79 Projects, page 1 of 16
This proposal aims at obtaining an annotated genome sequence of the powdery mildew fungus Blumeria graminis f sp hordei. This fungus is an obligate biotrophic pathogen that causes one the agronomically most important diseases of barley and is a 'model' organism for the study of powdery mildew diseases in other crops. We will sequence the genome with a 7-fold coverage. The sequence will be assembled automatically. An EST library of cDNAs isolated from haustoria will also be sequenced and annotated; this will complement the existing collections and complete the coverage of all the important stages in the pathogen's life cycle. The ESTs are instrumental in training the gene finding processes that drive the annotation. The annotation of the genomic sequence will be carried out using a series of pipelines already used for other genome projects (Botrytis and tomato). The results from the semi-automated annotation will then be verified by manual curation and reviewed by specialist researchers in the sequencing consortium. The results will be placed on publicly accessible web-sites and a meeting will be convened with the world wide user community to bring train potential users, present major outcomes of the sequencing and the first annotations and discuss the results.
Flat-panel displays now outsell those based on cathode ray tube technologies and by far the most popular of these are liquid crystal displays. However, OLEDs represent a competitive technology that can have niche applications and that are very compatible with printing technologies and mechanically flexible displays. Organic LED materials (e.g. polymers LEDs) emit from singlet states created in the device by charge injection, but the triplet states produced have lifetimes that are too long (i.e. milliseconds) to be useful. As three times as many triplet state are produced compared to singlet states, efficiency in these systems is not optimised. To be useful, triplet emitters need much shorter lifetimes. This can be accomplished in metal complexes containing heavy transition elements where efficient spin-orbit coupling 'circumvents' the spin-forbibben nature of triplet decay, allowing emission from singlet and triplet states. The metal complexes currently used in devices contain iridium(III) (these are the red emitting component).A significant development in the application of triplet emitters could be realised if the complexes were prepared as liquid crystalline derivatives, as this could lead to alignment and, therefore, polarised emission. White, polarised emission would greatly improve the efficiency of backlighting for liquid crystal displays by removing the need for the back polariser, reducing absorptive losses hugely. However, liquid crystallinity is not readily compatible with the geometries of the iridium(III) complexes (octahedral).We have now demonstrated that this incompatibility can be addressed and we have the first examples of LC iridium emitters. In the proposal for development of these systems we propose:-tuning of the available liquid crystal range;-modified design to allow ready tuning of the chromophore;-evaluation of device characteristics to provide essential data to potential end users.
When a solid is heated, at some temperature it will melt to form a liquid (eg the melting of ice to form water). However some compounds exist in a state that is intermediate between the solid and liquid states and has some properties of both. This state is known as a 'liquid crystal phase' and the compounds that form it are called liquid crystals (LCs). LCs are familiar to all as liquid crystal displays found in mobile phones, calculators, laptop computers etc. LCs are important in other ways, too and, it is known that they are important in the workings of the cells of living organisms and are the reason soaps and washing-up liquids clean so well.The molecules which make up liquid crystals have a special shape, being either long and thin (like a pencil), or thin and flat (like a pizza), and chemists knows how to make molecules with these shapes. Occasionally it is possible to make these molecules by using two parts instead of one. Thus, if we want to make a rod-shaped molecule, then while neither of the two parts would be long enough to show a LC phase, joining them together would give a 'supermolecule' that did show a liquid crystal phase. Normally, very strong bonds hold the atoms in these molecules together, but here the two parts are held together by a very specific but rather weak interaction.One of these weak interactions, the 'hydrogen bond', has been known for many years, but there is a very similar interaction that is weaker and much less well known called the 'halogen bond'. Recently the Exeter team showed that it could make LCs by using a halogen bond to hold together a supermolecule. We now want to make more examples where we vary the two parts carefully so that we learn more about these supermolecules. Because halogen bonding is used in other parts of chemistry, what we learn will be important for others, too.As the name suggests, halogen bonds involve the elements we call the halogens, and one of the two parts (the acceptor) will contain at least one halogen; in this work the halogen will be iodine. In the acceptor the iodine carries some positive charge because the acceptor design means negative charge is pulled away from it. It is then be happy to find another part to join with that carries some negative charge. This other part is called a donor and ours contain a nitrogen atom. In the donor, negative charge is pushed towards nitrogen allowing it to be attracted to the positive iodine. The two are attracted and a supermolecule is formed.We will first investigate how positive the iodine must be for the supermolecule to form by making several related acceptors. Then, if we put two iodines in our acceptor, we can bind two donors - a different type of supermolecule. We can also change the shape of the donor so that these 2-to-1 supermolecules look more like a pizza than a pencil. Next we can vary the donor, for if we add an oxygen atom to the nitrogen, it is then the oxygen that is attracted to the iodine of the acceptor; the oxygen is attracted more strongly than the nitrogen so the properties of the supermolecule will change.After we make these new systems, we need to look at the donor-acceptor interaction and the LC behaviour; this needs special experiments. We can see how strongly the donor and acceptor are attracted to each other in the solid state of the supermolecule using X-rays which 'see' the distance between the iodine and the nitrogen. We use light to help us understand the LC behaviour (the liquid crystal causes pretty patterns to be seen), and we can use light in a different way to estimate the separation of the iodine and nitrogen in the liquid crystal phase (the light absorbed by the donor changes depending how far the iodine is from the nitrogen).This work will give a precise picture of the behaviour of the halogen bond in general and, in particular, in liquid crystals, and show how it might usefully be used in the future.NB This was tried on my 14 year-old daughter!
This project seeks to improve our understanding of how and why languages tend to change when they come into contact, with a particular focus on Arabic and the many languages it has influenced and been influenced by in its 1500 years of written and spoken history. The project has three strands. First, there is a theoretical strand, in which the aim is to construct a general model of the cognitive processes at work in the minds of bilingual individuals that cause them to introduce changes into one or both of their languages - changes which can then be acquired by children learning their first languages. In my previous work in this area I have focused on contact between languages that are mutually unintelligible to monolingual speakers of each. In this project I will extend the model so that it also accounts for changes that result from contact between related dialects, and I will also show how this model of contact-induced change can be integrated into existing models that focus on linguistic change that is caused by internal factors, not language contact. The second strand of the project involves collaboration with the project partner, Stefano Manfredi (SeDyL-CNRS), and the project research assistant, to edit a handbook of Arabic and contact-induced language change. Chapters will be contributed by leading experts on this subject, giving accessible summaries of topics including: contact-induced change in the Arabic dialects of various regions, such as Morocco, Malta and Cyprus; the Pidgin/Creole varieties of Arabic spoken in Uganda and South Sudan; Arabic influences on languages such as Aramaic, Swahili and Somali; the influence of different Arabic dialects on each other; and specific areas of Arabic grammar in which contact-induced change has played a role. This handbook will be published by Language Science Press, an open access publisher, so it will be freely available for anyone to read online. The third strand of the project aims at raising awareness of the importance of language and dialect contact for the practice of 'LADO' (language analysis for the determination of origin) in asylum claims by Arabic-speaking individuals in the UK. LADO is a tool used by some governments to aid in decisions on whether asylum claims are genuine. Typically, claimants are interviewed, in Arabic, and their speech in this interview is then examined to see if it exhibits the known features of the dialect of the claimant's stated region of origin. But there is a problem with how LADO is practiced in the initial stages of an asylum claim. In all such LADO reports that I have seen, produced by commercial organisations contracted by the UK government, no account is taken of the fact that the speech of emigrant Arabic speakers is likely to be influenced by the other languages and Arabic dialects they are exposed to daily, as well as by the speech of their interviewer. The project will address this problem by collecting and publishing data on the speech of Arabic speakers resident in London, with a view to providing concrete evidence that Arabic speakers who have left their region of origin are more likely than not to exhibit influence in their speech from dialects other than their own. A second use of LADO is at the appeal stage of an asylum claim, where an independent expert is contracted to produce a new LADO report. Here the problem is that experts are producing their reports in virtual isolation, without common standards of best practice, while solicitors seem to be contacting potential experts on a haphazard, word-of-mouth basis. The project will address this problem through consultative workshops with stakeholders in Arabic-based LADO that aim to establish and then promote the necessary best practices, and by producing and maintaining an online register of LADO-active Arabic linguists for solicitors to contact. The project thus intends to have a genuine impact both in academic linguistics and on the UK asylum system.