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  • 1
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    Online Resource
    Functional equivalence and evolutionary convergence in complex communities of microbial sponge symbionts
    Proceedings of the National Academy of Sciences ; 2012
    In:  Proceedings of the National Academy of Sciences Vol. 109, No. 27 ( 2012-07-03)
    Details
    In: Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 109, No. 27 ( 2012-07-03)
    Abstract: Although much progress has been made with simple symbiont systems, our understanding of common or unique properties that underpin symbiosis and evolution in complex systems is limited ( 1 ). Extensive research during the last decade has provided a good understanding of the phylogenetic diversity of host-associated microorganisms but has shown that few archetypal symbionts exist for complex systems ( 1 ). Our finding on the functional convergence of complex microbial communities addresses fundamental issues in the field of symbiosis research by revealing how symbionts in disparate host species have found different “genomic solutions” to provide core symbiotic functions. Functional equivalence of microbial communities in the absence of phylogenetic similarity has been noted recently in host-associated systems of the green algae Ulva australis ( 4 ) and in the human gut ( 5 ). In these two systems, symbionts often are acquired horizontally (or environmentally), and the final composition of the community is thought to be determined largely by neutral or niche selection following a “priority theory” or “lottery hypothesis” ( 4 ). In contrast, sponges transfer many symbionts vertically via a larval stage, potentially leading to coevolution within a host species for possibly hundreds of millions of years. This coevolution is supported by the consistent patterns of microbial phylogeny we observed in replicates of the same sponge species and our observation that communities in different species have evolved to provide similar functions. The high abundance of mobile genetic elements we found in these symbiont communities further suggests that they play a key role in the evolution of functional convergence by facilitating the exchange of essential genes between community members. These core functions are provided in each sponge species not only by phylogenetically distinct community members but also by analogous enzymes, pathways, or genetic systems. Examples include the types of mobile genetic elements involved in horizontal gene transfer and the analogous nitrate reductase proteins involved in denitrification. These results show that function is independent of the underlying gene phylogeny and that the complex symbiont communities have undergone functional convergence during their evolution. Sponges (Porifera) are primitive multicellular organisms that form permanent, highly specific symbiotic relationships with microorganisms that are essential for the sponge’s function ( 3 ). Thus sponges are ideal models for exploring the function and evolution of complex symbiont communities. Here, we perform extensive metagenomic and bioinformatic analyses to define the phylogenetic and functional profiles of natural microbial communities in six different sponge species (each in triplicate) in comparison with those in seawater. Our analysis shows that microbial symbiont assemblages within a particular sponge species have highly consistent patterns of phylogeny and function. In contrast, the symbiont communities in different sponge species are phylogenetically distinct but still contain a core set of functional genes that are common to sponge symbionts but generally are rare or absent in planktonic communities ( Fig. P1 ). This analysis demonstrates functional equivalence of complex symbiont communities across divergent hosts. These core functions are not only consistent with our current understanding of the biological and ecological roles of sponge symbionts but also provide insights into previously unknown symbiotic functions. For example, sponge symbionts contain a large abundance and variety of eukaryotic-like proteins that likely mediate specific molecular interactions with the host. Moreover, specific aspects of nutrient utilization indicate metabolic interdependence between the symbiosis partners. Microorganisms and higher eukaryotes often form symbiotic relationships whose complexity can range from a relationship with one dominant symbiont to associations with hundreds of symbiont species ( 1 ). The mechanisms that shape the structure of complex symbiont communities are largely unknown. Here, we use the symbiosis between microbes and sponges as a model to unveil key principles governing the evolution of complex symbiont communities. We demonstrate that microbial communities from phylogenetically divergent and geographically disparate sponge hosts have converged to perform a set of core functions and that frequent genetic exchange within these communities may drive their evolution. Microbial symbionts occupying equivalent niches in different eukaryotic hosts may share functional aspects, and convergent genome evolution has been reported for simple symbiont systems in insects ( 2 ). We possess only a limited understanding of the prevalence of functional equivalence in complex symbiont communities and whether equivalent functions are conducted by evolutionarily convergent mechanisms.
    Type of Medium: Online Resource
    ISSN: 0027-8424 , 1091-6490
    URL: Article
    DOI: 10.1073/pnas.1203287109
    RVK:
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    Language: English
    Publisher: Proceedings of the National Academy of Sciences
    Publication Date: 2012
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    detail.hit.zdb_id: 1461794-8
    SSG: 11
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  • 2
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    Online Resource
    A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars
    American Association for the Advancement of Science (AAAS) ; 2014
    In:  Science Vol. 343, No. 6169 ( 2014-01-24)
    Details
    In: Science, American Association for the Advancement of Science (AAAS), Vol. 343, No. 6169 ( 2014-01-24)
    Abstract: The Curiosity rover discovered fine-grained sedimentary rocks, which are inferred to represent an ancient lake and preserve evidence of an environment that would have been suited to support a martian biosphere founded on chemolithoautotrophy. This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both iron and sulfur species. Carbon, hydrogen, oxygen, sulfur, nitrogen, and phosphorus were measured directly as key biogenic elements; by inference, phosphorus is assumed to have been available. The environment probably had a minimum duration of hundreds to tens of thousands of years. These results highlight the biological viability of fluvial-lacustrine environments in the post-Noachian history of Mars.
    Type of Medium: Online Resource
    ISSN: 0036-8075 , 1095-9203
    URL: Article
    DOI: 10.1126/science.1242777
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    RVK:
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    Language: English
    Publisher: American Association for the Advancement of Science (AAAS)
    Publication Date: 2014
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    detail.hit.zdb_id: 2066996-3
    detail.hit.zdb_id: 2060783-0
    SSG: 11
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  • 3
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    Online Resource
    Elemental Geochemistry of Sedimentary Rocks at Yellowknife Bay, Gale Crater, Mars
    American Association for the Advancement of Science (AAAS) ; 2014
    In:  Science Vol. 343, No. 6169 ( 2014-01-24)
    Details
    In: Science, American Association for the Advancement of Science (AAAS), Vol. 343, No. 6169 ( 2014-01-24)
    Abstract: Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous conditions. Analyses of diagenetic features (including concretions, raised ridges, and fractures) at high spatial resolution indicate that they are composed of iron- and halogen-rich components, magnesium-iron-chlorine–rich components, and hydrated calcium sulfates, respectively. Composition of a cross-cutting dike-like feature is consistent with sedimentary intrusion. The geochemistry of these sedimentary rocks provides further evidence for diverse depositional and diagenetic sedimentary environments during the early history of Mars.
    Type of Medium: Online Resource
    ISSN: 0036-8075 , 1095-9203
    URL: Article
    DOI: 10.1126/science.1244734
    RVK:
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    RVK:
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    Language: English
    Publisher: American Association for the Advancement of Science (AAAS)
    Publication Date: 2014
    detail.hit.zdb_id: 128410-1
    detail.hit.zdb_id: 2066996-3
    detail.hit.zdb_id: 2060783-0
    SSG: 11
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  • 4
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    Online Resource
    Brain injury in COVID-19 is associated with dysregulated innate and adaptive immune responses
    Oxford University Press (OUP) ; 2022
    In:  Brain Vol. 145, No. 11 ( 2022-11-21), p. 4097-4107
    Details
    In: Brain, Oxford University Press (OUP), Vol. 145, No. 11 ( 2022-11-21), p. 4097-4107
    Abstract: COVID-19 is associated with neurological complications including stroke, delirium and encephalitis. Furthermore, a post-viral syndrome dominated by neuropsychiatric symptoms is common, and is seemingly unrelated to COVID-19 severity. The true frequency and underlying mechanisms of neurological injury are unknown, but exaggerated host inflammatory responses appear to be a key driver of COVID-19 severity. We investigated the dynamics of, and relationship between, serum markers of brain injury [neurofilament light (NfL), glial fibrillary acidic protein (GFAP) and total tau] and markers of dysregulated host response (autoantibody production and cytokine profiles) in 175 patients admitted with COVID-19 and 45 patients with influenza. During hospitalization, sera from patients with COVID-19 demonstrated elevations of NfL and GFAP in a severity-dependent manner, with evidence of ongoing active brain injury at follow-up 4 months later. These biomarkers were associated with elevations of pro-inflammatory cytokines and the presence of autoantibodies to a large number of different antigens. Autoantibodies were commonly seen against lung surfactant proteins but also brain proteins such as myelin associated glycoprotein. Commensurate findings were seen in the influenza cohort. A distinct process characterized by elevation of serum total tau was seen in patients at follow-up, which appeared to be independent of initial disease severity and was not associated with dysregulated immune responses unlike NfL and GFAP. These results demonstrate that brain injury is a common consequence of both COVID-19 and influenza, and is therefore likely to be a feature of severe viral infection more broadly. The brain injury occurs in the context of dysregulation of both innate and adaptive immune responses, with no single pathogenic mechanism clearly responsible.
    Type of Medium: Online Resource
    ISSN: 0006-8950 , 1460-2156
    URL: Article
    DOI: 10.1093/brain/awac321
    RVK:
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    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2022
    detail.hit.zdb_id: 1474117-9
    SSG: 12
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  • 5
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    Curiosity at Gale Crater, Mars: Characterization and Analysis of the Rocknest Sand Shadow
    American Association for the Advancement of Science (AAAS) ; 2013
    In:  Science Vol. 341, No. 6153 ( 2013-09-27)
    Details
    In: Science, American Association for the Advancement of Science (AAAS), Vol. 341, No. 6153 ( 2013-09-27)
    Abstract: The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand 〈 150 micrometers in size contains ~55% crystalline material consistent with a basaltic heritage and ~45% x-ray amorphous material. The amorphous component of Rocknest is iron-rich and silicon-poor and is the host of the volatiles (water, oxygen, sulfur dioxide, carbon dioxide, and chlorine) detected by the Sample Analysis at Mars instrument and of the fine-grained nanophase oxide component first described from basaltic soils analyzed by MERs. The similarity between soils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basaltic materials or globally and regionally sourced basaltic components deposited locally at all three locations.
    Type of Medium: Online Resource
    ISSN: 0036-8075 , 1095-9203
    URL: Article
    DOI: 10.1126/science.1239505
    RVK:
    TA 1000
    RVK:
    WA 15000
    Language: English
    Publisher: American Association for the Advancement of Science (AAAS)
    Publication Date: 2013
    detail.hit.zdb_id: 128410-1
    detail.hit.zdb_id: 2066996-3
    detail.hit.zdb_id: 2060783-0
    SSG: 11
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  • 6
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    Martian Fluvial Conglomerates at Gale Crater
    American Association for the Advancement of Science (AAAS) ; 2013
    In:  Science Vol. 340, No. 6136 ( 2013-05-31), p. 1068-1072
    Details
    In: Science, American Association for the Advancement of Science (AAAS), Vol. 340, No. 6136 ( 2013-05-31), p. 1068-1072
    Abstract: Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcrop show a predominantly feldspathic composition, consistent with minimal aqueous alteration of sediments. Sediment was mobilized in ancient water flows that likely exceeded the threshold conditions (depth 0.03 to 0.9 meter, average velocity 0.20 to 0.75 meter per second) required to transport the pebbles. Climate conditions at the time sediment was transported must have differed substantially from the cold, hyper-arid modern environment to permit aqueous flows across several kilometers.
    Type of Medium: Online Resource
    ISSN: 0036-8075 , 1095-9203
    URL: Article
    DOI: 10.1126/science.1237317
    RVK:
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    RVK:
    WA 15000
    Language: English
    Publisher: American Association for the Advancement of Science (AAAS)
    Publication Date: 2013
    detail.hit.zdb_id: 128410-1
    detail.hit.zdb_id: 2066996-3
    detail.hit.zdb_id: 2060783-0
    SSG: 11
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  • 7
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    Volatile and Organic Compositions of Sedimentary Rocks in Yellowknife Bay, Gale Crater, Mars
    American Association for the Advancement of Science (AAAS) ; 2014
    In:  Science Vol. 343, No. 6169 ( 2014-01-24)
    Details
    In: Science, American Association for the Advancement of Science (AAAS), Vol. 343, No. 6169 ( 2014-01-24)
    Abstract: H 2 O, CO 2 , SO 2 , O 2 , H 2 , H 2 S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H 2 O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO 2 . Concurrent evolution of O 2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.
    Type of Medium: Online Resource
    ISSN: 0036-8075 , 1095-9203
    URL: Article
    DOI: 10.1126/science.1245267
    RVK:
    TA 1000
    RVK:
    WA 15000
    Language: English
    Publisher: American Association for the Advancement of Science (AAAS)
    Publication Date: 2014
    detail.hit.zdb_id: 128410-1
    detail.hit.zdb_id: 2066996-3
    detail.hit.zdb_id: 2060783-0
    SSG: 11
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  • 8
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    Soil Diversity and Hydration as Observed by ChemCam at Gale Crater, Mars
    American Association for the Advancement of Science (AAAS) ; 2013
    In:  Science Vol. 341, No. 6153 ( 2013-09-27)
    Details
    In: Science, American Association for the Advancement of Science (AAAS), Vol. 341, No. 6153 ( 2013-09-27)
    Abstract: The ChemCam instrument, which provides insight into martian soil chemistry at the submillimeter scale, identified two principal soil types along the Curiosity rover traverse: a fine-grained mafic type and a locally derived, coarse-grained felsic type. The mafic soil component is representative of widespread martian soils and is similar in composition to the martian dust. It possesses a ubiquitous hydrogen signature in ChemCam spectra, corresponding to the hydration of the amorphous phases found in the soil by the CheMin instrument. This hydration likely accounts for an important fraction of the global hydration of the surface seen by previous orbital measurements. ChemCam analyses did not reveal any significant exchange of water vapor between the regolith and the atmosphere. These observations provide constraints on the nature of the amorphous phases and their hydration.
    Type of Medium: Online Resource
    ISSN: 0036-8075 , 1095-9203
    URL: Article
    DOI: 10.1126/science.1238670
    RVK:
    TA 1000
    RVK:
    WA 15000
    Language: English
    Publisher: American Association for the Advancement of Science (AAAS)
    Publication Date: 2013
    detail.hit.zdb_id: 128410-1
    detail.hit.zdb_id: 2066996-3
    detail.hit.zdb_id: 2060783-0
    SSG: 11
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  • 9
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    In Situ Radiometric and Exposure Age Dating of the Martian Surface
    American Association for the Advancement of Science (AAAS) ; 2014
    In:  Science Vol. 343, No. 6169 ( 2014-01-24)
    Details
    In: Science, American Association for the Advancement of Science (AAAS), Vol. 343, No. 6169 ( 2014-01-24)
    Abstract: We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age of 4.21 ± 0.35 billion years represents a mixture of detrital and authigenic components and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray–produced 3 He, 21 Ne, and 36 Ar yield concordant surface exposure ages of 78 ± 30 million years. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation.
    Type of Medium: Online Resource
    ISSN: 0036-8075 , 1095-9203
    URL: Article
    DOI: 10.1126/science.1247166
    RVK:
    TA 1000
    RVK:
    WA 15000
    Language: English
    Publisher: American Association for the Advancement of Science (AAAS)
    Publication Date: 2014
    detail.hit.zdb_id: 128410-1
    detail.hit.zdb_id: 2066996-3
    detail.hit.zdb_id: 2060783-0
    SSG: 11
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  • 10
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    Volatile, Isotope, and Organic Analysis of Martian Fines with the Mars Curiosity Rover
    American Association for the Advancement of Science (AAAS) ; 2013
    In:  Science Vol. 341, No. 6153 ( 2013-09-27)
    Details
    In: Science, American Association for the Advancement of Science (AAAS), Vol. 341, No. 6153 ( 2013-09-27)
    Abstract: Samples from the Rocknest aeolian deposit were heated to ~835°C under helium flow and evolved gases analyzed by Curiosity’s Sample Analysis at Mars instrument suite. H 2 O, SO 2 , CO 2 , and O 2 were the major gases released. Water abundance (1.5 to 3 weight percent) and release temperature suggest that H 2 O is bound within an amorphous component of the sample. Decomposition of fine-grained Fe or Mg carbonate is the likely source of much of the evolved CO 2 . Evolved O 2 is coincident with the release of Cl, suggesting that oxygen is produced from thermal decomposition of an oxychloride compound. Elevated δD values are consistent with recent atmospheric exchange. Carbon isotopes indicate multiple carbon sources in the fines. Several simple organic compounds were detected, but they are not definitively martian in origin.
    Type of Medium: Online Resource
    ISSN: 0036-8075 , 1095-9203
    URL: Article
    DOI: 10.1126/science.1238937
    RVK:
    TA 1000
    RVK:
    WA 15000
    Language: English
    Publisher: American Association for the Advancement of Science (AAAS)
    Publication Date: 2013
    detail.hit.zdb_id: 128410-1
    detail.hit.zdb_id: 2066996-3
    detail.hit.zdb_id: 2060783-0
    SSG: 11
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