Hypoxia acclimation increases novelty response strength during fast-starts in the African mormyrid, Marcusenius victoriae

2017 ◽  
Vol 213 ◽  
pp. 36-45 ◽  
Author(s):  
Kerri L. Ackerly ◽  
Lauren J. Chapman ◽  
Rüdiger Krahe
Keyword(s):  
Response Strength ◽  
Novelty Response ◽  
Hypoxia Acclimation

Response Strength of Young Children in Operant Audiometry

1985 ◽  
Vol 28 (4) ◽  
pp. 539-547 ◽  
Author(s):  
Michael A. Primus ◽  
Gary Thompson
Keyword(s):  
Young Children ◽  
Response Strength ◽  
Ratio Schedule ◽  
Intermittent Reinforcement ◽  
Response Recovery ◽  
Conditioning Rate ◽  
Response Performance ◽  
Response Consistency ◽  
Measured Response ◽  
Response Habituation

An operant conditioning discrimination paradigm was evaluated in terms of relationships between response behavior of young children and two stimulus components of the paradigm, the discriminative stimulus (DS) and the reinforcing stimulus (RS). Experiment I measured response performance in normal 1-year-old subjects as a function of differences in intensity and/or complexity among three DSs. Results showed no significant differences in conditioning rate, habituation, or consistency of the conditioned response relative to variable properties of the DS. Experiment II examined response performance of normal 2-year-old children as a function of two modifications in the RS, reinforcement schedule and reinforcement novelty. Subjects reinforced on a variable-ratio schedule of intermittent reinforcement and subjects reinforced on a 100% schedule demonstrated equivalent response habituation and consistency. In the second part of the experiment, subjects receiving novel RSs showed significantly greater response recovery than subjects reinforced with familiar RSs. Comparison of normal 1- and 2-year-old children revealed similar rates of conditioning and response consistency. However, 2-year-olds habituated more rapidly than 1-year-olds.

scholarly journals Ag-Yb Alloy-Novel Tunable Plasmonic Material

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 288
Author(s):  
Suetying Ching ◽  
Chakming Chan ◽  
Jack Ng ◽  
Kokwai Cheah
Keyword(s):  
Beam Steering ◽  
Volume Ratio ◽  
Response Strength ◽  
Transmission Efficiency ◽  
Spatial Light Modulators ◽  
Alloy Thin Film ◽  
Ellipsometric Measurement ◽  
Plasmonic Material ◽  
Light Modulators ◽  
Surface Plasmon Coupling

Metals are commonly used in plasmonic devices because of their strong plasmonic property. However, such properties are not easily tuned. For applications such as spatial light modulators and beam steering, tunable plasmonic properties are essential, and neither metals nor other plasmonic materials possess truly tunable plasmonic properties. In this work, we show that the silver alloy silver–ytterbium (Ag-Yb) possesses tunable plasmonic properties; its plasmonic response strength can be adjusted as a function of Yb concentration. Such tunability can be explained in terms of the influence of Yb on bound charge and interaction of its dielectric with the dielectric of Ag. The change in transition characteristics progressively weakens Ag’s plasmonic properties. With a spectral ellipsometric measurement, it was shown that the Ag-Yb alloy thin film retains the properties of Ag with high transmission efficiency. The weakened surface plasmon coupling strength without dramatic change in the coupling wavelengths implies that the tunability of the Ag-Yb alloy is related to its volume ratio. The principle mechanism of the plasmonic change is theoretically explained using a model. This work points to a potential new type of tunable plasmonic material.

Is there a bias in spatial maze judgment bias tests? Individual differences in subjects’ novelty response can affect test results

2021 ◽  
pp. 113262
Author(s):  
Veridiana Jardim ◽  
Aurélie Verjat ◽  
Christophe Féron ◽  
Nicolas Châline ◽  
Heiko G. Rödel
Keyword(s):  
Individual Differences ◽  
Test Results ◽  
Judgment Bias ◽  
Novelty Response

scholarly journals Rocker outsole shoe is not a threat to postural stability in patients with diabetic neuropathy

2014 ◽  
Vol 40 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Banafshe Ghomian ◽  
Mojtaba Kamyab ◽  
Hassan Jafari ◽  
Mohammadebrahim Khamseh ◽  
Aoife Healy
Keyword(s):  
Diabetic Neuropathy ◽  
Response Latency ◽  
Postural Stability ◽  
Response Strength ◽  
Diabetic Patients ◽  
Foot Ulceration ◽  
Objective Evidence ◽  
Significant Difference ◽  
Quasi Experimental ◽  
Force Displacement

Background: Rocker outsole shoes are commonly prescribed to patients with diabetic neuropathy to offload a particular area of the foot sole, thereby decreasing the risk of foot ulceration. Contrary to this, some evidence has reported a postural destabilising effect of these shoes in healthy adults. Objective: To explore the postural stability of patients with diabetic neuropathy who wear a rocker outsole shoe. Study design: Quasi-experimental. Method: In total, 17 patients with diabetic neuropathy (aged 49.29 ± 7.48 years; 7 female, 10 males) participated in this study. A Motor Control Test measuring centre of force displacement, response strength scale and response latency in medium and large perturbations was conducted using the EquiTest system to evaluate postural stability while wearing a baseline shoe (without a rocker outsole) or a rocker outsole shoe (with a toe-only rocker sole). Results: No significant difference was observed between the shoe conditions in centre of force displacement and response latency of the participants (p > 0.05). The results indicated a significant increase in the response strength scale of participants by the rocker outsole, for medium forward and backward and large forward perturbations ( p = 0.014, p = 0.001 and p = 0.027, respectively). Conclusion: When the immediate effect is a concern, the rocker outsole shoe did not negatively affect postural stability in patients with diabetic neuropathy. Clinical relevance This article will provide objective evidence about the effect of rocker outsole on postural balance in diabetic patients. In prescription of rocker outsole to prevent plantar ulceration of diabetic foot, immediate postural destabilising is not a concern.

scholarly journals Stability of response strength hierarchies in continued word association

1967 ◽  
Vol 7 (4) ◽  
pp. 129-130
Author(s):  
Burton G. Andreas ◽  
Michael Mills
Keyword(s):  
Word Association ◽  
Response Strength

The Transition to Air Breathing in Fishes:: I. Environmental Effects on the Facultative Air Breathing of Ancistrus Chagresi and Hypostomus Plecostomus Loricariidae

1982 ◽  
Vol 96 (1) ◽  
pp. 53-67 ◽  
Author(s):  
JEFFREY B. GRAHAM ◽  
TROY A. BAIRD
Keyword(s):  
Fish Species ◽  
Environmental Effects ◽  
Breathing Rate ◽  
Breathing Frequency ◽  
Rate Reduction ◽  
Air Breathing ◽  
Aquatic Respiration ◽  
Saturated Water ◽  
Important Regulator ◽  
Hypoxia Acclimation

In response to progressive aquatic hypoxia, the armoured loricariid catfishes Ancistrus chagresi and Hypostomus plecostomus become facultative air-breathers and utilize their stomachs as accessory air-breathing organs. Hypostomus initiates air breathing at a higher aquatic O2 tension (Pw, Ow, O2) than does Ancistrus (60 v. 33 mmHg). Once begun, the air-breathing frequencies of both species increase with decreasing Pw, Ow, O2; the frequency of Ancistrus, however, is greater than and increases more with hypoxia than does that of Hypostomus, which appears to be a more efficient air breather. Hypoxia acclimation reduces the air-breathing rate of both species. A larger rate reduction occurs in Ancistrus, which, however, continues to require more frequent breaths than Hypostomus. Hypoxia acclimation does not affect the air-breathing threshold of either species, suggesting that external O2 receptors initiate facultative air breathing. In progressive aquatic hypercapnia Ancistrus has a lower air-breathing CO2 threshold (8.7 mmHg) than Hypostomus (12.8 mmHg). However, in some tests, individual fish of both species did not initiate air breathing even at Pw, COw, CO2 as high as 21 mmHg. Also, air breathing evoked by hypercapnia was short-lived; both species quickly compensated for this gas and resumed exclusively aquatic respiration within a few hours of exposure. Thus, CO2 is not an important regulator of air breathing in these species. Between 25 and 35 °C, the Pw, Ow, O2 air breathing threshold of Ancistrus is temperature-independent, but air-breathing frequency increases with temperature. Ancistrus and Hypostomus do not breathe air in normoxic (air-saturated) water; their air-breathing responses are evoked by environmental hypoxia. This is fundamentally different from other fish species that breathe air in normoxia in order to meet heightened metabolic demands. Also, the facultative air-breathing adaptations of Ancistrus and Hypostomus differ in scope and magnitude from those utilized by species that breathe air in nor-moxia and adapt to hypoxia by increasing air-breathing rate.

scholarly journals Plasticity of non-shivering thermogenesis and brown adipose tissue in high-altitude deer mice

2021 ◽  
Author(s):  
Soren Z. Coulson ◽  
Cayleih E. Robertson ◽  
Sajeni Mahalingam ◽  
Grant B. McClelland
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
High Altitude ◽  
Heat Production ◽  
Mitochondrial Function ◽  
Mitochondrial Respiration ◽  
Deer Mice ◽  
Brown Adipose ◽  
Hypoxia Acclimation ◽  
Shivering Thermogenesis

High altitude environments challenge small mammals with persistent low ambient temperatures that require high rates of aerobic heat production in face of low O2 availability. An important component of thermogenic capacity in rodents is non-shivering thermogenesis (NST) mediated by uncoupled mitochondrial respiration in brown adipose tissue (BAT). NST is plastic, and capacity for heat production increases with cold acclimation. However, in lowland native rodents, hypoxia inhibits NST in BAT. We hypothesize that highland deer mice (Peromyscus maniculatus) overcome the hypoxic inhibition of NST through changes in BAT mitochondrial function. We tested this hypothesis using lab born and raised highland and lowland deer mice, and a lowland congeneric (P. leucopus), acclimated to either warm normoxia (25°C, 760 mmHg) or cold hypoxia (5°C, 430 mmHg). We determined the effects of acclimation and ancestry on whole-animal rates of NST, the mass of interscapular BAT (iBAT), and uncoupling protein (UCP)-1 protein expression. To identify changes in mitochondrial function, we conducted high-resolution respirometry on isolated iBAT mitochondria using substrates and inhibitors targeted to UCP-1. We found that rates of NST increased with cold hypoxia acclimation but only in highland deer mice. There was no effect of cold hypoxia acclimation on iBAT mass in any group, but highland deer mice showed increases in UCP-1 expression and UCP-1 stimulated mitochondrial respiration in response to these stressors. Our results suggest that highland deer mice have evolved to increase the capacity for NST in response to chronic cold hypoxia, driven in part by changes in iBAT mitochondrial function.

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