A roadmap to cope with common problems in E-learning research designs

E-learning research is plenty of difficulties, as also research in education is. Usually, the high number of features involved in e-learning processes complicates and masks the identification and isolation of the factors which cause the expected benefits, when they exist. At the same time, a bunch of threats are ready to weaken the validity of the research, for example, disregard of previous research, use of small samples, absence of randomization in the assignment to groups, ineffective designs, lack of objectivity in the measuring process, poor descriptions of the research in publications (which implies few possibilities of replication), wrong statistical procedures, inappropriate inference of results, etc. All of these obstacles accumulate and are carried along the whole research, resulting in low quality studies or irrelevant ones. This theoretical paper suggests a roadmap in order to face the most common problems in e-learning research. The roadmap informs about some cautions which must be considered at each stage of the research and recommendations to increase the validity and reproducibility of results. The roadmap and conclusions included in this paper have been obtained from our experience in educational and e-learning research, also from our long path as reviewers in key journals of these fields, and from readings of significant research handbooks. This is not a strict guide but a set of milestones on which it is necessary to stop and reflect

Nonlinear field theories during homogeneous spatial dilation

The effect of a uniform dilation of space on stochastically driven nonlinear field theories is examined. This theoretical question serves as a model problem for examining the properties of nonlinear field theories embedded in expanding Euclidean Friedmann-Lema\^{\i}tre-Robertson-Walker metrics in the context of cosmology, as well as different systems in the disciplines of statistical mechanics and condensed matter physics. Field theories are characterized by the speed at which they propagate correlations within themselves. We show that for linear field theories correlations stop propagating if and only if the speed at which the space dilates is higher than the speed at which correlations propagate. The situation is in general different for nonlinear field theories. In this case correlations might stop propagating even if the velocity at which space dilates is lower than the velocity at which correlations propagate. In particular, these results imply that it is not possible to characterize the dynamics of a nonlinear field theory during homogeneous spatial dilation {\it a priori}. We illustrate our findings with the nonlinear Kardar-Parisi-Zhang equation

Non-spiky density of states of an icosahedral quasicrystal

The density of states of the ideal three-dimensional Penrose tiling, a quasicrystalline model, is calculated with a resolution of 10 meV. It is not spiky. This falsifies theoretical predictions so far, that spikes of width 10-20 meV are generic for the density of states of quasicrystals, and it confirms recent experimental findings. The qualitative difference between our results and previous calculations is partly explained by the small number of k points that has usually been included in the evaluation of the density of states of periodic approximants of quasicrystals. It is also shown that both the density of states of a small approximant of the three-dimensional Penrose tiling and the density of states of the ideal two-dimensional Penrose tiling do have spiky features, which also partly explains earlier predictions.Comment: 8 pages, 4 figures. Changes in this version: longer introduction, details of figures shown in inset

Two species coagulation approach to consensus by group level interactions

We explore the self-organization dynamics of a set of entities by considering the interactions that affect the different subgroups conforming the whole. To this end, we employ the widespread example of coagulation kinetics, and characterize which interaction types lead to consensus formation and which do not, as well as the corresponding different macroscopic patterns. The crucial technical point is extending the usual one species coagulation dynamics to the two species one. This is achieved by means of introducing explicitly solvable kernels which have a clear physical meaning. The corresponding solutions are calculated in the long time limit, in which consensus may or may not be reached. The lack of consensus is characterized by means of scaling limits of the solutions. The possible applications of our results to some topics in which consensus reaching is fundamental, like collective animal motion and opinion spreading dynamics, are also outlined

Media, Memory, and Forgiveness: Case Studies in South Africa and Argentina\u27s Conflict Resolution Processes

Studies of conflict frames\u27 customarily include neither mid- to long-term resolution nor the role of the media in that healing process. In theory, the formal reconciliation processes that have followed internal conflicts in many nations provide resolution and a pathway to long-term healing. But do they? As the chief cultural guardians of national memories, what is the role of the media? Between the spikes of crisis reporting, are there persistent frames of journalistic messages that affect how ever-receding events are viewed by new generations? This paper looks at media behavior in two contrasting nations, Argentina and South Africa, while arguing that longitudinal studies would provide valuable understanding to the key question of whether reconciliation processes are a bandage or a cure to conflicts within nation

Phenomenological viability of orbifold models with three Higgs families

We discuss the phenomenological viability of string multi-Higgs doublet models, namely a scenario of heterotic $Z_3$ orbifolds with two Wilson lines, which naturally predicts three supersymmetric families of matter and Higgs fields. We study the orbifold parameter space, and discuss the compatibility of the predicted Yukawa couplings with current experimental data. We address the implications of tree-level flavour changing neutral processes in constraining the Higgs sector of the model, finding that viable scenarios can be obtained for a reasonably light Higgs spectrum. We also take into account the tree-level contributions to indirect CP violation, showing that the experimental value of $\epsilon_K$ can be accommodated in the present framework.Comment: 31 pages, 12 figures. Comments and references added. Final version to be published in JHE

Blow-up of the hyperbolic Burgers equation

The memory effects on microscopic kinetic systems have been sometimes modelled by means of the introduction of second order time derivatives in the macroscopic hydrodynamic equations. One prototypical example is the hyperbolic modification of the Burgers equation, that has been introduced to clarify the interplay of hyperbolicity and nonlinear hydrodynamic evolution. Previous studies suggested the finite time blow-up of this equation, and here we present a rigorous proof of this fact

Experience of stigma and discrimination and the implications for healthcare seeking behavior among people living with HIV/AIDS in resource-limited setting

Background: Stigma and discrimination can limit access to care and treatment services. Stigma hides HIV from the public, resulting in reduced pressure for behavioral change. For effective behavior change, empirically grounded and theory-based behavioral change approaches are fundamental as a prevention interventions directed on decreasing stigma and discrimination. The objective of the study was to assess the experience of stigma and discrimination on the psychosocial and health care seeking behavior of people living with HIV/AIDS (PLHIV) in Arba Minch, Ethiopia.Methods: This study uses qualitative methods involving focus-group discussions and in-depth interviews conducted in Arba Minch town and nearby Kebeles. Our sample consisted of PLHIV and other key informants who were purposively selected. Data were analyzed manually using thematic content analysis framework.Results: It appears that the magnitude of stigma and discrimination in the area has decreased to a considerably lower level, however, the problem’s severity is still being influenced by various factors including: current residence, disclosure status and level of community’s awareness about HIV/AIDS. Care and support services provided to PLHIV were well accepted by the respondents and the majority of them were willing to make use of any service available. Health information messages that have been disseminated to the public through mass media since the start of the epidemic in 1984 and AIDS cases in 1986 have played a significant role regarding the current prevailing problem of stigma and discrimination of PLHIV.Conclusion: Stigma and discrimination have come to a level that can be tolerated by most PLHIV that live in this region, especially those who have disclosed their HIV status and were living in urban areas. This calls for a strategy that improves the rates of serostatus disclosure after HIV counseling and testing and strengthens and integrates activities in the task of expanding care and support activities.Keywords: HIV/AIDS, stigma, discrimination, EPPM, Ethiopi