The raft-promoting property of virion-associated cholesterol, but not the presence of virion-associated brij 98 rafts, is a determinant of human immunodeficiency virus type 1 infectivity

Lipid rafts are enriched in cholesterol and sphingomyelin and are isolated on the basis of insolubility in detergents, such as Brij 98 and Triton X-100. Recent work by Holm et al. has shown that rafts insoluble in Brig 98 can be found in human immunodeficiency virus type 1 (HIV-1) virus-like particles, although it is not known whether raft-like structures are present in authentic HIV-1 and it is unclear whether a virion-associated raft-like structure is required for HIV replication. Independently, it was previously reported that virion-associated cholesterol is critical for HIV-1 infectivity, although the specific requirement of virion cholesterol in HIV-1 was not examined. In the present study, we have demonstrated that infectious wild-type HIV-1 contains Brij 98 rafts but only minimal amounts of Triton X-100 rafts. To directly assess the functional requirement of virion-associated rafts and various features of cholesterol on HIV-1 replication, we replaced virion cholesterol with exogenous cholesterol analogues that have demonstrated either raft-promoting or -inhibiting capacity in model membranes. We observed that variable concentrations of exogenous analogues are required to replace a defined amount of virion-associated cholesterol, showing that structurally diverse cholesterol analogues have various affinities toward HIV-1. We found that replacement of 50% of virion cholesterol with these exogenous cholesterol analogues did not eliminate the presence of Brij 98 rafts in HIV-1. However, the infectivity levels of the lipid-modified HIV-1s directly correlate with the raft-promoting capacities of these cholesterol analogues. Our data provide the first direct assessment of virion-associated Brij 98 rafts in retroviral replication and illustrate the importance of the raft-promoting property of virion-associated cholesterol in HIV-1 replication.

Novel approaches to process bamboo plants into fibres and their UV-blocking property

Currently viscose production methods are primarily used to process bamboo into commercial textile fibres. However, viscose methods use large quantities of chemicals and hence the process is not considered as environmentally friendly. The process also fails to retain bamboo’s inherent unique properties such as ultraviolet (UV) screening and antibacterial functions. Hence, it is necessary to design an effective and more eco-friendly manufacturing method that would also retain the unique properties of raw bamboo plant into the fibres. In this research, bamboo was processed using new methods involving thermo mechanical treatments such as ultra-sonication, shaker milling and boiling with continuous stirring. Sodium hydroxide, hydrogen peroxide, enzyme and water were used separately in this process and their effects on fibre processing were compared. The morphology and UV shielding ability were analysed before and after processing. It was demonstrated that bamboo can be processed into fibres using only water and ball milling without the aid of any hazardous chemicals. The combination of mild acid hydrolysis and ultrasonic treatment with hydrogen peroxide was effective in the fibre separation and provided better appearance of fibres.

Intellectual property rights in indigenous cultural heritage : basic concepts and continuing controversies

The developments at international level in the debate on what intellectual property (IP) lawyers refer to as traditional cultural expressions (TCEs) have to be seen in the context of the decolonisation movements after the Second World War. Post-war developments saw the formation of the United Nations (UN) and the emphasis on human rights in the UN Charter. With this emphasis came development programmes for indigenous peoples and the recognition of indigenous rights in the ILO Convention No. 107 of the 1957 Concerning the Protection and Intergration of Indigenous and Other Tribal and Semi-Tribal Populations in the Independant Countries. The decolonisation movements also initiated or renewed a parallel debate about the repatriation of items of cultural heritage. There was a remarkable shift in this discussion from 'cultural heritage of mankind' to cultural particularism and an emphasis on 'cultural property' ....