Pedagogical theory of today gives high priority to social components of learning. Within the field of computer supported learning there are many attempts to acknowledge this. One approach involves the addition of virtual characters to electronic learning environments. Such character enhanced systems are the focus of the present article. Firstly, a systematic overview is given of pedagogical benefi

Over a century ago workers such as J. Lubbock and K. von Frisch developed behavioural criteria for establishing that non-human animals see colour. Many animals in most phyla have since then been shown to have colour vision. Colour is used for specific behaviours, such as phototaxis and object recognition, while other behaviours such as motion detection are colour blind. Having established the exis

Purpose: To evaluate against Monte-Carlo the performance of various dose calculations algorithms regarding lung turnout coverage in stereotactic body radiotherapy (SBRT) conditions. Materials and methods: Dose distributions in virtual lung phantoms have been calculated using four commercial Treatment Planning System (TPS) algorithms and one Monte Carlo (MC) system (EGSnrc). We compared the perform

We report measurements and theoretical calculations for the lifetimes of the 5d(9)6p levels in Hg nr with J = 0,2,3,4. This is an extension of earlier measurements of the lifetimes of the 5d(9)6p levels in Hg III with J = 1, and now provides data for all 12 of the levels. The results also provide an isoelectronic comparison with earlier studies of these levels in Au II of the Pt sequence, and a ho

Male moths rely on female sex pheromones to find their mating partner and on plant volatiles for the detection of food sources. In the noctuid moth, Agrotis ipsilon, plasticity of central sex pheromone processing has been shown previously in the antennal lobe. The sensitivity of antennal lobe interneurons increases with age and juvenile hormone level. Here we investigated whether age affects not o

We have performed a detailed calculation of the inter-Wannier-Stark-ladder Zener tunneling probability P(F) in a wide-miniband GaAs/Al0.3Ga0.7As superlattice under a strong electric field F, the terahertz emission spectrum I(F) of which was measured experimentally. By comparing P(F) and I(F), we confirm that the oscillating behavior of I(F) is due to the Zener tunneling between Wannier-Stark level

With the proper design of semiconductor tunneling barrier structures, we can inject low-energy electrons via resonant tunneling, and take out high-energy electrons via a thermionic process. This is the operation principle of our semiconductor heterostructure refrigerator (SHR) without the need of applying a temperature gradient across the device. Even for the bad thermoelectric material AlGaAs, ou

The role of androgens for bone health in elderly men is unclear. We show that free testosterone within the normal range is a predictor of BMD at predominantly cortical bone sites and of previous osteoporosis-related fractures in elderly Swedish men. Introduction: Osteoporosis-related fractures constitute a major health concern not only in women but also in men. Previous studies have clearly shown

There are quite detailed structural data on the extracellular ligand-binding domain and the intramembrane channel-forming domain of the nicotinic acetylcholine receptors (nAChR). However, the structure of the intracellular domain, which has variable amino acid sequences in different nAChR subunits, remains unknown. We expressed in Escherichia coli the intracellular loops (between transmembrane fra

Breeding Ospreys were studied in southern Sweden and 13 birds were tracked by satellite telemetry on autumn migration to the African wintering grounds. This was supplemented with studies of migrating birds at Falsterbo and radar trackings From southern Sweden. Females generally left the nest site 2-3 weeks ahead of males and juveniles. Among males, failed bleeders migrated significantly earlier th

Spatial variation in selection has long been recognized as promoting population divergence and in maintaining genetic polymorphisms, but selection at a fine spatial scale is seldom measured directly. We analyzed spatial and temporal variation in selective regimes on egg size using long-term population data of the side-blotched lizard ( Uta stansburiana). Juvenile survival rates varied between year

In this paper we extend the eliminant construction of Burchnall and Chaundy for commuting differential operators in the Heisenberg algebra to the q-deformed Heisenberg algebra and show that it again provides annihilating curves for commuting elements, provided q satisfies a natural condition. As a side result we obtain estimates on the dimensions of the eigenspaces of elements of this algebra in i

The atmospheric effects of soot aerosols include interference with radiative transfer, visibility impairment, and alteration of cloud formation and are highly sensitive to the manner by which soot is internally mixed with other aerosol constituents. We present experimental studies to show that soot particles acquire a large mass fraction of sulfuric acid during atmospheric aging, considerably alte

Extensive microscopic molecular dynamics simulations have been performed to study the effects of short-chain alcohols, methanol and ethanol, on two different fully hydrated lipid bilayer systems (POPC and DPPC) in the fluid phase at 323 K. It is found that ethanol has a stronger effect on the structural properties of the membranes. In particular, the bilayers become more fluid and permeable: ethan

Coherent perception of objects in our environment often requires perceptual integration of auditory and visual information. Recent behavioral data suggest that audiovisual integration depends on attention. The current study investigated the neural basis of audiovisual integration using 3-Tesla functional magnetic resonance imaging (fMRI) in 12 healthy volunteers during attention to auditory or vis

Aggrecan, versican, neurocan, and brevican are important components of the extracellular matrix in various tissues. Their amino-terminal globular domains bind to hyaluronan, but the function of their carboxyl-terminal globular domains has long remained elusive. A picture is now emerging where the C-type lectin motif of this domain mediates binding to other extracellular matrix proteins. We here de

PURPOSE: To describe and compare eating difficulties from admission to discharge, with regard to length of stay (LOS) and discharge to institutional care, as well as in relation to gender. METHOD: Patients, aged 65 or above, admitted for stroke rehabilitation, having at least one eating difficulty were observed (n =108) as regards to eating on admission and at discharge. Analysis followed earlier