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Ding YE, Li Z. Termites can learn. Behav Processes 2024; 217:105012. [PMID: 38493970 DOI: 10.1016/j.beproc.2024.105012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 02/21/2024] [Accepted: 02/27/2024] [Indexed: 03/19/2024]
Abstract
It is generally believed that termites can't learn and are not "intelligent". This study aimed to test whether termites could have any form of memory. A Y-shaped test device with one release chamber and two identical test chambers was designed and constructed by 3D printing. A colony of damp wood termites was harvested from the wild. Worker termites were randomly selected for experiment. Repellent odors that could mimic the alarm pheromone for termites were first identified. Among all substances tested, a tea tree oil and lemon juice were found to contain repellent odors for the tested termites, as they significantly reduced the time that termites spent in the chamber treated with these substances. As control, a trail pheromone was found to be attractive. Subsequently, a second cohort of termites were operant conditioned by punishment using both tea tree oil and lemon juice, and then tested for their ability to remember the path that could lead to the repellant odors. The test device was thoroughly cleaned between trials. It was found that conditioned termites displayed a reduced tendency to choose the path that led to expectant punishment as compared with naïve termites. Thus, it is concluded that damp wood termites are capable of learning and forming "fear memory", indicative of "intelligence" in termites. This result challenges established presumption about termites' intelligence.
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Affiliation(s)
- Yifan Evan Ding
- Boston Latin School, 78 Avenue Louis Pasteur, Boston, MA 02115, United States.
| | - Zhenghui Li
- Department of Neurosurgery, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan 450052, PR China
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2
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Oberst S, Martin R. Feature-preserving synthesis of termite-mimetic spinodal nest morphology. iScience 2024; 27:108674. [PMID: 38292166 PMCID: PMC10825051 DOI: 10.1016/j.isci.2023.108674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 07/09/2023] [Accepted: 12/05/2023] [Indexed: 02/01/2024] Open
Abstract
Termite-built topology is complex due to group interactions and environmental feedback. Being interlinked with material characteristics and related to functionality, an accurate synthesis of termite mound topology has never been achieved. We scanned inner termite mound pieces via high-resolution micro-computed tomography. A wavelet scattering transform followed by optimization extracts features that are fed into a Gaussian Random Fields (GRFs) approach to synthesize termite-mimetic spinodal topology. Compared to natural structures the GRF topology is more regular. Irregularity is related to anisotropy, indicative of directionality caused by porous network connectivity of chambers and corridors. Since GRFs are related to diffusion, we assume that deterministic behavioral traits play a significant role in the development of these local differences. We pioneer a framework to reliably mimic termite mound spinodal features. Engineering termite-inspired structures will allow to inspect aspects of termite architectures and their behavior to manufacture novel material concepts with imprinted multi-functionality.
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Affiliation(s)
- Sebastian Oberst
- Centre for Audio, Acoustics and Vibration, University of Technology Sydney, Sydney, NSW 2007, Australia
- School of Engineering and IT, University of New South Wales, University of New South Wales, Canberra, ACT 2612, Australia
| | - Richard Martin
- Centre for Audio, Acoustics and Vibration, University of Technology Sydney, Sydney, NSW 2007, Australia
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3
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Floegel M, Kasper J, Perrier P, Kell CA. How the conception of control influences our understanding of actions. Nat Rev Neurosci 2023; 24:313-329. [PMID: 36997716 DOI: 10.1038/s41583-023-00691-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2023] [Indexed: 04/01/2023]
Abstract
Wilful movement requires neural control. Commonly, neural computations are thought to generate motor commands that bring the musculoskeletal system - that is, the plant - from its current physical state into a desired physical state. The current state can be estimated from past motor commands and from sensory information. Modelling movement on the basis of this concept of plant control strives to explain behaviour by identifying the computational principles for control signals that can reproduce the observed features of movements. From an alternative perspective, movements emerge in a dynamically coupled agent-environment system from the pursuit of subjective perceptual goals. Modelling movement on the basis of this concept of perceptual control aims to identify the controlled percepts and their coupling rules that can give rise to the observed characteristics of behaviour. In this Perspective, we discuss a broad spectrum of approaches to modelling human motor control and their notions of control signals, internal models, handling of sensory feedback delays and learning. We focus on the influence that the plant control and the perceptual control perspective may have on decisions when modelling empirical data, which may in turn shape our understanding of actions.
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Affiliation(s)
- Mareike Floegel
- Department of Neurology and Brain Imaging Center, Goethe University Frankfurt, Frankfurt, Germany
| | - Johannes Kasper
- Department of Neurology and Brain Imaging Center, Goethe University Frankfurt, Frankfurt, Germany
| | - Pascal Perrier
- Univ. Grenoble Alpes, CNRS, Grenoble INP, GIPSA-lab, Grenoble, France
| | - Christian A Kell
- Department of Neurology and Brain Imaging Center, Goethe University Frankfurt, Frankfurt, Germany.
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4
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Di Pietro V, Govoni P, Chan KH, Oliveira RC, Wenseleers T, van den Berg P. Evolution of self-organised division of labour driven by stigmergy in leaf-cutter ants. Sci Rep 2022; 12:21971. [PMID: 36539468 PMCID: PMC9768137 DOI: 10.1038/s41598-022-26324-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Social insects owe their widespread success to their ability to efficiently coordinate behaviour to carry out complex tasks. Several leaf-cutter ant species employ an advanced type of division of labour known as task partitioning, where the task of retrieving leaves is distributed between workers that cut and drop and those that collect the fallen leaves. It is not entirely clear how such highly coordinated behaviour can evolve, as it would seem to require the simultaneous mutations of multiple traits during the same generation. Here, we use an agent-based simulation model to show how task partitioning in leaf-cutter ants can gradually evolve by exploiting stigmergy (indirect coordination through the environment) through gravity (leaves falling from the treetop on the ground forming a cache). Our simple model allows independent variation in two core behavioural dimensions: the tendency to drop leaves and the tendency to pick up dropped leaves. Task partitioning readily evolves even under these minimal assumptions through adaptation to an arboreal environment where traveling up and down the tree is costly. Additionally, we analyse ant movement dynamics to demonstrate how the ants achieve efficient task allocation through task switching and negative feedback control.
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Affiliation(s)
- Viviana Di Pietro
- grid.5596.f0000 0001 0668 7884Laboratory of Socioecology and Social Evolution, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
| | - Patrick Govoni
- grid.5596.f0000 0001 0668 7884Dynamics in Biological Systems Lab, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Kin Ho Chan
- Laboratory of Biodiversity and Evolutionary Genomics, Charles Deberiostraat 32, 3000 Leuven, Belgium
| | - Ricardo Caliari Oliveira
- grid.5596.f0000 0001 0668 7884Laboratory of Socioecology and Social Evolution, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium ,grid.7080.f0000 0001 2296 0625Departament de Biologia Animal, de Biologia Vegetal I d’Ecologia - Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona Spain
| | - Tom Wenseleers
- grid.5596.f0000 0001 0668 7884Laboratory of Socioecology and Social Evolution, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
| | - Pieter van den Berg
- grid.5596.f0000 0001 0668 7884Evolutionary Modelling Group, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
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Sansom TM, Oberst S, Richter A, Lai JCS, Saadatfar M, Nowotny M, Evans TA. Low radiodensity μCT scans to reveal detailed morphology of the termite leg and its subgenual organ. ARTHROPOD STRUCTURE & DEVELOPMENT 2022; 70:101191. [PMID: 35816830 DOI: 10.1016/j.asd.2022.101191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 05/27/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
Termites sense tiny substrate-borne vibrations through subgenual organs (SGOs) located within their legs' tibiae. Little is known about the SGOs' structure and physical properties. We applied high-resolution (voxel size 0.45 μm) micro-computed tomography (μCT) to Australian termites, Coptotermes lacteus and Nasutitermes exitiosus (Hill) to test two staining techniques. We compared the effectiveness of a single stain of Lugol's iodine solution (LS) to LS followed by Phosphotungstic acid (PTA) solutions (1% and 2%). We then present results of a soldier of Nasutitermes exitiosus combining μCT with LS + 2%PTS stains and scanning electron microscopy to exemplify the visualisation of their SGOs. The termite's SGO due to its approximately oval shape was shown to have a maximum diameter of 60 μm and a minimum of 48 μm, covering 60 ± 4% of the leg's cross-section and 90.4 ± 5% of the residual haemolymph channel. Additionally, the leg and residual haemolymph channel cross-sectional area decreased around the SGO by 33% and 73%, respectively. We hypothesise that this change in cross-sectional area amplifies the vibrations for the SGO. Since SGOs are directly connected to the cuticle, their mechanical properties and the geometric details identified here may enable new approaches to determine how termites sense micro-vibrations.
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Affiliation(s)
- Travers M Sansom
- University of Technology Sydney, Centre for Audio, Acoustics and Vibration, Sydney, NSW, 2007, Australia.
| | - Sebastian Oberst
- University of Technology Sydney, Centre for Audio, Acoustics and Vibration, Sydney, NSW, 2007, Australia; School of Engineering and IT, University of New South Wales Canberra, Northcott Dr, Campbell ACT, 2612, Australia.
| | - Adrian Richter
- Institute of Zoology and Evolutionary Research, Friedrich-Schiller-University, Jena, Germany
| | - Joseph C S Lai
- School of Engineering and IT, University of New South Wales Canberra, Northcott Dr, Campbell ACT, 2612, Australia
| | - Mohammad Saadatfar
- School of Civil Engineering, The University of Sydney, 2006, Sydney, Australia
| | - Manuela Nowotny
- Institute of Zoology and Evolutionary Research, Friedrich-Schiller-University, Jena, Germany
| | - Theodore A Evans
- School of Biological Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA, 6009, Australia
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A Stigmergy-Based Differential Evolution. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12126093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Metaheuristic algorithms are techniques that have been successfully applied to solve complex optimization problems in engineering and science. Many metaheuristic approaches, such as Differential Evolution (DE), use the best individual found so far from the whole population to guide the search process. Although this approach has advantages in the algorithm’s exploitation process, it is not completely in agreement with the swarms found in nature, where communication among individuals is not centralized. This paper proposes the use of stigmergy as an inspiration to modify the original DE operators to simulate a decentralized information exchange, thus avoiding the application of a global best. The Stigmergy-based DE (SDE) approach was tested on a set of benchmark problems to compare its performance with DE. Even though the execution times of DE and SDE are very similar, our proposal has a slight advantage in most of the functions and can converge in fewer iterations in some cases, but its main feature is the capability to maintain a good convergence behavior as the dimensionality grows, so it can be a good alternative to solve complex problems.
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Korsa G, Masi C, Konwarh R, Tafesse M. Harnessing the potential use of cellulolytic Klebsiella oxytoca (M21WG) and Klebsiella sp. (Z6WG) isolated from the guts of termites (Isoptera). ANN MICROBIOL 2022. [DOI: 10.1186/s13213-021-01662-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
For many years, denim-heavy quality cotton twill colored with indigo colors and with a well-worn/faded look has held a lot of appeal. Machine damage, drainage system blockage, and other issues come with the conventional usage of pumice stones for “stone-washing” denims. In view of the abovementioned information, a range of works has been done to investigate the economic prospects of bacterial cellulase enzymes for use in industrial processes, including biopolishing in the textile sector. Ethiopia has excellent termite diversity to isolate bacterial gut-associated cellulose enzymes for biostoning applications. The main purpose of this study was, therfore, to decipher how to isolate and characterize cellulase enzymes from termite (Isoptera) gut bacteria with the intention of employing it for biostoning of textiles.
Purpose
To use cellulolytic enzymes of Klebsiella oxytoca (M21WG) and Klebsiella sp. (Z6WG) isolated from termite guts in biostoning of textiles and improving garment quality.
Methods
Cellulase enzyme-producing bacteria were isolated and screened from the guts of worker termites sampled from Meki and Zeway termite mounds in the Central Rift Valley region of Ethiopia. Bacterial screening, biochemical, morphological, and 16S rRNA sequence identification techniques were employed to characterize the bacterial strains. In addition, the production, optimization, and purification of the associated cellulase enzymes were employed, and the potential application of the enzymes for biostoning of a textile was demonstrated.
Result
The isolated M21WG was found to be 99% identical to the Klebsiella oxytoca (MT104573.1) strain, while the isolated Z6WG showed 97.3% identity to the Klebsiella sp. strain (MN629242.1). At an ideal pH of 7, a temperature of 37 °C, a 72-h incubation time, and a substrate concentration of 1.5% carboxymethylcellulose sodium, the maximum activity of the crude cellulase extract from these bacteria was assessed. These bacteria produced cellulase enzymes that were moderately efficient. Consequently, it was determined that the cellulase enzymes were effective for biostoning of denim cloth.
Conclusion
It was determined that Klebsiella oxytoca (M21WG) and Klebsiella sp. (Z6WG) could be used as a doorway to better understand harnessing the use of these cellulase-producing bacteria from termite (Isoptera) guts. In this study, it was also attempted to assess the effectiveness of the two bacterial isolates in biostoning in anticipation of their potential application in the textile realm.
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Oberst S, Martin R, Halkon BJ, Lai JCS, Evans TA, Saadatfar M. Submillimetre mechanistic designs of termite-built structures. J R Soc Interface 2021; 18:20200957. [PMID: 33947222 PMCID: PMC8097512 DOI: 10.1098/rsif.2020.0957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 04/12/2021] [Indexed: 11/12/2022] Open
Abstract
Termites inhabit complex underground mounds of intricate stigmergic labyrinthine designs with multiple functions as nursery, food storage and refuge, while maintaining a homeostatic microclimate. Past research studied termite building activities rather than the actual material structure. Yet, prior to understanding how multi-functionality shaped termite building, a thorough grasp of submillimetre mechanistic architecture of mounds is required. Here, we identify for Nasutitermes exitiosus via granulometry and Fourier transform infrared spectroscopy analysis, preferential particle sizes related to coarse silts and unknown mixtures of organic/inorganic components. High-resolution micro-computed X-ray tomography and microindentation tests reveal wall patterns of filigree laminated layers and sub-millimetre porosity wrapped around a coarse-grained inner scaffold. The scaffold geometry, which is designed of a lignin-based composite and densely biocementitious stercoral mortar, resembles that of trabecula cancellous bones. Fractal dimension estimates indicate multi-scaled porosity, important for enhanced evaporative cooling and structural stability. The indentation moduli increase from the outer to the inner wall parts to values higher than those found in loose clays and which exceed locally the properties of anthropogenic cementitious materials. Termites engineer intricately layered biocementitious composites of high elasticity. The multiple-scales and porosity of the structure indicate a potential to pioneer bio-architected lightweight and high-strength materials.
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Affiliation(s)
- Sebastian Oberst
- Centre for Audio, Acoustics and Vibrations, Faculty of Engineering and IT, University of Technology Sydney, Sydney, New South Wales 2040, Australia
- School of Engineering and Information Technology, University of New South Wales, Canberra, Australian Capital Territory 2600, Australia
| | - Richard Martin
- Centre for Audio, Acoustics and Vibrations, Faculty of Engineering and IT, University of Technology Sydney, Sydney, New South Wales 2040, Australia
| | - Benjamin J. Halkon
- Centre for Audio, Acoustics and Vibrations, Faculty of Engineering and IT, University of Technology Sydney, Sydney, New South Wales 2040, Australia
| | - Joseph C. S. Lai
- School of Engineering and Information Technology, University of New South Wales, Canberra, Australian Capital Territory 2600, Australia
| | - Theodore A. Evans
- School of Animal Biology, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Mohammed Saadatfar
- School of Civil Engineering, The University of Sydney, 2006, Sydney, Australia
- Department of Applied Mathematics, The Australian National University, Canberra, 2601, Australia
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