Online Automatic Marking of Diagrams

This article describes the way in which the Open University is expanding its online quiz engine to enable students to draw free-form diagrams in response to a quiz question. The new quiz engine automatically marks a student’s diagram and provides feedback either instantaneously when used in formative mode or later when used in summative mode. The new quiz engine is hosted within the Open University’s quiz module, OpenMark, which interfaces to the Moodle VLE which is responsible for rendering both the question and the feedback in the user’s browser. The article outlines the general nature of the diagrams that our system has been designed to deal with. This is followed by an example of the use of the new question type as implemented within our e-assessment system. The article also briefly summarizes the results of experiments carried out on the accuracy of the automatic marker and reports on feedback from students who have used the new diagramming question type.     

Defects in whirlin,a PDZ domain molecule involved in stereocilia elongation,cause deafness in the whirler mouse and families with DFNB31

The whirler mouse mutant (wi) does not respond to sound stimuli, and detailed ultrastructural analysis of sensory hair cells in the organ of Corti of the inner ear indicates that the whirler gene encodes a protein involved in the elongation and maintenance of stereocilia in both inner hair cells (IHCs) and outer hair cells (OHCs). BAC-mediated transgene correction of the mouse phenotype and mutation analysis identified the causative gene as encoding a novel PDZ protein called whirlin. The gene encoding whirlin also underlies the human autosomal recessive deafness locus DFNB31. In the mouse cochlea, whirlin is expressed in the sensory IHC and OHC stereocilia. Our findings suggest that this novel PDZ domain-containing molecule acts as an organizer of submembranous molecular complexes that control the coordinated actin polymerization and membrane growth of stereocilia.     

Internalization of cationic peptides: the road less (or more?) traveled

Facilitating the entry of molecules into mammalian cells is of great interest to fields as diverse as cell biology and drug delivery. The discovery of natural protein transduction domains and the development of artificial ones, including polyarginine, provides a means to achieve this goal. Here, we comment on key chemical and biological aspects of cationic peptide internalization, including the physiological relevance of this process. Received 13 April 2006; received after revision 21 May 2006; accepted 2 June 2006     

Simulating the European economies under alternative monetary policy assumptions

This paper examines the implications of alternative monetary policy rules for economic stabilization within Europe, using the OECD world model, INTERLINK. The results suggest that policy linkage through the Exchange Rate Mechanism will have differing effects on the effectiveness of stabilization policies depending on the nature of economic shocks. For demand shocks, the choice of monetary rule in the country of the ‘anchor’ currency is of more consequence than the flexibility of exchange rates. For supply shocks, exchange rate rigidity is likely to have more problematic effects on economic adjustment. Spillover effects are also important when the shock is felt primarily by the ‘anchor’ economy.     

Similar response of labile and resistant soil organic matter pools to changes in temperature

Our understanding of the relationship between the decomposition of soil organic matter (SOM) and soil temperature affects our predictions of the impact of climate change on soil-stored carbon. One current opinion is that the decomposition of soil labile carbon is sensitive to temperature variation whereas resistant components are insensitive. The resistant carbon or organic matter in mineral soil is then assumed to be unresponsive to global warming. But the global pattern and magnitude of the predicted future soil carbon stock will mainly rely on the temperature sensitivity of these resistant carbon pools. To investigate this sensitivity, we have incubated soils under changing temperature. Here we report that SOM decomposition or soil basal respiration rate was significantly affected by changes in SOM components associated with soil depth, sampling method and incubation time. We find, however, that the temperature sensitivity for SOM decomposition was not affected, suggesting that the temperature sensitivity for resistant organic matter pools does not differ significantly from that of labile pools, and that both types of SOM will therefore respond similarly to global warming.