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We describe here a previously unreported source of diatom contamination that may prove relevant in routine diatom analysis in suspected drowning cases. Glass microscope slides utilized in the process, during their manufacture, undergo a washing process, after which, diatomaceous earth (kieselguhr, fossil diatoms) is added to avoid producing stuck slides during the last rinse. The diatomaceous earth can be removed at this point only by means of aggressive cleaning, but the possibility exists that some fossil diatoms will remain on the slides. This potential contamination source explained a recurrent and otherwise puzzling appearance of Aulacoseira diatom genus in samples both from definite drowning cases and from non-drowned control cases. Discrimination by expert diatomologists between present-day fresh diatoms and fossil diatoms, together with awareness of the ubiquity of diatoms in nature and of their extensive use in the manufacturing industry, corroborate our view that potential sources of laboratory contamination should not be a rational impediment to performing diatom tests.
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http://dx.doi.org/10.1007/s00414-025-03527-w | DOI Listing |
PeerJ
August 2025
Department of Life Sciences and Systems Biology, University of Turin, Torino, Italy.
Artificial lighting in show caves is responsible for the growth of nuisance photosynthetic organisms, the so-called , causing aesthetic, chemical and physical damage to cave cultural heritage, including paleontological resources . This study focuses on the role of substrate in determining the concentration of on paleontological findings in show caves, using the bone deposit "Cimitero degli Orsi" in the Toirano show cave (NW-Italy) as a testing ground. Specifically, we investigated whether the concentration of three distinct photosynthetic microorganisms-cyanobacteria, diatoms, and green algae-varies on different substrates, , bones, rock, and soil, also keeping into account the role of light intensity.
View Article and Find Full Text PDFInt J Legal Med
June 2025
Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, Helsinki Institute of Sustainability Science (HELSUS), University of Helsinki, Helsinki, FI-00014, Finland.
We describe here a previously unreported source of diatom contamination that may prove relevant in routine diatom analysis in suspected drowning cases. Glass microscope slides utilized in the process, during their manufacture, undergo a washing process, after which, diatomaceous earth (kieselguhr, fossil diatoms) is added to avoid producing stuck slides during the last rinse. The diatomaceous earth can be removed at this point only by means of aggressive cleaning, but the possibility exists that some fossil diatoms will remain on the slides.
View Article and Find Full Text PDFMethodsX
June 2025
CNRS, Aix Marseille Univ, IRD, INRA, CEREGE, Aix-en-Provence, France.
Phytoliths are amorphous silica particles that precipitate within and between plant cells, and their fossilized morphological assemblages are widely used to reconstruct paleo-vegetation. The triple oxygen isotope composition of phytoliths, expressed by the O-excess, is a promising proxy to reconstruct atmospheric relative humidity (RH). However, fossil phytoliths in lake or peat sediments often coexist with diatom frustules and sponge spicules, whose oxygen isotope signatures contribute to the average isotopic composition of biogenic silica, biasing the RH reconstruction.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
June 2025
Department of Botany and Biodiversity Research, University of Vienna, Vienna 1030, Austria.
Evolution is often uneven in its pace and outcomes, with long periods of stasis interrupted by abrupt increases in morphological and ecological disparity. With thousands of gene histories, phylogenomics can uncover the genomic signatures of these broad macroevolutionary trends. Diatoms are a species-rich lineage of microeukaryotes that contribute greatly to the global cycling of carbon, oxygen, and silica, which they use to build elaborately structured cell walls.
View Article and Find Full Text PDFSci Total Environ
December 2024
Department of Paleoecology, Institute of Botany of the Czech Academy of Sciences, Lidická 25/27, 602 00 Brno, Czech Republic; Department of the Botany and Zoology, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic.
Quantitative paleoecological reconstructions using biological proxies, such as diatoms, Cladocera, and chironomids, have revolutionized paleolimnology and have greatly contributed to the understanding of the past local and regional environmental changes, as well as to nature conservation. While macrophytes are good ecological indicators, they have rarely been used to reconstruct past lake-water chemistry. The present study investigates which environmental variable best explains aquatic plant community composition in Finnish, Polish, and Swedish lakes for its further use in quantitative paleoenvironmental reconstructions.
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