Search results for "Divergence"
showing 10 items of 257 documents
Context dependent variation in corticosterone and phenotypic divergence of Rana arvalis populations along an acidification gradient
2022
Background Physiological processes, as immediate responses to the environment, are important mechanisms of phenotypic plasticity and can influence evolution at ecological time scales. In stressful environments, physiological stress responses of individuals are initiated and integrated via the release of hormones, such as corticosterone (CORT). In vertebrates, CORT influences energy metabolism and resource allocation to multiple fitness traits (e.g. growth and morphology) and can be an important mediator of rapid adaptation to environmental stress, such as acidification. The moor frog, Rana arvalis, shows adaptive divergence in larval life-histories and predator defense traits along an acidi…
Asymptotic Hölder regularity for the ellipsoid process
2020
We obtain an asymptotic Hölder estimate for functions satisfying a dynamic programming principle arising from a so-called ellipsoid process. By the ellipsoid process we mean a generalization of the random walk where the next step in the process is taken inside a given space dependent ellipsoid. This stochastic process is related to elliptic equations in non-divergence form with bounded and measurable coefficients, and the regularity estimate is stable as the step size of the process converges to zero. The proof, which requires certain control on the distortion and the measure of the ellipsoids but not continuity assumption, is based on the coupling method.
Transcriptional Rewiring, Adaptation, and the Role of Gene Duplication in the Metabolism of Ethanol of Saccharomyces cerevisiae
2020
Ethanol is the main by-product of yeast sugar fermentation that affects microbial growth parameters, being considered a dual molecule, a nutrient and a stressor. Previous works demonstrated that the budding yeast arose after an ancient hybridization process resulted in a tier of duplicated genes within its genome, many of them with implications in this ethanol “produce-accumulate-consume” strategy. The evolutionary link between ethanol production, consumption, and tolerance versus ploidy and stability of the hybrids is an ongoing debatable issue. The implication of ancestral duplicates in this metabolic rewiring, and how these duplicates differ transcriptionally, remains unsolved. Here, we …
An efficient grid-based RF fingerprint positioning algorithm for user location estimation in heterogeneous small cell networks
2014
This paper proposes a novel technique to enhance the performance of grid-based Radio Frequency (RF) fingerprint position estimation framework. First enhancement is an introduction of two overlapping grids of training signatures. As the second enhancement, the location of the testing signature is estimated to be a weighted geometric center of a set of nearest grid units whereas in a traditional grid-based RF fingerprinting only the center point of the nearest grid unit is used for determining the user location. By using the weighting-based location estimation, the accuracy of the location estimation can be improved. The performance evaluation of the enhanced RF fingerprinting algorithm was c…
Genomic divergence landscape in recurrently hybridizing Chironomus sister taxa suggests stable steady state between mutual gene flow and isolation
2021
Abstract Divergence is mostly viewed as a progressive process often initiated by selection targeting individual loci, ultimately resulting in ever increasing genomic isolation due to linkage. However, recent studies show that this process may stall at intermediate stable equilibrium states without achieving complete genomic isolation. We tested the extent of genomic isolation between two recurrently hybridizing nonbiting midge sister taxa, Chironomus riparius and Chironomus piger, by analyzing the divergence landscape. Using a principal component‐based method, we estimated that only about 28.44% of the genomes were mutually isolated, whereas the rest was still exchanged. The divergence land…
Competing Against Simulated Equilibrium Price Dispersions: An Experiment on Internet-Assisted Search Markets
2005
In a four-treatment experiment, we test some of the hypotheses in García-Gallego et al. (2004) concerning competition among a number of firms of which some (or all) are indexed by a price-comparison engine facilitating buyers’ search process. In this paper, we isolate individual behavior from noise due to other players’ actions and learning, facing each subject with simulated rivals whose prices are extracted from mixed strategy equilibrium distributions. We find systematic deviations from both theoretical distributions and previous data obtained in sessions where all players were human. Specifically, departures of experimental data from the corresponding theoretical predictions are enhance…
Global Divergence in Growth Regressions
2013
This paper extends the standard growth regression model by adding an assumption that a country follows the global technology frontier either fully or partially. This additional assumption changes significantly the growth regression model and its results in three main ways. First, it shows that although a country converges to its long-run growth path, this path can diverge from the countries at the global frontier. We measure the degree of divergence for each country and find that most indeed diverge from the frontier. Second, we estimate growth dynamics without controlling for additional variables. Third, our new method enables us to disentangle the effects of the explanatory variables on t…
Radio frequency fingerprinting for outdoor user equipment localization
2017
The recent advancements in cellular mobile technology and smart phone usage have opened opportunities for researchers and commercial companies to develop ubiquitous low cost localization systems. Radio frequency (RF) fingerprinting is a popular positioning technique which uses radio signal strength (RSS) values from already existing infrastructures to provide satisfactory user positioning accuracy in indoor and densely built outdoor urban areas where Global Navigation Satellite System (GNSS) signal is poor and hard to reach. However a major requirement for the RF fingerprinting to maintain good localization accuracy is the collection and updating of large training database. The Minimization…
Yoga en España. Proceso de regulación profesional
2015
New approaches to spirituality go hand in hand with emerging physical, psychological and spiritual movements that have had a clear impact on many areas, and in particular on health and well-being. It is increasingly common to find nurses teaching yoga or doctors prescribing mindfulness. Use of socalled Complementary and Alternative Medicine (CAM) is becoming mainstream. Health centres, medical practices and even schools are offering a growing number of alternative therapies, resulting in the need for effective legal regulation of these activities, both in terms of professional recognition and training. In Spain, recent legislation represents a significant breakthrough in the regulation of y…
Power holders: one versus many. Leadership and elite theories
2016
‘Leadership’ and ‘elites’ are two crucial concepts that refer to individuals who hold power within a community. The aim of the article was to demonstrate to what extent the two concepts and theories are linked with each other in the literature. A quantitative and qualitative content analysis of the encyclopedic and dictionary entries demonstrates a divergence of approaches: on the one hand, a fundamental separation between the two theories, while on the other hand, a tendency to identify the one with the other. This shows the need for much more dialog between the frameworks of these two closely related phenomena.