La rupture et la violation du contrat psychologique : distinction conceptuelle et conséquences sur les comportements de citoyenneté organisationnelle et l'intention de départ volontaire

La rupture et la violation du contrat psychologique sont deux notions proches mais conceptuellement distinctes. La rupture est la perception cognitive que l’organisation a échoué à réaliser une ou plusieurs des obligations objets du contrat. Quant à la violation, elle désigne un état affectif et émotionnel négatif, caractérisé par la déception et la colère et susceptible d’accompagner la perception de rupture. L’objectif de cet article est de valider empiriquement cette distinction. Les résultats montrent que les conséquences de la rupture sur les comportements de citoyenneté organisationnelle et l’intention de départ volontaire sont distinctes de celles de la violation : la violation est directement et négativement associée aux comportements de citoyenneté alors que les effets de la rupture sont médiatisés par la satisfaction au travail. L’effet négatif de la rupture des obligations transactionnelles sur l’intention de départ est plus intense que celui de la violation, vu le caractère transactionnel de la relation d’échange. Enfin, la sensibilité à l’équité modère le lien entre la violation et les comportements de citoyenneté profitant à l’organisation ainsi que le lien entre la rupture et les comportements de citoyenneté orientés vers les individus dans l’organisation

Influence de la carbonatation sur le relargage de l'arsenic et du plomb et sur les propriétés chimiques et minéralogiques des matrices cimentaires

La contamination des sols est un enjeu important qui constitue une vraie menace pour la santé humaine. La stabilisation/solidification (S/S) est une technique de traitement des sols contaminés qui consiste à ajouter un liant hydraulique, la plupart du temps du ciment Portland, dans le sol contaminé. Cette technique transforme les contaminants mobiles en formes plus stables. Bien que son efficacité ait été démontrée, cette méthode n’est pas fréquemment utilisée au Québec, entre autres à cause du potentiel d’altération des sols S/S à long terme qui demeure méconnu. Ce projet porte sur la carbonatation des sols S/S, soit la réaction de la matrice cimentaire avec le CO2 atmosphérique, un des phénomènes qui peut affecter les performances à long termes des sols S/S. On s’intéresse particulièrement à l’impact de la carbonatation sur le relargage de l’arsenic et du plomb des matrices cimentaires et sur l’évolution de la minéralogie et les caractéristiques chimiques de ces matériaux suite à ce phénomène. Des essais de lixiviation en batch, basés sur l’équilibre thermodynamique, ont été utilisés pour évaluer la solubilité de ces métaux lourds en fonction du pH et au pH naturel des matrices non carbonatées et carbonatées. L’analyse thermogravimétrique, la phénolphtaléine et l’analyse par diffraction des rayons X ont été utilisées pour suivre l’évolution de la carbonatation au cours du temps et son effet sur les propriétés chimiques et minéralogiques des monolithes. Les résultats obtenus montrent que la carbonatation provoque la diminution du pH des matériaux S/S et la transformation complète de la portlandite et partielle des C-SH en carbonate de calcium. Suite à la carbonatation, la dissolution de ces hydrates de ciment, qui jouent un rôle important dans la rétention des métaux lourds, cause le relargage de l’arsenic immobilisé par le traitement S/S sur tout l’intervalle du pH. Le plomb, quant à lui, est fixé davantage par la carbonatation

Geophysical survey to estimate the 3D sliding surface and the 4D evolution of the water pressure on part of a deep seated landslide

International audienceGeophysical surveys were conducted on the very unstable front part of the La Clapière landslide in the French Alps (Alpes Maritimes). The electrical resistivity survey was carried out to obtain, for the first time on this deep-seated landslide, 3D information on the slipping surface and the vertical drained faults. Moreover, we planned to follow within time (6 months) the evolution of the saturated zones (presence of gravitational water) and their percolation into the shearing zones. Our 4D results showed the importance of the complex water channelization within the slope and relation to geological discontinuities

Impact of a blood-sucking parasite on the chemical composition of fatty acids in the white muscle of garfish (Belone belone, Belonidae) from Tunisian coasts (Central Mediterranean)

The objective of this study was to compare the composition of fatty acids in the garfish (Belone belone) white muscle removed from parasitized and non parasitized specimens. The chemical analysis results revealed low contents of total fatty acids for both parasitized and non-parasitized specimens. Their values, less than 2 g/100 g of fresh muscle, allowed the classification of the garfish as a lean fish. High ratios of saturated fatty acids were found in the garfish muscle reaching 58.4% of total fatty acids. These fatty acids were represented mainly by lauric, miristic and palmitic at a level of 50.3%. As a lean fish, garfish contains 16% polyunsaturated fatty acids (n-3). Two major fatty acids are docosahexaenoic and eicosapentaenoic with respective percentages of 9 and 1.17% of total fatty acids. The parasitized garfish showed increase in their fatty acids, mainly in pentadecanoic, pentadecenoic, docosahexaenoic and arachidonic acids and decreases in saturated acids especially lauric, miristic and palmitic. This drop is correlated with a very significant increase in PUFA from 16 to 26% of total fatty acids. In order to obtain 0.5 g/day of EPA + DHA, the amount of garfish required is 641 g of non-parasitized and 436 g parasitized fish.Key words: Garfish, blood-sucking, parasite, parasitized fish, fatty acid analysis, Tunisia

Frequency Change-Point Detection in physiological Signals : an Algebraic Approach

International audienceThis paper considers the problem of change-point detection for noisy data. Estimation of signal frequency content relies on differential algebra and non-commutative algebra together with operational calculus. We adapt this approach to the study of changes that may be observed in EEG signal dynamics during epileptic seizure and in ECG signal during the occurrence of a QRS complex. The correlation with frequency change is what this idea is based on. The interest of our estimator is firstly il lustrated according to several academic examples. Then, the method is applied on real physiological signals to detect abrupt frequency changes

Enhanced rock-slope failure following ice-sheet deglaciation : timing and causes

This research was supported by NERC Cosmogenic Isotope Analysis Facility [Grant Number: 9046.0308]The temporal pattern of rock-slope failures (RSFs) following Late Pleistocene deglaciation on tectonically stable terrains is controversial: previous studies variously suggest (1) a rapid response due to removal of supporting ice (‘debuttressing’), (2) a progressive decline in RSF frequency, and (3) a millennial-scale delay before peak RSF activity. We test these competing models through beryllium-10 (10Be) exposure dating of five closely-spaced quartzite RSFs on the Isle of Jura, Scotland, to establish the relationship between timing of failure and those of deglaciation, episodes of rapid warming and periods of rapid glacio-isostatic uplift. All five dated RSFs occurred at least 720–2240 years after deglaciation, with the probability of failure peaking ~2 ka after deglaciation, consistent with millennial-scale delay model (3). This excludes debuttressing as an immediate cause of failure, though it is likely that time-dependent stress release due to deglacial unloading resulted in progressive development of failure planes within the rock. Thaw of permafrost ice in joints is unlikely to have been a prime trigger of failure as some RSFs occurred several centuries after the onset of interstadial warming. Conversely, the timespan of the RSFs coincides with the period of maximum glacio-isostatic crustal uplift, suggesting that failure was triggered by uplift-driven seismic events acting on fractured rock masses. Implications of this and related research are: (1) that retreat of the last Pleistocene ice sheets across tectonically-stable mountainous terrains was succeeded by a period of enhanced rock-slope failure due to deglacial unloading and probably uplift-driven seismicity; (2) that the great majority of RSFs in the British Isles outside the limits of Loch Lomond Stadial (= Younger Dryas) glaciation are of Lateglacial (pre-Holocene) age; and (3) numerous RSFs must also have occurred inside Loch Lomond Stadial (LLS) glacial limits, but that runout debris was removed by LLS glaciers.PostprintPeer reviewe

Ethical Decision-Making in Islamic Financial Institutions in Light of Maqasid Al-Sharia: A Conceptual Framework

This article develops a conceptual framework for ethical decision‐making in Islamic financial institution based on the Islamic methodological approaches on ethics. While making use of the similarities between the scientific method and the Islamic jurisprudence method, a framework is developed by means of argumentation and reasoning to integrate Sharia doctrines with the “plan, do, check and act” (PDCA) cycle as a managerial tool. Using Al‐Raysuni's analysis of Al‐Shatibi's work on maqasid al‐sharia, this article develops a framework to assess the ethical aspects of Islamic financial operations, which is then applied to hypothetical cases. This approach can help overcome the methodological deficiencies in measuring ethical performance in Islamic finance by focusing on the process of ethical decision‐making that leads to the outcomes of organizational behavior beyond legality of contracts. The framework outlines the conditions under which an activity that is considered legal and permissible contractually could lead to outcomes that can make it ethical or unethical

VIP Enhances Phagocytosis of Fibrillar Beta-Amyloid by Microglia and Attenuates Amyloid Deposition in the Brain of APP/PS1 Mice

Vasoactive intestinal peptide (VIP) is a multifunctional neuropeptide with demonstrated immunosuppressive and neuroprotective activities. It has been shown to inhibit Amyloid beta (Aβ)-induced neurodegeneration by indirectly suppressing the production and release of a variety of inflammatory and neurotoxic factors by activated microglia. We demonstrated that VIP markedly increased microglial phagocytosis of fibrillar Aβ42 and that this enhanced phagocytotic activity depended on activation of the Protein kinase C (PKC) signaling pathway. In addition, VIP suppressed the release of tumor necrosis factor alpha (TNF-α) and nitric oxide(NO) from microglia activated by combined treatment with fibrillar Aβ42 and low dose interferon-γ (IFN-γ). We utilized an adenovirus-mediated gene delivery method to overexpress VIP constitutively in the hippocampus of APPswPS1 transgenic mice. The Aβ load was significantly reduced in the hippocampus of this animal model of Alzheimer's disease, possibly due to the accumulation and activation of cd11b-immunoactive microglial cells. The modulation of microglial activation, phagocytosis, and secretion by VIP is a promising therapeutic option for the treatment of Alzheimer's disease(AD)

Higher ethical objective (Maqasid al-Shari'ah) augmented framework for Islamic banks : assessing the ethical performance and exploring its determinants.

This study utilises higher objectives postulated in Islamic moral economy or the maqasid al-Shari’ah theoretical framework’s novel approach in evaluating the ethical, social, environmental and financial performance of Islamic banks. Maqasid al-Shari’ah is interpreted as achieving social good as a consequence in addition to well-being and, hence, it goes beyond traditional (voluntary) social responsibility. This study also explores the major determinants that affect maqasid performance as expressed through disclosure analysis. By expanding the traditional maqasid al-Shari’ah,, we develop a comprehensive evaluation framework in the form of a maqasid index, which is subjected to a rigorous disclosure analysis. Furthermore, in identifying the main determinants of the maqasid disclosure performance, panel data analysis is used by including several key variables alongside political and socio-economic environment, ownership structures, and corporate and Shari’ah governance-related factors. The sample includes 33 full-fledged Islamic banks from 12 countries for the period of 2008–2016. The findings show that although during the nine-year period the disclosure of maqasid performance of the sampled Islamic banks has improved, this is still short of ‘best practices’. Through panel data analysis, this study finds that the Muslim population indicator, CEO duality, Shari’ah governance, and leverage variables positively impact the disclosure of maqasid performance. However, the effect of GDP, financial development and human development index of the country, its political and civil rights, institutional ownership, and a higher share of independent directors have an overall negative impact on the maqasid performance. The findings reported in this study identify complex and multi-faceted relations between external market realities, corporate and Shari’ah governance mechanisms, and maqasid performance