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Die Autoren beleuchten hochschulische Bildungsmöglichkeiten mit Massive Open Online Cours (MOOC) von der Erstellung bis zur Durchführung derartiger Kurse. Dabei scheinen die beliebige Wiederholbarkeit von Vorlesungen und die dauernde Abrufbarkeit von Lektionen wesentlich zum Erfolg des Formats beizutragen. (DIPF/Orig.)

International audience; Continuous environmental change-such as slowly rising temperatures-may create permanent maladaptation of natural populations: Even if a population adapts evolutionarily, its mean phenotype will usually lag behind the phenotype favored in the current environment, and if the resulting phenotypic lag becomes too large, the population risks extinction. We analyze this scenario using a moving-optimum model, in which one or more quantitative traits are under stabilizing selection towards an optimal value that increases at a constant rate. We have recently shown that, in the limit of infinitely small mutations and high mutation rate, the evolution of the phenotypic lag converges to an Ornstein-Uhlenbeck process around a long-term equilibrium value. Both the mean and the variance of this equilibrium lag have simple analytical formulas. Here, we study the properties of this limit and compare it to simulations of an evolving population with finite mutational effects. We find that the small-jumps limit provides a reasonable approximation, provided the mean lag is so large that the optimum cannot be reached by a single mutation. This is the case for fast environmental change and/or weak selection. Our analysis also provides insights into population extinction: Even if the mean lag is small enough to allow a positive growth rate, stochastic fluctuations of the lag will eventually cause extinction. We show that the time until this event follows an exponential distribution, This study benefited from a PHC Amadeus exchange grant (project number 31642SJ) to whose mean depends strongly on a composite parameter that relates the speed of environmental change to the adaptive potential of the population.

bstract: In general, participants use MOOCs for individual learning purposes by selecting certain contents of a MOOC in which they are interested. Simultaneously, MOOCs are used in the context of online-lectures offered to students who must or may enroll for a specific course to earn credits. However, many participants do not successfully complete all units of a MOOC. Therefore, completion rates —in general— are rather low. Certificates like PDF-documents or electronic badges can be an adequate stimulation to complete a course. This research raises the questions, how the certification of MOOC-participants can be managed and if certificates have an impact on completion rates. Firstly, general aspects of certification are discussed. This is followed by a practical insight into the certification practice based on experiences of the Austrian MOOC-platform iMooX operators. As a conclusion, results are summarized and related challenges and further research questions are addressed. De forma general, los participantes de los cursos MOOC acuden a ellos por deseos personales de aprender, por lo que seleccionan ciertos contenidos del MOOC en el que están interesados. A su vez, los MOOC también se emplean en el contexto de clases en línea que se ofrecen al alumnado que necesita alcanzar créditos académicos en su formación. Sin embargo, muchos participantes no finalizan todo el curso MOOC y las tasas de éxito son, en general, relativamente bajas. Los certificados en forma de documentos PDF, o distintivos en forma de credencial (badges), pueden resultar de estímulo para finalizar estos cursos. Esta investigación analiza cómo se puede afrontar la certificación de los participantes en un curso MOOC y si la certificación tiene, de alguna manera, incidencia en las tasas de éxito. En primer lugar, se discuten aspectos generales de la certificación y, a continuación, se realiza un análisis práctico con base en la plataforma MOOC austriaca iMooX. Las conclusiones muestran los principales retos e investigaciones derivadas del estudio y su desarrollo futuro.

Adaptation lies at the heart of Darwinian evolution. Accordingly, numerous studies have tried to provide a formal framework for the description of the adaptive process. Of these, two complementary modeling approaches have emerged: While so-called adaptive-walk models consider adaptation from the successive fixation of de novo mutations only, quantitative genetic models assume that adaptation proceeds exclusively from preexisting standing genetic variation. The latter approach, however, has focused on short-term evolution of population means and variances rather than on the statistical properties of adaptive substitutions. Our aim is to combine these two approaches by describing the ecological and genetic factors that determine the genetic basis of adaptation from standing genetic variation in terms of the effect-size distribution of individual alleles. Specifically, we consider the evolution of a quantitative trait to a gradually changing environment. By means of analytical approximations, we derive the distribution of adaptive substitutions from standing genetic variation, that is, the distribution of the phenotypic effects of those alleles from the standing variation that become fixed during adaptation. Our results are checked against individual-based simulations. We find that, compared to adaptation from de novo mutations, (i) adaptation from standing variation proceeds by the fixation of more alleles of small effect and (ii) populations that adapt from standing genetic variation can traverse larger distances in phenotype space and, thus, have a higher potential for adaptation if the rate of environmental change is fast rather than slow.

Blended learning became the most popular educational model that universities apply for teaching and learning. This model combines online and face-to-face learning environments, in order to enhance learning with implementation of new web technologies and tools in learning process. In this paper principles of DeLone and Mclean success model for information system are applied to Kano two-dimensional model, for categorizing quality attributes related to satisfaction of students with web based learning system used in blended learning model. Survey results are obtained among the students at “Mediterranean” University in Montenegro. The (dys)functional dimensions of Kano model, including Kano basic matrix for assessment of the degree of students’ satisfaction level, have been considered in some more detail through corresponding numerical, graphical, and statistical analysis.

International audience; An increasing number of studies demonstrate phenotypic and genetic changes in natural populations that are subject to climate change, and there is hope that some of these changes will contribute to avoiding species extinctions ('evolutionary rescue'). Here, we review theoretical models of rapid evolution in quantitative traits that can shed light on the potential for adaptation to a changing climate. Our focus is on quantitative-genetic models with selection for a moving phenotypic optimum. We point out that there is no one-to-one relationship between the rate of adaptation and population survival, because the former depends on relative fitness and the latter on absolute fitness. Nevertheless, previous estimates that sustainable rates of genetically based change usually do not exceed 0.1 haldanes (i.e., phenotypic standard deviations per generation) are probably correct. Survival can be greatly facilitated by phenotypic plasticity, and heritable variation in plasticity can further speed up genetic evolution. Multivariate selection and genetic correlations are frequently assumed to constrain adaptation, but this is not necessarily the case and depends on the geometric relationship between the fitness landscape and the structure of genetic variation. Similar conclusions hold for adaptation to shifting spatial gradients. Recent models of adaptation in multispecies communities indicate that the potential for rapid evolution is strongly influenced by interspecific competition.

Ebner, Martin [Hrsg.]; Schön, Sandra [Hrsg.]: L3T. Lehrbuch für Lernen und Lehren mit Technologien. 2. Auflage. 2013, [8] S., Das Lehren und Lernen mit Technologien bedarf einiger zentraler Grundvoraussetzungen, um sich an den Hochschulen möglichst effizient und nachhaltig etablieren zu können. Der Beitrag fokussiert daher zunächst die bestehenden und zu schaffenden Rahmenbedingungen, wobei der Schwerpunkt auf rechtlichen und organisationalen Fragestellungen liegt. Ausgehend von der ebenfalls notwendigen technischen Infrastruktur werden die besonderen Herausforderungen im Bereich der Präsenz-Massenlehrveranstaltungen analysiert. Konkrete Beispiele vermitteln, wie Technologien hier in Hinblick auf Interaktion, Aufzeichnung und Übertragung sowie bei Prüfungsdurchführungen unterstützen können. Abschließend erfolgt ein Überblick über die sich an den Lehrveranstaltungstypen orientierenden didaktischen Modelle. Beispiele aus der Praxis ergänzen das Kapitel. (DIPF/Orig.)

We consider a model of sympatric speciation due to frequency-dependent competition, in which it was previously assumed that the evolving traits have a very simple genetic architecture. In the present study, we use numerical simulations to test the consequences of relaxing this assumption. First, previous models assumed that assortative mating evolves in infinitesimal steps. Here, we show that the range of parameters for which speciation is possible increases when mutational steps are large. Second, it was assumed that the trait under frequency-dependent selection is determined by a single locus with to alleles and additive effects. As a consequence, the resultant intermediate phenotype is always heterozygous and can never breed true. To relax this assumption, we now add a second locus influencing the trait. We find three new possible evolutionary outcomes: evolution of three reproductive isolated species, a monomorphic equilibrium with only the intermediate phenotype, and a randomly mating population with a steep unimodal distribution of phenotypes. Both extensions of the original model thus increase the likelihood of competitive speciation.

We consider a population that adapts to a gradually changing environment. Our aim is to describe how ecological and genetic factors combine to determine the genetic basis of adaptation. Specifically, we consider the evolution of a polygenic trait that is under stabilizing selection with a moving optimum. The ecological dynamics are defined by the strength of selection, \documentclass[10pt]{article} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{pmc} \usepackage[Euler]{upgreek} \pagestyle{empty} \oddsidemargin -1.0in \begin{document} \begin{equation*}{\mathrm{\tilde {{\sigma}}}}\end{equation*}\end{document}, and the speed of the optimum, \documentclass[10pt]{article} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{pmc} \usepackage[Euler]{upgreek} \pagestyle{empty} \oddsidemargin -1.0in \begin{document} \begin{equation*}\tilde {{\upsilon}}\end{equation*}\end{document}; the key genetic parameters are the mutation rate Θ and the variance of the effects of new mutations, ω. We develop analytical approximations within an “adaptive-walk” framework and describe how selection acts as a sieve that transforms a given distribution of new mutations into the distribution of adaptive substitutions. Our analytical results are complemented by individual-based simulations. We find that (i) the ecological dynamics have a strong effect on the distribution of adaptive substitutions and their impact depends largely on a single composite measure \documentclass[10pt]{article} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{pmc} \usepackage[Euler]{upgreek} \pagestyle{empty} \oddsidemargin -1.0in \begin{document} \begin{equation*}{\mathrm{{\gamma}}}=\tilde {{\upsilon}}/({\mathrm{\tilde {{\sigma}}}}{\Theta}{\mathrm{{\omega}}}^{3})\end{equation*}\end{document}, which combines the ecological and genetic parameters; (ii) depending on γ, we can distinguish two distinct adaptive regimes: for large γ the adaptive process is mutation limited and dominated by genetic constraints, whereas for small γ it is environmentally limited and dominated by the external ecological dynamics; (iii) deviations from the adaptive-walk approximation occur for large mutation rates, when different mutant alleles interact via linkage or epistasis; and (iv) in contrast to predictions from previous models assuming constant selection, the distribution of adaptive substitutions is generally not exponential.

We propose a model to analyze a quantitative trait under frequency-dependent disruptive selection. Selection on the trait is a combination of stabilizing selection and intraspecific competition, where competition is maximal between individuals with equal phenotypes. In addition, there is a density-dependent component induced by population regulation. The trait is determined additively by a number of biallelic loci, which can have different effects on the trait value. In contrast to most previous models, we assume that the allelic effects at the loci can evolve due to epistatic interactions with the genetic background. Using a modifier approach, we derive analytical results under the assumption of weak selection and constant population size, and we investigate the full model by numerical simulations. We find that frequency-dependent disruptive selection favors the evolution of a highly asymmetric genetic architecture, where most of the genetic variation is concentrated on a small number of loci. We show that the evolution of genetic architecture can be understood in terms of the ecological niches created by competition. The phenotypic distribution of a population with an adapted genetic architecture closely matches this niche structure. Thus, evolution of the genetic architecture seems to be a plausible way for populations to adapt to regimes of frequency-dependent disruptive selection. As such, it should be seen as a potential evolutionary pathway to discrete polymorphisms and as a potential alternative to other evolutionary responses, such as the evolution of sexual dimorphism or assortative mating.

§ Equal contribution. Abstract Whereas a rich literature exists for estimating population genetic divergence, metrics of phenotypic trait divergence are lacking, particularly for comparing multiple traits among three or more populations. Here, we review and analyze via simula- tion Hedges' g, a widely used parametric estimate of effect size. Our analyses indicate that g is sensitive to a combination of un- equal trait variances and unequal sample sizes among populations and to changes in the scale of measurement. We then go on to derive and explain a new, non-parametric distance measure, "Δp", which is calculated based upon a joint cumulative distribution function (CDF) from all populations under study. More precisely, distances are measured in terms of the percentiles in this CDF at which each population's median lies. Δp combines many desirable features of other distance metrics into a single metric; namely, compared to other metrics, p is relatively insensitive to unequal variances and sample sizes among the populations sam- pled. Furthermore, a key feature of Δp—and our main motivation for developing it—is that it easily accommodates simultaneous comparisons of any number of traits across any number of populations. To exemplify its utility, we employ Δp to address a ques- tion related to the role of sexual selection in speciation: are sexual signals more divergent than ecological traits in closely related taxa? Using traits of known function in closely related populations, we show that traits predictive of reproductive performance are, indeed, more divergent and more sexually dimorphic than traits related to ecological adaptation (Current Zoology 58 (3): 426439, 2012).