Dichanthium annulatum is one of the dominant grasses of India, North Africa, Southeast Asia, China, Australia, Fiji, New Guinea, Cuba, Haiti and Puerto Rico. This drought-tolerant grass is an excellent fodder in mixed pastures. Developing varieties with improved quality and tolerance to various abiotic stresses is hampered due to its apomictic nature. Germplasm collection, characterization, genetic diversity analysis and core subset development followed by selection for desirable traits seems to be the most plausible breeding tool for developing new cultivars. In the present study, 498 genotypes collected from different agro-ecological zones in India were included. Genotypes were characterized for various metric and non-numeric traits; and the nutritional parameters. Agglomerative clustering analysis, using the Euclidean distance method, showed 14 distinct clusters. High variability was recorded for green forage yield, quantitative traits and nutritive quality parameters. A core subset of 50 accessions was identified, which captured most of the morphological and nutritional variability present in the total germplasm. Clustering of genotypes was observed to be related to the climatic conditions of the place of collection. High genetic variability observed for various morphological traits as well as forage yield indicated that these genotypes or subset of genotypes can be evaluated in different abiotic stress conditions such as salt, light and moisture stress for the identification of suitable varieties for the respective areas. Variability was attributed to inter-generic, inter-specific crossing together with the occasional presence of sexual plants in nature.

Guinea grass (Megathyrsus maximus Jacq.) is an important forage species in vast rangelands/grasslands of India and several tropical countries owing to its high biomass yield, good nutritional quality and wide adaptation. Evaluation of the existing natural variation and selection of desirable genotypes is the most plausible breeding method for this apomictic and polyploid grass. Developing a core sub-set to narrow down the number of germplasm required for future genetic studies is also pertinent. The present study involved characterization of 152 diverse M. maximus germplasm representing collections from different agro-ecological zones of India as well as those procured from Africa and Brazil; and development of a core sub-set. Nineteen metric, seven non-metric and nine nutritive traits together established the presence of wide variability among the genotypes. Clustering of the genotypes resulted in eight distinct clusters. The largest cluster included genotypes from Ethiopia, north India, north-western India, south India and north-eastern hill region, thus represented the highest diversity. Eleven of the total 26 Ethiopian genotypes clustered together. Non-metric morphological traits effectively differentiated the genotypes, and were associated with nutritional quality also. Genotypes which flowered once in a year showed slightly better crude protein and digestibility. The clusters were further sub-clustered and representatives were selected to develop the core sub-set of 23 genotypes comprising 20 indigenous and three exotic accessions. Comparison of the range of diversity and mean value for traits as obtained in the core sub-set and that in the total germplasm indicated successful capturing of maximum diversity in the core sub-set.

Oxygen isotope analysis was performed on enamel phosphate of mammalian teeth from archaeological sites Kalli Pachchhim and Dadupur in the central Ganga plain and Charda in the northern Ganga plain. The bulk oxygen isotopic compositions of enamel phosphate from third molars (M3) of Bos indicus individuals belonging to different cultural periods were used to understand the climatic changes during the past 3600 cal yr B.P. Oxygen isotope ratios indicate humid conditions around 3600 cal yr B.P., followed by a trend toward drier conditions until around 2800 cal yr B.P. Then from 2500 to 1500 cal yr B.P. there is a trend toward higher humidity, followed by the onset of a dry period around 1300 cal yr B.P. The study of intratooth δ18O variations in teeth from different periods demonstrates that the monsoon seasonality was prominent. Spatial changes in the amount of annual rainfall are also reflected in the δ18O values. Teeth derived from areas with intense rainfall have lighter isotope ratios compared to teeth from regions receiving less rain, but they show similar seasonal patterns. The long-term paleoclimatic variations reflected by fluctuations in bulk δ18Op values from M3 teeth match well with the regional paleoenvironmental records and show a good correlation to the cultural changes that took place during this time span in Ganga plain.

Baspa Glacier occupies an area of about 35 km2 in the south-eastern part of Kinnaur District, Himachal Pradesh, and it is the source of the Baspa River, a major tributary of the Sutlej. It is a longitudinal valley-type glacier with a large cirque area. The field evidence indicates that the glacier has retreated considerably in the recent past.

We present our results on spatio-temporal evolution of laser plasma produced shockwaves (SWs) and hot core plasma (HCP) created by focused second harmonic (532 nm, 7 ns) of Nd-YAG laser in quiescent atmospheric air at f/#10 focusing geometry. Time resolved shadowgraphs imaged with the help of an ICCD camera with 1.5 ns temporal resolution revealed the presence of two co-existing sources simultaneously generating SWs. Each of the two sources independently led to a spherical SW following Sedov-Taylor theory along the laser propagation direction with a maximum velocity of 7.4 km/s and pressure of 57 MPa. While the interaction of SWs from the two sources led to a planar SW in the direction normal to the laser propagation direction. The SW detaches from the HCP and starts expanding into the ambient air at around 3 µs indicating the onset of asymmetric expansion of the HCP along the z-axis. The asymmetric expansion is observed till 10 µs beyond which the SW leaves the field of view followed by a deformation of the irradiated region in the XY-plane due to the penetration of surrounding colder air in to the HCP. The deformation in the XY-plane lasts till 600 µs. The dynamics of rapidly expanding HCP is observed to be analogous to that of cavitation bubble dynamics in fluids.

A detailed study of Wakefield excitation in very dense quantum plasma is presented. Electric and magnetic Wakefields have been obtained for a particular profile of the laser pulse, using perturbative technique involving orders of the incident laser beam. The Wakefields can trap electrons and accelerate them to extremely high energies. It is observed that the quantum effects significantly change the classical nature of the Wakefield. The axial and radial forces acting on a test electron due to the Wakefields have been evaluated.

Structural, optical and nanomechanical properties of nanocrystalline Zinc Telluride (ZnTe) films of thickness upto 10 microns deposited at room temperature on borosilicate glass substrates are reported. X-ray diffraction patterns reveal that the films were preferentially oriented along the (1 1 1) direction. The maximum refractive index of the films was 2.74 at a wavelength of 2000 nm. The optical band gap showed strong thickness dependence. The average film hardness and Young's modulus obtained from load-displacement curves and analyzed by Oliver-Pharr method were 4 and 70 GPa respectively. Hardness of (1 1 1) oriented ZnTe thin films exhibited almost 5 times higher value than bulk. The studies show clearly that the hardness increases with decreasing indentation size, for indents between 30 and 300 nm in depth indicating the existence of indentation size effect. The coefficient of friction for these films as obtained from the nanoscratch test was ~0.4.

The tissue reactions in mice, experimentally infected with normal and irradiated cercariae of S. incognitum were studied. The lesions observed in the skin, liver, lungs and the intestine of mice infected with normal cercariae are briefly described, and compared with those observed with cercariae irradiated at 3000 r of gamma rays. In general, the reactions in mice exposed to normal cercariae were more intense than in those infected with irradiated cercariae. The severity of the reactions appeared largely due to the deposition of eggs in the tissues of the mice infected with normal cercariae. The experimental evidence suggested that most of the flukes from the irradiated cercariae are destroyed in the liver by tissue reaction.

The stimulated Brillouin scattering of Alfvén waves is studied in low-density plasmas. It is shown that ion-sound oscillations may be excited by this mechanism under suitable ionospheric conditions and that the presence of negative ions reduces the probability of such excitations.

This paper presents an investigation of the excitation of an upper hybrid wave in a hot collisionless magnetoplasma by a Gaussian EM beamm propagation perpendicular to the static magnetic field and having its electric vector polarized along the direction of the static magnetic field (ordinary mode). On account of the Gaussian intensity distribution of the EM beam the ponderomotive force becomes finite and the electorns are redistributed. The amplitude of the upper hybrid wave, which depends on the background electron concentration, is thus nonlinearly coupled with the EM wave. When the initial power of the EM wave is between the two critical powers Pcr1 and Pcr2 (Pcr1 < Pcr2) self-focusing occurs. On the other hand, for very low powers (P < Pcrl) and high powers (P > Pcr2), monotonic and oscillatory defocusing of the EM wave occurs. The dynamics of the excitation of the upper hybrid wave in these different power domains of the pump wave is accordingly modified. Moreover it is seen that the effect of changing the strength of the static magnetic field on the nonlinear coupling, and hence on the dynamics of the excitation of the upper hybrid wave, is significant.

Following Akhmanov's approach, self-focusing of a laser pulse in a transient plasma has been studied. The beamwidth parameter and hence the laser intensity and the frequency shift (time derivative of the phase) have been evaluated as a function of time and the distance of propagation. It is seen that the time dependence of the axial intensity changes appreciably as the pulse propagates. The present investigation is restricted to a pulse whose incident intensity has Gaussian radial dependence.

The concept of a laminated near-ring was introduced in [2]. We recall briefly what it is. Let N be a near-ring and let a∈N. Define a new multiplication on N by x * y = xay for all x,y∈N. With this new multiplication and the same addition as before we have another near-ring which we denote by Na. The near-ring Na is referred to as a laminated near-ring, the original near-ring N is the base near-ring and a is the laminator or laminating element.

In [3] we initiated our study of the automorphism groups of a certain class of near-rings. Specifically, let P be any complex polynomial and let P denote the near-ring of all continuous selfmaps of the complex plane where addition of functions is pointwise and the product fg of two functions f and g in P is defined by fg=f∘P∘g. The near-ring P is referred to as a laminated near-ring with laminating element P. In [3], we characterised those polynomials P(z)=anzn + an−1zn−1 +…+a0 for which Aut P is a finite group. We are able to show that Aut P is finite if and only if Deg P≧3 and ai ≠ 0 for some i ≠ 0, n. In addition, we were able to completely determine those infinite groups which occur as automorphism groups of the near-rings P. There are exactly three of them. One is GL(2) the full linear group of all real 2×2 nonsingular matrices and the other two are subgroups of GL(2). In this paper, we begin our study of the finite automorphism groups of the near-rings P. We get a result which, in contrast to the situation for the infinite automorphism groups, shows that infinitely many finite groups occur as automorphism groups of the near-rings under consideration. In addition to this and other results, we completely determine Aut P when the coefficients of P are real and Deg P = 3 or 4.

We will assume throughout this paper that polynomials are nonconstant. Let P be any complex polynomial and let p denote the near-ring of all continuous selfmaps of the complex plane where addition of functions is pointwise and multiplication is defined by fg = f ο P ο g for all f,g∈p. The near-ring p is referred to as a laminated near-ring and P is referred to as the laminating element or laminator. In [1] the problem was posed of determining Aut p the automorphism group of p. It was shown that exactly three infinite groups occur as automorphism groups of the laminated near-rings p and for each of the three groups those polynomials P were characterized such that Aut p is isomorphic to that particular group. The infinite groups turn out to be GL(2), the full linear group of all 2×2 nonsingular real matrices and two of its subgroups.

A NPK factorial experiment was conducted during two successive cropping seasons to study direct and residual effects of various treatments on the flower initiation and yield of soybeans. Plants were slower to reach the maximum flowering stage in the year of fertilizer application than in the following year. During the first year potassium in association with phosphorus delayed the flower forming process, whereas potassium alone hastened flowering in the second year unless associated with a high dosage of nitrogen. All the treatments gave far greater yields in the first season, suggesting that fertilizers should be applied during every cropping season. Nitrogen and phosphorus at 20 pounds of N2 and P2O5, per acre gave the biggest yields, but potassium failed to show any response. The residual responses to potassium and phosphorus during the second year were significant but not to nitrogen.

A split-plot field experiment was conducted to investigate the influence of planting dates on the formation of nodules in a variety of cowpea (Paraguay 6). Results indicated that the principal factor influencing both nodulation and yield was day-length, the highest number of effective nodules being produced from the June planting.

A two-year field experiment was conducted with fifteen varieties of cowpeas to evaluate responses to three different planting dates in relation to flowering and yield of beans. It appeared that most of the cowpea varieties required a day length of more than 12 hours to initiate flower formation. During both years 1962 and 1963, May plantings gave the best results, and July, August and September plantings failed to form flowers.

A factorial (3 × 3 × 3) experiment using three levels of nitrogen, phosphate and potassium was conducted to evaluate the effects of these elements on the formation of nodules. Results indicated that increasing levels of nitrogen depressed the formation of both effective and ineffective nodules, but phosphorus and potash did not produce any significant effects. Although the soils of the experimental plots were highly leached and strongly acid in nature, the native strains of rhizobia were able to produce copious amounts of effective nodules on plants growing on plots where no nitrogen was applied. It appeared that the naturally occurring rhizobia strains in these soils are well adapted to their natural environments.