600 research outputs found

    Sukuk: Literature Review

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    Abstract. At the heart of a global financial crisis triggered since 2008, Islamic finance has been seen as an alternative less affected by the global crisis to cover the financing and investment needs and bringing a new vision that involves sharing of losses and gains and thus prohibit the notion of the interest rate. With the emergence of the concept of Islamic finance a new market has emerged known as sukuk market where its last ones play the role of bonds. These financial instruments have been able, like conventional bonds, to constitute a reliable investment alternative for both companies and governments that want to conduct their business within a framework that respects the precepts of the Sharia. The purpose of this article is to understand the concept and the mechanism of these obligations and to present a review of the literature on sukuks.Keywords. Sukuk, Islamic Finance, Bonds, Financial Instruments.JEL. A10, H12

    Tensin1 expression and function in chronic obstructive pulmonary disease

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    open access articleChronic obstructive pulmonary disease (COPD) constitutes a major cause of morbidity and mortality. Genome wide association studies have shown significant associations between airflow obstruction or COPD with a non-synonymous SNP in the TNS1 gene, which encodes tensin1. However, the expression, cellular distribution and function of tensin1 in human airway tissue and cells are unknown. We therefore examined these characteristics in tissue and cells from controls and people with COPD or asthma. Airway tissue was immunostained for tensin1. Tensin1 expression in cultured human airway smooth muscle cells (HASMCs) was evaluated using qRT-PCR, western blotting and immunofluorescent staining. siRNAs were used to downregulate tensin1 expression. Tensin1 expression was increased in the airway smooth muscle and lamina propria in COPD tissue, but not asthma, when compared to controls. Tensin1 was expressed in HASMCs and upregulated by TGFβ1. TGFβ1 and fibronectin increased the localisation of tensin1 to fibrillar adhesions. Tensin1 and α-smooth muscle actin (αSMA) were strongly co-localised, and tensin1 depletion in HASMCs attenuated both αSMA expression and contraction of collagen gels. In summary, tensin1 expression is increased in COPD airways, and may promote airway obstruction by enhancing the expression of contractile proteins and their localisation to stress fibres in HASMCs

    Activation of tumor necrosis factor receptor 1 in airway smooth muscle: a potential pathway that modulates bronchial hyper-responsiveness in asthma?

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    The cellular and molecular mechanisms that are involved in airway hyper-responsiveness are unclear. Current studies suggest that tumor necrosis factor (TNF)-α, a cytokine that is produced in considerable quantities in asthmatic airways, may potentially be involved in the development of bronchial hyper-responsiveness by directly altering the contractile properties of the airway smooth muscle (ASM). The underlying mechanisms are not known, but growing evidence now suggests that most of the biologic effects of TNF-α on ASM are mediated by the p55 receptor or tumor necrosis factor receptor (TNFR)1. In addition, activation of TNFR1 coupled to the tumor necrosis factor receptor-associated factor (TRAF)2-nuclear factor-κB (NF-κB) pathway alters calcium homeostasis in ASM, which appears to be a new potential mechanism underlying ASM hyper-responsiveness

    The effect of confined Longitudinal Optical Phonons on the Binding Energy of an impurity in CdSe Quantum Dot

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    Using a variational approach, the effect of the confined LO-phonon on the binding energy in CdSe Quantum Dot has been calculated. The charge-carrier-phonon coupling is treated within the adiabatic approximation. Our results show that the effect of the confined LO-phonon on the binding energy decreases with the dot size. However the correction of the confined LO-phonon to bound state energy increases with dot size.Using a variational approach, the effect of the confined LO-phonon on the binding energy in CdSe Quantum Dot has been calculated. The charge-carrier-phonon coupling is treated within the adiabatic approximation. Our results show that the effect of the confined LO-phonon on the binding energy decreases with the dot size. However the correction of the confined LO-phonon to bound state energy increases with dot size

    Histoire des femmes dans la France des XIXe et XXe siècles

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    Les recherches récentes mettent en évidence les femmes comme objets du regard ou de la politique, et montrent les femmes comme sujets, actrices de l\u27histoire, actives dans tous les domaines de la vie publique. Confinées dans la vie privée par l\u27idéologie dominante qui les veut épouses, mères et ménagères, les femmes sont en effet, qu\u27elles le veuillent ou non, mêlées à toutes les évolutions de la société française au fil des XIXe et XXe siècles. Cette période les voit conquérir de nouveaux droits, revendiquer l\u27égalité et l\u27indépendance, se libérer de nombreux tabous… Une révolution féministe s\u27accomplit, à travers l\u27accès à l\u27éducation, au droit de vote, sans oublier la maîtrise de la fécondité. Si l\u27ouvrage dessine une « condition féminine » en évolution, il montre aussi l\u27hétérogénéité, la diversité des statuts, des appartenances sociales, culturelles… Centré sur les femmes, dans leur diversité, il est aussi une histoire du genre attentive aux rapports de pouvoir entre les sexes, à la domination masculine et à la fabrique du féminin et du masculin

    Expression and activation of the oxytocin receptor in airway smooth muscle cells: Regulation by TNFα and IL-13

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    <p>Abstract</p> <p>Background</p> <p>During pregnancy asthma may remain stable, improve or worsen. The factors underlying the deleterious effect of pregnancy on asthma remain unknown. Oxytocin is a neurohypophyseal protein that regulates a number of central and peripheral responses such as uterine contractions and milk ejection. Additional evidence suggests that oxytocin regulates inflammatory processes in other tissues given the ubiquitous expression of the oxytocin receptor. The purpose of this study was to define the role of oxytocin in modulating human airway smooth muscle (HASMCs) function in the presence and absence of IL-13 and TNFα, cytokines known to be important in asthma.</p> <p>Method</p> <p>Expression of oxytocin receptor in cultured HASMCs was performed by real time PCR and flow cytomery assays. Responses to oxytocin was assessed by fluorimetry to detect calcium signals while isolated tracheal rings and precision cut lung slices (PCLS) were used to measure contractile responses. Finally, ELISA was used to compare oxytocin levels in the bronchoalveloar lavage (BAL) samples from healthy subjects and those with asthma.</p> <p>Results</p> <p>PCR analysis demonstrates that OXTR is expressed in HASMCs under basal conditions and that both interleukin (IL)-13 and tumor necrosis factor (TNFα) stimulate a time-dependent increase in OXTR expression at 6 and 18 hr. Additionally, oxytocin increases cytosolic calcium levels in fura-2-loaded HASMCs that were enhanced in cells treated for 24 hr with IL-13. Interestingly, TNFα had little effect on oxytocin-induced calcium response despite increasing receptor expression. Using isolated murine tracheal rings and PCLS, oxytocin also promoted force generation and airway narrowing. Further, oxytocin levels are detectable in bronchoalveolar lavage (BAL) fluid derived from healthy subjects as well as from those with asthma.</p> <p>Conclusion</p> <p>Taken together, we show that cytokines modulate the expression of functional oxytocin receptors in HASMCs suggesting a potential role for inflammation-induced changes in oxytocin receptor signaling in the regulation of airway hyper-responsiveness in asthma.</p

    Comparative assessment of total phenolics content and in vitro antioxidant capacity variations of leaf extracts of Origanum grossii and Thymus pallidus

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    The objective of this research was to assess the efficacy of extracts derived from Origanum grossii and Thymus pallidus leaves, focusing on their inherent phenolic compounds with varying antioxidant processes. The extracts were obtained through the utilization of a Soxhlet apparatus for hot extraction. Several parameters including overall phenolic and flavonoid content, total antioxidant activity (TAC), ferric reduction capacity (FRAP), DPPH scavenging capacity, and ABTS capability were investigated. The total phenolic content ranged from 292.91±1.51 to 3.804±0.22 mg/g DW in oregano samples and from 284.3±1.78 to 3.435±0.23 mg/g DW in thyme fractions, employing gallic acid equivalents as the measurement unit. The sequence of extraction effectiveness, ranked from highest to lowest, was methanolic extracts &gt; aqueous extracts &gt; ethyl acetate extracts for both, oregano and thyme. Furthermore, the methanolic extracts displayed the greatest reducing and antiradical power, along with the highest total antioxidant capacities, for both plant species. These remarkable antioxidant properties of the extracts demonstrated a strong correlation with the levels of total phenols (TP) and total flavonoids (TF). Oregano and thyme leaves showcased promising antioxidant capacities, underscoring their potential as abundant sources of phenolic compounds with diverse antioxidant characteristics, thereby indicating their viability as natural preservatives

    Broadband Fields Radiated in a Solid by Water-Coupled Transducers: A Comparison of Approximate Models, Numerical Approaches and Experiments

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    In number of configurations, ultrasonic tests in the French nuclear industry are made using water-coupled focused transducers. To study the influence of the various parameters involved in transducer/piece configurations, model-based predictions of the field radiated by transducers are very useful. A model (called Champ-Sons) has been developed at the French Atomic Energy Commission (CEA) to calculate the field radiated by focused or unfocused transducer through liquid/solid interface at normal or oblique incidence [1]. It can deal with radiating surface of complex (3-D) shape (spherical focusing, Fermat’s surfaces, multiple-elements [2] etc.). The calculation is done directly in the time domain for broadband sources and in the frequency domain for narrowband sources. In its present form Champ-Sons deals with either plane or cylindrical interfaces between a fluid and an isotropic solid. It is implemented in a user-friendly software developed at the CEA called CIVA [3] for NDT data processing (eddy-current, ultrasonics, neutrongraphy, radiography). Since non-canonical configurations are considered and pure numerical schemes are too computer intensive, the model treats the refraction at the fluid/solid interface in an approximate way. It has been validated experimentally [1]

    Role of rhizospheric microbiota as a bioremediation tool for the protection of soil-plant systems from microcystins phytotoxicity and mitigating toxin-related health risk

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    Frequent toxic cyanoblooms in eutrophic freshwaters produce various cyanotoxins such as the monocyclic heptapeptides microcystins (MCs), known as deleterious compounds to plant growth and human health. Recently, MCs are a recurrent worldwide sanitary problem in irrigation waters and farmland soils due to their transfer and accumulation in the edible tissues of vegetable produce. In such cases, studies about the persistence and removal of MCs in soil are scarce and not fully investigated. In this study, we carried out a greenhouse trial on two crop species: faba bean (Vicia faba var. Alfia 321) and common wheat (Triticum aestivum var. Achtar) that were grown in sterile (microorganism-free soil) and non-sterile (microorganism-rich soil) soils and subjected to MC-induced stress at 100 µg equivalent MC-LR L−1. The experimentation aimed to assess the prominent role of native rhizospheric microbiota in mitigating the phytotoxic impact of MCs on plant growth and reducing their accumulation in both soils and plant tissues. Moreover, we attempted to evaluate the health risk related to the consumption of MC-polluted plants for humans and cattle by determining the estimated daily intake (EDI) and health risk quotient (RQ) of MCs in these plants. Biodegradation was liable to be the main removal pathway of the toxin in the soil; and therefore, bulk soil (unplanted soil), as well as rhizospheric soil (planted soil), were used in this experiment to evaluate the accumulation of MCs in the presence and absence of microorganisms (sterile and non-sterile soils). The data obtained in this study showed that MCs had no significant effects on growth indicators of faba bean and common wheat plants in non-sterile soil as compared to the control group. In contrast, plants grown in sterile soil showed a significant decrease in growth parameters as compared to the control. These results suggest that MCs were highly bioavailable to the plants, resulting in severe growth impairments in the absence of native rhizospheric microbiota. Likewise, MCs were more accumulated in sterile soil and more bioconcentrated in root and shoot tissues of plants grown within when compared to non-sterile soil. Thereby, the EDI of MCs in plants grown in sterile soil was more beyond the tolerable daily intake recommended for both humans and cattle. The risk level was more pronounced in plants from the sterile soil than those from the non-sterile one. These findings suggest that microbial activity, eventually MC-biodegradation, is a crucial bioremediation tool to remove and prevent MCs from entering the agricultural food chain. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This project has received funding from the European Union?s Horizon 2020 research and innovation program under the Marie Sk?odowska-Curie grant agreement No. 823860 and co-sup-ported by the strategical funding from FCT UIDB/04423/2020 and UIDP/04423/2020

    Hollow-core fiber-based speckle displacement sensor

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    The research enterprise towards achieving high-performance hollow-core photonic crystal fibers has led to impressive advancements in the latest years. Indeed, using this family of fibers becomes nowadays an overarching strategy for building a multitude of optical systems ranging from beam delivery devices to optical sources and sensors. In most applications, an effective single-mode operation is desired and, as such, the fiber microstructure or the light launching setups are typically designed for achieving such a behavior. Alternatively, one can identify the use of large-core multimode hollow-core fibers as a promising avenue for the development of new photonic devices. Thus, in this manuscript, we propose and demonstrate the utilization of a large-core tubular-lattice fiber for accomplishing a speckle-based displacement sensor, which has been built up by inserting and suitably dislocating a single-mode fiber inside the void core of the hollow fiber. The work reported herein encompasses both simulation and experimental studies on the evolution of the multimode intensity distributions within the device as well as the demonstration of a displacement sensor with an estimated resolution of 0.7 {\mu}m. We understand that this investigation identifies a new opportunity for the employment of large-core hollow fibers within the sensing framework hence widening the gamut of applications of this family of fibers
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