Three DNA buoyant density species (nuclear, 1.692 g cm(-3); mitochondria 1.705 g cm(-3); and proplastid, 1.713 g cm(-3)) can be detected in extracts from castor bean endosperm. No other buoyant density species can be identified. DNA extracts from sucrose density gradient purified glyoxysomes exhibit varying amounts of each of the three identified DNAs but no other distinguishable DNA species. R...

We propose a theory for axial segregation of suspensions of non-neutrally buoyant particles in a rotating cylinder. The cylinder is oriented in the horizontal plane, so that any axial forces must arise from interparticle interactions. We show that the hydrodynamic interaction between pairs of particles produces a relative motion in the axial direction, independent of the gravitational force. If...

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. [1] When carbon dioxide (CO 2) dissolves into water, the density of water increases. This seemingly insubstantial p...

The use of lattice gas (cellular automaton) models has recently been advocated as an interesting method for the simulat ion of fluid flow . Th ese automata are an idealizat ion of the real microscopic molecula r dynamics. We present a model derived from the hexagonal lat t ice gas ru les of Frisch Hasslacher and Pomea u (FHP) that incorporates buoyant forces and d iscusses its prope rt ies. We ...

Small particles on supports have been of interest for many years both scientifically and with respect to their uses in heterogeneous catalysis. One of the common and often critical questions is the shape of a small particle, i.e., spherical or faceted, since many of the properties depend upon the relative populations of different surface planes and edges. The question of the equilibrium shape o...

The impact of shelf slope on the linear stability of buoyant coastal currents and on the nonlinear formation of coastal meanders and eddies is investigated. The authors consider a simplified two-layer stratification in cylindrical geometry where a buoyant surface current flows along the coast above a denser water, with a flat bottom or steep shelves. Simulations were performed using the Nucleus...

Measurements of seafloor asymmetry at about 360000 pairs of conjugate points along 1250 profiles across the midAtlantic Ridge (MAR) provide new constraints on models for the upwelling of the buoyant asthenosphere. The sign and amplitude of the asymmetry vary systematically and are functions of the distance between the spreading center and the location of the inferred location of maximum regiona...

This paper examines the effect of the poor road transportation network on crop production in one of the rural agrarian local government of Kwara State, Nigeria. A well-structured interview schedule was conducted to elicit information from 120 crop farmers using a two-stage sampling technique. Findings from the study revealed that the poor road transportation network in their area had led to a r...

Cell walls made by Bacillus subtilis bacteria grown in D(2)O medium have buoyant densities in CsCl which are different from walls made by cells grown in H(2)O medium. Cell wall turnover was studied by measuring the change in wall buoyant density after a B. subtilis culture was shifted from growth in D(2)O medium to aeration in H(2)O medium. Walls from the hemispherical caps were isolated after ...