scholarly journals A state-space approach to understand responses of organisms, populations and communities to multiple environmental drivers

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Luis Giménez ◽  
Adreeja Chatterjee ◽  
Gabriela Torres
Keyword(s):  
Exotic Species ◽  
Native Species ◽  
Spatial Scales ◽  
Environmental Drivers ◽  
Biological Organization ◽  
State Space Approach ◽  
Cold Adapted ◽  
Negative Effect ◽  
Space Approach

AbstractUnderstanding the response of biotic systems to multiple environmental drivers is one of the major concerns in ecology. The most common approach in multiple driver research includes the classification of interactive responses into categories (antagonistic, synergistic). However, there are situations where the use of classification schemes limits our understanding or cannot be applied. Here, we introduce and explore an approach that allows us to better appreciate variability in responses to multiple drivers. We then apply it to a case, comparing effects of heatwaves on performance of a cold-adapted species and a warm-adapted competitor. The heatwaves had a negative effect on the native (but not on the exotic) species and the approach highlighted that the exotic species was less responsive to multivariate environmental variation than the native species. Overall, we show how the proposed approach can enhance our understanding of variation in responses due to different driver intensities, species, genotypes, ontogeny, life-phases or among spatial scales at any level of biological organization.

scholarly journals Neuronal dynamics of signal selective motor plan cancellation in the macaque dorsal premotor cortex

2020 ◽  
Author(s):  
Giarrocco Franco ◽  
Bardella Giampiero ◽  
Giamundo Margherita ◽  
Fabbrini Francesco ◽  
Brunamonti Emiliano ◽  
...  
Keyword(s):  
Premotor Cortex ◽  
Movement Control ◽  
Behavioral Strategy ◽  
Behavioral Strategies ◽  
Inhibitory Process ◽  
Neuronal Dynamics ◽  
State Space Approach ◽  
Stop Task ◽  
Space Approach

Primates adopt various strategies to interact with the environment. Yet, no study has examined the effects of behavioral strategies with regard to how movement inhibition is implemented at the neuronal level. We modified a classical approach to study movement control (stop-task) by adding an extra signal – termed the Ignore signal – which influenced movement inhibition only under a specific strategy. We simultaneously recorded multisite neuronal activity from the dorsal premotor (PMd) cortex of macaque monkeys during a task and applied a state-space approach. As a result, we found that movement generation is characterized by neuronal dynamics that evolve between subspaces. When the movement is halted, this evolution is arrested and inverted. Conversely, when the Ignore signal is presented, inversion of the evolution is observed briefly and only when a specific behavioral strategy is adopted. Moreover, neuronal signatures during the inhibitory process were predictive of how PMd processes inhibitory signals, allowing the classification of the resulting behavioral strategy. Our data corroborate the PMd as a critical node in movement inhibition.

scholarly journals The Theory of Island Biogeography on the Hawaiki Archipelago

2021 ◽  
Author(s):  
◽  
Khoi Dinh
Keyword(s):  
Exotic Species ◽  
Island Biogeography ◽  
Native Species ◽  
Physical Geography ◽  
Geographical Information ◽  
Similar Species ◽  
North East ◽  
The North ◽  
Theory Of Island Biogeography ◽  
Negative Effect

<p>This thesis addresses MacArthur and Wilson‟s Theory of Island Biogeography (1967) on a set of islands around the north-east coast of the North Island of New Zealand. The flora species lists from these islands were obtained from both published and unpublished island surveys whilst Geographical Information Systems (GIS) techniques were utilised in order to calculate the physical geography of islands.  These islands were an ideal study site for such research because they display natural gradients in both physical geography as well as native and exotic species richness. The literature on the Theory of Island Biogeography has yet to comprehensively understand the differences between the patterns of exotic richness and native richness. Furthermore, the importance of studies on exotics species is increasingly relevant given the negative effect they have had on native communities worldwide.  The results of my research illustrated that there were similar species-area and species-isolation relationships between exotic and native species. These two relationships were also consistent with what is expected under classical island biogeography principles. Interestingly however, I found that distance from the mainland had a stronger negative effect on exotics species. There were a significantly lower proportion of exotics with increasing isolation.  This result has applicable outcomes for conservation management on the Hawaiki archipelago. I suggested that weeding effort focus on larger islands and in particular the islands closer to the mainland. Globally, the biogeographical patterns of exotic species are still poorly examined. With insights from this study and other similar research the Theory of Island Biogeography may be an informative approach to dealing with the ominous threat of exotic species.</p>

scholarly journals The Theory of Island Biogeography on the Hawaiki Archipelago

2021 ◽  
Author(s):  
◽  
Khoi Dinh
Keyword(s):  
Exotic Species ◽  
Island Biogeography ◽  
Native Species ◽  
Physical Geography ◽  
Geographical Information ◽  
Similar Species ◽  
North East ◽  
The North ◽  
Theory Of Island Biogeography ◽  
Negative Effect

<p>This thesis addresses MacArthur and Wilson‟s Theory of Island Biogeography (1967) on a set of islands around the north-east coast of the North Island of New Zealand. The flora species lists from these islands were obtained from both published and unpublished island surveys whilst Geographical Information Systems (GIS) techniques were utilised in order to calculate the physical geography of islands.  These islands were an ideal study site for such research because they display natural gradients in both physical geography as well as native and exotic species richness. The literature on the Theory of Island Biogeography has yet to comprehensively understand the differences between the patterns of exotic richness and native richness. Furthermore, the importance of studies on exotics species is increasingly relevant given the negative effect they have had on native communities worldwide.  The results of my research illustrated that there were similar species-area and species-isolation relationships between exotic and native species. These two relationships were also consistent with what is expected under classical island biogeography principles. Interestingly however, I found that distance from the mainland had a stronger negative effect on exotics species. There were a significantly lower proportion of exotics with increasing isolation.  This result has applicable outcomes for conservation management on the Hawaiki archipelago. I suggested that weeding effort focus on larger islands and in particular the islands closer to the mainland. Globally, the biogeographical patterns of exotic species are still poorly examined. With insights from this study and other similar research the Theory of Island Biogeography may be an informative approach to dealing with the ominous threat of exotic species.</p>

Towards a functional classification of behaviour: a taxonomy based on outcomes

2021 ◽  
pp. 105971232110405
Author(s):  
Dave EW Mallpress
Keyword(s):  
First Principles ◽  
Formal Language ◽  
State Space Approach ◽  
Future Goals ◽  
Intermediate Outcomes ◽  
Hierarchical Nature ◽  
Why Questions ◽  
Space Approach

The classification of behaviour has historically been done using one of the two approaches, either through the hypothetical causes (such as ‘instincts’, ‘drives’ and ‘needs’) or through the cataloguing of the observable form of behaviour using an ethogram. This article offers an alternative framework for classification of behaviour based upon only the behavioural outcomes. The framework is specified from first principles of a state-space approach, allowing us to discuss intermediate outcomes that may have instrumental value. This approach could provide a firmer foundation to consider the hierarchical nature of goals and allows us to address both the ‘how’ and the ‘why’ questions within a single framework. This taxonomy is designed to complement rather than replace existing attempts; the classification of behaviour by outcome is orthogonal to questions of the mechanisms of decision making or of the implementation of actions. This article specifies nine basic classes of behaviour and provides precise definitions for each of these. We then develop a formal language for the description of observed activities, the representation of behavioural hierarchies and for the analysis of possibility sets for achieving future goals. We follow up with some critique and discussion of the problems such a framework poses.

GENERALIZED THEORY OF MAGNETO-THERMO-VISCOELASTIC SPHERICAL CAVITY PROBLEM UNDER FRACTIONAL ORDER DERIVATIVE: STATE SPACE APPROACH

2020 ◽  
Vol 9 (11) ◽  
pp. 9769-9780
Author(s):  
S.G. Khavale ◽  
K.R. Gaikwad
Keyword(s):  
State Space ◽  
Fractional Order ◽  
Order Derivative ◽  
Laplace Inversion ◽  
State Space Approach ◽  
Spherical Region ◽  
Fractional Order Derivative ◽  
Numerical Laplace Inversion ◽  
Mathcad Software ◽  
Space Approach

This paper is dealing the modified Ohm's law with the temperature gradient of generalized theory of magneto-thermo-viscoelastic for a thermally, isotropic and electrically infinite material with a spherical region using fractional order derivative. The general solution obtained from Laplace transform, numerical Laplace inversion and state space approach. The temperature, displacement and stresses are obtained and represented graphically with the help of Mathcad software.

scholarly journals A Bayesian State-Space Approach to Mapping Directional Brain Networks

2020 ◽  
pp. 1-24
Author(s):  
Huazhang Li ◽  
Yaotian Wang ◽  
Guofen Yan ◽  
Yinge Sun ◽  
Seiji Tanabe ◽  
...  
Keyword(s):  
State Space ◽  
Brain Networks ◽  
State Space Approach ◽  
Space Approach
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