Search results for "metric"

Synchronicity in population systems: cause and consequence mixed

1999

Effects of predation pressure and resource use on morphological divergence in omnivorous prey fish

2013

Background. Body shape is one of the most variable traits of organisms and responds to a broad array of local selective forces. In freshwater fish, divergent body shapes within single species have been repeatedly observed along the littoral-pelagic axes of lakes, where the structural complexity of near shore habitats provides a more diverse set of resources compared to the open-water zones. It remains poorly understood whether similar resource-driven polymorphism occurs among lakes that vary in structural complexity and predation pressure, and whether this variation is heritable. Here, we analyzed body shape in four populations of omnivorous roach (Rutilus rutilus) inhabiting shallow lakes.…

Différenciation morphologique et génétique des populations de douroucoulis (Aotus infulatus, Primates, Platyrhiniens, Cebidae) provenant des rives dr…

2007

11 pages; La morphologie crânienne de 28 spécimens de douroucoulis (genre Aotus), provenant du Bassin amazonien, a été étudiée à l'aide de méthodes de morphométrie géométrique en trois dimensions. De nouveaux résultats concernant la distinction morphologique de populations de l'espèce Aotus infulatus, réparties de part et d'autre du rio Tocantins, sont proposés. Ces résultats morphologiques concordent avec la distinction génétique de ces populations publiée par Schneider – et Sampaio –, et indiquent probablement de récents et rapides changements évolutifs au sein de cette espèce. Les résultats de cette étude ont une application taxinomique, mais pourraient également ouvrir de nouvelles pers…

Worldwide Scientific Research on Nanotechnology: A Bibliometric Analysis of Tendencies, Funding, and Challenges

2020

[EN] The main objective of this investigation was to analyze the scientific production in global research on nanotechnology, integrating scientific production, funding of studies, collaborations between countries, and the most cited publications. The source for obtaining the research papers for our analysis was the Science Citation Index Expanded from the Web of Science. A total of 3546 documents were extracted during the period of 1997-2018. Food science & technology, chemistry (applied and analytical), spectroscopy, and agriculture appeared as the main areas where the articles were published. Most prolific and cited journals were Analytical Methods, Journal of Agricultural and Food Chemis…

Forest Fragmentation and Selective Logging Have Inconsistent Effects on Multiple Animal-Mediated Ecosystem Processes in a Tropical Forest

2011

Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six animal-mediated ecosystem processes and recorded species richness and community composition of all animal taxa involved in these processes. We used linear models and a formal meta-analysis to test whether forest fragmentation and selective logging affected ecosystem processes and biodiversity and used structural equation models to disentangle di…

Biometric Fish Classification of Temperate Species Using Convolutional Neural Network with Squeeze-and-Excitation

2019

Our understanding and ability to effectively monitor and manage coastal ecosystems are severely limited by observation methods. Automatic recognition of species in natural environment is a promising tool which would revolutionize video and image analysis for a wide range of applications in marine ecology. However, classifying fish from images captured by underwater cameras is in general very challenging due to noise and illumination variations in water. Previous classification methods in the literature relies on filtering the images to separate the fish from the background or sharpening the images by removing background noise. This pre-filtering process may negatively impact the classificat…

Degradation in landscape matrix has diverse impacts on diversity in protected areas.

2017

Introduction: A main goal of protected areas is to maintain species diversity and the integrity of biological assemblages. Intensifying land use in the matrix surrounding protected areas creates a challenge for biodiversity conservation. Earlier studies have mainly focused on taxonomic diversity within protected areas. However, functional and especially phylogenetic diversities are less studied phenomena, especially with respect to the impacts of the matrix that surrounds protected areas. Phylogenetic diversity refers to the range of evolutionary lineages, the maintenance of which ensures that future evolutionary potential is safeguarded. Functional diversity refers to the range of ecologic…

Cross inhibition improves activity selection when switching incurs time costs

2015

Abstract We consider a behavioural model of an animal choosing between two activities, based on positive feedback, and examine the effect of introducing cross inhibition between the motivations for the two activities. While cross-inhibition has previously been included in models of decision making, the question of what benefit it may provide to an animal’s activity selection behaviour has not previously been studied. In neuroscience and in collective behaviour cross-inhibition, and other equivalent means of coupling evidence-accumulating pathways, have been shown to approximate statistically-optimal decision-making and to adaptively break deadlock, thereby improving decision performance. Sw…

The cost of open access publication of papers by spanish authors in five areas of the social sciences

2021

[ES] La publicación en abierto de los artículos conlleva unos gastos conocidos como cargos por procesamiento de artículos (APC, en sus siglas en inglés). El objetivo de este trabajo es determinar el coste de los artículos publicados en abierto mediante APC de autoría española en cinco categorías temáticas de las ciencias sociales: Humanities (Multidisciplinary), Sociology, Information Science & Library Science, Education & Educational Research y Communication de la Colección Principal de la Web of Science (WoS) durante el periodo 2012-2019. Se han identificado las revistas, las instituciones financiadoras y los modelos de publicación más frecuentes. El estudio indica que de las 223 revistas…

Ocean Acidification and the Loss of Phenolic Substances in Marine Plants

2012

Rising atmospheric CO(2) often triggers the production of plant phenolics, including many that serve as herbivore deterrents, digestion reducers, antimicrobials, or ultraviolet sunscreens. Such responses are predicted by popular models of plant defense, especially resource availability models which link carbon availability to phenolic biosynthesis. CO(2) availability is also increasing in the oceans, where anthropogenic emissions cause ocean acidification, decreasing seawater pH and shifting the carbonate system towards further CO(2) enrichment. Such conditions tend to increase seagrass productivity but may also increase rates of grazing on these marine plants. Here we show that high CO(2) …