572 research outputs found

    The Naked Mole-Rat: An Unusual Organism with an Unexpected Latent Potential for Increased Intelligence?

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    Naked mole-rats are eusocial, hairless mammals that are uniquely adapted to their harsh, low-oxygen subsurface habitat. Although their encephalization quotient, a controversial marker of intelligence, is low, they exhibit many features considered tell-tale signs of highly intelligent species on our planet including longevity, plasticity, social cohesion and interaction, rudimentary language, sustainable farming abilities, and maintaining sanitary conditions in their self-built complex housing structures. It is difficult to envision how naked mole-rats would reach even higher levels of intelligence in their natural sensory-challenged habitat, but such an evolutionary path cannot be excluded if they would expand their range onto the earth’s surface.EC/FP7/339231/EU/Habitability of Martian Environments: Exploring the Physiological and Environmental Limits of Life/HOM

    Der Einsatz Synthetischer Aufgabenumgebungen zur Untersuchung kollaborativer Prozesse in Leitzentralen am Beispiel der "generic Control Center Task Environment" (ConCenT)

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    Leitzentralen sind sozio-technische Systeme, deren EffektivitĂ€t in großem Maße von den FĂ€higkeiten ihrer Mitarbeiter zum koordinierten Handeln abhĂ€ngt. Es wurde eine synthetische Aufgabenumgebung ConCenT entwickelt, welche darauf ausgelegt ist, Koordinationsmuster im kognitiven System „Team“ im Kontext einer sich entfaltenden Aufgabenbearbeitung anhand von ĂŒbergeordneten Blickbewegungsmustern erkennbar und messbar zu machen. Der Schwerpunkte des Beitrags liegt in der Vorstellung des Entwicklungsprozesses und der Versuchsumgebung ConCenT (generic Control Center Task Environment) und endet mit einem Ausblick auf geplante experimentelle Studien

    Accurate and precise quantification of Cu,Zn-SOD in human red blood cells using species-specific double and triple IDMS

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    Acknowledgements This research was undertaken within the EMRP project HLT05. The EMRP was jointly funded by the EMRP participating countries within EURAMET and the European Union. We gratefully acknowledge support by the Braunschweig International Graduate School of Metrology B-IGSM.Peer reviewedPostprin

    Functional Traits Co-Occurring with Mobile Genetic Elements in the Microbiome of the Atacama Desert

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    Mobile genetic elements (MGEs) play an essential role in bacterial adaptation and evolution. These elements are enriched within bacterial communities from extreme environments. However, very little is known if specific genes co-occur with MGEs in extreme environments and, if so, what their function is. We used shotgun-sequencing to analyse the metagenomes of 12 soil samples and characterized the composition of MGEs and the genes co-occurring with them. The samples ranged from less arid coastal sites to the inland hyperarid core of the Atacama Desert, as well as from sediments below boulders, protected from UV-irradiation. MGEs were enriched at the hyperarid sites compared with sediments from below boulders and less arid sites. MGEs were mostly co-occurring with genes belonging to the Cluster Orthologous Group (COG) categories “replication, recombination and repair,” “transcription” and “signal transduction mechanisms.” In general, genes coding for transcriptional regulators and histidine kinases were the most abundant genes proximal to MGEs. Genes involved in energy production were significantly enriched close to MGEs at the hyperarid sites. For example, dehydrogenases, reductases, hydrolases and chlorite dismutase and other enzymes linked to nitrogen metabolism such as nitrite- and nitro-reductase. Stress response genes, including genes involved in antimicrobial and heavy metal resistance genes, were rarely found near MGEs. The present study suggests that MGEs could play an essential role in the adaptation of the soil microbiome in hyperarid desert soils by the modulation of housekeeping genes such as those involved in energy production.EC/FP7/339231/EU/Habitability of Martian Environments: Exploring the Physiological and Environmental Limits of Life/HOM

    Model-based tool design for the manufacturing of hypocycloidal internal profiles by polygon turning

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    Polygon turning is a machining process for manufacturing internal and external hypocycloidal profiles, which are becoming increasingly important for shaft-hub-connections. The highly productive process can be integrated on lathe machines. Existing analytical models are not sufficient to address the main challenge when designing tools for manufacturing internal profiles. In this work a dexel-based numerical approach is presented to calculate the limits of tool design. The findings are made usable for tool design with an analogy model and are finally validated experimentally using an alternative drive system for bone screws as an example

    Evolution of default genetic control mechanisms

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    We present a model of the evolution of control systems in a genome under environmental constraints. The model conceptually follows the Jacob and Monod model of gene control. Genes contain control elements which respond to the internal state of the cell as well as the environment to control expression of a coding region. Control and coding regions evolve to maximize a fitness function between expressed coding sequences and the environment. 118 runs of the model run to an average of 1.4 x 10^6 `generations' each with a range of starting parameters probed the conditions under which genomes evolved a `default style' of control. Unexpectedly, the control logic that evolved was not significantly correlated to the complexity of the environment. Genetic logic was strongly correlated with genome complexity and with the fraction of genes active in the cell at any one time. More complex genomes correlated with the evolution of genetic controls in which genes were active (`default on'), and a low fraction of genes being expressed correlated with a genetic logic in which genes were biased to being inactive unless positively activated (`default off' logic). We discuss how this might relate to the evolution of the complex eukaryotic genome, which operates in a `default off' mode.Comment: 25 pages, 8 figures, 1 tabl

    Variations in climate habitability parameters and their effect on Earth's biosphere during the Phanerozoic Eon

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    Essential insights on the characterization and quality of a detectable biosphere are gained by analyzing the effects of its environmental parameters. We compiled environmental and biological properties of the Phanerozoic Eon from various published data sets and conducted a correlation analysis to assess variations in parameters relevant to the habitability of Earth's biosphere. We showed that environmental parameters such as oxygen, global average surface temperatures, runoff rates and carbon dioxide are interrelated and play a key role in the changes of biomass and biodiversity. We showed that there were several periods with a highly thriving biosphere, with one even surpassing present day biodiversity and biomass. Those periods were characterized by increased oxygen levels and global runoff rates, as well as moderate global average surface temperatures, as long as no large or rapid positive and/or negative temperature excursions occurred. High oxygen contents are diagnostic of biomass production by continental plant life. We find that exceptionally high oxygen levels can at least in one instance compensate for decreased relative humidities, providing an even more habitable environment compared to today. Beyond Earth, these results will help us to understand how environmental parameters affect biospheres on extrasolar planets and guide us in our search for extraterrestrial life

    A New Record for Microbial Perchlorate Tolerance: Fungal Growth in NaClO4 Brines and its Implications for Putative Life on Mars

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    The habitability of Mars is strongly dependent on the availability of liquid water, which is essential for life as we know it. One of the few places where liquid water might be found on Mars is in liquid perchlorate brines that could form via deliquescence. As these concentrated perchlorate salt solutions do not occur on Earth as natural environments, it is necessary to investigate in lab experiments the potential of these brines to serve as a microbial habitat. Here, we report on the sodium perchlorate (NaClO4) tolerances for the halotolerant yeast Debaryomyces hansenii and the filamentous fungus Purpureocillium lilacinum. Microbial growth was determined visually, microscopically and via counting colony forming units (CFU). With the observed growth of D. hansenii in liquid growth medium containing 2.4 M NaClO4, we found by far the highest microbial perchlorate tolerance reported to date, more than twice as high as the record reported prior (for the bacterium Planococcus halocryophilus). It is plausible to assume that putative Martian microbes could adapt to even higher perchlorate concentrations due to their long exposure to these environments occurring naturally on Mars, which also increases the likelihood of microbial life thriving in the Martian brines.EC/H2020/339231/EU/Habitability of Martian Environments: Exploring the Physiological and Environmental Limits of Life/HOM
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