Variations of Wave Energy Power in Shoaling Zone of Benin Coastal Zone

Today, we observe at the population level, that the improvement in comfort is accompanied by an increase in the electrical energy required. The predicted exhaustion of fossil energy resources maintains some speculation. Their unequal geographical distribution justifies the energy dependence of Benin overlooked from outside. So it is urgent to explore the various sources of renewable energy available to Benin. In this work, using measurements made ​​by the Millennium Challenge Account (MCA-Benin) as part of the extension of the port of Cotonou, with Boussinesq equations (Peregrine) and Stokes waves dispersion relation, we characterized the variations of various swell parameters (height, wavelength, velocities) in the shoaling zone on the study site and proceeded to estimate variations in wave energy power from deep waters to the bathymetric breaking point. Finally, the zone with high energy power (where the conversion of this energy into electrical energy would be profitable) of these waves is highlighted on the site, the local water depth at the point of breaking waves is evaluated and results obtained allowed to justify the very energetic character take by these swells on this coast when they are close to the beach

The Formation and Stabilization of a Novel G-Quadruplex in the 5′-Flanking Region of the Relaxin Gene

It has been reported that binding of STAT3 protein to the 5′-flanking region of the relaxin gene may result in downregulation of the relaxin expression. There is a Guanine(G)-rich segment located in about 3.8 Kb upstream of the relaxin gene and very close to the STAT3's binding site. In our study, NMR spectroscopy revealed the formation of G-quadruplex by this G-rich strand, and the result was confirmed by ESI mass spectrometry and CD spectroscopy. The theoretical structure of RLX G-quadruplex was constructed and refined by molecular modeling. When this relaxin G-quadruplex was stabilized by berberine(ΔTm = 10°C), a natural alkaloid from a Chinese herb, the gene expression could be up-regulated in a dose-dependent manner which was proved by luciferase assay. This result is different from the general G-quadruplex function that inhibiting the telomere replication or down-regulating many oncogenes expression. Therefore, our study reported a novel G-quadruplex in the relaxin gene and complemented the regulation mechanism about gene expression by G-quadruplexes

Paying with a selfie: a hybrid micro-payment framework based on visual cryptography

In developing countries, the mobile revolution is happening in these days, and technology is now improving life conditions and providing new opportunities for the developing of the economies. In this paper, we provide a micro-payment framework that can be used to conclude everyday financial transactions. The novelty of the approach relies on the usage of techniques of easy understanding and application, even for uncultured people. The security of the system is also ensured by exploiting visual cryptography schemes, whose reconstruction phase requires no particular technical skills and relies only on human activities. The description of usage scenarios and the prototypal architecture of the framework are provided together with the initial plan for the experimental deployment

Time-Resolved FRET-Based Assays to Characterize G Protein-Coupled Receptor Hetero-oligomer Pharmacology

International audienc

Telomerase inhibitors based on quadruplex ligands selected by a fluorescence assay

The reactivation of telomerase activity in most cancer cells supports the concept that telomerase is a relevant target in oncology, and telomerase inhibitors have been proposed as new potential anticancer agents. The telomeric G-rich single-stranded DNA can adopt in vitro an intramolecular quadruplex structure, which has been shown to inhibit telomerase activity. We used a fluorescence assay to identify molecules that stabilize G-quadruplexes. Intramolecular folding of an oligonucleotide with four repeats of the human telomeric sequence into a G-quadruplex structure led to fluorescence excitation energy transfer between a donor (fluorescein) and an acceptor (tetramethylrhodamine) covalently attached to the 5′ and 3′ ends of the oligonucleotide, respectively. The melting of the G-quadruplex was monitored in the presence of putative G-quadruplex-binding molecules by measuring the fluorescence emission of the donor. A series of compounds (pentacyclic crescent-shaped dibenzophenanthroline derivatives) was shown to increase the melting temperature of the G-quadruplex by 2–20°C at 1 μM dye concentration. This increase in T(m) value was well correlated with an increase in the efficiency of telomerase inhibition in vitro. The best telomerase inhibitor showed an IC(50) value of 28 nM in a standard telomerase repeat amplification protocol assay. Fluorescence energy transfer can thus be used to reveal the formation of four-stranded DNA structures, and its stabilization by quadruplex-binding agents, in an effort to discover new potent telomerase inhibitors

pH-mediated fluorescence and G-quadruplex binding of amido phthalocyanines

A new family of G-quadruplex ligands termed “amido phthalocyanines” (APcs) was synthesized by reacting variable amino acids with tetraamino zinc phthalocyanine. Variation in the number of methylene units separating the APc scaffold from terminal ammonium groups systematically modulated ammonium pKa values that, in turn, mediated APc aggregation and DNA binding. Certain APcs exhibited nearly 1000-fold enhancements in fluorescence quantum yield upon binding G-quadruplex DNA under physiological conditions of pH and ionic strength. G-quadruplexes derived from the c-myc and c-kit promoters and the human telomeric repeat were evaluated for APc affinity and specificity using two complementary and direct fluorescence binding assays that revealed apparent dissociation constants ranging from 20 to 200 nM. Approximately 500-fold lower affinities for duplex and single-stranded DNAs were observed. Interestingly, APc−quadruplex binding was relatively insensitive to ionic strength (0.03−1 M KCl) but highly dependent on the pH of the solution. Our results provide a mechanism for the “turn-on” fluorescence properties exhibited by these compounds that will assist in future rational design of new G-quadruplex-specific fluorescent probes and drug candidates