scholarly journals Cardiotonic Steroids and the Sodium Trade Balance: New Insights into Trade-Off Mechanisms Mediated by the Na+/K+-ATPase

2018 ◽  
Vol 19 (9) ◽  
pp. 2576 ◽  
Author(s):  
Fatimah Khalaf ◽  
Prabhatchandra Dube ◽  
Amal Mohamed ◽  
Jiang Tian ◽  
Deepak Malhotra ◽  
...  
Keyword(s):  
Volume Overload ◽  
Physiological Adaptation ◽  
Ion Pump ◽  
Trade Off ◽  
Trade Offs ◽  
Target Organs ◽  
Clinical Disorders ◽  
Adaptation Processes

In 1972 Neal Bricker presented the “trade-off” hypothesis in which he detailed the role of physiological adaptation processes in mediating some of the pathophysiology associated with declines in renal function. In the late 1990’s Xie and Askari published seminal studies indicating that the Na+/K+-ATPase (NKA) was not only an ion pump, but also a signal transducer that interacts with several signaling partners. Since this discovery, numerous studies from multiple laboratories have shown that the NKA is a central player in mediating some of these long-term “trade-offs” of the physiological adaptation processes which Bricker originally proposed in the 1970’s. In fact, NKA ligands such as cardiotonic steroids (CTS), have been shown to signal through NKA, and consequently been implicated in mediating both adaptive and maladaptive responses to volume overload such as fibrosis and oxidative stress. In this review we will emphasize the role the NKA plays in this “trade-off” with respect to CTS signaling and its implication in inflammation and fibrosis in target organs including the heart, kidney, and vasculature. As inflammation and fibrosis exhibit key roles in the pathogenesis of a number of clinical disorders such as chronic kidney disease, heart failure, atherosclerosis, obesity, preeclampsia, and aging, this review will also highlight the role of newly discovered NKA signaling partners in mediating some of these conditions.

scholarly journals The role of ventromedial prefrontal cortex in reward valuation and future thinking during intertemporal choice

2021 ◽  
Author(s):  
Elisa Ciaramelli ◽  
Flavia De Luca ◽  
Donna Kwan ◽  
Jenkin N. Y. Mok ◽  
Francesca Bianconi ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Reward Magnitude ◽  
Intertemporal Choice ◽  
Ventromedial Prefrontal Cortex ◽  
Future Thinking ◽  
Long Term Outcomes ◽  
Trade Offs ◽  
Reward Valuation

Intertemporal choices require trade-offs between short-term and long-term outcomes. Ventromedial prefrontal cortex (vmPFC) damage causes steep discounting of future rewards (delay discounting; DD) and impoverished episodic future thinking (EFT). The role of vmPFC in reward valuation, EFT, and their interaction during intertemporal choice is still unclear. Here, twelve patients with lesions to vmPFC and forty-one healthy controls chose between smallerimmediate and larger-delayed rewards while we manipulated reward magnitude and the availability of EFT cues. In the EFT condition, participants imagined personal events to occur at the delays associated with the larger-delayed rewards. We found that DD was steeper in vmPFC patients compared to controls, and not modulated by reward magnitude. However, EFT cues downregulated DD in vmPFC patients as well as controls. These findings indicate that vmPFC integrity is critical for the valuation of (future) rewards, but not to instill EFT in intertemporal choice.

scholarly journals Using Artificial Intelligence to classify Jobseekers: The Accuracy-Equity Trade-off

2020 ◽  
pp. 1-19
Author(s):  
SAM DESIERE ◽  
LUDO STRUYVEN
Keyword(s):  
Artificial Intelligence ◽  
Maximum Level ◽  
Employment Services ◽  
Trade Off ◽  
The Public ◽  
Foreign Origin ◽  
Trade Offs ◽  
Graphical Tool ◽  
The Cost

Abstract Artificial intelligence (AI) is increasingly popular in the public sector to improve the cost-efficiency of service delivery. One example is AI-based profiling models in public employment services (PES), which predict a jobseeker’s probability of finding work and are used to segment jobseekers in groups. Profiling models hold the potential to improve identification of jobseekers at-risk of becoming long-term unemployed, but also induce discrimination. Using a recently developed AI-based profiling model of the Flemish PES, we assess to what extent AI-based profiling ‘discriminates’ against jobseekers of foreign origin compared to traditional rule-based profiling approaches. At a maximum level of accuracy, jobseekers of foreign origin who ultimately find a job are 2.6 times more likely to be misclassified as ‘high-risk’ jobseekers. We argue that it is critical that policymakers and caseworkers understand the inherent trade-offs of profiling models, and consider the limitations when integrating these models in daily operations. We develop a graphical tool to visualize the accuracy-equity trade-off in order to facilitate policy discussions.

The shape of a defense-growth trade-off governs seasonal trait dynamics in natural phytoplankton

2018 ◽  
Author(s):  
Elias Ehrlich ◽  
Nadja J. Kath ◽  
Ursula Gaedke
Keyword(s):  
Fitness Landscape ◽  
Functional Trait ◽  
Grazing Pressure ◽  
Trait Variation ◽  
Trade Off ◽  
Community Persistence ◽  
Trade Offs ◽  
Combining Data ◽  
Persistence Theory

Functional trait compositions of communities can adapt to altered environmental conditions ensuring community persistence. Theory predicts that the shape of trade-offs between traits crucially affects these trait dynamics, but its empirical verification from the field is missing. Here, we show how the shape of a defense-growth trade-off governs seasonal trait dynamics of a natural community, using high-frequency, long-term measurements of phytoplankton from Lake Constance. As expected from the lab-derived concave trade-off curve, we observed an alternating dominance of several fast-growing species with intermediate defense levels and gradual changes of the biomass-trait distribution due to seasonally changing grazing pressure. By combining data and modelling, we obtain mechanistic insights on the underlying fitness landscape, and show that low fitness differences can maintain trait variation along the trade-off curve. We provide firm evidence for a frequently assumed trade-off and conclude that quantifying its shape allows to understand environmentally driven trait changes within communities.

Are speed/accuracy trade-offs caused by neuromotor noise, or not?

1997 ◽  
Vol 20 (2) ◽  
pp. 306-307 ◽  
Author(s):  
Willem P. De Jong ◽  
Gerard P. Van Galen
Keyword(s):  
Kinematic Model ◽  
Psychological Processes ◽  
Trade Off ◽  
Kinematic Theory ◽  
Trade Offs ◽  
Biomechanical Constraints ◽  
Speed Accuracy ◽  
Existing Data ◽  
The Way

Notwithstanding its overwhelming descriptive power for existing data, it is not clear whether the kinematic theory of Plamondon & Alimi could generate new insights into biomechanical constraints and psychological processes underlying the way organisms trade off speed for accuracy. The kinematic model should elaborate on the role of neuromotor noise and on biomechanical strategies for reducing endpoint variability related to such noise.

ACCELERATING HIGH INVOLVEMENT: THE ROLE OF NEW TECHNOLOGIES IN ENABLING EMPLOYEE PARTICIPATION IN INNOVATION

2013 ◽  
Vol 17 (06) ◽  
pp. 1340020 ◽  
Author(s):  
NAGWAN ABU EL-ELLA ◽  
MARTIN STOETZEL ◽  
JOHN BESSANT ◽  
ANDREAS PINKWART
Keyword(s):  
Social Networks ◽  
Learning Curve ◽  
Transaction Costs ◽  
New Technologies ◽  
Early Experience ◽  
Trade Off ◽  
High Involvement ◽  
New Approaches

The experience of implementing employee involvement in innovation can be viewed as a bounded opportunity. Whilst long-term strategic benefits could flow from organising participation across the workforce, creating structures that sustain such a culture is highly complex. In effect the "transaction costs" of high involvement innovation limit its implementation. However a number of technological and social developments (such as innovation platforms and company social networks) offer new options in this space which may change this. In particular the "reach" and "richness" trade-off could be changed to permit higher levels of participation in larger-scale projects. Much depends on the ways in which implementation of systems deploying these new approaches is undertaken and the development of appropriate behavioural routines to support them. This paper explores a number of cases within German enterprises and reports early experience along this learning curve.

Neuropsychological Investigations of Human Amnesia: Insights Into the Role of the Medial Temporal Lobes in Cognition

2017 ◽  
Vol 23 (9-10) ◽  
pp. 732-740 ◽  
Author(s):  
Mieke Verfaellie ◽  
Margaret M. Keane
Keyword(s):  
Long Term Memory ◽  
Medial Temporal Lobes ◽  
Theoretical Understanding ◽  
Temporal Lobes ◽  
The Past ◽  
Clinical Disorders ◽  
Nuanced Understanding ◽  
The One

AbstractThe past 30 years of research on human amnesia has yielded important changes in our understanding of the role of the medial temporal lobes (MTL) in memory. On the one hand, this body of evidence has highlighted that not all types of memory are impaired in patients with MTL lesions. On the other hand, this research has made apparent that the role of the MTL extends beyond the domain of long-term memory, to include working memory, perception, and future thinking. In this article, we review the discoveries and controversies that have characterized this literature and that set the stage for a new conceptualization of the role of the MTL in cognition. This shift toward a more nuanced understanding of MTL function has direct relevance for a range of clinical disorders in which the MTL is implicated, potentially shaping not only theoretical understanding but also clinical practice. (JINS, 2017, 23, 732–740)

scholarly journals Injury alters motivational trade-offs in calves during the healing period

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah J. J. Adcock ◽  
Cassandra B. Tucker
Keyword(s):  
Startle Response ◽  
Risk Avoidance ◽  
Motivational State ◽  
Trade Off ◽  
Milk Bottle ◽  
Trade Offs ◽  
Long Term Changes ◽  
Motivational Changes ◽  
Time Since Injury

AbstractInjury can produce long-lasting motivational changes that may alter decisions made under risk. Our objective was to determine whether a routine painful husbandry procedure, hot-iron disbudding, affects how calves trade off risk avoidance against a competing motivation (i.e., feeding), and whether this response depends on time since injury. We used a startle test to evaluate this trade-off in calves disbudded 0 or 21 days previously and non-injured control calves. For 3 days, calves were individually habituated to the testing arena in which they received a 0.5 L milk meal via a rubber teat. On the 4thday, upon approaching the milk reward, the calf was startled by a sudden noise. We assessed the duration and magnitude of the calf’s startle response, their latency to return to the milk bottle, and duration spent suckling after startling. No treatment differences were observed in the duration and magnitude of the startle response or in the probability of returning to the bottle after startling. However, among those who did return, disbudded calves spent longer suckling, indicating they accepted more risk in order to feed compared to controls. In addition, calves with 21-day-old injuries tended to return to the bottle faster compared to newly disbudded calves and controls. We suggest that hot-iron disbudding increases calves’ motivation to suckle, as they were more likely to prioritize this behaviour over risk avoidance compared to control calves. This effect was most evident 21 days after disbudding, indicating that injury can produce long-term changes in motivational state.

scholarly journals Herbivore Population Dynamics in Response to Plant Allocation Strategies

2021 ◽  
Author(s):  
Fang Ji ◽  
Christopher R Stieha ◽  
Karen C Abbott
Keyword(s):  
Food Limitation ◽  
Energetic Cost ◽  
Insect Herbivores ◽  
Insect Outbreaks ◽  
Tolerance Mechanisms ◽  
Trade Off ◽  
Trade Offs ◽  
Plant Allocation ◽  
Allocation Strategies

Abstract When herbivores feed, plants may respond by altering the quantity of edible biomass available to future feeders through mechanisms such as compensatory regrowth of edible structures or allocation of biomass to inedible reserves. Previous work showed that some forms of compensatory regrowth can drive insect outbreaks, but this work assumed regrowth occurred without any energetic cost to the plant. While this is a useful simplifying assumption for gaining preliminary insights, plants face an inherent trade-off between allocating energy to regrowth versus storage. Therefore, we cannot truly understand the role of compensatory regrowth in driving insect outbreaks without continuing on to more realistic scenarios. In this paper, we model the interaction between insect herbivores and plants that have a trade-off between compensatory regrowth and allocation to inedible reserves in response to herbivory. We found that the plant's allocation strategy, described in our model by parameters representing the strength of the overcompensatory response and the rates at which energy is stored and mobilized for growth, strongly affect whether herbivore outbreaks occur. Additional factors, such as the strength of food limitation and herbivore interference while feeding, influence the frequency of the outbreaks. Overall, we found a possible new role of overcompensation to promote herbivore fluctuations when it co-occurs with allocation to inedible reserves. We highlight the importance of considering trade-offs between tolerance mechanisms that plants use in response to herbivory by showing that new dynamics arise when different plant allocation strategies occur simultaneously.

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