Les pucerons du Maroc: abrégé bioécologique des espèces évoluant sur les cultures

Les observations réalisées, depuis 1980, sur diverses espèces végétales cultivées et spontanées du Maroc, ont permis d’identifier environ 150 espèces de pucerons dont une quarantaine seulement évolue sur les plantes cultivées. Les espèces qui se montrent constamment nuisibles aux cultures, ne dépassent pas la douzaine. Les pucerons se caractérisent par des cycles biologiques complexes qui combinent différents modes de reproduction (sexué avec femelles ovipares et parthénogénétique avec femelles vivipares) et qui possèdent les 2 formes de l’imago, aptère et ailée. Ces particularités bioécologiques leur confèrent un caractère adaptatif et leur permettent la dissémination et la survie de l’espèce. C’est ainsi que plusieurs espèces de pucerons, après leur introduction au Maroc, ont modifié leur cycle biologique pour s’adapter au contexte local dont les conditions agro-climatiques favorisent l’anholocyclie. Les températures élevées et les ennemis naturels jouent un rôle important dans la régulation des populations aphidiennes. Une stratégie de lutte est proposée

Surface Optical Waves at Air/Metal Interfaces: Surface Plasmon Polaritons

The surface plasmon resonance (SPR) phenomenon has been known for nearly five decades now; since then this method has made great advances in terms of instrumentation development and applications, and it still attracts researchers because of certain subtle issues that could benefit from it mainly detection and analysis of chemical and biochemical substances in different areas including medicine, environmental monitoring, biotechnology and drug and food monitoring. Our interest is focused on the use of this technique for studying thin coating and some application in nanophotonics. In this paper, we discuss the configuration of surface plasmons at air/metal interface by Atenuated total reflection (ATR) technique in the Kretchman configuration, and we present preliminary experimental results on surface plasmons at a Ag/air interface that we obtained in our laboratory.The surface plasmon resonance (SPR) phenomenon has been known for nearly five decades now; since then this method has made great advances in terms of instrumentation development and applications, and it still attracts researchers because of certain subtle issues that could benefit from it mainly detection and analysis of chemical and biochemical substances in different areas including medicine, environmental monitoring, biotechnology and drug and food monitoring. Our interest is focused on the use of this technique for studying thin coating and some application in nanophotonics. In this paper, we discuss the configuration of surface plasmons at air/metal interface by Atenuated total reflection (ATR) technique in the Kretchman configuration, and we present preliminary experimental results on surface plasmons at a Ag/air interface that we obtained in our laboratory

(E)-2-{Eth­yl[4-(4-nitro­phenyl­diazen­yl)phen­yl]amino}ethyl anthracene-9-carboxyl­ate

The crystal structure of the title compound, C31H26N4O4, displays a trans conformation for the nitro­phenyl­diazenyl portion of the mol­ecule. Packing diagrams indicate that weak C—H⋯O hydrogen bonds, likely associated with a strong dipole moment present in the mol­ecule, dictate the arrangement of mol­ecules in the crystal structure

X-ray-Induced Reversible Switching of an Azobenzene Derivative Adsorbed on Bi(111)

We report on the adsorption of a submonolayer of di-m-cyanoazobenzene (DMC) on Bi(111) and on the reversible switching of these molecules induced by resonant X-ray illumination. DMC adsorbs in at least two configurations, the flat trans and the nonflat cis isomer. We find that in 0.8 monolayers at least 26% of the molecules change their configuration at 110 K by excitation of the N1s → LUMO transition at the azo group, and by a thermally induced back reaction at 120 K. Nonresonant excitation with X-ray light does not induce any reversible changes

Exchange rate volatility and capital inflows: role of financial development

There is vast literature examining the impact of exchange rate volatility on various macroeconomic aggregates such as economic growth, trade flows, domestic investment, and more recently capital flows. However, these studies have ignored the role of financial development while examining the impact of exchange rate volatility on capital flows. This study aims to analyze the impact of exchange rate volatility on capital inflows towards developing countries by incorporating the role of financial development over the time period 1980–2013. In this regard, the behavior of two types of capital flows is examined: physical capital inflows measured as foreign direct investment, and financial inflows quantified through remittance inflows. The empirical investigation comprises the direct as well as indirect effect of exchange rate volatility on capital inflows. The study employs dynamic system GMM estimation technique to empirically estimate the effect of exchange rate volatility on capital inflows. The empirical results of the study identify that exchange rate volatility dampens both physical and financial inflows towards developing countries. The indirect impact of exchange rate volatility through financial development, however, turns out positive and statistically significant. This finding reflects that financial development helps in reduc- ing the harmful impact of exchange rate volatility on capital inflows. Hence, the study concludes that a developed financial system is an important channel through which developing countries may improve capital inflows in the long run.info:eu-repo/semantics/publishedVersio

In Vivo Methods for the Assessment of Topical Drug Bioavailability

This paper reviews some current methods for the in vivo assessment of local cutaneous bioavailability in humans after topical drug application. After an introduction discussing the importance of local drug bioavailability assessment and the limitations of model-based predictions, the focus turns to the relevance of experimental studies. The available techniques are then reviewed in detail, with particular emphasis on the tape stripping and microdialysis methodologies. Other less developed techniques, including the skin biopsy, suction blister, follicle removal and confocal Raman spectroscopy techniques are also described