scholarly journals Foraging behavior across paths that vary in risk cues and frequency of occurrence

2019 ◽  
Author(s):  
Emily K. Lessig ◽  
Peter Nonacs
Keyword(s):  
Food Sources ◽  
Frequency Of Occurrence ◽  
Complex Environments ◽  
Argentine Ants ◽  
Dear Enemy ◽  
Multiple Paths ◽  
Foraging Site ◽  
Foraging Ability ◽  
Defensive Chemical ◽  
Over Time

AbstractCooperatively foraging species often adjust their search strategies in complex environments to efficiently find and exploit food sources. These strategies become more complicated when food and risk can be simultaneously present and when they differ in predictability. For example, there may be multiple paths to reach a foraging site that vary in risk. This study examines how colonies of Argentine ants (Linepithema humile) respond to such a situation where identical-length paths differ in how they present risk. The risk cues are either a live competitor (velvety tree ants, Liometopum occidentale (LO)) or formic acid (FA), a defensive chemical commonly associated with formicine ant species. Across four paths to food, the presence of cues also varied from always to never present. Although the non-risky path was used more often, in no case did colonies completely avoid the paths with risk. Overall, more L. humile workers explored paths associated with LO than with FA. This had a significant impact on foraging ability where LO colonies were faster at finding food than FA colonies. Further, L. humile workers’ response to FA was similar over time while declined for LO, suggesting a ‘dear enemy’ habituation and reduction in aggression over time. Thus, it appears that L. humile foragers categorize risk cues and will vary their responses in potentially effective ways.

scholarly journals Agri-food Exports and Challenges of Foreign Markets for a Small region: a Network Approach

2021 ◽  
Vol 17 (2) ◽  
pp. 607-618
Author(s):  
Roberta Sisto ◽  
Alba Marseglia ◽  
Edgardo Sica
Keyword(s):  
Small And Medium Enterprises ◽  
Research Question ◽  
Small Region ◽  
Complex Environments ◽  
Trade Patterns ◽  
Essential Condition ◽  
Eu Countries ◽  
Depth Analysis ◽  
Medium Enterprises ◽  
Over Time

Over the last decades, the agri-food sector has been involved in a substantial process of internationalisation. For many agri-food firms, internationalisation has become a significant element of competitiveness and an essential condition for their survival and success in spite of the possible initial difficulties in competing and organising activities in uncertain and complex environments. These challenges concern mainly agri-food small and medium enterprises (SMEs) that, due to their size, are in a more vulnerable position in relation to trade barriers compared to larger firms. Based on these premises, we investigated the structure of the agrifood exports of a small region by exploring its characteristics and evolution over time. While this research is relevant per sé, it can also explain the macroeconomic dynamics of the whole area and determine the further development of agri-food exports of a small region to non-EU countries. The analysis concentrates on exports to extra-EU countries from agri-food firms located in the province of Foggia (the south-east of Italy), a small area characterised by a large presence of SMEs and micro firms that are mainly devoted to agricultural production and food processing. To answer the research question, we employ the social network analysis, a method increasingly used for analysing international trade patterns. The use of this methodology has allowed us to conduct an in-depth analysis of firms and countries that occupy a strategic position in the network. These actors are crucial for the network’s survival since their removal could make the network more fragmented and disconnected. The analysis has been conducted in a dynamic way by exploring the characteristics of the network in 2014–2019, allowing us to assess its evolution over time. The results show that the structural properties of the analysed network have remarkably enhanced over time. However, the current network structure is not satisfactory yet since it relies, for the most part, on the connections among a few leading firms and a limited number of destination countries.

Hermies-III: A step toward autonomous mobility, manipulation and perception

Robotica ◽  
1990 ◽  
Vol 8 (1) ◽  
pp. 7-12 ◽  
Author(s):  
C. R. Weisbin ◽  
B. L. Burks ◽  
J. R. Einstein ◽  
R. R. Feezell ◽  
W. W. Manges ◽  
...  
Keyword(s):  
Sensory Information ◽  
Experimental Program ◽  
Laser Range Finder ◽  
Complex Environments ◽  
Ongoing Research ◽  
Human Scale ◽  
Multiple Paths ◽  
Cooperating Robots ◽  
Autonomous Mobility ◽  
Effective Use

SUMMARYHERMIES-III is an autonomous robot comprised of a seven degree-of-freedom (DOF) manipulator designed for human scale tasks, a laser range finder, a sonar array, an omnidirectional wheel-driven chassis, multiple cameras, and a dual computer system containing a 16-node hypercube expandable to 128 nodes. The current experimental program involves performance of human-scale tasks (e.g., valve manipulation, use of tools), integration of a dexterous manipulator and platform motion in geometrically complex environments, and effective use of multiple cooperating robots (HERMIES-IIB and HERMIES-III). The environment in which the robots operate has been designed to include multiple valves, pipes, meters, obstacles on the floor, valves occluded from view, and multiple paths of differing navigation complexity. The ongoing research program supports the development of autonomous capability for HERMIES-IIB and III to perform complex navigation and manipulation under time constraints, while dealing with imprecise sensory information.

scholarly journals Sea turtle diving and foraging behaviour around the Greek Island of Kefalonia

2000 ◽  
Vol 80 (4) ◽  
pp. 761-762 ◽  
Author(s):  
Jonathan D.R. Houghton ◽  
Andrew Woolmer ◽  
Graeme C. Hays
Keyword(s):  
Foraging Behaviour ◽  
Mytilus Galloprovincialis ◽  
Posidonia Oceanica ◽  
Sea Turtle ◽  
Bivalve Mollusc ◽  
Food Sources ◽  
Neutral Buoyancy ◽  
Sea Grass ◽  
Foraging Site ◽  
Greek Island

The discovery of a shallow water (<2 m) foraging site off the Greek Island of Kefalonia, where diving and foraging behaviour of male loggerhead turtles (Caretta caretta) could be observed simultaneously, was of great interest. The preferred food sources were shown to be the bivalve mollusc Mytilus galloprovincialis, the sea grass Posidonia oceanica, and the entrails of fish discarded by local fishermen. Whilst foraging, the turtles generally rested on the seabed and employed their forelimbs to clear away detritus from their selected prey. Foraging dives were of short duration (mean ±SE = 2.3 ±0.43 min, N=96) compared to deeper dives reported in the literature presumably, because of the small lung volumes required to attain neutral buoyancy at such shallow depths.

scholarly journals Dynamics and variability in the pleiotropic effects of adaptation in laboratory budding yeast populations

2021 ◽  
Author(s):  
Christopher W Bakerlee ◽  
Angela M Phillips ◽  
Alex N Nguyen Ba ◽  
Michael M Desai
Keyword(s):  
Budding Yeast ◽  
Pleiotropic Effects ◽  
Evolutionary Adaptation ◽  
Complex Environments ◽  
Space And Time ◽  
Constant Environment ◽  
Fluctuating Environments ◽  
Evolutionary Trajectories ◽  
Multiple Environments ◽  
Over Time

Evolutionary adaptation to a constant environment is driven by the accumulation of mutations which can have a range of unrealized pleiotropic effects in other environments. These pleiotropic consequences of adaptation can influence the emergence of specialists or generalists, and are critical for evolution in temporally or spatially fluctuating environments. While many experiments have examined the pleiotropic effects of adaptation at a snapshot in time, very few have observed the dynamics by which these effects emerge and evolve. Here, we propagated hundreds of diploid and haploid laboratory budding yeast populations in each of three environments, and then assayed their fitness in multiple environments over 1000 generations of evolution. We find that replicate populations evolved in the same condition share common patterns of pleiotropic effects across other environments, which emerge within the first several hundred generations of evolution. However, we also find dynamic and environment-specific variability within these trends: variability in pleiotropic effects tends to increase over time, with the extent of variability depending on the evolution environment. These results suggest shifting and overlapping contributions of chance and contingency to the pleiotropic effects of adaptation, which could influence evolutionary trajectories in complex environments that fluctuate across space and time.

scholarly journals The influence of semiochemicals on the co-occurrence patterns of a global invader and native species

2021 ◽  
Author(s):  
◽  
Fabian Westermann
Keyword(s):  
Chemical Communication ◽  
Argentine Ant ◽  
Food Sources ◽  
Large Field ◽  
Pest Species ◽  
Foraging Success ◽  
Resident Species ◽  
Argentine Ants ◽  
Invasive Ant ◽  
Introduced Range

<p>The success of invasive species in their introduced range is often influenced by interactions with resident species communities. Chemical communication is one the factors which contributes to a variety of aspects of a species life cycle, ranging from mating, to food localization and interactions with members of the same and other species. In my thesis, I investigate the effects of venoms and semiochemicals on interactions between the invasive Argentine ant (Linepethima humile) with other resident ant species and demonstrate how pheromones can potentially be utilized as an area wide control mechanism of this species, by disrupting their foraging success.  I studied the effects of venom composition, their toxicity and utilization on the outcome of aggressive interactions between the Argentine ant and the four Monomorium species in New Zealand occurring. The toxicity of the venom of the two species co-occurring with Argentine ants was significantly higher than the toxicity of the species which do not. However, no correlation between venom toxicity and Monomorium survival was found. For M. antipodum a significant relationship between venom utilization and its mortality was found, indicating that the way venom is used might be an important aspect of these interactions. Physical Aggression between Monomorium and Argentine ants also had strong effects on Monomorium worker mortality, which provided evidence that a variety of factors and strategies contribute to the ability of interacting organisms to withstand the pressure of a dominant invader at high abundance.  I conducted bioassays with food sources and synthetic trail pheromones, providing a proof of concept on disrupting the foraging ability of Argentine ants. Other resident species benefited from the reduced success of Argentine ants, but to a varying degree. Behavioural variations between the resident species provided an explanation for observed differences in foraging success and how much each of these individual competitors was able to increase their foraging. The mechanism for the observed increase in resource acquisition of resident species appeared to be a decrease in aggressive behaviour displayed by Argentine ants.  I expanded the usage of the synthetic pheromone to a commercial vineyard, were Argentine ants can have negative effects on crop development by dispersing and tending to homopteran pest species. Argentine ants’ access to the crop canopy could be significantly reduced by placing pheromone dispensers at the base of the vine plant, while dispensers in the plant canopy had little effect on Argentine ant numbers. Doubling the amount of pheromone did not result in an additional reduction of ant activity.   Lastly incorporating the knowledge gained in the previous chapter, I extended the application of the pheromone to a large field trial over a three month period. Argentine ant activity and foraging success was significantly supressed compared to untreated control plots, providing evidence that this form of large scale application might be a possible way to control large invasive ant populations by disrupting their trail following and foraging behaviour for a prolonged period of time. While initial calculations have suggested that the treatment is currently not feasible (13.3 US$/mg/ha), I found a significant reduction in body fat in workers collected from treated plots compared with untreated plots, suggesting adverse effects on nest fitness.  My findings provide new insights into chemical communication between invasive and resident species, support existing dominance hierarchy models in ant populations, and help to establish a target specific potential management technique of wide-spread invasive ant species.</p>

BIBLICAL PHRASEOLOGY IN CNN PUBLICATIONS

2020 ◽  
pp. 94-103
Author(s):  
Tatyana Yu. MA ◽  
◽  
SERGEY V. BOBROV ◽  
NATALYA M. ZALESOVA ◽  
◽  
...  
Keyword(s):  
Native Speakers ◽  
Frequency Of Occurrence ◽  
Original Source ◽  
Second Stage ◽  
The Bible ◽  
Associative Connection ◽  
Over Time

This paper presents the results of the study of biblical phraseological units (BPUs) found in CNN publications during the period of 2015-2019 (the total of 1643 articles). At the first stage of the experiment, the analysis of 156 BPUs used in the articles demonstrated different distribution of the tokens in CNN rubrics. It was discovered that BPUs in the rubrics “Politics” and “Entertainment” were characterized by considerably higher frequency of occurrence than those in “Style” and “Sports”. At the second stage, specifically designed questionnaire was given to 30 American native speakers to determine the perceptual boundaries of the Bible words. The obtained data revealed indirect correlation between phraseological units frequency of occurrence and the American speakers’ awareness degree of their associative connection with the original source - the Bible: the higher the awareness, the lower the frequency of occurrence. The obtained results enable to assume that the readers do not always identify these units as part of the Holy Scripture, because some BPUs lose their sacred connotations over time. However, journalists often use such units as stylistic means due to their imaginative stylistic and evaluation potential.

scholarly journals Effects of age and reproductive status on individual foraging site fidelity in a long-lived marine predator

2017 ◽  
Vol 284 (1859) ◽  
pp. 20171068 ◽  
Author(s):  
Stephen C. Votier ◽  
Annette L. Fayet ◽  
Stuart Bearhop ◽  
Thomas W. Bodey ◽  
Bethany L. Clark ◽  
...  
Keyword(s):  
Site Fidelity ◽  
Foraging Strategies ◽  
Common Component ◽  
Small Component ◽  
Phenotypic Differences ◽  
Marine Predator ◽  
Global Positioning ◽  
Foraging Site ◽  
Foraging Ability ◽  
Foraging Specialization

Individual foraging specializations, where individuals use a small component of the population niche width, are widespread in nature with important ecological and evolutionary implications. In long-lived animals, foraging ability develops with age, but we know little about the ontogeny of individuality in foraging. Here we use precision global positioning system (GPS) loggers to examine how individual foraging site fidelity (IFSF), a common component of foraging specialization, varies between breeders, failed breeders and immatures in a long-lived marine predator—the northern gannet Morus bassanus . Breeders (aged 5+) showed strong IFSF: they had similar routes and were faithful to distal points during successive trips. However, centrally placed immatures (aged 2–3) were far more exploratory and lacked route or foraging site fidelity. Failed breeders were intermediate: some with strong fidelity, others being more exploratory. Individual foraging specializations were previously thought to arise as a function of heritable phenotypic differences or via social transmission. Our results instead suggest a third alternative—in long-lived species foraging sites are learned during exploratory behaviours early in life, which become canalized with age and experience, and refined where possible—the exploration-refinement foraging hypothesis. We speculate similar patterns may be present in other long-lived species and moreover that long periods of immaturity may be a consequence of such memory-based individual foraging strategies.

scholarly journals The Effects of Team Mental Model Complexity on Team Information Search and Performance Trajectories

2021 ◽  
pp. 105960112110232
Author(s):  
Sjir Uitdewilligen ◽  
Mary J. Waller ◽  
Robert A. Roe ◽  
Peter Bollen
Keyword(s):  
Information Search ◽  
Business Strategy ◽  
Mental Model ◽  
Longitudinal Research ◽  
Model Complexity ◽  
Complex Environments ◽  
And Performance ◽  
Team Mental Model ◽  
Model Similarity ◽  
Over Time

Drawing on the concept of requisite complexity, we propose that mental model complexity is crucial for teams to thrive in dynamic complex environments. Using a longitudinal research design, we examined the influence of team mental model complexity on team information search and performance trajectories in a sample of 64 teams competing in a business strategy simulation over time. We found that team information search positively influences performance growth over time. More specifically, and consistent with requisite complexity, we found that mental model complexity positively influences both performance growth and information search over time, above and beyond the effects of mental model similarity and accuracy.

scholarly journals The Relationship of the Components of the "I"-Image with the Mental States of Students in the Process of Studying over Time

2021 ◽  
Author(s):  
Marina Evgen'evna Valiullina ◽  
Irina Sergeevna Reshetnikova
Keyword(s):  
Correlation Analysis ◽  
University Students ◽  
Mental States ◽  
Frequency Of Occurrence ◽  
The Past ◽  
High Level ◽  
Relationship Of ◽  
The Relationship ◽  
Time Continuum ◽  
Over Time

The study is devoted to the study of the structure of the interconnections of the components of the "I" -image of students with the various mental states they experience in the context of studying at a university. Students determined the severity of the components of the "I" -image in three time continua - in the past (1st year), in the present (3rd year), in the future (4th year). They also determined the frequency of occurrence of mental states during the first two years of study using a special questionnaire. Then a correlation analysis was carried out, which made it possible to find relationships with a high level of reliability between the components of the "I" -image of students and some mental states experienced in two educational situations, which differ qualitatively depending on the time continuum. Based on the results obtained, conclusions were drawn about the presence of relationships, thanks to which it is possible to exert a certain influence on the experienced mental sta

scholarly journals Tracing multisensory food experiences on Twitter

2021 ◽  
Vol 6 (2) ◽  
pp. 181-212 ◽  
Author(s):  
Maija Kāle ◽  
Jurģis Šķilters ◽  
Matīss Rikters
Keyword(s):  
Social Media ◽  
Research Field ◽  
Frequency Of Occurrence ◽  
Potential Utility ◽  
Human Food ◽  
Food Items ◽  
Food Experience ◽  
Food And Drink ◽  
Multisensory Experience ◽  
Over Time

How a food, or a dish, is named and how its components and attributes are described can all influence the perception and the enjoyment of the food. Therefore, tracing patterns in food descriptions and determining their role can be of value. The aims of this study were the following: (1) to describe the multisensory food experience as represented in microblog entries concerning food and drink on Twitter, (2) to provide an overview of the changes in the above-mentioned food representations during the period 2011–20, and (3) to contribute to a broader understanding of the human–food relationship as reflected on social media – in this case Twitter – and outline its potential utility for the research field of gastrophysics. The combinations of various multisensory attributes co-occurring in a tweet (which we term ‘collocations’) found in the Twitter corpus were examined through the categories of texture, colour, taste, smell/odour, shape and sound. We mapped the collocations of the 20–25 most frequently mentioned food items and their multisensory experience pairings over time. Such time-based knowledge led to a better understanding of the multisensory experience triggers as reflected on Twitter. By analysing the multisensory experience’s frequency of occurrence, we could conclude that the category of colour is the dominant one, while textural, olfactory and auditory collocations with food are rare. In most of the cases, food tweets appear to render a food experience ‘tasty’, ‘good’ and ‘interesting’.

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