The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Virginia Highlands - One of the best experts on this subject based on the ideXlab platform.
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winter Rooting activity of the european wild boar in the great smoky mountains national park thomas d howe and susan power bratton
2016Co-Authors: Virginia HighlandsAbstract:Since the European wild boar (Sus scrofa L.) was accidently introduced into the Great Smoky Mountains National Park, its population has expanded and presently occupies about three-quarters of the Park. The hogs' Rooting activities have severely damaged the herbaceous understories of several types of forest. In the winter, Rooting activity is concentrated in the low elevation successional Tulip Forest, and Tulip-Silverbell Forest. At high elevations the hogs root around the shrubs on the Grassy Balds. In Northern Hardwoods and Gray Beech Forests, winter Rooting is minor in comparison with the Rooting activity in late spring and early summer. Most of the food plants involved in the Rooting activity had starchy tubers, bulbs, or rhizomes. These plants included Lilium superbum, Dioscorea batatas, Medeola virginiana, Stachys clingmanii, and Aristolochia spp.
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winter Rooting activity of the european wild boar in the great smoky mountains national park thomas d howe and susan power bratton
2016Co-Authors: Virginia HighlandsAbstract:Since the European wild boar (Sus scrofa L.) was accidently introduced into the Great Smoky Mountains National Park, its population has expanded and presently occupies about three-quarters of the Park. The hogs' Rooting activities have severely damaged the herbaceous understories of several types of forest. In the winter, Rooting activity is concentrated in the low elevation successional Tulip Forest, and Tulip-Silverbell Forest. At high elevations the hogs root around the shrubs on the Grassy Balds. In Northern Hardwoods and Gray Beech Forests, winter Rooting is minor in comparison with the Rooting activity in late spring and early summer. Most of the food plants involved in the Rooting activity had starchy tubers, bulbs, or rhizomes. These plants included Lilium superbum, Dioscorea batatas, Medeola virginiana, Stachys clingmanii, and Aristolochia spp.
Rasmus Nielsen - One of the best experts on this subject based on the ideXlab platform.
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assessing uncertainty in the Rooting of the sars cov 2 phylogeny
Molecular Biology and Evolution, 2021Co-Authors: Lenore Pipes, Hongru Wang, John P Huelsenbeck, Rasmus NielsenAbstract:The Rooting of the SARS-CoV-2 phylogeny is important for understanding the origin and early spread of the virus. Previously published phylogenies have used different Rootings that do not always provide consistent results. We investigate several different strategies for Rooting the SARS-CoV-2 tree and provide measures of statistical uncertainty for all methods. We show that methods based on the molecular clock tend to place the root in the B clade, while methods based on outgroup Rooting tend to place the root in the A clade. The results from the two approaches are statistically incompatible, possibly as a consequence of deviations from a molecular clock or excess back-mutations. We also show that none of the methods provide strong statistical support for the placement of the root in any particular edge of the tree. These results suggest that phylogenetic evidence alone is unlikely to identify the origin of the SARS-CoV-2 virus and we caution against strong inferences regarding the early spread of the virus based solely on such evidence. Keyword SARS-CoV-2 phylogeny, outgroup Rooting, molecular clock Rooting.
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assessing uncertainty in the Rooting of the sars cov 2 phylogeny
bioRxiv, 2020Co-Authors: Lenore Pipes, Hongru Wang, John P Huelsenbeck, Rasmus NielsenAbstract:The Rooting of the SARS-CoV-2 phylogeny is important for understanding the origin and early spread of the virus. Previously published phylogenies have used different Rootings that do not always provide consistent results. We use several different strategies for Rooting the SARS-CoV-2 tree and provide measures of statistical uncertainty for all methods. We show that methods based on the molecular clock tend to place the root in the B clade, while methods based on outgroup Rooting tend to place the root in the A clade. The results from the two approaches are statistically incompatible, possibly as a consequence of deviations from a molecular clock or excess back-mutations. We also show that none of the methods provide strong statistical support for the placement of the root in any particular edge of the tree. Our results suggest that inferences on the origin and early spread of SARS-CoV-2 based on rooted trees should be interpreted with caution.
Annelie Ahlman - One of the best experts on this subject based on the ideXlab platform.
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origin timing and gene expression profile of adventitious Rooting in arabidopsis hypocotyls and stems
American Journal of Botany, 2014Co-Authors: Margareta Welander, Thomas Geier, Anders Smolka, Annelie AhlmanAbstract: Premise of the study: Adventitious root (AR) formation is indispensable for vegetative propagation, but diffi cult to achieve in many crops. Understanding its molecular mechanisms is thus important for such species. Here we aimed at developing a Rooting protocol for direct AR formation in stems, locating cellular AR origins in stems and exploring molecular differences underlying adventitious Rooting in hypocotyls and stems. Methods: In-vitro-grown hypocotyls or stems of wild-type and transgenic ecotype Columbia (Col-0) of Arabidopsis thaliana were rooted on Rooting media. Anatomy of AR formation, qRT-PCR of some Rooting-related genes and in situ GUS expression were carried out during Rooting from hypocotyls and stems. Key results: We developed a Rooting protocol for AR formation in stems and traced back root origins in stems by anatomical and in situ expression studies. Unlike Rooting in hypocotyls, Rooting in stems was slower, and AR origins were mainly from lateral parenchyma of vascular bundles and neighboring starch sheath cells as well as, to a lesser extent, from phloem cap and xylem parenchyma. Transcript levels of GH3-3 , LBD16 , LBD29 , and LRP1 in hypocotyls and stems were similar, but transcript accumulation was delayed in stems. In situ expression signals of DR5::GUS , LBD16::GUS , LBD29::GUS , and rolB::GUS reporters in stems mainly occurred at the root initiation sites, suggesting their involvement in AR formation. Conclusions: We have developed an effi cient Rooting protocol using half-strength Lepoivre medium for studying AR formation in stems, traced back the cellular AR origins in stems, and correlated expression of Rooting-related genes with root initiation sites.
Ricardo M Holdo - One of the best experts on this subject based on the ideXlab platform.
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Rooting depth varies differentially in trees and grasses as a function of mean annual rainfall in an african savanna
Oecologia, 2018Co-Authors: Ricardo M Holdo, Jesse B Nippert, Michelle C MackAbstract:A significant fraction of the terrestrial biosphere comprises biomes containing tree–grass mixtures. Forecasting vegetation dynamics in these environments requires a thorough understanding of how trees and grasses use and compete for key belowground resources. There is disagreement about the extent to which tree–grass vertical root separation occurs in these ecosystems, how this overlap varies across large-scale environmental gradients, and what these Rooting differences imply for water resource availability and tree–grass competition and coexistence. To assess the extent of tree–grass Rooting overlap and how tree and grass Rooting patterns vary across resource gradients, we examined landscape-level patterns of tree and grass functional Rooting depth along a mean annual precipitation (MAP) gradient extending from ~ 450 to ~ 750 mm year−1 in Kruger National Park, South Africa. We used stable isotopes from soil and stem water to make inferences about relative differences in Rooting depth between these two functional groups. We found clear differences in Rooting depth between grasses and trees across the MAP gradient, with grasses generally exhibiting shallower Rooting profiles than trees. We also found that trees tended to become more shallow-rooted as a function of MAP, to the point that trees and grasses largely overlapped in terms of Rooting depth at the wettest sites. Our results reconcile previously conflicting evidence for Rooting overlap in this system, and have important implications for understanding tree–grass dynamics under altered precipitation scenarios.
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revisiting the two layer hypothesis coexistence of alternative functional Rooting strategies in savannas
PLOS ONE, 2013Co-Authors: Ricardo M HoldoAbstract:The two-layer hypothesis of tree-grass coexistence posits that trees and grasses differ in Rooting depth, with grasses exploiting soil moisture in shallow layers while trees have exclusive access to deep water. The lack of clear differences in maximum Rooting depth between these two functional groups, however, has caused this model to fall out of favor. The alternative model, the demographic bottleneck hypothesis, suggests that trees and grasses occupy overlapping Rooting niches, and that stochastic events such as fires and droughts result in episodic tree mortality at various life stages, thus preventing trees from otherwise displacing grasses, at least in mesic savannas. Two potential problems with this view are: 1) we lack data on functional Rooting profiles in trees and grasses, and these profiles are not necessarily reflected by differences in maximum or physical Rooting depth, and 2) subtle, difficult-to-detect differences in Rooting profiles between the two functional groups may be sufficient to result in coexistence in many situations. To tackle this question, I coupled a plant uptake model with a soil moisture dynamics model to explore the environmental conditions under which functional Rooting profiles with equal Rooting depth but different depth distributions (i.e., shapes) can coexist when competing for water. I show that, as long as rainfall inputs are stochastic, coexistence based on Rooting differences is viable under a wide range of conditions, even when these differences are subtle. The results also indicate that coexistence mechanisms based on Rooting niche differentiation are more viable under some climatic and edaphic conditions than others. This suggests that the two-layer model is both viable and stochastic in nature, and that a full understanding of tree-grass coexistence and dynamics may require incorporating fine-scale Rooting differences between these functional groups and realistic stochastic climate drivers into future models.
Jose Manuel Perezperez - One of the best experts on this subject based on the ideXlab platform.
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quantitative analysis of adventitious root growth phenotypes in carnation stem cuttings
PLOS ONE, 2015Co-Authors: Virginia Birlanga, Joan Villanova, Antonio Cano, E Cano, Manuel Acosta, Jose Manuel PerezperezAbstract:Carnation is one of the most important species on the worldwide market of cut flowers. Commercial carnation cultivars are vegetatively propagated from terminal stem cuttings that undergo a Rooting and acclimation process. For some of the new cultivars that are being developed by ornamental breeders, poor adventitious root (AR) formation limits its commercial scaling-up, due to a significant increase in the production costs. We have initiated a genetical-genomics approach to determine the molecular basis of the differences found between carnation cultivars during adventitious Rooting. The detailed characterization of AR formation in several carnation cultivars differing in their Rooting losses has been performed (i) during commercial production at a breeders’ Rooting station and (ii) on a defined media in a controlled environment. Our study reveals the phenotypic signatures that distinguishes the bad-Rooting cultivars and provides the appropriate set-up for the molecular identification of the genes involved in AR development in this species.
