scholarly journals Response of insect swarms to dynamic illumination perturbations

2019 ◽  
Vol 16 (150) ◽  
pp. 20180739 ◽  
Author(s):  
Michael Sinhuber ◽  
Kasper van der Vaart ◽  
Nicholas T. Ouellette
Keyword(s):  
Light Exposure ◽  
Collective Behaviour ◽  
Environmental Perturbations ◽  
Full Control ◽  
In The Wild ◽  
Variable Light ◽  
Classical Thermodynamics ◽  
Natural Settings ◽  
Thermodynamic Phase ◽  
Swarming Behaviour

Many animal species across taxa spontaneously form aggregations that exhibit collective behaviour. In the wild, these collective systems are unavoidably influenced by ubiquitous environmental perturbations such as wind gusts, acoustic and visual stimuli, or the presence of predators or other animals. The way these environmental perturbations influence the animals' collective behaviour, however, is poorly understood, in part because conducting controlled quantitative perturbation experiments in natural settings is challenging. To circumvent the need for controlling environmental conditions in the field, we study swarming midges in a laboratory experiment where we have full control over external perturbations. Here, we consider the effect of controlled variable light exposure on the swarming behaviour. We find that not only do individuals in the swarm respond to light changes by speeding up during brighter conditions but also the swarm as a whole responds to these perturbations by compressing and simultaneously increasing the attraction of individual midges to its centre of mass. The swarm-level response can be described by making an analogy to classical thermodynamics, with the state of the swarm moving along an isotherm in a thermodynamic phase plane.

scholarly journals Environmental perturbations induce correlations in midge swarms

2020 ◽  
Vol 17 (164) ◽  
pp. 20200018 ◽  
Author(s):  
Kasper van der Vaart ◽  
Michael Sinhuber ◽  
Andrew M. Reynolds ◽  
Nicholas T. Ouellette
Keyword(s):  
Long Range ◽  
Large Scale ◽  
Collective Behaviour ◽  
Biting Midge ◽  
External Perturbations ◽  
Environmental Perturbations ◽  
Range Correlation ◽  
In The Wild ◽  
New Research ◽  
External Stimuli

Although collectively behaving animal groups often show large-scale order (such as in bird flocks), they need not always (such as in insect swarms). It has been suggested that the signature of collective behaviour in disordered groups is a residual long-range correlation. However, results in the literature have reported contradictory results as to the presence of long-range correlation in insect swarms, with swarms in the wild displaying correlation but those in a controlled laboratory environment not. We resolve these apparently incompatible results by showing that the external perturbations generically induce the emergence of correlations. We apply a range of different external stimuli to laboratory swarms of the non-biting midge Chironomus riparius , and show that in all cases correlations appear when perturbations are introduced. We confirm the generic nature of these results by showing that they can be reproduced in a stochastic model of swarms. Given that swarms in the wild will always have to contend with environmental stimuli, our results thus harmonize previous findings. These findings emphasize that collective behaviour cannot be understood in isolation without considering its environmental context, and that new research is needed to disentangle the distinct roles of intrinsic dynamics and external stimuli.

scholarly journals Mechanical spectroscopy of insect swarms

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw9305 ◽  
Author(s):  
Kasper van der Vaart ◽  
Michael Sinhuber ◽  
Andrew M. Reynolds ◽  
Nicholas T. Ouellette
Keyword(s):  
Information Flow ◽  
Collective Behavior ◽  
Mechanical Spectroscopy ◽  
Bulk Materials ◽  
Animal Groups ◽  
Environmental Perturbations ◽  
Storage And Loss Moduli ◽  
Social Animals ◽  
In The Wild ◽  
Flow Through

Social animals routinely form groups, which are thought to display emergent, collective behavior. This hypothesis suggests that animal groups should have properties at the group scale that are not directly linked to the individuals, much as bulk materials have properties distinct from those of their constituent atoms. Materials are often probed by measuring their response to controlled perturbations, but these experiments are difficult to conduct on animal groups, particularly in the wild. Here, we show that laboratory midge swarms have emergent continuum mechanical properties, displaying a collective viscoelastic response to applied oscillatory visual stimuli that allows us to extract storage and loss moduli for the swarm. We find that the swarms strongly damp perturbations, both viscously and inertially. Thus, unlike bird flocks, which appear to use collective behavior to promote lossless information flow through the group, our results suggest that midge swarms use it to stabilize themselves against environmental perturbations.

scholarly journals Embryonic geometry underlies phenotypic variation in decanalized conditions

2019 ◽  
Author(s):  
A. Huang ◽  
T. E. Saunders
Keyword(s):  
Phenotypic Variation ◽  
Regulatory Network ◽  
Physical Space ◽  
Model Organisms ◽  
Wild Type ◽  
Environmental Perturbations ◽  
Key Factor ◽  
In The Wild ◽  
Gene Regulatory ◽  
Anterior Posterior

AbstractDuring development, many mutations cause increased variation in phenotypic outcomes, a phenomenon termed decanalization. Such variations can often be attributed to genetic and environmental perturbations. However, phenotypic discordance remains even in isogenic model organisms raised in homogeneous environments. To understand the mechanisms underlying phenotypic variation, we used as a model the highly precise anterior-posterior (AP) patterning of the early Drosophila embryo. We decanalized the system by depleting the maternal bcd product and found that in contrast to the highly scaled patterning in the wild-type, the segmentation gene boundaries shift away from the scaled positions according to the total embryonic length. Embryonic geometry is hence a key factor predetermining patterning outcomes in such decanalized conditions. Embryonic geometry was also found to predict individual patterning outcomes under bcd overexpression, another decanalizing condition. Further analysis of the gene regulatory network acting downstream of the morphogen identified vulnerable points in the networks due to limitations in the available physical space.

scholarly journals Novel Phototransformable Fluorescent Protein SAASoti with Unique Photochemical Properties

2019 ◽  
Vol 20 (14) ◽  
pp. 3399 ◽  
Author(s):  
Ilya D. Solovyev ◽  
Alexandra V. Gavshina ◽  
Alexander P. Savitsky
Keyword(s):  
Fluorescent Protein ◽  
Light Exposure ◽  
Mass Spectrometry Analysis ◽  
Fast Recovery ◽  
Spectrometry Analysis ◽  
Before And After ◽  
In The Wild ◽  
Photochemical Properties ◽  
Type Gene ◽  
Red Form

SAASoti is a unique fluorescent protein (FP) that combines properties of green-to-red photoconversion and reversible photoswitching (in its green state), without any amino acid substitutions in the wild type gene. In the present work, we investigated its ability to photoswitch between fluorescent red (‘on’) and dark (‘off’) states. Surprisingly, generated by 400 nm exposure, the red form of SAASoti (R1) does not exhibit any reversible photoswitching behavior under 550 nm illumination, while a combination of prior 470 nm and subsequent 400 nm irradiation led to the appearance of another—R2—form that can be partially photoswitched (550 nm) to the dark state, with a very fast recovery time. The phenomenon might be explained by chemical modification in the chromophore microenvironment during prior 470 nm exposure, and the resulting R2 SAASoti differs chemically from the R1 form. The suggestion is supported by the mass spectrometry analysis of the tryptic peptides before and after 470 nm light exposure, that revealed Met164 oxidation, as proceeds in another dual phototransformable FP, IrisFP.

scholarly journals Resource availability affects the structure of a natural bacteria–bacteriophage community

2010 ◽  
Vol 7 (2) ◽  
pp. 201-204 ◽  
Author(s):  
Timothée Poisot ◽  
Gildas Lepennetier ◽  
Esteban Martinez ◽  
Johan Ramsayer ◽  
Michael E. Hochberg
Keyword(s):  
Resource Availability ◽  
Bipartite Network ◽  
Environmental Perturbations ◽  
In The Wild ◽  
Resource Levels

Antagonistic networks are known to be structured in the wild, but knowledge on how this structure may change as a response to environmental perturbations is scarce. We describe a natural bipartite network between bacteria and lytic bacteriophages, and investigate how it is affected by environmental productivity in the form of different resource levels for the bacteria. We report that low amounts of resource decrease phage generality and lead to less robust and less stable communities. We discuss how resource levels in nature may alter the structure of complex communities.

scholarly journals Personality composition is more important than group size in determining collective foraging behaviour in the wild

2014 ◽  
Vol 281 (1796) ◽  
pp. 20141424 ◽  
Author(s):  
Carl N. Keiser ◽  
Jonathan N. Pruitt
Keyword(s):  
Group Size ◽  
Foraging Behaviour ◽  
Collective Behaviour ◽  
Nest Architecture ◽  
Social Spider ◽  
The Social ◽  
In The Wild ◽  
Behavioural Phenotypes ◽  
Collective Foraging ◽  
Animal Societies

Describing the factors that shape collective behaviour is central to our understanding of animal societies. Countless studies have demonstrated an effect of group size in the emergence of collective behaviours, but comparatively few have accounted for the composition/diversity of behavioural phenotypes, which is often conflated with group size. Here, we simultaneously examine the effect of personality composition and group size on nest architecture and collective foraging aggressiveness in the social spider Stegodyphus dumicola . We created colonies of two different sizes (10 or 30 individuals) and four compositions of boldness (all bold, all shy, mixed bold and shy, or average individuals) in the field and then measured their collective behaviour. Larger colonies produced bigger capture webs, while colonies containing a higher proportion of bold individuals responded to and attacked prey more rapidly. The number of attackers during collective foraging was determined jointly by composition and size, although composition had an effect size more than twice that of colony size: our results suggest that colonies of just 10 bold spiders would attack prey with as many attackers as colonies of 110 ‘average’ spiders. Thus, personality composition is a more potent (albeit more cryptic) determinant of collective foraging in these societies.

scholarly journals Creativity in the Wild: Improving Creative Reasoning through Immersion in Natural Settings

PLoS ONE ◽  
2012 ◽  
Vol 7 (12) ◽  
pp. e51474 ◽  
Author(s):  
Ruth Ann Atchley ◽  
David L. Strayer ◽  
Paul Atchley
Keyword(s):  
Creative Reasoning ◽  
In The Wild ◽  
Natural Settings

scholarly journals Co-expression Networks From Gene Expression Variability Between Genetically Identical Seedlings Can Reveal Novel Regulatory Relationships

2020 ◽  
Vol 11 ◽  
Author(s):  
Sandra Cortijo ◽  
Marcel Bhattarai ◽  
James C. W. Locke ◽  
Sebastian E. Ahnert
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
New Approach ◽  
Biologically Relevant ◽  
Expression Variability ◽  
Environmental Perturbation ◽  
Environmental Perturbations ◽  
In The Wild ◽  
New Gene ◽  
And Function

Co-expression networks are a powerful tool to understand gene regulation. They have been used to identify new regulation and function of genes involved in plant development and their response to the environment. Up to now, co-expression networks have been inferred using transcriptomes generated on plants experiencing genetic or environmental perturbation, or from expression time series. We propose a new approach by showing that co-expression networks can be constructed in the absence of genetic and environmental perturbation, for plants at the same developmental stage. For this, we used transcriptomes that were generated from genetically identical individual plants that were grown under the same conditions and for the same amount of time. Twelve time points were used to cover the 24-h light/dark cycle. We used variability in gene expression between individual plants of the same time point to infer a co-expression network. We show that this network is biologically relevant and use it to suggest new gene functions and to identify new targets for the transcriptional regulators GI, PIF4, and PRR5. Moreover, we find different co-regulation in this network based on changes in expression between individual plants, compared to the usual approach requiring environmental perturbation. Our work shows that gene co-expression networks can be identified using variability in gene expression between individual plants, without the need for genetic or environmental perturbations. It will allow further exploration of gene regulation in contexts with subtle differences between plants, which could be closer to what individual plants in a population might face in the wild.

scholarly journals Multimodal Human and Environmental Sensing for Longitudinal Behavioral Studies in Naturalistic Settings: Framework for Sensor Selection, Deployment, and Management (Preprint)

2018 ◽  
Author(s):  
Brandon M Booth ◽  
Karel Mundnich ◽  
Tiantian Feng ◽  
Amrutha Nadarajan ◽  
Tiago H Falk ◽  
...  
Keyword(s):  
Data Collection ◽  
Human Behavior ◽  
Well Being ◽  
Sensor Selection ◽  
Sensor Data ◽  
Unexpected Events ◽  
Minimal Impact ◽  
In The Wild ◽  
Natural Settings

BACKGROUND Recent advances in mobile technologies for sensing human biosignals are empowering researchers to collect real-world data outside of the laboratory, in natural settings where participants can perform their daily activities with minimal disruption. These new sensing opportunities usher a host of challenges and constraints for both researchers and participants. OBJECTIVE This viewpoint paper aims to provide a comprehensive guide to aid research teams in the selection and management of sensors before beginning and while conducting human behavior studies in the wild. The guide aims to help researchers achieve satisfactory participant compliance and minimize the number of unexpected procedural outcomes. METHODS This paper presents a collection of challenges, consideration criteria, and potential solutions for enabling researchers to select and manage appropriate sensors for their research studies. It explains a general data collection framework suitable for use with modern consumer sensors, enabling researchers to address many of the described challenges. In addition, it provides a description of the criteria affecting sensor selection, management, and integration that researchers should consider before beginning human behavior studies involving sensors. On the basis of a survey conducted in mid-2018, this paper further illustrates an organized snapshot of consumer-grade human sensing technologies that can be used for human behavior research in natural settings. RESULTS The research team applied the collection of methods and criteria to a case study aimed at predicting the well-being of nurses and other staff in a hospital. Average daily compliance for sensor usage measured by the presence of data exceeding half the total possible hours each day was about 65%, yielding over 355,000 hours of usable sensor data across 212 participants. A total of 6 notable unexpected events occurred during the data collection period, all of which had minimal impact on the research project. CONCLUSIONS The satisfactory compliance rates and minimal impact of unexpected events during the case study suggest that the challenges, criteria, methods, and mitigation strategies presented as a guide for researchers are helpful for sensor selection and management in longitudinal human behavior studies in the wild.

scholarly journals Diversity of Olfactory Responses and Skills in Astyanax Mexicanus Cavefish Populations Inhabiting different Caves

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 395 ◽  
Author(s):  
Maryline Blin ◽  
Julien Fumey ◽  
Camille Lejeune ◽  
Maxime Policarpo ◽  
Julien Leclercq ◽  
...  
Keyword(s):  
Single Species ◽  
Constant Darkness ◽  
Astyanax Mexicanus ◽  
Olfactory Responses ◽  
In The Wild ◽  
Genetic Mechanisms ◽  
Olfactory Detection ◽  
Northeastern Mexico ◽  
Olfactory Detection Thresholds ◽  
Natural Settings

Animals in many phyla are adapted to and thrive in the constant darkness of subterranean environments. To do so, cave animals have presumably evolved mechano- and chemosensory compensations to the loss of vision, as is the case for the blind characiform cavefish, Astyanax mexicanus. Here, we systematically assessed the olfactory capacities of cavefish and surface fish of this species in the lab as well as in the wild, in five different caves in northeastern Mexico, using an olfactory setup specially developed to test and record olfactory responses during fieldwork. Overall cavefish showed lower (i.e., better) olfactory detection thresholds than surface fish. However, wild adult cavefish from the Pachón, Sabinos, Tinaja, Chica and Subterráneo caves showed highly variable responses to the three different odorant molecules they were exposed to. Pachón and Subterráneo cavefish showed the highest olfactory capacities, and Chica cavefish showed no response to the odors presented. We discuss these data with regard to the environmental conditions in which these different cavefish populations live. Our experiments in natural settings document the diversity of cave environments inhabited by a single species of cavefish, A. mexicanus, and highlight the complexity of the plastic and genetic mechanisms that underlie cave adaptation.

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