Stigmergic construction and topochemical information shape ant nest architecture

The nests of social insects are not only impressive because of their sheer complexity but also because they are built from individuals whose work is not centrally coordinated. A key question is how groups of insects coordinate their building actions. Here, we use a combination of experimental and modeling approaches to investigate nest construction in the ant Lasius niger. We quantify the construction dynamics and the 3D structures built by ants. Then, we characterize individual behaviors and the interactions of ants with the structures they build. We show that two main interactions are involved in the coordination of building actions: (i) a stigmergic-based interaction that controls the amplification of depositions at some locations and is attributable to a pheromone added by ants to the building material; and (ii) a template-based interaction in which ants use their body size as a cue to control the height at which they start to build a roof from existing pillars. We then develop a 3D stochastic model based on these individual behaviors to analyze the effect of pheromone presence and strength on construction dynamics. We show that the model can quantitatively reproduce key features of construction dynamics, including a large-scale pattern of regularly spaced pillars, the formation and merging of caps over the pillars, and the remodeling of built structures. Finally, our model suggests that the lifetime of the pheromone is a highly influential parameter that controls the growth and form of nest architecture.

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Pipeline design to identify key features and classify the chemotherapy response on lung cancer patients using large-scale genetic data

BMC Systems Biology ◽

10.1186/s12918-018-0615-5 ◽

2018 ◽

Vol 12 (S5) ◽

Cited By ~ 1

Author(s):

María Gabriela Valdés ◽

Iván Galván-Femenía ◽

Vicent Ribas Ripoll ◽

Xavier Duran ◽

Jun Yokota ◽

...

Keyword(s):

Lung Cancer ◽

Cancer Patients ◽

Large Scale ◽

Genetic Data ◽

Chemotherapy Response ◽

Lung Cancer Patients ◽

Key Features ◽

Pipeline Design

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Body size information in large-scale acoustic bat databases

PeerJ ◽

10.7717/peerj.5370 ◽

2018 ◽

Vol 6 ◽

pp. e5370 ◽

Cited By ~ 4

Author(s):

Caterina Penone ◽

Christian Kerbiriou ◽

Jean-François Julien ◽

Julie Marmet ◽

Isabelle Le Viol

Keyword(s):

Body Size ◽

Large Scale ◽

Principal Component ◽

Acoustic Signals ◽

Species Traits ◽

Climatic Variables ◽

Characteristic Frequencies ◽

Acoustic Data ◽

Forearm Length ◽

Broad Scale

Background Citizen monitoring programs using acoustic data have been useful for detecting population and community patterns. However, they have rarely been used to study broad scale patterns of species traits. We assessed the potential of acoustic data to detect broad scale patterns in body size. We compared geographical patterns in body size with acoustic signals in the bat species Pipistrellus pipistrellus. Given the correlation between body size and acoustic characteristics, we expected to see similar results when analyzing the relationships of body size and acoustic signals with climatic variables. Methods We assessed body size using forearm length measurements of 1,359 bats, captured by mist nets in France. For acoustic analyses, we used an extensive dataset collected through the French citizen bat survey. We isolated each bat echolocation call (n = 4,783) and performed automatic measures of signals, including the frequency of the flattest part of the calls (characteristic frequency). We then examined the relationship between forearm length, characteristic frequencies, and two components resulting from principal component analysis for geographic (latitude, longitude) and climatic variables. Results Forearm length was positively correlated with higher precipitation, lower seasonality, and lower temperatures. Lower characteristic frequencies (i.e., larger body size) were mostly related to lower temperatures and northern latitudes. While conducted on different datasets, the two analyses provided congruent results. Discussion Acoustic data from citizen science programs can thus be useful for the detection of large-scale patterns in body size. This first analysis offers a new perspective for the use of large acoustic databases to explore biological patterns and to address both theoretical and applied questions.

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Anthropometric Resources vs. Civilian Needs

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/1071181378022001157 ◽

1978 ◽

Vol 22 (1) ◽

pp. 600-600

Author(s):

John T. McConville

Keyword(s):

World War Ii ◽

Body Size ◽

Law Enforcement ◽

Large Scale ◽

Law Enforcement Officers ◽

World War ◽

Occupational Groups ◽

Military Populations ◽

Wide Assortment ◽

Size Data

For several decades after World War II, the only comprehensive source of body size data was that of large-scale anthropometric surveys of military personnel. While the range of most dimensions measured on military populations, both male and female, are comparable to those found in the overall U.S. population, self-selection or body size criteria dictated by particular jobs often result in considerable physical variability among occupational groups, a phenomenon which has been amply borne out by surveys of such diverse populations as law enforcement officers and airline stewardess trainees. It has become clear in the civilian sector that “all-purpose” body size data are often misleading and inadequate and that designers of clothing, equipment and workspaces are increasingly faced with the need for a wide assortment of differentiated data to meet many specialized needs. Resources will be explored and solutions suggested.

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Geographic variation in body size and sexual size dimorphism of North American Ratsnakes (Pantherophis spp. s.l.)

Canadian Journal of Zoology ◽

10.1139/cjz-2018-0005 ◽

2018 ◽

Vol 96 (11) ◽

pp. 1196-1202 ◽

Cited By ~ 1

Author(s):

Brett A. DeGregorio ◽

Gabriel Blouin-Demers ◽

Gerardo L.F. Carfagno ◽

J. Whitfield Gibbons ◽

Stephen J. Mullin ◽

...

Keyword(s):

Body Size ◽

Large Scale ◽

Sexual Size Dimorphism ◽

Size Variation ◽

Sexually Dimorphic ◽

Male Body ◽

Complex Species ◽

Size Dimorphism ◽

Body Size Variation ◽

Female Body Size

Because body size affects nearly all facets of an organism’s life history, ecologists have long been interested in large-scale patterns of body-size variation, as well as why those large-scale patterns often differ between sexes. We explored body-size variation across the range of the sexually dimorphic Ratsnake complex (species of the genus Pantherophis Fitzinger, 1843 s.l.; formerly Elaphe obsoleta (Say in James, 1823)) in North America. We specifically explored whether variation in body size followed latitudinal patterns or varied with climatic variables. We found that body size did not conform to a climatic or latitudinal gradient, but instead, some of the populations with the largest snakes occurred near the core of the geographic range and some with the smallest occurred near the northern, western, and southern peripheries of the range. Males averaged 14% larger than females, although the degree of sexual size dimorphism varied between populations (range: 2%–25%). There was a weak trend for male body size to change in relation to temperature, whereas female body size did not. Our results indicate that relationships between climate and an ectotherm’s body size are more complicated than linear latitudinal clines and likely differ for males and females.

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Body Size Differences between Foraging and Intranidal Workers of the Monomorphic Ant Lasius niger

Insects ◽

10.3390/insects11070433 ◽

2020 ◽

Vol 11 (7) ◽

pp. 433

Author(s):

Mateusz Okrutniak ◽

Bartosz Rom ◽

Filip Turza ◽

Irena M. Grześ

Keyword(s):

Body Size ◽

Field Experiment ◽

Important Determinant ◽

Size Variation ◽

Division Of Labour ◽

The Body ◽

Food Type ◽

Lasius Niger ◽

Worker Size ◽

Body Sizes

The association between the division of labour and worker body size of ants is typical for species that maintain physical castes. Some studies showed that this phenomenon can be also observed in the absence of distinct morphological subcastes among workers. However, the general and consistent patterns in the size-based division of labour in monomorphic ants are largely unidentified. In this study, we performed a field experiment to investigate the link between worker body size and the division of labour of the ant Lasius niger (Linnaeus, 1758), which displays limited worker size variation. We demonstrated that the body size of workers exploring tuna baits is slightly but significantly smaller than the size of workers located in the upper parts of the nest. Comparing the present results with existing studies, large workers do not seem to be dedicated to work outside the nest. We suggest that monomorphic workers of certain body sizes are flexible in the choice of task they perform, and food type may be the important determinant of this choice.

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Bystander Training as Leadership Training: Notes on the Origins, Philosophy, and Pedagogy of the Mentors in Violence Prevention Model

Violence Against Women ◽

10.1177/1077801217753322 ◽

2018 ◽

Vol 24 (15) ◽

pp. 1755-1776 ◽

Cited By ~ 15

Author(s):

Jackson Katz

Keyword(s):

Social Justice ◽

Violence Prevention ◽

Leadership Training ◽

Large Scale ◽

College Campuses ◽

Gender Violence ◽

Sports Culture ◽

Prevention Model ◽

Key Features ◽

The U.S

This article outlines the origins, philosophy, and pedagogy of the Mentors in Violence Prevention (MVP) program, which has played a significant role in the gender violence prevention field since its inception in 1993. MVP was one of the first large-scale programs to target men for prevention efforts, as well as the first to operate systematically in sports culture and the U.S. military. MVP also introduced the “bystander” approach to the field. MVP employs a social justice, gender-focused approach to prevention. Key features of this approach are described and contrasted with individualistic, events-based strategies that have proliferated on college campuses and elsewhere in recent years.

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Rapid up- and down-regulation of pheromone signalling due to trail crowding in the ant Lasius niger

Behaviour ◽

10.1163/1568539x-00003157 ◽

2014 ◽

Vol 151 (5) ◽

pp. 669-682 ◽

Cited By ~ 6

Author(s):

Tomer J. Czaczkes ◽

Christoph Grüter ◽

Francis L.W. Ratnieks

Keyword(s):

Cuticular Hydrocarbons ◽

Social Insects ◽

Glass Beads ◽

Lasius Niger ◽

Base Line ◽

Baseline Levels ◽

Line Level ◽

Pheromone Signalling ◽

Repeat Visits ◽

Pheromone Trail

Social insects often respond to signals and cues from nest-mates, and these responses may include changes in the information they, in turn, transmit. During foraging, Lasius niger deposits a pheromone trail to recruit nestmates, and ants that experience trail crowding deposit pheromone less often. Less studied, however, is the time taken for signalling to revert to baseline levels after conditions have returned to baseline levels. In this paper we study the behaviour of L. niger foragers on a trail in which crowding is simulated by using dummy ants — black glass beads coated in nestmate cuticular hydrocarbons. Ants were allowed to make four repeat visits to a feeder with dummy ants, and thus crowding, being present on the trail on all visits (CCCC), none (UUUU) or only the first two (CCUU). If dummy ants were always present (CCCC), pheromone deposition probability was low in the first two visits (54% of ants deposited pheromone) and remained low in visits 3 and 4 (51%). If dummy ants were never present (UUUU) pheromone deposition probability was high in the first two visits (93%) and remained high in visits 3 and 4 (83%). If dummy ants were present on the first two visits but removed on the second two visits (CCUU) pheromone deposition probability was low in the first two visits (61%) but rose in the second two visits (69%). This demonstrates that even after pheromone deposition has been down-regulated due to crowding in the first two visits, it is rapidly up-regulated when crowding is reduced, although it does not immediately return to the base line level.

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Predicting the Cloud Patterns for the Boreal Summer Intraseasonal Oscillation Through a Low-Order Stochastic Model

Mathematics of Climate and Weather Forecasting ◽

10.1515/mcwf-2015-0001 ◽

2015 ◽

Vol 1 (1) ◽

Cited By ~ 9

Author(s):

Nan Chen ◽

Andrew J. Majda

Keyword(s):

Time Series ◽

Stochastic Model ◽

Brightness Temperature ◽

Large Scale ◽

Hidden Variables ◽

Boreal Summer ◽

Ensemble Spread ◽

Nonlinear Stochastic Model ◽

Non Gaussian ◽

Cloud Patterns

AbstractWe assess the predictability limits of the large-scale cloud patterns in the boreal summer intraseasonal variability (BSISO), which are measured by the infrared brightness temperature, a proxy for convective activity. A recent developed nonlinear data analysis technique, nonlinear Laplacian spectrum analysis (NLSA), is applied to the brightness temperature data, defining two spatial modes with high intermittency associated with the BSISO time series. Then a recent developed data-driven physics-constrained low-ordermodeling strategy is applied to these time series. The result is a four dimensional system with two observed BSISO variables and two hidden variables involving correlated multiplicative noise through the nonlinear energyconserving interaction. With the optimal parameters calibrated by information theory, the non-Gaussian fat tailed probability distribution functions (PDFs), the autocorrelations and the power spectrum of the model signals almost perfectly match those of the observed data. An ensemble prediction scheme incorporating an effective on-line data assimilation algorithm for determining the initial ensemble of the hidden variables shows the useful prediction skill in the non-El Niño years is at least 30 days and even reaches 55 days in those years with regular oscillations and the skillful prediction lasts for 18 days in the strong El Niño year (year 1998). Furthermore, the ensemble spread succeeds in indicating the forecast uncertainty. Although the reduced linear model with time-periodic stable-unstable damping is able to capture the non-Gaussian fat tailed PDFs, it is less skillful in forecasting the BSISO in the years with irregular oscillations. The failure of the ensemble spread to include the truth also indicates failure in quantification of the uncertainty. In addition, without the energy-conserving nonlinear interactions, the linear model is sensitive with parameter variations. mcwfnally, the twin experiment with nonlinear stochastic model has comparable skill as the observed data, suggesting the nonlinear stochastic model has significant skill for determining the predictability limits of the large-scale cloud patterns of the BSISO.

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Connecting pH with body size in the marine gastropod Trophon geversianus in a latitudinal gradient along the south-western Atlantic coast

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315416001557 ◽

2016 ◽

Vol 98 (3) ◽

pp. 449-456 ◽

Cited By ~ 3

Author(s):

Mariano E. Malvé ◽

Sandra Gordillo ◽

Marcelo M. Rivadeneira

Keyword(s):

Body Size ◽

Shell Length ◽

Large Scale ◽

Atlantic Coast ◽

Size Variation ◽

Environmental Drivers ◽

Shell Weight ◽

Western Atlantic ◽

Asymptotic Size ◽

The Impact

There is growing concern about the impact of contemporaneous ocean acidification on marine ecosystems, but strong evidence for predicting the consequences is still scant. We have used the gastropod Trophon geversianus as a study model for exploring the importance of oceanographic variables (sea surface temperature, chlorophyll a, oxygen, calcite and pH) on large-scale latitudinal variation in mean shell length and relative shell weight. Data were collected from a survey carried out in 34 sites along ~1600 km. Neither shell length nor relative shell weight showed any monotonic latitudinal trend, and the patterns of spatial variability were rather complex. After correcting for spatial autocorrelation, only pH showed a significant correlation with mean shell length and relative shell weight, but contrary to expectations, the association was negative in both cases. We hypothesize that this could mirror the negative effect of acidification on growth rate, which may cause larger asymptotic size. Latitudinal trends of body size variation are not easy to generalize using ecogeographic rules, and may be the result of a complex interaction of environmental drivers and life-history responses.

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A New MEMS Stochastic Model Order Reduction Method: Research and Application

Journal of Sensors ◽

10.1155/2015/125621 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10

Author(s):

Bian Xiangjuan ◽

Youping Gong ◽

Chen Guojin ◽

Lv Yunpeng

Keyword(s):

Finite Element ◽

Stochastic Model ◽

Model Order Reduction ◽

Large Scale ◽

Reduction Method ◽

Order Reduction ◽

Fast Time ◽

Random Input ◽

Model Order ◽

Order Reduction Method

Modeling and simulation of MEMS devices is a very complex tasks which involve the electrical, mechanical, fluidic, and thermal domains, and there are still some uncertainties that need to be accounted for during the robust design of MEMS actuators caused by uncertain material and/or geometric parameters. According to these problems, we put forward stochastic model order reduction method under random input conditions to facilitate fast time and frequency domain analyses; the method makes use of polynomial chaos expansions in terms of the random input variables for the matrices of a finite element model of the system and then uses its transformation matrix to reduce the model; the method is independent of the MOR algorithm, so it is seamlessly compatible with MOR method used in popular finite element solvers. The simulation results verify the method is effective in large scale MEMS design process.

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