Novel universality classes of coupled driven diffusive systems

Motivated by the phenomenologies of dynamic roughening of strings in random media and magnetohydrodynamics, we examine the universal properties of driven diffusive system with coupled fields. We demonstrate that cross-correlations between the fields lead to amplitude-ratios and scaling exponents varying continuosly with the strength of these cross-correlations. The implications of these results for experimentally relevant systems are discussed.Comment: To appear in Phys. Rev. E (Rapid Comm.) (2003

Comparative pharmacokinetics of ceftriaxone and tazobactam (8:1) between healthy and Escherichia coli induced diarrhoeic birds

Antibiotic-resistant Escherichia coli infection of poultry causes significant economic losses. Extended spectrum β lactamases (ESBL) producing E. coli was inoculated in a broiler, Rhode Island Red and Haringhata Black birds orally at 56×108 c.f.u. mL-1 for induction of diarrhoea. Pharmacokinetics of ceftriaxone-tazobactam combination (8:1) was studied following a single intramuscular injection at 28.125 mg kg-1 and the combination was administered twice daily to treat such infection. Plasma concentration of both ceftriaxone persisted up to 8 h in experimental birds and maintained an approximate ratio of 8:1 with tazobactam for a period of 2 h, 0.25 h and 0.75 h, respectively in a broiler, Rhode Island Red and Haringhata Black birds. The Kel was significantly lower in all experimental birds compared to healthy birds. Efficacy study was conducted in diarrhoeic birds by administration of ceftriaxone-tazobactam combination at 28.125 mg kg-1 body weight twice daily intramuscularly for three days which caused an increase in specific antibody titre in the broiler on 5th day and in Rhode Island Red birds 10th day. However, Haringhata black birds were inherently showed more resistance towards the infection. The combination of ceftriaxone and tazobactam in the ratio of 8:1 can be an effective treatment to combat ESBL producing E. coli infections

Directional filtering for linear feature enhancement in geophysical maps

Geophysical maps of data acquired in ground and airborne surveys are extensively used for mineral, groundwater, and petroleum exploration. Lineaments in these maps are often indicative of contacts, basement faulting, and other tectonic features of interest. To aid the interpretation of these maps, a versatile processing technique of directional filtering, based on the 2-D normal Radon transform, is used to enhance or suppress specific lineaments. Synthetic data and field examples using electromagnetic and radiometric data are used to demonstrate the superiority of the Radon transform method over conventional Fourier transform filtering. The Radon transform technique is shown to be more versatile and less susceptible to processing artefacts than the Fourier transform method

A joint inversion algorithm to process geoelectric and sutface wave seismic data. Part I: basic ideas

For the exploration of near-surface structures, seismic and geoelectric methods are often applied. Usually, these two types of method give, independently of each other, a sufficiently exact model of the geological structure. However, sometimes the inversion of the seismic or geoelectric data fails. These failures can be avoided by combining various methods in one joint inversion which leads to much better parameter estimations of the model than the independent inversions. A suitable seismic method for exploring near-surface structures is the use of dispersive surface waves: the dispersive characteristics of Rayleigh and Love surface waves depend strongly on the structural and petrophysical (seismic velocities) features of the near-surface underground. Geoelectric exploration of the structure underground may be carried out with the well-known methods of DC resistivity sounding, such as the Schlumberger, the radial-dipole and the two-electrode arrays. The joint inversion algorithm is tested by means of synthetic data. It is demonstrated that the geoelectric joint inversion of Schlumberger, radial-dipole and two-electrode sounding data yields more reliable results than the single inversion of a single set of these data. The same holds for the seismic joint inversion of Love and Rayleigh group slowness data. The best inversion result is achieved by performing a joint inversion of both geoelectric and surface-wave data. The effect of noise on the accuracy of the solution for both Gaussian and non-Gaussian (sparsely distributed large) errors is analysed. After a comparison between least-square (LSQ) and least absolute deviation (LAD) inversion results, the LAD joint inversion is found to be an accurate and robust method