Tunis University

About: Tunis University is a education organization based out in Tunis, Tunisia. It is known for research contribution in the topics: Population & Thin film. The organization has 11745 authors who have published 15400 publications receiving 154900 citations. The organization is also known as: University of Tunis & UT.

The relationship between dividend policy, financial structure, profitability and firm value

Abstract: This paper investigates the value creation process in the Tunisia stock exchange using a sample including more than 90% of the listed companies. In order to find out the determinants of the value creation of the selected companies, it uses the random probit model estimation procedure with unbalanced panel data. The results indicate that the probability of creating future values is positively and significantly correlated with profitability factor. In addition, the results also suggest that the value creation is affected by industry patterns (listed banks are the more value creator in the Tunisia stock exchange), by size (the probability to create value is stronger in small firms than in big ones) and by nature of property (the probability to create value is stronger in private-owned firms than in public-owned ones). Last but not least, the time trend factor is positive and highly significant. This finding suggests that the progressive reforms of the Tunisian stock exchange have attracted new investors, who...

Nitrogen Metabolism in Tomato Plants Under Cadmium Stress

Abstract: Young seedlings of tomato (Lycopersicon esculentum Mill.) grown on nitric medium and treated with different cadmium (Cd) concentrations (0–50 µM) were used. Results obtained show that Cd remains predominantly located in the roots, which then seem to play the role of trap‐organs. Increasing Cd concentration in the medium leads particularly to a decrease in NO3 − accumulation, together with decrease in the activities of nitrate reductase (NR), nitrite reductase (NiR), and glutamine synthetase (GS). On the other hand, stimulations were observed for ammonium accumulation, anabolitic activity of glutamate dehydrogenase (GDH) and protease activity. Contrarily, decreases were obtained for soluble protein contents and catabolitic activity of GDH. These results were discussed in relation to the hypothesis attributing to the mitochondrial enzyme NADH‐dependent GDH, an important role in the plant defense processes, in maintaining the glutamate pool in conditions where the need for NH4 + detoxification is in...

WNT signaling and chondrocytes: from cell fate determination to osteoarthritis physiopathology.

Abstract: Context: Osteoarthritis (OA) is an articular disorder leading to the degradation of articular cartilage phenotypical chondrocytes modifications, including the acquisition of a fibroblast-like morphology, decreased expression of collagen type II, and increased expression of fetal collagen type I, metalloproteinase 13 and nitric oxide synthase. This promotes matrix degradation and unsuccessful cartilage repair. WNT signaling constitutes one of the most critical biological processes during cell fate assignment and homeostasis. Objectives: This review aims to give an insight on results from the studies that were interested in the involvement of WNT in OA. Methods: Studies were selected through a pubmed search. Results: Recent genetic data showed that aberration in WNT signaling may be involved in OA. WNT signals are transduced through at least three cascades: the canonical WNT/β-catenin pathway, the WNT/Ca2+ pathway and the WNT/planar cell polarity pathway. Most of the studies used in-vitro models to ...

Hydrothermal synthesis, phase structure, optical and photocatalytic properties of Zn2SnO4 nanoparticles.

Abstract: Zinc stannate (Zn 2 SnO 4 or ZTO) nanoparticles were synthesized v ia hydrothermal method using NaOH as a mineralizer. X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) of the synthesized ZTO nanoparticles revealed the formation of highly pure ZTO phase with the spinel-like structure. The nanoparticles have spherical shape with an average size of about 25 nm. The Raman spectrum of the sample was dominated by the A 1g vibration mode of pure ZTO phase. From UV–Vis measurement, a band gap E g of 3.465 eV was determined. The photocatalytic activity of the ZTO nanoparticles was evaluated for the photodegradation of rhodamine B (RhB) under visible light irradiation. The influence of catalyst concentration and irradiation time on the photocatalytic process was investigated. The ZTO catalyst showed the best photocatalytic performance at a concentration of 0.2 g/L, and the photodecomposition of RhB followed first-order kinetics with a rate constant k = 0.0249 min −1 . The ZTO-assisted photocatalytic degradation of RhB occurred via two competitive processes: a photocatalytic process and a photosensitized process. The detection of hydroxyl radicals by fluorescence measurements suggests that these species play an important role in the photocatalytic process.