The Penn Effect and Transition: The New EU Member States in International Perspective

Recent panel studies have found relatively high point estimates for the elasticity of ag-gregate price measures with respect to productivity in (former) transition economies, while other studies report price-productivity elasticity estimates to depend positively on average productivity in the sample. We aim to reconcile both results by putting com-parative price developments of transition economies in an international perspective. We argue that estimating simple price-productivity relationships without the inclusion of other real factors connected to reform effort might severely bias estimates for CEEC economies. Our results imply that, when controlling for reform effort and therefore avoiding this endogeneity problem, the price-productivity-elasticity for CEEC econo-mies was not different from that of non-transition economies during the first 15 years of transition

Can We Identify Balassa-Samuelson Effects with Measures of Product Variety?

The Balassa-Samuelson hypothesis - i.e. that real exchange rates between each pair of countries increase with the tradables sector productivities ratio between these countries, and decrease with their non-tradables sector productivities ratio - has been one of the most prominent frameworks in open economy macroeconomics for more than forty years. However, empirical studies have often been unable to confirm it. We argue that this might at least in part be due to measurement errors leading to downward-biased estimates. We test the Balassa-Samuelson hypothesis with innovative trade-based vari-ety measures to differentiate between tradables and non-tradables sector productivities that do not suffer from such errors-in-variables. Using a pairwise regression approach, we find stable and very robust Balassa-Samuelson effects over all our specifications

Concurrent starbursts in molecular gas disks within a pair of colliding galaxies at z = 1.52

We report on the discovery of a merger-driven starburst at z = 1.52, PACS-787, based on high signal-to-noise ALMA observations. CO(5-4) and continuum emission (850um) at a spatial resolution of 0.3" reveal two compact (r_1/2 ~ 1 kpc) and interacting molecular gas disks at a separation of 8.6 kpc thus indicative of an early stage in a merger. With a SFR of 991 Msun/yr, this starburst event should occur closer to final coalescence, as usually seen in hydrodynamical simulations. From the CO size, inclination, and velocity profile for both disks, the dynamical mass is calculated through a novel method that incorporates a calibration using simulations of galaxy mergers. Based on the dynamical mass, we measure (1) the molecular gas mass, independent from the CO luminosity, (2) the ratio of the total gas mass and the CO(1 - 0) luminosity (alpha_CO = M_gas/L'_CO(1-0)), and (3) the gas-to-dust ratio, with the latter two being lower than typically assumed. We find that the high star formation, triggered in both galaxies, is caused by a set of optimal conditions: a high gas mass/fraction, a short depletion time (t_depl=85 and 67 Myrs) to convert gas into stars, and the interaction of likely counter-rotating molecular disks that may accelerate the loss of angular momentum. The state of interaction is further established by the detection of diffuse CO and continuum emission, tidal debris that bridges the two nuclei and is associated with stellar emission seen by HST/WFC3. This observation demonstrates the power of ALMA to study the dynamics of galaxy mergers at high redshift

Context dependent learning in the serial RT task

This study investigated the development of contextual dependencies for sequential perceptual-motor learning on static features in the learning environment. In three experiments we assessed the effect of manipulating task irrelevant static context features in a serial reaction-time task. Experiment 1 demonstrated impaired performance after simultaneously changing display color, placeholder shape, and placeholder location. Experiment 2 showed that this effect was mainly caused by changing placeholder shape. Finally, Experiment 3 indicated that changing context affected both the application of sequence knowledge and the selection of individual responses. It is proposed either that incidental stimulus features are integrated with a global sequence representation, or that the changed context causes participants to strategically inhibit sequence skills

Learners in a Changing Learning Landscape: Reflections from an Instructional Design Perspective

Van Merriënboer, J. J. G., & Stoyanov, S. (2008). Learners in a changing learning landscape: Reflections from an instructional design perspective. In J. Visser & M. Visser-Valfrey (Eds.), Learners in a changing learning landscape: Reflections from a dialogue on new roles and expectations (pp. 69-90). Dordrecht, The Netherlands: Springer.Both learners and teachers find themselves in a learning landscape that is rapidly changing, along with fast societal and technological developments. This paper discusses the new learning landscape from an instructional design perspective. First, with regard to what is learned, people more than ever need flexible problem-solving and reasoning skills allowing them to deal with new, unfamiliar problem situations in their professional and everyday life. Second, with regard to the context in which learning takes place, learning in technology-rich, informal and professional 24/7 settings is becoming general practice. And third, with regard to the learners themselves, they can more often be characterized as lifelong learners who are mature, bring relevant prior knowledge, and have very heterogeneous expectations and perceptions of learning. High-quality instructional design research should focus on the question which instructional methods and media-method combinations are effective, efficient and appealing in this new learning landscape. Some innovative instructional methods that meet this requirement are discussed

The consolidation of implicit sequence memory in obstructive sleep apnea

Obstructive Sleep Apnea (OSA) Syndrome is a relatively frequent sleep disorder characterized by disrupted sleep patterns. It is a well-established fact that sleep has beneficial effect on memory consolidation by enhancing neural plasticity. Implicit sequence learning is a prominent component of skill learning. However, the formation and consolidation of this fundamental learning mechanism remains poorly understood in OSA. In the present study we examined the consolidation of different aspects of implicit sequence learning in patients with OSA. We used the Alternating Serial Reaction Time task to measure general skill learning and sequence-specific learning. There were two sessions: a learning phase and a testing phase, separated by a 10-hour offline period with sleep. Our data showed differences in offline changes of general skill learning between the OSA and control group. The control group demonstrated offline improvement from evening to morning, while the OSA group did not. In contrast, we did not observe differences between the groups in offline changes in sequence-specific learning. Our findings suggest that disrupted sleep in OSA differently affects neural circuits involved in the consolidation of sequence learning

Covert Reorganization of Implicit Task Representations by Slow Wave Sleep

There is evidence that slow wave sleep (SWS) promotes the consolidation of memories that are subserved by mediotemporal- and hippocampo-cortical neural networks. In contrast to implicit memories, explicit memories are accompanied by conscious (attentive and controlled) processing. Awareness at pre-sleep encoding has been recognized as critical for the off-line memory consolidation. The present study elucidated the role of task-dependent cortical activation guided by attentional control at pre-sleep encoding for the consolidation of hippocampus-dependent memories during sleep.A task with a hidden regularity was used (Number Reduction Task, NRT), in which the responses that can be implicitly predicted by the hidden regularity activate hippocampo-cortical networks more strongly than responses that cannot be predicted. Task performance was evaluated before and after early-night sleep, rich in SWS, and late-night sleep, rich in rapid eye movement (REM) sleep. In implicit conditions, slow cortical potentials (SPs) were analyzed to reflect the amount of controlled processing and the localization of activated neural task representations.During implicit learning before sleep, the amount of controlled processing did not differ between unpredictable and predictable responses, nor between early- and late-night sleep groups. A topographic re-distribution of SPs indicating a spatial reorganization occurred only after early, not after late sleep, and only for predictable responses. These SP changes correlated with the amount of SWS and were covert because off-line RT decrease did not differentiate response types or sleep groups.It is concluded that SWS promotes the neural reorganization of task representations that rely on the hippocampal system despite absence of conscious access to these representations.Original neurophysiologic evidence is provided for the role of SWS in the consolidation of memories encoded with hippocampo-cortical interaction before sleep. It is demonstrated that this SWS-mediated mechanism does not depend critically on explicitness at learning nor on the amount of controlled executive processing during pre-sleep encoding