S U M M A R Y A three-stage inversion scheme for surface wave tomography working with multimode phase dispersion as a function of frequency provides a means of combining a wide range of data in a common framework. The phase average approximation is applied directly to phase slowness and there is no need to invoke perturbation arguments for the interpretation of path-averaged velocity models der...

The uncatalyzed, thermal N-inversion reactions were studied of pyrimidin-4(3H)-imine (PMI), pyridin-2(1H)-imine (PYI), and 1H-purine-6(9H)-imine (PUI). Relevant regions of the potential energy surfaces were explored with second-order Moller-Plesset perturbation theory (MP2(full)/6-31G(d)) and with coupled cluster theory (CCSD/6-31G(d), CCSD/6-31+G(d)). The thermochemistry of stationary structur...

The shufflon, a multiple DNA inversion system in the plasmid R64, consists of four DNA segments flanked and separated by seven 19-bp repeat sequences. Site-specific recombinations mediated by the rci product occur between each inverted repeat sequence, resulting in inversions of the four segments independently or in groups. The seven 19-bp repeat sequences are classified into four types (repeat...

In the present work, two asymmetric polymer membranes based on polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) with chitin and chitosan (as extractive agents) were synthesized through the phase inversion technique. The mechanisms of oriented process for the facilitated extraction of blue P3R dye across the as-prepared membranes were elucidated through different experiments. Furthe...

79 UN CO RR EC Multiple methods exist to calculate and represent 3-D fractals. For example, spectacular, artistic images can be obtained using quaternion algebra [1]. In this article, I will briefly discuss three relatively simple methods to calculate fractal shapes consisting only of spheres. All these methods use iterative sphere inversions. A sphere inversion is the 3-D equivalent of a circl...

background: in 30 to 40% of patients with type 2 diabetes mellitus (t2dm) nephropathy is developed. the aim of the present study was to find the synergistic effect of two polymorphisms of methylenetetrahydrofolate reductase (mthfr) c677t and angiotensin converting enzyme insertion/ deletion (ace i/d) polymorphism on the risk of diabetic nephropathy and its progression. methods:   in a case-cont...

In this paper, we present a one-dimensional (1-D) inversion algorithm for triaxial induction logging tools in multi-layered transverse isotropic (TI) formation. A non-linear least-square model based on Gauss-Newton algorithm is used in the inversion. Cholesky factorization is implemented to improve the stability and the reliability of the inversion. Zero-D inversion is conducted at the center o...

Faces are difficult to recognise when presented upside down. This effect of face inversion was effectively demonstrated with the 'Thatcher illusion' by Thompson (1980 Perception 9 483-484). It has been tacitly assumed that this effect is due to inversion relative to retinal coordinates. Here we tested whether it is due to egocentric (i.e. retinal) inversion or whether the orientation of the bod...

Background: Fish have been at high risk of atrazine toxicity. Comparative atrazine toxicity on the tissues of Clarias gariepinus is scanty. Therefore, acute and chronic effects of atrazine on some biochemical parameters in Clarias gariepinus were investigated in this study. Methods: Atrazine toxicity was determined by assessing the responses of glucose, protein, alanine aminotransferase (ALT...