Određivanje konstanata stabilnosti kompleksa metal-metilcistein i metal-metilcistein-cistein papirnom ionoforezom

A method, involving the use of an advanced paper ionophoretic technique is described for the study of equilibria in mixed complex systems in solution. The method is based on the migration of a spot of metal ion, with the complexants added in the background electrolyte. The concentration of one of the complexants, methylcysteine, is kept constant while that of the second ligand, cysteine, is varied. A graph of log [cysteine] against mobility is used to obtain information on the mixed-ligand complexes and to calculate their stability constants. Stability constants of metal-methylcysteine-cysteine complexes were found to be 3.05 ± 0.13 and 4.31 ± 0.11 (logarithm of stability constant values) for aluminium(III) and thorium(IV) respectively, at ionic strength of 0.1 mol dm–3 and a temperature of 35 °COpisana je tehnika papirne ionoforeze kao metode za izučavanje ravnoteže u sustavima mješovito-ligandnih kompleksa u otopini. Metoda je temeljena na gibanju mrlje metalnoga iona, pri čemu su sredstva za kompleksiranje dodana u pozadinski elektrolit. Koncentracija jednoga od liganada, metilcisteina, držana je konstantom, dok je koncentracija drugoga, cisteina, mijenjana. Dijagram ovisnosti log[cistein] vs. pokretljivost iona poslužio je za izračunavanje konstanata stabilnosti nastalih kompleksa. Pri ionskoj jakosti od 0.1 mol dm–3 i temperaturi od 35 °C konstante stabilnosti (log K) kompleksa metal-metilcistein-cistein iznose: 3.05 ± 0.13 za aluminij(III) i 4.31 ± 0.11 za torij(IV)

Određivanje konstanata stabilnosti kompleksa metal-metilcistein i metal-metilcistein-cistein papirnom ionoforezom

A method, involving the use of an advanced paper ionophoretic technique is described for the study of equilibria in mixed complex systems in solution. The method is based on the migration of a spot of metal ion, with the complexants added in the background electrolyte. The concentration of one of the complexants, methylcysteine, is kept constant while that of the second ligand, cysteine, is varied. A graph of log [cysteine] against mobility is used to obtain information on the mixed-ligand complexes and to calculate their stability constants. Stability constants of metal-methylcysteine-cysteine complexes were found to be 3.05 ± 0.13 and 4.31 ± 0.11 (logarithm of stability constant values) for aluminium(III) and thorium(IV) respectively, at ionic strength of 0.1 mol dm–3 and a temperature of 35 °COpisana je tehnika papirne ionoforeze kao metode za izučavanje ravnoteže u sustavima mješovito-ligandnih kompleksa u otopini. Metoda je temeljena na gibanju mrlje metalnoga iona, pri čemu su sredstva za kompleksiranje dodana u pozadinski elektrolit. Koncentracija jednoga od liganada, metilcisteina, držana je konstantom, dok je koncentracija drugoga, cisteina, mijenjana. Dijagram ovisnosti log[cistein] vs. pokretljivost iona poslužio je za izračunavanje konstanata stabilnosti nastalih kompleksa. Pri ionskoj jakosti od 0.1 mol dm–3 i temperaturi od 35 °C konstante stabilnosti (log K) kompleksa metal-metilcistein-cistein iznose: 3.05 ± 0.13 za aluminij(III) i 4.31 ± 0.11 za torij(IV)

Phytoplankton Fluctuatuations under the Stress of Abiotic Factors at Kohargaddi Dam, Balrampur, India

ABSTRACT: In this investigation, water samples were collected in different seasons such as rainy, winter and summer from Kohargaddi dam. Then phytoplankton diversity was studied in relation to same physico-chemical parameters. Total 18 species of phytoplankton were identified belonging Cyanophyceae, Chlorophyceae, Bacillariophyceae and Euglenophyceae. Cyanophyceae includes Nostoc sp., Oscillatoria sp., Anabaena sp., Microcystic sp., Gleocapsa sp., Spirulina sp., while Chlorophyceae includes Ulothrix sp., Chlorella sp., Spirogyra sp., Hydrodictyon sp., Pediastrum sp., Besides these, Bacillariophyceae includes Cyclotella sp., Navicula sp., Diatom sp., Synedra ulna and Euglenophyceae includes Euglena sp., Trachelomonas sp., Volvocinia sp.  During phytoplankton analysis, Chlorophyceae group contributed maximum phytoplankton density followed by Cyanophyceae, Bacillariophyceae, Euglenophyceae respectively. The study reveals that plankton population is dependent upon quality of water and climatic factors.                                               Key words: Physico-chemical parameters, Water quality, Phytoplanktons, Kohargaddi dam  Environmental Biology lab. Department of Botany, M.L.K.(P.G.) College. Balrampur-271201 Please Cite This Article As:  Mishra, B. B. Chaturvedi, G. B. and Tewari, D. D. 2010. Phytoplankton Fluctuatuations under the Stress of Abiotic Factors at Kohargaddi Dam, Balrampur.  J. Exp. Sci. 1(5):22-24.  Â

Diamagnetic susceptibility obtained from the six-vertex model and its implications for the high-temperature diamagnetic state of cuprate superconductors

We study the diamagnetism of the 6-vertex model with the arrows as directed bond currents. To our knowledge, this is the first study of the diamagnetism of this model. A special version of this model, called F model, describes the thermal disordering transition of an orbital antiferromagnet, known as d-density wave (DDW), a proposed state for the pseudogap phase of the high-Tc cuprates. We find that the F model is strongly diamagnetic and the susceptibility may diverge in the high temperature critical phase with power law arrow correlations. These results may explain the surprising recent observation of a diverging low-field diamagnetic susceptibility seen in some optimally doped cuprates within the DDW model of the pseudogap phase.Comment: 4.5 pages, 2 figures, revised version accepted in Phys. Rev. Let

Ginzburg-Landau theory for the conical cycloid state in multiferroics: applications to CoCr2_2O4_4

We show that the cycloidal magnetic order of a multiferroic can arise in the absence of spin and lattice anisotropies, for e.g., in a cubic material, and this explains the occurrence of such a state in CoCr$_2$O$_4$. We discuss the case when this order coexists with ferromagnetism in a so called `conical cycloid' state, and show that a direct transition to this state from the ferromagnet is necessarily first order. On quite general grounds, the reversal of the direction of the uniform magnetization in this state can lead to the reversal of the electric polarization as well, without the need to invoke `toroidal moment' as the order parameter.Comment: 6 pages, 3 figures, accepted for publication in Phys. Rev.

EgoFace: Egocentric Face Performance Capture and Videorealistic Reenactment

Face performance capture and reenactment techniques use multiple cameras and sensors, positioned at a distance from the face or mounted on heavy wearable devices. This limits their applications in mobile and outdoor environments. We present EgoFace, a radically new lightweight setup for face performance capture and front-view videorealistic reenactment using a single egocentric RGB camera. Our lightweight setup allows operations in uncontrolled environments, and lends itself to telepresence applications such as video-conferencing from dynamic environments. The input image is projected into a low dimensional latent space of the facial expression parameters. Through careful adversarial training of the parameter-space synthetic rendering, a videorealistic animation is produced. Our problem is challenging as the human visual system is sensitive to the smallest face irregularities that could occur in the final results. This sensitivity is even stronger for video results. Our solution is trained in a pre-processing stage, through a supervised manner without manual annotations. EgoFace captures a wide variety of facial expressions, including mouth movements and asymmetrical expressions. It works under varying illuminations, background, movements, handles people from different ethnicities and can operate in real time

Association of 16S and 23S ribosomal RNAs to form a bimolecular complex

Association of the 30S and 50S subunits to generate the 70S ribosomes of Escherichia coli has long been known but the mechanism of this interaction remains obscure. Light-scattering studies indicate that naked 16S and 23S RNAs can also associate under conditions similar to those required for the assembly of ribosomes from the constituent RNAs and proteins. The RNA-RNA association also takes place in the presence of ethanol, which promotes folding of 16S and 23S RNAs into specific compact structures with the morphological features of 30S and 50S ribosomes, respectively. Equimolar amounts of the two RNAs are involved in the association. The formation of a stoichiometric complex was shown by light scattering, sucrose density gradient centrifugation, and composite polyacrylamide/agarose gel electrophoresis. The presence of the two species of RNA in the complex was also shown by gel electrophoresis. The association of naked 16S and 23S RNAs suggests that RNA-RNA interaction may play an important role in the association of 30S and 50S subunits