Stable isotope-based community metrics as a tool to identify patterns in food web structure in east African estuaries

1.Quantitative tools to describe biological communities are important for conservation and ecological management. The analysis of trophic structure can be used to quantitatively describe communities. Stable isotope analysis is useful to describe trophic organization, but statistical models that allow the identification of general patterns and comparisons between systems/sampling periods have only recently been developed. 2.Here, stable isotope-based Bayesian community-wide metrics are used to investigate patterns in trophic structure in five estuaries that differ in size, sediment yield and catchment vegetation cover (C3/C4): the Zambezi in Mozambique, the Tana in Kenya and the Rianila, the Betsiboka and Pangalanes Canal (sampled at Ambila) in Madagascar. 3.Primary producers, invertebrates and fish of different trophic ecologies were sampled at each estuary before and after the 2010–2011 wet season. Trophic length, estimated based on δ15N, varied between 3·6 (Ambila) and 4·7 levels (Zambezi) and did not vary seasonally for any estuary. Trophic structure differed the most at Ambila, where trophic diversity and trophic redundancy were lower than at the other estuaries. Among the four open estuaries, the Betsiboka and Tana (C4-dominated) had lower trophic diversity than the Zambezi and Rianila (C3-dominated), probably due to the high loads of suspended sediment, which limited the availability of aquatic sources. 4.There was seasonality in trophic structure at Ambila and Betsiboka, as trophic diversity increased and trophic redundancy decreased from the prewet to the postwet season. For Ambila, this probably resulted from the higher variability and availability of sources after the wet season, which allowed diets to diversify. For the Betsiboka, where aquatic productivity is low, this was likely due to a greater input of terrestrial material during the wet season. 5.The comparative analysis of community-wide metrics was useful to detect patterns in trophic structure and identify differences/similarities in trophic organization related to environmental conditions. However, more widespread application of these approaches across different faunal communities in contrasting ecosystems is required to allow identification of robust large-scale patterns in trophic structure. The approach used here may also find application in comparing food web organization before and after impacts or monitoring ecological recovery after rehabilitation.

Trophic cul-de-sac, Pyrazus ebeninus, limits trophic transfer through an estuarine detritus-based food web

The importance to food-webs of trophic cul-de-sacs, species that channel energy flow away from higher trophic levels, is seldom considered outside of the pelagic systems in which they were first identified. On intertidal mudflats, inputs of detritus from saltmarshes, macroalgae or microphytobenthos are generally regarded as a major structuring force underpinning food-webs and there has been no consideration of trophic cul-de-sacs to date. A fully orthogonal three-factor experiment manipulating the density of the abundant gastropod, Pyrazus ebeninus, detritus and macrobenthic predators on a Sydney mudflat revealed large deleterious effects of the gastropod, irrespective of detrital loading or the presence of predators. Two months after experimental manipulation, the standing-stock of microphytobenthos in plots with high (44 per m²) densities of P. ebeninus was 20% less than in plots with low (4 per m²) densities. Increasing densities of P. ebeninus from low to high halved the abundance of macroinvertebrates and the average number of species. In contrast, the addition of detritus had differing effects on microphytobenthos (positively affected) and macroinvertebrates (negatively affected). Over the two-months of our experiment, no predatory mortality of P. ebeninus was observed and high densities of P. ebeninus decreased impacts of predators on macroinvertebrate abundances. Given that the dynamics of southeast Australian mudflats are driven more by disturbance than seasonality in predators and their interactions with prey, it is likely that Pyrazus would be similarly resistant to predation and have negative effects on benthic assemblages at other times of the year, outside of our study period. Thus, in reducing microphytobenthos and the abundance and species richness of macrofauna, high abundances of the detritivore P. ebeninus may severely limit the flow of energy up the food chain to commercially-important species. This study therefore suggests that trophic cul-de-sacs are not limited to the eutrophied pelagic systems in which they were first identified, but may exist in other systems as well.

A model of web use in direct and online marketing strategy

There has been less than a decade of rapid diffusion of the Internet and related technologies into the commercial world, with resultant changes in business processes, business structure and financial valuations of adopting businesses. Advocates and critics of new online business models are still addressing the relationship between online or electronic marketing using the Internet (Net) and marketing and financial outcomes. There remains a need for empirical research into specific aspects of online marketing strategy beyond click-through analysis, Web audience analysis and scrutiny of website properties to mention the most widely examined elements. This paper discusses conceptualizations underpinning development of a model of Web use in marketing strategy. The aim of the paper is to aid both business practitioner and academician alike in connecting direct and online marketing using the Web with performance outcomes

Matrix model for web page community construction

The World Wide Web is now a huge information source with its own characteristics. In most cases, traditional database-based technologies are no longer suitable for web information processing and management. For effectively processing and managing web. information, it is necessary to reveal intrinsic relationships/structures among concerned web information objects such as web pages. In this work, a set of web pages that has its own intrinsic structure is called a web page community. This paper proposes a matrix model to describe relationships among concerned web pages. Based on this model, intrinsic relationships among pages could be revealed, and in turn a web page community could be constructed. The issues that are related to this model in its application are deeply investigated and studied. Some applications based on this model are presented, which demonstrate the potential of this matrix model in different kinds of web page community construction and information processing.

A co-recommendation algorithm for web searching

This paper presents an approach called the Co-Recommendation Algorithm, which consists of the features of the recommendation rule and the co-citation algorithm. The algorithm addresses some challenges that are essential for further searching and recommendation algorithms. It does not require users to provide a lot of interactive communication. Furthermore, it supports other queries, such as keyword, URL and document investigations. When the structure is compared to other algorithms, the scalability is noticeably easier. The high online performance can be obtained as well as the repository computation, which can achieve a high group-forming accuracy using only a fraction of Web pages from a cluster.

An web content based data mining for car consumption in China

This paper introduces an incremental FP-Growth approach for Web content based data mining and its application in solving a real world problem The problem is solved in the following ways. Firstly, we obtain the semi-structured data from the Web pages of Chinese car market and structure them and save them in local database. Secondly, we use an incremental FP-Growth algorithm for mining association rules to discover Chinese consumers' car consumption preference. To find more general regularities, an attribute-oriented induction method is also utilized to find customer's consumption preference among a range of car categories. Experimental results have revealed some interesting consumption preferences that are useful for the decision makers to make the policy to encourage and guide car consumption. Although the current data we used may not be the best representative of the actual market in practice, it is still good enough for the decision making purpose in terms of reflecting the real situation of car consumption preference under the two assumptions in the context.

Sharing and reuse of web developers experience

Development of commercial web systems is laborious, lengthy and costly. This is partly due to the fact that the methods of their development can hardly cope with the complexity of provided services. Such services may need to be distributed and collaborative, require sophisticated software architecture, be rich in form, content and interactivity, and have a wide range of potentially casual users. While web development methodologies are slowly emerging from research methodologies, their adoption is far from wide-spread. To improve this situation, the authors propose an approach based on the observed practices of professional web developers, who openly share and reuse their web development experience, while guarding their development workproducts. To this end, we suggest to enhance web development methods, by collecting problem-solving experience of web developers, packaging it into a reusable form, and providing a navigable decision structure assisting developers in identifying proven expert solutions suitable for a given problem context.

Web enabled just-in-time salvaged material management for demolition projects

The demolition activities of buildings produce numerous environmental pressures as a large proportion of demolition waste materials are sent to landfill directly in many projects. Web-based waste exchange systems could provide right solutions for releasing these pressures. Because the approaches adopted in current waste exchange systems are inefficient, these systems cannot generate waste exchange, not achieving their final goal, environmental protection. The Just-in-time (JIT) philosophy has been applied in the manufacture industry for decades and it is proven to be effective to eliminate or minimise inventory during production. This research aims to adopt the JIT philosophy into a demolition project management informapon system so that the system is more efficient in handling waste exchange. The system structure, key components and Just-in-time adoption are proposed and identified. Finally, a proto typed system is demonstrated.

An immune network approach for web document clustering

The human immune system provides inspiration for solving a wide range of innovative problems. In this paper, we propse an immune network based approach for web document clustering. All the immune cells in the network competitively recognize the antigens (web documents) which are presented to the network one by one. The interaction between immune cells and an antigen leads to an augment of the network through the clonal selection and somatic mutation of the stimulated immune cells, while the interaction among immune cells results in a network compression. The structure of the immune network is well maintained by learning and self-regularity. We use a public web document data set to test the effectiveness of our method and compare it with other approaches. The experimental results demonstrate that the most striking advantage of immune-based data clustering is its adaptation in dynamic environment and the capability of finding new clusters automatically.

Matrix model for web page community

Discovering intrinsic relationships/structures among concerned web information objects such as web pages is important for effectively processing and managing web information. In this work, a set of web pages that has its own intrinsic structure is called a web page community. This paper proposes a matrix model to describe relationships among concerned web pages. Based on this model, intrinsic relationships among pages could be revealed, and in turn a web page community could be constructed. The issues that are related to this model and its applications are investigated and studied. Some applications based on this model are presented, which demonstrate the potential of this matrix model in different kinds of web page community construction and information processing.

Ownership structure and corporate performance : Australian evidence

This paper seeks to analyse the relationship between ownership structure and corporate performance for fifty firms listed on the Australian Stock Exchange during 2002-2003. The study initially tests a two equation model similar to that in the existing literature, but is distinguished from prior literature by subsequently reclassifying leverage. By categorising leverage as an endogenous variable, an examination of the relationship between ownership and performance is undertaken through ordinary least squares and two stage least squares analysis of a three equation econometric model. Interestingly, empirical results illustrate the fact that managerial ownership impacts negatively on firm performance which is consistent with the management entrenchment hypothesis.

The importance of family management, closeness with father and family structure in early adolescent alcohol use

Aims To examine the importance of family management, family structure and father–adolescent relationships on early adolescent alcohol use.

Design Cross-sectional data was collected across 30 randomly selected Australian communities stratified to represent a range of socio-economic and regional variation.

Setting Data were collected during school time from adolescents attending a broad range of schools.

Participants The sample consisted of a combined 8256 students (aged 10–14 years).

Measurements Students completed a web-based survey as part of the Healthy Neighbourhoods project.

Findings Family management—which included practices such as parental monitoring and family rules about alcohol use—had the strongest and most consistent relationship with alcohol use in early adolescence. Adolescents reporting higher family management were less likely to have drunk alcohol in their life-time, less likely to drink alcohol in the preceding 30 days and less likely to have had an alcohol binge. Adolescents reporting emotionally close relationships with their fathers were less likely to have drunk alcohol in their life-time and less likely to have had an alcohol binge in the preceding fortnight.

Conclusions Findings indicate that family management practices may contribute to alcohol abstinence in adolescents. Furthermore, emotionally close father–adolescent relationships may also foster abstinence; however, fathers’ drinking behaviours need to be considered.

Web 2.0 for networked learning : from collaboration to shared cognition and knowledge networking

This poster presents research-in-progress into the educational affordances of so-called Web 2.0 sites, services, with a particular emphasis on those applications that involve forms of shared human-machine cognition and that promote public knowledge networking. This research involves reviewing many hundreds of Web 2.0 tools and selecting approximately 50 for further analysis and exploration as learning applications. In doing so, the research will generate examples of unusual affordances provided by Web 2.0; it will also present a more structured categorisation of the kinds of uses and benefits of these tools. This approach is valuable because much current research and analysis of the impact of Web 2.0 on education, particularly higher education, has emphasised a relatively limited array of tools – principally blogs, wikis and social networking services – that offer educators and students opportunities for student-led collaborative work. Such opportunities involve strong emphasis on constructivist pedagogy: students’ interactions with each other, mediated via the Internet, are viewed as the positive benefit which networked learning can provide. However, Web 2.0 is far more than just collaboration, and associated shared self-expression. In particular, Web 2.0 includes many examples of services that take one form of input from a user and, rather than just sharing it with others, enable the transformation of that input into different forms, either as visualisations, maps, or other re-representations. Web 2.0 is also starting to see the development of knowledge-work engines that embody the concept of shared cognition, in which the service and the user cooperate in the production of some final knowledge output or which present to users knowledge that has already been processed more extensively than through simple searching. Web 2.0 is also closely associated with the idea that knowledge work is now networked and distributed; it involves users appropriating, creating and sharing knowledge products in a very public way, far beyond the narrow ‘audience’ of a particular course or program of study. The research presented in this poster will provide, firstly, examples of the Web 2.0 tools which emphasise these additional ways of exploiting the Internet for networked learning; secondly, the research will provide a first iteration of the overarching structure of categories and classifications which can be used to assess any proposed Web 2.0 application in terms of its affordances for learning as knowledge networking. By understanding these technologies, truly collaborative networked learning can be developed that blends with the emerging cultures of online behaviour increasingly common to contemporary student populations.

Web malware that targets web applications

Web applications have steadily increased, making them very important in areas, such as financial sectors, e-commerce, e-government, social media network, medical data, e-business, academic an activities, e-banking, e-shopping, e-mail. However, web application pages support users interacting with the data stored in their website to insert, delete and modify content by making a web site their own space. Unfortunately, these activities attracted writers of malicious software for financial gain, and to take advantage of such activities to perform their malicious objectives. This chapter focuses on severe threats to web applications specifically on Structure Query Language Injection Attack (SQLIA) and Zeus threats. These threats could adopt new obfuscation techniques to evade and thwart countermeasures Intrusion Detection Systems (IDS). Furthermore, this work explores and discusses the techniques to detect and prevent web application malwar.