University of Queensland

About: University of Queensland is a education organization based out in Brisbane, Queensland, Australia. It is known for research contribution in the topics: Population & Poison control. The organization has 51138 authors who have published 155721 publications receiving 5717659 citations. The organization is also known as: UQ & The University of Queensland.

N-FINDR: an algorithm for fast autonomous spectral end-member determination in hyperspectral data

Abstract: The analysis of hyperspectral data sets requires the determination of certain basis spectra called 'end-members.' Once these spectra are found, the image cube can be 'unmixed' into the fractional abundance of each material in each pixel. There exist several techniques for accomplishing the determination of the end-members, most of which involve the intervention of a trained geologist. Often these-end-members are assumed to be present in the image, in the form of pure, or unmixed, pixels. In this paper a method based upon the geometry of convex sets is proposed to find a unique set of purest pixels in an image. The technique is based on the fact that in N spectral dimensions, the N-volume contained by a simplex formed of the purest pixels is larger than any other volume formed from any other combination of pixels. The algorithm works by 'inflating' a simplex inside the data, beginning with a random set of pixels. For each pixel and each end-member, the end-member is replaced with the spectrum of the pixel and the volume is recalculated. If it increases, the spectrum of the new pixel replaces that end-member. This procedure is repeated until no more replacements are done. This algorithm successfully derives end-members in a synthetic data set, and appears robust with less than perfect data. Spectral end-members have been extracted for the AVIRIS Cuprite data set which closely match reference spectra, and resulting abundance maps match published mineral maps.

Entanglement in a simple quantum phase transition

Abstract: What entanglement is present in naturally occurring physical systems at thermal equilibrium? Most such systems are intractable and it is desirable to study simple but realistic systems that can be solved. An example of such a system is the one-dimensional infinite-lattice anisotropic XY model. This model is exactly solvable using the Jordan-Wigner transform, and it is possible to calculate the two-site reduced density matrix for all pairs of sites. Using the two-site density matrix, the entanglement of formation between any two sites is calculated for all parameter values and temperatures. We also study the entanglement in the transverse Ising model, a special case of the XY model, which exhibits a quantum phase transition. It is found that the next-nearest-neighbor entanglement (though not the nearest-neighbor entanglement) is a maximum at the critical point. Furthermore, we show that the critical point in the transverse Ising model corresponds to a transition in the behavior of the entanglement between a single site and the remainder of the lattice.

Chronic obstructive pulmonary disease: current burden and future projections

Abstract: SERIES “THE GLOBAL BURDEN OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE” Edited by K.F. Rabe and J.B. Soriano Number 2 in this Series ### Summary ⇓Information about the comparative magnitude of the burden from various diseases and injuries is a critical input into building the evidence base for health policies and programmes. Such information should be based on a critical evaluation of all available epidemiological data using standard and comparable procedures across diseases and injuries, including information on the age at death and the incidence, duration and severity of cases who do not die prematurely from the disease. A summary measure, disability-adjusted life yrs (DALYs), has been developed to simultaneously measure the amount of disease burden due to premature mortality and the amount due to the nonfatal consequences of disease. Approximately 2.7 million deaths from chronic obstructive pulmonary disease (COPD) occurred in 2000, half of them in the Western Pacific Region, with the majority of these occurring in China. About 400,000 deaths occur each year from COPD in industrialised countries. The increase in global COPD deaths between 1990 and 2000 (0.5 million) is likely to be partly real, and partly due to better methods and more extensive data availability in 2000. The regional (adult) prevalence in 2000 varied from 0.5% in parts of Africa to 3–4% in North America. ### Introduction Health systems must increasingly address a broad spectrum of health issues, ranging from epidemic outbreaks to advanced therapeutic care. They must, or should, also support disease prevention and health-promotion activities. Recognising that resources for health were unlikely to grow as quickly as demand, in 1993, the World Bank proposed a series of intervention packages for countries at different stages of development which, if implemented, would probably lead to the greatest gains in population health at affordable cost. The evidence for these recommendations was based …

A World Without Mangroves

Abstract: At a meeting of world mangrove experts held last year in Australia, it was unanimously agreed that we face the prospect of a world deprived of the services offered by mangrove ecosystems, perhaps within the next 100 years Mangrove forests once covered more than 200,000 km2 of sheltered tropical

Structure and function of long noncoding RNAs in epigenetic regulation

Abstract: Genomes of complex organisms encode an abundance and diversity of long noncoding RNAs (lncRNAs) that are expressed throughout the cell and fulfill a wide variety of regulatory roles at almost every stage of gene expression. These roles, which encompass sensory, guiding, scaffolding and allosteric capacities, derive from folded modular domains in lncRNAs. In this diverse functional repertoire, we focus on the well-characterized ability for lncRNAs to function as epigenetic modulators. Many lncRNAs bind to chromatin-modifying proteins and recruit their catalytic activity to specific sites in the genome, thereby modulating chromatin states and impacting gene expression. Considering this regulatory potential in combination with the abundance of lncRNAs suggests that lncRNAs may be part of a broad epigenetic regulatory network.