Fuzzy Sphere Dynamics and Non-Abelian DBI in Curved Backgrounds

We consider the non-Abelian action for the dynamics of $N Dp'$-branes in the background of $M Dp$-branes, which parameterises a fuzzy sphere using the SU(2) algebra. We find that the curved background leads to collapsing solutions for the fuzzy sphere except when we have $D0$ branes in the $D6$ background, which is a realisation of the gravitational Myers effect. Furthermore we find the equations of motion in the Abelian and non-Abelian theories are identical in the large $N$ limit. By picking a specific ansatz we find that we can incorporate angular momentum into the action, although this imposes restriction upon the dimensionality of the background solutions. We also consider the case of non-Abelian non-BPS branes, and examine the resultant dynamics using world-volume symmetry transformations. We find that the fuzzy sphere always collapses but the solutions are sensitive to the combination of the two conserved charges and we can find expanding solutions with turning points. We go on to consider the coincident $NS$5-brane background, and again construct the non-Abelian theory for both BPS and non-BPS branes. In the latter case we must use symmetry arguments to find additional conserved charges on the world-volumes to solve the equations of motion. We find that in the Non-BPS case there is a turning solution for specific regions of the tachyon and radion fields. Finally we investigate the more general dynamics of fuzzy $\mathbb{S}^{2k}$ in the $Dp$-brane background, and find collapsing solutions in all cases.Comment: 49 pages, 3 figures, Latex; Version to appear in JHE

2009 Influenza A(H1N1) seroconversion rates and risk factors among distinct adult cohorts in Singapore

10.1001/jama.2010.404JAMA - Journal of the American Medical Association303141383-139

Black areas: Urban kampongs and power relations in post-war Singapore historiography

By analysing a collection of key texts, this paper examines state-society relations in post-war Singapore in social and spatial terms. It traces the history of state regulation of urban space and a parallel story ot resistance by the Chinese population, This paper analyses the making of modern Singapore as a contestation over urban space in the post-war years. A strategic theatre of this struggle was the autonomous Chinese kampongs on the urban periphery. A controlling discourse, representing the urban kampongs as sites of social pollution, made possible the state's efforts to eradicate them by relocating their dwellers in public housing

History, memory, and identity in modern Singapore: Testimonies from the urban margins

In 2006-2007, I interviewed elderly Singaporeans on their experiences of resettlement from an urban kampong (village) to emergency public housing after a great fire in 1961. I learned much about the lives of semiautonomous dwellers in an unauthorized settlement and the individual and social transformation following their rehousing. My informants also highlighted what the experiences meant to them and their identity in a modern city-state. This paper treats the testimonies as both source and social memory and seeks to avoid the essentialism into which many social historians, oral history practitioners, and memory scholars have fallen in their approach toward the craft. As a source of social history, when used in conjunction with other historical sources, the reminiscences are patently useful for understanding the role of public housing in transforming a marginal population into an integrated citizenry. This enables the writing of a new social history of postwar Singapore that departs from the discursive official accounts of urban kampong life and of the 1961 inferno. At the same time, the oral history also underlines powerful social and political influences on individual memory, being marked by nostalgia for the kampong and ambivalence toward the imagined character of younger Singaporeans. Statements on the rumors of government-inspired arson in the 1961 calamity, however, constitute a significant countermyth in contemporary society, revealing a more critical side to the social memory

Intralaryngeal thyroglossal duct cyst: Implications for the migratory pathway of the thyroglossal duct

Annals of Otology, Rhinology and Laryngology1152114-11

The role of radiation in delayed hearing loss in nasopharyngeal carcinoma

Journal of Laryngology and Otology1142139-144JLOT

Rhinosporidiosis: An unusual cause of nasal masses gains prominence

Singapore Medical Journal455224-226SIMJ

Subclavian-oesophageal Fistula as a Complication of Foreign Body Ingestion: A Case Report

Annals of the Academy of Medicine Singapore272277-278AAMS

Diet and feeding in the sea star Astropecten indicus (Döderlein, 1888)

Raffles Bulletin of Zoology592251-25