32 research outputs found

    Genomic resolution of linkages in carbon, nitrogen, and sulfur cycling among widespread estuary sediment bacteria

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    Abstract Background Estuaries are among the most productive habitats on the planet. Bacteria in estuary sediments control the turnover of organic carbon and the cycling of nitrogen and sulfur. These communities are complex and primarily made up of uncultured lineages, thus little is known about how ecological and metabolic processes are partitioned in sediments. Results De novo assembly and binning resulted in the reconstruction of 82 bacterial genomes from different redox regimes of estuary sediments. These genomes belong to 23 bacterial groups, including uncultured candidate phyla (for example, KSB1, TA06, and KD3-62) and three newly described phyla (White Oak River (WOR)-1, WOR-2, and WOR-3). The uncultured phyla are generally most abundant in the sulfate-methane transition (SMTZ) and methane-rich zones, and genomic data predict that they mediate essential biogeochemical processes of the estuarine environment, including organic carbon degradation and fermentation. Among the most abundant organisms in the sulfate-rich layer are novel Gammaproteobacteria that have genes for the oxidation of sulfur and the reduction of nitrate and nitrite. Interestingly, the terminal steps of denitrification (NO3 to N2O and then N2O to N2) are present in distinct bacterial populations. Conclusions This dataset extends our knowledge of the metabolic potential of several uncultured phyla. Within the sediments, there is redundancy in the genomic potential in different lineages, often distinct phyla, for essential biogeochemical processes. We were able to chart the flow of carbon and nutrients through the multiple geochemical layers of bacterial processing and reveal potential ecological interactions within the communities.http://deepblue.lib.umich.edu/bitstream/2027.42/111044/1/40168_2015_Article_77.pd

    Cutting improves the productivity of lucerne-rich stands used in the revegetation of degraded arable land in a semi-arid environment

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    Understanding the relationships between vegetative and environmental variables is important for revegetation and ecosystem management on the Loess Plateau, China. Lucerne (Medicago sativa L.) has been widely used in the region to improve revegetation, soil and water conservation, and to enhance livestock production. However, there is little information on how environmental factors influence long-term succession in lucerne-rich vegetation. Our objective was to identify the main environmental variables controlling the succession process in lucerne-rich vegetation such that native species are not suppressed after sowing on the Loess Plateau. Vegetation and soil surveys were performed in 31 lucerne fields (three lucerne fields without any management from 2003-2013 and 28 fields containing 11-year-old lucerne with one cutting each year). Time after planting was the most important factor affecting plant species succession. Cutting significantly affected revegetation characteristics, such as aboveground biomass, plant density and diversity. Soil moisture content, soil organic carbon, soil available phosphorus and slope aspect were key environmental factors affecting plant species composition and aboveground biomass, density and diversity. Long-term cutting can cause self-thinning in lucerne, maintain the stability of lucerne production and slow its degradation. For effective management of lucerne fields, phosphate fertilizer should be applied and cutting performed

    Comfort of two shoulder actuation mechanisms for arm therapy exoskeletons: a comparative study in healthy subjects

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    Robotic exoskeletons can be used to study and treat patients with neurological impairments. They can guide and support the human limb over a large range of motion, which requires that the movement trajectory of the exoskeleton coincide with the one of the human arm. This is straightforward to achieve for rather simple joints like the elbow, but very challenging for complex joints like the human shoulder, which is comprised by several bones and can exhibit a movement with multiple rotational and translational degrees of freedom. Thus, several research groups have developed different shoulder actuation mechanism. However, there are no experimental studies that directly compare the comfort of two different shoulder actuation mechanisms. In this study, the comfort and the naturalness of the new shoulder actuation mechanism of the ARMin III exoskeleton are compared to a ball-and-socket-type shoulder actuation. The study was conducted in 20 healthy subjects using questionnaires and 3D-motion records to assess comfort and naturalness. The results indicate that the new shoulder actuation is slightly better than a ball-and-socket-type actuation. However, the differences are small, and under the tested conditions, the comfort and the naturalness of the two tested shoulder actuations do not differ a lot

    Mapping species richness of plant families in European vegetation

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    none40siAims: Biodiversity is traditionally studied mostly at the species level, but biogeographical and macroecological studies at higher taxonomic levels can provide valuable insights into the evolutionary processes at large spatial scales. Our aim was to assess the representation of vascular plant families within different vegetation formations across Europe. Location: Europe. Methods: We used a data set of 816,005 vegetation plots from the European Vegetation Archive (EVA). For each plot, we calculated the relative species richness of each plant family as the number of species belonging to that family divided by the total number of species. We mapped the relative species richness, averaged across all plots in 50 km × 50 km grid cells, for each family and broad habitat groups: forests, grasslands, scrub and wetlands. We also calculated the absolute species richness and the Shannon diversity index for each family. Results: We produced 522 maps of mean relative species richness for a total of 152 vascular plant families occurring in forests, grasslands, scrub and wetlands. We found distinct spatial patterns for many combinations of families and habitat groups. The resulting series of 522 maps is freely available, both as images and GIS layers. Conclusions: The distinct spatial patterns revealed in the maps suggest that the relative species richness of plant families at the community level reflects the evolutionary history of individual families. We believe that the maps and associated data can inspire further biogeographical and macroecological studies and strengthen the ongoing integration of phylogenetic, functional and taxonomic diversity concepts.noneVecera M.; Axmanova I.; Padulles Cubino J.; Lososova Z.; Divisek J.; Knollova I.; Acic S.; Biurrun I.; Boch S.; Bonari G.; Campos J.A.; Carni A.; Carranza M.L.; Casella L.; Chiarucci A.; Custerevska R.; Delbosc P.; Dengler J.; Fernandez-Gonzalez F.; Gegout J.-C.; Jandt U.; Jansen F.; Jaskova A.; Jimenez-Alfaro B.; Kuzemko A.; Lebedeva M.; Lenoir J.; Lysenko T.; Moeslund J.E.; Pielech R.; Ruprecht E.; Sibik J.; Silc U.; Skvorc Z.; Swacha G.; Tatarenko I.; Vassilev K.; Wohlgemuth T.; Yamalov S.; Chytry M.Vecera M.; Axmanova I.; Padulles Cubino J.; Lososova Z.; Divisek J.; Knollova I.; Acic S.; Biurrun I.; Boch S.; Bonari G.; Campos J.A.; Carni A.; Carranza M.L.; Casella L.; Chiarucci A.; Custerevska R.; Delbosc P.; Dengler J.; Fernandez-Gonzalez F.; Gegout J.-C.; Jandt U.; Jansen F.; Jaskova A.; Jimenez-Alfaro B.; Kuzemko A.; Lebedeva M.; Lenoir J.; Lysenko T.; Moeslund J.E.; Pielech R.; Ruprecht E.; Sibik J.; Silc U.; Skvorc Z.; Swacha G.; Tatarenko I.; Vassilev K.; Wohlgemuth T.; Yamalov S.; Chytry M
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