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1

Muir-Torre Syndrome  

MedlinePLUS

... Editorial Board , 11/2013 Overview What is Muir-Torre syndrome? Muir-Torre syndrome is a form of ... his or her medical care. What causes Muir-Torre syndrome? Muir-Torre syndrome is a genetic condition. ...

2

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....

3

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.

4

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,...

5

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.

6

Ant Colony Optimisation for Machine Layout Problems  

Microsoft Academic Search

Flexible machine layout problems describe the dynamic arrangement of machines to optimise the trade-off between material handling and rearrangement costs under changing and uncertain production environments. A previous study used integer-programming techniques to solve heuristically reduced versions of the problem. As an alternative, this paper introduces an ant colony optimisation (ACO) algorithm to generate good solutions. Experimental results are presented,

Paul Corry; Erhan Kozan

2004-01-01

7

Parallel Ant Colonies for the quadratic assignment problem  

Microsoft Academic Search

Ant Colonies optimization take inspiration from the behavior of real ant colonies to solve optimization problems. This paper presents a parallel model for ant colonies to solve the quadratic assignment problem (QAP). The cooperation between simulated ants is provided by a pheromone matrix that plays the role of a global memory. The exploration of the search space is guided by

El-ghazali Talbi; Olivier H. Roux; Cyril Fonlupt; Denis Robillard

2001-01-01

8

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

9

Reply to James Muir  

ERIC Educational Resources Information Center

In "EPAT", vol. 36, no. 1, 2004, James Muir takes the author and fellow philosophers of education to task for their ignorance of the history of philosophy of education. "[T]oo many currently influential educationists, Professor White in particular, are literally unaware that educational philosophy has a history more than three hundred years in…

White, John

2004-01-01

10

JOHN MUIR WILDERNESS, CALIFORNIA.  

USGS Publications Warehouse

The mineral survey of the John Muir Wilderness, California revealed eight areas of probable and substantiated potential for the occurrence of mineral resources. Tungsten, with accompanying resources of gold, copper, silver, and molybdenum, is found along contacts between granitic rocks and metamorphosed calcareous sedimentary rocks; it is estimated that more than 1 million tons of demonstrated tungsten resources exist in areas of sustantiated resource potential within the wilderness. Resources of gold, silver, lead, copper, zinc, molydenum, and cobalt, occur in small deposits not associated with tungsten; however, the known deposits of these commodities are small and the possibility of the occurrence of larger ones is unlikely. The geologic setting precludes the presence of fossil fuel resources.

Dellinger, David, A.; Johnson, Frederick, L.

1984-01-01

11

Ant Colony algorithm for routing problem using rule-mining  

Microsoft Academic Search

The proposed work presented a modified MAX-MIN Ant System (MMAS) algorithm to solve the routing problem, in which known demand are supplied from a store house with parallel routes for new local search. Routing Problem is an optimization problem and solved to nearly optimum by heuristics. The objective of routing issues is to use a fleet of vehicles with specified

K. Sankar; K. Krishnamoorthy

2010-01-01

12

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.

Science, Lawrence H.

1980-01-01

13

Glacial Geology of Muir Inlet, Southeast Alaska.  

National Technical Information Service (NTIS)

Muir Inlet is in the northeast part of Glacier Bay National Monument in Southeastern Alaska, about 135 kilometers northeast of Juneau. Muir Inlet is part of a large dendritic glacial valley system that has three tidal glaciers. It is flanked on the east, ...

G. M. Haselton

1966-01-01

14

Ant colony optimization for solving university facility layout problem  

NASA Astrophysics Data System (ADS)

Quadratic Assignment Problems (QAP) is classified as the NP hard problem. It has been used to model a lot of problem in several areas such as operational research, combinatorial data analysis and also parallel and distributed computing, optimization problem such as graph portioning and Travel Salesman Problem (TSP). In the literature, researcher use exact algorithm, heuristics algorithm and metaheuristic approaches to solve QAP problem. QAP is largely applied in facility layout problem (FLP). In this paper we used QAP to model university facility layout problem. There are 8 facilities that need to be assigned to 8 locations. Hence we have modeled a QAP problem with n <= 10 and developed an Ant Colony Optimization (ACO) algorithm to solve the university facility layout problem. The objective is to assign n facilities to n locations such that the minimum product of flows and distances is obtained. Flow is the movement from one to another facility, whereas distance is the distance between one locations of a facility to other facilities locations. The objective of the QAP is to obtain minimum total walking (flow) of lecturers from one destination to another (distance).

Mohd Jani, Nurul Hafiza; Mohd Radzi, Nor Haizan; Ngadiman, Mohd Salihin

2013-04-01

15

A Modified Max-Min Ant System for Vehicle Routing Problems  

Microsoft Academic Search

The vehicle routing problem (VRP) is an important problem occurring in many distribution systems, which is also defined as a family of different versions such as the capacitated vehicle routing problem (CVRP) and the vehicle routing problem with time windows (VRPTW). The ant colony optimization (ACO) is a metaheuristic for combinatorial optimization problems, and the max-min ant system (MMAS) is

Gang Zhao; Wenjuan Luo; Ruoying Sun; Chunhua Yin

2008-01-01

16

Incremental Local Search in Ant Colony Optimization: Why It Fails for the Quadratic Assignment Problem  

Microsoft Academic Search

Ant colony optimization algorithms are currently among the best performing algorithms for the quadratic assignment problem. These algorithms contain two main search procedures: solution construction by articial ants and local search to improve the solutions constructed by the ants. Incremental local search is an approach that consists in re- optimizing partial solutions by a local search algorithm at regular inter-

Prasanna Balaprakash; Mauro Birattari; Thomas Stützle; Marco Dorigo

2006-01-01

17

Solution to 0\\/1 Knapsack Problem Based on Improved Ant Colony Algorithm  

Microsoft Academic Search

Ant colony algorithms analogize the social behaviour of ant colonies, they are a class of meta-heuristics which are inspired from the behavior of real ants. It was applied successfully to the well-known traveling salesman problem and other hard combinational optimization problems. In order to apply it to the classical 0\\/1 knapsack problem, this paper compares the difference between the traveling

Hanxiao Shi

2006-01-01

18

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

19

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...

20

Historic Furnishings Report: Strentzel-Muir House. John Muir National Historic Site, Martinez, CA.  

National Technical Information Service (NTIS)

Dr. John T. Strentzel and his wife, Louisiana Erwin Strentzel, moved to Martinez, California, in 1853. Dr. Strentzel practiced medicine, grew fruit commercially, and made wine. The Strentzels only daughter, Louisiana, married John Muir in 1880 and they al...

M. Grassick

2006-01-01

21

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

22

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

23

Ant Colony Optimization for the Single Vehicle Pickup and Delivery Problem with Time Window  

Microsoft Academic Search

The single vehicle pickup and delivery problem with time window (1-PDPTW) is an important class of vehicle routing problem. This problem aims to find a shortest route for a single vehicle to deliver objects from origin to destination, subject to load limit and time window of delivery. This study develops an ant colony optimization (ACO) method for the 1-PDPTW. Specifically,

Yu-Hsuan Huang; Chuan-Kang Ting

2010-01-01

24

Ant-CSP: An Ant Colony Optimization Algorithm for the Closest String Problem  

Microsoft Academic Search

Algorithms for sequence analysis are of central importance in computational molecular biology and coding theory. A very interesting\\u000a problem in this field is the Closest String Problem (CSP) which consists in finding a string t with minimum Hamming distance from all strings in a given finite set. To overcome the NP-hardness of the CSP problem, we\\u000a propose a new algorithm,

Simone Faro; Elisa Pappalardo

2010-01-01

25

36 CFR 7.6 - Muir Woods National Monument.  

Code of Federal Regulations, 2010 CFR

...Public Property 1 2010-07-01 2010-07-01 false Muir Woods National Monument. 7.6 Section 7.6 Parks...SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.6 Muir Woods National Monument. (a) Fires. Fires are...

2010-07-01

26

36 CFR 7.6 - Muir Woods National Monument.  

Code of Federal Regulations, 2010 CFR

...Public Property 1 2009-07-01 2009-07-01 false Muir Woods National Monument. 7.6 Section 7.6 Parks...SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.6 Muir Woods National Monument. (a) Fires. Fires are...

2009-07-01

27

Muir Glacier in Glacier Bay National Monument 1950  

USGS Multimedia Gallery

This August 1950 photo documents the significant changes that occurred during the 9 years between photographs A and B. Muir Glacier has retreated more than 2 miles, exposing Muir Inlet, and thinned 340 feet or more. However, it still is connected with tributary Riggs Glacier....

28

36 CFR 7.6 - Muir Woods National Monument.  

Code of Federal Regulations, 2013 CFR

...Property 1 2013-07-01 2013-07-01 false Muir Woods National Monument. 7.6 Section 7.6 Parks, Forests...REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.6 Muir Woods National Monument. (a) Fires. Fires are prohibited...

2013-07-01

29

Ant Colony Optimization Algorithms with Local Search for the Dynamic Vehicle Routing Problem  

Microsoft Academic Search

Abstract This report demonstrates the use of eective,local search to im- prove the performance of simple Ant Colony Optimization (ACO) algorithms as applied to an extension of the Vehicle Routing Problem (VRP) known as the Dynamic Vehicle Routing Problem (DVRP). The static VRP presents all orders a priori, however the DVRP requires scheduling to begin without a complete knowledge of

Andrew Runka

30

Ant colony algorithm for the shortest loop design problem  

Microsoft Academic Search

In this paper, a new algorithm for solving the shortest loop design problem is presented. The shortest loop design problem is to find the shortest loop for an automated guided vehicle covering at least one edge of each department of a block layout. In this paper, first it is shown that this problem can be represented as a graph model.

Kourosh Eshghi; Morteza Kazemi

2006-01-01

31

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

32

An immunity-based ant colony optimization algorithm for solving weapon-target assignment problem  

Microsoft Academic Search

In this paper, an immunity-based ant colony optimization (ACO) algorithm for solving weapon–target assignment (WTA) problems is proposed. The WTA problem, known as a NP-complete problem, is to find a proper assignment of weapons to targets with the objective of minimizing the expected damage of own-force assets. The general idea of the proposed algorithm is to combine the advantages of

Zne-jung Lee; Chou-yuan Lee; Shun-feng Su

2002-01-01

33

Hybrid ant systems for the dynamic facility layout problem  

Microsoft Academic Search

Today's consumer market demands that manufacturers must be competitive. This requires the efficient operation of manufacturing plants and their ability to quickly respond to changes in product mix and demand. In addition, studies show that material-handling cost make up between 20 and 50 percent of the total operating cost. Therefore, this paper considers the problem of arranging and rearranging, when

Alan R. McKendall Jr.; Jin Shang

2006-01-01

34

ANALYZING A VEHICLE ROUTING PROBLEM WITH STOCHASTIC DEMANDS USING ANT COLONY OPTIMIZATION  

Microsoft Academic Search

In this paper the classical Vehicle Routing Problem (VRP) is extended to cover the more realistic case of uncertainty about customer demands. This case is modelled as a VRP with stochastic demands and tackled with a heuristic solution approach based on Ant Colony Optimization (ACO). The main issues studied in this paper are the modelling of the uncertainty (i) in

Marc REIMANN

35

An improved ant colony optimization algorithm for the vehicle routing problems with time windows  

Microsoft Academic Search

This paper presents an improved scheme for the vehicle routing problems with time windows based on ant colony optimization algorithm. The new scheme makes the change of heuristic message fast and speeds the convergence process by improving updating method of global pheromone and visibility strategy. Simulation results from eight groups of vehicle transportation case show that the new scheme performs

Bi Wang; Hewei Yu

2010-01-01

36

Boundary Search for Constrained Numerical Optimization Problems With an Algorithm Inspired by the Ant Colony Metaphor  

Microsoft Academic Search

This paper presents a novel boundary approach that is included as a constraint-handling technique in an algorithm inspired by the ant colony metaphor. The necessity of approaching the boundary between the feasible and infeasible search space for many constrained optimization problems is a paramount challenge for every constraint-handling technique. Our proposed technique precisely focuses the search on the boundary region

Guillermo Leguizamon; Carlos Artemio Coello Coello

2009-01-01

37

Community Wind Electrical Power Case Study: Muir Beach. Final Report.  

National Technical Information Service (NTIS)

Muir Beach experiences relatively steady northwest coastal winds. Recordings at anemometer stations have indicated wind speeds averaging 10 to 12 mph over the year. This compares favorably with the minimum of 8 to 9 mph generally considered necessary for ...

R. Bluhm R. Freebairn-Smith

1979-01-01

38

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

39

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

40

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

41

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

42

The Muir-Torre syndrome: A 25-year retrospect  

Microsoft Academic Search

The Torre or Muir-Torre syndrome consists of certain types of sebaceous neoplasms of the skin, with or without keratoacanthomas, and one or more low-grade visceral malignancies in the absence of other predisposing factors. The sebaceous tumors are relatively uncommon or rare: sebaceous adenoma, sebaceous epithelioma, basal cell epithelioma with sebaceous differentiation, and sebaceous carcinoma. Sebaceous hyperplasia and hamartomas such as

Robert A Schwartz; Douglas P Torre

1995-01-01

43

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

44

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

45

An Application of the Ant Colony System Metaheuristic to the Vehicle Routing Problem with Pickup and Delivery and Time Windows  

Microsoft Academic Search

In this paper, it is presented a methodology for solving the Vehicle Routing Problem with Pickup and Delivery and Time Windows (VRPPDTW). The proposed methodology can be divided in two phases, i.e, the construction phase and the refinement phase. In the construction phase, the generation of an initial solution is made through Ant Colony Optimization (ACO) meta-heuristic with the elitism

Eduardo Goecking Carabetti; S. R. de Souza; M. C. P. Fraga; P. H. A. Gama

2010-01-01

46

Gallipoli: Personal Records of War. The Gallipoli Diary of Archie Muir [and] Teacher's Guide.  

ERIC Educational Resources Information Center

This document is a compilation of materials for teaching about Australian involvement in the First World War, with a specific focus on the battle of Gallipoli (Turkey) in which several thousand Australian soldiers were killed. The materials include "The Gallipoli Diary of Archie Muir" and thirty photographs of Matthew Brown (Muir and Brown were…

Tasmanian Education Dept., Hobart (Australia).

47

Interlaminated ice-proximal glacimarine sediments in Muir Inlet, Alaska  

USGS Publications Warehouse

Muir Inlet in Glacier Bay, Alaska, is a glacial fjord receiving a tremendous volume of sediment annually. The rate of sediment accumulation is greatest proximal to Muir Glacier (about 9 m yr-1) and decreases away from the glacier. The primary sediment sources are meltwater streams discharging at subglacial and ice-marginal positions to form overflows, interflows, and underflows (continuous turbidity currents). Overflows and interflows interact with diurnal tidal currents and their volume and sediment concentration varies diurnally and annually with meltwater discharge. These effects produce cyclic deposits of a thin fine-grained sand or silt lamina that grades normally to a thicker poorly to very poorly sorted mud lamina. This lamina couplet is termed a cyclopel. Underflows are suggested to occur in this glacimarine environment because of conditions unique to subglacial fluvial systems. Underflow deposits occur only in proximal positions (177 ??m) is ubiquitous, though low (<5% by weight), and occurs as isolated particles, frozen pellets, or as lenses that in cores may have a lamina appearance. Proximally, ice-rafted debris is difficult to identify because proximal sediment is often as coarse-grained. Deposited sediment may be reworked by tidal currents, and sediment gravity flows. Depositional processes operating in Muir Inlet produce interlaminated sand/silt/clay that characterizes sediment proximal to a glacier and fines seaward to mud. Sediment is classified into one of three sediment types: 1. (1) Type I sediment is very fine grained (mean 8.65-7.17 ??), low in sand (0.1-11.2%), and very poorly to poorly sorted. It is the dominant sediment type in Muir Inlet, and is transported by plumes and deposited by suspension settling. 2. (2) Type II sediment is fine- to coarse-grained (mean 6.70-3.12 ??), low to high in sand (5.1-86.6%), and very poorly to moderately sorted. It represents reworked sediment, proximal plume deposits, or coarse-grained laminae of cyclopels. 3. (3) Type III sediment is coarse-grained (mean 3.89-2.38 ??), high in sand (58.0-100.0%), and poorly to well sorted. It is deposited by sediment gravity flows or underflows. ?? 1984.

Mackiewicz, N. E.; Powell, R. D.; Carlson, P. R.; Molnia, B. F.

1984-01-01

48

Muir-Torre-like syndrome in Fhit-deficient mice  

PubMed Central

To investigate the role of the Fhit gene in carcinogen induction of neoplasia, we have inactivated one Fhit allele in mouse embryonic stem cells and produced (129/SvJ × C57BL/6J) F1 mice with a Fhit allele inactivated (+/?). Fhit +/+ and +/? mice were treated intragastrically with nitrosomethylbenzylamine and observed for 10 wk posttreatment. A total of 25% of the +/+ mice developed adenoma or papilloma of the forestomach, whereas 100% of the +/? mice developed multiple tumors that were a mixture of adenomas, squamous papillomas, invasive carcinomas of the forestomach, as well as tumors of sebaceous glands. The visceral and sebaceous tumors, which lacked Fhit protein, were similar to those characteristic of Muir–Torre familial cancer syndrome.

Fong, Louise Y. Y.; Fidanza, Vincenzo; Zanesi, Nicola; Lock, Leslie F.; Siracusa, Linda D.; Mancini, Rita; Siprashvili, Zurab; Ottey, Michelle; Martin, S. Eric; Druck, Teresa; McCue, Peter A.; Croce, Carlo M.; Huebner, Kay

2000-01-01

49

Cultural Landscape Report for John Muir National Historic Site. Volume 2: Treatment.  

National Technical Information Service (NTIS)

The Cultural Landscape Report (CLR) for the John Muir National Historic Site (NHS) includes a site history, existing conditions assessment, analysis of significance and integrity, and treatment recommendations to guide management of the park's cultural la...

J. Killion

2005-01-01

50

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

51

[Sebaceous gland tumor with a rare gene mutation within a tumor syndrome: Muir-Torre syndrome].  

PubMed

Muir-Torre syndrome is a rare autosomal dominant subtype of hereditary nonpolyposis colorectal carcinoma and is characterized by the simultaneous occurrence of sebaceous gland neoplasms with visceral and urogenital malignancies. This article describes the case of a 72-year-old patient who was referred to our clinic for removal of an upper eyelid tumor, showing the course from the clinical findings to the rare diagnosis of Muir-Torre syndrome. PMID:23774967

Voigt, E; Sommer, F; Geiger, K D; Pillunat, L E

2014-04-01

52

Ant colony optimization and local search for bin packing and cutting stock problems  

Microsoft Academic Search

The Bin Packing Problem and the Cutting Stock Problem are two related classes of NP-hard combinatorial optimization problems. Exact solution methods can only be used for very small instances, so for real-world problems, we have to rely on heuristic methods. In recent years, researchers have started to apply evolutionary approaches to these problems, including Genetic Algorithms and Evolutionary Programming. In

J Levine; F Ducatelle

2004-01-01

53

Ant colony optimization algorithm to solve split delivery vehicle routing problem  

Microsoft Academic Search

As a combinatorial optimization problem, vehicle routing problem (VRP) is a typical NP-hard problem; an assumption that the demand of customers can not be split is given to the traditional VRP formulation. However, the transportation cost can be reduced by means of splitting the demand of customers in practical logistics operation. This paper solved the split delivery vehicle routing problem

Lu-si Sui; Jia-fu Tang; Zhendong Pan; Shu-an Liu

2008-01-01

54

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

55

An Ant Colony Optimization Approach to Solve Cooperative Transportation Planning Problems  

Microsoft Academic Search

In this paper, we suggest efficient heuristics to solve a cooperative transportation planning problem that is motivated by a scenario found in the German food industry. After an appropriate decomposition of the entire problem into sub problems, we obtain a set of rich vehicle routing problems (VRP) including due dates for the delivery of the orders, capacity constraints and maximum

Ralf Sprenger; Lars Mönch

2009-01-01

56

An Improved Ant Colony Algorithm for the Time-Dependent Vehicle Routing Problem  

Microsoft Academic Search

Vehicle routing problem is an important combinatorial optimization problem. It has an important position in logistics optimization and supply chain management theory. Due to traffic flow, traffic incidents and other factors, the travel speed and travel time of road has large time-variability and randomness in real transport network. The study of vehicle routing problem in time-dependent network has even more

Liu Yongqiang; Chang Qing; Xiong Huagang

2010-01-01

57

Odorant binding proteins of the red imported fire ant, Solenopsis invicta: an example of the problems facing the analysis of widely divergent proteins.  

PubMed

We describe the odorant binding proteins (OBPs) of the red imported fire ant, Solenopsis invicta, obtained from analyses of an EST library and separate 454 sequencing runs of two normalized cDNA libraries. We identified a total of 18 putative functional OBPs in this ant. A third of the fire ant OBPs are orthologs to honey bee OBPs. Another third of the OBPs belong to a lineage-specific expansion, which is a common feature of insect OBP evolution. Like other OBPs, the different fire ant OBPs share little sequence similarity (? 20%), rendering evolutionary analyses difficult. We discuss the resulting problems with sequence alignment, phylogenetic analysis, and tests of selection. As previously suggested, our results underscore the importance for careful exploration of the sensitivity to the effects of alignment methods for data comprising widely divergent sequences. PMID:21305009

Gotzek, Dietrich; Robertson, Hugh M; Wurm, Yannick; Shoemaker, DeWayne

2011-01-01

58

Marine Benthic Habitat Mapping of Muir Inlet, Glacier Bay National Park and Preserve, Alaska with an Evaluation of the Coastal and Marine Ecological Clissification Standard III.  

National Technical Information Service (NTIS)

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 ...

G. R. Cochran L. A. Mayer L. D. Trusel L. L. Etherington R. D. Powell

2010-01-01

59

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

60

An Ant based Simulation Optimization for Vehicle Routing Problem with Stochastic Demands  

Microsoft Academic Search

The Vehicle Routing Problem (VRP) is of considerable economic significance in logistic systems as it manages the distribu- tion of goods to make an efficient transportation system. Considering a practical application, this paper solves a vehicle routing problem with stochastic demand (VRPSD) in which the customer demand has been modeled as a stochastic variable as opposed to conventional VRP. To

Mukul Tripathi; Glenn Kuriger; Hung-da Wan

2009-01-01

61

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.

62

An ant colony optimisation algorithm for the 2D and 3D hydrophobic polar protein folding problem  

PubMed Central

Background The protein folding problem is a fundamental problems in computational molecular biology and biochemical physics. Various optimisation methods have been applied to formulations of the ab-initio folding problem that are based on reduced models of protein structure, including Monte Carlo methods, Evolutionary Algorithms, Tabu Search and hybrid approaches. In our work, we have introduced an ant colony optimisation (ACO) algorithm to address the non-deterministic polynomial-time hard (NP-hard) combinatorial problem of predicting a protein's conformation from its amino acid sequence under a widely studied, conceptually simple model – the 2-dimensional (2D) and 3-dimensional (3D) hydrophobic-polar (HP) model. Results We present an improvement of our previous ACO algorithm for the 2D HP model and its extension to the 3D HP model. We show that this new algorithm, dubbed ACO-HPPFP-3, performs better than previous state-of-the-art algorithms on sequences whose native conformations do not contain structural nuclei (parts of the native fold that predominantly consist of local interactions) at the ends, but rather in the middle of the sequence, and that it generally finds a more diverse set of native conformations. Conclusions The application of ACO to this bioinformatics problem compares favourably with specialised, state-of-the-art methods for the 2D and 3D HP protein folding problem; our empirical results indicate that our rather simple ACO algorithm scales worse with sequence length but usually finds a more diverse ensemble of native states. Therefore the development of ACO algorithms for more complex and realistic models of protein structure holds significant promise.

Shmygelska, Alena; Hoos, Holger H

2005-01-01

63

An ant colony algorithm for solving budget constrained and unconstrained dynamic facility layout problems  

Microsoft Academic Search

The main characteristic of today's manufacturing environments is volatility. Under a volatile environment, demand is not stable. It changes from one production period to another. To operate efficiently under such environments, the facilities must be adaptive to changing production requirements. From a layout point of view, this situation requires the solution of the dynamic layout problem (DLP). DLP is a

Adil Baykasoglu; Turkay Dereli; Ibrahim Sabuncu

2006-01-01

64

A Method for Solving Optimization Problems in Continuous Space Using Ant Colony Algorithm  

Microsoft Academic Search

We state our algorithm using the nonlinear programming (NLP) problem, objective function G is a given non-linear function.\\u000a Constraint conditions that represented by a set of inequalities form a convex domain of R\\u000a n. We can obtain the minimal n-d hypercube that can be defined as the following inequalities: l\\u000a i?x\\u000a i?U\\u000a i (I = 1, 2, …, n). Let

Ling Chen; Jie Sheng; Ling Qin; Hongjian Chen

2002-01-01

65

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

66

Small Mammal Survey at Big Lagoon, Muir Beach, Marin County, CA.  

National Technical Information Service (NTIS)

Big Lagoon at Muir Beach, in Marin County, California is part of the Golden Gate National Recreation Area (GGNRA) and is a popular destination for park visitors, receiving approximately 440,000 visitors annually. Today, Big Lagoon consists of fragmented h...

J. Y. Takekawa M. A. Bias I. Woo S. A. Demers E. E. Boydston

2003-01-01

67

Historic Resource Study for Muir Woods National Monument. Golden Gate National Recreation Area.  

National Technical Information Service (NTIS)

Since first being widely discovered by hikers and tourists in the late nineteenth century, Muir Woods National Monument has become renowned across the country and beyond for its old-growth forest of coast redwoods, Sequoia sempervirens, located in the mid...

2007-01-01

68

Muir-Torre syndrome-is it really a new syndrome?  

PubMed

E.G. Muir and D. Torre independently described widespread cutaneous changes associated with internal malignancy, which are presently known as the Muir-Torre syndrome. This syndrome is defined as the coexistence of sebaceous adenomas, sebaceus carcinomas, keratoacanthomas, and pedunculated tumors, some with lobulated structure. The cutaneous involvement (sebaceous gland tumor) is associated with at least a single internal malignancy; mostly colonorectal or genitourinary malignancies. The syndrome is believed to be very rare, but some cases seem to have been unrecognized or misdiagnosed. It is inherited as an autosomal dominant trait with a variable degree of penetrance. Although Muir and Torre described this syndrome in 1967/1968, we found a report on a very similar case as described by C. Hilton Fagge from Guy Hospital in London, which was published 100 years earlier. In this case, there were very abundant small tumors, some pedunculated, and some deeper ones, with a finely lobulated structure, containing "a hair follicle or the external dermal coat of the follicle." The lobulated structures developed from the sebaceous glands, which were larger than normal, and surrounded by abundant fibrous tissue. For this reason, these changes were described under the misleading name of Molluscum Fibrosum. The clinical description of this case, however, is excellent and enables the recognition of the Muir-Torre syndrome. PMID:19955878

Grzybowski, Andrzej; Jab?o?ska, Stefania

2009-12-01

69

Solving a time constrained two-crane routing problem for material handling with an ant colony optimisation approach: an application in the roof-tile industry  

Microsoft Academic Search

This paper presents an ant colony optimisation (ACO)-based solution approach for a real-world two-crane routing problem, where a number of different load carriers must be moved within a given cycle time by two gantry cranes in a continuous production process for roof tiles. The cranes have to transport the roof-tile batches and to return the load carriers and intermediate pads

Patrick Hirsch; Andreas Palfi; Manfred Gronalt

2012-01-01

70

Aspect angle dependency of the HF modification measured with MUIR at HAARP  

NASA Astrophysics Data System (ADS)

In this paper we present results of height-resolved observations of F-region Langmuir turbulence measured with MUIR (Modular UHF Ionospheric Radar; 446 MHz) at HAARP (High frequency Active Auroral Research Program) in Alaska, USA. The scientific objective of this paper is to study aspect angle dependency of the HF modification. The best way to achieve the objective is the simultaneous multi-position measurement with the incoherent- scatter (IS) radar. However, general IS radars take, at least, a few seconds to change the radar beam position. MUIR is the best diagnostic tool for this study because it can change the beam direction every IPP (interpulse period) with the phased array system. We conducted two experiments at HAARP; 26 March 2006 and 31 July 2007. For the March 2006 experiment, three MUIR beam positions were selected: geographical vertical, up B (elevation angle = 75 degree), and midway between the two (elevation angle = 82 degree). This experiment was arranged for studying the aspect angle dependency of Langmuir oscillations associated with low HF duty cycle (1%: on/off = 0.1s / 9.9s). The radar-backscatter spectra with 10-ms time resolution were deduced at individual radar-beam positions. For the July 2007 experiment, nine MUIR beam positions around the up B position were selected under relatively high HF duty cycle (50%: on/off = 3min/3min). The presentation will report aspect angle dependencies of (1) the Langmuir oscillation development in the first 100 ms after HF turn-on using data taken during the March 2006 experiment and (2) persistency of the Langmuir oscillation using data taken during the August 2007 experiment.

Oyama, S.; Watkins, B. J.

2007-12-01

71

Ant Colony System for JSP  

Microsoft Academic Search

\\u000a This paper discusses the application of ACS metaheuristics (based on behaviour of real ants: stigmergy and synergetic effect\\u000a among ants) for Job-Shop Scheduling problem (JSP). This algorithm is improved by introducing the concept of critical events,\\u000a in which two new techniques will be applied. Thus, a more flexible heuristic technique is obtained, which improves the performance\\u000a of ant colony system

Urszula Boryczka

2004-01-01

72

Anaphylaxis due to Red fire ant bite.  

PubMed

Ant allergy is a rare problem and most published reports are from outside India. We report a toddler who suffered from severe anaphylaxis reaction due to bite of Red fire ant (Solenopsis geminata). PMID:22484742

Havaldar, Parvat V; Patil, Shailesh S; Phadnis, Chandrashekhar

2012-03-01

73

A temporal ant colony optimization approach to the shortest path problem in dynamic scale-free networks  

NASA Astrophysics Data System (ADS)

A large number of networks in the real world have a scale-free structure, and the parameters of the networks change stochastically with time. Searching for the shortest paths in a scale-free dynamic and stochastic network is not only necessary for the estimation of the statistical characteristics such as the average shortest path length of the network, but also challenges the traditional concepts related to the “shortest path” of a network and the design of path searching strategies. In this paper, the concept of shortest path is defined on the basis of a scale-free dynamic and stochastic network model, and a temporal ant colony optimization (TACO) algorithm is proposed for searching for the shortest paths in the network. The convergence and the setup for some important parameters of the TACO algorithm are discussed through theoretical analysis and computer simulations, validating the effectiveness of the proposed algorithm.

Yu, Feng; Li, Yanjun; Wu, Tie-Jun

2010-02-01

74

Path Integration in Desert Ants, Cataglyphis fortis  

Microsoft Academic Search

Foraging desert ants, Cataglyphis fortis, continually keep track of their own positions relative to home--i.e., integrate their tortuous outbound routes and return home along straight (inbound) routes. By experimentally manipulating the ants' outbound trajectories we show that the ants solve this path integration problem not by performing a true vector summation (as a human navigator does) but by employing a

Martin Muller; Rudiger Wehner

1988-01-01

75

Influence on Retention of Changes in Background and Attitude of Muir College Freshmen, UCSD, between 1968 and 1984.  

ERIC Educational Resources Information Center

An examination of the results of two surveys of the attitudes of entering freshmen at Muir College, University of California at San Diego (UCSD) is presented. The surveys were conducted in 1968 and 1984 in conjunction with national surveys coordinated by the Cooperative Institutional Research Program. Information is presented on: (1) changes in…

Evans-Layng, Michael

76

An Efficient Ant Algorithm for Swarm-Based Image Clustering  

Microsoft Academic Search

A collective approach to resolve the segmentation problem was proposed. AntClust is a new ant-based algorithm that uses the self-organizing and autonomous brood sorting behavior observed in real ants. Ants and pixels are scatted on a discrete array of cells represented the ants' environment. Using simple local rules and without any central control, ants form homogeneous clusters by moving pixels

Salima Ouadfel; Mohamed Batouche

2007-01-01

77

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.

0002-11-30

78

Ant Database  

NSDL National Science Digital Library

Research entomologist Ted Schultz from the Smithsonian Institution maintains this impressive work in progress. This online database represents the Smithsonian's identified ant collection, including 4,580 valid named species or subspecies. The taxonomy is current with Bolton's 1995 catalog and includes reported holdings through June 1998. The database may be queried by Subfamily, Tribe, Genus, Subgenus, Species, Subspecies, Author, or Types, and typical returns give concise taxonomic information, total specimens (workers, females, and males), author, and year.

Schultz, Ted.

2000-01-01

79

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

80

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

81

The muir-torre syndrome: a rare variant of hereditary nonpolyposis colorectal cancer associated with hmsh2 mutation  

Microsoft Academic Search

The Muir-Torre syndrome is a rare autosomal dominant disorder characterized by the association of visceral malignancies with typical skin lesions. This syndrome is now considered a subtype of the more common hereditary nonpolyposis colorectal cancer syndrome (HNPCC). This last condition has been ascribed to mutations in four mismatch repair genes, and similar mutations, mostly located at hMSH2 gene, are now

Alexandra Suspiro; Paulo Fidalgo; Mar??lia Cravo; Cristina Albuquerque B. S; Eunice Ramalho B. S; C. Nobre Leitão; F. Costa Mira

1998-01-01

82

Fire Ant Bites  

MedlinePLUS

... Favorite Name: Category: Share: Yes No, Keep Private Fire Ant Bites Share | Fire ants are aggressive, venomous insects that have pinching ... across the United States, even into Puerto Rico. Fire ant stings usually occur on the feet or ...

83

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.

0002-11-30

84

Prevention of Fire Ant Damage to Signal Control.  

National Technical Information Service (NTIS)

The report addresses the problem of imported fire ants infesting traffic signal control cabinets. The study focused on developing and testing treatments for minimizing fire ant infestation of traffic signal cabinets. A treatment program based on annual ma...

W. P. MacKay S. O. Majdi S. B. Vinson C. J. Messer J. P. Irving

1989-01-01

85

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

86

A World of Ants.  

ERIC Educational Resources Information Center

Presents a discussion of interesting aspects of ants that was launched by the author's reading of "The Ants" by Holldobler and Wilson (1990). Describes how the study of the early history of ant taxonomy could be viewed as "entertaining." Their huge numbers and segregation into colonial social systems makes ants good research organisms. (PR)

Flannery, Maura C.

1992-01-01

87

Ant colony system with communication strategies  

Microsoft Academic Search

In this paper an ant colony system (ACS) with communication strategies is devel- oped. The artificial ants are partitioned into several groups. Seven communication methods for updating the pheromone level between groups in ACS are proposed and work on the traveling salesman problem using our system is presented. Experimental results based on three well-known traveling salesman data sets demonstrate the

Shu-chuan Chu; John F. Roddick; Jeng-shyang Pan

2004-01-01

88

Evaluation of conditions along the grounding line of temperate marine glaciers: An example from Muir Inlet, Glacier Bay, Alaska  

USGS Publications Warehouse

In the marine environment, stability of the glacier terminus and the location of subglacial streams are the dominant controls on the distribution of grounding-line deposits within morainal banks. A morainal bank complex in Muir Inlet, Glacier Bay, SE Alaska, is used to develop a model of terminus stability and location of subglacial streams along the grounding line of temperate marine glaciers. This model can be used to interpret former grounding-line conditions in other glacimarine settings from the facies architecture within morainal bank deposits. The Muir Inlet morainal bank complex was deposited between 1860 A.D. and 1899 A.D., and historical observations provide a record of terminus positions, glacial retreat rates and sedimentary sources. These data are used to reconstruct the depositional environment and to develop a correlation between sedimentary facies and conditions along the grounding line. Four seismic facies identified on the high-resolution seismic-reflection profiles are used to interpret sedimentary facies within the morainal bank complex. Terminus stability is interpreted from the distribution of sedimentary facies within three distinct submarine geomorphic features, a grounding-line fan; stratified ridges, and a field of push ridges. The grounding-line fan was deposited along a stable terminus and is represented on seismic-reflection profiles by two distinct seismic facies, a proximal and a distal fan facies. The proximal fan facies was deposited at the efflux of subglacial streams and indicates the location of former glacifluvial discharges into the sea. Stratified ridges formed as a result of the influence of a quasi-stable terminus on the distribution of sedimentary facies along the grounding line. A field of push ridges formed along the grounding line of an unstable terminus that completely reworked the grounding-line deposits through glacitectonic deformation. Between 1860 A.D. and 1899 A.D. (39 years), 8.96 x 108 m3 of sediment were deposited within the Muir Inlet morainal bank complex at an average annual sediment accumulation rate of 2.3 x 107 m3/a. This rate represents the annual sediment production capacity of the glacier when the Muir Inlet drainage basin is filled with glacial ice.

Seramur, K. C.; Powell, R. D.; Carlson, P. R.

1997-01-01

89

Sebaceous hyperplasia of the vulva: a series of cases reporting no association with the muir-torre syndrome.  

PubMed

Sebaceous gland hyperplasia is a common skin condition, very rarely reported in the female genital region. We present 13 cases from 12 patients, the first case series of sebaceous gland hyperplasia of the vulva. Differences in age at presentation and clinical presentation compared with classic sebaceous gland hyperplasia from the head and neck region were noted. Also, it was rarely included in the clinical differential diagnosis. Immunohistochemical studies to determine any possible association with the Muir-Torre syndrome were performed and mismatch repair protein loss was not identified. PMID:24901406

Roma, Andres A; Barry, Jessica; Pai, Rish K; Billings, Steven D

2014-07-01

90

Black (samsum) ant induced anaphylaxis in Saudi Arabia.  

PubMed

Ant allergy is a rare clinical problem that ranges from local to systemic reaction and life-threatening anaphylaxis. Different types of ants including the imported fire ants, the black (samsum) ants, and others, are considered health hazard in many parts of the world. We report a 32-year-old Saudi female from Hafr-Al-Batin in the Northern region of Saudi Arabia, with history of recurrent anaphylaxis following black (samsum) ant stings and we review the related literature. This is the first report of black (samsum) ant allergy in Saudi Arabia. PMID:17106560

Al-Shahwan, Mohammed; Al-Khenaizan, Sultan; Al-Khalifa, Mohammed

2006-11-01

91

Attenuated familial adenomatous polyposis and Muir-Torre syndrome linked to compound biallelic constitutional MYH gene mutations.  

PubMed

Attenuated familial adenomatous polyposis and Muir-Torre syndrome linked to compound biallelic constitutional MYH gene mutations.Peculiar dermatologic manifestations are present in several heritable gastrointestinal disorders. Muir-Torre syndrome (MTS) is a genodermatosis whose peculiar feature is the presence of sebaceous gland tumors associated with visceral malignancies. We describe one patient in whom multiple sebaceous gland tumors were associated with early onset colon and thyroid cancers and attenuated polyposis coli. Her family history was positive for colonic adenomas. She had a daughter presenting with yellow papules in the forehead region developed in the late infancy. Skin and visceral neoplasms were tested for microsatellite instability and immunohistochemical status of mismatch repair (MMR), APC and MYH proteins. The proband colon and skin tumors were microsatellite stable and showed normal expression of MMR proteins. Cytoplasmic expression of MYH protein was revealed in colonic cancer cells. Compound heterozygosity due to biallelic mutations in MYH, R168H and 379delC, was identified in the proband. The 11-year-old daughter was carrier of the monoallelic constitutional mutation 379delC in the MYH gene; in the sister, the R168H MYH gene mutation was detected. This report presents an interesting case of association between MYH-associated polyposis and sebaceous gland tumors. These findings suggest that patients with MTS phenotype that include colonic polyposis should be screened for MYH gene mutations. PMID:16207212

Ponti, G; Ponz de Leon, M; Maffei, S; Pedroni, M; Losi, L; Di Gregorio, C; Gismondi, V; Scarselli, A; Benatti, P; Roncari, B; Seidenari, S; Pellacani, G; Varotti, C; Prete, E; Varesco, L; Roncucci, L

2005-11-01

92

The ant raft  

NASA Astrophysics Data System (ADS)

To survive floods, fire ants link their arms together to assemble a raft with their own bodies. Because ants are nearly as dense as water, this cooperative behavior requires that a portion of the ant colony must sacrifice itself by remaining underwater to support the colony's weight. Surprisingly, few ants drown during this process due to a striking metamorphosis of the raft: as we show using time-lapse photography, the raft morphs from a spherical to a pancake shape. This pancake configuration--a monolayer of floating ants supporting their dry counterparts--allows all ants to both breathe and remain united as a colony. Data is presented in the form of the dimensions and the rates of formation of the ant raft. We use the statics of small floating bodies to account for the equilibrium raft size as a function of the initial mass and density of the ants.

Mlot, Nathan; Hu, David; Equabai, Solomon

2009-11-01

93

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 ... a Serious Reaction For people with fire ant allergy, stings may cause a life-threatening reaction called ...

94

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

Planet, Pulse O.

2007-01-26

95

Potential hazards from floodflows within the John Muir House National Historic Site, Franklin Creek drainage basin, California  

USGS Publications Warehouse

The drainage-area-ratio method, adjusted by multiple regression coefficients, was used to determine flood magnitudes of specific recurrence intervals in the Franklin Creek drainage basin, John Muir House National Historic Site in California. Water-surface elevations and inundation areas were determined using hydraulic equations that assume uniform flow and stable channel geometry as surveyed in the 1984 water year. Franklin Creek is expected to overflow its banks during all floods greater than the 25-year flood. Maximum flood discharges within the historic site boundaries are limited by the large culvert that conveys floodwaters into the site. The historically significant structures were constructed above the flood elevation of the 100-year flood; therefore, with the exception of the carriage house, there is little or no danger to the irreplaceable structures at the site. The carriage house could be inundated several feet during the 100-year flood.

Meyer, R. W.

1994-01-01

96

Structure of the human MSH2 locus and analysis of two Muir-Torre kindreds for msh2 mutations  

SciTech Connect

Hereditary nonpolyposis colorectal carcinoma (HNPCC) is a major cancer susceptibility syndrome known to be caused by inheritance of mutations in genes such as hMSH2 and hMLH1, which encode components of a DNA mismatch repair system. The MSH2 genomic locus has been cloned and shown to cover {approximately}73 kb of genomic DNA and to contain 16 exons. The sequence of all of the intron-exon junctions has been determined and used to develop methods for analyzing each MSH2 exon for mutations. These methods have been used to analyze two large HNPCC kindreds exhibiting features of the Muir-Torre syndrome and demonstrate that cancer susceptibility is due to the inheritance of a frameshift mutation in the MSH2 gene in one family and a nonsense mutation in the MSH2 gene in the other family. 59 refs., 5 figs., 1 tab.

Kolodner, R.D.; Lipford, J.; Kane, M.F. [Dana-Farber Cancer Institute, Boston, MA (United States)] [and others] [Dana-Farber Cancer Institute, Boston, MA (United States); and others

1994-12-01

97

Museum Management Plan for John Muir National Historic Site, Eugene O'Neill National Historic Site, Port Chicago Naval Magazine National Memorial and Rosie the Riveter/World War II Home Front National Historical Park.  

National Technical Information Service (NTIS)

This Museum Management Plan for the consolidated operation of three units of the NPS, Eugene ONeill (EUON), John Muir (JOMU), Rosie the Riveter (RORI) and one affiliated area, Port Chicago (POCH), identifies the issues facing the parks, and presents recom...

2007-01-01

98

Solving permutation flow shop sequencing using ant colony optimization  

Microsoft Academic Search

This paper proposes an ant colony algorithm for permutation flow shop scheduling problem. The objective considered is to minimize makespan. Two priority rules are developed as heuristic information based on Johnson's Rule and total processing times. A local search is used for improving the constructed solutions. The proposed ant colony algorithm is tested on the benchmark problem set of Taillard.

Fardin Ahmadizar; Farnaz Barzinpour; Jamal Arkat

2007-01-01

99

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

Daugherty, Belinda

2001-02-01

100

Ant colony optimization for disaster relief operations  

Microsoft Academic Search

This paper presents a meta-heuristic of ant colony optimization (ACO) for solving the logistics problem arising in disaster relief activities. The logistics planning involves dispatching commodities to distribution centers in the affected areas and evacuating the wounded people to medical centers. The proposed method decomposes the original emergency logistics problem into two phases of decision making, i.e., the vehicle route

Wei Yi; Arun Kumar

2007-01-01

101

An ant colony algorithm Hybridized with Iterated Local Search for the QAP  

Microsoft Academic Search

The quadratic assignment problem (QAP) is considered one of the hardest combinatorial optimization problems. Ant colony algorithm (ACA), inspired by the food-searching behavior of ants, is an evolutionary algorithm and performs well in discrete optimization. In this paper, through an analysis of the constructive procedure of the solution in the ACA, a hybrid ant colony system (ACAILS) with iterated local

Mingping Xia

2009-01-01

102

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.

103

Hang Gliding, Ant Style  

NSF Publications Database

... canopy chart specific courses to safety View videoCertain species of tree-dwelling ants glide to ... of white nail polish and capturing impressive video images, Yanoviak proved his initial supposition ...

104

Surface water quality along the Central John Muir Trail in the Sierra Nevada Mountains: coliforms and algae.  

PubMed

The John Muir Trail (JMT) in the Sierra Nevada Mountains of California is one of the most popular alpine wilderness trails in the United States, where backpackers depend on trailside water sources for more than 335 km (208 miles). This study addressed the risk of acquiring waterborne disease by analyzing prevalence and changes in coliform bacteria and Escherichia coli (E. coli) in lakes and streams adjacent to the central JMT. Chlorophyll-a levels were also measured as an indicator of high elevation eutrophication. Categories of environmental land use which might affect water quality were defined as: Pristine areas rarely traversed by humans; Backpack off-trail areas not traversed by pack or stock animals; and Multiuse areas with backpacker and animal use. We analyzed surface water at 36 different sites three separate times over an eight week period in the summer of 2008. Chlorophyll-a concentration increased significantly in Backpack and Multiuse sites over the summer months, but not in Pristine sites. Similar results were obtained for coliforms, with prevalence also increasing significantly over the summer months in Backpack and Multiuse sites. There was a much higher prevalence of E. coli in Multiuse sites compared to Pristine and Backpack sites. Our study provides evidence pack and stock animals serve as a source of microbial contamination of water along this section of trail. PMID:20039816

Ursem, Carling; Evans, C Scott; Ger, Kemal Ali; Richards, John R; Derlet, Robert W

2009-01-01

105

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.

0002-11-30

106

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

107

BIOCHEMICAL POLYMORPHISM IN ANTS.  

PubMed

Ants of different sexes and castes produce different odorous compounds. In Pheidole fallax Mayr, soldier ants produce an indole base, probably skatole, whereas minor workers produce a trial substance, Males of certain species of Lasius and Acanthomyops produce mixtures of terpenes and an indole base. These mixtures are discharged during mating pheromones. The terpene mixtures are qualitatively similar, but each species produces a blend of distinctive proportions. Citronellol and 2,6-dimethyl-5-hepten-1-ol have been identified in the mixtures by gas chromatography and mass spectrometry. PMID:14325157

LAW, J H; WILSON, W O; MCCLOSKEY, J A

1965-07-30

108

FDTD-ANT user manual  

NASA Technical Reports Server (NTRS)

This manual explains the theory and operation of the finite-difference time domain code FDTD-ANT developed by Analex Corporation at the NASA Lewis Research Center in Cleveland, Ohio. This code can be used for solving electromagnetic problems that are electrically small or medium (on the order of 1 to 50 cubic wavelengths). Calculated parameters include transmission line impedance, relative effective permittivity, antenna input impedance, and far-field patterns in both the time and frequency domains. The maximum problem size may be adjusted according to the computer used. This code has been run on the DEC VAX and 486 PC's and on workstations such as the Sun Sparc and the IBM RS/6000.

Zimmerman, Martin L.

1995-01-01

109

Motif Finding Using Ant Colony Optimization  

Microsoft Academic Search

\\u000a A challenging problem in molecular biology is the identification of the specific binding sites of transcription factors in\\u000a the promoter regions of genes referred to as motifs. This paper presents an Ant Colony Optimization approach that can be used\\u000a to provide the motif finding problem with promising solutions. The proposed approach incorporates a modified form of the Gibbs\\u000a sampling technique

Salim Bouamama; Abdellah Boukerram; Amer F. Al-Badarneh

2010-01-01

110

A castration parasite of an ant-plant mutualism  

PubMed Central

Exploring the factors governing the maintenance and breakdown of cooperation between mutualists is an intriguing and enduring problem for evolutionary ecology, and symbioses between ants and plants can provide useful experimental models for such studies. Hundreds of tropical plant species have evolved structures to house and feed ants, and these ant–plant symbioses have long been considered classic examples of mutualism. Here, we report that the primary ant symbiont, Allomerus cf. demerarae, of the most abundant ant-plant found in south-east Peru, Cordia nodosa Lam., castrates its host plant. Allomerus workers protect new leaves and their associated domatia from herbivory, but destroy flowers, reducing fruit production to zero in most host plants. Castrated plants occupied by Allomerus provide more domatia for their associated ants than plants occupied by three species of Azteca ants that do not castrate their hosts. Allomerus colonies in larger plants have higher fecundity. As a consequence, Allomerus appears to benefit from its castration behaviour, to the detriment of C. nodosa. The C. nodosa–ant system exhibits none of the retaliatory or filtering mechanisms shown to stabilize cheating in other cooperative systems, and appears to persist because some of the plants, albeit a small minority, are inhabited by the three species of truly mutualistic Azteca ants.

Yu, D. W.; Pierce, N. E.

1998-01-01

111

Tiny, Powerful Awesome Ants!  

NSDL National Science Digital Library

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.

Tate, Kathleen

2007-11-01

112

The Fuzzy Ant  

Microsoft Academic Search

We apply fuzzy modeling to transform a verbal description of the foraging behavior of ants into a well-defined mathematical model. The resulting model is simpler, more plausible, and more amenable to analysis than previously suggested models. We believe that fuzzy modeling may be suitable for addressing biomimicry, that is, the development of artificial products or machines that mimic biological phenomena,

Valeri Rozin; Michael Margaliot

2007-01-01

113

Simple Ant Routing Algorithm  

Microsoft Academic Search

A mobile ad-hoc network has limited and scarce resources and thus routing protocols in such environments must be kept as simple as possible. This paper presents a MANET routing protocol, inspired in insect societies' biological models, the simple ant routing algorithm (SARA), which provides a simple and efficient routing solution. SARA uses a controlled neighbour broadcast route discovery procedure, aimed

Fernando Correia; T. Vazao

2008-01-01

114

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.

Biology

2009-09-22

115

Solving the Mixed Vrp with Backhauling Using Ants  

NASA Astrophysics Data System (ADS)

The mixed vehicle routing problem with backhauls is investigated using an ant system heuristic. This distribution problem seems to suffer from a lack of published work even though it has immense practical applicability especially within logistic systems. Some enhancements to the basic ant system algorithm are embedded into the search. In particular a focus is on the choice in the placement of ants, the use of a site-dependent candidate list, the introduction of a look ahead-based visibility, and appropriate strategies for updating local and global trails. Encouraging computational results are reported when tested on benchmark data sets.

Wassan, N. A.; Salhi, S.; Nagy, G.

2009-08-01

116

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

117

An improved ant colony algorithm with diversified solutions based on the immune strategy  

PubMed Central

Background Ant colony algorithm has emerged recently as a new meta-heuristic method, which is inspired from the behaviours of real ants for solving NP-hard problems. However, the classical ant colony algorithm also has its defects of stagnation and premature. This paper aims at remedying these problems. Results In this paper, we propose an adaptive ant colony algorithm that simulates the behaviour of biological immune system. The solutions of the problem are much more diversified than traditional ant colony algorithms. Conclusion The proposed method for improving the performance of traditional ant colony algorithm takes into account the polarization of the colonies, and adaptively adjusts the distribution of the solutions obtained by the ants. This makes the solutions more diverse so as to avoid the stagnation and premature phenomena.

Qin, Ling; Pan, Yi; Chen, Ling; Chen, Yixin

2006-01-01

118

Loading Containers with Ants  

NASA Astrophysics Data System (ADS)

Loading containers is like loading a subset of given three-dimensional rectangular boxes of different sizes into a three-dimensional rectangular container of fixed dimensions in order to achieve optimal space utilization. In this paper, Ant Colony Optimization (ACO) with its probabilistic decision rule is used to construct towers of boxes and to arrange them into the container. Some initial computational results on benchmark data set will be presented.

Yap, Ching Nei; Lee, Lai Soon; Majid, Zanariah Abdul; Seow, Hsin Vonn

119

A modified ant colony optimization algorithm based on differential evolution for chaotic synchronization  

Microsoft Academic Search

Optimization algorithms inspired by the ants’ foraging behavior have been initially used for solving combinatorial optimization problems. Since the emergence of ant algorithms as an optimization tool, some attempts were also made to use them for tackling continuous optimization problems. In recent years, the investigation of synchronization and control problem for discrete chaotic systems has attracted much attention, and many

Leandro dos Santos Coelho; Diego Luis de Andrade Bernert

2010-01-01

120

A new approach to fault section estimation in power systems using Ant system  

Microsoft Academic Search

In this paper, a new method to fault section estimation problem in power systems is developed using Ant System. Based on the information from the operated protective relays and tripped circuit breakers, the fault section estimation is first formulated as a combinatorial optimization problem. Then, a new approach known as the Ant System is applied to solve this optimization problem.

C. S. Chang; L. Tian; F. S. Wen

1999-01-01

121

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

122

The metapleural gland of ants.  

PubMed

The metapleural gland (MG) is a complex glandular structure unique to ants, suggesting a critical role in their origin and ecological success. We synthesize the current understanding of the adaptive function, morphology, evolutionary history, and chemical properties of the MG. Two functions of the MG, sanitation and chemical defence, have received the strongest empirical support; two additional possible functions, recognition odour and territorial marking, are less well supported. The design of the MG is unusual for insects; glandular secretions are stored in a rigid, non-compressible invagination of the integument and the secretion is thought to ooze out passively through the non-closable opening of the MG or is groomed off by the legs and applied to target surfaces. MG loss has occurred repeatedly among the ants, particularly in the subfamilies Formicinae and Myrmicinae, and the MG is more commonly absent in males than in workers. MG chemistry has been characterized mostly in derived ant lineages with unique biologies (e.g. leafcutter ants, fire ants), currently precluding any inferences about MG chemistry at the origin of the ants. A synthetic approach integrating functional morphology, phylogenetic transitions and chemical ecology of the MGs of both the derived and the unstudied early-branching (basal) ant lineages is needed to elucidate the evolutionary origin and diversification of the MG of ants. PMID:21504532

Yek, Sze Huei; Mueller, Ulrich G

2011-11-01

123

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

124

An ACO algorithm for graph coloring problem  

Microsoft Academic Search

Ant colony optimization (ACO) is a well-known metaheuristic in which a colony of artificial ants cooperate in exploring good solutions to a combinatorial optimization problem. In this paper, an ACO algorithm is presented for the graph coloring problem. This ACO algorithm conforms to max-min ant system structure and exploits a local search heuristic to improve its performance. Experimental results on

Ehsan Salari; Kourosh Eshghi

2005-01-01

125

Multiroute memories in desert ants  

PubMed Central

When offered a permanent food source, central Australian desert ants, Melophorus bagoti, develop individually distinct, view-based foraging routes, which they retrace with amazing accuracy during each foraging trip. Using a particular channel setup connected to an artificial feeder, we trained M. bagoti ants to either two or three inward routes that led through different parts of their maze-like foraging grounds. Here, we show that ants are able to adopt multiple habitual paths in succession and that they preserve initially acquired route memories even after they have been trained to new routes. Individual ants differ in the consistency with which they run along habitual pathways. However, those ants that follow constant paths retain their route-specific memories for at least 5 days of suspended foraging, which suggests that even multiple route memories, once acquired, are preserved over the entire lifetime of a forager.

Sommer, Stefan; von Beeren, Christoph; Wehner, Rudiger

2008-01-01

126

California Academy of Sciences: AntWeb  

NSDL National Science Digital Library

AntWeb, an excellent service of the California Academy of Sciences, provides users with "tools for exploring the diversity and identification of ants (Hymenoptera: Formicidae). These tools have been developed to facilitate the use of ants in inventory and monitoring programs and provide ant taxonomists with images and types." At present, AntWeb offers information on all ant genera worldwide as well as highlighting ants of Madagascar and California in particular. The site provides a search engine for the comprehensive AntWeb database which contains images of, and information about, ants from all over the world. AntWeb also offers an awesome World Ants Slide Show which includes Head, Profile, and Dorsal Views of many ants.

127

FORMIDABEL: The Belgian Ants Database  

PubMed Central

Abstract FORMIDABEL is a database of Belgian Ants containing more than 27.000 occurrence records. These records originate from collections, field sampling and literature. The database gives information on 76 native and 9 introduced ant species found in Belgium. The collection records originated mainly from the ants collection in Royal Belgian Institute of Natural Sciences (RBINS), the ‘Gaspar’ Ants collection in Gembloux and the zoological collection of the University of Liège (ULG). The oldest occurrences date back from May 1866, the most recent refer to August 2012. FORMIDABEL is a work in progress and the database is updated twice a year. The latest version of the dataset is publicly and freely accessible through this url: http://ipt.biodiversity.be/resource.do?r=formidabel. The dataset is also retrievable via the GBIF data portal through this link: http://data.gbif.org/datasets/resource/14697 A dedicated geo-portal, developed by the Belgian Biodiversity Platform is accessible at: http://www.formicidae-atlas.be Purpose: FORMIDABEL is a joint cooperation of the Flemish ants working group “Polyergus” (http://formicidae.be) and the Wallonian ants working group “FourmisWalBru” (http://fourmiswalbru.be). The original database was created in 2002 in the context of the preliminary red data book of Flemish Ants (Dekoninck et al. 2003). Later, in 2005, data from the Southern part of Belgium; Wallonia and Brussels were added. In 2012 this dataset was again updated for the creation of the first Belgian Ants Atlas (Figure 1) (Dekoninck et al. 2012). The main purpose of this atlas was to generate maps for all outdoor-living ant species in Belgium using an overlay of the standard Belgian ecoregions. By using this overlay for most species, we can discern a clear and often restricted distribution pattern in Belgium, mainly based on vegetation and soil types.

Brosens, Dimitri; Vankerkhoven, Francois; Ignace, David; Wegnez, Philippe; Noe, Nicolas; Heughebaert, Andre; Bortels, Jeannine; Dekoninck, Wouter

2013-01-01

128

FORMIDABEL: The Belgian Ants Database.  

PubMed

FORMIDABEL is a database of Belgian Ants containing more than 27.000 occurrence records. These records originate from collections, field sampling and literature. The database gives information on 76 native and 9 introduced ant species found in Belgium. The collection records originated mainly from the ants collection in Royal Belgian Institute of Natural Sciences (RBINS), the 'Gaspar' Ants collection in Gembloux and the zoological collection of the University of Liège (ULG). The oldest occurrences date back from May 1866, the most recent refer to August 2012. FORMIDABEL is a work in progress and the database is updated twice a year. THE LATEST VERSION OF THE DATASET IS PUBLICLY AND FREELY ACCESSIBLE THROUGH THIS URL: http://ipt.biodiversity.be/resource.do?r=formidabel. The dataset is also retrievable via the GBIF data portal through this link: http://data.gbif.org/datasets/resource/14697 A dedicated geo-portal, developed by the Belgian Biodiversity Platform is accessible at: http://www.formicidae-atlas.be Purpose: FORMIDABEL is a joint cooperation of the Flemish ants working group "Polyergus" (http://formicidae.be) and the Wallonian ants working group "FourmisWalBru" (http://fourmiswalbru.be). The original database was created in 2002 in the context of the preliminary red data book of Flemish Ants (Dekoninck et al. 2003). Later, in 2005, data from the Southern part of Belgium; Wallonia and Brussels were added. In 2012 this dataset was again updated for the creation of the first Belgian Ants Atlas (Figure 1) (Dekoninck et al. 2012). The main purpose of this atlas was to generate maps for all outdoor-living ant species in Belgium using an overlay of the standard Belgian ecoregions. By using this overlay for most species, we can discern a clear and often restricted distribution pattern in Belgium, mainly based on vegetation and soil types. PMID:23794918

Brosens, Dimitri; Vankerkhoven, François; Ignace, David; Wegnez, Philippe; Noé, Nicolas; Heughebaert, André; Bortels, Jeannine; Dekoninck, Wouter

2013-01-01

129

Ant colony optimisation for virtual-wavelength-path routing and wavelength allocation  

Microsoft Academic Search

Ant Colony Optimisation (ACO) is applied to the problem of routing and wavelength allocation in a multi-wavelength all-optical virtual-wavelength-path routed transport network. Three variants of our ACO algorithm are proposed: local update (LU), global update\\/distance (GU\\/D) and global update\\/occupancy (GU\\/O). All three extend the usual practice that ants are attracted by the pheromone trail of ants from their own colony:

Griselda Navarro Varela; Mark C. Sinclair

1999-01-01

130

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

131

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

132

Multi-ant colonies algorithms for the VRPSPDTW  

Microsoft Academic Search

The vehicle routing problem with simultaneous pickups and deliveries and time windows (VRP-SPDTWj is the problem of optimally integrating forward (good distribution) and reverse logistics (returning materials) for cost saving and environmental protection. We constructed a general mixed integer programming model of VRP-SPDTW We present an Improved Ant Colony System (ACS) for the VRPSPDTW (Vehicle Routing Problem with Simultaneous Pick-up

L. Boubahri; S.-A. Addouche; A. El Mhamedi

2011-01-01

133

Optimization of multi-pass turning operations using ant colony system  

Microsoft Academic Search

This paper proposes a new optimization technique based on the ant colony algorithm for solving multi-pass turning optimization problems. The cutting process has roughing and finishing stages. The machining parameters are determined by minimizing the unit production cost, subject to various practical machining constraints. The results indicate that the proposed ant colony framework is effective compared to other techniques carried

K. Vijayakumar; G. Prabhaharan; P. Asokan; R. Saravanan

2003-01-01

134

Scheduling Continuous Casting of Aluminum Using a Multiple-Objective Ant Colony Optimization Metaheuristic  

Microsoft Academic Search

This paper presents an ant colony optimizationmetaheuristic for the solution of an industrialscheduling problem in an aluminum castingcenter. We present an efficient representation of acontinuous horizontal casting process which takesaccount of a number of objectives that areimportant to the scheduler. We have incorporatedthe methods proposed in software that has beenimplemented in the plant.Keywords: scheduling, metaheuristic, ant colonyoptimization, aluminum, casting,...

Marc Gravel; Wilson L. Price

2001-01-01

135

Research on the optimization of empty wagon distribution based on Ant Colony System  

Microsoft Academic Search

Ant Colony System (ACS) algorithm is a kind of intelligent optimization algorithm which has been inspired by the behavior of real ant colonies, in particular, by their foraging behavior. Aiming at the problem of the substitution of Empty Distribution Types in rail transport tension, the model of the substitution of Empty Distribution Types which aims at the minimization of consuming

Fu Wu; Xijuan Yang

2011-01-01

136

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.

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

2010-01-01

137

ANT-VDAC1 interaction is direct and depends on ANT isoform conformation in vitro.  

PubMed

The voltage-dependent anion channel (VDAC) and the adenine nucleotide translocase (ANT) have central roles in mitochondrial functions such as nucleotides transport and cell death. The interaction between VDAC, an outer mitochondrial membrane protein and ANT, an inner membrane protein, was studied in isolated mitochondria and in vitro. Both proteins were isolated from various mitochondrial sources and reconstituted in vitro using a biomimetic system composed of recombinant human VDAC isoform 1 (rhVDAC1) immobilized on a surface plasmon resonance (SPR) sensor chip surface. Two enriched-preparations of (H)ANT (ANT from heart, mainly ANT1) and (L)ANT (ANT from liver, mainly ANT2) isoforms interacted differently with rhVDAC1. Moreover, the pharmacological ANT inhibitors atractyloside and bongkrekic acid modulated this interaction. Thus, ANT-VDAC interaction depends both on ANT isoform identity and on the conformation of ANT. PMID:23131554

Allouche, Maya; Pertuiset, Claire; Robert, Jean-Luc; Martel, Cécile; Veneziano, Rémi; Henry, Céline; dein, Ossama Sharaf el; Saint, Nathalie; Brenner, Catherine; Chopineau, Joel

2012-12-01

138

Combined effect of hemipteran control and liquid bait on Argentine ant populations.  

PubMed

The invasive Argentine ant, Linepithema humile (Mayr), has become a worldwide problem capable of inflicting significant ecological and economic injury on urban, agricultural, and natural environments. The mobility of this pest ant has long been noted, rapidly moving nests to new food resources and then away as resources are depleted. This ant, like many pest ant species, has a special affinity for honeydew excreted by phloem-feeding Hemiptera. We investigated the effect of various hemipteran control strategies on terrapin scale densities and measured their indirect effect on local Argentine ant densities and foraging effort. We then determined whether this indirect treatment strategy improved the performance of an ant bait. We predicted that Argentine ants would move nests away from trees treated for Hemiptera and then move nests back when a liquid bait was offered, followed by a decline in ant numbers due to intake of the toxicant. A horticultural oil spray and soil application of the systemic insecticide, imidacloprid, had no effect on terrapin scale numbers. However, trunk-injected dicrotophos caused a reduction in scale and a decline in local Argentine ant nest density and canopy foraging effort. We also recorded a reduction in local Argentine ant ground foraging when large amounts of liquid bait were applied, and we found no evidence that combining dicrotophos with liquid ant bait performed better than each treatment alone. We suggest that a strategy of combined hemipteran control plus application of liquid ant bait can reduce local Argentine ant densities, when both components of this system are highly efficacious. PMID:21061981

Brightwell, R J; Bambara, S B; Silverman, J

2010-10-01

139

Reentry trajectory planning optimization based on ant colony algorithm  

Microsoft Academic Search

An optimal trajectory is very important to reusable launch vehicle (RLV) which faces the critical heating and aero force when it comes back from outer space through the dense atmosphere. However, the trajectory planning is a sort of typically large scale and multi-constraint optimization problem. Ant colony algorithm is a new class of population algorithm which has the potential to

Zhang Qingzhen; Liu Cunjia; Yang Bo; Ren Zhang

2007-01-01

140

OPTIMIZING BUS TRANSIT NETWORK WITH PARALLEL ANT COLONY ALGORITHM  

Microsoft Academic Search

This study develop an optimization model for bus transit network based on road network and zonal OD. The model aims at achieving minimum transfers and maximum passenger flow per unit length with line length and non-linear rate as constraints. The coarse-grain parallel ant colony algorithm (CPACA) is used to solve the problem. To effectively search the global optimal solution, we

Zhongzhen Yang; Chuntian Cheng; Chong Liu

2005-01-01

141

Satellite Constellation Design with Adaptively Continuous Ant System Algorithm  

Microsoft Academic Search

The ant system algorithm (ASA) has proved to be a novel meta-heuristic algorithm to solve many multivariable problems. In this paper, the earth coverage of satellite constellation is analyzed and a -fold coverage rate is put forward to evaluate the coverage performance of a satellite constellation. An optimization model of constellation parameters is established on the basis of the coverage

Quan He; Chao Han

2007-01-01

142

AN APPLICATION OF ANT COLONY OPTIMIZATION TO IMAGE CLUSTERING  

Microsoft Academic Search

Content-based image retrieval can be dramatically improved by providing a good initial clustering of visual data. The problem of image clustering is that most current algorithms are not able to identify individual clusters that exist in different feature subspaces. In this paper, we propose a novel approach for subspace clustering based on Ant Colony Optimization and its learning mechanism. The

Tomas Piatrik; Ebroul Izquierdo

143

Dynamic Optimization of Chemical Processes using Ant Colony Framework  

Microsoft Academic Search

Ant colony framework is illustrated by considering dynamic optimization of six important bench marking examples. This new computational tool is simple to implement and can tackle problems with state as well as terminal constraints in a straightforward fashion. It requires fewer grid points to reach the global optimum at relatively very low computational effort. The examples with varying degree of

J. Rajesh; Kapil Gupta; Hari Shankar Kusumakar; Vaidyanathan K. Jayaraman; Bhaskar D. Kulkarni

2001-01-01

144

Do Antbirds Help or Hinder Army Ants?  

NSDL National Science Digital Library

In this activity, students examine the nature of the interaction between army ants and ant-following birds. Ant-following birds benefit from the relationship by staying just ahead of the ants and capturing prey animals that are disturbed by the ants. While early studies suggested that the birds' foraging might in turn benefit the ants, it is possible that the birds remove prey that the ants would capture. Using figures from a research paper, students determine whether the species interaction is mutualism, commensalism, or parasitism. Students design a hypothetical experiment to measure the effect of birds on army ant foraging success, interpret figures from a real experiment, and consider the consequences of the interaction on the ant colony and the forest community.

Kuhlmann, Mark

2010-02-16

145

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.; Taylor, Brian.

1998-01-01

146

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

147

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 $4 \\times 10^{â3}$ grams and an elephant has a mass of approximately 8 metric tons. How many ants does it take to ha...

148

Vision-based innate aversion to ants and ant mimics  

Microsoft Academic Search

Innate vision-based aversions to model and mimic were investigated using a mimicry system in which the models were ants (Formicidae), and both the mimics and the predators were jumping spiders (Salticidae). Jumping spiders are a large group of predatory invertebrates that usually prey opportunistically on prey of similar size. We used 12 representative species from this group, the \\

Ximena J. Nelson; Robert R. Jackson

2006-01-01

149

The evolution of invasiveness in garden ants.  

PubMed

It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects. PMID:19050762

Cremer, Sylvia; Ugelvig, Line V; Drijfhout, Falko P; Schlick-Steiner, Birgit C; Steiner, Florian M; Seifert, Bernhard; Hughes, David P; Schulz, Andreas; Petersen, Klaus S; Konrad, Heino; Stauffer, Christian; Kiran, Kadri; Espadaler, Xavier; d'Ettorre, Patrizia; Aktaç, Nihat; Eilenberg, Jørgen; Jones, Graeme R; Nash, David R; Pedersen, Jes S; Boomsma, Jacobus J

2008-01-01

150

Mirex, Fire Ants, and Estuaries.  

National Technical Information Service (NTIS)

The insecticide mirex was used for 16 years (1962-1978) in the Southeastern United States to control the imported fire ant. During 1969-1971, a field monitoring study, carried out in conjunction with an aerial application of mirex to coastal areas in Sout...

J. I. Lowe

1982-01-01

151

Cerebral extraocular photoreceptors in ants  

Microsoft Academic Search

Clusters of dark pigmented cells, called putative cerebral extraocular photoreceptors (CEPs), are described in the optic lobes of four ant species: Atta sexdens, Camponotus rufipes, Camponotus crassus, and Pseudomyrmex adustus. Electron-micrographs of CEPs show a central rhabdom-like structure formed by tightly interleaved cells containing shielding pigments, with axons projecting toward the outer optic chiasm. The presence of a great number

F. Felisberti; D. F. Ventura

1996-01-01

152

FORMIS: A Master Bibliography of Ant Literature  

NSDL National Science Digital Library

FORMIS is a composite of several ant literature databases. It contains citations for a large fraction of the world's ant literature (about 38,000 references). FORMIS contains all known ant taxonomic literature (through 1996). It also contains comprehensive bibliographies of leaf-cutting ants, fire ants, and Russian wood ants. FORMIS is also the only database which covers ant literature before the 1970s. For further details please see contributions and credits. This database is designed to allow convenient searches of titles, keywords and abstracts when available (online searches or downloads). Citations from this database can be exported to create specialty databases or personal reprint indexes. FORMIS is only updated every year or two, so it is not a source for the most recent ant literature.

0002-11-30

153

Hey! A Fire Ant Stung Me!  

MedlinePLUS

... Injuries Jellyfish The Pink Locker Society 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 ...

154

Termites, hemimetabolous diploid white ants?  

PubMed Central

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 ants evolved from predatory wasps. In this review, I will concentrate on termites with an ancestral life type, the wood-dwelling termites, to compare them with ants. Their different ancestries provided both groups with different life history pre-adaptations for social evolution. Like their closest relatives, the woodroaches, wood-dwelling termites live inside their food, a piece of wood. Thus, intensive costly food provisioning of their young is not necessary, especially as young instars are rather independent due to their hemimetabolous development. In contrast, ants are progressive food provisioners which have to care intensively for their helpless brood. Corresponding to the precocial – altricial analogy, helping by workers is selected in ants, while new evidence suggests that wood-dwelling termite workers are less engaged in brood care. Rather they seem to stay in the nest because there is generally low selection for dispersal. The nest presents a safe haven with no local resource competition as long as food is abundant (which is generally the case), while founding a new colony is very risky. Despite these differences between ants and termites, their common dwelling life style resulted in convergent evolution, especially winglessness, that probably accounts for the striking similarity between both groups. In ants, all workers are wingless and winglessness in sexuals evolved in several taxa as a derived trait. In wood-dwelling termites, workers are by default wingless as they are immatures. These immatures can develop into winged sexuals that disperse and found a new nest or into neotenic replacement reproductives that inherit the natal colony. Depending on the worker instar from which the latter develop, the neotenic reproductives are either apterous or brachypterous, but never winged. I propose that this wing polyphenism might present a basis for the evolution of social life in termites.

Korb, Judith

2008-01-01

155

Graded recruitment in a ponerine ant  

Microsoft Academic Search

(1) The giant tropical ant, Paraponera clavata, exhibits graded recruitment responses, depending on the type, quantity, and quality of a food source. More ants are initially recruited to a large prey or scavenge item than to a large quantity of sugar water. (2) Individual ants encountering prey items gauge the size and\\/or unwieldiness of the item, regardless of the weight,

Michael D. Breed; Jennifer H. Fewell; Allen J. Moore; Kristina R. Williams

1987-01-01

156

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.

Tschinkel, Walter R.

2010-01-01

157

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

158

A Hybrid Routing Algorithm Based on Ant Colony and ZHLS Routing Protocol for MANET  

NASA Astrophysics Data System (ADS)

Mobile Ad hoc networks (MANETs) require dynamic routing schemes for adequate performance. This paper, presents a new routing algorithm for MANETs, which combines the idea of ant colony optimization with Zone-based Hierarchical Link State (ZHLS) protocol. Ant colony optimization (ACO) is a class of Swarm Intelligence (SI) algorithms. SI is the local interaction of many simple agents to achieve a global goal. SI is based on social insect for solving different types of problems. ACO algorithm uses mobile agents called ants to explore network. Ants help to find paths between two nodes in the network. Our algorithm is based on ants jump from one zone to the next zones which contains of the proactive routing within a zone and reactive routing between the zones. Our proposed algorithm improves the performance of the network such as delay, packet delivery ratio and overhead than traditional routing algorithms.

Rafsanjani, Marjan Kuchaki; Asadinia, Sanaz; Pakzad, Farzaneh

159

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.

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

2014-01-01

160

Quantifying ant activity using vibration measurements.  

PubMed

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

161

Team swimming in ant spermatozoa.  

PubMed

In species where females mate promiscuously, competition between ejaculates from different males to fertilize the ova is an important selective force shaping many aspects of male reproductive traits, such as sperm number, sperm length and sperm-sperm interactions. In eusocial Hymenoptera (bees, wasps and ants), males die shortly after mating and their reproductive success is ultimately limited by the amount of sperm stored in the queen's spermatheca. Multiple mating by queens is expected to impose intense selective pressure on males to optimize the transfer of sperm to the storage organ. Here, we report a remarkable case of cooperation between spermatozoa in the desert ant Cataglyphis savignyi. Males ejaculate bundles of 50-100 spermatozoa. Sperm bundles swim on average 51% faster than solitary sperm cells. Team swimming is expected to increase the amount of sperm stored in the queen spermatheca and, ultimately, enhance male posthumous fitness. PMID:24919705

Pearcy, Morgan; Delescaille, Noémie; Lybaert, Pascale; Aron, Serge

2014-06-01

162

Introduced fire ants can exclude native ants from critical mutualist-provided resources.  

PubMed

Animals frequently experience resource imbalances in nature. For ants, one resource that may be particularly valuable for both introduced and native species is high-carbohydrate honeydew from hemipteran mutualists. We conducted field and laboratory experiments: (1) to test if red imported fire ants (Solenopsis invicta) competed with native ants for access to mutualisms with aphids, and (2) to quantify the effects of aphid honeydew presence or absence on colony growth of native ants. We focused on native dolichoderine ants (Formicidae, Dolichoderinae) because they are abundant ants that have omnivorous diets that frequently include mutualist-provided carbohydrates. At two sites in the southeastern US, native dolichoderine ants were far less frequent, and fire ants more frequent, at carbohydrate baits than would be expected based on their frequency in pitfall traps. A field experiment confirmed that a native ant species, Dorymyrmex bureni, was only found tending aphids when populations of S. invicta were suppressed. In the laboratory, colonies of native dolichoderine ants with access to both honeydew and insect prey had twice as many workers and over twice as much brood compared to colonies fed only ad libitum insect prey. Our results provide the first experimental evidence that introduced ants compete for access to mutualist-provided carbohydrates with native ants and that these carbohydrates represent critical resources for both introduced and native ants. These results challenge traditional paradigms of arthropod and ant nutrition and contribute to growing evidence of the importance of nutrition in mediating ecological interactions. PMID:23053235

Wilder, Shawn M; Barnum, Thomas R; Holway, David A; Suarez, Andrew V; Eubanks, Micky D

2013-05-01

163

Ants Can Learn to Forage on One-Way Trails  

PubMed Central

The trails formed by many ant species between nest and food source are two-way roads on which outgoing and returning workers meet and touch each other all along. The way to get back home, after grasping a food load, is to take the same route on which they have arrived from the nest. In many species such trails are chemically marked by pheromones providing orientation cues for the ants to find their way. Other species rely on their vision and use landmarks as cues. We have developed a method to stop foraging ants from shuttling on two-way trails. The only way to forage is to take two separate roads, as they cannot go back on their steps after arriving at the food or at the nest. The condition qualifies as a problem because all their orientation cues – chemical, visual or any other - are disrupted, as all of them cannot but lead the ants back to the route on which they arrived. We have found that workers of the leaf-cutting ant Atta sexdens rubropilosa can solve the problem. They could not only find the alternative way, but also used the unidirectional traffic system to forage effectively. We suggest that their ability is an evolutionary consequence of the need to deal with environmental irregularities that cannot be negotiated by means of excessively stereotyped behavior, and that it is but an example of a widespread phenomenon. We also suggest that our method can be adapted to other species, invertebrate and vertebrate, in the study of orientation, memory, perception, learning and communication.

Ribeiro, Pedro Leite; Helene, Andre Frazao; Xavier, Gilberto; Navas, Carlos; Ribeiro, Fernando Leite

2009-01-01

164

Penalty adapting ant algorithm: application to pipe network optimization  

NASA Astrophysics Data System (ADS)

A penalty adapting ant algorithm is presented in an attempt to eliminate the dependency of ant algorithms on the penalty parameter used for the solution of constrained optimization problems. The method uses an adapting mechanism for determination of the penalty parameter leading to elimination of the costly process of penalty parameter tuning. The method is devised on the basis of observation that for large penalty parameters, infeasible solutions will have a higher total cost than feasible solutions and vice versa. The method therefore uses the best feasible and infeasible solution costs of the iteration to adaptively adjust the penalty parameter to be used in the next iteration. The pheromone updating procedure of the max-min ant system is also modified to keep ants on and around the boundary of the feasible search space where quality solutions can be found. The sensitivity of the proposed method to the initial value of the penalty parameter is investigated and indicates that the method converges to optimal or near-optimal solutions irrespective of the initial starting value of the penalty parameter. This is significant as it eliminates the need for sensitivity analysis of the method with respect to the penalty factor, thus adding to the computational efficiency of ant algorithms. Furthermore, it is shown that the success rate of the search algorithm in locating an optimal solution is increased when a self-adapting mechanism is used. The presented method is applied to a benchmark pipe network optimization problem in the literature and the results are presented and compared with those of existing algorithms.

Afshar, M. H.

2008-10-01

165

Runtime Analysis of an Ant Colony Optimization Algorithm for TSP Instances  

Microsoft Academic Search

Ant colony optimization (ACO) is a relatively new random heuristic approach for solving optimization problems. The main application of the ACO algorithm lies in the field of combinatorial optimization, and the traveling salesman problem (TSP) is the first benchmark problem to which the ACO algorithm has been applied. However, relatively few results on the runtime analysis of the ACO on

Yuren Zhou

2009-01-01

166

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

167

The production scheduling model of optical components oriented ant colony optimization algorithm  

NASA Astrophysics Data System (ADS)

Optical components production belongs to the typical jobbing work, and its scheduling problem is a significant research in advanced optical manufacture technique. According to the manufacturing technology for high precision optical components, the production scheduling model which is combined workshop scheduling theory with improved Ant Colony Algorithm (ACA) is introduced in this paper. In order to reduce the inherent deficiency of traditional ant algorithm for local optimal solution and stagnation, an improved algorithm which can simulate real ant colony sensation and consciousness may enhance the efficiency of basic ACA. The simulation experiment shows the robustness for this improved algorithm.

Wang, Juan; Wang, Jian; Tang, Dingyong

2010-05-01

168

Fire ant-detecting canines: a complementary method in detecting red imported fire ants.  

PubMed

In this investigation, detection dogs are trained and used in identifying red imported fire ants, Solenopsis invicta Buren, and their nests. The methodology could assist in reducing the frequency and scope of chemical treatments for red imported fire ant management and thus reduce labor costs and chemical use as well as improve control and quarantine efficiency. Three dogs previously trained for customs quarantine were retrained to detect the scents of red imported fire ants. After passing tests involving different numbers of live red imported fire ants and three other ant species--Crematogaster rogenhoferi Mayr, Paratrechina longicornis Latreille, and Pheidole megacephala F.--placed in containers, ajoint field survey for red imported fire ant nests by detection dogs and bait traps was conducted to demonstrate their use as a supplement to conventional detection methods. The most significant findings in this report are (1) with 10 or more red imported fire ants in scent containers, the dogs had >98% chance in tracing the red imported fire ant. Upon the introduction of other ant species, the dogs still achieved on average, a 93% correct red imported fire ant indication rate. Moreover, the dogs demonstrated great competence in pinpointing emerging and smaller red imported fire ant nests in red imported fire ant-infested areas that had been previously confirmed by bait trap stations. (2) Along with the bait trap method, we also discovered that approximately 90% of red imported fire ants foraged within a distance of 14 m away from their nests. The results prove detection dogs to be most effective for red imported fire ant control in areas that have been previously treated with pesticides and therefore containing a low density of remaining red imported fire ant nests. Furthermore, as a complement to other red imported fire ant monitoring methods, this strategy will significantly increase the efficacy of red imported fire ant control in cases of individual mount treatment. PMID:21404862

Lin, Hui-Min; Chi, Wei-Lien; Lin, Chung-Chi; Tseng, Yu-Ching; Chen, Wang-Ting; Kung, Yu-Ling; Lien, Yi-Yang; Chen, Yang-Yuan

2011-02-01

169

8.EE Ants versus humans  

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: The average mass of an adult human is about 65 kilograms while the average mass of an ant is approximately $4 \\times 10^{-3}$ grams. The total human po...

170

On Data Clustering With Artificial Ants  

Microsoft Academic Search

We present in this paper a new ant based approachnamed AntClass for data clustering. Thisalgorithm uses the stochastic principles of an antcolony in conjunction with the deterministic principlesof the Kmeans algorithm. It first createsan initial partition using an improved ant-basedapproach, which does not require any informationon the input data (such as the number of classes,or an initial partition). Then it

Nicolas Monmarché

1999-01-01

171

An ant colony optimization algorithm for continuous optimization: application to feed-forward neural network training  

Microsoft Academic Search

Ant colony optimization (ACO) is an optimization technique that was inspired by the foraging behaviour of real ant colonies.\\u000a Originally, the method was introduced for the application to discrete optimization problems. Recently we proposed a first\\u000a ACO variant for continuous optimization. In this work we choose the training of feed-forward neural networks for pattern classification\\u000a as a test case for

Krzysztof Socha; Christian Blum

2007-01-01

172

Ant distribution patterns in a cameroonian cocoa plantation: investigation of the ant mosaic hypothesis  

Microsoft Academic Search

Investigation of the spatial distribution of tropical ant species has shown that in tree crop plantations, abundant species have mutually exclusive distributions generated by competition thus forming a ‘mosaic’ of territories in the tree canopies. This study compares the spatial distribution of ants which live in the trees with that of ants which live on the ground in a cocoa

D. A. Jackson

1984-01-01

173

Ants and extrafloral nectaries: no evidence for plant protection in Helichrysum spp. — ant interactions  

Microsoft Academic Search

Characterstics of Australian endemic Helichrysum bracteratum and H. viscosum suggest that foraging ants act as “guards” of developing flowerheads, protecting capitula from seed predators: (1) extrafloral nectar is secreted from leaves subtending the capitula and from bracts encircling the floral disc during pre- to post-flowering periods; (2) capitula are attended by ants; and, (3) encounters between ants and other capitula

Dennis J. O'Dowd; E. A. Catchpole

1983-01-01

174

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

175

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

176

Resource leveling scheduling by an ant colony-based model  

NASA Astrophysics Data System (ADS)

In project scheduling, many problems can arise when resource fluctuations are beyond acceptable limits. To overcome this, mathematical techniques have been developed for leveling resources. However, these produce a hard and inflexible approach in scheduling projects. The authors propose a simple resource leveling approach that can be used in scheduling projects with multi-mode execution activities. In the mentioned approach, an ant algorithm determines the execution mode of each activity so that resource leveling index and project time become optimum. In the model, some visibility functions (defined in accordance with problem characteristics) are utilized, and the best, which return the best result, is selected for the model.

Garmsiri, Mohsen; Abassi, Mohammad Reza

2012-07-01

177

The evolution of genome size in ants  

Microsoft Academic Search

BACKGROUND: Despite the economic and ecological importance of ants, genomic tools for this family (Formicidae) remain woefully scarce. Knowledge of genome size, for example, is a useful and necessary prerequisite for the development of many genomic resources, yet it has been reported for only one ant species (Solenopsis invicta), and the two published estimates for this species differ by 146.7

Neil D Tsutsui; Andrew V Suarez; Joseph C Spagna; J Spencer Johnston

2008-01-01

178

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

179

Clustering outdoor soundscapes using fuzzy ants  

Microsoft Academic Search

A classification algorithm for environmental sound recordings or ldquosoundscapesrdquo is outlined. An ant clustering approach is proposed, in which the behavior of the ants is governed by fuzzy rules. These rules are optimized by a genetic algorithm specially designed in order to achieve the optimal set of homogeneous clusters. Soundscape similarity is expressed as fuzzy resemblance of the shape of

Bert De Coensel; Dick Botteldooren; Kenny Debacq; Mats E. Nilsson; Birgitta Berglund

2008-01-01

180

Butterflies and ants: The communicative domain  

Microsoft Academic Search

Associations with ants, termed myrmecophily, are widespread in the butterfly family Lycaenidae and range from mere co-existence to more or less specific mutualistic or even parasitic interactions. Secretions of specialized epidermal glands are crucial for mediating the interactions. Transfer of nutrients (carbohydrates, amino acids) from butterfly larvae to ants plays a major role, but manipulative communication with the help of

K. Fiedler; B. Hölldobler; P. Seufert

1996-01-01

181

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

182

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

183

Uncovering the complexity of ant foraging trails  

PubMed Central

The common garden ant Lasius niger use both trail pheromones and memory of past visits to navigate to and from food sources. In a recent paper we demonstrated a synergistic effect between route memory and trail pheromones: the presence of trail pheromones results in experienced ants walking straighter and faster. We also found that experienced ants leaving a pheromone trail deposit less pheromone. Here we focus on another finding of the experiment: the presence of cuticular hydrocarbons (CHCs), which are used as home range markers by ants, also affects pheromone deposition behavior. When walking on a trail on which CHCs are present but trail pheromones are not, experienced foragers deposit less pheromone on the outward journey than on the return journey. The regulatory mechanisms ants use during foraging and recruitment behavior is subtle and complex, affected by multiple interacting factors such as route memory, travel direction and the presence trail pheromone and home-range markings.

Gruter, Christoph; Jones, Sam M.; Ratnieks, Francis L.W.

2012-01-01

184

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

185

Diaspore trait preferences of dispersing ants.  

PubMed

Elaiosomes of myrmecochorous plant seeds are known to enhance the attraction of diaspore-dispersing ants by serving as a nutritional reward. However, it remained unclear which (nutritional) compounds affect diaspore preferences of ants. We hypothesized that apart from elaiosome/seed-size ratio, volume, and physical surface of diaspores, the quantity and the composition of fatty acids, amino acids, and sugars strongly influence the diaspore preferences of different species. Chemical (nutritional) profiles as well as structural properties of seeds with and without elaiosomes were analyzed and correlated with observed seed choice behavior of ants. Cafeteria experiments in the field confirmed the enhanced attractiveness of elaiosome-bearing seeds for all three ant species tested (Lasius fuliginosus, Myrmica ruginodis, and Temnothorax nylanderi), although seeds lacking elaiosomes also were transported. In multiple-choice cafeteria experiments with simultaneously offered diaspores of 16 plant species with and without elaiosome and with highly varying structural and chemical properties, all three ant species showed distinct preferences for certain diaspore species. Correlation analyses confirmed that the presence of an elaiosome represents the crucial factor that favors ant diaspore dispersal. In addition, the composition and the content of free amino acids, and to varying degrees fatty acids, were found to significantly affect preferences of each ant species, whereas the effect of single fatty acids acting as chemical triggers for diaspore transport by ants, as supposed by several studies, was not confirmed. In conclusion, although at least some diaspore species lacking elaiosomes attract ants for diaspore removal services by presenting nutritional seed coats, the production of elaiosomes seems to provide a worthwhile investment. Elaiosomes ensure rapid diaspore detection and removal due to chemical cue compounds and by offering a highly nutritional food supply, probably fitting the nutritional demands of ants. PMID:22903746

Reifenrath, Kerstin; Becker, Christine; Poethke, Hans Joachim

2012-09-01

186

Using Ant Colony Optimisation to Improve the Efficiency of Small Meander Line RFID Antennas  

Microsoft Academic Search

Increasing the efficiency of meander line antennas is an im- portant real-world problem within radio frequency identi- fication (RFID). Meta-heuristic search algorithms, such as ant colony optimisation, are very efficient at solving prob- lems that require paths to be constructed. This search tech- nique is adapted to solve the grid based path problem for meander line antennas and incorporates the

Marcus Randall; Andrew Lewis; Amir Galehdar; David Thiel

2007-01-01

187

Local search for Ant colony system to improve the efficiency of small meander line RFID antennas  

Microsoft Academic Search

The efficient design of meander line antennas for RFID devices is a significant real-world problem. Traditional manual tuning of antenna designs is becoming impractical for larger problems. Thus the use of automated techniques, in the form of combinatorial search algorithms, is a necessity. Ant colony system (ACS) is a very efficient meta-heuristic that is commonly used to solve path construction

Gerhard Weiß; Andrew Lewis; Marcus Randall; Amir Galehdar; David Thiel

2008-01-01

188

Regulation of ants' foraging to resource productivity.  

PubMed

We investigate the behavioural rule used by ant societies to adjust their foraging response to the honeydew productivity of aphids. When a scout finds a single food source, the decision to lay a recruitment trail is an all-or-none response based on the opportunity for this scout to ingest a desired volume acting as a threshold. Here, we demonstrate, through experimental and theoretical approaches, the generic value of this recruitment rule that remains valid when ants have to forage on multiple small sugar feeders to reach their desired volume. Moreover, our experiments show that when ants decide to recruit nest-mates they lay trail marks of equal intensity, whatever the number of food sources visited. A model based on the 'desired volume' rule of recruitment as well as on experimentally validated parameter values was built to investigate how ant societies adjust their foraging response to the honeydew productivity profile of aphids. Simulations predict that, with such recruiting rules, the percentage of recruiting ants is directly related to the total production of honeydew. Moreover, an optimal number of foragers exists that maximizes the strength of recruitment, this number being linearly related to the total production of honeydew by the aphid colony. The 'desired volume' recruitment rule that should be generic for all ant species is enough to explain how ants optimize trail recruitment and select aphid colonies or other liquid food resources according to their productivity profile. PMID:12908982

Mailleux, Anne-Catherine; Deneubourg, Jean-Louis; Detrain, Claire

2003-08-01

189

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

190

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

2014-01-01

191

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

192

Teaching in tandem-running ants.  

PubMed

The ant Temnothorax albipennis uses a technique known as tandem running to lead another ant from the nest to food--with signals between the two ants controlling both the speed and course of the run. Here we analyse the results of this communication and show that tandem running is an example of teaching, to our knowledge the first in a non-human animal, that involves bidirectional feedback between teacher and pupil. This behaviour indicates that it could be the value of information, rather than the constraint of brain size, that has influenced the evolution of teaching. PMID:16407943

Franks, Nigel R; Richardson, Tom

2006-01-12

193

Ant Colonies Shed Light on Metabolism  

NSDL National Science Digital Library

Press Release. Ants are usually regarded as the unwanted guests at a picnic. But a recent study of California seed harvester ants (Pogonomyrmex californicus) examining their metabolic rate in relation to colony size may lead to a better appreciation for the social, six-legged insects, whose colonies researchers say provide a theoretical framework for understanding cellular networks. Mr. Waters presented his paper, Scaling of Metabolism, Growth and Network Organization in Colonies of the Seed Harvester Ant, Pogonomyrmex californicus, at the American Physiological SocietyÃÂs Intersociety Meeting Global Science: Comparative Physiology in a Changing World. The program is located at http://the-aps.org/meetings/aps/comparative/preprogram.htm.

APS Communications Office (American Physiological Society Communications Office)

2010-08-26

194

Ant Colony Optimization With Combining Gaussian Eliminations for Matrix Multiplication.  

PubMed

One of the main unsolved problems in computer algebra is to determine the minimal number of multiplications which is necessary to compute the product of two matrices. For practical value, the small format is of special interest. This leads to a combinatorial optimization problem which is unlikely solved in polynomial time. In this paper, we present a method called combining Gaussian eliminations to reduce the number of variables in this optimization problem and use heuristic ant colony algorithm to solve the problem. The results of experiments on 2 × 2 case show that our algorithm achieves significant performance gains. Extending this algorithm from 2 × 2 case to 3 × 3 case is also discussed. PMID:22835561

Zhou, Yuren; Lai, Xinsheng; Li, Yuanxiang; Dong, Wenyong

2012-07-20

195

Male parentage in army ants.  

PubMed

In most social insects workers do not mate, but have retained the ability to produce haploid eggs that can develop into viable male offspring. Under what circumstances this reproductive potential is realized and how the ensuing worker-queen conflict over male production is resolved, is an area of active research in insect sociobiology. Here we present microsatellite data for 176 males from eight colonies of the African army ant Dorylus (Anomma) molestus. Comparison with worker genotypes and inferred queen genotypes from the same colonies show that workers do not or at best very rarely reproduce in the presence of the queen. Queens of D. (A.) molestus are known to be highly multiply mated. This implies that workers are on average more closely related to queen sons than to other workers' sons, so that our results are consistent with predictions from inclusive fitness theory. It remains unknown, however, whether worker sterility is maintained by active worker policing or by self-restraint. PMID:16599973

Kronauer, Daniel J C; Schöning, Caspar; Boomsma, Jacobus J

2006-04-01

196

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

2013-10-01

197

Non-ant antiherbivore defenses before plant-ant colonization in Macaranga myrmecophytes  

Microsoft Academic Search

We examined changes in the intensity of non-ant defenses of three myrmecophytic Macaranga species before and after the initiation of symbiosis with ants in a Bornean dipterocarp forest. The intensities of non-ant\\u000a defenses at different growth stages of each Macaranga species were estimated by measuring the survival rate of larvae of the common cutworm, Spodoptera litura, when the larvae were

Masahiro Nomura; Takao Itioka; Kaori Murase

2001-01-01

198

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

199

Imported Fire Ant Program Manual, First Edition.  

National Technical Information Service (NTIS)

This manual will prepare you to accomplish the following tasks: Perform accurate surveys for Imported Fire Ant (IFA) along the leading edge of infestation; Determine the movement (entry) status of regulated and nonregulated articles; Facilitate the moveme...

2004-01-01

200

Structure and formation of ant transportation networks  

PubMed Central

Many biological systems use extensive networks for the transport of resources and information. Ants are no exception. How do biological systems achieve efficient transportation networks in the absence of centralized control and without global knowledge of the environment? Here, we address this question by studying the formation and properties of inter-nest transportation networks in the Argentine ant (Linepithema humile). We find that the formation of inter-nest networks depends on the number of ants involved in the construction process. When the number of ants is sufficient and networks do form, they tend to have short total length but a low level of robustness. These networks are topologically similar to either minimum spanning trees or Steiner networks. The process of network formation involves an initial construction of multiple links followed by a pruning process that reduces the number of trails. Our study thus illuminates the conditions under and the process by which minimal biological transport networks can be constructed.

Latty, Tanya; Ramsch, Kai; Ito, Kentaro; Nakagaki, Toshiyuki; Sumpter, David J. T.; Middendorf, Martin; Beekman, Madeleine

2011-01-01

201

Structure and formation of ant transportation networks.  

PubMed

Many biological systems use extensive networks for the transport of resources and information. Ants are no exception. How do biological systems achieve efficient transportation networks in the absence of centralized control and without global knowledge of the environment? Here, we address this question by studying the formation and properties of inter-nest transportation networks in the Argentine ant (Linepithema humile). We find that the formation of inter-nest networks depends on the number of ants involved in the construction process. When the number of ants is sufficient and networks do form, they tend to have short total length but a low level of robustness. These networks are topologically similar to either minimum spanning trees or Steiner networks. The process of network formation involves an initial construction of multiple links followed by a pruning process that reduces the number of trails. Our study thus illuminates the conditions under and the process by which minimal biological transport networks can be constructed. PMID:21288958

Latty, Tanya; Ramsch, Kai; Ito, Kentaro; Nakagaki, Toshiyuki; Sumpter, David J T; Middendorf, Martin; Beekman, Madeleine

2011-09-01

202

Ant navigation: resetting the path integrator  

Microsoft Academic Search

Desert ants use path integration as their predominant system of long-distance navigation, but they also make use of route-defining and nest-defining visual landmarks. Such landmark-gained information might override the information provided by the path integrator, but nevertheless the path integrator keeps running. Here we show that only cues that are associated with the ant being inside the nest are able

Markus Knaden; Rüdiger Wehner

2006-01-01

203

Ant Inspired Methods for Organic Computing  

Microsoft Academic Search

\\u000a In recent years social insects have been a major inspiration in the design of new computational methods. This chapter describes\\u000a three examples of the application of ant-inspired methods in the domain of Organic Computing. The first example illustrates\\u000a implications of theoretical findings in response-threshold models that explain division of labour in ants for Organic Computing\\u000a systems. The second example outlines

Alexander Scheidler; Arne Brutschy; Konrad Diwold; Daniel Merkle; Martin Middendorf

204

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.

205

Positive effects of shade and shelter construction by ants on leafhopper-ant mutualism.  

PubMed

The myrmecophilous five-spotted gamagrass leafhopper, Dalbulus quinquenotatus DeLong and Nault, and its tending ants on gamagrass Tripsacum dactyloides L. were examined to determine the influence of shade and ant-constructed shelters on the population sizes of D. quinquenotatus and ants. Gamagrass plants hosting ants and leafhoppers were exposed to 50, 30, or 0% artificially constructed shade. The greatest numbers of leafhoppers and ants were found on plants that received 50% shade. Shelters made by the ant Solenopsis geminata (F.) contained large numbers of leafhoppers and ants but were found only on T. dactyloides exposed to 50% shade in artificially constructed habitats. Additional sampling was conducted on wild gamagrass plants in the field to explore the presence of ants tending leafhoppers in shelters and to evaluate whether ant-constructed shelters protect leafhopper nymphs from parasitoid wasps. Large aggregations of S. geminata in shelters were also found in natural gamagrass habitats. Leafhopper nymphs living in shelters made by S. geminata may be protected against the dryinid wasp parasitoid Anteon ciudadi Olmi. No sheltered nymphs were parasitized by dryinids, whereas 24% of unsheltered nymphs had dryinid parasitism. PMID:19161690

Moya-Raygoza, Gustavo; Larsen, Kirk J

2008-12-01

206

Habitat complexity facilitates coexistence in a tropical ant community  

Microsoft Academic Search

The role of habitat complexity in the coexistence of ant species is poorly understood. Here, we examine the influence of habitat complexity on coexistence patterns in ant communities of the remote Pacific atoll of Tokelau. The invasive yellow crazy ant, Anoplolepis gracilipes (Smith), exists in high densities on Tokelau, but still coexists with up to seven other epigeic ant species.

M. Sarty; K. L. Abbott; P. J. Lester

2006-01-01

207

Detection and dispersal of explosives by ants  

NASA Astrophysics Data System (ADS)

The ability of animals to detect explosives is well documented. Mammalian systems, insects and even single celled organisms have all been studied and in a few cases employed to detect explosives. This paper will describe the potential ability of ants to detect, disperse and possibly neutralize bulk explosives. In spring 2008 a team of DRDC and Itres scientists conducted experiments on detecting surface-laid and buried landmines, improvised explosive devices (IEDs) and their components. Measurements were made using state-of-the-art short wave and thermal infrared hyperspectral imagers mounted on a personnel lift. During one of the early morning measurement sessions, a wispy, long linear trail was seen to emanate several meters from piles of explosives that were situated on the ground. Upon close visual inspection, it was observed that ants had found the piles of explosives and were carrying it to their ant hill, a distance of almost 20 meters from the piles. Initial analysis of the hyperspectral images clearly revealed the trail to the ant hill of explosives, despite being present in quantities not visible to the unaided eye. This paper details these observations and discusses them in the context of landmine and IED detection and neutralization. Possible reasons for such behaviour are presented. A number of questions regarding the behaviour, many pertinent to the use of ants in a counter-landmine/IED role, are presented and possible methods of answering them are discussed. Anecdotal evidence from deminers of detection and destruction of explosives by ants are presented.

McFee, John E.; Achal, Steve; Faust, Anthony A.; Puckrin, Eldon; House, Andrew; Reynolds, Damon; McDougall, William; Asquini, Adam

2009-05-01

208

The macroevolutionary dynamics of ant diversification.  

PubMed

The availability of increasingly comprehensive phylogenies has provided unprecedented opportunities to assess macroevolutionary patterns, yet studies on invertebrate diversification are few. In particular, despite the ecological and evolutionary importance of ants, little is known about their tempo and mode of diversification. Recent advances in ant phylogenetics can now provide a basis for rigorous analyses of the diversification of ant lineages. The goals of the present study are threefold. First, we demonstrate that a hypothesized disproportionate increase in ant diversification during the angiosperm radiation is largely artifactual. Rather, current evidence points to a fairly constant rate of lineage growth during its history. Moreover, an analysis of diversification patterns across the ant phylogeny indicates considerable rate heterogeneity among lineages. Indeed, and contrary to the expectation if lineages had experienced a single rate of lineage increase, we found no correspondence between genus age and diversity. Finally, we demonstrate a statistically significant phylogenetic signal in ant diversification: closely related genera have diversities that are more similar to one another than one would expect by chance. This suggests that the capacity for diversification may be itself a biological trait that evolved during the radiation of the family Formicidae. PMID:19619225

Pie, Marcio R; Tschá, Marcel K

2009-11-01

209

A biologically inspired improvement strategy for particle filter: Ant colony optimization assisted particle filter  

Microsoft Academic Search

Particle Filter (PF) is a sophisticated model estimation technique based on simulation. Due to the natural limitations of\\u000a PF, two problems, namely particle impoverishment and sample size dependency, frequently occur during the particles updating\\u000a stage and these problems will limit the accuracy of the estimation results. In order to alleviate these problems, Ant Colony\\u000a Optimization is incorporated into the generic

Junpei Zhong; Yu-fai Fung; Mingjun Dai

2010-01-01

210

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

211

Bacterial Associates of Arboreal Ants and Their Putative Functions in an Obligate Ant-Plant Mutualism? †  

PubMed Central

Bacterial communities are highly diverse and have great ecological importance. In the present study, we used an in silico analysis of terminal restriction fragments (tRF) to characterize the bacterial community of the plant ant Pseudomyrmex ferrugineus. This species is an obligate inhabitant of Acacia myrmecophytes and feeds exclusively on plant-derived food sources. Ants are the dominant insect group in tropical rain forests. Associations of ants with microbes, which contribute particularly to the ants’ nitrogen nutrition, could allow these insects to live on mostly or entirely plant-based diets and could thus contribute to the explanation of the high abundances that are reached by tropical ants. We found tRF patterns representing at least 30 prokaryotic taxa, of which the Acidobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Planctomycetes, Proteobacteria, and Spirochaetes comprised 93%. Because most bacterial taxa were found in all ant-derived samples studied and because the bacteria detected on the ants’ host plant revealed little overlap with this community, we regard our results as reliably representing the bacterial community that is associated with P. ferrugineus. Genera with a likely function as ant symbionts were Burkholderia, Pantoea, Weissella, and several members of the Enterobacteriaceae. The presence of these and various other groups was confirmed via independent PCR and cultivation approaches. Many of the bacteria that we detected belong to purportedly N-fixing taxa. Bacteria may represent important further partners in ant-plant mutualisms, and their influences on ant nutrition can contribute to the extraordinary abundance and evolutionary success of tropical arboreal ants.

Eilmus, Sascha; Heil, Martin

2009-01-01

212

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

213

Data mining with an ant colony optimization algorithm  

Microsoft Academic Search

This work proposes an algorithm for data mining called Ant-Miner (Ant Colony-based Data Miner). The goal of Ant-Miner is to extract classification rules from data. The algorithm is inspired by both research on the behavior of real ant colonies and some data mining concepts and principles. We compare the performance of Ant-Miner with CN2, a well-known data mining algorithm for

Rafael S. Parpinelli; Heitor S. Lopes; Alex Alves Freitas

2002-01-01

214

Defensive behavior of ants in a mutualistic relationship with aphids  

Microsoft Academic Search

Mutualistic relationships between ants and aphids are well studied but it is unknown if aphid-attending ants place a greater relative importance on defending aphids from aphid-predators or from competing ant colonies. We tested the hypothesis that aphid-attending ants defend their aphids against aphid-predators more aggressively than against ants from neighboring colonies. We conducted introduction trials by placing an individual non-predatory

Iain D. Phillips; Craig K. R. Willis

2005-01-01

215

Neural Network Ensemble Based Ant Colony Classification Rule Mining  

Microsoft Academic Search

Generalization ability and comprehensibility are very important for classification rule mining. This paper proposes an improved ant colony classification rule mining method named ant-classifier with strong comprehensibility. Neural network ensemble is with good generalization ability. A novel algorithm NeAnt is also proposed which integrates neural network ensemble and ant-classifier's merit. In the NeAnt, neural network ensemble is used for preprocessing

Chuan Chen; Youqing Chen; Junbing He

2006-01-01

216

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.

217

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

218

Preference of food particle size among several urban ant species.  

PubMed

Appropriate particle size may be a critical characteristic for effective granular ant baits. We examined the particle size preference of six species of pest ants to an anchovy-based bait. We also examined head capsule widths of Argentine ants, Linepithema humile (Mayr) (mean = 0.54 mm), California harvester ants, Pogonomyrmex californicus (Buckley) (mean = 1.63 mm), red imported fire ants, Solenopsis invicta Buren (mean = 0.9 mm), and southern fire ants, Solenopsis xyloni McCook (mean = 0.76 mm) and compared them with the first and second most preferred particle size. There were differences between particle size of which the most mass was removed and of which there were more particles removed by ants. California Argentine ants, southern fire ants, and Alabama Argentine ants removed more 840 to 1,000-microm particle mass of the anchovy diet but had more visits to dishes containing 420 to 590 microm particles. California harvester ants and Allegheny mound ants, Formica spp., removed more >2,000 microm particle mass but visited dishes containing 1,000 to 2,000 microm particles more often. Red imported fire ants also removed more >2,000 microm particle mass but visited dishes with 590 to 840-microm particles most often. Pharaoh ants, Monomorium pharaonis (L.), removed and visited 420 to 590-microm particles more than any other size. A linear regression model determined that particle size preferred by each ant species relates to forager head width. The majority of particles of commercial ant bait, including Amdro, Ascend, Award, Bushwhacker, Max Force with fipronil, and old and new formulations of Max Force with hydramethylnon, were 1,000 to 2,000 microm, but the majority of Niban particles were <420 microm. Altering the size of particles of toxic ant baits to fit the particle size preference of each pest ant species may increase the efficacy of ant baits. PMID:12539835

Hooper-Bùi, Linda M; Appel, Arthur G; Rust, Michael K

2002-12-01

219

Applying DACS3 in the Capacitated Vehicle Routing Problem  

Microsoft Academic Search

Ant Colony System (ACS) is a well known optimization algorithm to find a good route solution for logistics and transportation industries such as Traveling Salesman Problem (TSP) or Vehicle Routing Problem (VRP), for the company maximize the efficiency and resource. Several versions of Ant Colony Optimization (ACO) algorithms have been proposed which aim to achieve an optimum solution includes Dynamic

Zulaiha Ali Othman; Abdul Razak Hamdan

2010-01-01

220

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.

Liu, Liqiang; Dai, Yuntao

2014-01-01

221

Path integration in desert ants, Cataglyphis: how to make a homing ant run away from home.  

PubMed Central

Path integration is an ant's lifeline on any of its foraging journeys. It results in a homebound global vector that continually informs the animal about its position relative to its starting point. Here, we use a particular (repeated training and displacement) paradigm, in which homebound ants are made to follow a familiar landmark route repeatedly from the feeder to the nest, even after they have arrived at the nest. The results show that during the repeated landmark-guided home runs the ant's path integrator runs continually, so that the current state of the homebound vector increasingly exceeds the reference state. The dramatic result is that the homing ants run away from home. This finding implies that the ants do not rely on cartographic information about the locations of nest and feeder (e.g. that the nest is always south of the feeder), but just behave according to what the state of their egocentric path integrator tells them.

Andel, David; Wehner, Rudiger

2004-01-01

222

Fossil evidence for the early ant evolution.  

PubMed

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. PMID:17891532

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

2008-02-01

223

Expanding habitat of the imported fire ant (Solenopsis invicta) : A public health concern  

Microsoft Academic Search

Residents in the southeastern United States would hardly describe life with the aggressive imported fire ant as peaceful coexistence. The continued spread of these insects has produced agricultural problems, changes in the ecosystem, and increasing numbers of subjects with sting sequelae, including hypersensitivity reactions, secondary infections, and rare neurologic sequelae. Evolutionary changes have facilitated their expansion northward into Virginia and

Stephen F. Kemp; Richard D. deShazo; John E. Moffitt; David F. Williams; William A. Buhner

2000-01-01

224

Ant Colony Optimization Applied to Route Planning Using Link Travel Time Predictions  

Microsoft Academic Search

Finding the shortest path in a road network is a well known problem. Various proven static algorithms such as Dijkstra and A* are extensively evaluated and implemented. When confronted with dynamic costs, such as link travel time predictions, alternative route planning algorithms have to be applied. This paper applies Ant Colony Optimization combined with link travel time predictions to find

Rutger Claes; Tom Holvoet

2011-01-01

225

Scheduling continuous casting of aluminum using a multiple objective ant colony optimization metaheuristic  

Microsoft Academic Search

This paper presents an ant colony optimization metaheuristic for the solution of an industrial scheduling problem in an aluminum casting center. We present an efficient representation of a continuous horizontal casting process which takes account of a number of objectives that are important to the scheduler. We have incorporated the methods proposed in software that has been implemented in the

Marc Gravel; Wilson L. Price; Caroline Gagné

2002-01-01

226

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

227

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

Microsoft Academic Search

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

Kenji Matsuura; Toshihisa Yashiro

2006-01-01

228

Desert Ants Learn Vibration and Magnetic Landmarks  

PubMed Central

The desert ants Cataglyphis navigate not only by path integration but also by using visual and olfactory landmarks to pinpoint the nest entrance. Here we show that Cataglyphis noda can additionally use magnetic and vibrational landmarks as nest-defining cues. The magnetic field may typically provide directional rather than positional information, and vibrational signals so far have been shown to be involved in social behavior. Thus it remains questionable if magnetic and vibration landmarks are usually provided by the ants' habitat as nest-defining cues. However, our results point to the flexibility of the ants' navigational system, which even makes use of cues that are probably most often sensed in a different context.

Buehlmann, Cornelia

2012-01-01

229

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

230

Ant-gardens of tropical Asian rainforests  

NASA Astrophysics Data System (ADS)

Ant-garden (AG) associations are systems of epiphytic plants and arboricolous (i.e., tree-living) ants, in which the ants build fragile carton nests containing organic material. They collect and incorporate seeds or fruits of epiphytes that then germinate and grow on the nest [sensu Corbara et al. (1999) 38:73-89]. The plant roots stabilize the nest carton. AGs have been well-known in the neotropics for more than 100 years. In contrast, reports on similar associations in the paleotropics are scarce so far. After discovering a first common AG system on giant bamboo [Kaufmann et al. (2001) 48:125-133], we started a large-scale survey for AGs in Peninsular Malaysia, Borneo, Java, and southern Thailand. A great variety of AG systems (altogether including 18 ant species and 51 plant species) was discovered and is described in the present paper. The high number of species participating in AG associations was reflected by a great variability in the specific appearances of the nest gardens. Frequently, further groups of organisms (e.g., hemipteran trophobionts, fungi) were also involved. Preference patterns of particular ant and epiphyte species for each other and for particular phorophytes (carrier trees) were detected. We integrate domatia-producing, so-called ant-house epiphytes in our study and compare their phases of establishment, as well as other characteristics, to “classical” AGs, coming to the conclusion that they should be regarded only as a special type of AG epiphyte and not as a separate ecological category.

Kaufmann, Eva; Maschwitz, Ulrich

2006-05-01

231

Explaining the abundance of ants in lowland tropical rainforest canopies.  

PubMed

The extraordinary abundance of ants in tropical rainforest canopies has led to speculation that numerous arboreal ant taxa feed principally as "herbivores" of plant and insect exudates. Based on nitrogen (N) isotope ratios of plants, known herbivores, arthropod predators, and ants from Amazonia and Borneo, we find that many arboreal ant species obtain little N through predation and scavenging. Microsymbionts of ants and their hemipteran trophobionts might play key roles in the nutrition of taxa specializing on N-poor exudates. For plants, the combined costs of biotic defenses and herbivory by ants and tended Hemiptera are substantial, and forest losses to insect herbivores vastly exceed current estimates. PMID:12738862

Davidson, Diane W; Cook, Steven C; Snelling, Roy R; Chua, Tock H

2003-05-01

232

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

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

2013-01-01

233

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

234

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 173Â176. ISSN 0002-7685, electronic ISSN 1938Â4211. ©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.; Sanou, Missa P.; Leidersdorf, Bil; Collier, Alexander

235

The Informational Content of Ex Ante Forecasts  

Microsoft Academic Search

The informational content of different forecasts can be compared by regressing the actual change in a variable to be forecasted on forecasts of the change. We use the procedure in Fair and Shiller (1987) to examine the informational content of three sets of ex ant. forecasts: the American Statistical Association and National Bureau of Economic Research Survey (ASA), Data Resources

Ray C. Fair; Robert J. Shiller

1989-01-01

236

SMART Power Systems for ANTS Missions  

Microsoft Academic Search

Autonomous NanoTechnology Swarm (ANTS) Architecture is based on Addressable Reconfigurable Technology (ART) adaptable for the full spectrum of activities in space. ART systems based on currently available electromechanical (EMS) technology could support human crews on the lunar surface within the next 10 to 15 years. Two or more decades from now, NEMS (Super Miniaturized ART or SMART) technology could perform

P. E. Clark; S. R. Floyd; S. A. Curtis; M. L. Rilee

2005-01-01

237

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.

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

2009-01-01

238

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.

0002-11-30

239

Water surface locomotion in tropical canopy ants.  

PubMed

Upon falling onto the water surface, most terrestrial arthropods helplessly struggle and are quickly eaten by aquatic predators. Exceptions to this outcome mostly occur among riparian taxa that escape by walking or swimming at the water surface. Here we document sustained, directional, neustonic locomotion (i.e. surface swimming) in tropical arboreal ants. We dropped 35 species of ants into natural and artificial aquatic settings in Peru and Panama to assess their swimming ability. Ten species showed directed surface swimming at speeds >3 body lengths s(-1), with some swimming at absolute speeds >10 cm s(-1). Ten other species exhibited partial swimming ability characterized by relatively slow but directed movement. The remaining species showed no locomotory control at the surface. The phylogenetic distribution of swimming among ant genera indicates parallel evolution and a trend toward negative association with directed aerial descent behavior. Experiments with workers of Odontomachus bauri showed that they escape from the water by directing their swimming toward dark emergent objects (i.e. skototaxis). Analyses of high-speed video images indicate that Pachycondyla spp. and O. bauri use a modified alternating tripod gait when swimming; they generate thrust at the water surface via synchronized treading and rowing motions of the contralateral fore and mid legs, respectively, while the hind legs provide roll stability. These results expand the list of facultatively neustonic terrestrial taxa to include various species of tropical arboreal ants. PMID:24920838

Yanoviak, S P; Frederick, D N

2014-06-15

240

Ant colony optimization for continuous domains  

Microsoft Academic Search

In this paper we present an extension of Ant Colony Optimization (ACO) to continuous domains. We show how ACO, which was initially developed to be a metaheuristic for combinatorial optimization, can be adapted to continuous opti- mization without any major conceptual change to its structure. We present the general idea, implementation, and results obtained. We compare the results with those

Krzysztof Socha; Marco Dorigo

2008-01-01

241

Multiobjective optimal placement of switches and protective devices in electric power distribution systems using ant colony optimization  

Microsoft Academic Search

This paper presents a multiobjective optimization methodology to optimally place switches and protective devices in electric power distribution networks. Identifying the type and location of them is a combinatorial optimization problem described by a nonlinear and nondifferential function. The multiobjective ant colony optimization (MACO) has been applied to this problem to minimize the total cost while simultaneously minimize two distribution

Wiwat Tippachon; Dulpichet Rerkpreedapong

2009-01-01

242

Leaf-cutting ants revisited: Towards rational management and control  

Microsoft Academic Search

Leaf-cutting ants, being the principal herbivores and ecosystem engineers in the Neotropics, have been considered to be a keystone species in natural ecosystems and agroecosystems, due to the direct and indirect effects of their plant defoliation activities. This review summarizes current concepts of the biological and ecological importance of leaf-cutting ants. The ants' pest status is briefly assessed from both

James Montoya-Lerma; Carolina Giraldo-Echeverri; Inge Armbrecht; Alejandro Farji-Brener; Zoraida Calle

2012-01-01

243

Queen primer pheromone affects conspecific fire ant ( Solenopsis invicta ) aggression  

Microsoft Academic Search

Monogyne fire ant, Solenopsis invicta, colony workers are territorial and are aggressive toward members of other fire ant colonies. In contrast, polygyne colony workers are not aggressive toward non-nestmates, presumably due to broader exposure to heritable and environmentally derived nestmate recognition cues (broad template). Workers from both monogyne and polygyne fire ant colonies execute newly mated queens after mating flights.

Robert K. Vander Meer; Leeanne E. Alonso

2002-01-01

244

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

245

Mutualistic ants as an indirect defence against leaf pathogens.  

PubMed

Mutualistic ants are commonly considered as an efficient indirect defence against herbivores. Nevertheless, their indirect protective role against plant pathogens has been scarcely investigated. We compared the protective role against pathogens of two different ant partners, a mutualistic and a parasitic ant, on the host plant Acacia hindsii (Fabaceae). The epiphytic bacterial community on leaves was evaluated in the presence and absence of both ant partners by cultivation and by 454 pyrosequencing of the 16S rRNA gene. Pathogen-inflicted leaf damage, epiphytic bacterial abundance (colony-forming units) and number of operational taxonomic units (OTUs) were significantly higher in plants inhabited by parasitic ants than in plants inhabited by mutualistic ants. Unifrac unweighted and weighted principal component analyses showed that the bacterial community composition on leaves changed significantly when mutualistic ants were removed from plants or when plants were inhabited by parasitic ants. Direct mechanisms provided by ant-associated bacteria would contribute to the protective role against pathogens. The results suggest that the indirect defence of mutualistic ants also covers the protection from bacterial plant pathogens. Our findings highlight the importance of considering bacterial partners in ant-plant defensive mutualisms, which can contribute significantly to ant-mediated protection from plant pathogens. PMID:24392817

González-Teuber, Marcia; Kaltenpoth, Martin; Boland, Wilhelm

2014-04-01

246

Exploratory behavior of Lasius pallitarsis ants encountering novel areas  

Microsoft Academic Search

Summary Lasius pallitarsis ants were placed in situations where they encountered unfamiliar areas and had to choose between one of two directions for further exploration. Workers advancing onto new ground apparently leave behind some chemical signature to which later ants orient. This orientation occurred under two types of experimental conditions. First, ants show a significant tendency to follow each other

P. Nonacs

1991-01-01

247

Angioedema following ingestion of fried flying red fire ants.  

PubMed

Red ants sting anaphylaxis was rarely reported from India. But angioedema due to ingestion of fried flying red fire ants in children is almost never reported from India and also very rarely reported from outside India. We report a case of recurrent non allergic angioedema following ingestion of fried flying red ants. PMID:23665605

Nandhakumar, V

2013-04-01

248

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

249

Microbiomes of ant castes implicate new microbial roles in the fungus-growing ant Trachymyrmex septentrionalis  

PubMed Central

Fungus-growing ants employ several defenses against diseases, including disease-suppressing microbial biofilms on their integument and in fungal gardens. Here, we compare the phenology of microbiomes in natural nests of the temperate fungus-growing ant Trachymyrmex septentrionalis using culture-dependent isolations and culture-independent 16S-amplicon 454-sequencing. 454-sequencing revealed diverse actinobacteria associated with ants, including most prominently Solirubrobacter (12.2–30.9% of sequence reads), Pseudonocardia (3.5–42.0%), and Microlunatus (0.4–10.8%). Bacterial abundances remained relatively constant in monthly surveys throughout the annual active period (late winter to late summer), except Pseudonocardia abundance declined in females during the reproductive phase. Pseudonocardia species found on ants are phylogenetically different from those in gardens and soil, indicating ecological separation of these Pseudonocardia types. Because the pathogen Escovopsis is not known to infect gardens of T. septentrionalis, the ant-associated microbes do not seem to function in Escovopsis suppression, but could protect against ant diseases, help in nest sanitation, or serve unknown functions.

Ishak, Heather D.; Miller, Jessica L.; Sen, Ruchira; Dowd, Scot E.; Meyer, Eli; Mueller, Ulrich G.

2011-01-01

250

Experimental tests of the mechanism for ant-enhanced growth in an ant-tended lycaenid butterfly  

Microsoft Academic Search

In a previous laboratory study, larvae of the ant-tended lycaenid butterfly Hemiargus isola developed into larger adults when reared with the ant Formica perpilosa than when reared without ants. Ants neither fed butterfly larvae nor significantly delayed developmental duration. We investigated\\u000a two non-exclusive hypotheses for the mechanism of this effect: larvae tended by F. perpilosa (1) consume more food, and

Diane Wagner; Carlos Martínez del Rio

1997-01-01

251

When are ant-attractant devices a worthwhile investment? Vicia faba extrafloral nectaries and Lasius niger ants  

Microsoft Academic Search

Most studies aiming to determine the beneficial effect of ants on plants simply consider the effects of the presence or exclusion\\u000a of ants on plant yield. This approach is often inadequate, however, as ants interact with both non-tended herbivores and tended\\u000a Homoptera. Moreover, the interaction with these groups of organisms is dependent on ant density, and these functional relationships\\u000a are

Thomas H. Oliver; James M. Cook; Simon R. Leather

2007-01-01

252

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.

Wang, JinFeng; Fan, XiaoLiang; Wan, Shuting

2014-01-01

253

Distribution, composition, and dispersal of ant gardens and tending ants in three kinds of central Amazonian habitats  

Microsoft Academic Search

Ant Gardens (AGs) grow on arboreal carton-ant nests and consist of taxonomically diverse epiphytic plants specific to this substrate. I compared the densities of AGs and their component flora in three habitats: rain forest, campinarana (transition) and campina (arid). I also observed the behavior of Azteca sp. and Pachycondyla goeldii Forel 1912 ants towards the seeds of Codonanthe sp. and

Onildo J. Marini-Filho

1999-01-01

254

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

255

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.

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

256

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.

1997-01-01

257

Ants under crowded conditions consume more energy.  

PubMed

Social insects live in colonies consisting of many workers, where worker interactions play an important role in regulating colony activities. Workers interact within the social space of the nest; therefore, constraints on nest space may alter worker behaviour and affect colony activities and energetics. Here we show in the ant Temnothorax rugatulus that changes in nest space have a significant effect on colony energetics. Colonies with restricted nest space showed a 14.2 per cent increase in metabolic rate when compared with the same colonies in large uncrowded nests. Our study highlights the importance of social space and shows that constraints on social space can significantly affect colony behaviour and energy use in ants. We discuss the implications of our findings regarding social insects in general. PMID:18765354

Cao, Tuan T; Dornhaus, Anna

2008-12-23

258

Fast and Flexible: Argentine Ants Recruit from Nearby Trails  

PubMed Central

Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

Flanagan, Tatiana P.; Pinter-Wollman, Noa M.; Moses, Melanie E.; Gordon, Deborah M.

2013-01-01

259

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.

260

Extrafloral nectar content alters foraging preferences of a predatory ant.  

PubMed

We tested whether the carbohydrate and amino acid content of extrafloral nectar affected prey choice by a predatory ant. Fire ants, Solenopsis invicta, were provided with artificial nectar that varied in the presence of carbohydrates and amino acids and were then provided with two prey items that differed in nutritional content, female and male crickets. Colonies of fire ants provided with carbohydrate supplements consumed less of the female crickets and frequently did not consume the high-lipid ovaries of female crickets. Colonies of fire ants provided with amino acid supplements consumed less of the male crickets. While a number of studies have shown that the presence of extrafloral nectar or honeydew can affect ant foraging activity, these results suggest that the nutritional composition of extrafloral nectar is also important and can affect subsequent prey choice by predatory ants. Our results suggest that, by altering the composition of extrafloral nectar, plants could manipulate the prey preferences of ants foraging on them. PMID:19864270

Wilder, Shawn M; Eubanks, Micky D

2010-04-23

261

Extrafloral nectar content alters foraging preferences of a predatory ant  

PubMed Central

We tested whether the carbohydrate and amino acid content of extrafloral nectar affected prey choice by a predatory ant. Fire ants, Solenopsis invicta, were provided with artificial nectar that varied in the presence of carbohydrates and amino acids and were then provided with two prey items that differed in nutritional content, female and male crickets. Colonies of fire ants provided with carbohydrate supplements consumed less of the female crickets and frequently did not consume the high-lipid ovaries of female crickets. Colonies of fire ants provided with amino acid supplements consumed less of the male crickets. While a number of studies have shown that the presence of extrafloral nectar or honeydew can affect ant foraging activity, these results suggest that the nutritional composition of extrafloral nectar is also important and can affect subsequent prey choice by predatory ants. Our results suggest that, by altering the composition of extrafloral nectar, plants could manipulate the prey preferences of ants foraging on them.

Wilder, Shawn M.; Eubanks, Micky D.

2010-01-01

262

Ant fat extraction with a Soxhlet extractor.  

PubMed

Stored fat can be informative about the relative age of an ant, its nutritional status, and the nutritional status of the colony. Several methods are available for the quantification of stored fat. Before starting a project involving fat extraction, investigators should weigh the advantages and disadvantages of different methods in order to choose the one that is best suited to the question being addressed. This protocol, although not as accurate as some alternatives, facilitates the rapid quantification of many individuals. PMID:20147208

Smith, Chris R; Tschinkel, Walter R

2009-07-01

263

Biomimicry: Further Insights from Ant Colonies?  

Microsoft Academic Search

Biomimicry means learning from nature. Well known examples include physical structures such as the Velcro fastener. But natural\\u000a selection has also “engineered” mechanisms by which the components of adaptive biological systems are organized. For example,\\u000a natural selection has caused the foragers in an ant colony to cooperate and communicate in order to increase the total foraging\\u000a success of the colony.

Francis L. W. Ratnieks

2007-01-01

264

Constructing participation practice: an ANT account  

Microsoft Academic Search

Purpose – The purpose of this paper is to explore how participation can be investigated as an open and non-exclusive sociomaterial practice. Design\\/methodology\\/approach – Framed by translation discourse and a view of the social world as a sociology of associations, participation in organisations is conceptualised as a network building practice. Actor-network theory (ANT) is used as an analytical method to

Suzanne Perillo

2008-01-01

265

Visual adaptation in nocturnal and diurnal ants  

Microsoft Academic Search

1.The compound eyes of three species ofCamponotus ants, one exclusively nocturnal (Camponotus irritans), one crepuscular and nocturnal (Camponotus ligniperda), and the third diurnal (Camponotus detritus) are compared with respect to day\\/night light sensitivity changes. AsCamponotus detritus sometimes stays outside the nest during the night, the strictly diurnal speciesCataglyphis bicolor is included in the comparison. Even though all four species are

Ursula Menzi

1987-01-01

266

Kin-informative recognition cues in ants  

PubMed Central

Although social groups are characterized by cooperation, they are also often the scene of conflict. In non-clonal systems, the reproductive interests of group members will differ and individuals may benefit by exploiting the cooperative efforts of other group members. However, such selfish behaviour is thought to be rare in one of the classic examples of cooperation—social insect colonies—because the colony-level costs of individual selfishness select against cues that would allow workers to recognize their closest relatives. In accord with this, previous studies of wasps and ants have found little or no kin information in recognition cues. Here, we test the hypothesis that social insects do not have kin-informative recognition cues by investigating the recognition cues and relatedness of workers from four colonies of the ant Acromyrmex octospinosus. Contrary to the theoretical prediction, we show that the cuticular hydrocarbons of ant workers in all four colonies are informative enough to allow full-sisters to be distinguished from half-sisters with a high accuracy. These results contradict the hypothesis of non-heritable recognition cues and suggest that there is more potential for within-colony conflicts in genetically diverse societies than previously thought.

Nehring, Volker; Evison, Sophie E. F.; Santorelli, Lorenzo A.; d'Ettorre, Patrizia; Hughes, William O. H.

2011-01-01

267

Evolution of cuticular hydrocarbon diversity in ants.  

PubMed

The cuticular hydrocarbons (CHCs) of ants provide important cues for nest-mate and caste recognition. There is enormous diversity in the composition of these CHCs, but the manner in which this diversity has evolved is poorly understood. We gathered data on CHC profiles for 56 ant species, relating this information to their phylogeny. We deduced the mode of evolution of CHC profiles by reconstructing character evolution and then relating the number of changes in CHC components along each branch of the phylogeny to the length of the branch. There was a strong correlation between branch length and number of component changes, with fewer changes occurring on short branches. Our analysis thereby indicated a gradual mode of evolution. Different ant species tend to use specific CHC structural types that are exclusive of other structural types, indicating that species differences may be generated in part by switching particular biosynthetic pathways on or off in different lineages. We found limited, and contradictory, evidence for abiotic factors (temperature and rainfall) driving change in CHC profiles. PMID:21375648

van Wilgenburg, E; Symonds, M R E; Elgar, M A

2011-06-01

268

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.

Bos, Nick; d'Ettorre, Patrizia

2012-01-01

269

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.

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

2010-01-01

270

Bioturbation by Fire Ants in the Coastal Prairie of Texas  

NASA Astrophysics Data System (ADS)

Fire ants (Solenopsis invicta) were introduced to the US in the early part of the last century. They have spread throughout the southeastern US in the absence of native competitors and predators with a range limited by abiotic factors. Each fire ant mound contains thousands of individuals, can be large, and can be numerous enough to comprise a dominant feature of the landscape. Studies of this species have focused upon its spread, formation of single- and multiple-queen colonies, genetic structure, and impact on native fauna and human health. Some studies have analyzed native fire ant-soil interactions, but few studies have examined the process of bioturbation by introduced fire ants in native ecosystems. Fire ants on the coastal prairie of Texas primarily are of the multiple-queen type that exhibit a much higher density of mounds than the single-queen type. Consequently, mound-building activities by fire ants can have a marked effect upon soil structure and nutrient content and may affect soil organisms and plants. Fire ant activity, mound density, mound dispersion, soil texture, soil permeability, soil moisture content, and soil nutrients were measured. Fire ants mounds are visible aboveground from April-November. Density of mounds was 117-738/ha, and average mound lifespan was 3.6 months with only 9% of the mounds remaining active throughout the entire season. Mounds were dispersed randomly. Foraging activity by fire ants was from June through October with a peak in July. Annual soil turnover was estimated by collecting and weighing mounds. There was no effect of ant mounds on soil texture, but water infiltration was higher in areas with ant mounds. Early-season samples showed no nutrient differences, but late-season samples showed that ant mounds contained higher amounts of micronutrients than random samples of soil. These data are compared to similar data on effects of mounds from native ants and from native and introduced ants in different habitats.

Cameron, G.; Williams, L.

2001-12-01

271

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

272

Autonomous NanoTechnology Swarm (ANTS) Prospecting Asteroid Mission (PAM), Asteroid Proximity Operations  

NASA Technical Reports Server (NTRS)

The Autonomous NanoTechnology Swarm (ANTS) is a generic mission architecture based on spatially distributed spacecraft, autonomous and redundant components, and hierarchical organization. The ANTS Prospecting Asteroid Mission (PAM) is an ANTS application which will nominally use a swarm of 1000 spacecraft. There would be 10 types of "specialists" with common spacecraft buses. There would be 10 subswarms of approximately 100 spacecraft each or approximately 10 of each specialist in each swarm. The ANTS PAM primary objective is the exploration of the asteroid belt in search of resources and material with astrobiologically relevant origins and signatures. The ANTS PAM spacecraft will nominally be released from a station in an Earth-Moon L1 libration point orbit, and they will use Solar sails for propulsion. The sail structure would be highly flexible, capable of changing morphology to change cross-section for capture of sunlight or to form effective "tip vanes" for attitude control. ANTS PAM sails would be capable of full to partial deployment, to change effective sail area and center of pressure, and thus allow attitude control. Results of analysis of a transfer trajectory from Earth to a sample target asteroid will be presented. ANTS PAM will require continuous coverage of different asteroid locations as close as one to two asteroid "diameters" from the surface of the asteroid for periods of science data collection during asteroid proximity operations. Hovering spacecraft could meet the science data collection objectives. The results of hovering analysis will be presented. There are locations for which hovering is not possible, for example on the illuminated side of the asteroid. For cases where hovering is not possible, the results of utilizing asteroid formations to orbit the asteroid and achieve the desired asteroid viewing will be presented for sample asteroids. The ability of ANTS PAM to reduce the area of the solar sail during asteroid proximity operations is critical to the maintenance of orbiting formations for a period of time. Results of analysis of potential "traffic" problems during asteroid proximity operations will be presented.

Marr, Greg; Cooley, Steve; Roithmayr, Carlos; Kay-Bunnell, Linda; Williams, Trevor

2004-01-01

273

Biodiversity below ground: probing the subterranean ant fauna of Amazonia.  

PubMed

Ants are abundant, diverse, and ecologically dominant in tropical forests. Subterranean ants in particular are thought to have a significant environmental impact, although difficulties associated with collecting ants underground and examining their ecology and behavior have limited research. In this paper, we present the results of a study of subterranean ant diversity in Amazonian Ecuador that employs a novel probe to facilitate the discovery of species inhabiting the soil horizon. Forty-seven species of ants in 19 genera, including new and apparently rare species, were collected in probes. Approximately 19% of the species collected at different depths in the soil were unique to probe samples. Analysis of similarity (ANOSIM) results showed that the species composition of ants collected with the probe was significantly different from samples collected using other techniques. Additionally, ANOSIM computations indicated the species assemblage of ants collected 12.5 cm below the surface was significantly different from those found at 25, 37.5, and 50 cm. Ant diversity and species accumulation rates decreased with increasing depth. There were no species unique to the lowest depths, suggesting that subterranean ants may not be distributed deep in the soil in Amazonia due to the high water table. The technique we describe could be used to gain new insights into the distribution and biology of subterranean ant species and other members of the species-rich soil invertebrate macrofauna. PMID:17457552

Ryder Wilkie, Kari T; Mertl, Amy L; Traniello, James F A

2007-09-01

274

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

275

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.

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

2013-01-01

276

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.

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

2014-01-01

277

Multiple Sequence Alignment by Ant Colony Optimization and Divide-and-Conquer  

Microsoft Academic Search

\\u000a Multiple sequence alignment is a common task in molecular biology and bioinformatics. Obtaining an accurate alignment of protein\\u000a sequences is a difficult computational problem because many heuristic techniques cannot achieve optimality in a reasonable\\u000a running time. A novel multiple sequence alignment algorithm based on ant colony optimization and divide-and-conquer technique\\u000a is proposed. The algorithm divides a set of sequences into

Yixin Chen; Yi Pan; Juan Chen; Wei Liu; Ling Chen

2006-01-01

278

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

279

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

280

A Clustering Algorithm Based on the Ants Self-Assembly Behavior  

Microsoft Academic Search

\\u000a We have presented in this paper an ants based clustering algorithm which is inspired from the self-assembling behavior observed\\u000a in real ants. These ants progressively become connected to an initial point called the support and then successively to other\\u000a connected ants. The artificial ants that we have defined similarly build a tree where each ant represents a node\\/data. Ants\\u000a use

Hanene Azzag; Nicolas Monmarché; Mohamed Slimane; Christiane Guinot; Gilles Venturini

2003-01-01

281

Millipede defense: use of detachable bristles to entangle ants.  

PubMed Central

The millipede Polyxenus fasciculatus (Diplopoda; Polyxenida) defends itself against ants by use of a pair of bristle tufts at its rear. When attacked, it wipes the tufts against the ants, thereby causing these to become encumbered by bristles that detach from the tufts. Ants contaminated with bristles desist from their assault. The bristles have grappling hooks at the tip by which they lock onto setae of the ants and barbs along their length by which they interlink. In attempting to rid themselves of bristles, ants may succeed only in further entangling themselves by causing the bristles to become enmeshed. Ants heavily contaminated may remain entangled and die. Most millipedes have chemical defenses; polyxenids, instead, have a mechanical weapon. Images Fig. 2

Eisner, T; Eisner, M; Deyrup, M

1996-01-01

282

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.

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

2012-01-01

283

Anting in a Semifree-ranging Group of Cebus apella  

Microsoft Academic Search

Capuchins apply many organic materials, especially leaves, to their skin. Protection against ectoparasites is the most commonly\\u000a discussed explanation for the behavior. We describe fur rubbing with carpenter ants(Camponotus rufipes) by semifree-ranging tufted capuchins(Cebus apella) in the Tietê Ecological Park, São Paulo, Brazil. Carpenter ants produce and secrete high concentrations of formic acid, which\\u000a repels tick nymphs. Anting occurred significantly

M. P. Verderane; T. Falótico; B. D. Resende; M. B. Labruna; P. Izar; E. B. Ottoni

2007-01-01

284

Ante-dependence Analysis of an Ordered Set of Variables  

Microsoft Academic Search

For a set of variables in a given order, $s$th ante-dependence will be said to obtain if each one of the variables, given at least $s$ immediate antecedent variables in the order, is independent of all further preceding variables. If the number of variables is $p$, ante-dependence is of some order between 0 and $p - 1.$ 0th ante-dependence and

K. R. Gabriel

1962-01-01

285

Ant clustering PHD filter for multiple-target tracking  

Microsoft Academic Search

A novel ant clustering filtering algorithm, under the guidance of first-order statistic moment of posterior multiple-target state (probability hypothesis density), is investigated and applied to estimate the time-varying number of targets and their individual states in a cluttered environment. The ant clustering filtering algorithm includes two clustering steps: the first step is called rough ant clustering, which involves the stochastic

Benlian Xu; Huigang Xu; Jihong Zhu

2011-01-01

286

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.

Gonthier, David J.

2012-01-01

287

Fire Ant Control with Entomopathogens in the USA  

Microsoft Academic Search

Fire ants are stinging invasive ants from South America that infest over 129.5 million hectares in the southern United States,\\u000a where eradication is no longer considered possible. The biological control of fire ants, especially by pathogens, is viewed\\u000a by some as the only sustainable tactic for suppression. Microscopic-based surveys conducted in South America during the 1970s\\u000a and 1980s led to

David H. Oi; Steven M. Valles

288

Scavenging in Mediterranean ecosystems: effect of the invasive Argentine ant  

Microsoft Academic Search

Above-ground invertebrates may represent a high proportion of animal biomass, but few data are available on their fate after\\u000a death. In Mediterranean ant communities, they are frequently scavenged by ants. Here, we assessed the consequences of Argentine\\u000a ant invasion on the removal of arthropod corpses in Doñana National Park (SW Spain). In three natural habitats that differed\\u000a in their degree

Elena Angulo; Stéphane Caut; Xim Cerdá

2011-01-01

289

Habitat complexity facilitates coexistence in a tropical ant community.  

PubMed

The role of habitat complexity in the coexistence of ant species is poorly understood. Here, we examine the influence of habitat complexity on coexistence patterns in ant communities of the remote Pacific atoll of Tokelau. The invasive yellow crazy ant, Anoplolepis gracilipes (Smith), exists in high densities on Tokelau, but still coexists with up to seven other epigeic ant species. The size-grain hypothesis (SGH) proposes that as the size of terrestrial walking organisms decreases, the perceived complexity of the environment increases and predicts that: (1) leg length increases allometrically with body size in ants, and (2) coexistence between ant species is facilitated by differential habitat use according to body size. Analysis of morphological variables revealed variation inconsistent with the morphological prediction of the SGH, as leg length increased allometrically with head length only. We also experimentally tested the ability of epigeic ants in the field to discover and dominate food resources in treatments of differing rugosity. A. gracilipes was consistently the first to discover food baits in low rugosity treatments, while smaller ant species were consistently the first to discover food baits in high rugosity treatments. In addition, A. gracilipes dominated food baits in planar treatments, while smaller ant species dominated baits in rugose treatments. We found that the normally predictable outcomes of exploitative competition between A. gracilipes and other ant species were reversed in the high rugosity treatments. Our results support the hypothesis that differential habitat use according to body size provides a mechanism for coexistence with the yellow crazy ant in Tokelau. The SGH may provide a mechanism for coexistence in other ant communities but also in communities of other terrestrial, walking insects that inhabit a complex landscape. PMID:16763839

Sarty, M; Abbott, K L; Lester, P J

2006-09-01

290

Interspecific hybridization and caste specificity of protein in fire ant.  

PubMed

One natural population of fire ant in Texas was found to be a hybrid between Solenopsis geminata and S. xyloni. Evidence from isozyme studies and breeding experiments is provided to demonstrate interspecific hybridization in ants. In this hybrid population, all worker ants have both parental types of nicotinamide adenine dinucleotide-malate dehydrogenase isozymes, but 95 percent of queens possess only the maternal type. PMID:17776925

Hung, A C; Vinson, S B

1977-06-24

291

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

292

Significance of the tropical fire ant Solenopsis geminata (hymenoptera: formicidae) as part of the natural enemy complex responsible for successful biological control of many tropical irrigated rice pests.  

PubMed

The tropical fire ant Solenopsis geminata (Fabricius) often nests very abundantly in the earthen banks (bunds) around irrigated rice fields in the tropics. Where some farmers habitually drain fields to the mud for about 3-4 days, the ants can quickly spread up to about 20 m into the fields where they collect food, including pest prey such as the eggs and young of the apple snail Pomacea caniculata (Lamarck) and insects such as lepidopterous larvae and hoppers, notably Nilaparvata lugens (Stäl) the brown planthopper (Bph) and green leafhoppers Nephotettix spp. Even in drained fields, the activity of S. geminata is restricted by rainfall in the wet season. The relatively few ant workers that forage characteristically into drained fields and on to the transplanted clumps of rice plants (hills) kill the normally few immigrant Bph adults but are initially slower acting than other species of the natural enemy complex. However, larger populations of Bph are fiercely attacked and effectively controlled by rapidly recruited ant workers; whereas, in the absence of the ant, the other natural enemies are inadequate. In normal circumstances, there is no ant recruitment in response to initially small populations of immigrant Bph and no evidence of incompatibility between ant foragers and other natural enemies such as spiders. However, when many ants are quickly and aggressively recruited to attack large populations of Bph, they temporarily displace some spiders from infested hills. It is concluded that, in suitable weather conditions and even when insecticides kill natural enemies within the rice field, periodic drainage that enables S. geminata to join the predator complex is valuable for ant-based control of pests such as snails and Lepidoptera, and especially against relatively large populations of Bph. Drainage practices to benefit ants are fully compatible with recent research, which shows that periodic drainage combats problems of 'yield decline' in intensively irrigated tropical rice and is also needed in South East Asia to make better use of seriously declining water supplies for irrigation. PMID:19203401

Way, M J; Heong, K L

2009-10-01

293

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

294

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

295

Signals can trump rewards in attracting seed-dispersing ants.  

PubMed

Both rewards and signals are important in mutualisms. In myrmecochory, or seed dispersal by ants, the benefits to plants are relatively well studied, but less is known about why ants pick up and move seeds. We examined seed dispersal by the ant Aphaenogaster rudis of four co-occurring species of plants, and tested whether morphology, chemical signaling, or the nutritional quality of fatty seed appendages called elaiosomes influenced dispersal rates. In removal trials, ants quickly collected diaspores (seeds plus elaiosomes) of Asarum canadense, Trillium grandiflorum, and Sanguinaria canadensis, but largely neglected those of T. erectum. This discrepancy was not explained by differences in the bulk cost-benefit ratio, as assessed by the ratio of seed to elaiosome mass. We also provisioned colonies with diaspores from one of these four plant species or no diaspores as a control. Colonies performed best when fed S. canadensis diaspores, worst when fed T. grandiflorum, and intermediately when fed A. canadense, T. erectum, or no diaspores. Thus, the nutritional rewards in elaiosomes affected colony performance, but did not completely predict seed removal. Instead, high levels of oleic acid in T. grandiflorum elaiosomes may explain why ants disperse these diaspores even though they reduce ant colony performance. We show for the first time that different elaiosome-bearing plants provide rewards of different quality to ant colonies, but also that ants appear unable to accurately assess reward quality when encountering seeds. Instead, we suggest that signals can trump rewards as attractants of ants to seeds. PMID:23967257

Turner, Kyle M; Frederickson, Megan E

2013-01-01

296

Looking and homing: how displaced ants decide where to go.  

PubMed

We caught solitary foragers of the Australian Jack Jumper ant, Myrmecia croslandi, and released them in three compass directions at distances of 10 and 15 m from the nest at locations they have never been before. We recorded the head orientation and the movements of ants within a radius of 20 cm from the release point and, in some cases, tracked their subsequent paths with a differential GPS. We find that upon surfacing from their transport vials onto a release platform, most ants move into the home direction after looking around briefly. The ants use a systematic scanning procedure, consisting of saccadic head and body rotations that sweep gaze across the scene with an average angular velocity of 90° s(-1) and intermittent changes in turning direction. By mapping the ants' gaze directions onto the local panorama, we find that neither the ants' gaze nor their decisions to change turning direction are clearly associated with salient or significant features in the scene. Instead, the ants look most frequently in the home direction and start walking fast when doing so. Displaced ants can thus identify home direction with little translation, but exclusively through rotational scanning. We discuss the navigational information content of the ants' habitat and how the insects' behaviour informs us about how they may acquire and retrieve that information. PMID:24395961

Zeil, Jochen; Narendra, Ajay; Stürzl, Wolfgang

2014-01-01

297

Using Metadata Snapshots for Extending Ant-Based Resource Discovery Service in Inter-cooperative Grid Communities  

Microsoft Academic Search

Much work is under way within the resource management community on issues associated with grid scheduling upon dynamically discovered information. In this paper we tackle the problem by exploiting a bio-inspired resource discovery mechanism, where information is provided by ant-based lightweight mobile agents traveling across a grid network and collecting data from each visited node. We start by providing the

Ye Huang; N. Bessis; A. Brocco; P. Kuonen; M. Courant; B. Hirsbrunner

2009-01-01

298

Optimizing expressway maintenance planning by coupling ant algorithm and geography information system transportation in Hubei province, China  

Microsoft Academic Search

Highway maintenance scheduling is a complex optimization problem and imposes a challenge for GIS-T research. In this paper, a new approach was put forward to determining the optimal set of alternatives for highway infrastructure facilities by using ant colony algorithm and GIS. In the proposed approach, GIS was used to analyze traffic flux, toll and maintenance time of each highway

Hongga Li; Xiaoxia Huang; Quan Feng

2011-01-01

299

Mapping lessons from ants to free flight: an ant-based weather avoidance algorithm in free flight airspace  

NASA Astrophysics Data System (ADS)

The continuing growth of air traffic worldwide motivates the need for new approaches to air traffic management that are more flexible both in terms of traffic volume and weather. Free Flight is one such approach seriously considered by the aviation community. However the benefits of Free Flight are severely curtailed in the convective weather season when weather is highly active, leading aircrafts to deviate from their optimal trajectories. This paper investigates the use of ant colony optimization in generating optimal weather avoidance trajectories in Free Flight airspace. The problem is motivated by the need to take full advantage of the airspace capacity in a Free Flight environment, while maintaining safe separation between aircrafts and hazardous weather. The experiments described herein were run on a high fidelity Free Flight air traffic simulation system which allows for a variety of constraints on the computed routes and accurate measurement of environments dynamics. This permits us to estimate the desired behavior of an aircraft, including avoidance of changing hazardous weather patterns, turn and curvature constraints, and the horizontal separation standard and required time of arrival at a pre determined point, and to analyze the performance of our algorithm in various weather scenarios. The proposed Ant Colony Optimization based weather avoidance algorithm was able to find optimum weather free routes every time if they exist. In case of highly complex scenarios the algorithm comes out with the route which requires the aircraft to fly through the weather cells with least disturbances. All the solutions generated were within flight parameters and upon integration with the flight management system of the aircraft in a Free Flight air traffic simulator, successfully negotiated the bad weather.

Alam, Sameer; Abbass, Hussein A.; Barlow, Michael; Lindsay, Peter

2005-01-01

300

Shape transition during nest digging in ants  

PubMed Central

Nest building in social insects is among the collective processes that show highly conservative features such as basic modules (chambers and galleries) or homeostatic properties. Although ant nests share common characteristics, they exhibit a high structural variability, of which morphogenesis and underlying mechanisms remain largely unknown. We conducted two-dimensional nest-digging experiments under homogeneous laboratory conditions to investigate the shape diversity that emerges only from digging dynamics and without the influence of any environmental heterogeneity. These experiments revealed that, during the excavation, a morphological transition occurs because the primary circular cavity evolves into a ramified structure through a branching process. Such a transition is observed, whatever the number of ants involved, but occurs more frequently for a larger number of workers. A stochastic model highlights the central role of density effects in shape transition. These results indicate that nest digging shares similar properties with various physical, chemical, and biological systems. Moreover, our model of morphogenesis provides an explanatory framework for shape transitions in decentralized growing structures in group-living animals.

Toffin, Etienne; Di Paolo, David; Campo, Alexandre; Detrain, Claire; Deneubourg, Jean-Louis

2009-01-01

301

How do ants assess food volume?  

PubMed

By comparing the behaviour of Lasius niger scouts at sucrose droplets of different volumes, we empirically identified the criterion used by each scout to assess the amount of food available as well as the rules governing its decision to lay a recruitment trail. When scouts discovered food volumes exceeding the capacity of their crop (3 or 6 µl), 90% immediately returned to the nest laying a recruitment trail. In contrast, when smaller food droplets (0.3, 0.7 or 1 µl) were offered, several scouts stayed on the foraging area, presumably exploring it for additional food. If unsuccessful, they returned to the nest without laying a trail. The droplet volume determined the percentage of trail-laying ants but had no influence on the intensity of marking when this was initiated. The key criterion that regulated the recruiting behaviour of scouts was their ability to ingest their own desired volume. This volume acted as a threshold triggering the trail-laying response of foragers. Collective regulation of foraging according to food size resulted from the interplay between the distribution of these desired volume thresholds among colony members and the food volume available. We relate some aspects of the foraging ecology of aphid-tending ants to this decision-making process. Copyright 2000 The Association for the Study of Animal Behaviour. PMID:10860533

Mailleux; Deneubourg; Detrain

2000-05-01

302

Nectar Theft and Floral Ant-Repellence: A Link between Nectar Volume and Ant-Repellent Traits?  

PubMed Central

As flower visitors, ants rarely benefit a plant. They are poor pollinators, and can also disrupt pollination by deterring other flower visitors, or by stealing nectar. Some plant species therefore possess floral ant-repelling traits. But why do particular species have such traits when others do not? In a dry forest in Costa Rica, of 49 plant species around a third were ant-repellent at very close proximity to a common generalist ant species, usually via repellent pollen. Repellence was positively correlated with the presence of large nectar volumes. Repellent traits affected ant species differently, some influencing the behaviour of just a few species and others producing more generalised ant-repellence. Our results suggest that ant-repellent floral traits may often not be pleiotropic, but instead could have been selected for as a defence against ant thieves in plant species that invest in large volumes of nectar. This conclusion highlights to the importance of research into the cost of nectar production in future studies into ant-flower interactions.

Ballantyne, Gavin; Willmer, Pat

2012-01-01

303

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.

2014-01-01

304

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

PubMed

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. PMID:16850309

Matsuura, Kenji; Yashiro, Toshihisa

2006-10-01

305

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

306

Asian weaver ants, Oecophylla smaragdina, and their repelling of pollinators  

Microsoft Academic Search

The Asian weaver ant, Oecophylla smaragdina, is known to have outstanding predatory power. This ant can protect the host plants from attacks of phytophagous insects and therefore has been used for biological control in the tropics. We present evidence for a possible negative effect of Oecophylla on the performance of host plants. Our observation in a fruit orchard of rambutan

Kazuki TSUJI; Ahsol HASYIM; Harlion; Koji NAKAMURA

2004-01-01

307

Colony level sex allocation in a polygynous and polydomous ant  

Microsoft Academic Search

The colony-level sex allocation pattern of eusocial Hymenoptera has attracted much attention in recent studies of evolutionary biology. We conducted a theoretical and empirical study on this subject using the dolichoderine ant Technomyrmex albipes. This ant is unusual in having a dispersal polymorphism in both males and females. New colonies are founded by an alate female after mating with one

Kazuki Tsuji; Katsusuke Yamauchi

1994-01-01

308

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

309

Pattern Formation and Optimization in Army Ant Raids  

Microsoft Academic Search

Army ant colonies display complex foraging raid patterns involving thousands of individuals communicating through chemical trails. In this paper we explore, by means of a simple search algorithm, the properties of these trails in order to test the hypothesis that their structure reflects an optimized mechanism for exporing and exploiting food resources. The raid patterns of three army ant species,

Ricard V. Solé; Eric Bonabeau; Jordi Delgado; Pau Fernández; Jesus Marín

1999-01-01

310

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

311

Transgenerational effects and the cost of ant tending in aphids.  

PubMed

In mutualistic interactions, partners obtain a net benefit, but there may also be costs associated with the provision of benefits for a partner. The question of whether aphids suffer such costs when attended by ants has been raised in previous work. Transgenerational effects, where offspring phenotypes are adjusted based on maternal influences, could be important in the mutualistic interaction between aphids and ants, in particular because aphids have telescoping generations where two offspring generations can be present in a mature aphid. We investigated the immediate and transgenerational influence of ant tending on aphid life history and reproduction by observing the interaction between the facultative myrmecophile Aphis fabae and the ant Lasius niger over 13 aphid generations in the laboratory. We found that the effect of ant tending changes dynamically over successive aphid generations after the start of tending. Initially, total aphid colony weight, aphid adult weight and aphid embryo size decreased compared with untended aphids, consistent with a cost of ant association, but these differences disappeared within four generations of interaction. We conclude that transgenerational effects are important in the aphid-ant interactions and that the costs for aphids of being tended by ants can vary over generations. PMID:23689730

Tegelaar, Karolina; Glinwood, Robert; Pettersson, Jan; Leimar, Olof

2013-11-01

312

Photogrowth: non-photorealistic renderings through ant paintings  

Microsoft Academic Search

We introduce photogrowth, an evolutionary approach to the production of non-photorealistic renderings of images. The painting algorithm - inspired by ant colony approaches - is described and explained, giving emphasis to its novel aspects: the evolution of the sensory parameters of the ants; the production of resolution independent images; the rendering lines of variable width. The experimental results highlight the

Penousal Machado; Luís Pereira

2012-01-01

313

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.

314

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

315

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 ...

316

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

317

Ant-Based Load Balancing in Telecommunications Networks  

Microsoft Academic Search

This paper describes a novel method of achieving load balancing in telecommunicationsnetworks. A simulated network models a typical distribution of calls betweennodes; nodes carrying an excess of traffic can become congested, causing calls to belost. In addition to calls, the network also supports a population of simple mobile agentswith behaviours modelled on the trail laying abilities of ants. The ants

Ruud Schoonderwoerd; Owen Holland Janet Bruten; Leon Rothkrantz

1996-01-01

318

AntModeler analysis of mechanical stress driven transcription in three cell types  

NASA Astrophysics Data System (ADS)

Cellular stress activates transcription of various genes that mediate stress-driven proliferation and differentiation in many cells including osteoblasts, endothelial cells, and fibroblasts. In response to mechanical stress, expression of some genes is altered regardless of cell types and that of others in specific cell types. Using the microarray-based expression data for primary fibroblasts isolated from fetal mouse cornea, skin and tendon, we conducted a model-based transcription analysis and predicted transcription-factor binding motifs (TFBMs) responsible for the observed gene alteration. The computational procedure was formulated as a combinatorial optimization problem, and the AntModeler using an ant algorithm was employed to select TFBMs for each of the three fibroblast types. The results indicate that the stress responses are regulated mostly through cell type specific TFBMs together with a limited number of common TFBMs. The predicted role of those TFBMs should be evaluated experimentally.

Lin, Nan; Chen, Andy; Mackley, Jennifer R.; Winder, Steven J.; Yokota, Hiroki

2007-11-01

319

Using Ant Colony System to produce session schedules for GPS surveying networks  

NASA Astrophysics Data System (ADS)

A GPS network can be defined as a set of stations which are coordinated by a series of sessions formed by placing receivers on the stations. The problem addressed is to determine the order in which each GPS receiver should be moved between the points giving the cheapest schedule using heuristic techniques within the field of Operational Research. Solving large networks to optimality requires impractical running time. To avoid this, Ant Colony approach tries to provide near-optimal solutions when an acceptable amount of computational effort has been implemented. Computational results are presented to show the effectiveness and performance of the developed Ant Colony technique with respect to solution quality and the computational effort using a GPS network in Tehran.

Abolhasani, S.; Sharifi, M. A.; Farokhi, S.

2011-12-01

320

Unit Commitment by Hybrid Ant System/Priority List Method based Probabilistic Approach  

NASA Astrophysics Data System (ADS)

This paper presents a new method to solve the unit commitment problem by using a hybrid ant system/priority list method based probabilistic approach (HASP). The proposed methodology employs ant system (AS) in cooperating with the priority list method to commit generating units probabilistically corresponding to the specific conditions as means of mutually combining the advantages of them in that a flexibility of the priority list method is reinforced, while AS algorithm can gain the benefit of using a set of heuristics for improving its performance during search process under the operating constraints. The proposed methodology including its effective techniques has been tested on a system up to 100 generating units with a scheduling time horizon of 24 hours. The simulation results show that HASP gives better economical saving in total operating cost as well as faster computational time when compared to the earlier literature results.

Nualhong, Dulyatat; Chusanapiputt, Songsak; Jantarang, Sujate

321

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

322

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.

Yang, Shunkun; Xu, Jiaqi

2014-01-01

323

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.

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

2011-01-01

324

Collective effects in traffic on bi-directional ant trails.  

PubMed

Motivated by recent experimental work of Burd et al., we propose a model of bi-directional ant traffic on pre-existing ant trails. It captures in a simple way some of the generic collective features of movements of real ants on a trail. Analysing this model, we demonstrate that there are crucial qualitative differences between vehicular- and ant-traffics. In particular, we predict some unusual features of the flow rate that can be tested experimentally. As in the uni-directional model a non-monotonic density-dependence of the average velocity can be observed in certain parameter regimes. As a consequence of the interaction between oppositely moving ants the flow rate can become approximately constant over some density interval. PMID:15380392

John, Alexander; Schadschneider, Andreas; Chowdhury, Debashish; Nishinari, Katsuhiro

2004-11-21

325

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

326

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

327

SMART Power Systems for ANTS Missions  

NASA Astrophysics Data System (ADS)

Autonomous NanoTechnology Swarm (ANTS) Architecture is based on Addressable Reconfigurable Technology (ART) adaptable for the full spectrum of activities in space. ART systems based on currently available electromechanical (EMS) technology could support human crews on the lunar surface within the next 10 to 15 years. Two or more decades from now, NEMS (Super Miniaturized ART or SMART) technology could perform fully autonomous surveys and operations beyond the reach of human crews. Power system requirements would range from 1 kg to generate tens of Watts for near term ART applications, such as a lunar or Mars Lander Amorphous Rover Antenna (LARA), to <0.1 kg to generate hundreds of mWatts for more advanced SMART applications.

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

2005-02-01

328

AntClass: discovery of clusters in numeric data by an hybridization of an ant colony with the Kmeans algorithm  

Microsoft Academic Search

We present in this paper a new hybrid algorithm for data clustering. This algorithm discovers automatically clusters in numerical data without prior knowledge of a possible number of classes, without any initial partition, and without complex parameter settings. It uses the stochastic and exploratory principles of an ant colony with the deterministic and heuristic principles of the Kmeans algorithm. Ants

Nicolas Monmarché; Mohamed Slimane; Gilles Venturini

1999-01-01

329

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.

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

2011-01-01

330

Ants mediate the structure of phytotelm communities in an ant-garden bromeliad.  

PubMed

The main theories explaining the biological diversity of rain forests often confer a limited understanding of the contribution of interspecific interactions to the observed patterns. We show how two-species mutualisms can affect much larger segments of the invertebrate community in tropical rain forests. Aechmea mertensii (Bromeliaceae) is both a phytotelm (plant-held water) and an ant-garden epiphyte. We studied the influence of its associated ant species (Pachycondyla goeldii and Camponotus femoratus) on the physical characteristics of the plants, and, subsequently, on the diversity of the invertebrate communities that inhabit their tanks. As dispersal agents for the bromeliads, P. goeldii and C. femoratus influence the shape and size of the bromeliad by determining the location of the seedling, from exposed to partially shaded areas. By coexisting on a local scale, the two ant species generate a gradient of habitat conditions in terms of available resources (space and food) for aquatic invertebrates, the diversity of the invertebrate communities increasing with greater volumes of water and fine detritus. Two-species mutualisms are widespread in nature, but their influence on the diversity of entire communities remains largely unexplored. Because macroinvertebrates constitute an important part of animal production in all ecosystem types, further investigations should address the functional implications of such indirect effects. PMID:20503886

Céréghino, Régis; Leroy, Céline; Dejean, Alain; Corbara, Bruno

2010-05-01

331

Correlation between the leaf turnover rate and anti-herbivore defence strategy (balance between ant and non-ant defences) amongst ten species of Macaranga (Euphorbiaceae)  

Microsoft Academic Search

We measured variation in the intensities of ant and non-ant anti-herbivore defences amongst ten Macaranga species in Sarawak, Malaysia. Intensities of non-ant defences were estimated by measuring effects of fresh leaves (provided\\u000a as food) of these Macaranga species on survival of common cutworm larvae [Spodoptera litura (Fabricius), Lepidoptera: Noctuidae]. Intensities of ant defences were estimated by measuring ant aggressiveness in

Masahiro Nomura; Aya Hatada; Takao Itioka

2011-01-01

332

A New Algorithm for Robot Path Planning Based on Scout Ant Cooperation  

Microsoft Academic Search

A new ant algorithm for robot path planning is presented according to the latest achievements of research on actual ants. In this algorithm, m scout ants collaborate with each other to search for an optimal or near-optimal path. Of m scout ants, n ants adopt nearest-neighbor search strategy and the left q=m-n ants adopt random search strategy. A section of

Qingbao Zhu; Lingling Wang

2008-01-01

333

Desert ants achieve reliable recruitment across noisy interactions.  

PubMed

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

2013-05-01

334

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.

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

2013-01-01

335

The diversity of microorganisms associated with Acromyrmex leafcutter ants  

PubMed Central

Background Molecular biological techniques are dramatically changing our view of microbial diversity in almost any environment that has so far been investigated. This study presents a systematic survey of the microbial diversity associated with a population of Acromyrmex leafcutter ants. In contrast to previous studies on social insects, which targeted specific groups of symbionts occurring in the gut (termites, Tetraponera ants) or in specialised cells (Camponotus ants) the objective of our present study was to do a total screening of all possible micro-organisms that can be found inside the bodies of these leafcutter ants. Results We amplified, cloned and sequenced SSU rRNA encoding gene fragments from 9 microbial groups known to have insect-associated representatives, and show that: (1) representatives of 5 out of 9 tested groups are present, (2) mostly several strains per group are present, adding up to a total of 33 different taxa. We present the microbial taxa associated with Acromymex ants in a phylogenetic context (using sequences from GenBank) to assess and illustrate to which known microorganisms they are closely related. The observed microbial diversity is discussed in the light of present knowledge on the evolutionary history of Acromyrmex leafcutter ants and their known mutualistic and parasitic symbionts. Conclusions The major merits of the screening approach documented here is its high sensitivity and specificity, which allowed us to identify several microorganisms that are promising candidates for further study of their interactions with Acromyrmex leafcutter ants or their gardens.

Van Borm, Steven; Billen, Johan; Boomsma, Jacobus J

2002-01-01

336

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.

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

2014-01-01

337

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

338

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

339

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

340

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.

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

2012-01-01

341

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

342

Public goods dilemma in asexual ant societies  

PubMed Central

Cooperation in biological, social, and economic groups is underpinned by public goods that are generated by group members at some personal cost. Theory predicts that public goods will be exploited by cheaters who benefit from the goods by not paying for them, thereby leading to the collapse of cooperation. This situation, described as the “public goods dilemma” in game theory, makes the ubiquity of cooperation a major evolutionary puzzle. Despite this generalization, the demonstration of genetic background and fitness effects of the public goods dilemma has been limited to interactions between viruses and between cells, and thus its relevance at higher levels of organismal complexity is still largely unexplored. Here we provide experimental evidence for the public goods dilemma in a social insect, the ant Pristomyrmex punctatus. In this species, all workers are involved in both asexual reproduction and cooperative tasks. Genetic cheaters infiltrate field colonies, reproducing more than the workers but shunning cooperative tasks. In laboratory experiments, cheaters outcompeted coexisting workers in both survival and reproduction, although a group composed only of cheaters failed to produce offspring. The operations of the public goods dilemma in P. punctatus showed a remarkable convergence with those in microbial societies, not only in fitness consequences but also in behavioral mechanisms. Our study reinforces the evolutionary impact of cheaters on diverse cooperative systems in the laboratory and in the field.

Dobata, Shigeto; Tsuji, Kazuki

2013-01-01

343

Occurrence of Antennal Glands in Ants  

PubMed Central

A previous report of the discovery of exocrine glands in the antennal club of queens and workers of Solenopsis invicta Buren, 1972 (Isidoro et al., Insectes Sociaux 47: 236-240, 2000) 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 if 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 connected to spherical reservoirs in queens. T. bicarinatum was only non-Solenopsis species examined which showed evidence for antennal glands in the distal funiculus.

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

2010-01-01

344

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

345

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

346

Communal peeing: a new mode of flood control in ants  

NASA Astrophysics Data System (ADS)

The behavioral response of the obligate bamboo-nesting ant Cataulacus muticus to nest flooding was studied in a perhumid tropical rainforest in Malaysia and in the laboratory. The hollow internodes of giant bamboo, in which C. muticus exclusively nests, are prone to flooding by heavy rains. The ants showed a two-graded response to flooding. During heavy rain workers block the nest entrances with their heads to reduce water influx. However, rainwater may still intrude into the nest chamber. The ants respond by drinking the water, leaving the nest and excreting water droplets on the outer stem surface. This cooperative 'peeing' behavior is a new survival mechanism adaptive to the ants' nesting ecology. Laboratory experiments conducted with two other Cataulacus species, C. catuvolcus colonizing small dead twigs and C. horridus inhabiting rotten wood, did not reveal any form of water-bailing behavior.

Maschwitz, Ulrich; Moog, J.

347

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.

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

2013-01-01

348

Primary Tetradecenyl Amines from the Ant 'Monomorium floricola'.  

National Technical Information Service (NTIS)

In contrast to other ants in the genus Monomorium that produce cyclic amines, extracts of Monomorium floricola contain (Z)-7-tetradecenylamine and (Z)-9-tetradecenylamine. The structures of these compounds were established from their spectral data and by ...

T. H. Jones J. A. Torres R. R. Snelling T. F. Spande

1996-01-01

349

FMR measurements in fire ants: evidence of magnetic material.  

National Technical Information Service (NTIS)

Based on the behavioral and the localization of iron-containing tissue fire ants were examined by EPR for magnetic material. Results suggest the presence of magnetite particles. (author) 12 refs., 1 fig.

D. M.S. Esquivel D. Acosta-Avalos L. J. El-Jaick A. D.M. Cunha M. G. Malheiros

1998-01-01

350

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.

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

2012-01-01

351

Disease dynamics in a specialized parasite of ant societies.  

PubMed

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

352

Patterns of reproduction in slave-making ants  

PubMed Central

Sex ratios in slave-making ants have been posed as important test cases for the hypothesis that eusociality evolved via kin selection in insects. Trivers and Hare proposed that sex ratios in slave-makers should reflect the queen's interests whereas sex ratios in free-living host ants should reflect the workers' interests. We analyse patterns of allocation to males versus females, as well as allocation to growth versus reproduction for slave-making ants in the tribe Formicoxenini. We find little support for the hypothesis of exclusive queen control; instead, our results implicate queen–worker conflict in slave-making ants, both over male allocation ratios and over allocation to growth versus reproduction.

Herbers, J. M.; Stuart, R. J.

1998-01-01

353

Ant mimicry by an aphid parasitoid, Lysiphlebus fabarum.  

PubMed

In Iran, Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae) is a uniparental parasitoid of the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), that possesses various highly evolved adaptations for foraging within ant-tended aphid colonies. Direct observations and video recordings were used to analyze the behavior of individual females foraging for A. fabae on bean leaf disks in open arenas in the laboratory. Females exploited aphids as hosts and as a source of food, allocating within-patch time as follows: resting - 10.4%, grooming - 8.2%, searching - 11.5%, antennation (host recognition) - 7.5%, antennation (honeydew solicitation mimicking ants) - 31.9%, abdominal bending (attack preparation) 19.7%, probing with the ovipositor (attack) - 10.8%. The mean handling time for each aphid encountered was 2.0 ± 0.5 min. Females encountered an average of 47.4 ± 6.4 aphids per hour, but laid only 1.2 eggs per hour. The ovipositor insertion time for parasitism ranged from 2 sec to longer than a minute, but most insertions did not result in an egg being laid. A. fabae defensive behaviors included kicking, raising and swiveling the body, and attempts to smear the attacker with cornicle secretions, sometimes with lethal results. Food deprivation for 4-6 h prior to testing increased the frequency of ant mimcry by L. fabarum. Females also used ant-like antennation to reduce A. fabae defensive behavior, e.g. the frequency of kicking. L. fabarum attacks primed A. fabae to be more responsive to subsequent honeydew solicitation, such that experienced females improved their feeding success by alternating between the roles of parasitoid and ant mimic. These results reveal the possibility for mutualisms to evolve between L. fabarum and the ant species that tend A. fabae, since L. fabarum receive ant protection for their progeny and may benefit the ants by improving A. fabae responsiveness to honeydew solicitation. PMID:20879920

Rasekh, Arash; Michaud, J P; Kharazi-Pakdel, Aziz; Allahyari, Hossein

2010-01-01

354

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

355

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

356

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

357

Queen Control of Sex Ratio in Fire Ants  

Microsoft Academic Search

The haplodiploid sex-determination system of ants gives rise to conflict between queens and workers over colony sex ratios, and the female-biased allocation ratios seen in many species suggest that workers often prevail in this conflict. We exchanged queens between male- and female-specialist colonies of the fire ant Solenopsis invicta. These exchanges quickly reversed the sex-ratio biases of adopting colonies. The

L. Passera; S. Aron; E. L. Vargo; L. Keller

2001-01-01

358

From the Cover: Major evolutionary transitions in ant agriculture  

Microsoft Academic Search

Agriculture is a specialized form of symbiosis that is known to have evolved in only four animal groups: humans, bark beetles, termites, and ants. Here, we reconstruct the major evolutionary transitions that produced the five distinct agricultural systems of the fungus-growing ants, the most well studied of the nonhuman agriculturalists. We do so with reference to the first fossil-calibrated, multiple-gene,

Ted R. Schultz; Seán G. Brady

2008-01-01

359

Ant Mimicry by an Aphid Parasitoid, Lysiphlebus fabarum  

PubMed Central

In Iran, Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae) is a uniparental parasitoid of the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), that possesses various highly evolved adaptations for foraging within ant-tended aphid colonies. Direct observations and video recordings were used to analyze the behavior of individual females foraging for A. fabae on bean leaf disks in open arenas in the laboratory. Females exploited aphids as hosts and as a source of food, allocating within-patch time as follows: resting - 10.4%, grooming - 8.2%, searching - 11.5%, antennation (host recognition) - 7.5%, antennation (honeydew solicitation mimicking ants) - 31.9%, abdominal bending (attack preparation) 19.7%, probing with the ovipositor (attack) - 10.8%. The mean handling time for each aphid encountered was 2.0 ± 0.5 min. Females encountered an average of 47.4 ± 6.4 aphids per hour, but laid only 1.2 eggs per hour. The ovipositor insertion time for parasitism ranged from 2 sec to longer than a minute, but most insertions did not result in an egg being laid. A. fabae defensive behaviors included kicking, raising and swiveling the body, and attempts to smear the attacker with cornicle secretions, sometimes with lethal results. Food deprivation for 4–6 h prior to testing increased the frequency of ant mimcry by L. fabarum. Females also used ant-like antennation to reduce A. fabae defensive behavior, e.g. the frequency of kicking. L. fabarum attacks primed A. fabae to be more responsive to subsequent honeydew solicitation, such that experienced females improved their feeding success by alternating between the roles of parasitoid and ant mimic. These results reveal the possibility for mutualisms to evolve between L. fabarum and the ant species that tend A. fabae, since L. fabarum receive ant protection for their progeny and may benefit the ants by improving A. fabae responsiveness to honeydew solicitation.

Rasekh, Arash; Michaud, J.P.; Kharazi-Pakdel, Aziz; Allahyari, Hossein

2010-01-01

360

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

361

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

362

Feature Subset Selection Using Ant Colony Optimization  

Microsoft Academic Search

Feature selection is an important step in many pattern classification problems. It is applied to select a subset of features, from a much larger set, such that the selected subset is sufficient to perform the classification task. Due to its importance, the problem of feature selection has been investigated by many researchers. In this paper, a novel feature subset search

Ahmed Al-Ani

2006-01-01

363

The distribution and density of a lycaenid butterfly in relation to Lasius ants  

Microsoft Academic Search

Larvae and pupae of lycaenid butteflies are often associated with ants: this is usually a mutualism in which ants guard the lycaenids from natural enemies, and the lycaenid larvae and pupae provide sugars and amino acids for the ants. A possible consequence of the interaction is spatially correlated ant and lycaenid distributions, but the phenomenon is poorly documented. We examined

D. Jordano; J. Rodríguez; C. D. Thomas; J. Fernández Haeger

1992-01-01

364

Ant mosaics in a tropical rainforest in Australia and elsewhere: A critical review  

Microsoft Academic Search

The concept of 'ant mosaics' has been established to describe the structure of arboreal ant communities in plantations and other relatively simple forest systems. It is essentially built upon the existence of negative and positive associations between ant species plus the concept of dominance hierarchies. Whether this concept can be applied to ant communities in more complex mature tropical rain

NICO BLÜTHGEN; NIGEL E. STORK

2007-01-01

365

Seed Predators Are Undeterred by Nectar-Feeding Ants on Chamaecrista nictitans (Caesalpineaceae)  

Microsoft Academic Search

There are many examples of mutualistic interactions between ants and plants bearing extrafloral nectaries (EFN). The annual legume Chamaecrista nictitans (Caesalpineaceae) secretes nectar from EFN, specialized structures that attract ants, spiders, and other arthropods. The effects of manipulated C. nictitans patch size and location on plant-ant interactions were tested. Defense from herbivores was not detected; plants with ants did not

Scott Ruhren

2003-01-01

366

Seed odor mediates an obligate ant-plant mutualism in Amazonian rainforests  

Microsoft Academic Search

Seed dispersal mutualisms are essential for the survival of diverse plant species and communities worldwide. Among invertebrates, only ants have a major role in seed dispersal, and thousands of plant species produce seeds specialized for ant dispersal in ``diffuse'' multispecies interactions. An outstanding but poorly understood ant-seed mutualism occurs in the Amazonian rainforest, where arboreal ants collect seeds of several

Elsa Youngsteadt; Satoshi Nojima; Christopher Häberlein; Stefan Schulz; Coby Schal

2008-01-01

367

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

368

Seed odor mediates an obligate ant-plant mutualism in Amazonian rainforests  

Microsoft Academic Search

Seed dispersal mutualisms are essential for the survival of diverse plant species and communities worldwide. Among invertebrates, only ants have a major role in seed dispersal, and thousands of plant species produce seeds specialized for ant dispersal in ''dif- fuse'' multispecies interactions. An outstanding but poorly under- stood ant-seed mutualism occurs in the Amazonian rainforest, where arboreal ants collect seeds

Elsa Youngsteadt; Satoshi Nojima; Christopher Haberlein; Stefan Schulz; Coby Schal

369

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

370

Colony Fusion in a Parthenogenetic Ant, Pristomyrmex punctatus  

PubMed Central

In the ant Pristomyrmex punctatus Smith (Hymenoptera: Formicidae), all young workers lay a small number of eggs parthenogenetically. Some colonies consist of monoclonal individuals that provide high inclusive fitness, according to the kin selection theory. However, in some populations, a majority of the colonies contain multiple lineages. Intracolonial genetic variation of parthenogenetic ants cannot be explained by the multiple mating of single founderesses or by the foundation of a colony by multiple foundresses, which are the usual causes of genetically diverse colonies in social insects. Here, we hypothesized that the fusion of established colonies might facilitate the formation of multiclonal colonies. Colony fusion decreases indirect benefits because of the reduction in intracolonial relatedness. However, when suitable nesting places for overwintering are scarce, colony fusion provides a strategy for the survival of colonies. Here, ants derived from different colonies were allowed to encounter one another in a container with just one nesting place. Initially, high aggression was observed; however, after several days, no aggression was observed and the ants shared the nest. When the fused colonies were allowed to transfer to two alternative nests, ants from different colonies occupied the same nest. This study highlights the importance of limiting the number of nesting places in order to understand the genetic diversity of parthenogenetic ant colonies.

Satow, Show; Satoh, Toshiyuki; Hirota, Tadao

2013-01-01

371

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

372

Water Stress Strengthens Mutualism Among Ants, Trees, and Scale Insects  

PubMed Central

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.

Pringle, Elizabeth G.; Akcay, Erol; Raab, Ted K.; Dirzo, Rodolfo; Gordon, Deborah M.

2013-01-01

373

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

374

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

375

The morphometry of solenopsis fire ants.  

PubMed

Size-related changes of body shape were explored in 15 polymorphic species of Solenopsis fire ants by analyzing body weight along with linear measurements of 24 body parts. Log regression slopes were used to detect changes of shape with increasing size. Within species, the largest workers weighed from about 5 to 30-fold as much as the smallest. The range of within-species body lengths varied from 1.6 mm to 4 mm. As worker size increased, the gaster tended to make up a larger proportion of body length, usually at the cost of the petiole, and rarely at the cost of head length or mesosoma length. In most, the relative volume of the gaster increased and that of the head and mesosoma decreased. Most also showed an increasingly "humped" mesosoma. For all species, head shape changed from barrel-shaped to heart-shaped as worker size increased. Antennae became relatively shorter as the relative size of the club decreased. Shape changes of the legs were more variable. S. geminata was exceptional in the extreme nature of its head shape change, and was the only species in which relative head volume increased and gaster volume decreased with increasing body size. With the exception of S. geminata, the allometric rules governing shape are remarkably similar across species, suggesting a genus-level developmental scheme that is not easily modified by evolution. It also suggests that the evolution of shape is highly constrained by these conserved growth rules, and that it acts primarily (perhaps only) through allometric growth. The results are discussed in light of the growth of imaginal discs in a resource-limited body (the pupa). The substantial variation of allometries within species and across localities is also discussed in relation to using allometric patterns to identify species or to construct phylogenies. PMID:24260250

Tschinkel, Walter R

2013-01-01

376

Foraging ants trade off further for faster: use of natural bridges and trunk trail permanency in carpenter ants  

NASA Astrophysics Data System (ADS)

Trail-making ants lay pheromones on the substrate to define paths between foraging areas and the nest. Combined with the chemistry of these pheromone trails and the physics of evaporation, trail-laying and trail-following behaviours provide ant colonies with the quickest routes to food. In relatively uniform environments, such as that provided in many laboratory studies of trail-making ants, the quickest route is also often the shortest route. Here, we show that carpenter ants ( Camponotus rufipes), in natural conditions, are able to make use of apparent obstacles in their environment to assist in finding the fastest routes to food. These ants make extensive use of fallen branches, twigs and lianas as bridges to build their trails. These bridges make trails significantly longer than their straight line equivalents across the forest floor, but we estimate that ants spend less than half the time to reach the same point, due to increased carriage speed across the bridges. We also found that these trails, mainly composed of bridges, are maintained for months, so they can be characterized as trunk trails. We suggest that pheromone-based foraging trail networks in field conditions are likely to be structured by a range of potentially complex factors but that even then, speed remains the most important consideration.

Loreto, Raquel G.; Hart, Adam G.; Pereira, Thairine M.; Freitas, Mayara L. R.; Hughes, David P.; Elliot, Simon L.

2013-10-01

377

Effect of Argentine ant invasions on ground-dwelling arthropods in northern California riparian woodlands  

Microsoft Academic Search

Although the Argentine ant (Linepithema humile) is a widespread invasive species that displaces native ants throughout its introduced range, the effects of these invasions\\u000a on arthropods other than ants remain poorly known. This study documents the consequences of Argentine ant invasions on ants\\u000a and other ground-dwelling arthropods in northern California riparian woodlands. Baits and unbaited pitfall traps were used\\u000a to

David A. Holway

1998-01-01

378

The intertwined population biology of two Amazonian myrmecophytes and their symbiotic ants.  

PubMed

A major question in ecology is: how do mutualisms between species affect population dynamics? For four years, we monitored populations of two Amazonian myrmecophytes, Cordia nodosa and Duroia hirsuta, and their symbiotic ants. In this system, we investigated how positive feedback between mutualistic plants and ant colonies influenced population processes at two scales: (1) how modular organisms such as plants and ant colonies grew, or eta-demography, and (2) how populations grew, or N-demography. We found evidence of positive feedback between ant colony and plant growth rates. Plants with mutualistic ants (Azteca spp. and Myrmelachista schumanni) grew in a geometric or autocatalytic manner, such that the largest plants grew the most. By contrast, the growth of plants with parasitic ants (Allomerus octoarticulatus) saturated. Ant colonies occupied new domatia as fast as plants produced them, suggesting that mutualistic ant colonies also grew geometrically or autocatalytically to match plant growth. Plants became smaller when they lost ants. While unoccupied, plants continued to become smaller until they had lost all or nearly all their domatia. Hence, the loss of mutualistic ants limited plant growth. C. nodosa and D. hirsuta live longer than their ant symbionts and were sometimes recolonized after losing ants, which again promoted plant growth. Plant growth had fitness consequences for ants and plants; mortality and fecundity depended on plant size. Positive feedback between ants and plants allowed a few plants and ant colonies to become very large; these probably produced the majority of offspring in the next generation. PMID:19569374

Frederickson, Megan E; Gordon, Deborah M

2009-06-01

379

Multiple endosymbionts in populations of the ant Formica cinerea  

PubMed Central

Background Many insects, including ants, are infected by maternally inherited Wolbachia endosymbiotic bacteria though other secondary endosymbionts have not been reported in ants. It has been suggested that the ability of Wolbachia to invade and remain in an ant population depends on the number of coexisting queens in a colony. We study the genetic and social structure of populations in the ant Formica cinerea which is known to have populations with either monogynous or polygynous colonies. We screen populations for several endosymbiotic bacteria to evaluate the presence of different endosymbionts, possible association between their prevalence and the social structure, and the association between endosymbiont prevalence and genetic differentiation of ant populations. Results We found three endosymbiotic bacteria; 19% of the nests were infected by Wolbachia, 3.8% by Cardinium and 33% by Serratia. There was significant variation among the populations regarding the proportion of nests infected by Serratia, Wolbachia and the pooled set of all the endosymbionts. Some individuals and colonies carried two of the bacteria, the frequency of double infections agreeing with the random expectation. The proportion of infected ants (individuals or colonies) did not correlate significantly with the population level relatedness values. The difference in the prevalence of Wolbachia between population pairs correlated significantly with the genetic distance (microsatellites) of the populations. Conclusions The discovery of several endosymbionts and co-infections by Wolbachia and Cardinium demonstrate the importance of screening several endosymbionts when evaluating their possible effects on social life and queen-worker conflicts over sex allocation. The low prevalence of Wolbachia in F. cinerea departs from the pattern observed in many other Formica ants in which all workers have been infected. It is likely that the strain of Wolbachia in F. cinerea differs from those in other Formica species. The correlation between the difference in Wolbachia prevalence and the pair-wise genetic distance of populations suggests that spreading of the bacteria is restricted by the isolation of the host populations.

2010-01-01

380

Experimental evidence that the introduced fire ant, Solenopsis invicta, does not competitively suppress co-occurring ants in a disturbed habitat  

Microsoft Academic Search

Summary 1. The fire ant, Solenopsis invicta, is a globally distributed invasive ant that is largely restricted to disturbed habitats in its introduced range. For more than half a century, biologists have believed its success results from superior competitive abilities relative to native ant species, as well as an escape from their natural enemies. 2. We used large volumes of

JOSHUA R. KING; WALTER R. TSCHINKEL

2006-01-01

381

Field Trapping the Little Fire Ant, Wasmannia auropunctata  

PubMed Central

Two detection methods for the little fire ant, Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae), both employing the pheromone attractant 2,5-dimethyl-3-(2-methylbutyl)pyrazine (2-MeBu-diMePy), were compared with peanut butter based detection, in order to evaluate differences in species specificity and detection reliability. Trapping was conducted using a transect through a macadamia orchard on the island of Hawaii. The transect consisted of a series of three-tree plots, each plot contained a peanut butter coated stick (the most common detection method used for W. auropunctata in Hawaii), a one—way trap treated with 2-MeBu-diMePy, and a piece of double-sided tape treated with 2-MeBu-diMePy. While there were no differences in the number of W. auropunctata counted with each detection method, and no differences in detection reliability (detecting the known presence of W. auropunctata in a plot), the pheromone—incorporating methods showed greater species specificity, retaining W. auropunctata almost exclusively. These results demonstrate the potential of pheromone—detection methods to selectively capture target ant species even when other ants are present and abundant. Combined data from all three detection methods and a previous visual survey along the transect showed a marked difference in the frequency of cohabitation among ant species. Of the 10 ant species collected, W. auropunctata was found as the sole ant species on a given tree at a significantly higher frequency than all other ant species except Pheidole fervens. 94% percent of the trees with W. auropunctata had only W. auropunctata, supporting previous observations that this species tends to displace other ant species. In addition, W. auropunctata microhabitat preferences were investigated using one—way traps containing 2-MeBu-diMePy, which were placed in three arboreal and three non—arboreal locations. While the number of ants captured did not differ by trap placement, when grouped, captures were significantly higher in arboreal than non-arboreal microhabitats.

Derstine, Nathan T.; Troyer, Elisa J.; Suttles, Caitlyn N.; Siderhurst, Leigh A.; Jang, Eric B.; Siderhurst, Matthew S.

2012-01-01

382

New fossil ants in French Cretaceous amber (Hymenoptera: Formicidae)  

NASA Astrophysics Data System (ADS)

Recent studies on the ant phylogeny are mainly based on the molecular analyses of extant subfamilies and do not include the extinct, only Cretaceous subfamily Sphecomyrminae. However, the latter is of major importance for ant relationships, as it is considered the most basal subfamily. Therefore, each new discovery of a Mesozoic ant is of high interest for improving our understanding of their early history and basal relationships. In this paper, a new sphecomyrmine ant, allied to the Burmese amber genus Haidomyrmex, is described from mid-Cretaceous amber of France as Haidomyrmodes mammuthus gen. and sp. n. The diagnosis of the tribe Haidomyrmecini is emended based on the new type material, which includes a gyne (alate female) and two incomplete workers. The genus Sphecomyrmodes, hitherto known by a single species from Burmese amber, is also reported and a new species described as S. occidentalis sp. n. after two workers remarkably preserved in a single piece of Early Cenomanian French amber. The new fossils provide additional information on early ant diversity and relationships and demonstrate that the monophyly of the Sphecomyrminae, as currently defined, is still weakly supported.

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

2008-02-01

383

Temperature limits trail following behaviour through pheromone decay in ants.  

PubMed

In Mediterranean habitats, temperature affects both ant foraging behaviour and community structure. Many studies have shown that dominant species often forage at lower temperature than subordinates. Yet, the factors that constrain dominant species foraging activity in hot environments are still elusive. We used the dominant ant Tapinoma nigerrimum as a model species to test the hypothesis that high temperatures hinder trail following behaviour by accelerating pheromone degradation. First, field observations showed that high temperatures (> 30°C) reduce the foraging activity of T. nigerrimum independently of the daily and seasonal rhythms of this species. Second, we isolated the effect of high temperatures on pheromone trail efficacy from its effect on worker physiology. A marked substrate was heated during 10 min (five temperature treatments from 25°C to 60°C), cooled down to 25°C, and offered in a test choice to workers. At hot temperature treatments (>40°C), workers did not discriminate the previously marked substrate. High temperatures appeared therefore to accelerate pheromone degradation. Third, we assessed the pheromone decay dynamics by a mechanistic model fitted with Bayesian inference. The model predicted ant choice through the evolution of pheromone concentration on trails as a function of both temperature and time since pheromone deposition. Overall, our results highlighted that the effect of high temperatures on recruitment intensity was partly due to pheromone evaporation. In the Mediterranean ant communities, this might affect dominant species relying on chemical recruitment, more than subordinate ant species, less dependent on chemical communication and less sensitive to high temperatures. PMID:22038287

van Oudenhove, Louise; Billoir, Elise; Boulay, Raphaël; Bernstein, Carlos; Cerdá, Xim

2011-12-01

384

Immune priming and pathogen resistance in ant queens  

PubMed Central

Growing empirical evidence indicates that invertebrates become more resistant to a pathogen following initial exposure to a nonlethal dose; yet the generality, mechanisms, and adaptive value of such immune priming are still under debate. Because life-history theory predicts that immune priming and large investment in immunity should be more frequent in long-lived species, we here tested for immune priming and pathogen resistance in ant queens, which have extraordinarily long life span. We exposed virgin and mated queens of Lasius niger and Formica selysi to a low dose of the entomopathogenic fungus Beauveria bassiana, before challenging them with a high dose of the same pathogen. We found evidence for immune priming in naturally mated queens of L. niger. In contrast, we found no sign of priming in virgin queens of L. niger, nor in virgin or experimentally mated queens of F. selysi, which indicates that immune priming in ant queens varies according to mating status and mating conditions or species. In both ant species, mated queens showed higher pathogen resistance than virgin queens, which suggests that mating triggers an up-regulation of the immune system. Overall, mated ant queens combine high reproductive output, very long life span, and elevated investment in immune defense. Hence, ant queens are able to invest heavily in both reproduction and maintenance, which can be explained by the fact that mature queens will be protected and nourished by their worker offspring.

Galvez, Dumas; Chapuisat, Michel

2014-01-01

385

Immune priming and pathogen resistance in ant queens.  

PubMed

Growing empirical evidence indicates that invertebrates become more resistant to a pathogen following initial exposure to a nonlethal dose; yet the generality, mechanisms, and adaptive value of such immune priming are still under debate. Because life-history theory predicts that immune priming and large investment in immunity should be more frequent in long-lived species, we here tested for immune priming and pathogen resistance in ant queens, which have extraordinarily long life span. We exposed virgin and mated queens of Lasius niger and Formica selysi to a low dose of the entomopathogenic fungus Beauveria bassiana, before challenging them with a high dose of the same pathogen. We found evidence for immune priming in naturally mated queens of L. niger. In contrast, we found no sign of priming in virgin queens of L. niger, nor in virgin or experimentally mated queens of F. selysi, which indicates that immune priming in ant queens varies according to mating status and mating conditions or species. In both ant species, mated queens showed higher pathogen resistance than virgin queens, which suggests that mating triggers an up-regulation of the immune system. Overall, mated ant queens combine high reproductive output, very long life span, and elevated investment in immune defense. Hence, ant queens are able to invest heavily in both reproduction and maintenance, which can be explained by the fact that mature queens will be protected and nourished by their worker offspring. PMID:24963375

Gálvez, Dumas; Chapuisat, Michel

2014-05-01

386

A novel property of spider silk: chemical defence against ants  

PubMed Central

Spider webs are made of silk, the properties of which ensure remarkable efficiency at capturing prey. However, remaining on, or near, the web exposes the resident spiders to many potential predators, such as ants. Surprisingly, ants are rarely reported foraging on the webs of orb-weaving spiders, despite the formidable capacity of ants to subdue prey and repel enemies, the diversity and abundance of orb-web spiders, and the nutritional value of the web and resident spider. We explain this paradox by reporting a novel property of the silk produced by the orb-web spider Nephila antipodiana (Walckenaer). These spiders deposit on the silk a pyrrolidine alkaloid (2-pyrrolidinone) that provides protection from ant invasion. Furthermore, the ontogenetic change in the production of 2-pyrrolidinone suggests that this compound represents an adaptive response to the threat of natural enemies, rather than a simple by-product of silk synthesis: while 2-pyrrolidinone occurs on the silk threads produced by adult and large juvenile spiders, it is absent on threads produced by small juvenile spiders, whose threads are sufficiently thin to be inaccessible to ants.

Zhang, Shichang; Koh, Teck Hui; Seah, Wee Khee; Lai, Yee Hing; Elgar, Mark A.; Li, Daiqin

2012-01-01

387

Specificity and transmission mosaic of ant nest-wall fungi.  

PubMed

Mutualism, whereby species interact to their mutual benefit, is extraordinary in a competitive world. To recognize general patterns of origin and maintenance from the plethora of mutualistic associations proves a persisting challenge. The simplest situation is believed to be that of a single mutualist specific to a single host, vertically transmitted from one host generation to the next. We characterized ascomycete fungal associates cultured for nest architecture by the ant subgenera Dendrolasius and Chthonolasius. The ants probably manage their fungal mutualists by protecting them against fungal competitors. The ant subgenera display different ant-to-fungus specificity patterns, one-to-two and many-to-one, and we infer vertical transmission, in the latter case overlaid by horizontal transmission. Possible evolutionary trajectories include a reversal from fungiculture by other Lasius subgenera and inheritance of fungi through life cycle interactions of the ant subgenera. The mosaic indicates how specificity patterns can be shaped by an interplay between host life-cycles and transmission adaptations. PMID:18195358

Schlick-Steiner, Birgit C; Steiner, Florian M; Konrad, Heino; Seifert, Bernhard; Christian, Erhard; Moder, Karl; Stauffer, Christian; Crozier, Ross H

2008-01-22

388

Consequences of prescribed fire and grazing on grassland ant communities.  

PubMed

Prescribed fire and livestock grazing are used for the management and restoration of native grasslands the world over; however, the effects of these management techniques on ant communities are unclear. We examined the response of ants to these disturbances in grasslands in northern California. Twenty-four 30 by 30 m plots were established across two sites that received one of four treatments: grazing, fire, grazing and fire, or no treatment. Ants were censused using 240 pitfall traps with one preburn and two postburn samples (14 d and 1 yr after burning). We analyzed ant abundance using broadly defined groups based on feeding habit and/or habitat use and detected no grazing effect but a significant fire effect that differed by group. Immediate postfire sampling showed an increase in cryptic species (particularly Brachymyrmex depilis). One year after the fire, no response was detected for cryptic species, but burned plots had greater abundance of seed harvesters. Analysis of vegetation showed burned plots had significantly greater forb cover, which might have provided greater food resources, and also lower biomass, which might have facilitated foraging. Understanding the effects of these management tools on ant abundance complements our understanding of their effect on vegetation and assists conservation practitioners effectively manage grassland ecosystems both in California and beyond. PMID:19389280

Underwood, Emma C; Christian, Caroline E

2009-04-01

389

Prey Capture Behavior in an Arboreal African Ponerine Ant  

PubMed Central

I studied the predatory behavior of Platythyrea conradti, an arboreal ponerine ant, whereas most species in this subfamily are ground-dwelling. The workers, which hunt solitarily only around dusk, are able to capture a wide range of prey, including termites and agile, nocturnal insects as well as diurnal insects that are inactive at that moment of the Nyctemeron, resting on tree branches or under leaves. Prey are captured very rapidly, and the antennal palpation used by ground-dwelling ponerine species is reduced to a simple contact; stinging occurs immediately thereafter. The venom has an instant, violent effect as even large prey (up to 30 times the weight of a worker) never struggled after being stung. Only small prey are not stung. Workers retrieve their prey, even large items, singly. To capture termite workers and soldiers defending their nest entrances, ant workers crouch and fold their antennae backward. In their role as guards, the termites face the crouching ants and end up by rolling onto their backs, their legs batting the air. This is likely due to volatile secretions produced by the ants' mandibular gland. The same behavior is used against competing ants, including territorially-dominant arboreal species that retreat further and further away, so that the P. conradti finally drive them from large, sugary food sources.

Dejean, Alain

2011-01-01

390

Shaken, not stirred: a serendipitous study of ants and earthquakes.  

PubMed

There is anecdotal evidence for profound behavioral changes prior to and during earthquakes in many organisms, including arthropods such as ants. Behavioral or physiological analysis has often, in light of these reports, been proposed as a means of earthquake prediction. We report here a serendipitous study of the effect of the powerful Landers earthquake in the Mojave Desert, USA (Richter magnitude 7.4) on ant trail dynamics and aerobic catabolism in the desert harvester ant Messor pergandei. We monitored trail traffic rates to and from the colony, trail speed, worker mass distributions, rates of aerobic catabolism and temperature at ant height before and during the earthquake, and for 3 days after the earthquake. Contrary to anecdotal reports of earthquake effects on ant behavior, the Landers earthquake had no effect on any measured aspect of the physiology or behavior of M. pergandei. We conclude that anecdotal accounts of the effects of earthquakes or their precursors on insect behavior should be interpreted with caution. PMID:16081608

Lighton, John R B; Duncan, Frances D

2005-08-01

391

Endophytic fungi reduce leaf-cutting ant damage to seedlings.  

PubMed

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 (E(high)) or low (E(low)) densities of endophytes. The E(high) seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the E(low) treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from E(low) relative to E(high) seedlings and had a tendency to recruit more ants to E(low) 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

2011-02-23

392

Temperature limits trail following behaviour through pheromone decay in ants  

NASA Astrophysics Data System (ADS)

In Mediterranean habitats, temperature affects both ant foraging behaviour and community structure. Many studies have shown that dominant species often forage at lower temperature than subordinates. Yet, the factors that constrain dominant species foraging activity in hot environments are still elusive. We used the dominant ant Tapinoma nigerrimum as a model species to test the hypothesis that high temperatures hinder trail following behaviour by accelerating pheromone degradation. First, field observations showed that high temperatures (> 30°C) reduce the foraging activity of T. nigerrimum independently of the daily and seasonal rhythms of this species. Second, we isolated the effect of high temperatures on pheromone trail efficacy from its effect on worker physiology. A marked substrate was heated during 10 min (five temperature treatments from 25°C to 60°C), cooled down to 25°C, and offered in a test choice to workers. At hot temperature treatments (>40°C), workers did not discriminate the previously marked substrate. High temperatures appeared therefore to accelerate pheromone degradation. Third, we assessed the pheromone decay dynamics by a mechanistic model fitted with Bayesian inference. The model predicted ant choice through the evolution of pheromone concentration on trails as a function of both temperature and time since pheromone deposition. Overall, our results highlighted that the effect of high temperatures on recruitment intensity was partly due to pheromone evaporation. In the Mediterranean ant communities, this might affect dominant species relying on chemical recruitment, more than subordinate ant species, less dependent on chemical communication and less sensitive to high temperatures.

van Oudenhove, Louise; Billoir, Elise; Boulay, Raphaël; Bernstein, Carlos; Cerdá, Xim

2011-12-01

393

Did the fire ant supergene evolve selfishly or socially?  

PubMed

The genetic basis for animal social organization is poorly understood. Fire ants provide one of the rare cases where variation in social organization has been demonstrated to be under genetic control, which amazingly, segregates as a single Mendelian locus. A recent genetic, genomic, and cytological analysis revealed that this locus actually consists of over 600 genes locked together in a supergene that possesses many characteristics of sex chromosomes. The fire ant social supergene also behaves selfishly, and an interesting evolutionary question is whether the genes incorporated first into the social supergene were those for social adaptation, selfish genetic drive, or something else. In depth, functional molecular genetic analysis in fire ants and comparative genomics in other closely related socially polymorphic species will be required to resolve this question. PMID:24272711

Huang, Yu-Ching; Wang, John

2014-02-01

394

Managing leaf-cutting ants: peculiarities, trends and challenges.  

PubMed

Leaf-cutting ants are generally recognized as important pest species in Neotropical America. They are eusocial insects that exhibit social organization, foraging, fungus-cultivation, hygiene and a complex nest structure, which render their management notoriously difficult. A lack of economic thresholds and sampling plans focused on the main pest species preclude the management of leaf-cutting ants; such management would facilitate their control and lessen insecticide overuse, particularly the use of insecticidal baits. Recent restrictions on the use of synthetic compounds for such purposes impose additional challenges for the management of leaf-cutting ants. Considerable effort has been exerted regarding these challenges, which are addressed herein, but which also remain challenges that are yet to be conquered. PMID:24115496

Della Lucia, Terezinha M C; Gandra, Lailla C; Guedes, Raul N C

2014-01-01

395

Suitability factor on the Capacitated Vehicle Routing Problem  

Microsoft Academic Search

Finding a good solution for logistics and transportation industries is a continuous effort to maximize the efficiencies especially on problem that relates to the industry such as Vehicle Routing Problem (VRP). One of the most popular solutions is using Ant Colony System (ACS) algorithm. Several versions of ACOs have been proposed which aim to achieve an optimum solution. A new

Zulaiha Ali Othman; Abdul Razak Hamdan

2010-01-01

396

Divergent Chemical Cues Elicit Seed Collecting by Ants in an Obligate Multi-Species Mutualism in Lowland Amazonia  

Microsoft Academic Search

In lowland Amazonian rainforests, specific ants collect seeds of several plant species and cultivate them in arboreal carton nests, forming species-specific symbioses called ant-gardens (AGs). In this obligate mutualism, ants depend on the plants for nest stability and the plants depend on ant nests for substrate and nutrients. AG ants and plants are abundant, dominant members of lowland Amazonian ecosystems,

Elsa Youngsteadt; Patricia Guerra Bustios; Coby Schal; Walter S. Leal

2010-01-01

397

Bait distribution among multiple colonies of Pharaoh ants (hymenoptera: Formicidae).  

PubMed

Pharaoh ant, Monomorium pharaonis (L.), infestations often consist of several colonies located at different nest sites. To achieve control, it is desirable to suppress or eliminate the populations of a majority of these colonies. We compared the trophallactic distribution and efficacy of two ant baits, with different modes of action, among groups of four colonies of Pharaoh ants. Baits contained either the metabolic-inhibiting active ingredient hydramethylnon or the insect growth regulator (IGR) pyriproxyfen. Within 3 wk, the hydramethylnon bait reduced worker and brood populations by at least 80%, and queen reductions ranged between 73 and 100%, when nests were in proximity (within 132 cm) to the bait source. However, these nest sites were reoccupied by ants from other colonies located further from the bait source. The pyriproxyfen bait was distributed more thoroughly to all nest locations with worker populations gradually declining by 73% at all nest sites after 8 wk. Average queen reductions ranged from 31 to 49% for all nest sites throughout the study. Even though some queens survived, brood reductions were rapid in the pyriproxyfen treatment, with reductions of 95% at all locations by week 3. Unlike the metabolic inhibitor, the IGR did not kill adult worker ants quickly, thus, more surviving worker ants were available to distribute the bait to all colonies located at different nest sites. Thus, from a single bait source, the slow-acting bait toxicant provided gradual, but long-term control, whereas the fast-acting bait toxicant provided rapid, localized control for a shorter duration. PMID:10985038

Oi, D H; Vail, K M; Williams, D F

2000-08-01

398

Phylogeny of the ants: diversification in the age of angiosperms.  

PubMed

We present a large-scale molecular phylogeny of the ants (Hymenoptera: Formicidae), based on 4.5 kilobases of sequence data from six gene regions extracted from 139 of the 288 described extant genera, representing 19 of the 20 subfamilies. All but two subfamilies are recovered as monophyletic. Divergence time estimates calibrated by minimum age constraints from 43 fossils indicate that most of the subfamilies representing extant ants arose much earlier than previously proposed but only began to diversify during the Late Cretaceous to Early Eocene. This period also witnessed the rise of angiosperms and most herbivorous insects. PMID:16601190

Moreau, Corrie S; Bell, Charles D; Vila, Roger; Archibald, S Bruce; Pierce, Naomi E

2006-04-01

399

Pretender punishment induced by chemical signalling in a queenless ant.  

PubMed

Animal societies are stages for both conflict and cooperation. Reproduction is often monopolized by one or a few individuals who behave aggressively to prevent subordinates from reproducing (for example, naked mole-rats, wasps and ants). Here we report an unusual mechanism by which the dominant individual maintains reproductive control. In the queenless ant Dinoponera quadriceps, only the alpha female reproduces. If the alpha is challenged by another female she chemically marks the pretender who is then punished by low-ranking females. This cooperation between alpha and low-rankers allows the alpha to inflict punishment indirectly, thereby maintaining her reproductive primacy without having to fight. PMID:12214231

Monnin, Thibaud; Ratnieks, Francis L W; Jones, Graeme R; Beard, Richard

2002-09-01

400

Phylogeny of the Ants: Diversification in the Age of Angiosperms  

NASA Astrophysics Data System (ADS)

We present a large-scale molecular phylogeny of the ants (Hymenoptera: Formicidae), based on 4.5 kilobases of sequence data from six gene regions extracted from 139 of the 288 described extant genera, representing 19 of the 20 subfamilies. All but two subfamilies are recovered as monophyletic. Divergence time estimates calibrated by minimum age constraints from 43 fossils indicate that most of the subfamilies representing extant ants arose much earlier than previously proposed but only began to diversify during the Late Cretaceous to Early Eocene. This period also witnessed the rise of angiosperms and most herbivorous insects.

Moreau, Corrie S.; Bell, Charles D.; Vila, Roger; Archibald, S. Bruce; Pierce, Naomi E.

2006-04-01

401

Mellein, a Trail Pheromone Component of the Ant Lasius fuliginosus  

Microsoft Academic Search

3,4-Dihydro-8-hydroxy-3-methylisocoumarin (mellein) and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one are among the volatile constituents identified from the hindgut of the formicine ant Lasius (Dendrolasius) fuliginosus Mellein induces trail-following behavior in worker ants of this species and evokes electrophysiological responses from their antennae. The trail-following activity released by (R)-(-)-mellein is significantly higher than that elicited by its (S)-(+) antipode, or the racemic mixture. The above-mentioned pyranone

Friedrich Kern; Rüdiger W. Klein; Edelgard Janssen; Hans-Jürgen Bestmann; Athula B. Attygalle; Doris Schäfer; Ulrich Maschwitz

1997-01-01

402

Response Ant Colony Optimization of End Milling Surface Roughness  

PubMed Central

Metal cutting processes are important due to increased consumer demands for quality metal cutting related products (more precise tolerances and better product surface roughness) that has driven the metal cutting industry to continuously improve quality control of metal cutting processes. This paper presents optimum surface roughness by using milling mould aluminium alloys (AA6061-T6) with Response Ant Colony Optimization (RACO). The approach is based on Response Surface Method (RSM) and Ant Colony Optimization (ACO). The main objectives to find the optimized parameters and the most dominant variables (cutting speed, feedrate, axial depth and radial depth). The first order model indicates that the feedrate is the most significant factor affecting surface roughness.

Kadirgama, K.; Noor, M. M.; Abd Alla, Ahmed N.

2010-01-01

403

Conflict over reproduction in an ant-plant symbiosis: why Allomerus octoarticulatus ants sterilize Cordia nodosa trees.  

PubMed

The evolutionary stability of mutualism is thought to depend on how well the fitness interests of partners are aligned. Because most ant-myrmecophyte mutualisms are persistent and horizontally transmitted, partners share an interest in growth but not in reproduction. Resources invested in reproduction are unavailable for growth, giving rise to a conflict of interest between partners. I investigated whether this explains why Allomerus octoarticulatus ants sterilize Cordia nodosa trees. Allomerus octoarticulatus nests in the hollow stem domatia of C. nodosa. Workers protect C. nodosa leaves against herbivores but destroy inflorescences. Using C. nodosa trees with Azteca ants, which do not sterilize their hosts, I cut inflorescences off trees to simulate sterilization by A. octoarticulatus. Sterilized C. nodosa grew faster than control trees, providing evidence for a trade-off between growth and reproduction. Allomerus octoarticulatus manipulates this trade-off to its advantage; sterilized trees produce more domatia and can house larger, more fecund colonies. PMID:19296734

Frederickson, Megan E

2009-05-01

404

Multiple Ant Species Tending Lac Insect Kerria yunnanensis (Hemiptera: Kerriidae) Provide Asymmetric Protection against Parasitoids  

PubMed Central

This study investigated the effects of ant attendance on the parasitoid community and parasitism of lac insect Kerria yunnanensis aggregations in Yunnan province, China. We manipulated ant attendance to establish three treatments: (1) ant exclusion; (2) low ant attendance by several ant species; and (3) high ant attendance by Crematogaster macaoensis. Five parasitoid species were collected, with two species contributing 82.7 and 13.2% of total abundance respectively. Total parasitoid abundance was lowest in the February sample when K. yunnanensis was in its younger life stage, being significantly lower in the ant exclusion treatment. In April, all three treatments had significantly different parasitoid abundances, being highest in the ant exclusion treatment and the lowest in the high ant attendance treatment. When ants were present, there were strong negative relationships between total parasitoid abundance and ant abundance, with the relationships being dependent upon the ant species composition and abundance. The patterns of total parasitoid abundance were driven by the two most abundant parasitoid species. Parasitoid species richness did not differ among treatments or between sample times, however, multivariate analysis confirmed that overall parasitoid community structure differed significantly among treatments and between sample times, with the high ant attendance treatment differing most from the other two treatments. Interestingly the absence of ants did not result in increased parasitism from four of the five parasitoids. Ants in lac insect farming systems have a clear role for agricultural pest management. A full understanding of the asymmetric abilities of ants to influence parasitoid communities, and affect parasitism of hosts will require further experimental manipulation to assess the relative roles of 1) the abundance of each individual ant species on parasitoid access to hosts, 2) competition among parasitoids, and 3) the interaction between the first two factors.

Li, Qiao; Hoffmann, Benjamin D.; Zhang, Wei

2014-01-01

405

Effect of Mediterranean ants (Hymenoptera: Formicidae) on California red scale (Hemiptera: Diaspididae) populations in citrus orchards.  

PubMed

We conducted an ant-exclusion experiment in a citrus orchard to evaluate the overall impact of three ant species native in the Mediterranean, Pheidole pallidula (Nylander), Plagiolepis schmitzii Forel, and Lasius grandis (Forel), on populations of Aonidiella aurantii Maskell (California red scale). The ant-exclusion was carried out in four experimental plots from March 2007 to November 2008. Another subset of four plots, adjacent to the ant-excluded plots, was used as control. We measured scale densities and percent parasitism on fruits at harvest in 2007 and 2008. Additionally, we sampled the seasonal trend of the scale on twigs and fruits in both treatments during 2008. California red scale densities in the ant-excluded treatment began to be significantly lower than in the ant-allowed control in May (1 mo after ant activity began), and this difference increased until November. Thus, the effect of the ants on California red scale density seems to be accumulative. At harvest, scale densities on fruits were significantly lower in the ant-excluded treatment. However, percent parasitism on fruits was similar between treatments. Finally, scale densities on the fruits of the ant-allowed plots were positively correlated with the number of ants that climbed to the citrus canopy. These results suggest that increases of scale densities induced by Mediterranean ants depend on the intensity of the ant-activity on citrus canopies. PMID:20550795

Pekas, A; Tena, A; Aguilar, A; Garcia-Marí, F

2010-06-01

406

Fire ants actively control spacing and orientation within self-assemblages.  

PubMed

To overcome obstacles and survive harsh environments, fire ants link their bodies together to form self-assemblages such as rafts, bridges and bivouacs. Such structures are examples of self-assembling and self-healing materials, as ants can quickly create and break links with one another in response to changes in their environment. Because ants are opaque, the arrangement of the ants within these three-dimensional networks was previously unknown. In this experimental study, we applied micro-scale computed tomography, or micro-CT, to visualize the connectivity, arrangement and orientation of ants within an assemblage. We identified active and geometric mechanisms that ants use to obtain favorable packing properties with respect to well-studied packing of inert objects such as cylinders. Ants use their legs to push against their neighbors, doubling their spacing relative to random packing of cylinders. These legs also permit active control of their orientation, an ability ants use to arrange themselves perpendicularly rather than in parallel. Lastly, we found an important role of ant polymorphism in promoting self-aggregation: a large distribution of ant sizes permits small ants to fit between the legs of larger ants, a phenomenon that increases the number of average connections per ant. These combined mechanisms lead to low packing fraction and high connectivity, which increase raft buoyancy and strength during flash floods. PMID:24920836

Foster, Paul C; Mlot, Nathan J; Lin, Angela; Hu, David L

2014-06-15

407

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

NASA Astrophysics Data System (ADS)

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 as well as a limited access to information. A variety of collective behaviour spontaneously outcome from multiple interactions between nestmates, even when there is no directing influence imposed by an external template, a pacemaker or a leader. By focussing this review on foraging structures, we show that ant societies display some properties which are usually considered in physico-chemical systems, as typical signatures of self-organization. We detail the key role played by feed-back loops, fluctuations, number of interacting units and sensitivity to environmental factors in the emergence of a structured collective behaviour. Nonetheless, going beyond simple analogies with non-living self-organized patterns, we stress on the specificities of social structures made of complex living units of which the biological features have been selected throughout the evolution depending on their adaptive value. In particular, we consider the ability of each ant individual to process information about environmental and social parameters, to accordingly tune its interactions with nestmates and ultimately to determine the final pattern emerging at the collective level. We emphasize on the parsimony and simplicity of behavioural rules at the individual level which allow an efficient processing of information, energy and matter within the whole colony.

Detrain, Claire; Deneubourg, Jean-Louis

2006-09-01

408

Problem? What Problem?  

ERIC Educational Resources Information Center

Successive administrations have responded to the serious shortage of competent mathematics teachers by trying to 'make do', adopting short-term strategies which fail to address the underlying problem. A sense of urgency, the will to act, and the imagination to see a way forward have been absent. The situation is now worse than ever. This paper…

Gardiner, Tony

409

Dynamics and kinematics of ant locomotion: do wood ants climb on level surfaces?  

PubMed

The biomechanics of running in small animals have remained poorly characterized because of the difficulty of recording three-dimensional ground reaction forces. Available techniques limit investigations to animals with a body mass above 1 g. Here we present, for the first time, single-leg ground reaction forces of ants (body mass 10 mg), measured with a custom-built miniature force plate. We investigated forces and high-speed kinematics for straight level runs (average speed: 8.4 cm s(-1)) of Formica polyctena workers. The major finding was that the time course of ground reaction forces strongly differed from previous observations of larger insects. Maximum vertical force was reached during the first third of the tripod contact phase. During this period the body was decelerated predominantly by the front legs. Subsequently, the front legs pulled and accelerated the body. This 'climbing' type of stride may be useful on the bumpy and unstable substrates that the animals face in their natural habitats, and may therefore also occur on level ground. Propulsive forces were generated predominantly by the front and hind legs. Dragging of the gaster on the substrate resulted in a breaking momentum, which was compensated by the legs. Future investigations will reveal, whether the identified pattern is due to specialization. PMID:19617436

Reinhardt, Lars; Weihmann, Tom; Blickhan, Reinhard

2009-08-01

410

Colony founding by pleometrosis in the fire ant, Solenopsis invicta  

Microsoft Academic Search

Newly mated queens of the fire ant, Solenopsis invicta, found colonies either alone (haplometrosis) or by joining with other newly mated queens (pleometrosis). Surveys after mating flights showed that nests and queens were usually aggregated in space, that queens were aggregated among occupied nest chambers, and that the occurrence and degree of pleometrosis was related to the mean queen density.

Walter R. Tschinkel; Dennis F. Howard

1983-01-01

411

Regulation of Diet in the Fire Ant, Solenopsis invicta  

Microsoft Academic Search

In social insects, colony nutrition depends upon the volume and quality of food distributed, ingested, and assimilated by its members. The ability of Solenopsis invicta workers and larvae to regulate the volume of food ingested individually has been well documented. In this paper, the ability of fire ant workers and larvae to regulate the quality and type of food ingested

Deby Lee Cassill; Walter R. Tschinkel

1999-01-01

412

The genome of the fire ant Solenopsis invicta.  

PubMed

Ants have evolved very complex societies and are key ecosystem members. Some ants, such as the fire ant Solenopsis invicta, are also major pests. Here, we present a draft genome of S. invicta, assembled from Roche 454 and Illumina sequencing reads obtained from a focal haploid male and his brothers. We used comparative genomic methods to obtain insight into the unique features of the S. invicta genome. For example, we found that this genome harbors four adjacent copies of vitellogenin. A phylogenetic analysis revealed that an ancestral vitellogenin gene first underwent a duplication that was followed by possibly independent duplications of each of the daughter vitellogenins. The vitellogenin genes have undergone subfunctionalization with queen- and worker-specific expression, possibly reflecting differential selection acting on the queen and worker castes. Additionally, we identified more than 400 putative olfactory receptors of which at least 297 are intact. This represents the largest repertoire reported so far in insects. S. invicta also harbors an expansion of a specific family of lipid-processing genes, two putative orthologs to the transformer/feminizer sex differentiation gene, a functional DNA methylation system, and a single putative telomerase ortholog. EST data indicate that this S. invicta telomerase ortholog has at least four spliceforms that differ in their use of two sets of mutually exclusive exons. Some of these and other unique aspects of the fire ant genome are likely linked to the complex social behavior of this species. PMID:21282665

Wurm, Yannick; Wang, John; Riba-Grognuz, Oksana; Corona, Miguel; Nygaard, Sanne; Hunt, Brendan G; Ingram, Krista K; Falquet, Laurent; Nipitwattanaphon, Mingkwan; Gotzek, Dietrich; Dijkstra, Michiel B; Oettler, Jan; Comtesse, Fabien; Shih, Cheng-Jen; Wu, Wen-Jer; Yang, Chin-Cheng; Thomas, Jerome; Beaudoing, Emmanuel; Pradervand, Sylvain; Flegel, Volker; Cook, Erin D; Fabbretti, Roberto; Stockinger, Heinz; Long, Li; Farmerie, William G; Oakey, Jane; Boomsma, Jacobus J; Pamilo, Pekka; Yi, Soojin V; Heinze, Jürgen; Goodisman, Michael A D; Farinelli, Laurent; Harshman, Keith; Hulo, Nicolas; Cerutti, Lorenzo; Xenarios, Ioannis; Shoemaker, Dewayne; Keller, Laurent

2011-04-01

413

Evolutionary patterns of proteinase activity in attine ant fungus gardens  

Microsoft Academic Search

BACKGROUND: Attine ants live in symbiosis with a basidiomycetous fungus that they rear on a substrate of plant material. This indirect herbivory implies that the symbiosis is likely to be nitrogen deprived, so that specific mechanisms may have evolved to enhance protein availability. We therefore hypothesized that fungal proteinase activity may have been under selection for efficiency and that different

Tatyana A Semenova; David P Hughes; Jacobus J Boomsma; Morten Schiøtt

2011-01-01

414

Bilingualism Aids Conflict Resolution: Evidence from the ANT Task  

ERIC Educational Resources Information Center

The need of bilinguals to continuously control two languages during speech production may exert general effects on their attentional networks. To explore this issue we compared the performance of bilinguals and monolinguals in the attentional network task (ANT) developed by Fan et al. [Fan, J., McCandliss, B.D. Sommer, T., Raz, A., Posner, M.I.…

Costa, Albert; Hernandez, Mirea; Sebastian-Galles, Nuria

2008-01-01

415

Host specificity among Maculinea butterflies in Myrmica ant nests  

Microsoft Academic Search

Ecological studies have been made of all 5 European species of Maculinea. These confirm that M. nausithous and M. rebeli live underground in Myrmica ant nests for 10 months of the year, as has long been known for the other 3 species. The main discovery was that each Maculinea species depends on a single, and different, host species of Myrmica.

J. A. Thomas; G. W. Elmes; J. C. Wardlaw; M. Woyciechowski

1989-01-01

416

Elephants, giraffes and the ants in their plants  

NSDL National Science Digital Library

Nobody wants to see the elephants, giraffes and other grazing animals disappear from the eastern African savanna, but it's not just people who would miss them. Researchers have discovered that many of the ants and trees that share the mammals' turf would suffer, too.

American Association for the Advancement of Science (AAAS;)

2008-01-10

417

Understanding IS Projects Evaluation in Practice through an ANT Inquiry  

Microsoft Academic Search

In this paper we propose a radical departure from the dominant conceptions in IS evaluation literature by adopting Actor-network Theory (ANT) to provide a better understanding of the development and evaluation of IS proposals in practice and examine the ways in which the evaluation process shapes and ensures the selection of the best IS projects. By drawing on a field

Dubravka Cecez-Kecmanovic; Fouad Nagm

418

Sociobiological studies of the polygynic ant Lasius sakagamii  

Microsoft Academic Search

Summary Sociobiological studies were made of the polygynic ant speciesLasius sakagamii Yamauchi et Hayashida. This species has a peculiar polydomous system characterized by 1) intranidal mating, 2) retention of newly emerged queens in the mother nest, resulting in a polygynic colony, 3) reduced territorial behavior, 4) colony multiplication by budding, 5) enlargement of colony size up to several millions of

Katsusuke Yamauchi; Kyoichi Kinomura; Shizuko Miyake

1981-01-01

419

Collective exploration and area marking in the ant Lasius niger  

Microsoft Academic Search

Summary: The aphid tending ant species, Lasius niger collectively explore new areas. Scouts are mobilised within the first five minutes of exploration with activity thereafter decreasing and stabilising after 40 minutes. Collective path choices of colonies underline the existence of chemical recruitment and area marking during exploration. To identify the territorial or home-range role of exploratory marking, we examined its

C. Devigne; C. Detrain

2002-01-01

420

Sperm parasitism in ants: selection for interspecific mating and hybridization.  

PubMed

Interspecific mating in eusocial Hymenoptera can be favored under certain conditions even if all hybrid offspring are completely infertile. This exploits two key features of the eusocial Hymenoptera: a haplodiploid genetic system and reproductive division of labor in females. Interspecifically mated queens can still produce viable sons that will mate intraspecifically. Apparent reduced fitness resulting from producing infertile daughter gynes can be also offset by advantages conferred by hybrid workers. An important advantage is likely to be superior ability at using marginal habitats. Interspecifically mated queens can nest in sites where intraspecific competition will be low. By mating interspecifically, a queen trades expected reproductive success through female offspring for a higher probability of achieving some reproductive success. Females that mate interspecifically can be considered "sperm parasites" on the males of the other species. I provide evidence that sperm parasitism is responsible for widespread hybridization in North America among two species of the ant subgenus Acanthomyops (genus Lasius), and review evidence for sperm parasitism in other hybridization phenomena in ants. Sperm parasitism in ants represents a novel form of social parasitism in ants and a dispersal polymorphism. It may also act as a precursor to the evolution of some other recently discovered phenomena, such as genetic caste determination. PMID:16995614

Umphrey, Gary J

2006-09-01

421

Standing on the shoulders of ants: stigmergy in the web  

Microsoft Academic Search

Stigmergy is a biological term used when discussing insect or swarm behaviour, and describes a model supporting environmental communication separately from artefacts or agents. This phenomenon is demonstrated in the behavior of ants and their food gathering process when following pheromone trails, or similarly termites and their termite mound building process. What is interesting with this mechanism is that highly

Aiden Charles Dipple; K Raymond; M Docherty

2011-01-01

422

Evaluation of control measures for black carpenter ant (Hymenoptera: Formicidae).  

PubMed

Current control methods for the black carpenter ant, Camponotus pennsylvanicus (De Geer), include the use of remedial and preventative residual sprays as well as toxic baits. We evaluated the acceptance of three baits (Maxforce, Niban, and Baygon) to field colonies of the black carpenter ant in the spring and fall. Maxforce bait granules were more readily accepted than either Niban or Baygon bait granules in the spring. A change in food preference from protein to sugar by the black carpenter ant appeared to reduce the number of Maxforce bait granules removed in the fall, resulting in no differences in bait acceptability. The longevity of Dursban 50W and Tempo 20WP were evaluated in the summer and fall on painted wood panels. Panels aged outside for 15 d under prevailing weather conditions exhibited increased LT50 values. For each sampling period, panels aged on the south face (in the sun) exhibited less insecticidal activity (i.e., large LT50 values) than panels on the north face (shaded; small LT50 values). At each sampling period, Tempo 20WP provided smaller LT50 values than Dursban 50W. Because of changing dietary preferences, our data highlight the importance of using various bait types for carpenter ant control. Moreover, the application of residual spays should be made to locations protected from direct sunlight. PMID:11057723

Tripp, J M; Suiter, D R; Bennett, G W; Klotz, J H; Reid, B L

2000-10-01

423

The short-term regulation of foraging in harvester ants  

Microsoft Academic Search

In the seed-eating ant Pogonomyrmex barbatus, the return of successful foragers stimulates inactive foragers to leave the nest. The rate at which successful foragers return to the nest depends on food availability; the more food available, the more quickly foragers will find it and bring it back. Field experiments examined how quickly a colony can adjust to a decline in

Deborah M. Gordon; Susan Holmes; S. Nacu

2007-01-01

424

Ex Post and Ex Ante Analysis of Provisional Data  

Microsoft Academic Search

In this paper we suggest a framework to assess the degree of reliability of provisional estimates as forecasts of final data, and we reexamine the question of the most appropriate way in which available data should be used for ex ante forecasting in the presence of a data revision process. Various desirable properties for provisional data are suggested, as well

Giampiero M. Gallo; Massimiliano Marcellino

1998-01-01

425

Mitochondrial genome evolution in fire ants (Hymenoptera: Formicidae)  

PubMed Central

Background Complete mitochondrial genome sequences have become important tools for the study of genome architecture, phylogeny, and molecular evolution. Despite the rapid increase in available mitogenomes, the taxonomic sampling often poorly reflects phylogenetic diversity and is often also biased to represent deeper (family-level) evolutionary relationships. Results We present the first fully sequenced ant (Hymenoptera: Formicidae) mitochondrial genomes. We sampled four mitogenomes from three species of fire ants, genus Solenopsis, which represent various evolutionary depths. Overall, ant mitogenomes appear to be typical of hymenopteran mitogenomes, displaying a general A+T-bias. The Solenopsis mitogenomes are slightly more compact than other hymentoperan mitogenomes (~15.5 kb), retaining all protein coding genes, ribosomal, and transfer RNAs. We also present evidence of recombination between the mitogenomes of the two conspecific Solenopsis mitogenomes. Finally, we discuss potential ways to improve the estimation of phylogenies using complete mitochondrial genome sequences. Conclusions The ant mitogenome presents an important addition to the continued efforts in studying hymenopteran mitogenome architecture, evolution, and phylogenetics. We provide further evidence that the sampling across many taxonomic levels (including conspecifics and congeners) is useful and important to gain detailed insights into mitogenome evolution. We also discuss ways that may help improve the use of mitogenomes in phylogenetic analyses by accounting for non-stationary and non-homogeneous evolution among branches.

2010-01-01

426

Desert ant navigation: how miniature brains solve complex tasks  

Microsoft Academic Search

This essay presents and discusses the state of the art in studies of desert ant ( Cataglyphis) navigation. In dealing with behavioural performances, neural mechanisms, and ecological functions these studies ultimately aim at an evolutionary understanding of the insect's navigational toolkit: its skylight (polarization) compass, its path integrator, its view-dependent ways of recognizing places and following landmark routes, and its

R. Wehner

2003-01-01

427

ANTS: Exploring the Solar System with an Autonomous Nanotechnology Swarm  

NASA Technical Reports Server (NTRS)

ANTS (Autonomous Nano-Technology Swarm), a NASA advanced mission concept, calls for a large (1000 member) swarm of pico-class (1 kg) totally autonomous spacecraft to prospect the asteroid belt. Additional information is contained in the original extended abstract.

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

2002-01-01

428

A 40-Year-Old Man with Ulcerated Skin Lesions Caused by Bites of Safari Ants  

PubMed Central

We report a 40-year old man in Uganda with ulcerated skins lesions, hypotension, and anaphylaxis caused by bites of safari ants. Treatment was successful. Physicians should be aware of anaphylaxis caused by ant bites.

Chianura, Leonardo; Pozzi, Federica

2010-01-01

429

Ant genomics sheds light on the molecular regulation of social organization  

PubMed Central

Ants are powerful model systems for the study of cooperation and sociality. In this review, we discuss how recent advances in ant genomics have contributed to our understanding of the evolution and organization of insect societies at the molecular level.

2013-01-01

430

The genomic impact of 100 million years of social evolution in seven ant species.  

PubMed

Ants (Hymenoptera, Formicidae) represent one of the most successful eusocial taxa in terms of both their geographic distribution and species number. The publication of seven ant genomes within the past year was a quantum leap for socio- and ant genomics. The diversity of social organization in ants makes them excellent model organisms to study the evolution of social systems. Comparing the ant genomes with those of the honeybee, a lineage that evolved eusociality independently from ants, and solitary insects suggests that there are significant differences in key aspects of genome organization between social and solitary insects, as well as among ant species. Altogether, these seven ant genomes open exciting new research avenues and opportunities for understanding the genetic basis and regulation of social species, and adaptive complex systems in general. PMID:21982512

Gadau, Jürgen; Helmkampf, Martin; Nygaard, Sanne; Roux, Julien; Simola, Daniel F; Smith, Chris R; Suen, Garret; Wurm, Yannick; Smith, Christopher D

2012-01-01

431

The genomic impact of 100 million years of social evolution in seven ant species  

PubMed Central

Ants (Hymenoptera, Formicidae) represent one of the most successful eusocial taxa in terms of both their geographic distribution and species number. The publication of seven ant genomes within the past year was a quantum leap for socio- and ant genomics. The diversity of social organization in ants makes them excellent model organisms to study the evolution of social systems. Comparing the ant genomes with those of the honeybee, a lineage that evolved eusociality independently from ants, and solitary insects suggests that there are significant differences in key aspects of genome organization between social and solitary insects, as well as among ant species. Altogether, these seven ant genomes open exciting new research avenues and opportunities for understanding the genetic basis and regulation of social species, and adaptive complex systems in general.

Gadau, Jurgen; Helmkampf, Martin; Nygaard, Sanne; Roux, Julien; Simola, Daniel F.; Smith, Chris R.; Suen, Garret; Wurm, Yannick; Smith, Christopher D.

2011-01-01

432

Regulation and specificity of antifungal metapleural gland secretion in leaf-cutting ants  

PubMed Central

Ants have paired metapleural glands (MGs) to produce secretions for prophylactic hygiene. These exocrine glands are particularly well developed in leaf-cutting ants, but whether the ants can actively regulate MG secretion is unknown. In a set of controlled experiments using conidia of five fungi, we show that the ants adjust the amount of MG secretion to the virulence of the fungus with which they are infected. We further applied fixed volumes of MG secretion of ants challenged with constant conidia doses to agar mats of the same fungal species. This showed that inhibition halos were significantly larger for ants challenged with virulent and mild pathogens/weeds than for controls and Escovopsis-challenged ants. We conclude that the MG defence system of leaf-cutting ants has characteristics reminiscent of an additional cuticular immune system, with specific and non-specific components, of which some are constitutive and others induced.

Yek, Sze Huei; Nash, David R.; Jensen, Annette B.; Boomsma, Jacobus J.

2012-01-01

433

Post-Glacial Ant Generated Desert Pavements in Southeastern Oregon  

NASA Astrophysics Data System (ADS)

Desert pavements typically require thousands to tens of thousands of years to reach a high level of development. In a pluvial lake valley in Southeastern Oregon I have observed harvester ants creating desert pavement-like features in less than two months. The summer lake basin is a fairly simple sedimentary system. In the eastern half of the basin, the basaltic bedrock is buried under tens of meters of alluvial deposits which lie beneath an approximately ten meter thick dune sheet. The dune sands are noticably different in grainsize and chemistry than the fine component of the alluvial deposits. The dunes began to form at the end of the last pluvial interval (Allison 1980) and continue to be active today. Roughly one fourth of the total area of the dune sheet is mantled with desert pavement, consisting of very coarse sand and fine pebbles (1-8 mm diameter). The dune sand is very fine grained with a considerable amount of silt and minimal clay. It forms thin (2-20 cm thick) well developed Av horizons beneath the desert pavement. Owyhee harvester ants (Pogonomyrmex owyheei) in the area use pebbles of the same size and petrology as the desert pavements to construct their hills. For the ants the closest source of these pebbles is often the alluvium, ten meters below the anthill, rather than in a desert pavement deposit at some distance away overland. An experiment conducted between June and August 1999 demonstrated that the ants rebuild their hills with newly excavated pebbles. When the colonies die off after 5-25 years, the pebbles are stranded at the surface. Processes such as those described by Haff and Werner (1996), where jackrabbits and birds were observed kicking desert pavement clasts aross the ground serve to redistribute the pebbles across the surface of the sand dunes. The sand dunes have been forming over an 8000 year period. Based on anthill-regrowth measurements, the lifespan of an individual colony of harvester ants leads to the excavation of only enough pebbles to cover a two meter square area with desert pavement. This study has determined the quantity of desert pavement currently present at the surface of the sand dunes, and the timescale over which ants can excavate pebbles from the alluvium. The episodic nature of ant colony activity remains to be fully incorporated into the study of desert pavement, usually thought of as a static landform.

Leonard, K. C.

2001-12-01

434

Balance Problems  

MedlinePLUS

... it could be a sign of a balance problem. Balance problems can make you feel unsteady or as if ... related injuries, such as hip fracture. Some balance problems are due to problems in the inner ear. ...

435

Assessing the distribution of the Argentine ant using physiological data  

NASA Astrophysics Data System (ADS)

To address the lack of physiological approaches in current models assessing the potential distribution of the Argentine ant, we used data on brood development from distinct sources to evaluate a series of degree-day models for Catalonia (NE Iberian Peninsula), and data on the brood survival and oviposition rates to develop a worker production model. The degree-day model generated using data from Newell and Barber (1913) and Benois (1973) indicated that the number of degree-days required for the complete development from egg to adult worker was 445.4 degree-days above a threshold of 15.9 °C, while the model calibrated using data from Abril et al. (2008, in press) suggested 599.5 degree-days above 18.4 °C. Comparisons between the degree-day model predictions and the currently known distribution of the Argentine ant suggested that the one generated using data from Newell and Barber (1913) and Benois (1973) overestimated the presence of the species, while the one calibrated using data from Abril et al. (2008; in press) underestimated it. On the other hand, the predicted daily net production of Argentine ant workers generated by the worker production model predicted more accurately the distribution of the Argentine ant than the degree-day models. Our results show the utility of incorporating physiological data in models to assess the distribution limits of the Argentine ant, which up to date have taken little account of the physiological needs of the species in terms of its establishment and dispersion in its introduced ranges.

Abril, Sílvia; Roura-Pascual, Núria; Oliveras, Jordi; Gómez, Crisanto

2009-09-01

436

AntNet: Routing Algorithm for Data Networks based on Mobile Agents  

Microsoft Academic Search

AntNet is an innovative algorithm for packet routing in communication networks, originally proposed by M. Dorigo and G. Di Caro, in 1997. In AntNet, a group of mobile agents (or artificial ants) build paths between pair of nodes, exploring the network concurrently and exchanging obtained information to update the routing tables. This work analyzes AntNet and proposes improvements that were

Benjamín Barán; Rubén Sosa

2001-01-01

437

Seed predators are undeterred by nectar-feeding ants on Chamaecrista nictitans (Caesalpineaceae)  

Microsoft Academic Search

There are many examples of mutualistic interactions between ants and plants bearing extrafloral nectaries (EFN). The annual\\u000a legume Chamaecrista nictitans (Caesalpineaceae) secretes nectar from EFN, specialized structures that attract ants, spiders, and other arthropods. The\\u000a effects of manipulated C. nictitans patch size and location on plant-ant interactions were tested. Defense from herbivores was not detected; plants with ants\\u000a did not

Scott Ruhren

2003-01-01

438

78 FR 70530 - Notice of Determination; New and Revised Treatments for the Imported Fire Ant Program  

Federal Register 2010, 2011, 2012, 2013

...and Revised Treatments for the Imported Fire Ant Program AGENCY: Animal and Plant Health...certain treatment schedules for the Imported Fire Ant Program in the Plant Protection and...and revised treatments in the imported fire ant program. Based on the treatment...

2013-11-26

439

The influence of ants on host plant selection by Jalmenus evagoras , a myrmecophilous lycaenid butterfly  

Microsoft Academic Search

(1) Females of the myrmecophilous lycaenid butterfly, Jalmenus evagoras are far more likely to lay eggs on plants that contain their attendant ants, Iridomyrmex sp. 25 than on plants without ants, although the clutch sizes of individual egg masses laid in either situation is the same. (2) Ovipositing females respond to the presence or absence of ants before they alight

Naomi E. Pierce; Mark A. Elgar

1985-01-01

440

An orb-weaver spider exploits an ant-acacia mutualism for enemy-free space.  

PubMed

Exploiters of protection mutualisms are assumed to represent an important threat for the stability of those mutualisms, but empirical evidence for the commonness or relevance of exploiters is limited. Here, I describe results from a manipulative study showing that an orb-weaver spider, Eustala oblonga, inhabits an ant-acacia for protection from predators. This spider is unique in the orb-weaver family in that it associates closely with both a specific host plant and ants. I tested the protective effect of acacia ants on E.?oblonga by comparing spider abundance over time on acacias with ants and on acacias from which entire ant colonies were experimentally removed. Both juvenile and adult spider abundance significantly decreased over time on acacias without ants. Concomitantly, the combined abundance of potential spider predators increased over time on acacias without ants. These results suggest that ant protection of the ant-acacia Acacia melanocerus also protects the spiders, thus supporting the hypothesis that E.?oblonga exploits the ant-acacia mutualism for enemy-free space. Although E.?oblonga takes advantage of the protection services of ants, it likely exacts little to no cost and should not threaten the stability of the ant-acacia mutualism. Indeed, the potential threat of exploiter species to protection mutualisms in general may be limited to species that exploit the material rewards traded in such mutualisms rather than the protection services. PMID:24558583

Styrsky, John D

2014-02-01

441

A Hybrid Strategy Based on Ant Colony and Taboo Search Algorithms for Fuzzy Job Shop Scheduling  

Microsoft Academic Search

A hybrid strategy base on ant colony and taboo search algorithms is proposed for fuzzy job shop scheduling purpose, which uses the ant colony algorithm as a global search algorithm, and adopt taboo search algorithms as a local search algorithm. TS algorithms have stronger ability of the local search, which can overcome the disadvantages of ant colony algorithms, so this

Xiaoyu Song; Yunlong Zhu; Chaowan Yin; Fuming Li

2006-01-01

442

Temporal organization of bi-directional traffic in the ant Lasius niger (L.)  

Microsoft Academic Search

Foraging in ants is generally organized along well- defined trails supporting a bi-directional flow of outbound and nestbound individuals and one can hypothesize that this flow is maximized to ensure a high rate of food return to the nest. In this paper we examine the effect of bottlenecks on the temporal organization of ant flow. In our experiments ants had

Audrey Dussutour; Jean-Louis Deneubourg; Vincent Fourcassié

2005-01-01

443

Nest structure of ant Lasius neoniger Emery and its implications to soil modification  

Microsoft Academic Search

The ant Lasius neoniger Emery is one of the most abundant ant species found in the temperate regions of North America and has been studied primarily from an entomological standpoint. This study was conducted to characterize its nest structure and implications to soil modification. To study the structure, development, and micromorphological characteristics of the ant nests, we constructed three-dimensional models

D. Wang; K. McSweeney; B. Lowery; J. M. Norman

1995-01-01

444

Chemical mimicry in a parasitoid (Hymenoptera: Eucharitidae) of fire ants (Hymenoptera: Formicidae)  

Microsoft Academic Search

A wasp (Orasema sp.) parasitic on the fire ant,Solenopsis invicta Buren, develops to the adult stage within the ant colony, where wasp larvae are ectoparasitic on ant pupae. This phase of the parasite's life cycle requires a mechanism of integration into the host colony. Gas Chromatographic profiles of hexane soaks of various stages of the parasite and host suggest that

Robert K. Vander Meer; Donald P. Jouvenaz; Daniel P. Wojcik

1989-01-01

445

Establishment and dispersal of the fire ant decapitating fly Pseudacteon tricuspis in North Florida  

Microsoft Academic Search

The decapitating fly Pseudacteon tricuspis Borgmeier was released at eight sites in North Florida between the summer of 1997 and the fall of 1999 as a self-sustaining biocontrol agent of the red imported fire ant, Solenopsis invicta Buren. Several releases used parasitized fire ant workers while most involved adult flies released over disturbed ant mounds. Establishment and dispersal of fly

Sanford D. Porter; Luiz Alexandre Nogueira De Saa; Lloyd W. Morrison

2004-01-01

446

Drowning out the protection racket: partner manipulation or drought can strengthen ant-plant mutualism.  

PubMed

Two recent reports discuss interactions between plants and ants that defend them from herbivores. Acacia trees provide their ant bodyguards with a diet that reduces their ability to benefit from alternate hosts. Provisioning of ants by Cordia trees during drought may buy insurance against extreme defoliation events, not just average-year benefits. PMID:24815041

Denison, R Ford

2014-07-01

447

ANTS AS BIOLOGICAL INDICATORS FOR MONITORING CHANGES IN ARID ENVIRONMENTS: LESSONS FOR MONITORING PROTECTED AREAS  

EPA Science Inventory

The responses of ant communities to structural change (removal of an invasive were studied in a replicated experiment in a Chihuahuan Desert grassland. The results from sampling of ant communities by pit-fall trapping were validated by mapping ant colonies on the expe...

448

ANTS AS BIOLOGICAL INDICATORS FOR MONITORING CHANGES IN ARID ENVIRONMENTS: LESSONS FOR MONITORING PROTECTED AREAS  

EPA Science Inventory

The responses of ant communities to structural change (removal of an invasive were studied in a replicated experiment in a Chihuahuan Desert grassland. The results from sampling of ant communities by pit-fall trapping were validated by mapping ant colonies on the experimental plo...

449

COMPARISON OF ANOVA AND KRIGING IN DETECTING ANT RESPONSES TO ENVIRONMENTAL STRESSORS  

EPA Science Inventory

In an ecosystems, ants effect ecosystem functions such as water infiltration, soil nutrient distribution and composition of the soil seed bank. Ants have also been used as indicators of ecosystems health. In a study, we hypothesized that some ant species would respond to changes ...

450

A case of the first documented fire ant anaphylaxis in Canada  

PubMed Central

The first documented confirmed case of an imported fire ant causing anaphylaxis in Canada is herein reported. In a patient with anaphylaxis to ants a physician in Canada should be aware that an allergic reaction to fire ant is a possibility.

2013-01-01

451

LIVESTOCK GRAZING EFFECTS ON ANT COMMUNITIES IN THE EASTERN MOJAVE DESERT, USA  

EPA Science Inventory

The effects of livestock grazing on composition and structure of ant communities were examined in the eastern Mojave Desert, USA for the purpose of evaluating ant communities as potential indicators of rangeland condition. Metrics for ant communities, vegetation, and other groun...

452

Ants benefit from attending facultatively myrmecophilous Lycaenidae caterpillars: evidence from a survival study  

Microsoft Academic Search

Workers of three ant species (Lasius niger, Lasius flavus, Myrmica rubra) were caged in the laboratory together with caterpillars and pupae of five species of lycaenid butterflies. Mortality of ants was 3–5 times higher when the ants were confined with larvae lacking a dorsal nectar organ (Lycaena phlaeas, Lycaena tityrus) rather than with caterpillars which possess a nectar gland (Aricia

Konrad Fiedler; Christine Saam

1995-01-01

453

Crystallization and preliminary X-ray diffraction analysis of AntE, a crotonyl-CoA carboxylase/reductase from Streptomyces sp. NRRL 2288.  

PubMed

AntE from Streptomyces sp. NRRL 2288 is a crotonyl-CoA carboxylase/reductase that catalyzes the reductive carboxylation of various ?,?-unsaturated acyl-CoAs to provide the building block at the C7 position for antimycin A biosynthesis. Recombinant AntE expressed in Escherichia coli was crystallized by the sitting-drop vapour-diffusion method. The crystals belonged to space group I222 or I212121, with unit-cell parameters a = 76.4, b = 96.7, c = 129.6?Å, ? = ? = ? = 90.0°. A diffraction data set was collected at the KEK Photon Factory to 2.29?Å resolution. PMID:24915081

Zhang, Lihan; Chen, Jing; Mori, Takahiro; Yan, Yan; Liu, Wen; Abe, Ikuro

2014-06-01

454

A synoptic review of the ant genera (Hymenoptera, Formicidae) of the Philippines  

PubMed Central

Abstract An overview of the history of myrmecology in the Philippine archipelago is presented. Keys are provided to the 11 ant subfamilies and the 92 ant genera known from the Philippines. Eleven ant genera (12%), including 3 undescribed genera, are recorded for the first time from the Philippines. The biology and ecology of the 92 genera, illustrated by full-face and profile photo-images, of Philippine ants are summarized in the form of brief generic accounts. A bibliography of significant taxonomic and behavioral papers on Philippine ants and a checklist of valid species and subspecies and their island distributions are provided.

General, David M.; Alpert, Gary D.

2012-01-01

455

Reinforcement interval type-2 fuzzy controller design by online rule generation and q-value-aided ant colony optimization.  

PubMed

This paper proposes a new reinforcement-learning method using online rule generation and Q-value-aided ant colony optimization (ORGQACO) for fuzzy controller design. The fuzzy controller is based on an interval type-2 fuzzy system (IT2FS). The antecedent part in the designed IT2FS uses interval type-2 fuzzy sets to improve controller robustness to noise. There are initially no fuzzy rules in the IT2FS. The ORGQACO concurrently designs both the structure and parameters of an IT2FS. We propose an online interval type-2 rule generation method for the evolution of system structure and flexible partitioning of the input space. Consequent part parameters in an IT2FS are designed using Q -values and the reinforcement local-global ant colony optimization algorithm. This algorithm selects the consequent part from a set of candidate actions according to ant pheromone trails and Q-values, both of which are updated using reinforcement signals. The ORGQACO design method is applied to the following three control problems: 1) truck-backing control; 2) magnetic-levitation control; and 3) chaotic-system control. The ORGQACO is compared with other reinforcement-learning methods to verify its efficiency and effectiveness. Comparisons with type-1 fuzzy systems verify the noise robustness property of using an IT2FS. PMID:19482582

Juang, Chia-Feng; Hsu, Chia-Hung

2009-12-01

456

Agents, assemblers, and ANTS: scheduling assembly with market and biological software mechanisms  

NASA Astrophysics Data System (ADS)

Nanoscale assemblers will need robust, scalable, flexible, and well-understood mechanisms such as software agents to control them. This paper discusses assemblers and agents, and proposes a taxonomy of their possible interaction. Molecular assembly is seen as a special case of general assembly, subject to many of the same issues, such as the advantages of convergent assembly, and the problem of scheduling. This paper discusses the contract net architecture of ANTS, an agent-based scheduling application under development. It also describes an algorithm for least commitment scheduling, which uses probabilistic committed capacity profiles of resources over time, along with realistic costs, to provide an abstract search space over which the agents can wander to quickly find optimal solutions.

Toth-Fejel, Tihamer T.

2000-06-01

457

Specific, non-nutritional association between an ascomycete fungus and Allomerus plant-ants  

PubMed Central

Ant–fungus associations are well known from attine ants, whose nutrition is based on a symbiosis with basidiomycete fungi. Otherwise, only a few non-nutritional ant–fungus associations have been recorded to date. Here we focus on one of these associations involving Allomerus plant-ants that build galleried structures