FINANCEMENT DES COOPERATIVES AGRICOLES MAROCAINES, STRUCTURE ET PERFORMANCE

This article aims identifying investment behavior of a sample of Moroccan agricultural cooperatives, especially from the region of Souss Massa Daraa (SMD). There is, first, to determine the preferences of cooperatives in funding methods, and second, to analyze the financial structure of cooperatives, through financial indicators and leverage. The research examines the impact of this financial structure on economic performance. The empirical study examines a sample of 31 cooperatives, through a survey conducted via a questionnaire, and an accounting and financial data analysis of the sample during the period 2009, 2010 and 2011. Assumptions validity tests are based on a descriptive approach, enhanced by an econometric cross-section model

Analysis of the molecular electrostatic potential of the chemical reactivity of p-nitrophenol, p-aminophenol and p-methylphenol by the quantum method

There are many methods in quantum chemistry such as semi-empirical methods, ab initio methods, and density functional methods. All of these methods can determine the atomic molecular properties. In this work, we chose the density functional method (DFT) to determine electrostatic potential, frontier molecular orbitals (FMO), and optimization of molecules such as p-nitrophenol, p-methylphenol, and p-aminophenol. The determination of interatomic distances, nonlinear optical descriptors (NLO) such as dipole moment (μ), polarizability (α), first hyperpolarizability (β) and second hyperpolarizability (γ). The analysis of the potential energy surface was carried out by the density functional theory (DFT) method using the Becke, Lee, Yang, and Parr Gradient Corrected Functional (B3LYP) exchange and correlation with the standard base 6-311G (d, p). This method is implemented in the program Gaussian 09. The results of the energy gap, chemical hardness, dipole moment, and hyperpolarizability show that p-nitrophenol is the reactive molecule, and p-aminophenol is the stable molecule. The electrophilic attack occurs at the O7, O10, and O9 sites for p-nitrophenol, O7 for p-methylphenol, and O7, N13 for p-aminophenol

Theoretical analysis of the Reactivity of phenol substituted in the para position by halides by the functional theory of density

Theoretical developments have made it possible to make quantum physics applied to chemistry an essential tool associated with experimental chemistry. Two avenues have emerged for this development: one addresses the problems by describing systems by a wave function; the other does so by its electron density. In this work, we studied the quantum method of the density functional theory (DFT) B3LYP / 6-311G (d, p) to determine the various quantum chemical descriptors and the optimization of the different molecules: p-bromophenol, p-fluorophenol and p-chlorophenol. The study of the global reactivity of molecules is based on the calculation of global indices deduced from electronic properties, such as ionization potential (I), Electronic affinity (A), chemical hardness (η)., Electronegativity x. and Overall softness (σ), Maximum charge transfer (ΔNmax), Overall electrophilicity (ω). Besides, we worked on nonlinear optical descriptors (NLO) such as the dipole moment (μ), the polarizability (α), the first hyperpolarizability (β), and the second hyperpolarizability (γ). To check the stability of the molecules we determined the 3D maps of the HOMO and LUMO orbitals, the Mulliken charges of each molecule, the electrostatic potential, the lengths, and the bond angles of the molecules of p-bromophenol, p-fluorophenol, and p-chlorophenol

Trace Metal Elements in Different Categories of Drinking Water by Exploratory Analysis

The objective of this work was to assess the quality of different categories of water intended for human consumption through monitoring and quantification of metallic trace elements. Chosen study matrix was made up of tap water, bottled Moroccan water, bottled foreign water and finally surface water from Beni Mellal area: Ain Asserdoune and Bouyakoub. Four trace elements were studied namely: As, Cd, Cr and Pb. The assays were carried out using inductively coupled plasma technique equipped with Atomic Emission Spectrometer (ICP-AES). Dissimilarities between waters and correlations between metallic trace elements were carried out by Principal Component Analysis. According to the analytical results, Arsenic (As) would be much more present in foreign waters with an average value of 6.33µg/L followed by Moroccan surface water category with an average value of 6.191 µg/L. Cadmium (Cd) was also more present in Moroccan surface water category. Chromium (Cr) was much more present in Moroccan waters especially in natural water category with an average value of 45.65 µg/L followed by tap water with of 44.875 µg/L value. Lead (Pb) was much more present in Moroccan waters compared to foreign waters. Analysis results allow us to locate the different samples analyzed in relation to Moroccan drinking water standard and that of World Health Organization on the one hand and to classify different types of water according to their concentrations of metallic elements on the other hand

Impact of culture conditions on the behavior of mesenchymal stem cells: choosing critical parameters related to cell quality

International audienceMesenchymal stromal/stem cells (MSCs) are of great interest in developing new therapies because of their capacity of self-renewal, differentiation and modulation of inflammation or even immunosuppression. However, in vitro expansion is essential before the use of these cells in the clinic, which can lead to changes in the cell properties. The challenge is to optimize the culture conditions and to choose the most appropriate media for the culture of MSC to ensure that they retain their functional properties and thus their therapeutic potential. Moreover, it is necessary to fix parameters related to cell quality that could allow the selection of samples to be used. Currently, the main sources of media supplements used are fetal calf serum (FCS) and human platelet lysate (hPL). The aim of our study was to compare the characteristics and potential of bone marrow and Wharton jelly MSCs cultured in parallel in FCS and in hPL-containing medium. Experiments were performed under hypoxia (2% O2) or normoxia (21% O2) conditions. This study revealed differences in cell behavior depending on the culture condition. The behavior of the cells was related to differential expression of some surface markers and morphological alterations. Cell differentiation capacities were found to be equivalent. These first results confirm the modification of the characteristics of MSCs according to the medium used. These observations must be combined with other functional tests depending on the intended therapeutic application before being able to conclude on the superiority of one culture method over the other