Ensemble Kalman Filter Assimilation of ERT Data for Numerical Modeling of Seawater Intrusion in a Laboratory Experiment

Seawater intrusion in coastal aquifers is a worldwide problem exacerbated by aquifer overexploitation and climate changes. To limit the deterioration of water quality caused by saline intrusion, research studies are needed to identify and assess the performance of possible countermeasures, e.g., underground barriers. Within this context, numerical models are fundamental to fully understand the process and for evaluating the effectiveness of the proposed solutions to contain the saltwater wedge; on the other hand, they are typically affected by uncertainty on hydrogeological parameters, as well as initial and boundary conditions. Data assimilation methods such as the ensemble Kalman filter (EnKF) represent promising tools that can reduce such uncertainties. Here, we present an application of the EnKF to the numerical modeling of a laboratory experiment where seawater intrusion was reproduced in a specifically designed sandbox and continuously monitored with electrical resistivity tomography (ERT). Combining EnKF and the SUTRA model for the simulation of density-dependent flow and transport in porous media, we assimilated the collected ERT data by means of joint and sequential assimilation approaches. In the joint approach, raw ERT data (electrical resistances) are assimilated to update both salt concentration and soil parameters, without the need for an electrical inversion. In the sequential approach, we assimilated electrical conductivities computed from a previously performed electrical inversion. Within both approaches, we suggest dual-step update strategies to minimize the effects of spurious correlations in parameter estimation. The results show that, in both cases, ERT data assimilation can reduce the uncertainty not only on the system state in terms of salt concentration, but also on the most relevant soil parameters, i.e., saturated hydraulic conductivity and longitudinal dispersivity. However, the sequential approach is more prone to filter inbreeding due to the large number of observations assimilated compared to the ensemble size

Contamination métallique de Gambusia holbrooki au niveau du lac Fouarat et de l’estuaire Sebou dans la région du Gharb (Maroc)

Situés dans l’agglomération de Kénitra, l’estuaire de Sebou et le lac Fouarat, sont soumis en permanence à de nombreux rejets d’eaux uséeset de déchets. L’impact de cette activité anthropique sur la qualité de cesmilieux a été estimé à travers le suivi spatio-temporel des teneurs corporelles en fer, du manganèse, du chrome, du cuivre, du zinc et duplomb chez Gambusia holbrooki. Ce poisson omnivore, constitue désormais un des maillons de la chaîne trophique au sein du lac et del’estuaire. Les résultats obtenus ont mis en évidence la contamination et l’accumulation des métaux par ce poisson avec une charge métalliqueimportante par rapport à celle des témoins et des autres poissons de l’estuaire. Par ailleurs, l’évolution saisonnière des teneurs a montré desdifférences de faible importance entre les deux milieux, liées essentiellement aux variations climatiques. Les résultats reflètent unedégradation croissante de la qualité de ces milieux qui ne cessent d’être le réceptacle de nombreux rejets divers. Cette situation peut engendrer des conséquences toxicologiques inquiétantes sur la santé, dans la mesure où le risque de contamination de la nappe phréatique qui alimente toute la région en eau potable n’est pas exclue. L’irrigation courante des parcelles agricoles avec les eaux contaminées du lac comporte aussi des risques qu’il convient d’éviter et surtout d’évaluer.Mots-clés : contamination métallique, Gambusia, lac Fouarat, estuaire Sebou, effluent, rejet

Investigation of Parietal Polysaccharides from Retama raetam Roots

This study characterizes the cell wall hemicellulose and pectins polymers of Retama raetam. This species develops a particularly important root system and is adapted to arid areas. The cellulose, hemicelluloses and pectins were extracted. The cellulose remains the major component of the wall (27% for young roots and 80% for  adult roots), hemicelluloses (14.3% for young roots and 3.6%  for adult roots) and pectins (17.3% for young roots and 4.1% for adult roots). The monosaccharidic composition of water soluble extracts determined by gas liquid chromatography (GLC) and completed by infrared (FTIR) spectroscopy of hemicellulosic shows the presence of xylose as a major monosaccharide in the non-cellulose polysaccharides (47.8% for young roots and 59.5% for adult roots). These results indicate the presence of the homogalacturonans and rhamnogalacturonans in pectin. This study constitutes the preliminary data obtained in the biochemical analysis of the parietal compounds of the roots of a species which grows in an arid area in comparison with those of its aerial parts.Keywords: Retama raetam, Roots, Cell Wall, Investigation, Polysaccharides, Monosaccharidi

Proposals for revised IWG 2018 hematological response criteria in patients with MDS included in clinical trials

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Recent AEM Case Study Examples of a Full Waveform Time-Domain System for Near-Surface and Groundwater Applications

Early time or high frequency airborne electromagnetic data (AEM) are desirable for shallow sounding or mapping of resistive areas but this poses difficulties due to a variety of issues, such as system bandwidth, system calibration and parasitic loop capacitance. In an effort to address this issue, a continued system design strategy, aimed at improving its early-channel VTEM data, has achieved fully calibrated, quantitative measurements closer to the transmitter current turn-off, while maintaining reasonably optimal deep penetration characteristics. The new design implementation, known as “Full Waveform” VTEM was previously described by Legault et al. (2012). This paper presents some case-study examples of a Full Waveform helicopter time-domain EM system for near-surface application

Cyanobacterial metabolites as a source of sunscreens and moisturizers: a comparison with current synthetic compounds

The recognition of the harmful effects of ultraviolet radiation on the skin has led to the commercial development of inorganic and synthetic organic UV filters that can attenuate the negative effects of sunlight exposure. In addition, chemical moisturizers are extensively used in cosmetic products to improve the ability of skin to retain water. Whilst these chemicals have clear beneficial qualities, they may also have adverse effects such as contact sensitivity, oestrogenicity and even tumorigenic effects on human skin. Furthermore, the accumulation of such chemicals in the aquatic environment could be potentially harmful. Consequently, there is interest in exploiting safer alternatives derived from biological sources, especially from photosynthetic organisms such as cyanobacteria that have developed mechanisms for coping with high UV irradiation and desiccation. In order to overcome the detrimental effects of UV radiation, these microorganisms produce UV screening compounds such as mycosporine-like amino acids and scytonemin, which are good candidates as alternatives to current synthetic UV filters. In addition, extracellular substances produced by some extremophilic species living in hyper-arid habitats have a high water retention capacity and could be used in cosmetic products as moisturizers. In this review, we present an overview of the literature describing the potential of cyanobacterial metabolites as an alternative source for sunscreens and moisturizers

A new view of electrochemistry at highly oriented pyrolytic graphite

Major new insights on electrochemical processes at graphite electrodes are reported, following extensive investigations of two of the most studied redox couples, Fe(CN)64–/3– and Ru(NH3)63+/2+. Experiments have been carried out on five different grades of highly oriented pyrolytic graphite (HOPG) that vary in step-edge height and surface coverage. Significantly, the same electrochemical characteristic is observed on all surfaces, independent of surface quality: initial cyclic voltammetry (CV) is close to reversible on freshly cleaved surfaces (>400 measurements for Fe(CN)64–/3– and >100 for Ru(NH3)63+/2+), in marked contrast to previous studies that have found very slow electron transfer (ET) kinetics, with an interpretation that ET only occurs at step edges. Significantly, high spatial resolution electrochemical imaging with scanning electrochemical cell microscopy, on the highest quality mechanically cleaved HOPG, demonstrates definitively that the pristine basal surface supports fast ET, and that ET is not confined to step edges. However, the history of the HOPG surface strongly influences the electrochemical behavior. Thus, Fe(CN)64–/3– shows markedly diminished ET kinetics with either extended exposure of the HOPG surface to the ambient environment or repeated CV measurements. In situ atomic force microscopy (AFM) reveals that the deterioration in apparent ET kinetics is coupled with the deposition of material on the HOPG electrode, while conducting-AFM highlights that, after cleaving, the local surface conductivity of HOPG deteriorates significantly with time. These observations and new insights are not only important for graphite, but have significant implications for electrochemistry at related carbon materials such as graphene and carbon nanotubes

Psychological treatment of depression: A meta-analytic database of randomized studies

Abstract Background A large number of randomized controlled studies have clearly demonstrated that psychological interventions are effective in the treatment of depression. The number of studies in this area is increasing rapidly. In this paper, we present a database of controlled and comparative outcome studies on psychological treatments of depression, based on a series of meta-analyses published by our group. The database can be accessed freely through the Internet. Description We conducted a comprehensive literature search of the major bibliographical databases (Pubmed; Psycinfo; Embase; Cochrane Central Register of Controlled Trials) and we examined the references of 22 earlier meta-analyses of psychological treatment of depression. We included randomized studies in which the effects of a psychological therapy on adults with depression were compared to a control condition, another psychological intervention, or a combined treatment (psychological plus pharmacological). We conducted nine meta-analyses of subgroups of studies taken from this dataset. The 149 studies included in these 9 meta-analyses are included in the current database. In the 149 included studies, a total of 11,369 patients participated. In the database, we present selected characteristics of each study, including characteristics of the patients (the study population, recruitment method, definition of depression); characteristics of the experimental conditions and interventions (the experimental conditions, N per condition, format, number of sessions); and study characteristics (measurement times, measures used, attrition, type of analysis and country). Conclusion The data on the 149 included studies are presented in order to give other researchers access to the studies we collected, and to give background information about the meta-analyses we have published using this dataset. The number of studies examining the effects of psychological treatments of depression has increased considerably in the past decades, and this will continue in the future. The database we have presented in this paper can help to integrate the results of these studies in future meta-analyses and systematic reviews on psychological treatments for depression

Cyanobacteria of the thermal spring at Pancharevo, Sofia, Bulgaria

Eight taxa of cyanobacteria were identified in the thermal spring at Pancharevo (in the Sofia basin, Bulgaria). As well as the widespread Lyngbya thermalis, Phormidesmis molle (syn. Phormidium molle), Phormidium papyraceum, Phormidium corium and Mastigocladus laminosus, four species were identified for the first time in Bulgaria: Calothrix thermalis, Gloeocapsa gelatinosa, Leibleinia epiphytica and Symploca thermalis

Cognitive behavioral therapy for depression among adults in Japanese clinical settings: a single-group study

<p>Abstract</p> <p>Background</p> <p>Empirical support for cognitive behavioral therapy (CBT) for treating Japanese patients with major depression is lacking, therefore, a feasibility study of CBT for depression in Japanese clinical settings is urgently required.</p> <p>Findings</p> <p>A culturally adapted, 16-week manualized individual CBT program for Japanese patients with major depressive disorder was developed. A total of 27 patients with major depression were enrolled in a single-group study with the purpose of testing the feasibility of the program. Twenty six patients (96%) completed the study. The mean total score on the Beck Depression Inventory-II (BDI-II) for all patients (Intention-to-treat sample) improved from 32.6 to 11.7, with a mean change of 20.8 (95% confidence interval: 17.0 to 24.8). Within-group effect size at the endpoint assessment was 2.64 (Cohen's d). Twenty-one patients (77.7%) showed treatment response and 17 patients (63.0%) achieved remission at the end of the program. Significant improvement was observed in measurement of subjective and objective depression severity (assessed by BDI-II, Quick Inventory of Depressive Symptomatology-Self Rated, and Hamilton Depression Rating Scale), dysfunctional attitude (assessed by Dysfunctional Attitude Scale), global functioning (assessed by Global Assessment of Functioning of DSM-IV) and subjective well-being (assessed by WHO Subjective Well-being Inventory) (all p values < 0.001).</p> <p>Conclusions</p> <p>Our manualized treatment comprised of a 16-week individual CBT program for major depression appears feasible and may achieve favorable treatment outcomes among Japanese patients with major depression. Further research involving a larger sample in a randomized, controlled trial design is warranted.</p> <p>Trial registration</p> <p>UMIN-CTR UMIN000002542.</p