Cost-reducing traits for agonistic head collisions: a case for neurophysiology

2021 ◽  
Author(s):  
Daniel J Tobiansky ◽  
Kira M Long ◽  
Jordan E Hamden ◽  
Jeffrey D Brawn ◽  
Matthew J Fuxjager
Keyword(s):  
Head Trauma ◽  
Animal Species ◽  
High Impact ◽  
Computational Studies ◽  
Independent Manner ◽  
Head Impacts ◽  
Impact Forces ◽  
Selection For ◽  
The Cost ◽  
Impact Head

Abstract Many animal species have evolved extreme behaviors requiring them to engage in repeated high-impact collisions. These behaviors include mating displays like headbutting in sheep and drumming in woodpeckers. To our knowledge, these taxa do not experience any notable acute head trauma, even though the deceleration forces would cause traumatic brain injury in most animals. Previous research has focused on skeletomuscular morphology, biomechanics, and material properties in an attempt to explain how animals moderate these high-impact forces. However, many of these behaviors are understudied, and most morphological or computational studies make assumptions about the behavior without accounting for the physiology of an organism. Studying neurophysiological and immune adaptations that co-vary with these behaviors can highlight unique or synergistic solutions to seemingly deleterious behavioral displays. Here, we argue that selection for repeated, high-impact head collisions may rely on a suite of coadaptations in intracranial physiology as a cost-reducing mechanism. We propose that there are three physiological systems that could mitigate the effects of repeated head trauma: (i) the innate neuroimmune response, (ii) the glymphatic system, and (iii) the choroid plexus. These systems are interconnected yet can evolve in an independent manner. We then briefly describe the function of these systems, their role in head trauma, and research that has examined how these systems may evolve to help reduce the cost of repeated, forceful head impacts. Ultimately, we note that little is known about cost-reducing intracranial mechanisms making it a novel field of comparative study that is ripe for exploration.

scholarly journals Evolution of mantis shrimp telson armour and its role in ritualized fighting

2019 ◽  
Vol 16 (157) ◽  
pp. 20190203 ◽  
Author(s):  
Jennifer R. A. Taylor ◽  
Nina I. Scott ◽  
Greg W. Rouse
Keyword(s):  
Comparative Analysis ◽  
Impact Resistance ◽  
High Impact ◽  
Mantis Shrimp ◽  
Impact Forces ◽  
Drop Tests ◽  
Impact Parameters ◽  
Ritualized Combat ◽  
Stiff Spring ◽  
The Impact

Mantis shrimp possess both formidable weapons and impact-resistant armour that clash during ritualized combat. The telson is one of few biological structures known to withstand the repeated high impact forces of smashing mantis shrimp strikes, and it is hypothesized that this pairing of armour and weapon is associated with the evolution of telson sparring. We carried out a comparative analysis of telson impact mechanics across 15 mantis shrimp species to assess if the telsons of sparring species (i) are consistently specialized for impact-resistance, (ii) are more impact-resistant than those of non-sparring species, and (iii) have impact parameters that correlate with body size, and thereby useful for assessment. Our data from ball drop tests show that the telsons of all species function like a stiff spring that dissipates most of the impact energy, but none of the measured impact parameters are correlated with the occurrence of sparring behaviour. Impact parameters were correlated with body mass for only some species, suggesting that it is not broadly useful for size assessment during ritualized fighting. Contrary to expectation, sparring mantis shrimp do not appear to have coevolved telson armour that is more robust to impact than non-sparring species. Rather, telson structure is inherently impact-resistant.

scholarly journals Why and How to Switch to Genomic Selection: Lessons From Plant and Animal Breeding Experience

2021 ◽  
Vol 12 ◽  
Author(s):  
◽  
Aline Fugeray-Scarbel ◽  
Catherine Bastien ◽  
Mathilde Dupont-Nivet ◽  
Stéphane Lemarié
Keyword(s):  
Genetic Diversity ◽  
Genomic Selection ◽  
Plant Species ◽  
Animal Species ◽  
Animal Breeding ◽  
Breeding Cycle ◽  
Breeding Programs ◽  
The Third ◽  
Wide Range ◽  
Selection For

The present study is a transversal analysis of the interest in genomic selection for plant and animal species. It focuses on the arguments that may convince breeders to switch to genomic selection. The arguments are classified into three different “bricks.” The first brick considers the addition of genotyping to improve the accuracy of the prediction of breeding values. The second consists of saving costs and/or shortening the breeding cycle by replacing all or a portion of the phenotyping effort with genotyping. The third concerns population management to improve the choice of parents to either optimize crossbreeding or maintain genetic diversity. We analyse the relevance of these different bricks for a wide range of animal and plant species and sought to explain the differences between species according to their biological specificities and the organization of breeding programs.

scholarly journals Fluctuations in blood biomarkers of head trauma in NCAA football athletes over the course of a season

2019 ◽  
Vol 130 (5) ◽  
pp. 1655-1662 ◽  
Author(s):  
Jonathan M. Oliver ◽  
Anthony J. Anzalone ◽  
Jason D. Stone ◽  
Stephanie M. Turner ◽  
Damond Blueitt ◽  
...  
Keyword(s):  
Head Trauma ◽  
Plasma Concentrations ◽  
Objective Measure ◽  
American Football ◽  
Neurological Injury ◽  
Cumulative Exposure ◽  
Serum Concentrations ◽  
Blood Biomarkers ◽  
Head Impacts ◽  
Subconcussive Head Trauma

OBJECTIVERepetitive subconcussive head trauma is a consequence of participation in contact sports and may be linked to neurodegenerative diseases. The degree of neurological injury caused by subconcussive head trauma is not easily detectible, and this injury does not induce readily identifiable clinical signs or symptoms. Recent advancements in immunoassays make possible the detection and quantification of blood biomarkers linked to head trauma. Identification of a blood biomarker that can identify the extent of neurological injury associated with subconcussive head trauma may provide an objective measure for informed decisions concerning cumulative exposure to subconcussive head trauma. The purpose of the current study was to examine changes in the blood biomarkers of subconcussive head trauma over the course of an American football season.METHODSThirty-five National Collegiate Athletic Association (NCAA) American football athletes underwent blood sampling throughout the course of a football season. Serial samples were obtained throughout the 2016 season, during which the number and magnitude of head impacts changed. Blood samples were analyzed for plasma concentrations of tau and serum concentrations of neurofilament light polypeptide (NF-L). Athletes were grouped based on their starter status, because athletes identified as starters are known to sustain a greater number of impacts. Between-group differences and time-course differences were assessed.RESULTSIn nonstarters, plasma concentrations of tau decreased over the course of the season, with lower values observed in starters; this resulted in a lower area under the curve (AUC) (starters: 416.78 ± 129.17 pg/ml/day; nonstarters: 520.84 ± 163.19 pg/ml/day; p = 0.050). Plasma concentrations of tau could not be used to discern between starters and nonstarters. In contrast, serum concentrations of NF-L increased throughout the season as head impacts accumulated, specifically in those athletes categorized as starters. The higher serum concentrations of NF-L observed in starters resulted in a larger AUC (starters: 1605.03 ± 655.09 pg/ml/day; nonstarters: 1067.29 ± 272.33 pg/ml/day; p = 0.007). The AUC of the receiver operating characteristic curve analyses displayed fair to modest accuracy to identify athletes who were starters with the use of serum NF-L following periods of repetitive impacts.CONCLUSIONSThe different patterns observed in serum NF-L and plasma tau concentrations provide preliminary evidence for the use of blood biomarkers to detect the neurological injury associated with repetitive subconcussive head trauma. Although further investigation is necessary, such findings might lay the foundation for the further development of an objective measure for the detection of neurological injury caused by subconcussive head trauma.

Reducing the cost of beef production through the genetic improvement of net feed efficiency

1998 ◽  
Vol 1998 ◽  
pp. 45-45
Author(s):  
R.M. Herd ◽  
J.A. Archer ◽  
P.F. Arthur ◽  
E.C. Richardson
Keyword(s):  
Feed Efficiency ◽  
Genetic Improvement ◽  
Production Systems ◽  
Growth Efficiency ◽  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Feed Conversion ◽  
Selection For ◽  
The Cost ◽  
Animal Production Systems

Feed is the single largest cost in most animal production systems. Feed conversion ratio (FCR) is a commonly used measure of growth efficiency. Previous research has shown that FCR is moderately heritable and highly related to growth rate. While selection for FCR is beneficial to those feeding growing cattle for slaughter, any associated increase in the size of breeding females will mean this benefit will be at a cost to the calf breeder, as larger breeding cows require more feed.

Fault Management in Transparent Optical Networks

2011 ◽  
pp. 88-108
Author(s):  
Carmen Mas Machuca
Keyword(s):  
Optical Networks ◽  
Low Cost ◽  
High Capacity ◽  
Fault Management ◽  
High Impact ◽  
Multiple Faults ◽  
Transparent Optical Networks ◽  
Complex Fault ◽  
The Cost ◽  
Detection And Localization

The advantages of transparent optical networks such as high capacity and low cost can be outweighed by their complex fault management and the high impact of the faults occurring within them. Indeed, transparent optical networks reduce unnecessary, complex, and expensive opto-electronic conversion, to the cost of having faults more deleterious and affecting longer distances than in opaque networks. Moreover, transparent optical networks have limited monitoring capabilities, which could hinder efficient and accurate fault detection and localization. Different approaches have been proposed in the literature to perform fault localization, targeting different fault scenarios (e.g. single/multiple faults or looking at the optical/higher layers), and considering different assumptions (e.g. ideal/existence of false or lost alarms). Furthermore, fault management depends on the placement of monitoring equipment, whose optimization has been studied and also presented in this chapter.

Microcontroller memory capability assessment and variant selection for reducing the cost of mechatronics

2012 ◽  
Vol 60 (3/4) ◽  
pp. 248
Author(s):  
C. Quigley ◽  
R.P. Jones ◽  
R. McMurran ◽  
P. Faithfull
Keyword(s):  
Variant Selection ◽  
Selection For ◽  
The Cost

scholarly journals Divergence in social traits in Trinidadian guppies selectively bred for high and low leadership in a cooperative context

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
S. Dimitriadou ◽  
D. P. Croft ◽  
S. K. Darden
Keyword(s):  
Poecilia Reticulata ◽  
Animal Species ◽  
Selective Breeding ◽  
Empirical Studies ◽  
Phenotypic Selection ◽  
Evolution Of Cooperation ◽  
Moderate Degree ◽  
Social Traits ◽  
Trinidadian Guppy ◽  
Selection For

AbstractIn many animal species, individuals with certain morphological, physiological, or behavioural traits may have a disproportionately large role in determining group behaviour. While most empirical studies of leadership have focused on behaviour of individuals exploring new environments or foraging, little is known about leading behaviour in other ecological contexts. Here, we use a selective breeding design in the Trinidadian guppy (Poecilia reticulata) to quantify the heritability of leadership in a cooperative context, and determine the behavioural traits associated with it. Firstly we found that phenotypic selection for high and low leadership (HL and LL, respectively) over three filial generations resulted in pronounced differences in leadership tendency with a moderate degree of heritability. In our assay of other social traits, LL males were more aggressive and sampled their social environment less than HL males, but HL and LL females did not differ in either aggressiveness or sociability. Traits such as boldness and exploratory tendency did not diverge between the two lines. Leading behaviour was thus associated with social traits in males, but not females; suggesting that there may be sex-specific mechanisms driving the emergence of leadership in this context. We discuss our findings in the context of the evolution of cooperation.

scholarly journals Understanding sex differences in the cost of terrestrial locomotion

2011 ◽  
Vol 279 (1729) ◽  
pp. 826-832 ◽  
Author(s):  
John J. Lees ◽  
Robert L. Nudds ◽  
Lars P. Folkow ◽  
Karl-Arne Stokkan ◽  
Jonathan R. Codd
Keyword(s):  
Sex Differences ◽  
Sexual Selection ◽  
Male And Female ◽  
Locomotor System ◽  
Terrestrial Locomotion ◽  
Female Data ◽  
Selection For ◽  
Morphological Differences ◽  
Lagopus Muta ◽  
The Cost

Little is known regarding the physiological consequences of the behavioural and morphological differences that result from sexual selection in birds. Male and female Svalbard rock ptarmigans ( Lagopus muta hyperborea ) exhibit distinctive behavioural differences during the breeding season. In particular, males continuously compete for and defend territories in order to breed successfully, placing large demands on their locomotor system. Here, we demonstrate that male birds have improved locomotor performance compared with females, showing both a lower cost of locomotion (CoL) and a higher top speed. We propose that the observed sex differences in locomotor capability may be due to sexual selection for improved male performance. While the mechanisms underlying these energetic differences are unclear, future studies should be wary when pooling male and female data.

OPTIMAL CONTROL APPLIED IN AN ANTHRAX EPIZOOTIC MODEL

2016 ◽  
Vol 24 (04) ◽  
pp. 495-517 ◽  
Author(s):  
BUDDHI PANTHA ◽  
JUDY DAY ◽  
SUZANNE LENHART
Keyword(s):  
Optimal Control ◽  
National Parks ◽  
Animal Species ◽  
Control Measure ◽  
Population Decline ◽  
Model Parameters ◽  
Carcass Disposal ◽  
The Cost ◽  
Wildlife Reserve ◽  
Proper Disposal

Anthrax is a rapidly fatal, infectious disease which occurs in many animal species, particularly herbivore mammals, and is one of the main causes of population decline in several national parks worldwide. As the infected animals face inevitable death and each infected carcass contributes spores to the surrounding environment, infected carcasses and the infected animals are the main sources of new infections. Thus any control measure should focus on vaccinating susceptible animals and the proper disposal of infected carcasses. In this paper, a system of ordinary differential equations modeling an anthrax epizootic in a wildlife reserve is formulated. Two controls representing vaccination of the susceptible animals and disposal of the infected carcasses are investigated in order to minimize the number of infected animals, the number of infected carcasses and the cost of vaccination and carcass disposal. Model parameters are estimated by using outbreak data from Malilangwe Wildlife Reserve, Zimbabwe, and some numerical results for the optimal control problem are presented.

A Review of the Effects of Out-Of-Round Wheels on Track and Vehicle Components

2005 ◽  
Vol 219 (3) ◽  
pp. 151-175 ◽  
Author(s):  
D W Barke ◽  
W K Chiu
Keyword(s):  
Prestressed Concrete ◽  
Numerical Models ◽  
Rolling Stock ◽  
Noise Levels ◽  
Total Cost ◽  
Dynamic Motion ◽  
Impact Forces ◽  
Vehicle Components ◽  
The Cost ◽  
Decision Making Tool

Out-of-round rollingstock wheels are caused by skidding or spalling of the wheel tread and by dynamic motion of wheels and wheelsets in service. Out-of-round wheels generate impact forces at the wheel-rail interface, which are transferred to train and to track components including rail and both bolted and welded rail joints, prestressed concrete sleepers, ballast, wheels, and bearings. To make a rational decision about removing out-of-round wheels from service, estimation of the damage caused by an individual wheel is required. Previous studies have used analytical and numerical models to illustrate the distribution of impact into track and rolling stock components. These models are compared here. The review details mathematical models and studies of the lives of the earlier-listed components, which would provide a means of determining the damage caused by impacting wheels. In addition, studies have found that impacting wheels increase fuel consumption and increase pass-by noise levels, which are also discussed here. Further study of the effect of impacting wheels on axle bearing lives, parent rail, and bridges would improve this decision-making tool. It is envisaged that these models would be combined to determine the total cost of operating rolling stock with impacting wheels. This could be offset against the cost of wheelset maintenance to determine when an impacting wheel should be reprofiled.

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