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2. Acoustic lattice instabilities at the magneto-structural transition in Fe$_{1.057(7)}$Te

Author

Guratinder, K., Chan, E., Rodriguez, E. E., Rodriguez-Rivera, J. A., Stuhr, U., Stunault, A., Travers, R., Green, M. A., Qureshi, N., and Stock, C.

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Materials Science
Abstract

Fe$_{1.057(7)}$Te undergoes a first-order tetragonal to monoclinc structural transition at T$_{S} \sim 70$ K, breaking the C$_{4}$ lattice symmetry and simultaneously breaking time reversal symmetry with bicollinear magnetic order. We investigate the soft acoustic lattice dynamics near this combined magneto-structural transition. We apply spherically neutron polarimetry to study the static magnetism near this transition, characterized with x-ray powder diffraction, and find no evidence of static incommensurate magnetic correlations near the onset of monoclinic and bicollinear antiferromagnetic order. This fixes the position of our single crystal sample in the Fe$_{1+x}$Te phase diagram in the magnetic bicollinear region and illustrates that our sample statically undergoes a transition from a paramagnetic phase to a low-temperature bicollinear phase. We then apply neutron spectroscopy to study the acoustic phonons, related to elastic deformations of the lattice. We find a temperature dependent soft acoustic branch for phonons propagating along [010] and polarized along [100]. The slope of this acoustic phonon branch is sensitive to the elastic constant $C_{66}$ and the shear modulus. The temperature dependence of this branch displays a softening with a minimum near the magneto-structural transition of T$_{S}$ $\sim$ 70 K and a recovery within the magnetically ordered low temperature phase. Soft acoustic instabilities are present in the collinear phases of the chalcogenides Fe$_{1+x}$Te where nematic order found in Fe$_{1+\delta}$Se is absent. We speculate, based on localized single-ion magnetism, that the relative energy scale of magnetic spin-orbital coupling on the Fe$^{2+}$ transition metal ion is important for the presence of a nematicity in the chalcogenides., Comment: (13 pages, 10 figures, to be published in Physical Review B)

Published
2023
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3. The accumulation of metals, PAHs and alkyl PAHs in the roots of Echinacea purpurea.

Author

Travers R Pretorius, Christiane Charest, Linda E Kimpe, and Jules M Blais

Subjects
Medicine, Science
Abstract

We examined the accumulation of polycyclic aromatic hydrocarbons (PAHs), alkyl PAHs, and toxic metals in soils by the roots of Echinacea purpurea (L.) Moench, in a 20-week greenhouse study and a 2-year field study. In the greenhouse study, inoculation by arbuscular mycorrhizal fungus (AMF), Rhizoglomus intraradices (N.C. Schenck & G.S. Sm.). increased the first order accumulation rates (k1) for PAHs by 10-fold, though had no effect on the bioaccumulation rates of toxic metals. In the greenhouse study, PAHs concentrations in soil increased over time with AMF inoculation, suggesting AMF promote 'solvent depletion' in soils by enhancing absorption of minerals and carbon by roots, concentrating the more hydrophobic PAHs in the residual soil. Under field conditions, contaminant concentrations in soils remained unchanged over the 2-year duration of the study. Despite this, all contaminants in E. purpurea roots increased significantly, as a result of a long term extraction of contaminants by plants from soil and a reduction in soil volume as a result of plant growth. First order accumulation rates by roots were inversely correlated to log Kow for the PAHs and alkyl PAHs, indicating that accumulation is inversely related to the compound's hydrophobicity. This study is the first to our knowledge to assess the accumulation of alkyl PAHs by roots, with implications for soil bioremediation by plants because alkyl PAHs are a major source of petrogenic contamination in soils.

Published
2018
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18. LBA69 Impact of the COVID-19 pandemic on management of medical cancer treatments and psychological consequence for the patients

Author

Joly, F., primary, Leconte, A., additional, Grellard, J-M., additional, Lequesne, J., additional, Binarelli, G., additional, Lange, M., additional, Tron, L., additional, Gernier, F., additional, Rieux, C., additional, Fernette, M., additional, Bastien, E., additional, Morel, A., additional, Legrand, B., additional, Richard, D., additional, Faveyrial, A., additional, Travers, R., additional, Pépin, L-F., additional, Rigal, O., additional, Jardin, F., additional, and Clarisse, B., additional

Published
2020
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26. The accumulation of metals, PAHs and alkyl PAHs in the roots of Echinacea purpurea

Author

Jules M. Blais, Linda E. Kimpe, Christiane Charest, and Travers R. Pretorius

Subjects
Topography, Applied Microbiology, 010501 environmental sciences, 01 natural sciences, Plant Roots, Contaminants, Agricultural Soil Science, Mycorrhizae, Ecological Remediation, Polycyclic Aromatic Hydrocarbons, Materials, chemistry.chemical_classification, Islands, Multidisciplinary, Ecology, Agriculture, 04 agricultural and veterinary sciences, Contamination, Chemistry, Agricultural soil science, Community Ecology, Bioaccumulation, Environmental chemistry, Physical Sciences, Medicine, Engineering and Technology, Cellular Structures and Organelles, Bioremediation, Research Article, Biotechnology, Environmental Monitoring, Environmental Engineering, Science, Materials Science, Soil Science, Bioengineering, Microbiology, Echinacea, Environmental Biotechnology, Aromatic Hydrocarbons, Vesicles, Alkyl, 0105 earth and related environmental sciences, Landforms, Inoculation, Extraction (chemistry), fungi, Ecology and Environmental Sciences, Chemical Compounds, Biology and Life Sciences, Geomorphology, Cell Biology, Hydrocarbons, chemistry, Soil water, 040103 agronomy & agriculture, Earth Sciences, 0401 agriculture, forestry, and fisheries
Abstract

We examined the accumulation of polycyclic aromatic hydrocarbons (PAHs), alkyl PAHs, and toxic metals in soils by the roots of Echinacea purpurea (L.) Moench, in a 20-week greenhouse study and a 2-year field study. In the greenhouse study, inoculation by arbuscular mycorrhizal fungus (AMF), Rhizoglomus intraradices (N.C. Schenck & G.S. Sm.). increased the first order accumulation rates (k1) for PAHs by 10-fold, though had no effect on the bioaccumulation rates of toxic metals. In the greenhouse study, PAHs concentrations in soil increased over time with AMF inoculation, suggesting AMF promote 'solvent depletion' in soils by enhancing absorption of minerals and carbon by roots, concentrating the more hydrophobic PAHs in the residual soil. Under field conditions, contaminant concentrations in soils remained unchanged over the 2-year duration of the study. Despite this, all contaminants in E. purpurea roots increased significantly, as a result of a long term extraction of contaminants by plants from soil and a reduction in soil volume as a result of plant growth. First order accumulation rates by roots were inversely correlated to log Kow for the PAHs and alkyl PAHs, indicating that accumulation is inversely related to the compound's hydrophobicity. This study is the first to our knowledge to assess the accumulation of alkyl PAHs by roots, with implications for soil bioremediation by plants because alkyl PAHs are a major source of petrogenic contamination in soils.

Published
2018

48. A look at rheumatology in China (2002)

Author

Enzenauer Rj, Ramanujam T, Straka Pc, Wallace D, Luk Aj, Pepmuellar Ph, Svara C, Lan X. Chen, Travers R, Weiss T, Schumacher Hr, Eberhardt R, Watanabe W, Queen Kt, Melnicoff I, and Horwitz Hm

Subjects
medicine.medical_specialty, Rheumatology, business.industry, Internal medicine, Disease patterns, Family medicine, Medicine, Health maintenance, Traditional Chinese medicine, business, China
Abstract

This report describes a visit by an international group interested in Rheumatology to the Rheumatology centers and traditional Chinese medicine units in the People's Republic of China. Differing disease patterns and treatment approaches offer opportunities for studies and collaborations. We can also learn from the traditional Chinese approach with individualization of therapy and attention to health maintenance.

Published
2006

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