Search

Extremophiles have gained prominence by providing an experimental approach to astrobiology. Extremophiles gain equal value by being part of a framework for high-level characterisation of the evolutionary mechanisms that must necessarily restrict or promote their emergence and presence on solar system bodies. Thus, extremophiles exist in extreme environments, and therein lies the paradox: extremophiles can only live in extreme environments but yet are not able to originate in such environments. Therefore, even though the range of extremophile capabilities in extreme environments is wider than that in mesophiles, the range of their emergence possibilities is still equally restricted. Therefore, even if one locates an extreme exoworld where terrestrial extremophiles could live here-and-now, it can be predicted that no extremophile analogues are present anyway. Furthermore, it is possible for a world to be uninhabited, yet be habitable, and therein arises the extreme environment paradox: an extreme environment can sustain chemical evolution as well as arriving non-native life, yet native life cannot be built up in that very environment. Thus, life may exist on an extraterrestrial extreme world (if imported there), and chemical evolution may be present on that world. However, it can be predicted that there is no native life anyway. This situation can be predicted to function as a chemosignature and eventually as a biosignature. However, the fact that a non-native extremopile in principle can exist in extreme environments may demonstrate that the intermediate step between chemical evolution and extremophiles can still occur in the form of a statistical deviation., Comment: 14 pages

Extreme environments on Earth are typically devoid of macro life forms and are inhabited predominantly by highly adapted and specialized microorganisms. The discovery and persistence of these extremophiles provides tools to model how life arose on Earth and inform us on the limits of life. Fungi, in particular, are among the most extreme-tolerant organisms with highly versatile lifestyles and stunning ecological and morphological plasticity. Here, we overview the most notable examples of extremophilic and stress-tolerant fungi, highlighting their key roles in the functionality and balance of extreme ecosystems. The remarkable ability of fungi to tolerate and even thrive in the most extreme environments, which preclude most organisms, have reshaped current concepts regarding the limits of life on Earth.

Acknowledgements: We thank the municipality of Jeddah, Saudi Arabia for supporting this research study and facilitating fieldwork and sampling operations which allowed us to have access and build wild mosquito colonies. We thank Nancy Endersby-Harshman for facilitating the import of mosquito populations into the quarantine insectary. We thank Meng-Jia Lau for advice on primers and Véronique Paris for assistance with colony maintenance. We thank Kim R Blasdell for providing lab assistance at ACDP. The authors acknowledge the capabilities of the Australian Centre for Disease Preparedness in undertaking this research, including infrastructure funded by the National Collaborative Research Infrastructure Strategy., Funder: CSIRO; Grant(s): WBS: R-91040-11, Aedes aegypti mosquitoes carrying self-spreading, virus-blocking Wolbachia bacteria are being deployed to suppress dengue transmission. However, there are challenges in applying this technology in extreme environments. We introduced two Wolbachia strains into Ae. aegypti from Saudi Arabia for a release program in the hot coastal city of Jeddah. Wolbachia reduced infection and dissemination of dengue virus (DENV2) in Saudi Arabian mosquitoes and showed complete maternal transmission and cytoplasmic incompatibility. Wolbachia reduced egg hatch under a range of environmental conditions, with the Wolbachia strains showing differential thermal stability. Wolbachia effects were similar across mosquito genetic backgrounds but we found evidence of local adaptation, with Saudi Arabian mosquitoes having lower egg viability but higher adult desiccation tolerance than Australian mosquitoes. Genetic background effects will influence Wolbachia invasion dynamics, reinforcing the need to use local genotypes for mosquito release programs, particularly in extreme environments like Jeddah. Our comprehensive characterization of Wolbachia strains provides a foundation for Wolbachia-based disease interventions in harsh climates.

High-entropy materials represent the state-of-the-art on the alloy design strategy for future applications in extreme environments. Recent data indicates that high-entropy alloys (HEAs) exhibit outstanding radiation resistance in face of existing diluted alloy counterparts due to suppressed damage formation and evolution. An extension of the HEA concept is presented in this paper towards the synthesis and characterization of novel high-entropy ceramics as emergent materials for application in environments where energetic particle irradiation is a major concern. A novel carbide within the quinary refractory system CrNbTaTiW has been synthesized using magnetron-sputtering. The material exhibited nanocrystalline grains, single-phase crystal structure and C content around 50 at.%. Heavy-ion irradiation with in-situ Transmission Electron Microscopy was used to assess the irradiation response of the new high-entropy carbide (HEC) at 573 K and a comparison with the HEA within the system is made. No displacement damage effects appear within the microstructures of both HEA and HEC up to a dose of 10 displacements-per-atom. Surprisingly, the HEC has not amorphized under the investigated conditions. Xe was implanted in both materials and bubbles nucleated, but smaller sizes compared with conventional nuclear materials shedding light they are potential candidates for use in nuclear energy.

The Momela soda lakes consist of seven small, hypersaline, alkaline lakes, situated in the East African rift valley at Arusha National Park, Tanzania. The lakes are fed by separate underground water sources with slightly varying mineral contents resulting in colour variation and supporting different kinds of prokaryotic and eukaryotic species. In this study, the diversity of Actinobacteria in surface water and sediments of five Lakes were investigated using culture-dependent and culture-independent molecular techniques. A total of 34 out of 112, and 13 out of 85, representatives of Actinobacteria isolates and clones, respectively, were selected for gene sequencing using the CD-HIT program. Analysis of their 16S rRNA gene sequences displayed the presence of species affiliated to 15 different genera, namely Mycobacterium, Rhodococcus, Microbacterium, Isoptericola, Dietzia, Leucobacter, Jonesia, Nesterenkonia, Micrococcus, Streptomyces, Hoyosella, Norcadiopsis, Cellulomonas, Bogoriella, and Agromyces. The results showed 5 and 12 putative new Actinobacteria isolates and clones, respectively. This is the first report of isolation of bacteria from the genus Mycobacterium from a soda lake globally, as well as the genera Hoyosella, Isoptericola, Jonesia, Micrococcus, Leucobacter and Agromyces from a soda lake in East Africa. Because Actinobacteria are known as a source of biotechnologically important compounds, the species revealed set a platform to search for novel bioactive compounds.

BACKGROUND: Maintaining psychologically adaptive relationships among team members operating in an isolated, confined, and extreme (ICE) environment for an extended period continues to be a challenge, with relevance for long-duration missions to the Moon and beyond.METHODS: Two male architects were studied who lived and worked over a 60-d period in a polar ICE environment in a lunar analog habitat they designed and helped construct. Psychological measures were completed at different points of the mission, including a post-mission debriefing interview.RESULTS: Team members were highly different from each other on a number of personality traits, personal values, and stress and coping factors. Marked differences were noted on NEO-PI-3 Agreeableness and Extraversion personality traits, and Portrait Values Questionnaire (PVQ) Stimulation, Power, and Achievement values. Team Effectiveness Questionnaire (TEQ) findings showed consistency between team members with high ratings on the Passion and Commitment and Purpose and Goals scales, and low ratings on the Roles scale. The leveling influence of decision authority and its deleterious effect on interpersonal interactions and work performance was evident. The interior design with attention to materials that made it more Earth-like and the circadian lighting system were associated with ease of work performance and promotion of relaxation and privacy.DISCUSSION: The study findings demonstrated the impact of incompatibility in personality traits and values on team performance, challenges regarding decision authority in a long-term dyadic relationship, and highlighted the human factors components of the habitat that facilitated effective individual and team functioning.Kjærgaard A, Leon GR, Chterev K. Team effectiveness and person-environment adaptation in an analog lunar habitat. Aerosp Med Hum Perform. 2022; 93(2):70–78.

A wide array of microorganisms, including many novel, phylogenetically deeply rooted taxa, survive and thrive in extreme environments. These unique and reduced-complexity ecosystems offer a tremendous opportunity for studying the structure, function and evolution of natural microbial communities. Marker gene surveys have resolved patterns and ecological drivers of these extremophile assemblages, revealing a vast uncultured microbial diversity and the often predominance of archaea in the most extreme conditions. New omics studies have uncovered linkages between community function and environmental variables, and have enabled discovery and genomic characterization of major new lineages that substantially expand microbial diversity and change the structure of the tree of life. These efforts have significantly advanced our understanding of the diversity, ecology and evolution of microorganisms populating Earth’s extreme environments, and have facilitated the exploration of microbiota and processes in more complex ecosystems. Microbial life can thrive in extreme environments such as terrestrial hot springs and deep sea hydrothermal vents, glaciers and permafrost, hypersaline habitats, acid mine drainage and the subsurface. In this Review, Shu and Huang explore the diversity, functions and evolution of bacteria and archaea inhabiting Earth’s major extreme environments.

Electrochemistry has been used for decades to study materials' degradation in situ in corrosive environments, whether it is in room-temperature chemically aggressive solutions containing halide ions or in high-temperature oxidizing media such as pressurized water, liquid metals, or molten salts. Thus, following the recent surge in high-throughput techniques in materials science, it seems quite natural that high-throughput electrochemistry is being considered to study materials' degradation in extreme environments, with the objective to reduce corrosion resistant alloy development time by orders of magnitude and identify complex degradation mechanisms. However, while there has been considerable interest in the development of high-throughput methods for accelerating the discovery of corrosion resistant materials in different environments, these extreme environments propose formidable and exciting challenges for high-throughput electrochemical instrumentation, characterization, and data analysis. It is the objective of this paper to highlight those challenges, to present relatively new efforts to tackle them, and to develop research perspectives on the future of this exciting field. This Perspective is articulated around four main interconnected topics, which must be conjointly considered to enable corrosion resistant alloy design using high-throughput electrochemical methods: (1) high-throughput processing methods to develop material libraries, (2) high-throughput electrochemical methods for corrosion testing and evaluation, (3) high-throughput machine-learning augmented electrochemical data analysis, and (4) high-throughput autonomous electrochemistry representing the future of accelerated electrochemistry research.

The high-throughput chromosome conformation capture (Hi-C) technique is widely used to study the functional roles of the three-dimensional (3D) architecture of genomes. However, the knowledge of the 3D genome structure and its dynamics during extreme environmental adaptations remains poor. Here, we characterized 3D genome architectures using the Hi-C technique for chicken liver cells. Upon comparing Lindian chicken (LDC) liver cells with Wenchang chicken (WCC) liver cells, we discovered that environmental adaptation contributed to the switching of A/B compartments, the reorganization of topologically associated domains (TADs), and TAD boundaries in both liver cells. In addition, the analysis of the switching of A/B compartments revealed that the switched compartmental genes (SCGs) were strongly associated with extreme environment adaption-related pathways, including tight junction, notch signaling pathway, vascular smooth muscle contraction, and the RIG-I-like receptor signaling pathway. The findings of this study advanced our understanding of the evolutionary role of chicken 3D genome architecture and its significance in genome activity and transcriptional regulation.

PALINKAS, L.A., and P. SUEDFELD. Psychosocial Issues in Isolated and Confined Extreme Environments. NEUROSCI BIOBEHAV REV (1) XXX-XXX, 2020. Psychosocial elements of behavior and performance will significantly impact the outcomes of long duration missions in space, ranging from individual and team decrements to positive benefits associated with successful adaptation. This paper reviews our current understanding of the individual, interpersonal and organizational issues related to living and working in isolated and confined extreme (ICE) environments. Individual issues include changes in emotions and cognitive performance; seasonal syndromes linked to changes in the physical environment; and positive effects of adapting to ICE environments. Interpersonal issues include processes of crew cohesion, tension and conflict; interpersonal relations and social support; the impact of group diversity and leadership styles on small group dynamics; and crew-mission control interactions. Organizational issues include the influence of organizational culture and mission duration on individual and group performance, crew autonomy, and managerial requirements for long duration missions. Improved screening and selection, leadership, coping and interpersonal skills training, and organizational change are key elements to optimizing adjustment to the environment and preventing decrements during and after long duration missions.

Exploring the limits of life is one of the objectives for better understanding how organisms have arisen on Earth, how they tolerate extreme conditions and how they might survive on other planets or moons. These investigations could help with understanding which Earth microorganisms could survive on other celestial bodies, such as the icy Moons: Europa (Jupiter) and Enceladus (Saturn). Furthermore, it might help with indicating how life could have developed on Earth or on the icy Moons of the Solar system. This project focuses on the insights from prokaryotic, eukaryotic and archaea organisms which can tolerate the simulated subsurface ocean environment of Europa and Enceladus. The moons have been speculated to have subsurface oceans which are heated by tidal movements or hydrothermal vents. These combined factors could create an environment suitable for life. Furthermore, the mechanism of radiation, desiccation and temperature survival could help us understand whether the organisms could survive a hitchhike on spacecraft surfaces travelling to the moons. During space exploration it is essential to avoid the contamination of planets and moons of astrobiological interest by microorganisms from Earth.The projects’ main question is: What are the boundaries of tolerance for cold-adapted halophilic microorganisms as determined by simulated space conditions? Furthermore, we also want to investigate the survival to simulated icy moon conditions. At this stage of the project two organisms have been investigated, the bacterium Planococcus halocryophilus and the yeast Rhodotorula frigidalcoholis. Our aim is to use one organism from each domain of life: prokaryote, eukaryote and archaea. Preliminary results have shown a fair survival of R. frigidalcoholis but not of P. halocryophilus to some simulated space conditions. In order to find better suited bacterial and archaea candidates we will be investigating cold adapted microorganisms from astrobiologically relevant sites. Examples include the Shaban deep, a brine sediment in the Northern Red sea, permafrost core, Antarctic soil samples, glacier ice and arctic sea-ice cores. The bacteria we have selected are the following: Paenisporosarcina antarctica, Psychromonas boydii, Cryobacterium flavum, Virgibacillus arcticus and Chromohalobacter saracensis. The archaea are: Halorubrum luteum and Halorhabdus tiamatea.The results we processed have shown that R. frigidalcoholis is more tolerant than P. halocryophilus to monochromatic UV-C (254 nm) and polychromatic UV (200-400 nm) as well as X-ray. When exposed to desiccating conditions, at different temperatures, the difference between the two organisms is not so noticeable. The results which we present here have been developed from the microorganisms grown under minimal media conditions, supplemented with a sole carbon source (L-Glutamic acid for R. frigidalcoholis and D-Alanine for P. halocryophilus). The decision to use minimal media and single carbon sources, not as common as glucose, was in support of simulating stress growth conditions to an extent similar to the ones on Europa and Enceladus. Planetary bodies where some simple organics have been detected in low concentrations.Despite the two organisms being isolated from similar environments, R. frigidalcoholis from ice cemented permafrost in University valley (Antarctic) and P. halocryophilus from permafrost active-layer soil in the Canadian High Arctic, they have great differences in their tolerance to extreme conditions. Tested conditions include desiccation survival at: room temperature, -20 and -80°C under oxic and anoxic conditions. Additionally, we can describe a fair survival of R. frigidalcoholis to weekly freeze-thaw conditions from -80°C to 25°C respectively.Being two organisms isolated from arctic-like environments, our hypothesis supported a great tolerance to freeze and thaw conditions. The reduction in relative survival of R. frigidalcoholis to an order of magnitude of 10-2, supports our hypothesis. Of importance to note for this experiment are the -80°C freezing conditions. In the literature similar tests are conducted at higher temperatures (-40 and -10°C).The preliminary results exposing R. frigidalcoholis and P. halocryophilus to harsh growth conditions are useful for initial expectations to survival in environments similar to the ones on Europa or Enceladus. For continuing and future research, this project could be of particular interest for defining a protocol for microbial exposure to simulated extreme environmental conditions. As well as to support the development of suitable planetary protection measures. The following graphs show the results of the described experiments. The figures include in formation on the relative survival of organisms and the F10 values for each condition. The F10 values have been included to represent the dose to which there is 10% survival to the exposed condition.UV-C Irradiation:Polychromatic UV Irradiation:X-ray Irradiation

In the austral summer of 2016, intertidal (IT) and subtidal (ST) corals from the macrotidal Kimberley region in NW Australia were exposed to an extreme heat wave. ST corals were severely affected by bleaching whereas IT corals only experienced moderate bleaching. We examined coral symbiont composition of both healthy and bleached corals in April (peak bleaching) and November (seven months recovery) 2016 via NGS. This project provides the raw sequencing data of the study.

It is a macro-micro model study for defect initiation, growth and crack propagation of metallic truss structure under high engine temperature and pressure conditions during the reentry atmosphere. Till now, the multi-scale simulation methods for these processes are still unclear. We explore the deformation and failure processes from macroscale to nanoscale using the Gas-Kinetic Unified Algorithm (GKUA) and all-atomic, molecular dynamic (MD) simulation method. The behaviors of the dislocations, defect evolution and crack propagation until failure for Aluminum-Magnesium (Al-Mg) alloy are considered with the different temperature background and strain fields. The results of distributions of temperature and strain field in the aerodynamic environment obtained by molecular dynamics simulations are in good agreement with those obtained from the macroscopic Boltzmann method. Compared to the tensile loading, the alloy structure is more sensitive to compression loading. The polycrystalline Al-Mg alloy has higher yield strength with a larger grain size. It is due to the translation of plastic deformation mode from grain boundary (GB) sliding to dislocation slip and the accumulation of dislocation line. Our findings have paved a new way to analyze and predict the metallic structural failure by micro-scale analysis under the aerodynamic thermal extreme environment of the reentry spacecraft on service expiration.

The rapid development of flexible electronic devices has caused a boom in researching flexible sensors based on hydrogels, but most of the flexible sensors can only work at room temperature, and they are difficult to adapt to extremely cold or dry environments. Here, the flexible hydrogel fibers (PEDOT:PSS@PVA) with excellent resistance to extreme environments have been prepared by adding glycerin (GL) to the mixture of poly(vinyl alcohol) (PVA) and poly 3,4-dioxyethylene thiophene:polystyrene sulfonic acid (PEDOT:PSS) because GL molecules can form dynamic hydrogen bonds with an elastic matrix of PVA molecules. It is found that the prepared sensor exhibits very good flexibility and mechanical strength, and the ultimate tensile strength can reach up to 13.76 MPa when the elongation at break is 519.9%. Furthermore, the hydrogel fibers possess excellent water retention performance and low-temperature resistance. After being placed in the atmospheric environment for 1 year, the sensor still shows good flexibility. At a low temperature of -60 °C, the sensor can stably endure 1000 repeated stretches and shrinks (10% elongation). In addition to the response to a large strain, this fiber sensor can also detect extremely small strains as low as 0.01%. It is proved that complex human movements such as knuckle bending, vocalization, pulse, and others can be monitored perfectly by this fiber sensor. The above results mean that the PEDOT:PSS@PVA fiber sensor has great application prospects in physiological monitoring.

Free-living amoebas (FLAs) are microorganisms, unicellular protozoa widely distributed in nature and present in different environments, such as water or soil; they are maintained in ecosystems and play a fundamental role in the biological control of bacteria, other protozoa, and mushrooms. In particular circumstances, some can reach humans or animals, promoting several health complications. Notably, FLAs are characterized by a robust capacity to survive in extreme environments. However, currently, there is no updated information on the existence and distribution of this protozoan in inhospitable places. Undoubtedly, the cellular physiology of these protozoan microorganisms is very particular. They can resist and live in extreme environments due to their encysting capacity and tolerance to different osmolarities, temperatures, and other environmental factors, which give them excellent adaptative resistance. In this review, we summarized the most relevant evidence related to FLAs and the possible mechanism, which could explain their adaptative capacity to several extreme environments.

This paper presents and discusses algorithms, hardware, and software architecture developed by the TEAM CoSTAR (Collaborative SubTerranean Autonomous Robots), competing in the DARPA Subterranean Challenge. Specifically, it presents the techniques utilized within the Tunnel (2019) and Urban (2020) competitions, where CoSTAR achieved second and first place, respectively. We also discuss CoSTAR¿s demonstrations in Martian-analog surface and subsurface (lava tubes) exploration. The paper introduces our autonomy solution, referred to as NeBula (Networked Belief-aware Perceptual Autonomy). NeBula is an uncertainty-aware framework that aims at enabling resilient and modular autonomy solutions by performing reasoning and decision making in the belief space (space of probability distributions over the robot and world states). We discuss various components of the NeBula framework, including (i) geometric and semantic environment mapping, (ii) a multi-modal positioning system, (iii) traversability analysis and local planning, (iv) global motion planning and exploration behavior, (v) risk-aware mission planning, (vi) networking and decentralized reasoning, and (vii) learning-enabled adaptation. We discuss the performance of NeBula on several robot types (e.g., wheeled, legged, flying), in various environments. We discuss the specific results and lessons learned from fielding this solution in the challenging courses of the DARPA Subterranean Challenge competition., The work is partially supported by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004), and Defense Advanced Research Projects Agency (DARPA).

Can life in extreme environments foster our understanding of the limits and adaptability of cognition and brain plasticity? We review characteristics of spaceflight and spaceflight analogues, such as bed rest, dry immersion, parabolic flights, and isolated and controlled confinement, and discuss the potential of utilizing these research settings to advance cognitive neuroscience.

Belgica antarctica (Diptera: Chironomidae), a brachypterous midge endemic to the maritime Antarctic, was first described in 1900. Over more than a century of study, a vast amount of information has been compiled on the species (3 750 000 Google search results as of January 10, 2021), encompassing its ecology and biology, life cycle and reproduction, polytene chromosomes, physiology, biochemistry and, increasingly, omics. In 2014, B. antarctica's genome was sequenced, further boosting research. Certain developmental stages can be cultured successfully in the laboratory. Taken together, this wealth of information allows the species to be viewed as a natural model organism for studies of adaptation and function in extreme environments.

Sleep and fatigue were investigated in aviation search and rescue, firefighting, emergency medical services and offshore transfer operations in 210 participants, for 21 days each, across 17 datasets in seven countries. Sleep data were collected using wrist-worn actigraphs and sleep diaries. Sustained attention was assessed using a 5-min Psychomotor Vigilance Task (PVT). Duty information was provided from corporate IT systems. Despite the number of 24 h operations, most work occurred during daytime hours, and most sleep occurred at night. There were seasonal changes in work and sleep patterns, with naps used to augment total sleep time. The proportion of sleep occurring during duty varied from zero to 30%. Differences in PVT response times were trivial to small. Legislation that defines flight, duty time and minimum rest limits assume that sleep is not obtained during duty periods, apart from some napping under Fatigue Risk Management Systems (FRMS). However, especially in cases where the aviation service requires waiting for tasks (e.g. search and rescue, emergency medical response), this assumption may not always hold. FRMS should accommodate different modes of working that safely facilitate sleep during duty time where appropriate.

The acid ponds of the Danakil Depression in northern Ethiopia are polyextreme environments that exceed the normal physicochemical limits of pH, salinity, ion content, and temperature. We tested for the occurrence of DNA-based life in this environment using Metagenomic Shotgun DNA sequencing approaches. The obtained sequences were examined by the bioinformatic tools MetaSpades, DIAMOND and MEGAN 6-CE, and we were able to bin more than 90% of the metagenomics contigs of Dallol and Black Water to the Bacteria domain, and to the Proteobacteria phylum. Predictions of gene function based on SEED disclosed the presence of different nutrient cycles in the acid ponds. For this study, we focused on partial or completely sequenced genes involved in nitrogen metabolism. The KEGG nitrogen metabolism pathway mapping results for both acid ponds showed that all the predicted genes are involved directly or indirectly in the assimilation of ammonia and no dissimilation or nitrification process was identified. Furthermore, the deduced nitrogen fixation in the two acid ponds based on SEED classification indicated the presence of different sets of nitrogen fixing (nif) genes for biosynthesis and maturation of nitrogenase. Based on the in silico analysis, the predicted proteins involved in nitrogen fixation, especially the cysteine desulfurase and [4Fe-4S] ferredoxin, from both acid ponds are unique with less than 80% sequence similarity to the next closest protein sequence. Considering the extremity of the environmental conditions of the two acid ponds in the Danakil depression, this metagenomics dataset can add to the study of unique gene functions in nitrogen metabolism that enable thriving biocommunities in hypersaline and highly acidic conditions.

A little explored area of human activity recognition (HAR) is in people operating in relation to extreme environments, e.g., mountaineers. In these contexts, the ability to accurately identify activities, alongside other data streams, has the potential to prevent death and serious negative health events to the operators. This study aimed to address this user group and investigate factors associated with the placement, number, and combination of accelerometer sensors. Eight participants (age = 25.0 ± 7 years) wore 17 accelerometers simultaneously during lab-based simulated mountaineering activities, under a range of equipment and loading conditions. Initially, a selection of machine learning techniques was tested. Secondly, a comprehensive analysis of all possible combinations of the 17 accelerometers was performed to identify the optimum number of sensors, and their respective body locations. Finally, the impact of activity-specific equipment on the classifier accuracy was explored. The results demonstrated that the support vector machine (SVM) provided the most accurate classifications of the five machine learning algorithms tested. It was found that two sensors provided the optimum balance between complexity, performance, and user compliance. Sensors located on the hip and right tibia produced the most accurate classification of the simulated activities (96.29%). A significant effect associated with the use of mountaineering boots and a 12 kg rucksack was established.

Physical activity can prevent many organic and mental pathologies. For people living in extreme southern high-latitude environments, weather conditions can affect these activities, altering their psychological well-being and favoring the prevalence of seasonal sensitivity (SS). This study aims to determine the relationships between the practice of physical activity, seasonal sensitivity and well-being in people living in high southern latitudes. A cross-sectional study was conducted, using the Seasonal Pattern Assessment Questionnaire (SPAQ), applying a psychological well-being scale, and determining sports practice according to the recommendations of the World Health Organization (WHO) for the 370 male (n = 209; 55%) and female (n = 173; 45%) participants. The main results indicated that 194 people (52 ± 7.7 years) reported physical activity. High-intensity physical activity practitioners recorded a significantly lower proportion of SS. In terms of psychological well-being, an adverse effect was found between the Seasonal Score Index (SSI) and five subcategories of the Ryff well-being scale. In conclusion, those who perform high-intensity physical activity have a lower SS, and those who have a higher SS have a lower psychological well-being.

The gray mangrove [Avicennia marina (Forsk.) Vierh.] is the most widely distributed mangrove species, ranging throughout the Indo-West Pacific. It presents remarkable levels of geographic variation both in phenotypic traits and habitat, often occupying extreme environments at the edges of its distribution. However, subspecific evolutionary relationships and adaptive mechanisms remain understudied, especially across populations of the West Indian Ocean. High-quality genomic resources accounting for such variability are also sparse. Here we report the first chromosome-level assembly of the genome of A. marina. We used a previously release draft assembly and proximity ligation libraries Chicago and Dovetail HiC for scaffolding, producing a 456,526,188-bp long genome. The largest 32 scaffolds (22.4–10.5 Mb) accounted for 98% of the genome assembly, with the remaining 2% distributed among much shorter 3,759 scaffolds (62.4–1 kb). We annotated 45,032 protein-coding genes using tissue-specific RNA-seq data in combination with de novo gene prediction, from which 34,442 were associated to GO terms. Genome assembly and annotated set of genes yield a 96.7% and 95.1% completeness score, respectively, when compared with the eudicots BUSCO dataset. Furthermore, an FST survey based on resequencing data successfully identified a set of candidate genes potentially involved in local adaptation and revealed patterns of adaptive variability correlating with a temperature gradient in Arabian mangrove populations. Our A. marina genomic assembly provides a highly valuable resource for genome evolution analysis, as well as for identifying functional genes involved in adaptive processes and speciation.

Endolithic (rock-dwelling) microbial communities are ubiquitous in hyper-arid deserts around the world and the last resort for life under extreme aridity. These communities are excellent models to explore biotic and abiotic drivers of diversity because they are of low complexity. Using high-throughput amplicon and metagenome sequencing, combined with X-ray computed tomography, we investigated how water availability and substrate architecture modulated the taxonomic and functional composition of gypsum endolithic communities in the Atacama Desert, Chile. We found that communities inhabiting gypsum rocks with a more fragmented substrate architecture had higher taxonomic and functional diversity, despite having less water available. This effect was tightly linked with community connectedness and likely the result of niche differentiation. Gypsum communities were functionally similar, yet adapted to their unique micro-habitats by modulating their carbon and energy acquisition strategies and their growth modalities. Reconstructed population genomes showed that these endolithic microbial populations encoded potential pathways for anoxygenic phototrophy and atmospheric hydrogen oxidation as supplemental energy sources.

Climate change is altering conditions in high-elevation streams worldwide, with largely unknown effects on resident communities of aquatic insects. Here, we review the challenges of climate change for high-elevation aquatic insects and how they may respond, focusing on current gaps in knowledge. Understanding current effects and predicting future impacts will depend on progress in three areas. First, we need better descriptions of the multivariate physical challenges and interactions among challenges in high-elevation streams, which include low but rising temperatures, low oxygen supply and increasing oxygen demand, high and rising exposure to ultraviolet radiation, low ionic strength, and variable but shifting flow regimes. These factors are often studied in isolation even though they covary in nature and interact in space and time. Second, we need a better mechanistic understanding of how physical conditions in streams drive the performance of individual insects. Environment-performance links are mediated by physiology and behavior, which are poorly known in high-elevation taxa. Third, we need to define the scope and importance of potential responses across levels of biological organization. Short-term responses are defined by the tolerances of individuals, their capacities to perform adequately across a range of conditions, and behaviors used to exploit local, fine-scale variation in abiotic factors. Longer term responses to climate change, however, may include individual plasticity and evolution of populations. Whether high-elevation aquatic insects can mitigate climatic risks via these pathways is largely unknown.

The heterotrophic nanoflagellate genus Cafeteria has been found to be ubiquitously distributed in the marine realm. We could isolate and cultivate ten strains morphologically similar to Cafeteria from various types of environment, including the deep sea, brackish waters and also meso- to hypersaline inland waters. Molecular analyses (18S rDNA, 28S rDNA) of newly isolated strains from the marine realm resulted in four more Cafeteria burkhardae strains from the deep North Atlantic Ocean and one new species (C. baltica sp. nov.) isolated from brackish waters of the Baltic Sea. Two strains isolated from the Atacama Desert belong to two new species (C. atacamiensis sp. nov. and C. paulosalfera sp. nov.), one other strain could not yet be assigned. Morphological characterizations of these strains obtained by high resolution microscopy revealed only small differences to already described species. However, molecular analyses showed a clear separation of the different Cafeteria species. We exposed several strains to different salt concentrations (2-150 PSU) to investigate their salinity tolerance. Only the marine strains of C. burkhardae were able to survive at salinities up to 150 PSU, indicating the possibility to inhabit a broader spectrum of habitats including hypersaline environments besides the deep sea with its high hydrostatic pressure.

The bacterial SAR324 cluster is ubiquitous and abundant in the ocean, especially around hydrothermal vents and in the deep sea, where it can account for up to 30% of the whole bacterial community. According to a new taxonomy generated using multiple universal protein-coding genes (instead of the previously used 16S rRNA single gene marker), the former Deltaproteobacteria cluster SAR324 has been classified since 2018 as its own phylum. Yet, very little is known about its phylogeny and metabolic potential. We downloaded all publicly available SAR324 genomes (65) from all natural environments and reconstructed 18 new genomes using publicly available oceanic metagenomic data and unpublished data from the waters underneath the Ross Ice Shelf. We calculated a global SAR324 phylogenetic tree and identified six clusters (namely 1A, 1B, 2A, 2B, 2C and 2D) within this clade. Genome annotation and metatranscriptome read mapping showed that SAR324 clades possess a flexible array of genes suited for survival in various environments. Clades 2A and 2C are mostly present in the surface mesopelagic layers of global oceans, while clade 2D dominates in deeper regions. Our results show that SAR324 has a very versatile and broad metabolic potential, including many heterotrophic, but also autotrophic pathways. While one surface water associated clade (2A) seems to use proteorhodopsin to gain energy from solar radiation, some deep-sea genomes from clade 2D contain the complete Calvin–Benson–Bassham cycle gene repertoire to fix carbon. This, in addition to a variety of other genes and pathways for both oxic (e.g., dimethylsulfoniopropionate degradation) and anoxic (e.g., dissimilatory sulfate reduction, anaerobic benzoate degradation) conditions, can help explain the ubiquitous presence of SAR324 in aquatic habitats., Biology, 11 (4), ISSN:2079-7737

The gradually depleting fossil resources and the biosafety of bisphenol A have always restricted the green development of the traditional epoxy resin field. In this Article, biomass macromolecule lignin sulfonates are selected as the raw material instead of traditional bisphenol A to prepare lignin-based epoxy resin adhesives. Lignin sulfonates are chemically modified and combined with a cross-linking agent to form lignin-based epoxy resin adhesives with double-interpenetrating-network structures. The resulting lignin-based epoxy adhesive exhibits a maximum tensile shear strength of 11.29 MPa, which is 213% higher than the strength before chemical modification. The tensile shear strength of the adhesive is still 10.13 MPa after 12 h of immersion in water (20 °C), and its tensile shear strength is 9.30 MPa after 12 h of immersion in boiling water (100 °C). The high-temperature and high-humidity environment has no significant effect on the properties of the resulting lignin-based epoxy adhesive.

Although terrestrial hydrothermal systems are considered among the most fascinating environments, how their unique and extreme conditions can affect microorganisms selection and the role in biogeochemical cycles has not yet been well elucidated. A combined geochemical and microbiological exploration in waters and sediments from 10 sampling points along a sharp temperature gradient (15–90°C) within an extremely acidic hydrothermal system (Pisciarelli Spring, Campi Flegrei area, southern Italy) displayed how hydrothermal fluids influence the microbial dynamics. This area was characterized by high levels of reduced gaseous species (e.g. H2S, H2, CH4, CO) and very low pH values (

The Rio Pearlfish, Nematolebias whitei, is a bi-annual killifish species inhabiting seasonal pools in the Rio de Janeiro region of Brazil that dry twice per year. Embryos enter dormant diapause stages in the soil, waiting for the inundation of the habitat which triggers hatching and commencement of a new life cycle. Rio Pearlfish represents a convergent, independent origin of annualism from other emerging killifish model species. While some transcriptomic datasets are available for Rio Pearlfish, thus far, a sequenced genome has been unavailable. Here, we present a high quality, 1.2 Gb chromosome-level genome assembly, genome annotations, and a comparative genomic investigation of the Rio Pearlfish as representative of a vertebrate clade that evolved environmentally cued hatching. We show conservation of 3D genome structure across teleost fish evolution, developmental stages, tissues, and cell types. Our analysis of mobile DNA shows that Rio Pearlfish, like other annual killifishes, possesses an expanded transposable element profile with implications for rapid aging and adaptation to harsh conditions. We use the Rio Pearlfish genome to identify its hatching enzyme gene repertoire and the location of the hatching gland, a key first step in understanding the developmental genetic control of hatching. The Rio Pearlfish genome expands the comparative genomic toolkit available to study convergent origins of seasonal life histories, diapause, and rapid aging phenotypes. We present the first set of genomic resources for this emerging model organism, critical for future functional genetic, and multiomic explorations of “Eco-Evo-Devo” phenotypes of resilience and adaptation to extreme environments.

In Antarctica, human access and presence are complex and require detailed planning and preparation in advance. The personnel of National Antarctic Programs (NAPs, i.e., scientists and support personnel, including military, civilians, and mountaineers) stay in different isolation, confinement, and extreme (ICE) environments such as ships, research stations, and scientific summer camps. Antarctica imposes harsh conditions that influence physiological and psychological responses impacting health, mood, and physical and cognitive performances. In this context, we argue why people should prepare in advance for staying in Antarctica and what to expect in ICE environments. We also spotlighted recommendations shared by different NAPs participant guides, including predeployment training. Next, we present a case study of the Brazilian Pre-Antarctic Training (PAT), a theoretical-practical training that provides technical and logistical information and assesses the adaptability and physical capacity of researchers and military personnel to perform fundamental activities in a polar environment. We evaluated and compared the individual’s mood at the beginning and the end of the PAT week and observed group-specific mood changes depending on the sex, functions, and the facilities that participants accessed. Finally, we proposed that conducting training before staying in Antarctica, besides promoting conditions to better plan the voyage and knowledge of the region, can contribute to dealing with the possible mood swings during expeditions and even promote positive affect. Therefore, the psychophysiological effects of PAT are topics for further investigations.

Examples from aviation and aerospace illustrate the potential consequences that emerge when organizations replace learning from experience with technology, a process referred to as a cognitive offloading strategy (COS). Examples include the Air France Flight 447 crash involving an Airbus 330-203 and the Lion Air Flight 610 crash involving a Boeing 737 Max. From the perspective of human performance in extreme environments, COS represents an underexplored source of organizational vulnerability which presents a particular challenge for learning in organizations. Decrements in learning result from COS because COS creates gaps in procedural knowledge and deprives operators of opportunities to learn in the face of event-induced stress. Due to the inevitability of COS in extreme environments, recommendations for building resilience include offering training scenarios that support the development of a positive stress response, facilitating the ability to learn in the face of uncertainty, and supporting highly engaged experiential learning to build procedural (and often tacit) knowledge of operations.

We summarize and elaborate on the challenges of researching in the field of human health in Antarctica based on the conceptual and methodological specificities of a line of investigation that aims to study the human presence in Antarctica in all of its dimensions (biological, psychological, and socio-anthropological). Herein, we discuss the principal results and limitations of the research carried out by researchers of MEDIANTAR (Antarctic medicine, physiology, and anthropology) group of Programa Antártico Brasileiro in isolated, confined, and extreme environments over the last six years. Fieldwork has been carried out in remote research camps, Brazilian navy ships (Almirante Maximiano/H-41 and Ary Rongel/H-44), and Comandante Ferraz Antarctic Station. Adaptative responses to isolated, confined, and extreme environments were studied based on questionnaires, interviews, participative observation, biological samples, anthropometric, and physiological parameters. Our researchers face the unique situation of concomitantly working under the stressful living conditions that are the object of their investigation. A critical examination of the socio-methodological characteristics and challenges of this research niche indicates the need for exchanging the lessons learned and limitations of these practices with researchers in the humanities field, with attention to the human resources needs in multidisciplinary human-related studies.

Current crop yield of the best ideotypes is stagnating and threatened by climate change. In this scenario, understanding wild plant adaptations in extreme ecosystems offers an opportunity to learn about new mechanisms for resilience. Previous studies have shown species specificity for metabolites involved in plant adaptation to harsh environments. Here, we combined multispecies ecological metabolomics and machine learning-based generalized linear model predictions to link the metabolome to the plant environment in a set of 24 species belonging to 14 families growing along an altitudinal gradient in the Atacama Desert. Thirty-nine common compounds predicted the plant environment with 79% accuracy, thus establishing the plant metabolome as an excellent integrative predictor of environmental fluctuations. These metabolites were independent of the species and validated both statistically and biologically using an independent dataset from a different sampling year. Thereafter, using multiblock predictive regressions, metabolites were linked to climatic and edaphic stressors such as freezing temperature, water deficit and high solar irradiance. These findings indicate that plants from different evolutionary trajectories use a generic metabolic toolkit to face extreme environments. These core metabolites, also present in agronomic species, provide a unique metabolic goldmine for improving crop performances under abiotic pressure.

Architecture deals with the design of spaces for human activities, providing comfort to its occupants, within a myriad of environmental conditions. When placed in extreme environments, architecture must be responsive and turn these adverse conditions into a comfort space for human occupation. The Extreme Architecture Unit at the Department of Architecture, in Yasar University, is a conceptual umbrella under which students are invited to develop architectural projects meeting the technical demands of designing buildings for extreme conditions. While confronted with the evidence of the nature of such extreme demands, students are requested to develop an extreme scenario, which is indeed the storyline wherein all design elements are rooted. In this sense, a visual narrative is the key instrument to code the projects’ syntax and to explain the logic by which each particular project can be understood. However, the unit demands the use of rather technical arguments to sustain a project that is responsive to extreme conditions, thus close to being developed through a scientific method. But then, how can visualizations express individual approaches to the otherwise obvious solution to a technical problem? How can visualizations maintain uniqueness while expressing the project’s response to the technical demands? To answer both questions, we must embrace the inherent complexity of extreme environments. The use of visualizations allows students to deal with such complexity from their own perspective, expressed in the language of those representations. In this essay, the authors attempt to provide answers to these questions by critically revising two projects developed in the unit.

Einleitung: Langzeitaufenthalte in extremen Umwelten wie der Antarktis sind mit verschiedenen Herausforderungen an den menschlichen Körper verbunden. Unter anderem verringert sich die Vitamin D-Produktion in der Haut durch das deutlich verminderte Sonnenlicht. Auswirkungen von Vitamin D-Mangel auf den Knochenstoffwechsel sind seit vielen Jahren anerkannt. In den letzten Jahrzehnten wurde Vitamin D zudem in Zusammenhang mit dem zentralen Nervensystem gebracht. Der Vitamin D-Rezeptor und die Vitamin D-Metaboliten wurden im Gehirn nachgewiesen und strukturelle Veränderungen des Gehirns sind mit Vitamin D assoziiert. Vitamin D soll auch neurotroph und neuroprotektiv wirken. Beobachtungsstudien haben auf einen Zusammenhang zwischen niedriger Vitamin D-Konzentration und kognitiver Dysfunktion bzw. Demenz hingewiesen. Interventionsstudien konnten dies jedoch nicht hinreichend bestätigen. Das Ziel der Studie ist es, den Einfluss der Vitamin D-Konzentration auf die kognitive Leistungsfähigkeit während eines Langzeitaufenthalts in der Antarktis zu untersuchen. Methodik: Langzeitüberwinterer hielten sich im Rahmen von drei Überwinterungskampagnen (33.–35.) für 14 Monate auf der deutschen Neumayer-Station III in der Antarktis auf. Studienteilnehmer (n = 9 pro Kampagne) waren die Antarktis-Forscher des Alfred-Wegener-Instituts. Die Vitamin D-Konzentration und die kognitive Leistungsfähigkeit wurden monatlich vor, während und nach der Überwinterung gemessen. Die kognitive Leistungsfähigkeit wurde mittels validierter computerbasierter Testbatterien (ANAM4TM oder Cognition) ermittelt. Die untersuchten Leistungsparameter waren die Effizienz und die Reaktionszeit. Die Datenanalyse erfolgte mithilfe eines linear gemischten Modells. Es wurde für Alter und Geschlecht kontrolliert. Ergebnisse: Die Vitamin D-Konzentration nahm während der Überwinterung bei allen Kampagnen signifikant ab und erholte sich zur Nachmessung nur bei den Teilnehmern der 33. und 34. Überwinterungskampagne im Vergleich zur Vormessung. Über die Zeit zeigte sich eine signifikante Verbesserung der Effizienz und der Reaktionszeit bei 9 bzw. 10 der 10 kognitiven Tests in der ANAM4TM-Batterie und bei 6 bzw. 8 der 10 kognitiven Tests in der Cognition-Batterie. Bei höherer Vitamin D-Konzentration verschlechterten sich die Effizienz und die Reaktionszeit signifikant bei 9 bzw. 10 Tests in der ANAM4TM-Batterie und bei 2 bzw. 4 Tests in der Cognition-Batterie. Schlussfolgerung: Die Verbesserung der kognitiven Leistungsfähigkeit über die Zeit beruht vermutlich auf einen Lerneffekt. Der signifikante negative Zusammenhang zwischen der Vitamin D-Konzentration und der kognitiven Leistungsfähigkeit bei den Langzeitüberwinterern in der Antarktis ist deshalb mit Vorsicht zu betrachten. Weitere Studien sind notwendig, um die Einflüsse von Vitamin D auf das Gehirn und die kognitive Leistungsfähigkeit zu klären., Introduction: Humans face different challenges during extended stays in extreme environments such as Antarctica. Among these challenges is the reduced solar radiation which results in less cutaneous vitamin D synthesis. The effects of vitamin D deficiency on skeletal diseases have been well established. During the past decades, vitamin D has been linked to the central nervous system, as the vitamin D Receptor and metabolites have been located in the brain and as vitamin D has been shown to have neurotrophic and neuroprotective effects. Previous research has also established correlations between vitamin D and structural alterations in the brain. Moreover, observational studies support a correlation between low vitamin D levels and cognitive decline and dementia, respectively. However, interventional studies fail to show this association. The aim of this study is to investigate the impact of vitamin D levels on cognitive performance during an extended stay in Antarctica. Methods: As part of three winter campaigns (33rd-35th), people were overwintering for a duration of 14 months per campaign at the Antarctic German research station Neumayer III. The participants were Antarctic scientists recruited by the Alfred Wegener Institute (n = 9 per campaign). Vitamin D levels and cognitive performance were measured before and after the expedition as well as monthly during their stay. Cognitive performance was determined by validated computerized test batteries (ANAM4TM or Cognition). The performance parameters efficiency and reaction time were evaluated. A linear mixed model was used for statistical analysis, while controlling for the effects of age and gender. Results: Vitamin D levels significantly decreased in all campaigns during overwintering and only for the 33rd and 34th campaign did they recover to the same levels after their return home. Over time, efficiency and reaction time showed significant improvement in 9 and 10 of the 10 ANAM4TM battery cognitive tests, respectively, as well as in 6 and 8 of the 10 Cognition battery cognitive tests, respectively. With high vitamin D levels, efficiency and reaction time worsened significantly in 9 and 10 of the ANAM4TM battery tests, respectively, as well as in 2 and 4 of the Cognition battery tests, respectively. Conclusion: The cognitive improvement over time is presumably caused by practice effects. The significant negative association between vitamin D levels and cognitive performance in the sample should therefore be interpreted with caution. More studies are needed to assess the impact of vitamin D on cognitive performance and the brain.

Fornasiero, Alessandro, Aldo Savoldelli, Federico Stella, Alexa Callovini, Lorenzo Bortolan, Andrea Zignoli, David A. Low, Laurent Mourot, Federico Schena, and Barbara Pellegrini. Shortening work-rest durations reduces physiological and perceptual load during uphill walking in simulated cold high-altitude conditions.

The deep ocean is the largest biome on Earth and yet it is among the least studied environments of our planet. Life at great depths requires several specific adaptations; however, their molecular mechanisms remain understudied. We examined patterns of positive selection in 416 genes from four brittle star (Ophiuroidea) families displaying replicated events of deep-sea colonization (288 individuals from 216 species). We found consistent signatures of molecular convergence in functions related to protein biogenesis, including protein folding and translation. Five genes were recurrently positively selected, including chaperonin-containing TCP-1 subunit α (CCTα), which is essential for protein folding. Molecular convergence was detected at the functional and gene levels but not at the amino-acid level. Pressure-adapted proteins are expected to display higher stability to counteract the effects of denaturation. We thus examined in silico local protein stability of CCTα across the ophiuroid tree of life (967 individuals from 725 species) in a phylogenetically corrected context and found that deep-sea-adapted proteins display higher stability within and next to the substrate-binding region, which was confirmed by in silico global protein stability analyses. This suggests that CCTα displays not only structural but also functional adaptations to deep-water conditions. The CCT complex is involved in the folding of ∼10% of newly synthesized proteins and has previously been categorized as a “cold-shock” protein in numerous eukaryotes. We thus propose that adaptation mechanisms to cold and deep-sea environments may be linked and highlight that efficient protein biogenesis, including protein folding and translation, is a key metabolic deep-sea adaptation.

Climate change is increasing weather unpredictability, causing more intense, frequent and longer extreme events including droughts, precipitation, and both heat and cold waves. The performance of parasites, and host-parasite interactions, under these unpredictable conditions, are directly influenced by the ability of parasites to cope with extremes and their capacity to adapt to the new conditions. Here, we review some of the structural, behavioural, life history and ecological characteristics of parasitic nematodes that allow them to persist and adapt to extreme and changing environmental conditions. We focus primarily, but not exclusively, on parasitic nematodes in the Arctic, where temperature extremes are pronounced, climate change is happening most rapidly, and changes in host-parasite interactions are already documented. We discuss how life-history traits, phenotypic plasticity, local adaptation and evolutionary history can influence the short and long term response of parasites to new conditions. A detailed understanding of the complex ecological processes involved in the survival of parasites in extreme and changing conditions is a fundamental step to anticipate the impact of climate change in parasite dynamics., Graphical abstract Image 1, Highlights • The adaptations of parasites to extreme environments are relevant to understand parasite dynamics in a changing world. • Life cycle, plasticity and thermal adaptation are important to effectively anticipate impacts of climate change in parasites. • The evolutionary history of parasites is a window to study their adaptive capacity to climate change.

Given the increased reporting of multi-resistant bacteria and the shortage of newly approved medicines, researchers have been looking towards extreme and unusual environments as a new source of antibiotics. Streptomyces currently provides many of the world’s clinical antibiotics, so it comes as no surprise that these bacteria have recently been isolated from traditional medicine. Given the wide array of traditional medicines, it is hoped that these discoveries can provide the much sought after core structure diversity that will be required of a new generation of antibiotics. This review discusses the contribution of Streptomyces to antibiotics and the potential of newly discovered species in traditional medicine. We also explore how knowledge of traditional medicines can aid current initiatives in sourcing new and chemically diverse antibiotics.

In this article we seek to explain how safety mechanisms and risks evolve over time. The article focuses on a sociotechnical system, that of a polar traverse (a transport operation in a polar environment). In the study spanning a period of 27 years data were collected with ethnographic participative observations on three of the 56 traverses already achieved. Activities were traced from the whole 1398 daily reports and scale models of the convoy vehicles were used to reconstruct events during the traverses. Self-confrontation interviews were also conducted. A traverse feedback process was carried out which revealed that (1) whereas proactive safety is aimed at maintaining the continuous improvement of a system, reactive safety makes it possible to maintain the system's level of safety; (2) the development of redundancy and mixed technology contribute positively to the safety system. Improvements made to the safety system, its dynamics, and embodied resilience are discussed as well as the study limitations and implications.

Legged robots are exceedingly versatile and have the potential to navigate complex, confined spaces due to their many degrees of freedom. As a result of the computational complexity, there exist no online planners for perceptive whole-body locomotion of robots in tight spaces. In this paper, we present a new method for perceptive planning for multilegged robots, which generates body poses, footholds, and swing trajectories for collision avoidance. Measurements from an onboard depth camera are used to create a three-dimensional map of the terrain around the robot. We randomly sample body poses then smooth the resulting trajectory while satisfying several constraints, such as robot kinematics and collision avoidance. Footholds and swing trajectories are computed based on the terrain, and the robot body pose is optimized to ensure stable locomotion while not colliding with the environment. Our method is designed to run online on a real robot and generate trajectories several meters long. We first tested our algorithm in several simulations with varied confined spaces using the quadrupedal robot ANYmal. We also simulated experiments with the hexapod robot Weaver to demonstrate applicability to different legged robot configurations. Then, we demonstrated our whole-body planner in several online experiments both indoors and in realistic scenarios at an emergency rescue training facility. ANYmal, which has a nominal standing height of 80 cm and a width of 59 cm, navigated through several representative disaster areas with openings as small as 60 cm. Three-meter trajectories were replanned with 500 ms update times.

Hypersaline lakes and saltern areas are important industrial and biodiversity resources in the Qaidam Basin of China that reside at > 2600 m asl. Most hypersaline environments in this area are characterized by saturated salinity (~ 300 g/L salinity), nearly neutral pH, intense ultraviolet radiation, and extremely variable temperature fluctuations. The core bacterial communities associated with these stressful environments have nevertheless remained uninvestigated. 16S rRNA gene Illumina sequencing analyses revealed that the bacterial communities were dominated by core lineages including the Proteobacteria (39.4–64.6%) and the Firmicutes (17.0–42.7%). However, the relative abundances of common lineages, and especially the five most abundant taxa of Pseudomonas, Lactococcus, Anoxybacillus, Acinetobacter, and Brevundimonas, were highly variable across communities and closely associated with hypersaline characteristics in the samples. Network analysis revealed the presence of co-occurrence high relative abundance taxa (cluster I) that were highly correlated across all hypersaline samples. Additionally, temperature, total organic carbon, K+, and Mg2+ correlated highest with taxonomic distributions across communities. These results highlight the potential mechanisms that could underlie survival and adaptation to these extreme hypersaline ecosystems.

New findings What is the topic of this review? This review describes the effect of extreme environments on the visual system. What advances does it highlight? The review highlights the way in which environmental stressors affect the eye and vision, both directly and indirectly. Abstract Much is known about the physiology and anatomy of the eye. Much less is known about the impact of different environments on the eye, and yet it is the pathophysiology that results from this interaction that is often the precursor to disaster. The present review focuses on the effect of different extreme environments on the visual system; in particular, the way in which such environments affect the sensory mechanism of that system.

Microorganisms, in the most hyperarid deserts around the world, inhabit the inside of rocks as a survival strategy. Water is essential for life, and the ability of a rock substrate to retain water is essential for its habitability. Here we report the mechanism by which gypsum rocks from the Atacama Desert, Chile, provide water for its colonizing microorganisms. We show that the microorganisms can extract water of crystallization (i.e., structurally ordered) from the rock, inducing a phase transformation from gypsum (CaSO4·2H2O) to anhydrite (CaSO4). To investigate and validate the water extraction and phase transformation mechanisms found in the natural geological environment, we cultivated a cyanobacterium isolate on gypsum rock samples under controlled conditions. We found that the cyanobacteria attached onto high surface energy crystal planes ({011}) of gypsum samples generate a thin biofilm that induced mineral dissolution accompanied by water extraction. This process led to a phase transformation to an anhydrous calcium sulfate, anhydrite, which was formed via reprecipitation and subsequent attachment and alignment of nanocrystals. Results in this work not only shed light on how microorganisms can obtain water under severe xeric conditions but also provide insights into potential life in even more extreme environments, such as Mars, as well as offering strategies for advanced water storage methods.

The light-harvesting phycobilisome complex is an important component of photosynthesis in cyanobacteria and red algae. Phycobilisomes are composed of phycobiliproteins, including the blue phycobiliprotein phycocyanin, that are considered high-value products with applications in several industries. Remarkably, several cyanobacteria and red algal species retain the capacity to harvest light and photosynthesise under highly selective environments such as hot springs, and flourish in extremes of pH and elevated temperatures. These thermophilic organisms produce thermostable phycobiliproteins, which have superior qualities much needed for wider adoption of these natural pigment–proteins in the food, textile, and other industries. Here we review the available literature on the thermostability of phycobilisome components from thermophilic species and discuss how a better appreciation of phycobiliproteins from extreme environments will benefit our fundamental understanding of photosynthetic adaptation and could provide a sustainable resource for several industrial processes.

The measure of hemolysis in humans is clinically important. Here we describe methods using a gas chromatograph equipped with a reduction gas detector to detect the human analyte carbon monoxide (CO) that were developed for the extreme environment of the International Space Station. These methods can be adapted to in-hospital use for clinical care with characteristics that may surpass existing measures of hemolysis. We demonstrate improved performance over previous-generation methods in terms of reproducibility, accuracy, control for physical and intervening factors to quantitatively assess hemolysis rates at unprecedented levels. The presented measure of hemolysis using CO elimination is based on a different physiological approach that can complement and augment existing detection tools. In addition to their suitability for extreme environments, the methods present distinctive advantages over existing markers for the diagnosis, monitoring and response to treatment of hemolytic anemia. These methods have the potential to fulfill a wide range of research and clinical applications.

Amur ide (Leuciscus waleckii, Family Cyprinidae) is widely distributed in Northeast Asia. L. waleckii usually inhabits freshwater environments but can also survive in the Lake Dali Nur, one of the most extreme aquatic environments on the earth, with an alkalinity up to 50 mmol/L (pH 9.6). To investigate mechanisms of mitogenomic evolution underlying adaptation to extreme environments, we determined 30 complete mitogenomes that included Lake Dali Nur (alkaline environment, AL) population and Amur basin (freshwater environment, FW) population. Through phylogenetic and divergence time analysis, we found that AL and FW populations forming distinct two groups which were consistent with geographic divergence (the formation of Lake Dali Nur). In addition, we found that almost of the windows exhibited higher nucleotide diversity in FW population (avg 0.0046) than AL population (avg 0.0012). This result indicated that severe environment selection had remarkably reduced the genetic diversity of mitogenome in AL population and suggested that severe environment selection had remarkably reduced the genetic diversity of mitogenome in the AL population. Compared with the FW population (ω = 0.064), the AL population (ω = 0.092) had a larger mean ω (dN/dS ratios) value for the 13 concatenated mitochondrial protein-coding genes, indicating that the high alkaline tolerated group had accumulated more nonsynonymous mutations. These nonsynonymous mutations had resulted in slightly beneficial amino acid changes that allowed adaption to the severe conditions. This study provides an additional view to decipher the adaptive mitogenome evolution of L. waleckii of the high alkaline environment.

Models of Titan predict that there is a subsurface ocean of water and ammonia under a layer of ice. Such an ocean would be important in the search for extraterrestrial life since it provides a potentially habitable environment. To evaluate how Earth-based proteins would behave in Titan's subsurface ocean environment, we used molecular dynamics simulations to calculate the properties of proteins with the most common secondary structure types (alpha helix and beta sheet) in both Earth and Titan-like conditions. The Titan environment was simulated by using a temperature of 300 K, a pressure of 1000 bar, and a eutectic mixture of water and ammonia. We analyzed protein compactness, flexibility, and backbone dihedral distributions to identify differences between the two environments. Secondary structures in the Titan environment were found to be less long-lasting, less flexible, and had small differences in backbone dihedral preferences (e.g., in one instance a pi helix formed). These environment-driven differences could lead to changes in how these proteins interact with other biomolecules and therefore changes in how evolution would potentially shape proteins to function in subsurface ocean environments.