scholarly journals The effect of individual variation on the structure and function of interaction networks in harvester ants

2011 ◽  
Vol 8 (64) ◽  
pp. 1562-1573 ◽  
Author(s):  
Noa Pinter-Wollman ◽  
Roy Wollman ◽  
Adam Guetz ◽  
Susan Holmes ◽  
Deborah M. Gordon
Keyword(s):  
Computer Simulations ◽  
Information Flow ◽  
Individual Variation ◽  
Hot Spot ◽  
Interaction Network ◽  
Structure And Function ◽  
Skewed Distribution ◽  
Interaction Frequency ◽  
Harvester Ants ◽  
And Function

Social insects exhibit coordinated behaviour without central control. Local interactions among individuals determine their behaviour and regulate the activity of the colony. Harvester ants are recruited for outside work, using networks of brief antennal contacts, in the nest chamber closest to the nest exit: the entrance chamber. Here, we combine empirical observations, image analysis and computer simulations to investigate the structure and function of the interaction network in the entrance chamber. Ant interactions were distributed heterogeneously in the chamber, with an interaction hot-spot at the entrance leading further into the nest. The distribution of the total interactions per ant followed a right-skewed distribution, indicating the presence of highly connected individuals. Numbers of ant encounters observed positively correlated with the duration of observation. Individuals varied in interaction frequency, even after accounting for the duration of observation. An ant's interaction frequency was explained by its path shape and location within the entrance chamber. Computer simulations demonstrate that variation among individuals in connectivity accelerates information flow to an extent equivalent to an increase in the total number of interactions. Individual variation in connectivity, arising from variation among ants in location and spatial behaviour, creates interaction centres, which may expedite information flow.

scholarly journals Persistent variation in spatial behavior affects the structure and function of interaction networks

2015 ◽  
Vol 61 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Noa Pinter-Wollman
Keyword(s):  
Network Structure ◽  
Interaction Network ◽  
Structure And Function ◽  
Spatial Behavior ◽  
Interaction Networks ◽  
Harvester Ants ◽  
Spatial Features ◽  
Physical Barriers ◽  
And Function ◽  
Animal Personalities

Abstract The function of a network is affected by its structure. For example, the presence of highly interactive individuals, or hubs, influences the extent and rate of information spread across a network. In a network of interactions, the duration over which individual variation in interactions persists may affect how the network operates. Individuals may persist in their behavior over time and across situations, often referred to as personality. Colonies of social insects are an example of a biological system in which the structure of the coordinated networks of interacting workers may greatly influence information flow within the colony, and therefore its collective behavior. Here I investigate the effects of persistence in walking patterns on interaction networks using computer simulations that are parameterized using observed behavior of harvester ants. I examine how the duration of persistence in spatial behavior influences network structure. Furthermore, I explore how spatial features of the environment affect the relationship between persistent behavior and network structure. I show that as persistence increases, the skewness of the weighted degree distribution of the interaction network increases. However, this relationship holds only when ants are confined in a space with boundaries, but not when physical barriers are absent. These findings suggest that the influence of animal personalities on network structure and function depends on the environment in which the animals reside.

scholarly journals Patterns of Individual Variation in Visual Pathway Structure and Function in the Sighted and Blind

PLoS ONE ◽  
2016 ◽  
Vol 11 (11) ◽  
pp. e0164677 ◽  
Author(s):  
Geoffrey K. Aguirre ◽  
Ritobrato Datta ◽  
Noah C. Benson ◽  
Sashank Prasad ◽  
Samuel G. Jacobson ◽  
...  
Keyword(s):  
Individual Variation ◽  
Visual Pathway ◽  
Structure And Function ◽  
And Function

scholarly journals Suppressors of Cleavage-Site Mutations in the p62 Envelope Protein of Semliki Forest Virus Reveal Dynamics in Spike Structure and Function

1998 ◽  
Vol 72 (4) ◽  
pp. 2825-2831 ◽  
Author(s):  
Ioannis Tubulekas ◽  
Peter Liljeström
Keyword(s):  
Cleavage Site ◽  
Semliki Forest Virus ◽  
Virus Entry ◽  
Hot Spot ◽  
Structure And Function ◽  
Vector System ◽  
Lower Probability ◽  
Suppressor Mutations ◽  
And Function ◽  
New Mutations

ABSTRACT The E2 spike glycoprotein of Semliki Forest virus is produced as a p62 precursor protein, which is cleaved by host proteases to its mature form, E2. Cleavage is not necessary for particle formation or release but is necessary for infectivity. Previous results had shown that phenotypic revertants of cleavage-deficient p62 mutants are generated, and here we show that these may contain second-site suppressor mutations in the vicinity of the cleavage site. These hot-spot sites were mutated to abolish the generation of such suppressor mutations; however, secondary mutations in another distant domain of the E2 protein appeared instead, all of which still caused cleavage-deficient mutations. Such mutants grew very poorly and were inefficient in virus entry and release. The mutated sites define domains of the spike protein which probably interact to regulate its structure and function. Because of their highly attenuated phenotype and the lower probability of reversion, the new mutations close to the cleavage site were used to make new helper vectors for packaging of recombinant RNA into infectious particles, thus increasing further the biosafety of the vector system based on the Semliki Forest virus replicon.

scholarly journals Computer Simulations in Service of Biology

2021 ◽  
Vol 8 ◽  
Author(s):  
Michael Levitt
Keyword(s):  
Computer Simulation ◽  
Structural Biology ◽  
Computer Simulations ◽  
Virtual World ◽  
Computer Game ◽  
Structure And Function ◽  
Important Research ◽  
Scientific World ◽  
The World ◽  
And Function

Computer simulation is an important research tool in today’s scientific world. Computers allow us to perform computations that mimic the behavior of complex (biological) systems in ways that we could not otherwise achieve. You could think of these simulations as a computer game, in which a virtual world is created that works according to certain (e.g., physical) rules. While we play the game, we learn the rules governing this virtual world and its environment, and also the way that we affect this world as players. In this article, I will explain how we use computer simulations in the world of structural biology to study the structure and function of molecules. I will also describe how I think that we could use insights from the world of biology and computer simulations to advance the society that we live in.

scholarly journals Importance of brain alterations in spinal cord injury

2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110311
Author(s):  
Can Zhao ◽  
Shu-Sheng Bao ◽  
Meng Xu ◽  
Jia-Sheng Rao
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cerebral Cortex ◽  
Information Flow ◽  
Brain Structure ◽  
Structure And Function ◽  
Cord Injury ◽  
Brain Structure And Function ◽  
And Function ◽  
The Brain

Spinal cord injury (SCI) destroys the sensorimotor pathway and blocks the information flow between the peripheral nerve and the brain, resulting in autonomic function loss. Numerous studies have explored the effects of obstructed information flow on brain structure and function and proved the extensive plasticity of the brain after SCI. Great progress has also been achieved in therapeutic strategies for SCI to restore the “re-innervation” of the cerebral cortex to the limbs to some extent. Although no thorough research has been conducted, the changes of brain structure and function caused by “re-domination” have been reported. This article is a review of the recent research progress on local structure, functional changes, and circuit reorganization of the cerebral cortex after SCI. Alterations of structure and electrical activity characteristics of brain neurons, features of brain functional reorganization, and regulation of brain functions by reconfigured information flow were also explored. The integration of brain function is the basis for the human body to exercise complex/fine movements and is intricately and widely regulated by information flow. Hence, its changes after SCI and treatments should be considered.

scholarly journals Drosophila Hsp67Bc hot-spot variants alter muscle structure and function

2018 ◽  
Vol 75 (23) ◽  
pp. 4341-4356 ◽  
Author(s):  
Jadwiga Jabłońska ◽  
Magda Dubińska-Magiera ◽  
Teresa Jagla ◽  
Krzysztof Jagla ◽  
Małgorzata Daczewska
Keyword(s):  
Hot Spot ◽  
Structure And Function ◽  
Muscle Structure ◽  
And Function

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Osseointegration interface of calcified bone and endosseous implants

1992 ◽  
Vol 50 (2) ◽  
pp. 1096-1097
Author(s):  
K.E. Krizan ◽  
J.E. Laffoon ◽  
M.J. Buckley
Keyword(s):  
Structure And Function ◽  
Titanium Implants ◽  
En Bloc ◽  
Endosseous Implants ◽  
Ultrastructural Studies ◽  
The Past ◽  
Cacodylate Buffer ◽  
One Year ◽  
And Function

With increase use of tissue-integrated prostheses in recent years it is a goal to understand what is happening at the interface between haversion bone and bulk metal. This study uses electron microscopy (EM) techniques to establish parameters for osseointegration (structure and function between bone and nonload-carrying implants) in an animal model. In the past the interface has been evaluated extensively with light microscopy methods. Today researchers are using the EM for ultrastructural studies of the bone tissue and implant responses to an in vivo environment. Under general anesthesia nine adult mongrel dogs received three Brånemark (Nobelpharma) 3.75 × 7 mm titanium implants surgical placed in their left zygomatic arch. After a one year healing period the animals were injected with a routine bone marker (oxytetracycline), euthanized and perfused via aortic cannulation with 3% glutaraldehyde in 0.1M cacodylate buffer pH 7.2. Implants were retrieved en bloc, harvest radiographs made (Fig. 1), and routinely embedded in plastic. Tissue and implants were cut into 300 micron thick wafers, longitudinally to the implant with an Isomet saw and diamond wafering blade [Beuhler] until the center of the implant was reached.

Use of human autoantibodies and immunoelectron microscopy to study structure and function of the nucleolus and nuclear bodies

1992 ◽  
Vol 50 (1) ◽  
pp. 506-507
Author(s):  
Robert L. Ochs
Keyword(s):  
Electron Microscopy ◽  
Structure And Function ◽  
Nuclear Bodies ◽  
Nuclear Interior ◽  
Coiled Bodies ◽  
Interchromatin Granules ◽  
And Function ◽  
Conventional Electron Microscopy ◽  
Perichromatin Granules ◽  
Perichromatin Fibrils

By conventional electron microscopy, the formed elements of the nuclear interior include the nucleolus, chromatin, interchromatin granules, perichromatin granules, perichromatin fibrils, and various types of nuclear bodies (Figs. 1a-c). Of these structures, all have been reasonably well characterized structurally and functionally except for nuclear bodies. The most common types of nuclear bodies are simple nuclear bodies and coiled bodies (Figs. 1a,c). Since nuclear bodies are small in size (0.2-1.0 μm in diameter) and infrequent in number, they are often overlooked or simply not observed in any random thin section. The rat liver hepatocyte in Fig. 1b is a case in point. Historically, nuclear bodies are more prominent in hyperactive cells, they often occur in proximity to nucleoli (Fig. 1c), and sometimes they are observed to “bud off” from the nucleolar surface.

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