scholarly journals The Atacama Desert in Northern Chile as an Analog Model of Mars

2022 ◽  
Vol 8 ◽  
Author(s):  
Armando Azua-Bustos ◽  
Carlos González-Silva ◽  
Alberto G. Fairén
Keyword(s):  
Atacama Desert ◽  
Analog Model ◽  
Patchy Distribution ◽  
Microbial Life ◽  
Environmental Extremes ◽  
Life On Mars ◽  
Domains Of Life ◽  
Mars Analog ◽  
The Impact

The Atacama Desert is by far the driest and oldest desert on Earth, showing a unique combination of environmental extremes (extreme dryness, the highest UV radiation levels on Earth, and highly saline and oxidizing soils), explaining why the Atacama has been largely investigated as a Mars analog model for almost 20 years. Based on the source and the amount of water available for life and its analogy with Mars, two ecosystems are of interest in the Atacama: its Coastal Range and the much drier hyperarid core, which we here review in detail. Members of the three domains of life have been found across these ecosystems living at the limit of habitability, suggesting the potential dry limits for each domain and also unveiling the highly patchy distribution of microbial life in its most extreme regions. The thorough study of the Atacama has allowed us to understand how life has adapted to its extreme conditions, the specific habitats that life occupies in each case (thus suggesting the most likely places in which to search for evidence for life on Mars), and the number of biosignatures detected across this desert. Also, the characterization of west-to-east transects across this desert has shown to be of significant value to understand the potential adaptations that Martian microorganisms may have followed in an ever-drying planet. All of this explains why the Atacama is actively used as the testing ground of the technologies (detection instruments, rovers, etc.) that were sent and will be sent to Mars. We also highlight the need to better inform the exact locations of the sites studied to understand general trends, the need to identify the true native microbial species of the Atacama, and the impact of climate change on the most arid and most Martian desert of Earth.

scholarly journals Biotechnological Applications Derived from Microorganisms of the Atacama Desert

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Armando Azua-Bustos ◽  
Carlos González-Silva
Keyword(s):  
Water Availability ◽  
High Salinity ◽  
Atacama Desert ◽  
Biotechnological Applications ◽  
Analog Model ◽  
The Past ◽  
Basic Understanding ◽  
Domains Of Life ◽  
Immense Potential

The Atacama Desert in Chile is well known for being the driest and oldest desert on Earth. For these same reasons, it is also considered a good analog model of the planet Mars. Only a few decades ago, it was thought that this was a sterile place, but in the past years fascinating adaptations have been reported in the members of the three domains of life: low water availability, high UV radiation, high salinity, and other environmental stresses. However, the biotechnological applications derived from the basic understanding and characterization of these species, with the notable exception of copper bioleaching, are still in its infancy, thus offering an immense potential for future development.

scholarly journals Inhabited subsurface wet smectites in the hyperarid core of the Atacama Desert as an analog for the search for life on Mars

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Armando Azua-Bustos ◽  
Alberto G. Fairén ◽  
Carlos González Silva ◽  
Daniel Carrizo ◽  
Miguel Ángel Fernández-Martínez ◽  
...  
Keyword(s):  
Microbial Community ◽  
Atacama Desert ◽  
Martian Surface ◽  
Microbial Life ◽  
Clay Deposits ◽  
Life On Mars ◽  
Subsurface Layers ◽  
Active Bacteria ◽  
Halophilic Species ◽  
Diverse Microbial Community

Abstract The modern Martian surface is unlikely to be habitable due to its extreme aridity among other environmental factors. This is the reason why the hyperarid core of the Atacama Desert has been studied as an analog for the habitability of Mars for more than 50 years. Here we report a layer enriched in smectites located just 30 cm below the surface of the hyperarid core of the Atacama. We discovered the clay-rich layer to be wet (a phenomenon never observed before in this region), keeping a high and constant relative humidity of 78% (aw 0.780), and completely isolated from the changing and extremely dry subaerial conditions characteristic of the Atacama. The smectite-rich layer is inhabited by at least 30 halophilic species of metabolically active bacteria and archaea, unveiling a previously unreported habitat for microbial life under the surface of the driest place on Earth. The discovery of a diverse microbial community in smectite-rich subsurface layers in the hyperarid core of the Atacama, and the collection of biosignatures we have identified within the clays, suggest that similar shallow clay deposits on Mars may contain biosignatures easily reachable by current rovers and landers.

scholarly journals Microbial colonization of halite from the hyper-arid Atacama Desert studied by Raman spectroscopy

2010 ◽  
Vol 368 (1922) ◽  
pp. 3205-3221 ◽  
Author(s):  
P. Vítek ◽  
H. G. M. Edwards ◽  
J. Jehlička ◽  
C. Ascaso ◽  
A. De Los Ríos ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Atacama Desert ◽  
Microbial Colonization ◽  
Microbial Life ◽  
Spectral Signatures ◽  
Arid Conditions ◽  
Life On Mars ◽  
Moisture Conditions ◽  
Micro Organisms ◽  
Non Destructive

The hyper-arid core of the Atacama Desert (Chile) is the driest place on Earth and is considered a close analogue to the extremely arid conditions on the surface of Mars. Microbial life is very rare in soils of this hyper-arid region, and autotrophic micro-organisms are virtually absent. Instead, photosynthetic micro-organisms have successfully colonized the interior of halite crusts, which are widespread in the Atacama Desert. These endoevaporitic colonies are an example of life that has adapted to the extreme dryness by colonizing the interior of rocks that provide enhanced moisture conditions. As such, these colonies represent a novel example of potential life on Mars. Here, we present non-destructive Raman spectroscopical identification of these colonies and their organic remnants. Spectral signatures revealed the presence of UV-protective biomolecules as well as light-harvesting pigments pointing to photosynthetic activity. Compounds of biogenic origin identified within these rocks differed depending on the origins of specimens from particular areas in the desert, with differing environmental conditions. Our results also demonstrate the capability of Raman spectroscopy to identify biomarkers within rocks that have a strong astrobiological potential.

The effects of climate change on the Atacama Desert as a pertinent Mars analog model

2020 ◽  
Author(s):  
Armando Azua-Bustos ◽  
Alberto G. Fairén
Keyword(s):  
Climate Change ◽  
Uv Radiation ◽  
Atacama Desert ◽  
Chemical Species ◽  
Saline Soils ◽  
Northern Chile ◽  
Analog Model ◽  
The Past ◽  
Mars Analog ◽  
New Instruments

<p>Since 2003 the Atacama Desert in northern Chile is well-known as Mars analog model due to its extreme aridity, high UV radiation and highly saline soils containing highly oxidizing chemical species. Is in this frame that our team and others for the past decades have described a number of sites in the Atacama and their pertinence as Mars analog. However, since 2015 a number of climatic events never reported before have affected the Atacama, thought to be caused by climate change, with effects yet to be fully understood. Given that new instruments, techniques and rovers are, and will be tested in the Atacama before to be sent to Mars, is critical to be aware of these changes in order to properly plan new explorations and testing missions in this desert. Here we present some of the evidences of the changes brought by these environmental alterations, suggesting also the regions of the Atacama that still may be less or unaffected by them.</p>

The Analyses of Learning Strategies in English as a Second Language: Theoretical Classification and Measurement Test

2020 ◽  
Vol 4 (2) ◽  
pp. 118-129
Author(s):  
Asti Gumartifa ◽  
◽  
Indah Windra Dwie Agustiani
Keyword(s):  
Language Learning ◽  
Learning Outcomes ◽  
Learning Strategies ◽  
Learning Process ◽  
English Learners ◽  
English Language ◽  
Point Of View ◽  
Effective Learning ◽  
The Impact

Gaining English language learning effectively has been discussed all years long. Similarly, Learners have various troubles outcomes in the learning process. Creating a joyful and comfortable situation must be considered by learners. Thus, the implementation of effective learning strategies is certainly necessary for English learners. This descriptive study has two purposes: first, to introduce the classification and characterization of learning strategies such as; memory, cognitive, metacognitive, compensation, social, and affective strategies that are used by learners in the classroom and second, it provides some questionnaires item based on Strategy of Inventory for Language Learning (SILL) version 5.0 that can be used to examine the frequency of students’ learning strategies in the learning process. The summary of this study explains and discusses the researchers’ point of view on the impact of learning outcomes by learning strategies used. Finally, utilizing appropriate learning strategies are certainly beneficial for both teachers and learners to achieve the learning target effectively.

scholarly journals Modulation of Gut Microbiota and Oxidative Status by β-Carotene in Late Pregnant Sows

2020 ◽  
Vol 7 ◽  
Author(s):  
Xupeng Yuan ◽  
Jiahao Yan ◽  
Ruizhi Hu ◽  
Yanli Li ◽  
Ying Wang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Dietary Supplementation ◽  
Basal Diet ◽  
Fecal Microbiota ◽  
Control Group ◽  
Metabolic Activities ◽  
The Impact ◽  
Positive Effect ◽  
Β Carotene

Recent evidences suggest that gut microbiota plays an important role in regulating physiological and metabolic activities of pregnant sows, and β-carotene has a potentially positive effect on reproduction, but the impact of β-carotene on gut microbiota in pregnant sows remains unknown. This study aimed to explore the effect and mechanisms of β-carotene on the reproductive performance of sows from the aspect of gut microbiota. A total of 48 hybrid pregnant sows (Landrace × Yorkshire) with similar parity were randomly allocated into three groups (n = 16) and fed with a basal diet or a diet containing 30 or 90 mg/kg of β-carotene from day 90 of gestation until parturition. Dietary supplementation of 30 or 90 mg/kg β-carotene increased the number of live birth to 11.82 ± 1.54 and 12.29 ± 2.09, respectively, while the control group was 11.00 ± 1.41 (P = 0.201). Moreover, β-carotene increased significantly the serum nitric oxide (NO) level and glutathione peroxidase (GSH-Px) activity (P < 0.05). Characterization of fecal microbiota revealed that 90 mg/kg β-carotene increased the diversity of the gut flora (P < 0.05). In particular, β-carotene decreased the relative abundance of Firmicutes including Lachnospiraceae AC2044 group, Lachnospiraceae NK4B4 group and Ruminococcaceae UCG-008, but enriched Proteobacteria including Bilophila and Sutterella, and Actinobacteria including Corynebacterium and Corynebacterium 1 which are related to NO synthesis. These data demonstrated that dietary supplementation of β-carotene may increase antioxidant enzyme activity and NO, an important vasodilator to promote the neonatal blood circulation, through regulating gut microbiota in sows.

scholarly journals Clonal approaches to understanding the impact of mutations on hematologic disease development

Blood ◽  
2019 ◽  
Vol 133 (13) ◽  
pp. 1436-1445 ◽  
Author(s):  
Jyoti Nangalia ◽  
Emily Mitchell ◽  
Anthony R. Green
Keyword(s):  
Somatic Mutations ◽  
Clonal Selection ◽  
Single Cells ◽  
Driver Mutations ◽  
Great Promise ◽  
Tumor Evolution ◽  
Disease Development ◽  
Hematopoietic Tissue ◽  
The Impact

Abstract Interrogation of hematopoietic tissue at the clonal level has a rich history spanning over 50 years, and has provided critical insights into both normal and malignant hematopoiesis. Characterization of chromosomes identified some of the first genetic links to cancer with the discovery of chromosomal translocations in association with many hematological neoplasms. The unique accessibility of hematopoietic tissue and the ability to clonally expand hematopoietic progenitors in vitro has provided fundamental insights into the cellular hierarchy of normal hematopoiesis, as well as the functional impact of driver mutations in disease. Transplantation assays in murine models have enabled cellular assessment of the functional consequences of somatic mutations in vivo. Most recently, next-generation sequencing–based assays have shown great promise in allowing multi-“omic” characterization of single cells. Here, we review how clonal approaches have advanced our understanding of disease development, focusing on the acquisition of somatic mutations, clonal selection, driver mutation cooperation, and tumor evolution.

scholarly journals Exploring the Characteristics and Influencing Factors of Leisure Walking Based on the Demand of Behavior

2021 ◽  
Vol 13 (8) ◽  
pp. 4105
Author(s):  
Yupei Jiang ◽  
Honghu Sun
Keyword(s):  
Health Benefits ◽  
Health Benefit ◽  
Public Health Research ◽  
Space Time ◽  
Time Behavior ◽  
Walking Behavior ◽  
Face To Face ◽  
Residential Neighborhood ◽  
The Impact

Leisure walking has been an important topic in space-time behavior and public health research. However, prior studies pay little attention to the integration and the characterization of diverse and multilevel demands of leisure walking. This study constructs a theoretical framework of leisure walking behavior demands from three different dimensions and levels of activity participation, space-time opportunity, and health benefit. On this basis, through a face-to-face survey in Nanjing, China (N = 1168, 2017–2018 data), this study quantitatively analyzes the characteristics of leisure walking demands, as well as the impact of the built environment and individual factors on it. The results show that residents have a high demand for participation and health benefits of leisure walking. The residential neighborhood provides more space opportunities for leisure walking, but there is a certain constraint on the choice of walking time. Residential neighborhood with medium or large parks is more likely to satisfy residents’ demands for engaging in leisure walking and obtaining high health benefits, while neighborhood with a high density of walking paths tends to limit the satisfaction of demands for space opportunity and health benefit. For residents aged 36 and above, married, or retired, their diverse demands for leisure walking are more likely to be fulfilled, while those with high education, medium-high individual income, general and above health status, or children (<18 years) are less likely to be fulfilled. These finding that can have important implications for the healthy neighborhood by fully considering diverse and multilevel demands of leisure walking behavior.

scholarly journals Size-resolved characterization of organic aerosol in the North China Plain: new insights from high resolution spectral analysis

2021 ◽  
Author(s):  
Weiqi Xu ◽  
Chun Chen ◽  
Yanmei Qiu ◽  
Conghui Xie ◽  
Yunle Chen ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
North China Plain ◽  
North China ◽  
Fine Particles ◽  
Large Fraction ◽  
Organic Aerosol ◽  
Size Distributions ◽  
The North ◽  
The Impact

Organic aerosol (OA), a large fraction of fine particles, has a large impact on climate radiative forcing and human health, and the impact depends strongly on size distributions. Here we...

scholarly journals Performance Analysis of Indentation Punch on High Energy Lithium Pouch Cells and Simulated Model Improvement

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1971
Author(s):  
Lihua Ye ◽  
Muhammad Muzamal Ashfaq ◽  
Aiping Shi ◽  
Syyed Adnan Raheel Shah ◽  
Yefan Shi
Keyword(s):  
Short Circuit ◽  
Lithium Ion ◽  
Mechanical Deformation ◽  
High Energy ◽  
State Of Charge ◽  
Punch Test ◽  
Short Course ◽  
Model Cell ◽  
The Impact

In this research, the aim relates to the material characterization of high-energy lithium-ion pouch cells. The development of appropriate model cell behavior is intended to simulate two scenarios: the first is mechanical deformation during a crash and the second is an internal short circuit in lithium-ion cells during the actual effect scenarios. The punch test has been used as a benchmark to analyze the effects of different state of charge conditions on high-energy lithium-ion battery cells. This article explores the impact of three separate factors on the outcomes of mechanical punch indentation experiments. The first parameter analyzed was the degree of prediction brought about by experiments on high-energy cells with two different states of charge (greater and lesser), with four different sizes of indentation punch, from the cell’s reaction during the indentation effects on electrolyte. Second, the results of the loading position, middle versus side, are measured at quasi-static speeds. The third parameter was the effect on an electrolyte with a different state of charge. The repeatability of the experiments on punch loading was the last test function analyzed. The test results of a greater than 10% state of charge and less than 10% state of charge were compared to further refine and validate this modeling method. The different loading scenarios analyzed in this study also showed great predictability in the load-displacement reaction and the onset short circuit. A theoretical model of the cell was modified for use in comprehensive mechanical deformation. The overall conclusion found that the loading initiating the cell’s electrical short circuit is not instantaneously instigated and it is subsequently used to process the development of a precise and practical computational model that will reduce the chances of the internal short course during the crash.

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