Short-term exposure to fine particulate matter exposure impairs innate immune and inflammatory responses to a pathogen stimulus: A functional study in the zebrafish model

Short-term exposure to fine particulate matter (PM 2.5 ) is associated with the activation of adverse inflammatory responses, increasing the risk of developing acute respiratory diseases, such as those caused by pathogen infections. However, the functional mechanisms underlying this evidence remain unclear. In the present study, we generated a zebrafish model of short-term exposure to a specific PM 2.5 , collected in the northern metropolitan area of Milan, Italy. First, we assessed the immunomodulatory effects of short-term PM 2.5 exposure and observed that it elicited pro -inflammatory effects by inducing the expression of cytokines and triggering hyper -activation of both neutrophil and macrophage cell populations. Moreover, we examined the impact of a secondary infectious pro -inflammatory stimulus induced through the injection of Pseudomonas aeruginosa lipopolysaccharide ( Pa -LPS) molecules after exposure to short-term PM 2.5 . In this model, we demonstrated that the innate immune response was less responsive to a second pro -inflammatory infectious stimulus. Indeed, larvae exhibited dampened leukocyte activation and impaired production of reactive oxygen species. The obtained results indicate that short-term PM 2.5 exposure alters the immune microenvironment and affects the inflammatory processes, thus potentially weakening the resistance to pathogen infections

Prediction of streamflow regimes over large geographical areas: interpolated flow–duration curves for the Danube region

ABSTRACTFlow–duration curves (FDCs) are essential to support decisions on water resources management, and their regionalization is fundamental for the assessment of ungauged basins. In comparison with calibrated rainfall–runoff models, statistical methods provide data-driven estimates representing a useful benchmark. The objective of this work is the interpolation of FDCs from ~500 discharge gauging stations in the Danube. To this aim we use total negative deviation top-kriging (TNDTK), as multi-regression models are shown to be unsuitable for representing FDCs across all durations and sites. TNDTK shows a high accuracy for the entire Danube region, with overall Nash-Sutcliffe efficiency values computed in a leave-p-out cross-validation scheme (p equal to one site, one-third and half of the sites), all above 0.88. A reliability measure based on kriging variance is attached to each interpolated FDC at ~4000 prediction nodes. The GIS layer of regionalized FDCs is made available for broader use in the region

Streamflow data availability in Europe: a detailed dataset of interpolated flow-duration curves

For about 24 000 river basins across Europe, we provide a continuous representation of the stream-flow regime in terms of empirical flow-duration curves (FDCs), which are key signatures of the hydrological behaviour of a catchment and are widely used for supporting decisions on water resource management as well as for assessing hydrologic change. In this study, FDCs are estimated by means of the geostatistical procedure termed total negative deviation top-kriging (TNDTK), starting from the empirical FDCs made available by the Joint Research Centre of the European Commission (DG-JRC) for about 3000 discharge measurement stations across Europe. Consistent with previous studies, TNDTK is shown to provide high accuracy for the entire study area, even with different degrees of reliability, which varies significantly over the study area. In order to provide this kind of information site by site, together with the estimated FDCs, for each catchment we provide indicators of the accuracy and reliability of the performed large-scale geostatistical prediction. The dataset is freely available at the PANGAEA open-access library (Data Publisher for Earth & Environmental Science) at https://doi.org/10.1594/PANGAEA.938975 (Persiano et al., 2021b)

Improved representation of phosphorus exchange on soil mineral surfaces reduces estimates of P limitation in temperate forest ecosystems

International audiencePhosphorus (P) availability affects the response of terrestrial ecosystems to environmental and climate change (e.g., elevated CO2), yet the magnitude of this effect remains uncertain. This uncertainty arises mainly from a lack of quantitative understanding of the soil biological and geochemical P cycling processes, particularly the P exchange with soil mineral surfaces, which is often described by a Langmuir sorption isotherm.We first conducted a literature review on P sorption experiments and terrestrial biosphere models (TBMs) using a Langmuir isotherm. We then developed a new algorithm to describe the inorganic P exchange between soil solution and soil matrix based on the double-surface Langmuir isotherm and extracted empirical equations to calculate the sorption capacity and Langmuir coefficient. We finally tested the conventional and new models of P sorption at five beech forest sites in Germany along a soil P stock gradient using the QUINCY (QUantifying Interactions between terrestrial Nutrient CYcles and the climate system) TBM.We found that the conventional (single-surface) Langmuir isotherm approach in most TBMs largely differed from P sorption experiments regarding the sorption capacities and Langmuir coefficients, and it simulated an overly low soil P-buffering capacity. Conversely, the double-surface Langmuir isotherm approach adequately reproduced the observed patterns of soil inorganic P pools. The better representation of inorganic P cycling using the double-surface Langmuir approach also improved simulated foliar N and P concentrations as well as the patterns of gross primary production and vegetation carbon across the soil P gradient. The novel model generally reduces the estimates of P limitation compared with the conventional model, particularly at the low-P site, as the model constraint of slow inorganic P exchange on plant productivity is reduced

A severe case of neuroleukemiosis caused by B cell chronic lymphocytic leukemia, presenting as mononeuritis multiplex.

To report an exceptional case of nerve infiltration by an otherwise benign chronic B cell leukemia, inducing severe mononeuritis multiplex. The patient underwent extensive evaluation, including nerve conduction study and myography, brain and plexus MRI, and nerve biopsy. The clinical and electrophysiological diagnosis was a mononeuritis multiplex with severe motor and sensory involvement; only the nerve biopsy allowed definite diagnosis and introduction of chemotherapy, leading to resolution of sensory deficit and progressive motor improvement. Neuroleukemiosis caused by chronic lymphoid leukemia is an exceptional diagnosis. The presence of other possible causes like cryoglobulinemia could induce avoidance of nerve biopsy thus undertreating patient, since steroid treatment is not expected to be efficient on lymphocytic proliferation. Our case stretches the importance of nerve biopsy and raises neuromuscular specialist's awareness of this rare entity

The Genome-wide impact of Nipblb loss-of-function on Zebrafish gene expression

Transcriptional changes normally occur during development but also underlie differences between healthy and pathological conditions. Transcription factors or chromatin modifiers are involved in orchestrating gene activity, such as the cohesin genes and their regulator NIPBL. In our previous studies, using a zebrafish model for nipblb knockdown, we described the effect of nipblb loss-of-function in specific contexts, such as central nervous system development and hematopoiesis. However, the genome-wide transcriptional impact of nipblb loss-of-function in zebrafish embryos at diverse developmental stages remains under investigation. By RNA-seq analyses in zebrafish embryos at 24 h post-fertilization, we examined genome-wide effects of nipblb knockdown on transcriptional programs. Differential gene expression analysis revealed that nipblb loss-of-function has an impact on gene expression at 24 h post fertilization, mainly resulting in gene inactivation. A similar transcriptional effect has also been reported in other organisms, supporting the use of zebrafish as a model to understand the role of Nipbl in gene regulation during early vertebrate development. Moreover, we unraveled a connection between nipblb-dependent differential expression and gene expression patterns of hematological cell populations and AML subtypes, enforcing our previous evidence on the involvement of NIPBL-related transcriptional dysregulation in hematological malignancies

Modelling the Stoichiometric Regulation of C-Rich Toxins in Marine Dinoflagellates

Toxin production in marine microalgae was previously shown to be tightly coupled with cellular stoichiometry. The highest values of cellular toxin are in fact mainly associated with a high carbon to nutrient cellular ratio. In particular, the cellular accumulation of C-rich toxins (i.e., with C:N > 6.6) can be stimulated by both N and P deficiency. Dinoflagellates are the main producers of C-rich toxins and may represent a serious threat for human health and the marine ecosystem. As such, the development of a numerical model able to predict how toxin production is stimulated by nutrient supply/deficiency is of primary utility for both scientific and management purposes. In this work we have developed a mechanistic model describing the stoichiometric regulation of C-rich toxins in marine dinoflagellates. To this purpose, a new formulation describing toxin production and fate was embedded in the European Regional Seas Ecosystem Model (ERSEM), here simplified to describe a monospecific batch culture. Toxin production was assumed to be composed by two distinct additive terms; the first is a constant fraction of algal production and is assumed to take place at any physiological conditions. The second term is assumed to be dependent on algal biomass and to be stimulated by internal nutrient deficiency. By using these assumptions, the model reproduced the concentrations and temporal evolution of toxins observed in cultures of Ostreopsis cf. ovata, a benthic/epiphytic dinoflagellate producing C-rich toxins named ovatoxins. The analysis of simulations and their comparison with experimental data provided a conceptual model linking toxin production and nutritional status in this species. The model was also qualitatively validated by using independent literature data, and the results indicate that our formulation can be also used to simulate toxin dynamics in other dinoflagellates. Our model represents an important step towards the simulation and prediction of marine algal toxicity

Ovatoxin-a, a palytoxin analogue isolated from Ostreopsis cf. ovata Fukuyo: cytotoxic activity and ELISA detection

This study provides the first evaluation of the cytotoxic effects of the recently identified palytoxin (PLTX) analog, ovatoxin-a (OVTX-a), the major toxin produced by Ostreopsis cf. ovata in the Mediterranean Sea. Its increasing detection during Ostreopsis blooms and in seafood highlights the need to characterize its toxic effects and to set up appropriate detection methods. OVTX-a is about 100 fold less potent than PLTX in reducing HaCaT cells viability (EC50 = 1.1 7 10 129 M vs 1.8 7 10 1211 M, MTT test) in agreement with a reduced binding affinity (Kd = 1.2 7 10 129 vs 2.7 7 10 1211 M, saturation experiments on intact cells). Similarly, OVTX-a hemolytic effect is lower than that of the reference PLTX compound. Ost-D shows the lowest cytotoxicity toward HaCaT keratinocytes, suggesting the lack of a hydroxyl group at C44 as a critical feature for PLTXs cytotoxic effects. A sandwich ELISA developed for PLTX detects also OVTX-a in a sensitive (LOD = 4.2 and LOQ = 5.6 ng/mL) and accurate manner (Bias = 0.3%), also in O. cf. ovata extracts and contaminated mussels. Although in vitro OVTXa appears less toxic than PLTX, its cytotoxicity at nanomolar concentrations after short exposure time rises some concern for human health. The sandwich ELISA can be a viable screening method for OVTXs detection in monitoring program

A hydrological model to estimate pollution from combined sewer overflows at the regional scale: application to Europe

Study region Combined Sewer Overflows (CSO) of 671 Functional Urban Areas (FUAs) throughout the European Union + UK (EU28), representing almost half of the EU28 population. Study focus CSO loads can be quantified at the local scale through measurements, or with calibrated hydrological models. However, they are difficult to quantify at a large scale (e.g. regional or national), due to a lack of data, and the models used at local scale cannot be applied in the absence of knowledge of the combined sewer (CS) network. This paper presents a 6-parameter lumped hydrological model to simulate a CS network and its overflows, using population and rainfall data of 671 EU28 FUAs. New hydrological insights for the region When properly calibrated, the model can predict the CSO hydrographs as well as aggregated CSO descriptors of a catchment with known impervious surface area connected to a CS with a reasonable reliability. When model calibration is not possible, using default values of the parameters enables a first approximation estimate of CSOs, accurate within one order of magnitude, which can be used to support scenario analysis for regional and continental CSO management. At the EU28 scale, the estimated total CSO volume is 5.7·103 Mm3/y, with a dry weather flow content in CSOs of 460 Mm3/y (assuming a dry weather flow of 200 l/population equivalent (PE)/day including sanitary discharges, industrial discharge and infiltration). A collection of case studies on CSOs is also provided