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1.
An Acad Bras Cienc ; 91(3): e20180583, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31365652

RESUMO

Isolation and screening of new fungal strains from extreme and understudied environments, such as caves, is a promising approach to find higher yields enzyme producers. Cellulolytic fungal strains isolated from a Brazilian cave were evaluated for their enzymatic production after submerged (SmF) and solid-state fermentation (SSF). After SmF, three strains were selected for their high enzymatic activities: Aspergillus ustus for endoglucanase (4.76 U/mg), Talaromyces bruneus for ß-glucosidase (11.71 U/mg) and Aspergillus sp. (CBMAI 1926) for total cellulase (1.70 U/mg). After SSF, these strains, showed better yields compared to the reference strain Aspergillus niger 3T5B8. Aspergillus sp. (CBMAI 1926) stood out as a new species that expressed activity of total cellulases (0.10 U/mg) and low protein concentration (0.44 mg/mL). In conclusion, these isolated strains have a more efficient and promising cellulolytic enzyme complex that can be used in fermentation and saccharification processes with a lower protein concentration and a higher enzymatic activity than the reference strain. Therefore, beside the new genetic material characterized, our study highlights the benefits of cave extreme environments exploitation to find new potentially valuable strains.


Assuntos
Cavernas , Celulases/metabolismo , Ambientes Extremos , Fungos/metabolismo , Brasil , Fungos/classificação
2.
Int J Mol Sci ; 20(14)2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31336824

RESUMO

Microbial biofilms are communities of aggregated microbial cells embedded in a self-produced matrix of extracellular polymeric substances (EPS). Biofilms are recalcitrant to extreme environments, and can protect microorganisms from ultraviolet (UV) radiation, extreme temperature, extreme pH, high salinity, high pressure, poor nutrients, antibiotics, etc., by acting as "protective clothing". In recent years, research works on biofilms have been mainly focused on biofilm-associated infections and strategies for combating microbial biofilms. In this review, we focus instead on the contemporary perspectives of biofilm formation in extreme environments, and describe the fundamental roles of biofilm in protecting microbial exposure to extreme environmental stresses and the regulatory factors involved in biofilm formation. Understanding the mechanisms of biofilm formation in extreme environments is essential for the employment of beneficial microorganisms and prevention of harmful microorganisms.


Assuntos
Biofilmes , Ambientes Extremos , Fenômenos Microbiológicos , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/efeitos da radiação , Concentração de Íons de Hidrogênio , Fenômenos Microbiológicos/efeitos dos fármacos , Fenômenos Microbiológicos/efeitos da radiação , Salinidade , Temperatura Ambiente , Raios Ultravioleta
3.
Hist Philos Life Sci ; 41(2): 26, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197607

RESUMO

In the first half of the twentieth century the attention of American and European researchers was drawn to the area of 'extreme physiology', partly because of expeditions to the north and south poles, and to high altitude, but also by global conflicts which were fought for the first time with aircraft, and involved conflict in non-temperate zones, deserts, and at the freezing Eastern front. In an attempt to help white Euro-Americans survive in extreme environments, physiologists, anthropologists, and explorers studied indigenous people's bodies, cultures, and technologies. This paper will sketch an outline of the science of white survival in three 'extreme' environments: the Antarctic and Arctic; high-altitude; and the Australian desert, with a particular focus on the ways in which indigenous populations were studied, or in some cases ignored, by Western biomedical scientists-despite their crucial and systematic contributions to the success of experiments and expeditions. Particularly focusing on altitude, and on blood in both its symbolic (hereditary) and literal sense, the article shows how assumptions about race, indigeneity, civilisation, and evolution shaped the ways White Westerners understood their own bodies as well as those of the people they encountered in cold, high and hot places on the earth. Despite new discoveries in physiology and evolutionary science, old racialised assumptions were maintained, especially those that figured the temperate body as civilised and the tropical body as primitive; and in at least one case it will be shown that these racialised assumptions significantly altered, if not retarded, the science of respiratory physiology.


Assuntos
Adaptação Biológica , Ambientes Extremos , Fisiologia/história , Grupos Populacionais , Racismo , Altitude , Regiões Antárticas , Regiões Árticas , Fenômenos Fisiológicos Sanguíneos , Clima Desértico , História do Século XX , Humanos
4.
Sci Total Environ ; 678: 639-646, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31078855

RESUMO

Exoelectrogenic communities for bioelectrochemical systems such as microbial fuel cells (MFCs) are usually enriched from microbial consortia of municipal wastewater treatment plants and other circumneutral and mesophilic environments. Thus, the study of extreme environments offers an enormous potential to find new exoelectrogens and expand the functionality and applications of MFC technology. In this study, a microbial community previously enriched from acid mine drainage (AMD) sediments was used as inoculum in single-chamber MFCs operated at pH 3.7. The power obtained from the AMD-derived inoculum reached 1 mW m-2 (27.1 ±â€¯7.8 mV with 1 kΩ external resistance), which compares to previous MFC studies operated under low-pH conditions. Additionally, polarization curves showed power-generation levels of 2.4 ±â€¯0.2 mW m-2 and 0.4 ±â€¯0.3 mW m-2, which were associated with the different inoculum sources: MFCs operated with sulfate concentrations of ~2000 and < 25 mg L-1, respectively. Microbial characterization performed at the end of the operation showed that both anodic and cathodic biofilm communities were highly dominated by the Proteobacteria phylum (>72% of 16S rRNA gene sequences), followed by Firmicutes (4-11%). Furthermore, the anodic microbial communities of the best-performing reactors were dominated by the Delftia genus (phylum Proteobacteria), which was recently identified as a taxon including exoelectrogenic candidates. These findings expand the literature of low-pH operated MFCs and acid-tolerant exoelectrogens, and also represent a starting point to apply this technology to treat acidic organic loads.


Assuntos
Fenômenos Fisiológicos Bacterianos , Fontes de Energia Bioelétrica/microbiologia , Biofilmes , Reatores Biológicos/microbiologia , Águas Residuárias/química , Poluentes da Água/química , Bactérias/classificação , Bactérias/metabolismo , Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Chile , Ambientes Extremos , Mineração
5.
Biol Sex Differ ; 10(1): 20, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30992051

RESUMO

BACKGROUND: Antarctica challenges human explorers by its extreme environment. The effects of these unique conditions on the human physiology need to be understood to best mitigate health problems in Antarctic expedition crews. Moreover, Antarctica is an adequate Earth-bound analogue for long-term space missions. To date, its effects on human physiology have been studied mainly in male cohorts though more female expeditioners and applicants in astronaut training programs are selected. Therefore, the identification of sex differences in stress and immune reactions are becoming an even more essential aim to provide a more individualized risk management. METHODS: Ten female and 16 male subjects participated in three 1-year expeditions to the German Antarctic Research Station Neumayer III. Blood, saliva, and urine samples were taken 1-2 months prior to departure, subsequently every month during their expedition, and 3-4 months after return from Antarctica. Analyses included cortisol, catecholamine and endocannabinoid measurements; psychological evaluation; differential blood count; and recall antigen- and mitogen-stimulated cytokine profiles. RESULTS: Cortisol showed significantly higher concentrations in females than males during winter whereas no enhanced psychological stress was detected in both sexes. Catecholamine excretion was higher in males than females but never showed significant increases compared to baseline. Endocannabinoids and N-acylethanolamides increased significantly in both sexes and stayed consistently elevated during the confinement. Cytokine profiles after in vitro stimulation revealed no sex differences but resulted in significant time-dependent changes. Hemoglobin and hematocrit were significantly higher in males than females, and hemoglobin increased significantly in both sexes compared to baseline. Platelet counts were significantly higher in females than males. Leukocytes and granulocyte concentrations increased during confinement with a dip for both sexes in winter whereas lymphocytes were significantly elevated in both sexes during the confinement. CONCLUSIONS: The extreme environment of Antarctica seems to trigger some distinct stress and immune responses but-with the exception of cortisol and blood cell counts-without any major relevant sex-specific differences. Stated sex differences were shown to be independent of enhanced psychological stress and seem to be related to the environmental conditions. However, sources and consequences of these sex differences have to be further elucidated.


Assuntos
Ambientes Extremos , Caracteres Sexuais , Estresse Psicológico , Adulto , Regiões Antárticas , Antígenos de Fungos/imunologia , Catecolaminas/urina , Citocinas/imunologia , Endocanabinoides/sangue , Feminino , Testes Hematológicos , Humanos , Hidrocortisona/metabolismo , Masculino , Pessoa de Meia-Idade , Mitógenos da Erva-dos-Cancros/imunologia , Estresse Psicológico/sangue , Estresse Psicológico/imunologia , Estresse Psicológico/metabolismo , Estresse Psicológico/urina , Adulto Jovem
6.
Proc Natl Acad Sci U S A ; 116(14): 7137-7146, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30894495

RESUMO

Crucihimalaya himalaica, a close relative of Arabidopsis and Capsella, grows on the Qinghai-Tibet Plateau (QTP) about 4,000 m above sea level and represents an attractive model system for studying speciation and ecological adaptation in extreme environments. We assembled a draft genome sequence of 234.72 Mb encoding 27,019 genes and investigated its origin and adaptive evolutionary mechanisms. Phylogenomic analyses based on 4,586 single-copy genes revealed that C. himalaica is most closely related to Capsella (estimated divergence 8.8 to 12.2 Mya), whereas both species form a sister clade to Arabidopsis thaliana and Arabidopsis lyrata, from which they diverged between 12.7 and 17.2 Mya. LTR retrotransposons in C. himalaica proliferated shortly after the dramatic uplift and climatic change of the Himalayas from the Late Pliocene to Pleistocene. Compared with closely related species, C. himalaica showed significant contraction and pseudogenization in gene families associated with disease resistance and also significant expansion in gene families associated with ubiquitin-mediated proteolysis and DNA repair. We identified hundreds of genes involved in DNA repair, ubiquitin-mediated proteolysis, and reproductive processes with signs of positive selection. Gene families showing dramatic changes in size and genes showing signs of positive selection are likely candidates for C. himalaica's adaptation to intense radiation, low temperature, and pathogen-depauperate environments in the QTP. Loss of function at the S-locus, the reason for the transition to self-fertilization of C. himalaica, might have enabled its QTP occupation. Overall, the genome sequence of C. himalaica provides insights into the mechanisms of plant adaptation to extreme environments.


Assuntos
Adaptação Fisiológica/genética , Altitude , Arabidopsis/genética , Brassicaceae/genética , Genes de Plantas/genética , Aclimatação/genética , Aclimatação/fisiologia , Adaptação Fisiológica/fisiologia , Arabidopsis/fisiologia , Brassicaceae/fisiologia , Capsella/genética , Capsella/fisiologia , Mudança Climática , Reparo do DNA/genética , Resistência à Doença/genética , Ambientes Extremos , Dosagem de Genes , Genes de Plantas/fisiologia , Proteínas Nucleares/genética , Filogenia , Proteínas de Plantas/genética , Seleção Genética , Autofertilização/genética , Alinhamento de Sequência , Tibet , Sequenciamento Completo do Genoma
7.
Science ; 363(6427): 631-635, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30733418

RESUMO

Species in extreme habitats increasingly face changes in seasonal climate, but the demographic mechanisms through which these changes affect population persistence remain unknown. We investigated how changes in seasonal rainfall and temperature influence vital rates and viability of an arid environment specialist, the Kalahari meerkat, through effects on body mass. We show that climate change-induced reduction in adult mass in the prebreeding season would decrease fecundity during the breeding season and increase extinction risk, particularly at low population densities. In contrast, a warmer nonbreeding season resulting in increased mass and survival would buffer negative effects of reduced rainfall during the breeding season, ensuring persistence. Because most ecosystems undergo seasonal climate variations, a full understanding of species vulnerability to global change relies on linking seasonal trait and population dynamics.


Assuntos
Adaptação Fisiológica , Ambientes Extremos , Fertilidade , Herpestidae/fisiologia , Animais , Botsuana , Mudança Climática , Feminino , Masculino , Densidade Demográfica , Dinâmica Populacional , Chuva , Estações do Ano , Temperatura Ambiente
8.
ISME J ; 13(6): 1457-1468, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30728468

RESUMO

The exploration of Earth's terrestrial subsurface biosphere has led to the discovery of several new archaeal lineages of evolutionary significance. Similarly, the deep subseafloor crustal biosphere also harbors many unique, uncultured archaeal taxa, including those belonging to Candidatus Hydrothermarchaeota, formerly known as Marine Benthic Group-E. Recently, Hydrothermarchaeota was identified as an abundant lineage of Juan de Fuca Ridge flank crustal fluids, suggesting its adaptation to this extreme environment. Through the investigation of single-cell and metagenome-assembled genomes, we provide insight into the lineage's evolutionary history and metabolic potential. Phylogenomic analysis reveals the Hydrothermarchaeota to be an early-branching archaeal phylum, branching between the superphylum DPANN, Euryarchaeota, and Asgard lineages. Hydrothermarchaeota genomes suggest a potential for dissimilative and assimilative carbon monoxide oxidation (carboxydotrophy), as well as sulfate and nitrate reduction. There is also a prevalence of chemotaxis and motility genes, indicating adaptive strategies for this nutrient-limited fluid-rock environment. These findings provide the first genomic interpretations of the Hydrothermarchaeota phylum and highlight the anoxic, hot, deep marine crustal biosphere as an important habitat for understanding the evolution of early life.


Assuntos
Archaea/isolamento & purificação , Archaea/metabolismo , Monóxido de Carbono/metabolismo , Archaea/classificação , Archaea/genética , Ecossistema , Ambientes Extremos , Genômica , Sedimentos Geológicos/microbiologia , Metagenoma , Nitratos/metabolismo , Filogenia , Sulfatos/metabolismo
9.
Bioresour Technol ; 280: 9-17, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30743055

RESUMO

Chalcopyrite bioleaching by 2, 4 and 6 acidophilic strains with the same inoculation density were studied, respectively. The results indicated that the 6-strain community firstly adapted to bioleaching environment, dissolved the chalcopyrite rapidly and maintained an efficient work until late stage. Transcriptome profiles of the 6-strain community at 6th and 30th day during bioleaching process were investigated by RNA-seq. Comparative transcriptomics identified 226 and 737 significantly up-regulated genes at early and late stage, respectively. Gene annotation results revealed that microorganisms adapted to the oligotrophic environment by enhancing cell proliferation, catalytic activation and binding action to maintain their life activities at early stage, and genes related to signal transduction, localization and transporter were highly expressed as an effective response to the stressful late stage. A graphical representation was presented to show how microorganisms adapted and resisted to the extreme environment by their inner functional properties and promoted the bioleaching efficiency.


Assuntos
Transcriptoma , Adaptação Fisiológica , Cobre/metabolismo , Ambientes Extremos
10.
Nature ; 566(7743): 190, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30742086
11.
Nat Ecol Evol ; 3(3): 469-478, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30804520

RESUMO

Icefishes (suborder Notothenioidei; family Channichthyidae) are the only vertebrates that lack functional haemoglobin genes and red blood cells. Here, we report a high-quality genome assembly and linkage map for the Antarctic blackfin icefish Chaenocephalus aceratus, highlighting evolved genomic features for its unique physiology. Phylogenomic analysis revealed that Antarctic fish of the teleost suborder Notothenioidei, including icefishes, diverged from the stickleback lineage about 77 million years ago and subsequently evolved cold-adapted phenotypes as the Southern Ocean cooled to sub-zero temperatures. Our results show that genes involved in protection from ice damage, including genes encoding antifreeze glycoprotein and zona pellucida proteins, are highly expanded in the icefish genome. Furthermore, genes that encode enzymes that help to control cellular redox state, including members of the sod3 and nqo1 gene families, are expanded, probably as evolutionary adaptations to the relatively high concentration of oxygen dissolved in cold Antarctic waters. In contrast, some crucial regulators of circadian homeostasis (cry and per genes) are absent from the icefish genome, suggesting compromised control of biological rhythms in the polar light environment. The availability of the icefish genome sequence will accelerate our understanding of adaptation to extreme Antarctic environments.


Assuntos
Adaptação Biológica , Ambientes Extremos , Genoma , Perciformes/genética , Animais , Regiões Antárticas , Feminino , Sequenciamento Completo do Genoma
12.
Extremophiles ; 23(2): 201-218, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30617527

RESUMO

The Khor Al-Adaid sabkha in Qatar is among the rare extreme environments on Earth where it is possible to study the formation of dolomite-a carbonate mineral whose origin remains unclear and has been hypothetically linked to microbial activity. By combining geochemical measurements with microbiological analysis, we have investigated the microbial mats colonizing the intertidal areas of sabhka. The main aim of this study was to identify communities and conditions that are favorable for dolomite formation. We inspected and sampled two locations. The first site was colonized by microbial mats that graded vertically from photo-oxic to anoxic conditions and were dominated by cyanobacteria. The second site, with higher salinity, had mats with an uppermost photo-oxic layer dominated by filamentous anoxygenic photosynthetic bacteria (FAPB), which potentially act as a protective layer against salinity for cyanobacterial species within the deeper layers. Porewater in the uppermost layers of the both investigated microbial mats was supersaturated with respect to dolomite. Corresponding to the variation of the microbial community's vertical structure, a difference in crystallinity and morphology of dolomitic phases was observed: dumbbell-shaped proto-dolomite in the mats dominated by cyanobacteria and rhombohedral ordered-dolomite in the mat dominated by FAPB.


Assuntos
Sedimentos Geológicos/microbiologia , Microbiota , Tolerância ao Sal , Carbonato de Cálcio/análise , Cianobactérias/genética , Cianobactérias/metabolismo , Ambientes Extremos , Sedimentos Geológicos/química , Magnésio/análise , Catar , Salinidade
13.
Med Sci Sports Exerc ; 51(3): 556-567, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30308528

RESUMO

PURPOSE: To explore the effects of the first all-female transantarctic expedition on hormonal axes pertinent to reproductive and metabolic function. METHODS: Six females (age, 28-36 yr; body mass index, 24.2 ± 0.97 kg·m) hauled 80-kg sledges 1700 km in 61 d. Estimated average energy intake was 20.8 ± 0.1 MJ·d (4970 ± 25 kcal·d). Whole and regional body composition was measured by dual-energy x-ray absorptiometry 1 and 2 months before and 15 d after, the expedition. Body fat was also estimated by skinfold and bioimpedance immediately before and after the expedition. Basal metabolic and endocrine blood markers and, after 0.25 mg dexamethasone suppression, 1-h 10-µg gonadorelin and 1.0 µg adrenocortiocotrophin-(1-24) tests were completed, 39-38 d preexpedition and 4 to 5 d and 15 to 16 d postexpedition. Cortisol was assessed in hair (monthly average concentrations) and saliva (five-point day curves and two-point diurnal sampling). RESULTS: Average body mass loss was 9.37 ± 2.31 kg (P < 0.0001), comprising fat mass only; total lean mass was maintained. Basal sex steroids, corticosteroids, and metabolic markers were largely unaffected by the expedition except leptin, which decreased during the expedition and recovered after 15 d, a proportionately greater change than body fat. Luteinizing hormone reactivity was suppressed before and during the expedition, but recovered after 15 d, whereas follicle-stimulating hormone did not change during or after the expedition. Cortisol reactivity did not change during or after the expedition. Basal (suppressed) cortisol was 73.25 ± 45.23 mmol·L before, 61.66 ± 33.11 mmol·L 5 d postexpedition and 54.43 ± 28.60 mmol·L 16 d postexpedition (P = 0.7). Hair cortisol was elevated during the expedition. CONCLUSIONS: Maintenance of reproductive and hypothalamic-pituitary-adrenal axis function in women after an extreme physical endeavor, despite energy deficiency, suggests high female biological capacity for extreme endurance exercise.


Assuntos
Ambientes Extremos , Genitália Feminina/fisiologia , Sistema Hipotálamo-Hipofisário/fisiologia , Sistema Hipófise-Suprarrenal/fisiologia , Esqui/fisiologia , Adulto , Regiões Antárticas , Composição Corporal , Expedições , Feminino , Humanos
14.
Sci Total Environ ; 655: 842-854, 2019 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-30481711

RESUMO

This paper presents study on the microbiome of a unique extreme environment - saline and alkaline lime, a by-product of soda ash and table salt production in Janikowo, central Poland. High-throughput 16S rDNA amplicon sequencing was used to reveal the structure of bacterial and archaeal communities in the lime samples, taken from repository ponds differing in salinity (2.3-25.5% NaCl). Surprisingly abundant and diverse bacterial communities were discovered in this extreme environment. The most important geochemical drivers of the observed microbial diversity were salinity, calcium ions, nutrients, and water content. The bacterial and archaeal communities in saline, alkaline lime were similar to those found in natural haloalkaline environments. Although the archaeal contribution to the whole microbial community was lower than 4%, the four archaeal genera Natronomonas, Halorubrum, Halobellus, and Halapricum constituted the core microbiome of saline, alkaline lime - a set of OTUs (> 0.1% of total archaeal relative abundance) present in all samples under study. The high proportion of novel, unclassified archaeal and bacterial sequences (not identified at 97% similarity level) in the 16S rRNA gene libraries indicated that potentially new genera, especially within the class of Thermoplasmata inhabit this unique environment.


Assuntos
Biodiversidade , Compostos de Cálcio , Microbiota/genética , Óxidos , Tanques/microbiologia , Salinidade , Hidróxido de Sódio , Archaea/classificação , Archaea/genética , Archaea/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Ambientes Extremos , Polônia , Tanques/análise , RNA Ribossômico 16S/genética , Cloreto de Sódio/análise
15.
Sci Total Environ ; 650(Pt 1): 384-393, 2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30199683

RESUMO

The ability to establish biofilms is a key trait for microorganisms growing in extreme environments. The extracellular polymeric substances (EPS) present in biofilms provide not only surface attachment, but also protection against all kinds of environmental stressors, including desiccation, salinity, temperature or heavy metal pollution. The acquisition of suitable biofilm characteristics might thus be an important process mediating the adaptation of microorganisms to novel environmental conditions. In this work we have characterized the EPS of 20 phylogenetically diverse biofilms collected in situ from five contrasting extreme environments, including two geothermal areas (Copahue, Argentina; Seltun, Iceland), two cold areas (Pastoruri glacier, Peru; Byers Peninsula, Antarctica) and one extremely acidic river (Río Tinto, Spain). Biofilms were subjected to biochemical characterization, glycan profiling and immunoprofiling with an antibody microarray. Our results showed that environmental conditions strongly influence biofilm characteristics, with microorganisms from the same environment achieving similar EPS compositions regardless of the phylogeny of their main species. The concentration of some monosaccharides in the EPS could be related to environmental conditions such as temperature or heavy metal toxicity, suggesting that in some cases stress resistance can be mediated by specific sugars. Overall, our results highlight the existence of conserved EPS compositional patterns for each extreme environment, which could in turn be exploited to engineer ecological adaptations in genetically modified microorganisms.


Assuntos
Adaptação Fisiológica/fisiologia , Biofilmes , Matriz Extracelular/química , Ambientes Extremos , Regiões Antárticas , Argentina , Bactérias/química , Bactérias/classificação , Bactérias/genética , Análise por Conglomerados , Islândia , Monossacarídeos/análise , Peru , Polissacarídeos/análise , RNA Ribossômico 16S/genética , Espanha
16.
Aerosp Med Hum Perform ; 90(1): 18-25, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30579373

RESUMO

BACKGROUND: While participation of women in the military has increased, research on performance of female teams engaged in arduous physical activity in isolated, confined, and extreme (ICE) environments remains sparse.METHODS: A team of six British military women completed the Multidimensional Personality Questionnaire-Brief Form, Triarchic Psychopathy Measure, and Personal Values Questionnaire (PVQ) prior to embarking on an expedition that traversed the Antarctic continent. Questionnaires were completed weekly on the ice; repeat of the PVQ and individual semistructured debriefing interviews were carried out within 9 d post-expedition.RESULTS: Personality findings indicated a generally well-adjusted group with notable individual differences in personality and personal values. Positive affect and camaraderie among teammates was evident throughout, although pace vs. distance in the strategy of the daily trek was a continuing point of tension. Honesty in communication was viewed as key to team effectiveness. A significant post-expedition decline in the tradition value (Pre M = -0.55, SD = 0.99; Post M = -0.82, SD = 1.12) and an increase in the conformity value (Pre M = -0.26, SD = 0.46; Post M = 0.18, SD = 0.27) was found.DISCUSSION: Congruence in personal and team goals among group members engaged in highly challenging activities is crucial for optimal team performance. Presence of two highly dominant individuals has a negative effect on team dynamics. Application of study findings to space exploration is considered.Blackadder-Weinstein J, Leon GR, Norris RC, Venables NC, Smith M. Individual attributes, values, and goals of an all-military women Antarctic expedition. Aerosp Med Hum Perform. 2019; 90(1):18-25.


Assuntos
Expedições , Ambientes Extremos , Militares , Saúde da Mulher , Adulto , Regiões Antárticas , Feminino , Humanos , Entrevistas como Assunto , Objetivos Organizacionais , Inventário de Personalidade , Inquéritos e Questionários , Reino Unido
17.
Res Sports Med ; 26(sup1): 186-198, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30431353

RESUMO

The participation of children and adolescents in wilderness and extreme environment sports is increasing. Engaging in these activities is not without risk of injury, illness, or death. To date, there is limited research investigating pediatric and adolescent injuries in wilderness and extreme environments. With the intent of creating awareness within the sports medicine field, this review begins by examining the growth in popularity of outdoor sports in wilderness and extreme environments and the injury impact they are registering. The review then examines reported pediatric and adolescent injuries in multiple wilderness and extreme environments. Close examination is paid to youth adventuring on global expeditions and entering high altitude environments. Future studies acquiring denominator data to help establish injury rates while keeping pace with the rapidly diversifying outdoor and extreme wilderness sport trends are necessary.


Assuntos
Traumatismos em Atletas/epidemiologia , Ambientes Extremos , Esportes , Meio Selvagem , Adolescente , Traumatismos em Atletas/prevenção & controle , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Fatores de Risco
18.
mBio ; 9(6)2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30459191

RESUMO

The continental subsurface is suggested to contain a significant part of the earth's total biomass. However, due to the difficulty of sampling, the deep subsurface is still one of the least understood ecosystems. Therefore, microorganisms inhabiting this environment might profoundly influence the global nutrient and energy cycles. In this study, in situ fixed RNA transcripts from two deep continental groundwaters from the Äspö Hard Rock Laboratory (a Baltic Sea-influenced water with a residence time of <20 years, defined as "modern marine," and an "old saline" groundwater with a residence time of thousands of years) were subjected to metatranscriptome sequencing. Although small subunit (SSU) rRNA gene and mRNA transcripts aligned to all three domains of life, supporting activity within these community subsets, the data also suggested that the groundwaters were dominated by bacteria. Many of the SSU rRNA transcripts grouped within newly described candidate phyla or could not be mapped to known branches on the tree of life, suggesting that a large portion of the active biota in the deep biosphere remains unexplored. Despite the extremely oligotrophic conditions, mRNA transcripts revealed a diverse range of metabolic strategies that were carried out by multiple taxa in the modern marine water that is fed by organic carbon from the surface. In contrast, the carbon dioxide- and hydrogen-fed old saline water with a residence time of thousands of years predominantly showed the potential to carry out translation. This suggested these cells were active, but waiting until an energy source episodically becomes available.IMPORTANCE A newly designed sampling apparatus was used to fix RNA under in situ conditions in the deep continental biosphere and benchmarks a strategy for deep biosphere metatranscriptomic sequencing. This apparatus enabled the identification of active community members and the processes they carry out in this extremely oligotrophic environment. This work presents for the first time evidence of eukaryotic, archaeal, and bacterial activity in two deep subsurface crystalline rock groundwaters from the Äspö Hard Rock Laboratory with different depths and geochemical characteristics. The findings highlight differences between organic carbon-fed shallow communities and carbon dioxide- and hydrogen-fed old saline waters. In addition, the data reveal a large portion of uncharacterized microorganisms, as well as the important role of candidate phyla in the deep biosphere, but also the disparity in microbial diversity when using standard microbial 16S rRNA gene amplification versus the large unknown portion of the community identified with unbiased metatranscriptomes.


Assuntos
Ambientes Extremos , Água Subterrânea/microbiologia , Microbiota/genética , Transcriptoma , Microbiologia da Água , Archaea/genética , Bactérias/genética , Biodiversidade , Perfilação da Expressão Gênica , Genes de RNAr , Filogenia , RNA Mensageiro/genética , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Análise de Sequência de DNA , Dióxido de Silício
19.
Artigo em Inglês | MEDLINE | ID: mdl-30279399

RESUMO

Lucina pectinata is a clam that lives in sulfide-rich environments and houses intracellular sulfide-oxidizing endosymbionts. To identify new Lucina pectinata proteins, we produced libraries for genome and transcriptome sequencing and assembled them de novo. We searched for histone-like sequences using the Lucina pectinata histone H3 partial nucleotide sequence against our previously described genome assembly to obtain the complete coding region and identify H3 coding sequences from mollusk sequences in Genbank. Solen marginatus histone nucleotide sequences were used as query sequences using the genome and transcriptome assemblies to identify the Lucina pectinata H1, H2A, H2B and H4 genes and mRNAs and obtained the complete coding regions of the five histone genes by RT-PCR combined with automated Sanger DNA sequencing. The amino acid sequence conservation between the Lucina pectinata and Solen marginatus histones was: 77%, 93%, 83%, 96% and 97% for H1, H2A, H2B, H3 and H4, respectively. As expected, the H3 and H4 proteins were the most conserved and the H1 proteins were most similar to H1's from aquatic organisms like Crassostrea gigas, Aplysia californica, Mytilus trossulus and Biomphalaria glabrata. The Lucina pectinata draft genome and transcriptome assemblies, obtained by semiconductor sequencing, were adequate for identification of conserved proteins as evidenced by our results for the histone genes.


Assuntos
Bivalves/genética , Evolução Molecular , Histonas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Sequência Conservada , Éxons , Ambientes Extremos , Filogenia , Porto Rico , RNA Mensageiro/genética , Análise de Sequência de DNA , Áreas Alagadas
20.
Mol Ecol ; 27(23): 4775-4786, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30346079

RESUMO

Thalassohaline ecosystems are hypersaline environments originating from seawater in which sodium chloride is the most abundant salt and the pH is alkaline. Studies focusing on microbial diversity in thalassohaline lakes are still scarce compared with those on athalassohaline lakes such as soda lakes that have no marine origin. In this work, we investigated multiple facets of bacterial, archaeal and eukaryotic diversity in the thalassohaline Lake Dziani Dzaha using a metabarcoding approach. We showed that bacterial and archaeal diversity were mainly affected by contrasting physicochemical conditions retrieved at different depths. While photosynthetic microorganisms were dominant in surface layers, chemotrophic phyla (Firmicutes or Bacteroidetes) and archaeal methanogens dominated deeper layers. In contrast, eukaryotic diversity was constant regardless of depth and was affected by seasonality. A detailed focus on eukaryotic communities showed that this constant diversity profile was the consequence of the high predominance of Picocystis salinarum, while nondominant eukaryotic groups displayed seasonal diversity turnover. Altogether, our results provided an extensive description of the diversity of the three domains of life in an unexplored extreme environment and showed clear differences in the responses of prokaryotic and eukaryotic communities to environmental conditions.


Assuntos
Archaea/classificação , Bactérias/classificação , Biodiversidade , Lagos/microbiologia , Microbiologia da Água , Comores , Eucariotos/classificação , Ambientes Extremos , Fotossíntese , Salinidade , Estações do Ano , Análise Espaço-Temporal
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