1,184 research outputs found
Chronique Espace judiciaire européen en matière civile - Obligations alimentaires : action en opposition à exécution et compétence de la juridiction de l'État membre d'exécution
No full textInternational audience(CJUE, 3e ch., 4 juin 2020, aff. C-41/19, FX c/ GZ, D. actu. 18 juin 2020, obs. G. Payan ; D. 2020. 1827, note D. Foussard ; AJ fam. 2020. 530, obs. A. Boiché
Two species of the deep-water shrimp genus Nematocarcinus A. Milne – Edwards, 1881 (Crustacea, Decapoda, Caridea, Nematocarcinidae) from the Mexican Pacific
No full textHernandez-Payan, J. C., Hendrickx, M. E. (2016): Two species of the deep-water shrimp genus Nematocarcinus A. Milne – Edwards, 1881 (Crustacea, Decapoda, Caridea, Nematocarcinidae) from the Mexican Pacific. Zootaxa 4126 (4): 587-599, DOI: 10.11646/zootaxa.4126.4.
Cysteine oxidation and redox signaling in dopaminergic neurons physiology and in Parkinson's disease
No full textParkinson's disease (PD)is a neurological disorder affecting dopaminergic neurons in the nigrostriatal pathways of the brain. PD is a multifactorial disease and its causes should be sought in detrimental interactions between genes and environment. Since early mechanistic studies, excessive oxidation – or oxidative stress – emerged as a recurring and fundamental pathogenic mechanism, and consequently received significant attention. More recent evidence obtained at single-cell resolution, however, indicates that dopaminergic neurons in the substantia nigra display increased oxidation levels also in normal, physiological conditions; differently than pathological oxidation, the importance of this phenomenon is underappreciated. The nigrostriatal dopaminergic system is involved in behavioral strategies that have been under strong evolutionary pressure. It is therefore improbable that physiological oxidation in dopamine neurons is accidental. Here, we review recent literature to argue that moderate oxidation improves redox signaling – which in dopamine neurons is intertwined with electrophysiological activity and is important to regulate dopamine release – and also has a protective role. We also reason that physiological oxidation provides an example of antagonistic pleiotropy therefore offering an advantage during reproductive stages of life while becoming detrimental during aging. Collectively, we believe that these observations provide a new perspective in the biology of dopaminergic neurons and in PD
Effect of Temperature and Humidity on the Synthesis of Alkali-Activated Binders Based on Bottom Ash from Municipal Waste Incineration
No full textWeathered bottom ash (WBA) from municipal solid waste incineration is a calcium aluminosilicate-rich material mainly used in construction and civil engineering as a secondary aggregate. However, its use is also being considered as a precursor in the manufacture of alkali-activated binders (AA-WBA). This preliminary research aimed to deepen understanding of the potential use of WBA (>8 mm fraction) as the sole precursor of alkali-activated binders. To gain better knowledge of this material, the physicochemical, mechanical, and environmental properties of AA-WBA binders were evaluated. In addition, the effect of curing temperature (25 °C, 45 °C, 65 °C, and 85 °C) and humidity conditions (oven and climate chamber) were assessed. The results of this study revealed that temperature and humidity conditions play a fundamental role during the early formation stages of AA-WBA binders. Maximum compactness and compressive strength (29.8 MPa) were obtained in the sample cured at 65 °C in the oven and room humidity. At higher temperatures (85 °C), a substantial decrease in mechanical strength (21.2 MPa) was observed due to a lower cohesion of the binder phases. Curing in the climate chamber led to an increase in humidity, and therefore a decrease in compressive strength. Finally, lower porosity and longer curing time substantially decreased the heavy metals and metalloid leaching concentration of AA-WBA binders
Nucleotide excision repair in chronic neurodegenerative diseases
No full textImpaired DNA repair involving the nucleotide excision repair (NER)/transcription-coupled repair (TCR) pathway cause human pathologies associated with severe neurological symptoms. These clinical observations suggest that defective NER/TCR might also play a critical role in chronic neurodegenerative disorders (ND), such as Alzheimer's and Parkinson's disease. Involvement of NER/TCR in these disorders is also substantiated by the evidence that aging constitutes the principal risk factor for chronic ND and that this DNA repair mechanism is very relevant for the aging process itself. Our understanding of the exact role of NER/TCR in chronic ND, however, is extremely rudimentary; while there is no doubt that defective NER/TCR can lead to neuronal death, evidence for its participation in the etiopathogenesis of ND is inconclusive thus far. Here we summarize the experimental observations supporting a role for NER/TCR in chronic ND and suggest questions and lines of investigation that might help in addressing this important issue. We also present a preliminary yet unprecedented meta-analysis on human brain microarray data to understand the expression levels of the various NER factors in the anatomical areas relevant for chronic ND pathogenesis. In summary, this review intends to highlight elements supporting a role of NER/TCR in these devastating disorders and to propose potential strategies of investigation. © 2013 Elsevier B.V
Nonlinear elasticity and slow dynamics: physical and numerical modeling
No full textInternational audienceVibrational experiments in rocks or concrete reveal that two different dynamics coexist [2,3]. First, a "fast" elastic dynamics occurs with a time scale ruled by the frequency of the excitation. Second, a "slow" dynamics governs the relaxation of the elastic modulus. Here, a "soft-ratchet" model [4] is preferred to the phenomenological Preisach-Mayergoyz model commonly used. The softening/recovering is related to the concentration of defects that evolves dynamically with the stress. This relaxation mechanisms is coupled to nonlinear elasticity. Lastly, viscoelasticity is introduced. Our contribution is two-fold [1]: • improvement of the physical model. A non-physical feature of the soft-ratchet model [4] is fixed. Moreover, the generalized Zener model introduced; • construction of a numerical scheme. Analytical tools used in [4] were unable to solve the full coupled system. On the contrary, we develop here a numerical strategy that enables to solve the whole equations. First, we introduce the physical model and its basic features: evolution of defects, nonlinear elasticity, and attenuation. Second, the evolution equations are written as a first-order system of partial differential equations. Third, the numerical method is introduced, based on a splitting strategy. The hyperbolic step is solved by a Godunov scheme, whereas the relaxation step is solved exactly. Fourth and last, numerical experiments show that the experimental observations performed by DAET are qualitatively recovered. [1] N. Favrie, B. Lombard, C. Payan, Fast and slow dynamics in a nonlinear elastic bar excited by longitudinal vibrations, submitted to Wave Motion (2015). [2] R.A. Guyer, P.A. Johnson, Nonlinear mesoscopic elasticity: Evidence for a new class of materials, Physics Today 52 (1999), 30-35. [3] J.A. Ten Cate, T.J. Shankland, Slow dynamics in the nonlinear elastic response of Berea sandstone, Geophys. Res. Lett., 23-21 (1996), 3019-3022. [4] O.O. Vakhnenko, V.O. Vakhnenko, T.J Shankland, Soft-ratchet modeling of end-point memory in the nonlinear resonant response of sedimentary rocks, Physical Review B71 (2005), 174103
Observed relation between evapotranspiration and soil moisture in the North American Monsoon region
No full textBioenergetic and proteolytic defects in fibroblasts from patients with sporadic Parkinson's disease
No full textBackground: Parkinson's disease (PD) is a complex disease and the current interest and focus of scientific research is both investigating the variety of causes that underlie PD pathogenesis, and identifying reliable biomarkers to diagnose and monitor the progression of pathology. Investigation on pathogenic mechanisms in peripheral cells, such as fibroblasts derived from patients with sporadic PD and age/gender matched controls, might generate deeper understanding of the deficits affecting dopaminergic neurons and, possibly, new tools applicable to clinical practice. Methods: Primary fibroblast cultures were established from skin biopsies. Increased susceptibility to the PD-related toxin rotenone was determined with apoptosis- and necrosis-specific cell death assays. Protein quality control was evaluated assessing the efficiency of the Ubiquitin Proteasome System (UPS) and protein levels of autophagic markers. Changes in cellular bioenergetics were monitored by measuring oxygen consumption and glycolysis-dependent medium acidification. The oxido-reductive status was determined by detecting mitochondrial superoxide production and oxidation levels in proteins and lipids. Results: PD fibroblasts showed higher vulnerability to necrotic cell death induced by complex I inhibitor rotenone, reduced UPS function and decreased maximal and rotenone-sensitive mitochondrial respiration. No changes in autophagy and redox markers were detected. Conclusions: Our study shows that increased susceptibility to rotenone and the presence of proteolytic and bioenergetic deficits that typically sustain the neurodegenerative process of PD can be detected in fibroblasts from idiopathic PD patients. Fibroblasts might therefore represent a powerful and minimally invasive tool to investigate PD pathogenic mechanisms, which might translate into considerable advances in clinical management of the disease. © 2014 Elsevier B.V
Analysis of Scalar Field Cosmology with Phase Space Deformations
No full textPhase space deformations on scalar field cosmology are studied. The deformation is introduced by
modifying the symplectic structure of the minisuperspace variables. The effects of the deformation are studied in the “C-frame” and the “NC-frame.” In order to remove the ambiguities of working on different frames, a new principle is introduced. When we impose that both frames should be physically equivalent, we conclude that the only possibility for this model, is to have an effective cosmological constant Λeff≥0. Finally we bound the parameter space for θ and β
Les restitutions consécutives à l'exécution d'un arrêt cassé
No full textInternational audience(Civ. 2e, 31 janv. 2019, n° 17-28.605, à paraître au Bulletin ; D. actu. 15 févr. 2019, obs. G. Payan ; Gaz. Pal. 26 mars 2019, p. 31, obs. C. Brenner ; Procédures 2019, n° 108, obs. Y. Strickler
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