We studied the dominant protists found in soils across the globe and their contributions to belowground food webs.
We studied the dominant protists found in soils across the globe and their contributions to belowground food webs.
How the multiple facets of soil fungal diversity vary worldwide remains virtually unknown, hindering the management of this essential species-rich group. By sequencing high-resolution DNA markers in over 4000 topsoil samples from natural and human-altered ecosystems across all continents, we illustrate the distributions and drivers of different levels of taxonomic and phylogenetic diversity of fungi and their ecological groups. We show the impact of precipitation and temperature interactions on local fungal species richness (alpha diversity) across different climates. Our findings reveal how temperature drives fungal compositional turnover (beta diversity) and phylogenetic diversity, linking them with regional species richness (gamma diversity). We integrate fungi into the principles of global biodiversity distribution and present detailed maps for biodiversity conservation and modeling of global ecological processes.
Soil tillage promotes changes in soil structure. The magnitude of the changes varies with the nature of the soil, tillage system and soil water content and decreases over time after tillage. The objective of this study was to evaluate short-term (one year period) and long-term (nine year period) effects of soil tillage and nutrient sources on some physical properties of a very clayey Hapludox. Five tillage systems were evaluated: no-till (NT), chisel plow + one secondary disking (CP), primary + two (secondary) diskings (CT), CT with burning of crop residues (CTb), and CT with removal of crop residues from the field (CTr), in combination with five nutrient sources: control without nutrient application (C); mineral fertilizers, according to technical recommendations for each crop (MF); 5 Mg ha-1 yr-1 of poultry litter (wetmatter) (PL); 60 m\uffc2\uffb3 ha-1 yr-1 of cattle slurry (CS) and; 40 m\uffc2\uffb3 ha-1 yr-1 of swine slurry (SS). Bulk density (BD), total porosity (TP), and parameters related to the water retention curve (macroporosity, mesoporosity and microporosity) were determined after nine years and at five sampling dates during the tenth year of the experiment. Soil physical properties were tillage and time-dependent. Tilled treatments increased total porosity and macroporosity, and reduced bulk density in the surface layer (0.00-0.05 m), but this effect decreased over time after tillage operations due to natural soil reconsolidation, since no external stress was applied in this period. Changes in pore size distribution were more pronounced in larger and medium pore diameter classes. The bulk density was greatest in intermediate layers in all tillage treatments (0.05-0.10 and 0.12-0.17 m) and decreased down to the deepest layer (0.27-0.32 m), indicating a more compacted layer around 0.05-0.20 m. Nutrient sources did not significantly affect soil physical and hydraulic properties studied.
", "keywords": ["2. Zero hunger", "distribui\u00e7\u00e3o de tamanho de poros", "bulk density", "pore size distribution", "manure", "dejetos animais", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "15. Life on land", "densidade do solo", "6. Clean water"]}, "links": [{"href": "https://doi.org/10.1590/s0100-06832008000400008"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Revista%20Brasileira%20de%20Ci%C3%AAncia%20do%20Solo", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1590/s0100-06832008000400008", "name": "item", "description": "10.1590/s0100-06832008000400008", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1590/s0100-06832008000400008"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2008-08-01T00:00:00Z"}}, {"id": "10.3389/fmicb.2020.568224", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:21:32Z", "type": "Journal Article", "created": "2020-10-27", "title": "Exopolysaccharide Features Influence Growth Success in Biocrust-forming Cyanobacteria, Moving From Liquid Culture to Sand Microcosms", "description": "Land degradation in drylands is a drawback of the combined action of climate change and human activities. New techniques have been developed to induce artificial biocrusts formation as a tool for restoration of degraded drylands, and among them soils inoculation with cyanobacteria adapted to environmental stress. Improvement of soil properties by cyanobacteria inoculation is largely related to their ability to synthesize exopolysaccharides (EPS). However, cyanobacterial EPS features [amount, molecular weight (MW), composition] can change from one species to another or when grown in different conditions. We investigated the differences in growth and polysaccharidic matrix features among three common biocrust-forming cyanobacteria (Nostoc commune, Scytonema javanicum, and Phormidium ambiguum), when grown in liquid media and on sandy soil microcosms under optimal nutrient and water, in controlled laboratory conditions. We extracted and analyzed the released EPS (RPS) and sheath for the liquid cultures, and the more soluble or loosely-bound (LB) and the more condensed or tightly-bound (TB) soil EPS fractions for the sandy soil microcosms. In liquid culture, P. ambiguum showed the greatest growth and EPS release. In contrast, on the sandy soil, S. javanicum showed the highest growth and highest LB-EPS content. N. commune showed no relevant growth after its inoculation of the sandy soil. A difference was observed in terms of MW distribution, showing that the higher MW of the polymers produced by P. ambiguum and S. javanicum compared to the polymers produced by N. commune, could have had a positive effect on growth for the first two organisms when inoculated on the sandy soil. We also observed how both RPS and sheath fractions reflected in the composition of the soil TB-EPS fraction, indicating the role in soil stabilization of both the released and the cell attached EPS. Our results indicate that the features of the polysaccharidic matrix produced by different cyanobacteria can influence their growth success in soil. These results are of great relevance when selecting suitable candidates for large-scale cyanobacteria applications in soil restoration.", "keywords": ["0301 basic medicine", "2. Zero hunger", "0303 health sciences", "EPS monosaccharidic composition", "15. Life on land", "sand inoculation", "semiarid soil", "Microbiology", "QR1-502", "6. Clean water", "03 medical and health sciences", "EPS molecular weight distribution", "13. Climate action", "cyanobacteria liquid culture", "cyanobacteria liquid culture", " sand inoculation", " sandy soil microcosms", " EPS monosaccharidic composition", " EPS molecular weight distribution", " semiarid soil", "sandy soil microcosms"]}, "links": [{"href": "https://flore.unifi.it/bitstream/2158/1215077/2/fmicb-11-568224.pdf"}, {"href": "https://doi.org/10.3389/fmicb.2020.568224"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3389/fmicb.2020.568224", "name": "item", "description": "10.3389/fmicb.2020.568224", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3389/fmicb.2020.568224"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-10-27T00:00:00Z"}}, {"id": "10.1785/0220200337", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:20:38Z", "type": "Journal Article", "created": "2020-12-16", "title": "\"Inconsistencies and Lurking Pitfalls in the Magnitude–Frequency Distribution of High-Resolution Earthquake Catalogs\"", "description": "AbstractEarthquake catalogs describe the distribution of earthquakes in space, time, and magnitude, which is essential information for earthquake forecasting and the assessment of seismic hazard and risk. Available high-resolution (HR) catalogs raise the expectation that their abundance of small earthquakes will help better characterize the fundamental scaling laws of statistical seismology. Here, we investigate whether the ubiquitous exponential-like scaling relation for magnitudes (Gutenberg\uffe2\uff80\uff93Richter [GR], or its tapered version) can be straightforwardly extrapolated to the magnitude\uffe2\uff80\uff93frequency distribution (MFD) of HR catalogs. For several HR catalogs such as of the 2019 Ridgecrest sequence, the 2009 L\uffe2\uff80\uff99Aquila sequence, the 1992 Landers sequence, and entire southern California, we determine if the MFD agrees with an exponential-like distribution using a statistical goodness-of-fit test. We find that HR catalogs usually do not preserve the exponential-like MFD toward low magnitudes and depart from it. Surprisingly, HR catalogs that are based on advanced detection methods depart from an exponential-like MFD at a similar magnitude level as network-based HR catalogs. These departures are mostly due to an improper mixing of different magnitude types, spatiotemporal inhomogeneous completeness, or biased data recording or processing. Remarkably, common-practice methods to find the completeness magnitude do not recognize these departures and lead to severe bias in the b-value estimation. We conclude that extrapolating the exponential-like GR relation to lower magnitudes cannot be taken for granted, and that HR catalogs pose subtle new challenges and lurking pitfalls that may hamper their proper use. The simplest solution to preserve the exponential-like distribution toward low magnitudes may be to estimate a moment magnitude for each earthquake.
", "keywords": ["statistical seismology", "earthquake statistics", "earthquake magnitude", "13. Climate action", "hypothesis testing", "0103 physical sciences", "earthquake catalog", "exponential distribution", "Gutenberg-Richter", "01 natural sciences", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://www.iris.unina.it/bitstream/11588/849560/4/Herrmann%20%282020%29%20Marzocchi%20%5bSRL%5d%20Inconsistencies%20and%20Lurking%20Pitfalls%20in%20the%20Magnitude%e2%80%93Frequency%20Distribution%20of%20High-Resolution%20Earthquake%20Catalogs.pdf"}, {"href": "https://doi.org/10.1785/0220200337"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Seismological%20Research%20Letters", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1785/0220200337", "name": "item", "description": "10.1785/0220200337", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1785/0220200337"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-12-16T00:00:00Z"}}, {"id": "10.3390/rs14102504", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:21:52Z", "type": "Journal Article", "created": "2022-05-24", "title": "Digital Mapping of Soil Organic Carbon with Machine Learning in Dryland of Northeast and North Plain China", "description": "Due to the importance of soil organic carbon (SOC) in supporting ecosystem services, accurate SOC assessment is vital for scientific research and decision making. However, most previous studies focused on single soil depth, leading to a poor understanding of SOC in multiple depths. To better understand the spatial distribution pattern of SOC in Northeast and North China Plain, we compared three machine learning algorithms (i.e., Cubist, Extreme Gradient Boosting (XGBoost) and Random Forest (RF)) within the digital soil mapping framework. A total of 386 sampling sites (1584 samples) following specific criteria covering all dryland districts and counties and soil types in four depths (i.e., 0\u201310, 10\u201320, 20\u201330 and 30\u201340 cm) were collected in 2017. After feature selection from 249 environmental covariates by the Genetic Algorithm, 29 variables were used to fit models. The results showed SOC increased from southern to northern regions in the spatial scale and decreased with soil depths. From the result of independent verification (validation dataset: 80 sampling sites), RF (R2: 0.58, 0.71, 0.73, 0.74 and RMSE: 3.49, 3.49, 2.95, 2.80 g kg\u22121 in four depths) performed better than Cubist (R2: 0.46, 0.63, 0.67, 0.71 and RMSE: 3.83, 3.60, 3.03, 2.72 g kg\u22121) and XGBoost (R2: 0.53, 0.67, 0.70, 0.71 and RMSE: 3.60, 3.60, 3.00, 2.83 g kg\u22121) in terms of prediction accuracy and robustness. Soil, parent material and organism were the most important covariates in SOC prediction. This study provides the up-to-date spatial distribution of dryland SOC in Northeast and North China Plain, which is of great value for evaluating dynamics of soil quality after long-term cultivation.
We revise the Merodon constans species group of the genus Merodon Meigen, 1803 (Diptera: Syrphidae), provide morphological diagnosesand descriptions, as well as an illustrated key and a discussion on the different taxonomic characters used. In total, 15 species were studied, their geographic distributions are presented on maps, and nine new species are described. Two species are redefined and neotypes are designated, lectotypes are designated for five species, and onespeciesis reinstated as valid. Following a detailed study of type material in different entomological collections, the status of several species is revised and three new synonymies are proposed. The M. constans species group was resolved as being monophyletic within the M. albifrons lineage based on molecular analyses using COI and 28S rRNA gene sequences. Three species morphologically similar to M. constans (Rossi, 1794) but occurring outside its distributional rangewere supported as being valid and distinct species on the basis of molecular data, but they were not distinguishable based on morphological characters. By contrast, continental populations of M. analis Meigen, 1822 could not be separated from Mediterranean M. constans based on differences in COI or 28S rRNA genes. The same molecular markers could not discriminate between two other species pairs. We conclude that these molecular markers only partially resolve species within the M. constans group. Geometric morphometry of wing shape successfully separated M. analis and M. constans, as well as M. spineus Vuji\u0107, \u0160a\u0161i\u0107 Zori\u0107 & Likov, sp. nov. in both species and population analyses.
Abstract. The particle size distribution (PSD) of mineral dust has a strong effect on the impacts of dust on climate. However, our understanding of the emitted dust PSD, including its variability and the fraction of super-coarse dust (diameter >10\u2009\u00b5m), remains limited. Here, we provide new insights into the size-resolved dust emission process based on a field campaign performed in the Moroccan Sahara in September\u00a02019 in the context of the FRontiers in dust minerAloGical coMposition and its Effects upoN climaTe (FRAGMENT) project. The obtained dust concentration and diffusive flux PSDs show significant dependencies upon the friction velocity (u*), wind direction and type of event (regular events versus haboob events). For instance, the number fraction of sub-micrometre particles increases with u*, along with a large decrease in the mass fraction of super-coarse dust. We identify dry deposition, which is modulated by u* and fetch length, as a potential cause for this PSD variability. Using a resistance model constrained with field observations to estimate the dry deposition flux and thereby also the emitted dust flux, we show that deposition could represent up to \u223c90\u2009% of the emission of super-coarse particles (>10\u2009\u00b5m) and up to \u223c65\u2009% of the emission of particles as small as \u223c5\u2009\u00b5m in diameter. Importantly, removing the deposition component significantly reduces the variability with u* in the PSD of the emitted dust flux compared with the diffusive flux, particularly for super-coarse dust. The differences between regular and haboob event concentration and diffusive flux PSDs are suspected to result from a smaller and variable dust source fetch during the haboob events, and/or an increased resistance of soil aggregates to fragmentation associated with the observed increase in relative humidity along the haboob outflow. Finally, compared to the invariant emitted dust flux PSD estimated based on brittle fragmentation theory, we obtain a substantially higher proportion of super-micrometre particles in the dust flux. Overall, our results suggest that dry deposition needs to be adequately considered to estimate the emitted PSD, even in studies limited to the fine and coarse size ranges (<10\u2009\u00b5m).
Mineral dust particles suspended in the atmosphere span more than three orders of magnitude in diameter, from less than 0.1 \u00b5m to more than 100 \u00b5m. This wide size range makes dust a unique aerosol species with the ability to interact with many aspects of the Earth system, including radiation, clouds, hydrology, atmospheric chemistry, and biogeochemistry. This review focuses on coarse and super-coarse dust aerosols, which we respectively define as dust particles with a diameter between 2.5 - 10 \u00b5m and 10 - 62.5 \u00b5m. We review several lines of observational evidence indicating that coarse and super-coarse dust particles are transported farther than previously expected and that the abundance of these particles is substantially underestimated in current global models. We synthesize previous studies that used observations, theories, and model simulations to highlight the impacts of coarse and super-coarse dust aerosols on the Earth system, including their effects on dust-radiation interactions, dust-cloud interactions, and atmospheric chemistry, and biogeochemistry. In addition, we examine several limitations in the representation of coarse and super-coarse dust aerosols in current model simulations and in remote-sensing retrievals. Because these limitations substantially contribute to the uncertainties in simulating the abundance and impacts of coarse and super-coarse dust aerosols, we offer some recommendations to facilitate future studies. Overall, we conclude that an accurate representation of coarse and super-coarse properties is critical in understanding the overall impacts of dust aerosols on the Earth system.
In this paper, the Merodon avidus (Diptera, Syrphidae) species complex was revised, whereupon we discovered and described four new species for science: Merodon atroavidus Vuji\u0107, Radenkovi\u0107 et Likov sp. nov., M. magnus Vuji\u0107, Ko\u010di\u0161 Tubi\u0107 et A\u010danski sp. nov., M. nigroscutum Vuji\u0107, Radenkovi\u0107 et Likov sp. nov. and M. pseudomoenium Vuji\u0107, Ko\u010di\u0161 Tubi\u0107 et A\u010danski sp. nov. An integrative taxonomy approach was used to delimit species boundaries. Two molecular markers (the mitochondrial COI gene and nuclear 28S rRNA gene\u2014newly analysed marker for the complex) and geometric morphometry of the wing shape, together with morphological data and distribution, successfully separated all species from the complex. The morphological variability of the analysed species is described and discussed and an illustrated diagnostic key for typical morpho-forms of species from the M. avidus complex is presented. A distribution map of all investigated species from the complex is provided. The level of endemicity of the M. avidus complex was discussed.
We analyzed the performance and throughput of currently available analytical techniques for quantifying body burden and cell internalization/distribution of silver nanoparticles (Ag NPs). Our review of Ag NP biological fate data shows that most of the evidence gathered for Ag NPs body burden actually points to total Ag and not only Ag NPs. On the other hand, Ag NPs were found inside the cells and tissues of some organisms, but comprehensive explanation of the mechanism(s) of NP entry and/or in situ formation is usually lacking. In many cases, the methods used to detect NPs inside the cells could not discriminate between ions and particles. There is currently no single technique that would discriminate between the metals species, and at the same time enable localization and quantification of NPs down to the cellular level. This paper serves as an orientation towards selection of the appropriate method for studying the fate of Ag NPs in line with their properties and the specific question to be addressed in the study. Guidance is given for method selection for quantification of NP uptake, biodistribution, precise tissue and cell localization, bioaccumulation, food chain transfer and modeling studies regarding the optimum combination of methods and key factors to consider.
", "keywords": ["0301 basic medicine", "2. Zero hunger", "spectroscopy", "Review", "01 natural sciences", "quantification", "body burden", "internalization", "03 medical and health sciences", "bioaccumulation", "microscopy", "silver nanoparticles review", "info:eu-repo/classification/udc/620.3", "biodistribution", "throughput", "performance", "0105 earth and related environmental sciences"]}, "links": [{"href": "http://www.mdpi.com/1996-1944/11/6/957/pdf"}, {"href": "https://doi.org/10.3390/ma11060957"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Materials", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3390/ma11060957", "name": "item", "description": "10.3390/ma11060957", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3390/ma11060957"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2018-06-05T00:00:00Z"}}, {"id": "10.4067/s0718-95162012005000030", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-06-23T16:22:04Z", "type": "Journal Article", "created": "2013-02-14", "title": "Effect Of Soil Water-To-Air Ratio On Biomass And Mineral Nutrition Of Avocado Trees", "description": "We investigated the variation patterns of organic carbon in soil and soil solution of four selected Robiniapseudoacacia forests aged 10a, 25a, 31a, and 35a, as well as a contrastive tillage site in a similar topography condition in Loess Plateau, China. The purpose was to explore the dynamics of soil organic carbon (SOC) and dissolved organic carbon (DOC) in R. pseudoacacia forests. On average depths of 20, 40, and 60 cm, SOC, active organic carbon (AOC), and DOC gradually increase with increased forest age. After forest restoration, the AOC/SOC ratio and resistant organic carbon/SOC ratio increase, whereas the slow organic carbon/SOC ratio decreases. The soil solutions in the subsoil layer have low DOC:DON ratio and high UV absorption at 280 nm. At 40 and 60 cm, the depth distribution is indicated as special low values for DOC concentration in the C99 site (10a site), as well as for soil water content, SOC, and AOC in the 25a forest site. Our results provide evidence that during forest restoration, SOC does not consistently increase linearly. The change points of different SOC proportions and DOC concentrations at various depths are not same, i.e., asynchronous changes exist.", "keywords": ["depth distribution", "soil organic carbon dynamics", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "15. Life on land", "active organic carbon (AOC)", "UV absorption at 280 nm"], "contacts": [{"organization": "Lv, H, Liang, Z,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.4067/s0718-95162012005000030"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Journal%20of%20soil%20science%20and%20plant%20nutrition", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.4067/s0718-95162012005000030", "name": "item", "description": "10.4067/s0718-95162012005000030", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.4067/s0718-95162012005000030"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2012-01-01T00:00:00Z"}}, {"id": "10.5194/we-19-39-2019", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:22:42Z", "type": "Journal Article", "created": "2019-06-06", "title": "Unassisted establishment of biological soil crusts on dryland road slopes", "description": "Abstract. Understanding patterns of habitat natural recovery after human-made disturbances is critical for the conservation of ecosystems under high environmental stress, such as drylands. In particular, the unassisted establishment of nonvascular plants such as biological soil crusts or biocrust communities (e.g., soil lichens, mosses and cyanobacteria) in newly formed habitats is not yet fully understood. However, the potential of biocrusts to improve soil structure and function at the early stages of succession and promote ecosystem recovery is enormous. In this study, we evaluated the capacity of lichen biocrusts to spontaneously establish and develop on road slopes in a Mediterranean shrubland. We also compared taxonomic and functional diversity of biocrusts between road slopes and natural habitats in the surroundings. Biocrust richness and cover, species composition, and functional structure were measured in 17 road slopes (nine roadcuts and eight embankments) along a 13\u2009km highway stretch. Topography, soil properties and vascular plant communities of road slopes were also characterized. We used Kruskal\u2013Wallis tests and applied redundancy analysis (RDA) to test the effect of environmental scenario (road slopes vs.\u00a0natural habitat) and other local factors on biocrust features. We found that biocrusts were common in road slopes after \u223c20\u00a0years of construction with no human assistance needed. However, species richness and cover were still lower than in natural remnants. Also, functional structure was quite similar between roadcuts (i.e., after soil excavation) and natural remnants, and topography and soil properties influenced species composition while environmental scenario type and vascular plant cover did not. These findings further support the idea of biocrusts as promising restoration tools in drylands and confirm the critical role of edaphic factors in biocrust establishment and development in land-use change scenarios.
Abstract. Characterizing physico-chemical properties of dust-emitting sediments in arid regions is fundamental to understand the effect of dust on climate and ecosystems. For high-latitude dust (HLD), this knowledge is scarce. This study focuses on the particle size distribution (PSD), mineralogy, cohesion, iron (Fe) mode of occurrence and Visible Near Infra-Red (VNIR) reflectance spectra of dust-emitting sediments from dust-hotspots in Iceland (HLD region). Extensive analysis was conducted on top sediments collected from seven dust-sources and an intensive at Jokuls\u00e1 basin including top sediments, sediments and aeolian ripples. Fully and minimally dispersed PSDs evidenced remarkable similarities with an average median diameter of 56\u00b169 and 55\u00b162 \u00b5m. Mineralogical analyses showed the prevalence of amorphous phases (68\u00b126 %), feldspars (17\u00b113 %), and pyroxenes (9.3\u00b17.2 %), aligned with the reflectance spectra. Fe content reached 9.5\u00b10.40 wt %, mainly in silicate structures (80\u00b16.3 %), complemented by magnetite (16\u00b15.5 %), hematite/goethite (4.5\u00b12.7 %), and readily exchangeable Fe-ions or Fe nano-oxides (1.6\u00b10.63 %). Icelandic top sediments have coarser PSD compared to the high dust-emitting crusts from mid-latitude arid regions, distinctive mineralogy, and threefold bulk Fe content, with a large presence of magnetite. The congruence between fully and minimally dispersed PSDs underscores a reduced particle aggregation and cohesion of Icelandic top sediments, suggesting that aerodynamic entrainment of dust may also play a role upon emission in this region, aside of saltation bombardment. The analysis of an extensive sampling in Dyngjusandur allowed this study to present a conceptual model to encapsulate Iceland's rapidly evolving high dust-emitting environments.
Abstract. Understanding the effect of dust upon climate and ecosystems needs comprehensive analyses of the physiochemical properties of dust-emitting sediments in arid regions. Here, we analyse a diverse set of crusts and aeolian ripples (n=55) from various dust-hotspots within the Mojave Desert, California, USA, with focus on their particle size distribution (PSD), mineralogy, aggregation/cohesion state and iron mode of occurrence characterization. Our results showed differences in fully and minimally dispersed PSDs, with crusts average median diameters (92 and 37 \u00b5m, respectively) compared to aeolian ripples (226 and 213 \u00b5m, respectively). Mineralogical analyses unveiled variations between crusts and ripples, with crusts enriched in phyllosilicates (24 vs 7.8 %), carbonates (6.6 vs 1.1 %), Na-salts (7.3 vs 1.1 %) and zeolites (1.2 and 0.12 %), while ripples enriched in feldspars (48 vs 37 %), quartz (32 vs 16 %), and gypsum (4.7 vs 3.1 %). Bulk Fe content analyses indicate higher concentrations in crusts (3.0\u00b11.3 wt %) compared to ripples (1.9\u00b11.1 wt %), with similar Fe speciation proportions; nano Fe-oxides/readily exchangeable Fe represent ~1.6 %, hematite/goethite ~15 %, magnetite/maghemite ~2.0 % and structural Fe in silicates ~80 % of the total Fe. We identified segregation patterns in PSD and mineralogy differences within the Mojave basins, influenced by sediment transportation dynamics and precipitates due to groundwater table fluctuations. Mojave Desert crusts show similarities with previously sampled crusts in the Moroccan Sahara for PSD and readily exchangeable Fe, yet exhibit differences in mineralogical composition, which could influence the emitted dust particles characteristics.
Abstract. One of the challenges in studying desert dust aerosol along with its numerous interactions and impacts is the paucity of direct in-situ measurements, particularly in the areas most affected by dust storms. Satellites typically provide columnintegrated aerosol measurements, but observationally-constrained continuous 3D dust fields are needed to assess dust variability, climate effects and impacts upon a variety of socio-economic sectors. Here, we present a high resolution regional reanalysis data set of desert dust aerosols that covers Northern Africa, the Middle East and Europe along with the Mediterranean sea and parts of Central Asia, and the Atlantic and Indian Oceans between 2007 and 2016. The horizontal resolution is 0.1\u00b0 latitude\u2009\u00d7\u20090.1\u00b0 longitude, and the temporal resolution is 3 hours. The reanalysis was produced using Local Ensemble Transform Kalman Filter (LETKF) data assimilation in the Multiscale Online Non-hydrostatic AtmospheRe CHemistry model (MONARCH) developed at the Barcelona Supercomputing Center (BSC). The assimilated data are coarse-mode dust optical depth retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue Level 2 products. The reanalysis data set consists of upper air (dust mass concentrations and extinction coefficient), surface (dust deposition and solar irradiance fields, among them) and total column (e.g., dust optical depth and load) variables. Some dust variables, such as concentrations and wet and dry deposition, are expressed for a binned size distribution that ranges from 0.2 to 20\u2009\u03bcm in particle diameter. Both analysis and first-guess (analysis-initialized simulation) fields are available for the variables that are diagnosed from the state vector. A set of ensemble statistics is archived for each output variable, namely the ensemble mean, standard deviation, maximum and median. The spatial and temporal distribution of the dust fields follows well-known dust cycle features controlled by seasonal changes in meteorology and vegetation cover. The analysis is statistically closer to the assimilated retrievals than the first-guess, which proves the consistency of the data assimilation method. Independent evaluation using AERONET dust-filtered optical depth retrievals indicates that the reanalysis data set is highly accurate (mean bias\u2009=\u2009\u22120.05, RMSE\u2009=\u20090.12, r\u2009=\u20090.81 when compared to retrievals from the spectral de-convolution algorithm on a 3-hourly basis). Verification statistics are broadly homogeneous in space and time with regional differences that can be partly attributed to model limitations (e.g., poor representation of small-scale emission processes), presence of aerosols other than dust in the observations used in the evaluation, and differences in the number of observations among seasons. Such a reliable high-resolution historical record of atmospheric desert dust will allow a better quantification of dust impacts upon key sectors of society and economy, including health, solar energy production and transportation. The reanalysis data set (Di Tomaso et al., 2021) is distributed via a Thematic Real-time Environmental Distributed Data Service (THREDDS) at BSC and freely available at http://hdl.handle.net/21.12146/c6d4a608-5de3-47f6-a004-67cb1d498d98.
Abstract. Understanding patterns of habitat natural recovery after human-made disturbances is critical for the conservation of ecosystems under high environmental stress, such as drylands. In particular, the unassisted establishment of nonvascular plants such as biological soil crusts or biocrust communities (e.g., soil lichens, mosses and cyanobacteria) in newly formed habitats is not yet fully understood. However, the potential of biocrusts to improve soil structure and function at the early stages of succession and promote ecosystem recovery is enormous. In this study, we evaluated the capacity of lichen biocrusts to spontaneously establish and develop on road slopes in a Mediterranean shrubland. We also compared taxonomic and functional diversity of biocrusts between road slopes and natural habitats in the surroundings. Biocrust richness and cover, species composition, and functional structure were measured in 17 road slopes (nine roadcuts and eight embankments) along a 13\u2009km highway stretch. Topography, soil properties and vascular plant communities of road slopes were also characterized. We used Kruskal\u2013Wallis tests and applied redundancy analysis (RDA) to test the effect of environmental scenario (road slopes vs.\u00a0natural habitat) and other local factors on biocrust features. We found that biocrusts were common in road slopes after \u223c20\u00a0years of construction with no human assistance needed. However, species richness and cover were still lower than in natural remnants. Also, functional structure was quite similar between roadcuts (i.e., after soil excavation) and natural remnants, and topography and soil properties influenced species composition while environmental scenario type and vascular plant cover did not. These findings further support the idea of biocrusts as promising restoration tools in drylands and confirm the critical role of edaphic factors in biocrust establishment and development in land-use change scenarios.
Abstract. Characterizing physico-chemical properties of dust-emitting sediments in arid regions is fundamental to understand the effect of dust on climate and ecosystems. For high-latitude dust (HLD), this knowledge is scarce. This study focuses on the particle size distribution (PSD), mineralogy, cohesion, iron (Fe) mode of occurrence and Visible Near Infra-Red (VNIR) reflectance spectra of dust-emitting sediments from dust-hotspots in Iceland (HLD region). Extensive analysis was conducted on top sediments collected from seven dust-sources and an intensive at Jokuls\u00e1 basin including top sediments, sediments and aeolian ripples. Fully and minimally dispersed PSDs evidenced remarkable similarities with an average median diameter of 56\u00b169 and 55\u00b162 \u00b5m. Mineralogical analyses showed the prevalence of amorphous phases (68\u00b126 %), feldspars (17\u00b113 %), and pyroxenes (9.3\u00b17.2 %), aligned with the reflectance spectra. Fe content reached 9.5\u00b10.40 wt %, mainly in silicate structures (80\u00b16.3 %), complemented by magnetite (16\u00b15.5 %), hematite/goethite (4.5\u00b12.7 %), and readily exchangeable Fe-ions or Fe nano-oxides (1.6\u00b10.63 %). Icelandic top sediments have coarser PSD compared to the high dust-emitting crusts from mid-latitude arid regions, distinctive mineralogy, and threefold bulk Fe content, with a large presence of magnetite. The congruence between fully and minimally dispersed PSDs underscores a reduced particle aggregation and cohesion of Icelandic top sediments, suggesting that aerodynamic entrainment of dust may also play a role upon emission in this region, aside of saltation bombardment. The analysis of an extensive sampling in Dyngjusandur allowed this study to present a conceptual model to encapsulate Iceland's rapidly evolving high dust-emitting environments.
Due to the importance of soil organic carbon (SOC) in supporting ecosystem services, accurate SOC assessment is vital for scientific research and decision making. However, most previous studies focused on single soil depth, leading to a poor understanding of SOC in multiple depths. To better understand the spatial distribution pattern of SOC in Northeast and North China Plain, we compared three machine learning algorithms (i.e., Cubist, Extreme Gradient Boosting (XGBoost) and Random Forest (RF)) within the digital soil mapping framework. A total of 386 sampling sites (1584 samples) following specific criteria covering all dryland districts and counties and soil types in four depths (i.e., 0\u201310, 10\u201320, 20\u201330 and 30\u201340 cm) were collected in 2017. After feature selection from 249 environmental covariates by the Genetic Algorithm, 29 variables were used to fit models. The results showed SOC increased from southern to northern regions in the spatial scale and decreased with soil depths. From the result of independent verification (validation dataset: 80 sampling sites), RF (R2: 0.58, 0.71, 0.73, 0.74 and RMSE: 3.49, 3.49, 2.95, 2.80 g kg\u22121 in four depths) performed better than Cubist (R2: 0.46, 0.63, 0.67, 0.71 and RMSE: 3.83, 3.60, 3.03, 2.72 g kg\u22121) and XGBoost (R2: 0.53, 0.67, 0.70, 0.71 and RMSE: 3.60, 3.60, 3.00, 2.83 g kg\u22121) in terms of prediction accuracy and robustness. Soil, parent material and organism were the most important covariates in SOC prediction. This study provides the up-to-date spatial distribution of dryland SOC in Northeast and North China Plain, which is of great value for evaluating dynamics of soil quality after long-term cultivation.
Abstract. Understanding the effect of dust upon climate and ecosystems needs comprehensive analyses of the physiochemical properties of dust-emitting sediments in arid regions. Here, we analyse a diverse set of crusts and aeolian ripples (n=55) from various dust-hotspots within the Mojave Desert, California, USA, with focus on their particle size distribution (PSD), mineralogy, aggregation/cohesion state and iron mode of occurrence characterization. Our results showed differences in fully and minimally dispersed PSDs, with crusts average median diameters (92 and 37 \u00b5m, respectively) compared to aeolian ripples (226 and 213 \u00b5m, respectively). Mineralogical analyses unveiled variations between crusts and ripples, with crusts enriched in phyllosilicates (24 vs 7.8 %), carbonates (6.6 vs 1.1 %), Na-salts (7.3 vs 1.1 %) and zeolites (1.2 and 0.12 %), while ripples enriched in feldspars (48 vs 37 %), quartz (32 vs 16 %), and gypsum (4.7 vs 3.1 %). Bulk Fe content analyses indicate higher concentrations in crusts (3.0\u00b11.3 wt %) compared to ripples (1.9\u00b11.1 wt %), with similar Fe speciation proportions; nano Fe-oxides/readily exchangeable Fe represent ~1.6 %, hematite/goethite ~15 %, magnetite/maghemite ~2.0 % and structural Fe in silicates ~80 % of the total Fe. We identified segregation patterns in PSD and mineralogy differences within the Mojave basins, influenced by sediment transportation dynamics and precipitates due to groundwater table fluctuations. Mojave Desert crusts show similarities with previously sampled crusts in the Moroccan Sahara for PSD and readily exchangeable Fe, yet exhibit differences in mineralogical composition, which could influence the emitted dust particles characteristics.
The relatively poor simulation of the below-ground processes is a severe drawback for many ecosystem models, especially when predicting responses to climate change and management. For a meaningful estimation of ecosystem production and the cycling of water, energy, nutrients and carbon, the integration of soil processes and the exchanges at the surface is crucial. It is increasingly recognized that soil biota play an important role in soil organic carbon and nutrient cycling, shaping soil structure and hydrological properties through their activity, and in water and nutrient uptake by plants through mycorrhizal processes. In this article, we review the main soil biological actors (microbiota, fauna and roots) and their effects on soil functioning. We review to what extent they have been included in soil models and propose which of them could be included in ecosystem models. We show that the model representation of the soil food web, the impact of soil ecosystem engineers on soil structure and the related effects on hydrology and soil organic matter (SOM) stabilization are key issues in improving ecosystem-scale soil representation in models. Finally, we describe a new core model concept (KEYLINK) that integrates insights from SOM models, structural models and food web models to simulate the living soil at an ecosystem scale.
Dust emission fluxes during wind soil erosion are usually estimated using a dust concentration vertical gradient, by assuming a constant dust flux layer between the surface and the dust measurement levels. Here, we investigate the existence of this layer during erosion events recorded in Iceland and Jordan. Size\uffe2\uff80\uff90resolved dust fluxes were estimated at three levels between 2 and 4\uffc2\uffa0m using the eddy\uffe2\uff80\uff90covariance method. Dust fluxes were found mainly constant only between the two upper levels in Iceland, the lower dust flux being often stronger and richer in coarse particles, while dust fluxes in Jordan were nearly constant across all levels. The wind dynamics could not explain the absence of a constant dust flux layer in Iceland. We show that the presence of stationary dust source patches in Iceland, related to surface humidity, created a non\uffe2\uff80\uff90uniform dust layer near the surface, named dust roughness sublayer (DRSL), where individual plumes behind each patch interact but do not fully mix. The lowest dust measurement level was probably located within this sublayer while the upper ones were located above, such that there the emitted dust became spatially well\uffe2\uff80\uff90mixed. This explains near the surface in Iceland, the more intermittent dust concentration, its low correlation with the dust concentrations above, and the richer dust flux in coarse particles due to their lower deposition contribution. Our findings highlight the importance of estimating dust fluxes above a dust blending height whose characteristics depend on the dust source patchiness caused by surface humidity or the presence of sparse non\uffe2\uff80\uff90erosive elements. Abstract. Understanding the effect of dust upon climate and ecosystems needs comprehensive analyses of the physiochemical properties of dust-emitting sediments in arid regions. Here, we analyse a diverse set of crusts and aeolian ripples (n=55) from various dust-hotspots within the Mojave Desert, California, USA, with focus on their particle size distribution (PSD), mineralogy, aggregation/cohesion state and iron mode of occurrence characterization. Our results showed differences in fully and minimally dispersed PSDs, with crusts average median diameters (92 and 37 \u00b5m, respectively) compared to aeolian ripples (226 and 213 \u00b5m, respectively). Mineralogical analyses unveiled variations between crusts and ripples, with crusts enriched in phyllosilicates (24 vs 7.8 %), carbonates (6.6 vs 1.1 %), Na-salts (7.3 vs 1.1 %) and zeolites (1.2 and 0.12 %), while ripples enriched in feldspars (48 vs 37 %), quartz (32 vs 16 %), and gypsum (4.7 vs 3.1 %). Bulk Fe content analyses indicate higher concentrations in crusts (3.0\u00b11.3 wt %) compared to ripples (1.9\u00b11.1 wt %), with similar Fe speciation proportions; nano Fe-oxides/readily exchangeable Fe represent ~1.6 %, hematite/goethite ~15 %, magnetite/maghemite ~2.0 % and structural Fe in silicates ~80 % of the total Fe. We identified segregation patterns in PSD and mineralogy differences within the Mojave basins, influenced by sediment transportation dynamics and precipitates due to groundwater table fluctuations. Mojave Desert crusts show similarities with previously sampled crusts in the Moroccan Sahara for PSD and readily exchangeable Fe, yet exhibit differences in mineralogical composition, which could influence the emitted dust particles characteristics. Volcanic soils are important resources because of their unique mineralogical and physical characteristics, and allophanic Andosols represent some of the world\u2019s most fertile soils. However, their unique properties can be lost when cultivated. Most soils in the Central Valley, Mexico, are derived from volcanic materials. This valley encompasses one of the largest water supply systems in the world by volume, but is affected by soil degradation and deforestation. Sustainably managing volcanic soils requires understanding how land use affects their hydrodynamic properties. Gas adsorption and mercury intrusion porosimetry, water retention curves, tension infiltrometry and X-ray tomography were used to describe pore structure characteristics. Two volcanic soils (one Andosol and one derived from indurated tuff \u2013 Tepetates), three land uses (maize monoculture, maize\u2013wheat rotation and fallow) and two horizons (Ap and A2 for maize monoculture and maize\u2013wheat rotation) were studied. Tillage affected topsoil by increasing the sand fraction by 38% and decreasing total porosity and macroporosity by 23% and 40% respectively. Macropore size was reduced and the number of isolated macropores was higher in the tilled layer under maize, compared with untilled subsoil. The plot under maize\u2013wheat rotation had lower allophane content, and saturated hydraulic conductivity was reduced by nearly an order of magnitude and water retention by half, compared with maize and fallow plots. Compared with Andosols, Tepetates showed differences in mineralogical composition with lower contents of amorphous compounds and in its porous network characteristics with twice the total and percolating macroporosity compared with the maize plot. Its high content of organic carbon (3.5%) seemed beneficial for its hydrodynamic properties. Sustainable agricultural management of these volcanic soils requires reducing mechanised tillage, avoiding periods when soil is bare, not applying maize\u2013wheat rotation and applying maize\u2013fallow rotation allowing natural vegetation growth. Abstract. Characterizing physico-chemical properties of dust-emitting sediments in arid regions is fundamental to understand the effect of dust on climate and ecosystems. For high-latitude dust (HLD), this knowledge is scarce. This study focuses on the particle size distribution (PSD), mineralogy, cohesion, iron (Fe) mode of occurrence and Visible Near Infra-Red (VNIR) reflectance spectra of dust-emitting sediments from dust-hotspots in Iceland (HLD region). Extensive analysis was conducted on top sediments collected from seven dust-sources and an intensive at Jokuls\u00e1 basin including top sediments, sediments and aeolian ripples. Fully and minimally dispersed PSDs evidenced remarkable similarities with an average median diameter of 56\u00b169 and 55\u00b162 \u00b5m. Mineralogical analyses showed the prevalence of amorphous phases (68\u00b126 %), feldspars (17\u00b113 %), and pyroxenes (9.3\u00b17.2 %), aligned with the reflectance spectra. Fe content reached 9.5\u00b10.40 wt %, mainly in silicate structures (80\u00b16.3 %), complemented by magnetite (16\u00b15.5 %), hematite/goethite (4.5\u00b12.7 %), and readily exchangeable Fe-ions or Fe nano-oxides (1.6\u00b10.63 %). Icelandic top sediments have coarser PSD compared to the high dust-emitting crusts from mid-latitude arid regions, distinctive mineralogy, and threefold bulk Fe content, with a large presence of magnetite. The congruence between fully and minimally dispersed PSDs underscores a reduced particle aggregation and cohesion of Icelandic top sediments, suggesting that aerodynamic entrainment of dust may also play a role upon emission in this region, aside of saltation bombardment. The analysis of an extensive sampling in Dyngjusandur allowed this study to present a conceptual model to encapsulate Iceland's rapidly evolving high dust-emitting environments.
Few studies have tested how plant quality and the presence of competitors interact in determining how herbivores choose between different leaves within a plant. We investigated this in two herbivorous spider mites sharing tomato plants: Tetranychus urticae, which generally induces plant defenses, and Tetranychus evansi, which suppresses them, creating asymmetrical effects on coinfesting competitors. On uninfested plants, both herbivore species preferred young leaves, coinciding with increased mite performance. On plants with heterospecifics, the mites did not prefer leaves on which they had a better performance. In particular, T.\uffc2\uffa0urticae avoided leaves infested with T.\uffc2\uffa0evansi, which is in agreement with T.\uffc2\uffa0urticae being outcompeted by T.\uffc2\uffa0evansi. In contrast, T.\uffc2\uffa0evansi did not avoid leaves with the other species, but distributed itself evenly over plants infested with heterospecifics. We hypothesize that this behavior of T.\uffc2\uffa0evansi may prevent further spread of T.\uffc2\uffa0urticae over the shared plant. Our results indicate that leaf age determines within\uffe2\uff80\uff90plant distribution of herbivores only in absence of competitors. Moreover, they show that this distribution depends on the order of arrival of competitors and on their effects on each other, with herbivores showing differences in behavior within the plant as a possible response to the outcome of those interactions.Greenhouse gas (GHGs) emissions from peatlands contribute significantly to ongoing climate change because of human land use. To develop reliable and comprehensive estimates and predictions of GHG emissions from peatlands, it is necessary to have GHG observations, including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), that cover different peatland types globally. We synthesize published peatland studies with field GHG flux measurements to identify gaps in observations and suggest directions for future research. Although GHG flux measurements have been conducted at numerous sites globally, substantial gaps remain in current observations, encompassing various peatland types, regions and GHGs. Generally, there is a pressing need for additional GHG observations in Africa, Latin America and the Caribbean regions. Despite widespread measurements of CO2 and CH4, studies quantifying N2O emissions from peatlands are scarce, particularly in natural ecosystems. To expand the global coverage of peatland data, it is crucial to conduct more eddy covariance observations for long-term monitoring. Automated chambers are preferable for plot-scale observations to produce high temporal resolution data; however, traditional field campaigns with manual chamber measurements remain necessary, particularly in remote areas. To ensure that the data can be further used for modeling purposes, we suggest that chamber campaigns should be conducted at least monthly for a minimum duration of one year with no fewer than three replicates and measure key environmental variables. In addition, further studies are needed in restored peatlands, focusing on identifying the most effective restoration approaches for different ecosystem types, conditions, climates, and land use histories. The relatively poor simulation of the below-ground processes is a severe drawback for many ecosystem models, especially when predicting responses to climate change and management. For a meaningful estimation of ecosystem production and the cycling of water, energy, nutrients and carbon, the integration of soil processes and the exchanges at the surface is crucial. It is increasingly recognized that soil biota play an important role in soil organic carbon and nutrient cycling, shaping soil structure and hydrological properties through their activity, and in water and nutrient uptake by plants through mycorrhizal processes. In this article, we review the main soil biological actors (microbiota, fauna and roots) and their effects on soil functioning. We review to what extent they have been included in soil models and propose which of them could be included in ecosystem models. We show that the model representation of the soil food web, the impact of soil ecosystem engineers on soil structure and the related effects on hydrology and soil organic matter (SOM) stabilization are key issues in improving ecosystem-scale soil representation in models. Finally, we describe a new core model concept (KEYLINK) that integrates insights from SOM models, structural models and food web models to simulate the living soil at an ecosystem scale. Mineral dust particles suspended in the atmosphere span more than three orders of magnitude in diameter, from less than 0.1 \u00b5m to more than 100 \u00b5m. This wide size range makes dust a unique aerosol species with the ability to interact with many aspects of the Earth system, including radiation, clouds, hydrology, atmospheric chemistry, and biogeochemistry. This review focuses on coarse and super-coarse dust aerosols, which we respectively define as dust particles with a diameter between 2.5 - 10 \u00b5m and 10 - 62.5 \u00b5m. We review several lines of observational evidence indicating that coarse and super-coarse dust particles are transported farther than previously expected and that the abundance of these particles is substantially underestimated in current global models. We synthesize previous studies that used observations, theories, and model simulations to highlight the impacts of coarse and super-coarse dust aerosols on the Earth system, including their effects on dust-radiation interactions, dust-cloud interactions, and atmospheric chemistry, and biogeochemistry. In addition, we examine several limitations in the representation of coarse and super-coarse dust aerosols in current model simulations and in remote-sensing retrievals. Because these limitations substantially contribute to the uncertainties in simulating the abundance and impacts of coarse and super-coarse dust aerosols, we offer some recommendations to facilitate future studies. Overall, we conclude that an accurate representation of coarse and super-coarse properties is critical in understanding the overall impacts of dust aerosols on the Earth system.
To evaluate whether the administration of desmopressin alters the risk for renal biopsy complications.
MethodsA multicenter registry containing 576 native kidney biopsies (NKb) with a serum creatinine above 150\uffc2\uffa0\uffce\uffbcmol/L in 527 patients (372 men and 155 women, median age 61\uffc2\uffa0years) was used. Most of the data were prospective. At one of the hospitals all biopsies with creatinine above 150\uffc2\uffa0\uffce\uffbcmol/L received desmopressin before biopsies (NKb 204). These were compared to outcome of biopsy complications against other centres where desmopressin was not given (NKb 372). Fisher's exact test, \uffcf\uff872 analyses, univariate and multiple binary logistic regression were used. Data were given as odds ratio (OR) and confidence interval (CI). A two sided P\uffe2\uff80\uff90value of <0.05 was considered significant.
ResultsIn NKb with creatinine >150\uffc2\uffa0\uffce\uffbcmol/L, those with desmopressin had less overall (3.4% vs 8.4%, OR 0.39, CI 0.17\uffe2\uff80\uff930.90) whereas major or minor complications were not different. While desmopressin did not exhibit difference in complications in men, women received less major (0% vs 8.6%, P\uffc2\uffa0=\uffc2\uffa00.03) and overall complications (0% vs 12.1%, P\uffc2\uffa0=\uffc2\uffa00.006). A multiple logistic regression revealed that, after adjusting for BMI, age and sex, prophylaxis with desmopressin showed less major (OR 0.38, CI 0.15\uffe2\uff80\uff930.96) and overall complications (OR 0.36, CI 0.15\uffe2\uff80\uff930.85).
ConclusionDesmopressin given before a native kidney biopsy in patients with impaired renal function can reduce the risk for complications.Physiologically based kinetic (PBK) models are widely used in pharmacology and toxicology for predicting the internal disposition of substances upon exposure, voluntarily or not. Due to their complexity, a large number of model parameters need to be estimated, either through in silico tools, in vitro experiments, or by fitting the model to in vivo data. In the latter case, fitting complex structural models on in vivo data can result in overparameterization and produce unrealistic parameter estimates. To address these issues, we propose a novel parameter grouping approach, which reduces the parametric space by co-estimating groups of parameters across compartments. Grouping of parameters is performed using genetic algorithms and is fully automated, based on a novel goodness-of-fit metric. To illustrate the practical application of the proposed methodology, two case studies were conducted. The first case study demonstrates the development of a new PBK model, while the second focuses on model refinement. In the first case study, a PBK model was developed to elucidate the biodistribution of titanium dioxide (TiO2) nanoparticles in rats following intravenous injection. A variety of parameter estimation schemes were employed. Comparative analysis based on goodness-of-fit metrics demonstrated that the proposed methodology yields models that outperform standard estimation approaches, while utilizing a reduced number of parameters. In the second case study, an existing PBK model for perfluorooctanoic acid (PFOA) in rats was extended to incorporate additional tissues, providing a more comprehensive portrayal of PFOA biodistribution. Both models were validated through independent in vivo studies to ensure their reliability.In this study we present data collected between August 2017 and December 2018 from submarine sediment trap M1 located in the eastern tropical North Atlantic and determine lithogenic and biogenic fluxes, and grain-size distributions of aerosol dust. An unprecedented high sampling resolution of four days in combination with satellite imagery allowed the identification of thirteen major dust events of two types within the 468-day series. Seven dust events were classified as high-flux events identified by a deposition of >=25 mg m-2 d-1. The average dust deposition rate increased by 461.3% during these types of events. The remaining six events were characterized by a high composition of giant particles (>7.3 vol%). Seasonal variations of dust flux were recorded, with highest fluxes observed in spring at an average deposition rate of 14.8 mg m-2 d-1, and lowest fluxes in fall with an average rate of 8.6 mg m-2 d-1. The estimated total dust flux in the tropical North Atlantic was 4040.02 mg m-2 y-1. We suggest that most of the summer dust was likely transported over the sampling site at high altitudes while winter transport occurred closer to the sea surface, resulting in generally higher background fluxes. Grain-size distributions exhibited seasonal variations with increased occurrences of giant particles (>62.5 \uffce\uffbcm) in fall 2017 and spring, and less occurrences in winter and fall 2018. Grain-size sorting was high in spring and most variable in summer. Precipitation did not affect depositional fluxes or grain-size distributions of the aeolian dust significantly. Organic matter was deposited continuously at the sampling site with a deposition rate ranging from 14.4\uffe2\uff80\uff93862.25 mg m-2 d-1. Organic matter fluxes increased by 199.5% during high-flux dust events but decreased by 13.6% during anomalous grain-size events. Spring experienced the highest number of dust events (n=5). This unprecedented high-resolution dataset of dust deposition in marine sediment-traps enabled the distinction of dust events and their relation to organic matter flux. This suggests the possibility of a dust fertilization or mineral ballasting effect. Light scatterometry combined with chemometrics can be a practical approach for the analysis of size and concentration of microplastics in water.