals and plants that create a diverse range of developing sites and potential sources of blood meals for local mosquitoes. This may imply unusual interspecific pathogen transmission risks involving zoo vertebrates, like avian malaria to captive penguins. Understanding mosquito ecology and host feeding patterns is necessary to improve mosquito control and disease prevention measures in these environments. Methods Mosquito sampling took place in Chester Zoo for 3 years (2017, 2018, and 2019) and for 1 year in Flamingo Land (2017) using different trapping methods. Blood-fed mosquitoes were identified and their blood meal was amplified by PCR, sequenced, and blasted for host species identification. Results In total, 640 blood-fed mosquitoes were collected [Culex pipiens (n = 497), Culiseta annulata (n = 81), Anopheles maculipennis s.l. (n = 7), An. claviger (n = 1), and unidentifiable (n = 55)]. Successful identification of the host species was achieved from 159 blood-fed mosquitoes. Mosquitoes fed on birds (n = 74), non-human mammals (n = 20), and humans (n = 71). There were mixed blood meals from two hosts (n = 6). The proportions of blood-fed mosquitoes varied across sampling seasons and sites within the zoos. The use of resting traps and aspiration of vegetation were more efficient techniques for capturing blood-fed mosquitoes than traps for host-seeking or gravid mosquitoes. By relating the locations of zoo vertebrates to where fed mosquitoes were trapped, the minimum travelling distances were calculated (13.7 to 366.7 m). Temperature, precipitation, relative humidity, proximity to zoo vertebrate exhibits, and vegetation level were found to be significantly associated with the proportion of captured blood-fed mosquitoes by generalized linear modelling. Conclusions Mosquito feeding behaviour in zoos is mainly influenced by time, location (sampling area), temperature, and host availability, which highlights the value of mosquito monitoring in complex settings to plan control strategies and potentially reduce inherent disease transmission risks for humans and threatened zoo vertebrates. Graphical Abstract

Humanity was entirely unprepared for COVID-19. Although other coronaviruses have crossed from animals to cause pandemics in the recent past, as soon as those pandemics faded away, any efforts to combat the responsible viruses faded away with them. This time, governments and pharmaceutical companies are banding together to make sure that that doesn’t happen again. As COVID-19 fades, hopefully people will retain the impetus to develop, find and, most importantly, test new antivirals. That way, people will be a bit more prepared for the next scourge when it arrives.

If you were offered an unproven treatment to make you feel younger or stave off illness, would you accept it? Proponents of stem-cell-based therapies are banking you would. This eye-opening article aims to raise awareness of the fact that in Japan and elsewhere, such therapies are becoming increasingly available despite concerns they are largely unproven and in some cases may be harmful. Will biomedical research ultimately prove them beneficial? This piece doesn’t offer a definitive answer, but it does raise important questions about standards of proof in the regulation of medical care.

China has more scientists using CRISPR than any other country. They’re not just making designer babies like He Jiankui did, much to the chagrin of his colleagues. Instead, they’re trying to engineer crops to help feed China’s growing population, make more accurate animal models to study diseases and provide organs for transplant, and develop more precise and effective medications. And like most governments around the world, the Chinese government is still struggling to figure out how to regulate the technology. This article offers an overview of how Chinese scientists are wielding this gene-editing tool.