Students’ tool-use within a web enhanced course: Explanatory mechanisms of students’ tool-use pattern

The popularity of content management systems (CMSs) in today’s higher education is driven by the assumption that providing a rich toolset and leaving the use of this toolset under learner control will stimulate self-regulated and deeper learning. Current evidence on students’ tool-use within CMS supported courses however tackles this assumption and indicates that CMSs may empower students’ learning only under particular learner-related conditions. The current study addresses this concern and investigates how students’ tool-use within a CMS supported course can be explained in terms of (a) students’ conceptions on the tool functionalities, (b) self-efficacy beliefs for self-regulated learning and (c) goal orientation. Data were collected within a first year undergraduate course ‘Learning and Instruction’. Students’ (n = 182) tool-use within the course was logged throughout the course episode and the influencing variables were measured through questionnaires. K-means cluster analyses revealed four clusters that reflected differences in students’ tool-choice and tool-use throughout the course. Multinominal regression analyses revealed that these tool-use differences could be explained in terms of students’ goal orientation. The study provides thus perspectives in order to capture students’ academic motivation through unobtrusive, behavioral, measures. Furthermore, questions are raised regarding the parallel between students’ tool-use pattern and study strategy use.     

The “shading twist,” a dynamical shape cue

When a light source moves, the isophotes of the illuminance field (observed as “shading” in the case of Lambertian surfaces) move over the surfaces of illuminated objects. The sense of rotation of the isophotes relative to the sense of rotation of the “surface illuminance flow,” that is the tangential component of the illumination direction over the surface, depends on the Gaussian curvature of the surface. The temporal change of orientation, the “shading twist,” reveals this purely surface related quality. Since the shading twist depends only on the local curvature of the surface it doesn’t matter at all how the light source moves or where the light sources are, the “shading twist” is a pure surface property, that is to say, it behaves as being painted upon the surface. The formal relations pertaining to the shading twist are analyzed and a numerical simulation is presented that fully corroborates the conclusions from the formal study. The algorithm is also tested on a real scene.     

The beta-cell in type 1 diabetes: What have we learned from proteomic studies?

Pancreatic beta-cells have a crucial role in the regulation of blood glucose homeostasis by the production and secretion of insulin. In type 1 diabetes (T1D), an autoimmune reaction against the beta-cells together with the presence of inflammatory cytokines and ROS in the islets leads to beta-cell dysfunction and death. This review gives an overview of proteomic studies that lead to better understanding of beta-cell functioning in T1D. Protein profiling of isolated islets and beta-cell lines in health and T1D contributed to the unraveling of pathways involved in cytokine-induced cell death. In addition, by studying the serological proteome of T1D patients, new biomarkers and beta-cell autoantigens were discovered, which may improve screening tests and follow-up of T1D development. Interestingly, an important role for PTMs was demonstrated in the generation of beta-cell autoantigens. To conclude, proteomic techniques are of indispensable value to improve the knowledge on beta-cell function in T1D and the search toward therapeutic targets.     

SPICA sub-Kelvin cryogenic chains

SPICA, a Japanese led mission, is part of the JAXA future science program and is planned for launch in 2018. SPICA will perform imaging and spectroscopic observations in the mid- and far-IR waveband, and is developing instrumentation spanning the 5–400 μm range. The SPICA payload features several candidate instruments, some of them requiring temperature down to 50 mK. This is currently the case for SAFARI, a core instrument developed by a European-based consortium, and BLISS proposed by CALTECH/JPL in the US.SPICA’s distinctive feature is to actively cool its telescope to below 6 K. In addition, SPICA is a liquid cryogen free satellite and all the cooling will be provided by radiative cooling (L2 orbit) down to 30 K and by mechanical coolers for lower temperatures. The satellite will launch warm and slowly equilibrate to its operating temperatures once in orbit. This warm launch approach makes it possible to eliminate a large liquid cryogen tank and to use the mass saved to launch a large diameter telescope (3.2 m). This 4 K cooled telescope significantly reduces its own thermal radiation, offering superior sensitivity in the infrared region.The cryogenic system that enables this warm launch/cooled telescope concept is a key issue of the mission. This cryogenic chain features a number of cooling stages comprising passive radiators, Stirling coolers and several Joule Thomson loops, offering cooling powers at typically 20, 4.5, 2.5 and 1.7 K. The SAFARI and BLISS detectors require cooling to temperatures as low as 50 mK. The instrument coolers will be operated from these heat sinks. They are composed of a small demagnetization refrigerator (ADR) pre cooled by either a single or a double sorption cooler, respectively for SAFARI and BLISS. The BLISS cooler maintains continuous cooling at 300 mK and thus suppresses the thermal equilibrium time constant of the large focal plane.These hybrid architectures allow designing low weight coolers able to reach 50 mK. Because the sorption cooler has extremely low mass for a sub-Kelvin cooler, it allows the stringent mass budget to be met. These concepts are discussed in this paper.     

A Multi-Disciplinary Contribution to the Provenance Determination of Ancient Greek and Roman Marble Artifacts

The problem of determining the provenance of the white marble used for antique artifacts has been tackled in different ways. During the past decade it became clear that a multimethod approach is required to solve the problem. In addition, reliable reference material, i.e., samples collected at the ancient quarry sites in an archaeologically and geologically justified manner, turned out to be a prerequisite for reliable provenance determination. A multimethod approach based on petrography, stable isotope analysis of O and C, and trace element analysis yields complementary information. These methods were applied to the same set of 225 quarry samples. When processed with powerful statistical methods, the data thus obtained allowed all major types of marble used in antiquity to be distinguished. Thus, most problems concerning the provenance of artifacts can be solved. This approach was successfully applied to the provenance determination of about 75 artifacts from different museums in Europe and the USA.     

Science in Brazil. Part 1: A macro-level comparative study

Summary In the present paper, the evolution of publication activity and citation impact in Brazil is studied for the period 1991-2003. Besides the analysis of trends in publication and citation patterns and of national publication profiles, an attempt is made to find statistical evidences of the relation between international co-authorship and both research profile and citation impact in the Latin American region. Despite similarities and strong co-publication links with the other countries in the region, Brazil has nonetheless a specific research profile, and forms the largest potential in the region.     

Optimization of Mineralogy and Microstructure of Solidified Basic Oxygen Furnace Slag Through SiO2 Addition or Atmosphere Control During Hot-Stage Slag Treatment

Metallurgical and Materials Transactions B - Valorization of basic oxygen furnace (BOF) slag is of significant importance for mitigation of the steel production’s environmental impact. The...     

Adaptive Routing on the New Switch Chip for IBM SP Systems

The IBM RS/6000 SP is one of the most successful commercially available multicomputers. SP owes its success partially to the scalable, high bandwidth, low latency network. This paper describes the architecture of Switch2 switch chip, the recently developed third generation switching element which future IBM RS/6000 SP systems may be based on. Switch2 offers significant enhancements over the existing SP switch chips by incorporating advances in both VLSI technology and interconnection network research. One of the major new features of Switch2 is the incorporation of adaptive routing support into it. We describe the adaptive source routing architecture of the Switch2 chip which is a unique feature of this chip. The performance of the adaptive source routing and oblivious routing for a wide range of system characteristics and traffic patterns is evaluated. It is shown that adaptive source routing outperforms or performs comparably with oblivious routing. We propose two novel algorithms for generating adaptive routes specifications required for enabling the usage of adaptive source routing. A comparison between the cost of these two algorithms and the performance improvement obtained from using these algorithms are discussed. We also propose different output selection functions to be used in switching elements for implementing the adaptive routing. We evaluate and compare the performance of these selection functions and discover that the best selection functions for BMINs are not dependent on the traffic pattern, message size, or system size.