Macquarie University

About: Macquarie University is a education organization based out in Sydney, New South Wales, Australia. It is known for research contribution in the topics: Population & Context (language use). The organization has 14075 authors who have published 47673 publications receiving 1416184 citations. The organization is also known as: Macquarie uni.

Determining the Value of Cultural Goods: How Much (or How Little) Does Contingent Valuation Tell Us?

Abstract: Contingent valuation methods (CVM) are now well established as a means of measuring the nonmarket demand for cultural goods and services. When combined with valuations provided through market processes (where relevant), an overall assessment of the economic value of cultural commodities can be obtained. Within a neoclassical framework, such assessments are thought to provide a complete picture of the value of cultural goods. But are there aspects of the value of cultural goods which are not fully captured, or not captured at all, within such a model? This paper argues that CVM provides an incomplete view of the nonmarket value of cultural goods, and that alternative measures need to be developed to provide a fuller account. of Sydney which sought to measure the community's willingness to pay (WTP) for the perceived public-good benefits of the arts. Around 825 respondents were questioned about the nature and extent of the nonmarket benefits they enjoyed from the existence of the subsidised arts in Australia - literature, visual arts, music, theatre, dance, etc. - and they were asked to nominate the dollar amounts they would be willing to pay out of their taxes to support the arts, under conditions of both liability and nonliability for actual payment. With appropriate caveats, we concluded from our research that aggregate WTP for the public-good benefits of the arts in Australia at that time exceeded the then-prevailing tax-price of cultural subsidy. What did we think we were measuring in this study and what did we actually measure? As far as the arts were concerned, our work was predicated on two princi- pal motivations, one theoretical and one practical. The theoretical drive came from a desire to test the longstanding proposition that the arts were a case of market failure. This hypothesis, first articulated in the 1960s (Baumol and Bowen, 1966; Peacock, 1969) and elaborated at length in our own book of 1979 (Throsby and

Why are non-photosynthetic tissues generally 13C enriched compared with leaves in C3 plants? Review and synthesis of current hypotheses.

Abstract: Non-photosynthetic, or heterotrophic, tissues in C3 plants tend to be enriched in 13C compared with the leaves that supply them with photosynthate. This isotopic pattern has been observed for woody stems, roots, seeds and fruits, emerging leaves, and parasitic plants incapable of net CO2 fixation. Unlike in C3 plants, roots of herbaceous C4 plants are generally not 13C-enriched compared with leaves. We review six hypotheses aimed at explaining this isotopic pattern in C3 plants: (1) variation in biochemical composition of heterotrophic tissues compared with leaves; (2) seasonal separation of growth of leaves and heterotrophic tissues, with corresponding variation in photosynthetic discrimination against 13C; (3) differential use of day v. night sucrose between leaves and sink tissues, with day sucrose being relatively 13C-depleted and night sucrose 13C-enriched; (4) isotopic fractionation during dark respiration; (5) carbon fixation by PEP carboxylase; and (6) developmental variation in photosynthetic discrimination against 13C during leaf expansion. Although hypotheses (1) and (2) may contribute to the general pattern, they cannot explain all observations. Some evidence exists in support of hypotheses (3) through to (6), although for hypothesis (6) it is largely circumstantial. Hypothesis (3) provides a promising avenue for future research. Direct tests of these hypotheses should be carried out to provide insight into the mechanisms causing within-plant variation in carbon isotope composition.

Achieving Secure Role-Based Access Control on Encrypted Data in Cloud Storage

Abstract: With the rapid developments occurring in cloud computing and services, there has been a growing trend to use the cloud for large-scale data storage. This has raised the important security issue of how to control and prevent unauthorized access to data stored in the cloud. One well known access control model is the role-based access control (RBAC), which provides flexible controls and management by having two mappings, users to roles and roles to privileges on data objects. In this paper, we propose a role-based encryption (RBE) scheme that integrates the cryptographic techniques with RBAC. Our RBE scheme allows RBAC policies to be enforced for the encrypted data stored in public clouds. Based on the proposed scheme, we present a secure RBE-based hybrid cloud storage architecture that allows an organization to store data securely in a public cloud, while maintaining the sensitive information related to the organization's structure in a private cloud. We describe a practical implementation of the proposed RBE-based architecture and discuss the performance results. We demonstrate that users only need to keep a single key for decryption, and system operations are efficient regardless of the complexity of the role hierarchy and user membership in the system.