Fate of tetracycline at high concentrations in enriched mixed culture system: biodegradation and behavior

2015 ◽  
Vol 91 (5) ◽  
pp. 1562-1568 ◽  
Author(s):  
Chao Song ◽  
Xue-Fei Sun ◽  
Yun-Kun Wang ◽  
Peng-Fei Xia ◽  
Fang-Hui Yuan ◽  
...  
Keyword(s):  
Mixed Culture ◽  
Culture System ◽  
High Concentrations ◽  
And Behavior

Feedback control of a competitive mixed-culture system

1980 ◽  
Vol 22 (1) ◽  
pp. 89-106 ◽  
Author(s):  
Carl T. Wilder ◽  
Theodore W. Cadman ◽  
Randolph T. Hatch
Keyword(s):  
Feedback Control ◽  
Mixed Culture ◽  
Culture System

Dynamics and control of an activated sludge process as a mixed culture system

AIChE Journal ◽  
1984 ◽  
Vol 30 (3) ◽  
pp. 368-376 ◽  
Author(s):  
Takeichiro Takamatsu ◽  
Suteaki Shioya ◽  
Hirokazu Kurome
Keyword(s):  
Activated Sludge ◽  
Mixed Culture ◽  
Culture System ◽  
Activated Sludge Process ◽  
Dynamics And Control ◽  
And Control

scholarly journals A 90-Day Oral (Dietary) Toxicity Study of Rebaudioside A in Sprague-Dawley Rats

2008 ◽  
Vol 27 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Andrey I Nikiforov ◽  
Alex K Eapen
Keyword(s):  
Clinical Pathology ◽  
Stevia Rebaudiana ◽  
Rebaudioside A ◽  
Sprague Dawley ◽  
Small Magnitude ◽  
Stevia Rebaudiana Bertoni ◽  
Sprague Dawley Rats ◽  
The Difference ◽  
High Concentrations ◽  
And Behavior

Rebaudioside A is one of several glycosides found in the leaves of Stevia rebaudiana (Bertoni) Bertoni (Compositae) stevia that has been identified as a potential sweetener. The present study (initiated in April 2006 and completed in October 2006) evaluated the safety of this sweetener when administered as a dietary admix at target exposure levels of 500, 1000, and 2000 mg/kg/day to Sprague-Dawley rats for 90 days. There were no treatment-related effects on the general condition and behavior of the animals as determined by clinical observations, functional observational battery, and locomotor activity assessments. Evaluation of clinical pathology parameters revealed no toxicologically relevant, treatment-related effects on hematology, serum chemistry, or urinalysis. Macroscopic and microscopic findings revealed no treatment-related effects on any organ evaluated. Lower mean body weight gains were noted in males in the 2000 mg/kg/day group throughout the study, which was considered to be test article related; however, given the small magnitude of the difference as compared to controls, this effect was not considered to be adverse. Results of this study clearly demonstrate that dietary administration of high concentrations of rebaudioside A for 90 consecutive days to Sprague-Dawley rats was not associated with any signs of toxicity.

Geophysical Variables and Behavior: V. Human Performance in Ionized Air

1982 ◽  
Vol 54 (2) ◽  
pp. 403-412 ◽  
Author(s):  
Eric W. Farmer ◽  
Andrea Bendix
Keyword(s):  
Human Performance ◽  
Memory Search ◽  
Negative Ions ◽  
Air Ions ◽  
Negative Air Ions ◽  
Search Tasks ◽  
Confounding Variables ◽  
High Concentrations ◽  
Ionized Air ◽  
And Behavior

An experiment was conducted to investigate the claim that human performance may be enhanced by exposure to artificially high concentrations of negative air ions. 16 subjects, only half of whom were informed of the ion level in each session, performed reasoning, psychomotor, and memory-search tasks. Despite adequate control of confounding variables, no clear evidence was obtained in support of the view that negative ions in the air influence performance.

l-arginine via nitric oxide is an inhibitory feedback modulator of Aplysia feeding

2011 ◽  
Vol 105 (4) ◽  
pp. 1642-1650 ◽  
Author(s):  
N. Miller ◽  
R. Saada ◽  
S. Markovich ◽  
I. Hurwitz ◽  
A. J. Susswein
Keyword(s):  
Nitric Oxide ◽  
Inhibitory Effect ◽  
Excitatory Effect ◽  
Physiological Concentration ◽  
No Donor ◽  
Nos Inhibitors ◽  
Inhibitory Feedback ◽  
High Concentrations ◽  
Access To Food ◽  
And Behavior

An increase in l-arginine hemolymph concentration acts as a postingestion signal inhibiting Aplysia feeding. At physiological concentrations (a 10-μM increase over background), the inhibitory effect of l-arginine is too weak to block feeding in hungry animals. However, a 10-μM increase in l-arginine concentration acts along with another inhibitory stimulus, the sustained presence of food odor, to inhibit feeding after a period of access to food. A physiological concentration of l-arginine also blocked the excitatory effect of a stimulus enhancing feeding, pheromones secreted by mating conspecifics. High concentrations of l-arginine (2.5 mM) alone also inhibited ad libitum feeding. l-arginine is the substrate from which nitric oxide synthase (NOS) produces nitric oxide (NO). Both an NO donor and a 10-μM increase in l-arginine inhibited biting in response to a weak food stimulus. Treatment with NOS inhibitors initiated food-finding and biting in the absence of food, indicating that food initiates feeding against a background of tonic nitrergic inhibition. Increased feeding in response to blocking NOS is accompanied by firing of the metacerebral (MCC) neuron, a monitor of food arousal. The excitatory effect on the MCC of blocking NOS is indirect. The data suggest that l-arginine acts by amplifying NO synthesis, which acts as a background stimulus inhibiting feeding. Background modulation of neural activity and behavior by NO may also be present in other systems, but such modulation may be difficult to identify because its effects are evident only in the context of additional stimuli modulating behavior.

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