scholarly journals Habitat features and performance interact to determine the outcomes of terrestrial predator–prey pursuits

2020 ◽  
Vol 89 (12) ◽  
pp. 2958-2971
Author(s):  
Rebecca Wheatley ◽  
Theodore P. Pavlic ◽  
Ofir Levy ◽  
Robbie S. Wilson
Keyword(s):  
Predator Prey ◽  
Habitat Features ◽  
Terrestrial Predator ◽  
And Performance

Relationships between riverine fish and woody debris: implications for lowland rivers

1999 ◽  
Author(s):  
D. A. Crook ◽  
A. I. Robertson
Keyword(s):  
Woody Debris ◽  
Fish Habitat ◽  
Reference Points ◽  
Positive Development ◽  
Lowland River ◽  
Predator Prey ◽  
Lowland Rivers ◽  
Habitat Features ◽  
Surface Areas ◽  
Riverine Fish

This paper reviews studies of relationships between riverine fish and woody debris at micro- and meso-habitat scales, and discusses the potential functions of instream structure for lowland river fish. Experimental research, mainly in North America, has identified three main functions of woody debris as microhabitat for fish in upland streams: overhead cover that decreases predation risk both vertically and horizontally; horizontal visual isolation that reduces contact between fish; and velocity refuge which minimizes energetic costs. As with habitat features in other aquatic environments, increasing spatial complexity of woody debris may modify predator–prey interactions and provide greater surface areas for the growth of prey items. Woody debris may also provide spatial reference points for riverine fish to assist them in orienting within their surroundings. Lowland rivers differ from upland streams in terms of a number of physical variables, including turbidity, depth and water turbulence. Relationships between fish and woody debris in lowland rivers are likely to rely on mechanisms different to those in upland streams. Recent initiatives involving the reintroduction of woody debris into previously cleared lowland rivers to replace lost fish habitat are a positive development for lowland river restoration. However, if woody debris reintroduction is to maximally benefit lowland river fisheries, there is a requirement for better understanding of the ecological functions of woody debris in lowland rivers.

scholarly journals Design and Analysis of Sustainable and Seasonal Profit Scaling Model in Cloud Environment

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Monika Kumari ◽  
G. Sahoo
Keyword(s):  
Genetic Algorithm ◽  
Differential Evolution ◽  
Resource Provisioning ◽  
Vertical Scaling ◽  
Predator Prey ◽  
Average Completion Time ◽  
Predator Prey Model ◽  
De Algorithm ◽  
Optimal Resource ◽  
And Performance

Cloud is a widely used platform for intensive computing, bulk storage, and networking. In the world of cloud computing, scaling is a preferred tool for resource management and performance determination. Scaling is generally of two types: horizontal and vertical. The horizontal scale connects users’ agreement with the hardware and software entities and is implemented physically as per the requirement and demand of the datacenter for its further expansion. Vertical scaling can essentially resize server without any change in code and can increase the capacity of existing hardware or software by adding resources. The present study aims at describing two approaches for scaling, one is a predator-prey method and second is genetic algorithm (GA) along with differential evolution (DE). The predator-prey method is a mathematical model used to implement vertical scaling of task for optimal resource provisioning and genetic algorithm (GA) along with differential evolution(DE) based metaheuristic approach that is used for resource scaling. In this respect, the predator-prey model introduces two algorithms, namely, sustainable and seasonal scaling algorithm (SSSA) and maximum profit scaling algorithm (MPSA). The SSSA tries to find the approximation of resource scaling and the mechanism for maximizing sustainable as well as seasonal scaling. On the other hand, the MPSA calculates the optimal cost per reservation and maximum sustainable profit. The experimental results reflect that the proposed logistic scaling-based predator-prey method (SSSA-MPSA) provides a comparable result with GA-DE algorithm in terms of execution time, average completion time, and cost of expenses incurred by the datacenter.

Performance of a Lotka-Volterra System for Representing Biofouling Processes

2014 ◽  
Author(s):  
Foteini Komninelli ◽  
Athanasios Iliopoulos ◽  
John G. Michopoulos
Keyword(s):  
Finite Element ◽  
Computational Domain ◽  
Control Parameters ◽  
Element Solution ◽  
Population Densities ◽  
Volterra System ◽  
Spatiotemporal Evolution ◽  
Predator Prey ◽  
Spatiotemporal Behavior ◽  
And Performance

In order to assess the feasibility and performance of a minimal multiphysics model for representing the spatiotemporal evolution of biofouling process, we selected the coupled diffusive generalization of the Lotka-Volterra PDEs to govern the spatiotemporal evolution of population densities of predator-prey colonies in a computational domain. The implementation of the finite element solution of the system was performed and the associated numerical solution of the system was achieved. An analysis was performed that highlights certain choices of the control parameters of the model and their effect on the spatiotemporal behavior of the system. Potential extensions of the model are presented to incorporate an agent that inhibits antibiofouling and study its effect. An evaluation of the features of the model are concluding the paper.

scholarly journals Modeling escape success in terrestrial predator–prey interactions

2020 ◽  
Vol 60 (2) ◽  
pp. 497-508 ◽  
Author(s):  
Robbie S Wilson ◽  
Theodore P Pavlic ◽  
Rebecca Wheatley ◽  
Amanda C Niehaus ◽  
Ofir Levy
Keyword(s):  
Theoretical Model ◽  
Prey Species ◽  
Escape Performance ◽  
Reproductive Behaviors ◽  
Predator Prey ◽  
Sprint Speed ◽  
Prey Animal ◽  
Terrestrial Predator ◽  
Curved Paths ◽  
Biomechanical Constraints

Synopsis Prey species often modify their foraging and reproductive behaviors to avoid encounters with predators; yet once they are detected, survival depends on out-running, out-maneuvering, or fighting off the predator. Though predation attempts involve at least two individuals—namely, a predator and its prey—studies of escape performance typically measure a single trait (e.g., sprint speed) in the prey species only. Here, we develop a theoretical model in which the likelihood of escape is determined by the prey animal’s tactics (i.e., path trajectory) and its acceleration, top speed, agility, and deceleration relative to the performance capabilities of a predator. The model shows that acceleration, top speed, and agility are all important determinants of escape performance, and because speed and agility are biomechanically related to size, smaller prey with higher agility should force larger predators to run along curved paths that do not allow them to use their superior speeds. Our simulations provide clear predictions for the path and speed a prey animal should choose when escaping from predators of different sizes (thus, biomechanical constraints) and could be used to explore the dynamics between predators and prey.

scholarly journals Silviculture approaches to restoring a predator-prey system: examples from the LiDea project in Boreal Alberta

2016 ◽  
Author(s):  
Michael Cody ◽  
Scott McNay ◽  
Glenn D. Sutherland ◽  
Geoff Sherman
Keyword(s):  
Habitat Restoration ◽  
Landscape Scale ◽  
Forest Site ◽  
Environmental Strategy ◽  
Linear Features ◽  
Predator Prey ◽  
Prey System ◽  
And Performance ◽  
Cold Lake ◽  
Site Types

The issue of Woodland caribou decline has been identified corporately as a top environmental priority for Cenovus energy Inc. Pursuant to this priority, a habitat centric environmental strategy and performance commitments have been developed. Beginning in 2008, Cenovus began applied investigation into the use of silviculture techniques for accelerated restoration, emphasizing the bog and fen forest site types that are characteristic of Boreal caribou habitat. In a larger scale project called LiDea, restoration treatments were ultimately applied to linear features throughout an area of 370 km 2 within the Cold Lake herd range. As indicated by metrics at the site level, as well as GPS collar re-locations, plant and animal response to restoration treatment are positive from a caribou perspective. Results from the LiDea series of projects have been strong enough to warrant the extension of these forest habitat restoration methods to the landscape scale.

scholarly journals Structure–behaviour correlations between two genetically closely related snail species

2020 ◽  
Vol 7 (1) ◽  
pp. 191471 ◽  
Author(s):  
H. Le Ferrand ◽  
Y. Morii
Keyword(s):  
Land Snails ◽  
Material Structure ◽  
Snail Species ◽  
Environmental Constraints ◽  
Environmental Pressures ◽  
Predator Prey ◽  
Defence Behaviour ◽  
And Performance ◽  
Biomimetic Structures

Species, through their structure and composition, have evolved to respond to environmental constraints. Predator–prey interactions are among environmental pressures that can lead to speciation, but it remains unclear how this pressure can be related to the material structure and performance. Recently, two land snails, Karaftohelix editha and Karaftohelix gainesi , were found to exhibit divergent phenotypes and responses to predation despite sharing the same habitat and most of their genome. Indeed, under attack from a beetle, K. editha snails retract into their shell whereas K. gainesi snails swing their shell. In this paper, we looked at the microstructure, composition, morphology and mechanics of the shells of those two species and discuss potential relationships between material structure and the snail defence behaviour. The results of this study provide additional arguments for the role of predator–prey interactions on speciation, as well as an unusual approach for the design of biomimetic structures adapted to a particular function.

scholarly journals Cryptic habitat use of white sharks in kelp forest revealed by animal-borne video

2019 ◽  
Vol 15 (4) ◽  
pp. 20190085 ◽  
Author(s):  
Oliver J. D. Jewell ◽  
Adrian C. Gleiss ◽  
Salvador J. Jorgensen ◽  
Samantha Andrzejaczek ◽  
Jerry H. Moxley ◽  
...  
Keyword(s):  
Kelp Forest ◽  
Video Data ◽  
Kelp Forests ◽  
Motion Sensing ◽  
Predator Prey ◽  
Habitat Features ◽  
Fur Seals ◽  
Cryptic Habitat ◽  
Large Predators ◽  
Marine Wildlife

Traditional forms of marine wildlife research are often restricted to coarse telemetry or surface-based observations, limiting information on fine-scale behaviours such as predator–prey events and interactions with habitat features. We use contemporary animal-attached cameras with motion sensing dataloggers, to reveal novel behaviours by white sharks, Carcharodon carcharias , within areas of kelp forest in South Africa. All white sharks tagged in this study spent time adjacent to kelp forests, with several moving throughout densely kelp-covered areas, navigating through channels and pushing directly through stipes and fronds. We found that activity and turning rates significantly increased within kelp forest. Over 28 h of video data revealed that white shark encounters with Cape fur seals, Arctocephalus pusillus pusillus , occurred exclusively within kelp forests, with seals displaying predator evasion behaviour during those encounters. Uniquely, we reveal the use of kelp forest habitat by white sharks, previously assumed inaccessible to these large predators.

scholarly journals Silviculture approaches to restoring a predator-prey system: examples from the LiDea project in Boreal Alberta

2016 ◽  
Author(s):  
Michael Cody ◽  
Scott McNay ◽  
Glenn D. Sutherland ◽  
Geoff Sherman
Keyword(s):  
Habitat Restoration ◽  
Landscape Scale ◽  
Forest Site ◽  
Environmental Strategy ◽  
Linear Features ◽  
Predator Prey ◽  
Prey System ◽  
And Performance ◽  
Cold Lake ◽  
Site Types

The issue of Woodland caribou decline has been identified corporately as a top environmental priority for Cenovus energy Inc. Pursuant to this priority, a habitat centric environmental strategy and performance commitments have been developed. Beginning in 2008, Cenovus began applied investigation into the use of silviculture techniques for accelerated restoration, emphasizing the bog and fen forest site types that are characteristic of Boreal caribou habitat. In a larger scale project called LiDea, restoration treatments were ultimately applied to linear features throughout an area of 370 km 2 within the Cold Lake herd range. As indicated by metrics at the site level, as well as GPS collar re-locations, plant and animal response to restoration treatment are positive from a caribou perspective. Results from the LiDea series of projects have been strong enough to warrant the extension of these forest habitat restoration methods to the landscape scale.

Transmission Scanning Electron Microscopy and Energy Analysis with the Siemens ELMISKOP 101

1972 ◽  
Vol 30 ◽  
pp. 450-451
Author(s):  
H. M. Thieringer
Keyword(s):  
Objective Lens ◽  
Transmission Microscopy ◽  
Image Recording ◽  
Mode Of Operation ◽  
Scanning Transmission ◽  
Electron Microscopes ◽  
And Performance ◽  
Convergent Beam ◽  
Ray Path ◽  
Beam Diffraction

It has repeatedly been show that with conventional electron microscopes very fine electron probes can be produced, therefore allowing various micro-techniques such as micro recording, X-ray microanalysis and convergent beam diffraction. In this paper the function and performance of an SIEMENS ELMISKOP 101 used as a scanning transmission microscope (STEM) is described. This mode of operation has some advantages over the conventional transmission microscopy (CTEM) especially for the observation of thick specimen, in spite of somewhat longer image recording times.Fig.1 shows schematically the ray path and the additional electronics of an ELMISKOP 101 working as a STEM. With a point-cathode, and using condensor I and the objective lens as a demagnifying system, an electron probe with a half-width ob about 25 Å and a typical current of 5.10-11 amp at 100 kV can be obtained in the back focal plane of the objective lens.

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