The University of East Anglia is an English public research university located in the city of Norwich. Established in 1963, the university comprises 4 faculties and 28 schools of study. Situated to the south-west of the city of Norwich, the university campus is approximately 320 acres in size.In 2012 the University was named the 10th best university in the world under 50 years old, and 3rd within the United Kingdom. In national league tables the university has most recently been ranked 14th in the UK by The Times and Sunday Times, 14th by The Guardian and 15th by The Complete University Guide. The university also ranked 1st for student satisfaction by the Times Higher Education magazine in 2013.Notable alumni include Nobel Laureate and President of the Royal Society Sir Paul Nurse, King of Tonga Tupou VI, and the Booker Prize-winning authors Ian McEwan, Kazuo Ishiguro and Anne Enright. Wikipedia.
Salman H.,University of East Anglia
Physical Review Letters | Year: 2013
We consider the propagation of breathers along a quantized superfluid vortex. Using the correspondence between the local induction approximation (LIA) and the nonlinear Schrödinger equation, we identify a set of initial conditions corresponding to breather solutions of vortex motion governed by the LIA. These initial conditions, which give rise to a long-wavelength modulational instability, result in the emergence of large amplitude perturbations that are localized in both space and time. The emergent structures on the vortex filament are analogous to loop solitons but arise from the dual action of bending and twisting of the vortex. Although the breather solutions we study are exact solutions of the LIA equations, we demonstrate through full numerical simulations that their key emergent attributes carry over to vortex dynamics governed by the Biot-Savart law and to quantized vortices described by the Gross-Pitaevskii equation. The breather excitations can lead to self-reconnections, a mechanism that can play an important role within the crossover range of scales in superfluid turbulence. Moreover, the observation of breather solutions on vortices in a field model suggests that these solutions are expected to arise in a wide range of other physical contexts from classical vortices to cosmological strings. © 2013 American Physical Society.
Dalmay T.,University of East Anglia
Essays in Biochemistry | Year: 2013
MicroRNAs regulate the expression of protein-coding genes in animals and plants. They function by binding to mRNA transcripts with complementary sequences and inhibit their expression. The level of sequence complementarity between the microRNA and mRNA transcript varies between animal and plant systems. Owing to this subtle difference, it was initially believed that animal and plant microRNAs act in different ways. Recent developments revealed that, although differences still remain in the two kingdoms, the differences are smaller than first thought. It is now clear that both animal and plant microRNAs mediate both translational repression of intact mRNAs and also cause mRNA degradation. © The Authors Journal compilation © 2013 Biochemical Society.
Bourke A.F.G.,University of East Anglia
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2014
Hamilton's rule is a central theorem of inclusive fitness (kin selection) theory and predicts that social behaviour evolves under specific combinations of relatedness, benefit and cost. This reviewprovides evidence for Hamilton's rule by presenting novel syntheses of results from two kinds of study in diverse taxa, including cooperatively breeding birds and mammals and eusocial insects. These are, first, studies that empirically parametrize Hamilton's rule in natural populations and, second, comparative phylogenetic analyses of the genetic, life-history and ecological correlates of sociality. Studies parametrizing Hamilton's rule are not rare and demonstrate quantitatively that (i) altruism (net loss of direct fitness) occurs even when sociality is facultative, (ii) in most cases, altruism is under positive selection via indirect fitness benefits that exceed direct fitness costs and (iii) social behaviour commonly generates indirect benefits by enhancing the productivity or survivorship of kin. Comparative phylogenetic analyses showthat cooperative breeding and eusociality are promoted by (i) high relatedness and monogamy and, potentially, by (ii) life-history factors facilitating family structure and high benefits of helping and (iii) ecological factors generating lowcosts of social behaviour. Overall, the focal studies strongly confirmthe predictions of Hamilton's rule regarding conditions for social evolution and their causes. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
Bochmann M.,University of East Anglia
Accounts of Chemical Research | Year: 2010
Ion-ion interactions are a crucial but often overlooked aspect of many polymerization reactions. The precise nature of cation-anion binding is as yet poorly understood, and little is known of the extent of ionic interactions in the typically nonaqueous, low-polarity reaction media of most polymerizations. Nevertheless, adequate control of cation-anion interactions can greatly enhance the productivity and efficiency of chemical processes and can provide low-energy alternatives to current methods. This is illustrated here with the carbocationic polymerization of isoalkenes. Carbocationic polymerizations involve, as the name implies, carbocations as propagating species. Of the various types of substrates that can be polymerized cationically, the copolymerization of isobutene to isobutene-isoprene rubber stands out as the only large-scale, industrially important implementation of this reaction type. The products, elastomers with controlled degrees of unsaturation for subsequent cross-linking, have excellent gas barrier and mechanical dampening properties that make them indispensable components in polymer composites. For such applications, the polymer molecular weight has to be high, 5 × 10 5 g/mol, with 1-2 mol % isoprene. Cationic polymerizations are however notoriously difficult to control. As a means of suppressing chain transfer, the process is carried out at temperatures as low as -100 °C, with aluminum chloride initiators in chloromethane. Current industrial production of isobutene-isoprene butyl rubber is thus highly energy intensive and produces aluminum and chloride effluent. This Account summarizes how highly electrophilic organometallics coupled with new types of very weakly coordinating counteranions can provide the basis for a more environmentally friendly, lower energy alternative. Because any copolymerization of two monomers, here primarily isobutene and isoprene, leads to two different propagating species, each of which is characterized by different chain growth and chain termination kinetics, variation of the associated counteranions can give rather unexpected results. With judicious choice of the initiator and the counteranion, new chemistry can be injected into such processes and can open avenues to new families of polymer materials. Mechanistic investigations of the initiation process with zirconocene hydrides illustrate the complexity of this first step. Replacing aluminum with zinc initiators not only provides a nontoxic alternative but also generates a system in which the polymer molecular weight is much less affected by temperature and comonomer concentration, which can lead to a range of products, from oligomeric lubricant precursors to C-C-rich high-molecular-weight elastomers. The key in all these cases is the construction of either preformed or in situ-generated complex anions that are resistant to electrophilic or redox degradation and are capable of stabilizing tightly associated carbocations. Such initiator systems allow much more benign operating temperatures, reduce the need for chlorocarbon solvents, and can operate at concentrations as low as 5 × 10-5 M. Along the way are provided the first examples of structurally characterized sec-alkyl carbocations and carbocation salts of organometallic zincates. © 2010 American Chemical Society.
Saiz-Lopez A.,Laboratory for Atmospheric and Climate Science CIAC |
Von Glasow R.,University of East Anglia
Chemical Society Reviews | Year: 2012
Halogen chemistry is well known for ozone destruction in the stratosphere, however reactive halogens also play an important role in the chemistry of the troposphere. In the last two decades, an increasing number of reactive halogen species have been detected in a wide range of environmental conditions from the polar to the tropical troposphere. Growing observational evidence suggests a regional to global relevance of reactive halogens for the oxidising capacity of the troposphere. This critical review summarises our current understanding and uncertainties of the main halogen photochemistry processes, including the current knowledge of the atmospheric impact of halogen chemistry as well as open questions and future research needs. © The Royal Society of Chemistry 2012.