Search results for "ABILITY"
showing 10 items of 18559 documents
Variational principle and bifurcations in stability analysis of panels
2014
In this paper, the stability of a simply supported axially moving elastic panel is considered. A complex variable technique and bifurcation theory are applied. As a result, variational equations and a variational principle are derived. Anal- ysis of the variational principle allows the study of qualitative properties of the bifurcation points. Asymptotic behaviour in a small neighbourhood around an arbitrary bifurcation point is analyzed and presented. It is shown analytically that the eigenvalue curves in the (ω, V0) plane cross both the ω and V0 axes perpendicularly. It is also shown that near each bifur- cation point, the dependence ω(V0) for each mode approximately follows the shape of …
Transparency reduces predator detection in mimetic clearwing butterflies
2019
International audience; Predation is an important selective pressure and some prey have evolved conspicuous warning signals that advertise unpalatability (i.e. aposematism) as an antipredator defence. Conspicuous colour patterns have been shown effective as warning signals, by promoting predator learning and memory. Unexpectedly, some butterfly species from the unpalatable tribe Ithomiini possess transparent wings, a feature rare on land but common in water, known to reduce predator detection.We tested if transparency of butterfly wings was associated with decreased detectability by predators, by comparing four butterfly species exhibiting different degrees of transparency, ranging from ful…
Weak warning signals can persist in the absence of gene flow
2019
Aposematic organisms couple conspicuous warning signals with a secondary defense to deter predators from attacking. Novel signals of aposematic prey are expected to be selected against due to positive frequency-dependent selection. How, then, can novel phenotypes persist after they arise, and why do so many aposematic species exhibit intrapopulation signal variability? Using a polytypic poison frog (Dendrobates tinctorius), we explored the forces of selection on variable aposematic signals using 2 phenotypically distinct (white, yellow) populations. Contrary to expectations, local phenotype was not always better protected compared to novel phenotypes in either population; in the white popul…
Defense against predators incurs high reproductive costs for the aposematic moth Arctia plantaginis
2020
Abstract To understand how variation in warning displays evolves and is maintained, we need to understand not only how perceivers of these traits select color and toxicity but also the sources of the genetic and phenotypic variation exposed to selection by them. We studied these aspects in the wood tiger moth Arctia plantaginis, which has two locally co-occurring male color morphs in Europe: yellow and white. When threatened, both morphs produce defensive secretions from their abdomen and from thoracic glands. Abdominal fluid has shown to be more important against invertebrate predators than avian predators, and the defensive secretion of the yellow morph is more effective against ants. Her…
Critical forms in Sicilian populations of annual Lysimachia L. (Primulaceae)
2018
Based on recent literature, in the Primrose family the genus Lysimachia L. absorbed Anagallis L. (1). As a result, new name combinations have been introduced for this genus, thus involving the increase of specific and intraspecific taxa (for Italian flora see 2 and 3). A further consequence, focused in this contribution, concerns the binomial combination Lysimachia arvensis (L.) U.Manns & Anderb., which has different synonyms and includes several specific and intraspecific taxa. As far as the taxonomic history of the annual taxa of Anagallis is concerned, different authors preferred to include some of them in A. arvensis and in A. foemina at the level of variety (4) or subspecies (2), w…
Assessing Transfer Entropy in cardiovascular and respiratory time series: A VARFI approach
2021
In the study of complex biomedical systems represented by multivariate stochastic processes, such as the cardiovascular and respiratory systems, an issue of great relevance is the description of the system dynamics spanning multiple temporal scales. Recently, the quantification of multiscale complexity based on linear parametric models, incorporating autoregressive coefficients and fractional integration, encompassing short term dynamics and long-range correlations, was extended to multivariate time series. Within this Vector AutoRegressive Fractionally Integrated (VARFI) framework formalized for Gaussian processes, in this work we propose to estimate the Transfer Entropy, or equivalently G…
Drying process strongly affects probiotics viability and functionalities
2015
International audience; Probiotic formulations are widely used and are proposed to have a variety of beneficial effects, depending on the probiotic strains present in the product. The impact of drying processes on the viability of probiotics is well documented. However, the impact of these processes on probiotics functionality remains unclear. In this work, we investigated variations in seven different bacterial markers after various desiccation processes. Markers were composed of four different viability evaluation (combining two growth abilities and two cytometric measurements) and in three in vitro functionalities: stimulation of IL-10 and IL-12 production by PBMCs (immunomodulation) and…
Distance Learning with Hands-on Exercises : Physical Device vs. Simulator
2022
This Research to Practice Full Paper presents a comparison between a physical device and a simulator in a distance learning context. Programming embedded devices is very commonly taught using embedded hardware. One of the most used solutions is the Arduino microcontroller platform, which allows small embedded applications to be built and commanded in a programming language. However, there are some challenges in using physical devices for educational purposes. These challenges are particularly acute in distance learning or when the course needs to be scalable to a varying number of students. To address these challenges, we explored the potential of a simulator as a replacement for a physical…
An intergenerational competency framework : Competencies for knowledge sustainability and start‐up development in the digital age
2022
In this study, we looked at the competencies and changes in the competency spectrum required for global start-ups in the digital age. Specifically, we explored intergenerational collaboration as an intervention in which experienced business-people from senior adult groups support young entrepreneurs. We conducted a Delphi study with 20 experts from different disciplines, considering the study context. The results of this study shed light on understanding the necessary competencies of entrepreneurs for intergenerationally supported start-up innovation by providing 27 competencies categorized as follows: intergenerational safety facilitation, cultural awareness, virtues for growth, effectual …
Opciones alternativas para prescribir actividad física entre niños y adolescentes obesos: marcha rápida con el apoyo de videojuegos activos
2015
Background: Physical inactivity has been identified as an important public health concern for children. An increasing sedentary way of life is directly related to obesity; hence, prevention and management of childhood obesity are commonly based on lifestyle interventions wherein increasing physical activity is one of the main targets. The use of exergames can be useful in promoting physical activity, but it is necessary more research. This study analyzes the effects of an exergaming platform that involves brisk walking, on perceived exertion, self-efficacy, positive expectations and satisfaction in a sample of clinically obese children, as compared with normal weight children. Physiological…