scholarly journals A motion compensation treadmill for untethered wood ants (Formica rufa): evidence for transfer of orientation memories from free-walking training

2020 ◽  
Vol 223 (24) ◽  
pp. jeb228601
Author(s):  
Roman Goulard ◽  
Cornelia Buehlmann ◽  
Jeremy E. Niven ◽  
Paul Graham ◽  
Barbara Webb
Keyword(s):  
Motion Compensation ◽  
Laboratory Experiments ◽  
Formica Rufa ◽  
Insect Navigation ◽  
Wood Ants ◽  
Long Time ◽  
Controlled Environments ◽  
Freely Moving ◽  
Time Frames ◽  
Natural Scale

ABSTRACTThe natural scale of insect navigation during foraging makes it challenging to study under controlled conditions. Virtual reality and trackball setups have offered experimental control over visual environments while studying tethered insects, but potential limitations and confounds introduced by tethering motivates the development of alternative untethered solutions. In this paper, we validate the use of a motion compensator (or ‘treadmill’) to study visually driven behaviour of freely moving wood ants (Formica rufa). We show how this setup allows naturalistic walking behaviour and preserves foraging motivation over long time frames. Furthermore, we show that ants are able to transfer associative and navigational memories from classical maze and arena contexts to our treadmill. Thus, we demonstrate the possibility to study navigational behaviour over ecologically relevant durations (and virtual distances) in precisely controlled environments, bridging the gap between natural and highly controlled laboratory experiments.

scholarly journals Transfer of orientation memories in untethered wood ants (Formica rufa) from walking in an arena to walking on a motion compensation treadmill

2020 ◽  
Author(s):  
Roman Goulard ◽  
Cornelia Buehlmann ◽  
Jeremy E. Niven ◽  
Paul Graham ◽  
Barbara Webb
Keyword(s):  
Motion Compensation ◽  
Laboratory Experiments ◽  
Insect Brain ◽  
Experimental Control ◽  
Formica Rufa ◽  
Insect Navigation ◽  
Wood Ants ◽  
Controlled Environments ◽  
Summary Statement ◽  
Freely Moving

AbstractThe scale of natural insect navigation during foraging makes it challenging to study, in a controlled way, the navigation processes that an insect brain can support. Virtual Reality and trackball setups have offered experimental control over visual environments while studying tethered insects, but potential limitations and confounds introduced by tethering motivates the development of alternative untethered solutions. In this paper we validate the use of a motion compensator (or ‘treadmill’) to study visually-driven behaviour of freely moving wood ants (Formica rufa). We show how this setup allows naturalistic walking behaviour and motivation over long timeframes. Furthermore, we show that ants are able to transfer associative and navigational memories from classical maze and arena contexts to our treadmill. Thus, we demonstrate the possibility to study navigational behaviour over ecologically relevant durations (and virtual distances) in precisely controlled environments, bridging the gap between natural and highly controlled laboratory experiments.1Summary statementWe have developed and validated a motion compensating treadmill for wood ants which opens new perspectives to study insect navigation behaviour in a fully controlled manner over ecologically relevant durations.

scholarly journals What Influences Customer Satisfaction When? Product and Service Over Time

2016 ◽  
Vol 8 (3) ◽  
pp. 45 ◽  
Author(s):  
Shueh-Chin Ting
Keyword(s):  
Customer Satisfaction ◽  
Service Performance ◽  
Customer Relationship ◽  
Long Time ◽  
Curvilinear Relationships ◽  
Short Time ◽  
Time Frames ◽  
Post Purchase ◽  
Product Weight ◽  
Over Time

<p>Though researchers have examined the changes in the effects of product and service performance on customer satisfaction, the short time frames of most studies prevents deeper understanding of this relationship. This study collects information from pre-purchase to 15 years post-purchase from 11,056 potential and existing automobile customers in the Taiwan market. The data is analyzed by a regression model. Results reveal that the importance of both product and service performance change over long time and the long-term trends of product and service performance weights are non-linear. In addition, from pre-purchase to the second year post-purchase, service weight is higher than product weight, but after the third year, product weight exceeds service weight. Product and service weight on customer satisfaction over time exhibit curvilinear relationships. Therefore, which one of product or service a company should stress depends on the stage in the customer relationship.</p>

scholarly journals A 2-DIMENSIONAL CELLULAR AUTOMATON FOR AGENTS MOVING FROM ORIGINS TO DESTINATIONS

2005 ◽  
Vol 16 (12) ◽  
pp. 1849-1860 ◽  
Author(s):  
NAJEM MOUSSA
Keyword(s):  
Cellular Automaton ◽  
Cluster Size ◽  
Bimodal Distribution ◽  
Minimal Distance ◽  
Time Step ◽  
Neighbor Site ◽  
Model Dynamics ◽  
Long Time ◽  
Freely Moving ◽  
Small Clusters

We develop a two-dimensional cellular automaton (CA) as a simple model for agents moving from origins to destinations. Each agent moves towards an empty neighbor site corresponding to the minimal distance to its destination. The stochasticity or noise (p) is introduced in the model dynamics, through the uncertainty in estimating the distance from the destination. The friction parameter "μ" is also introduced to control the probability that movement of all involved agents to the same site (conflict) is denied at each time step. This model displays two states; namely the freely moving and the jamming state. If μ is large and p is low, the system is in the jamming state even if the density is low. However, if μ is large and p is high, a freely moving state takes place whenever the density is low. The cluster size and the travel time distributions in the two states are studied in detail. We find that only very small clusters are present in the freely moving state, while the jamming state displays a bimodal distribution. At low densities, agents can take a very long time to reach their destinations if μ is large and p is low (jamming state); but long travel times are suppressed if p becomes large (freely moving state).

scholarly journals Turbulent Simulation of the Flow around Different Positions of Mussel Shocks

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 574
Author(s):  
George Pechlivanidis ◽  
Evangelos Keramaris ◽  
Yiannis Savvidis
Keyword(s):  
Significant Role ◽  
Laboratory Experiments ◽  
Central Axis ◽  
Velocity Measurements ◽  
Mussel Farming ◽  
Natural Scale

This study presents the results of laboratory experiments that were performed to simulate the positions of mussel shocks which were selected aiming at the optimization of the quality of mussels’ production in mussel farming areas. The mussel shocks were studied in natural scale. Velocity measurements were taken upstream of two successive mussel shocks and for different positions in relation to the central axis of the channel and different distances between the shocks for three different mean velocities. Based on the results of several numbers of experiments, the main conclusion of this study was that the position and the distance between the mussel shocks play a significant role to the quality of mussels’ production in mussel farming areas. This is due to the fact that the different distances between the mussel shocks influence the velocities and the eddies around them.

scholarly journals Fight tactics in wood ants: individuals in smaller groups fight harder but die faster

2011 ◽  
Vol 278 (1722) ◽  
pp. 3243-3250 ◽  
Author(s):  
Tim P. Batchelor ◽  
Mark Briffa
Keyword(s):  
Group Size ◽  
Negative Influence ◽  
Resource Holding Potential ◽  
Attrition Rates ◽  
Formica Rufa ◽  
Wood Ants ◽  
Social Animals ◽  
Group Members ◽  
Per Capita ◽  
The Individual

When social animals engage in inter-group contests, the outcome is determined by group sizes and individual masses, which together determine group resource-holding potential (‘group RHP’). Individuals that perceive themselves as being in a group with high RHP may receive a motivational increase and increase their aggression levels. Alternatively, individuals in lower RHP groups may increase their aggression levels in an attempt to overcome the RHP deficit. We investigate how ‘group RHP’ influences agonistic tactics in red wood ants Formica rufa . Larger groups had higher total agonistic indices, but per capita agonistic indices were highest in the smallest groups, indicating that individuals in smaller groups fought harder. Agonistic indices were influenced by relative mean mass, focal group size, opponent group size and opponent group agonistic index. Focal group attrition rates decreased as focal group relative agonistic indices increased and there was a strong negative influence of relative mean mass. The highest focal attrition rates were received when opponent groups were numerically large and composed of large individuals. Thus, fight tactics in F. rufa seem to vary with both aspects of group RHP, group size and the individual attributes of group members, indicating that information on these are available to fighting ants.

scholarly journals Speech can produce jet-like transport relevant to asymptomatic spreading of virus

2020 ◽  
Vol 117 (41) ◽  
pp. 25237-25245 ◽  
Author(s):  
Manouk Abkarian ◽  
Simon Mendez ◽  
Nan Xue ◽  
Fan Yang ◽  
Howard A. Stone
Keyword(s):  
Social Interactions ◽  
Disease Transmission ◽  
Laboratory Experiments ◽  
Scaling Laws ◽  
Mitigation Strategies ◽  
Directed Transport ◽  
Transport Distance ◽  
Long Time ◽  
Phonetic Features

Many scientific reports document that asymptomatic and presymptomatic individuals contribute to the spread of COVID-19, probably during conversations in social interactions. Droplet emission occurs during speech, yet few studies document the flow to provide the transport mechanism. This lack of understanding prevents informed public health guidance for risk reduction and mitigation strategies, e.g., the “6-foot rule.” Here we analyze flows during breathing and speaking, including phonetic features, using orders-of-magnitude estimates, numerical simulations, and laboratory experiments. We document the spatiotemporal structure of the expelled airflow. Phonetic characteristics of plosive sounds like “P” lead to enhanced directed transport, including jet-like flows that entrain the surrounding air. We highlight three distinct temporal scaling laws for the transport distance of exhaled material including 1) transport over a short distance (<0.5 m) in a fraction of a second, with large angular variations due to the complexity of speech; 2) a longer distance, ∼1 m, where directed transport is driven by individual vortical puffs corresponding to plosive sounds; and 3) a distance out to about 2 m, or even farther, where sequential plosives in a sentence, corresponding effectively to a train of puffs, create conical, jet-like flows. The latter dictates the long-time transport in a conversation. We believe that this work will inform thinking about the role of ventilation, aerosol transport in disease transmission for humans and other animals, and yield a better understanding of linguistic aerodynamics, i.e., aerophonetics.

Seasonal Changes in Sugar and Amino Acid Preference in Red Wood Ants of The Formica rufa Group

Sociobiology ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 144
Author(s):  
Natalia E.L. Madsen ◽  
Joachim Offenberg
Keyword(s):  
Amino Acid ◽  
Seasonal Changes ◽  
Food Sources ◽  
Individual Species ◽  
Sugar Solution ◽  
Formica Rufa ◽  
Red Wood Ants ◽  
Wood Ants ◽  
Formica Rufa Group ◽  
Mutualistic Relationship

Red wood ants of the Formica rufa group are important ecosystem engineers throughout the Northern Hemisphere with potential to be commercially produced and used as predatory agents in biological control programs. However, in order to do that, their mutualistic relationship with aphids needs to be disrupted. This may be achieved by developing artificial sugar-based solutions with a composition that makes them more attractive than aphid honeydew. The present field study investigated Formica rufa’s preference for several sugar and amino acid sources, as well as potential seasonal changes in these preferences. Red wood ants consistently preferred sucrose to monosaccharides and were most attracted to solutions containing an amino acid source, albeit seasonal differences were observed with regard to which amino acid sources were most preferred. Recruitment to offered sugar solutions was highest during July, when colony requirements were high, and during October, when alternative food sources were scarce. Since ant preference for sugar solution constituents seems to be species-specific and show seasonal dynamics, artificial food aimed at disrupting ant-aphid mutualisms should be tailored to individual species and seasons.

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