Unsteady Magnetohydrodynamic Free Convection Flow of a Second Grade Fluid in a Porous Medium with Ramped Wall Temperature

Magnetic field influence on unsteady free convection flow of a second grade fluid near an infinite vertical flat plate with ramped wall temperature embedded in a porous medium is studied. It has been observed that magnitude of velocity as well as skin friction in case of ramped temperature is quite less than the isothermal temperature. Some special cases namely: (i) second grade fluid in the absence of magnetic field and porous medium and (ii) Newtonian fluid in the presence of magnetic field and porous medium, performing the same motion are obtained. Finally, the influence of various parameters is graphically shown.     

Population genetic structure of turbot (Scophthalmus maximus L., 1758) in the Black Sea

Turbot, Scophthalmus maximus, is a commercially important demersal flatfish species distributed throughout the Black Sea. Several studies performed locally with a limited number of specimens using both mitochondrial DNA (mtDNA) and microsatellite markers evidenced notable genetic variation among populations. However, comprehensive population genetic studies are required to help management of the species in the Black Sea. In the present study eight microsatellite loci were used to resolve the population structure of 414 turbot samples collected from 12 sites across the Black Sea. Moreover, two mtDNA genes, COI and Cyt-b, were used for taxonomic identification. Microsatellite markers of Smax-04 and B12-I GT14 were excluded from analysis due to scoring issues. Data analysis was performed with the remaining six loci. Loci were highly polymorphic (average of 17.8 alleles per locus), indicating high genetic variability. Locus 3/20CA17, with high null allele frequency (>30%), significantly deviated from HW equilibrium. Pairwise comparison of the F_ST index showed significant differences between most of the surveyed sampling sites (P < 0.01). Cluster analysis evidenced the presence of three genetic groups among sampling sites. Significant genetic differentiation between Northern (Sea of Azov and Crimea) and Southern (Turkish Black Sea Coast) Black Sea sampling sites were detected. The Mantel test supported an isolation by distance model of population structure. These findings are vital for long-term sustainable management of the species and development of conservation programs. Moreover, generated mtDNA sequences would be useful for the establishment of a database for S. maximus.     

Synthesis of naphthalimide derivatives with potential anticancer activity,their comparative ds- and G-quadruplex-DNA binding studies and related biological activities

Molecular Biology Reports - Two new cytotoxic 1,8-naphthalimide derivatives have been synthesized and characterized. Their biological activities as cytotoxicity and antimicrobial activities and...     

Molecular dynamics simulation of helium–argon gas mixture under various wall conditions

As computational capabilities increase, molecular dynamics (MD) simulations become important tools of simulating reality. These simulations are especially useful for compressible gas mixture problems. In this study, binary diffusion of helium and argon was examined using a hard-sphere MD simulation method. For the sake of computational speed, low spacing ratios were chosen. Binary mass diffusion of gases in two equally sized halves of a box was simulated for identical initial kinetic energies and number densities. It has been noted that a purely mass diffusion mechanism of different gases is not physically possible. The resultant gas mixtures of several diffusion simulations were used as initial conditions for combined heat transfer – Couette flow, and heating and cooling experiments. The results showed the interesting behaviour of the mixture, which was subjected to various wall conditions. Energy of heavier molecules is found to be more sensitive to the wall velocities and less sensitive to the wall temperatures than lighter molecules. Diffusion, heat transfer, viscosity and heat capacity coefficients are deduced as well.     

Heat Transfer in a Micropolar Fluid over a Stretching Sheet with Newtonian Heating

This article looks at the steady flow of Micropolar fluid over a stretching surface with heat transfer in the presence of Newtonian heating. The relevant partial differential equations have been reduced to ordinary differential equations. The reduced ordinary differential equation system has been numerically solved by Runge-Kutta-Fehlberg fourth-fifth order method. Influence of different involved parameters on dimensionless velocity, microrotation and temperature is examined. An excellent agreement is found between the present and previous limiting results.     

Evaluation of haploidization efficiency in winter squash (Cucurbita maxima Duch.) and pumpkin (Cucurbita moschata Duch.) through anther culture

The production of large numbers of haploids is the crucial point of the dihaploidisation process. Although in vitro haploid plants were successfully produced by irradiated pollen technique in winter squash (Cucurbita maxima Duch.) and pumpkin (Cucurbita moschata Duch.), the frequency is still insufficient for using in a large-scale breeding programme. Thus, the present study was conducted to determine the efficacy of the anther culture technique on the production of in vitro haploids in the aforementioned species for which there have been no successful reports concerning by androgenesis. The anthers at uninucleate microspore stage were collected at different florescence times and then cultured on a solid MS medium supplemented by different combinations of 2,4-D (2,4-dichlorophenoxyacetic acid), BAP (6-benzylaminopurine), KN (kinetin) with the constant addition of NAA (naphthalene acetic acid) to induce callogenesis, embryogenesis and plantlet initiation. The combination of PGR, genotype and anther collection time played an important role in the androgenic response. The highest response was obtained from 57S?21 and G9 lines with the combination of 2.0 or 4.0 mg/l BAP?+?0.05 mg/l NAA (E6 medium) at the first anther collection time. Plantlets were regenerated and rooted on MS medium supplemented by 0.01 mg/l IAA. In total, 74 plants were recovered and propagated with micro-cuttings. The ploidy analyses revealed that 35 plants (47.3?%) were haploid (n?=?20), and the others (52.7?%) were diploid (2n?=?40).