Analysing and controlling the self-assembly of Gelation

We describe new methods to analyse and control the self-assembly of gelation leading to exciting new soft materials. These materials have been shown to be of use to a wide range of applications including antimicrobial coatings, OPV devices, thermochromic materials and biomedical materials. Many of the described methods are novel or go beyond the state of the art. One of the analytical methods probes the surface chemistry of self-assembled hydrogel fibres to determine their pKa. This method not only determines the gel’s pKa but whether indeed a gel would form from a small molecule and what its rheological stiffness would be. This is the first incident of electrochemistry being used to determine the rheology of gels. Furthermore, a method to probe in the real time the self-assembly kinetics of a gelator to form a gel using multiple pulse amperometry is described. This method is expanded to complex multicomponent systems. Electrochemically fabricated hydrogels are developed and for the first time we show how the rheological properties can be controlled by controlling the electrochemical parameters. In addition to controlled rheological properties, the gels formed have unique mesh sizes and thermochromic properties. We introduce a new gelation trigger method for low molecular weight hydrogels. Dopamine autoxidation can be used to control the self-assembly of small molecules to form gels and we go on to describe how these gels can be used for antimicrobial purposes. To expand on the electrochemically fabricated hydrogels, we propose the oxidation of dopamine as a new electrochemical trigger. We describe how the rheological properties of the gels can be controlled and how they are potentially suitable for biomedical applications. Finally, we describe a method to control the self-assembly of both single and multi-component gel networks by temperature and use an array of analytical techniques to show this. We expand on this work to show how the temperature control can form gels with varying networks which lead directly to changes in the efficiency of electron transfer

Child–parent interaction in relation to road safety education : Part 2 – main report

• Children and young people are particularly vulnerable road users. • Child pedestrian injury rates are poor compared with the rest of Europe. • The factors that impact on children’s road safety and their capability in traffic are numerous, multi-faceted and complex. • • The systematic review conducted by Cattan et al. (2008) as the initial phase of this study shows that: • parents see themselves as being responsible for developing their children’s road safety awareness and skills; • holding hands is the most common road-crossing interaction between parents and children; • adults rarely make use of road-crossing events to give oral instructions; • few parents and children are consistent in their road-crossing behaviour; • roadside training by volunteer parents for groups of children can lead to significant improvements in children’s road safety behaviour; • belief in fate seems to influence the likelihood of parents using restraints, such as seat belts or car seats, with their children; and • parents’ understanding of the child’s perspective in carrying out road safety tasks and their motivation to actively involve their child in making decisions at the roadside can be improved through training. • Social Cognitive Theory (Bandura, 1986) suggests that the modelling role of parents can make a significant contribution to children’s learning about road use and their development of traffic competence whether or not parents are aware of this. • The main aim of this study was to explore the way parents influence children and young people aged 0–16 years to be safer road users. • This study included children and young people aged 5–16 and parents of children aged 0–16 years old

Attentional processes in mosquito-eating jumping spiders: search imagesand cross-modality priming

Evarcha culicivora, a species of jumping spider (Araneae: Salticidae from the Lake Victoria region of East Africa, has unusual prey-choice behaviour. It preferred prey is blood-carrying mosquitoes. It also has unusually complex mate-choice behaviour, with mutual mate choice being pronounced. This thesis is a study of E. culicivora’s prey-choice behaviour and mate-choice behaviour, as well as a study of processes underlying selective attention in this unusual species. E. culicivora uses olfaction in unique and often surprising ways. This includes identifying potential mates by odour alone, as well as choosing the odour of potential mates that have recently fed on blood-carrying mosquitoes. The odour of potential mates also primes both sexes for escalating conflict with potential rivals, as well as priming selective attention to the masked odour of specifically potential mates. Besides all this, the odour of blood-carrying mosquitoes primes E. culicivora to selectively attend to the masked odour of specifically this prey. Moreover, the appearance of blood-carrying mosquitoes and of potential mates primes E. culicivora to selectively attend to specifically the appearance of cryptic blood-carrying mosquitoes and cryptic potential mates, respectively. Vision and olfaction can even work together, with olfactory and visual cues from blood-carrying mosquitoes priming E. culicivora to selectively attend to the appearance and odour, respectively, of blood-carrying mosquitoes. Furthermore, E. culicivora has a poorly-understood relationship with two plant species, Lantana camara and Ricinus communis, and E. culicivora can identify these two plant species by odour alone. These plants may be relevant to this salticid as a nectar source by which it supplements its insect diet, but these plants may also be as sites at which E. culicivora males and females find potential mates, with E. culicivora’s interactions on these plants being especially exaggerated and complex

How mosquito-eating jumping spiders communicate: complex display sequences, selective attention and cross-modality priming

Evarcha culicivora is a salticid with an unusual preferred diet (vertebrate blood obtained indirectly by preying on female mosquitoes that have themselves had recent blood meals) and an unusual affinity for particular plant species (Lantana camara and Ricinus communis). This thesis is a study of how individuals of this species interact with each other, with a general objective being to clarify the role of visual attention and crossmodality priming in the mate-choice behaviour of this species. E. culicivora’s courtship and display behaviour was shown to be especially complex and highly variable. Experiments on vision-based mate-choice showed that mutual mate-choice behaviour is pronounced in E. culicivora and that both sexes prefer large mates over small mates. Olfactometer experiments showed that E. culicivora is attracted to the odours of bloodfed female mosquitoes, Lantana camara and Ricinus communis and opposite-sex conspecifics. A prior diet of blood-fed female mosquitoes enhances attractiveness to the opposite sex. Opposite-sex conspecifics paired with the odour of blood-fed female mosquitoes are also more attractive. Cross-modality priming effects were investigated in other experiments that showed individuals of E. culicivora responded more to visual cues of opposite-sex conspecifics when in the presence of certain odours (of opposite-sex conspecifics, blood-fed female mosquitoes and L. camara)

The reproductive biology of the exploited razor clam, Ensis siliqua, in the Irish Sea

Knowledge of the reproductive cycle of a species is a prerequisite for sustainable management of a fishery. The infaunal marine bivalve, Ensis siliqua, is a commercially important species in Europe, and is exploited in many countries, including Ireland, where it is sold by wet weight. Seasonal variations in the reproductive cycle of subtidal razor clams from the Skerries region of the Irish Sea, an important fisheries area, were examined between June 2010 and September 2011 while monitoring weight. Histological examination revealed that the E. siliqua sex-ratio was not different from parity, and no hermaphrodites were observed in the samples collected. In the summer months of 2010 all female clams were either spent or in early development, with just a small percentage of males still spawning. The gonads of both sexes developed over the autumn and winter months of 2010, with the first spawning individuals recorded in January 2011. Spawning peaked in March 2011, but unlike in 2010, spawning continued through June and July with all animals spent in August 2011. The earlier and longer spawning period found in this species in 2011 compared to 2010 may have been due to the colder than normal temperature observed during the winter of 2010 plus the relatively warmer temperatures of Spring 2011, which could have affected the gametogenic development of E. siliqua in the Irish Sea. It was noted that wet weight dropped in the summer months of both years, immediately after the spawning period which may impact on the practicality of fishing for this species during this period. Timing of development and spawning is compared with other sites in the Irish Sea and elsewhere in Europe, including the Iberian Peninsula

Estimating the potential of beekeeping to alleviate household poverty in rural Uganda

<div><p>Robust evidence underpinning the role of beekeeping in poverty alleviation is currently lacking. This study estimated the production potential for beekeepers in Northern Uganda by quantifying current production assets (equipment and knowledge) and impact on rural income streams range of proposed interventions. Intervention scenarios evaluated the economic benefits to be derived from different hive types combined with year-round provision of a nectar source (<i>Calliandra calothyrsus</i>) planted at varying density. Findings show that the type and number of beehive combinations used influenced the amount of revenue streams generated by the beekeepers. Addition of 20 log hives increased incomes 10 times, 20 KTBs increased revenues 16 times and Langstroth 18 times. Adding <i>Calliandra</i> trees as a forage source to the baseline scenario yielded revenues up to 17.6 times higher than the baseline. Implying that good management plus the introduction of a reliable nectar source, to off-set dry season challenges (absconding), could improve beekeeping productivity in Northern Uganda. Further research is required to validate <i>in situ</i> the impact of modelled scenarios on both honey yield and other ecosystem service benefits.</p></div