Search results for "SEL"
showing 10 items of 14031 documents
Resource polymorphism in European whitefish: Analysis of fatty acid profiles provides more detailed evidence than traditional methods alone
2019
Published version, licensed CC BY-NC-ND 4.0. , available at: http://dx.doi.org/10.1371/journal.pone.0221338 Resource polymorphism—whereby ancestral generalist populations give rise to several specialised morphs along a resource gradient—is common where species colonise newly formed ecosystems. This phenomenon is particularly well documented in freshwater fish populations inhabiting postglacial lakes formed at the end of the last ice age. However, knowledge on how such differential exploitation of resources across contrasting habitats might be reflected in the biochemical compositions of diverging populations is still limited, though such patterns might be expected. Here, we aimed to assess …
Resource Partitioning in Food, Space and Time between Arctic Charr (Salvelinus alpinus), Brown Trout (Salmo trutta) and European Whitefish (Coregonus…
2017
Arctic charr and European whitefish are considered to be strong competitors in lakes, with the latter usually being the superior species. However, high niche plasticity and lake morphometry may suggestively facilitate resource partitioning and coexistence between charr and whitefish. Here, we explore the trophic niche utilization (diet and habitat use) of charr and whitefish co-occurring with brown trout in the deep and oligotrophic Lake Fyresvatnet, southern Norway (59˚05’N, 8˚10’E). Using CPUE, stomach contents and stable isotope analyses, a distinct resource partitioning was revealed between brown trout and the other two species. Brown trout typically occupied the littoral zone, feeding …
Model‐based approaches to unconstrained ordination
2014
Summary Unconstrained ordination is commonly used in ecology to visualize multivariate data, in particular, to visualize the main trends between different sites in terms of their species composition or relative abundance. Methods of unconstrained ordination currently used, such as non-metric multidimensional scaling, are algorithm-based techniques developed and implemented without directly accommodating the statistical properties of the data at hand. Failure to account for these key data properties can lead to misleading results. A model-based approach to unconstrained ordination can address this issue, and in this study, two types of models for ordination are proposed based on finite mixtu…
Benchmark database for fine-grained image classification of benthic macroinvertebrates
2018
Managing the water quality of freshwaters is a crucial task worldwide. One of the most used methods to biomonitor water quality is to sample benthic macroinvertebrate communities, in particular to examine the presence and proportion of certain species. This paper presents a benchmark database for automatic visual classification methods to evaluate their ability for distinguishing visually similar categories of aquatic macroinvertebrate taxa. We make publicly available a new database, containing 64 types of freshwater macroinvertebrates, ranging in number of images per category from 7 to 577. The database is divided into three datasets, varying in number of categories (64, 29, and 9 categori…
Does recognized genetic management in supportive breeding prevent genetic changes in life-history traits?
2014
International audience; Supportive breeding is one of the last resort conservation strategies to avoid species extinction. Management of captive populations is challenging because several harmful genetic processes need to be avoided. Several recommendations have been proposed to limit these deleterious effects, but empirical assessments of these strategies remain scarce. We investigated the outcome of a genetic management in a supportive breeding for the Houbara Bustard. At the phenotypic level, we found an increase over generations in the mean values of gamete production, body mass and courtship display rate. Using an animal model, we found that phenotypic changes reflected genetic changes…
Protected areas buffer against harvest selection and rebuild phenotypic complexity
2020
14 pages, 6 figures, 4 tables.-- This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited
Leaf-Level Spectral Fluorescence Measurements : Comparing Methodologies for Broadleaves and Needles
2019
Successful measurements of chlorophyll fluorescence (ChlF) spectral properties (typically in the wavelength range of 650–850 nm) across plant species, environmental conditions, and stress levels are a first step towards establishing a quantitative link between solar-induced chlorophyll fluorescence (SIF), which can only be measured at discrete ChlF spectral bands, and photosynthetic functionality. Despite its importance and significance, the various methodologies for the estimation of leaf-level ChlF spectral properties have not yet been compared, especially when applied to leaves with complex morphology, such as needles. Here we present, to the best of our knowledge, a first comparison of …
A nondestructive intelligent approach to real‐time evaluation of chicken meat freshness based on computer vision technique
2019
In this study, the capability of a procedure based on combination of computer vision (CV) and artificial intelligence techniques examined for intelligent and nondestructive prediction of chicken meat freshness during the spoilage process at 4°C. The proposed system comprises the following stages: capture images, image preprocessing, image processing, computing channels, feature extraction, feature selection by a hybrid of genetic algorithm (GA) and artificial neuronal network (ANN), and prediction by using ANN. The number of neurons in input layer was determined 33 (selected features) and freshness used as the output. The ideal ANN model was obtained with 33‐10‐1 topology. The high performa…
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…
Ovule discounting in an outcrossing, cryptically dioecious tree.
2006
9 páginas, 1 figura, 1 tabla.