25 research outputs found
A consensus protocol for the recovery of mercury methylation genes from metagenomes
Mercury (Hg) methylation genes (hgcAB) mediate the formation of the toxic methylmercury and have been identified from diverse environments, including freshwater and marine ecosystems, Arctic permafrost, forest and paddy soils, coal-ash amended sediments, chlor-alkali plants discharges and geothermal springs. Here we present the first attempt at a standardized protocol for the detection, identification and quantification of hgc genes from metagenomes. Our Hg-cycling microorganisms in aquatic and terrestrial ecosystems (Hg-MATE) database, a catalogue of hgc genes, provides the most accurate information to date on the taxonomic identity and functional/metabolic attributes of microorganisms responsible for Hg methylation in the environment. Furthermore, we introduce "marky-coco", a ready-to-use bioinformatic pipeline based on de novo single-metagenome assembly, for easy and accurate characterization of hgc genes from environmental samples. We compared the recovery of hgc genes from environmental metagenomes using the marky-coco pipeline with an approach based on coassembly of multiple metagenomes. Our data show similar efficiency in both approaches for most environments except those with high diversity (i.e., paddy soils) for which a coassembly approach was preferred. Finally, we discuss the definition of true hgc genes and methods to normalize hgc gene counts from metagenomes
Fast virtual histology using X-ray in-line phase tomography: application to the 3D anatomy of maize developing seeds
DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France
We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR = 2.05, 95%CI = 1.39â3.02, p < 0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR = 0.42, 95%CI = 0.18â0.99, p = 0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon
Altimetry for the future: Building on 25 years of progress
In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ââGreenâ Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instrumentsâ development and satellite missionsâ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion
Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study
Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008â11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003â13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 Ă 10â10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 Ă 10â8 DHFR p=8·37 Ă 10â7 MTRNR2L2 p=2·15 Ă 10â9) and to a lesser extent in REGISTRY (MSH3 p=9·36 Ă 10â4 DHFR p=8·45 Ă 10â4 MTRNR2L2 p=1·20 Ă 10â3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 Ă 10â8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16â0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06â0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation
Altimetry for the future: building on 25 years of progress
In 2018 we celebrated 25âŻyears of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology.
The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the âGreenâ Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instrumentsâ development and satellite missionsâ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion
Architecting an electro-chemical separation platform : from the business case to the first commercial product
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2018.Page 49 blank. Cataloged from PDF version of thesis.Includes bibliographical references (page [48] ).Electrosorption technology is currently gaining significant tractions as a viable separation technique due to its low energy consumption, its intrinsic reversibility and its reagent free nature. As most companies thrive towards a more sustainable approach, electro-chemical based process become more and more attractive. The group of Prof. Hatton of the Chemical Engineering department at MIT has improved further the state of the art of electro-chemical technologies by using functionalized metallocene-based pseudo-capacitors. Their research demonstrates that the technology they developed can selectively remove specific compounds such as carboxylates, sulfonates, phosphonates and potentially heavy metals. The aim of this thesis is to help the technology find a first market fit and build the foundation for a successful scale-up by defining its positioning within the treatment train of the production of the identified markets. Two main markets were identified. The selection of each market was based on the price of the end-product, the size and growth of the market and the numbers of applications and potential customers. The lactic acid and the lithium carbonate markets were selected. Both are growing markets sustaining a real demand over the years to come with very promising and diversified applications. We collected real-life feedbacks and identified the pain points in each respective industry by conducting interviews with professionals in the field. Several unmet needs and possible alignments with the benefits brought by the selective electrosorption technology were identified thanks to this endeavor. New potential production lines were proposed. The new innovative treatment line allows for the simplification of the process train, a reduction of the chemical and reagent needed and a likely decrease in solid waste and wastewater volume.by Adrien A. Moreau.S.M. in Engineering and Managemen
Xylobolus subpileatus , a specialized basidiomycete functionally linked to old canopy gaps
International audienceDocumenting succession in forest canopy gaps provides insights into the ecological processes governing the temporal dynamics of species within communities. We analyzed the fruiting patterns of a rare but widely distributed saproxylic macro- mycete, Xylobolus subpileatus, during the ageing of natural canopy gaps in oak forests. In one of the last remaining Quercus ilex L. old-growth forests (on the island of Corsica, western Mediterranean basin), we systematically recorded and conducted molecular analyses of X. subpileatus basidiomes in 80 dated natural canopy gaps representing a 45-year long sequence of residence time of tree logs on the forest floor. Xylobolus subpileatus fruited exclusively on Q. ilex logs. The probability of fruiting of X. subpileatus significantly increases during the process of wood decomposition to reach its maximum in the oldest gaps, approximately 40 years after treefall. In contrast, the abundance and the richness of saprobic and ectomycorrhizal fruitbodies decrease as canopy gaps age. Our results emphasize the high ecological specialization of X. subpileatus. They also highlight the imperative need to conserve the last patches of old-growth Mediterranean forests to secure the persistence of this endangered and functionally unique macromycete whose presence is highly dependent on old wood in advanced stages of decomposition.LâeÌtude des successions eÌcologiques ayant lieu dans les ouvertures de canopeÌe forestieÌre offre lâopportuniteÌ de mieux comprendre les processus eÌcologiques gouvernant la dynamique temporelle des espeÌces a` lâinteÌrieur des communauteÌs. Nous avons analyseÌ la distribution des fructifications dâune espeÌce, rare mais largement distribueÌe, de macromyceÌte saproxilique, Xylobolus subpileatus, au cours du vieillissement de troueÌes naturelles dans les foreÌts de cheÌnes. Dans lâune des dernieÌres foreÌts anciennes de cheÌne vert (Quercus ilex L.) (iÌle de Corse, ouest du bassin meÌditerraneÌen), nous avons eÌchantillonneÌ systeÌmatique- ment et analyseÌ moleÌculairement les basidiomes de X. subpileatus dans 80 troueÌes dateÌes qui repreÌsentent une chronoseÌquence de 45 ans de temps de reÌsidence au sol des troncs dâarbres. Xylobolus subpileatus ne fructifie que sur les troncs de cheÌne vert. Sa probabiliteÌ de fructification est positivement correÌleÌe a` lâaÌge des troueÌes et atteint un maximum dans les plus vieilles troueÌes (environ 40 ans apreÌs la chute de lâarbre). A contrario, lâabondance et la richesse des fructifications de champignons deÌcompo- seurs et ectomycorhiziens deÌcroissent avec le vieillissement de la troueÌe. Nos reÌsultats soulignent la speÌcialisation eÌcologique pousseÌe de X. subpileatus et mettent en avant le besoin impeÌratif de preÌserver les dernieÌres parcelles de foreÌts anciennes meÌditerraneÌennes afin de proteÌger cette espeÌce de macromyceÌte fonctionnellement originale dont la preÌsence deÌpend forte- ment de la compleÌtion du processus naturel de deÌcomposition