Evaluation de la dynamique et des origines de la turbidité dans un aquifère karstique multicouche en utilisant la distribution de taille et la nature des particules en suspension associées aux variations géochimiques

International audienc

Tracing water perturbation using NO3−, doc, particles size determination, and bacteria: A method development for karst aquifer water quality hazard assessment

Karst systems, as well as springs, are vulnerable to water perturbation brought by infiltration. In this research, sources of water perturbations were examined. The first objective is to provide a method that can determine the origin of the water flowing in the karst outlet. The second objective is to identify the associated water quality hazards caused by the infiltration source. The method relies on these parameters: turbidity, DOC, NO3−, particle size, and bacteria (E. coli, enterococcus and total coliforms). As the method was applied during flood events, measurement of the water flow is also needed to have a basic knowledge on the hydrodynamic of the water resource.The proposed method is based on a high resolution monitoring of physico chemical parameters of the water flowing during flood events. Using this proposed method, (1) the origin of the water can be identified, (2) the type and nature of water perturbation can be described, and (3) the type of water perturbation that accompanies contaminants such as the one with anthropogenic source (e.g. NO3−) and bacterial nature can be determined. In identifying the water origin, this proposed method employed NO3− and DOC data normalization. Values are projected in the NO3−_norm = f(DOC_norm) reference frame. These are aligned to the slope. Depending on the obtained slope (α), water origin can be disclosed. If α > 1, the increase of concentration of DOC weighs more, characterizing water from surface runoff. Whereas, if α < 1, the consideration is more on the increase of NO3− concentration, characterizing water from unsaturated zone. However if α cannot be calculated because there is no evident slope, this characterizes the water already present in the system.Water originating from the surface runoff is prone to inorganic and bacterial contamination adsorbed by the particles. Identifying the type of water perturbation needing water treatment is important in managing the water resource. Hence, the evolution through time of NO3− and DOC with the particle size distribution, anthropogenic nature type of contaminant (i.e. in this study NO3−), and presence or absence of bacteria were examined.This method was applied in the springs of the Toulon, an important drinking water source of the city of Périgueux in France. This site was chosen considering the following factors: (1) its karst nature being vulnerable to infiltrations, having fractures and sinkholes; (2) its land use being influenced by the anthropogenic activities such as agriculture; and (3) its observed pronounced turbidity incidence. The first flood events of two hydrological cycles were assessed.Three water origins of the spring water and the respective water quality hazards were identified: (i) water from saturated zone with minerals, (ii) water from unsaturated zone with nitrate, and (iii) water from surface runoff with the presence of bacteria. The second and third types of water perturbation gave evidence that the Toulon springs can be contaminated. Hence, in terms of resource management, the information obtained can be used as a basis in forecasting and planning the management actions or water quality treatments needed

Evaluation de la dynamique et des origines de la turbidité dans un aquifère karstique multicouche en utilisant la distribution de taille et la nature des particules en suspension associées aux variations géochimiques

International audienc

Influence of operating conditions on the persistence of E. coli, enterococci, Clostridium perfringens and Clostridioides difficile in semi-continuous mesophilic anaerobic reactors

International audienceThis study examined the combined effect of hydraulic retention time (HRT), organic loading rate (OLR) and heat pretreatment of manure (70 degrees C, 1 h) on the fate of E. coli, enterococci, C. perfringens, C. difficile, and on chemical parameters (volatile fatty acids and ammonia) that may inactivate pathogens. Semi-continuous mesophilic anaerobic reactors were fed with pig manure and horse feed. The operating conditions were 2, 3, 4 COD.L-1.d(-1) (OLR), 24, 35, 46 days (HRT) and use or not of a thermal pretreatment. The levels of the chemical parameters did not reach concentrations capable of inactivating the four bacteria. Anaerobic digestion led to a Log io removal > 3 (E. coli), 0.9-2.1 (enterococci), 0.1-0.6 (C. perfringens) and 0-1 (C. difficile). Increasing HRT only reduced the concentration of E. coli in the digestate. Increasing OLR reduced the Log(10) removal of enterococci and C. difficile. The heat pretreatment led to non-detection of E. coli in the digestate, reduced the concentration of C. perfringens by 0.8-1.3 Log(10) and increased the concentration of C. difficile by 0.04-0.7 Log(10). Enterococci, not detected in the heated manure, were present in the digestate. The distribution of genes encoding virulence factors of C. difficile (tcdA and tcdB) and C. perfringens (cpa, cpb2 and cpb) was not impacted by anaerobic digestion or by the heat pretreatment. Enterococci, C. perfringens, C. difficile were present in the digestate at relatively stable concentrations regardless of the operating conditions, indicating that even with heat pretreatment, the biosafety of digestate cannot be guaranteed in mesophilic conditions

Personalized Oncogenomics: Clinical Experience with Malignant Peritoneal Mesothelioma Using Whole Genome Sequencing

<div><p>Peritoneal mesothelioma is a rare and sometimes lethal malignancy that presents a clinical challenge for both diagnosis and management. Recent studies have led to a better understanding of the molecular biology of peritoneal mesothelioma. Translation of the emerging data into better treatments and outcome is needed. From two patients with peritoneal mesothelioma, we derived whole genome sequences, RNA expression profiles, and targeted deep sequencing data. Molecular data were made available for translation into a clinical treatment plan. Treatment responses and outcomes were later examined in the context of molecular findings. Molecular studies presented here provide the first reported whole genome sequences of peritoneal mesothelioma. Mutations in known mesothelioma-related genes <i>NF2</i>, <i>CDKN2A</i>, <i>LATS2</i>, amongst others, were identified. Activation of <i>MET</i>-related signaling pathways was demonstrated in both cases. A hypermutated phenotype was observed in one case (434 vs. 18 single nucleotide variants) and was associated with a favourable outcome despite sarcomatoid histology and multifocal disease. This study represents the first report of whole genome analyses of peritoneal mesothelioma, a key step in the understanding and treatment of this disease.</p></div

Patient 1 and 2 large-scale genomic alterations.

<p>Circos Plots for patients 1 (A) and 2 (B). Copy number gains shown in red, copy number losses shown in green (height of bars is proportional to the number of copies gained or lost). Purple lines indicate interchromosomal translocations. Orange lines indicate intrachromosomal translocation.</p

Select SNVs from patients 1 and 2.

<p><i>NF2</i> loss-of-function mutations were common to both patients, as well as mutations in <i>CNTNAP3B</i> (shown in bold). For a complete list of SNVs see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0119689#pone.0119689.s003" target="_blank">S1 File</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0119689#pone.0119689.s004" target="_blank">S2 File</a>.</p><p>Select SNVs from patients 1 and 2.</p

Patient 2 pertinent radiology and pathology.

<p>(A)Vaginal mass biopsy showing malignant mesothelial cells with sarcomatoid features (H&E 20X). (B) CT/PET scan showing uptake in vaginal mass. (C) CT/PET showing additional uptake in the cecum. (D) Surgical specimen from the cecum showing epithelioid mesothelial proliferation with heavy lymphoplasmacytic infiltrate (H&E 20X). (E) Post-treatment CT/PET showing resolution of the vaginal mass (as compared to B). (F) Post-treatment CT/PET showing persistence of the cecal mass (compared with C). Imaging of associated inguinal lymphadenopathy not shown.</p