Galactic cosmic ray environment predictions for the NASA BioSentinel mission.

BioSentinel is a nanosatellite deployed from Artemis-I designed to conduct in-situ biological measurements on yeast cells in the deep space radiation environment. Along with the primary goal of measuring damage and response in cells exposed during spaceflight, on-board active dosimetry will provide measurements of the radiation field encountered behind moderate shielding provided by the BioSentinel housing and internal components. The measurements are particularly important to enable interpretation of biological observations but also provide an opportunity to validate integrated computational models used to calculate radiation environments. In this work, models are used to predict the galactic cosmic ray exposure anticipated for the BioSentinel payload and on-board dosimeter. The model calculations presented herein were completed prior to the Artemis-I launch on November 16, 2022, and therefore represent actual predictions (i.e., unbiased by a priori knowledge of on-board measurements). Such time-forward predictions are rarely performed for space radiation applications due to limitations of environmental models, but truly independent model validation will be possible in the future when on-board measurements become available. The method used to facilitate future projections within an existing GCR (galactic cosmic ray) environmental model is described, and projection uncertainties are quantified and contextualized.

BioSentinel: Validating Sensitivity of Yeast Biosensors to Deep Space Relevant Radiation.

With the imminent human exploration of deep space, it is more important than ever to understand the biological risks of deep space radiation exposure. The BioSentinel mission will be the first biological payload to study the effects of radiation beyond low Earth orbit in 50 years. This study is the last in a collection of articles about the BioSentinel biological CubeSat mission, where budding yeast cells will be used to investigate the response of a biological organism to long-term, low-dose deep space radiation. In this study, we define the methodology for detecting the biological response to space-like radiation using simulated deep space radiation and a metabolic indicator dye reduction assay. We show that there is a dose-dependent decrease in yeast cell growth and metabolism in response to space-like radiation, and this effect is significantly more pronounced in a strain of yeast that is deficient in DNA damage repair (rad51Δ) compared with a wild-type strain. Furthermore, we demonstrate the use of flight-like instrumentation after exposure to space-like ionizing radiation. Our findings will inform the development of novel and improved biosensors and technologies for future missions to deep space.

BioSentinel: A Biological CubeSat for Deep Space Exploration.

BioSentinel is the first biological CubeSat designed and developed for deep space. The main objectives of this NASA mission are to assess the effects of deep space radiation on biological systems and to engineer a CubeSat platform that can autonomously support and gather data from model organisms hundreds of thousands of kilometers from Earth. The articles in this special collection describe the extensive optimization of the biological payload system performed in preparation for this long-duration deep space mission. In this study, we briefly introduce BioSentinel and provide a glimpse into its technical and conceptual heritage by detailing the evolution of the science, subsystems, and capabilities of NASA's previous biological CubeSats. This introduction is not intended as an exhaustive review of CubeSat missions, but rather provides insight into the unique optimization parameters, science, and technology of those few that employ biological model systems.

BioSentinel: A Biofluidic Nanosatellite Monitoring Microbial Growth and Activity in Deep Space.

Small satellite technologies, particularly CubeSats, are enabling breakthrough research in space. Over the past 15 years, NASA Ames Research Center has developed and flown half a dozen biological CubeSats in low Earth orbit (LEO) to conduct space biology and astrobiology research investigating the effects of the space environment on microbiological organisms. These studies of the impacts of radiation and reduced gravity on cellular processes include dose-dependent interactions with antimicrobial drugs, measurements of gene expression and signaling, and assessment of radiation damage. BioSentinel, the newest addition to this series, will be the first deep space biological CubeSat, its heliocentric orbit extending far beyond the radiation-shielded environment of low Earth orbit. BioSentinel's 4U biosensing payload, the first living biology space experiment ever conducted beyond the Earth-Moon system, will use a microbial bioassay to assess repair of radiation-induced DNA damage in eukaryotic cells over a duration of 6-12 months. Part of a special collection of articles focused on BioSentinel and its science mission, this article describes the design, development, and testing of the biosensing payload's microfluidics and optical systems, highlighting improvements relative to previous CubeSat life-support and bioanalytical measurement technologies.

The Mediterranean limpet Patella caerulea (Gastropoda, Mollusca) to assess marine ecotoxicological risk: a case study of Tunisian coasts contaminated by metals.

Participants in the coastal socio-economy of the Mediterranean Sea, such as industries, aquaculture, urban populations, conglomerates, and tourists, create intense anthropogenic pressures on marine ecosystems (such as the release of trace metals). This raises concerns about their impact on the surrounding environment and on marine organisms, including those collected for human consumption. This study introduces the possibility of using Patella caerulea (Linnaeus 1758), indigenous to the Mediterranean Sea, as a biosentinel of marine pollution. This study proposes coupling environmental (bioaccumulation) and toxicological (redox homeostasis) measures of bioavailability with genetic variability (COI mtDNA) assessments. Concentrations of six trace metals (cadmium, copper, iron, lead, nickel, and zinc) were measured in surface seawater and in P. caerulea individuals collected from four coastal stations on the Tunisian coast where different levels of metal contamination have occurred. The quantified biomarkers involved the determination of antioxidant defense enzymes, catalase (CAT), glutathione peroxidase (GPX), superoxide dismutase (SOD), and the measurement of lipid peroxidation indicated by malondialdehyde (MDA) levels. Our study identified critical levels of metal contamination among locations in the Gulf of Gabes. Concomitantly, the induction of antioxidant biomarkers (especially SOD and GPX) was observed, highlighting the potential of P. caerulea to acclimate to stressful pollution conditions. Molecular analysis of COI (mtDNA) revealed low discrimination between the four P. caerulea populations, highlighting the role of marine currents in the Mediterranean Sea in the dispersal and passive transportation of limpet larvae, allowing an exchange of individuals among physically separated, P. caerulea populations.

Angiostrongylus cantonensis in North African hedgehogs as vertebrate hosts, Mallorca, Spain, October 2018.

In October 2018, two Atelerix algirus hedgehogs were admitted to the Wildlife Rehabilitation Hospital in Mallorca (Balearic Islands, Spain) with signs of acute neurological disease. Necropsy detected immature, fully developed nematodes in the subarachnoid space of both hedgehogs, including a gravid female worm. DNA-based molecular tools confirmed the nematode as Angiostrongylus cantonensis, an important aetiological agent of eosinophilic meningitis in humans. So far this zoonotic parasite in has not been reported in western European wildlife.

Can animals predict earthquakes?: Bio-sentinels as seismic sensors in communist China and beyond.

This paper examines the international research on abnormal animal behavior prior to earthquakes, with a focus on Chinese seismology during the Cultural Revolution. China experienced a series of powerful earthquakes in the 1960s and 1970s; in response, its scientists developed approaches to earthquake prediction, including the use of bio-sentinels. The paper demonstrates that Chinese seismology did not treat an earthquake simply as a geophysical event, but rather as an amalgam of environmental phenomena, including sensory experiences. Hence, distributive experience and sensory networks of humans and bio-sentinels constituted an important component of studying the environment. This historical case suggests insights into bio-monitoring of the global environment.

Cosmic-ray interaction data for designing biological experiments in space.

There is growing interest in flying biological experiments beyond low-Earth orbit (LEO) to measure biological responses potentially relevant to those expected during a human mission to Mars. Such experiments could be payloads onboard precursor missions, including unmanned private-public partnerships, as well as small low-cost spacecraft (satellites) designed specifically for biosentinel-type missions. It is the purpose of this paper to provide physical cosmic-ray interaction data and related information useful to biologists who may be planning such experiments. It is not the objective here to actually design such experiments or provide radiobiological response functions, which would be specific for each experiment and biological endpoint. Nuclide-specific flux and dose rates were calculated using OLTARIS and these results were used to determine particle traversal rates and doses in hypothetical biological targets. Comparisons are provided between GCR in interplanetary space and inside the ISS. Calculated probabilistic estimates of dose from solar particle events are also presented. Although the focus here is on biological experiments, the information provided may be useful for designing other payloads as well if the space radiation environment is a factor to be considered.

Using bald eagles to track spatial (1999-2008) and temporal (1987-1992, 1999-2003, and 2004-2008) trends of contaminants in Michigan's aquatic ecosystems.

The bald eagle (Haliaeetus leucocephalus) is an extensively researched tertiary predator. Studies have delineated information about its life history and the influences of various stressors on its reproduction. Due to the bald eagle's position at the top of the food web, it is susceptible to biomagnification of xenobiotics. The Michigan Department of Environmental Quality implemented a program in 1999 to monitor persistent chemicals including polychlorinated biphenols (PCBs) and dichlorodiphenyltrichloroethane (DDE). The objectives of the present study were to evaluate spatial and temporal trends of PCBs and organochlorine pesticides in nestling bald eagles of Michigan. The authors' study found that concentrations of PCBs and DDE were higher in Great Lakes areas with Lakes Michigan and Lake Huron having the highest concentrations of DDE and Lake Erie having the highest concentrations of PCBs. Temporally (1987-1992, 1999-2003, and 2004-2008) the present study found declines in PCB and DDE concentrations with a few exceptions. Continued monitoring of Michigan bald eagle populations is suggested for a couple of reasons. First, nestling blood contaminant levels are an appropriate method to monitor ecosystem contaminant levels. Second, from 1999 to 2008 PCB and DDE concentrations for 30% and 40%, respectively, of the nestling eagles sampled were above the no observable adverse effect level (NOAEL) for bald eagles. Lastly, with the continued development and deployment of new chemistries a continuous long term monitoring program is an invaluable resource. Environ Toxicol Chem 2016;35:1995-2002. © 2016 SETAC.

Modeling Hematologic and Biochemical Parameters with Spatiotemporal Analysis for the Free-Ranging Eastern Box Turtle (Terrapene carolina carolina) in Illinois and Tennessee, a Potential Biosentinel.

Box turtles are long-lived, inhabit both aquatic and terrestrial habitats, and have relatively small home ranges making them a suitable candidate as a sentinel. To characterize their changes in response to environmental health, assessment of observed variation of this species is required. Thus, a comparative health assessment was employed in 825 Eastern box turtles in east central Illinois and Oak Ridge, Tennessee, to establish a baseline health assessment with regard to sex, age class, season, and location, identify temporal trends, and map parameters. Hematological and plasma biochemical variables measured included packed cell volume, total solids, white blood cell and differential counts, calcium, phosphorus, aspartate aminotransferase, bile acids, creatine kinase, and uric acid. These variables were reduced to four principle components that explained 68.8 % of the cumulative variance. The top model included the main effects of year, location, and sex, but no interactions. Spatial analysis of turtles in Tennessee demonstrated increased WBC and decreased PCV in 2011 associated with a clear-cut silviculture site. The results of this health assessment can serve as a baseline of population health in future studies and aid in the utility of this species as a sentinel.

The development and implementation of a method using blue mussels (Mytilus spp.) as biosentinels of Cryptosporidium spp. and Toxoplasma gondii contamination in marine aquatic environments.

Surveillance monitoring for microbial water quality typically involves collecting single discrete grab samples for analyzing only one contaminant. While informative, current approaches suffer from poor recoveries and only provide a limited snapshot of the microbial contaminants only at the time of collection. To overcome these limitations, bivalves have been proposed as effective biosentinels of water quality particularly for their ability to efficiently concentrate and retain microbial contaminants for long periods of time. In this study, we examined the use of indigenous blue mussels (Mytilus spp.) as biosentinels to monitor for the presence of Toxoplasma gondii and Cryptosporidium water. An efficient method to extract oocyst DNA from various mussel tissues followed by PCR-based detection of these pathogens was developed, which resulted in the detection down to 10 oocysts. This method was then used to conduct a small survey in Point Lobos and Morro Bay, California to determine prevalence T. gondii and Cryptosporidium. Results revealed that mussels from Morro Bay were contaminated with T. gondii (33 %), while mussels from Point Lobos were contaminated with T. gondii (54 %) and Cryptosporidium (26.9 %) oocysts. Phylogenetic analysis using the SSU rRNA gene identified two novel Cryptosporidium parvum-like genotypes. Overall, this study demonstrated the application of using native California Mytilus spp. as biosentinels for pathogen contamination along the central California shorelines. More importantly, T. gondii and Cryptosporidium were found at higher prevalence rates in Morro Bay and in Point Lobos, an area not previously reported to be contaminated with these pathogens.

Serological anthrax surveillance in wild boar (Sus scrofa) in Ukraine.

Anthrax, caused by Bacillus anthracis, is an acute disease affecting wildlife, livestock, and humans worldwide, although its impact on these populations is underappreciated. In Ukraine, surveillance is passive, and anthrax is often detected in livestock. However, wildlife is not subject to surveillance, although anthrax deaths (such as in wild boar, Sus scrofa) have been documented. The wild boar is a plentiful and widespread species in Ukraine and is frequently hunted. We initiated a screening study testing Ukrainian wild boar blood samples for antibodies to B. anthracis. We mapped results relative to known livestock anthrax hotspots. We discovered evidence of exposure in wild boar up to 35 km from livestock anthrax hotspots and over 400 km from previous anthrax reports in boars. We make recommendations about using wildlife species as biosentinels for anthrax in Ukraine.

Predictors of mercury spatial patterns in San Francisco Bay forage fish.

Pollution reduction efforts should be targeted toward those sources that result in the highest bioaccumulation. For mercury (Hg) in estuaries and other complex water bodies, carefully designed biosentinel monitoring programs can help identify predictors of bioaccumulation and inform management priorities for source reduction. This study employed a probabilistic forage fish Hg survey with hypothesis testing in San Francisco Bay (California, USA). The goal was to determine what pollution sources, regions, and landscape features were associated with elevated Hg bioaccumulation. Across 99 sites, whole-body Hg concentrations in Mississippi silversides (Menidia audens) and topsmelt (Atherinops affinis) followed a broad spatial gradient, declining with distance from the Guadalupe River (Pearson's r = -0.69 and -0.42, respectively), which drains historic mining areas. Site landscape attributes and local Hg sources had subtle effects, which differed between fish species. Topsmelt Hg increased in embayment sites (i.e., enclosed sites including channels, creek mouths, marinas, and coves) and sites with historic Hg-contaminated sediment, suggesting an influence of legacy industrial and mining contamination. In 2008, Mississippi silverside Hg was reduced at sites draining wastewater-treatment plants. Fish Hg was not related to abundance of surrounding wetland cover but was elevated in some watersheds draining from historic Hg-mining operations. Results indicated both regional and site-specific influences for Hg bioaccumulation in San Francisco Bay, including legacy contamination and proximity to treated wastewater discharge.