Analysis of primary user duty cycle impact on spectrum sensing performance

Spectrum sensing is considered to be one of the most important tasks in cognitive radio. Many sensing detectors have been proposed in the literature, with the common assumption that the primary user is either fully present or completely absent within the window of observation. In reality, there are scenarios where the primary user signal only occupies a fraction of the observed window. This paper aims to analyse the effect of the primary user duty cycle on spectrum sensing performance through the analysis of a few common detectors. Simulations show that the probability of detection degrades severely with reduced duty cycle regardless of the detection method. Furthermore we show that reducing the duty cycle has a greater degradation on performance than lowering the signal strength.

We’ve had the Redfern Park Speech and The Apology: What’s next?

What really changed for Australian Aboriginal and Torres Strait Islander people between Paul Keating’s Redfern Park Speech (Keating 1992) and Kevin Rudd’s Apology to the stolen generations (Rudd 2008)? What will change between the Apology and the next speech of an Australian Prime Minister? The two speeches were intricately linked, and they were both personal and political. But do they really signify change at the political level? This paper reflects my attempt to turn the gaze away from Aboriginal and Torres Strait Islander people, and back to where the speeches originated: the Australian Labor Party (ALP). I question whether the changes foreshadowed in the two speeches – including changes by the Australian public and within Australian society – are evident in the internal mechanisms of the ALP. I also seek to understand why non-Indigenous women seem to have given in to the existing ways of the ALP instead of challenging the status quo which keeps Aboriginal and Torres Strait Islander peoples marginalised. I believe that, without a thorough examination and a change in the ALP’s practices, the domination and subjugation of Indigenous peoples will continue – within the Party, through the Australian political process and, therefore, through governments.

Constructing the hallucinations of psychosis in Virtual Reality

Schizophrenia is a mental disorder affecting 1-2% of the population and it is estimated 12-16% of hospital beds in Australia are occupied by patients with psychosis. The suicide rate for patients with this diagnosis is higher than that of the general population. Any technique which enhances training and treatment of this disorder will have a significant societal and economic impact. A significant research project using Virtual Reality (VR), in which both visual and auditory hallucinations are simulated, is currently being undertaken at the University of Queensland. The virtual environments created by the new software are expected to enhance the experiential learning outcomes of medical students by enabling them to experience the inner world of a patient with psychosis. In addition the Virtual Environment has the potential to provide a technologically advanced therapeutic setting where behavioral, exposure therapies can be conducted with exactly controlled exposure stimuli with an expected reduction in risk of harm. This paper reports on the current work of the project, previous stages of software development and future educational and clinical applications of the Virtual Environments. (C) 2004 Elsevier Ltd. All rights reserved.

Thinking Collaboratively about the Peer-Review Process for Journal- Article Publication

In this conversation, Kevin K. Kumashiro shares his reflections on challenges to publishing anti-oppressive research in educational journals. He then invites eight current and former editors of leading educational research journals--William F. Pinar, Elizabeth Graue, Carl A. Grant, Maenette K. P. Benham, Ronald H. Heck, James Joseph Scheurich, Allan Luke, and Carmen Luke--to critique and expand on his analysis. Kumashiro begins the conversation by describing his own experiences submitting manuscripts to educational research journals and receiving comments by anonymous reviewers and journal editors. He suggests three ways to rethink the collaborative potential of the peer-review process: as constructive, as multilensed, and as situated. The eight current and former editors of leading educational research journals then critique and expand Kumashiro's analysis. Kumashiro concludes the conversation with additional reflections on barriers and contradictions involved in advancing anti-oppressive educational research in educational journals. (Contains 3 notes.)

Relaxin stimulates leukocyte adhesion and migration through a relaxin receptor LGR7-dependent mechanism

Leukocytes are critical effectors of inflammation and tumor biology. Chemokine-like factors produced by such inflammatory sites are key mediators of tumor growth that activate leukocytic recruitment and tumor infiltration and suppress immune surveillance. Here we report that the endocrine peptide hormone, relaxin, is a regulator of leukocyte biology with properties important in recruitment to sites of inflammation. This study uses the human monocytic cell line THP-1 and normal human peripheral blood mononuclear cells to define a novel role for relaxin in regulation of leukocyte adhesion and migration. Our studies indicate that relaxin promotes adenylate cyclase activation, substrate adhesion, and migratory capacity of mononuclear leukocytes through a relaxin receptor LGR7-dependent mechanism. Relaxin-stimulated cAMP accumulation was observed to occur primarily in non-adherent cells. Relaxin stimulation results in increased substrate adhesion and increased migratory activity of leukocytes. In addition, relaxin-stimulated substrate adhesion resulted in enhanced chemotaxis to monocyte chemoattractant protein-1. These responses in THP-1 and peripheral blood mononuclear cells are relaxin dose-dependent and proportional to cAMP accumulation. We further demonstrate that LGR7 is critical for mediating these biological responses by use of RNA interference lentiviral short hairpin constructs. In summary, we provide evidence that relaxin is a novel leukocyte stimulatory agent with properties affecting adhesion and chemomigration

A study of environmental and management drivers of non-co2 greenhouse gas emissions in Australian agro-ecosystems

Australian climate, soils and agricultural management practices are significantly different from those of the northern hemisphere nations. Consequently, experimental data on greenhouse gas production from European and North American agricultural soils and its interpretation are unlikely to be directly applicable to Australian systems.

Response to the apology : Queenslanders reflect : a State Library of Queensland project

On the 13th February 2008 Prime Minister Kevin Rudd made an apology to Australia’s Indigenous Peoples on behalf of the Australian Parliament. The State Library of Queensland (SLQ) with assistance from Queensland University of Technology and Queensland’s Aboriginal and Torres Strait Islander communities, has captured responses to this historic event. ‘Responses to the 2008 Apology’ is a collection of digital stories created as part of this research initiative. Until recently, digital storytelling has not generally been treated as a necessary addition to the research collections of Australian libraries. However, libraries increasingly aim to promote new literacies and active audiences as they seek innovative ways to encourage life-long learning by their users, and digital storytelling is one methodology that can contribute to these goals. The State Library of Queensland is the only Australian State Library to have undertaken a major role in the collection of digital stories. They currently lead the way with their Queensland Stories digital storytelling program. This presentation will report findings and outcomes from this research project.

Organ printing

Organ printing techniques offer the potential to produce living 3D tissue constructs to repair or replace damaged or diseased human tissues and organs. Using these techniques, spatial variations along multiple axes with high geometric complexity can be obtained.. The level of control offered by these technologies to develop printed tissues will allow tissue engineers to better study factors that modulate tissue formation and function, and provide a valuable tool to study the effect of anatomy on graft performance. In this chapter we discuss the history behind substrate patterning and cell and organ printing, and the rationale for developing organ printing techniques with respect to limitations of current clinical tissue engineering strategies to effectively repair damaged tissues. We discuss current 2-dimensional and 3-dimesional strategies for assembling cells as well as the necessary support materials such as hydrogels, bioinks and natural and synthetic polymers adopted for organ printing research. Furthermore, given the current state-of-the-art in organ printing technologies, we discuss some of their limitations and provide recommendations for future developments in this rapidly growing field.

Landcorp Farming Limited : cultivating livestock, ideas and innovation

In 1987 Landcorp was corporatised as a state-owned enterprise under New Zealand's public sector reforms and began operating as a collection of farms located throughout the country. Twenty years later, Landcorp had established a record of careful land management, productivity growth and solid financial returns, transforming from a fledgling company into one of the country's largest farmers. Landcorp was a major agribusiness with assets of more than $1.4 billion, built on a culture of continuous improvement and an innovative approach to business. The challenge going forward was to continue growth without increasing land ownership : cultivating ideas to grow in less conventional ways. This case study examines the operations, development and innovative approach to business undertaken by Landcorp Farming Limited, concentrating on the challenges faced by the company to maintain profits and growth, and its strategic direction for the future.