Search results for " connectivity"
showing 10 items of 167 documents
Expanding genetic graphs' potential to analyse ecological connectivity: assessment of graphs construction methods
2019
International audience; Dispersal movements are often constrained in human-shaped landscapes, thereby threatening species survival. Landscape genetics approaches are commonly used to analyse ecological connectivity because genetic data well reflect dispersal capacities. When species occupy discrete habitat patches, graph-theoretic methods are a particularly relevant approach to study dispersal-driven gene flow. The links of a genetic graph can be weighted using different genetic distances between populations (nodes). Similarly, graph pruning (link set selection) can rely on different criteria. However, despite growing interest in genetic graphs, the influence of these parameters remains mos…
Graphab: A software dedicated to the modelling of landscape networks
2016
International audience; Land cover changes resulting from urban sprawl, transport network intensification and agricultural changes contribute to fragment wildlife habitats and may lead to question viability of animal and plant populations. Landscape ecologists have shown that populations living in fragmented habitats are forced to adopt specific dynamics (patchy populations or metapopulations) making them highly dependent on fluxes between their habitat patches. Landscape connectivity may be defined as the functional response of a given species in terms of movement and individual fluxes to the potential links between habitat patches provided by the landscape structure.Many methods are used …
Influence of the regional landscape connectivity on the location of roe deer roadkill hotspots
2016
International audience; Linear infrastructures threaten ecosystems and have both direct and indirect effects on ecological habitats and individuals. The fragmentation effect (i.e. splitting or loss of habitat patches) and the barrier effect (i.e. fences, traffic noise avoidance, and roadkill) are widely reported. Wildlife-vehicle collisions are the most visible direct effect and can result in severe human injuries. In Europe, the roe deer population is growing and roe deer roadkills are becoming more common. Roe deer movements depend on landscape features and regional-scale connectivity. Here, we investigate the influence of the landscape network on the location of roe deer roadkill hotspot…
Increased Gamma Connectivity in the Human Prefrontal Cortex during theBereitschaftspotential
2017
The Bereitschaftspotential (BP) is a slow negative cortical potential preceding voluntary movement. Since movement preparation is dependent upon the synchronous activity of a variety of neurons, BP may develop through the exchange of information among motor-related neurons. However, the relationship between BP and information flow is not yet well-known. In the present study, we aimed to investigate how the connectivity in the prefrontal cortex (PFC) changes during the occurrence of BP. Electrocorticography (ECoG) was recorded in five patients with epilepsy. The subjects performed self-paced hand grasping. We compared the intraregional connectivity between PFC and non-PFC regions using parti…
The ends of manifolds with bounded geometry and linear growth
2004
We prove that simply connected open manifolds of bounded geometry, linear growth and sublinear filling growth (e.g. finite filling area) are simply connected at infinity.
An Introduction to Ontology Based Structured Knowledge Base System: Knowledge Acquisition Module
2013
The following text presents the method of supplementing and verifying information stored in a framework system of the semantic knowledge base. The indicated method refers to the knowledge of ontological character, in other words to information about definitions of concepts and relationships among them. The aim of the method is the constant supplementing and verifying of the knowledge, and making more precise and detailed information about existing connections between concepts. The key aspect of the method is questions generating strictly dependent on the preconceived structure of stored knowledge.
Conceptual Ontological Object Knowledge Base and Language
2008
This paper deals with AI in aspect of knowledge acquisition and ontology base structure. The core of the system was designed in an object model to optimize it for further processing. Direct concept linking was used to assure fast semantic network processing. Predefined attributes used in the core minimize the number of basic connections within the ontology and help in inference. The system is assumed to generate questions and to specify the knowledge. The AI system defined in this way opens a possibility for better understanding of such basic human mind mechanisms as learning or analyzing.
Connectedness and connectivity of the Natura 2000 network of protected areas across country borders in the European Union
2012
Abstract We studied the spatial connectedness of Natura 2000 site boundaries and the functional connectivity of the Natura 2000 network across the 34 terrestrial borders of the European Union. Connectivity was measured by the dispersal success of 192 reptile, amphibian, invertebrate and plant species from Annex II of the European Union Habitats Directive, based on the presence of same species on both sides of the borders. Connectedness and connectivity varied greatly between state borders, with good and bad examples found in all parts of the European Union. Connectedness and connectivity were positively correlated. However, a few outlying examples showed that good connectedness is not neces…
Neuronal Growth and Behavioral Alterations in Mice Deficient for the Psychiatric Disease-Associated Negr1 Gene
2018
Neuronal growth regulator 1 (NEGR1), a member of the immunoglobulin superfamily cell adhesion molecule subgroup IgLON, has been implicated in neuronal growth and connectivity. In addition, genetic variants in or near the NEGR1 locus have been associated with obesity and more recently with learning difficulties, intellectual disability and psychiatric disorders. However, experimental evidence is lacking to support a possible link between NEGR1, neuronal growth and behavioral abnormalities. Initial expression analysis of NEGR1 mRNA in C57Bl/6 wildtype (WT) mice by in situ hybridization demonstrated marked expression in the entorhinal cortex (EC) and dentate granule cells. In co-cultures of co…
Neuronal Growth and Behavioral Alterations in Mice Deficient for the Psychiatric Disease-Associated
2017
Neuronal growth regulator 1 (NEGR1), a member of the immunoglobulin superfamily cell adhesion molecule subgroup IgLON, has been implicated in neuronal growth and connectivity. In addition, genetic variants in or near the NEGR1 locus have been associated with obesity and more recently with learning difficulties, intellectual disability and psychiatric disorders. However, experimental evidence is lacking to support a possible link between NEGR1, neuronal growth and behavioral abnormalities. Initial expression analysis of NEGR1 mRNA in C57Bl/6 wildtype (WT) mice by in situ hybridization demonstrated marked expression in the entorhinal cortex (EC) and dentate granule cells. In co-cultures of co…