Maintenance of the gag/gag-pol ratio is important for human immunodeficiency virus type 1 RNA dimerization and viral infectivity

Production of the human immunodeficiency virus type 1 (HIV_-1) Gag-Pol precursor protein results from a −1 ribosomal frameshifting event. In infected cells, this generates Gag and Gag-Pol in a ratio that is estimated to be 20:1, a ratio that is conserved among retroviruses. To examine the impact of this ratio on HIV_-1 replication and viral assembly, we altered the Gag/Gag-Pol ratio in virus-producing cells by cotransfecting HIV_-1 proviral DNA with an HIV_-1 Gag-Pol expression vector. Two versions of the Gag-Pol expression vector were used; one contains an active protease [PR(+)], and the other contains an inactive protease [PR(−)]. In an attempt to produce viral particles with Gag/Gag-Pol ratios ranging from 20:21 to 20:1 (wild type), 293T cells were cotransfected with various ratios of wild-type proviral DNA and proviral DNA from either Gag-Pol expression vector. Viral particles derived from cells with altered Gag/Gag-Pol ratios via overexpression of PR(−) Gag-Pol showed a ratio-dependent defect in their virion protein profiles. However, the defects in virion infectivity were independent of the nature of the Gag-Pol expression vector, i.e., PR(+) or PR(−). Based on equivalent input of reverse transcriptase activity, we estimated that HIV_-1 infectivity was reduced 250- to 1,000-fold when the Gag/Gag-Pol ratio in the virion-producing cells was altered from 20:1 to 20:21. Although virion RNA packaging was not affected by altering Gag/Gag-Pol ratios, changing the ratio from 20:1 to 20:21 progressively reduced virion RNA dimer stability. The impact of the Gag/Gag-Pol ratio on virion RNA dimerization was amplified when the Gag-Pol PR(−) expression vector was expressed in virion-producing cells. Virions produced from cells expressing Gag and Gag-Pol PR(−) in a 20:21 ratio contained mainly monomeric RNA. Our observations provide the first direct evidence that, in addition to proteolytic processing, the ratio of Gag/Gag-Pol proteins is also important for RNA dimerization and that stable RNA dimers are not required for encapsidation of genomic RNA in HIV_-1.

Understanding equity as an asset to national interest: developing a social contract analysis of policy

Alongside the influence of market-based reforms in education policy has been the growth of policy that has largely been overlooked – those that outline social contracts. This paper draws on policies that connect with equity as a way of illustrating this social contract turn in policy and develops a conceptualisation of social contracts as they apply to education policy. The argument provides three principles that underpin social contracts, including informed consent, negotiation and accountability. This paper applies these principles to three levels of social contract. At the first level are broad social contracts, which are associated with debates about the kinds of things that states should expect from its citizens, and the things that citizens could expect from governments and the state. The second level of social contract is an institutional or field-based social contract, which spells out the obligations and connections between a specific field and other fields. This level names a kind of social contract that is often exemplified in policies or statements by specific institutions. The third level of social contract deals with contract-like mechanisms embedded in fields that make tangible the obligations and expectations of citizens in fulfilling the expectations of fields.

Bone marrow chimeric mice reveal a role for CX3CR1 in maintenance of the monocyte-derived cell population in the olfactory neuroepithelium

Macrophages in the olfactory neuroepithelium are thought to play major roles in tissue homeostasis and repair. However, little information is available at present about possible heterogeneity of these monocyte-derived cells, their turnover rates, and the role of chemokine receptors in this process. To start addressing these issues, this study used Cx3cr1gfp mice, in which the gene sequence for eGFP was knocked into the CX3CR1 gene locus in the mutant allele. Using neuroepithelial whole-mounts from Cx3cr1gfp/+ mice, we show that eGFP+ cells of monocytic origin are distributed in a loose network throughout this tissue and can be subdivided further into two immunophenotypically distinct subsets based on MHC-II glycoprotein expression. BM chimeric mice were created using Cx3cr1gfp/+ donors to investigate turnover of macrophages (and other monocyte-derived cells) in the olfactory neuroepithelium. Our data indicate that the monocyte-derived cell population in the olfactory neuroepithelium is actively replenished by circulating monocytes and under the experimental conditions, completely turned over within 6 months. Transplantation of Cx3cr1gfp/gfp (i.e., CX3CR1-deficient) BM partially impaired the replenishment process and resulted in an overall decline of the total monocyte-derived cell number in the olfactory epithelium. Interestingly, replenishment of the CD68lowMHC-II+ subset appeared minimally affected by CX3CR1 deficiency. Taken together, the established baseline data about heterogeneity of monocyte-derived cells, their replenishment rates, and the role of CX3CR1 provide a solid basis to further examine the importance of different monocyte subsets for neuroregeneration at this unique frontier with the external environment.

Value relevance of information in hi-tech industries in Australia : accounting information and intangible asset disclosures

The main objective of this study is to test the value relevance of financial and non-financial information in high-tech industries in Australia. Ninety-one companies were selected from the sectors of Pharmaceuticals, Biotechnology and Life Sciences; Technology, Hardware and Equipment; and Telecommunication Services of ASX for the analysis. Both financial and non-financial sections of annual reports were scrutinized in order to obtain data for the analysis. The unaudited sections of annual reports were particularly analysed using NVivo to obtain the word-count of intangible assets. Ohlson’s (1995) Equity Valuation Model (modified for the intangible assets disclosures) was explicitly applied to examine the value relevance of financial and non-financial information. The overall results provide evidence that book value is the most significant factor and earnings are the least significant factor in deciding share prices in high-tech industries in Australia. This finding supports the previous studies that showed value relevance declined in earnings but increased in book value. This research proved that voluntary disclosures of intangible assets are value relevant, providing support for the previous US and Australian studies and the conclusion that investors probably increasingly rely upon alternative information sources.

Maintenance of cultural identity

The aim of this qualitative study is to explore the transmission of health beliefs among three generations of Greek families in Melbourne, Australia and the way they understand both health and disease as an aspect of cultural maintenance in the context of the larger Australian society. More specifically this paper will discuss the extent to which the immigrant generation has created a memory culture and how this has affected the sense of cultural identity of the first and second generation Greek Australians. Unlike the mainstream Australian community, the Greek population has so far maintaned a traditional framework due to the importance they ascribe to both culture and traditions that have been handed down from from the immigrant generation to the first and second generation Greek Australians. However, it is not only the immigrant generation that holds on to these traditions. More and more the first and second generation Greek Australians are set on maintaining their Hellenic heritage, and many community organizations in Melbourne, Australia are now largely supported by the younger generations. The results of this study have practical applications in elucidating how the memory culture that has been created by the immigrant generation may impact this cultural group’s conceptualization of health and the potential this may have to impact the use of health care by providin insight into the role of culture in forming individual or group conceptulizations of health in this community.

An assessment of empowerment through highly participatory asset-based community development in Myanmar

Asset-based community development (ABCD) is a highly participatory approach to development that seeks to empower communities to draw on tangible and social community assets to manage their own development. The strength of ABCD is its ability to facilitate people imagining their world differently, resulting in action to change their circumstances. Previous research has shown international non-government organisations have found highly participatory, community-led approaches to development to have been particularly effective forms of poverty mitigation and community empowerment within Myanmar, even before the current reforms, which is surprising given the restrictive socio-political context created by authoritarian rule by a regime with an international reputation for human rights violations. 

This paper documents ABCD programs within Myanmar, one of the poorest countries in Asia suffering major underdevelopment and ranking poorly across a wide range of socioeconomic indicators. It explores the operation, effectiveness and reasons behind the success of ABCD programs in this environment, and reflects on the role of outsiders in ABCD in the light of underlying theory and this contemporary experience. This research draws largely on recent field interviews and personal experience working in this sector within Myanmar, as well as surveying a number of evaluation reports which have been made publically available.

Attrition and maintenance of the Berber language in Tunisia

In this article, I examine the situation of Tunisian Berber from a linguistic and sociolinguistic perspective. The prolonged institutional marginalization of this language, the lack to date of a comprehensive documentation, and the passive attitude of the speakers themselves are contributing factors to its current decline. Present predictions as to its immediate extinction are alarming. However, conclusions drawn in other studies are not adequately supported and evidence from data recently collected in southern Tunisia partially refutes the claim that the decline of Tunisian Berber is irreversible. Even though attrition is evident in borrowing en masse from Arabic, grammatical evidence shows little structural change. After many years of neglect, efforts to document fully the remaining vernaculars are a positive step towards the revival of this variety of Berber. In this article I have three goals. First, to give an assessment of the problems and the challenges facing Tunisian Berber. Second, to describe the extent of attrition of this language based on field-collected data and, third, to suggest some directions for future studies of Tunisian Berber and strategies to stimulate its revival. Complete oral narratives, the first to be published, will be appended to the text in order to allow the linguistic community access to materials in its language.