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1

Muir Inlet  

USGS Multimedia Gallery

Muir Glacier has retreated more than 2 km and ceased to have a tidewater terminus. Note that the retreat of Muir Glacier has left several ice-cored morainal mounds between the shoreline and the terminus. Since 1980, Muir Glacier has thinned by several hundred meters permitting a view of a mountain w...

2

Muir Inlet  

USGS Multimedia Gallery

This ship-deck-based photograph of Muir Glacier and Muir Inlet, Glacier Bay National Park and Preserve, St. Elias Mountains, Alaska, is taken towards the north-northwest and shows the nearly 50-m-high retreating tidewater terminus of the glacier with part of its face capped by a few angular sé...

3

Muir Glacier and Muir Inlet 1980  

USGS Multimedia Gallery

This ship-deck-based August 1980 photograph of Muir Glacier and Muir Inlet, Glacier Bay National Park and Preserve, St. Elias Mountains, Alaska, shows the nearly 200-ft-high retreating tidewater end of Muir Glacier with part of its face capped by a few angular pinnacles of ice, called séracs....

4

John Muir Exhibit  

NSDL National Science Digital Library

Compiled by Harold Wood and Harvey Chinn and hosted by the Sierra Club, this site features interesting information on the father of modern conservation and founder of the Sierra Club. The site contains a list of Muir's publications, favorite quotes, and many other Muir-related items such as: study guides, information on historic sites, live dramatic presentations of Muir, places named after Muir, and songs and music related and dedicated to Muir. Also included is a section on Muir scholarship including an annotated bibliography. Multimedia items include video clips (RealPlayer or VivoActive Player) from portrayals of Muir, and RealAudio recordings of some of the many actors currently performing live portraits of Muir.

5

Muir Glacier and Muir Inlet 2003  

USGS Multimedia Gallery

This photo was taken in September 2003; in the 23 years between photographs, Muir Glacier has retreated more than a mile and ceased to have a tidewater terminus. Since 1980, Muir Glacier has thinned by more than 600 ft, permitting a view of a mountain with a summit elevation of greater than 4000 ft,...

6

Ant Algorithms Solve Difficult Optimization Problems  

E-print Network

Ant Algorithms Solve Difficult Optimization Problems Marco Dorigo IRIDIA Universit´e Libre de Bruxelles 50 Avenue F. Roosevelt B-1050 Brussels, Belgium mdorigo@ulb.ac.be Abstract. The ant algorithms research field builds on the idea that the study of the behavior of ant colonies or other social insects

Libre de Bruxelles, Université

7

John Muir Photographs  

NSDL National Science Digital Library

John Muir was a wanderer, a thinker, and a tinkerer of great repute. This digital collection from the University of the Pacific in Stockton, California brings together images of this great American for use by researchers, scholars, and anyone else with a penchant for Muir's life and times. The images come from their special collections, and they include items from the formal John Muir Papers collection and the James Eastman Shone Collection of Muiriana. There are 242 images in the collection, and visitors can look over them at their leisure, or perform their own detailed search. There's much to look at here, as the shots include Muir with Andrew Carnegie in Los Angeles, Muir at his home in Martinez, and a fair number of shots of Muir walking through the wilderness he loved so dearly.

8

GENI Ants for the Traveling Salesman Problem  

Microsoft Academic Search

In this paper, the probabilistic nearest neighbor heuristic, which is at the core of classical ant colony systems for the\\u000a Traveling Salesman Problem, is replaced by an alternative insertion procedure known as the GENI heuristic. The benefits provided\\u000a by GENI-based ants are empirically demonstrated on a set of benchmark problems, through a comparison with the classical ant\\u000a colony system and

François-xavier Le Louarn; Michel Gendreau; Jean-yves Potvin

2004-01-01

9

Muir Glacier Retreats  

USGS Multimedia Gallery

Muir Glacier has retreated out of the field of view and is now nearly 5 miles to the northwest. Riggs Glacier has retreated as much as 2000 ft and thinned by more than 800 feet. Note the dense vegetation that has developed. Also note the correlation between Muir Glacier’s 1941 thickness and th...

10

Solving the ANTS Problem with Asynchronous Finite State Machines  

E-print Network

Solving the ANTS Problem with Asynchronous Finite State Machines Yuval Emek, Tobias Langner, Jara + D) #12;Previous Work ANTS problem (Ants Nearby Treasure Search) introduced by Feinerman, Korman, Lotker, Sereni [PODC 2012] = #12;Previous Work ANTS problem (Ants Nearby Treasure Search) introduced

11

Solving the ANTS Problem with Asynchronous Finite State Machines  

E-print Network

Solving the ANTS Problem with Asynchronous Finite State Machines Yuval Emek1 , Tobias Langner2 the Ants Nearby Treasure Search (ANTS) problem introduced by Feinerman, Korman, Lotker, and Sereni (PODC-time of any ANTS algorithm. 1 Introduction "They operate without any central control. Their collective

12

Problems with ants The noted gourmet Pangolini Aardvark is preparing a late night snack of "Ant  

E-print Network

Problems with ants The noted gourmet Pangolini Aardvark is preparing a late night snack of "Ant au Chocolat" and "Ant au Fromage". This requires the use of a five foot pole. One end of the pole is over a bucket of melted chocolate and the other is over a bucket of melted cheese. Pangolini sprinkles some ants

Sadeh, Norman M.

13

The John Muir Award.  

ERIC Educational Resources Information Center

The John Muir Award was established in the United Kingdom to respond to minimal environmental awareness, especially among youth. The Award has three levels of effort; all involve discovering a wild place, exploring its wildness, helping to conserve it, and sharing the experience with a wider audience. There is an effort to establish the award in…

White, Graham

2002-01-01

14

Solving Permutation Constraint Satisfaction Problems with Artificial Ants  

E-print Network

Solving Permutation Constraint Satisfaction Problems with Artificial Ants Christine Solnon 1 Abstract. We describe in this paper Ant­P­solver, a generic con­ straint solver based on the Ant Colony Optimization (ACO) meta­ heuristic. The ACO metaheuristic takes inspiration on the observa­ tion of real ants

Solnon, Christine

15

Muir and Riggs Glaciers, Muir Inlet, Alaska - 1941  

USGS Multimedia Gallery

This northeast-looking photograph, on the southeastern side of White Thunder Ridge ,shows the lower reaches of Muir Glacier, then a large tidewater calving valley glacier, and its tributary Riggs Glacier. The séracs in the lower right-hand corner of the photograph mark Muir Glacier’s te...

16

Muir and Riggs Glaciers, Muir Inlet, Alaska - 1950  

USGS Multimedia Gallery

This, the first of two repeat photographs, documents significant changes that have occurred during the nine years between photographs A and B. Although Muir Glacier has retreated more than 3 kilometers and thinned more than 100 meters, exposing Muir Inlet, it remains connected with tributary Riggs G...

17

Muir and Riggs Glaciers, Muir Inlet, Alaska - 2004  

USGS Multimedia Gallery

The second repeat photograph documents significant changes that have occurred during the 63 years between photographs A and C, and during the 54 years between photographs B and C. Muir Glacier has retreated out of the field of view and is now more than 7 kilometers northwest. Riggs Glacier has retre...

18

Ant Colony Optimization and the minimum spanning tree problem  

Microsoft Academic Search

Ant Colony Optimization (ACO) is a kind of metaheuristic that has become very popular for solving problems from combinatorial optimization. Solutions for a given problem are constructed by a random walk on a so-called construction graph. This random walk can be influenced by heuristic information about the problem. In contrast to many successful applications, the theoretical foundation of this kind

Frank Neumann; Carsten Witt

2010-01-01

19

The John Muir Exhibit: Educational Resources  

NSDL National Science Digital Library

The John Muir Exhibit was created by the Sierra Club to display and commemorate the life of John Muir and his role in the environmental movement. The Educational Resources that are provided are for students and teachers from grade school to graduate school, interested in studying Muir's legacy as a naturalist, writer, conservationist and founder of the Sierra Club. A student page provides research materials from biographies to articles, and study guides assists teachers in preparing commemorations of Muir and his work, with focus on John Muir Day. A listing of John Muir awards provides students with the opportunity to apply for and win scholarships. Other John Muir Education programs are listed such as poster contests and case studies history projects.

20

Hybrid Ant Algorithm and Applications for Vehicle Routing Problem  

NASA Astrophysics Data System (ADS)

Ant colony optimization (ACO) is a metaheuristic method that inspired by the behavior of real ant colonies. ACO has been successfully applied to several combinatorial optimization problems, but it has some short-comings like its slow computing speed and local-convergence. For solving Vehicle Routing Problem, we proposed Hybrid Ant Algorithm (HAA) in order to improve both the performance of the algorithm and the quality of solutions. The proposed algorithm took the advantages of Nearest Neighbor (NN) heuristic and ACO for solving VRP, it also expanded the scope of solution space and improves the global ability of the algorithm through importing mutation operation, combining 2-opt heuristics and adjusting the configuration of parameters dynamically. Computational results indicate that the hybrid ant algorithm can get optimal resolution of VRP effectively.

Xiao, Zhang; Jiang-qing, Wang

21

Ants  

NSDL National Science Digital Library

In this outdoor activity, learners investigate ant behavior by testing ant feeding reactions to different types of food. Learners attempt to discover an ant "superfood" and use that food to try and get some ants from a colony to start a new one at a different location. Based on what learners observe, they also consider how ants communicate with each other.

Lawrence Hall of Science

1980-01-01

22

Ant Colony Optimization and the Minimum Spanning Tree Problem  

Microsoft Academic Search

Ant Colony Optimization (ACO) is a kind of metaheuristic that has become very popular for solving problems from combinatorial\\u000a optimization. Solutions for a given problem are constructed by a random walk on a so-called construction graph. This random\\u000a walk can be influenced by heuristic information about the problem. In contrast to many successful applications, the theoretical\\u000a foundation of this kind

Frank Neumann; Carsten Witt

2007-01-01

23

Cunning Ant System for Quadratic Assignment Problem with Local Search and Parallelization  

E-print Network

Cunning Ant System for Quadratic Assignment Problem with Local Search and Parallelization. The previously proposed cunning ant system (cAS), a vari- ant of the ACO algorithm, worked well on the TSP have proposed a variant of the ACO algorithm called the cunning Ant System (cAS) and evaluated it using

Tsutsui, Shigeyoshi

24

Ant colony system: a cooperative learning approach to the traveling salesman problem  

Microsoft Academic Search

This paper introduces ant colony system (ACS), a distributed algorithm that is applied to the traveling salesman problem (TSP). In ACS, a set of cooperating agents called ants cooperate to find good solutions to TSPs. Ants cooperate using an indirect form of communication mediated by pheromone they deposit on the edges of the TSP graph while building solutions. We study

Marco Dorigo; Luca Maria Gambardella

1997-01-01

25

Ant-Q: A Reinforcement Learning approach to the traveling salesman problem  

E-print Network

Ant-Q: A Reinforcement Learning approach to the traveling salesman problem Luca M. Gambardella@ulb.ac.be http://iridia.ulb.ac.be/dorigo/dorigo.html Abstract In this paper we introduce Ant-Q, a family to the solution of symmetric and asym- metric instances of the traveling salesman prob- lem (TSP). Ant

Gambardella, Luca Maria

26

An Ant Algorithm with a New Pheromone Evaluation Rule for Total Tardiness Problems  

Microsoft Academic Search

Ant Colony Optimization is an evolutionary method that has recently been applied to scheduling problems. We propose an ACO algorithm for the Single Machine Total Weighted Tardiness Problem. Compared to an existing ACO algorithm for the unweighted Total Tardiness Problem our algorithm has several improvements. The main novelty is that in our algorithm the ants are guided on their way

Daniel Merkle; Martin Middendorf

2000-01-01

27

Muir Glacier in Glacier Bay National Monument 1941  

USGS Multimedia Gallery

This August 1941 photograph is of Muir Glacier in Glacier Bay National Monument, Alaska. It shows the lower reaches of Muir Glacier, then a large, tidewater calving valley glacier and its tributary, Riggs Glacier. For nearly two centuries before 1941, Muir Glacier had been retreating. In places, a t...

28

An Ant Colony Optimization Algorithm for the 2D HP Protein Folding Problem  

E-print Network

An Ant Colony Optimization Algorithm for the 2D HP Protein Folding Problem Alena Shmygelska, Rosal, the two dimensional hydrophobic-polar (2D HP) protein folding problem. We introduce an ant colony algorithm closely approaches that of specialised, state-of-the methods for 2D HP protein folding. 1

Hoos, Holger H.

29

Houston, We Have a Problem: Rasberry Crazy Ants  

E-print Network

Since first discovered in Pasadena in 2002 by pest control operator Tom Rasberry, Rasberry crazy ants have spread to 11 southeast Texas counties. Here are facts about these ants, with information for the public about what to do to avoid spreading...

Drees, Bastiaan M.

2009-03-15

30

A Knowledge-Based Ant Colony Optimization for Flexible Job Shop Scheduling Problems  

Microsoft Academic Search

A Knowledge-Based Ant Colony Optimization (KBACO) algorithm is proposed in this paper for the Flexible Job Shop Scheduling Problem (FJSSP). KBACO algorithm provides an effective integration between Ant Colony Optimization (ACO) model and knowledge model. In the KBACO algorithm, knowledge model learns some available knowledge from the optimization of ACO, and then applies the existing knowledge to guide the current

Li-Ning Xing; Ying-Wu Chen; Peng Wang; Qing-Song Zhao; Jian Xiong

2010-01-01

31

Ant Colony Optimization with Memory and Its Application to Traveling Salesman Problem  

NASA Astrophysics Data System (ADS)

Ant Colony Optimization (ACO) is one of the most recent techniques for solving combinatorial optimization problems, and has been unexpectedly successful. Therefore, many improvements have been proposed to improve the performance of the ACO algorithm. In this paper an ant colony optimization with memory is proposed, which is applied to the classical traveling salesman problem (TSP). In the proposed algorithm, each ant searches the solution not only according to the pheromone and heuristic information but also based on the memory which is from the solution of the last iteration. A large number of simulation runs are performed, and simulation results illustrate that the proposed algorithm performs better than the compared algorithms.

Wang, Rong-Long; Zhao, Li-Qing; Zhou, Xiao-Fan

32

Ants on a Doughnut Purpose. In this project you will use calculus to solve a geometry problem. This project  

E-print Network

Ants on a Doughnut Purpose. In this project you will use calculus to solve a geometry problem. This project serves as an introduction to differential geometry. The Problem. Two ants are exploring a doughnut and grease. The two regions are as far apart on the doughnut as they can be. The ants must leave a path

Brand, Neal

33

Study on MAX-MIN Ant System with Random Selection in Quadratic Assignment Problem  

NASA Astrophysics Data System (ADS)

Ant Colony Optimization (ACO), which is a type of swarm intelligence inspired by ants' foraging behavior, has been studied extensively and its effectiveness has been shown by many researchers. The previous studies have reported that MAX-MIN Ant System (MMAS) is one of effective ACO algorithms. The MMAS maintains the balance of intensification and diversification concerning pheromone by limiting the quantity of pheromone to the range of minimum and maximum values. In this paper, we propose MAX-MIN Ant System with Random Selection (MMASRS) for improving the search performance even further. The MMASRS is a new ACO algorithm that is MMAS into which random selection was newly introduced. The random selection is one of the edgechoosing methods by agents (ants). In our experimental evaluation using ten quadratic assignment problems, we have proved that the proposed MMASRS with the random selection is superior to the conventional MMAS without the random selection in the viewpoint of the search performance.

Iimura, Ichiro; Yoshida, Kenji; Ishibashi, Ken; Nakayama, Shigeru

34

Ant Colony System for a Dynamic Vehicle Routing Problem  

Microsoft Academic Search

An aboundant literature on vehicle routing problems is available. How- ever, most of the work deals with static problems, where all data are known in advance, i.e. before the optimization has started. The technological advances of the last few years give rise to a new class of problems, namely the dynamic vehicle routing problems, where new or- ders are received

Roberto Montemanni; Luca Maria Gambardella; Andrea Emilio Rizzoli; Alberto V. Donati

2005-01-01

35

An improved ant colony algorithm for multi-objective flexible job shop scheduling problem  

Microsoft Academic Search

Flexible job shop scheduling problem is a very important research in the field of combinatorial optimization. An improved ant colony algorithm for multi-objective flexible job shop scheduling problem is presented in this paper. The rule of our algorithm is described from the following aspects: local update, global update, trail intensities, solution set, local search, suitable parameters. The algorithm we presented

Li Li; Keqi Wang

2009-01-01

36

Combining two Pheromone Structures for Solving the Car Sequencing Problem with Ant  

E-print Network

Combining two Pheromone Structures for Solving the Car Sequencing Problem with Ant Colony) algorithm for solving this problem, and we introduce two different pheromone structures for this algorithm: the first pheromone structure aims at learn- ing for "good" sequences of cars, whereas the second pheromone

Solnon, Christine

37

An Elitist-Ant System for Solving the Post-Enrolment Course Timetabling Problem  

NASA Astrophysics Data System (ADS)

Ant System algorithms are nature-inspired population-based metaheuristics derived from the field of swarm intelligence. Seemingly, the ant system has a lack of search diversity control since it has only a global pheromone update that intensifies the search. Hence, one or more assistant mechanisms are required to strengthen the search of the ant system. Therefore, we propose, in this study, an elitist-ant system to strike a balance between search diversity and intensification while maintaining the quality of solutions. This process is achieved by employing two diversification and intensification mechanisms to assist both pheromone evaporation and elite pheromone updating, in order to gain a good control over the search exploration and exploitation. The diversification mechanism is employed to avoid early convergence, whilst the intensification mechanism is employed to exploore the neighbors of a solution more effectively. In this paper, we test our algorithm on post-enrolment course timetabling problem. Experimental results show that our algorithm produces good quality solutions and outperforms some results reported in the literature (with regards to Socha's instances) including other ant system algorithms. Therefore, we can conclude that our elitist-ant system has performed an efficient problem's specific knowledge exploitation, and an effective guided search exploration to obtain better quality solutions.

Jaradat, Ghaith M.; Ayob, Masri

38

An Improved Ant Colony Optimisation Algorithm for the 2D HP Protein Folding Problem  

Microsoft Academic Search

The prediction of a protein's structure from its amino-acid sequence is one of the most important problems in computational biology. In the current work, we focus on a widely studied abstraction of this problem, the 2-dimensional hydrophobic-polar (2D HP) protein folding problem. We present an improved version of our recently proposed Ant Colony Optimisation (ACO) algorithm for this -hard combinatorial

Alena Shmygelska; Holger H. Hoos

2003-01-01

39

Ant Colony Optimization with Genetic Operation and Its Application to Traveling Salesman Problem  

NASA Astrophysics Data System (ADS)

Ant colony optimization (ACO) algorithms are a recently developed, population-based approach which has been successfully applied to optimization problems. However, in the ACO algorithms it is difficult to adjust the balance between intensification and diversification and thus the performance is not always very well. In this work, we propose an improved ACO algorithm in which some of ants can evolve by performing genetic operation, and the balance between intensification and diversification can be adjusted by numbers of ants which perform genetic operation. The proposed algorithm is tested by simulating the Traveling Salesman Problem (TSP). Experimental studies show that the proposed ACO algorithm with genetic operation has superior performance when compared to other existing ACO algorithms.

Wang, Rong-Long; Zhou, Xiao-Fan; Okazaki, Kozo

40

Ant colony optimization algorithm for stochastic project crashing problem in PERT networks using MC simulation  

Microsoft Academic Search

This paper describes a new approach based on ant colony optimization (ACO) metaheuristic and Monte Carlo (MC) simulation technique,\\u000a for project crashing problem (PCP) under uncertainties. To our knowledge, this is the first application of ACO technique for\\u000a the stochastic project crashing problem (SPCP), in the published literature. A confidence-level-based approach has been proposed\\u000a for SPCP in program evaluation and

Abdollah Aghaie; Hadi Mokhtari

2009-01-01

41

An Improved Ant Colony Algorithm Combined with Particle Swarm Optimization Algorithm for Multi-objective Flexible Job Shop Scheduling Problem  

Microsoft Academic Search

In this paper an improved ant colony algorithm is presented and an algorithm in combination with particle swarm optimization algorithm and the improved ant colony algorithm for multi-objective flexible job shop scheduling problem are employed. The algorithm proposed in this paper includes two parts. The first part makes use of the fast convergence of PSO to search the particles optimum

Li Li; Wang Keqi; Zhou Chunnan

2010-01-01

42

Interactive Fuzzy Multi-objective Ant Colony Optimization with Linguistically Quantified Decision Functions for Flexible Job Shop Scheduling Problems  

Microsoft Academic Search

Scheduling for the flexible job shop is very important in the fields of production management and combinatorial optimization. It proposes an Ant Colony Optimization with Linguistically Quantified Decision Functions (ACO-LQDF) for the Flexible Job Shop Scheduling Problems (FJSSP) in this work. The novelty of the proposed approach is the interactive and fuzzy multi-objective nature of the Ant Colony Optimization (ACO)

Li-ning Xing; Ying-wu Chen; Ke-wei Yang

2007-01-01

43

Coupling ant colony optimization and the extended great deluge algorithm for the discrete facility layout problem  

NASA Astrophysics Data System (ADS)

This article uses a hybrid optimization approach to solve the discrete facility layout problem (FLP), modelled as a quadratic assignment problem (QAP). The idea of this approach design is inspired by the ant colony meta-heuristic optimization method, combined with the extended great deluge (EGD) local search technique. Comparative computational experiments are carried out on benchmarks taken from the QAP-library and from real life problems. The performance of the proposed algorithm is compared to construction and improvement heuristics such as H63, HC63-66, CRAFT and Bubble Search, as well as other existing meta-heuristics developed in the literature based on simulated annealing (SA), tabu search and genetic algorithms (GAs). This algorithm is compared also to other ant colony implementations for QAP. The experimental results show that the proposed ant colony optimization/extended great deluge (ACO/EGD) performs significantly better than the existing construction and improvement algorithms. The experimental results indicate also that the ACO/EGD heuristic methodology offers advantages over other algorithms based on meta-heuristics in terms of solution quality.

Nourelfath, M.; Nahas, N.; Montreuil, B.

2007-12-01

44

Ant Colony Algorithm for Multiple-Depot Vehicle Routing Problem with Shortest Finish Time  

NASA Astrophysics Data System (ADS)

The objective of the multiple-depot vehicle routing problem (MDVRP) is to shorten the finish time, in the emergency management and special delivery research. In this paper, an ant colony algorithm for multiple-depot vehicle routing problem with shortest finish time (FTMDVRP) is studied. We discuss the concept and framework of FTMDVRP. The methods of making use of improved split algorithm to divide cars for given customer sequence is presented. We use the max flow algorithm allocate cars to each depot. Our experimental results confirm that our approach is effective in multiple-depot vehicle routing.

Ma, Jianhua; Yuan, Jie

45

An Improved Ant Colony Algorithm for the Shortest Path Problem in Time-Dependent Networks  

NASA Astrophysics Data System (ADS)

Research of the shortest path problem in time-dependent networks has important practical value. An improved pheromone update strategy suitable for time-dependent networks was proposed. Under this strategy, the residual pheromone of each road can accurately reflect the change of weighted value of each road. An improved selection strategy between adjacent cities was used to compute the cities' transfer probabilities, as a result, the amount of calculation is greatly reduced. To avoid the algorithm converging to the local optimal solution, the ant colony algorithm was combined with genetic algorithm. In this way, the solutions after each traversal were used as the initial species to carry out single-point crossover. An improved ant colony algorithm for the shortest path problem in time-dependent networks based on these improved strategies was presented. The simulation results show that the improved algorithm has greater probability to get the global optimal solution, and the convergence rate of algorithm is better than traditional ant colony algorithm.

Chang, Qing; Liu, Yongqiang; Xiong, Huagang

46

Solving optimum operation of single pump unit problem with ant colony optimization (ACO) algorithm  

NASA Astrophysics Data System (ADS)

For pumping stations, the effective scheduling of daily pump operations from solutions to the optimum design operation problem is one of the greatest potential areas for energy cost-savings, there are some difficulties in solving this problem with traditional optimization methods due to the multimodality of the solution region. In this case, an ACO model for optimum operation of pumping unit is proposed and the solution method by ants searching is presented by rationally setting the object function and constrained conditions. A weighted directed graph was constructed and feasible solutions may be found by iteratively searching of artificial ants, and then the optimal solution can be obtained by applying the rule of state transition and the pheromone updating. An example calculation was conducted and the minimum cost was found as 4.9979. The result of ant colony algorithm was compared with the result from dynamic programming or evolutionary solving method in commercial software under the same discrete condition. The result of ACO is better and the computing time is shorter which indicates that ACO algorithm can provide a high application value to the field of optimal operation of pumping stations and related fields.

Yuan, Y.; Liu, C.

2012-11-01

47

A modify ant colony optimization for the grid jobs scheduling problem with QoS requirements  

NASA Astrophysics Data System (ADS)

Job scheduling with customers' quality of service (QoS) requirement is challenging in grid environment. In this paper, we present a modify Ant colony optimization (MACO) for the Job scheduling problem in grid. Instead of using the conventional construction approach to construct feasible schedules, the proposed algorithm employs a decomposition method to satisfy the customer's deadline and cost requirements. Besides, a new mechanism of service instances state updating is embedded to improve the convergence of MACO. Experiments demonstrate the effectiveness of the proposed algorithm.

Pu, Xun; Lu, XianLiang

2011-10-01

48

John Muir and the Modern Passion for Nature  

Microsoft Academic Search

If we follow John Muir very long, he will wear us out with his incessant gab. The man never stopped talking, and he talked with everyone he met—white farmers, black freedmen, women of all ages, hordes of children, ministers of the gospel, a canoe full of Tlingits paddling along the Alaska coast. Mostly, they talked, and talked passionately, about nature.

Donald Worster

2005-01-01

49

Muir Glacier in Glacier Bay National Monument 2004  

USGS Multimedia Gallery

This August 2004 photo further documents the significant changes that have occurred during the 63 years between photographs A and C, and during the 54 years between photographs B and C. Muir Glacier has retreated out of the field of view and is now nearly 5 miles to the northwest. Riggs Glacier has ...

50

Coed Trecastell: A Personal Experience of the John Muir Award.  

ERIC Educational Resources Information Center

A John Muir Award participant describes his satisfying experience cleaning up a wooded gorge near his home in Wales. Sidebar explains how the British award achieves its purpose of empowering people to conserve wild places through four challenges: discover a wild place, explore it, conserve it, and share the experience with others. The award has…

Collister, Rob

1999-01-01

51

Microsatellite Instability in Muir-Torre Syndrome1  

Microsoft Academic Search

Muir-Torre syndrome (MTS) is characterized by the presence of at least one sebaceous tumor and at least one visceral malignancy. Although a wide range of internal malignancies have been reported, the most frequently observed internal neoplasm is colorectal carcinoma. MTS and hereditary nonpolyposis colorectal carcinoma (HNPCC) share many clinical and pathological characteristics and thus may share similar genetic mecha nisms

Ronald Honchel; Kevin C. Hailing; Daniel J. Schaid; Mark Pittelkow; Stephen N. Thibodeau

1994-01-01

52

A New Local Search Based Ant Colony Optimization Algorithm for Solving Combinatorial Optimization Problems  

NASA Astrophysics Data System (ADS)

Ant Colony Optimization (ACO) algorithms are a new branch of swarm intelligence. They have been applied to solve different combinatorial optimization problems successfully. Their performance is very promising when they solve small problem instances. However, the algorithms' time complexity increase and solution quality decrease for large problem instances. So, it is crucial to reduce the time requirement and at the same time to increase the solution quality for solving large combinatorial optimization problems by the ACO algorithms. This paper introduces a Local Search based ACO algorithm (LSACO), a new algorithm to solve large combinatorial optimization problems. The basis of LSACO is to apply an adaptive local search method to improve the solution quality. This local search automatically determines the number of edges to exchange during the execution of the algorithm. LSACO also applies pheromone updating rule and constructs solutions in a new way so as to decrease the convergence time. The performance of LSACO has been evaluated on a number of benchmark combinatorial optimization problems and results are compared with several existing ACO algorithms. Experimental results show that LSACO is able to produce good quality solutions with a higher rate of convergence for most of the problems.

Hassan, Md. Rakib; Islam, Md. Monirul; Murase, Kazuyuki

53

Fuzzy Random ?-Mean SAD Portfolio Selection Problem: An Ant Colony Optimization Approach  

NASA Astrophysics Data System (ADS)

To reach the investment goal, one has to select a combination of securities among different portfolios containing large number of securities. Only the past records of each security do not guarantee the future return. As there are many uncertain factors which directly or indirectly influence the stock market and there are also some newer stock markets which do not have enough historical data, experts' expectation and experience must be combined with the past records to generate an effective portfolio selection model. In this paper the return of security is assumed to be Fuzzy Random Variable Set (FRVS), where returns are set of random numbers which are in turn fuzzy numbers. A new ?-Mean Semi Absolute Deviation (?-MSAD) portfolio selection model is developed. The subjective opinions of the investors to the rate of returns of each security are taken into consideration by introducing a pessimistic-optimistic parameter vector ?. ?-Mean Semi Absolute Deviation (?-MSAD) model is preferred as it follows absolute deviation of the rate of returns of a portfolio instead of the variance as the measure of the risk. As this model can be reduced to Linear Programming Problem (LPP) it can be solved much faster than quadratic programming problems. Ant Colony Optimization (ACO) is used for solving the portfolio selection problem. ACO is a paradigm for designing meta-heuristic algorithms for combinatorial optimization problem. Data from BSE is used for illustration.

Thakur, Gour Sundar Mitra; Bhattacharyya, Rupak; Mitra, Swapan Kumar

2010-10-01

54

Ant System Thomas Stutzle  

E-print Network

¡£¢ ­ ¤¦¥ Ant System Thomas St¨utzle § Universit´e Libre de Bruxelles IRIDIA Brussels, Belgium Ant System, the first Ant Colony Optimization algorithm, showed to be a viable method for attacking Problem. To show that Ant Colony Opti- mization algorithms could be good alternatives to existing

Hoos, Holger H.

55

A Pareto Ant Colony Algorithm Applied to the Class Integration and Test Order Problem  

NASA Astrophysics Data System (ADS)

In the context of Object-Oriented software, many works have investigated the Class Integration and Test Order (CITO) problem, proposing solutions to determine test orders for the integration test of the program classes. The existing approaches based on graphs can generate solutions that are sub-optimal, and do not consider the different factors and measures that can affect the stubbing process. To overcome this limitation, solutions based on Genetic Algorithms (GA) have presented promising results. However, the determination of a cost function, which is able to generate the best solutions, is not always a trivial task, mainly for complex systems with a great number of measures. Therefore, we introduce, in this paper, a multi-objective optimization approach to better represent the CITO problem. The approach generates a set of good solutions that achieve a balanced compromise between the different measures (objectives). It was implemented by a Pareto Ant Colony (P-ACO) algorithm, which is described in detail. The algorithm was used in a set of real programs and the obtained results are compared to the GA results. The results allow discussing the difference between single and multi-objective approaches especially for complex systems with a greater number of dependencies among the classes.

da Veiga Cabral, Rafael; Pozo, Aurora; Vergilio, Silvia Regina

56

Ant Programming: Or how to use ants for automatic programming  

E-print Network

Ant Programming: Or how to use ants for automatic programming Olivier ROUX, Cyril FONLUPT,fonlupt�@lil.univ­littoral.fr Abstract Ant Programming (AP) is a new method which applies the principle of the ants systems for the resolution of com­ binatorial optimization problems. Among the most recent work have emerged the ants systems

Fernandez, Thomas

57

Improved understanding of the searching behavior of ant colony optimization algorithms applied to the water distribution design problem  

NASA Astrophysics Data System (ADS)

Evolutionary algorithms (EAs) have been applied successfully to many water resource problems, such as system design, management decision formulation, and model calibration. The performance of an EA with respect to a particular problem type is dependent on how effectively its internal operators balance the exploitation/exploration trade-off to iteratively find solutions of an increasing quality. For a given problem, different algorithms are observed to produce a variety of different final performances, but there have been surprisingly few investigations into characterizing how the different internal mechanisms alter the algorithm's searching behavior, in both the objective and decision space, to arrive at this final performance. This paper presents metrics for analyzing the searching behavior of ant colony optimization algorithms, a particular type of EA, for the optimal water distribution system design problem, which is a classical NP-hard problem in civil engineering. Using the proposed metrics, behavior is characterized in terms of three different attributes: (1) the effectiveness of the search in improving its solution quality and entering into optimal or near-optimal regions of the search space, (2) the extent to which the algorithm explores as it converges to solutions, and (3) the searching behavior with respect to the feasible and infeasible regions. A range of case studies is considered, where a number of ant colony optimization variants are applied to a selection of water distribution system optimization problems. The results demonstrate the utility of the proposed metrics to give greater insight into how the internal operators affect each algorithm's searching behavior.

Zecchin, A. C.; Simpson, A. R.; Maier, H. R.; Marchi, A.; Nixon, J. B.

2012-09-01

58

Ant Colony Optimization  

NSDL National Science Digital Library

The Ant Colony Optimization project uses the behavior of ants as a model to solve optimization problems, such as how to minimize Internet traffic congestion. Several downloadable research papers are included on the project's homepage, as well as links to news stories, radio broadcasts, and conference proceedings about ant algorithms.

Dorigo, Marco

59

John Muir, Yosemite, and the Sublime Response: A Study in the Rhetoric of Preservationism.  

ERIC Educational Resources Information Center

Shows how Muir's writing succeeded in transforming his readers' imaginative experience of scenic grandeur into an obligation to support preservationist legislation. Demonstrates how he influenced the establishment of Yosemite National Park and the preservation of wilderness reserves. (PD)

Oravec, Christine

1981-01-01

60

Ant hill  

NSDL National Science Digital Library

Ants build ant hills as a result of digging underground. They dig several different chambers underground to live in and raise young ants in. As they make these chambers, the ants bring the unneeded soil to the surface, forming what we see as an ant hill.

Peter N/A (None; )

2006-01-10

61

A new algorithm for a Dynamic Vehicle Routing Problem based on Ant Colony System  

Microsoft Academic Search

An aboundant literature on vehicle routing problems is available. However, almost all the work deals with static problems where all data are known in advance, i.e. before the optimization has started. The technological advances of the last few years give rise to a new class of problems, namely the dynamic vehicle routing problems, where new orders are received as time

R. Montemanni; L. M. Gambardella; A. E. Rizzoli; A. V. Donati

2003-01-01

62

Diagnostic error: what Muir-Torre syndrome has taught us.  

PubMed

A low-grade sebaceous carcinoma was excised from a 55-year-old woman's neck. At follow-up, 11?months later, a recent diagnosis of mucinous adenocarcinoma of the colon and history of clear cell endometrial carcinoma were identified. A strong family history of bowel cancer suggested Muir-Torre syndrome. Unexpectedly, hereditary non-polyposis colorectal cancer had previously been genetically confirmed; the results were found loosely filed in the paper chart. The patient had not informed us about her diagnosis; having discussed the case with other physicians she felt the diagnosis would be common knowledge. In 1999, US National Institute of Medicine estimated that preventable medical error resulted in the deaths of 44-98?000 people yearly in US hospitals. Four categories of medical error, including diagnosis, treatment, preventive and 'other' were described, while the reasoning processes that result in these errors are outlined by Reason et al. We utilise this rare case to illustrate these important concepts. PMID:25795746

Wall, Dmitri; Hackett, Caitriona Bridget; Healy, Vourneen; Ramsay, Bart

2015-01-01

63

Honey Ants.  

ERIC Educational Resources Information Center

Provides background information on honey ants. These ants are found in dry or desert regions of North America, Africa, and Australia. Also provides a list of activities using local species of ants. (JN)

Conway, John R.

1984-01-01

64

At-Least Version of the Generalized Minimum Spanning Tree Problem: Optimization Through Ant Colony System and Genetic Algorithms  

NASA Technical Reports Server (NTRS)

The At-Least version of the Generalized Minimum Spanning Tree Problem (L-GMST) is a problem in which the optimal solution connects all defined clusters of nodes in a given network at a minimum cost. The L-GMST is NPHard; therefore, metaheuristic algorithms have been used to find reasonable solutions to the problem as opposed to computationally feasible exact algorithms, which many believe do not exist for such a problem. One such metaheuristic uses a swarm-intelligent Ant Colony System (ACS) algorithm, in which agents converge on a solution through the weighing of local heuristics, such as the shortest available path and the number of agents that recently used a given path. However, in a network using a solution derived from the ACS algorithm, some nodes may move around to different clusters and cause small changes in the network makeup. Rerunning the algorithm from the start would be somewhat inefficient due to the significance of the changes, so a genetic algorithm based on the top few solutions found in the ACS algorithm is proposed to quickly and efficiently adapt the network to these small changes.

Janich, Karl W.

2005-01-01

65

Turning Points of Wisconsin: Original Manuscript Letters of John Muir, 1861-1914  

NSDL National Science Digital Library

From his days as a young man studying at the University of Wisconsin to his time in the wilderness areas of California, John Muir evolved from a "fundamental Christian to tree-hugging Transcendentalist", and these rather glorious letters that he wrote during this long period are now available on this site, provided by the Wisconsin Historical Society. Here visitors can peruse more than 100 pages of original letters written by Muir which deal with a wide range of topics, including his student days in Madison, the birth of his first child, and the publication of his now famous autobiography. Perusing the collection, visitors can view the original handwritten letters side by side with typed versions and their transcriptions. Overall, this is a fine collection, and anyone with an interest in Muir or the history of the American conservation movement will enjoy it.

66

An Improved Ant Colony Optimisation Algorithm for the 2D HP Protein Folding Problem  

E-print Network

of a protein's structure from its amino-acid sequence is one of the most important problems in computational Colony Optimisation (ACO) algorithm for this £¥¤ -hard combinatorial problem and demonstrate its ability Colony Optimisation (ACO) is a population-based approach for solving combi- natorial optimisation

Hoos, Holger H.

67

Carpenter Ants  

E-print Network

professional pest control operator to control carpenter ants. Professionals are familiar with the biology and control of these ants and have experience in finding the nests. Carpenter ants tend to be noisy within their nest, so pest control opera- tors may... can help the opera- tor find and eliminate colonies. Baits with active ingredients such as abamectin, fipronil and hydramethylnon are labeled for carpenter ants. The colony can be controlled successfully if for- aging ants take the baits and pass...

Gold, Roger E.; Glenn, Grady J.; Brown, Elizabeth

2006-08-07

68

The Ants Go Marching Millions by Millions: Invasive Ant Research  

Technology Transfer Automated Retrieval System (TEKTRAN)

Invasive ants are a worldwide problem that is expanding both geographically and in intensity. Population explosions of invasive ants can overrun landscapes and inundate structures. Pest management professionals are often the first responders to complaints about invading ants. This session will fo...

69

The ants go marching millions by millions: invasive ant research  

Technology Transfer Automated Retrieval System (TEKTRAN)

Invasive ants are a worldwide problem that is expanding both geographically and in intensity. Population explosions of invasive ants can overrun landscapes and inundate structures. Pest management professionals are often the first responders to complaints about invading ants. This session will fo...

70

Multi-route railroad blocking problem by improved model and ant colony algorithm in real world  

Microsoft Academic Search

In rail freight transportation, general merchandise freight cars may pass through many classification stations on their route from origin to destination. The Railroad Blocking Problem (RBP) is to reclassify inbound traffic from various origins in the classification stations and put them on outbound trains with the same or close destinations, the objective of the RBP is to minimize the total

Yixiang Yue; Leishan Zhou; Qunxing Yue; Zhenping Fan

2011-01-01

71

Muir-Torre syndrome: a variant of the cancer family syndrome  

Microsoft Academic Search

Muir-Torre syndrome is characterised by the association of sebaceous tumours of the skin with internal malignancy. In many instances there is a strong family history of cancer and the autosomal dominant mode of inheritance, tumour spectrum, and high incidence of synchronous and metachronous tumours show parallels with the cancer family syndrome or Lynch II syndrome. We report a five generation

N R Hall; M A Williams; V A Murday; J A Newton; D T Bishop

1994-01-01

72

Framing a Philosophy of Environmental Action: Aldo Leopold, John Muir, and the Importance of Community  

ERIC Educational Resources Information Center

A philosophy of action consists of a theory about how and why we do things and what motivates us to act. By juxtaposing the theory of environmental action implied by the works and life of John Muir with the philosophy of action suggested by Aldo Leopold's Land Ethic, we will illuminate the importance of a philosophy of action in determining one's…

Goralnik, Lissy; Nelson, Michael P.

2011-01-01

73

Ant Colony Optimization From Scholarpedia  

E-print Network

Ant Colony Optimization From Scholarpedia From Scholarpedia, the free peer-reviewed encyclopedia p.18620 Curator: Marco Dorigo, IRIDIA, Université Libre de Bruxelles, Brussels, Belgium Ant colony to difficult optimization problems. In ACO, a set of software agents called artificial ants search for good

Libre de Bruxelles, Université

74

Harvester ants  

NSDL National Science Digital Library

Shows several different views of harvester ants, a major food source of the Texas horned lizard. The video is large and a highspeed connection is recommended. The video shows ants entering their nest and moving on pathways that have been cleared of debris. The nest entrance has guards that are checking each of the returning ants.

0000-00-00

75

MANAGING IMPORTED FIRE ANTS IN URBAN AREAS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The two species of imported fire ants (red imported fire ant, Solenopsis invicta, and black imported fire ant, Solenopsis richteri) and their sexually reproducing hybrid are invasive insects whose stings can cause serious medical problems. Imported fire ants interfere with outdoor activities and ha...

76

Farming ants run microbe motels  

NSDL National Science Digital Library

The ants that grow fungus in little gardens face a problem that is well known to human farmers - pests. Scientists have just discovered that farming ants are covered in little "motel rooms" that serve as shelter for bacteria that protect their crops.

American Association for the Advancement of Science (AAAS; )

2006-01-05

77

A case of Muir-Torre syndrome with multiple cancers of bilateral eyelids and breast.  

PubMed

We report a case of Muir-Torre syndrome (MTS) with a very rare combination of cancers, involving bilateral eyelid cancers and breast cancer. A 71-year-old female with a history of breast cancer from 18 years prior presented with bilateral eyelid tumors. One of her siblings had lung cancer, and another had pancreatic cancer. She underwent excisional biopsy of the eyelid tumors and histopathology revealed sebaceous carcinoma of the right eyelid and basal cell carcinoma of the left. She was diagnosed with MTS: a skin cancer associated with visceral malignancy. Immunohistochemical tests for mutS homolog 2 showed a lack of expression in both eyelid carcinomas. PMID:23730114

Kamisasanuki, Taro; Uchino, Eisuke; Fukushima, Jun-Ichi; Yoshikawa, Hiroshi; Ishibashi, Tatsuro; Sakamoto, Taiji

2013-06-01

78

A Case of Muir-Torre Syndrome with Multiple Cancers of Bilateral Eyelids and Breast  

PubMed Central

We report a case of Muir-Torre syndrome (MTS) with a very rare combination of cancers, involving bilateral eyelid cancers and breast cancer. A 71-year-old female with a history of breast cancer from 18 years prior presented with bilateral eyelid tumors. One of her siblings had lung cancer, and another had pancreatic cancer. She underwent excisional biopsy of the eyelid tumors and histopathology revealed sebaceous carcinoma of the right eyelid and basal cell carcinoma of the left. She was diagnosed with MTS: a skin cancer associated with visceral malignancy. Immunohistochemical tests for mutS homolog 2 showed a lack of expression in both eyelid carcinomas. PMID:23730114

Kamisasanuki, Taro; Uchino, Eisuke; Fukushima, Jun-ichi; Yoshikawa, Hiroshi; Ishibashi, Tatsuro

2013-01-01

79

Ant colony search algorithm for unit commitment  

Microsoft Academic Search

In this paper, the ant colony search algorithm (ACSA) is proposed to solve the thermal unit commitment problem. ACSA is a new cooperative agents approach, which is inspired by the observation of the behaviors of real ant colonies on the topic of ant trial formation and foraging methods. In the ACSA, a set of cooperating agents called \\

T. Sum-im; W. Ongsakul

2003-01-01

80

Pest Ants and Cockroaches  

NSDL National Science Digital Library

Tutorials on pest ants and cockroaches. Each tutorial has 50 questions; incorrect answers lead to additional information. Covers acrobat ant, Argentine ant, bigheaded ant, crazy ant, Florida carpenter ant, ghost ant, imported fire ant, little fire ant, native fire ant and Pharaoh ant, American cockroach, Australian cockroach, brown cockroach, brownbanded cockroach, Cuban cockroach, Florida woods cockroaches, German cockroach, oriental cockroach, smokybrown cockroach and Surinam cockroach. Requires Windows. program must be downloaded on to hardrive, but once installed is intuitive. many of the species depicted in these tutorials are restricted to Florida and the extreme southern U.S. $15. Part number SW 157.

0000-00-00

81

AN ANT COLONY SYSTEM APPROACH FOR SOLVING THE AT-LEAST VERSION OF THE GENERALIZED MINIMUM SPANNING TREE PROBLEM  

E-print Network

, the Minimum Spanning Tree (MST) problem seeks to find a spanning tree on the nodes such that the cost's and Kruskal's algorithms [1]. An extension to the MST, the Generalized Minimum Span- ning Tree (GMST) problem of the GMST, introduced by Ihler et. al. [3], is the L- GMST, where a minimum weight spanning tree is sought

Arabshahi, Payman

82

The genetic basis of Muir-Torre syndrome includes the hMLH1 locus  

SciTech Connect

Muir-Torre syndrome (MTS) (McKusick 158320) is an autosomal dominant disorder characterized by the development of sebaceous gland tumors and skin cancers, including keratoacanthomas and basal cell carcinomas. Affected family members may manifest a wide spectrum of internal malignancies, which include colorectal, endometrial, urologic, and upper gastrointestinal neoplasms. Sebaceous gland tumors, which are rare in the general population, are considered to be the hallmark of MTS and may arise prior to the development of other visceral cancers. Despite the high incidence of synchronous and metachronous tumors, prognosis is often favorable. Hereditary nonpolyposis colorectal cancer (HNPCC) is one of the most common autosomal dominantly inherited colorectal cancer susceptibility syndromes. In some HNPCC families, extracolonic tumors of the endometrium, ovary, small bowel, and renal and biliary tract occur at an increased frequency. On the basis of similarities in clinical symptoms of MTS and HNPCC, it is proposed that these two syndromes may have a common genetic basis. 24 refs., 2 figs.

Bapat, B.; Xia, L.; Mitri, A. [Univ. of Toronto (Canada)] [and others

1996-09-01

83

Understanding and Managing Experiential Aspects of Soundscapes at Muir Woods National Monument  

NASA Astrophysics Data System (ADS)

Research has found that human-caused noise can detract from the quality of the visitor experience in national parks and related areas. Moreover, impacts to the visitor experience can be managed by formulating indicators and standards of quality as suggested in park and outdoor recreation management frameworks, such as Visitor Experience and Resource Protection (VERP), as developed by the U.S. National Park Service. The research reported in this article supports the formulation of indicators and standards of quality for human-caused noise at Muir Woods National Monument, California. Phase I identified potential indicators of quality for the soundscape of Muir Woods. A visitor “listening exercise” was conducted, where respondents identified natural and human-caused sounds heard in the park and rated the degree to which each sound was “pleasing” or “annoying.” Certain visitor-caused sounds such as groups talking were heard by most respondents and were rated as annoying, suggesting that these sounds may be a good indicator of quality. Loud groups were heard by few people but were rated as highly annoying, whereas wind and water were heard by most visitors and were rated as highly pleasing. Phase II measured standards of quality for visitor-caused noise. Visitors were presented with a series of 30-second audio clips representing increasing amounts of visitor-caused sound in the park. Respondents were asked to rate the acceptability of each audio clip on a survey. Findings suggest a threshold at which visitor-caused sound is judged to be unacceptable, and is therefore considered as noise. A parallel program of sound monitoring in the park found that current levels of visitor-caused sound sometimes violate this threshold. Study findings provide an empirical basis to help formulate noise-related indicators and standards of quality in parks and related areas.

Pilcher, Ericka J.; Newman, Peter; Manning, Robert E.

2009-03-01

84

Understanding and managing experiential aspects of soundscapes at Muir woods national monument.  

PubMed

Research has found that human-caused noise can detract from the quality of the visitor experience in national parks and related areas. Moreover, impacts to the visitor experience can be managed by formulating indicators and standards of quality as suggested in park and outdoor recreation management frameworks, such as Visitor Experience and Resource Protection (VERP), as developed by the U.S. National Park Service. The research reported in this article supports the formulation of indicators and standards of quality for human-caused noise at Muir Woods National Monument, California. Phase I identified potential indicators of quality for the soundscape of Muir Woods. A visitor "listening exercise" was conducted, where respondents identified natural and human-caused sounds heard in the park and rated the degree to which each sound was "pleasing" or "annoying." Certain visitor-caused sounds such as groups talking were heard by most respondents and were rated as annoying, suggesting that these sounds may be a good indicator of quality. Loud groups were heard by few people but were rated as highly annoying, whereas wind and water were heard by most visitors and were rated as highly pleasing. Phase II measured standards of quality for visitor-caused noise. Visitors were presented with a series of 30-second audio clips representing increasing amounts of visitor-caused sound in the park. Respondents were asked to rate the acceptability of each audio clip on a survey. Findings suggest a threshold at which visitor-caused sound is judged to be unacceptable, and is therefore considered as noise. A parallel program of sound monitoring in the park found that current levels of visitor-caused sound sometimes violate this threshold. Study findings provide an empirical basis to help formulate noise-related indicators and standards of quality in parks and related areas. PMID:19020928

Pilcher, Ericka J; Newman, Peter; Manning, Robert E

2009-03-01

85

Ant nebula  

NASA Technical Reports Server (NTRS)

A new Hubble Space Telescope image of a celestial object called the Ant Nebula may shed new light on the future demise of our Sun. The image is available at http://www.jpl.nasa.gov/pictures/wfpc .

The nebula, imaged on July 20, 1997, and June 30, 1998, by Hubble's Wide Field and Planetary Camera 2, was observed by Drs. Raghvendra Sahai and John Trauger of NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Bruce Balick of the University of Washington in Seattle; and Vincent Icke of Leiden University in the Netherlands. JPL designed and built the camera.

The Ant Nebula, whose technical name is Mz3, resembles the head and thorax of an ant when observed with ground-based telescopes. The new Hubble image, with 10 times the resolution revealing 100 times more detail, shows the 'ant's' body as a pair of fiery lobes protruding from a dying, Sun- like star. The Ant Nebula is located between 3,000 and 6,000 light years from Earth in the southern constellation Norma.

The image challenges old ideas about what happens to dying stars. This observation, along with other pictures of various remnants of dying stars called planetary nebulae, shows that our Sun's fate will probably be much more interesting, complex and dramatic than astronomers previously believed.

Although the ejection of gas from the dying star in the Ant Nebula is violent, it does not show the chaos one might expect from an ordinary explosion, but instead shows symmetrical patterns. One possibility is that the central star has a closely orbiting companion whose gravitational tidal forces shape the outflowing gas. A second possibility is that as the dying star spins, its strong magnetic fields are wound up into complex shapes like spaghetti in an eggbeater. Electrically charged winds, much like those in our Sun's solar wind but millions of times denser and moving at speeds up to 1,000 kilometers per second (more than 600 miles per second) from the star, follow the twisted field lines on their way out into space.

The Space Telescope Science Institute, Baltimore, Md., manages space operations for the Hubble Space Telescope for NASA's Office of Space Science, Washington, D.C. The Institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA under contract with NASA's Goddard Space Flight Center, Greenbelt, Md. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. JPL is a division of the California Institute of Technology in Pasadena.

Additional information about the Hubble Space Telescope is available at http://www.stsci.edu . More information about the Wide Field and Planetary Camera 2 is available at http://wfpc2.jpl.nasa.gov.

1999-01-01

86

The Ants Have It!  

ERIC Educational Resources Information Center

Uses the GEMS guide, "Ants at Home Underground", to explore the life of ants and teach about them in a classroom setting. The activity applies students' knowledge of ants and students learn about ant colonies, what ants eat, and how they live. (SAH)

Daugherty, Belinda

2001-01-01

87

Odorant binding proteins (OBPs) of the Red Imported Fire Ant, Solenopsis invicta (Hymenoptera: Formicidae): An example of the problems facing the analysis of widely divergent proteins  

Technology Transfer Automated Retrieval System (TEKTRAN)

We describe the odorant binding proteins (OBPs) of the red imported fire ant, Solenopsis invicta, obtained from analyses of a single EST library and data generated from separate 454 sequencing runs of two normalized cDNA libraries. We identified a total of 18 OBPs in this ant, which is the smallest ...

88

A New Ant Algorithm for Graph Coloring Alain Hertz1  

E-print Network

A New Ant Algorithm for Graph Coloring Alain Hertz1 and Nicolas Zufferey2 1 D´epartement de math describe in this paper a new ant algorithm for the k-coloring problem. Computational experiments give evidence that our algorithm is competitive with the existing ant algorithms for this problem, while giving

Hertz, Alain

89

Fire Ants and Thelohania Fire Ant Disease  

NSDL National Science Digital Library

Excellent summary of how Thelohania fire ant disease works as a biological control measure against fire ants. Unhurried pace with great supporting video and graphics. Good choice for introducing students to the idea of biological control. Video quality is excellent. This video should probably be used in conjunction with the other two fire ant biocontrol videos produced by the same workers.

0000-00-00

90

Synchronous gastric and sebaceous cancers, a rare manifestation of MLH1-related Muir-Torre syndrome  

PubMed Central

Muir-Torre syndrome (MTS), a rare variant of the hereditary non polyposis colorectal cancer syndrome, is an autosomal dominant genodermatosis characterised by coincidence of sebaceous gland neoplasms (sebaceous adenoma, epithelioma, or carcinoma) and at least one internal malignancy. The underlying cause of MTS is a germline mutation in DNA mismatch repair genes MSH2, MLH1 and MSH6. We report the case of a 52-year-old caucasian woman with the development of metachronous colon cancer at the age of 38 years, uterine cancer at the age of 43 years, and unique occurrence of synchronous gastric and sebaceous carcinomas related to germline point mutation c. 2194A>T in the last exon of MLH1 gene, resulting in truncated protein in C-terminal region p. Lys732X due to premature stop codon. This mutation, not previously reported in MTS, disrupts the function of MutL complexes presumably by preventing the interaction with PMS1/PMS2 and impairing the endonuclease active site. This case points out the importance of sebaceous neoplasia, especially sebaceous adenocarcinoma, as cutaneous markers of MTS for timely implementation of cancer screening programs. PMID:25197397

Švec, Ji?í; Schwarzová, Lucie; Janošíková, Bohumila; Štekrová, Jitka; Mandys, Václav; Kment, Milan; Vodi?ka, Pavel

2014-01-01

91

Marine benthic habitat mapping of Muir Inlet, Glacier Bay National Park and Preserve, Alaska, with an evaluation of the Coastal and Marine Ecological Classification Standard III  

USGS Publications Warehouse

Seafloor geology and potential benthic habitats were mapped in Muir Inlet, Glacier Bay National Park and Preserve, Alaska, using multibeam sonar, ground-truth information, and geological interpretations. Muir Inlet is a recently deglaciated fjord that is under the influence of glacial and paraglacial marine processes. High glacially derived sediment and meltwater fluxes, slope instabilities, and variable bathymetry result in a highly dynamic estuarine environment and benthic ecosystem. We characterize the fjord seafloor and potential benthic habitats using the Coastal and Marine Ecological Classification Standard (CMECS) recently developed by the National Oceanic and Atmospheric Administration (NOAA) and NatureServe. Substrates within Muir Inlet are dominated by mud, derived from the high glacial debris flux. Water-column characteristics are derived from a combination of conductivity temperature depth (CTD) measurements and circulation-model results. We also present modern glaciomarine sediment accumulation data from quantitative differential bathymetry. These data show Muir Inlet is divided into two contrasting environments: a dynamic upper fjord and a relatively static lower fjord. The accompanying maps represent the first publicly available high-resolution bathymetric surveys of Muir Inlet. The results of these analyses serve as a test of the CMECS and as a baseline for continued mapping and correlations among seafloor substrate, benthic habitats, and glaciomarine processes.

Trusel, Luke D.; Cochrane, Guy R.; Etherington, Lisa L.; Powell, Ross D.; Mayer, Larry A.

2010-01-01

92

“Anting” in Blue Jays  

PubMed Central

Summary Anting, the plumage-dipping behavior to which ants (mostly formicines) are commonly subjected by birds (mostly passerines), is shown in tests with hand-raised Blue Jays (Cyanocitta cristata) and the ant Formica exsectoides to be instinctive: the birds displayed typical renditions of the behavior on the first occasion that they encountered ants. Evidence is presented supportive of the view that anting is a strategy by which birds render ants fit for ingestion. Formicine ants are ordinarily protected by their formic acid-containing spray. Being wiped into the bird’s plumage causes them to discharge that spray, without harm to the bird, to the point of almost total emptying of the glandular sac in which the secretion is stored. The ants are therefore essentially secretion-free by the time they are swallowed. Further evidence indicates that it is the ant’s possession of the acid sac that triggers the anting behavior in the bird. If F. exsectoides are surgically deprived of their acid sac, they are eaten by the birds without first being subjected to anting. Data are also presented indicating that the ant’s crop, which is especially capacious in formicines (its contents may amount to over 30% of the formicine’s mass), and which appears to survive the anting procedure intact, constitutes, at least when laden, a valuable component of the trophic package that the bird accesses by anting. PMID:19169379

Eisner, Thomas; Aneshansley, Daniel

2008-01-01

93

Acacia Tree Ants  

NSDL National Science Digital Library

The phenomenon is the symbiotic relationship between the acacia ant and the swollen thorn acacia tree, shown in a 2:18 minute video. The ant provides protection for the tree against preying insects and other plants competing for sunlight, and the tree provides nourishment and shelter for the ant and the ants' larvae.

94

THE IMPORTED FIRE ANTS AND THEIR MANAGEMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Imported fire ants (IFA) cause many problems for humans, domestic animals, and agriculture. Imported fire ants are very aggressive, build conspicuous mounds, and have a sting that gives a burning sensation. IFAs have also had a major impact on wildlife and their effects on quail populations can be s...

95

How Many Ants Does It Take To Find the Food? Yuval Emek1  

E-print Network

How Many Ants Does It Take To Find the Food? Yuval Emek1 , Tobias Langner2 , David Stolz2 , Jara the Ants Nearby Treasure Search (ANTS) problem, where n mobile agents, initially placed at the origin constant-size mes- sages. We show that the minimum number of agents required to solve the ANTS problem

96

Higher Order Pheromone Models in Ant Colony Optimisation  

E-print Network

Higher Order Pheromone Models in Ant Colony Optimisation James Montgomery Faculty of Information problem-specific components. A pa- rameterised model known as pheromone--an analogue of the trail phero. Keywords: Ant colony optimisation, pheromone model, model-based search. 1 Introduction Ant colony

Montgomery, James

97

Using Ant Colony Optimization to guide a CP search  

E-print Network

Using Ant Colony Optimization to guide a CP search Madjid Khichane1, Patrick Albert1, and Christine;Introduction Ant-CP Car sequencing Results I/D study Conclusion Motivations Constraint Programming High level Describe the problem with Ilog solver Use Ilog solver to propagate and verify constraints Use Ant Colony

Solnon, Christine

98

The ANT Architecture { An Architecture For CS1  

E-print Network

The ANT Architecture { An Architecture For CS1 Dan Ellard, Penelope Ellard, James Megquier, J this problem, we have developed a sim- ple virtual machine called ANT for use in our intro- ductory computer science (CS1) curriculum. ANT is designed to be simple enough that a CS1 student can quickly understand it

99

Applying Ant Colony Optimization Methods in an Artificial Chemistry  

E-print Network

Applying Ant Colony Optimization Methods in an Artificial Chemistry Context to Routing Problems.traumfisch.ch . #12;Abstract The foraging task of ants show several similarities with the task of packet routing in networks. This thesis describes the implementation of a combina- tion of existing ant inspired routing

Vetter, Thomas

100

Management of Imported Fire Ants in Cattle Production Systems  

E-print Network

ANR-1248 ALABAMA A&M AND AUBURN UNIVERSITIES Management of Imported Fire Ants in Cattle Production Systems I mported fire ants are now a major pest problem throughout the southeastern United States, including in cattle production operations (Figures... imported fire ant problems in cattle operations. The goal of integrated pest management is to control a pest only when the potential cost of the problem meets or exceeds the cost of the solution. This publication also provides tips to help reduce the cost...

Fuchs, Thomas W.; Drees, Bastiaan M.

2004-03-31

101

Fire Ant Allergy  

MedlinePLUS

Share | Fire Ant Allergy This article has been reviewed by Thanai Pongdee, MD, FAAAAI Fire ants are a stinging insect typically found in ... Symptoms of a Serious Reaction For people with fire ant allergy, stings may cause a life-threatening ...

102

Steve Yanoviak's Gliding Ants  

NSDL National Science Digital Library

Home page of the gliding ant research of Steve Yanoviak including many videos of ants falling and swerving back to the tree, comparison videos of non-gliding ants are given for comparison. This is a fascinating insect behavior that may be an evolutionary step in insect flight.

0000-00-00

103

Taste test for ants  

NSDL National Science Digital Library

Scientists put a bunch of ants through a taste test. In particular, the new research looks at the relationship between the ants that protect certain plants from other insects, plants and diseases. In return for their work, the ants get a place to live as well as nectar to eat.

American Association for the Advancement of Science (AAAS; )

2005-04-21

104

Fire ant trail  

NSDL National Science Digital Library

Fire ants mark their trail with a substance from the Dufour's gland. The trail used by a group of fire ants is shown. Several examples of groups of ants following each other are shown. File size is large and a highspeed connection is recommended.

0000-00-00

105

Red Harvester Ants  

E-print Network

& Garden Insect Killer boric acid 7.5% AntX 75 hydramethylnon 0.365% plus s-methoprene 0.250% Extinguish Plus hydramethylnon 0.73% Amdro Pro Fire Ant Bait hydramethylnon 1.0% Maxforce Fire Ant Killer Granular Bait Maxforce Professional Insect Control Fine...

Drees, Bastiaan M.

2006-04-24

106

A Dynamically Reconfigurable Asynchronous K.A. Fawaz, T. Arslan, S. Khawam, M. Muir, I. Nousias, I. Lindsay, and A. Erdogan  

E-print Network

-power ARM processor, while maintaining their throughput performance. For example, our processor resulted in a reduction in power consumption over the ARM7 processor of over 9 times when running the bilinear demosaicingA Dynamically Reconfigurable Asynchronous Processor K.A. Fawaz, T. Arslan, S. Khawam, M. Muir, I

Arslan, Tughrul

107

Smoke on the Water: Energy usage of the Muir-Samuelson Natatorium Jillian Hancock, 17 May 2009, GEOS 206-01  

E-print Network

during a time of economic crisis, it may be beneficial to assess pool facility costs in order to better1 Smoke on the Water: Energy usage of the Muir-Samuelson Natatorium Jillian Hancock, 17 May 2009,340 kWh per month (Clark, Appendix, Table 1). Assuming electricity costs $0.13 per kWh, it requires $564

Aalberts, Daniel P.

108

Fire Ants: Ecological Bullies  

NSDL National Science Digital Library

This two-minute radio program looks at factors that contribute to Brazilian fire ants' dominance over native ant species in the southeastern United States. An ecologist describes some of these factors, including a lack of control agents, which allow Brazilian fire ants to out compete local ants. The program includes examples of the sounds that Brazilian fire ants use to help coordinate their invasions. The archived program, part of the Pulse of the Planet radio show, is available here in text and audio formats. Copyright 2005 Eisenhower National Clearinghouse

Pulse of the Planet

2007-01-26

109

[The ants: a strategy of population concentration].  

PubMed

Ants are provided with a balanced system of reactions either to the original paucity of socia or to their secondary depopulation. This system can be defined as a strategy of population concentration. Both a successful reproduction of workers and queen fertilization are necessary conditions for ant communities' survival and development. Thus, the anthills must be large enough to ensure optimal conditions for reproduction. It is the strategy of population concentration that is directed to an accelerated attainment (or rehabilitation) by a socium of a state of stable development by way of concentrating the existent ant staff in an accessible number of viable nests. This strategy is realized throughout the life of ant communities by way of (a) fusing the starting family cells left by founder females, (b) fusing small anthills during artificial ant migrations, (c) uniting smaller socia or their joining other anthills, (d) reintegrating the secondary anthills (fragmentants) after an exogenous fragmentation of formicaries. Pooling and the attraction of deficient demographic resources from outside form the most efficient and quickest ways of reaching or restoring the threshold density levels. By realizing this strategy, the ants solve their paramount problems of anthill or settlement conservation at any particular time, as well as of providing some prospects for ant existence in the future. These problems are so vital for ant socia that they appear to hold priority over such other characteristics of utmost importance as genetic kinship or even species identity. The priority of social basics over genetic ones is unequivocally supported through mixed formicaries. A necessary condition for the realization of the strategy of population concentration is tolerance of highly developed social systems to the diversity of forms and to deviations from the norm. The use of one and the same mechanism at all stages of the life both of an individual socium and large ant settlements is evidence of the universality of this strategy, as well as of its unconditioned importance to the life of ant communities. PMID:21954628

Zakharov, A A

2011-01-01

110

Acoustic communication by ants  

NASA Astrophysics Data System (ADS)

Many ant species communicate acoustically by stridulating, i.e., running a scraper over a washboard-like set of ridges. Ants appear to be insensitive to airborne sound. Consequently, myrmecologists have concluded that the stridulatory signals are transmitted through the substrate. This has tended to diminish the importance of acoustic communication, and it is currently believed that ant communication is based almost exclusively on pheromones, with acoustic communication assigned an almost nonexistent role. However, it can be shown that acoustic communication between ants is effective only if the medium is air and not the substrate. How, then, is it possible for ants to appear deaf to airborne sound and yet communicate through the air? An explanation is provided in a paper [R. Hickling and R. L. Brown, ``Analysis of acoustic communication by ants,'' J. Acoust. Soc. Am. 108, 1920-1929 (2000)]. Ants are small relative to the wavelengths they generate. Hence, they create a near field, which is characterized by a major increase in sound velocity (particle velocity of sound) in the vicinity of the source. Hair sensilla on the ants' antennae respond to sound velocity. Thus, ants are able to detect near-field sound from other ants and to exclude extraneous airborne sound.

Hickling, Robert

2002-05-01

111

Ants of Borneo  

NSDL National Science Digital Library

The names Aenictinae, Ceraphachyine, Dorylinae, and Dolichoderinae may not mean much to those outside the world of entomology, but these are but a few of the subfamilies of ants profiled on this nice website designed by Martin Pfeiffer of the University of Ulm. These subfamilies of ants are all present in Kinabulu National Park in Malaysia, a tropical rainforest that has the notable distinction of containing the world's most diverse ant population. Visitors to the site can browse images of over 130 species of ants (divided by their respective subfamily), presented in more than 520 high resolution photographs. Culled from the work of a number of different researchers, the ants photographed for this site were mostly collected during fieldwork that took place between 1991 and 2002. Those persons unfamiliar with the world of the ants of Borneo will have a most intimate understanding of these fascinating creatures and some sense of their sheer diversity after traversing this site.

Pfeiffer, Martin

112

Managing Household Ant Pests  

E-print Network

workers and not ants in the nest. Boric acid products are commonly formu- lated in sugar water (25 percent sucrose) and placed in a dispenser. Concentrations of 0.5 to 3.7 percent are most attractive to Argentine ants. Higher concentrations are less... attractive. Boric acid is a slow-acting stomach poison. Be careful using it outdoors because it is toxic to plants. For pharaoh ants, if the nest cannot be located, use a bait (e.g., Drax ? Ant Kill Gel containing 5 percent orthoboric acid or Terro...

Drees, Bastiaan M.

2005-12-02

113

Caribbean Crazy Ants and their look-alikes in Florida  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Caribbean crazy ant (Nylanderia pubens) continues to grow as a nuisance pest problem in Florida. Homeowners and pest management professionals alike have difficulty in controlling the huge populations that can occur on infested properties. Key to dealing with any pest ant problem is to identify...

114

Leaf cutter ants  

NSDL National Science Digital Library

There is much diversity between ants. Leaf cutter ants use their mandibles to cut leaf fragments and take them back to their home. They don't eat the leaves, but instead use them to grow fungus on. They then eat the fungus.

N/A N/A (None; )

2007-12-15

115

The Ants Have It!  

NSDL National Science Digital Library

This memorable activity creatively applied students' knowledge of ants--and it all started with a wonderful Lawrence Hall GEMS guide and a teacher with a sweet tooth. The students learned that the success of the colony depends on each ant doing its job. Th

Belinda Daugherty

2001-02-01

116

An Ant System Approach to Redundancy Allocation Yun-Chia Liang  

E-print Network

An Ant System Approach to Redundancy Allocation Yun-Chia Liang Department of Industrial Engineering and demonstrating a problem-specific Ant System. The problem is to select components and redundancy-levels to maximize system reliability, given system-level constraints on cost and weight. The Ant System algorithm

Smith, Alice E.

117

The Fire Ant Sting  

NSDL National Science Digital Library

Mississippi State University extension page dealing with the symptoms of fire ant stings. A series of photographs track the initial sting, resulting pustules, and eventual healing common to such an encounter.

0000-00-00

118

Japanese Ant Image Database  

NSDL National Science Digital Library

The 2003 revised edition of the Japanese Ant Image Database was developed under the direction of the Japanese Ant Database Group (JADG). The website, which merges taxonomic information and stunning photographs, will no doubt delight myrmecologists and others. Information about different types of ants can be accessed through browseable, hyperlinked lists organized by subfamily, genus, and species. Genus and species profiles include images, references, descriptive information, simple distribution maps, and more. The site includes a Japanese Ant Image Library with hundreds of quality images, and a smaller SEM Image Library as well. The site also offers sections with Type Specimens and Taxonomic Keys. Please note that the site has not been updated since 2003; there are future plans to revisit the project when updates and corrections become necessary.

119

Chemicalmimicry Male ants disguised by  

E-print Network

Chemicalmimicry Male ants disguised by the queen's bouquet M ales of the tropical ant Cardiocondyla the coexistence and equal mating success of two male morphs. Ants typically mate during short nuptial flights-day-old ants, all four groups were clearly separated (Fig. 1b). We conclude that the odour similarity

Zachos, James

120

Biological Control of Fire Ants  

NSDL National Science Digital Library

Demonstrates fire ant invasion of the southern United States and two biological control approaches: decapitating flies and disease. Upbeat music and corny graphics may make it similar to DDT videos of yesteryear, but it is valuable to quickly demonstrate the problem to students. The video appears to overstate the potential impact of these biological control agents but is a good, and fairly entertaining, introduction to the topic of biocontrol for the RIA. It will be importantant to use this video in the propoer context.

0000-00-00

121

DEACO: Hybrid Ant Colony Optimization with Differential Evolution  

Microsoft Academic Search

Ant colony optimization (ACO) algorithm is a novel meta-heuristic algorithm for the approximate solution of combinatorial optimization problems that has been inspired by the foraging behavior of real ant colonies. ACO has strong robustness and easy to combine with other methods in optimization, but it has the shortcomings of stagnation that limits the wide application to the various areas. In

Xiangyin Zhang; Haibin Duan; Jiqiang Jin

2008-01-01

122

Evolution of supercolonies: The Argentine ants of southern Europe  

Microsoft Academic Search

Some ants have an extraordinary social organization, called unicoloniality, whereby individuals mix freely among physically separated nests. This type of social organization is not only a key attribute responsible for the ecological domination of these ants, but also an evolutionary paradox and a potential problem for kin selection theory because relatedness between nest mates is effectively zero. The introduction of

Tatiana Giraud; Jes S. Pedersen; Laurent Keller

2002-01-01

123

Ant Colony Optimization and Data Mining: Techniques and Trends  

Microsoft Academic Search

The Ant Colony Optimization (ACO) technique was inspired by the ants' behaviour throughout their exploration for food. The use of this technique has been very successful for several problems. Besides, Data Mining (DM) has emerged as an important technology with numerous practical applications, due to the wide availability of a vast amount of data. The collaborative use of ACO and

Ioannis Michelakos; Nikolaos Mallios; Elpiniki Papageorgiou; Michael Vassilakopoulos

2010-01-01

124

Does Trichomes on the Plant Epidermic Surface Disturb Ants Locomotion?  

Microsoft Academic Search

Problem Statement: Many morphological characteristics, both physical and chemical, are used in the defense against herbivores on plants. Trichomes are structures used by plants as physics defense and when associated with glands combine physics and chemistry defense. Many species of ants are herbivores and use leaves and seeds, others ants use Extra Floral Nectars as a food resource, and the

Danon Clemes Cardoso; Maykon Passos Cristiano; Lenise Cristina; Moraes Vilela

2009-01-01

125

Ants, Crickets and Frogs in Cyclic Pursuit  

E-print Network

Ants, Crickets and Frogs in Cyclic Pursuit A.M. Bruckstein 1 , N. Cohen 2 , A. Efrat 1 Abstract. We and with preassigned, varying speeds. We also consider two discrete analogs, in which crickets or frogs are engaged with synchronized crickets that jump together every unit of time. Here the relative complexity of the problem

Efrat, Alon

126

Clustering Web Search Results Using Fuzzy Ants  

E-print Network

Clustering Web Search Results Using Fuzzy Ants Steven Schockaert,* Martine De Cock, Chris Cornelis and Uncertainty Modelling Research Unit, Krijgslaan 281 (S9), B-9000 Gent, Belgium Algorithms for clustering Web existing approaches and illustrates how our algorithm can be applied to the problem of Web search results

Gent, Universiteit

127

Alate susceptibility in ants.  

PubMed

Pathogens are predicted to pose a particular threat to eusocial insects because infections can spread rapidly in colonies with high densities of closely related individuals. In ants, there are two major castes: workers and reproductives. Sterile workers receive no direct benefit from investing in immunity, but can gain indirect fitness benefits if their immunity aids the survival of their fertile siblings. Virgin reproductives (alates), on the other hand, may be able to increase their investment in reproduction, rather than in immunity, because of the protection they receive from workers. Thus, we expect colonies to have highly immune workers, but relatively more susceptible alates. We examined the survival of workers, gynes, and males of nine ant species collected in Peru and Canada when exposed to the entomopathogenic fungus Beauveria bassiana. For the seven species in which treatment with B. bassiana increased ant mortality relative to controls, we found workers were significantly less susceptible compared with both alate sexes. Female and male alates did not differ significantly in their immunocompetence. Our results suggest that, as with other nonreproductive tasks in ant colonies like foraging and nest maintenance, workers have primary responsibility for colony immunity, allowing alates to specialize on reproduction. We highlight the importance of colony-level selection on individual immunity in ants and other eusocial organisms. PMID:25540683

Ho, Eddie K H; Frederickson, Megan E

2014-11-01

128

Alate susceptibility in ants  

PubMed Central

Pathogens are predicted to pose a particular threat to eusocial insects because infections can spread rapidly in colonies with high densities of closely related individuals. In ants, there are two major castes: workers and reproductives. Sterile workers receive no direct benefit from investing in immunity, but can gain indirect fitness benefits if their immunity aids the survival of their fertile siblings. Virgin reproductives (alates), on the other hand, may be able to increase their investment in reproduction, rather than in immunity, because of the protection they receive from workers. Thus, we expect colonies to have highly immune workers, but relatively more susceptible alates. We examined the survival of workers, gynes, and males of nine ant species collected in Peru and Canada when exposed to the entomopathogenic fungus Beauveria bassiana. For the seven species in which treatment with B. bassiana increased ant mortality relative to controls, we found workers were significantly less susceptible compared with both alate sexes. Female and male alates did not differ significantly in their immunocompetence. Our results suggest that, as with other nonreproductive tasks in ant colonies like foraging and nest maintenance, workers have primary responsibility for colony immunity, allowing alates to specialize on reproduction. We highlight the importance of colony-level selection on individual immunity in ants and other eusocial organisms. PMID:25540683

Ho, Eddie K H; Frederickson, Megan E

2014-01-01

129

ASGA: Improving the Ant System by Integration with Genetic Tony White, Bernard Pagurek, Franz Oppacher 1  

E-print Network

ASGA: Improving the Ant System by Integration with Genetic Algorithms Tony White, Bernard Pagurek. Adaptation is achieved by integrating a genetic algorithm with the ant system and maintaining a population. This paper applies the Ant System with Genetic Algorithm (ASGA) system to the problem of path finding

White, Tony

130

Advances in Research on the Venom Chemistry of Imported Fire Ants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Workers of the imported fire ants, including red imported fire ants, Solenopsis invicta Buren, black imported fire ants, S. richteri Forel, and their hybrid (S. invicta × S. richteri), are vicious stingers. Since the venomous sting is a significant medical problem to humans, the chemistry of import...

131

Pheromone Biosynthesis Activating Neuropeptide (PBAN)/Pyrokinin Family of Peptides and Fire Ants, Solenopsis spp.  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fire ant, Solenopsis invicta, is an economically important invasive pest ant, causing over 6 billion dollars in control and repair costs each year in the United States. The fire ant is becoming a global problem increasing its importance and the need for the development of biologically-based con...

132

An Ant Colony Optimization Algorithm for the Optimization of the Keyboard Arrangement  

E-print Network

An Ant Colony Optimization Algorithm for the Optimization of the Keyboard Arrangement Problem Jan account of ergonomic criteria is proposed. Based on the generic framework of Ant Colony Optimiza- tion computations, ant colony optimization, key- board arrangement 1 Introduction A computer user or typist

Paris-Sud XI, Université de

133

Routing Vehicles with Ants  

NASA Astrophysics Data System (ADS)

Routing vehicles involve the design of an optimal set of routes for a fleet of vehicles to serve a number of customers with known demands. This research develops an Ant Colony Optimization for the vehicle routing with one central depot and identical vehicles. The procedure simulates the behavior of real ants that always find the shortest path between their nest and a food source through a form of communication, pheromone trail. Finally, preliminary results on the learning of the algorithm testing on benchmark data set will be presented in this paper.

Tan, Wen Fang; Lee, Lai Soon; Majid, Zanariah Abdul; Seow, Hsin Vonn

134

Universality in ant behaviour  

PubMed Central

Prediction for social systems is a major challenge. Universality at the social level has inspired a unified theory for urban living but individual variation makes predicting relationships within societies difficult. Here, we show that in ant societies individual average speed is higher when event duration is longer. Expressed as a single scaling function, this relationship is universal because for any event duration an ant, on average, moves at the corresponding average speed except for a short acceleration and deceleration at the beginning and end. This establishes cause and effect within a social system and may inform engineering and control of artificial ones. PMID:25411406

Christensen, Kim; Papavassiliou, Dario; de Figueiredo, Alexandre; Franks, Nigel R.; Sendova-Franks, Ana B.

2015-01-01

135

Ice-proximal sediment dynamics and their effect on the stability of Muir Glacier, Alaska: A case study of non-climatic glacier response  

SciTech Connect

Recent studies have shown that water depth at tidewater termini affect calving rates and, therefore, glacier mass balance and terminus stability. Grounding-line water depths are themselves governed by glacial and marine processes that interact during the formation of morainal bank depocenters. These morainal banks can fluctuate 10s of meters in height within an interval of a few weeks. Recent investigations in Glacier Bay have focused on quantitatively assessing sediment budgets in the ice-proximal environment. The monitoring of morainal banks in upper Muir Inlet has included repeated bathymetric mapping, sediment trap studies, bottom grab sampling, glacier and iceberg sampling, and submersible ROV investigations within 1 km of the terminus. Such relationships are important in interpreting recent changes in the dynamics of Muir Glacier where a century of retreat has been succeeded by quasi stability. The new glacier regime has accompanied basin infilling from approximately 100 m depth to a maximum of 52 m at the grounding line. Two large grounding-line fans have aggraded to deltas and reduced the length of the calving margin from 900 m to 290 m wide. These effects have reduced the ice flow velocities by 45%. Annual morainal bank growth ranged from 10[sup 6] to 10[sup 7] m[sup 3] and is the result of glacifluvial dumping, suspension settling from turbid overflow plumes, debris dumping from ice-cliff and iceberg melting, glacier squeezing and pushing of morainal bank sediment, and sediment gravity flow processes. Each of these processes are an integral facet of the morainal bank dynamics and glacier response. These studies of Muir Glacier indicate that glacier response to sediment dynamics need to be addresses before climatic implications are made.

Hunter, L.E.; Powell, R.D. (Northern Illinois Univ., Dekalb, IL (United States). Dept. of Geology)

1992-01-01

136

Simulation of an Ant Colony Optimization Technique in Continuous Space-Time  

NASA Astrophysics Data System (ADS)

The ant colony optimization system is an algorithm inspired by the ants' foraging behavior. The good results obtained by this system on academic problems has made it appealing for applications in industrial settings, one of the current hot topics of the method is the application in continuous problems. In this work, a modified model is presented which is based on autonomous agents, the ants, which behave like the ants in the ant colony system. These agents communicate by the biological inspired pheromone mechanism in order to find sources of food which located near their nest (optimal solutions).

Vlachos, D. S.

2008-11-01

137

Flooding and Fire Ants  

E-print Network

within the first 15 to 20 minutes. Some people report that the irrita- tion of a fire ant sting can be relieved by applying a 50:50 solution of bleach and water. Other home remedies include ammonia, meat tenderizer, tea tree oil and camphor...

Nester, Paul

2008-08-05

138

Tiny, Powerful, Awesome Ants!  

ERIC Educational Resources Information Center

Peering through a thematic science lens--elementary students embarked on a one-week study of ants during a month-long summer school program. This integrated unit addressed reading and writing skills while developing the science-process skills of observation, inferring, and communicating in a motivating and authentic way. Pre- and post-assessments…

Tate, Kathleen

2007-01-01

139

Ant Hill in Pantanal  

USGS Multimedia Gallery

Ant hill with flowers in Copernicia alba palm savannah near the Rio Negro river. Yellow flowers are 2 species of Asteraceae, blue flowers are a Commelina spp. Located near RAMSAR site and Rio Negro National Park in the Pantanal ecoregion, near the border between Paraguay and Bolivia. This region, si...

140

Face to Face with Ants  

NSDL National Science Digital Library

Imagine being the size of an ant. Be careful - a face-to-face encounter with an ant would be scary and potentially life-threatening! But, if you avoided being eaten, you could learn a lot about ant anatomy from a close-up view. Ants have many body parts that are normally hard to see without a magnifying glass or microscope. And each structure has its own special function.

Dr. Biology

141

Ant Algorithms for Discrete Optimization  

E-print Network

versa, ants deposit on the ground a substance called pheromone, forming in this way a pheromone trail. Ants can smell pheromone, and when choosing their way, they tend to choose, in probability, paths marked by strong pheromone concentrations. The pheromone trail allows the ants to find their way back

Libre de Bruxelles, Université

142

Ant Algorithms for Discrete Optimization  

E-print Network

versa, ants deposit on the ground a substance called pheromone, forming in this way a pheromone trail. Ants can smell pheromone and, when choosing their way, they tend to choose, in probability, paths marked by strong pheromone concentrations. The pheromone trail allows the ants to #12;nd their way back

Ducatelle, Frederick

143

Ant Algorithms for Discrete Optimization  

E-print Network

Ant Algorithms for Discrete Optimization Marco Dorigo Gianni Di Caro IRIDIA CP 194/6 Universit@iridia.ulb.ac.be Luca M. Gambardella IDSIA Corso Elvezia 36 CH-6900 Lugano Switzerland luca@idsia.ch Keywords ant algorithms, ant colony optimiza- tion, swarm intelligence, metaheuris- tics, natural computation Abstract

Hutter, Frank

144

Ants: the supreme soil manipulators  

Technology Transfer Automated Retrieval System (TEKTRAN)

This review focuses on the semiochemical interactions between ants and their soil environment. Ants occupy virtually every ecological niche and have evolved mechanisms to not just cope with, but also manipulate soil organisms. The metapleural gland, specific to ants was thought to be the major sourc...

145

The ant’s estimation of distance travelled: experiments with desert ants, Cataglyphis fortis  

Microsoft Academic Search

Foraging desert ants, Cataglyphis fortis, monitor their position relative to the nest by path integration. They continually update the direction and distance to the nest by employing a celestial compass and an odometer. In the present account we addressed the question of how the precision of the ant’s estimate of its homing distance depends on the distance travelled. We trained

S. Sommer; R. Wehner

2004-01-01

146

Ant-Based Cyber Security  

SciTech Connect

We describe a swarming-agent-based, mixed-initiative approach to infrastructure defense where teams of humans and software agents defend cooperating organizations in tandem by sharing insights and solutions without violating proprietary boundaries. The system places human administrators at the appropriate level where they provide system guidance while lower-level agents carry out tasks humans are unable to perform quickly enough to mitigate today’s security threats. Cooperative Infrastructure Defense (CID) uses our ant-based approach to enable dialogue between humans and agents to foster a collaborative problem-solving environment, increase human situational awareness and influence using visualization and shared control. We discuss theoretical implementation characteristics along with results from recent proof-of-concept implementations.

Haack, Jereme N.; Fink, Glenn A.; Maiden, Wendy M.; McKinnon, Archibald D.; Templeton, Steven J.; Fulp, Errin W.

2011-07-12

147

Chaos-order transition in foraging behavior of ants.  

PubMed

The study of the foraging behavior of group animals (especially ants) is of practical ecological importance, but it also contributes to the development of widely applicable optimization problem-solving techniques. Biologists have discovered that single ants exhibit low-dimensional deterministic-chaotic activities. However, the influences of the nest, ants' physical abilities, and ants' knowledge (or experience) on foraging behavior have received relatively little attention in studies of the collective behavior of ants. This paper provides new insights into basic mechanisms of effective foraging for social insects or group animals that have a home. We propose that the whole foraging process of ants is controlled by three successive strategies: hunting, homing, and path building. A mathematical model is developed to study this complex scheme. We show that the transition from chaotic to periodic regimes observed in our model results from an optimization scheme for group animals with a home. According to our investigation, the behavior of such insects is not represented by random but rather deterministic walks (as generated by deterministic dynamical systems, e.g., by maps) in a random environment: the animals use their intelligence and experience to guide them. The more knowledge an ant has, the higher its foraging efficiency is. When young insects join the collective to forage with old and middle-aged ants, it benefits the whole colony in the long run. The resulting strategy can even be optimal. PMID:24912159

Li, Lixiang; Peng, Haipeng; Kurths, Jürgen; Yang, Yixian; Schellnhuber, Hans Joachim

2014-06-10

148

Combining Immune with Ant Colony Algorithm for Geometric Constraint Solving  

Microsoft Academic Search

Geometric constraint problem can be transformed to an optimization problem which the objective function and constraints are non-convex functions. In this paper an evolutionary algorithm based on ant colony optimization algorithm and the immune system model is proposed to provide solution to the geometric constraints problem. In the new algorithm, affinity calculation process and pheromone trail lying is embedded to

Hua Yuan; Yi Li; Wenhui Li; Kong Zhao; Duo Wang; Rongqin Yi

2008-01-01

149

Artificial ants deposit pheromone to search for regulatory DNA elements  

PubMed Central

Background Identification of transcription-factor binding motifs (DNA sequences) can be formulated as a combinatorial problem, where an efficient algorithm is indispensable to predict the role of multiple binding motifs. An ant algorithm is a biology-inspired computational technique, through which a combinatorial problem is solved by mimicking the behavior of social insects such as ants. We developed a unique version of ant algorithms to select a set of binding motifs by considering a potential contribution of each of all random DNA sequences of 4- to 7-bp in length. Results Human chondrogenesis was used as a model system. The results revealed that the ant algorithm was able to identify biologically known binding motifs in chondrogenesis such as AP-1, NF?B, and sox9. Some of the predicted motifs were identical to those previously derived with the genetic algorithm. Unlike the genetic algorithm, however, the ant algorithm was able to evaluate a contribution of individual binding motifs as a spectrum of distributed information and predict core consensus motifs from a wider DNA pool. Conclusion The ant algorithm offers an efficient, reproducible procedure to predict a role of individual transcription-factor binding motifs using a unique definition of artificial ants. PMID:16942615

Liu, Yunlong; Yokota, Hiroki

2006-01-01

150

Distributed nestmate recognition in ants.  

PubMed

We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response. PMID:25833853

Esponda, Fernando; Gordon, Deborah M

2015-05-01

151

Binary-Coding-Based Ant Colony Optimization and Its Convergence  

Microsoft Academic Search

Ant colony optimization (ACO for short) is a meta-heuristics for hard combinatorial optimization problems. It is a population-based\\u000a approach that uses exploitation of positive feedback as well as greedy search. In this paper, genetic algorithm's (GA for\\u000a short) ideas are introduced into ACO to present a new binary-coding based ant colony optimization. Compared with the typical\\u000a ACO, the algorithm is

Tian-ming Bu; Song-Nian Yu I; Hui-wei Guan

2004-01-01

152

Application of ant colony optimization to optimal foragaing theory: comparison of simulation and field results  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ant Colony Optimization (ACO) refers to the family of algorithms inspired by the behavior of real ants and used to solve combinatorial problems such as the Traveling Salesman Problem (TSP).Optimal Foraging Theory (OFT) is an evolutionary principle wherein foraging organisms or insect parasites seek ...

153

Multi-objective flexible job shop schedule based on improved ant colony algorithm  

Microsoft Academic Search

Flexible job shop scheduling problem is a very important research in the field of combinatorial optimization. It is also important for practical production. A method for solving multi-objective flexible job shop scheduling problem based on ant colony algorithm is presented in this paper. Ant colony algorithm is improved from the following aspects in this paper: The number of subsets is

Li Li; Keqi Wang

2009-01-01

154

A Multiple Objective Ant-Q Algorithm for the Design of Water Distribution Irrigation Networks  

Microsoft Academic Search

The difficulty in solving multiple objective optimization problemswith traditional techniques, has urge researchers to use alternativeapproaches. Ant-Q algorithms have shown good results in the solutionof combinatorial optimization problems, however little work hasbeen done for multiple objective problems. This paper describes anAnt-Q algorithm called MOAQ, that can solve multiple objective optimizationproblems. MOAQ considers a family of agents for eachobjective function...

Carlos Mariano; Eduardo Morales

1999-01-01

155

Automated selection of appropriate pheromone representations in ant colony optimization.  

PubMed

Ant colony optimization (ACO) is a constructive metaheuristic that uses an analogue of ant trail pheromones to learn about good features of solutions. Critically, the pheromone representation for a particular problem is usually chosen intuitively rather than by following any systematic process. In some representations, distinct solutions appear multiple times, increasing the effective size of the search space and potentially misleading ants as to the true learned value of those solutions. In this article, we present a novel system for automatically generating appropriate pheromone representations, based on the characteristics of the problem model that ensures unique pheromone representation of solutions. This is the first stage in the development of a generalized ACO system that could be applied to a wide range of problems with little or no modification. However, the system we propose may be used in the development of any problem-specific ACO algorithm. PMID:16053571

Montgomery, James; Randall, Marcus; Hendtlass, Tim

2005-01-01

156

USING ANT COMMUNITIES FOR RAPID ASSESSMENT OF TERRESTRIAL ECOSYSTEM HEALTH  

SciTech Connect

Ecosystem health with its near infinite number of variables is difficult to measure, and there are many opinions as to which variables are most important, most easily measured, and most robust, Bioassessment avoids the controversy of choosing which physical and chemical parameters to measure because it uses responses of a community of organisms that integrate all aspects of the system in question. A variety of bioassessment methods have been successfully applied to aquatic ecosystems using fish and macroinvertebrate communities. Terrestrial biotic index methods are less developed than those for aquatic systems and we are seeking to address this problem here. This study had as its objective to examine the baseline differences in ant communities at different seral stages from clear cut back to mature pine plantation as a precursor to developing a bioassessment protocol. Comparative sampling was conducted at four seral stages; clearcut, 5 year, 15 year and mature pine plantation stands. Soil and vegetation data were collected at each site. All ants collected were preserved in 70% ethyl alcohol and identified to genus. Analysis of the ant data indicates that ants respond strongly to the habitat changes that accompany ecological succession in managed pine forests and that individual genera as well as ant community structure can be used as an indicator of successional change. Ants exhibited relatively high diversity in both early and mature seral stages. High ant diversity in the mature seral stages was likely related to conditions on the forest floor which favored litter dwelling and cool climate specialists.

Wike, L; Doug Martin, D; Michael Paller, M; Eric Nelson, E

2007-01-12

157

Muir-Torre Syndrome  

MedlinePLUS

... increases the risk for this hereditary cancer syndrome. Preimplantation genetic diagnosis (PGD) is a medical procedure done ... a complex procedure with financial, physical, and emotional factors for couples to consider before starting. For more ...

158

A Graph-based Ant System and its convergence  

Microsoft Academic Search

A general framework for solving combinatorial optimization problems heuristically by the Ant System approach is developed. The framework is based on the concept of a construction graph, a graph assigned to an instance of the optimization problem under consideration, encoding feasible solutions by walks. It is shown that under certain conditions, the solutions generated in each iteration of this Graph{based

Walter J. Gutjahr

2000-01-01

159

DNA Codewords Design Using Ant Colony Optimization Algorithm  

Microsoft Academic Search

Before performing the DNA computation, a set of specific DNA sequences are required. However, this is a burdensome task as too many constraints need to be satisfied. In this paper, ant colony algorithm is applied to solve the problem of DNA codewords design. Inspired by the traveling salesman problem, first a city matrix with T rows and S columns is

Xinjin Wang; Yongpeng Shen; Xuncai Zhang; Guangzhao Cui; Yanfeng Wang

2010-01-01

160

Ant Algorithms: Theory and Applications  

Microsoft Academic Search

This paper reviews the theory and applications of ant algorithms, new methods of discrete optimization based on the simulation of self-organized colony of biologic ants. The colony can be regarded as a multi-agent system where each agent is functioning independently by simple rules. Unlike the nearly primitive behavior of the agents, the behavior of the whole system happens to be

S. D. Shtovba

2005-01-01

161

Ant Algorithms for Discrete Optimization  

E-print Network

called pheromone, forming in this way a pheromone trail. Ants can smell pheromone and, when choosing their way, they tend to choose, in probability, paths marked by strong pheromone concentrations. The pheromone trail allows the ants to find their To appear in Artificial Life, MIT Press, 1999. 1 #12;15 cm

Gambardella, Luca Maria

162

Areawide suppression of fire ants  

Technology Transfer Automated Retrieval System (TEKTRAN)

An areawide integrated management of fire ants project was funded by USDA/ARS. The project was possible after self-sustaining biological control agents became available and a combination of biological control and toxic bait methodologies could be applied to imported fire ant population reduction. T...

163

Temperature: Human Regulating, Ants Conforming  

ERIC Educational Resources Information Center

Biological processes speed up as temperature rises. Procedures for demonstrating this with ants traveling on trails, and data gathered by students on the Argentine ant ("Linepithema humile") are presented. The concepts of temperature regulation and conformity are detailed with a focus on the processes rather than on terms that label the organisms.

Clopton, Joe R.

2007-01-01

164

Evolution of Fire Ant Control  

Technology Transfer Automated Retrieval System (TEKTRAN)

The imported fire ants that entered the United States over 70 years ago have spread within the country to over 129.5 million ha. Efforts to stop the expansion and suppress fire ant populations have resulted in changing methods of control. Initial efforts focused on treating individual nests with h...

165

MOEA/D-ACO: a multiobjective evolutionary algorithm using decomposition and AntColony.  

PubMed

Combining ant colony optimization (ACO) and the multiobjective evolutionary algorithm (EA) based on decomposition (MOEA/D), this paper proposes a multiobjective EA, i.e., MOEA/D-ACO. Following other MOEA/D-like algorithms, MOEA/D-ACO decomposes a multiobjective optimization problem into a number of single-objective optimization problems. Each ant (i.e., agent) is responsible for solving one subproblem. All the ants are divided into a few groups, and each ant has several neighboring ants. An ant group maintains a pheromone matrix, and an individual ant has a heuristic information matrix. During the search, each ant also records the best solution found so far for its subproblem. To construct a new solution, an ant combines information from its group's pheromone matrix, its own heuristic information matrix, and its current solution. An ant checks the new solutions constructed by itself and its neighbors, and updates its current solution if it has found a better one in terms of its own objective. Extensive experiments have been conducted in this paper to study and compare MOEA/D-ACO with other algorithms on two sets of test problems. On the multiobjective 0-1 knapsack problem,MOEA/D-ACO outperforms the MOEA/D with conventional genetic operators and local search on all the nine test instances. We also demonstrate that the heuristic information matrices in MOEA/D-ACO are crucial to the good performance of MOEA/D-ACO for the knapsack problem. On the biobjective traveling salesman problem, MOEA/D-ACO performs much better than the BicriterionAnt on all the 12 test instances. We also evaluate the effects of grouping, neighborhood, and the location information of current solutions on the performance of MOEA/D-ACO. The work in this paper shows that reactive search optimization scheme, i.e., the "learning while optimizing" principle, is effective in improving multiobjective optimization algorithms. PMID:23757576

Ke, Liangjun; Zhang, Qingfu; Battiti, Roberto

2013-12-01

166

A Deterministic Model for Analyzing the Dynamics of Ant System Algorithm and Performance Amelioration through a New Pheromone Deposition Approach  

E-print Network

Ant Colony Optimization (ACO) is a metaheuristic for solving difficult discrete optimization problems. This paper presents a deterministic model based on differential equation to analyze the dynamics of basic Ant System algorithm. Traditionally, the deposition of pheromone on different parts of the tour of a particular ant is always kept unvarying. Thus the pheromone concentration remains uniform throughout the entire path of an ant. This article introduces an exponentially increasing pheromone deposition approach by artificial ants to improve the performance of basic Ant System algorithm. The idea here is to introduce an additional attracting force to guide the ants towards destination more easily by constructing an artificial potential field identified by increasing pheromone concentration towards the goal. Apart from carrying out analysis of Ant System dynamics with both traditional and the newly proposed deposition rules, the paper presents an exhaustive set of experiments performed to find out suitable p...

Acharya, Ayan; Konar, Amit; Janarthanan, Ramadoss

2008-01-01

167

Three-dimensional ant  

NSDL National Science Digital Library

Three-dimensional rendering of an ant. This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the Â?HelpÂ? page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the orginal models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0000-00-00

168

Ant Colony Optimization for Constraint Satisfaction  

E-print Network

) Ants lay pheromone trails while walking Ants randomly choose paths w.r.t. phero. trails Pheromone by real ants... Ants lay pheromone on vertices and/or edges Greedy randomized construction of paths w.r.t. pheromone Pheromone evaporates ...with extra capabilities Pheromone laying is delayed and proportional

Solnon, Christine

169

Biological Control of Imported Fire Ants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Since 1998, the Alabama Fire Ant Management Program has been releasing natural enemies of imported fire ants. These natural enemies are being studied to determine their impact on fire ants. It is hoped that eventually the overall number of fire ants in Alabama can be reduced through biological cont...

170

Ants in Parking Lots Arnold L. Rosenberg  

E-print Network

Ants in Parking Lots Arnold L. Rosenberg Electrical & Computer Engineering Colorado State University Fort Collins, CO 80523, USA rsnbrg@colostate.edu Abstract Ants provide an attractive metaphor of ant-based computation models. We study the ability of ant-robots that are essentially mobile finite

Massachusetts at Amherst, University of

171

Ant Foraging Revisited Liviu Alexandru Panait1  

E-print Network

Ant Foraging Revisited Liviu Alexandru Panait1 and Sean Luke1 1. Department of Computer Science: lpanait@cs.gmu.edu Abstract Previous artificial (non-biological) ant foraging models have to date relied ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

Luke, Sean

172

Dripping faucet with ants Eric Bonabeau,1,  

E-print Network

Dripping faucet with ants Eric Bonabeau,1, * Guy Theraulaz,2 Jean-Louis Deneubourg,3 Arnaud Lioni,2 Brussels, Belgium Received 21 November 1997 The formation of droplets of ants is observed under certain, and a droplet containing up to 40 ants eventually falls down. When the flux of incoming ants is sufficient

Theraulaz, Guy

173

SRO-NERP-14 r: THE ANTS....,~  

E-print Network

SRO-NERP-14 r: THE ANTS....,~ (Hymenoptera: Formicidae) OF THE SAVANNAH RIVER PLANT; SOUTH CAROLINA MARCH,I985 Copies may be obtained from Savannah River Ecology Laboratory #12;r». The Ants (Hymenoptera. Distribution and Nesting Information for Ants of the Savannah River Plant Table 2. Frequencies of Foraging Ants

Georgia, University of

174

Implementation of Ant System for DNA Sequence Optimization  

NASA Astrophysics Data System (ADS)

In DNA based computation, the design of good DNA sequences has turned out to be a fundamental problem and one of the most practical and important research topics. Although the design of DNA sequences is dependent on the protocol of biological experiments, it is highly required to establish a method for the systematic design of DNA sequences, which could be applied to various design constraints. Much works have focused on designing the DNA sequences to obtain a set of good DNA sequences. In this paper, Ant System (AS) is proposed to solve the DNA sequence optimization problem. AS, which is the first approach proposed in Ant Colony Optimization (ACO), uses some ants to search the solutions based on the pheromone information. A model is adapted, which consists of four nodes representing four DNA bases. The results of the proposed approach are compared with other methods, such as evolutionary algorithm.

Kurniawan, Tri Basuki; Ibrahim, Zuwairie; Saaid, Muhammad Faiz Muhammed; Yahya, Azli

2009-06-01

175

Ant Colony Approach to Predict Amino Acid Interaction Networks Le Havre University  

E-print Network

Ant Colony Approach to Predict Amino Acid Interaction Networks Omar GACI Le Havre University LITIS the notion of protein interaction network. This is a graph whose vertices are the proteins amino acids's interaction network from its amino acid sequence. An ant colony approach is used to solve this problem. 1

Boyer, Edmond

176

Ants and Their Control There are many species of ants in Maryland but only a few  

E-print Network

1 Ants and Their Control There are many species of ants in Maryland but only a few are pests in the home. Two species of ants may require special attention because of their behavior. Carpenter ants can cause structural damage. They are covered in the Entomology leaflet #115 on Carpenter Ants

Hill, Wendell T.

177

Allee effects in ants.  

PubMed

1. Allee effects occur when the aggregation of individuals result in mutually beneficial intraspecific interactions whereby individual fitness, or per capita growth rate, increases with the number of individuals. Allee effects are common in social species due to their cooperative behaviours, such as breeding, feeding or defence. Allee effects have important implications for many aspects of basic and applied ecology. Over the past decades, the study of Allee effects has influenced population dynamics, community ecology, endangered species management and invasion biology. 2. Despite the fact that cooperation is the basis of their social structure, Allee effects have received little attention among eusocial insects. Extreme cooperation is common, and reproductive specialization of individuals occurs due to division of labour. These life-history traits suggest that the potential contribution of each caste to reproduction and survival may be differential and nonadditive. 3. We studied Allee effects in the invasive Argentine ant (Linepithema humile). In this species, many queens and workers are present in colonies, which allowed us to explore the differential effects of castes on the presence of Allee effects. In the laboratory, we measured brood production and individual survival in experimental colonies that differed in the initial numbers of queens and workers.4. Our results highlight the differential effect of queens and workers on survival and productivity. We found three positive density-dependent relationships indicative of component Allee effects at the colony level: both workers and queens had a positive effect on the productivity of the other caste, and queens had a positive effect on worker survivorship. 5. Our experimental results suggest a potential positive feedback between worker and queen abundance, which may have contributed to the evolution of large colony sizes. Our study provides the first evidence of Allee effects in eusocial insects and highlights the need to consider castes separately in population dynamics. Division of labour and differential reproductive rates are factors that should be integrated into the study of Allee effects. PMID:23672650

Luque, Gloria M; Giraud, Tatiana; Courchamp, Franck

2013-09-01

178

Monoculture of Leafcutter Ant Gardens  

PubMed Central

Background Leafcutter ants depend on the cultivation of symbiotic Attamyces fungi for food, which are thought to be grown by the ants in single-strain, clonal monoculture throughout the hundreds to thousands of gardens within a leafcutter nest. Monoculture eliminates cultivar-cultivar competition that would select for competitive fungal traits that are detrimental to the ants, whereas polyculture of several fungi could increase nutritional diversity and disease resistance of genetically variable gardens. Methodology/Principal Findings Using three experimental approaches, we assessed cultivar diversity within nests of Atta leafcutter ants, which are most likely among all fungus-growing ants to cultivate distinct cultivar genotypes per nest because of the nests' enormous sizes (up to 5000 gardens) and extended lifespans (10–20 years). In Atta texana and in A. cephalotes, we resampled nests over a 5-year period to test for persistence of resident cultivar genotypes within each nest, and we tested for genetic differences between fungi from different nest sectors accessed through excavation. In A. texana, we also determined the number of Attamyces cells carried as a starter inoculum by a dispersing queens (minimally several thousand Attamyces cells), and we tested for genetic differences between Attamyces carried by sister queens dispersing from the same nest. Except for mutational variation arising during clonal Attamyces propagation, DNA fingerprinting revealed no evidence for fungal polyculture and no genotype turnover during the 5-year surveys. Conclusions/Significance Atta leafcutter ants can achieve stable, fungal monoculture over many years. Mutational variation emerging within an Attamyces monoculture could provide genetic diversity for symbiont choice (gardening biases of the ants favoring specific mutational variants), an analog of artificial selection. PMID:20844760

Mueller, Ulrich G.; Scott, Jarrod J.; Ishak, Heather D.; Cooper, Michael; Rodrigues, Andre

2010-01-01

179

Spinning reserve scheduling of power systems: An ant colony approach  

Microsoft Academic Search

This paper presents an Ant Colony System (ACS) based optimization approach to solve the optimal spinning reserve problem for a power system. Unit commitment risk is used as an index to evaluate the level of spinning reserve. The outage cost and the fuel cost of thermal units were considered in the unit commitment program. The optimal spinning reserve and unit

2006-01-01

180

Reconstructing Amino Acid Interaction Networks by an Ant Colony Approach  

E-print Network

Reconstructing Amino Acid Interaction Networks by an Ant Colony Approach Omar GACI and Stefan BALEV are the proteins amino acids and whose edges are the interactions between them. We consider the problem of reconstructing protein's interaction network from its amino acid sequence. We rely on a probability that two

Paris-Sud XI, Université de

181

An Ant-Based Optimization Approach for Inventory Routing  

E-print Network

activities with inventory management. Such problems are usually tackled by independently solving of integrating and coordinating decisions can be found in Vendor Managed In- ventory (VMI), where customers makeAn Ant-Based Optimization Approach for Inventory Routing Vasileios A. Tatsis1 , Konstantinos E

Parsopoulos, Konstantinos

182

INVASIVE ANTS Invasive species, those species that demonstrate  

E-print Network

a management approach incor- porating pest risk analysis, public education, data collection, cost an opportunity to apply everything we currently know about ants to a rapid- ly growing problem. Fundamental and population ecology provided earlier in the book. The first two chapters delve into pro- cesses mediating

Suarez, Andrew V.

183

Understanding the Pheromone System within Ant Colony Optimization  

E-print Network

Understanding the Pheromone System within Ant Colony Optimization Stephen Gilmour and Mark Dras are good parameters for ACO algorithms, little research has been done as to how the ACO pheromone system) pheromone system in this direction. It is difficult to apply ACS to new problems when the variables within

Dras, Mark

184

Ants as bioindicators of soil function in rural environments  

Microsoft Academic Search

Farmers are being encouraged to redress the problems of land degradation by implementing a series of changes in their land management. However, there are few tools to monitor soil condition which can reliably inform farmers of the state of their soil. This paper examines ants and their importance in ecosystem functioning, principally their ability to maintain or restore soil quality

L. A. Lobry de Bruyn

1999-01-01

185

How Ants Drop Out: Ant Abundance on Tropical Mountains  

PubMed Central

In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica) and examined the impact of elevation (as a proxy for temperature) and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops. PMID:25098722

Longino, John T.; Branstetter, Michael G.; Colwell, Robert K.

2014-01-01

186

Improved Robustness through Population Variance in Ant Colony Optimization  

NASA Astrophysics Data System (ADS)

Ant Colony Optimization algorithms are population-based Stochastic Local Search algorithms that mimic the behavior of ants, simulating pheromone trails to search for solutions to combinatorial optimization problems. This paper introduces Population Variance, a novel approach to ACO algorithms that allows parameters to vary across the population over time, leading to solution construction differences that are not strictly stochastic. The increased exploration appears to help the search escape from local optima, significantly improving the robustness of the algorithm with respect to suboptimal parameter settings.

Matthews, David C.; Sutton, Andrew M.; Hains, Doug; Whitley, L. Darrell

187

Ant Routing Simulation B.A. Bagula, H.A.C. de Villiers, J. du Toit, A.E. Krzesinski, M. Loubser, J.G. van der Horst  

E-print Network

behaviour of social insect colonies and other animal societies. The idea of applying the natural paradigm of foraging ants to network routing problems has received much attention. The distributed nature of ant algorithms in modern telecommunication networks. In this paper we present a simulation of an ant routing

Geldenhuys, Jaco

188

The Ants of West Africa  

NSDL National Science Digital Library

Brian Taylor, of the University of Nottingham, has created this impressive resource on the ants of West Africa. Targeted "for anyone wishing to know more of how invertebrate populations are structured and determined," the site offers detailed taxonomic information, keys, and illustrations for "over 850 species and numerous 'forms' (from 85 genera and eleven subfamilies)," in addition to type locations, geographical information, and notes on bionomics. The five main sections (chapters) cover Geography & History, Ant Mosaics, Economic Importance of Ants, Biodiversity and Niches, and Taxonomy. Hundreds of references (since 1945) are available for download; a glossary offers explanations of key terms, and the text has extensively links, "including indices to a vast number of species names (subspecies, junior synonyms, varieties, etc.)."

Gilbert, Francis S.

189

NOVA: Lord of the Ants  

NSDL National Science Digital Library

As a young man growing up in Depression-era Alabama, E.O.Wilson spent a great time outdoors observing everything from butterflies to ants. His fascination with ants grew into a lifelong passion, and amidst his many accomplishments in later life, he would win a Pulitzer Prize for his 1991 work "The Ants". Today Wilson continues to be well-known as a strong advocate for the protection of the environment and his work in the field of sociobiology. Wilson was recently profiled in an episode of the popular PBS program "NOVA, and this site allows visitors to watch the program in its entirety as well as view a transcript or purchase a DVD of the program.

2008-05-20

190

8.EE Ant and Elephant  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: An ant has a mass of approximately $4 \\times 10^{?3}$ grams and an elephant has a mass of approximately 8 metric tons. How many ants does it take to ha...

191

A Multi-Objective Ant Colony Optimization Algorithm for Infrastructure Routing  

E-print Network

An algorithm is presented that is capable of producing Pareto-optimal solutions for multi-objective infrastructure routing problems: the Multi-Objective Ant Colony Optimization (MOACO). This algorithm offers a constructive search technique...

McDonald, Walter

2012-07-16

192

Do aphids actively search for ant partners?  

PubMed

The aphid-ant mutualistic relationships are not necessarily obligate for neither partners but evidence is that such interactions provide them strong advantages in terms of global fitness. While it is largely assumed that ants actively search for their mutualistic partners namely using volatile cues; whether winged aphids (i.e., aphids' most mobile form) are able to select ant-frequented areas had not been investigated so far. Ant-frequented sites would indeed offer several advantages for these aphids including a lower predation pressure through ant presence and enhanced chances of establishing mutuaslistic interactions with neighbor ant colonies. In the field, aphid colonies are often observed in higher densities around ant nests, which is probably linked to a better survival ensured by ants' services. Nevertheless, this could also result from a preferential establishment of winged aphids in ant-frequented areas. We tested this last hypothesis through different ethological assays and show that the facultative myrmecophilous black bean aphid, Aphis fabae L., does not orientate its search for a host plant preferentially toward ant-frequented plants. However, our results suggest that ants reduce the number of winged aphids leaving the newly colonized plant. Thus, ants involved in facultative myrmecophilous interactions with aphids appear to contribute to structure aphid populations in the field by ensuring a better establishment and survival of newly established colonies rather than by inducing a deliberate plant selection by aphid partners based on the proximity of ant colonies. PMID:24659520

Fischer, Christophe Y; Vanderplanck, Maryse; Lognay, Georges C; Detrain, Claire; Verheggen, François J

2015-04-01

193

A Smarter Look to Nature: GENetically Adapted VErsatile Heterogonous Ant Colony System  

NASA Astrophysics Data System (ADS)

ACS algorithms have been used in solving NP-hard and optimization problems in recent years. ACS ant colonies are homogeneous, but natural colonies are not. In this paper, a new ACS algorithm is proposed. It uses heterogeneous ant colonies which are evolved using a new type of genetic algorithm. Experimental results obtained from solving TSP problem, show the superiority of proposed algorithm over classical ACS.

Zaeri, Ahmad; Zamanifar, Kamran; Nematbakhsh, Mohammad Ali; Fatemi, Afsaneh

2009-04-01

194

The invasion of alien ants across continents with special reference to Argentine Ants and Red Imported Fire Ants  

Microsoft Academic Search

Alien ants are considered to be among the more damaging of invasive insects. Five ant species are ranked among the 100 world's worst invaders by the IUCN. Within the introduced regions, they displace or disrupt the local arthropod fauna, cause agricultural damage by protecting plant pests, and even affect human health. The Argentine Ant, Linepithema humile, has successfully spread from

Maki N. Inoue; Koichi Goka

2009-01-01

195

Hey! A Fire Ant Stung Me!  

MedlinePLUS

... How the Body Works Main Page Hey! A Fire Ant Stung Me! KidsHealth > Kids > Illnesses & Injuries > Bug ... Do How to Avoid Getting Bitten What's a Fire Ant? There are many different types of fire ...

196

Termites, hemimetabolous diploid white ants?  

Microsoft Academic Search

Ants and termites are the most abundant animals on earth. Their ecological success is attributed to their social life. They live in colonies consisting of few reproducing individuals, while the large majority of colony members (workers\\/soldiers) forego reproduction at least temporarilly. Despite their apparent resemblance in social organisation, both groups evolved social life independently. Termites are basically social cockroaches, while

Judith Korb

2008-01-01

197

Chemical crypsis in predatory ants  

Microsoft Academic Search

Summary The repellent responses of worker termites to ants are determined by the exocrine gland secretions of the latter. Specialized termite predators produce non-repellent aliphatic alcohols as the major components of their mandibular glands, whereas unspecialized con-generics usually produce repellent ketones and aldehydes.

C. Longhurst; R. Baker; P. E. Howse

1979-01-01

198

Ant Hill Near Tebicuary River  

USGS Multimedia Gallery

Ant hill near grassland-forest ecotone near Tebicuary river. This former pasture has not been grazed since an endangered bird species was discovered here half a dozen years ago. The Ñeembucú Region is typified by extensive grasslands and wetlands. Near 26°34’52’’S...

199

Ant Colony Optimization and Data Mining  

Microsoft Academic Search

\\u000a The Ant Colony Optimization (ACO) technique was inspired by the ants’ behavior throughout their exploration for food. In nature,\\u000a ants wander randomly, seeking for food. After succeeding, they return to their nest. During their move, they lay down pheromone\\u000a that forms an evaporating chemical path. Other ants that locate this trail, follow it and reinforce it, since they also lay

Ioannis Michelakos; Nikolaos Mallios; Elpiniki Papageorgiou; Michael Vassilakopoulos

200

Red Imported Fire Ant Biology Red imported fire ants live in colonies that contain  

E-print Network

Red Imported Fire Ant Biology Red imported fire ants live in colonies that contain cream-colored to white immature ants, often called brood. The brood is comprised of the eggs, larvae, and pupae. Also within the colonies are adult ants of different types, or castes. The castes include winged males, winged

Balasundaram, Balabhaskar "Baski"

201

Biological control of red imported fire ants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two species of Imported Fire Ants (IFA), the Red Imported Fire Ant, Solenopsis invicta Buren, and the Black Imported Fire Ant, S. richteri Forel, were introduced into the United States in the early 1900s and currently inhabit over 320 million acres in the southern United States and Puerto Rico. Red ...

202

FIRE ANT, BIOLOGY, ECOLOGY, AND BIOCONTROL  

Technology Transfer Automated Retrieval System (TEKTRAN)

The red fire ant Solenopsis invicta was accidentally introduced into the United States from South America sometime in the 1930s. These ants do best in open, disturbed habitats associated with human activities. Fire ants construct large earthen mounds which function as solar collecting devises. Fire...

203

Using Ants to Investigate the Environment  

ERIC Educational Resources Information Center

The best place for students to begin to understand complex environmental relationships is in their own back yards. Doing investigations of ants allows students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenance, and increase their understanding of the environment and their…

Hagevik, Rita A.

2005-01-01

204

Using Ants To Investigate the Environment.  

ERIC Educational Resources Information Center

Describes three inquiry-based activities designed for students to begin to understand complex environmental relationships in their own backyard. Includes investigations of ants, which allow students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenances, and increase student…

Hagevik, Rita A.

2003-01-01

205

Modeling Ant Behavior Under a Variable Environment  

E-print Network

Modeling Ant Behavior Under a Variable Environment Karla Vittori1 , Jacques Gautrais2 , Aluizio F.61.55.67.31, Fax: (033) 5.61.55. 61.54 theraula@cict.fr Abstract. This paper studies the behavior of ants when source. The ant responses when temporarily blocking the access to some branches of the maze were observed

Theraulaz, Guy

206

Interactions between Ants and Pine Weevils  

E-print Network

Interactions between Ants and Pine Weevils Effects on Forest Regeneration Subtitle (if any-91-576-8157-7 © 2014 Vítzslav Maák, Uppsala Print: SLU Service/Repro, Uppsala 2014 Cover: Red wood ant and pine weevil. Artwork by Henrik Nordenhem (photo: V. Maák) #12;Interactions between Ants and Pine Weevils: Effects

207

ANTS with Firefly Communication Chin A. Lua  

E-print Network

ANTS with Firefly Communication Chin A. Lua Department of Computer Science & Operations Research -- Autonomous Nano-Technology Swarm (ANTS) from NASA employs numerous, autonomous, l-kg solar sails swarm behaviors and unorthodox sensors for testing feasibility of ANTS using EA. The communication

Nygard, Kendall E.

208

Pseudo-Hierarchical Ant-Based Clustering  

Microsoft Academic Search

The behavior and self-organization of ant colonies has been widely studied to address distributed clustering. However, most models that directly mimic ants produce too many clusters and converge too slowly. A wide range of research has attempted to address this through various means, but a number of sources of inefficiency remain, including: i) ants must physically move from one cluster

Jeremy B. Brown; Manfred Huber

2010-01-01

209

Mineralogy, petrology and chemistry of ANT-suite rocks from the lunar highlands  

NASA Technical Reports Server (NTRS)

Anorthositic-noritic-troctolitic (ANT) rocks are the oldest and most abundant rocks of the lunar surface, and comprise about 90% of the suite of the lunar highlands. Consideration is given to the mineralogy, petrology, bulk chemistry, and origin of ANT-suite rocks. Problems associated in classifying and labeling lunar highland rocks because of textural complexities occurring from impact modifications are discussed. The mineralogy of ANT-suite rocks, dominated by plagioclase, olivine and pyrozene, and containing various minor minerals, is outlined. The petrology of ANT-suite rocks is reviewed along with the major element bulk composition of these rocks, noting that they are extremely depleted in K2O and P2O5. Various models describing the origin of ANT-suite rocks are summarized, and it is suggested that this origin involves a parental liquid of high-alumina basalt with low Fe/Fe+Mg.

Prinz, M.; Keil, K.

1977-01-01

210

Methods for Casting Subterranean Ant Nests  

PubMed Central

The study of subterranean ant nests has been impeded by the difficulty of rendering their structures in visible form. Here, several different casting materials are shown to make perfect casts of the underground nests of ants. Each material (dental plaster, paraffin wax, aluminum, zinc) has advantages and limitations, which are discussed. Some of the materials allow the recovery of the ants entombed in the casts, allowing a census of the ants to be connected with features of their nest architecture. The necessary equipment and procedures are described in the hope that more researchers will study this very important aspect of ant natural history. PMID:20673073

Tschinkel, Walter R.

2010-01-01

211

Quantifying Ant Activity Using Vibration Measurements  

PubMed Central

Ant behaviour is of great interest due to their sociality. Ant behaviour is typically observed visually, however there are many circumstances where visual observation is not possible. It may be possible to assess ant behaviour using vibration signals produced by their physical movement. We demonstrate through a series of bioassays with different stimuli that the level of activity of meat ants (Iridomyrmex purpureus) can be quantified using vibrations, corresponding to observations with video. We found that ants exposed to physical shaking produced the highest average vibration amplitudes followed by ants with stones to drag, then ants with neighbours, illuminated ants and ants in darkness. In addition, we devised a novel method based on wavelet decomposition to separate the vibration signal owing to the initial ant behaviour from the substrate response, which will allow signals recorded from different substrates to be compared directly. Our results indicate the potential to use vibration signals to classify some ant behaviours in situations where visual observation could be difficult. PMID:24658467

Oberst, Sebastian; Baro, Enrique Nava; Lai, Joseph C. S.; Evans, Theodore A.

2014-01-01

212

Revolutionizing Remote Exploration with ANTS  

NASA Astrophysics Data System (ADS)

We are developing the Autonomous Nano-Technology Swarm (ANTS) architecture based on an insect colony analogue for the cost-effective, efficient, systematic survey of remote or inaccessible areas with multiple object targets, including planetary surface, marine, airborne, and space environments. The mission context is the exploration in the 2020s of the most compelling remaining targets in the solar system: main belt asteroids. Main belt asteroids harbor important clues to Solar System origins and evolution which are central to NASA's goals in Space Science. Asteroids are smaller than planets, but their number is far greater, and their combined surface area likely dwarfs the Earth's. An asteroid survey will dramatically increase our understanding of the local resources available for the Human Exploration and Development of Space. During the mission composition, shape, gravity, and orbit parameters could be returned to Earth for perhaps several thousand asteroids. A survey of this area will rival the great explorations that encircled this globe, opened up the New World, and laid the groundwork for the progress and challenges of the last centuries. The ANTS architecture for a main belt survey consists of a swarm of as many as a thousand or more highly specialized pico-spacecraft that form teams to survey as many as one hundred asteroids a month. Multi-level autonomy is critical for ANTS and the objective of the proposed study is to work through the implications and constraints this entails. ANTS couples biologically inspired autonomic control for basic functions to higher level artificial intelligence that together enable individual spacecraft to operate as specialized, cooperative, social agents. This revolutionary approach postulates highly advanced, but familiar, components integrated and operated in a way that uniquely transcends any evolutionary extrapolation of existing trends and enables thousand-spacecraft missions.

Clark, P. E.; Rilee, M. L.; Curtis, S.; Truszkowski, W.

2002-05-01

213

Appeared in Ant Algorithms Proceedings of ANTS 2002, Third International Workshop on Ant Algorithms, Brussels, Belgium, September 12--14, 2002, SpringerVerlag, Lecture Notes in  

E-print Network

Appeared in Ant Algorithms ­ Proceedings of ANTS 2002, Third International Workshop on Ant. 2463, 2002 Toward the formal foundation of Ant Programming Mauro Birattari, Gianni Di Caro, and Marco,gdicaro,mdorigog@ulb.ac.be Abstract This paper develops the formal framework of ant programming with the goal of gaining a deeper

Ducatelle, Frederick

214

Metatranscriptomics and pyrosequencing facilitate discovery of potential viral natural enemies of the invasive Caribbean crazy ant, Nylanderia pubens  

Technology Transfer Automated Retrieval System (TEKTRAN)

Background: Nylanderia pubens (Forel) is an invasive ant species that in recent years has developed into a serious nuisance problem in the Caribbean and United States. A rapidly expanding range, explosive localized population growth, and control difficulties have elevated this ant to pest status. ...

215

Improved Clonal Selection Algorithm Combined with Ant Colony Optimization  

NASA Astrophysics Data System (ADS)

Both the clonal selection algorithm (CSA) and the ant colony optimization (ACO) are inspired by natural phenomena and are effective tools for solving complex problems. CSA can exploit and explore the solution space parallely and effectively. However, it can not use enough environment feedback information and thus has to do a large redundancy repeat during search. On the other hand, ACO is based on the concept of indirect cooperative foraging process via secreting pheromones. Its positive feedback ability is nice but its convergence speed is slow because of the little initial pheromones. In this paper, we propose a pheromone-linker to combine these two algorithms. The proposed hybrid clonal selection and ant colony optimization (CSA-ACO) reasonably utilizes the superiorities of both algorithms and also overcomes their inherent disadvantages. Simulation results based on the traveling salesman problems have demonstrated the merit of the proposed algorithm over some traditional techniques.

Gao, Shangce; Wang, Wei; Dai, Hongwei; Li, Fangjia; Tang, Zheng

216

Mimetic host shifts in an endangered social parasite of ants  

PubMed Central

An emerging problem in conservation is whether listed morpho-species with broad distributions, yet specialized lifestyles, consist of more than one cryptic species or functionally distinct forms that have different ecological requirements. We describe extreme regional divergence within an iconic endangered butterfly, whose socially parasitic young stages use non-visual, non-tactile cues to infiltrate and supplant the brood in ant societies. Although indistinguishable morphologically or when using current mitochondrial and nuclear sequence-, or microsatellite data, Maculinea rebeli from Spain and southeast Poland exploit different Myrmica ant species and experience 100 per cent mortality with each other's hosts. This reflects major differences in the hydrocarbons synthesized from each region by the larvae, which so closely mimic the recognition profiles of their respective hosts that nurse ants afford each parasite a social status above that of their own kin larvae. The two host ants occupy separate niches within grassland; thus, conservation management must differ in each region. Similar cryptic differentiation may be common, yet equally hard to detect, among the approximately 10 000 unstudied morpho-species of social parasite that are estimated to exist, many of which are Red Data Book listed. PMID:23193127

Thomas, Jeremy A.; Elmes, Graham W.; Sielezniew, Marcin; Stankiewicz-Fiedurek, Anna; Simcox, David J.; Settele, Josef; Schönrogge, Karsten

2013-01-01

217

The study of water supply network optimization based on the immune mechanism of ant colony algorithm  

NASA Astrophysics Data System (ADS)

For ant colony algorithm to search for a long time, easy to occur Stagnant phenomenon and sink into local most superior defects, and puts forward a kind of immune mechanism of the ant colony algorithm, and the algorithm is applied to typical water supply network in the combinatorial optimization problem. Combined with water supply network for example problem using respectively based on immune mechanisms of the ant colony algorithm and genetic algorithm and the basic ant colony algorithm for example to analysis. The results show that the improved algorithm is easier to realize the global optimal solution, and high efficiency, the optimization algorithm is better than other traditional optimization for solving water distribution network ability. So demonstrate the effectiveness of the algorithm.

Wang, Zongjiang

2013-03-01

218

Blind and myopic ants in heterogeneous networks  

NASA Astrophysics Data System (ADS)

The diffusion processes on complex networks may be described by different Laplacian matrices due to heterogeneous connectivity. Here we investigate the random walks of blind ants and myopic ants on heterogeneous networks: While a myopic ant hops to a neighbor node every step, a blind ant may stay or hop with probabilities that depend on node connectivity. By analyzing the trajectories of blind ants, we show that the asymptotic behaviors of both random walks are related by rescaling time and probability with node connectivity. Using this result, we show how the small eigenvalues of the Laplacian matrices generating the two random walks are related. As an application, we show how the return-to-origin probability of a myopic ant can be used to compute the scaling behaviors of the Edwards-Wilkinson model, a representative model of load balancing on networks.

Hwang, S.; Lee, D.-S.; Kahng, B.

2014-11-01

219

Ant cuticular response to phthalate pollution.  

PubMed

Phthalates are common atmospheric contaminants used in the plastic industry. Ants have been shown to constitute good bioindicators of phthalate pollution. Hence, phthalates remain trapped on ant cuticles which are mostly coated with long-chain hydrocarbons. In this study, we artificially contaminated Lasius niger ants with four phthalates: dibutyl phthalate (DBP), diisobutyl phthalate (DiBP), di(2-ethylhexyl) phthalate (DEHP), and benzyl butyl phthalate (BBP). The first three have previously been found on ants in nature in Touraine (France), while the fourth has not. The four phthalates disappeared rapidly (less than 5 days) from the cuticles of live ants. In contrast, on the cuticles of dead ants, DEHP quantities remained unchanged over time. These results indicate that phthalates are actively absorbed by the cuticles of live ants. Cuticular absorption of phthalates is nonspecific because eicosane, a nonnatural hydrocarbon on L. niger cuticle, was similarly absorbed. Ants are important ecological engineers and may serve as bioindicators of ecosystem health. We also suggest that ants and more generally terrestrial arthropods may contribute to the removal of phthalates from the local environment. PMID:25012205

Lenoir, Alain; Touchard, Axel; Devers, Séverine; Christidès, Jean-Philippe; Boulay, Raphaël; Cuvillier-Hot, Virginie

2014-12-01

220

An adaptive multiagent routing algorithm inspired by ants behavior  

E-print Network

An adaptive multi­agent routing algorithm inspired by ants behavior Gianni Di Caro and Marco Dorigo introduces AntNet, a novel adaptive approach to routing tables learning in connectionless communications networks. AntNet is inspired by the stigmergy communication model observed in ant colonies. We compare Ant

Ducatelle, Frederick

221

Imported Fire Ants: An Agricultural Pest and a  

E-print Network

Imported Fire Ants: An Agricultural Pest and a Human Health Hazard Imported fire ants (Solenopsis. The black imported fire ant was brought to Mobile, AL, in 1918. The red imported fire ant arrived) Animal and Plant Health Inspection Service (APHIS) for advice about how to manage imported fire ants

Balasundaram, Balabhaskar "Baski"

222

Prevalence of Oryzopsis hymenoides near harvester ant mounds: indirect facilitation by ants  

Microsoft Academic Search

The distribution of plants in relation to harvester ant mounds was investigated at two study areas to examine associations between ants and plants in semiarid, sagebrush steppe vegetation. The bunchgrass Oryzopsis hymenoides usually was the closest plant to the center of Pogonomyrmex owyheei ant mounds and often was the only plant found within the disk-shaped areas around mounds that is

R. S. Nowak; C. L. Nowak; T. DeRocher; N. Cole; M. A. Jones

1990-01-01

223

Plants in Your Ants: Using Ant Mounds to Test Basic Ecological Principles  

ERIC Educational Resources Information Center

Urban students often have limited access to field sites for ecological studies. Ubiquitous ants and their mounds can be used to study and test ecology-based questions. We describe how soil collected from ant mounds can be used to investigate how biotic factors (ants) can affect abiotic factors in the soil that can, in turn, influence plant growth.

Zettler, Jennifer A.; Collier, Alexander; Leidersdorf, Bil; Sanou, Missa Patrick

2010-01-01

224

An Adaptive Pheromone Updation of the Ant-System using LMS Technique  

NASA Astrophysics Data System (ADS)

We propose a modified model of pheromone updation for Ant-System, entitled as Adaptive Ant System (AAS), using the properties of basic Adaptive Filters. Here, we have exploited the properties of Least Mean Square (LMS) algorithm for the pheromone updation to find out the best minimum tour for the Travelling Salesman Problem (TSP). TSP library has been used for the selection of benchmark problem and the proposed AAS determines the minimum tour length for the problems containing large number of cities. Our algorithm shows effective results and gives least tour length in most of the cases as compared to other existing approaches.

Paul, Abhishek; Mukhopadhyay, Sumitra

2010-10-01

225

Spectacular Batesian mimicry in ants  

NASA Astrophysics Data System (ADS)

The mechanism by which palatable species take advantage of their similarity in appearance to those that are unpalatable, in order to avoid predation, is called Batesian mimicry. Several arthropods are thought to be Batesian mimics of social insects; however, social insects that are Batesian mimics among themselves are rare. In Malaysia we found a possible Batesian mimic in an arboreal ant species, Camponotus sp., which was exclusively observed on foraging trails of the myrmicine ant Crematogaster inflata. The bright yellow and black colouring pattern, as well as the walking behaviour, were very similar in both species. We observed general interactions between the two species, and tested their palatability and the significance of the remarkably similar visual colour patterns for predator avoidance. Prey offered to C. inflata was also eaten by Camponotus workers in spite of their being attacked by C. inflata, indicating that Camponotus sp. is a commensal of C. inflata. An experiment with chicks as potential predators suggests that Camponotus sp. is palatable whereas C. inflata is unpalatable. After tasting C. inflata, the chicks no longer attacked Camponotus sp., indicating that Camponotus sp. is a Batesian mimic of Crematogaster inflata.

Ito, Fuminori; Hashim, Rosli; Huei, Yek Sze; Kaufmann, Eva; Akino, Toshiharu; Billen, Johan

2004-10-01

226

Influence of Argentine and coastal brown ant (Hymenoptera: Formicidae) invasions on ant communities in Perth gardens, Western Australia  

Microsoft Academic Search

A survey examined the influence of Argentine (Linepithema humile (Mayr)) and coastal brown ant (Pheidole megacephala (Fabricius)) populations on other ants in the Perth metropolitan area, Western Australia. Twelve gardens (yards) were sampled; four infested by Argentine ants, three infested by coastal brown ants, and five controls where these two tramp ants were absent or collected only as isolated strays.

B. E. Heterick; J. Casella; J. D. Majer

2000-01-01

227

An Improved Ant Algorithm for Grid Task Scheduling Strategy  

NASA Astrophysics Data System (ADS)

Task scheduling is an important factor that directly influences the performance and efficiency of the system. Grid resources are usually distributed in different geographic locations, belonging to different organizations and resources' properties are vastly different, in order to complete efficiently, intelligently task scheduling, the choice of scheduling strategy is essential. This paper proposes an improved ant algorithm for grid task scheduling strategy, by introducing a new type pheromone and a new node redistribution selection rule. On the one hand, the algorithm can track performances of resources and tag it. On the other hand, add algorithm to deal with task scheduling unsuccessful situations that improve the algorithm's robustness and the successful probability of task allocation and reduce unnecessary overhead of system, shortening the total time to complete tasks. The data obtained from simulation experiment shows that use this algorithm to resolve schedule problem better than traditional ant algorithm.

Wei, Laizhi; Zhang, Xiaobin; Li, Yun; Li, Yujie

228

A Hybrid Ant Colony Algorithm for Loading Pattern Optimization  

NASA Astrophysics Data System (ADS)

Electricité de France (EDF) operates 58 nuclear power plant (NPP), of the Pressurized Water Reactor (PWR) type. The loading pattern (LP) optimization of these NPP is currently done by EDF expert engineers. Within this framework, EDF R&D has developed automatic optimization tools that assist the experts. The latter can resort, for instance, to a loading pattern optimization software based on ant colony algorithm. This paper presents an analysis of the search space of a few realistic loading pattern optimization problems. This analysis leads us to introduce a hybrid algorithm based on ant colony and a local search method. We then show that this new algorithm is able to generate loading patterns of good quality.

Hoareau, F.

2014-06-01

229

A Study of Greedy, Local Search, and Ant Colony Optimization Approaches for Car  

E-print Network

A Study of Greedy, Local Search, and Ant Colony Optimization Approaches for Car Sequencing Problems and compares several heuristic approa- ches for the car sequencing problem. We first study greedy heuristics, for which it was formerly unknown whether it is satisfiable or not. 1 Introduction The car sequencing

Solnon, Christine

230

Ants (Hymenoptera: Formicidae) of the Yukon  

Microsoft Academic Search

Ant material examined from the Yukon suggests that 19 recognized species occur there, taking into account outdated species taxonomy for the genera Myrmica, Leptothorax (sensu stricto) and Formica that compose the core of the ant fauna of the Yukon. The Palaearctic Formica gagatoides, a species associated with taiga environments in Eurasia, is recorded for the first time in North America.

ANDRÉ FRANCOEUR

231

CONTROL FIRE ANTS BY USING DECAPITATING FLIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Researchers with the USDA, ARS Biological Control of Pests Research Unit are rearing Pseudacteon curvatus, a tiny fly in the family Phoridae that parasitizes and kills imported fire ants. The flies only attack fire ants, and are not attracted to vegetables (12 kinds), fruit (13 kinds), raw meat (7 ...

232

Operant conditioning in the ant Myrmica sabuleti  

Microsoft Academic Search

Operant conditioning could be obtained in the ant Myrmica sabuleti by presenting to the workers, during a six-day period, an apparatus containing either sugared water or meat as a reward. The conditioning obtained using sugared water as a reward was short lasting. A reconditioning was more persistent and lasted four hours. The ants’ response was very precise, since they exhibited

M. C. Cammaerts

2004-01-01

233

Neuropeptidomics of the Carpenter Ant Camponotus floridanus.  

PubMed

Ants show a rich behavioral repertoire and a highly complex organization, which have been attracting behavioral and sociobiological researchers for a long time. The neuronal underpinnings of ant behavior and social organization are, however, much less understood. Neuropeptides are key signals that orchestrate animal behavior and physiology, and it is thus feasible to assume that they play an important role also for the social constitution of ants. Despite the availability of different ant genomes and in silico prediction of ant neuropeptides, a comprehensive biochemical survey of the neuropeptidergic communication possibilities of ants is missing. We therefore combined different mass spectrometric methods to characterize the neuropeptidome of the adult carpenter ant Camponotus floridanus. We also characterized the local neuropeptide complement in different parts of the nervous and neuroendocrine system, including the antennal and optic lobes. Our analysis identifies 39 neuropeptides encoded by different prepropeptide genes, and in silico predicts new prepropeptide genes encoding CAPA peptides, CNMamide as well as homologues of the honey bee IDLSRFYGHFNT- and ITGQGNRIF-containing peptides. Our data provides basic information about the identity and localization of neuropeptides that is required to anatomically and functionally address the role and significance of neuropeptides in ant behavior and physiology. PMID:25641051

Schmitt, Franziska; Vanselow, Jens T; Schlosser, Andreas; Kahnt, Jörg; Rössler, Wolfgang; Wegener, Christian

2015-03-01

234

Urban Pest Management of Ants in California  

Technology Transfer Automated Retrieval System (TEKTRAN)

Keeping pace with the dynamic and evolving landscape of invasive ants in California presents a formidable challenge to the pest management industry. Pest management professionals (PMPs) are on the frontlines when it comes to battling these exotic ant pests, and are often the first ones to intercept ...

235

Butterfly larvae fool ants into mothering them  

NSDL National Science Digital Library

Danish researchers have found that in some areas in their country, beautiful blue Alcon butterflies fool ants into raising the butterfly larvae instead of their own, a report explains. The reason? The butterflies have developed an outer coating that mimics that of the ants.

American Association for the Advancement of Science (AAAS; )

2008-01-03

236

Key to Identifying Common Household Ants  

NSDL National Science Digital Library

A short lucid key to 8 common household ant species with control strategies. The information presented is accurate and the key easy to use; ancillary pages are also useful. The key may present difficulties if other ant species are encountered or in other parts of the U.S.

0000-00-00

237

Area-wide Suppression of Fire Ants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fire ants, Solenopsis richteri and Solenopsis invicta, infest over 129.5 million ha in the USA. Fire ants, with their tremendous reproduction, mobility, and ability to occupy a wide range of habitats make their eradication very difficult. In the USA, rapid and extensive spread of these stinging an...

238

TERRITORIAL BEHAVIOR OF THE IMPORTED FIRE ANT  

Technology Transfer Automated Retrieval System (TEKTRAN)

The imported fire ant (IFA), Solenopsis invicta Buren, is an exotic species introduced to the United States from parts of South America. It has spread throughout much of the southeastern United States despite the presence of indigenous ant species. The IFA uses tunnels that afford access to foragi...

239

Community ecology Ants defend aphids against  

E-print Network

Community ecology Ants defend aphids against lethal disease Charlotte Nielsen1,, Anurag A. Agrawal1 colonies and some species also protect their mutualist partners. In mutualisms with aphids, ants typically feed on honeydew produced by aphids and, in turn guard and shelter aphid colonies from insect natural

Agrawal, Anurag

240

Modeling shortest path selection of the ant Linepithema humile using psychophysical theory and realistic parameter values.  

PubMed

The emergence of self-organizing behavior in ants has been modeled in various theoretical approaches in the past decades. One model explains experimental observations in which Argentine ants (Linepithema humile) selected the shorter of two alternative paths from their nest to a food source (shortest path experiments). This model serves as an important example for the emergence of collective behavior and self-organization in biological systems. In addition, it inspired the development of computer algorithms for optimization problems called ant colony optimization (ACO). In the model, a choice function describing how ants react to different pheromone concentrations is fundamental. However, the parameters of the choice function were not deduced experimentally but freely adapted so that the model fitted the observations of the shortest path experiments. Thus, important knowledge was lacking about crucial model assumptions. A recent study on the Argentine ant provided this information by measuring the response of the ants to varying pheromone concentrations. In said study, the above mentioned choice function was fitted to the experimental data and its parameters were deduced. In addition, a psychometric function was fitted to the data and its parameters deduced. Based on these findings, it is possible to test the shortest path model by applying realistic parameter values. Here we present the results of such tests using Monte Carlo simulations of shortest path experiments with Argentine ants. We compare the choice function and the psychometric function, both with parameter values deduced from the above-mentioned experiments. Our results show that by applying the psychometric function, the shortest path experiments can be explained satisfactorily by the model. The study represents the first example of how psychophysical theory can be used to understand and model collective foraging behavior of ants based on trail pheromones. These findings may be important for other models of pheromone guided ant behavior and might inspire improved ACO algorithms. PMID:25769943

von Thienen, Wolfhard; Metzler, Dirk; Witte, Volker

2015-05-01

241

Ant-seed mutualisms: Can red imported fire ants sour the relationship?  

USGS Publications Warehouse

Invasion by the red imported fire ant, Solenopsis invicta, has had negative impacts on individual animal and plant species, but little is known about how S. invicta affects complex mutualistic relationships. In some eastern forests of North America, 30% of herbaceous species have ant-dispersed seeds. We conducted experiments to determine if fire ants are attracted to seeds of these plant species and assessed the amount of scarification or damage that results from handling by fire ants. Fire ants removed nearly 100% of seeds of the ant-dispersed plants Trillium undulatum, T. discolor, T. catesbaei, Viola rotundifolia, and Sanguinaria canadensis. In recovered seeds fed to ant colonies, fire ants scarified 80% of S. canadensis seeds and destroyed 86% of V. rotundifolia seeds. Our study is the first to document that red imported fire ants are attracted to and remove seeds of species adapted for ant dispersal. Moreover, fire ants might damage these seeds and discard them in sites unfavorable for germination and seedling establishment. ?? 2001 Elsevier Science Ltd. All rights reserved.

Zettler, J.A.; Spira, T.P.; Allen, C.R.

2001-01-01

242

Ant Colony Optimization with Markov Random Walk for Community Detection in Graphs  

Microsoft Academic Search

\\u000a Network clustering problem (NCP) is the problem associated to the detection of network community structures. Building on Markov\\u000a random walks we address this problem with a new ant colony optimization strategy, named as ACOMRW, which improves prior results\\u000a on the NCP problem and does not require knowledge of the number of communities present on a given network. The framework of

Di Jin; Dayou Liu; Bo Yang; Carlos Baquero; Dongxiao He

243

Spatiotemporal chemotactic model for ant foraging  

NASA Astrophysics Data System (ADS)

In this paper, we present a generic theoretical chemotactic model that accounts for certain emergent behaviors observed in ant foraging. The model does not have many of the constraints and limitations of existing models for ants colony dynamics and takes into account the distinctly different behaviors exhibited in nature by ant foragers in search of food and food ferrying ants. Numerical simulations based on the model show trail formation in foraging ant colonies to be an emergent phenomenon and, in particular, replicate behavior observed in experiments involving the species P. megacephala. The results have broader implications for the study of randomness in chemotactic models. Potential applications include the developments of novel algorithms for stochastic search in engineered complex systems such as robotic swarms.

Ramakrishnan, Subramanian; Laurent, Thomas; Kumar, Manish; Bertozzi, Andrea L.

2014-12-01

244

We have all had ants invade or at least appear in our honey bee hives -most often they are carpenter ants. Carpenter ants  

E-print Network

We have all had ants invade or at least appear in our honey bee hives - most often they are carpenter ants. Carpenter ants cannot sting, but can deliver slicing bites into which they spray formic acid. These ants, of which there are numerous species, are omnivorous, eating honeydew, nectar, honey, other

Jawitz, James W.

245

Identification, Distribution, and Biology of Fire Ants in Texas.  

E-print Network

Cook)..........................................17 Desert Fire Ant (Solenopsis aurea W heeler)................................................17 Tropical Fire Ant (Solenopsis geminata [Fabricius]) .................................. 18 Black Imported Fire Ant (Solenopsis richteri Forel... fire ant sting, but a pustule seldom forms. The desert fire ant (S. aurea) is the least common specie of fire ant in Texas, reported from only two Texas counties. Nests are built in a fully exposed position in dry, coarse, gravelly soil, under...

Hung, Akey C.F.; Barlin, Margaret R.; Vinson, S. Bradleigh

1977-01-01

246

Spatial patterns in ant colonies  

NASA Astrophysics Data System (ADS)

The origins of large-scale spatial patterns in biology have been an important source of theoretical speculation since the pioneering work by Turing (1952) on the chemical basis of morphogenesis. Knowing how these patterns emerge and their functional role is important to our understanding of the evolution of biocomplexity and the role played by self organization. However, so far, conclusive evidence for local activation-long-range inhibition mechanisms in real biological systems has been elusive. Here a well-defined experimental and theoretical analysis of the pattern formation dynamics exhibited by clustering behavior in ant colonies is presented. These experiments and a simple mathematical model show that these colonies do indeed use this type of mechanism. All microscopic variables have been measured and provide the first evidence, to our knowledge, for this type of self-organized behavior in complex biological systems, supporting early conjectures about its role in the organization of insect societies.

Theraulaz, Guy; Bonabeau, Eric; Nicolis, Stamatios C.; Solé, Ricard V.; Fourcassié, Vincent; Blanco, Stéphane; Fournier, Richard; Joly, Jean-Louis; Fernández, Pau; Grimal, Anne; Dalle, Patrice; Deneubourg, Jean-Louis

2002-07-01

247

How to be an ant on figs  

NASA Astrophysics Data System (ADS)

Mutualistic interactions are open to exploitation by one or other of the partners and a diversity of other organisms, and hence are best understood as being embedded in a complex network of biotic interactions. Figs participate in an obligate mutualism in that figs are dependent on agaonid fig wasps for pollination and the wasps are dependent on fig ovules for brood sites. Ants are common insect predators and abundant in tropical forests. Ants have been recorded on approximately 11% of fig species, including all six subgenera, and often affect the fig-fig pollinator interaction through their predation of either pollinating and parasitic wasps. On monoecious figs, ants are often associated with hemipterans, whereas in dioecious figs ants predominantly prey on fig wasps. A few fig species are true myrmecophytes, with domatia or food rewards for ants, and in at least one species this is linked to predation of parasitic fig wasps. Ants also play a role in dispersal of fig seeds and may be particularly important for hemi-epiphytic species, which require high quality establishment microsites in the canopy. The intersection between the fig-fig pollinator and ant-plant systems promises to provide fertile ground for understanding mutualistic interactions within the context of complex interaction networks.

Bain, Anthony; Harrison, Rhett D.; Schatz, Bertrand

2014-05-01

248

Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant-plant mutualism.  

PubMed

In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant-plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output. PMID:24807259

Pringle, Elizabeth G

2014-06-22

249

Pheromone disruption of Argentine ant trail integrity  

USGS Publications Warehouse

Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m2) to 1- and 4-m2 plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected. ?? 2008 Springer Science+Business Media, LLC.

Suckling, D.M.; Peck, R.W.; Manning, L.M.; Stringer, L.D.; Cappadonna, J.; El-Sayed, A. M.

2008-01-01

250

Managing Imported Fire Ants in Urban Areas  

E-print Network

and formulations, with generic names of active ingredients and examples of product names 4 5 9 11 16 18 19 20 Managing Imported Fire Ants in Urban Areas The two species of imported fire ants (red imported fire ant, Solenopsis invicta Buren, and black imported... and fall, broadcast a bait-formulated insecticide or use an outdoor bait station product as directed on the la- bel. Most conventional baits are applied at a rate of 1 to 1 1 ?2 pounds of product per acre, although some products are applied at higher...

Drees, Bastiaan M.

2006-08-17

251

How to Control Ants at Home  

E-print Network

homemade bait can be prepared using boric acid. Remember that although boric acid is not dangerous to handle, it can be toxic if eaten. Keep it clearly labeled and away from food con- tainers to avoid accidents. Directions to mix bait Choose an attractive... food for the ants (jelly or peanut butter). Mix 1 teaspoon of boric acid with 1 cup of food. Do not add more boric acid because this reduces its effectiveness. Place the bait where you have seen ants, then watch and follow ants to their nest. Keep...

Merchant, Michael E.

2002-08-23

252

A Stochastic Inversion Method for Potential Field Data: Ant Colony Optimization  

NASA Astrophysics Data System (ADS)

Simulating natural ants' foraging behavior, the ant colony optimization (ACO) algorithm performs excellently in combinational optimization problems, for example the traveling salesman problem and the quadratic assignment problem. However, the ACO is seldom used to inverted for gravitational and magnetic data. On the basis of the continuous and multi-dimensional objective function for potential field data optimization inversion, we present the node partition strategy ACO (NP-ACO) algorithm for inversion of model variables of fixed shape and recovery of physical property distributions of complicated shape models. We divide the continuous variables into discrete nodes and ants directionally tour the nodes by use of transition probabilities. We update the pheromone trails by use of Gaussian mapping between the objective function value and the quantity of pheromone. It can analyze the search results in real time and promote the rate of convergence and precision of inversion. Traditional mapping, including the ant-cycle system, weaken the differences between ant individuals and lead to premature convergence. We tested our method by use of synthetic data and real data from scenarios involving gravity and magnetic anomalies. The inverted model variables and recovered physical property distributions were in good agreement with the true values. The ACO algorithm for binary representation imaging and full imaging can recover sharper physical property distributions than traditional linear inversion methods. The ACO has good optimization capability and some excellent characteristics, for example robustness, parallel implementation, and portability, compared with other stochastic metaheuristics.

Liu, Shuang; Hu, Xiangyun; Liu, Tianyou

2014-07-01

253

Plants in Your Ants: Using Ant Mounds to Test Basic Ecological Principles  

NSDL National Science Digital Library

[PDF] Article from The American Biology Teacher, Vol. 72, No. 3, pages 173?176. ISSN 0002-7685, electronic ISSN 1938?4211. ©2010 by National Association of Biology Teachers. This is an article about providing urban students with a field site for ecological studies, using ants and their mounds. The authors describe how soil collected from ant mounds can be used to investigate how biotic factors (ants) can affect abiotic factors in the soil that can, in turn, influence plant growth.

Zettler, Jennifer A.

254

Ant assemblages in the taiga biome: testing the role of territorial wood ants  

Microsoft Academic Search

Ants were collected with sets of pitfall traps in four coniferous-forest habitats in southern Finland. A three-level competition hierarchy concept was used to generate predictions on ant community structure. The levels of the hierarchy, and the respective predictions, from top to bottom were: (1) The dominant territorial wood ants (Formica rufa-group species), expected to exclude each other. (2) The other

R. Savolainen; K. Vepsäläinen; H. Wuorenrinne

1989-01-01

255

Broadcast Baits for Fire Ant Control  

E-print Network

This guide addresses common questions from both consumers and professional pesticide applicators about using broadcast baits to control fire ants. It covers bait basics, treatment method choices, applicator and environmental safety, product...

Barr, Charles L.

2005-10-17

256

College of Arts and Sciences ANT Anthropology  

E-print Network

.Thecoursewillincludeconsiderationofthestatus of Native Americans in present-day North America. ANT 222 MIDDLE EAST CULTURES. (3) Aspartofthe AMERICA. (3) ThisisasurveyoftheaboriginalNativeAmericanculturesofNorthAmericansocieties.Particularemphasisisplacedoncomparingandcontrastingculturalcharacteristics ofNativeAmericangroupslivinginecologicallydiverseregionsofNorthAmerica

MacAdam, Keith

257

Ant-plants and fungi: a new threeway symbiosis  

Microsoft Academic Search

Summary • Symbioses between plants and fungi, fungi and ants, and ants and plants all play important roles in ecosystems. Symbioses involving all three partners appear to be rare. Here, we describe a novel tripartite symbiosis in which ants and a fungus inhabit domatia of an ant-plant, and present evidence that such interactions are widespread.  We investigated 139 individuals

Emmanuel Defossez; Marc-André Selosse; Marie-Pierre Dubois; Laurence Mondolot; Antonella Faccio; Champlain Djieto-Lordon; Doyle McKey; Rumsaïs Blatrix

2009-01-01

258

GLYCEROL IN NEST MATERIAL OF RED IMPORTED FIRE ANTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Red imported fire ant is a nest-building ant species. Workers build the nest by excavating soils. It was reported that red imported fire ants incorporated ant-derived compounds in their nest soil, such as cuticular hydrocarbons (Vander Meer R. K. unpublished data) and venom alkaloids (Blum, M. S. ...

259

Leaf litter ant diversity in Guyana JOHN S. LAPOLLA1,  

E-print Network

-1 Leaf litter ant diversity in Guyana JOHN S. LAPOLLA1, *, TED SUMAN1 , JEFFREY SOSA-CALVO1 Shield, Leaf litter ants Abstract. Leaf litter ants are an important group of organisms for informing conservation plan- ning. This study presents the beginning of a leaf litter ant dataset for Guyana. Following

Schultz, Ted

260

A Deterministic Metaheuristic Approach Using "Logistic Ants" for Combinatorial Optimization  

E-print Network

A Deterministic Metaheuristic Approach Using "Logistic Ants" for Combinatorial Optimization of "logistic ants" which uses chaotic maps to govern the behavior of the artificial ants. We illustrate¸cois Charpillet In the same way, we propose the deterministic model of "logistic ants" in this paper. This model

Paris-Sud XI, Université de

261

Symbiont choice in a fungus-growing ant (Attini, Formicidae)  

Microsoft Academic Search

Cultivars of fungus-growing (attine) ants are vertically transmitted through inheritance from parent to offspring nest, but horizontal cultivar transfer between ant nests occurs occasionally, resulting in cultivar replacement within ant lineages. Two mechanisms could theoretically prevent the invasion of suboptimal cultivar strains and thus stabilize ant--cultivar coevolution: first, partner feedback inherent in vertical cultivar transmission and second, partner (symbiont) choice

Ulrich G. Mueller; Jessica Poulin; Rachelle M. M. Adamsa

2004-01-01

262

ORIGINAL ARTICLE Collective decisions in ants when foraging  

E-print Network

ORIGINAL ARTICLE Collective decisions in ants when foraging under crowded conditions Audrey-recruiting ant Lasius niger. In our experiment, ants had to go from their nest to a food source by crossing underlying the choice of route in ants. A mathematical model was developed to evaluate the impor- tance

Nicolis, Stamatios C.

263

Ant Colony Optimisation1 12.1 Introduction  

E-print Network

Chapter 12 Ant Colony Optimisation1 12.1 Introduction Real ants can find a shortest path from the old one is no longer feasible due to a new obstacle. In Figure (12.1 A) ants are moving on a straight line that connects a food source to their nest. An ant: · deposits pheromone while walking

Grant, P. W.

264

Ant Foraging Revisited Liviu A. Panait and Sean Luke  

E-print Network

Ant Foraging Revisited Liviu A. Panait and Sean Luke George Mason University, Fairfax, VA 22030 lpanait@cs.gmu.edu, sean@cs.gmu.edu Abstract Most previous artificial ant foraging models have to date re the artificial ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

George Mason University

265

Ant-Inspired Navigation In Unknown Environments Stergios I. Roumeliotis  

E-print Network

Ant-Inspired Navigation In Unknown Environments Stergios I. Roumeliotis Computer Science Dpt-0781 maja@robotics.usc.edu In contrast to mostother ant species, desert ants (Cataglyphis fortis) do not use) information. Indeed desert ants and honeybees use such information in addition to path integration. On a fa

Roumeliotis, Stergios I.

266

Ant Foraging Revisited Liviu A. Panait and Sean Luke  

E-print Network

Ant Foraging Revisited Liviu A. Panait and Sean Luke George Mason University, Fairfax, VA 22030 lpanait@cs.gmu.edu, sean@cs.gmu.edu Abstract Most previous artificial ant foraging algorithms have to date the artificial ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

Turk, Greg

267

When Fire Ants Move In, Others Leave Elizabeth Pennisi  

E-print Network

ECOLOGY: When Fire Ants Move In, Others Leave Elizabeth Pennisi For Amy Arnett, getting a Ph, collecting ants at 33 sites along the way. They had set out to look at how the food resources for ant lions, insects that prey on ants, changed from north to south along the East Coast. But in the process

Gotelli, Nicholas J.

268

Musings on the management of Nylanderia fulva Crazy Ants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nylanderia fulva is an invasive crazy ant that can inundate landscapes and structures. This invasive ant has been called the Caribbean crazy ant in Florida and the Rasberry [sic] crazy ant in Texas. The species was thought to be Nylanderia pubens or Nylanderia near pubens, in Florida and Texas, resp...

269

Ant eating behavior of mountain gorillas  

Microsoft Academic Search

Eleven cases of feeding on driver ants (Dorylus sp.) by mountain gorillas (Gorilla gorilla beringei) are described. Ant eating provides the gorillas with more animal protein and other nutrients per unit feeding time than\\u000a do other forms of insectivory that contribute to their diet, but it is so rare that it is unlikely to be of real nutritional\\u000a significance. Gorillas

David P. Watts

1989-01-01

270

Science Nation: Leaf-cutter Ants  

NSDL National Science Digital Library

In established colonies, millions of leaf-cutter ants cut and carry sections of leaves larger than their own bodies as part of a well choreographed, highly functioning society. With support from the National Science Foundation (NSF),bacteriologist Cameron Currie and his team study ants and their complex, productive societies to help address some of human society's most pressing challenges, such as better drugs and cleaner energy.

271

Balancing Exploration and Exploitation by an Elitist Ant System with Exponential Pheromone Deposition Rule  

E-print Network

The paper presents an exponential pheromone deposition rule to modify the basic ant system algorithm which employs constant deposition rule. A stability analysis using differential equation is carried out to find out the values of parameters that make the ant system dynamics stable for both kinds of deposition rule. A roadmap of connected cities is chosen as the problem environment where the shortest route between two given cities is required to be discovered. Simulations performed with both forms of deposition approach using Elitist Ant System model reveal that the exponential deposition approach outperforms the classical one by a large extent. Exhaustive experiments are also carried out to find out the optimum setting of different controlling parameters for exponential deposition approach and an empirical relationship between the major controlling parameters of the algorithm and some features of problem environment.

Acharya, Ayan; Banerjee, Aritra; Konar, Amit

2008-01-01

272

Visual scene perception in navigating wood ants.  

PubMed

Ants, like honeybees, can set their travel direction along foraging routes using just the surrounding visual panorama. This ability gives us a way to explore how visual scenes are perceived. By training wood ants to follow a path in an artificial scene and then examining their path within transformed scenes, we identify several perceptual operations that contribute to the ants' choice of direction. The first is a novel extension to the known ability of insects to compute the "center of mass" of large shapes: ants learn a desired heading toward a point on a distant shape as the proportion of the shape that lies to the left and right of the aiming point--the 'fractional position of mass' (FPM). The second operation, the extraction of local visual features like oriented edges, is familiar from studies of shape perception. Ants may use such features for guidance by keeping them in desired retinal locations. Third, ants exhibit segmentation. They compute the learned FPM over the whole of a simple scene, but over a segmented region of a complex scene. We suggest how the three operations may combine to provide efficient directional guidance. PMID:23583550

Lent, David D; Graham, Paul; Collett, Thomas S

2013-04-22

273

Invention and modification of a new tool use behavior: ant-fishing in trees by a wild chimpanzee (Pan troglodytes verus) at Bossou, Guinea.  

PubMed

Wild chimpanzees are known to have a different repertoire of tool use unique to each community. For example, "ant-dipping" is a tool use behavior known in several chimpanzee communities across Africa targeted at driver ants (Dorylus spp.) on the ground, whereas "ant-fishing," which is aimed at carpenter ants (Camponotus spp.) in trees, has primarily been observed among the chimpanzees of Mahale in Tanzania. Although the evidence for differences between field sites is accumulating, we have little knowledge on how these tool use behaviors appear at each site and on how these are modified over time. This study reports two"ant-fishing" sessions which occurred 2 years apart by a young male chimpanzee at Bossou, Guinea. Ant-fishing had never been observed before in this community over the past 27 years. During the first session, at the age of 5, he employed wands of similar length when ant-fishing in trees to those used for ant-dipping on the ground, which is a customary tool use behavior of this community. Two years later, at the age of 7, his tools for ant-fishing were shorter and more suitable for capturing carpenter ants. This observation is a rare example of innovation in the wild and does provide insights into problem-solving and learning processes in chimpanzees. PMID:18459112

Yamamoto, Shinya; Yamakoshi, Gen; Humle, Tatyana; Matsuzawa, Tetsuro

2008-07-01

274

Strong Combination of Ant Colony Optimization with Constraint Programming Optimization  

NASA Astrophysics Data System (ADS)

We introduce an approach which combines ACO (Ant Colony Optimization) and IBM ILOG CP Optimizer for solving COPs (Combinatorial Optimization Problems). The problem is modeled using the CP Optimizer modeling API. Then, it is solved in a generic way by a two-phase algorithm. The first phase aims at creating a hot start for the second: it samples the solution space and applies reinforcement learning techniques as implemented in ACO to create pheromone trails. During the second phase, CP Optimizer performs a complete tree search guided by the pheromone trails previously accumulated. The first experimental results on knapsack, quadratic assignment and maximum independent set problems show that this new algorithm enhances the performance of CP Optimizer alone.

Khichane, Madjid; Albert, Patrick; Solnon, Christine

275

Syllabus dtaill, ANT 3820, Anthropologie, Migration et Sant Page 1 sur 11 ANT 3820 Anthropologie, migration & sant  

E-print Network

Syllabus détaillé, ANT 3820, Anthropologie, Migration et Santé Page 1 sur 11 ANT 3820 Anthropologie début de séance #12;Syllabus détaillé, ANT 3820, Anthropologie, Migration et Santé Page 2 sur 11 (suite'anthropologie) sera pénalisé en raison de 2% par jour de retard. #12;Syllabus détaillé, ANT 3820, Anthropologie

Leclercq, Remi

276

Summary. The Argentine ant, Linepithema humile, has invaded many areas of the world, displacing native ants. Its  

E-print Network

Summary. The Argentine ant, Linepithema humile, has invaded many areas of the world, displacing native ants. Its behavior may contribute to its competitive success. Staged and natural encounters were observed at food resources in the field, between Argentine ants and eight ant species native to northern

Gordon, Deborah

277

Of ants and urns: estimation of the parameters of a reinforced random walk and application to ants  

E-print Network

Of ants and urns: estimation of the parameters of a reinforced random walk and application to ants of a path by laboratory ants. We study our estimators in a general framework and then restrict to a particular model in order to do a simulation study and an application to a an experiment with ants. Our

Paris-Sud XI, Université de

278

Positive Association Between Densities of the Red Imported Fire Ant, Solenopsis invicta (Hymenoptera: Formicidae), and Generalized Ant and Arthropod Diversity  

Microsoft Academic Search

The invasive ant, Solenopsis invicta Buren, is a threat to native arthropod biodiversity. We compared areas with naturally varying densities of mostly monogyne S. invicta and examined the association of S. invicta density with three diversity variables: (1) the species richness of ants, (2) the species richness of non-ant arthropods, and (3) the abundance of non-S. invicta ants. Pitfall traps

Lloyd W. Morrison; Sanford D. Porter

2003-01-01

279

Extensions to the Ant-Miner Classification Rule Discovery Algorithm  

Microsoft Academic Search

\\u000a Ant-Miner is an ant-based algorithm for the discovery of classification rules. This paper proposes four extensions to Ant-Miner:\\u000a 1) we allow the use of a logical negation operator in the antecedents of constructed rules; 2) we use stubborn ants, an ACO-variation\\u000a in which an ant is allowed to take into consideration its own personal past history; 3) we use multiple

Khalid M. Salama; Ashraf M. Abdelbar

2010-01-01

280

Texas Imported Fire Ant Research and Management Plan  

NSDL National Science Digital Library

The Department of Entomology at Texas A&M University provides this informative Web site focused on the invasive imported fire ant. Visitors will find all the latest in fire ant research and management, as well as an introduction to fire ant natural history and environmental impact. Materials include multimedia presentations, downloadable publications and factsheets, and lots of related links. Visitors can also check out an audio clip of fire ant stridulations -- a weird little sound the ants make rubbing thorax against abdomen.

281

Are red imported fire ants facilitators of native seed dispersal?  

Microsoft Academic Search

Invasive ants threaten native communities, in part, through their potential to disrupt mutualisms, yet invasive species may\\u000a also facilitate native species. The red imported fire ant (Solenopsis invicta) is one of the most conspicuous invasive ants in North America and its high densities, combined with its potential to displace\\u000a native ants, have led to concerns that it may disrupt ant-plant

Katharine L. Stuble; L. Katherine Kirkman; C. Ronald Carroll

2010-01-01

282

Evolution of ant-cultivar specialization and cultivar switching in Apterostigma fungus-growing ants.  

PubMed

Almost all of the more than 200 species of fungus-growing ants (Formicidae: Attini) cultivate litter-decomposing fungi in the family Lepiotaceae (Basidiomycota: Agaricales). The single exception to this rule is a subgroup of ant species within the lower attine genus Apterostigma, which cultivate pterulaceous fungi distantly related to the Lepiotaceae. Comparison of cultivar and ant phylogenies suggests that a switch from lepiotaceous to pterulaceous fungiculture occurred only once in the history of the fungus-growing ants. This unique switch occurred after the origin of the genus Apterostigma, such that the basal Apterostigma lineages retained the ancestral attine condition of lepiotaceous fungiculture, and none of the Apterostigma lineages in the monophyletic group of pterulaceous fungiculturists are known to have reverted back to lepiotaceous fungiculture. The origin of pterulaceous fungiculture in attine ants may have involved a unique transition from the ancestral cultivation of litter-decomposing lepiotaceous fungi to the cultivation of wood-decomposing pterulaceous fungi. Phylogenetic analyses further indicate that distantly related Apterostigma ant species sometimes cultivate the same cultivar lineage, indicating evolutionarily frequent, and possibly ongoing, exchanges of fungal cultivars between Apterostigma ant species. The pterulaceous cultivars form two sister clades, and different Apterostigma ant lineages are invariably associated with, and thus specialized on, only one of the two cultivar clades. However, within clades Apterostigma ant species are able to switch between fungi. This pattern of broad specialization by attine ants on defined cultivar clades, coupled with flexible switching between fungi within cultivar clades, is also found in other attine lineages and appears to be a general phenomenon of fungicultural evolution in all fungus-growing ants. PMID:15562688

Villesen, Palle; Mueller, Ulrich G; Schultz, Ted R; Adams, Rachelle M M; Bouck, Amy C

2004-10-01

283

Inverse transient radiation analysis in one-dimensional participating slab using improved Ant Colony Optimization algorithms  

NASA Astrophysics Data System (ADS)

As a heuristic intelligent optimization algorithm, the Ant Colony Optimization (ACO) algorithm was applied to the inverse problem of a one-dimensional (1-D) transient radiative transfer in present study. To illustrate the performance of this algorithm, the optical thickness and scattering albedo of the 1-D participating slab medium were retrieved simultaneously. The radiative reflectance simulated by Monte-Carlo Method (MCM) and Finite Volume Method (FVM) were used as measured and estimated value for the inverse analysis, respectively. To improve the accuracy and efficiency of the Basic Ant Colony Optimization (BACO) algorithm, three improved ACO algorithms, i.e., the Region Ant Colony Optimization algorithm (RACO), Stochastic Ant Colony Optimization algorithm (SACO) and Homogeneous Ant Colony Optimization algorithm (HACO), were developed. By the HACO algorithm presented, the radiative parameters could be estimated accurately, even with noisy data. In conclusion, the HACO algorithm is demonstrated to be effective and robust, which had the potential to be implemented in various fields of inverse radiation problems.

Zhang, B.; Qi, H.; Ren, Y. T.; Sun, S. C.; Ruan, L. M.

2014-01-01

284

Ecology of a fig ant-plant  

NASA Astrophysics Data System (ADS)

Mutualistic interactions are embedded in networks of interactions that affect the benefits accruing to the mutualistic partners. Figs and their pollinating wasps are engaged in an obligate mutualism in which the fig is dependent on the fig pollinator for pollination services and the pollinator is dependent on fig ovules for brood sites. This mutualism is exploited by non-pollinating fig wasps that utilise the same ovules, but do not provide a pollination service. Most non-pollinating wasps oviposit from outside the inflorescence (syconium), where they are vulnerable to ant predation. Ficus schwarzii is exposed to high densities of non-pollinating wasps, but Philidris sp. ants patrolling the syconia prevent them from ovipositing. Philidris rarely catch wasps, but the fig encourages the patrolling by providing a reward through extra-floral nectaries on the surface of syconia. Moreover, the reward is apparently only produced during the phase when parasitoids are ovipositing. An ant-exclusion experiment demonstrated that, in the absence of ants, syconia were heavily attacked and many aborted as a consequence. Philidris was normally rare on the figs during the receptive phase or at the time of day when wasp offspring are emerging, so predation on pollinators was limited. However, Myrmicaria sp. ants, which only occurred on three trees, preyed substantially on pollinating as well as non-pollinating wasps. F. schwarzii occurs in small clusters of trees and has an exceptionally rapid crop turnover. These factors appear to promote high densities of non-pollinating wasps and, as a consequence, may have led to both a high incidence of ants on trees and increased selective pressure on fig traits that increase the payoffs of the fig-ant interaction for the fig. The fig receives no direct benefit from the reward it provides, but protects pollinating wasps that will disperse its pollen.

Harrison, Rhett D.

2014-05-01

285

No detection of Vairimorpha invictae in fire ant decapitating flies reared from V. invictae- infected ants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vairimorpha invictae is a microsporidian entomopathogen that is under evaluation as a biological control agent for red imported fire ants, Solenopsis invicta. Infections of V. invictae alone and in combination with another pathogen of fire ants, Thelohania solenopsae, have resulted in declines of 5...

286

two ants 11/13/2007 1 A rectangular room has dimensions 121230 (feet). There  

E-print Network

foot from the floor, and a female ant is on the other, 1 foot from the ceil- ing. How far does the male expectantly. The argument seems fine--why am I not saying anything? 12 30 12 F M This problem is found in Ball

Taylor, Peter

287

Management of Mobile Agent Systems: Learning From the Ants Tony White1  

E-print Network

Management of Mobile Agent Systems: Learning From the Ants Tony White1 , Bernard Pagurek2 , Dwight@scs.carleton.ca, bernie@sce.carleton.ca, deugo@scs.carleton.ca} Abstract The management of mobile agent systems that solve problems in a network is an issue that must be addressed if mobile agents are to be deployed industrially

288

Research on capacity planning of WDM networks using improved ant colony algorithm  

NASA Astrophysics Data System (ADS)

A cost-effective capacity planning method of WDM networks is proposed for increase of traffic load. An improved costbased ant colony algorithm is presented from pheromone increase and update mechanisms to solve the planning problem. Simulation results show the applicability of our planning method.

Luo, Pei; Huang, Shanguo; Lv, Lin; Li, Bin; Zhang, Jie; Gu, Wanyi

2009-11-01

289

Candidate Set Strategies for Ant Colony Optimisation Marcus Randall and James Montgomery  

E-print Network

Candidate Set Strategies for Ant Colony Optimisation Marcus Randall and James Montgomery School the number of element choices to a sensible subset, or candidate set. This paper describes some novel generic candidate set strategies and tests these on the travelling salesman and car sequencing problems. The results

Montgomery, James

290

Force controlled manipulation is a common technique for compli antly contacting and manipulating uncertain environments. Visual  

E-print Network

Abstract Force controlled manipulation is a common technique for compli­ antly contacting guide a manipulator simplifies the force control problem by allowing the effective use of low gain force classes of tasks must be derived. The most common method of implementing force control is through a wrist

291

Clustering Web People Search Results using Fuzzy Ants E. Lefever,a,b  

E-print Network

finders" is person name ambiguity due to the fact that one person name can refer to different individuals, USA Abstract Person name queries often bring up web pages that correspond to individu- als sharing presents a fuzzy ant based clustering approach for this multi-document person name dis- ambiguation problem

De Cock, Martine

292

Fault-Tolerant ANTS Tobias Langner, Jara Uitto, David Stolz, and Roger Wattenhofer  

E-print Network

mobile agents, controlled by finite automata, search collaboratively for a treasure hidden study a variation of the ANTS problem, where the n agents are controlled by randomized finite state, it was shown that the treasure can be located with randomized finite-state machines in optimal time

293

Improvement of the Road Traffic Management by an Ant-Hierarchical Fuzzy System  

E-print Network

of traffic congestions states as well as their negative effects: delays, wasting time, drivers' stress problems [9]. Thus, the current trend of research work in traffic and transportation is to investigateImprovement of the Road Traffic Management by an Ant-Hierarchical Fuzzy System Habib M. Kammoun

Casillas Barranquero, Jorge

294

Energy-saving scheduling strategy for elevator group control system based on ant colony optimization  

Microsoft Academic Search

Elevator group control scheduling is to dispatch every elevator to serve call requests from different floors based on some certain goal. It's a kind of typical combinatorial optimization problems. Ant colony algorithm is good at solving the discrete combinatorial optimization, its well global optimization ability and quick convergence velocity are both necessary to a scheduling algorithm. Moreover, reducing passengers' waiting

Jing-long Zhang; Jie Tang; Qun Zong; Jun-fang Li

2010-01-01

295

Induced responses to herbivory in the Neotropical ant-plant association between Azteca ants and Cecropia trees: response of ants to potential inducing cues  

Microsoft Academic Search

Plant defense against herbivores often involves constitutive and inducible mechanisms of resistance. Obligate ant-plants,\\u000a which provide food and housing for ants, are thought to primarily rely on ants for defense against herbivores. This form of\\u000a plant defense has largely been viewed as static. We have been investigating the dynamic nature of Azteca ants as an inducible defense of Cecropia trees.

Anurag A. Agrawal; Benjamin J. Dubin-Thaler

1999-01-01

296

Ant Colony Optimization Algorithm for Continuous Domains Based on Position Distribution Model of Ant Colony Foraging  

PubMed Central

Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules of ant colony position, and the processing method of constraint condition. Algorithm performance against a set of test trials was unconstrained optimization test functions and a set of optimization test functions, and test results of other algorithms are compared and analyzed to verify the correctness and effectiveness of the proposed algorithm. PMID:24955402

Liu, Liqiang; Dai, Yuntao

2014-01-01

297

Induced responses to herbivory in the Neotropical ant-plant association between Azteca ants and Cecropia trees: response of ants to potential inducing cues  

Microsoft Academic Search

Received: 23 March 1998 \\/Accepted after revision: 5 July 1998 Abstract Plant defense against herbivores often involves constitutive and inducible mechanisms of resistance. Obligate ant-plants, which provide food and housing for ants, are thought to primarily rely on ants for defense against herbivores. This form of plant defense has largely been viewed as static. We have been investigating the dynamic

B. J. Dubin-Thaler

298

Fossil evidence for the early ant evolution  

NASA Astrophysics Data System (ADS)

Ants are one of the most studied insects in the world; and the literature devoted to their origin and evolution, systematics, ecology, or interactions with plants, fungi and other organisms is prolific. However, no consensus yet exists on the age estimate of the first Formicidae or on the origin of their eusociality. We review the fossil and biogeographical record of all known Cretaceous ants. We discuss the possible origin of the Formicidae with emphasis on the most primitive subfamily Sphecomyrminae according to its distribution and the Early Cretaceous palaeogeography. And we review the evidence of true castes and eusociality of the early ants regarding their morphological features and their manner of preservation in amber. The mid-Cretaceous amber forest from south-western France where some of the oldest known ants lived, corresponded to a moist tropical forest close to the shore with a dominance of gymnosperm trees but where angiosperms (flowering plants) were already diversified. This palaeoenvironmental reconstruction supports an initial radiation of ants in forest ground litter coincident with the rise of angiosperms, as recently proposed as an ecological explanation for their origin and successful evolution.

Perrichot, Vincent; Lacau, Sébastien; Néraudeau, Didier; Nel, André

2008-02-01

299

Impacts of residual insecticide barriers on perimeter-invading ants, with particular reference to the odorous house ant, Tapinoma sessile.  

PubMed

Three liquid insecticide formulations were evaluated as barrier treatments against perimeter-invading ants at a multifamily housing complex in West Lafayette, IN. Several ant species were present at the study site, including (in order of abundance) pavement ant, Tetramorium caespitum (L.); honey ant, Prenolepis imparis (Say); odorous house ant, Tapinoma sessile (Say); thief ant, Solenopsis molesta (Say); acrobat ant, Crematogaster ashmeadi (Mayr); crazy ant, Paratrechina longicornis (Latrielle), field ants, Formica spp.; and carpenter ant Camponotus pennsylvanicus (DeGeer). Studies began in May 2001 and concluded 8 wk later in July. Individual replicate treatments were placed 0.61 in (2 feet) up and 0.92 m (3 feet) out from the ends of 46.1 by 10.1-m (151 by 33-foot) apartment buildings. Ant sampling was performed with 10 placements of moist cat food for 1 h within treatment zones, followed by capture and removal of recruited ants for later counting. All treatments led to substantial reductions in ant numbers relative to untreated controls. The most effective treatment was fipronil, where 2% of before-treatment ant numbers were present at 8 wk after treatment. Both imidacloprid and cyfluthrin barrier treatments had efficacy comparative with fipronil, but to 4 and 2 wk, respectively. Odorous house ants were not sampled before treatment. Comparisons of ant species composition between treatments and controls revealed an increase in odorous house ant frequencies at 1-8 wk after treatment in treated locations only. These results demonstrate efficacy for both nonrepellent and repellent liquid insecticides as perimeter treatments for pest ants. In addition, our findings with odorous house ant highlight an apparent invasive-like characteristic of this species that may contribute to its dramatic increase in structural infestation rates in many areas of the United States. PMID:15154488

Scharf, Michael E; Ratliff, Catina R; Bennett, Gary W

2004-04-01

300

Polygynous colony formation in the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae)  

E-print Network

). This thesis follows the style of the Annals of the ~ to 1 ' 1 ~S' t of A g. ~ti ''p t, ig health problems for livestock, wildlife, and pets (Rhoades & Davis 1967). The fire ant can cause serious allergic reactions in the human population, sometimes... leading to death. Mound building causes physical damage to farm machinery and electrical equipment such as transformers, junction boxes and traffic signals (Hamman et al. 1987). The ant can also cause highway subsidence and is a pest of certain crops...

Stamps, William Terrell

1989-01-01

301

Markovian Ants in a Queuing System  

NASA Astrophysics Data System (ADS)

The synthesis of memoryless Markovian systems and Ant based concept with memory characteristics of deposit pheromone is the basis for the presented artificial intelligence hybrid. Only the initial elements of the system are specified in this paper by illustrating the routes of two ants. The pheromone capacity was first modelled as an exponential-type random variable. The Ant Queueing System was formed. The pheromone capacity was then used to form two independent exponential random variables. The convolution of these variables induces significant quality and quantity changes, mainly the decrease in entropy. The study also provides a possible method for dealing with stationary queueing systems when we are familiar with the state probability and the arrival rate and service rate are unknown.

Tanackov, Ilija; Simi?, Dragan; Sremac, Siniša; Tepi?, Jovan; Koci?-Tanackov, Sun?ica

302

Ant Colony Optimization for Markowitz Mean-Variance Portfolio Model  

NASA Astrophysics Data System (ADS)

This work presents Ant Colony Optimization (ACO), which was initially developed to be a meta-heuristic for combinatorial optimization, for solving the cardinality constraints Markowitz mean-variance portfolio model (nonlinear mixed quadratic programming problem). To our knowledge, an efficient algorithmic solution for this problem has not been proposed until now. Using heuristic algorithms in this case is imperative. Numerical solutions are obtained for five analyses of weekly price data for the following indices for the period March, 1992 to September, 1997: Hang Seng 31 in Hong Kong, DAX 100 in Germany, FTSE 100 in UK, S&P 100 in USA and Nikkei 225 in Japan. The test results indicate that the ACO is much more robust and effective than Particle swarm optimization (PSO), especially for low-risk investment portfolios.

Deng, Guang-Feng; Lin, Woo-Tsong

303

Recruitment Strategies and Colony Size in Ants  

PubMed Central

Ants use a great variety of recruitment methods to forage for food or find new nests, including tandem running, group recruitment and scent trails. It has been known for some time that there is a loose correlation across many taxa between species-specific mature colony size and recruitment method. Very small colonies tend to use solitary foraging; small to medium sized colonies use tandem running or group recruitment whereas larger colonies use pheromone recruitment trails. Until now, explanations for this correlation have focused on the ants' ecology, such as food resource distribution. However, many species have colonies with a single queen and workforces that grow over several orders of magnitude, and little is known about how a colony's organization, including recruitment methods, may change during its growth. After all, recruitment involves interactions between ants, and hence the size of the colony itself may influence which recruitment method is used—even if the ants' behavioural repertoire remains unchanged. Here we show using mathematical models that the observed correlation can also be explained by recognizing that failure rates in recruitment depend differently on colony size in various recruitment strategies. Our models focus on the build up of recruiter numbers inside colonies and are not based on optimality arguments, such as maximizing food yield. We predict that ant colonies of a certain size should use only one recruitment method (and always the same one) rather than a mix of two or more. These results highlight the importance of the organization of recruitment and how it is affected by colony size. Hence these results should also expand our understanding of ant ecology. PMID:20694195

Planqué, Robert; van den Berg, Jan Bouwe; Franks, Nigel R.

2010-01-01

304

An ants-eye view of an ant-plant protection mutualism  

PubMed Central

Ant protection of extrafloral nectar-secreting plants (EFN plants) is a common form of mutualism found in most habitats around the world. However, very few studies have considered these mutualisms from the ant, rather than the plant, perspective. In particular, a whole-colony perspective that takes into account the spatial structure and nest arrangement of the ant colonies that visit these plants has been lacking, obscuring when and how colony-level foraging decisions might affect tending rates on individual plants. Here, we experimentally demonstrate that recruitment of Crematogaster opuntiae (Buren) ant workers to the extrafloral nectar-secreting cactus Ferocactus wislizeni (Englem) is not independent between plants up to 5m apart. Colony territories of C. opuntiae are large, covering areas of up to 5000m2, and workers visit between five and thirty-four extrafloral nectar-secreting barrel cacti within the territories. These ants are highly polydomous, with up to twenty nest entrances dispersed throughout the territory and interconnected by trail networks. Our study demonstrates that worker recruitment is not independent within large polydomous ant colonies, highlighting the importance of considering colonies rather than individual workers as the relevant study unit within ant/plant protection mutualisms PMID:23515612

Lanan, M. C.; Bronstein, J. L.

2013-01-01

305

Wolbachia transmission dynamics in Formica wood ants  

PubMed Central

Background The role of Wolbachia endosymbionts in shaping the mitochondrial diversity of their arthropod host depends on the effects they have on host reproduction and on the mode of transmission of the bacteria. We have compared the sequence diversity of wsp (Wolbachia surface protein gene) and the host mtDNA in a group of Formica ant species that have diverged approximately 0.5 million years ago (MYA). The aim was to study the relationship of Wolbachia and its ant hosts in terms of vertical and horizontal transmission of the bacteria. Results All studied ant species were doubly infected with two Wolbachia strains (wFex1 and wFex4) all over their geographical distribution area in Eurasia. The most common haplotypes of these strains were identical with strains previously described from a more distantly related Formica ant, with an estimated divergence time of 3.5 – 4 MYA. Some strain haplotypes were associated to the same or closely related mtDNA haplotypes as expected under vertical transmission. However, in several cases the wsp haplotypes coexisted with distant mtDNA haplotypes, a pattern which is more compatible with horizontal transmission of the bacteria. Conclusion Two lines of evidence suggest that the sharing of Wolbachia strains by all F. rufa species is rather due to horizontal than vertical transmission. First, the fact that endosymbiont strains identical to those of F. rufa ants have been found in another species that diverged 3.5–4 MYA strongly suggests that horizontal transfer can and does occur between Formica ants. Second, the frequent sharing of identical Wolbachia strains by distant mitochondrial lineages within the F. rufa group further shows that horizontal transmission has occurred repeatedly. Nevertheless, our dataset also provides some evidence for longer-term persistence of infection, indicating that Wolbachia infection within this host clade has been shaped by both horizontal and vertical transmission of symbionts. The fact that all the ants were infected irrespective of the family structure of their societies gives no support to the proposed hypotheses that the spreading of Wolbachia in ants might be associated to the types of their societies. PMID:18291041

2008-01-01

306

Detection of Mitochondrial COII DNA Sequences in Ant Guts as a Method for Assessing Termite Predation by Ants  

PubMed Central

Termites and ants contribute more to animal biomass in tropical rain forests than any other single group and perform vital ecosystem functions. Although ants prey on termites, at the community level the linkage between these groups is poorly understood. Thus, assessing the distribution and specificity of ant termitophagy is of considerable interest. We describe an approach for quantifying ant-termite food webs by sequencing termite DNA (cytochrome c oxidase subunit II, COII) from ant guts and apply this to a soil-dwelling ant community from tropical rain forest in Gabon. We extracted DNA from 215 ants from 15 species. Of these, 17.2 % of individuals had termite DNA in their guts, with BLAST analysis confirming the identity of 34.1 % of these termites to family level or better. Although ant species varied in detection of termite DNA, ranging from 63 % (5/7; Camponotus sp. 1) to 0 % (0/7; Ponera sp. 1), there was no evidence (with small sample sizes) for heterogeneity in termite consumption across ant taxa, and no evidence for species-specific ant-termite predation. In all three ant species with identifiable termite DNA in multiple individuals, multiple termite species were represented. Furthermore, the two termite species that were detected on multiple occasions in ant guts were in both cases found in multiple ant species, suggesting that ant-termite food webs are not strongly compartmentalised. However, two ant species were found to consume only Anoplotermes-group termites, indicating possible predatory specialisation at a higher taxonomic level. Using a laboratory feeding test, we were able to detect termite COII sequences in ant guts up to 2 h after feeding, indicating that our method only detects recent feeding events. Our data provide tentative support for the hypothesis that unspecialised termite predation by ants is widespread and highlight the use of molecular approaches for future studies of ant-termite food webs. PMID:25853549

Fayle, Tom M.; Scholtz, Olivia; Dumbrell, Alex J.; Russell, Stephen; Segar, Simon T.; Eggleton, Paul

2015-01-01

307

A New Rank Based Version of the Ant System - A Computational Study  

Microsoft Academic Search

The ant system is a new meta-heuristic for hard combinatorial optimizationproblems. It is a population-based approach that uses exploitation of positivefeedback as well as greedy search. It was first proposed for tackling the wellknown Traveling Salesman Problem (TSP), but has been also successfully appliedto problems such as quadratic assignment, job-shop scheduling, vehiclerouting and graph colouring.In this paper we introduce a

Bernd Bullnheimer; Richard F. Hartl; Christine Strauß

1997-01-01

308

Automated Selection of Appropriate Pheromone Representations in Ant Colony Optimisation  

E-print Network

Automated Selection of Appropriate Pheromone Representations in Ant Colony Optimisation James an analogue of ant trail pheromones to learn about good features of solutions. ACO implementations. In this paper, we present a novel system for automatically generating appropriate parsimonious pheromone

Montgomery, James

309

Automated Selection of Appropriate Pheromone Representations in Ant Colony Optimisation  

E-print Network

Automated Selection of Appropriate Pheromone Representations in Ant Colony Optimisation James of ant trail pheromones to learn about good features of solutions. Critically, the phero- mone solutions. In this article, we present a novel system for automatically generating appropriate pheromone

Montgomery, James

310

Farmers, Warriors, Builders: The Hidden Life of Ants  

NSDL National Science Digital Library

The website of the Smithsonian National Museum of Natural History has a highly informative and just plain delightful interactive exhibit on ants. The exhibit explains how, much like humans, "ants achieve domination by being social creatures". Dividing the ants' lives into "food", "warriors", "shelter" and "communication", the exhibit offers an array of photos in its photo gallery to illustrate the variety of ant life and behavior on earth. Clicking on the thumbnails will enlarge the photos and reveal a brief description of the photo. More than half a dozen videos of ants taken throughout the world can be found under the "Ant Videos" link on the left side of the page. Visitors interested in learning more about myrmecology (ant science) would be remiss if they didn't visit the "Ant Web Links" section of the website, which can also be found on the left side of the page.

311

Ants and Habitat Specificity in Aphids  

Microsoft Academic Search

A number of rare butterflies are known to only utilise their host plant species when they grow in particular situations. Field data are presented showing that two rare species of aphid also only utilised their host plants when they grew in particular situations, namely near ant nests. The oak-feeding aphid Stomaphis quercus only occupied trees within 17 m of a

G. W. Hopkins; J. I. Thacker

1999-01-01

312

Fire Ants and the Decapitating Fly  

NSDL National Science Digital Library

Excellent summary of how the decapitating fly works as a biological control measure against fire ants. Unhurried pace with great supporting video. Good choice for introducing students to the idea of biological control. Video quality is extremely high and the depiction of the complete lifecycle of the fly is valuable.

0000-00-00

313

Candidate Set Strategies for Ant Colony Optimisation  

E-print Network

Candidate Set Strategies for Ant Colony Optimisation Marcus Randall and James Montgomery School to overcome this is to limit the number of element choices to a sensible subset, or candidate set. This paper describes some novel generic candidate set strategies and tests these on the travelling salesman and car

Montgomery, James

314

Ants recognize foes and not friends  

PubMed Central

Discriminating among individuals and rejecting non-group members is essential for the evolution and stability of animal societies. Ants are good models for studying recognition mechanisms, because they are typically very efficient in discriminating ‘friends’ (nest-mates) from ‘foes’ (non-nest-mates). Recognition in ants involves multicomponent cues encoded in cuticular hydrocarbon profiles. Here, we tested whether workers of the carpenter ant Camponotus herculeanus use the presence and/or absence of cuticular hydrocarbons to discriminate between nest-mates and non-nest-mates. We supplemented the cuticular profile with synthetic hydrocarbons mixed to liquid food and then assessed behavioural responses using two different bioassays. Our results show that (i) the presence, but not the absence, of an additional hydrocarbon elicited aggression and that (ii) among the three classes of hydrocarbons tested (unbranched, mono-methylated and dimethylated alkanes; for mono-methylated alkanes, we present a new synthetic pathway), only the dimethylated alkane was effective in eliciting aggression. Our results suggest that carpenter ants use a fundamentally different mechanism for nest-mate recognition than previously thought. They do not specifically recognize nest-mates, but rather recognize and reject non-nest-mates bearing odour cues that are novel to their own colony cuticular hydrocarbon profile. This begs for a reappraisal of the mechanisms underlying recognition systems in social insects. PMID:19364750

Guerrieri, Fernando J.; Nehring, Volker; Jørgensen, Charlotte G.; Nielsen, John; Galizia, C. Giovanni; d'Ettorre, Patrizia

2009-01-01

315

Ants, Crickets and Frogs in Cyclic Pursuit  

Microsoft Academic Search

. We consider a deterministic continuous pursuit, in which n ants chase each otherin cyclic order and with preassigned, varying speeds. We also consider two discrete analogs, inwhich crickets or frogs are engaged in cyclic pursuit with constant and equal speeds. We examinethe possible evolutions of these pursuits as time goes to infinity: collision, limit points, equilibriumstates and periodic motion.IntroductionImagine

A. m. Bruckstein; N. Cohen; A. Efrat

1991-01-01

316

The AntSynNet Algorithm: Network Synthesis using Ant Colony Optimization Simon Wilkinson, Tony White  

E-print Network

pheromone, forming in this way a pheromone trail. Ants can smell pheromone and, when choosing their way, they tend to choose, in probability, paths marked by strong pheromone concentrations. The pheromone trail

White, Tony

317

Dynamics of an ant-ant Obligate Mutualism: Colony Growth, Density Dependence and Frequency Dependence  

Technology Transfer Automated Retrieval System (TEKTRAN)

In insect societies, worker versus queen development (reproductive caste) is typically governed by environmental factors, but many Pogonomyrmex seed-harvester ants exhibit strict genetic caste determination, resulting in an obligate mutualism between two reproductively isolated lineages. Same-linea...

318

Resource redistribution in polydomous ant nest networks: local or global?  

PubMed Central

An important problem facing organisms in a heterogeneous environment is how to redistribute resources to where they are required. This is particularly complex in social insect societies as resources have to be moved both from the environment into the nest and between individuals within the nest. Polydomous ant colonies are split between multiple spatially separated, but socially connected, nests. Whether, and how, resources are redistributed between nests in polydomous colonies is unknown. We analyzed the nest networks of the facultatively polydomous wood ant Formica lugubris. Our results indicate that resource redistribution in polydomous F. lugubris colonies is organized at the local level between neighboring nests and not at the colony level. We found that internest trails connecting nests that differed more in their amount of foraging were stronger than trails between nests with more equal foraging activity. This indicates that resources are being exchanged directly from nests with a foraging excess to nests that require resources. In contrast, we found no significant relationships between nest properties, such as size and amount of foraging, and network measures such as centrality and connectedness. This indicates an absence of a colony-level resource exchange. This is a clear example of a complex behavior emerging as a result of local interactions between parts of a system. PMID:25214755

Franks, Daniel W.; Robinson, Elva J.H.

2014-01-01

319

Structural and Molecular Basis for Resistance to Aminoglycoside Antibiotics by the Adenylyltransferase ANT(2?)-Ia  

PubMed Central

ABSTRACT ? The aminoglycosides are highly effective broad-spectrum antimicrobial agents. However, their efficacy is diminished due to enzyme-mediated covalent modification, which reduces affinity of the drug for the target ribosome. One of the most prevalent aminoglycoside resistance enzymes in Gram-negative pathogens is the adenylyltransferase ANT(2?)-Ia, which confers resistance to gentamicin, tobramycin, and kanamycin. Despite the importance of this enzyme in drug resistance, its structure and molecular mechanism have been elusive. This study describes the structural and mechanistic basis for adenylylation of aminoglycosides by the ANT(2?)-Ia enzyme. ANT(2?)-Ia confers resistance by magnesium-dependent transfer of a nucleoside monophosphate (AMP) to the 2?-hydroxyl of aminoglycoside substrates containing a 2-deoxystreptamine core. The catalyzed reaction follows a direct AMP transfer mechanism from ATP to the substrate antibiotic. Central to catalysis is the coordination of two Mg2+ ions, positioning of the modifiable substrate ring, and the presence of a catalytic base (Asp86). Comparative structural analysis revealed that ANT(2?)-Ia has a two-domain structure with an N-terminal active-site architecture that is conserved among other antibiotic nucleotidyltransferases, including Lnu(A), LinB, ANT(4?)-Ia, ANT(4?)-Ib, and ANT(6)-Ia. There is also similarity between the nucleotidyltransferase fold of ANT(2?)-Ia and DNA polymerase ?. This similarity is consistent with evolution from a common ancestor, with the nucleotidyltransferase fold having adapted for activity against chemically distinct molecules. Importance ? To successfully manage the threat associated with multidrug-resistant infectious diseases, innovative therapeutic strategies need to be developed. One such approach involves the enhancement or potentiation of existing antibiotics against resistant strains of bacteria. The reduction in clinical usefulness of the aminoglycosides is a particular problem among Gram-negative human pathogens, since there are very few therapeutic options for infections caused by these organisms. In order to successfully circumvent or inhibit the activity of aminoglycoside-modifying enzymes, and to thus rejuvenate the activity of the aminoglycoside antibiotics against Gram-negative pathogens, structural and mechanistic information is crucial. This study reveals the structure of a clinically prevalent aminoglycoside resistance enzyme [ANT(2?)-Ia] and depicts the molecular basis underlying modification of antibiotic substrates. Combined, these findings provide the groundwork for the development of broad-spectrum inhibitors against antibiotic nucleotidyltransferases. PMID:25564464

Cox, Georgina; Stogios, Peter J.; Savchenko, Alexei

2015-01-01

320

Fertility signalling and reproductive skew in queenless ants  

Microsoft Academic Search

Social insects often show an extreme reproductive skew. In queenless ants, colonies consist of morphologically identical workers that can all potentially reproduce sexually. Similarly to that in social vertebrates, aggression in these ants functions to select the reproductive(s). We investigated the mechanisms underlying reproductive skew in the monogynous queenless ant Streblognathus peetersi. Behavioural observations of disturbed hierarchies were integrated with

Virginie Cuvillier-Hot; Alain Lenoir; Robin Crewe; Christian Malosse; Christian Peeters

2004-01-01

321

The Natural History of the Arboreal Ant, Crematogaster ashmeadi  

Microsoft Academic Search

The arboreal ant, Crematogaster ashmeadi Emery (Hymenoptera: Formicidae), is the most dominant arboreal ant in the pine forests of the coastal plain of northern Florida. The majority of pine trees harbor a colony of these ants. The colonies inhabit multiple chambers abandoned by bark-mining caterpillars, especially those of the family Cossidae, in the outer bark of living pines. They also

Walter R. Tschinkel

2002-01-01

322

Competition between harvester ants and rodents in the cold desert  

Microsoft Academic Search

Local distribution patterns of three rodent species (Perognathus parvus, Peromyscus maniculatus, Reithrodontomys megalotis) were studied in areas of high and low densities of harvester ants (Pogonomyrmex owyheei) in Raft River Valley, Idaho. Numbers of rodents were greatest in areas of high ant-density during May, but partially reduced in August; whereas, the trend was reversed in areas of low ant-density. Seed

D. S. Landeen; C. D. Jorgensen; H. D. Smith

1979-01-01

323

TWO NEW SPECIES OF THE ANT GENUS PERISSOMYRMEX SMITH  

E-print Network

TWO NEW SPECIES OF THE ANT GENUS PERISSOMYRMEX SMITH (HYMENOPTERA: FORMICIDAE) FROM CHINA1 Shanyi Zhou2 and Jianhua Huang3 ABSTRACT: Two new species of the ant genus Perissomyrmex Smith are described, China The ant genus Perissomyrmex was described by M. R. Smith in 1947 based on the type species P

Villemant, Claire

324

Dynamics of an ant-plant-pollinator model  

NASA Astrophysics Data System (ADS)

In this paper, we consider plant-pollinator-ant systems in which plant-pollinator interaction and plant-ant interaction are both mutualistic, but there also exists interference of pollinators by ants. The plant-pollinator interaction can be described by a Beddington-DeAngelis formula, so we extend the formula to characterize plant-pollinator mutualisms, including the interference by ants, and form a plant-pollinator-ant model. Using dynamical systems theory, we show uniform persistence of the model. Moreover, we demonstrate conditions under which boundary equilibria are globally asymptotically stable. The dynamics exhibit mechanisms by which the three species could coexist when ants interfere with pollinators. We define a threshold in ant interference. When ant interference is strong, it can drive plant-pollinator mutualisms to extinction. Furthermore, if the ants depend on pollination mutualism for their persistence, then sufficiently strong ant interference could lead to their own extinction as well. Yet, when ant interference is weak, plant-ant and plant-pollinator mutualisms can promote the persistence of one another.

Wang, Yuanshi; DeAngelis, Donald L.; Nathaniel Holland, J.

2015-03-01

325

Fire ant control with Entomopathogens in the USA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fire ants, Solenopsis richteri and Solenopsis invicta, are stinging invasive ants from South America that infest over 129.5 million hectares in the southern United States. In the southern U.S., eradication is no longer considered possible and toxicant-based fire ant baiting is currently the primary...

326

Trail pheromone disruption of red imported fire ant  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world but toxic bait systems affect non-target ant species and can not be used in sensitive ecosystems. The fire ant uses recruitment pheromones to organize the retrieval of food resources back to the colony....

327

ORIGINAL PAPER Invasive Argentine ants reduce fitness of red maple  

E-print Network

species form mutual- isms with honeydew-producing Hemiptera and their aggressive presence deters the natural enemies of the Hemiptera. Invasive ant species like the Argentine ant have often been associated decades (Bronstein 1994; Bruno et al. 2003). Mutualisms involving ants and Hemiptera have been described

Buckel, Jeffrey A.

328

CHECK LIST OF THE ANTS (HYMENOPTERA: FORMICIDJ2) OF ASIA  

E-print Network

#12;#12;#12;#12;CHECK LIST OF THE ANTS (HYMENOPTERA: FORMICIDJ2) OF ASIA JAMES W. CHAPMAN Formerly of the senior author's ant collection was still in Dumaguete, though a great deal had been sent to Dr. W. M. The ant literature, records of some twenty- live years collecting, card catalogue, and an incomplete draft

Villemant, Claire

329

Introduction Ants are among the most ecologically diverse and  

E-print Network

Introduction Ants are among the most ecologically diverse and successful animals on our planet and mutualists [1]. Understanding the eco- logical dominance of ants requires investigation into the complex organization of their societies. The past three years have seen the publication of seven ant genomes [2

Alvarez, Nadir

330

Ants (Formicidae): Models for Social Complexity Chris R. Smith,1  

E-print Network

Ants (Formicidae): Models for Social Complexity Chris R. Smith,1 Adam Dolezal, Dorit Eliyahu, C INTRODUCTION The family Formicidae (ants) is composed of more than 12,000 described species that vary greatly in size, morphology, behavior, life history, ecology, and social organization. Ants occur in most

Tschinkel, Walter R.

331

New records of ants (Hymenoptera: Formicidae) OMID PAKNIA1  

E-print Network

New records of ants (Hymenoptera: Formicidae) from Iran OMID PAKNIA1 ,ALEXANDER RADCHENKO2's email: omid.paknia@uni-ulm.de ABSTRACT. The ant species list of Iran is far from complete. So far, only the majority of ant material in two periods of field work in spring and summer of 2007 and 2008. In total, we

Villemant, Claire

332

HOUSEHOLD AND STRUCTURAL INSECTS Trap-Mulching Argentine Ants  

E-print Network

HOUSEHOLD AND STRUCTURAL INSECTS Trap-Mulching Argentine Ants JULES SILVERMAN,1 CLYDE E. SORENSON. Econ. Entomol. 99(5): 1757Ð1760 (2006) ABSTRACT Argentine ant, Linepithema humile (Mayr), management ants are repelled from a broad domain of nest sites to smaller deÞned areas, which are subsequently

Buckel, Jeffrey A.

333

A MATHEMATICAL MODEL FOR THE POPULATION DYNAMICS OF ARMY ANT  

E-print Network

A MATHEMATICAL MODEL S FOR THE POPULATION DYNAMICS OF ARMY ANT N # N.F. BRITTO Centre for the population dynamics of the army ant c Eciton burchelli on Barro Colorado Island in Panama was set up. Introduction Army ants are among the most spectacular of social animals, living in organised r f colonies

Bath, University of

334

Ant Algorithms and Generalized Finite Urns Christopher Leith  

E-print Network

Ant Algorithms and Generalized Finite Urns by Christopher Leith A thesis submitted behaviour of pheromone trail laying biological agents. These ant algorithms, as they are commonly called system. Our interest lies mainly with the latter application. Analyzing the effectiveness of ant

Linder, Tamás

335

Pareto Ant Colony Optimization with ILP preprocessing in multiobjective project  

E-print Network

Pareto Ant Colony Optimization with ILP preprocessing in multiobjective project portfolio selection the computational effort necessary and the quality of an approximated solution space, Pareto Ant Colony Optimization at a low cost. Key words: Ant Colony Optimization, Project Portfolio Selection, Multiobjective

Gutjahr, Walter

336

TWO ANT COLONY ALGORITHMS FOR BESTEFFORT ROUTING IN DATAGRAM NETWORKS  

E-print Network

TWO ANT COLONY ALGORITHMS FOR BEST­EFFORT ROUTING IN DATAGRAM NETWORKS GIANNI DI CARO and MARCO, Belgium fgdicaro,mdorigog@ulb.ac.be ABSTRACT In this paper we present two versions of AntNet, a novel approach to adaptive learning of routing tables in wide area best­effort datagram networks. Ant

Ducatelle, Frederick

337

Symbiont choice in a fungus-growing ant (Attini, Formicidae)  

E-print Network

Symbiont choice in a fungus-growing ant (Attini, Formicidae) Ulrich G. Mueller,a,b Jessica Poulin of California at Irvine, Irvine, CA 92717, USA Cultivars of fungus-growing (attine) ants are vertically suggests that the ant­fungus mutualism is stabilized evolutionarily not only by partner feedback inherent

Schultz, Ted

338

In search of ant ancestors Ted R. Schultz*  

E-print Network

to a modern ant subfamily that contains many familiar extant species, including carpenter ants. Combined species and an estimated 3,000 to 9,000 additional species as yet unknown to science. Today ants occupy keystone posi- tions in most terrestrial environments, serv- ing as major conduits of energy and organic

Schultz, Ted

339

Hybrid Continuous Interacting Ant Colony aimed at Enhanced Global Optimization  

Microsoft Academic Search

Ant colony algorithms are a class of metaheuristics which ar e inspired from the behaviour of real ants. The original idea consisted in simulating the stigmergic communication , therefore these algorithms are considered as a form of adaptive memory programming. A new formalization was propo sed for the design of ant colony algorithms, introducing the biological notions of heterarchy and

Johann Dréo; Patrick Siarry

2007-01-01

340

Continuous interacting ant colony algorithm based on dense heterarchy  

Microsoft Academic Search

Ant colony algorithms are a class of metaheuristics which are inspired from the behavior of real ants. The original idea consisted in simulating the stigmergic communication, therefore these algorithms are considered as a form of adaptive memory programming. A new formalization is proposed for the design of ant colony algorithms, introducing the biological notions of heterarchy and communication channels. We

Johann Dréo; Patrick Siarry

2004-01-01

341

Model Specification Searches Using Ant Colony Optimization Algorithms  

ERIC Educational Resources Information Center

Ant colony optimization is a recently proposed heuristic procedure inspired by the behavior of real ants. This article applies the procedure to model specification searches in structural equation modeling and reports the results. The results demonstrate the capabilities of ant colony optimization algorithms for conducting automated searches.

Marcoulides, George A.; Drezner, Zvi

2003-01-01

342

A Novel delivery Method for Ant (Hymenoptera: Formicidae) toxicants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Described here is a new delivery method for ant toxicants consisting of an inert carrier, an attractant, and a toxicant. Unlike baits, this system does not contain a food source, but uses ant to ant contact rather than trophallaxis as the mechanism for horizontal dispersal of the toxicant through th...

343

Plant lock and ant key: pairwise coevolution of an exclusion filter in an ant-plant mutualism.  

PubMed Central

Although observations suggest pairwise coevolution in specific ant-plant symbioses, coevolutionary processes have rarely been demonstrated. We report on, what is to the authors' knowledge, the strongest evidence yet for reciprocal adaptation of morphological characters in a species-specific ant-plant mutualism. The plant character is the prostoma, which is a small unlignified organ at the apex of the domatia in which symbiotic ants excavate an entrance hole. Each myrmecophyte in the genus Leonardoxa has evolved a prostoma with a different shape. By performing precise measurements on the prostomata of three related myrmecophytes, on their specific associated ants and on the entrance holes excavated by symbiotic ants at the prostomata, we showed that correspondence of the plant and ant traits forms a morphological and behavioural filter. We have strong evidence for coevolution between the dimensions and shape of the symbiotic ants and the prostoma in one of the three ant-Leonardoxa associations. PMID:11600077

Brouat, C.; Garcia, N.; Andary, C.; McKey, D.

2001-01-01

344

A Graph-Based Ant Colony Optimization Approach for Process Planning  

PubMed Central

The complex process planning problem is modeled as a combinatorial optimization problem with constraints in this paper. An ant colony optimization (ACO) approach has been developed to deal with process planning problem by simultaneously considering activities such as sequencing operations, selecting manufacturing resources, and determining setup plans to achieve the optimal process plan. A weighted directed graph is conducted to describe the operations, precedence constraints between operations, and the possible visited path between operation nodes. A representation of process plan is described based on the weighted directed graph. Ant colony goes through the necessary nodes on the graph to achieve the optimal solution with the objective of minimizing total production costs (TPC). Two cases have been carried out to study the influence of various parameters of ACO on the system performance. Extensive comparative experiments have been conducted to demonstrate the feasibility and efficiency of the proposed approach. PMID:24995355

Wang, JinFeng; Fan, XiaoLiang; Wan, Shuting

2014-01-01

345

THE FORMIS ANT BIBLIOGRAPHY: A WINDOW ON THE WORLD'S ANT LITERATURE AND A DOOR INTO MYRMECOLOGY'S FUTURE  

Technology Transfer Automated Retrieval System (TEKTRAN)

FORMIS 2001 is a composite of several ant literature databases. It contains citations for a large fraction of the world's ant literature (over 30,000 references). It can be downloaded or searched online: http://cmave.usda.ufl.edu/~formis/. General contributions include: UCD Ant Literature Databas...

346

USDA: FORMIS: A Master Bibliography of Ant Literature  

NSDL National Science Digital Library

Hosted by the USDA's Center for Medical, Agricultural, and Veterinary Entomology, this Master Bibliography of Ant Literature, entitled FORMIS, "is a composite of several ant literature databases. It contains citations for a large fraction of the world's ant literature (about 32,000 references). FORMIS contains all known ant taxonomic literature (through 1996)." In addition, FORMIS features comprehensive bibliographies of fire ants, Russian wood ants, and leaf-cutting ants. The website offers options for online searches and downloads. The site was last modified in April 2004; however, it should be noted that FORMIS has not been updated since 2003, thus users should not expect to find the most recent literature. Despite the lack of up-to-date literature, FORMIS remains a substantial resource for myrmecologists and other researchers. Furthermore, the editors are requesting assistance for the continued expansion and updating of FORMIS.

347

Exploring with PAM: Prospecting ANTS Missions for Solar System Surveys  

NASA Technical Reports Server (NTRS)

ANTS (Autonomous Nano-Technology Swarm), a large (1000 member) swarm of nano to picoclass (10 to 1 kg) totally autonomous spacecraft, are being developed as a NASA advanced mission concept. ANTS, based on a hierarchical insect social order, use an evolvable, self-similar, hierarchical neural system in which individual spacecraft represent the highest level nodes. ANTS uses swarm intelligence attained through collective, cooperative interactions of the nodes at all levels of the system. At the highest levels this can take the form of cooperative, collective behavior among the individual spacecraft in a very large constellation. The ANTS neural architecture is designed for totally autonomous operation of complex systems including spacecraft constellations. The ANTS (Autonomous Nano Technology Swarm) concept has a number of possible applications. A version of ANTS designed for surveying and determining the resource potential of the asteroid belt, called PAM (Prospecting ANTS Mission), is examined here.

Clark, P. E.; Rilee, M. L.; Curtis, S. A.

2003-01-01

348

Harvester ant bioassay for assessing hazardous chemical waste sites  

SciTech Connect

A technique was developed for using harvester ants, Pogonomyrmex owhyeei, in terrestrial bioassays. Procedures were developed for maintaining stock populations, handling ants, and exposing ants to toxic materials. Relative toxicities were determined by exposing ants to 10 different materials. These materials included three insecticides, Endrin, Aldrin, and Dieldrin; one herbicide, 2,4-D; three oil-like compounds, wood preservative, drilling fluid, and slop oil; and three heavy metals, copper, zinc, and cadmium. Ants were exposed in petri dishes containing soil amended with a particular toxicant. Under these test conditions, ants showed no sensitivity to the metals or 2,4-D. Ants were sensitive to the insecticides and oils in repeated tests, and relative toxicity remained consistent throughout. Aldrin was the most toxic material, followed by Dieldrin, Endrin, wood preservative, drilling fluid, and slop oil. 10 refs., 2 figs., 2 tabs.

Gano, K.A.; Carlile, D.W.; Rogers, L.E.

1984-12-01

349

The Ants: A Community of Microrobots  

NSDL National Science Digital Library

A community of cubic-inch microrobots called "ants" is located at the Massachusetts Institute of Technology artificial intelligence laboratory. As part of a larger initiative to develop technologies for planetary exploration, the two main goals of the Ants project are "to push the limit of microrobotics by integrating many sensors and actuators into a small package, and to form a structured robotic community from the interactions of many simple individuals." Information pertaining to topics such as Hardware, Software, Related Research at the MIT AI Lab, Related Research Elsewhere, and Related Web Sites is listed under these subheadings. At the Website, the user will also find links to related MIT project sites such as Explosive Ordnance Disposal and Mars Exploration. These projects are an example of the many applications of robotic communities.

350

Caste-Specific Tyramides from Myrmicine Ants#  

PubMed Central

Analysis of the extracts of male ants of Monomorium minimum and M. ebeninum, by GC-MS and GC-FTIR revealed the presence of tyramides 2 and 4c, for which the structures were established by comparison with synthetic samples. These compounds and their analogs 1 and 3 were also found in males of other Monomorium species, males of Myrmicaria opaciventris, and males of several Solenopsis (Diplorhoptrum) species. Vapor-phase FTIR spectra revealed critically important structural clues to two of the tyramides, which had methyl-branching in the tyramide acyl moiety. Tyramide 4c exhibited a strong intramolecular amide NH hydrogen bond where an ?-keto group was deduced to be present in the acyl moiety and also showed the overlap of this ketone group frequency with that of the amide ?C=O. The biological function of these compounds is uncertain; however their role in ant-mating behavior may be suggested by a large body of evidence. PMID:20102169

Jones, Tappey. H.; Garraffo, H. Martin; Spande, Thomas F.; Andriamaharavo, Nirina R.; Gorman, Jeffrey S. T.; Snyder, Alexander J.; Jeter, Andrew W.; Torres, Juan A.; Snelling, Roy R.; Daly, John W.

2010-01-01

351

Optic disc detection using ant colony optimization  

NASA Astrophysics Data System (ADS)

The retinal fundus images are used in the treatment and diagnosis of several eye diseases, such as diabetic retinopathy and glaucoma. This paper proposes a new method to detect the optic disc (OD) automatically, due to the fact that the knowledge of the OD location is essential to the automatic analysis of retinal images. Ant Colony Optimization (ACO) is an optimization algorithm inspired by the foraging behaviour of some ant species that has been applied in image processing for edge detection. Recently, the ACO was used in fundus images to detect edges, and therefore, to segment the OD and other anatomical retinal structures. We present an algorithm for the detection of OD in the retina which takes advantage of the Gabor wavelet transform, entropy and ACO algorithm. Forty images of the retina from DRIVE database were used to evaluate the performance of our method.

Dias, Marcy A.; Monteiro, Fernando C.

2012-09-01

352

Atypical vitellins in ponerine ants (Formicidae: Hymenoptera)  

Microsoft Academic Search

Higher hymenopteran vitellogenin\\/vitellins have been characterized as containing one large apoprotein. We show that in the ant subfamily Ponerinae, species in the tribes Odontomachini, Platythyrini, and Amblyoponini, also have a vitellin with this simple structure, containing a single apoprotein of 180–190kDa. Species in tribes Ponerini and Ectatommini, however, have vitellins containing multiple subunits. The size and number of the subunits

Diana Wheeler; Jürgen Liebig; Bert Hölldobler

1999-01-01

353

Using VisANT to Analyze Networks  

PubMed Central

VisANT is a Web-based workbench for the integrative analysis of biological networks with unique features such as exploratory navigation of interaction network and multi-scale visualization and inference with integrated hierarchical knowledge. It provides functionalities for convenient construction, visualization, and analysis of molecular and higher order networks based on functional (e.g., expression profiles, phylogenetic profiles) and physical (e.g., yeast two-hybrid, chromatin-immunoprecipitation and drug target) relations from either the Predictome database or user-defined data sets. Analysis capabilities include network structure analysis, overrepresentation analysis, expression enrichment analysis etc. Additionally, network can be saved, accessed, and shared online. VisANT is able to develop and display meta-networks for meta-nodes that are structural complexes or pathways or any kind of subnetworks. Further, VisANT supports a growing number of standard exchange formats and database referencing standards, e.g., PSI-MI, KGML, BioPAX, SBML(in progress) Multiple species are supported to the extent that interactions or associations are available (i.e., public datasets or Predictome database). PMID:25422679

Hu, Zhenjun

2014-01-01

354

Polydomy in the ant Ectatomma opaciventre  

PubMed Central

Tropical ants commonly exhibit a hyper-dispersed pattern of spatial distribution of nests. In polydomous species, nests may be satellites, that is, secondary structures of the main nest, where the queen is found. In order to evaluate whether the ant Ectatomma opaciventre Roger (Formicidae: Ectatomminae) uses the strategy of building polydomous nests, the spatial distribution pattern of 33 nests in a 1,800 m2 degraded area located in Rio Claro, SP, Brazil, were investigated using the nearest neighbor method. To complement the results of this investigation, the cuticular chemical profile of eight colonies was analyzed using Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS). The nests of E. opaciventre presented a hyper-dispersed or regular distribution, which is the most common in ants. The analysis of the cuticular hydrocarbons apparently confirmed the hypothesis that this species is polydomous, since the chemical profiles of all studied colonies with nests at different sites were very similar to the chemical signature of the single found queen and were also different from those of colonies used as control. PMID:25373168

Tofolo, Viviane C.; Giannotti, Edilberto; Neves, Erika F.; Andrade, Luis H. C.; Lima, Sandro M.; Súarez, Yzel R.; Antonialli-Junior, William F.

2014-01-01

355

Recognition of Social Identity in Ants  

PubMed Central

Recognizing the identity of others, from the individual to the group level, is a hallmark of society. Ants, and other social insects, have evolved advanced societies characterized by efficient social recognition systems. Colony identity is mediated by colony specific signature mixtures, a blend of hydrocarbons present on the cuticle of every individual (the “label”). Recognition occurs when an ant encounters another individual, and compares the label it perceives to an internal representation of its own colony odor (the “template”). A mismatch between label and template leads to rejection of the encountered individual. Although advances have been made in our understanding of how the label is produced and acquired, contradictory evidence exists about information processing of recognition cues. Here, we review the literature on template acquisition in ants and address how and when the template is formed, where in the nervous system it is localized, and the possible role of learning. We combine seemingly contradictory evidence in to a novel, parsimonious theory for the information processing of nestmate recognition cues. PMID:22461777

Bos, Nick; d’Ettorre, Patrizia

2012-01-01

356

Reconnaissance and latent learning in ants  

PubMed Central

We show that ants can reconnoitre their surroundings and in effect plan for the future. Temnothorax albipennis colonies use a sophisticated strategy to select a new nest when the need arises. Initially, we presented colonies with a new nest of lower quality than their current one that they could explore for one week without a need to emigrate. We then introduced a second identical low quality new nest and destroyed their old nest so that they had to emigrate. Colonies showed a highly significant preference for the (low quality) novel new nest over the identical but familiar one. In otherwise identical experiments, colonies showed no such discrimination when the choice was between a familiar and an unfamiliar high-quality nest. When, however, either all possible pheromone marks were removed, or landmarks were re-orientated, just before the emigration, the ants chose between identical low-quality new nests at random. These results demonstrate for the first time that ants are capable of assessing and retaining information about the quality of potential new nest sites, probably by using both pheromones and landmark cues, even though this information may only be of strategic value to the colony in the future. They seem capable, therefore, of latent learning and, more explicitly, learning what not to do. PMID:17426016

Franks, Nigel R; Hooper, James W; Dornhaus, Anna; Aukett, Philippa J; Hayward, Alexander L; Berghoff, Stefanie M

2007-01-01

357

Ant antennae: are they sites for magnetoreception?  

PubMed Central

Migration of the Pachycondyla marginata ant is significantly oriented at 13° with respect to the geomagnetic north–south axis. On the basis of previous magnetic measurements of individual parts of the body (antennae, head, thorax and abdomen), the antennae were suggested to host a magnetoreceptor. In order to identify Fe3+/Fe2+ sites in antennae tissue, we used light microscopy on Prussian/Turnbull's blue-stained tissue. Further analysis using transmission electron microscopy imaging and diffraction, combined with elemental analysis, revealed the presence of ultra-fine-grained crystals (20–100 nm) of magnetite/maghaemite (Fe3O4/?-Fe2O3), haematite (?-Fe2O3), goethite (?-FeOOH) besides (alumo)silicates and Fe/Ti/O compounds in different parts of the antennae, that is, in the joints between the third segment/pedicel, pedicel/scape and scape/head, respectively. The presence of (alumo)silicates and Fe/Ti/O compounds suggests that most, if not all, of the minerals in the tissue are incorporated soil particles rather than biomineralized by the ants. However, as the particles were observed within the tissue, they do not represent contamination. The amount of magnetic material associated with Johnston's organ and other joints appears to be sufficient to produce a magnetic-field-modulated mechanosensory output, which may therefore underlie the magnetic sense of the migratory ant. PMID:19474081

de Oliveira, Jandira Ferreira; Wajnberg, Eliane; de Souza Esquivel, Darci Motta; Weinkauf, Sevil; Winklhofer, Michael; Hanzlik, Marianne

2010-01-01

358

Relative effects of disturbance on red imported fire ants and native ant species in a longleaf pine ecosystem.  

PubMed

The degree to which changes in community composition mediate the probability of colonization and spread of non-native species is not well understood, especially in animal communities. High species richness may hinder the establishment of non-native species. Distinguishing between this scenario and cases in which non-native species become established in intact (lacking extensive anthropogenic soil disturbance) communities and subsequently diminish the abundance and richness of native species is challenging on the basis of observation alone. The red imported fire ant (Solenopsis invicta), an invasive species that occurs throughout much of the southeastern United States, is such an example. Rather than competitively displacing native species, fire ants may become established only in disturbed areas in which native species richness and abundance are already reduced. We used insecticide to reduce the abundance of native ants and fire ants in four experimental plots. We then observed the reassembly and reestablishment of the ants in these plots for 1 year after treatment. The abundance of fire ants in treated plots did not differ from abundance in control plots 1 year after treatment. Likewise, the abundance of native ants increased to levels comparable to those in control plots after 1 year. Our findings suggest that factors other than large reductions in ant abundance and species density (number of species per unit area) may affect the establishment of fire ants and that the response of native ants and fire ants to disturbance can be comparable. PMID:21561472

Stuble, Katharine L; Kirkman, L Katherine; Carroll, C Ronald; Sanders, Nathan J

2011-06-01

359

Chemically armed mercenary ants protect fungus-farming societies.  

PubMed

The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies. PMID:24019482

Adams, Rachelle M M; Liberti, Joanito; Illum, Anders A; Jones, Tappey H; Nash, David R; Boomsma, Jacobus J

2013-09-24

360

Predaceous ants, beach replenishment, and nest placement by sea turtles.  

PubMed

Ants known for attacking and killing hatchling birds and reptiles include the red imported fire ant (Solenopsis invicta Buren), tropical fire ant [Solenopsis geminata (Fabr.)], and little fire ant [Wasmannia auropunctata (Roger)]. We tested whether sea turtle nest placement influenced exposure to predaceous ants. In 2000 and 2001, we surveyed ants along a Florida beach where green turtles (Chelonia mydas L.), leatherbacks (Dermochelys coriacea Vandelli), and loggerheads (Caretta caretta L.) nest. Part of the beach was artificially replenished between our two surveys. As a result, mean beach width experienced by nesting turtles differed greatly between the two nesting seasons. We surveyed 1,548 sea turtle nests (2000: 909 nests; 2001: 639 nests) and found 22 ant species. S. invicta was by far the most common species (on 431 nests); S. geminata and W. auropunctata were uncommon (on 3 and 16 nests, respectively). In 2000, 62.5% of nests had ants present (35.9% with S. invicta), but in 2001, only 30.5% of the nests had ants present (16.4% with S. invicta). Turtle nests closer to dune vegetation had significantly greater exposure to ants. Differences in ant presence on turtle nests between years and among turtle species were closely related to differences in nest placement relative to dune vegetation. Beach replenishment significantly lowered exposure of nests to ants because on the wider beaches turtles nested farther from the dune vegetation. Selective pressures on nesting sea turtles are altered both by the presence of predaceous ants and the practice of beach replenishment. PMID:18284732

Wetterer, James K; Wood, Lawrence D; Johnson, Chris; Krahe, Holly; Fitchett, Stephanie

2007-10-01

361

Chemically armed mercenary ants protect fungus-farming societies  

PubMed Central

The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies. PMID:24019482

Adams, Rachelle M. M.; Liberti, Joanito; Illum, Anders A.; Jones, Tappey H.; Nash, David R.; Boomsma, Jacobus J.

2013-01-01

362

Ant colony optimization analysis on overall stability of high arch dam basis of field monitoring.  

PubMed

A dam ant colony optimization (D-ACO) analysis of the overall stability of high arch dams on complicated foundations is presented in this paper. A modified ant colony optimization (ACO) model is proposed for obtaining dam concrete and rock mechanical parameters. A typical dam parameter feedback problem is proposed for nonlinear back-analysis numerical model based on field monitoring deformation and ACO. The basic principle of the proposed model is the establishment of the objective function of optimizing real concrete and rock mechanical parameter. The feedback analysis is then implemented with a modified ant colony algorithm. The algorithm performance is satisfactory, and the accuracy is verified. The m groups of feedback parameters, used to run a nonlinear FEM code, and the displacement and stress distribution are discussed. A feedback analysis of the deformation of the Lijiaxia arch dam and based on the modified ant colony optimization method is also conducted. By considering various material parameters obtained using different analysis methods, comparative analyses were conducted on dam displacements, stress distribution characteristics, and overall dam stability. The comparison results show that the proposal model can effectively solve for feedback multiple parameters of dam concrete and rock material and basically satisfy assessment requirements for geotechnical structural engineering discipline. PMID:25025089

Lin, Peng; Liu, Xiaoli; Chen, Hong-Xin; Kim, Jinxie

2014-01-01

363

Ant Colony Optimization Analysis on Overall Stability of High Arch Dam Basis of Field Monitoring  

PubMed Central

A dam ant colony optimization (D-ACO) analysis of the overall stability of high arch dams on complicated foundations is presented in this paper. A modified ant colony optimization (ACO) model is proposed for obtaining dam concrete and rock mechanical parameters. A typical dam parameter feedback problem is proposed for nonlinear back-analysis numerical model based on field monitoring deformation and ACO. The basic principle of the proposed model is the establishment of the objective function of optimizing real concrete and rock mechanical parameter. The feedback analysis is then implemented with a modified ant colony algorithm. The algorithm performance is satisfactory, and the accuracy is verified. The m groups of feedback parameters, used to run a nonlinear FEM code, and the displacement and stress distribution are discussed. A feedback analysis of the deformation of the Lijiaxia arch dam and based on the modified ant colony optimization method is also conducted. By considering various material parameters obtained using different analysis methods, comparative analyses were conducted on dam displacements, stress distribution characteristics, and overall dam stability. The comparison results show that the proposal model can effectively solve for feedback multiple parameters of dam concrete and rock material and basically satisfy assessment requirements for geotechnical structural engineering discipline. PMID:25025089

Liu, Xiaoli; Chen, Hong-Xin; Kim, Jinxie

2014-01-01

364

Performance analysis of elitism in multi-objective ant colony optimization algorithms  

Microsoft Academic Search

This paper investigates the effect of elitism on multi-objective ant colony optimization algorithms (MACOs). We use a straightforward and systematic approach in this investigation with elitism implemented through the use of local, global and mixed non-dominated solutions. Experimental work is conducted using a suite of multi-objective traveling salesman problems (mTSP), each with two objectives. The experimental results indicate that elitism

Lam Thu Bui; James M. Whitacre; Hussein A. Abbass

2008-01-01

365

Scope of Various Random Number Generators in Ant System Approach for TSP  

NASA Technical Reports Server (NTRS)

Experimented on heuristic, based on an ant system approach for traveling Salesman problem, are several quasi and pseudo-random number generators. This experiment is to explore if any particular generator is most desirable. Such an experiment on large samples has the potential to rank the performance of the generators for the foregoing heuristic. This is just to seek an answer to the controversial performance ranking of the generators in probabilistic/statically sense.

Sen, S. K.; Shaykhian, Gholam Ali

2007-01-01

366

Self-organized structures in a superorganism: do ants “behave” like molecules?  

Microsoft Academic Search

While the striking structures (e.g. nest architecture, trail networks) of insect societies may seem familiar to many of us, the understanding of pattern formation still constitutes a challenging problem. Over the last two decades, self-organization has dramatically changed our view on how collective decision-making and structures may emerge out of a population of ant workers having each their own individuality

Claire Detrain; Jean-Louis Deneubourg

2006-01-01

367

AntCast: Web-Window on the Life of Ants  

NSDL National Science Digital Library

The leafcutter ant colony at London's Natural History Museum is now live on the Web, "using an infrared camera to give a secret view into the lives of these fascinating creatures. Visitors can view live video or static images of the colony as they tend to their fungus farm. Only ten users at a time can view the live video, but the static images are updated every ten seconds, so no need feel too deprived. The images are accompanied by interesting ant facts, but for more detailed information visitors will have to look elsewhere.

368

Cascading trait-mediated interactions induced by ant pheromones  

PubMed Central

Trait-mediated indirect interactions (TMII) can be as important as density-mediated indirect interactions. Here, we provide evidence for a novel trait-mediated cascade (where one TMII affects another TMII) and demonstrate that the mechanism consists of a predator eavesdropping on chemical signaling. Ants protect scale insects from predation by adult coccinellid beetles – the first TMII. However, parasitic phorid flies reduce ant foraging activity by 50% – the second TMII, providing a window of opportunity for female beetles to oviposit in high-quality microsites. Beetle larvae are protected from ant predation and benefit from living in patches with high scale densities. We demonstrate that female beetles can detect pheromones released by the ant when attacked by phorids, and that only females, and especially gravid females, are attracted to the ant pheromone. As ants reduce their movement when under attack by phorids, we conclude that phorids facilitate beetle oviposition, thus producing the TMII cascade. PMID:23139877

Hsieh, Hsun-Yi; Liere, Heidi; Soto, Estelí J; Perfecto, Ivette

2012-01-01

369

Reduced Chitinase Activities in Ant Plants of the Genus Macaranga  

NASA Astrophysics Data System (ADS)

Many plant species have evolved mutualistic associations with ants, protecting their host against detrimental influences such as herbivorous insects. Letourneau (1998) reported in the case of Piper that ants defend their plants principally against stem-boring insects and also reduce fungal infections on inflorescences. Macaranga plants that were experimentally deprived of their symbiotic Crematogaster ants suffered heavily from shoot borers and pathogenic fungi (Heil 1998). Here we report that ants seem to reduce fungal infections actively in the obligate myrmecophyte Macarangatriloba (Euphorbiaceae), while ant-free plants can be easily infected. We also found extremely low chitinase activity in Macaranga plants. The plants' own biochemical defense seems to be reduced, and low chitinase activity perhaps may represent a predisposition for the evolution of myrmecophytism. These plants are therefore highly dependent on their ants, which obviously function not only as an antiherbivore defense but also as an effective agent against fungal pathogens.

Heil, Martin; Fiala, Brigitte; Linsenmair, K. Eduard; Boller, Thomas

370

Improved multi-objective ant colony optimization algorithm and its application in complex reasoning  

NASA Astrophysics Data System (ADS)

The problem of fault reasoning has aroused great concern in scientific and engineering fields. However, fault investigation and reasoning of complex system is not a simple reasoning decision-making problem. It has become a typical multi-constraint and multi-objective reticulate optimization decision-making problem under many influencing factors and constraints. So far, little research has been carried out in this field. This paper transforms the fault reasoning problem of complex system into a paths-searching problem starting from known symptoms to fault causes. Three optimization objectives are considered simultaneously: maximum probability of average fault, maximum average importance, and minimum average complexity of test. Under the constraints of both known symptoms and the causal relationship among different components, a multi-objective optimization mathematical model is set up, taking minimizing cost of fault reasoning as the target function. Since the problem is non-deterministic polynomial-hard(NP-hard), a modified multi-objective ant colony algorithm is proposed, in which a reachability matrix is set up to constrain the feasible search nodes of the ants and a new pseudo-random-proportional rule and a pheromone adjustment mechinism are constructed to balance conflicts between the optimization objectives. At last, a Pareto optimal set is acquired. Evaluation functions based on validity and tendency of reasoning paths are defined to optimize noninferior set, through which the final fault causes can be identified according to decision-making demands, thus realize fault reasoning of the multi-constraint and multi-objective complex system. Reasoning results demonstrate that the improved multi-objective ant colony optimization(IMACO) can realize reasoning and locating fault positions precisely by solving the multi-objective fault diagnosis model, which provides a new method to solve the problem of multi-constraint and multi-objective fault diagnosis and reasoning of complex system.

Wang, Xinqing; Zhao, Yang; Wang, Dong; Zhu, Huijie; Zhang, Qing

2013-09-01

371

Weeding and grooming of pathogens in agriculture by ants  

Microsoft Academic Search

The ancient mutualism between fungus-growing ants and the fungi they cultivate for food is a textbook example of symbiosis. Fungus-growing ants'ability to cultivate fungi depends on protection of the garden from the aggressive microbes associated with the substrate added to the garden as well as from the specialized virulent garden parasite Escovopsis. We examined ants' ability to remove alien microbes

Cameron R. Currie; Alison E. Stuart

2001-01-01

372

Protein structure optimization with a "Lamarckian" ant colony algorithm.  

PubMed

We describe the LamarckiAnt algorithm: a search algorithm that combines the features of a "Lamarckian" genetic algorithm and ant colony optimization. We have implemented this algorithm for the optimization of BLN model proteins, which have frustrated energy landscapes and represent a challenge for global optimization algorithms. We demonstrate that LamarckiAnt performs competitively with other state-of-the-art optimization algorithms. PMID:24407312

Oakley, Mark T; Richardson, E Grace; Carr, Harriet; Johnston, Roy L

2013-01-01

373

Do Herbivores Eavesdrop on Ant Chemical Communication to Avoid Predation?  

PubMed Central

Strong effects of predator chemical cues on prey are common in aquatic and marine ecosystems, but are thought to be rare in terrestrial systems and specifically for arthropods. For ants, herbivores are hypothesized to eavesdrop on ant chemical communication and thereby avoid predation or confrontation. Here I tested the effect of ant chemical cues on herbivore choice and herbivory. Using Margaridisa sp. flea beetles and leaves from the host tree (Conostegia xalapensis), I performed paired-leaf choice feeding experiments. Coating leaves with crushed ant liquids (Azteca instabilis), exposing leaves to ant patrolling prior to choice tests (A. instabilis and Camponotus textor) and comparing leaves from trees with and without A. instabilis nests resulted in more herbivores and herbivory on control (no ant-treatment) relative to ant-treatment leaves. In contrast to A. instabilis and C. textor, leaves previously patrolled by Solenopsis geminata had no difference in beetle number and damage compared to control leaves. Altering the time A. instabilis patrolled treatment leaves prior to choice tests (0-, 5-, 30-, 90-, 180-min.) revealed treatment effects were only statistically significant after 90- and 180-min. of prior leaf exposure. This study suggests, for two ecologically important and taxonomically diverse genera (Azteca and Camponotus), ant chemical cues have important effects on herbivores and that these effects may be widespread across the ant family. It suggests that the effect of chemical cues on herbivores may only appear after substantial previous ant activity has occurred on plant tissues. Furthermore, it supports the hypothesis that herbivores use ant chemical communication to avoid predation or confrontation with ants. PMID:22235248

Gonthier, David J.

2012-01-01

374

Insect communication: 'no entry' signal in ant foraging.  

PubMed

Forager ants lay attractive trail pheromones to guide nestmates to food, but the effectiveness of foraging networks might be improved if pheromones could also be used to repel foragers from unrewarding routes. Here we present empirical evidence for such a negative trail pheromone, deployed by Pharaoh's ants (Monomorium pharaonis) as a 'no entry' signal to mark an unrewarding foraging path. This finding constitutes another example of the sophisticated control mechanisms used in self-organized ant colonies. PMID:16306981

Robinson, Elva J H; Jackson, Duncan E; Holcombe, Mike; Ratnieks, Francis L W

2005-11-24

375

Do herbivores eavesdrop on ant chemical communication to avoid predation?  

PubMed

Strong effects of predator chemical cues on prey are common in aquatic and marine ecosystems, but are thought to be rare in terrestrial systems and specifically for arthropods. For ants, herbivores are hypothesized to eavesdrop on ant chemical communication and thereby avoid predation or confrontation. Here I tested the effect of ant chemical cues on herbivore choice and herbivory. Using Margaridisa sp. flea beetles and leaves from the host tree (Conostegia xalapensis), I performed paired-leaf choice feeding experiments. Coating leaves with crushed ant liquids (Azteca instabilis), exposing leaves to ant patrolling prior to choice tests (A. instabilis and Camponotus textor) and comparing leaves from trees with and without A. instabilis nests resulted in more herbivores and herbivory on control (no ant-treatment) relative to ant-treatment leaves. In contrast to A. instabilis and C. textor, leaves previously patrolled by Solenopsis geminata had no difference in beetle number and damage compared to control leaves. Altering the time A. instabilis patrolled treatment leaves prior to choice tests (0-, 5-, 30-, 90-, 180-min.) revealed treatment effects were only statistically significant after 90- and 180-min. of prior leaf exposure. This study suggests, for two ecologically important and taxonomically diverse genera (Azteca and Camponotus), ant chemical cues have important effects on herbivores and that these effects may be widespread across the ant family. It suggests that the effect of chemical cues on herbivores may only appear after substantial previous ant activity has occurred on plant tissues. Furthermore, it supports the hypothesis that herbivores use ant chemical communication to avoid predation or confrontation with ants. PMID:22235248

Gonthier, David J

2012-01-01

376

Evolution and ecology of directed aerial descent in arboreal ants.  

PubMed

Directed aerial descent (DAD) is used by a variety of arboreal animals to escape predators, to remain in the canopy, and to access resources. Here, we build upon the discovery of DAD in ants of tropical canopies by summarizing its known phylogenetic distribution among ant genera, and within both the subfamily Pseudomyrmecinae and the genus Cephalotes. DAD has multiple evolutionary origins in ants, occurring independently in numerous genera in the subfamilies Myrmicinae, Formicinae, and Pseudomyrmecinae. Ablation experiments and video recordings of ants in a vertical wind tunnel showed that DAD in Cephalotes atratus is achieved via postural changes, specifically orientation of the legs and gaster. The occurrence of DAD in Formicinae indicates that the presence of a postpetiole is not essential for the behavior. Evidence to date indicates that gliding behavior is accomplished by visual targeting mediated by the compound eyes, and is restricted to diurnally active ants that nest in trees. Occlusion of ocelli in Pseudomyrmex gracilis workers had no effect on their success or performance in gliding. Experimental assessment of the fate of ants that fall to the understory showed that ants landing in water are 15 times more likely to suffer lethal attacks than are ants landing in leaf litter. Variation in both the aerodynamic mechanisms and selective advantages of DAD merits further study given the broad taxonomic diversity of arboreal ants that engage in this intriguing form of flight. PMID:21562023

Yanoviak, Stephen P; Munk, Yonatan; Dudley, Robert

2011-12-01

377

Ant plant herbivore interactions in the neotropical cerrado savanna  

NASA Astrophysics Data System (ADS)

The Brazilian cerrado savanna covers nearly 2 million km2 and has a high incidence on foliage of various liquid food sources such as extrafloral nectar and insect exudates. These liquid rewards generate intense ant activity on cerrado foliage, making ant plant herbivore interactions especially prevalent in this biome. We present data on the distribution and abundance of extrafloral nectaries in the woody flora of cerrado communities and in the flora of other habitats worldwide, and stress the relevance of liquid food sources (including hemipteran honeydew) for the ant fauna. Consumption by ants of plant and insect exudates significantly affects the activity of the associated herbivores of cerrado plant species, with varying impacts on the reproductive output of the plants. Experiments with an ant plant butterfly system unequivocally demonstrate that the behavior of both immature and adult lepidopterans is closely related to the use of a risky host plant, where intensive visitation by ants can have a severe impact on caterpillar survival. We discuss recent evidence suggesting that the occurrence of liquid rewards on leaves plays a key role in mediating the foraging ecology of foliage-dwelling ants, and that facultative ant plant mutualisms are important in structuring the community of canopy arthropods. Ant-mediated effects on cerrado herbivore communities can be revealed by experiments performed on wide spatial scales, including many environmental factors such as soil fertility and vegetation structure. We also present some research questions that could be rewarding to investigate in this major neotropical savanna.

Oliveira, Paulo S.; Freitas, André V. L.

2004-12-01

378

Five new records of ants (Hymenoptera: Formicidae) for Nebraska  

USGS Publications Warehouse

Ants are ubiquitous and influential organisms in terrestrial ecosystems. About 1,000 ant species occur in North America, where they are found in nearly every habitat (Fisher and Cover 2007). Ants are critical to ecological processes and structure. Ants affect soils via tunneling activity (Baxter and Hole 1967), disperse plant seeds (Lengyel et al. 2009), prey upon a variety of insects and other invertebrates (Way and Khoo 1992, Folgarait 1998), are often effective primary consumers through their prodigious consumption of floral and especially extrafloral nectar, and honeydew (Tobin 1994), and serve as prey for invertebrates (Gotelli 1996, Gastreich 1999) and vertebrates (Reiss 2001).

Nemec, Kristine T.; Trager, James C.; Manley, Elizabeth; Allen, Craig R.

2012-01-01

379

Ants are among the most prevalent pests in households. Ants also invade restau-  

E-print Network

, offices, warehouses, and other buildings where they can find food and water. On outdoor and sometimes- ing larvae. The sterile female workers gather food, feed and care for larvae, build tunnels in number. For additional information about how to identify different ant species, see the Key

Ishida, Yuko

380

Toxicity of formic acid against red imported fire ants, Solenopsis invicta Buren  

Technology Transfer Automated Retrieval System (TEKTRAN)

BACKGROUND: Formic acid is a common defensive chemical of formicine ants. Ants often compete with other ants for resources. However, the toxicity of formic acid to any ant species has not been well understood. This study examined the toxicity of formic acid against the red imported fire ants, Sole...

381

Urban ants of North America and Europe: identification, biology, and management by John Klotz, Laurel Hansen,  

E-print Network

Urb-ants Urban ants of North America and Europe: identification, biology, and management by John division of Cornell University Press), Ithaca and London. ISBN 978-0-8014-7473. $27.95. Ants rank among of established ant pests and also regarding the prevention of the spread of invasive ants,which pose a serious

Lucky, Andrea

382

The ejaculatory biology of leafcutter ants.  

PubMed

The eusocial ants are unique in that females (queens) acquire and store sperm on a single mating flight early in adult life. This event largely determines the size (possibly millions of workers), longevity (possibly decades) and genetic variation of the colonies that queens found, but our understanding of the fundamental biology of ejaculate production, transfer and physiological function remains extremely limited. We studied the ejaculation process in the leafcutter ant Atta colombica and found that it starts with the appearance of a clear pre-ejaculatory fluid (PEF) at the tip of the endophallus that is followed by the joint expulsion of the remainder of accessory gland (AG) secretion, sperm, accessory testes (AT) secretion, and a small mating plug. PEF, AG secretion and AT secretion all contribute to sperm survival, but PEF and AG secretion also reduce the survival of sperm from other males. We show that PEF is produced in the AGs and is likely identical to AG secretion because protein-banding patterns of PEF and AG secretion were similar on 1D electrophoresis gels, but differed from the protein-banding pattern of AT secretion. We show that proteins in AG secretion are responsible for the incapacitation of rival sperm and infer that transfer of AG secretion prior to sperm may allow these components to interact with rival sperm, while at the same time providing a supportive biochemical environment for the arrival of own sperm. PMID:25702828

den Boer, Susanne P A; Stürup, Marlene; Boomsma, Jacobus J; Baer, Boris

2015-03-01

383

Ant colony optimisation inversion of surface and borehole magnetic data under lithological constraints  

NASA Astrophysics Data System (ADS)

The ant colony optimisation algorithm has successfully been used to invert for surface magnetic data. However, the resolution of the distributions of the recovered physical property for deeply buried magnetic sources is not generally very high because of geophysical ambiguities. We use three approaches to deal with this problem. First, the observed surface magnetic data are taken together with the three-component borehole magnetic anomalies to recover the distributions of the physical properties. This cooperative inversion strategy improves the resolution of the inversion results in the vertical direction. Additionally, as the ant colony tours the discrete nodes, we force it to visit the nodes with physical properties that agree with the drilled lithologies. These lithological constraints reduce the non-uniqueness of the inversion problem. Finally, we also implement a K-means cluster analysis for the distributions of the magnetic cells after each iteration, in order to separate the distributions of magnetisation intensity instead of concentrating the distribution in a single area. We tested our method using synthetic data and found that all tests returned favourable results. In the case study of the Mengku iron-ore deposit in northwest China, the recovered distributions of magnetisation are in good agreement with the locations and shapes of the magnetite orebodies as inferred by drillholes. Uncertainty analysis shows that the ant colony algorithm is robust in the presence of noise and that the proposed approaches significantly improve the quality of the inversion results.

Liu, Shuang; Hu, Xiangyun; Liu, Tianyou; Xi, Yufei; Cai, Jianchao; Zhang, Henglei

2015-01-01

384

The Effect of Diet and Opponent Size on Aggressive Interactions Involving Caribbean Crazy Ants (Nylanderia fulva)  

PubMed Central

Biotic interactions are often important in the establishment and spread of invasive species. In particular, competition between introduced and native species can strongly influence the distribution and spread of exotic species and in some cases competition among introduced species can be important. The Caribbean crazy ant, Nylanderia fulva, was recently introduced to the Gulf Coast of Texas, and appears to be spreading inland. It has been hypothesized that competition with the red imported fire ant, Solenopsis invicta, may be an important factor in the spread of crazy ants. We investigated the potential of interspecific competition among these two introduced ants by measuring interspecific aggression between Caribbean crazy ant workers and workers of Solenopsis invicta. Specifically, we examined the effect of body size and diet on individual-level aggressive interactions among crazy ant workers and fire ants. We found that differences in diet did not alter interactions between crazy ant workers from different nests, but carbohydrate level did play an important role in antagonistic interactions with fire ants: crazy ants on low sugar diets were more aggressive and less likely to be killed in aggressive encounters with fire ants. We found that large fire ants engaged in fewer fights with crazy ants than small fire ants, but fire ant size affected neither fire ant nor crazy ant mortality. Overall, crazy ants experienced higher mortality than fire ants after aggressive encounters. Our findings suggest that fire ant workers might outcompete crazy ant workers on an individual level, providing some biotic resistance to crazy ant range expansion. However, this resistance may be overcome by crazy ants that have a restricted sugar intake, which may occur when crazy ants are excluded from resources by fire ants. PMID:23776702

Horn, Katherine C.; Eubanks, Micky D.; Siemann, Evan

2013-01-01

385

April 5, 2004 19:5 Proceedings Trim Size: 9in x 6in FuzzyAnts EFFICIENT CLUSTERING WITH FUZZY ANTS  

E-print Network

April 5, 2004 19:5 Proceedings Trim Size: 9in x 6in FuzzyAnts EFFICIENT CLUSTERING WITH FUZZY ANTS, various clustering algorithms based on the behaviour of real ants were proposed. The main advantage or the number of clusters, is needed. In this paper we show how the combination of the ant-based approach

Gent, Universiteit

386

Dorigo and Gambardella -A study of some properties of Ant-Q 1 A STUDY OF SOME PROPERTIES OF ANT-Q  

E-print Network

Dorigo and Gambardella - A study of some properties of Ant-Q 1 A STUDY OF SOME PROPERTIES OF ANT, Corso Elvezia 36, CH-6900 Lugano, Switzerland dorigo@idsia.ch, luca@idsia.ch Abstract. Ant-Q is an algorithm belonging to the class of ant colony based methods, that is, of combinatorial optimization methods

Gambardella, Luca Maria

387

Aphid egg protection by ants: a novel aspect of the mutualism between the tree-feeding aphid Stomaphis hirukawai and its attendant ant Lasius productus  

NASA Astrophysics Data System (ADS)

Aphids often form mutualistic associations with ants, in which the aphids provide the ants with honeydew and the ants defend the aphids from predators. In this paper, we report aphid egg protection by ants as a novel aspect of the deeply interdependent relationship between a tree-feeding aphid and its attendant ant. The ant Lasius productus harbours oviparous females, males, and eggs of the hinoki cypress-feeding aphid Stomaphis hirukawai in its nests in winter. We investigated the behaviour of ants kept with aphid eggs in petri dishes to examine whether the ants recognise the aphid eggs and tend them or only provide a refuge for the aphids. Workers carried almost all of the aphid eggs into the nest within 24 h. The ants indiscriminately tended aphid eggs collected from their own colonies and those from other ant colonies. The ants cleaned the eggs and piled them up in the nest, and egg tending by ants dramatically increased aphid egg survival rates. Starving the ants showed no significant effect on aphid egg survivorship. Without ants, aphid eggs were rapidly killed by fungi. These results suggested that grooming by the ants protected the aphid eggs, at least, against pathogenic fungi. This hygienic service afforded by the ants seems indispensable for egg survival of these aphids in an environment rich in potentially pathogenic microorganisms.

Matsuura, Kenji; Yashiro, Toshihisa

2006-10-01

388

Structural link prediction based on ant colony approach in social networks  

NASA Astrophysics Data System (ADS)

As the size and number of online social networks are increasing day by day, social network analysis has become a popular issue in many branches of science. The link prediction is one of the key rolling issues in the analysis of social network's evolution. As the size of social networks is increasing, the necessity for scalable link prediction algorithms is being felt more. The aim of this paper is to introduce a new unsupervised structural link prediction algorithm based on the ant colony approach. Recently, ant colony approach has been used for solving some graph problems. Different kinds of networks are used for testing the proposed approach. In some networks, the proposed scalable algorithm has the best result in comparison to other structural unsupervised link prediction algorithms. In order to evaluate the algorithm results, methods like the top- n precision, area under the Receiver Operating Characteristic (ROC) and Precision-Recall curves are carried out on real-world networks.

Sherkat, Ehsan; Rahgozar, Maseud; Asadpour, Masoud

2015-02-01

389

Multiple sequence alignment algorithm based on a dispersion graph and ant colony algorithm.  

PubMed

In this article, we describe a representation for the processes of multiple sequences alignment (MSA) and used it to solve the problem of MSA. By this representation, we took every possible aligning result into account by defining the representation of gap insertion, the value of heuristic information in every optional path and scoring rule. On the basis of the proposed multidimensional graph, we used the ant colony algorithm to find the better path that denotes a better aligning result. In our article, we proposed the instance of three-dimensional graph and four-dimensional graph and advanced a special ichnographic representation to analyze MSA. It is yet only an experimental software, and we gave an example for finding the best aligning result by three-dimensional graph and ant colony algorithm. Experimental results show that our method can improve the solution quality on MSA benchmarks. PMID:19130503

Chen, Weiyang; Liao, Bo; Zhu, Wen; Xiang, Xuyu

2009-10-01

390

The rise of army ants and their relatives: diversification of specialized predatory doryline ants  

PubMed Central

Background Army ants are dominant invertebrate predators in tropical and subtropical terrestrial ecosystems. Their close relatives within the dorylomorph group of ants are also highly specialized predators, although much less is known about their biology. We analyzed molecular data generated from 11 nuclear genes to infer a phylogeny for the major dorylomorph lineages, and incorporated fossil evidence to infer divergence times under a relaxed molecular clock. Results Because our results indicate that one subfamily and several genera of dorylomorphs are non-monophyletic, we propose to subsume the six previous dorylomorph subfamilies into a single subfamily, Dorylinae. We find the monophyly of Dorylinae to be strongly supported and estimate the crown age of the group at 87 (74–101) million years. Our phylogenetic analyses provide only weak support for army ant monophyly and also call into question a previous hypothesis that army ants underwent a fundamental split into New World and Old World lineages. Outside the army ants, our phylogeny reveals for the first time many old, distinct lineages in the Dorylinae. The genus Cerapachys is shown to be non-monophyletic and comprised of multiple lineages scattered across the Dorylinae tree. We recover, with strong support, novel relationships among these Cerapachys-like clades and other doryline genera, but divergences in the deepest parts of the tree are not well resolved. We find the genus Sphinctomyrmex, characterized by distinctive abdominal constrictions, to consist of two separate lineages with convergent morphologies, one inhabiting the Old World and the other the New World tropics. Conclusions While we obtain good resolution in many parts of the Dorylinae phylogeny, relationships deep in the tree remain unresolved, with major lineages joining each other in various ways depending upon the analytical method employed, but always with short internodes. This may be indicative of rapid radiation in the early history of the Dorylinae, but additional molecular data and more complete species sampling are needed for confirmation. Our phylogeny now provides a basic framework for comparative biological analyses, but much additional study on the behavior and morphology of doryline species is needed, especially investigations directed at the non-army ant taxa. PMID:24886136

2014-01-01

391

Arboreal ants as key predators in tropical lowland rainforest trees  

Microsoft Academic Search

Ants numerically dominate the canopy fauna of tropical lowland rain forests. They are considered to be key predators but their effects in this regard have only rarely been studied on non-myrmecophytes. A conspicuously low abundance of less mobile, mainly holometabolous arthropods like Lepidoptera larvae corresponds with ant dominance, while hemimetabolous highly mobile nymphs occur regularly and in large numbers in

Andreas Floren; Alim Biun; Eduard K. Linsenmair

2002-01-01

392

DETECTING RED HARVESTER ANT MOUNDS WITH PANCHROMATIC QUICKBIRD IMAGERY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Natural resource managers have an interest in locating red harvester ant (Pogonomyrex barbatus) mounds because of the impact that heavy infestations have on pastures and because of the importance of the ants to the survival of the threatened Texas horned lizard (Phrynosoma cornutum). This study eva...

393

Horned lizards (Phrynosoma) incapacitate dangerous ant prey with mucus.  

PubMed

Horned lizards (Iguanidae, Phrynosomatinae, Phrynosoma) are morphologically specialized reptiles characterized by squat, tank-like bodies, short limbs, blunt snouts, spines and cranial horns, among other traits. They are unusual among lizards in the degree to which they specialize on a diet of ants, but exceptional in the number of pugnacious, highly venomous, stinging ants they consume, especially harvester ants (genus Pogonomyrmex). Like other iguanian lizards, they capture insect prey on the tongue, but unlike other lizards, they neither bite nor chew dangerous prey before swallowing. Instead, they employ a unique kinematic pattern in which prey capture, transport and swallowing are combined. Nevertheless, horned lizards consume dozens of harvester ants without harm. We show that their derived feeding kinematics are associated with unique, mucus-secreting pharyngeal papillae that apparently serve to immobilize and incapacitate dangerous ants as they are swallowed by compacting them and binding them in mucus strands. Radially branched esophageal folds provide additional mucus-secreting surfaces the ants pass through as they are swallowed. Ants extracted from fresh-killed horned lizard stomachs are curled ventrally into balls and bound in mucus. We conclude that the pharyngeal papillae, in association with a unique form of hyolingual prey transport and swallowing, are horned lizard adaptations related to a diet of dangerous prey. Harvester ant defensive weapons, along with horned lizard adaptations against such weapons, suggest a long-term, predator-prey, co-evolutionary arms race between Phrynosoma and Pogonomyrmex. PMID:18570329

Sherbrooke, Wade C; Schwenk, Kurt

2008-10-01

394

ANT COMMUNITIES AND LIVESTOCK GRAZING IN THE GREAT BASIN, USA  

EPA Science Inventory

The objectives of this study were to determine if metrics for ant species assemblages can be used as indicators of rangeland condition, and to determine the influence of vegetation and ground cover variables, factors often influenced by livestock grazing, on ant communities. The ...

395

Dynamics and shape of large fire ant rafts  

PubMed Central

To survive floods, fire ants link their bodies together to build waterproof rafts. Such rafts can be quite large, exceeding 100,000 individuals in size. In this study, we make two improvements on a previously reported model on the construction rate of rafts numbering between 3,000 and 10,000 individuals. That model was based upon experimental observations of randomly-directed linear ant trajectories atop the raft. Here, we report anomalous behavior of ants atop larger rafts of up to 23,000 ants. As rafts increase in size, the behavior of ants approaches diffusion, which is in closer alignment with other studies on the foraging and scouting patterns of ants. We incorporate this ant behavior into the model. Our modified model predicts more accurately the growth of large rafts. Our previous model also relied on an assumption of raft circularity. We show that this assumption is not necessary for large rafts, because it follows from the random directionality of the ant trajectories. Our predicted relationship between raft size and circularity closely fits experimental data. PMID:23336030

Mlot, Nathan J.; Tovey, Craig; Hu, David L.

2012-01-01

396

Ants as Naturally Long-lived Insect Models for Aging.  

E-print Network

castes. The traditional model systems used to study aging (Drosophila melanogaster, CaenborabditisAnts as Naturally Long-lived Insect Models for Aging. Joel D. Parker and Karen M. Parker Department models in understanding the mechanisms of aging. It includes an introduction highlighting how ants

Alvarez, Nadir

397

Tracing the Rise of Ants - Out of the Ground  

PubMed Central

The evolution of ants (Hymenoptera: Formicidae) is increasingly well-understood due to recent phylogenetic analyses, along with estimates of divergence times and diversification rates. Yet, leading hypotheses regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic and subterranean. Where the ants evolved, in respect to habitat, and how habitat shifts took place over time have not been formally tested. Here, we reconstruct the habitat transitions of crown-group ants through time, focusing on where they nest and forage (in the canopy, litter, or soil). Based on ancestral character reconstructions, we show that in contrast to the current consensus based on verbal arguments that ants evolved in tropical leaf litter, the soil is supported as the ancestral stratum of all ants. We also find subsequent movements up into the litter and, in some cases, into the canopy. Given the global importance of ants, because of their diversity, ecological influence and status as the most successful eusocial lineage on Earth, understanding the early evolution of this lineage provides insight into the factors that made this group so successful today. PMID:24386323

Lucky, Andrea; Trautwein, Michelle D.; Guénard, Benoit S.; Weiser, Michael D.; Dunn, Robert R.

2013-01-01

398

The self-organizing exploratory pattern of the argentine ant  

Microsoft Academic Search

Workers of the Argentine ant, Iridomyrmex humilis,start to explore a chemically unmarked territory randomly. As the exploratory front advances, other explorers are recruited and a trail extends from it to the nest. Whereas recruitment trails are generally constructed between two points, these exploratory trails have no fixed destination, and strongly resemble the foraging patterns of army ants. A minimal model

J.-L. Deneubourg; S. Aron; S. Goss; J. M. Pasteels

1990-01-01

399

An Introduction to Ants (Formicidae) of the Tallgrass Prairie  

NSDL National Science Digital Library

Originally published in fall 1998 in the Missouri Prairie Journal, this newly online resource provides a brief introduction to the ecological role of ants, their taxonomy, and the effect of prairie restoration on tallgrass prairie ants (some 60 species are mentioned in table format). The publication may be downloaded as a .zip file.

400

Newly discovered sister lineage sheds light on early ant evolution  

E-print Network

Newly discovered sister lineage sheds light on early ant evolution Christian Rabeling§ , Jeremy M studies, however, led to contradicting views of early ant evolution, in part because of high levels a new subfamily, the Martialinae, and discuss the implications of this discovery for the early evolution

Villemant, Claire

401

ACOUSTICAL ANALYSIS OF WINGBEAT FREQUENCIES FOR ALATE IMPORTED FIRE ANTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The red imported fire ant (RIFA), Solenopsis invicta Buren and the black imported fire ant (BIFA), Solenopsis richteri Forel coexist in the state of Mississippi along with reproductively viable F1 hybrids of these two species. The objective of this study was to determine and compare the wingbeat fre...

402

SYSTEMATICS Taxonomy and Distribution of the Argentine Ant, Linepithema humile  

E-print Network

SYSTEMATICS Taxonomy and Distribution of the Argentine Ant, Linepithema humile (Hymenoptera Ann. Entomol. Soc. Am. 97(6): 1204Ð1215 (2004) ABSTRACT The taxonomy of an invasive pest species humile, taxonomy, invasive species THE ARGENTINE ANT, Linepithema humile (Mayr) 1868, is among the world

Villemant, Claire

403

Dynamics and shape of large fire ant rafts.  

PubMed

To survive floods, fire ants link their bodies together to build waterproof rafts. Such rafts can be quite large, exceeding 100,000 individuals in size. In this study, we make two improvements on a previously reported model on the construction rate of rafts numbering between 3,000 and 10,000 individuals. That model was based upon experimental observations of randomly-directed linear ant trajectories atop the raft. Here, we report anomalous behavior of ants atop larger rafts of up to 23,000 ants. As rafts increase in size, the behavior of ants approaches diffusion, which is in closer alignment with other studies on the foraging and scouting patterns of ants. We incorporate this ant behavior into the model. Our modified model predicts more accurately the growth of large rafts. Our previous model also relied on an assumption of raft circularity. We show that this assumption is not necessary for large rafts, because it follows from the random directionality of the ant trajectories. Our predicted relationship between raft size and circularity closely fits experimental data. PMID:23336030

Mlot, Nathan J; Tovey, Craig; Hu, David L

2012-11-01

404

SURVEY OF IMPORTED FIRE ANT POPULATIONS IN MISSISSIPPI  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study determined the distribution of the red and black imported fire ant, and their hybrid ant populations in Mississippi. The range of hybrid populations was found to extend to fifteen counties in Mississippi. Biological control strategies can be species specific, so the distribution of the...

405

Fire ant polymorphism: the ergonomics of brood production  

Microsoft Academic Search

Social organization is generally assumed to increase colony efficiency and survival; however, little quantitative information is available to support this assumption. Polymorphism is an important aspect of labor division in colonies of the fire ant, Solenopsis invicta. Our objective was to investigate the effect of fire ant polymorphism on brood production efficiency. We set up standardized polymorphic colonies with a

Sanford D. Porter; Walter R. Tschinkel

1985-01-01

406

Visual landmarks and route following in desert ants  

Microsoft Academic Search

Summary Little is known about the way in which animals far from home use familiar landmarks to guide their homeward path. Desert ants, Cataglyphis spp., which forage individually over long distances are beginning to provide some answers. We find that ants running 30 m from a feeding place to their nest memorise the visual characteristics of prominent landmarks which lie

T. S. Collett; E. Dillmann; A. Giger; R. Wehner

1992-01-01

407

Butterfly Project Report Ant Farm: A Lightweight Process Programming  

E-print Network

Butterfly Project Report 21 Ant Farm: A Lightweight Process Programming Environment M.L. Scott is a library package for the BBN Butterfly Parallel Processor that allows programs to split computational effort across many lightweight threads of control. On each node of the Butterfly, Ant Farm provides

Scott, Michael L.

408

The genome of the fire ant Solenopsis invicta  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ants have evolved very complex societies and are key ecosystem members. Some of them are also major pests, as exemplified by the fire ant Solenopsis invicta. We present here the draft genome of S. invicta, assembled from 454 and Illumina reads obtained from a focal haploid male and his brothers. In ...

409

Ant–plant–herbivore interactions in the neotropical cerrado savanna  

Microsoft Academic Search

The Brazilian cerrado savanna covers nearly 2 million km 2 and has a high incidence on foliage of various liquid food sources such as extrafloral nectar and insect exudates. These liquid rewards generate intense ant activity on cerrado foliage, making ant–plant–herbivore interactions especially prevalent in this biome. We present data on the distribution and abundance of extrafloral nectaries in the woody

Paulo S. Oliveira; André V. L. Freitas

2004-01-01

410

Linking Science and Writing With Two Bad Ants  

NSDL National Science Digital Library

Two Bad Ants , a fictional story detailing the journey of "two bad ants" that stray from their colony and choose to stay in a container full of large, white, sweet-tasking crystals (sugar)--was the catalyst for an engaging five-day study with third

Ingrid Hekman Fournier

2009-07-01

411

Thelohania solenopsae as a factor of fire ant populations  

Technology Transfer Automated Retrieval System (TEKTRAN)

The inadvertent introduction of fire ants into the United States over 70 years ago initially resulted in large-scale efforts to eradicate the invasive pest. Large populations, mobility, and ability to occupy diverse habitats make fire ants a dominant arthropod in infested regions and very difficult...

412

The recovery of ant communities in regenerating temperate conifer forests  

Microsoft Academic Search

Although ants perform many critical functions in forested ecosystems, little is known about how they respond to timber harvesting, especially in temperate systems. We examined ground-foraging ant communities and 11 forest characteristics in temperate conifer forests of southwestern Oregon, USA that ranged in age from 5 to 427 years. Seven forest characteristics were related to stand age and were summarized

Jennifer D. Palladini; Maureen G. Jones; Nathan J. Sanders; Erik S. Jules

2007-01-01

413

Chemically armed mercenary ants protect fungus-farming societies  

E-print Network

Chemically armed mercenary ants protect fungus-farming societies Rachelle M. M. Adamsa,b,1 document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net ben- efit from

Schultz, Ted

414

Dentigerumycin: a bacterial mediator of an ant-fungus  

E-print Network

Dentigerumycin: a bacterial mediator of an ant-fungus symbiosis Dong-Chan Oh1,3, Michael Poulsen2,3, Cameron R Currie2 & Jon Clardy1 Fungus-growing ants engage in mutualistic associations with both the fungus they cultivate for food and actinobacteria (Pseudonocardia spp.) that produce selective

Richner, Heinz

415

DISTRIBUTION OF IMPORTED FIRE ANT POPULATIONS IN ALABAMA  

Technology Transfer Automated Retrieval System (TEKTRAN)

The black imported fire ant, Solenopsis richteri Forel, was the first imported fire ant identified in the United sTates (Loding, 1929) and was originally referred to as Solenopsis saevissima (Fr. Smith). Wilson (1951, 1953) indicated that the population consisted of a "dark phase" for the first ten ...

416

Do long-lived ants affect soil microbial communities?  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study was designed to test the hypothesis that desert ant species that build nests that remain viable at a particular point in space for more than a decade produce soil conditions that enhance microbial biomass and functional diversity. We studied the effects of a seed-harvester ant, Pogonomyrm...

417

Diversity of peptide toxins from stinging ant venoms.  

PubMed

Ants (Hymenoptera: Formicidae) represent a taxonomically diverse group of arthropods comprising nearly 13,000 extant species. Sixteen ant subfamilies have individuals that possess a stinger and use their venom for purposes such as a defence against predators, competitors and microbial pathogens, for predation, as well as for social communication. They exhibit a range of activities including antimicrobial, haemolytic, cytolytic, paralytic, insecticidal and pain-producing pharmacologies. While ant venoms are known to be rich in alkaloids and hydrocarbons, ant venoms rich in peptides are becoming more common, yet remain understudied. Recent advances in mass spectrometry techniques have begun to reveal the true complexity of ant venom peptide composition. In the few venoms explored thus far, most peptide toxins appear to occur as small polycationic linear toxins, with antibacterial properties and insecticidal activity. Unlike other venomous animals, a number of ant venoms also contain a range of homodimeric and heterodimeric peptides with one or two interchain disulfide bonds possessing pore-forming, allergenic and paralytic actions. However, ant venoms seem to have only a small number of monomeric disulfide-linked peptides. The present review details the structure and pharmacology of known ant venom peptide toxins and their potential as a source of novel bioinsecticides and therapeutic agents. PMID:25448389

Aili, Samira R; Touchard, Axel; Escoubas, Pierre; Padula, Matthew P; Orivel, Jérôme; Dejean, Alain; Nicholson, Graham M

2014-12-15

418

Ant system: optimization by a colony of cooperating agents  

Microsoft Academic Search

An analogy with the way ant colonies function has suggested the definition of a new computational paradigm, which we call ant system (AS). We propose it as a viable new approach to stochastic combinatorial optimization. The main characteristics of this model are positive feedback, distributed computation, and the use of a constructive greedy heuristic. Positive feedback accounts for rapid discovery

Marco Dorigo; Vittorio Maniezzo; Alberto Colorni

1996-01-01

419

SIX NEW SPECIES OF ANTS (INSECTA: HYMENOPTERA: FORMICIDAE) FROM EGYPT  

E-print Network

SIX NEW SPECIES OF ANTS (INSECTA: HYMENOPTERA: FORMICIDAE) FROM EGYPT HASSAN H. FADL, REDA F. BAKR, RAWDA M. BADAWY AND MOSTAFA R. SHARAF Entomology Dept., Fac. Science, Ain Shams University, Cairo, Egypt. ABSTRACT Six new ant species from Egypt Cerapachys collingwoodi, Cataglyphis agostii, Messor eglalae

Villemant, Claire

420

ORIGINAL PAPER New fossil ants in French Cretaceous amber  

E-print Network

-Verlag 2007 Abstract Recent studies on the ant phylogeny are mainly based on the molecular analyses of extant of the Sphecomyrminae, as currently defined, is still weakly supported. Keywords Insecta . Formicidae . Sphecomyrminae Cretaceous is far from complete, owing to the relative scarcity of primitive fossils. The phylogeny of ants

Villemant, Claire

421

Zombie fire ant workers: behavior controlled by decapitating fly parasitoids  

Microsoft Academic Search

.  Laboratory observations were conducted on four separate red imported fire ant, Solenopsis invicta, colonies that contained workers parasitized by the decapitating fly, Pseudacteon tricuspis. Parasitized S. invicta workers remained inside the nest during parasitoid larval development and left the nest approximately 8 – 10 hours before\\u000a decapitation by the parasitoid. When parasitized ants left the nest, they were highly mobile,

D. C. Henne; S. J. Johnson

2007-01-01

422

NOTE / NOTE An indirect mutualism: ants deter seed predators  

E-print Network

NOTE / NOTE An indirect mutualism: ants deter seed predators from ovipositing in yucca fruit Jennifer C. Perry, Edward B. Mondor, and John F. Addicott Abstract: An indirect mutualism arises when on yuccas. Thus, we suggest that an indirect mutualism can occur between wood ants and yuccas when non

Mondor, Ed

423

Science News: Ants Take a Cue From Facebook  

NSDL National Science Digital Library

A new study finds that, whereas most red harvester ants share information with a small number of nestmates, a few convey news to a wide network of others. The results help explain how ant colonies quickly respond to predators and natural disasters.

Carrie Arnold (AAAS; )

2011-04-12

424

Odorous House Ants (Tapinoma sessile) as Back-Seat Drivers of Localized Ant Decline in Urban Habitats  

PubMed Central

Invasive species and habitat disturbance threaten biodiversity worldwide by modifying ecosystem performance and displacing native organisms. Similar homogenization impacts manifest locally when urbanization forces native species to relocate or reinvade perpetually altered habitat. This study investigated correlations between ant richness and abundance in response to urbanization and the nearby presence of invasive ant species, odorous house ants (Tapinoma sessile), within its native region. Surveying localized ant composition within natural, semi-natural, and urban habitat supported efforts to determine whether T. sessile appear to be primary (drivers) threats as instigators or secondary (passengers) threats as inheritors of indigenous ant decline. Sampling 180 sites, evenly split between all habitats with and without T. sessile present, yielded 45 total species. Although urbanization and T. sessile presence factors were significantly linked to ant decline, their interaction correlated to the greatest reduction of total ant richness (74%) and abundance (81%). Total richness appeared to decrease from 27 species to 18 when natural habitat is urbanized and from 18 species to 7 with T. sessile present in urban plots. Odorous house ant presence minimally influenced ant communities within natural and semi-natural habitat, highlighting the importance of habitat alteration and T. sessile presence interactions. Results suggest urbanization releases T. sessile from unknown constraints by decreasing ant richness and competition. Within urban environment, T. sessile are pre-adapted to quickly exploit new resources and grow to supercolony strength wherein T. sessile drive adjacent biodiversity loss. Odorous house ants act as passengers and drivers of ecological change throughout different phases of urban ‘invasion’. This progression through surviving habitat alteration, exploiting new resources, thriving, and further reducing interspecific competition supports a “back-seat driver” role and affects pest management strategies. As demonstrated by T. sessile, this article concludes native species can become back-seat drivers of biodiversity loss and potentially thrive as “metro-invasive” species. PMID:25551819

Salyer, Adam; Bennett, Gary W.; Buczkowski, Grzegorz A.

2014-01-01

425

Fecundity and longevity of argentine ant (Hymenoptera: Formicidae) queens in response to irradiation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Irradiation is a postharvest quarantine treatment option to control ants and other hitchhiker pests on fresh horticultural products traded between countries. As little is known about irradiation effects on ants, radiotolerance of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae...

426

Variation in thermal tolerance of North American ants.  

PubMed

Changing climates are predicted to alter the distribution of thermal niches. Small ectotherms such as ants may be particularly vulnerable to heat injury and death. We quantified the critical thermal maxima of 92 ant colonies representing 14 common temperate ant species. The mean CTmax for all measured ants was 47.8°C (±0.27; range=40.2-51.2°C), and within-colony variation was lower than among-colony variation. Critical thermal maxima differed among species and were negatively correlated with body size. Results of this study illustrate the importance of accounting for mass, among and within colony variation, and interspecific differences in diel activity patterns, which are often neglected in studies of ant thermal physiology. PMID:25660632

Verble-Pearson, Robin M; Gifford, Matthew E; Yanoviak, Stephen P

2015-02-01

427

The origin of the attine ant-fungus mutualism.  

PubMed

Cultivation of fungus for food originated about 45-65 million years ago in the ancestor of fungus-growing ants (Formicidae, tribe Attini), representing an evolutionary transition from the life of a hunter-gatherer of arthropod prey, nectar, and other plant juices, to the life of a farmer subsisting on cultivated fungi. Seven hypotheses have been suggested for the origin of attine fungiculture, each differing with respect to the substrate used by the ancestral attine ants for fungal cultivation. Phylogenetic information on the cultivated fungi, in conjunction with information on the nesting biology of extant attine ants and their presumed closest relatives, reveal that the attine ancestors probably did not encounter their cultivars-to-be in seed stores (von Ihering 1894), in rotting wood (Forel 1902), as mycorrhizae (Garling 1979), on arthropod corpses (von Ihering 1894) or ant faeces in nest middens (Wheeler 1907). Rather, the attine ant-fungus mutualism probably arose from adventitious interactions with fungi that grew on walls of nests built in leaf litter (Emery 1899), or from a system of fungal myrmecochory in which specialized fungi relied on ants for dispersal (Bailey 1920) and in which the ants fortuitously vectored these fungi from parent to offspring nests prior to a true fungicultural stage. Reliance on fungi as a dominant food source has evolved only twice in ants: first in the attine ants, and second in some ant species in the solenopsidine genus Megalomyrmex that either coexist as trophic parasites in gardens of attine hosts or aggressively usurp gardens from them. All other known ant-fungus associations are either adventitious or have nonnutritional functions (e.g., strengthening of carton-walls in ant nests). There exist no unambiguous reports of facultative mycophagy in ants, but such trophic ant-fungus interactions would most likely occur underground or in leaf litter and thus escape easy observation. Indirect evidence of fungivory can be deduced from contents of the ant alimentary canal and particularly from the contents of the infrabuccal pocket, a pharyngeal device that filters out solids before liquids pass into the intestine. Infrabuccal pocket contents reveal that ants routinely ingest fungal spores and hyphal material. Infrabuccal contents are eventually expelled as a pellet on nest middens or away from the nest by foragers, suggesting that the pellet provides fungi with a means for the dispersal of spores and hyphae. Associations between such "buccophilous" fungi and ants may have originated multiple times and may have become elaborated and externalized in the case of the attine ant-fungus mutualism. Thus, contrary to the traditional model in which attine fungi are viewed as passive symbionts that happened to come under ant control, this alternative model of a myrmecochorous origin of the attine mutualism attributes an important role to evolutionary modifications of the fungi that preceded the ant transition from hunter-gatherer to fungus farmer. PMID:11409051

Mueller, U G; Schultz, T R; Currie, C R; Adams, R M; Malloch, D

2001-06-01

428

Endophytic fungi reduce leaf-cutting ant damage to seedlings  

PubMed Central

Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (Ehigh) or low (Elow) densities of endophytes. The Ehigh seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the Elow treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from Elow relative to Ehigh seedlings and had a tendency to recruit more ants to Elow plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities. PMID:20610420

Bittleston, L. S.; Brockmann, F.; Wcislo, W.; Van Bael, S. A.

2011-01-01

429

Improved ant algorithms for software testing cases generation.  

PubMed

Existing ant colony optimization (ACO) for software testing cases generation is a very popular domain in software testing engineering. However, the traditional ACO has flaws, as early search pheromone is relatively scarce, search efficiency is low, search model is too simple, positive feedback mechanism is easy to produce the phenomenon of stagnation and precocity. This paper introduces improved ACO for software testing cases generation: improved local pheromone update strategy for ant colony optimization, improved pheromone volatilization coefficient for ant colony optimization (IPVACO), and improved the global path pheromone update strategy for ant colony optimization (IGPACO). At last, we put forward a comprehensive improved ant colony optimization (ACIACO), which is based on all the above three methods. The proposed technique will be compared with random algorithm (RND) and genetic algorithm (GA) in terms of both efficiency and coverage. The results indicate that the improved method can effectively improve the search efficiency, restrain precocity, promote case coverage, and reduce the number of iterations. PMID:24883391

Yang, Shunkun; Man, Tianlong; Xu, Jiaqi

2014-01-01

430

Improved Ant Algorithms for Software Testing Cases Generation  

PubMed Central

Existing ant colony optimization (ACO) for software testing cases generation is a very popular domain in software testing engineering. However, the traditional ACO has flaws, as early search pheromone is relatively scarce, search efficiency is low, search model is too simple, positive feedback mechanism is easy to porduce the phenomenon of stagnation and precocity. This paper introduces improved ACO for software testing cases generation: improved local pheromone update strategy for ant colony optimization, improved pheromone volatilization coefficient for ant colony optimization (IPVACO), and improved the global path pheromone update strategy for ant colony optimization (IGPACO). At last, we put forward a comprehensive improved ant colony optimization (ACIACO), which is based on all the above three methods. The proposed technique will be compared with random algorithm (RND) and genetic algorithm (GA) in terms of both efficiency and coverage. The results indicate that the improved method can effectively improve the search efficiency, restrain precocity, promote case coverage, and reduce the number of iterations. PMID:24883391

Yang, Shunkun; Xu, Jiaqi

2014-01-01

431

Model Checking Algorithm Based on Ant Colony Swarm Intelligence  

NASA Astrophysics Data System (ADS)

This paper proposes a novel model checking algorithm. This algorithm distributes mobile agents, artificial ants modeled natural ants, on control flow graph and states graph of the programs. While the ants reversely track correct traces and error traces, and deposit two kinds of pheromone representing respectively correct traces and error traces along the travel between vertexes of the control flow graph. According to pheromone deposited on traces by ants, causes of the specific errors can be automatically located. Furthermore, the independent and synchronous performance of ants makes it possbile to track different correct traces and error traces at the same time, and locate multiple causes of different errors synchronously. The results of the experiments on medium and small size programs show that the algorithm is effective.

Wu, Xiangning; Hu, Chengyu; Wang, Yuan

432

A theoretical model for uni-directional ant trails  

NASA Astrophysics Data System (ADS)

A theoretical model of uni-directional ant traffic, motivated by the motion of ants in trail is proposed. Two different type of ants, one of which smells very well and the other does not, are considered. The flux of ants in this model is investigated as functions of the probability of evaporation rate of pheromone. The obtained results indicate that the mean velocity of the ants varies non-monotonically with their density. In addition, it is observed that phase transition in the flux and the mean velocity vs. density occurs at certain density for a fixed evaporation rate. The effective hopping probability is investigated as well depending on the evaporation rate of pheromone. It is worth to note that the proposed model can be generalized for vehicular traffic on freeways.

Kayacan, Ozhan

2011-03-01

433

Ecological consequences of traffic organisation in ant societies  

NASA Astrophysics Data System (ADS)

Many species of ants engage in social foraging in which traffic develops over pathways defined by pheromones or physical roads cleared through debris. Worker ants from the same colony have a common underlying evolutionary interest in their collective performance. Thus, ant traffic makes an interesting comparison to other kinds of cellular or organismal traffic composed of elements with varying degrees of shared or disparate goals. Recent studies have revealed how small-scale interactions among ants amplify to create large-scale traffic structure, such as segregation of counterflows. However, much less is known about the ecological costs and benefits of different kinds of traffic organization. The common assumption that maximum traffic flux provides maximum ecological benefit needs closer scrutiny. Ant traffic provides a potentially useful model system for experimental study of crowd panics, and for assessing the role of transport networks in creating scaling relationships between the size and activity rates of the entities they serve.

Burd, Martin

2006-12-01

434

Indirect defense in a highly specific ant-plant mutualism  

NASA Astrophysics Data System (ADS)

Although associations between myrmecophytes and their plant ants are recognized as a particularly effective form of protective mutualism, their functioning remains incompletely understood. This field study examined the ant-plant Hirtella physophora and its obligate ant associate Allomerus decemarticulatus. We formulated two hypotheses on the highly specific nature of this association: (1) Ant presence should be correlated with a marked reduction in the amount of herbivory on the plant foliage; (2) ant activity should be consistent with the "optimal defense" theory predicting that the most vulnerable and valuable parts of the plant are the best defended. We validated the first hypothesis by demonstrating that for ant-excluded plants, expanding leaves, but also newly matured ones in the long term, suffered significantly more herbivore damage than ant-inhabited plants. We showed that A. decemarticulatus workers represent both constitutive and inducible defenses for their host, by patrolling its foliage and rapidly recruiting nestmates to foliar wounds. On examining how these activities change according to the leaves’ developmental stage, we found that the number of patrolling ants dramatically decreased as the leaves matured, while leaf wounds induced ant recruitment regardless of the leaf’s age. The resulting level of these indirect defenses was roughly proportional to leaf vulnerability and value during its development, thus validating our second hypothesis predicting optimal protection. This led us to discuss the factors influencing ant activity on the plant’s surface. Our study emphasizes the importance of studying both the constitutive and inducible components of indirect defense when evaluating its efficacy and optimality.

Grangier, Julien; Dejean, Alain; Malé, Pierre-Jean G.; Orivel, Jérôme

2008-10-01

435

Ultraviolet radiation as an ant repellent  

SciTech Connect

In an effort to repel red imported fire ants (RIFA) from electrical devices, such as transformers, ultraviolet (UV) light was tested. Initial tests determined if RIFA`s tolerate a UV-irradiated environment when given a choice between UV-irradiated and non-irradiated. All replications in this test indicated that RIFA`s are intolerant of UV-irradiation and sought to escape it. RIFA`s moved to shaded environments and transported their brood out its well. A second test sought to determine if long-term UV-irradiation of the entire colonies cause increased RIFA mortality. Queenright colonies were exposed to UV irradiation of 254nm constantly for 115 days and colonies had a higher mortality rate than did a control colony. RIFA`s attempted to escape UV light and had increased rate when exposed to UV (254nm), but a practical application of this technique may be detrimental to insulation on electrical wiring.

Thorvilson, H.G.; Russell, S.A.; Green, B.; Gransberg, D. [Texas Tech Univ., Lubbock, TX (United States)

1996-12-31

436

Disruption of a protective ant-plant mutualism by an invasive ant increases elephant damage to savanna trees  

E-print Network

of mutualisms. The2 mutualism between the whistling thorn acacia (Acacia drepanolobium) and four species of3 by disrupting this system's keystone acacia-ant mutualism.17 18 Key words: Acacia drepanolobium; big-headed ant; elephant; Laikipia; Pheidole megacephala;19 tree cover; whistling thorn acacia20 21 Introduction22 #12

Rubenstein, Daniel I.

437

Is extrafloral nectar production induced by herbivores or ants in a tropical facultative ant-plant mutualism?  

E-print Network

Is extrafloral nectar production induced by herbivores or ants in a tropical facultative ant herbivores are absent but shunt energy to defense when herbivores are present. In3 contrast, constitutive defenses are expressed continuously regardless of herbivore presence. Induction has4 been widely documented

Coley, Phyllis

438

POSITIVE ASSOCIATION BETWEEN DENSITIES OF THE RED IMPORTED FIRE ANT, SOLENOPSIS INVICTA (HYMENOPTERA: FORMICIDAE) AND GENERALIZED ANT AND ARTHROPOD DIVERSITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

The invasive ant, Solenopsis invicta Buren, is a threat to native arthropod biodiversity. We compared areas with naturally varying densities of mostly monogyne S. invicta and examined the association of S. invicta density with three diversity variables: (1) the species richness of ants, (2) the spe...

439

Facultative AntPlant Interactions: Nectar Sugar Preferences of Introduced Pest Ant Species in South Florida1  

Microsoft Academic Search

ABSTRACT We observed nectar use by native and exotic ant species in nature, garden, and urban situations, and found ants utilizing floral and extrafloral nectar of a variety of flowering plant species. We collected 31 plant nectars (29 floral, 2 extrafloral) and used them in feeding preference tests against standard solutions of sugars (20 percent fructose, glucose, and sucrose, and

Suzanne Koptur; Ni Truong

1998-01-01

440

Selective broadcast of fenoxycarb bait on fire ant infested prairie: effect on native ant community  

E-print Network

Meadow are slowly permeable clays and in places shallow depressions, or gilgai, hold water over extended periods. The latter support small wetland plant communities including sedge and rush species ( Carex spp, , Juncus spp. ). Red imported fire ant... eucotricha), a sedge ( Carex sp. ) and 6 forbs, aster, eryngo, poppy-mallow, western ragweed (Ambrosi a 26 psf/ostachya), bl ue-eyed grass (Si syrinchi um sp. ), and showy primrose ( Oenothera speci osa) were identified. One grass, Texas wintergrass...

Morris, John Robert

1994-01-01

441

Chemical Defense by the Native Winter Ant (Prenolepis imparis) against the Invasive Argentine Ant (Linepithema humile)  

PubMed Central

The invasive Argentine ant (Linepithema humile) is established worldwide and displaces native ant species. In northern California, however, the native winter ant (Prenolepis imparis) persists in invaded areas. We found that in aggressive interactions between the two species, P. imparis employs a potent defensive secretion. Field observations were conducted at P. imparis nest sites both in the presence and absence of L. humile. These observations suggested and laboratory assays confirmed that P. imparis workers are more likely to secrete when outnumbered by L. humile. Workers of P. imparis were also more likely to secrete near their nest entrances than when foraging on trees. One-on-one laboratory trials showed that the P. imparis secretion is highly lethal to L. humile, causing 79% mortality. The nonpolar fraction of the secretion was chemically analyzed with gas chromatography/mass spectrometry, and found to be composed of long-chain and cyclic hydrocarbons. Chemical analysis of dissected P. imparis workers showed that the nonpolar fraction is derived from the Dufour's gland. Based on these conclusions, we hypothesize that this chemical defense may help P. imparis to resist displacement by L. humile. PMID:21526231

Kauhanen, Peter G.; Fitzgerald, Katherine; Sturgis, Shelby J.; Chen, Jimmy; Dijamco, Cheri A.; Basurto, Kimberly N.; Gordon, Deborah M.

2011-01-01

442

Desert ants achieve reliable recruitment across noisy interactions  

PubMed Central

We study how desert ants, Cataglyphis niger, a species that lacks pheromone-based recruitment mechanisms, inform each other about the presence of food. Our results are based on automated tracking that allows us to collect a large database of ant trajectories and interactions. We find that interactions affect an ant's speed within the nest. Fast ants tend to slow down, whereas slow ones increase their speed when encountering a faster ant. Faster ants tend to exit the nest more frequently than slower ones. So, if an ant gains enough speed through encounters with others, then she tends to leave the nest and look for food. On the other hand, we find that the probability for her to leave the nest depends only on her speed, but not on whether she had recently interacted with a recruiter that has found the food. This suggests a recruitment system in which ants communicate their state by very simple interactions. Based on this assumption, we estimate the information-theoretical channel capacity of the ants’ pairwise interactions. We find that the response to the speed of an interacting nest-mate is very noisy. The question is then how random interactions with ants within the nest can be distinguished from those interactions with a recruiter who has found food. Our measurements and model suggest that this distinction does not depend on reliable communication but on behavioural differences between ants that have found the food and those that have not. Recruiters retain high speeds throughout the experiment, regardless of the ants they interact with; non-recruiters communicate with a limited number of nest-mates and adjust their speed following these interactions. These simple rules lead to the formation of a bistable switch on the level of the group that allows the distinction between recruitment and random noise in the nest. A consequence of the mechanism we propose is a negative effect of ant density on exit rates and recruitment success. This is, indeed, confirmed by our measurements. PMID:23486172

Razin, Nitzan; Eckmann, Jean-Pierre; Feinerman, Ofer

2013-01-01

443

Patterns of Positive Selection in Seven Ant Genomes  

PubMed Central

The evolution of ants is marked by remarkable adaptations that allowed the development of very complex social systems. To identify how ant-specific adaptations are associated with patterns of molecular evolution, we searched for signs of positive selection on amino-acid changes in proteins. We identified 24 functional categories of genes which were enriched for positively selected genes in the ant lineage. We also reanalyzed genome-wide data sets in bees and flies with the same methodology to check whether positive selection was specific to ants or also present in other insects. Notably, genes implicated in immunity were enriched for positively selected genes in the three lineages, ruling out the hypothesis that the evolution of hygienic behaviors in social insects caused a major relaxation of selective pressure on immune genes. Our scan also indicated that genes implicated in neurogenesis and olfaction started to undergo increased positive selection before the evolution of sociality in Hymenoptera. Finally, the comparison between these three lineages allowed us to pinpoint molecular evolution patterns that were specific to the ant lineage. In particular, there was ant-specific recurrent positive selection on genes with mitochondrial functions, suggesting that mitochondrial activity was improved during the evolution of this lineage. This might have been an important step toward the evolution of extreme lifespan that is a hallmark of ants. PMID:24782441

Roux, Julien; Privman, Eyal; Moretti, Sébastien; Daub, Josephine T.; Robinson-Rechavi, Marc; Keller, Laurent

2014-01-01

444

Ant-mediated seed dispersal in a warmed world  

PubMed Central

Climate change affects communities both directly and indirectly via changes in interspecific interactions. One such interaction that may be altered under climate change is the ant-plant seed dispersal mutualism common in deciduous forests of eastern North America. As climatic warming alters the abundance and activity levels of ants, the potential exists for shifts in rates of ant-mediated seed dispersal. We used an experimental temperature manipulation at two sites in the eastern US (Harvard Forest in Massachusetts and Duke Forest in North Carolina) to examine the potential impacts of climatic warming on overall rates of seed dispersal (using Asarum canadense seeds) as well as species-specific rates of seed dispersal at the Duke Forest site. We also examined the relationship between ant critical thermal maxima (CTmax) and the mean seed removal temperature for each ant species. We found that seed removal rates did not change as a result of experimental warming at either study site, nor were there any changes in species-specific rates of seed dispersal. There was, however, a positive relationship between CTmax and mean seed removal temperature, whereby species with higher CTmax removed more seeds at hotter temperatures. The temperature at which seeds were removed was influenced by experimental warming as well as diurnal and day-to-day fluctuations in temperature. Taken together, our results suggest that while temperature may play a role in regulating seed removal by ants, ant plant seed-dispersal mutualisms may be more robust to climate change than currently assumed. PMID:24688863

Patterson, Courtney M.; Rodriguez-Cabal, Mariano A.; Ribbons, Relena R.; Dunn, Robert R.; Sanders, Nathan J.

2014-01-01

445

Species richness, equitability, and abundance of ants in disturbed landscapes  

USGS Publications Warehouse

Ants are used as indicators of environmental change in disturbed landscapes, often without adequate understanding of their response to disturbance. Ant communities in the southeastern United States displayed a hump-backed species richness curve against an index of landscape disturbance. Forty sites at Fort Benning, in west-central Georgia, covered a spectrum of habitat disturbance (military training and fire) in upland forest. Sites disturbed by military training had fewer trees, less canopy cover, more bare ground, and warmer, more compact soils with shallower A-horizons. We sampled ground-dwelling ants with pitfall traps, and measured 15 habitat variables related to vegetation and soil. Ant species richness was greatest with a relative disturbance of 43%, but equitability was greatest with no disturbance. Ant abundance was greatest with a relative disturbance of 85%. High species richness at intermediate disturbance was associated with greater within-site spatial heterogeneity. Species richness was also associated with intermediate values of the normalized difference vegetation index (NDVI), a correlate of net primary productivity (NPP). Available NPP (the product of NDVI and the fraction of days that soil temperature exceeded 25 ??C), however, was positively correlated with species richness, though not with ant abundance. Species richness was unrelated to soil texture, total ground cover, and fire frequency. Ant species richness and equitability are potential state indicators of the soil arthropod community. Moreover, equitability can be used to monitor ecosystem change. ?? 2008 Elsevier Ltd.

Graham, J.H.; Krzysik, A.J.; Kovacic, D.A.; Duda, J.J.; Freeman, D.C.; Emlen, J.M.; Zak, J.C.; Long, W.R.; Wallace, M.P.; Chamberlin-Graham, C.; Nutter, J.P.; Balbach, H.E.

2009-01-01

446

Ant diversity and distribution in Acadia National Park, Maine.  

PubMed

Exotic ant species are a primary threat to ant biological diversity, posing a negative impact to native ant communities. In this study, we examine species richness of ants (family Formicidae) in Acadia National Park, ME, as a fundamental step toward understanding the present impact of the exotic species Myrmica rubra on native ant species. Twelve habitat types were sampled, along six transects, with pitfall traps, visual searching, bait traps, and leaf litter extraction, and the aid of 34 volunteers. We report 42 species of ants in Acadia National Park, comprising five subfamilies (Amblyoponinae, Dolichoderinae, Formicinae, Myrmicinae, and Ponerinae) and 15 genera; the cataloged species represents 75% of the species originally recorded in the area by Procter (1946). Our findings suggest M. rubra is currently not a dominant species throughout the entire island. However, where this species has invaded locally, few competing native species coexist. The species Lasius alienus, Formica subsericea, Myrmica detritinodis, Camponotus herculeanus, Formica argentea, Formica aserva, and Tapinoma sessile occurred most often in our survey. We report the ant species Amblyopone pallipes and Dolichoderus mariae as two new records for the state of Maine. PMID:22546439

Ouellette, Gary D; Drummond, Francis A; Choate, Beth; Groden, Eleanor

2010-10-01

447

Stridulations Reveal Cryptic Speciation in Neotropical Sympatric Ants  

PubMed Central

The taxonomic challenge posed by cryptic species underlines the importance of using multiple criteria in species delimitation. In the current paper we tested the use of acoustic analysis as a tool to assess the real diversity in a cryptic species complex of Neotropical ants. In order to understand the potential of acoustics and to improve consistency in the conclusions by comparing different approaches, phylogenetic relationships of all the morphs considered were assessed by the analysis of a fragment of the mitochondrial DNA cytochrome b. We observed that each of the cryptic morph studied presents a morphologically distinct stridulatory organ and that all sympatric morphs produce distinctive stridulations. This is the first evidence of such a degree of specialization in the acoustic organ and signals in ants, which suggests that stridulations may be among the cues used by these ants during inter-specific interactions. Mitochondrial DNA variation corroborated the acoustic differences observed, confirming acoustics as a helpful tool to determine cryptic species in this group of ants, and possibly in stridulating ants in general. Congruent morphological, acoustic and genetic results constitute sufficient evidence to propose each morph studied here as a valid new species, suggesting that P. apicalis is a complex of at least 6 to 9 species, even if they present different levels of divergence. Finally, our results highlight that ant stridulations may be much more informative than hitherto thought, as much for ant communication as for integrative taxonomists. PMID:21203529

Ferreira, Ronara Souza; Poteaux, Chantal; Delabie, Jacques Hubert Charles; Fresneau, Dominique; Rybak, Fanny

2010-01-01

448

Prey capture kinematics of ant-eating lizards.  

PubMed

While morphological and behavioral feeding specializations are obvious in many vertebrate groups, among lizards there appear to be few dietary specialists. By comparing the prey capture kinematics and overall feeding behavior in two highly specialized ant-eating lizards (Moloch horridus and Phrynosoma platyrhinos) with those of two closely related dietary generalists (Pogona vitticeps and Uma notata), we investigate whether dietary specialization has been accompanied by changes in the function and use of the feeding system. We quantified kinematic variables from high-speed video recordings (200-250 frames s(-1)) of each species feeding on ants. Prey capture was strikingly different in M. horridus to that of other species, being characterized by a suite of unusual behaviors including the lack of a body lunge, faster tongue protrusion, reduced prey processing and, most notably, the ability to modulate the slow open phase of the gape cycle. In concert, these traits make a single feeding event in M. horridus faster than that in any other iguanian lizard studied to date. Prey capture behavior in P. platyrhinos is kinematically more similar to U. notata and P. vitticeps than to M. horridus, but the ant specialists are similar in that both lack distinct prey processing behaviors, resulting in faster overall capture and feeding events. While ant feeding in P. vitticeps is faster than feeding on other prey, the duration of a single feeding event is still four times longer than in either ant specialist, because of extensive prey processing. Additionally, a phylogenetic comparison of ant specialist lizards with dietary generalists revealed that ant-eating lizards require significantly less time to capture and process prey. Thus there are not only significant behavioral modifications in these ant-eating lizards, but also multiple strategies among specialists, suggesting differing selective pressures or phylogenetic constraints in the evolution of ant eating in lizards. PMID:15601883

Meyers, Jay J; Herrel, Anthony

2005-01-01

449

The Molecular Clockwork of the Fire Ant Solenopsis invicta  

PubMed Central

The circadian clock is a core molecular mechanism that allows organisms to anticipate daily environmental changes and adapt the timing of behaviors to maximize efficiency. In social insects, the ability to maintain the appropriate temporal order is thought to improve colony efficiency and fitness. We used the newly sequenced fire ant (Solenopsis invicta) genome to characterize the first ant circadian clock. Our results reveal that the fire ant clock is similar to the clock of the honeybee, a social insect with an independent evolutionary origin of sociality. Gene trees for the eight core clock genes, period, cycle, clock, cryptochrome-m, timeout, vrille, par domain protein 1 & clockwork orange, show ant species grouping closely with honeybees and Nasonia wasps as an outgroup to the social Hymenoptera. Expression patterns for these genes suggest that the ant clock functions similar to the honeybee clock, with period and cry-m mRNA levels increasing during the night and cycle and clockwork orange mRNAs cycling approximately anti-phase to period. Gene models for five of these genes also parallel honeybee models. In particular, the single ant cryptochrome is an ortholog of the mammalian-type (cry-m), rather than Drosophila-like protein (cry-d). Additionally, we find a conserved VPIFAL C-tail region in clockwork orange shared by insects but absent in vertebrates. Overall, our characterization of the ant clock demonstrates that two social insect lineages, ants and bees, share a similar, mammalian-like circadian clock. This study represents the first characterization of clock genes in an ant and is a key step towards understanding socially-regulated plasticity in circadian rhythms by facilitating comparative studies on the organization of circadian clockwork. PMID:23152747

Ingram, Krista K.; Kutowoi, Alexander; Wurm, Yannick; Shoemaker, DeWayne; Meier, Rudolf; Bloch, Guy

2012-01-01

450

The molecular clockwork of the fire ant Solenopsis invicta.  

PubMed

The circadian clock is a core molecular mechanism that allows organisms to anticipate daily environmental changes and adapt the timing of behaviors to maximize efficiency. In social insects, the ability to maintain the appropriate temporal order is thought to improve colony efficiency and fitness. We used the newly sequenced fire ant (Solenopsis invicta) genome to characterize the first ant circadian clock. Our results reveal that the fire ant clock is similar to the clock of the honeybee, a social insect with an independent evolutionary origin of sociality. Gene trees for the eight core clock genes, period, cycle, clock, cryptochrome-m, timeout, vrille, par domain protein 1 & clockwork orange, show ant species grouping closely with honeybees and Nasonia wasps as an outgroup to the social Hymenoptera. Expression patterns for these genes suggest that the ant clock functions similar to the honeybee clock, with period and cry-m mRNA levels increasing during the night and cycle and clockwork orange mRNAs cycling approximately anti-phase to period. Gene models for five of these genes also parallel honeybee models. In particular, the single ant cryptochrome is an ortholog of the mammalian-type (cry-m), rather than Drosophila-like protein (cry-d). Additionally, we find a conserved VPIFAL C-tail region in clockwork orange shared by insects but absent in vertebrates. Overall, our characterization of the ant clock demonstrates that two social insect lineages, ants and bees, share a similar, mammalian-like circadian clock. This study represents the first characterization of clock genes in an ant and is a key step towards understanding socially-regulated plasticity in circadian rhythms by facilitating comparative studies on the organization of circadian clockwork. PMID:23152747

Ingram, Krista K; Kutowoi, Alexander; Wurm, Yannick; Shoemaker, Dewayne; Meier, Rudolf; Bloch, Guy

2012-01-01

451

An empirically based simulation of group foraging in the harvesting ant, Messor pergandei.  

PubMed

We present an empirically based group model of foraging interactions in Messor pergandei, the Sonoran desert harvesting ant. M. pergandei colonies send out daily foraging columns consisting of tens of thousands of individual ants. Each day, the directions of the columns may change depending on the resource availability and the neighbor interactions. If neighboring columns meet, ants fight, and subsequent foraging is suppressed. M. pergandei colonies face a general problem which is present in many systems: dynamic spatial partitioning in a constantly changing environment, while simultaneously minimizing negative competitive interactions with multiple neighbors. Our simulation model of a population of column foragers is spatially explicit and includes neighbor interactions. We study how different behavioral strategies influence resource exploitation and space use for different nest distributions and densities. Column foraging in M. pergandei is adapted to the spatial and temporal properties of their natural habitat. Resource and space use is maximized both at the colony and the population level by a model with a behavioral strategy including learning and fast forgetting rates. PMID:23978772

Plowes, Nicola J R; Ramsch, Kai; Middendorf, Martin; Hölldobler, Bert

2014-01-01

452

Plant defense, herbivory, and the growth of Cordia alliodora trees and their symbiotic Azteca ant colonies.  

PubMed

The effects of herbivory on plant fitness are integrated over a plant's lifetime, mediated by ontogenetic changes in plant defense, tolerance, and herbivore pressure. In symbiotic ant-plant mutualisms, plants provide nesting space and food for ants, and ants defend plants against herbivores. The benefit to the plant of sustaining the growth of symbiotic ant colonies depends on whether defense by the growing ant colony outpaces the plant's growth in defendable area and associated herbivore pressure. These relationships were investigated in the symbiotic mutualism between Cordia alliodora trees and Azteca pittieri ants in a Mexican tropical dry forest. As ant colonies grew, worker production remained constant relative to ant-colony size. As trees grew, leaf production increased relative to tree size. Moreover, larger trees hosted lower densities of ants, suggesting that ant-colony growth did not keep pace with tree growth. On leaves with ants experimentally excluded, herbivory per unit leaf area increased exponentially with tree size, indicating that larger trees experienced higher herbivore pressure per leaf area than smaller trees. Even with ant defense, herbivory increased with tree size. Therefore, although larger trees had larger ant colonies, ant density was lower in larger trees, and the ant colonies did not provide sufficient defense to compensate for the higher herbivore pressure in larger trees. These results suggest that in this system the tree can decrease herbivory by promoting ant-colony growth, i.e., sustaining space and food investment in ants, as long as the tree continues to grow. PMID:22562422

Pringle, Elizabeth G; Dirzo, Rodolfo; Gordon, Deborah M

2012-11-01

453

From individual to collective dynamics in Argentine ants (Linepithema humile).  

PubMed

In this paper we propose a model for the formation of paths in Argentine ants when foraging in an empty arena. Based on experimental observations, we provide a distribution for the random change in direction that they approximately undergo while foraging as a mixture of a Gaussian and a Pareto distribution. By following the principles described in previous work [32], we consider persistence and reinforcement to create a model for the motion of ants in the plane. Numerical simulations based on this model lead to the formation of branched ant-trails analogous to those observed experimentally. PMID:25640869

Vela-Pérez, M; Fontelos, M A; Garnier, S

2015-04-01

454

Chimpanzees detect ant-inhabited dead branches and stems: a study of the utilization of plant-ant relationships in the Mahale Mountains, Tanzania.  

PubMed

Chimpanzees in the Mahale Mountains of Tanzania consume several species of stem- and branch-inhabiting ants throughout the year, without tools. Those ants are cryptic species, and it was unknown how to find them constantly. There has been little research on how the chimpanzees locate these ants. In this study, I use behavioral observations of the chimpanzee predators and surveys of the ant fauna and plants across different habitats to test the hypothesis that chimpanzees use plant species as a cue to efficiently locate ant colonies in litter units (dead parts of the plant). Ants were found to be associated with live plants and with spaces within litter units which provide nesting places. Such ant-plant litter relationships were not necessarily as strong as the mutualism often observed between live plants and ants. The proportion of available litter units inhabited by ants was 20 %, and litter units of three plant species (Vernonia subligera, Dracaena usambarensis, and Senna spectabilis) were well occupied by ants in the home range of the chimpanzees. The ant-inhabited ratio in chimpanzee-foraged litter units was higher than that in the available units in the home range. Chimpanzees fed more often on Crematogaster spp. than on other resident ants and at a higher rate than expected from their occurrence in the litter units. Above three plant species were well occupied by Crematogaster sp. 3 or C. sp. 18. It is concluded that chimpanzees locate ants by selecting litter units of plant species inhabited by ants. PMID:23842594

Fuse, Mieko

2013-10-01

455

A new ant based distributed framework for urban road map updating from high resolution satellite imagery  

NASA Astrophysics Data System (ADS)

Receiving updated information about the network of roads from high resolution satellite imagery is a crucially important issue in continuously changing developing urban regions. Considering experiences in road extraction and also exploiting distributed evolutionary computational approaches, in this paper a new framework for road map updating from remotely sensed data is proposed. Three main computational entities of ant-agent, seed extractor and algorithm library are designed and road map updating is performed through three main stages of verification of the old map, extraction of possible roads and grouping of the results of both stages. Extracting corresponding pixels to each road element in the map, an object level supervised classification or any available road verification algorithm from the library capable of producing a road likeliness value is applied. Since road extraction is a simple and also a complex problem, more comprehensive algorithms are chosen from library iteratively by ant-agents so the decision about verification and rejection of each road element is finally made. Ant-agents facilitate choosing road elements and moving of ant agents via stigmergic communication by pheromone cast and evaporation. The proposed method is developed and tested using GeoEye-1 pan-sharpen imagery and 1:2000 corresponding digital vector map of the region. As observed, the results are satisfactory in terms of detection, verification and extraction of roads and generation of the updated map specifically in case of inspection of main roads. Besides, some missed road items are reported in case of inspection of bystreets and alleys specially when situated at the margin of the image. Completeness, correctness and quality measures are computed for evaluation of the initial and the resulted updated maps. The computed measures verify the improvement of the updated map.

Zarrinpanjeh, Nima; Samadzadegan, Farhad; Schenk, Toni

2013-04-01

456

Symbiotic mutualism with a community of opportunistic ants: protection, competition, and ant occupancy of the myrmecophyte Barteria nigritana (Passifloraceae)  

NASA Astrophysics Data System (ADS)

Barteria nigritana is a myrmecophyte tree of Lower Guinea coastal vegetation. Unlike the more specialised B. fistulosa, which harbours a single host-specific mutualistic ant, B. nigritana is associated with several opportunistic ants. Such symbiotic, yet opportunistic, ant-plant associations have been little studied. On 113 clumps of B. nigritana, we censused ant associates and herbivores and compared herbivory on plants occupied by different ants. In addition to these correlative data, protection conferred by different ant species was compared by herbivore-placement experiments. Identity of ant associate changed predictably over plant ontogeny. Pheidole megacephala was restricted to very small plants; saplings were occupied by either Oecophylla longinoda or Crematogaster sp., and the latter species was the sole occupant of larger trees. Damage by caterpillars of the nymphalid butterfly Acraea zetes accounted for much of the herbivory to leaves. Ant species differed in the protection provided to hosts. While P. megacephala provided no significant protection, plants occupied by O. longinoda and Crematogaster sp. suffered less damage than did unoccupied plants or those occupied by P. megacephala. Furthermore, O. longinoda provided more effective protection than did Crematogaster sp. Herbivore-placement experiments confirmed these results. Workers of O. longinoda killed or removed all larval instars of A. zetes. Crematogaster preyed on only the two first larval instars, and P. megacephala preyed mainly on eggs, only rarely attacking the two first larval instars. Opportunistic ants provided significant protection to this relatively unspecialised myrmecophyte. The usual associate of mature trees was not the species that provided most protection.

Djiéto-Lordon, Champlain; Dejean, Alain; Gibernau, Marc; Hossaert-McKey, Martine; McKey, Doyle

2004-10-01

457

A Possibility of the Aeromagnetic Survey by a Small Unmanned Aerial Vehicles, Ant-Plane  

NASA Astrophysics Data System (ADS)

Magnetic surveys by helicopters and airplanes are a useful technique to estimate the geological structure under the ice sheets in Antarctica. However, it is not easy to employ this due to the transportation of the planes, logistic supports, security, and financial problems. Members of Ant-Plane Project have investigated the unmanned aerial vehicles (UAV, Ant-Plane) for the solution of the problems. Recently the aeromagnetic survey is verified by a model airplane navigated by GPS and a magneto-resistant (MR) magnetometer. The airplane (Ant-Plane) consists of 2m wing length, 2-cycles and 2-cylinder 85cc gasoline engine, GPS navigation system by microcomputer and radio telemeter system. The total weight is 15kg including 2 litter fuels, the MR magnetometer, a video camera and an emergency parachute. The speed is 130 km/h and maximum height is 2000m. The magnetometer system consists of a 3- component MR magnetometer, GPS and data logger. Three components of magnetic field, latitude, longitude, altitude, number of satellite and time are recorded in every second during 3 hours. The sensitivity of the magnetometer is 7 nT and we use a total magnetic field intensity for magnetic analysis due to unknown heading of the plane. November 2003 we succeeded the magnetic survey by the Ant-Plane at the slope of Sakurajima Volcano, Kyushu, Japan. The plane rotated 9 times along the programmed route of about 4x1 km, total flight distance of 80 km, keeping the altitude of 700 m. Consequently we obtained almost similar field variation on the route. The maximum deviation of each course was less than 100 m. Therefore, we concluded that the aeromagnetic survey in the relatively large anomaly areas can be performed by Ant-Plane with the MR magnetometer system. Finally the plane flew up 1400m with a video camera to take the photo of active volcano Sakurajima (1117m). It succeeded to take photos of craters through steam from the volcano.

Funaki, M.

2004-12-01

458

CURRICULUM VITAE Edward W. Muir, Jr.  

E-print Network

-93 Alice Berlin Kaplan Center for the Humanities, Fellow, 1996-97 Rockefeller Foundation, Residential University, Research Grant, Summer 1980 Gladys Krieble Delmas Foundation, Travel and Research Grant, Summer Foundation, Fellowship, 1985 The Folger Institute of the Folger Shakespeare Library Director of Seminar

Grzybowski, Bartosz A.

459

Atypical vitellins in ponerine ants (Formicidae: Hymenoptera).  

PubMed

Higher hymenopteran vitellogenin/vitellins have been characterized as containing one large apoprotein. We show that in the ant subfamily Ponerinae, species in the tribes Odontomachini, Platythyrini, and Amblyoponini, also have a vitellin with this simple structure, containing a single apoprotein of 180-190kDa. Species in tribes Ponerini and Ectatommini, however, have vitellins containing multiple subunits. The size and number of the subunits varies, with differences even among species within the same genus. This is the first report of diversity in vitellogenin structure in the higher Hymenoptera. Vitellin and vitellogenin in Harpegnathos saltator (Ponerini) contain two large subunits of about 165kDa and two small subunits of about 45 and 43kDa. N-terminal sequence analysis suggests that provitellogenin is cleaved at two different sites, producing two large and two small subunits differing slightly in size. Diversity of vitellin types in Ponerini and Ectatommini is similar to that found in the more primitive tenthredinoid sawflies (Hymenoptera, Symphyta), and may indicate polyphyly in the Ponerinae. Insect vitellogenins and yolk proteins show considerably more diversity than originally believed, and the possibility of the functional significance of these differences should be considered. PMID:12770376

Wheeler, D; Liebig, J; Hölldobler, B

1999-03-01

460

Antioxidant activity of Chinese ant extract preparations.  

PubMed

Chinese ant extract preparations (CAEP) are a Chinese traditional medicine which is mainly used as a health food or drink for the treatment of rheumatism, rheumatoid arthritis, chronic hepatitis, sexual hypofunction, and antiaging in China. The effects on free radicals were examined by electron spin resonance spectrometry using the spin trapping agent 5.5-dimethyl-1-pyrroline-1-oxide (DMPO). Superoxide radicals (3.35 x 10(15) spins/ml) were quenched 50% by the extract at 0.5 mg/ml. The CAEP extract at 0.7 mg/ml inhibited 50% of hydroxyl radicals (52.0 x 10(15) spins/ml) generated by the Fenton reaction. Against DPPH radical, the scavenging action of CAEP was observed at 1.8 mg/ml of the extract and 50% of the DPPH radicals (8.14 x 10(15) spins/ml) were quenched. In vitro tests showed that CAEP inhibited the production of thiobarbituric acid-reactive substances, an index of lipid peroxidation, in rat brain homogenate. PMID:8770235

Zhao, Y; Wang, X; Kawai, M; Liu, J; Liu, M; Mori, A

1995-12-01

461

Occurrence of antennal glands in ants.  

PubMed

A previous report of the discovery of exocrine glands in the antennal club of queens and workers of Solenopsis invicta Buren, 1972 left open the question of the extent to which similar glands occur in the Formicidae family. We wanted to know if these antennal glands are unique to Solenopsis, or they are found in a wider taxonomic group. Using scanning electron microscopy, we examined the antennae of 41 ant species. Presence of the antennal glands was indicated by a characteristic circumferential ring of pores in a distal antennal segment of workers. Pores were found in the 9th antennal segment of all 26 species of Solenopsis examined. Pores were absent in the following: Monomorium minimum, M. pharaonis, Pheidole sp., Crematogaster sp., Linepithema humile, Forelius sp., Dorymyrmex sp., Paratrechina sp., Oecophylla smaragdina, Campanotus sp., Ectatomma ruidum, E. tuberlatum, and Pseudomyrmex ferruginea. However, pores were found in the antennal club of Tetramorium bicarinatum workers and queens. After KOH digestion of T. bicarinatum antennae, internal canals were observed in both workers and queens, and the canals are connected to spherical reservoirs in queens. T. bicarinatum was the only non-Solenopsis species examined, which showed evidence for antennal glands in the distal funiculus. PMID:18655135

Renthal, Robert; Velasquez, Daniel; Olmos, David; Vinson, S Bradleigh

2008-11-01

462

Ants of Ambon Island - diversity survey and checklist.  

PubMed

The present checklist of ants (Hymenoptera: Formicidae) of Ambon is the first comprehensive overview of ant species recorded on the island during the last 150 years. The species list is based on literature and museum collections' records combined with data from our field survey in 2010. In total, there are 74 ant species and subspecies representing 34 genera and six subfamilies known from Ambon. Five of the species found in undisturbed forest were exotic and indicate the overall habitat degradation on the island. The largest proportion of Ambon ant fauna are species with affinities to the Oriental region and species of Oriental-Austro-Melanesian origin. At least 20% of the species are regional endemics. In comparison to other islands in the region, the Ambon fauna seems more diverse and better sampled; however it is clear that a large part of it still remains to be described. PMID:25632248

Latumahina, Fransina; Borovanska, Michaela; Musyafa; Sumardi; Putra, Nugroho Susetya; Janda, Milan

2015-01-01

463

Disease Dynamics in a Specialized Parasite of Ant Societies  

PubMed Central

Coevolution between ant colonies and their rare specialized parasites are intriguing, because lethal infections of workers may correspond to tolerable chronic diseases of colonies, but the parasite adaptations that allow stable coexistence with ants are virtually unknown. We explore the trade-offs experienced by Ophiocordyceps parasites manipulating ants into dying in nearby graveyards. We used field data from Brazil and Thailand to parameterize and fit a model for the growth rate of graveyards. We show that parasite pressure is much lower than the abundance of ant cadavers suggests and that hyperparasites often castrate Ophiocordyceps. However, once fruiting bodies become sexually mature they appear robust. Such parasite life-history traits are consistent with iteroparity– a reproductive strategy rarely considered in fungi. We discuss how tropical habitats with high biodiversity of hyperparasites and high spore mortality has likely been crucial for the evolution and maintenance of iteroparity in parasites with low dispersal potential. PMID:22567151

Andersen, Sandra B.; Ferrari, Matthew; Evans, Harry C.; Elliot, Simon L.; Boomsma, Jacobus J.; Hughes, David P.

2012-01-01

464

Pollution diminishes intra-specific aggressiveness between wood ant colonies.  

PubMed

A variety of common environmental pollutants are known to affect the animal behaviour, but the occurrence and extent of pollution-induced behavioural changes in wild populations are practically unknown. Here we show that heavy metal pollution reduces the normal intra-specific aggressive behaviour in wild populations of the wood ant, Formica aquilonia, a dominant territorial ant species in boreal forests. Ants exposed to long-term pollution around a copper smelter showed higher heavy metal concentrations and were less aggressive towards the member of foreign unpolluted colony than the ants from an uncontaminated area. A pollution-related decline in the level of aggressiveness in this keystone general predator species may potentially affect the structure of invertebrate community of boreal and temperate forests. Further studies are needed to find out whether the change in aggressiveness is directly caused by metal toxicity or indirectly via secondary pollution effects, such as changed resource levels. PMID:20434195

Sorvari, Jouni; Eeva, Tapio

2010-07-15

465

Widespread occurrence of the micro-organism Wolbachia in ants  

E-print Network

and feminization of males. This paper reports on a ¢rst PCR-based Wolbachia screening in ants. Out of 50 Indo reproduction, feminization of genetic males and increasing the fertilization frequency in male haploids

Wenseleers, Tom

466

Ants of Ambon Island – diversity survey and checklist  

PubMed Central

Abstract The present checklist of ants (Hymenoptera: Formicidae) of Ambon is the first comprehensive overview of ant species recorded on the island during the last 150 years. The species list is based on literature and museum collections’ records combined with data from our field survey in 2010. In total, there are 74 ant species and subspecies representing 34 genera and six subfamilies known from Ambon. Five of the species found in undisturbed forest were exotic and indicate the overall habitat degradation on the island. The largest proportion of Ambon ant fauna are species with affinities to the Oriental region and species of Oriental-Austro-Melanesian origin. At least 20% of the species are regional endemics. In comparison to other islands in the region, the Ambon fauna seems more diverse and better sampled; however it is clear that a large part of it still remains to be described. PMID:25632248

Latumahina, Fransina; Borovanska, Michaela; Musyafa; Sumardi; Putra, Nugroho Susetya; Janda, Milan

2015-01-01

467

Efficient Egress of Escaping Ants Stressed with Temperature  

PubMed Central

In the present work we investigate the egress times of a group of Argentine ants (Linepithema humile) stressed with different heating speeds. We found that the higher the temperature ramp is, the faster ants evacuate showing, in this sense, a group-efficient evacuation strategy. It is important to note that even when the life of ants was in danger, jamming and clogging was not observed near the exit, in accordance with other experiments reported in the literature using citronella as aversive stimuli. Because of this clear difference between ants and humans, we recommend the use of some other animal models for studying competitive egress dynamics as a more accurate approach to understanding competitive egress in human systems. PMID:24312264

Boari, Santiago; Josens, Roxana; Parisi, Daniel R.

2013-01-01

468

ANT-GARDEN EPIPHYTES ARE PROTECTED AGAINST DROUGHT IN A VENEZUELAN LOWLAND RAIN FOREST  

Microsoft Academic Search

Neotropical ant gardens (AGs) represent a classic mutualism between ants and epiphytic plants. Previous studies showed that these plants benefit from effective fruit dispersal and improved nutrition provided by gardening ants. Here we show an additional positive impact of gardening ants and their substrate on the fitness and survival of the AG epiphyte Peperomia macrostachya (Piperaceae) and seedlings of other

Viviane Schmit-Neuerburg; Nico Blüthgen

469

USE OF BAITS FOR EVALUATION OF FIRE ANT POPULATIONS IN THE USDA AREAWIDE PROJECT  

Technology Transfer Automated Retrieval System (TEKTRAN)

In sites used in the USDA-ARS Areawide Fire Ant Suppression project, fire ant populations are monitored using baits (ant activity monitoring) or mound counts (mounds rated using the USDA Population Index [PI] rating). For ant activity monitoring, 10 slices of beef wieners are placed about 8-paces ap...

470

Health Hazards of Imported Fire Fire ants are stinging insects that belong to the same  

E-print Network

Health Hazards of Imported Fire Ant Stings Background Fire ants are stinging insects that belong to the same order as bees and wasps. The red-black imported fire ant now infests more than 260 million acres hazard. Fire ant mounds may measure up to three feet in diameter and 18 inches in height. Each mound may

Balasundaram, Balabhaskar "Baski"

471

Ant Routing in Mobile Ad Hoc Networks S. S. Dhillon, X. Arbona and P. Van Mieghem  

E-print Network

Ant Routing in Mobile Ad Hoc Networks S. S. Dhillon, X. Arbona and P. Van Mieghem Delft University the performance of ant routing for static and dynamic network topologies. We also compare the per- formance of ant routing with AODV and DSR for ad hoc networks. The simulations show that the ant routing al- gorithm

Van Mieghem, Piet

472

Spatial Distribution of Dominant Arboreal Ants in a Malagasy Coastal Rainforest: Gaps and Presence of an  

E-print Network

Spatial Distribution of Dominant Arboreal Ants in a Malagasy Coastal Rainforest: Gaps and Presence at increasing distances from the coast to determine whether a non-random arboreal ant assemblage, such as an ant populous colonies of territorially dominant arboreal ant species defend absolute territories distributed

Paris-Sud XI, Université de

473

Box 12.1 Trap-jaw ants Andrew V. Suarez and Joseph C. Spagna  

E-print Network

Box 12.1 Trap-jaw ants Andrew V. Suarez and Joseph C. Spagna The success of ants is often attributed to their remarkable social behaviour and cooperation. Group foraging species such as army ants can insect or even a small vertebrate. How- ever, not all ants are social hunters -- some of the most

Suarez, Andrew V.

474

Tracing the Rise of Ants -Out of the Ground Andrea Lucky1,2  

E-print Network

Tracing the Rise of Ants - Out of the Ground Andrea Lucky1,2 *, Michelle D. Trautwein3,4 , Benoit S The evolution of ants (Hymenoptera: Formicidae) is increasingly well-understood due to recent phylogenetic regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic

Lucky, Andrea

475

The Ant Colony Paradigm for Reliable Systems Yun-Chia Liang  

E-print Network

The Ant Colony Paradigm for Reliable Systems Design Yun-Chia Liang Department of Industrial- rial optimization, the ant colony. The ant colony algorithm is a multiple solution global optimizer annealing, it is in- spired by observation of natural systems, in this case, the behavior of ants

Smith, Alice E.

476

Nesting biology of the fungus-growing ant Cyphomyrmex longiscapus Weber (Attini, Formicidae)  

E-print Network

Nesting biology of the fungus-growing ant Cyphomyrmex longiscapus Weber (Attini, Formicidae) U, Republic of Panama, e-mail: wcislow@tivoli.si.edu Key words: Cyphomyrmex longiscapus, fungus-growing ants, nesting biology, ant- fungus symbiosis. Summary The fungus-growing ant Cyphomymrex longiscapus Weber

Bermingham, Eldredge

477

Deterrency and Toxicity of Essential Oils to Argentine and Red Imported Fire Ants (Hymenoptera: Formicidae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Laboratory assays were conducted to evaluate deterrency and contact toxicity of six essential oils to the Argentine ant, Linepithema humile (Mayr), and the red imported fire ant, Solenopsis invicta Buren. In choice tests, both Argentine ants and fire ants crossed barriers treated with multiple rates...

478

Active use of the metapleural glands by ants in controlling fungal infection  

E-print Network

or are they selectively used when ants are challenged by pathogens? In 26 species from five subfamilies, ants use foreleg, after which it returns to baseline levels. Ants with open MGs produce more infrabuccal pellets (IP) than structures that are diagnostic for identifying both fossil and extant ants (Formicidae), apart from some taxa

Bermingham, Eldredge

479

Asymmetric Dispersal and Colonization Success of Amazonian Plant-Ants Queens  

Microsoft Academic Search

BackgroundThe dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is

Emilio M. Bruna; Thiago J. Izzo; Brian D. Inouye; Maria Uriarte; Heraldo L. Vasconcelos

2011-01-01

480

Antaphid mutualism: the influence of ants on the aphid summer cycle  

E-print Network

61 Ant­aphid mutualism: the influence of ants on the aphid summer cycle Karolina Tegelaar, Mattias on the effects on aphids of being tended by ants. The aim of this study is to investigate how the presence of ants influences settling decisions by colonizing aphids and the post-settlement growth and survival

Leimar, Olof

481

Low-energy routing based on ant colony algorithm genetic algorithm in wireless sensor networks  

NASA Astrophysics Data System (ADS)

While designing the routing protocol in wireless sensor networks (WSN), one of the key problems is to keep the energy-load balance over the network for prolonging its lifetime. In this paper, we propose a low-energy clustering WSN routing protocol based on Ant Colony Algorithm Genetic Algorithm (ACAGA). The protocol divides the network into several clusters and selects cluster heads according to the relative locations and the residual energy status of nodes. While keeping the energy-load balance over the whole network, it accomplishes a low-energy routing and prolongs the whole network's lifetime by using the distributed computation and global route optimization capabilities of ACAGA.

Zhang, Shi; Lu, Qiannan; Zhang, Zhe; Chen, Jian

2006-11-01

482

Scope of Various Random Number Generators in ant System Approach for TSP  

NASA Technical Reports Server (NTRS)

Experimented on heuristic, based on an ant system approach for traveling salesman problem, are several quasi- and pseudo-random number generators. This experiment is to explore if any particular generator is most desirable. Such an experiment on large samples has the potential to rank the performance of the generators for the foregoing heuristic. This is mainly to seek an answer to the controversial issue "which generator is the best in terms of quality of the result (accuracy) as well as cost of producing the result (time/computational complexity) in a probabilistic/statistical sense."

Sen, S. K.; Shaykhian, Gholam Ali

2007-01-01

483

Genomic Comparison of the Ants Camponotus floridanus and Harpegnathos saltator  

Microsoft Academic Search

The organized societies of ants include short-lived worker castes displaying specialized behavior and morphology and long-lived queens dedicated to reproduction. We sequenced and compared the genomes of two socially divergent ant species: Camponotus floridanus and Harpegnathos saltator. Both genomes contained high amounts of CpG, despite the presence of DNA methylation, which in non-Hymenoptera correlates with CpG depletion. Comparison of gene

Roberto Bonasio; Guojie Zhang; Chaoyang Ye; Navdeep S. Mutti; Xiaodong Fang; Nan Qin; Greg Donahue; Pengcheng Yang; Qiye Li; Cai Li; Pei Zhang; Zhiyong Huang; Shelley L. Berger; Danny Reinberg; Jun Wang; Jürgen Liebig

2010-01-01

484

Carbohydrate supply limits invasion of natural communities by Argentine ants.  

PubMed

The ability of species to invade new habitats is often limited by various biotic and physical factors or interactions between the two. Invasive ants, frequently associated with human activities, flourish in disturbed urban and agricultural environments. However, their ability to invade and establish in natural habitats is more variable. This is particularly so for the invasive Argentine ant (Linepithema humile). While biotic resistance and low soil moisture limits their invasion of natural habitats in some instances, the effect of food availability has been poorly explored. We conducted field experiments to determine if resource availability limits the spread and persistence of Argentine ants in remnant natural forest in North Carolina. Replicated transects paired with and without sucrose solution feeding stations were run from invaded urban edges into forest remnants and compared over time using baits and direct counts at feeding stations. Repeated under different timing regimes in 2006 and 2007, access to sucrose increased local Argentine ant abundances (1.6-2.5 fold) and facilitated their progression into the forest up to 73 +/- 21% of 50-m transects. Resource removal caused an expected decrease in Argentine ant densities in 2006, in conjunction with their retreat to the urban/forest boundary. However, in 2007, Argentine ant numbers unexpectedly continued to increase in the absence of sugar stations, possibly through access to alternative resources or conditions not available the previous year such as honeydew-excreting Hemiptera. Our results showed that supplementing carbohydrate supply facilitates invasion of natural habitat by Argentine ants. This is particularly evident where Argentine ants continued to thrive following sugar station removal. PMID:19452171

Rowles, Alexei D; Silverman, Jules

2009-08-01

485

Carbohydrate supply limits invasion of natural communities by Argentine ants  

Microsoft Academic Search

The ability of species to invade new habitats is often limited by various biotic and physical factors or interactions between\\u000a the two. Invasive ants, frequently associated with human activities, flourish in disturbed urban and agricultural environments.\\u000a However, their ability to invade and establish in natural habitats is more variable. This is particularly so for the invasive\\u000a Argentine ant (Linepithema humile).

Alexei D. Rowles; Jules Silverman

2009-01-01

486

Comparative Biology of Fungus Cultivation in Termites and Ants  

Microsoft Academic Search

\\u000a We review the two known mutualistic symbioses between basidiomycete fungi and social insects: the attine ants and macrotermitine\\u000a termites, comparing their origin, history and patterns of co-evolution, and stability. It is argued that ants are “specialised\\u000a farmers of unspecialised crops”, whereas termites are “specialised farmers of specialised crops”. Furthermore, despite differences\\u000a in symmetry and symbiont transmission mode, in both relationships

Tânia Nobre; Corinne Rouland-Lefèvre; Duur K. Aanen

487

The ecological role of ants in two Mexican agroecosystems  

Microsoft Academic Search

The development of the ant communities and their foraging dynamics were studied in two annual agroecosystems of the Mexican tropical lowlands: a “forest milpa” of corn, beans, and squash made by cutting and buring 40-year-old forest, and a “field milpa” of corn, beans, and squash made by plowing 1-year-old second growth. The ant community was sampled using tuna fish baits

Stephen J. Risch; C. Ronald Carroll

1982-01-01

488

Exocrine chemistry of the myrmicine ant Zacryptocerus pusillus (Hymenoptera: Formicidae).  

PubMed

Minor workers of the ant Zacryptocerus pusillus have unusual exocrine secretions in both their mandibular and Dufour glands. The mandibular glands contain a 3:1 mixture of 4-heptanone and 4-heptanol, a mixture found only in the related species Z. varians. The Dufour gland contains a mixture of 13 aldehydes from C9 to C18, not previously encountered in ant secretions. The venom glands gave variable results with only nonanal present consistently. PMID:16921517

Morgan, E David; Keegans, Sarah J; Billen, Johan

2006-09-01

489

Remarks of Elliptic Curves Derived from Ant Colony Routing  

NASA Astrophysics Data System (ADS)

We deal with an ant colony based routing model for wireless multi-hop networks. Our model adopts an elliptic curve equation, which is beneficial to design pheromone dynamics for load balancing and packet delivery robustness. Due to the attribute of an elliptic curve equation, our model prevents the over-utilization of a specific node, distinctively from conventional ant colony based schemes. Numerical simulations exhibit the characteristics of our model with respect to various parameters.

Jung, Sangsu; Kim, Daeyeoul; Singh, Dhananjay

2011-09-01

490

Improved ant colony algorithm and its simulation study  

NASA Astrophysics Data System (ADS)

Ant colony algorithm is development a new heuristic algorithm through simulation ant foraging. For its convergence rate slow, easy to fall into local optimal solution proposed for the adjustment of key parameters, pheromone update to improve the way and through the issue of TSP experiments, results showed that the improved algorithm has better overall search capabilities and demonstrated the feasibility and effectiveness of this method.

Wang, Zongjiang

2013-03-01

491

[Control of the Pharaoh's ant with borax bait formulations].  

PubMed

Results are given for the experimental control of Pharaoh ants, Monomorium pharaonis L., with persistent borax baits in the laboratory and the field. DYBH-bait formulations with about 17 per cent borax are very attractive and have a good effectivity. In 5 different objects infested with this ant eradication was proved to be possible with this experimental formulations. The progress of eradication depends essentially on the good organisational preparation of control measures. PMID:2095049

Klunker, R; Scheurer, S; Neumann, T

1990-12-01

492

Searching behaviour of desert ants, genus Cataglyphis (Formicidae, Hymenoptera)  

Microsoft Academic Search

1.If a homing ant (Cataglyphis bicolor,C. albicans) gets lost, it does not perform a random walk but adopts a stereotyped search strategy. During its search the ant performs a number of loops of ever-increasing size, starting and ending at the origin and pointing at different azimuthal directions. This strategy ensures that the centre area where the nest is most likely

Rfidiger Wehner; Mandyam V. Srinivasan

1981-01-01

493

Waste management in the leaf-cutting ant Atta colombica  

Microsoft Academic Search

Unlike most leaf-cutting ants, which have underground waste dumps, the leaf-cutting ant Atta colombica dumps waste in a heap outside the nest. Waste is hazardous, as it is contaminated with pathogens. We investigated the organization of the workforce involved in outside-nest tasks (foraging, waste disposal) and quantified task switching and heap location to test hypotheses that these tasks are organized

Adam G. Hart; Francis L. W. Ratnieks

2002-01-01

494

Adapting an Ant Colony Metaphor for Multi-Robot Chemical Plume Tracing  

PubMed Central

We consider chemical plume tracing (CPT) in time-varying airflow environments using multiple mobile robots. The purpose of CPT is to approach a gas source with a previously unknown location in a given area. Therefore, the CPT could be considered as a dynamic optimization problem in continuous domains. The traditional ant colony optimization (ACO) algorithm has been successfully used for combinatorial optimization problems in discrete domains. To adapt the ant colony metaphor to the multi-robot CPT problem, the two-dimension continuous search area is discretized into grids and the virtual pheromone is updated according to both the gas concentration and wind information. To prevent the adapted ACO algorithm from being prematurely trapped in a local optimum, the upwind surge behavior is adopted by the robots with relatively higher gas concentration in order to explore more areas. The spiral surge (SS) algorithm is also examined for comparison. Experimental results using multiple real robots in two indoor natural ventilated airflow environments show that the proposed CPT method performs better than the SS algorithm. The simulation results for large-scale advection-diffusion plume environments show that the proposed method could also work in outdoor meandering plume environments. PMID:22666056

Meng, Qing-Hao; Yang, Wei-Xing; Wang, Yang; Li, Fei; Zeng, Ming

2012-01-01

495

Water stress strengthens mutualism among ants, trees, and scale insects.  

PubMed

Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism. PMID:24223521

Pringle, Elizabeth G; Akçay, Erol; Raab, Ted K; Dirzo, Rodolfo; Gordon, Deborah M

2013-11-01

496

Trail Pheromone Disruption of Argentine Ant Trail Formation and Foraging  

USGS Publications Warehouse

Trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. Argentine ant trail pheromone, (Z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against Argentine ant populations in 400 m2 field plots in Hawai'i Volcanoes National Park. A widely dispersed point source strategy for trail pheromone disruption was used. Traffic rates of ants in bioassays of treated filter paper, protected from rainfall and sunlight, indicated the presence of behaviorally significant quantities of pheromone being released from the formulation for up to 59 days. The proportion of plots, under trade wind conditions (2-3 m s-1), with visible trails was reduced for up to 14 days following treatment, and the number of foraging ants at randomly placed tuna-bait cards was similarly reduced. The success of these trail pheromone disruption trials in a natural ecosystem highlights the potential of this method for control of invasive ant species in this and other environments. ?? Springer Science+Business Media, LLC 2010.

Suckling, D.M.; Peck, R.W.; Stringer, L.D.; Snook, K.; Banko, P.C.

2010-01-01

497

Social prophylaxis through distant corpse removal in ants  

NASA Astrophysics Data System (ADS)

Living in groups raises important issues concerning waste management and related sanitary risks. Social insects such as ants live at high densities with genetically related individuals within confined and humid nests, all these factors being highly favorable for the spread of pathogens. Therefore, in addition to individual immunity, a social prophylaxis takes place, namely, by the removal of risky items such as corpses and their rejection at a distance from the ant nest. In this study, we investigate how Myrmica rubra workers manage to reduce encounters between potentially hazardous corpses and nestmates. Using both field and laboratory experiments, we describe how the spatial distribution and the removal distance of waste items vary as a function of their associated sanitary risks (inert item vs. corpse). In the field, corpse-carrying ants walked in a rather linear way away from the nest entrance and had an equal probability of choosing any direction. Therefore, they did not aggregate corpses in dedicated areas but scattered them in the environment. In both field and laboratory experiments, ants carrying corpses dropped their load in more remote—and less frequented—areas than workers carrying inert items. However, for equidistant areas, ants did not avoid dropping corpses at a location where they perceived area marking as a cue of high occupancy level by nestmates. Our results suggest that ants use distance to the nest rather than other occupancy cues to limit sanitary risks associated with dead nestmates.

Diez, Lise; Deneubourg, Jean-Louis; Detrain, Claire

2012-10-01

498

Ant colonies prefer infected over uninfected nest sites.  

PubMed

During colony relocation, the selection of a new nest involves exploration and assessment of potential sites followed by colony movement on the basis of a collective decision making process. Hygiene and pathogen load of the potential nest sites are factors worker scouts might evaluate, given the high risk of epidemics in group-living animals. Choosing nest sites free of pathogens is hypothesized to be highly efficient in invasive ants as each of their introduced populations is often an open network of nests exchanging individuals (unicolonial) with frequent relocation into new nest sites and low genetic diversity, likely making these species particularly vulnerable to parasites and diseases. We investigated the nest site preference of the invasive pharaoh ant, Monomorium pharaonis, through binary choice tests between three nest types: nests containing dead nestmates overgrown with sporulating mycelium of the entomopathogenic fungus Metarhizium brunneum (infected nests), nests containing nestmates killed by freezing (uninfected nests), and empty nests. In contrast to the expectation pharaoh ant colonies preferentially (84%) moved into the infected nest when presented with the choice of an infected and an uninfected nest. The ants had an intermediate preference for empty nests. Pharaoh ants display an overall preference for infected nests during colony relocation. While we cannot rule out that the ants are actually manipulated by the pathogen, we propose that this preference might be an adaptive strategy by the host to "immunize" the colony against future exposure to the same pathogenic fungus. PMID:25372856

Pontieri, Luigi; Vojvodic, Svjetlana; Graham, Riley; Pedersen, Jes Søe; Linksvayer, Timothy A

2014-01-01

499

Metabolism and the rise of fungus cultivation by ants.  

PubMed

Most ant colonies are comprised of workers that cooperate to harvest resources and feed developing larvae. Around 50 million years ago (MYA), ants of the attine lineage adopted an alternative strategy, harvesting resources used as compost to produce fungal gardens. While fungus cultivation is considered a major breakthrough in ant evolution, the associated ecological consequences remain poorly understood. Here, we compare the energetics of attine colony-farms and ancestral hunter-gatherer colonies using metabolic scaling principles within a phylogenetic context. We find two major energetic transitions. First, the earliest lower-attine farmers transitioned to lower mass-specific metabolic rates while shifting significant fractions of biomass from ant tissue to fungus gardens. Second, a transition 20 MYA to specialized cultivars in the higher-attine clade was associated with increased colony metabolism (without changes in garden fungal content) and with metabolic scaling nearly identical to hypometry observed in hunter-gatherer ants, although only the hunter-gatherer slope was distinguishable from isometry. Based on these evolutionary transitions, we propose that shifting living-tissue storage from ants to fungal mutualists provided energetic storage advantages contributing to attine diversification and outline critical assumptions that, when tested, will help link metabolism, farming efficiency, and colony fitness. PMID:25141145

Shik, Jonathan Z; Santos, Juan C; Seal, Jon N; Kay, Adam; Mueller, Ulrich G; Kaspari, Michael

2014-09-01

500

Ant Colonies Prefer Infected over Uninfected Nest Sites  

PubMed Central

During colony relocation, the selection of a new nest involves exploration and assessment of potential sites followed by colony movement on the basis of a collective decision making process. Hygiene and pathogen load of the potential nest sites are factors worker scouts might evaluate, given the high risk of epidemics in group-living animals. Choosing nest sites free of pathogens is hypothesized to be highly efficient in invasive ants as each of their introduced populations is often an open network of nests exchanging individuals (unicolonial) with frequent relocation into new nest sites and low genetic diversity, likely making these species particularly vulnerable to parasites and diseases. We investigated the nest site preference of the invasive pharaoh ant, Monomorium pharaonis, through binary choice tests between three nest types: nests containing dead nestmates overgrown with sporulating mycelium of the entomopathogenic fungus Metarhizium brunneum (infected nests), nests containing nestmates killed by freezing (uninfected nests), and empty nests. In contrast to the expectation pharaoh ant colonies preferentially (84%) moved into the infected nest when presented with the choice of an infected and an uninfected nest. The ants had an intermediate preference for empty nests. Pharaoh ants display an overall preference for infected nests during colony relocation. While we cannot rule out that the ants are actually manipulated by the pathogen, we propose that this preference might be an adaptive strategy by the host to “immunize” the colony against future exposure to the same pathogenic fungus. PMID:25372856

Pontieri, Luigi; Vojvodic, Svjetlana; Graham, Riley; Pedersen, Jes Søe; Linksvayer, Timothy A.

2014-01-01