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The effect of uniform wind flow on modulational instability of two crossing waves is studied here. This is an extension of an earlier work to the case of a finite-depth water body. Evolution equations are obtained as a set of three coupled nonlinear equations correct up to third order in wave steepness. Figures presented in this paper display the variation in the growth rate of instability of a pair of obliquely interacting uniform wave trains with respect to the changes in the air-flow velocity, depth of water medium and the angle between the directions of propagation of the two wave packets. We observe that the growth rate of instability increases with the increase in the wind velocity and the depth of water medium. It also increases with the decrease in the angle of interaction of the two wave systems.
Declining pulse production has caused wide concern in recent years. A field experiment was conducted to investigate effects of balance fertilizers based on soil test values and targeted yield equations on soil biological activities, soil quality, nutrient acquisition and grain yield of lentil. Treatments included the use of farmyard manure (FYM), bio-inoculants and inorganic fertilizers at different rates and combinations. The results revealed significant improvement in nodulation, microbial counts, microbial biomass carbon (MBC), soil respiration, soil enzymes and soil organic carbon (SOC) with integrated approaches (i.e. fertilizer plus FYM or bio-inoculants); these improvements led to achievement of the specific target yield of 1.50 t/ha. Although the highest yield was achieved with fertilizers applied for a target yield of 2.0 t/ha, there was significant decline in nodulation, microbial counts, MBC, soil respiration, soil enzymes, SOC and soil quality. Correlation between soil quality index (SQI) and grain yield suggested a significant influence of balanced fertilization based on soil tests and target yield. Principal component analysis revealed the average contribution of soil quality indicators towards SQI was in descending order of SOC > acid phosphatase activity > total culturable fungi > available phosphorus > BMC, which are crucial for sustainable lentil production in alluvial soils.
This paper intends to study the dispersion and attenuation characteristics of Love-type wave propagation due to a disturbance point source in a hydrostatic stressed magneto-viscoelastic layer, lying over a heterogeneous fibre-reinforced elastic half-space. The shear elastic moduli and mass density of half-space are the functions of depth and heterogeneity parameters. The coupled field equations are solved with the aid of Green's function technique and Fourier transform. The dispersion and damping equations have been obtained for the wave. The deduced equations coincide with the classical Love-wave condition for the uniform homogeneous isotropic structure. Numerical computations are carried out for involved parameters and demonstrated with the help of graphs. The effects of hydrostatic stress, magnetic coupling parameter, dissipation factor, attenuation coefficient, reinforcement parameters, heterogeneity parameters and order of the depth variation on the dispersion and damping curves are highlighted.
In the propagation of seismic waves through layered media, the boundaries play crucial role. The boundaries separating the different layers of the earth are irregular in nature and not perfectly plane. It is, therefore, necessary to take into account the corrugation of the boundaries while dealing with the problem of reflection and refraction of seismic waves. The present study explores the reflection and refraction phenomena of SH-waves at a corrugated interface between visco-elastic half-space and fibre-reinforced half-space. Method of approximation given by Rayleigh is adopted and the expressions for reflection and transmission coefficients are obtained in closed form for the first and second order approximation of the corrugation. The closed form formulae of these coefficients are presented for a corrugated interface of periodic shape (cosine law interface). It is found that these coefficients depend upon the amplitude of corrugation of the boundary, angle of incidence and frequency of the incident wave. Numerical computations for a particular type of corrugated interface are performed and a number of graphs are plotted. Some special cases are derived.
The efficient organization and communication of brain networks underlie cognitive processing and their disruption can lead to pathological behaviours. Few studies have focused on whole-brain networks in obesity and binge eating disorder (BED). Here we used multi-echo resting-state functional magnetic resonance imaging (rsfMRI) along with a data-driven graph theory approach to assess brain network characteristics in obesity and BED.
Multi-echo rsfMRI scans were collected from 40 obese subjects (including 20 BED patients) and 40 healthy controls and denoised using multi-echo independent component analysis (ME-ICA). We constructed a whole-brain functional connectivity matrix with normalized correlation coefficients between regional mean blood oxygenation level-dependent (BOLD) signals from 90 brain regions in the Automated Anatomical Labeling atlas. We computed global and regional network properties in the binarized connectivity matrices with an edge density of 5%–25%. We also verified our findings using a separate parcellation, the Harvard–Oxford atlas parcellated into 470 regions.
Obese subjects exhibited significantly reduced global and local network efficiency as well as decreased modularity compared with healthy controls, showing disruption in small-world and modular network structures. In regional metrics, the putamen, pallidum and thalamus exhibited significantly decreased nodal degree and efficiency in obese subjects. Obese subjects also showed decreased connectivity of cortico-striatal/cortico-thalamic networks associated with putaminal and cortical motor regions. These findings were significant with ME-ICA with limited group differences observed with conventional denoising or single-echo analysis.
Using this data-driven analysis of multi-echo rsfMRI data, we found disruption in global network properties and motor cortico-striatal networks in obesity consistent with habit formation theories. Our findings highlight the role of network properties in pathological food misuse as possible biomarkers and therapeutic targets.
The present study deals with the affected behaviour of SH-wave propagation through a viscoelastic layer sandwiched between an anisotropic porous layer of finite thickness and an isotropic half space. The sandwiched viscoelastic layer is considered as heterogeneous medium of finite thickness and isotropic half-space is considered as initially stressed medium. The method of separation of variables has been applied to obtain the dispersion equation of SH-wave in their respective media. The obtained complex dispersion relation has been separated into real and imaginary parts. Moreover, the dispersion relation has been satisfied with the classical condition of Love waves. The effects of heterogeneity, attenuation constant, dissipation factor of viscoelasticity, initial stress (compressive), thickness ratio of two layers and porosity on the propagation of SH-waves have been shown by number of graphs. Graphs have been plotted for the dimensionless phase and damping velocity on the propagation of SH-waves with respect to the dimensionless real wave number. The results may be useful to explore the nature and peculiarity of SH-wave propagation in the viscoelastic structure.
One of the goals of the EUVE observation of AB Doradus was to search for rotational modulation of the EUV emissions. In support of this goal we carried out optical photometry in Chile, Australia and South Africa and radio observations in Australia. In addition, an ASCA observation of AB Dor was scheduled to occur during the campaign. Several spectacular X-ray and optical flares with accompanying brightening in the EUV were seen, but no rotational modulation of the EUV emission was evident, except for a dip in the He II 304 Å line coincident with the optical minimum. An X-ray flare was seen with no accompanying EUV flare.
We obtained simultaneous images of solar plage on 7 May 1991 with Goddard Space Flight Center’s Solar EUV Rocket Telescope and Spectrograph (SERTS), the Very Large Array (VLA), and the NASA/NSO spectromagnetograph at Kitt Peak. Using intensity ratios of Fe XVI to Fe XV emission lines, we find that the coronal plasma temperature is 2.5 ± 0.3 ×lO6 K throughout the region. The column emission measure ranges from 2.6 × 1027 to 1.3 × 1028 cm−5. The calculated structure and intensity of the 20 cm wavelength thermal bremsstrahlung emission from the hot plasma observed by SERTS is quite similar to the observed structure and intensity of the 20 cm microwave emission observed by the VLA. Using the revised coronal iron abundance of Meyer (1991, 1992), we find no evidence for either cool absorbing plasma or for contributions from thermal gyroemission. Combining the observed microwave polarization and the SERTS plasma parameters, we calculate a map of the coronal longitudinal magnetic field. The resulting values, ~ 30 – 60 Gauss, are comparable to extrapolated values of the potential field at heights of 5,000 and 10,000 km.
Solar radio emission at centimeter and millimeter wavelengths originates in the chromosphere and transition region and is a useful probe for the temperature and density in these regions. High spatial resolution observations of the quiet sun provide valuable information on the structure of the solar atmosphere. We have performed high resolution (~ 6″ (E-W) x 15″ (N-S)) observations at 6 cm with the Westerbork Synthesis Radio Telescope (WSRT) in June 1976 in order to search for the radio analog of the supergranulation network and to study the extent and symmetry of limb brightening. The use of the WSRT for high spatial resolution solar mapping has been described by Bregman and Felli (1976), Kundu et al. (1977), and others.
The Andaman & Nicobar Islands are a group of 572 large and small islands & islets in the southeastern part of the Bay of Bengal. This preliminary study reports on husbandry practices and phenotypic characterization of indigenous Nicobari pig, in its home tract (Nicobar group of islands). A total of 377 families were surveyed in randomly selected villages on Car Nicobar, Nancowrie, Teressa, Katchal and Chowra islands. Results of the study revealed that Nicobari pigs were mostly semi feral in nature and reared under a free range system. Pigs were fed mainly with coconut and other locally available resources. The Nicobari pigs appeared short with long body. They showed high prolificacy with an average litter size of 8–10 numbers. These pigs were considered as a family asset among the Nicobari tribe. No commercial farms and slaughter was practiced by the tribes. It is concluded that the Nicobari pigs are considered as an indigenous pig breed/germplasm (Sus scrofa Nicobaricus) belonging to this island territory. Owing to its adaptation and performance under resource-driven island ecosystem, Nicobari pig warrants conservation and improvement. In addition, genetic characterization this pig using SNP would help to confirm their genetic distinctiveness and recognition as a new breed for conservation and sustainable utilization.
The unsteady MHD free convection and mass transfer boundary layer flow of an incompressible electrically conducting fluid past an accelerated infinite vertical flat plate embedded in porous medium with ramped wall temperature is considered here. It is assumed that the plate accelerates in its own plane in the presence of thermal radiation incorporating first order chemical reaction. The governing equations are solved analytically using the Laplace transformation technique. The flow phenomenon has been characterized with the help of flow parameters such as permeability parameter, Hartmann number, phenomenon has been characterized with the help of flow parameters such as permeability parameter, Hartmann number, thermal radiation parameter etc. The influences of these parameters on the velocity, temperature field and concentration distribution have been studied and the results are presented graphically and discussed quantitatively. Also, the effects of the various parameters on the skin friction coefficient, the rate of heat and mass transfer at the surface are discussed.
Nuclear DNA syntheses have been measured microspectrophotometrically in course of meiotic nuclear development in Neurospora crassa. The purpose of the study has been to establish the timing of these DNA syntheses in relation to meiosis and in the formation of its final products in an ideal genetic material, where the products of the meiotic division can be recovered and identified. Spectrophotometric analysis has indicated that the last premeiotic DNA replication is completed before caryogamy; a postmeiotic DNA replication takes place at the tetrad of the nuclei level; and finally a second postmeiotic DNA replication occurs in the ascospores to result in eight binucleated ascospores. The timing of postmeiotic replication is compatible with the models explaining gene conversion through the postulated mechanisms involving heteroduplex formation.
Plasma cell polyps of the vocal fold (plasma cell granulomas) are rare inflammatory polyps of the larynx. They should be included in the clinical and histological differential diagnosis of laryngeal polyps. Histologically they are polyclonal aggregates of plasma cells. It is essential to distinguish them from monoclonal, neoplastic plasma cell proliferations. The treatment of choice is surgical resection, although radiotherapy, laser ablation, antibiotics and steroids have been used successfully. We present a case of plasma cell granuloma presenting as a vocal fold polyp, treated surgically.
An approximate analysis, based on the standard perturbation technique, is described in this paper to find the corrections, up to first order to the reflection and transmission coefficients for the scattering of water waves by a submerged slender barrier, of finite length, in deep water. Analytical expressions for these corrections for a submerged nearly vertical plate as well as for a submerged vertically symmetric slender barrier of finite length are also deduced, as special cases, and identified with the known results. It is verified, analytically, that there is no first order correction to the transmitted wave at any frequency for a submerged nearly vertical plate. Computations for the reflection and transmission coefficients up to O(ε), where ε is a small dimensionless quantity, are also performed and presented in the form of both graphs and tables.