Synthesis of fused cyclic systems containing medium-sized rings through tandem ROM-RCM of norbornene derivatives embedded in a carbohydrate template

A general approach for the synthesis of fused cyclic systems containing medium-sized rings (7-9) has been developed. The key steps involve a diastereoface-selective Diels-Alder reaction of the dienophiles 4a-d attached to a furanosugar with cyclopentadiene and ring opening (ROM)-ring closing metathesis (RCM) of the resulting norbornene derivatives 10a-d and 11a-d. Diels-Alder reaction of the dienophiles 4a-d with cyclopentadiene in the absence of a catalyst produced 10a-d as the major product arising through addition of the diene to the unhindered Si-face. The most interesting and new aspect of the Diels-Alder reaction of these dienophiles is the accessibility of the Re-face that was blocked by the alkenyl chains under Lewis acid catalysis producing the diastereoisomers 11a-d exclusively. The reversal of facial selectivity from an uncatalyzed reaction to a catalyzed one is unprecedented. The observed stereochemical dichotomy is attributed to rotation of the enone moiety along the or bond linking the sugar moiety during formation of the chelate 13. This makes the Re-face of the enone moiety in 4a-d unhindered. Diels-Alder reaction of the carbocyclic analogue 15 under Lewis acid catalysis produced a 1: 1 mixture of the adducts 16 and 17 confirming the participation of sugar ring oxygen in chelate formation. Finally ROM-RCM of 10a-d and 11a-d with Grubbs' catalyst afforded the cis-syn-cis and cis-anti-cis bicyclo-annulated sugars 21a-d and 23a-d, respectively, containing 7-9 membered rings.

Silica-encapsulated nanomagnetic particle as a new recoverable biocatalyst carrier

Enzymes are versatile biocatalysts with major advantages of ultrahigh reaction selectivity and specificity under mild conditions, which currently find increasing applications. However, their applications are often hampered by difficulties in recovery and recycling. As a result, we carried out detailed investigations on the synthesis and characterization of silica-encapsulated iron oxide magnetic nanoparticles of controlled dimension as an enzyme carrier. It is shown that the relatively smaller sized silica-coated magnetic nanoparticle prepared by the microemlusion technique can a carry bulky enzyme, beta-lactamase, via chemical linkages on the silica overlayer without severely blocking the enzymatic active center ( which is commonly encountered in conventional solid supports). An activity study by Michalis-Menten kinetics reflects that this new type of immobilization allows enzyme isolation with accessibility as good as free enzyme. The recovery and reusability of the nanoparticle-supported enzyme upon application of magnetic separation are also demonstrated.

Introducing assistive technologies (AT) into the existing homes of older people

The design of accessible environments, for use by all, is a legal requirement for all public buildings, under the Disability Discrimination Act 1995 (DDA, 1995) since October 1999 and the removal of all physical barriers becomes enforceable in 2004. Accessibility has transferred from being a social and moral issue to a legal requirement. The Research Group for Inclusive Environments at the University of Reading undertakes research to better understand methods to make the built environment more accessible. This paper presents the findings from the research project, Project Crystal, investigating the design of environments for better communication for deaf and hard of hearing people. At the last COBRA conference the preliminary findings from the pilot questionnaire were presented. During the year the questionnaire has been distributed more widely and a test environment has been used to investigate the effects the variables of lighting and colour have on people's ability to communicate. This paper will present some of the findings from the project, which is almost complete, and generalise on the effect wall surface design has on accessibility of an environment for people with a hearing impairment.

The children that time forgot: Reframing housing standards to incorporate children's needs

This paper presents the findings from a recent study funded by the Joseph Rowntree Foundation examining the housing and neighbourhood needs of 44 visually impaired children. Our research found that disabled people’s needs have been too narrowly based on ‘accessibility’ criteria, which do not take into account the health and safety issues so important for children. Indeed, the home environment is the main site of accidental death or injury for young children under 4 years, and children from low income families are particularly susceptible to burns, scalds, falls, swallowing foreign objects or poisonous substances within it (CRDU 1994). As disabled children are statistically more likely to be in low income families, this places them at high risk. If ‘accessibility’ is to be reconceived as design for usability throughout the lifecourse, this challenges us to move beyond the pragmatic but limited application of design prescriptions for disabled people as a separate and adult group, and to re-think all of the dimensions of the housing quality framework in the light of this expanded approach.

Effects of lactoperoxidase and hydrogen peroxide on rheological properties of yoghurt

The effects of activation of the lactoperoxidase (LPO) system by H2O2-NaSCN and hydrogen peroxide (H2O2) on the accessibility of sulphydryl groups (SH) in skimmed milk, and on the dynamic rheological properties of the resulting yoghurt were investigated. Four different concentrations of each reagent (20-80 mg H2O2-NaSCN/kg milk and 100-400 mg H2O2/kg milk) were compared. Clear negative correlations were noted between the accessibility of SH groups and both LPO activation rate and H2O2 concentration. Also the native PAGE pattern of the heat-treated samples showed that with increase in the H2O2-NaSCN and H2O2 concentrations, the level of interaction between beta-lactoglobulin (beta-Ig) and kappa-casein (K-CN) decreased. The complex modulus (G*) of skimmed milk yoghurts declined gradually with the decrease in the concentration of accessible SH groups accordingly. Tan delta values of yoghurt samples were found to be different from the control, but close to each other, indicating that protein interaction forces taking place in the formation of gel networks of treated yoghurts were different from the control.

G protein ss gamma subunits mediate presynaptic inhibition of transmitter release from rat superior cervical ganglion neurones in culture

The activation of presynaptic G protein-coupled receptors (GPCRs) is widely reported to inhibit transmitter release; however, the lack of accessibility of many presynaptic terminals has limited direct analysis of signalling mediators. We studied GPCR-mediated inhibition of fast cholinergic transmission between superior cervical ganglion neurones (SCGNs) in culture. The adrenoceptor agonist noradrenaline (NA) caused a dose-related reduction in evoked excitatory postsynaptic potentials (EPSPs). NA-induced EPSP decrease was accompanied by effects on the presynaptic action potential (AP), reducing AP duration and amplitude of the after-hyperpolarization (AHP), without affecting the pre- and postsynaptic membrane potential. All effects of NA were blocked by yohimbine and synaptic transmission was reduced by clonidine, consistent with an action at presynaptic alpha 2-adrenoceptors. NA-induced inhibition of transmission was sensitive to pre-incubation of SCGNs with pertussis toxin (PTX), implicating the involvement of G alpha(i)/(o)beta y subunits. Expression of G alpha transducin, an agent which sequesters G protein beta gamma (G beta y) subunits, in the presynaptic neurone caused a time-dependent attenuation of NA-induced inhibition. Injection of purified G beta gamma subunits into the presynaptic neurone inhibited transmission, and also reduced the AHP amplitude. Furthermore, NA-induced inhibition was occluded by pre-injection of G beta gamma subunits. The Ca2+ channel blocker Cd2+ mimicked NA effects on transmitter release. Cd2+, NA and G beta gamma subunits also inhibited somatic Ca2+ current. In contrast to effects on AP-evoked transmitter release, NA had no clear action on AP-independent EPSPs induced by hypertonic solutions. These results demonstrate that G beta gamma subunits functionally mediate inhibition of transmitter release by alpha 2-adrenoceptors and represent important regulators of synaptic transmission at mammalian presynaptic terminals.

Learning how older adults undertake computer tasks [poster]

This paper describes a study that was conducted to learn more about how older adults use the tools in a GUI to undertake tasks in Windows applications. The objective was to gain insight into what people did and what they found most difficult. File and folder manipulation, and some aspects of formatting presented difficulties, and these were thought to be related to a lack of understanding of the task model, the correct interpretation of the visual cues presented by the interface, and the recall and translation of the task model into a suitable sequence of actions.

Visual eye disease simulator

Visually impaired people have a very different view of the world such that seemingly simple environments as viewed by a ‘normally’ sighted people can be difficult for people with visual impairments to access and move around. This is a problem that can be hard to fully comprehend by people with ‘normal vision’ even when guidelines for inclusive design are available. This paper investigates ways in which image processing techniques can be used to simulate the characteristics of a number of common visual impairments in order to provide, planners, designers and architects, with a visual representation of how people with visual impairments view their environment, thereby promoting greater understanding of the issues, the creation of more accessible buildings and public spaces and increased accessibility for visually impaired people in everyday situations.

Production of relative clauses in monolingual Turkish children

Research on the production of relative clauses (RCs) has shown that in English, although children start using intransitive RCs at an earlier age, more complex, bi-propositional object RCs appear later (Hamburger & Crain, 1982; Diessel and Tomasello, 2005), and children use resumptive pronouns both in acceptable and unacceptable ways (McKee, McDaniel, & Snedeker, 1998; McKee & McDaniel, 2001). To date, it is unclear whether or not the same picture emerges in Turkish, a language with an SOV word-order and overt case marking. Some studies suggested that subject RCs are more frequent in adults and children (Slobin, 1986) and yield a better performance than object RCs (Özcan, 1996), but others reported the opposite pattern (Ekmekçi, 1990). Our study addresses this issue in Turkish children and adults, and uses participants’ errors to account for the emerging asymmetry between subject and object RCs. 37 5-to-8 year old monolingual Turkish children and 23 adult controls participated in a novel elicitation task involving cards, each consisting of four different pictures (see Figure 1). There were two sets of cards, one for the participant and one for the researcher. The former had animals with accessories (e.g., a hat) whereas the latter had no accessories. Participants were instructed to hold their card without showing it to the researcher and describe the animals with particular accessories. This prompted the use of subject and object RCs. The researcher had to identify the animals in her card (see Figure 2). A preliminary repeated measures ANOVA with the factor Group (pre-school, primary-school children) showed no differences between the groups in the use of RCs (p>.1), who were therefore collapsed into one for further analyses. A repeated measures ANOVA with the factors Group (children, adults) and RC-Type (Subject, Object) showed that children used fewer RCs than adults (F(1,58)=7.54, p<.01), and both groups used fewer object than subject RCs (F(1,58)=22.46, p<.001), but there was no Group by RC-Type interaction (see Figure 3). A similar ANOVA on the rate of grammatical RCs showed a main effect of Group (F(1,58)=77.25, p<.001), a main effect of RC-Type (F(1,58)=66.33, p<.001), and an interaction of Group by RC-Type (F(1,58)=64.6, p<.001) (see Figure 4). Children made more errors than adults in object RCs (F(1,58)=87.01, p<.001), and children made more errors in object compared to subject RCs (F(1,36)=106.35, p<.001), but adults did not show this asymmetry. The error analysis revealed that children systematically avoided the object-relativizing morpheme –DIK, which requires possessive agreement with the genitive-marked subject. They also used resumptive pronouns and resumptive full-DPs in the extraction site similarly to English children (see Figure 5). These findings are in line with Slobin (1986) and Özcan (1996). Children’s errors suggest that they avoid morphosyntactic complexity of object RCs and try to preserve the canonical word order by inserting resumptive pronouns in the extraction site. Finally, cross-linguistic similarity in the acquisition of RCs in typologically different languages suggests a higher accessibility of subject RCs both at the structural (Keenan and Comrie, 1977) and conceptual level (Bock and Warren, 1986).

Self-centred memories: the reminiscence bump and the self

The self-memory relationship is thought to be bidirectional, in such a way that memories provide context for the self, and equally, the self exercises control over retrieval (Conway, 2005). Autobiographical memories are not distributed equally across the life span; instead, memories peak between ages 10 and 30. This reminiscence bump has been suggested to support the emergence of a stable and enduring self. In the present study, the relationship between memory accessibility and self was explored with a novel methodology that used generation of self images in the form of I am statements. Memories generated from I am cues clustered around the time of emergence for that particular self image. We argue that, when a new self-image is formed, it is associated with the encoding of memories that are relevant to that self and that remain highly accessible to the rememberer later in life. This study offers a new methodology for academics and clinicians interested in the relationship between memory and identity.

The domestic garden: its contribution to urban green infrastructure

Domestic gardens provide a significant component of urban green infrastructure but their relative contribution to eco-system service provision remains largely un-quantified. ‘Green infrastructure’ itself is often ill-defined, posing problems for planners to ascertain what types of green infrastructure provide greatest benefit and under what circumstances. Within this context the relative merits of gardens are unclear; however, at a time of greater urbanization where private gardens are increasingly seen as a ‘luxury’, it is important to define their role precisely. Hence, the nature of this review is to interpret existing information pertaining to gardens /gardening per se, identify where they may have a unique role to play and to highlight where further research is warranted. The review suggests that there are significant differences in both form and management of domestic gardens which radically influence the benefits. Nevertheless, gardens can play a strong role in improving the environmental impact of the domestic curtilage, e.g. by insulating houses against temperature extremes they can reduce domestic energy use. Gardens also improve localized air cooling, help mitigate flooding and provide a haven for wildlife. Less favourable aspects include contributions of gardens and gardening to greenhouse gas emissions, misuse of fertilizers and pesticides, and introduction of alien plant species. Due to the close proximity to the home and hence accessibility for many, possibly the greatest benefit of the domestic garden is on human health and well-being, but further work is required to define this clearly within the wider context of green infrastructure.

Mouse movements of motion-impaired users: a submovement analysis

Understanding human movement is key to improving input devices and interaction techniques. This paper presents a study of mouse movements of motion-impaired users, with an aim to gaining a better understanding of impaired movement. The cursor trajectories of six motion-impaired users and three able-bodied users are studied according to their submovement structure. Several aspects of the movement are studied, including the frequency and duration of pauses between submovements, verification times, the number of submovements, the peak speed of submovements and the accuracy of submovements in two-dimensions. Results include findings that some motion-impaired users pause more often and for longer than able-bodied users, require up to five times more submovements to complete the same task, and exhibit a correlation between error and peak submovement speed that does not exist for able-bodied users.

Access to the countryside of England and Wales: public/private partnership or the privatisation of public rights?

This paper examines the evolution of public rights of access to private land in England and Wales. Since the Eighteenth Century the administration and protection of these rights has been though a form of public/private partnership in which the judiciary, while maintaining the dominance of private property, have safeguarded de facto public access by refusing consistently to punish simple trespass. While this situation has been modified, principally by post-World War II legislation, to allow for some formalisation of access arrangements and consequent compensation to landowners in areas of high recreational pressure and low legal accessibility, recent policy initiatives suggest that the balance of the partnership has now shifted in favour of landowners. In particular, the new access payment schemes, developed by the UK Government in response to the European Commission's Agri-Environment Regulations, locate the landowner as the beneficiary of the partnership, financed by tax revenue and justified on the spurious basis of improved 'access provision'. As such the state, as the former upholder of citizen rights, now assumes the duplicitous position of underwriting private property ownership through the commodification of access, while proclaiming a significant improvement in citizens' access rights.

Partnership in the provision of recreational access: the reconstruction of the public interest in private land in England and Wales

This paper examines the evolution of public rights of access to private land in England and Wales. Since the Eighteenth Century the administration and protection of these rights has been though a form of public/private partnership in which the judiciary, while maintaining the dominance of private property, have safeguarded de facto public access by refusing consistently to punish simple trespass. While this situation has been modified, principally by post-World War II legislation, to allow for some formalisation of access arrangements and consequent compensation to landowners in areas of high recreational pressure and low legal accessibility, recent policy initiatives suggest that the balance of the partnership has now shifted in favour of landowners. In particular, the new access payment schemes, developed by the UK Government in response to the European Commission's Agri-Environment Regulations, identify the landowner as the beneficiary of the partnership, financed by tax revenue and justified on the spurious basis of improved 'access provision'. As such the State, as the former upholder of citizen rights, now assumes the duplicitous position of underwriting private property ownership through the commodification of access, while proclaiming a significant improvement in citizens' access rights.