Renewal Rate Formula

2020 ◽  
Vol 16 (8) ◽  
pp. 5-5
Keyword(s):  
Renewal Rate

Positioning changes of mayfly nymphs due to behavioral regulation of oxygen consumption

1980 ◽  
Vol 58 (4) ◽  
pp. 618-622 ◽  
Author(s):  
Michael J. Wiley ◽  
Steven L. Kohler
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Field Conditions ◽  
Experimental Investigations ◽  
Behavioral Patterns ◽  
Behavioral Regulation ◽  
Dissolved Oxygen Concentration ◽  
Habitat Distribution ◽  
Renewal Rate

Experimental investigations in a small artificial stream showed that the positioning of mayfly nymphs (Ephemeroptera) on stones varied with dissolved oxygen concentration (DO). At low DO levels nymphs moved to current-exposed positions, presumably to increase the renewal rate of oxygen at respiratory exchange surfaces. The expected magnitude of positioning changes under field conditions was determined and suggests that behavioral regulation of oxygen consumption may commonly influence both habitat distribution and diel behavioral patterns. The implications of these results to drift studies are also discussed.

scholarly journals Virus Attachment to Transparent Exopolymeric Particles along Trophic Gradients in the Southwestern Lagoon of New Caledonia

2007 ◽  
Vol 73 (16) ◽  
pp. 5245-5252 ◽  
Author(s):  
Xavier Mari ◽  
Marie-Emmanuelle Kerros ◽  
Markus G. Weinbauer
Keyword(s):  
Hot Spots ◽  
Magnetic Beads ◽  
Water Mass ◽  
New Caledonia ◽  
Virus Attachment ◽  
Renewal Rate ◽  
Mixed Aggregates ◽  
Transparent Exopolymeric Particles ◽  
Virus Abundance ◽  
Trophic Gradients

ABSTRACT Viruses on organic aggregates such as transparent exopolymeric particles (TEP) are not well investigated. The number of TEP-attached viruses was assessed along trophic gradients in the southwestern lagoon of New Caledonia by determining the fraction of viruses removed after magnetic isolation of TEP. In order to isolate TEP magnetically, TEP were formed in the presence of magnetic beads from submicrometer precursors collected along the trophic gradients. The mixed aggregates of TEP-beads-viruses were removed from solution with a magnetic field. The percentage of viruses associated with newly formed TEP averaged 8% (range, 3 to 13%) for most of the stations but was higher (ca. 30%) in one bay characterized by the low renewal rate of its water mass. The number of viruses (N) attached to TEP varied as a function of TEP size (d [in micrometers]) according to the formulas N = 100d 1.60 and N = 230d 1.75, respectively, for TEP occurring in water masses with short (i.e., <40 days) and long (i.e., >40 days) residence times. These two relationships imply that viral abundance decreases with TEP size, and they indicate that water residence time influences viral density and virus-bacterium interactions within aggregates. Our data suggest that the fraction of viruses attached to TEP is highest in areas characterized by a low renewal rate of the water mass and can constitute at times a significant fraction of total virus abundance. Due to the small distance between viruses and hosts on TEP, these particles may be hot spots for viral infection.

scholarly journals Delayed Renewal Process with Uncertain Random Inter-Arrival Times

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1943
Author(s):  
Xiaoli Wang ◽  
Gang Shi ◽  
Yuhong Sheng
Keyword(s):  
Random Process ◽  
Renewal Process ◽  
Random Variable ◽  
Random Delay ◽  
Renewal Theorem ◽  
Arrival Times ◽  
Chance Distribution ◽  
Renewal Rate ◽  
First Arrival

An uncertain random variable is a tool used to research indeterminacy quantities involving randomness and uncertainty. The concepts of an ’uncertain random process’ and an ’uncertain random renewal process’ have been proposed in order to model the evolution of an uncertain random phenomena. This paper designs a new uncertain random process, called the uncertain random delayed renewal process. It is a special type of uncertain random renewal process, in which the first arrival interval is different from the subsequent arrival interval. We discuss the chance distribution of the uncertain random delayed renewal process. Furthermore, an uncertain random delay renewal theorem is derived, and the chance distribution limit of long-term expected renewal rate of the uncertain random delay renewal system is proved. Then its average uncertain random delay renewal rate is obtained, and it is proved that it is convergent in the chance distribution. Finally, we provide several examples to illustrate the consistency with the existing conclusions.

scholarly journals Variable renewal rate and growth properties of cell populations in colon crypts

2010 ◽  
Vol 81 (6) ◽  
Author(s):  
A. Di Garbo ◽  
M. D. Johnston ◽  
S. J. Chapman ◽  
P. K. Maini
Keyword(s):  
Cell Populations ◽  
Renewal Rate ◽  
Growth Properties

scholarly journals Effect of the Carbon Concentration, Blend Concentration, and Renewal Rate in the Growth Kinetic ofChlorellasp.

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Adriano Arruda Henrard ◽  
Gabriel Martins da Rosa ◽  
Luiza Moraes ◽  
Michele Greque de Morais ◽  
Jorge Alberto Vieira Costa
Keyword(s):  
Specific Growth ◽  
Biomass Productivity ◽  
Cost Effective ◽  
Batch Cultivation ◽  
Maximum Specific Growth Rate ◽  
Residual Water ◽  
Microalgae Cultivation ◽  
Renewal Rate ◽  
Alternative Sources ◽  
Semicontinuous Cultivation

The microalgae cultivation can be used as alternative sources of food, in agriculture, residual water treatment, and biofuels production. Semicontinuous cultivation is little studied but is more cost-effective than the discontinuous (batch) cultivation. In the semicontinuous cultivation, the microalga is maintained in better concentration of nutrients and the photoinhibition by excessive cell is reduced. Thus, biomass productivity and biocompounds of interest, such as lipid productivity, may be higher than in batch cultivation. The objective of this study was to examine the influence of blend concentration, medium renewal rate, and concentration of sodium bicarbonate on the growth ofChlorellasp. during semicontinuous cultivation. The cultivation was carried out in Raceway type bioreactors of 6 L, for 40 d at 30°C, 41.6 µmol m−2 s−1, and a 12 h light/dark photoperiod. Maximum specific growth rate (0.149 d−1) and generating biomass (2.89 g L−1) were obtained when the blend concentration was 0.80 g L−1, the medium renewal rate was 40%, and NaHCO3was 1.60 g L−1. The average productivity (0.091 g L−1 d−1) was achieved with 0.8 g L−1of blend concentration and NaHCO3concentration of 1.6 g L−1, independent of the medium renewal rate.

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