Neural signal analysis by landmark-based spectral clustering with estimated number of clusters

Spike sorting plays an important role in analysing electrophysiological data and understanding neural functions. Developing spike sorting methods that are highly accurate and computationally inexpensive is always a challenge in the biomedical engineering practice. This paper proposes an automatic unsupervised spike sorting method using the landmark-based spectral clustering (LSC) method in connection with features extracted by the locality preserving projection (LPP) technique. Gap statistics is employed to evaluate the number of clusters before the LSC can be performed. Experimental results show that LPP spike features are more discriminative than those of the popular wavelet transformation (WT). Accordingly, the proposed method LPP-LSC demonstrates a significant dominance compared to the existing method that is the combination between WT feature extraction and the superparamagnetic clustering. LPP and LSC are both linear algorithms that help reduce computational burden and thus their combination can be applied into realtime spike analysis.

Food security: one of a number of ‘securities’ we need for a full life: an Australian perspective

Although agriculture in Australia is very productive, the current food supply systems in Australia fail to deliver healthy diets to all Australians and fail to protect the natural resources on which they depend. The operation of the food systems creates ‘collateral damage’ to the natural environment including biodiversity loss. In coming decades, Australia’s food supply systems will be increasingly challenged by resource price inflation and climate change. Australia exports more than half of its current agricultural production. Government and business are aiming to substantially increase production to bolster exports. This will increase pressure on agricultural resources and exacerbate ‘collateral’ damage to the environment. The Australian public have a deep and ongoing interest in a very wide range of issues associated with the food systems including the environment, health and sustainability. Food is something we require in order to live and a good diet is something we have to have to be healthy. For health over a life-time we need food security. However, we also require a range of other material goods and social arrangements in order to develop and flourish as human beings. And we need these other things to be secure over a life-time. Food is therefore one security among a range of other securities we need in order to flourish. The paper outlines a number of approaches, as examples, that help to identify what these other goods and arrangements might be. The approaches mentioned in this paper include human rights, national securities, human needs, authentic happiness, capabilities, sustainability and environmental ethics. The different approaches provide a way of evaluating the current situation and indicating a direction for change within the food systems that will address the problems. However, changing large systems such as those involved in food supply is difficult because inertias and vested interests make the current food supply systems resilient to change. The paper suggests that one of the first and ongoing tasks is to develop an understanding of the situation from a comprehensive social–ecological systems perspective. The paper also suggests that a practical leverage point for system change is restructuring the flow of information on the health, natural resources and biodiversity loss issues related to the food supply systems.

On the determination of the number of factors using information criteria with data-driven penalty

As is well known, when using an information criterion to select the number of common factors in factor models the appropriate penalty is generally indetermine in the sense that it can be scaled by an arbitrary constant, c say, without affecting consistency. In an influential paper, Hallin and Liška (J Am Stat Assoc102:603–617, 2007) proposes a data-driven procedure for selecting the appropriate value of c. However, by removing one source of indeterminacy, the new procedure simultaneously creates several new ones, which make for rather complicated implementation, a problem that has been largely overlooked in the literature. By providing an extensive analysis using both simulated and real data, the current paper fills this gap.

Noisy neighbours at the frog pond: effects of invasive cane toads on the calling behaviour of native Australian frogs

Invasive species can disrupt the communication systems that native biota use for reproductive interactions. In tropical Australia, invasive cane toads (Rhinella marina) breed in many of the same waterbodies that are used by native frogs, and males of both the invader and the native taxa rely on vocal signals to attract mates. We conducted playback experiments to test the hypothesis that calls of toads may influence the calling behaviour of frogs (Limnodynastes convexiusculus and Litoria rothii). Male L. convexiusculus adjusted their calling rate and the variance in inter-call interval in response to a variety of sounds, including the calls of cane toads as well as those of other native frog species, and other anthropogenic noise, whereas L. rothii did not. Within the stimulus periods of playbacks, male L. convexiusculus called more intensely during long silent gaps than during calling blocks. Thus, males of one frog species reduced their calling rate, possibly to minimise energy expenditure during periods of acoustic interference generated by cane toads. In spite of such modifications, the number of overlapping calls (within stimulus periods) did not differ significantly from that expected by chance. In natural conditions, the calls of cane toads are continuous rather than episodic, leaving fewer gaps of silence that male frogs could exploit. Future work could usefully quantify the magnitude of temporal (e.g. diel and seasonal) and spatial overlap between calling by toads and by frogs and the impact of call-structure shifts on the ability of male frogs to attract receptive females.

Industrial wastewater minimization

Industrial pollution emitted to the environment has created a drastic damage to the environment. Natural purification processes such as dilution and dispersion are not applicable due to the enormous amounts of discharged wastes, as they exceed the assimilative capacity of the local environment. Concern about the environment by the general public has forced governments to establish effluent standards for industrial wastes and emissions. Increasing numbers of industries each year has exerted pressure on the environment compelling regulators to further tighten the standards. This has led to modification and improvement in the existing end-of-pipe treatment facilities resulting in higher investment as well as operation and maintenance cost, whereas in recent years, implementation of proactive methods of waste minimization is gaining much attention within industrial sectors. Various waste minimization techniques such as improved housekeeping, change in process technology, change in product, change in input materials, recycling of chemical and raw materials, and recovery of byproducts are discussed in detail. A number of successful examples discussed in this paper indicate that substantial benefits can be gained by implementing waste minimization programs.

Introduction to evolutionary computing in system design

In this chapter, an introduction on the use of evolutionary computing techniques, which are considered as global optimization and search techniques inspired from biological evolutions, in the domain of system design is presented. A variety of evolutionary computing techniques are first explained, and the motivations of using evolutionary computing techniques in tackling system design tasks are then discussed. In addition, a number of successful applications of evolutionary computing to system design tasks are described.

Integrating online social networks with e-commerce : a CBR approach

Integrating online social networks (OSN) with e-commerce is a part of Enterprise 2.0 and social media and is of significance for development of e-commerce and online social networking services. However, how to integrate online social networks including Facebook with e-commerce is still a big issue for companies. Case based reasoning (CBR) has a number of successful applications in e-commerce and web services. This article examines how to integrate OSN with e-commerce, how to integrate CBR with e-commerce and how to integrate CBR with OSN. This article also proposes a CBR architecture for integrating online social networks with e-commerce using CBR as an intelligent intermediary. One of the research findings indicates that the principle of CBR is a useful marketing strategy for integrating e-commerce and OSN. The approach proposed in this research will facilitate the development of e-commerce, Enterprise 3.0 and online social networking services.

Isolation and characterisation of polymorphic microsatellite loci for Noisy Miners Manorina melanocephala, with successful cross-amplification in Bell Miners M. melanophrys

We characterized 15 polymorphic microsatellite loci identified from a Noisy Miner (Manorina melanocephala) blood sample using 454 whole genome shotgun sequencing. Levels of polymorphism were assessed using 15 Noisy Miners. The average number of alleles per locus was 5.1. These loci were then cross-amplified to assess their suitability in a single population of Bell Miners (M. melanophrys). Given the landscape level impact that these species are having on the health of vegetation and biodiversity of a range of vertebrates throughout much of south-eastern Australia, these primers will help identify colony dispersal patterns and thus aid in modeling predictions of miner presence and tenure length in threatened ecosystems.

Modelling daylight for preserving identity : simulation of daylight levels for successful intervention in historic buildings

Historical listed buildings have their own unique cultural identity, which is one of the criteria used by decision mechanisms for their statutory protection. The identity of many of these buildings is often related to their tangible features/components, such as period characteristics (geometry, size, colour, form, and shape), materials and construction. Daylight is one of the in/tangible elements that have contributed to the distinctiveness of many historical buildings, yet when constructing preservation schemes of historical buildings, daylight is rarely introduced or considered as one of the components that shape the character of buildings. One of the reasons is the limited number of credible simulation studies that identify such interrelationships. As many of these buildings were originally designed to accommodate different activities to today's requirements, maintaining the quality of daylight that originally contributed to their visual identity can be a very challenging task, especially if the building is to be adapted to accommodate a different activity. In this paper we will discuss the conflict between maintaining the original visual identity of historical buildings and meeting the visual requirements of restored buildings. The paper discusses the visual performance of a traditional bathhouse (Hammam) in the city of Bursa in Turkey. The change in the visual performance of the selected case study will be discussed in terms of daylight conditions. The paper explores the possibility of maintaining the original daylight conditions of renovated historical buildings while meeting the visual requirements of the new use.

Letters, green cards, telephone calls and postcards: systematic and meta-analytic review of brief contact interventions for reducing self-harm, suicide attempts and suicide

BACKGROUND: There is growing interest in brief contact interventions for self-harm and suicide attempt. AIMS: To synthesise the evidence regarding the effectiveness of brief contact interventions for reducing self-harm, suicide attempt and suicide. METHOD: A systematic review and random-effects meta-analyses were conducted of randomised controlled trials using brief contact interventions (telephone contacts; emergency or crisis cards; and postcard or letter contacts). Several sensitivity analyses were conducted to examine study quality and subgroup effects. RESULTS: We found 14 eligible studies overall, of which 12 were amenable to meta-analyses. For any subsequent episode of self-harm or suicide attempt, there was a non-significant reduction in the overall pooled odds ratio (OR) of 0.87 (95% CI 0.74-1.04, P = 0119) for intervention compared with control. The number of repetitions per person was significantly reduced in intervention v. control (incidence rate ratio IRR = 066, 95% CI 0.54-0.80, P<0001). There was no significant reduction in the odds of suicide in intervention compared with control (OR = 0.58, 95% CI 0.24-1.38). CONCLUSIONS: A non-significant positive effect on repeated self-harm, suicide attempt and suicide and a significant effect on the number of episodes of repeated self-harm or suicide attempts per person (based on only three studies) means that brief contact interventions cannot yet be recommended for widespread clinical implementation. We recommend further assessment of possible benefits in well-designed trials in clinical populations.

Understanding global student mobility: exploring new ways of capturing international experiences using in-county overseas students

Australian universities have large numbers of overseas students who do not engage meaningfully with local students about their international experience. The objective of this research, an initiative that was part of a project funded by Australian Government Office for Learning and Teaching (OLT), entitled the Global Canopy, was to develop pedagogy to promote local students’ awareness about international study based on an in-country teaching program. The research study aimed to develop new knowledge about how domestic students understand global mobility through interacting with international students enrolled in the same university. The initiative included two workshops that brought together a number of project team members, three overseas students and academic staff mentors, representatives from Deakin Global Student Mobility office, and 31 undergraduate domestic students. Data was collected from a series of in-depth interviews with students involved in the program. Initial findings suggested that the workshops were successful, with 12 undergraduate students enrolled in winter schools in India after completion of the program. The paper concludes with lessons learned from the initiative and calls for exploring new ways of identifying international experiences that can be facilitated within discipline curriculum of the home university.