Faculty Opinions recommendation of Theory of active transport in filopodia and stereocilia.

2015 ◽  
Author(s):  
Laurent Blanchoin
Keyword(s):  
Active Transport

On the structural organization of biological pumps and channels

1984 ◽  
Vol 42 ◽  
pp. 138-141
Author(s):  
G. Zampighi ◽  
M. Kreman
Keyword(s):  
Active Transport ◽  
Transport System ◽  
Plasma Membranes ◽  
Transport Proteins ◽  
Molecular Organization ◽  
Passive Transport ◽  
Concentration Gradients ◽  
Cell Functions ◽  
Natural Concentration ◽  
Active Transport System

The plasma membranes of most animal cells contain transport proteins which function to provide passageways for the transported species across essentially impermeable lipid bilayers. The channel is a passive transport system which allows the movement of ions and low molecular weight molecules along their concentration gradients. The pump is an active transport system and can translocate cations against their natural concentration gradients. The actions and interplay of these two kinds of transport proteins control crucial cell functions such as active transport, excitability and cell communication. In this paper, we will describe and compare several features of the molecular organization of pumps and channels. As an example of an active transport system, we will discuss the structure of the sodium and potassium ion-activated triphosphatase [(Na+ +K+)-ATPase] and as an example of a passive transport system, the communicating channel of gap junctions and lens junctions.

Pneumatically-driven Microfluidic Device for Evaluating Active Transport by Kinesin Motor Protein

2016 ◽  
Vol 136 (9) ◽  
pp. 384-389
Author(s):  
Kazuya Fujimoto ◽  
Hirofumi Shintaku ◽  
Hidetoshi Kotera ◽  
Ryuji Yokokawa
Keyword(s):  
Active Transport ◽  
Microfluidic Device ◽  
Motor Protein ◽  
Kinesin Motor

Chloride secretion and conductance of teleost opercular membrane: effects of prolactin

1982 ◽  
Vol 242 (3) ◽  
pp. R380-R389 ◽  
Author(s):  
J. K. Foskett ◽  
T. E. Machen ◽  
H. A. Bern
Keyword(s):  
Active Transport ◽  
Short Circuit ◽  
Chloride Secretion ◽  
Alternative Interpretation ◽  
Chloride Cells ◽  
Dependent Manner ◽  
Transport Pathway ◽  
Accurate Analysis ◽  
Equivalent Circuit Analysis ◽  
Fish Yield

Effects of prolactin on transport properties of opercular membranes from seawater-adapted tilapia, Sarotherodon mossambicus, have been examined. These membranes are high conductance (average Gt approximately 4 mS.cm-2) tissues with short-circuit currents (I) equal to net chloride secretion. Despite high Gt, nonlinear current-voltage relationships suggest that opercular membranes cannot be classified as "leaky" tissues. Variability among membranes is reflected in a linear relationship between I and Gt with a slope equal to 26 mV and the zero-current Gt intercept equal to 0.45 mS.cm-2. Prolactin injections decrease I and Gt in a dose-dependent manner. Phosphodiesterase inhibition, without effect on I in untreated fish, often partially reverses these prolactin effects. Gt-I data from prolactin-treated fish yield a slope of 18 mV and a Gt intercept of 0.10 mS.cm-2. The effects of prolactin are discussed in terms of conventional equivalent circuit analysis. Discrepancies between predictions based on this model and the actual data indicate that an alternative interpretation, based on a heterogeneous cell population, is more accurate. Analysis of this circuit suggests that the ratio of paracellular to active transport pathway conductances associated with chloride cells is constant and that differences in Gt and I are due to parallel changes in these conductances. Prolactin may effectively "remove" chloride cells from these membranes as well as inhibit (reversible by elevated cellular cAMP levels) active transport pathway conductance of remaining cells.

Carrier-Mediated Active Transport of a Novel Thromboxane A2 Receptor Antagonist [2-(4-Chlorophenylsulfonylaminomethyl)indan-5-yl]acetate (Z-335) into Rat Liver

2002 ◽  
Vol 30 (5) ◽  
pp. 498-504 ◽  
Author(s):  
Yoshihiro Kawabata ◽  
Shigeru Furuta ◽  
Yutaka Shinozaki ◽  
Tadashi Kurimoto ◽  
Ryuichiro Nishigaki
Keyword(s):  
Receptor Antagonist ◽  
Active Transport ◽  
Rat Liver ◽  
Thromboxane A2 ◽  
Thromboxane A2 Receptor

A Distributed Multiplayer Game to Promote Active Transport at Workplaces: User-Centered Design, Implementation, and Lessons Learned

2020 ◽  
Vol 12 (4) ◽  
pp. 386-397
Author(s):  
Teemu H. Laine ◽  
Jorgen Normark ◽  
Helena Lindvall ◽  
Anna-Karin Lindqvist ◽  
Stina Rutberg
Keyword(s):  
Active Transport ◽  
Lessons Learned ◽  
User Centered Design ◽  
User Centered

scholarly journals Association between the school physical activity environment, measured and self-reported student physical activity and active transport behaviours in Victoria, Australia

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Nicholas Crooks ◽  
Laura Alston ◽  
Melanie Nichols ◽  
Kristy A. Bolton ◽  
Steven Allender ◽  
...  
Keyword(s):  
Physical Activity ◽  
Active Transport ◽  
Primary Schools ◽  
Weight Status ◽  
School Principal ◽  
Primary School Children ◽  
Physically Active ◽  
Physical Activity Environment ◽  
Policy Practice ◽  
Socioeconomic Composition

Abstract Background Environments within schools including the physical, social-cultural and policy/practice environments have the potential to influence children’s physical activity (PA) behaviours and weight status. This Australian first study comprehensively examined the association(s) of physical, social-cultural and policy/practice environments with PA, active transport (AT) and weight status among regional primary school children. Methods Data were from two childhood obesity monitoring systems in regional Victoria, Australia. Measured height and weight were collected from students in Year 2 (aged approx. 7–8 years), Year 4 (9–10 years), and Year 6 (11–12 years). Self–reported PA behaviour, including AT were collected from students in Year 4 and 6 and a sub-sample wore an ActiGraph (wGT3X-BT) accelerometer for 7-days. A school physical activity environment audit was completed by the school principal and responses were used to calculate school physical activity environment scores (PAES) and active transport environment scores (ATES). Mixed effects logistic regression was used to assess the relationship between the proportion of students meeting the PA guidelines (≥60mins/day of moderate-to-vigorous PA) and PAES tertiles (low, medium, high) and those using AT and school ATES tertiles, controlling for gender, school size/type and socioeconomic composition. Results The analysed sample included 54/146 (37%) schools and 3360/5376 (64%) students. In stratified analysis, girls in schools with a medium PAES score were more likely to meet the objectively measured PA guideline compared to low PAES score (OR 2.3, 95%CI 1.27, 4.16). Similarly, students in schools with a medium or high ATES score had higher odds of self-reported AT (medium OR 3.15, 95%CI 1.67, 5.94; high OR 3.71, 95%CI: 1.80, 7.64). No association between PAES or ATES and weight status were observed. Self-reported AT among boys (OR 1.59, 95%CI 1.19, 2.13) and girls (OR 1.56, 95%CI 1.08, 2.27) was associated with higher odds of meeting self-reported PA guidelines on all 7-days than those who did not report using AT. Conclusions In this study of regional Victorian primary schools, PA environments were only associated with girls’ adherence to PA guidelines. School AT environments were strongly associated with students’ AT behaviours and with increased likelihood of students being physically active.

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