Using multimedia to enhance the accessibility of the learning environment for disabled students: reflections from the Skills for Access project

As educators' awareness of their responsibilities towards ensuring the accessibility of the learning environment to disabled students increases, significant debate surrounds the implications of accessibility requirements on educational multimedia. There would appear to be widespread concern that the fundamental principles of creating accessible web‐based materials seem at odds with the creative and innovative use of multimedia to support learning and teaching, as well as concerns over the time and cost of providing accessibility features that can hold back resource development and application. Yet, effective use of multimedia offers a way of enhancing the accessibility of the learning environment for many groups of disabled students. Using the development of ‘Skills for Access’, a web resource supporting the dual aims of creating optimally accessible multimedia for learning, as an example, the attitudinal, practical and technical challenges facing the effective use of multimedia as an accessibility aid in a learning environment will be explored. Reasons why a holistic approach to accessibility may be the most effective in ensuring that multimedia reaches its full potential in enabling and supporting students in learning, regardless of any disability they may have, will be outlined and discussed

Nest visitors of Vespula wasps and their potential use for biological control in an invaded range

The common and the German wasp, Vespula vulgaris and V. germanica, have proved to be prolific invasive species capable of degrading local ecosystems and costing invaded countries millions of dollars annually. Despite clear incentive, control strategies are yet to have any significant deleterious impact on invasive populations. Several species of arthropods are known to inhabit Vespula nests and feed upon developing larvae as either parasitoids or predators. Recent control strategies propose the use of such parasitoids as agents of biocontrol against invasive wasps (Volucella inanis in particular). Despite a general understanding of parasitoid ecology, some aspects such as prevalence, distribution, and behaviour remain limited. Here, we surveyed natural enemy prevalence in wasp nests over the period of three years and we tested larvae prey preference of two Volucella species, V. inanis and V. zonaria towards Vespula wasps. We find V. inanis to be the most prevalent of four prominent candidates for Vespid biocontrol—V. inanis, V. zonaria, Sphecophaga vesparum, and Metoecus paradoxus. Using two-choice assays, we find larvae of V. inanis to have slight yet significant prey preference for V. vulgaris larvae over V. germanica larvae, whilst V. zonaria display no preference. Furthermore, V. inanis were not averse to still predating upon V. germanica, doing so in 41% of trials. Prior exposure has no effect on the prey-preference. Our work provides experimental evidence that V. inanis is a promising candidate for biocontrol of invasive Vespula wasps, as the larvae predate on both target species of Vespula and display no exclusive preference among them

Microstructural and mechanical characterisation of post-tentioning strands following elevated temperature exposure

Prestressing strands lose strength and become more susceptible to creep deformation when they are heated during a fire. The consequent loss in prestressing force could under certain conditions result in structural collapse, potentially outwith the heated region of the structure. This paper describes a test programme characterising the changes in microstructure of steel prestressing tendons exposed to elevated temperatures. The residual strength tests, hardness testing, and elevated temperature mechanical test were performed to demonstrate how recovery and recrystallisation of the initially work-hardened steel produce changes in its mechanical properties at elevated temperatures. The research results of this paper are beneficial not only in the fire design of post-tensioned structures using modern prestressing steel, but also in the assessment of the tendons’ residual strength after being affected by fire