Tracking the Temporal Dynamics of Intracellular Lead Speciation in a Green Alga

2015 ◽  
Vol 49 (18) ◽  
pp. 11176-11181 ◽  
Author(s):  
T. J. Stewart ◽  
J. Szlachetko ◽  
L. Sigg ◽  
R. Behra ◽  
M. Nachtegaal
Keyword(s):  
Green Alga ◽  
Temporal Dynamics ◽  
Lead Speciation ◽  
Intracellular Lead

scholarly journals Fluid-phase and membrane markers reveal spatio-temporal dynamics of membrane traffic and repair in the green alga Chara australis

PROTOPLASMA ◽  
2021 ◽  
Author(s):  
Aniela Sommer ◽  
Margit Hoeftberger ◽  
Ilse Foissner
Keyword(s):  
Green Alga ◽  
Temporal Dynamics ◽  
Brefeldin A ◽  
Fluid Phase ◽  
Minor Role ◽  
Pulse Labelling ◽  
Membrane Repair ◽  
Styryl Dyes ◽  
Chara Australis ◽  
Spatio Temporal

AbstractWe investigated the mechanisms and the spatio-temporal dynamics of fluid-phase and membrane internalization in the green algaChara australisusing fluorescent hydrazides markers alone, or in conjunction with styryl dyes.Using live-cell imaging, immunofluorescence and inhibitor studies we revealed that both fluid-phase and membrane dyes were actively taken up into the cytoplasm by clathrin-mediated endocytosis and stained various classes of endosomes including brefeldin A- and wortmannin-sensitive organelles (trans-Golgi network and multivesicular bodies). Uptake of fluorescent hydrazides was poorly sensitive to cytochalasin D, suggesting that actin plays a minor role in constitutive endocytosis inCharainternodal cells. Sequential pulse-labelling experiments revealed novel aspects of the temporal progression of endosomes inCharainternodal cells. The internalized fluid-phase marker distributed to early compartments within 10 min from dye exposure and after about 30 min, it was found almost exclusively in late endocytic compartments. Notably, fluid cargo consecutively internalized at time intervals of more than 1h, was not targeted to the same vesicular structures, but was sorted into distinct late compartments. We further found that fluorescent hydrazide dyes distributed not only to rapidly recycling endosomes but also to long-lived compartments that participated in plasma membrane repair after local laser injury. Our approach highlights the benefits of combining different fluid-phase markers in conjunction with membrane dyes in simultaneous and sequential application modus for investigating vesicle traffic, especially in organisms, which are still refractory to genetic transformation like characean algae.

Effect of Iron Limitation on the Ultrastructure of Agmenellum Quadruplicatum

1981 ◽  
Vol 39 ◽  
pp. 410-411
Author(s):  
L. P. Hardie ◽  
D. L. Balkwill ◽  
S. E. Stevens
Keyword(s):  
Growth Medium ◽  
Green Alga ◽  
Natural Habitat ◽  
Iron Limitation ◽  
Natural Environments ◽  
Blue Green Alga ◽  
Marine Cyanobacterium ◽  
Natural Systems ◽  
Thin Sectioning ◽  
Agmenellum Quadruplicatum

Agmenellum quadruplicatum is a unicellular, non-nitrogen-fixing, marine cyanobacterium (blue-green alga). The ultrastructure of this organism, when grown in the laboratory with all necessary nutrients, has been characterized thoroughly. In contrast, little is known of its ultrastructure in the specific nutrient-limiting conditions typical of its natural habitat. Iron is one of the nutrients likely to limit this organism in such natural environments. It is also of great importance metabolically, being required for both photosynthesis and assimilation of nitrate. The purpose of this study was to assess the effects (if any) of iron limitation on the ultrastructure of A. quadruplicatum. It was part of a broader endeavor to elucidate the ultrastructure of cyanobacteria in natural systemsActively growing cells were placed in a growth medium containing 1% of its usual iron. The cultures were then sampled periodically for 10 days and prepared for thin sectioning TEM to assess the effects of iron limitation.

Characterization of lead-bearing phases in municipal waste combustor fly ash

1996 ◽  
Vol 54 ◽  
pp. 516-517
Author(s):  
L. L. Sutter ◽  
G. R. Dewey ◽  
J. F. Sandell
Keyword(s):  
Fly Ash ◽  
Bottom Ash ◽  
Municipal Waste ◽  
Primary Concern ◽  
Leaching Behavior ◽  
Waste Combustion ◽  
Lead And Cadmium ◽  
Lead Speciation ◽  
Accepted Practice

Municipal waste combustion typically involves both energy recovery as well as volume reduction of municipal solid waste prior to landfilling. However, due to environmental concerns, municipal waste combustion (MWC) has not been a widely accepted practice. A primary concern is the leaching behavior of MWC ash when it is stored in a landfill. The ash consists of a finely divided fly ash fraction (10% by volume) and a coarser bottom ash (90% by volume). Typically, MWC fly ash fails tests used to evaluate leaching behavior due to high amounts of soluble lead and cadmium species. The focus of this study was to identify specific lead bearing phases in MWC fly ash. Detailed information regarding lead speciation is necessary to completely understand the leaching behavior of MWC ash.

Effects of Monetary Incentives on Task Switching

2012 ◽  
Vol 59 (4) ◽  
pp. 216-226 ◽  
Author(s):  
Thomas Kleinsorge ◽  
Gerhard Rinkenauer
Keyword(s):  
Task Switching ◽  
Temporal Dynamics ◽  
Reward Processing ◽  
General Level ◽  
Monetary Incentives ◽  
Switch Costs ◽  
Expectancy Effect ◽  
Reward Expectancy ◽  
Trial Basis

In two experiments, effects of incentives on task switching were investigated. Incentives were provided as a monetary bonus. In both experiments, the availability of a bonus varied on a trial-to-trial basis. The main difference between the experiments relates to the association of incentives to individual tasks. In Experiment 1, the association of incentives to individual tasks was fixed. Under these conditions, the effect of incentives was largely due to reward expectancy. Switch costs were reduced to statistical insignificance. This was true even with the task that was not associated with a bonus. In Experiment 2, there was a variable association of incentives to individual tasks. Under these conditions, the reward expectancy effect was bound to conditions with a well-established bonus-task association. In conditions in which the bonus-task association was not established in advance, enhanced performance of the bonus task was accompanied by performance decrements with the task that was not associated with a bonus. Reward expectancy affected mainly the general level of performance. The outcome of this study may also inform recently suggested neurobiological accounts about the temporal dynamics of reward processing.

Spatial and temporal dynamics of lexico-semantic processing in American Sign Language

2011 ◽  
Author(s):  
M. Leonard ◽  
N. Ferjan Ramirez ◽  
C. Torres ◽  
M. Hatrak ◽  
R. Mayberry ◽  
...  
Keyword(s):  
American Sign Language ◽  
Sign Language ◽  
Semantic Processing ◽  
Temporal Dynamics ◽  
American Sign ◽  
Spatial And Temporal Dynamics

Temporal dynamics of auditory perceptual learning: Impact of progressive order

2010 ◽  
Author(s):  
Matthew G. Wisniewski ◽  
Barbara A. Church ◽  
Estella H. Liu ◽  
Eduardo Mercado
Keyword(s):  
Perceptual Learning ◽  
Temporal Dynamics

Switch Hands! Mapping Temporal Dynamics of Proactive Cognitive Control Via Anticues

2014 ◽  
Author(s):  
Joseph Adam ◽  
Selas Jennings ◽  
Thamar Bovendeerdt ◽  
Pascal Van Gerven ◽  
Petra Hurks
Keyword(s):  
Cognitive Control ◽  
Temporal Dynamics
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