The sleeping chironomid (Polypedilum vanderplanki Hinton) lives on temporary rock pools in the semi‐arid tropical regions of Africa. Its larvae are able to survive the dry season in a completely desiccated ametabolic state known as anhydrobiosis. So far, P. vanderplanki was the only species among all insects showing demonstrated anhydrobiotic ability. Here, we show that a new related species originating from Malawi, Polypedilum pembai sp.n., is also anhydrobiotic and that its desiccation tolerance mechanism is probably similar to what is observed in P. vanderplanki. The new species, P. pembai sp.n., is described with special attention to the common and different morphological features, compared with P. vanderplanki. Phylogenetic analysis showed that both species are closely related, suggesting that anhydrobiosis evolved only once in their common ancestor about 49 Ma somewhere in Africa, before the divergence of two species, one in the sub‐Saharan area and another in southeastern Africa.

Non‐Newtonian flow of moderately concentrated solutions of polyvinyl alcohol (PVA) in water and polystyrene (PS) in toluene were measured with a Maron‐Krieger‐Sisko viscometer at various temperatures and concentrations. The usual dependences of the apparent and zero shear viscosities for two polymers on rate of shear, temperature, and molecular weight have been found. The log‐log plot of zero‐shear viscosity versus concentration can be represented by two straight lines intersecting at one point (critical concentration cc). The critical concentration in volume fraction of polymer, v2c, multiplied by the chain length Z is not constant but decreases with decreasing Z, although it has the same order of magnitude as the value of Zcv2 obtained from the log‐log plots of viscosity versus Z for many systems of polar and nonpolar polymers. The product ccρZ1/2 (ρ = density of the solution) is constant and independent of Z. To explain the constancy of this product, an equivalent sphere model is presented. When the volume fraction of spheres is assumed to be unity, the extension of molecules agrees very well with the unperturbed extension evaluated from intrinsic viscosity data in ⊖ solvent.

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SUMMARYIn general, internal cells are required to solve elastoplasticity problems using a conventional boundary element method (BEM). However, in this case, the merit of BEM, which is the easy method of preparation of data, is lost. The conventional multiple-reciprocity boundary element method (MRBEM) cannot be used to solve the elastoplasticity problems because the distribution of initial strain or initial stress cannot be determined analytically. In this paper, we show that two-dimensional elastoplasticity problems can be solved without the use of internal cells, by using the triple-reciprocity boundary element method. An initial strain formulation is adopted and the initial strain distribution is interpolated using boundary integral equations. A new computer programme was developed and applied to several problems.

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Abstract. The general KdV equation (gKdV) derived by T. Chou is one of the famous (1 + 1) dimensional soliton equations with variable coefficients. It is well-known that the gKdV equation is integrable. In this paper a higher-dimensional gKdV equation, which is integrable in the sense of the Painlevé test, is presented. A transformation that links this equation to the canonical form of the Calogero-Bogoyavlenskii-Schiff equation is found. Furthermore, the form and similar transformation for the higher-dimensional modified gKdV equation are also obtained.

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