scholarly journals Flow system fluorescence polarization measurements on fluorescein diacetate-stained EL4 cells.

1977 ◽  
Vol 25 (7) ◽  
pp. 821-826 ◽  
Author(s):  
M Epstein ◽  
A Norman ◽  
D Pinkel ◽  
R Udkoff
Keyword(s):  
Fluorescence Intensity ◽  
Fluorescence Polarization ◽  
Flow System ◽  
Fixed Time ◽  
Fluorescein Diacetate ◽  
Quantitative Relation ◽  
Polarization Measurements ◽  
Percent Polarization ◽  
Kinetics Of ◽  
Do So

We have adapted a multiparameter cell sorter to measure the distribution of fluorescence polarization in cell populations. Measurements carried out on EL4 cells show that the percent polarization of fluorescein fluorescence decreases with increasing fluorescence intensity. This inverse relationship between polarization and intensity is shown both within the cell population and by the average values of the two quantities during both the increase and decrease of fluorescence intensity. The quantitative relation between intensity and polarization is different in hypertonic than in isotonic media. These results suggest that polarization measurements carried out at a fixed time after incubation of cells with fluorescein diacetate, which is converted to fluorescein within the cells, may depend in part on the rate of fluorescein accumulation, and that agents that have been reported to change the polarization of fluorescein in living cells may do so by changing the kinetics of fluorescein accumulation.

scholarly journals Fluorescence Polarization Measurements to Probe Alignment of a Bithiophene Dye in One-Dimensional Channels of Self-Assembled Phenylethynylene Bis-Urea Macrocycle Crystals

2017 ◽  
Vol 121 (33) ◽  
pp. 18102-18109 ◽  
Author(s):  
Preecha Kittikhunnatham ◽  
Bozumeh Som ◽  
Vitaly Rassolov ◽  
Matthias Stolte ◽  
Frank Würthner ◽  
...  
Keyword(s):  
Fluorescence Polarization ◽  
One Dimensional ◽  
Polarization Measurements ◽  
Self Assembled

Self-Controlled Practice Within a Fixed Time Period Facilitates the Learning of a Basketball Set Shot

2014 ◽  
Vol 2 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Phillip G. Post ◽  
Jeffrey T. Fairbrother ◽  
Joao A. C. Barros ◽  
J. D. Kulpa
Keyword(s):  
Motor Learning ◽  
Instructional Support ◽  
Fixed Time ◽  
Relevant Information ◽  
Self Control ◽  
Time Period ◽  
Trial Basis ◽  
Practice Trials ◽  
Additional Support ◽  
Do So

Allowing self-control over various modes of instructional support has been shown to facilitate motor learning. Most research has examined factors that directly altered task-relevant information on a trial-to-trial basis (e.g., feedback). Recent research suggests that self-control (SC) effects extend to the manipulation of other types of factors (e.g., total number of practice trials completed). This research also illustrated that learners sometimes select a very small amount of practice when given latitude to do so. The purpose of the current study was to examine the effects of SC practice within a fixed time period on the learning of a basketball set shot. SC participants chose when to attempt each shot within two 15-min practice sessions, thereby controlling both the total number of shots taken and the spacing of shots. Yoked participants completed the same number of shots as their SC counterparts. Spacing of shots was also matched across groups. The SC group was more accurate and had higher form scores and longer preshot times during retention. These findings provided additional support for the generalizability of SC effects and extended prior research, showing that autonomy over total practice duration was not a prerequisite for the observed effects.

scholarly journals Evolution and the City

2017 ◽  
Vol 139 (02) ◽  
pp. 44-49
Author(s):  
Adrian Bejan
Keyword(s):  
Travel Time ◽  
Urban Design ◽  
Flow System ◽  
Modern Technology ◽  
Trial And Error ◽  
Street Network ◽  
Scientific Principle ◽  
The City ◽  
Natural Way ◽  
Do So

This article analyzes the organization of a city in terms of how well it enables humans to move from any point to the whole area. In accordance with Constructal Law, the natural way to assemble and connect a road and street network is to ensure that travel time is reduced at every turn and with every change in the flow design. The article also highlights that predicting the future and constructing changes based on a proven scientific principle is much faster and more economical than trial and error. Due to the modern technology, urban design expands not only outward, into suburbs, and inward, toward dense city centers, but also vertically. Experts suggest that if we can anticipate the urban features that emerge naturally from the need for greater access, we can plan ahead and design with confidence the features that not only serve the population, but do so with staying power. A city is a live flow system with freely changing architecture, many small streets, few large streets, and beltways.

Reactions of free radicals with aromatic compounds in the gaseous phase. I. Kinetics of the reaction of methyl radicals with toluene

1964 ◽  
Vol 17 (12) ◽  
pp. 1329 ◽  
Author(s):  
MFR Mulcahy ◽  
DJ Williams ◽  
JR Wilmshurst
Keyword(s):  
Flow System ◽  
Methyl Radicals ◽  
Methyl Radical ◽  
Hydrogen Atoms ◽  
Methyl Group ◽  
Benzyl Radical ◽  
Toluene Molecule ◽  
Benzyl Radicals ◽  
Butyl Peroxide ◽  
Kinetics Of

The kinetics of abstraction of hydrogen atoms from the methyl group of the toluene molecule by methyl radicals at 430-540�K have been determined. The methyl radicals were produced by pyrolysis of di-t-butyl peroxide in a stirred-flow system. The kinetics ,agree substantially with those obtained by previous authors using photolytic methods for generating the methyl radicals. At toluene and methyl-radical concentrations of about 5 x 10-7 and 10-11 mole cm-3 respectively the benzyl radicals resulting from the abstraction disappear almost entirely by combination with methyl radicals at the methylenic position. In this respect the benzyl radical behaves differently from the iso-electronic phenoxy radical, which previous work has shown to combine with a methyl radical mainly at ring positions. The investigation illustrates the application of stirred-flow technique to the study of the kinetics of free-radical reactions.

Inactivation kinetics of waterborne virus by ozone determined by a continuous quench flow system

2020 ◽  
Vol 186 ◽  
pp. 116291 ◽  
Author(s):  
Shotaro Torii ◽  
Masae Itamochi ◽  
Hiroyuki Katayama
Keyword(s):  
Flow System ◽  
Inactivation Kinetics ◽  
Waterborne Virus ◽  
Kinetics Of
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