The Risk Premium on Mediterranean Emerging Stock Markets

In this paper, we test a conditional version of the international asset pricing model, using the multivariate GARCH process of De Santis and Gerard (1998). The model is estimated, over the period January 1997-March 2007, for five markets: the global, USA, Egyptian, Turkish and Israeli markets. We analyze a version of the ICAPM with a constant market risk price as well as the exchange rate risk price, while the conditional covariances vary over time. The results show that risk premium vary significantly across markets and over time, for all stock markets the contribution of currency premium to the total risk premium is economically significant. This study confirms that currency risk is a significant factor in the international valuation of financial assets.</jats:p

IMPACT OF URBAN EXPANSION ON URBAN TRANSPORT IN THE CITY, STUDY CASE: CITY OF BORDJ BOU ARRERIDJ, ALGERIA

Urban transport is one of the most dynamic and a vital element within the urban sphere, as it has a significant impact on the growth and development of cities in all respects; it determines the size and direction of urbanization and directs it properly as well. Bordj Bou Arreridj is an Algerian city that witnessed a spectacular urban expansion, which resulted in great difficulties in terms of urban transport. This resulted in the inability to fulfill the role assigned to it, especially with regard to the urban expansion of the city, given the insufficient means of urban transport, especially collective ones - Old urban bus barns – and thus, meeting the growing demand for transport due to the large demographic growth. In addition to that, the fragility of the urban transport system as a whole has led to lack of harmony and interconnectedness of all parts of the city, and to the imbalance in the management of the sector. The study concluded that the urban area of the city is characterized by an important network of roads and streets that ensure good connectivity between its parts, but the existing urban transport network does not cover all its components (49% is the covered area in the city), as some areas lack urban transport service, especially those located on its suburbs as a result of the rapid urbanization. In order to redress this phenomenon, it was necessary to reconsider the general urban transportation system on both management and organizational sides, taking into account all urban components of the city, especially future expansions, in order to reach a harmonious and interconnected city under a balanced and effective transportation system.</jats:p

THE EFFECT OF SPATIAL DIFFERENCES ON THE QUALITY OF URBAN LIFE A COMPARATIVE ANALYTICAL STUDY OF THREE CITIES IN THE HIGH PLATEAUX REGION OF ALGERIA

The urban areas in Algeria suffer from several imbalances in different regions, where the inequality of opportunities has led to an imbalance in the population density “from north to south”. And to the urban chaos, this matter made it face many challenges, which prompted us to search for this defect. Development plans in Algeria focus on the role of cities with high hills in restoring balance to the national sphere and reducing these disparities. The study aims to extract and evaluate the spatial differences of the three cities and reveal the spatial disparities, in order to establish a balanced regional development, while preparing the various development plans, based on several criteria by integrating the Delphi method with the analytical hierarchy process, and determining its spatial regions in the (GIS) environment. Through a comparative study of three cities, the study showed the progress of the city of Setif, achieving (11%) of the study area, achieving high quality, with an area (14.50 km²), Al-M’sila (03%) with an area (7.99 km²). Barika (01%) with an area of (3.98 km2). The results can be used during the preparation of development plans for this region.</jats:p

Root Application Efficacy of Plant Biostimulants in a Tunisian Portulaca Oleracea l. Cultivar Grown under Salt Stress

Plants biostimulants (PBs) have been shown to play multiple roles in plant growth and to improve crop tolerance to abiotic stresses such as salinity. The present investigation was undertaken for the first time to study the effect of PBs - a plant-derived protein hydrolysate (PH), a root activator (RA) and a root stimulator (RS) - on Portulaca oleracea L. tolerance to salt stress. For this purpose, a Tunisian P. oleracea cultivar was cultivated in pots under a greenhouse. Plants were treated with a factorial combination of three nutrient solutions (non-salt control, 50 and 100 mM NaCl) and three PBs were applied to roots. Growth and physiological parameters were then determined. Main results showed that salt stress decreased shoot and root dry biomass, chlorophyll and carotenoid contents while it increased the content in total soluble sugars, proline and relative water contents. However, root application of the three PBs induced some significant differences in the agronomical and physiological responses between PB treated and untreated plants when subjected to sodium chloride salinity from 50 and 100 mM NaCl. Overall, the present study proves that the root application of these PBs increases the performance of P. oleracea plants under salinity conditions. Therefore, PBs can be used to improve the salt-stress tolerance of vegetable crops by increasing their physiological responses to abiotic stress Portulaca oleracea L.; plant; salinity; biostimulant; growth; physiology</jats:p