Perturbirana kutna gama-gama korelacija 208.00 - 59.54 keV u 237Np

The perturbed directional 208.00 - 59.54 keV gamma-gamma angular correlation was measured in 237Np. The static hyperfine coupling between the nuclear magnetic moment and the angular momentum of the electronic states was found present both in the liquid source and in the polycrystallinic source. The spin sequence for the 208.00 → 59.54 → O keV transition was confirmed to be 3/3, 5/2, 5/2 with the mixing ratio δ = + 0.145 for the E2 admixture in the preferably M1 transition. The agreement between directional correlation and internal conversion data was shown to be fairly good. The angular momentum J of the electronic states was determined for both sources : for the polycrystallinic source the J = 1 value gives the attenuation factor G22 (t)J-1 in good agreement with the experimental results, while for the liquid source, the best J value was shown to be J = 3/2. The J-dependent hyperfine structure constant a was determined for the polycrystalinic source as a/ħ = 83 ± 3 MHz and for the liquid source as a/ ħ = 44 ± 2 MHz. The average magnetic field at the place of 237Np nuclei was deduced for the polycrystallinic source H (O)J-1 = 54 ± 14 [kOe] and for the liquid source H (O)J-3/2 = 42 ± 12 [kOe].Mjerena j e perturbirana kutna gama-gama korelacija 208.00 -59.54 keV u 237Np. Pokazano j e da perturbacija ove korelacije za vrijeme života (T1/2 = 63 ns) medijalnog 59.54 keV stanja dolazi od magnetske hiperfine interakcije između magnetskog dipolnog momenta j ezgre i kutne količine gibanja elektronskih stanja za tekući i polikristaliničan izvor. Potvrđen je niz spinova 3/2, 5/2, 5/2 za prijelaz 208.00 → 59.54 → O keV. Omjer miješanja δ = + 0,145 za E 2 primjesu u 208.00 keV u uglavnom M 1 prijelazu je u vrlo dobrom slaganju sa mjerenjima konverzionih koeficijenata. Određena je kutna količina gibanja J = 1 elektronskih stanja za izvor u polikristalnom obliku i J = 3/2 za tekući izvor. Konstanta hiperfine interakcije a (zavisna o kutnoj količini gibanja elektronskih stanja) određena je za oba izvora (u jedinicama ħ): za polikristaliničan izvor a/ ħ = 83 ± 3 [MHz], a za tekući izvor a/ ħ = 44 ± 2 [MHz] . To omogućuje izračunavanje prosječnog magnetskog polja na mjestu jezgre za polikristaliničan izvor H (O)J-1 = 54 ± 14 [kOe] i za tekući izvor H (O)J-3/2 = 42 ± 12 [kOe]

Perturbirana kutna gama-gama korelacija 208.00 - 59.54 keV u 237Np

The perturbed directional 208.00 - 59.54 keV gamma-gamma angular correlation was measured in 237Np. The static hyperfine coupling between the nuclear magnetic moment and the angular momentum of the electronic states was found present both in the liquid source and in the polycrystallinic source. The spin sequence for the 208.00 → 59.54 → O keV transition was confirmed to be 3/3, 5/2, 5/2 with the mixing ratio δ = + 0.145 for the E2 admixture in the preferably M1 transition. The agreement between directional correlation and internal conversion data was shown to be fairly good. The angular momentum J of the electronic states was determined for both sources : for the polycrystallinic source the J = 1 value gives the attenuation factor G22 (t)J-1 in good agreement with the experimental results, while for the liquid source, the best J value was shown to be J = 3/2. The J-dependent hyperfine structure constant a was determined for the polycrystalinic source as a/ħ = 83 ± 3 MHz and for the liquid source as a/ ħ = 44 ± 2 MHz. The average magnetic field at the place of 237Np nuclei was deduced for the polycrystallinic source H (O)J-1 = 54 ± 14 [kOe] and for the liquid source H (O)J-3/2 = 42 ± 12 [kOe].Mjerena j e perturbirana kutna gama-gama korelacija 208.00 -59.54 keV u 237Np. Pokazano j e da perturbacija ove korelacije za vrijeme života (T1/2 = 63 ns) medijalnog 59.54 keV stanja dolazi od magnetske hiperfine interakcije između magnetskog dipolnog momenta j ezgre i kutne količine gibanja elektronskih stanja za tekući i polikristaliničan izvor. Potvrđen je niz spinova 3/2, 5/2, 5/2 za prijelaz 208.00 → 59.54 → O keV. Omjer miješanja δ = + 0,145 za E 2 primjesu u 208.00 keV u uglavnom M 1 prijelazu je u vrlo dobrom slaganju sa mjerenjima konverzionih koeficijenata. Određena je kutna količina gibanja J = 1 elektronskih stanja za izvor u polikristalnom obliku i J = 3/2 za tekući izvor. Konstanta hiperfine interakcije a (zavisna o kutnoj količini gibanja elektronskih stanja) određena je za oba izvora (u jedinicama ħ): za polikristaliničan izvor a/ ħ = 83 ± 3 [MHz], a za tekući izvor a/ ħ = 44 ± 2 [MHz] . To omogućuje izračunavanje prosječnog magnetskog polja na mjestu jezgre za polikristaliničan izvor H (O)J-1 = 54 ± 14 [kOe] i za tekući izvor H (O)J-3/2 = 42 ± 12 [kOe]

Interactive and Single Effects of Ectomycorrhiza Formation and Bacillus cereus on Metallothionein MT1 Expression and Phytoextraction of Cd and Zn by Willows

Single and joint ectomycorrhizal (+ Hebeloma mesophaeum) and bacterial (+ Bacillus cereus) inoculations of willows (Salix viminalis) were investigated for their potential and mode of action in the promotion of cadmium (Cd) and zinc (Zn) phytoextraction. Dual fungal and bacterial inoculations promoted the biomass production of willows in contaminated soil. Single inoculations either had no effect on the plant growth or inhibited it. All inoculated willows showed increased concentrations of nutritional elements (N, P, K and Zn) and decreased concentrations of Cd in the shoots. The lowest biomass production and concentration of Cd in the willows (+ B. cereus) were combined with the strongest expression of metallothioneins. It seems that biotic stress from bacterial invasion increased the synthesis of these stress proteins, which responded in decreased Cd concentrations. Contents of Cd and Zn in the stems of willows were combination-specific, but were always increased in dual inoculated plants. In conclusion, single inoculations with former mycorrhiza-associated B. cereus strains decreased the phytoextraction efficiency of willows by causing biotic stress. However, their joint inoculation with an ectomycorrhizal fungus is a very promising method for promoting the phytoextraction of Cd and Zn through combined physiological effects on the plant

Environmental metabarcoding reveals contrasting belowground and aboveground fungal communities from poplar at a Hg phytomanagement site

Characterization of microbial communities in stressful conditions at a field level is rather scarce, especially when considering fungal communities from aboveground habitats. We aimed at characterizing fungal communities from different poplar habitats at a Hg-contaminated phytomanagement site by using Illumina-based sequencing, network analysis approach, and direct isolation of Hg-resistant fungal strains. The highest diversity estimated by the Shannon index was found for soil communities, which was negatively affected by soil Hg concentration. Among the significant correlations between soil operational taxonomic units (OTUs) in the co-occurrence network, 80% were negatively correlated revealing dominance of a pattern of mutual exclusion. The fungal communities associated with Populus roots mostly consisted of OTUs from the symbiotic guild, such as members of the Thelephoraceae, thus explaining the lowest diversity found for root communities. Additionally, root communities showed the highest network connectivity index, while rarely detected OTUs from the Glomeromycetes may have a central role in the root network. Unexpectedly high richness and diversity were found for aboveground habitats, compared to the root habitat. The aboveground habitats were dominated by yeasts from the Lalaria, Davidiella, and Bensingtonia genera, not detected in belowground habitats. Leaf and stem habitats were characterized by few dominant OTUs such as those from the Dothideomycete class producing mutual exclusion with other OTUs. Aureobasidium pullulans, one of the dominating OTUs, was further isolated from the leaf habitat, in addition to Nakazawaea populi species, which were found to be Hg resistant. Altogether, these findings will provide an improved point of reference for microbial research on inoculation-based programs of tailings dumps

Halophyte–Endophyte Interactions: Linking Microbiome Community Distribution and Functionality to Salinity

Many plants are unable to adapt to rapid environmental changes (e.g., salinity, drought, or limited nutrients) and may acquire assistance from microbes that have the capacity to increase tolerance of host-plants in stress conditions. By having the right microbes, the plants are more resilient! Such microbes include endophytes that inhabit inner tissues of the plant without causing symptoms of disease in their host. However, this plant–endophytic association exists only when chemical equilibrium is maintained between both, therefore making this mutualistic interaction even more unique. Therefore it is interesting to decode the endophytic community composition in halophytes specifically in the most salt-tolerant halophyte species Salicornia europaea, and further determine the factors that could affect this association. Moreover, understanding the endophytes potential plant growth-promoting activities in association with host (S. europaea) and non-host plant (non-halophytes) are the focus of this chapter

A window into fungal endophytism in Salicornia europaea: deciphering fungal characteristics as plant growth promoting agents

Aim Plant-endophytic associations exist only when equilibrium is maintained between both partners. This study analyses the properties of endophytic fungi inhabiting a halophyte growing in high soil salinity and tests whether these fungi are beneficial or detrimental when non-host plants are inoculated. Method Fungi were isolated from Salicornia europaea collected from two sites differing in salinization history (anthropogenic and naturally saline) and analyzed for plant growth promoting abilities and non-host plant interactions. Results Most isolated fungi belonged to Ascomycota (96%) including dematiaceous fungi and commonly known plant pathogens and saprobes. The strains were metabolically active for siderophores, polyamines and indole-3-acetic acid (mainly Aureobasidium sp.) with very low activity for phosphatases. Many showed proteolytic, lipolytic, chitinolytic, cellulolytic and amylolytic activities but low pectolytic activity. Different activities between similar fungal species found in both sites were particularly seen for Epiccocum sp., Arthrinium sp. and Trichoderma sp. Inoculating the non-host Lolium perenne with selected fungi increased plant growth, mainly in the symbiont (Epichloë)-free variety. Arthrinium gamsii CR1-9 and Stereum gausapatum ISK3-11 were most effective for plant growth promotion. Conclusions This research suggests that host lifestyle and soil characteristics have a strong effect on endophytic fungi, and environmental stress could disturb the plant-fungi relations. In favourable conditions, these fungi may be effective in facilitating crop production in non-cultivable saline lands

Mossbauer mineralogy of rock, soil, and dust at Meridiani Planum, Mars: Opportunity's journey across sulfate-rich outcrop, basaltic sand and dust, and hematite lag deposits

The Mössbauer (MB) spectrometer on Opportunity measured the Fe oxidation state, identified Fe-bearing phases, and measured relative abundances of Fe among those phases at Meridiani Planum, Mars. Eight Fe-bearing phases were identified: jarosite (K,Na,H3O)(Fe,Al)(OH)6(SO4)2, hematite, olivine, pyroxene, magnetite, nanophase ferric oxides (npOx), an unassigned ferric phase, and metallic Fe (kamacite). Burns Formation outcrop rocks consist of hematite-rich spherules dispersed throughout S-rich rock that has nearly constant proportions of Fe3+ from jarosite, hematite, and npOx (29%, 36%, and 20% of total Fe). The high oxidation state of the S-rich rock (Fe3+/FeT ~ 0.9) implies that S is present as the sulfate anion. Jarosite is mineralogical evidence for aqueous processes under acid-sulfate conditions because it has structural hydroxide and sulfate and it forms at low pH. Hematite-rich spherules, eroded from the outcrop, and their fragments are concentrated as hematite-rich soils (lag deposits) on ripple crests (up to 68% of total Fe from hematite). Olivine, pyroxene, and magnetite are primarily associated with basaltic soils and are present as thin and locally discontinuous cover over outcrop rocks, commonly forming aeolian bedforms. Basaltic soils are more reduced (Fe3+/FeT ~ 0.2–0.4), with the fine-grained and bright aeolian deposits being the most oxidized. Average proportions of total Fe from olivine, pyroxene, npOx, magnetite, and hematite are 33%, 38%, 18%, 6%, and 4%, respectively. TheMB parameters of outcrop npOx and basaltic-soil npOx are different, but it is not possible to infer mineralogical information beyond octahedrally coordinated Fe3+. Basaltic soils at Meridiani Planum and Gusev crater have similar Fe-mineralogical compositions.Additonal co-authors: P Gütlich, E Kankeleit, T McCoy, DW Mittlefehldt, F Renz, ME Schmidt, B Zubkov, SW Squyres, RE Arvidso