Certain cheU mutants of Salmonella show inverted chemotactic behavior, being repelled by attractants and attracted by repellents. Such a dramatic change in behavioral pattern would seem at first glance to require drastic and complex alterations in the sensory processing system. In fact, the behavior can be explained by a simple shift in the level of a response regulator and the subtle effects o...

a newly developed heavy duty diesel engine in dual fuel mode of operation has been studied in detail. the main fuel would be natural gas and diesel oil as pilot injection. the importance and effects of mixture preparation and formation through ports, valves and in cylinder flow field with different swirl ratio and tumble on diesel combustion phenomena is an accepted feature which has been studi...

Interactions between parenting styles and children’s negative affect in the prediction of reticent, solitary-active, and rough-and-tumble play behaviours were examined. The present study involved 98 children, their mothers and their preschool teachers. Participants (53 boys and 45 girls) were a mean age of 3.83 years (standard deviation = 0.69). Mothers completed questionnaires pertaining to th...

A 1arge-scale tumble rather than swirl would exist in cylinders in the case of two valves’ opening in a fourvalve engine. A strong swirl is generated when one valve is closed, yet the flow capacity is less than that of two valves being opened. In order to change it, different lifts of valves (DLV) present are achieved. In the case of using different lifts of two intake valves, both tumble and s...

A newly developed heavy duty diesel engine in dual fuel mode of operation has been studied in detail. The main fuel would be natural gas and diesel oil as pilot injection. The importance and effects of mixture preparation and formation through ports, valves and in cylinder flow field with different swirl ratio and tumble on diesel combustion phenomena is an accepted feature which has been studi...

Escherichia coli is a motile bacterium that moves up a chemoattractant gradient by performing a biased random walk composed of alternating runs and tumbles. Previous models of run and tumble chemotaxis neglect one or more features of the motion, namely (a) a cell cannot directly detect a chemoattractant gradient but rather makes temporal comparisons of chemoattractant concentration, (b) rather ...

The classical macroscopic chemotaxis equations have previously been derived from an individual-based description of the tactic response of cells that use a “run-and-tumble” strategy in response to environmental cues [17,18]. Here we derive macroscopic equations for the more complex type of behavioral response characteristic of crawling cells, which detect a signal, extract directional informati...

There is mounting evidence that enzyme diffusivity is enhanced when the enzyme is catalytically active. Here, using superresolution microscopy [stimulated emission-depletion fluorescence correlation spectroscopy (STED-FCS)], we show that active enzymes migrate spontaneously in the direction of lower substrate concentration ("antichemotaxis") by a process analogous to the run-and-tumble foraging...