A temporally and spatially explicit, data-driven estimation of airborne ragweed pollen concentrations across Europe.

Ongoing and future climate change driven expansion of aeroallergen-producing plant species comprise a major human health problem across Europe and elsewhere. There is an urgent need to produce accurate, temporally dynamic maps at the continental level, especially in the context of climate uncertainty. This study aimed to restore missing daily ragweed pollen data sets for Europe, to produce phenological maps of ragweed pollen, resulting in the most complete and detailed high-resolution ragweed pollen concentration maps to date. To achieve this, we have developed two statistical procedures, a Gaussian method (GM) and deep learning (DL) for restoring missing daily ragweed pollen data sets, based on the plant's reproductive and growth (phenological, pollen production and frost-related) characteristics. DL model performances were consistently better for estimating seasonal pollen integrals than those of the GM approach. These are the first published modelled maps using altitude correction and flowering phenology to recover missing pollen information. We created a web page (http://euragweedpollen.gmf.u-szeged.hu/), including daily ragweed pollen concentration data sets of the stations examined and their restored daily data, allowing one to upload newly measured or recovered daily data. Generation of these maps provides a means to track pollen impacts in the context of climatic shifts, identify geographical regions with high pollen exposure, determine areas of future vulnerability, apply spatially-explicit mitigation measures and prioritize management interventions.

Effects of non-toxic zinc exposure on human epidermal keratinocytes.

Zinc is an essential microelement; its importance to the skin is highlighted by the severe skin symptoms in hereditary or acquired zinc deficiency, by the improvement of several skin conditions using systemic or topical zinc preparations and by the induced intracellular zinc release upon UVB exposure, which is the main harmful environmental factor to the skin. Understanding the molecular background of the role of zinc in skin may help gain insight into the pathology of skin disorders and provide evidence for the therapeutic usefulness of zinc supplementation. Herein, we studied the effects of zinc chloride (ZnCl2) exposure on the function of HaCaT keratinocytes, and the results showed that a non-toxic elevation in the concentration of extracellular zinc (100 µM) facilitated cell proliferation and induced significant alterations in the mRNA expression of NOTCH1, IL8, and cyclooxygenase-2. In addition, increased heme oxygenase-1 (HMOX1) expression and non-toxic generation of superoxide were detected in the first 4 h. Regarding the effects on the UVB-induced toxicity, although the level of cyclobutane pyrimidine dimers in the keratinocytes pre-treated with zinc for 24 h was reduced 3 h after UVB irradiation, significantly enhanced superoxide generation was observed 10 h after UVB exposure in the zinc pre-exposed cells. The overall survival was unaffected; however, there was a decrease in the percentage of early apoptotic cells and an increase in the percentage of late apoptotic plus necrotic cells. These results suggest that the exposure of human keratinocytes to non-toxic concentrations of ZnCl2 impacts gene expression, cell proliferation and the responses to environmental stress in the skin. It would be important to further examine the role of zinc in skin and further clarify whether this issue can affect our thinking regarding the pathogenesis of skin diseases.