Simulation evaluation on a compact monitor for gamma-emitting tracers in plant stems

Non-destructive monitoring of radioactivities derived from radioactive tracers at multiple points in plant stems can be used to evaluate the velocity of element transport in living plants. In this study, we calculated absorption-efficiency distributions for several detector geometries to determine appropriate shapes for non-destructive monitoring of radioactivities in the stem. The efficiency distributions were calculated by Monte Carlo simulations, and the flatnesses and spatial resolutions were evaluated. It was found that the placement of four detectors around the stem could limit the percentage of standard deviation to the mean of the pixel values to less than 5%. We could determine a compact detector geometry with the spatial resolution of 1.35 cm using four small detectors. The detection efficiencies were 0.014, 0.0030 and 0.00063 cm at the initial gamma-ray energies of 0.5, 1 and 2 MeV, which is sufficiently applicable to detect 10 kBq/cm of radioactivity.

The position of geochemical variables as causal co-factors of diseases of unknown aetiology

The term diseases of unknown aetiology (DUA) or idiopathic diseases refers to diseases that are of uncertain or unknown cause or origin. Among plausible geoenvironmental (co-)factors in causation of DUA, this article focusses on the entry of trace elements, including metals and metalloids into biological systems, and their involvement in humoral and cellular immune responses, representing potentially toxic agents with implications as co-factors for certain DUA. Several trace elements/metals/metalloids (micronutrients) play vital roles as cofactors for essential enzymes and antioxidant molecules, thus, conferring protection against disease. However, inborn errors of trace element/metal/metalloid metabolisms can occur to produce toxicity, such as when there are basic defects in the element transport mechanism. Ultimately, it is the amount of trace element, metal or metalloid that is taken up, its mode of accumulation in human tissues, and related geomedical attributes such as the chemical form and bioavailability that decisively determine whether the exerted effects are toxic or beneficial. Several case descriptions of DUA that are common worldwide are given to illustrate our knowledge so far of how trace element/metal/metalloid interactions in the immune system may engender its dysregulation and be implicated as causal co-factors of DUA.

Supplemental Material: Quantifying metasomatic high-field-strength and rare-earth element transport from alkaline magmas

Petrographic information, parameterization of the Grant model, description of the HFSE tonnage estimation method, and supplemental tables of whole-rock data, standardization, and HFSE volume-tonnage calculations.<br>

Supplemental Material: Quantifying metasomatic high-field-strength and rare-earth element transport from alkaline magmas

Petrographic information, parameterization of the Grant model, description of the HFSE tonnage estimation method, and supplemental tables of whole-rock data, standardization, and HFSE volume-tonnage calculations.<br>

Nanobiofertilization as a novel technology for highly efficient foliar application of Fe and B in almond trees

Nanofertilization is postulated as a new technology to deal with the environmental problems caused by the intensive use of traditional fertilizers. One of the aims of this new technology is to improve foliar fertilization, which has many environmental advantages, but currently there are numerous factors that limit its efficiency. In this research, the objective was to study the potential of membrane vesicles derived from plant material as nanofertilizers of iron (Fe) and boron (B) for foliar application in almond trees (Prunus dulcis L.). The results show that the application of vesicles caused invaginations in the plasma membrane of the leaf cells. Also, the increase in leaf B and Fe was greater when these elements were applied in an encapsulated form rather than in a non-encapsulated form. The distribution of these elements in leaf tissues indicated the existence of an intracellular element transport pathway and accumulation areas, enabling greater element entry and mobility.