Les facteurs déterminants la performance des actifs financiers marocains et tunisiens

Cet article se propose d’appliquer les variantes des modèles classiques de gestion de portefeuille sur un échantillon d’entreprises cotées sur les places de Casablanca et de Tunis, dans un cadre hypothétique d’efficience des marchés financiers. Le modèle d’équilibre des actifs financiers (MEDAF) est ainsi connu pour être le modèle ayant eu plus grand nombre d’évolutions en Finance. Nous appliquons les différentes versions du modèle sur un échantillon d’actions issues des places financières marocaine et tunisienne sur la période 2006-2015, qui tourne autour des événements du printemps arabe. Nous avons trouvé que, selon notre période d’étude, et contrairement à l’évolution de la théorie dans ce domaine, ce sont plutôt les modèles à trois facteurs de Fama French (1993) et celui de Carhart (1997) qui permettent d’améliorer sensiblement le pouvoir explicatif et peuvent donc mieux servir en gestion de portefeuille. Tout en restant  dans le paradigme rationnel et sans aller à la finance comportementale, l’apport de cette recherche pour les gestionnaires de portefeuille demeure dans le constat que  les modèles les plus récents n’apportent pas plus de pouvoir explicatif

Causality between investor sentiment and the shares return on the Moroccan and Tunisian financial markets

This paper aims to test the relationship between investor sentiment and the profitability of stocks listed on two emergent financial markets, the Moroccan and Tunisian ones. Two indirect measures of investor sentiment are used, SENT and ARMS. These sentiment indicators show that there is an important relationship between the stocks returns and investor sentiment. Indeed, the results of modeling investor sentiment by past observations show that sentiment has weak memory; on the other hand, series of changes in sentiment have significant memory. The results of the Granger causality test between stock return and investor sentiment show us that profitability causes investor sentiment and not the other way around for the two financial markets studied. Thanks to four autoregressive relationships estimated between investor sentiment, change in sentiment, stock return and change in stock return, we find firstly that the returns predict the changes in sentiments which confirms with our hypothesis and secondly, the variation in profitability negatively affects investor sentiment. We conclude that whatever sentiment measure is used there is a positive and significant relationship between investor sentiment and profitability, but sentiment cannot be predicted from our various variables

The Determinants of Home Bias in Stock Portfolio: An Emerging and Developed Markets Study

The objective of this paper is to measure the degree of Home Bias within holdings portfolio and to identify their determining factors. By following literature and an international CAPM, we have chosen quite a number of susceptible factors that impact Home Bias. This model is, hence, estimated for 20 countries, with cross-section econometrics, between 2008 and 2013. Our results show that all countries have recorded a high level of Home bias in their holdings portfolio. After that, we test if the Home Bias of the emerging markets and that of the developed markets react differently to the determining factors. The volatility of the exchange rate is statistically significant with emerging markets, while it is hardly remarkable for the developed countries. Co-variance, size, distance, language, legal framework and foreign organization stocks prevents American investors to invest abroad. Keywords: International portfolio, Home Bias, exchange rate, emerging market, CAPM JEL Classifications: F31, G1

Understanding and Optimising the Social Impact of Venture Capital: Three Lessons from Ghana

Background: Mobilising investment for sustainable development is a priority for many African governments and their international allies. There are many claims about the social impact of investments in small and growing businesses, and yet these mostly focus on good news stories or a narrow set of metrics (jobs created, tax revenue, etc.). There are relatively few studies that consider the diversity of social impacts, particularly in an African context.Objectives: The aim of this research was to work collaboratively with investors in Ghana to better understand social change and contribute to their own work on improved performance and reporting.Method: Using a theory-based examination of social impacts, the research purposively selected a subset of 13 investments from the Venture Capital Trust Fund (VCTF) in Ghana. Theories of change were used to explore the available documentation, triangulated with insights from fund managers, entrepreneurs, senior managers and, where possible, employees. The findings were validated with VCTF staff.Results: While the research demonstrated the usefulness of a theory-based approach, it found it helpful to develop a smaller set of typologies to capture different impact pathways – a more efficient way to assess and report on social returns. In particular, the research highlights how commonly used metrics like job creation undervalue the social impact of some types of investment. Other lessons also included the value of rural businesses (not typically favoured by venture capitalists) and the potential to further extend impacts to lower income groups, but that this required real intent and leadership on the part of investors and entrepreneurs.Conclusion: We conclude that further research is merited on two fronts. Firstly, research into the scale of the small and medium enterprises and the associated investment required to support the operating costs to really manage, improve, monitor and evaluate social impact. And secondly, further field testing of different evaluation techniques to help stakeholders better understand and improve the social benefits of venture capital

Syzygium aromaticum aqueous extract inhibits human neutrophils myeloperoxidase and protects mice from LPS-induced lung inflammation

International audienceContext: Syzygium aromaticum (L.) Merr. & Perry (Myrtaceae), commonly known as clove, originally found in the Muluku Islands in East Indonesia, is widely used as a spice and has numerous medicinal properties.Objective: This study investigated the antioxidant potential of S. aromaticum aqueous extract (SAAE) in vitro and its protective effects on lipopolysaccharide (LPS)-induced lung inflammation in mice.Material and methods: Neutrophils were isolated from healthy donors and reactive oxygen species (ROS) generation was measured by luminol-amplified chemiluminescence. Superoxide anion generation was detected by cytochrome c reduction assay. H 2 O 2 was detected by DCFH fluorescence assay. Myeloperoxidase (MPO) activity was mesured by tetramethyl benzidine oxidation method. To study the anti-inflammatory activity of SAAE, lung inflammation was induced in mice (BALB/c) by intra-tracheal instillation of lypopolysaccharide (5 mg/mouse), and SAAE (200 mg/kg body weight) was injected intraperitoneally prior to LPS administration. Bronchoalveolar lavage and lung tissue were collected to assess inflammatory cells count and total protein content. Metalloproteinases activity was detected by zymography technique.Results: SAAE inhibited luminol-amplified chemiluminescence of resting neutrophils and N-formylmethionyl-leucyl-phenylalanine-or phorbol myristate acetate-stimulated neutrophils, with an inhibitory effect starting at a concentration as low as 0.5 mg/mL. Moreover, SAAE reduced significantly MPO activity and it exhibits a dose-dependent action (IC 50 ¼ 0.5 mg/mL). In vivo results showed that SAAE decreased markedly neutrophil count (From 61% to 15%) and proteins leakage into bronchoalveolar lavage fluid. Gelatin zymography assay showed that S. aromaticum inhibited MMP-2 (15%) and MMP-9 (18%) activity in lung homogenates.Discussion and conclusion: Our results suggest that the anti-inflammatory activity of SAAE, in vivo, is due to the inhibition of ROS production and metalloproteinases activity via its action on MPO. According to these findings, SAAE could be a potential source of new compounds with anti-inflammatory activity

Activation of the phagocyte NADPH oxidase/NOX2 and myeloperoxidase in the mouse brain during pilocarpine-induced temporal lobe epilepsy and inhibition by ketamine

International audienceExcessive reactive oxygen species (ROS) production can induce tissue injury involved in a variety of neurodegenerative disorders such as neurodegeneration observed in pilocarpine-induced temporal lobe epilepsy. Ketamine, a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist has beneficial effects in pilocarpine-induced temporal lobe epilepsy when administered within minutes of seizure to avoid the harmful neurological lesions induced by pilocarpine. However, the enzymes involved in ROS productions and the effect of ketamine on this process remain less documented. Here we show that during pilocarpine-induced epilepsy in mice, the expression of the phagocyte NADPH oxidase NOX2 subunits (NOX2/gp91 phox , p22 phox , and p47 phox) and the expression of myeloperoxidase (MPO) were dramatically increased in mice brain treated with pilocarpine. Interestingly, treatment of mice with ketamine before or after pilocarpine administration decreased this process mainly when injected before pilocarpine. Finally, our results showed that pilocarpine induced p47 phox phosphorylation and H 2 O 2 production in mice brain and ketamine was able to inhibit these processes. Our results show that pilocarpine-induced NOX2 activation to produce ROS in mice brain and that administration of ketamine before or after the induction of temporal lobe epilepsy by pilocarpine inhibited this activation in mice brain. These results suggest a key role of the phagocyte NADPH oxidase NOX2 and MPO in epilepsy and identify a novel effect of ketamine

Eugenol prevents fMLF-induced superoxide anion production in human neutrophils by inhibiting ERK1/2 signaling pathway and p47phox phosphorylation

International audienc