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Статті в журналах з теми "Hyper-accumulation":
1
Padmavathiamma, Prabha K., and Loretta Y. Li. "Phytoremediation Technology: Hyper-accumulation Metals in Plants." Water, Air, and Soil Pollution 184, no. 1-4 (May 22, 2007): 105–26. http://dx.doi.org/10.1007/s11270-007-9401-5.
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Liang, Le, Ran Zhang, Yan Zhao, Ying Zhu, Qiaoman Ao, and Yi Tang. "Effects of hyperaccumulator plant straw on biomass and cadmium accumulation of lettuce." E3S Web of Conferences 136 (2019): 07005. http://dx.doi.org/10.1051/e3sconf/201913607005.
Анотація:
To study the effects of hyper-accumulator plant straw on the biomass and cadmium (Cd) accumulation of lettuce (Lactuca sativa), the pot experiments were conducted to study the effects of straw application of three hyper-accumulator plants (Solanum nigrum, Bidens pilosa and Galinsoga parviflora) on the biomass and Cd accumulation of lettuce under Cd stress. The results show that: compared with no straw application, the biomass of lettuce was increased after applying three kinds of hyper-accumulator plant straw: S. nigrum, B. pilosa and G. parviflora, Cd content in the above ground part of lettuce was increased by 4.46%, 1.20% and 0.63% respectively, compared with that of non-application, and Cd content in the root of lettuce was decreased. The application of three kinds of hyperaccumulator plant straw promoted the growth of lettuce and increased Cd uptake by lettuce of aerial part.
3
Hussain, Jamshaid, Wajeeha Saeed, Tatheer Alam Naqvi, Mohammad Maroof Shah, Raza Ahmad, Amjad Hassan, and Qaisar Mahmood. "Dietary Toxicity of Lead and Hyper-Accumulation in Petroselinum crispum." Arabian Journal for Science and Engineering 40, no. 7 (November 28, 2014): 1819–24. http://dx.doi.org/10.1007/s13369-014-1526-4.
4
Wei, Feng, Zhu Yan, Tian Yongchao, Cao Weixing, Yao Xia, and Li Yingxue. "Monitoring leaf nitrogen accumulation in wheat with hyper-spectral remote sensing." Acta Ecologica Sinica 28, no. 1 (January 2008): 23–32. http://dx.doi.org/10.1016/s1872-2032(08)60018-9.
5
Wang, Yuyi, Rongzhi Tan, Chyandeng Jan, and Bing Tian. "Gravel accumulation in deposits of viscous debris flows with hyper-concentration." Journal of Mountain Science 6, no. 1 (February 13, 2009): 88–95. http://dx.doi.org/10.1007/s11629-009-0120-9.
6
Meroni, Marica, Paola Dongiovanni, Miriam Longo, Fabrizia Carli, Guido Baselli, Raffaela Rametta, Serena Pelusi, et al. "Mboat7 down-regulation by hyper-insulinemia induces fat accumulation in hepatocytes." EBioMedicine 52 (February 2020): 102658. http://dx.doi.org/10.1016/j.ebiom.2020.102658.
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Sengupta, Soumya, Gargee Bhattacharya, Subhasmita Mohanty, Shubham K. Shaw, Gajendra M. Jogdand, Rohila Jha, Prakash K. Barik, Jyoti R. Parida, and Satish Devadas. "IL-21, Inflammatory Cytokines and Hyperpolarized CD8+ T Cells Are Central Players in Lupus Immune Pathology." Antioxidants 12, no. 1 (January 12, 2023): 181. http://dx.doi.org/10.3390/antiox12010181.
Анотація:
Systemic lupus erythematous (SLE) is a chronic autoimmune disorder, broadly characterized by systemic inflammation along with heterogeneous clinical manifestations, severe morbidity, moribund organ failure and eventual mortality. In our study, SLE patients displayed a higher percentage of activated, inflamed and hyper-polarized CD8+ T cells, dysregulated CD8+ T cell differentiation, significantly elevated serum inflammatory cytokines and higher accumulation of cellular ROS when compared to healthy controls. Importantly, these hyper-inflammatory/hyper-polarized CD8+ T cells responded better to an antioxidant than to an oxidant. Terminally differentiated Tc1 cells also showed plasticity upon oxidant/antioxidant treatment, but that was in contrast to the SLE CD8+ T cell response. Our studies suggest that the differential phenotype and redox response of SLE CD8+ T cells and Tc1 cells could be attributed to their cytokine environs during their respective differentiation and eventual activation environs. The polarization of Tc1 cells with IL-21 drove hyper-cytotoxicity without hyper-polarisation suggesting that the SLE inflammatory cytokine environment could drive the extreme aberrancy in SLE CD8+ T cells.
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YAMAZAKI, H., K. ISHII, S. MATSUYAMA, A. TERAKAWA, Y. KIKUCHI, Y. KAWAMURA, K. FUJIKI, et al. "PIXE STUDY ON ARSENIC ACCUMULATION BY A FERN (PTERIS VITTATA)." International Journal of PIXE 20, no. 03n04 (January 2010): 119–25. http://dx.doi.org/10.1142/s012908351000204x.
Анотація:
Pteris vittata is a fern reported to be an arsenic hyper-accumulator. To develop the practical application of the fern to a phytoremediation technique, it is necessary to explicate the effective accumulation mechanism. In this study, the arsenic distribution and the elemental correlation in the cellular level were examined in the fronds supplied with arsenate and arsenite separately via xylem vessel using an in-air micro-PIXE system at Tohoku University. The difference in transportation rate between arsenate and arsenite as well as the translocation of elements necessary for plant metabolism was revealed in different tissues of the fronds accumulating arsenic in high concentration. Hence, the in-air micro-PIXE analysis is an effective measure for undertaking phytoremediation research of hyper-accumulator plants.
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Chukkapalli, Vineela, Kristi L. Berger, Sean M. Kelly, Meryl Thomas, Alexander Deiters, and Glenn Randall. "Daclatasvir inhibits hepatitis C virus NS5A motility and hyper-accumulation of phosphoinositides." Virology 476 (February 2015): 168–79. http://dx.doi.org/10.1016/j.virol.2014.12.018.
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Petelenz-Kurdziel, Elzbieta, Clemens Kuehn, Bodil Nordlander, Dagmara Klein, Kuk-Ki Hong, Therese Jacobson, Peter Dahl, et al. "Quantitative Analysis of Glycerol Accumulation, Glycolysis and Growth under Hyper Osmotic Stress." PLoS Computational Biology 9, no. 6 (June 6, 2013): e1003084. http://dx.doi.org/10.1371/journal.pcbi.1003084.
Дисертації з теми "Hyper-accumulation":
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Rande, Hugo. "Effets du niveau de pollution métallique et des stratégies fonctionnelles sur les types d’effets en jeu dans les interactions entre plantes au niveau d’anciens sites miniers des Pyrénées." Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0032.
Анотація:
Les interactions entre plantes dans les milieux impactés par les métaux/métalloïdes dépendent de nombreux facteurs et sont encore très peu connues. Tout d’abord elles semblent dépendre du niveau de pollution métallique du milieu, mais aussi des stratégies fonctionnelles végétales des plantes interagissant. D’autre part, les plantes peuvent avoir plusieurs types d’effets sur leur environnement proche, effets s’exprimant à des temporalités différentes. En effet, les plantes ont un effet immédiat via leur canopée et racines sur les ressources et le microclimat à proximité. Aussi, au cours d’une saison de végétation, les plantes peuvent avoir des effets liés à la production de la litière et sa décomposition dans les sols sous leur canopée. A plus long-terme, lorsque ce cycle de production/décomposition est répété au fil des années, les plantes vont avoir un effet lié à la dynamique de la matière organique dans les sols. Dans cette thèse, notre objectif principal était de différencier ces effets, et de comprendre comment les stratégies fonctionnelles végétales des plantes pouvaient influencer les différents effets en jeu le long de gradients de pollution métallique. Nous avons étudié ces effets pendant trois années (entre 2020 et 2022) dans une ancienne vallée minière des Pyrénées Ariégeoises (Sentein, France). Dans cette zone d’étude, nous avons étudié les interactions entre plantes par des méthodes observationnelles et de transplantations de cibles avec contrôle de la présence de canopée et/ou de la litière des plantes, sur trois sites d’étude : un terril avec une pollution homogène et deux zones de résidus miniers avec des pollutions hétérogènes créant un gradient de pollution. Le long des gradients étudiés, les effets de canopée et de prélèvement racinaire ont suivi l’Hypothèse du Gradient de Stress, passant de la compétition à la facilitation avec l’augmentation de la pollution. Cette facilitation était d’autant plus forte que les espèces produisant l’effet sont dites « exploitatrices » (en lien avec l’exploitation des ressources du sol et Leaf Economic Spectrum), et bénéficiait le plus aux plantes les moins tolérantes aux métaux. Les effets positifs étaient surtout liés à l’amélioration des conditions microclimatiques lors d’épisodes chauds et secs en été. Concernant les effets liés à la production et décomposition des litières, des effets négatifs sur les plantes cibles ont été démontrés, suggérant des effets dits d’allélopathie élémentaire, et liés à la forte concentration en éléments métalliques dans les litières en décomposition. Ces effets négatifs de litière étaient maximums dans les milieux les moins pollués où les plantes métallophytes accumulatrices (qui ont des fortes teneurs en métaux dans leurs feuilles) et les plantes moins tolérantes aux métaux interagissaient. Ils étaient particulièrement marqués pour les cibles sensibles à la pollution métallique. Les résultats de cette thèse donnent des pistes potentielles pour utiliser la facilitation dans un cadre de phyto-management de milieux pollués par les métaux/métalloïdes, en prenant en compte explicitement les stratégies fonctionnelles végétales des plantes en interactions et le niveau de pollution en jeu. Des résultats obtenus pendant la canicule de 2022 nous donnent aussi une bonne vision des évolutions attendues des différents effets impliqués dans les interactions entre plantes dans les écosystèmes métallifères dans un contexte de changement climatiquePlant-plant interactions have been overlooked in metal/metalloids-impacted environments and are likely driven by several factors whose influence is barely known. First, plant-plant interactions depend on the level of metal pollution, but also on the functional plant strategies of the interacting plants. Furthermore, plants can have several type of effects on their immediate environment, acting at different timescales. Plants canopy and roots have an instantaneous influence on the microclimate and available resources in their immediate vicinity. Then, during a growing season, the production of litter and its decomposition beneath their canopy can influence soil chemical and physical properties. In the longer term, when this cycle of litter production/decomposition is repeated over the years, the dynamics of the organic matter will influence soil conditions even more. In this thesis, our main objective was to delineate these effects, and to understand how plant functional strategies can influence these various effects along metal pollution gradients. We studied these effects during three consecutive years (from 2020 to 2022) in a former mining valley in the French Pyrenees (Sentein, Ariège, France). In this area, we studied interactions between plants using observational and target transplantation methods controlling for the presence of plant canopy and/or plant litter, in three study sites: a slag heap with homogeneous pollution and two mine tailings areas with heterogeneous pollution creating a gradient of pollution. Along these gradients, short-term canopy and root-uptake effects followed the Stress Gradient Hypothesis, switching from competition to facilitation as pollution increased. This facilitation was stronger when the species producing the effect were acquisitive (in relation with soil resources and the Leaf Economic Spectrum), and benefits more the low metal-tolerant plants. These positive effects were mainly due to the improvement of micro-climatic conditions during hot and dry episodes in summer. Concerning the effects linked to litter production and decomposition, negative effects on target plants were found, suggesting the so-called “elemental allelopathic” effects, in relation with the high concentration of metallic elements in the decomposing litter. These negative litter effects were more important in the least polluted environments, where metal-accumulating metallophyte plants (which have high concentration of metals in their leaves) and less metal-tolerant plants interacts. They were particularly marked for targets sensitive to metal pollution. The results of this thesis give important perspectives regarding the use of facilitation for the phyto-management of metals/metalloids-polluted environments, given that the functional strategies of interacting plants and the level of pollution involved are explicitly considered. Additionnaly, the results obtained during the 2022 heatwave provide useful insights regarding the expected evolution of the different effects driving plant interactions in metalliferous ecosystems in a climate change context
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Wang, Jung-Hao, and 王榮顥. "Study on the Growth and the Hyper-accumulation of Nicotine in Hairy Roots of Nicotiana tabacum." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/54530143729788594570.
Анотація:
博士國立臺灣大學
生化科技學系
103
Hairy root, which resulted from T-DNA transformation of Agrobacterium rhizogenes, is widely used in studying root biology. It is also applied in producing diverse plant secondary metabolites due to its fast-growth and metabolite-accumulating abilities. However, the regulatory mechanisms of hairy root initiation, growth, and metabolite accumulation are largely unknown. To expand the applicability of hairy roots, we used Nicotiana tabacum L. var Wisconsin 38, its pathogen A. rhizogenes A4, and its well-known metabolite nicotine as a study model to unveil the mechanisms that regulate hairy root growth and secondary metabolite accumulation. In the part of growth regulation, we focused on four rol genes, including rolA, B, C, and D, which are located on TL-DNA of A. rhizogenes A4. These rol genes are known to participate in rooting; however, the means by which the rol genes contribute to the initiation and the maintenance of hairy roots remain unknown. In this study, we knocked-out these rol genes in A. rhizogenes A4 respectively, and used for inducing hairy roots. We found that A. rhizogenes lacking rolB or rolC induced hairy roots with less rooting ability than wild-type A. rhizogenes, whereas lacking rolA or rolD showed no significant differences. Moreover, tobacco hairy roots lacking either rolB or rolC exhibited fewer branch roots and lost their growth ability after long-term subculture than wild-type-induced hairy roots, whereas lacking of rolA or rolD did not show significant differences. We considered rolB and rolC involved mainly in the regulation of hairy root growth. Our microarray analysis revealed that the expression of several groups of genes encoding lipid transfer proteins (LTP) and reactive oxygen species (ROS)-related genes was significantly suppressed in rolB- or rolC- deficient hairy roots. We also found that hairy root clones that exhibited greater branching also had higher levels of RolB, RolC, and the microarray-identified LTP genes. In addition, we compared the transcriptomic difference between hairy roots and un-infected intact roots by microarray, and the expression levels of the above mentioned LTP-encoding genes were dramatically higher in the hairy root. Moreover, ROS staining showed that ROS level were lower in rolB- or rolC- deficient hairy roots. We therefore suggest that up-regulating LTP and increasing the level of ROS are important for hairy root growth. In the part of secondary metabolite regulation, we found that tobacco hairy roots accumulate much more nicotine than the intact roots, and the nicotine contents were positively correlated with the amount of another metabolite anabasine, indicating hairy roots had higher secondary metabolic flux. By real-time PCR analysis, hairy roots had more abundant expression of genes encoding enzymes in nicotine biosynthetic pathway and storage transporters, indicating the accumulation of nicotine in hairy roots is via transcriptional regulation. Moreover, hairy roots with a higher growth rate had greater nicotine content, suggesting that growth and nicotine production are regulated synchronically. Nicotine up-regulation in hairy roots was regulated by ethylene response factor (ERF)189 and ERF199 to activate the key enzymes putrescine N-methyltransferase and N-methylputrescine oxidase with a jasmonic acid (JA)-independent signal. However, the possible regulator has not been identified. These findings indicate high secondary metabolites accumulated hairy root clones can be simply selected by measuring their growth rate, which expand the hairy root researches and applications in secondary metabolites.
Частини книг з теми "Hyper-accumulation":
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Fattorini, Daniele, and Francesco Regoli. "Hyper-Accumulation of Vanadium in Polychaetes." In Vanadium, 73–92. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-0913-3_4.
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Formato, Enrico. "New Urbanization Phenomena and Potential Landscapes: Rhizomatic Grids and Asymmetrical Clusters." In Regenerative Territories, 135–45. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-78536-9_8.
Анотація:
AbstractMore and more nowadays, the Circular Economy is at the heart of European public policies. As a result of the “Next Generation EU” Recovery Plans, a huge amount of financial resources will be available in the coming years to give shape the concept of “ecological transition". For that purpose, radical vision and operational concreteness are needed.In order to strengthen the territorial dimension of public policies aimed at ecological transition, the paper points to consider the status quo of the European territory, looking for recurring elements and differences. In this perspective, a return of “hard” urban studies, focusing on the issues of land ownership, land parcelling, infrastructural and urbanization procedures (and their relationships with the environment and the landscape) should be conducted at the European scale.A central role for the future of contemporary territories is recognized in the so-called “fringe area”, the part of the urban region where patterns of building development and unbuilt space interwave: its intermediary character, as a place between the compact city and the suburban countryside, makes this zone favourable to the collaboration between the two worlds. In addition, its easy accessibility from both the denser contexts and the outer areas makes it the perfect place to locate the equipment required to create short supply chains, so relevant for the circular economy and the ecological transition.These transition areas need to be rethought as new collective spaces of the contemporary city, areas for the proliferation of biodiversity, inhibited from settlement increase and subject to restrictions on car traffic. In them, the circular dimension of the new green economy could give shape to certain spatial conditions and new landscapes.Two main spatial models can describe this sustainable reform of the peri-urban territories. The first one assumes the figure of the “cluster”: a territorially and functionally defined region with one or more reference centres and an edge marking the discontinuity from other clusters. The second model is based on the figure of the “grid”: an unlimited mesh, which gives measure and organizes space according to a replicable and open system. This spatiality is built on a redundant and weak infrastructure, devoid of hierarchy, which can give rise to a sponge rich in pores, with neither internal nor external boundaries.The concept of the materiality also deals with the physical status of each context where the clusters of shortening flows would define local metabolisms, self-sufficient, marked by the use and recycling of what can be produced or “extracted” in the cluster itself. The closing of short supply chains for the use and recycling of materials, also with reference to the construction cycle and CDW recycling, would have direct consequences on the architectural character of the new arrangements: a kind of hyper-contextualism in which the landscape takes on grains, colours, materiality, closely linked to the local condition.Finally, a reflection on the rationales of the project is outlined. What is proposed, in fact, requires going beyond the traditional way in which the project has been conceived. In fact, these urban reconfiguration processes, structurally open to uncertainty, would take advantage of a programmatic choice of spatial incompleteness: a condition of “unfinished”, open to the accumulation over time of functions, forms, aggregations and densifications.
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"Mechanism of Heavy Metal ATPase (HMA2, HMA3 and HMA4) Genes." In Nano-Phytoremediation Technologies for Groundwater Contaminates, 104–17. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-9016-3.ch008.
Анотація:
Heavy metals are the most important pollutants that are non-biodegradable and increasingly accumulate in the environment. Phytoremediation can be defined as the use of plants for the extraction, immobilization, containment, or degradation of contaminants. It provides an ecologically, environmentally sound and safe method for restoration and remediation of contaminated land. Plant species vary in their capacity of hyper-accumulation of heavy metals. The chapter reviews the current findings on the molecular mechanism involved in heavy metals tolerance, which is a valuable tool for phytoremediation. The heavy metal tolerance genes help in the hyper-accumulation trait of a plant. Heavy metal transporter ATPases (HMAs) genes help in the refluxing of heavy metal ions from the cytosol, either into the apoplast, the vacuole, or other organelles, which help in the hyperaccumulation of metal. Understanding the signaling mechanism of transporter genes will be an important tool to understand the genetics of hyperaccumulation.
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Gibbs, Nick. "Instrumentality, Competitiveness, and Hyper-conformity." In The Muscle Trade, 72–79. Policy Press, 2023. http://dx.doi.org/10.1332/policypress/9781529227949.003.0005.
Анотація:
Building out from Chapter 4’s psychoanalytic foundations, this chapter examines the instrumental reasons why the sample used IPEDs to build their bodies. First, the role of competitive sporting activity is considered as a driver of consumption, and the underlying competitive individualist mindset present among the men under study is interrogated. Following this, the utility of attaining a muscular enhanced body for professionals working in the health and fitness industry, particularly personal training and online coaching, is investigated. This analysis is contextualized within the post-industrial political economy of Potsford and an argument is advanced that IPED consumption ought to be viewed as a means of hyper-conformity to the edicts of late-capitalist accumulation, particularly given the precarious nature of many roles in the sector. Ultimately, the chapter concludes that both the sporting context of consumption and the insecure local health and fitness economy represent ‘dopogenic environments’.
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Stearns, T., and R. A. Kahn. "ARFl and ARF2." In Secretory Pathway, 124–25. Oxford University PressOxford, 1994. http://dx.doi.org/10.1093/oso/9780198599425.003.0075.
Анотація:
Abstract ARF1 was cloned by homology with a mammalian ARF gene1; ARF2 was cloned by hybridization with ARF7. Null mutations have been constructed in each of the genes by gene disruption. arf1 mutants grow more slowly than wild-type, are cold-sensitive, and are hyper-sensitive to fluoride ion in the medium. At all temperatures, invertase in arf7 null mutants is only partially glycosylated relative to wild-type, and there is some intracellular accumulation of the protein3 arf2 mutants are indistinguishable from wildtype for all phenotypes. In a strain that has both chromosomal copies of ARF deleted and a plasmid bearing ARF1 under control of the GAL1 promoter, depletion of ARF protein by shifting carbon source results in accumulation of core-glycosylated invertase, and is lethal after approximately 8 hours. Overexpression of ARF1 using this GAL1 promoter construct in wild-type ARF1 ARF2 cells is also lethal.
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Prakash, Ved, and Sarika Saxena. "Molecular Overview of Heavy Metal Phytoremediation." In Handbook of Research on Inventive Bioremediation Techniques, 247–63. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-2325-3.ch010.
Анотація:
Metal toxification has remained one of the problems with the advent of industrial revolution. Plant based remediation are showing increasing promise for use in soils contaminated with organic and inorganic pollutants. A large number of plant families has been identified which has shown significant result in detoxification of heavy metals. Hyperaccumulator plant is capable of sequestering heavy metals in their shoot tissues. High tolerance to HM toxicity is dependent on a reduced metal uptake or increased internal sequestration, which depends on plant and environmental condition. Recent progresses on understanding cellular/molecular mechanisms of metal tolerance by plants are reviewed. This chapter aims to focus on molecular mechanism involved in heavy metal detoxification and tolerance by plants. A different method by which plant effectively converts toxic metal in less toxic compounds has been explained in this chapter. Further, mode of accumulation and sequestration of metals have been explained which are utilized by hyper accumulators.
7
Acerbi, Alberto. "Cumulation." In Cultural Evolution in the Digital Age, 186–212. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198835943.003.0008.
Анотація:
Chapter 8 considers what cultural evolutionists call cumulative cultural evolution, that is, the idea that culture increases in complexity. For a cultural domain being defined as cumulative, it needs to show accumulation (more traits), improvement (traits are more efficient), and ratcheting (new traits build on previous innovations). The author proposes that this is not a necessary outcome, and that different domains show different signs of cumulation. It is suggested that the fidelity and the hyper-availability provided by digital media allow for more cumulation in domains where it was limited before. Not surprisingly, they also allow for the retention of vast amounts of useless information—junk culture. A central challenge for the coming years is thus finding efficient mechanisms of online cultural selection. Algorithmic selection is finally discussed, along with how mainstream criticisms, such as the fact that algorithms are biased or opaque to users, are not decisive arguments against their efficacy and utility.
8
Krishnasamy, Selvanayaki, Ramkumar Lakshmanan, and Mythili Ravichandran. "Phytoremediatiation of Metal and Metalloid Pollutants from Farmland: An In-Situ Soil Conservation." In Biodegradation Technology of Organic and Inorganic Pollutants. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.98659.
Анотація:
Phytoremediation is an effective technology for in-situ remediation of high level polluted soils. Phytoremediation is a plant-mediated approach, which involves the use of plants to absorb and remove elemental pollutants or lower their concentration or bioavailability to soil. Plants have efficacy to absorb compounds in the soil even at low concentration through their root system. Plant root system has geotropism which helps them to extend into the soil matrix and hyper accumulate heavy metals to increase their bioavailability considerably and thereby the polluted soil is domesticated and the soil fertility is enhanced. The heavy-metal-resistant endophytes give the promising effect on plant growth, by decreasing metal phytotoxicity and affecting metal translocation and accumulation in plants. It is an eye opening for researches to implement the phytoremediation of organic contaminants through endophytes that produce various enzymes to metabolize organic contaminants and reduce both the phytotoxicity and evapotranspiration of volatile contaminants. Here, we focus on the most widely used phytoremediation strategies, phytostabilization, phytoextraction, phytovolatilization, and phytofiltration in the remediation of heavy metal-polluted soil.
Тези доповідей конференцій з теми "Hyper-accumulation":
1
Agarwal, Mohit, and Assimina A. Pelegri. "Hyper-Viscoelastic 3D Response of Axons Subjected to Repeated Tensile Loads in Brain White Matter." In ASME 2022 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/imece2022-97059.
Анотація:
Abstract A novel finite element method (FEM) is developed to study mechanical response of axons embedded in extra cellular matrix (ECM) when subjected to harmonic uniaxial stretch under purely non-affine kinematic boundary conditions. The proposed modeling approach combines hyper-elastic (such as Ogden model) and time/frequency domain viscoelastic constitutive models to evaluate the effect of parametrically varying oligodendrocyte-axon tethering under harmonic stretch at 50Hz. A hybrid hyper-viscoelastic material (HVE) model enabled the analysis of repeated uniaxial load on stress propagation and damage accumulation in white matter. In the proposed FEM, oligodendrocyte connections to axons are depicted via a spring-dashpot model. This tethering technique facilitates contact definition at various locations, parameterizes connection points and varies stiffness of connection hubs. Results from a home-grown FE submodel configuration of a single oligodendrocyte tethered to axons at various locations are presented. Root mean square deviation (RMSD) are computed between stress-strain plots to depict trends in mechanical response. Steady-state dynamic (SSD) simulations show stress relaxation in axons. Gradual axonal softening under repetitive loads is illustrated employing Prony series - HVE models. Representative von-Mises stress plots indicate that undulated axons experience bending stresses along their tortuous path, suggesting greater susceptibility to damage accumulation and fatigue failure due to repeated strains.
2
Pietsch, Carlie, Cliff Harrison, and Warren D. Allmon. "DELTAS AND DIVERSITY: GLAUCONITIC MATURATION AND THE ACCUMULATION OF HYPER-DIVERSE FOSSILIFEROUS BEDS IN THE PALEOGENE GULF COASTAL PLAIN." In GSA Annual Meeting in Denver, Colorado, USA - 2016. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016am-287024.
3
Breit, Mara, E. Marie Muehe, Maria Májeková, Katja Tielbörger, Evgenia Blagodatskaya, and Ute Kreamer. "What determines intraspecific variability in heavy metal hyper-accumulation efficacy of Arabidopsis halleri? – Plant traits or soil biogeochemistry?" In Goldschmidt2023. France: European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.20399.
4
Suo, Wei, MengYang Sun, Peng Wang, and Qi Wu. "Proposal-free One-stage Referring Expression via Grid-Word Cross-Attention." In Thirtieth International Joint Conference on Artificial Intelligence {IJCAI-21}. California: International Joint Conferences on Artificial Intelligence Organization, 2021. http://dx.doi.org/10.24963/ijcai.2021/143.
Анотація:
Referring Expression Comprehension (REC) has become one of the most important tasks in visual reasoning, since it is an essential step for many vision-and-language tasks such as visual question answering. However, it has not been widely used in many downstream tasks because it suffers 1) two-stage methods exist heavy computation cost and inevitable error accumulation, and 2) one-stage methods have to depend on lots of hyper-parameters (such as anchors) to generate bounding box. In this paper, we present a proposal-free one-stage (PFOS) model that is able to regress the region-of-interest from the image, based on a textual query, in an end-to-end manner. Instead of using the dominant anchor proposal fashion, we directly take the dense-grid of image as input for a cross-attention transformer that learns grid-word correspondences. The final bounding box is predicted directly from the image without the time-consuming anchor selection process that previous methods suffer. Our model achieves the state-of-the-art performance on four referring expression datasets with higher efficiency, comparing to previous best one-stage and two-stage methods.
Звіти організацій з теми "Hyper-accumulation":
1
Savaldi-Goldstein, Sigal, and Siobhan M. Brady. Mechanisms underlying root system architecture adaptation to low phosphate environment. United States Department of Agriculture, January 2015. http://dx.doi.org/10.32747/2015.7600024.bard.
Анотація:
In order to advance our understanding towards potential biotechnology improvement of plant performance, we studied root responses to limited P in two different plants, Arabidopsis and tomato. Arabidopsis is among the most studied model plants that allows rapid application of molecular and developmental experiments while tomato is an important crop, with application in agriculture. Using Arabidopsis we found that steroid hormones modulate the extent of root elongation in response to limited P, by controlling the accumulation of iron in the root. We also found that the availability of P and iron control the activity of the steroid hormone in the root. Finally, we revealed the genes involved in this nutrient-hormone interaction. Hence, the ferroxidase LPR1 that promotes iron accumulation in response to low P is repressed by the transcription factor BES1/BZR1. Low P inhibits the steroid hormone pathway by enhancing the accumulation of BKI1. High levels of BKI1 inhibit the activity of the steroid hormone receptor at the cell surface and iron accumulation increases inside the root, resulting in a slow growth. Together, the extent of root elongation depends on interactions between an internal cue (steroid hormone) and cues derived from the availability of P and iron in the environment. Using tomato, we found that the response of two cultivated tomato varieties (M82 and New Yorker) to limited P is distinct from that of the wild species, Solanumpennellii. This is implicated at both the levels of root development and whole plant physiology. Specifically, while the root system architecture of cultivated tomato is modulated by limited P availability, that of the wild type species remained unaffected. The wild species appears to be always behaving as if it is always in phosphate deprived conditions, despite sufficient levels of phosphate. Hyper-accumulation of metals appears to mediate this response. Together, this knowledge will be used to isolate new genes controlling plant adaptation to limited P environment.
2
Whitham, Steven A., Amit Gal-On, and Victor Gaba. Post-transcriptional Regulation of Host Genes Involved with Symptom Expression in Potyviral Infections. United States Department of Agriculture, June 2012. http://dx.doi.org/10.32747/2012.7593391.bard.
Анотація:
Understanding how RNA viruses cause disease symptoms in their hosts is expected to provide information that can be exploited to enhance modern agriculture. The helper component-proteinase (HC-Pro) protein of potyviruses has been implicated in symptom development. Previously, we demonstrated that symptom expression is associated with binding of duplex small-interfering-RNA (duplex-siRNA) to a highly conserved FRNK amino acid motif in the HC-Pro of Zucchini yellow mosaic virus (ZYMV). This binding activity also alters host microRNA (miRNA) profiles. In Turnip mosaic virus (TuMV), which infects the model plant Arabidopsis, mutation of the FRNK motif to FINK was lethal providing further indication of the importance of this motif to HC-Pro function. In this continuation project, our goal was to further investigate how ZYMV and TuMV cause the mis-expression of genes in cucurbits and Arabidopsis, respectively, and to correlate altered gene expression with disease symptoms. Objective 1 was to examine the roles of aromatic and positively charged residues F164RNH and K215RLF adjacent to FR180NK in small RNA binding. Objective 2 was to determine the target genes of the miRNAs which change during HC-Pro expression in infected tissues and transgenic cucumber. Objective 3 was to characterize RNA silencing mechanisms underlying differential expression of host genes. Objective 4 was to analyze the function of miRNA target genes and differentially expressed genes in potyvirus-infected tissues. We found that the charged K/R amino acid residues in the FKNH and KRLF motifs are essential for virus viability. Replacement of K to I in FKNH disrupted duplex-siRNA binding and virus infectivity, while in KRLF mutants duplex-siRNA binding was maintained and virus infectivity was limited: symptomless following a recovery phenomenon. These findings expanded the duplex-siRNA binding activity of HC-Pro to include the adjacent FRNK and FRNH sites. ZYMV causes many squash miRNAs to hyper-accumulate such as miR166, miR390, mir168, and many others. Screening of mir target genes showed that only INCURVATA-4 and PHAVOLUTA were significantly upregulated following ZYMVFRNK infection. Supporting this finding, we found similar developmental symptoms in transgenic Arabidopsis overexpressing P1-HC-Pro of a range of potyviruses to those observed in miR166 mutants. We characterized increased transcription of AGO1 in response to infection with both ZYMV strains. Differences in viral siRNA profiles and accumulation between mild and severe virus infections were characterized by Illumina sequencing, probably due to the differences in HC-Pro binding activity. We determined that the TuMV FINK mutant could accumulate and cause symptoms in dcl2 dcl4 or dcl2 dcl3 dcl4 mutants similar to TuMV FRNK in wild type Arabidopsis plants. These dcl mutant plants are defective in antiviral defenses, and the results show that factors other than HC-ProFRNK motif can induce symptoms in virus-infected plants. As a result of this work, we have a better understanding of the FRNK and FKNH amino acid motifs of HC-Pro and their contributions to the duplex-siRNA binding functions. We have identified plant genes that potentially contribute to infectivity and symptoms of virus infected plants when they are mis-expressed during potyviral infections. The results establish that there are multiple underlying molecular mechanisms that lead viral pathogenicity, some dependent on HC-Pro. The potential benefits include the development of novel strategies for controlling diseases caused by viruses, methods to ensure stable expression of transgenes in genetically improved crops, and improved potyvirus vectors for expression of proteins or peptides in plants.
3
Steffens, John C., and Eithan Harel. Polyphenol Oxidases- Expression, Assembly and Function. United States Department of Agriculture, January 1995. http://dx.doi.org/10.32747/1995.7571358.bard.
Анотація:
Polyphenol oxidases (PPOs) participate in the preparation of many plant products on the one hand and cause considerable losses during processing of plant products on the other hand. However, the physiological functions of plant PPO were still a subject of controversy at the onset of the project. Preliminary observations that suggested involvement of PPOs in resistance to herbivores and pathogens held great promise for application in agriculture but required elucidation of PPO's function if modulation of PPO expression is to be considered for improving plant protection or storage and processing of plant products. Suggestions on a possible role of PPO in various aspects of chloroplast metabolism were also relevant in this context. The characterization of plant PPO genes opened a way for achieving these goals. We reasoned that "understanding PPO targeting and routing, designing ways to manipulate its expression and assessing the effects of such modifications will enable determination of the true properties of the enzyme and open the way for controlling its activity". The objective of the project was to "obtain an insight into the function and biological significance of PPOs" by examining possible function(s) of PPO in photosynthesis and plant-pest interactions using transgenic tomato plants; extending our understanding of PPO routing and assembly and the mechanism of its thylakoid translocation; preparing recombinant PPOs for use in import studies, determination of the genuine properties of PPOs and understanding its assembly and determining the effect of PPO's absence on chloroplast performance. Results obtained during work on the project made it necessary to abandon some minor objectives and devote the effort to more promising topics. Such changes are mentioned in the 'Body of the report' which is arranged according to the objectives of the original proposal. The complex expression pattern of tomato PPO gene family was determined. Individual members of the family are differentially expressed in various parts of the plant and subjected to developmentally regulated turnover. Some members are differentially regulated also by pathogens, wounding and chemical wound signals. Wounding systemically induces PPO activity and level in potato. Only tissues that are developmentally competent to express PPO are capable of responding to the systemic wounding signal by increased accumulation of PPO mRNA. Down regulation of PPO genes causes hyper susceptibility to leaf pathogens in tomato while over expression regulation of PPO expression in tomato plants is their apparent increased tolerance to drought. Both the enhanced disease resistance conferred by PPO over expression and the increased stress tolerance due to down regulation can be used in the engineering of improved crop plants. Photosynthesis rate and variable fluorescence measurements in wild type, and PPO-null and over expressing transgenic tomato lines suggest that PPO does not enable plants to cope better with stressful high light intensities or reactive oxygen species. Rather high levels of the enzyme aggravate the damage caused under such conditions. Our work suggests that PPO's primary role is in defending plants against pathogens and herbivores. Jasmonate and ethylene, and apparently also salicylate, signals involved in responses to wounding and defense against herbivores and pathogens, enhance markedly and specifically the competence of chloroplasts to import and process pPPO. The interaction of the precursor with thylakoid membranes is primarily affected. The routing of PPO shows other unusual properties: stromal processing occurs in two sites, resulting in intermediates that are translocated across thylakoids by two different mechanisms - a DpH- and a Sec-dependent one. It is suggested that the dual pattern of processing and routing constitutes a'fail safe' mechanism, reflecting the need for a rapid and flexible response to defense challenges. Many of the observations described above should be taken into consideration when manipulation of PPO expression is contemplated for use in crop improvement.