Role of Repulsive Forces in Determining the Equilibrium Structure of Simple Liquids

1971 ◽  
Vol 54 (12) ◽  
pp. 5237-5247 ◽  
Author(s):  
John D. Weeks ◽  
David Chandler ◽  
Hans C. Andersen
Keyword(s):  
Equilibrium Structure ◽  
Simple Liquids ◽  
Structure Of Simple Liquids ◽  
Repulsive Forces

Equilibrium Structure of Simple Liquids

1970 ◽  
Vol 25 (3) ◽  
pp. 149-152 ◽  
Author(s):  
David Chandler ◽  
John D. Weeks
Keyword(s):  
Equilibrium Structure ◽  
Simple Liquids ◽  
Structure Of Simple Liquids

Structure of simple liquids as a problem of percolation in the Voronoi grid

1989 ◽  
Vol 30 (2) ◽  
pp. 253-260 ◽  
Author(s):  
N. N. Medvedev ◽  
V. P. Voloshin ◽  
Yu. I. Naberukhin
Keyword(s):  
Simple Liquids ◽  
Voronoi Grid ◽  
Structure Of Simple Liquids

scholarly journals The role of mixotrophy in plankton bloom dynamics, and the consequences for productivity

2005 ◽  
Vol 62 (5) ◽  
pp. 833-840 ◽  
Author(s):  
Astrid C. Hammer ◽  
Jonathan W. Pitchford
Keyword(s):  
Phytoplankton Bloom ◽  
Equilibrium Structure ◽  
Structure Stability ◽  
Type I ◽  
Single Individual ◽  
Predator Prey ◽  
Type Iii ◽  
Predator Prey Model ◽  
Plankton Bloom

Abstract Mixotrophy (=heterotrophy and photosynthesis by a single individual) is a common phenomenon in aquatic ecosystems, in particular under light- or nutrient-limitation. However, it is not usually considered in mathematical models of biological populations. This paper shows how different types of mixotrophy might be usefully incorporated into a general predator–prey model, and explores the consequences for plankton bloom dynamics and productivity. It is demonstrated, analytically and numerically, that even small levels of type III mixotrophy (a small fraction of the zooplankton also being involved in primary production) have significant effects on a system's equilibrium structure, stability, and short-term dynamics. Type III mixotrophy has a stabilizing effect on the system by reducing its excitability, i.e. its propensity to exhibit blooms. Compared with the non-mixotrophic benchmark, for a phytoplankton bloom to be triggered in a system with type III mixotrophy, a much larger perturbation is necessary. Type II mixotrophy (a small fraction of algae engage in phagotrophy) and type I mixotrophy (equal phagotrophy and phototrophy) are briefly discussed. The potential consequences for productivity are also studied. Our results indicate that the phytoplankton–zooplankton system becomes more productive in the presence of type III mixotrophy.

Geometrical analysis of the structure of simple liquids: percolation approach

1991 ◽  
Vol 73 (4) ◽  
pp. 917-936 ◽  
Author(s):  
Yu. I. Naberukhin ◽  
V.P. Voloshin ◽  
N.N. Medvedev
Keyword(s):  
Geometrical Analysis ◽  
Simple Liquids ◽  
Structure Of Simple Liquids

scholarly journals Role of Capsular Colanic Acid in Adhesion of Uropathogenic Escherichia coli

2003 ◽  
Vol 69 (8) ◽  
pp. 4474-4481 ◽  
Author(s):  
Andrea Hanna ◽  
Michael Berg ◽  
Valerie Stout ◽  
Anneta Razatos
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Bacterial Adhesion ◽  
Specific Binding ◽  
Binding Interactions ◽  
Colanic Acid ◽  
Mutant Strains ◽  
Tract Infections ◽  
Repulsive Forces

ABSTRACT Urinary tract infections are the most common urologic disease in the United States and one of the most common bacterial infections of any organ system. Biofilms persist in the urinary tract and on catheter surfaces because biofilm microorganisms are resistant to host defense mechanisms and antibiotic therapy. The first step in the establishment of biofilm infections is bacterial adhesion; preventing bacterial adhesion represents a promising method of controlling biofilms. Evidence suggests that capsular polysaccharides play a role in adhesion and pathogenicity. This study focuses on the role of physiochemical and specific binding interactions during adhesion of colanic acid exopolysaccharide mutant strains. Bacterial adhesion was evaluated for isogenic uropathogenic Escherichia coli strains that differed in colanic acid expression. The atomic force microscope (AFM) was used to directly measure the reversible physiochemical and specific binding interactions between bacterial strains and various substrates as bacteria initially approach the interface. AFM results indicate that electrostatic interactions were not solely responsible for the repulsive forces between the colanic acid mutant strains and hydrophilic substrates. Moreover, hydrophobic interactions were not found to play a significant role in adhesion of the colanic acid mutant strains. Adhesion was also evaluated by parallel-plate flow cell studies in comparison to AFM force measurements to demonstrate that prolonged incubation times alter bacterial adhesion. Results from this study demonstrate that the capsular polysaccharide colanic acid does not enhance bacterial adhesion but rather blocks the establishment of specific binding as well as time-dependent interactions between uropathogenic E. coli and inert substrates.

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