Lime treated soil erodibility investigated by EFA erosion testing

Erosion is susceptible to reduce the overall stability of a structure under hydraulic and static loads, but also can lead to the development of a fast breach. In parallel, dikes and levees builders and designers have not so many ways to improve initial properties of materials available on site, for the construction or restoration of hydraulic embankments. In this context, soil treatment with lime is a relevant procedure that is reported to improve the mechanical properties and erosion behavior of silty and clayey soils. This study focuses on the changes induced by lime treatment on the erosion resistance of a silty soil, and the evolution of relevant erosion parameters with curing time. EFA (Erosion Function Apparatus) tests on a silty soil from Marche-les-Dames (Belgium) were performed on the native soil, and after 2.5 % lime addition at several curing times (1, 7 and 28 days). After 1 day curing time, a slight increase in the soil erosion resistance is recorded, whereas after seven days submitted to a water flow velocity above 3 m/s, the soil passes from a medium to a low erodibility level. After 28 days, the soil has a very low erodibility for the same water velocity

Application d'un produit polymère à la consolidation des sables carbonatés

L'injection est un procédé de construction de plus en plus utilisé pour l'étanchement ou la consolidation des sols. Le choix du produit d'injection dépend des caractéristiques du sol et de l'objectif du traitement. Les coulis de ciment, injectés sous pression, sont couramment utilisés. Cependant, l'utilisation de produits chimiques peut être plus avantageuse grâce, principalement, à leur faible viscosité assurant une meilleure pénétrabilité des terrains à injecter.Cet article décrit les travaux réalisés avec un nouveau produit polymère utilisé pour la consolidation des sables carbonatés. Ces formations présentent des caractéristiques mécaniques faibles à très faibles, et le traitement envisagé permet d'augmenter leur résistance mécanique.L'expérimentation, utilisant en grande partie l'essai de compression simple, porte sur des échantillons de sable préalablement injectés. Des valeurs de la résistance de 3,5 à 4 MPa sont régulièrement obtenues dès quelques heures de conservation dans l’eau. L’amélioration de la résistance mécanique est étudiée en fonction des principaux paramètres liés aux problèmes d'injection

Time-course of the tDCS antidepressant effect: An individual participant data meta-analysis

Introduction: Prefrontal transcranial direct current stimulation (tDCS) shows promise as an effective treatment for depression. However, factors influencing treatment and the time-course of symptom improvements remain to be elucidated. Methods: Individual participant data was collected from ten randomised controlled trials of tDCS in depression. Depressive symptom scores were converted to a common scale, and a linear mixed effects individual growth curve model was fit to the data using k-fold cross-validation to prevent overfitting. Results: Data from 576 participants were analysed (tDCS: n = 311; sham: n = 265), of which 468 were unipolar and 108 had bipolar disorder. tDCS effect sizes reached a peak at approximately 6 weeks, and continued to diverge from sham up to 10 weeks. Significant predictors associated with worse response included higher baseline depression severity, treatment resistance, and those associated with better response included bipolar disorder and anxiety disorder. Conclusions: Our findings suggest that longer treatment courses, lasting at least 6 weeks in duration, may be indicated. Further, our results show that tDCS is effective for depressive symptoms in bipolar disorder. Compared to unipolar depression, participants with bipolar disorder may require additional maintenance sessions to prevent rapid relapse

Hind limb unloading, a model of spaceflight conditions, leads to decreased B lymphopoiesis similar to aging

Within the bone marrow, the endosteal niche plays a crucial role in B-cell differentiation. Because spaceflight is associated with osteoporosis, we investigated whether changes in bone microstructure induced by a ground-based model of spaceflight, hind limb unloading (HU), could affect B lymphopoiesis. To this end, we analyzed both bone parameters and the frequency of early hematopoietic precursors and cells of the B lineage after 3, 6, 13, and 21 d of HU. We found that limb disuse leads to a decrease in both bone microstructure and the frequency of B-cell progenitors in the bone marrow. Although multipotent hematopoietic progenitors were not affected by HU, a decrease in B lymphopoiesis was observed as of the common lymphoid progenitor (CLP) stage with a major block at the progenitor B (pro-B) to precursor B (pre-B) cell transition (5- to 10-fold decrease). The modifications in B lymphopoiesis were similar to those observed in aged mice and, as with aging, decreased B-cell generation in HU mice was associated with reduced expression of B-cell transcription factors, early B-cell factor (EBF) and Pax5, and an alteration in STAT5-mediated IL-7 signaling. These findings demonstrate that mechanical unloading of hind limbs results in a decrease in early B-cell differentiation resembling age-related modifications in B lymphopoiesis.status: publishe

Repetitive transcranial magnetic stimulation treatment for depressive disorders: current knowledge and future directions

Purpose of review After three decades of clinical research on repetitive transcranial magnetic stimulation (rTMS), major depressive disorder (MDD) has proven to be the primary field of application. MDD poses a major challenge for health systems worldwide, emphasizing the need for improving clinical efficacy of existing rTMS applications and promoting the development of novel evidence-based rTMS treatment approaches. Recent findings Several promising new avenues have been proposed: novel stimulation patterns, targets, and coils; combinatory treatments and maintenance; and personalization and stratification of rTMS parameters, and treatment of subpopulations. This opinion review summarizes current knowledge in the field and addresses the future direction of rTMS treatment in MDD, facilitating the establishment of this clinical intervention method as a standard treatment option and continuing to improve response and remission rates, and take the necessary steps to personalize rTMS-based treatment approaches