Method of Reducing VM-exit Rate Generated by Handling Access to Virtualized Hardware

2020 ◽  
Author(s):  
Egor Vedyashkin ◽  
Alexander Kovtushenko
Keyword(s):  
Exit Rate

scholarly journals Evidence for nonvectorial, retrograde transferrin trafficking in the early endosomes of HEp2 cells.

1995 ◽  
Vol 128 (4) ◽  
pp. 549-561 ◽  
Author(s):  
R N Ghosh ◽  
F R Maxfield
Keyword(s):  
Steady State ◽  
Digital Image Analysis ◽  
Carcinoma Cells ◽  
Exit Rate ◽  
Human Carcinoma ◽  
First Order ◽  
First Order Kinetics ◽  
Early Endosomes ◽  
Retrograde Traffic ◽  
Endosomal System

We have previously characterized the trafficking of transferrin (Tf) through HEp2 human carcinoma cells (Ghosh, R. N., D. L. Gelman, and F. R. Maxfield, 1994. J. Cell Sci. 107:2177-2189). Early endosomes in these cells are comprised of both sorting endosomes and recycling compartments, which are distinct separate compartments. Endocytosed Tf initially appears in punctate sorting endosomes that also contain recently endocytosed LDL. After short loading pulses, Tf rapidly sorts from LDL with first-order kinetics (t1/2 approximately 2.5 min), and it enters the recycling compartment before leaving the cell (t1/2 approximately 7 min). Here, we report a second, slower rate for Tf to leave sorting endosomes after HEp2 cells were labeled to steady state with fluorescein Tf instead of the brief pulse used previously. We determined this rate using digital image analysis to measure the Tf content of sorting endosomes that also contained LDL. With an 11-min chase, the Tf in sorting endosomes was 24% of steady-state value. This was in excess of the amount expected (5% of steady state) from the rate of Tf exit after short filling pulses. The excess could not be accounted for by reinternalization of recycled cell surface Tf, implying that either some Tf was retained in sorting endosomes, or that Tf was delivered back to the sorting endosomes from the recycling compartment. The former is unlikely since nearly all sorting endosomes contain detectable Tf after an 11-min chase, even though more than one third of the sorting endosomes were formed during the chase time. Furthermore, while observing living cells by confocal microscopy, we saw vesicle movements that appeared to be fluorescent Tf returning from recycling compartments to sorting endosomes. The slow rate of exit after steady-state labeling was similar to the Tf exit rate from the cell, suggesting an equilibration of Tf throughout the early endosomal system by this retrograde pathway. This retrograde traffic may be important for delivering molecules from the recycling compartment, which is a long-lived organelle, to sorting endosomes, which are transient.

scholarly journals The Polyamine Binding Site in Inward Rectifier K+ Channels

2006 ◽  
Vol 127 (5) ◽  
pp. 467-480 ◽  
Author(s):  
Harley T. Kurata ◽  
Laurence J. Marton ◽  
Colin G. Nichols
Keyword(s):  
Binding Site ◽  
Exit Rate ◽  
Physical Constraints ◽  
Kir Channel ◽  
Inwardly Rectifying Potassium Channels ◽  
Voltage Dependent ◽  
Deep Site ◽  
Inwardly Rectifying ◽  
Polyamine Binding Site ◽  
Deep Location

Strongly inwardly rectifying potassium channels exhibit potent and steeply voltage-dependent block by intracellular polyamines. To locate the polyamine binding site, we have examined the effects of polyamine blockade on the rate of MTSEA modification of cysteine residues strategically substituted in the pore of a strongly rectifying Kir channel (Kir6.2[N160D]). Spermine only protected cysteines substituted at a deep location in the pore, between the “rectification controller” residue (N160D in Kir6.2, D172 in Kir2.1) and the selectivity filter, against MTSEA modification. In contrast, blockade with a longer synthetic polyamine (CGC-11179) also protected cysteines substituted at sites closer to the cytoplasmic entrance of the channel. Modification of a cysteine at the entrance to the inner cavity (169C) was unaffected by either spermine or CGC-11179, and spermine was clearly “locked” into the inner cavity (i.e., exhibited a dramatically slower exit rate) following modification of this residue. These data provide physical constraints on the spermine binding site, demonstrating that spermine stably binds at a deep site beyond the “rectification controller” residue, near the extracellular entrance to the channel.

scholarly journals Market Conditions and the Exit Rate of Private Equity Investments in an Emerging Economy

2019 ◽  
Vol 16 (2) ◽  
Author(s):  
Andréa Maria Accioly Fonseca Minardi ◽  
Adriana Bruscato Bortoluzzo ◽  
Piero Rosatelli ◽  
Priscila Fernandes Ribeiro
Keyword(s):  
Private Equity ◽  
Emerging Economy ◽  
Exit Rate ◽  
Market Conditions ◽  
Equity Investments ◽  
Private Equity Investments

scholarly journals When a trap is not a trap: converging entry and exit rates and their effect on trap saturation of black sea bass (Centropristis striata)

2013 ◽  
Vol 70 (4) ◽  
pp. 873-882 ◽  
Author(s):  
Nathan M. Bacheler ◽  
Zeb H. Schobernd ◽  
David J. Berrane ◽  
Christina M. Schobernd ◽  
Warren A. Mitchell ◽  
...  
Keyword(s):  
Black Sea ◽  
Sea Bass ◽  
Exit Rate ◽  
Underwater Video ◽  
Entry And Exit ◽  
Trap Catch ◽  
Entry Rate ◽  
Centropristis Striata ◽  
Black Sea Bass ◽  
Catch Rates

Abstract Bacheler, N. M., Schobernd, Z. H., Berrane, D. J., Schobernd, C. M., Mitchell, W. A., and Geraldi, N. R. 2013. When a trap is not a trap: converging entry and exit rates and their effect on trap saturation of black sea bass (Centropristis striata) – ICES Journal of Marine Science, 70: 873–882. Catch rates are often used to index the abundance of marine organisms, but catch saturation (i.e. declining catch rate as fishing time increases) can decouple catch and abundance. Researchers have struggled to account for saturation when using trap catch to infer population dynamics. We used the underwater video to document entries and exits of black sea bass (Centropristis striata) from chevron traps (n = 26) to quantify catch saturation. Black sea bass catch varied between 3 and 188 individuals for soak times of ∼90 min. Overall, 3564 black sea bass entered the traps and 1826 exited; therefore, over half (51%) of black sea bass entering traps exited before traps were retrieved. Black sea bass catch rates were non-linear and asymptotic for most (81%) trap samples, despite short soak times. Moreover, catch saturation occurred at 50 min, when the entry rate declined and the exit rate increased to a point where their confidence intervals overlapped. Several lines of evidence suggest that the level of black sea bass catch once saturation occurred may be positively related to true abundance, but additional research is needed to more fully test this hypothesis.

Transport of radioiodide between thyroid gland and blood in mice and rats

1958 ◽  
Vol 196 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Seymour H. Wollman ◽  
Franklin E. Reed
Keyword(s):  
Single Dose ◽  
Thyroid Gland ◽  
Rate Constant ◽  
Experimental Error ◽  
Compartment Model ◽  
Exit Rate ◽  
Follicular Cells ◽  
Thyroid Activity ◽  
Two Compartment Model ◽  
Rats And Mice

Equilibration data were obtained for thyroids of various activities in rats and mice given a single dose of propylthiouracil to block organic binding of radioiodine. Data were compared with an open two-compartment model of the thyroid characterized by a one-way thyroid clearance of serum radioiodide and an exit rate constant for the transport of radioiodide from the thyroid to the blood. The model generally fitted the data within experimental error. Clearances increased with thyroid activity. Exit rate constants were much larger for animals fed thiouracil than for other animals. Thiocyanate increased the exit rate constant but did not change the thyroid clearance of serum radioiodide significantly. A new open three-compartment thyroid model was introduced and was used to explain how thiocyanate could increase the exit rate constant by inhibiting the transport of iodide from the follicular cells to the lumen of the follicle.

AN EXPERIMENTAL ANALYSIS OF THE EFFECTS OF OESTROGEN ON THE THYROID GLAND OF CASTRATED ADULT MALE RATS

1968 ◽  
Vol 40 (4) ◽  
pp. 397-408 ◽  
Author(s):  
J. F. BITHELL ◽  
K. BROWN-GRANT
Keyword(s):  
Thyroid Gland ◽  
Rate Constant ◽  
Adult Male ◽  
Time Course ◽  
Hormone Secretion ◽  
Male Rats ◽  
Male Rat ◽  
Exit Rate ◽  
Experimental Conditions

SUMMARY The uptake of 131I by the thyroid gland of the castrated adult male rat is increased 24 hr. and is maximal 48 hr. after the injection of a single dose of 50 μg. oestradiol. The response is not dose-dependent between 25 and 1600 μg. The thyroid:serum (T:S) concentration ratio for 131I is also increased by oestradiol with a time-course similar to the changes in uptake, but release of 131I-labelled hormone from the gland in vivo and radioactive phosphate uptake were not affected. Analysis of the kinetics of 131I accumulation by the blocked gland show that the effects on 131I uptake and T:S ratio were due to an increase in the clearance rate with a possible associated decrease in the exit rate constant for iodide from the gland to the blood. Under the conditions of these experiments, the effects of oestradiol are not consistent with their being produced by an increase in pituitary thyrotrophic hormone secretion; a direct action on the gland appears likely. These conclusions apply solely to the experimental conditions described here and do not provide the basis for any generalization about the action of oestrogens on the thyroid gland. The method of analysis developed for the estimation of the unilateral clearance constant and the exit rate constant, together with their standard deviations, is presented in an appendix.

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