Introduction to special issue: Meeting the challenges of HIV/AIDS in Southeast and East Asia

Out of a total of 38 million people living with HIV/AIDS globally today, the Asia‐Pacific is home to about 7.4 million – a figure which constitutes a sharp rise to previous years. In absolute numbers, infections in Asia are projected to exceed African figures within a decade. This has largely to do with economic changes towards market‐based capitalism, widening socioeconomic disparities and increased levels of mobility (internal and cross‐border), as for instance in China and Indonesia. Overall, the epidemic in Asia has been described as more complex than in Africa involving a multiplicity of transmission modes. The case studies presented in the contributions to this special issue discuss the connections between issues of mobility, gender, (trans)nationalism and sexuality in understanding the HIV/AIDS challenge in the region. The various ways in meeting the challenges of HIV/AIDS in Southeast and East Asia are analysed, whereby non‐governmental and community‐based responses often emerge as more effective than state interventions.     

Negotiating ‘home’ and ‘national identity’: Chinese‐Malaysian transmigrants in Singapore

Abstract: Part of the globalisation phenomenon involves an increasing number of elite transmigrants traversing national boundaries in response to the global demand for skilled labour while maintaining multifaceted social ties astride political, geographic and cultural borders, linking home and host countries together. As transmigrants ‘live’ in several communities simultaneously, their identities, behaviour and values are often not limited by location. Thus, notions of ‘home’ and ‘national identity’ are also being reviewed given the discrepancies between these concepts and locality. In this context, this paper explores questions of ‘home’ and ‘national identity’ among skilled Chinese‐Malaysians working and residing in Singapore, portraying them as active participants of two (or more) countries. It focuses on their strategies and struggles in negotiating ideologies of ‘home’ and ‘national identities’ across borders in a setting of two neighbouring countries umbilically linked in a volatile political relationship. It further examines their degree of concern in the political affairs of both countries. Between ‘home’ and ‘host’, Chinese‐Malaysians redefine their practices of home(‐making) in relation to their national identity, drawing on the resources and resilience of familial ties, nostalgic memories and other practical lifecourse needs.     

Toxicity and horizontal transfer of chlorantraniliprole against the Asian subterranean termite Coptotermes gestroi (Wasmann): effects of donor:recipient ratio, exposure duration and soil type

BACKGROUND: The effectiveness of chlorantraniliprole and other insecticides (bifenthrin, fipronil, indoxacarb, imidacloprid and chlorfenapyr) were tested against Coptotermes gestroi (Wasmann). Four experiments were conducted: a topical bioassay, a horizontal transfer study, an insecticide bioavailability test and a feeding bioassay. RESULTS: The topical bioassay showed that chlorantraniliprole was significantly less active to C. gestroi at 24 h post‐treatment compared with the other insecticides tested. Nevertheless, it is likely that a lesser amount of chlorantraniliprole was required to cause 50% mortality of C. gestroi at 7 and 14 days post‐treatment. The exposure duration and donor:recipient ratio affect the mortality of recipient termites. Mortality after exposure to chlorantraniliprole in sandy clay was significantly lower than in sand; however, by 14 days, > 90% of donor and recipient termites died in both substrates, irrespective of concentration. Fipronil and imidacloprid showed faster action, and high to moderate toxicity to C. gestroi. Termite workers also ceased to feed after exposure for 1 h to 50 mg kg^?1 chlorantraniliprole‐treated sandy clay. CONCLUSION: Chlorantraniliprole demonstrated delayed toxicity at the lowest label rate (50 mg kg^?1) in sandy clay. Its slow action will enable greater transfer of toxicant between nestmates, while feeding cessation will promote greater social interaction between healthy and exposed termites. Copyright © 2011 Society of Chemical Industry     

Linamarin content and genetic stability of cassava plants derived by somatic embryogenesis

A protocol was established for high frequency cyclic somatic embryogenesis for different varieties of cassava. An efficient plant regeneration system was developed for the high cyanogenic variety PRC60a. Linamarin content and linamarase activity were determined in various tissues of secondary somatic embryos and regenerated plants of PRC 60a. Both linamarin and linamarase activity were not detected in embryogenic callus, roots induced from callus and somatic embryo tissues. The stems and leaves of regenerated plants (in vitro) and storage roots and leaves of mature plants (in vivo), however, contained variable amounts of linamarin and linamarase activity whereas in the non storage root tissues (in vitro) only linamarin was detected. The present study suggested that the linamarin biosynthetic pathway may be absent or not switched on in the embryogenic callus and somatic embryos. The ploidy level and somatic chromosome number of the regenerated plants were found to be same as the source plants. The availability of this regeneration system would be useful not only for investigating cyanogenesis but also for genetic manipulation in cassava. This revised version was published online in July 2006 with corrections to the Cover Date.