scholarly journals Group size elicits specific physiological response in herbivores

2012 ◽  
Vol 8 (4) ◽  
pp. 537-539 ◽  
Author(s):  
Pablo Michelena ◽  
Marie-Hélène Pillot ◽  
Carole Henrion ◽  
Sylvain Toulet ◽  
Alain Boissy ◽  
...  
Keyword(s):  
Predation Risk ◽  
Group Size ◽  
Small Groups ◽  
Physiological Response ◽  
Cortisol Concentration ◽  
Cortisol Response ◽  
Predator Cues

With increasing group size, individuals commonly spend less time standing head-up (scanning) and more time feeding. In small groups, a higher predation risk is likely to increase stress, which will be reflected by behavioural and endocrine responses. However, without any predator cues, we ask how the predation risk is actually processed by animals as group size decreases. We hypothesize that group size on its own acts as a stressor. We studied undisturbed groups of sheep under controlled pasture conditions, and measured in situ the cortisol and vigilance responses of identified individuals in groups ranging from 2 to 100 sheep. Both vigilance and average cortisol concentration decreased as group size increased. However, the cortisol response varied markedly among individuals in small groups, resulting in a lack of correlation between cortisol and vigilance responses. Further experiments are required to explore the mechanisms that underlie both the decay and the convergence of individual stress in larger groups, and whether these mechanisms promote adaptive anti-predator responses.

scholarly journals In Silico Hemostasis Modeling and Prediction

2020 ◽  
Vol 40 (04) ◽  
pp. 524-535
Author(s):  
Dmitry Y. Nechipurenko ◽  
Aleksey M. Shibeko ◽  
Anastasia N. Sveshnikova ◽  
Mikhail A. Panteleev
Keyword(s):  
In Silico ◽  
Physiological Response ◽  
Platelet Adhesion ◽  
State Of The Art ◽  
Thrombus Formation ◽  
The State ◽  
Modeling And Prediction ◽  
Hemostatic System ◽  
Single Enzyme

AbstractComputational physiology, i.e., reproduction of physiological (and, by extension, pathophysiological) processes in silico, could be considered one of the major goals in computational biology. One might use computers to simulate molecular interactions, enzyme kinetics, gene expression, or whole networks of biochemical reactions, but it is (patho)physiological meaning that is usually the meaningful goal of the research even when a single enzyme is its subject. Although exponential rise in the use of computational and mathematical models in the field of hemostasis and thrombosis began in the 1980s (first for blood coagulation, then for platelet adhesion, and finally for platelet signal transduction), the majority of their successful applications are still focused on simulating the elements of the hemostatic system rather than the total (patho)physiological response in situ. Here we discuss the state of the art, the state of the progress toward the efficient “virtual thrombus formation,” and what one can already get from the existing models.

In-Situ SEM Observations of Moving Interfaces during Recrystallisation

2006 ◽  
Vol 519-521 ◽  
pp. 1341-1348 ◽  
Author(s):  
Sybrand van der Zwaag ◽  
E. Anselmino ◽  
A. Miroux ◽  
David J. Prior
Keyword(s):  
Grain Boundaries ◽  
Small Groups ◽  
Detailed Understanding ◽  
Small Areas ◽  
Orientation Contrast ◽  
Moving Interfaces ◽  
Innovative Method ◽  
Before And After ◽  
In Situ Observations

To obtain further progress and a more detailed understanding of the mechanisms involved in recrystallisation, new and more accurate techniques such as in-situ observations are necessary. This innovative method has been used to monitor the recrystallisation process in a FEGSEM equipped with hot stage. Observations are done in backscatter mode with particular attention to orientation contrast. EBSD maps of the observed areas can be acquired before and after recrystallisation. Details of the movement of the interfaces between the recrystallised region and the parent structure are recorded and analysed. The results show that the grain boundaries observed do not move smoothly but with a jerky motion. The recrystallising front sweeps through small areas, corresponding to single sub-grains or small groups of them, very rapidly and then stops at other sub-grain boundaries for varying time before progressing to the following area.

Hunted hunters? Effect of group size on predation risk and growth in the Australian subsocial crab spider Diaea ergandros

2013 ◽  
Vol 67 (5) ◽  
pp. 785-794 ◽  
Author(s):  
Bianca Unglaub ◽  
Jasmin Ruch ◽  
Marie E. Herberstein ◽  
Jutta M. Schneider
Keyword(s):  
Predation Risk ◽  
Group Size ◽  
Crab Spider

scholarly journals Video in situ simulation for medical student education during the COVID-19 pandemic

2021 ◽  
Author(s):  
Monika Bilic ◽  
Alim Nagji ◽  
Erich Hanel
Keyword(s):  
Medical Student ◽  
Medical Students ◽  
Small Groups ◽  
Medical Student Education ◽  
Simple Design ◽  
In Situ Simulation ◽  
Student Education

Implication statement The COVID-19 pandemic has limited in-person experiences for medical students, especially in situations involving aerosol-generating procedures. We designed a video in situ simulation to orient students to critical steps in COVID-19 intubation algorithms. Small groups of students were paired virtually with facilitators (faculty and residents) and watched a video of an in situ simulation of emergency staff performing a protected intubation, with discussion points appearing on screen at discrete times. The simple design drives engagement, discussion and allows for scheduling flexibility with no risk to the learners. It can be adapted to several different scenarios or levels of training.

scholarly journals Group-size-mediated habitat selection and group fusion–fission dynamics of bison under predation risk

Ecology ◽  
2009 ◽  
Vol 90 (9) ◽  
pp. 2480-2490 ◽  
Author(s):  
Daniel Fortin ◽  
Marie-Eve Fortin ◽  
Hawthorne L. Beyer ◽  
Thierry Duchesne ◽  
Sabrina Courant ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Predation Risk ◽  
Group Size ◽  
Group Fusion

Cortisol Response of Sows to Alternative Farrowing Systems

1994 ◽  
Vol 1994 ◽  
pp. 44-44
Author(s):  
A.R. Rudd ◽  
M.T. Mendl ◽  
D.M. Broom ◽  
P.H. Simmins
Keyword(s):  
Salivary Cortisol ◽  
Physiological Response ◽  
Farm Animals ◽  
Cortisol Response ◽  
Lactating Sows ◽  
Two Systems

Variation in circulating Cortisol is often used as an indicator of stress in farm animals. In this study the variation in baseline salivary Cortisol of farrowing and lactating sows was examined, to assess their physiological response to three different farrowing systems. It was part of a larger project examining alternative farrowing systems.Three farrowing systems in neighbouring rooms were compared. In two systems the sows were loose-housed and could move freely: five strawed pens (2.5m x 1.5m) with farrowing rail (Pen), and five crates modified to allow the sows to walk through (Free Crate). Sows had access via a passageway to a transponder-controlled feeder and a north facing outside area with two water drinkers.

scholarly journals In situ predator conditioning of naive prey prior to reintroduction

2019 ◽  
Vol 374 (1781) ◽  
pp. 20180058 ◽  
Author(s):  
Daniel T. Blumstein ◽  
Mike Letnic ◽  
Katherine E. Moseby
Keyword(s):  
Small Groups ◽  
Large Scale ◽  
Management Tool ◽  
Behavioural Ecology ◽  
Ecological Community ◽  
Theme Issue ◽  
Selection For ◽  
Future Work ◽  
Dynamics Of Populations

Many translocations and introductions to recover threatened populations fail because predators kill prey soon after release; a problem exacerbated for predator-naive prey. While pre-release training has been shown to work in some situations, it is time consuming and relies on using inferred predator cues and treating small groups. We review a relatively new and very promising management tool: in situ , pre-release predator conditioning. Here, the goal is to allow prey in large enclosures to live with low densities of predators to accelerate selection for antipredator traits (in an evolutionary sense) or provide prey essential experience with predators that they will later encounter. We review the published results of a large-scale, controlled experiment where we have permitted burrowing bettongs ( Bettongia lesueur ) and greater bilblies ( Macrotis lagotis ) to live with low densities of feral cats ( Felis catus ), a species implicated in their widespread decline and localized extinction. We found that both species could persist with cats, suggesting that future work should define coexistence thresholds—which will require knowledge of prey behaviour as well as the structure of the ecological community. Compared to control populations, predator-naive prey exposed to cats has a suite of morphological and behavioural responses that seemingly have increased their antipredator abilities. Results suggest that predator-conditioned bilbies survive better when released into a large enclosure with an established cat population; future work will determine whether this increased survival extends to the wild. This article is part of the theme issue ‘Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation’.

Ecological drivers of group size in female Alpine chamois, Rupicapra rupicapra

Mammalia ◽  
2015 ◽  
Vol 79 (4) ◽  
Author(s):  
Roberta Chirichella ◽  
Andrea Mustoni ◽  
Marco Apollonio
Keyword(s):  
Predation Risk ◽  
Energy Intake ◽  
Group Size ◽  
Food Availability ◽  
Herd Size ◽  
Rupicapra Rupicapra ◽  
Trade Off ◽  
Mammalian Herbivores ◽  
Alpine Chamois

AbstractIn large mammalian herbivores, an increase in herd size not only reduces predation risk but also energy intake. As a consequence, the size of the groups made up by herbivores is often assumed to be the outcome of a trade-off depending on local predation risk and food availability. We studied Alpine chamois (

scholarly journals Prey synchronize their vigilant behaviour with other group members

2007 ◽  
Vol 274 (1615) ◽  
pp. 1287-1291 ◽  
Author(s):  
Olivier Pays ◽  
Pierre-Cyril Renaud ◽  
Patrice Loisel ◽  
Maud Petit ◽  
Jean-François Gerard ◽  
...  
Keyword(s):  
Predation Risk ◽  
Group Size ◽  
Prey Species ◽  
Group Members ◽  
The Individual ◽  
The Cost ◽  
Group Member

It is generally assumed that an individual of a prey species can benefit from an increase in the number of its group's members by reducing its own investment in vigilance. But what behaviour should group members adopt in relation to both the risk of being preyed upon and the individual investment in vigilance? Most models assume that individuals scan independently of one another. It is generally argued that it is more profitable for each group member owing to the cost that coordination of individual scans in non-overlapping bouts of vigilance would require. We studied the relationships between both individual and collective vigilance and group size in Defassa waterbuck, Kobus ellipsiprymnus defassa , in a population living under a predation risk. Our results confirmed that the proportion of time an individual spent in vigilance decreased with group size. However, the time during which at least one individual in the group scanned the environment (collective vigilance) increased. Analyses showed that individuals neither coordinated their scanning in an asynchronous way nor scanned independently of one another. On the contrary, scanning and non-scanning bouts were synchronized between group members, producing waves of collective vigilance. We claim that these waves are triggered by allelomimetic effects i.e. they are a phenomenon produced by an individual copying its neighbour's behaviour.

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