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The study presents a multimodal analytical approach combining X-ray fluorescence (XRF) and micro-Raman spectroscopy to characterize the mineralogical and geochemical complexity of several meteorites, including ureilites, CO3 carbonaceous chondrite and Rumuruti meteorite. XRF provided bulk elemental compositions, revealing low Ni and low Co metal enrichments in ureilites and Mg-Si-dominated matrices in the carbonaceous chondrite and Rumuruti sample. Micro-Raman spectroscopy enabled spatially resolved identification of carbon phases and silicate mineralogies, uncovering presence of shock-induced nanodiamonds coexisting with graphite in the ureilite samples, and disordered carbonaceous matter in the CO3 chondrite. Olivine and pyroxene compositions exhibited distinct redox histories, with ureilites showing low-Ca pyroxene and coarse-grained olivine, contrasting with the Rumuruti sample’s ferroan olivine (Fa38). The synergy of XRF and micro-Raman spectroscopy resolved ambiguities in shock-induced carbon phase discrimination, particularly in distinguishing nanodiamonds from amorphous carbon. Our results demonstrate the necessity of complementary techniques for deciphering meteoritic heterogeneity, with micro-Raman spectroscopy proving indispensable for probing shock metamorphism and spatially complex mineral assemblages. This work advances methodologies for extraterrestrial sample analysis, emphasizing the role of high-resolution, non-destructive tools in planetary material studies.

In natural conditions, plants growth and development depends on environmental conditions, including the availability of micro- and macroelements in the soil. Nutrient status should thus be examined not by establishing the effects of single nutrient deficiencies on the physiological state of the plant but by combinations of them. Differences in the nutrient content significantly affect the photochemical process of photosynthesis therefore playing a crucial role in plants growth and development. In this work, an attempt was made to find a connection between element content in (i) different soils, (ii) plant leaves, grown on these soils and (iii) changes in selected chlorophyll a fluorescence parameters, in order to find a method for early detection of plant stress resulting from the combination of nutrient status in natural conditions. To achieve this goal, a mathematical procedure was used which combines principal component analysis (a tool for the reduction of data complexity), hierarchical k-means (a classification method) and a machine-learning method—super-organising maps. Differences in the mineral content of soil and plant leaves resulted in functional changes in the photosynthetic machinery that can be measured by chlorophyll a fluorescent signals. Five groups of patterns in the chlorophyll fluorescent parameters were established: the ‘no deficiency’, Fe-specific deficiency, slight, moderate and strong deficiency. Unfavourable development in groups with nutrient deficiency of any kind was reflected by a strong increase in Fo and ΔV/Δt0 and decline in φPo, φEoδRo and φRo. The strong deficiency group showed the suboptimal development of the photosynthetic machinery, which affects both PSII and PSI. The nutrient-deficient groups also differed in antenna complex organisation. Thus, our work suggests that the chlorophyll fluorescent method combined with machine-learning methods can be highly informative and in some cases, it can replace much more expensive and time-consuming procedures such as chemometric analyses.

Photosynthetic oxygen evolution (measured by polarographic oxygen rate electrode) and pulse amplitude modulated chlorophyll fluorescence were used to assess the effect of sanosil-induced oxidative stress on photosystem II (PSII) in the green alga Chlorella vulgaris and the cyanobacterium Synechocystis salina isolated from Antarctic and mesophilic environments. This study revealed a relatively stronger influence of sanosil (especially its main component, hydrogen peroxide) on the donor site (oxygen evolving complex) compared to the acceptor side of the PSII in both green algae and cyanobacteria. The inhibition of the oxygen evolution results mainly from a decrease in the fast operating PSII centers. In addition, the obtained data showed that the effects of the oxidative stress on the cyanobacterium and the green alga strongly depend on the antenna size of PSII.

The green alga Chlorella vulgaris and the cyanobacterium Synechocystis salina cells isolated from Antarctic and mesophilic environments, grown in batch cultures under continuous visible light, were used to assess the effect of the UV-B radiation on the photosystem II (PSII). UV-induced changes in its functional activity were estimated by Pulse Amplitude Modulated chlorophyll fluorescence and oxygen evolution (measured with oxygen rate electrode). The data reveal a relatively stronger UV-B-induced inhibition of oxygen evolution in comparison to that of the primary photochemistry of the PSII in both green algae and cyanobacteria. The inhibition of oxygen evolution was a result of the decrease in the number of functionally active PSII centers. The modification of active reaction centers was also recorded through the relatively more effect on fast operating PSII centers than that of the slow operating PSII centers. On the other hand, the PSII activity of cyanobacteria was more vulnerable to UV-B radiation than that of green algae. Likewise, the mesophilic strain of S. salina was more susceptible to UV-B radiation than the Antarctic isolates.