Spanwise vorticity measurements in a perturbed boundary layer

Hot-wire measurements of the spanwise vorticity fluctuation _z have been carried out in a turbulent boundary layer subjected to concentrated suction, applied through a porous wall strip. The results indicate that, relative to the no-suction case, the rms value of _z is significantly reduced in the near-wall region, with this reduction increasing with the suction rate . The reduction near the wall suggests an alteration in the dynamics of the layer. As the Reynolds number increases, the dynamics of the layer in the near-wall region become more intense and suction becomes less effective.     

Validation and quality control of methylmercury determinations by means of capillary electrophoresis

Methyl-Hg is one of the most dangerous pollutants in the environment. It is highly toxic and accumulates through the food chain. Tuna fish especially tends to concentrate Hg in the form of methyl-Hg. Quality assurance is a well established routine in analytical laboratories to control the variability of analytical results and to maintain adequate stability, detection power and reproducibility. Capillary electrophoresis (CE) has shown in recent years powerful capabilities for the resolution and analysis of very complex samples. The high resolution and peak capacity characteristics of this technique could be used favourably in speciation studies of organo-Hg compounds. Since the time needed for separation is usually very short in this technique, it lends itself to routine analysis. The application of quality control approaches in the analysis of methyl-Hg in tuna freeze-dried materials using CE is reported.     

Fast decoding of Gabidulin codes

Gabidulin codes are the analogues of Reed–Solomon codes in rank metric and play an important role in various applications. In this contribution, a method for efficient decoding of Gabidulin codes up to their error correcting capability is shown. The new decoding algorithm for Gabidulin codes (defined over ${\mathbb{F}_{q^m}}$ ) directly provides the evaluation polynomial of the transmitted codeword. This approach can be seen as a Gao-like algorithm and uses an equivalent of the Euclidean Algorithm. In order to achieve low complexity, a fast symbolic product and a fast symbolic division are presented. The complexity of the whole decoding algorithm for Gabidulin codes is ${\mathcal{O} (m^3 \, \log \, m)}$ operations over the ground field ${\mathbb{F}_q}$ .     

6‐Formylindolo[3,2‐b]carbazole (FICZ) is a Very Minor Photoproduct of Tryptophan at Biologically Relevant Doses of UVB and Simulated Sunlight

Exposure to solar UV is at the origin of numerous photodegradation pathways in biomolecules. Tryptophan is readily modified by UVB radiation into ring‐opened and oxidized photoproducts. One of them, 6‐formylindolo[3,2‐b]carbazole (FICZ), has been extensively studied in the recent years because it very efficiently binds to AhR, a major factor in numerous biologic processes, such as metabolism of xenobiotics. Unfortunately, little information is available on the actual yield of FICZ upon exposure to low and biologically relevant doses of UV radiation. In the present work, we used a sensitive and specific HPLC‐tandem mass spectrometry assay to quantify a series of photoproducts induced by UVB and simulated sunlight (SSL) in solutions of tryptophan. FICZ represented only a minute amount of the photoproducts (0.02 and 0.03%, respectively). Experiments were repeated in culture medium where the yield of FICZ was also found to be very low, even when Trp was added. Last, no FICZ could be detected in cytosolic fractions of cultured cells exposed to SSL. Altogether, the present results show that FICZ is a very minor photoproduct and that it cannot be considered the only endogenous photoproduct responsible for the induction of AhR‐dependent responses in UV‐irradiated cells.     

Performance of Pleurotus ostreatus Mushrooms and Spent Substrate for the Biosorption of Cd(II) From Aqueous Solution

The capacities of Pleurotus ostreatus mushroom and spent substrate were evaluated for the biosorption of cadmium (II) from aqueous solution in order to select the most efficient material for bioremediation. The optimum sorption conditions were optimized, including the pH of the aqueous solution, contact time, biomass dosage, initial metal concentration, and temperature. The sorption of cadmium on both biosorbents was also evaluated by several kinetic, equilibrium, and thermodynamic models. The possible heavy metal biosorption mechanisms were evaluated through point of zero charge (pH_pzc), Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX). Based on the results of column studies, the effectiveness of the P. ostreatus spent substrate was confirmed as a biosorbent for Cd(II) removal from aqueous solutions.