Effects of students' participation in authoring of multimedia materials on student acquisition of vocabulary

This study investigated the effects on vocabulary acquisition of student participation in authoring a multimedia instructional module. Sixty-two subjects were randomly assigned to two groups, and each group was randomly assigned to one of two treatments. The control subjects were asked to study a French text downloaded from the Internet and presented on a computer. In the text, 20 relatively low-frequency words were annotated with text, sound, and pictures. The experimental subjects had the same text but without annotations. They were asked to participate in creating annotations for the same 20 target words. The study produced evidence that students learn vocabulary significantly better when they participate in the creation of the instructional module, provided time is not considered. However, when the variable of time on task is taken into account, there is no statistically significant difference between the experimental and the control treatments. In addition, annotations containing text, sound, and pictures were found to be more helpful for vocabulary learning than annotations with sound and text only. The results are discussed in light of theories of vocabulary acquisition and active student involvement in the learning process. Practical applications and ideas for further research are suggested

Quasi-Stationary Approximation of a Dynamical Model of MicroRNA Target Regulation. Part II. Application of the QSSA Theorem

The QSSA theorem is applied to the dynamical model of microRNA target regulation after special selection of model variables, presented in Part I of this article. On the basis of this theorem the complete model, represented as a system of seven nonlinear ordinary differential equations, is reduced to a degenerate one, comprising only two ordinary differential equations. As a result it is proved that the proteins, produced by miRNAs are identified to play a driving role of the dynamical behaviour of the genetic process investigated, but in post-initial (or quasi-stationary) stage

Quasi-Stationary Approximation of a Dynamical Model of microRNA Target Regulation. Part I. Establishment of Time Hierarchy in the Model Dynamics

The Quasi-Steady-State Approximation (QSSA) theorem is considered as a basic approach for reduction of dimensionality of a dynamical model of microRNA target regulation. On the basis of previously determined parameters, seven ordinary differential equations of the model are written in a form appropriate to evaluate their terms for further reduction. In accordance with the terminology of the QSSA theorem, it is established that five of the system components are fast varying such that the corresponding kinetic equations form an attached system. The other two variables are slow varying and their kinetic equations form a degenerate system

The Great Recession and social preferences: Evidence from Ukraine

We use detailed survey data to document stark differences between West and East Ukraine when it comes to household attitudes toward market-based economies and democratic institutions. Along both of these dimensions, Eastern Ukrainians are decidedly less supportive of liberal systems. We also find that economic attitudes changed in response to the global financial crisis. West Ukrainian households who were affected more extensively by the crisis were more disappointed with the market and private ownership, while in Eastern Ukraine economic attitudes became less pro-market across the board. Our evidence suggests that attitudes and values are determined by both deep-rooted factors and more transient macroeconomic shocks

Half-quadratic regularization for MRI image restoration

We consider the reconstruction of MRI images by minimizing regularized cost-functions. To accelerate the computation of the estimate, two forms of half-quadratic regularization, multiplicative and additive, are often used. In Nikolova and Ng (2002), we have compared both theoretically and experimentally the efficiency of these two forms using one-dimensional signals. The goal of this paper is to compare experimentally the efficiency of these two forms using MRI image reconstruction. We find that using the additive form is more computationally effective than using the multiplicative form.published_or_final_versio

Effects of Visible and Invisible Hyperlinks on Vocabulary Acquisition and Reading Comprehension for High- and Average-Foreign Language Achievers

This study investigated the effects of visible and invisible links for annotated words in a computer module for learning French on the vocabulary acquisition and reading comprehension of two types of students – high- and average- achievers. Two hundred and sixty-four second-semester students of French were identified as high- or average-achievers. Each type of students was then randomly assigned to two groups – with visible or invisible hyperlinks. All students were instructed to read a short passage in French (181 words) for general comprehension and allowed to consult the annotated words (made visible by bold face for the visible links group) as much as they needed. The students took a vocabulary pretest and an immediate and delayed (two weeks) vocabulary and reading comprehension posttest. The results of the study showed that average- achievers benefited more from the visible links for vocabulary acquisition and reading comprehension than high- achievers. The results are discussed in light of second language acquisition and gifted-student theories and suggestions for future research are made

STUDIES ON CYTOMEGALOVIRAL (CMV) INFECTIONS IN NEWBORN CHILDREN

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Tractable Pathfinding for the Stochastic On-Time Arrival Problem

We present a new and more efficient technique for computing the route that maximizes the probability of on-time arrival in stochastic networks, also known as the path-based stochastic on-time arrival (SOTA) problem. Our primary contribution is a pathfinding algorithm that uses the solution to the policy-based SOTA problem---which is of pseudo-polynomial-time complexity in the time budget of the journey---as a search heuristic for the optimal path. In particular, we show that this heuristic can be exceptionally efficient in practice, effectively making it possible to solve the path-based SOTA problem as quickly as the policy-based SOTA problem. Our secondary contribution is the extension of policy-based preprocessing to path-based preprocessing for the SOTA problem. In the process, we also introduce Arc-Potentials, a more efficient generalization of Stochastic Arc-Flags that can be used for both policy- and path-based SOTA. After developing the pathfinding and preprocessing algorithms, we evaluate their performance on two different real-world networks. To the best of our knowledge, these techniques provide the most efficient computation strategy for the path-based SOTA problem for general probability distributions, both with and without preprocessing.Comment: Submission accepted by the International Symposium on Experimental Algorithms 2016 and published by Springer in the Lecture Notes in Computer Science series on June 1, 2016. Includes typographical corrections and modifications to pre-processing made after the initial submission to SODA'15 (July 7, 2014