Projection-pursuit-based method for blind separation of nonnegative sources

This paper presents a projection pursuit (PP) based method for blind separation of nonnegative sources. First, the available observation matrix is mapped to construct a new mixing model, in which the inaccessible source matrix is normalized to be column-sum-to-1. Then, the PP method is proposed to solve this new model, where the mixing matrix is estimated column by column through tracing the projections to the mapped observations in specified directions, which leads to the recovery of the sources. The proposed method is much faster than Chan's method, which has similar assumptions to ours, due to the usage of optimal projection. It is also more advantageous in separating cross-correlated sources than the independence- and uncorrelation-based methods, as it does not employ any statistical information of the sources. Furthermore, the new method does not require the mixing matrix to be nonnegative. Simulation results demonstrate the superior performance of our method.

Understanding the sources of uncertainty to reduce the risks of undesirable outcomes in large-scale freshwater ecosystem restoration projects: an example from the Murray–Darling Basin, Australia

There are a growing number of large-scale freshwater ecological restoration projects worldwide. Assessments of the benefits and costs of restoration often exclude an analysis of uncertainty in the modelled outcomes. To address this shortcoming we explicitly model the uncertainties associated with measures of ecosystem health in the estuary of the Murray– Darling Basin, Australia and how those measures may change with the implementation of a Basin-wide Plan to recover water to improve ecosystem health. Specifically, we compare two metrics – one simple and one more complex – to manage end-of-system flow requirements for one ecosystem asset in the Basin, the internationally important Coorong saline wetlands. Our risk assessment confirms that the ecological conditions in the Coorong are likely to improve with implementation of the Basin Plan; however, there are risks of a Type III error (where the correct answer is found for the wrong question) associated with using the simple metric for adaptive management. 

Dietary sources and meal distribution of sodium and potassium in a sample of Australian adults

Aim
Reducing dietary sodium and increasing dietary potassium are recommended to reduce blood pressure. This study aimed to determine the main foods sources of sodium and potassium.

Methods
Participants were recruited via advertisements or blood pressure screening sessions. Food sources of sodium and potassium were assessed via 24-hour dietary records in 299 free-living Australian adults (141 male, 158 female; age 54.6(9.5)years; BMI 29.4(3.9)kg/m2).

Results
The mean sodium intake was 118(51)mmol/d (2725(1176)mg/d) and the mean potassium intake was 91(28)mmol/d (3550(1098)mg/d). Breads and cereals provided the majority (38%) of sodium with bread contributing 20%. Vegetable products/dishes contributed most potassium (23%) with potatoes providing 9%. Main meals provided 89% of sodium and 85% of potassium. Lunch and dinner provided similar sodium proportions (34% and 38%, respectively) but more energy was consumed at dinner (26% vs 40%, respectively). Lunch had the highest sodium density of all meals (420 mg/MJ).

Conclusion
A reduction in the salt content of processed foods, particularly bread, is recommended to decrease sodium intake. This reduction in salt content combined with meal specific education focusing on choosing lower sodium foods at lunch in particular, as well as incorporating more fruits and vegetables, could effectively reduce dietary sodium and increase potassium.

Prospect of renewable energy sources and integrating challenges in Victoria, Australia

The Australian Government has targeted 20% of electricity generation from renewable energy sources by 2020. The 20% renewable energy target (RET) for Australia will be around 45000GWH in 2020. Renewable energy of Victoria also includes as part of support to achieve 20% RET in Australia. In Victoria wind and solar resources are abundant as compared to other sources of renewable energy. Solar radiation and wind speed data for Victoria State was collected from NASA surface meteorology and solar energy web site. A feasibility analysis has been carried out to explore the potentialities of wind and solar energy for Victoria State using hybrid optimization model of electric renewable (HOMER) software. This paper also represents the estimation analysis of RET for Victoria and describes the integrating challenges of renewable energy sources to the utility grid.

Mixing Matrix Estimation From Sparse Mixtures With Unknown Number of Sources

In blind source separation, many methods have been proposed to estimate the mixing matrix by exploiting sparsity. However, they often need to know the source number a priori, which is very inconvenient in practice. In this paper, a new method, namely nonlinear projection and column masking (NPCM), is proposed to estimate the mixing matrix. A major advantage of NPCM is that it does not need any knowledge of the source number. In NPCM, the objective function is based on a nonlinear projection and its maxima just correspond to the columns of the mixing matrix. Thus a column can be estimated first by locating a maximum and then deflated by a masking operation. This procedure is repeated until the evaluation of the objective function decreases to zero dramatically. Thus the mixing matrix and the number of sources are estimated simultaneously. Because the masking procedure may result in some small and useless local maxima, particle swarm optimization (PSO) is introduced to optimize the objective function. Feasibility and efficiency of PSO are also discussed. Comparative experimental results show the efficiency of NPCM, especially in the cases where the number of sources is unknown and the sources are relatively less sparse.

Food Product Information: Trusted Sources and Delivery Media

Consumers receive food-related information from various sources and strive to make informed food choices regarding their health, lifestyle and belief. To be effective and reliable, the information consumers receive needs to be from a credible source and delivered to them in a way they trust. The aim of this study was to investigate the sources and media channels of that information consumer trust. An online and hardcopy survey of 298 consumers currently living in Australia was carried out. Many consumers believe that the source of food product information is important (87%). As a source of general and nutritional information, Health Professionals, Scientists and Government sources are the most trusted sources, with at least 80% of participants confident of the information coming from these sources. Retailer advertising and social media are the least trusted sources with just 29% and 11%, respectively, confident of these sources. As a delivery medium, printed food labels (67%) and printed brochures or fact sheets (56%) remain the most trusted delivery media compared with electronic media, such as mobile phone or the Internet.

Sources, perceived usefulness and understanding of information disseminated to families who entered home quarantine during the H1N1 pandemic in Victoria, Australia: a cross-sectional study

Background Voluntary home quarantine of cases and close contacts was the main non-pharmaceutical intervention used to limit transmission of pandemic (H1N1) 2009 influenza (pH1N1) in the initial response to the outbreak of the disease in Australia. The effectiveness of voluntary quarantine logically depends on affected families having a clear understanding of what they are being asked to do. Information may come from many sources, including the media, health officials, family and friends, schools, and health professionals. We report the extent to which families who entered home quarantine received and used information on what they were supposed to do. Specifically, we outline their sources of information; the perceived usefulness of each source; and associations between understanding of recommendations and compliance. Methods Cross-sectional survey administered via the internet and computer assisted telephone interview to families whose school children were recommended to go into home quarantine because they were diagnosed with H1N1 or were a close contact of a case. The sample included 314 of 1157 potentially eligible households (27% response rate) from 33 schools in metropolitan Melbourne. Adjusting for clustering within schools, we describe self-reported 'understanding of what they were meant to do during the quarantine period'; source of information (e.g. health department) and usefulness of information. Using logistic regression we examine whether compliance with quarantine recommendations was associated with understanding and the type of information source used. Results Ninety per cent understood what they were meant to do during the quarantine period with levels of understanding higher in households with cases (98%, 95% CI 93%-99% vs 88%, 95% CI 84%-91%, P = 0.006). Over 87% of parents received information about quarantine from the school, 63% from the health department and 44% from the media. 53% of households were fully compliant and there was increased compliance in households that reported that they understood what they were meant to do (Odds Ratio 2.27, 95% CI 1.35-3.80). Conclusions It is critical that public health officials work closely with other government departments and media to provide clear, consistent and simple information about what to do during quarantine as high levels of understanding will maximise compliance in the quarantined population.