Airborne Microorganisms at Hellenic Atmospheric Aerosol and Climate Change Station in Helmos Mountain (Greece)
Bibliographic record
Abstract
High Resolution Image Download MS PowerPoint Slide Cultural-based methods of bacteria and fungi and molecular identification of bacteria were combined with parallel continuous measurements of aerosol chemical composition, number size distribution, ice-nucleating concentration, and fluorescent particle size distribution and characteristics. Measurements took place at the Helmos Hellenic Atmospheric Aerosol and Climate Change Station (HAC) 2, Greece, during the 2021 CALISHTO campaign. The objective was to characterize the microorganism levels at the (HAC) 2 station and further investigate the associations between bioaerosols and aerosols in atmospheric processes that play a key role in the formation of ice crystals. Very low concentrations of viable, cultivable heterotrophic bacteria (4 ± 4 CFU/m 3 ) were measured, whereas fast-growing fungi were not affected (182 ± 86 CFU/m 3 ) by the environmental conditions at the station. The size distribution of heterotrophic bacteria was bimodal with peaks at fine (1.1–2.1 μm) and coarse size fractions ( d > 7 μm), whereas airborne fungi exhibited a monomodal distribution (2.1–3.3 μm). Bacterial populations identified using 16S rRNA correlated well ( r = 0.82) with the averaged concentrations of fluorescent particles (A and C channels). Strong correlations were obtained between total bacterial and particle volume concentrations of coarser fractions (>1 μm, 0.61–0.86), suggesting their strong presence in these sizes. No correlation was found with ice nuclei (INP) ( r = −0.04) and low to medium negative correlations with the organics and ions (SO 4 2–, NH 4 +, NO 3 –, Cl – ) possibly due to their relatively lower sizes. In accordance with the culture-dependent analysis, relatively low total bacterial concentrations were determined by real-time PCR, with concentrations ranging from 33.4 to 117.2 Escherichia coli GE/m 3 . High bacterial diversity was found with 123 bacterial Operational Taxonomy Units (OTUs) classified in 10 phyla, 16 classes, 56 families, and 78 genera. Origin of the air masses was a significant driver to bacterial communities. Enrichment of specific species such as Geodermatophilus africanus and Actinomycetales bacterium was observed during Saharan dust episodes, while in the presence of continental air masses, characteristic species such as Rhizobium sp ., Corynebacterium sp ., and Staphylococcus caprae had higher relative abundance. Our study provides a comprehensive analysis and quantification of the varying drivers and variability in microorganisms in high-altitude site.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".