RAPD and ISSR Marker-Based Comparative Evaluation of Genetic Diversity Among Indian Germplasms of <Emphasis Type="Italic">Euryale ferox</Emphasis>: an Aquatic Food Plant

Euryale ferox Salisbury is an important aquatic food plant cultivated largely in eastern India. E. ferox is a monotypic genus, and breeding programmes have mostly relied on the variability present in the primary gene pool. Knowledge of the genetic structure of the population is limited, and there are very few reports available on the genetic diversity of E. ferox. In this study, comprehensive research on the genetic diversity of 16 germplasms of E. ferox was carried out using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Out of 320 RAPD and 95 ISSR primers screened initially, 61 primers (40 RAPD and 21 ISSR) gave reproducible bands and were selected for further work. Amplification of the 40 RAPD primers gave 533 polymorphic bands with an average of 13.32 polymorphic bands per primer. The percentage of polymorphism ranged from 37.5 to 100, with an average of 88.3 %. The 21 ISSR primers produced 259 bands, of which 214 were polymorphic, with an average of 10.19 polymorphic bands per primer. The percentage of polymorphism using ISSR primers ranged from 50 to 100, with a mean of 82.6 %. Jaccard’s coefficient ranged from 0.45 to 0.69 (RAPD), 0.50 to 0.77 (ISSR) and 0.48 to 0.71 (RAPD and ISSR). Molecular characterization of different germplasms of E. ferox not only is essential for its conservation but also can be used in further breeding programmes.     

Metagenome Analysis: a Powerful Tool for Enzyme Bioprospecting

Microorganisms are found throughout every corner of nature, and vast number of microorganisms is difficult to cultivate by classical microbiological techniques. The advent of metagenomics has revolutionized the field of microbial biotechnology. Metagenomics allow the recovery of genetic material directly from environmental niches without any cultivation techniques. Currently, metagenomic tools are widely employed as powerful tools to isolate and identify enzymes with novel biocatalytic activities from the uncultivable component of microbial communities. The employment of next-generation sequencing techniques for metagenomics resulted in the generation of large sequence data sets derived from various environments, such as soil, the human body and ocean water. This review article describes the state-of-the-art techniques and tools in metagenomics and discusses the potential of metagenomic approaches for the bioprospecting of industrial enzymes from various environmental samples. We also describe the unusual novel enzymes discovered via metagenomic approaches and discuss the future prospects for metagenome technologies.     

Polarized non-abelian representations of slim near-polar spaces

In (Bull Belg Math Soc Simon Stevin 4:299–316, 1997), Shult introduced a class of parapolar spaces, the so-called near-polar spaces. We introduce here the notion of a polarized non-abelian representation of a slim near-polar space, that is, a near-polar space in which every line is incident with precisely three points. For such a polarized non-abelian representation, we study the structure of the corresponding representation group, enabling us to generalize several of the results obtained in Sahoo and Sastry (J Algebraic Comb 29:195–213, 2009) for non-abelian representations of slim dense near hexagons. We show that with every polarized non-abelian representation of a slim near-polar space, there is an associated polarized projective embedding.     

On the dipole–dipole correlation and dielectric anisotropy of some N(4-N-alkyloxy benzylidene)4′-N-alkylaniline compounds doped with silver nanoparticles

Dielectric study of the compounds N(4-n-heptyloxy benzylidene)4′-n-butylaniline and N(4-n-heptyloxy benzylidene)4′-n-hexylaniline at low frequency region (1 kHz–1 MHz) is performed using LCR meter (Agilent 4284 A). A qualitative interpretation in terms of dipole–dipole correlation for both the parallel and the perpendicular components of the dipole moment is given. Further study on the change in the dielectric permittivity and the dielectric anisotropy is made by doping the two compounds separately with dodecanethiol capped silver nanoparticles (0.25% by weight). The molecular positional ordering and relative smectic layer distance influences the change of degree (or type) of dipole–dipole pairing.     

Combustion behavior of ammonia blended with diethyl ether

Ammonia (NH₃) is recognized as a carbon-free hydrogen-carrier fuel with a high content of hydrogen atoms per unit volume. Recently, ammonia has received increasing attention as a promising alternative fuel for internal combustion engine and gas turbine applications. However, the viability of ammonia fueling future combustion devices has several barriers to overcome. To overcome the challenge of its low reactivity, it is proposed to blend it with a high-reactivity fuel. In this work, we have investigated the combustion characteristics of ammonia/diethyl ether (NH₃/DEE) blends using a rapid compression machine (RCM) and a constant volume spherical reactor (CVSR). Ignition delay times (IDTs) of NH₃/DEE blends were measured using the RCM over a temperature range of 620 to 942 K, pressures near 20 and 40 bar, equivalence ratios (Φ) of 1 and 0.5, and a range of mole fractions of DEE, χ_DEE, from 0.05 to 0.2 (DEE/NH₃ = 5 – 20%). Laminar burning velocities of NH₃/DEE premixed flames were measured using the CVSR at 298 K, 1 bar, Φ of 0.9 to 1.3, and χ_DEE from 0.1 to 0.4. Our results indicate that DEE promotes the reactivity of fuel blends resulting in significant shortening of the ignition delay times of ammonia under RCM conditions. IDTs expectedly exhibited strong dependence on pressure and equivalence ratio for a given blend. Laminar burning velocity was found to increase with increasing fraction of DEE. The burnt gas Markstein length increased with equivalence ratio for χ_DEE = 0.1 as seen in NH₃-air flames, while the opposite evolution of Markstein length was observed with Φ for 0.1 < χ_DEE ≤ 0.4, as observed in isooctane-air flames. A detailed chemical kinetics model was assembled to analyze and understand the combustion characteristics of NH₃/DEE blends.     

Thermodynamics of event horizon with modified Hawking temperature in scalar-tensor gravity

In recent past, Hawking temperature has been modified for the validity of thermodynamical laws at the event horizon in general relativity context. This lead to the introduction of modified Hawking temperature and it has been found that the modified Hawking temperature is more realistic on the event horizon. With this motivation, here we investigate the thermodynamical consistency of scalar-tensor gravity based models by examining the validity of the generalized second law of thermodynamics (GSLT) and thermodynamical equilibrium (TE) at the event horizon. In order to attain our goal, we consider a spatially flat Friedman–Robertson–Walker Universe filled with ordinary matter and the boundary of the Universe bounded by the event horizon that is in thermal equilibrium with modified Hawking temperature. Next, we calculate the general expressions for the GSLT and TE using modified Hawking temperature in the context of the more general action of scalar-tensor gravity where there is a non-minimally coupling between the scalar field and matter Lagrangian (as the chameleon field). From the general expression of GSLT, we find that the null energy condition must hold for a viable scalar-tensor model of the Universe dominated by a perfect fluid. Furthermore, in order to better understand these complicated general expressions of GSLT and TE, we explore the validity of the GSLT and TE for two viable models of scalar-tensor gravity namely Brans–Dicke gravity with a self-interacting potential and Chameleon gravity at the event horizon using special cosmological solutions. Finally, some graphical representation of the GSLT and TE have been presented. From the graphical analysis, we found that the power-law forms of the scale factor and scalar field is much favourable for the study of universal thermodynamics as compared to other choices of the scalar field and the analytic function.     

On a Class of Generalized Lacunary Difference Sequence Spaces Defined by Orlicz Functions

In this article we introduce the generalized lacunary difference sequence spaces [N_θ,M,Δ~m]_0,[N_θ,M,Δ~m]_1 and [N_θ,M,Δ~m]_∞using m~(th)- difference.We study their properties like completeness,solidness,symmetricity.Also we obtain some inclusion relations involving the spaces [N_θ,M,Δ~m]_0,[N_θ,M,Δ~m]_1 and[N_θ,M,Δ~m]_∞and the Cesàro summable and strongly Cesàro summable sequences.