scholarly journals Rufous-and-white wrens Thryophilus rufalbus do not exhibit a dear enemy effects towards conspecific or heterospecific competitors

2015 ◽  
Vol 61 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Matthew M. Battiston ◽  
David R. Wilson ◽  
Brendan A. Graham ◽  
Kristin A. Kovach ◽  
Daniel J. Mennill
Keyword(s):  
Experimental Approach ◽  
Shared Resources ◽  
Dear Enemy ◽  
Wide Range ◽  
Dear Enemy Effect

Abstract Many territorial animals exhibit reduced aggression towards neighbours. Known as “the dear enemy effect”, this phenomenon has been documented among conspecific animals across a wide range of animal taxa. In theory, the dear enemy effect can also exist between individuals of different species, particularly when those species compete for shared resources. To date, a heterospecific dear enemy effects has only been documented in ants. In this study, we test for both a conspecific and heterospe-cific dear enemy effect in neotropical rufous-and-white wrens Thryophilus rufalbus. This species competes for resources with banded wrens Thryophilus pleurostictus, a closely related sympatric congener. We used acoustic playback to simulate ruf-ous-and-white wren and banded wren neighbours and non-neighbours at the edges of rufous-and-white wren territories. Ruf-ous-and-white wrens responded more strongly to signals from their own species, demonstrating that resident males discriminate between conspecific and heterospecific rivals. They did not, however, exhibit a conspecific dear enemy effect. Further, they did not exhibit a heterospecific dear enemy effect. This could be due to neighbours and non-neighbours posing similar levels of threat in this system, to the possibility that playback from the edges of the subjects’ large territories did not simulate a threatening signal, or to other factors. Our study provides the first test of a heterospecific dear enemy effect in vertebrates, and presents a valuable experimental approach for testing for a heterospecific dear enemy effect in other animals.

scholarly journals Prediction of Experimental Electromagnetic Coupling to a UAV Model Using Characteristic Mode Analysis

2021 ◽  
Author(s):  
Mohamed Hamdalla ◽  
Benjamin Bissen ◽  
James D. Hunter ◽  
Liu Yuanzhuo ◽  
Victor Khilkevich ◽  
...  
Keyword(s):  
Experimental Measurement ◽  
Experimental Approach ◽  
Electromagnetic Coupling ◽  
Mode Analysis ◽  
Angle Of Incidence ◽  
Characteristic Mode ◽  
System A ◽  
Wide Range ◽  
Aerial Vehicle ◽  
Excitation Conditions

<p>In this work, we study the current coupled to a simplified Unmanned Aerial Vehicle (UAV) model using a dual computational and experimental approach. The surrogate structure reduced the computational burden and facilitated the experimental measurement of the coupled currents. For a practical system, a wide range of simulations and measurements must be performed to analyze the induced current variations with respect to the incident excitation properties such as the frequency, angle of incidence, and polarization. To simplify this analysis, Characteristic Mode Analysis (CMA) was used to compute the eigen-currents of the UAV model and predict where and under which RF excitation conditions, the coupled current is maximized. We verified these predictions using direct experimental measurement of the coupled currents. The presented simulations and measurements show the usefulness of CMA for studying electromagnetic coupling to practical systems. </p>

scholarly journals Prediction of Experimental Electromagnetic Coupling to a UAV Model Using Characteristic Mode Analysis

2021 ◽  
Author(s):  
Mohamed Hamdalla ◽  
Benjamin Bissen ◽  
James D. Hunter ◽  
Liu Yuanzhuo ◽  
Victor Khilkevich ◽  
...  
Keyword(s):  
Experimental Measurement ◽  
Experimental Approach ◽  
Electromagnetic Coupling ◽  
Mode Analysis ◽  
Angle Of Incidence ◽  
Characteristic Mode ◽  
System A ◽  
Wide Range ◽  
Aerial Vehicle ◽  
Excitation Conditions

<p>In this work, we study the current coupled to a simplified Unmanned Aerial Vehicle (UAV) model using a dual computational and experimental approach. The surrogate structure reduced the computational burden and facilitated the experimental measurement of the coupled currents. For a practical system, a wide range of simulations and measurements must be performed to analyze the induced current variations with respect to the incident excitation properties such as the frequency, angle of incidence, and polarization. To simplify this analysis, Characteristic Mode Analysis (CMA) was used to compute the eigen-currents of the UAV model and predict where and under which RF excitation conditions, the coupled current is maximized. We verified these predictions using direct experimental measurement of the coupled currents. The presented simulations and measurements show the usefulness of CMA for studying electromagnetic coupling to practical systems. </p>

scholarly journals Minimizing Polymorphic Risk Through Cooperative Computational and Experimental Exploration

2020 ◽  
Author(s):  
Christopher R. Taylor ◽  
Matthew T. Mulvee ◽  
Domonkos S. Perenyi ◽  
Michael R. Probert ◽  
Graeme Day ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Structure Prediction ◽  
Experimental Approach ◽  
Significant Risk ◽  
Free Energy Calculations ◽  
Crystal Structure Prediction ◽  
Crystal Forms ◽  
Wide Range ◽  
Solid Form

<div> <p>We combine state-of-the-art computational crystal structure prediction (CSP) techniques with a wide range of experimental crystallization methods to understand and explore crystal structure in pharmaceuticals and minimize the risk of unanticipated late-appearing polymorphs. Initially, we demonstrate the power of CSP to rationalize the difficulty in obtaining polymorphs of the well-known pharmaceutical isoniazid and show that CSP provides the structure of the recently discovered, but unsolved, Form III of this drug despite there being only a single known form for almost 70 years. More dramatically, our blind CSP study predicts a significant risk of polymorphism for the related iproniazid. Employing a wide variety of experimental techniques, including high-pressure experiments, we experimentally obtained the first three known non-solvated crystal forms of iproniazid, all of which were successfully predicted in the CSP procedure. We demonstrate the power of CSP methods and free energy calculations to rationalize the observed elusiveness of the third form of iproniazid, the success of high-pressure experiments in obtaining it, and the ability of our synergistic computational-experimental approach to “de-risk” solid form landscapes.</p> </div>

The Key Requirements for deploying Knowledge Management Services in a Semantic Grid Environment

2011 ◽  
pp. 363-379
Author(s):  
Mirghani Mohamed ◽  
Michael Stankosky ◽  
Vincent Ribière
Keyword(s):  
Knowledge Management ◽  
Semantic Web ◽  
Grid Computing ◽  
Information Overload ◽  
Service Model ◽  
Shared Resources ◽  
Grid Environment ◽  
Semantic Grid ◽  
Early Results ◽  
Wide Range

The purpose of this article is to investigate the requirements of knowledge management (KM) services deployment in a Semantic Grid environment. A wide range of literature on Grid Computing, Semantic Web, and KM have been reviewed, related, and interpreted. The benefits of the Semantic Web and the Grid Computing convergence have been enumerated and related to KM principles in a complete service model. Although the Grid Computing contributed the shared resources, most of the KM tool obstacles within the grid are to be resolved at the semantic and cultural levels more than at the physical or logical grid levels. The early results from academia show a synergy and the potentiality of leveraging knowledge at a wider scale. However, the plethora of information produced in this environment will result in a serious information overload, unless proper standardization, automated relations, syndication, and validation techniques are developed.

Aggression towards unfamiliar intruders by male lizards Eurolophosaurus nanuzae depends on contestant’s body traits: a test of the dear enemy effect

Behaviour ◽  
2017 ◽  
Vol 154 (6) ◽  
pp. 693-708 ◽  
Author(s):  
Eduardo C. Quintana ◽  
Conrado A.B. Galdino
Keyword(s):  
Saving Energy ◽  
Potential Threat ◽  
Dear Enemy ◽  
Holding Power ◽  
Resource Holding Power ◽  
Dear Enemy Phenomenon ◽  
Dear Enemy Effect ◽  
Tail Condition

A reduction of territory owners’ aggression towards their neighbours in relation to the intrusion of strangers characterises the dear enemy phenomenon. Supposedly, the disparity in aggression levels of territory owners is due to a higher threat imposed by strangers compared to the threat imposed by neighbours. To evaluate the occurrence of the phenomenon in males of the small-sized lizard Eurolophosaurus nanuzae we performed a field manipulative study. We considered three models to run intrusions in males’ territories: neighbour, tailed stranger (unfamiliar) and tailless stranger intruders. Our results lend support to the presence of dear enemy for this species as residents acted more aggressively towards strangers than to neighbours. In addition, the information we provide supports the relative threat hypothesis as territory owners were more aggressive towards tailed stranger intruders than to tailless stranger intruders. In this sense, tail condition can represent a trait that signals the ‘resource holding power’ (RHP) of a lizard. Therefore, we show that beyond neighbourhood recognition, residents are able to evaluate the potential threat of stranger intruders in general, thereby extending the evolutionary gains of the dear enemy by saving energy even in the context they are expected to acts with higher costs.

scholarly journals An Experimental Approach on Industrial Pd-Ag Supported α-Al2O3 Catalyst Used in Acetylene Hydrogenation Process: Mechanism, Kinetic and Catalyst Decay

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 136
Author(s):  
Ourmazd Dehghani ◽  
Mohammad Rahimpour ◽  
Alireza Shariati
Keyword(s):  
Kinetic Model ◽  
Experimental Approach ◽  
Catalyst Deactivation ◽  
Catalyst Activity ◽  
Hydrogenation Process ◽  
Support Surface ◽  
Acetylene Hydrogenation ◽  
Wide Range ◽  
Α Al2o3 ◽  
Al2o3 Catalyst

The current research presents an experimental approach on the mechanism, kinetic and decay of industrial Pd-Ag supported α-Al2O3 catalyst used in the acetylene hydrogenation process. In the first step, the fresh and deactivated hydrogenation catalysts are characterized by XRD, BET (Brunauer–Emmett–Teller), SEM, TEM, and DTG analyses. The XRD results show that the dispersed palladium particles on the support surface experience an agglomeration during the reaction run time and mean particle size approaches from 6.2 nm to 11.5 nm. In the second step, the performance of Pd-Ag supported α-Al2O3 catalyst is investigated in a differential reactor in a wide range of hydrogen to acetylene ratio, temperature, gas hourly space velocity and pressure. The full factorial design method is used to determine the experiments. Based on the experimental results ethylene, ethane, butene, and 1,3-butadiene are produced through the acetylene hydrogenation. In the third step, a detailed reaction network is proposed based on the measured compounds in the product and the corresponding kinetic model is developed, based on the Langmuir-Hinshelwood-Hougen-Watson approach. The coefficients of the proposed kinetic model are calculated based on experimental data. Finally, based on the developed kinetic model and plant data, a decay model is proposed to predict catalyst activity and the parameters of the activity model are calculated. The results show that the coke build-up and condensation of heavy compounds on the surface cause catalyst deactivation at low temperature.

Dear enemy effect in the Mexican volcano mouse Neotomodon alstoni: Implications of sex in the agonistic behaviour among neighbours

2020 ◽  
Vol 181 ◽  
pp. 104251
Author(s):  
Jorge Vázquez ◽  
Juan A. Fargallo ◽  
Nallely Jiménez ◽  
Fernando Aguilar-Montiel ◽  
Luisa Rodríguez-Martínez
Keyword(s):  
Agonistic Behaviour ◽  
Dear Enemy ◽  
Dear Enemy Effect

scholarly journals The emergence and resilience of self-organized governance in coupled infrastructure systems

2020 ◽  
Vol 117 (9) ◽  
pp. 4617-4622 ◽  
Author(s):  
Rachata Muneepeerakul ◽  
John M. Anderies
Keyword(s):  
System Analysis ◽  
Coupled System ◽  
Small Scale ◽  
Shared Resources ◽  
Infrastructure Systems ◽  
Self Organized ◽  
Trade Offs ◽  
Wide Range ◽  
Rigorous Treatment ◽  
Coupled Infrastructure Systems

Studies of small-scale, self-organized social-ecological systems have contributed to our understanding of successful governance of shared resources. However, the lack of formal analytically tractable models of such coupled infrastructure systems makes it difficult to connect this understanding to such concepts as stability, robustness, and resilience, which are increasingly important in considering such systems. In this paper, we mathematically operationalize a widely used conceptual framework via a stylized dynamical model. The model yields a wide range of system outcomes: sustainability or collapse, infrastructure at full or partial capacity, and social agents seeking outside opportunities or exclusively engaging in the system. The low dimensionality of the model enables us to derive these conditions in clear relationships of biophysical and social factors describing the coupled system. Analysis of the model further reveals regime shifts, trade-offs, and potential pitfalls that one may face in governing these self-organized systems. The intuition and insights derived from the model lay ground for more rigorous treatment of robustness and resilience of self-organized coupled infrastructure systems, which can lead to more effective governance.

Enemies are not always dear: male song sparrows adjust dear enemy effect expression in response to female fertility

2017 ◽  
Vol 126 ◽  
pp. 17-22 ◽  
Author(s):  
Christopher Moser-Purdy ◽  
Elizabeth A. MacDougall-Shackleton ◽  
Daniel J. Mennill
Keyword(s):  
Female Fertility ◽  
Dear Enemy ◽  
Male Song ◽  
Song Sparrows ◽  
Dear Enemy Effect

Differential attack by a cichlid fish on resident and non-resident fish of another cichlid species

Behaviour ◽  
2012 ◽  
Vol 149 (1) ◽  
pp. 99-109 ◽  
Author(s):  
Satoshi Awata ◽  
Masanori Kohda ◽  
Haruki Ochi
Keyword(s):  
Field Experiment ◽  
Lake Tanganyika ◽  
Cichlid Fish ◽  
Previous Experience ◽  
Alternative Mechanism ◽  
Differential Attack ◽  
Dear Enemy ◽  
Resident Fish ◽  
Cichlid Species ◽  
Dear Enemy Effect

AbstractAn algivorous cichlid, Variabilichromis moorii( Vm), defends permanent territories in Lake Tanganyika, Africa. A zoobenthivorous cichlid, Neolamprologus mustax( Nm), spends 60% of daylight hours foraging in Vmterritories, from which other zoobenthivorous fishes are chased out and consequently which are much richer in prey animals than areas outside of Vmterritories. We conducted a field experiment to examine whether Nmresidents and non-residents received different degrees of attacks from Vm. Nmfish were caught in their territories, released at a point distant from these territories, and followed to observe interactions with Vmfish. The frequency of attacks received by the displaced Nmfish was greater than attacks received by Nmresidents, indicating that Nmresidents had easier access to Vmterritories than non-residents did. A possible mechanism for this is reduced aggression of Vmtowards Nmresidents, as a result of the ‘dear enemy’ effect that has been reported in territorial contests between rivals. An alternative mechanism is that tolerance towards Nmdiffers among Vmfish and Nmresidents selectively visit more tolerant Vmfish due to previous experience while non-residents randomly approach both tolerant and hostile Vmfish. The ability of Vmto discriminate between Nmresidents and non-residents is essential to the former mechanism but not to the latter. To more specifically examine which mechanism works in the Vm– Nmcommensal system, we will need to follow individually identified Vmfish interacting with Nmresidents and non-residents.

Sign in / Sign up

Export Citation Format

Share Document