A pure bacterial culture is composed of clonal cells in different physiological states. Separation of those subpopulations is critical for further characterization and for understanding various processes in the cultured cells. We used density-dependent cell sorting with Percoll to separate subpopulations from cultures of a marine bacterium, Vibrio parahaemolyticus. Cells from cultures in the ex...

Two of eighteen strains of Bacillus subtilis examined contained covalently closed circular duplex deoxyribonucleic acid (DNA) of homogeneous size and buoyant density. Strain ATCC 15841 contained about 16 copies per chromosome of plasmid pPL1, a circular DNA element having a molecular weight of about 4.7 times 10(6) and a buoyant density of 1.700. Strain ATCC 7003 contained about one to two copi...

The protozoa Crithidia and Trypanosoma contain within a mitochondrion a mass of DNA known as kinetoplast DNA (kDNA) which consists mainly of an association of thousands of small circular molecules of similar size held together by topological interlocking. Using kDNA from Crithidia acanthocephali, Crithidia luciliae, and Trypanosoma lewisi, physicochemical studies have been carried out with inta...

The crisis of the standard cooling flow model brought about by Chandra and XMM-Newton observations of galaxy clusters, has led to the development of several models which explore different heating processes in order to assess if they can quench the cooling flow. Among the most appealing mechanisms are thermal conduction and heating through buoyant gas deposited in the ICM by AGNs. We combine Vir...

Xyloglucan from the walls of Rosa cells that had been cultured on [12C]- or [13C]-glucose formed bands in caesium trifluoroacetate with mean buoyant densities of 1.575 or 1.616 g/ml respectively. Incubation of a mixture of [13C,3H]xyloglucan and [12C,1H]xyloglucan in the presence of xyloglucan endotransglycosylase (XET) activity caused the mean buoyant density of the radioactive material to dec...

The flow-field characteristics of high-temperature annular buoyant jets as well as the development laws influenced by ventilation system were studied using numerical methods to eliminate the pollutants effectively in this paper. The development laws of high-temperature annular buoyant jets were analyzed and compared with previous studies, including radial velocity distribution, axial velocity a...

The expression of preproinsulin (ppIns), proglucagon, prosomatostatin, and propancreatic polypeptide was investigated in thymic extracts, thymic cells, and thymic cell lines from C57BL/6 mice by RT-PCR. The expression of pancreatic hormones was similar in thymic extracts taken from neonatal and 2-, 4-, and 8-week-old animals, but was decreased in 20-week-old animals. Pancreatic hormone expressi...

[1] Although Mars is currently not tectonically active, it may have experienced plate tectonics early in its history. The southern hemisphere of Mars possesses a thick crust which probably renders the lithosphere positively buoyant. In this paper we present numerical and scaling arguments which show that if the area of positively buoyant lithosphere grows beyond a critical fraction ( 50% for Ma...

The rates of specific catalytic events in the mitochondrial inner membrane were determined after enriching the membrane bilayer with exogenous phospholipid. Inner membranes were fused with soybean phospholipid, then separated into four buoyant-distinct fractions by sucrose density centrifugation. Analysis revealed a progressively increasing phospholipid to protein ratio from the least buoyant (...

Interactions of DNA and the gene product D5 (gpD5) of bacteriophage T5, a DNA-binding protein that binds preferentially and cooperatively to double-stranded DNA, were analyzed by metrizamide gradient centrifugation. Conditions were set so that DNA and DNA protein complex sedimented to apparent equilibrium positions. DNA has a buoyant density of 1.12 g/cm3, and DNA saturated with gpD5 has a buoy...