430 resultados para Shrimp culture systems


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Understanding the complex dynamic and uncertain characteristics of organisational employees who perform authorised or unauthorised information security activities is deemed to be a very important and challenging task. This paper presents a conceptual framework for classifying and organising the characteristics of organisational subjects involved in these information security practices. Our framework expands the traditional Human Behaviour and the Social Environment perspectives used in social work by identifying how knowledge, skills and individual preferences work to influence individual and group practices with respect to information security management. The classification of concepts and characteristics in the framework arises from a review of recent literature and is underpinned by theoretical models that explain these concepts and characteristics. Further, based upon an exploratory study of three case organisations in Saudi Arabia involving extensive interviews with senior managers, department managers, IT managers, information security officers, and IT staff; this article describes observed information security practices and identifies several factors which appear to be particularly important in influencing information security behaviour. These factors include values associated with national and organisational culture and how they manifest in practice, and activities related to information security management.

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The move to a market model of schooling has seen a radical restructuring of the ways schooling is “done” in recent times in Western countries. Although there has been a great deal of work to examine the effects of a market model on local school management (LSM), teachers’ work and university systems, relatively little has been done to examine its effect on parents’ choice of school in the non-government sector in Australia. This study examines the reasons parents give for choosing a non-government school in the outer suburbs of one large city in Australia. Drawing on the work of Bourdieu specifically his ideas on “cultural capital” (1977), this study revealed that parents were choosing the non-government school over the government school to ensure that their children would be provided, through the school’s emphasis on cultural capital, access to a perceived “better life” thus enhancing the potential to facilitate “extraordinary children”, one of the school’s marketing claims.

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The complex relationship between the hydrodynamic environment and surrounding tissues directly impacts on the design and production of clinically useful grafts and implants. Tissue engineers have generally seen bioreactors as 'black boxes' within which tissue engineering constructs (TECs) are cultured. It is accepted that a more detailed description of fluid mechanics and nutrient transport within process equipment can be achieved by using computational fluid dynamics (CFD) technology. This review discusses applications of CFD for tissue engineering-related bioreactors -- fluid flow processes have direct implications on cellular responses such as attachment, migration and proliferation. We conclude that CFD should be seen as an invaluable tool for analyzing and visualizing the impact of fluidic forces and stresses on cells and TECs.

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This paper investigates the links between various approaches to managing equity and diversity and their effectiveness in changing the measures of inclusivity of women in organisations as a means of auditing and mapping managing diversity outcomes in Australia. The authors argue that managing diversity is more than changing systems and counting numbers it is also about managing the substantive culture change required in order to achieve inclusivity particularly intercultural inclusivity. Research in one sector of the education industry that investigated the competency skills required for culture change is offered as a model or guide for understanding and reflecting upon intercultural competency and its sequential development.

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Reforms to the national research and research training system by the Commonwealth Government of Australia sought to effectively connect research conducted in universities to Australia's national innovation system. Research training has a key role in ensuring an adequate supply of highly skilled people for the national innovation system. During their studies, research students produce and disseminate a massive amount of new knowledge. Prior to this study, there was no research that examined the contribution of research training to Australia's national innovation system despite the existence of policy initiatives aiming to enhance this contribution. Given Australia's below average (but improving) innovation performance compared to other OECD countries, the inclusion of Finland and the United States provided further insights into the key research question. This study examined three obvious ways that research training contributes to the national innovation systems in the three countries: the international mobility and migration of research students and graduates, knowledge production and distribution by research students, and the impact of research training as advanced human capital formation on economic growth. Findings have informed the concept of a research training culture of innovation that aims to enhance the contribution of research training to Australia's national innovation system. Key features include internationally competitive research and research training environments; research training programs that equip students with economically-relevant knowledge and the capabilities required by employers operating in knowledge-based economies; attractive research careers in different sectors; a national commitment to R&D as indicated by high levels of gross and business R&D expenditure; high private and social rates of return from research training; and the horizontal coordination of key organisations that create policy for, and/or invest in research training.

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The paper has a twofold purpose. First it highlights the importance of accounting information in the economic development of developing countries, with a particular focus on the nation of Libya. Secondly, using the case of Libya's General Company for Pipelines (GCP), it demonstrates that the use of accounting information to achieve economic development goals is determined to a large extent by the political/ideological setting in which it is generated. The study is based on a literature review and archival research, reinforced by a qualitative case study comprised of interviews, attendance at meetings and a study of internal documents. A study of The General Company for Pipelines (GCP) revealed that frequent politically driven changes in the structure and number of popular congresses and committees severely limited the use of accounting information, relegating it to a formal role. In consequence, accounting information had litle effect on stimulating economic development in Libya. This study focuses on one case study which does limit generalisability. However, it also suggests fruitful research areas considering the historic factors which have determined the accounting role in developing and planned economies. By providing insights about social factors which have determined the use of accounting in a planned economy, this study has implications for similar economies as they move towards a more globalised mode of operations which enhance the role of accounting in meeting economic development needs. If devleoping countries are to harness the potential of accounting aid in the achievement of their development plans, the social and political setting in which accounting has been conducted needs to be understood.

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The hydrodynamic environment “created” by bioreactors for the culture of a tissue engineered construct (TEC) is known to influence cell migration, proliferation and extra cellular matrix production. However, tissue engineers have looked at bioreactors as black boxes within which TECs are cultured mainly by trial and error, as the complex relationship between the hydrodynamic environment and tissue properties remains elusive, yet is critical to the production of clinically useful tissues. It is well known in the chemical and biotechnology field that a more detailed description of fluid mechanics and nutrient transport within process equipment can be achieved via the use of computational fluid dynamics (CFD) technology. Hence, the coupling of experimental methods and computational simulations forms a synergistic relationship that can potentially yield greater and yet, more cohesive data sets for bioreactor studies. This review aims at discussing the rationale of using CFD in bioreactor studies related to tissue engineering, as fluid flow processes and phenomena have direct implications on cellular response such as migration and/or proliferation. We conclude that CFD should be seen by tissue engineers as an invaluable tool allowing us to analyze and visualize the impact of fluidic forces and stresses on cells and TECs.

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xpanding human chondrocytes in vitro while maintaining their ability to form cartilage remains a key challenge in cartilage tissue engineering. One promising approach to address this is to use microcarriers as substrates for chondrocyte expansion. While microcarriers have shown beneficial effects for expansion of animal and ectopic human chondrocytes, their utility has not been determined for freshly isolated adult human articular chondrocytes. Thus, we investigated the proliferation and subsequent chondrogenic differentiation of these clinically relevant cells on porous gelatin microcarriers and compared them to those expanded using traditional monolayers. Chondrocytes attached to microcarriers within 2 days and remained viable over 4 weeks of culture in spinner flasks. Cells on microcarriers exhibited a spread morphology and initially proliferated faster than cells in monolayer culture, however, with prolonged expansion they were less proliferative. Cells expanded for 1 month and enzymatically released from microcarriers formed cartilaginous tissue in micromass pellet cultures, which was similar to tissue formed by monolayer-expanded cells. Cells left attached to microcarriers did not exhibit chondrogenic capacity. Culture conditions, such as microcarrier material, oxygen tension, and mechanical stimulation require further investigation to facilitate the efficient expansion of clinically relevant human articular chondrocytes that maintain chondrogenic potential for cartilage regeneration applications.

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Gay community media functions as a system with three nodes, in which the flows of information and capital theoretically benefit all parties: the gay community gains a sense of cohesion and citizenship through media; the gay media outlets profit from advertisers’ capital; and advertisers recoup their investments in lucrative ‘pink dollar’ revenue. But if a necessary corollary of all communication systems is error or noise, where—and what—are the errors in this system? In this paper we argue that the ‘error’ in the gay media system is Queerness, and that the gay media system ejects (in a process of Kristevan abjection) these Queer identities in order to function successfully. We examine the ways in which Queer identities are excluded from representation in such media through a discourse and content analysis of The Sydney Star Observer (Australia’s largest gay and lesbian paper). First, we analyse the way Queer bodies are excluded from the discourses that construct and reinforce both the ideal gay male body and the notions of homosexual essence required for that body to be meaningful. We then argue that abject Queerness returns in the SSO’s discourses of public health through the conspicuous absence of the AIDS-inflicted body (which we read as the epitome of the abject Queer), since this absence paradoxically conjures up a trace of that which the system tries to expel. We conclude by arguing that because the ‘Queer error’ is integral to the SSO, gay community media should practise a politics of Queer inclusion rather than exclusion.

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Dental pulp cells (DPCs) have shown promising potential in dental tissue repair and regeneration. However, during in vitro culture, these cells undergo replicative senescence and result in significant alteration in cell proliferation and differentiation. Recently, the transcription factors of Oct-4, Sox2, c-Myc, and Klf4 have been reported to play a regulatory role in the stem cell self-renewal process, namely cell reprogramming. Therefore, it is interesting to know whether the replicative senescence during the culture of dental pulp cells is related to the diminishing of the expression of these transcription factors. In this study, we investigated the expression of the reprogramming markers Oct-4, Sox2, and c-Myc in the in vitro explant cultured dental pulp tissues and explant cultured dental pulp cells (DPCs) at various passages by immunofluorescence staining and real-time polymerase chain reaction analysis. Our results demonstrated that Oct-4, Sox2, and c-Myc translocated from nucleus in the first 2 passages to cytoplasm after the third passage in explant cultured DPCs. The mRNA expression of Oct-4, Sox2, and c-Myc elevated significantly over the first 2 passages, peaked at second passage (P < .05), and then decreased along the number of passages afterwards (P < .05). For the first time we demonstrated that the expression of reprogramming markers Oct-4, Sox2, and c-Myc was detectable in the early passaged DPCs, and the sequential loss of these markers in the nucleus during DPC cultures might be related to the cell fate of dental pulp derived cells during the long-term in vitro cultivation under current culture conditions.

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This thesis argues that in order to establish a sound information security culture it is necessary to look at organisation's information security systems in a socio- technical context. The motivation for this research stems from the continuing concern of ineffective information security in organisations, leading to potentially significant monetary losses. It is important to address both technical and non- technical aspects when dealing with information security management. Culture has been identified as an underlying determinant of individuals' behaviour and this extends to information security culture, particularly in developing countries. This research investigates information security culture in the Saudi Arabia context. The theoretical foundation for the study is based on organisational and national culture theories. A conceptual framework for this study was constructed based on Peterson and Smith's (1997) model of national culture. This framework guides the study of national, organisational and technological values and their relationships to the development of information security culture. Further, the study seeks to better understand how these values might affect the development and deployment of an organisation's information security culture. Drawing on evidence from three exploratory case studies, an emergent conceptual framework was developed from the traditional human behaviour and the social environment perspectives used in social work, This framework contributes to in- formation security management by identifying behaviours related to four modes of information security practice. These modes provide a sound basis that can be used to evaluate individual organisational members' behaviour and the adequacy of ex- isting security measures. The results confirm the plausibility of the four modes of practice. Furthermore, a final framework was developed by integrating the four modes framework into the research framework. The outcomes of the three case stud- ies demonstrate that some of the national, organisational and technological values have clear impacts on the development and deployment of organisations' informa- tion security culture. This research, by providing an understanding the in uence of national, organi- sational and technological values on individuals' information security behaviour, contributes to building a theory of information security culture development within an organisational context. The research reports on the development of an inte- grated information security culture model that highlights recommendations for developing an information security culture. The research framework, introduced by this research, is put forward as a robust starting point for further related work in this area.

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Cell based therapies require cells capable of self renewal and differentiation, and a prerequisite is the ability to prepare an effective dose of ex vivo expanded cells for autologous transplants. The in vivo identification of a source of physiologically relevant cell types suitable for cell therapies is therefore an integral part of tissue engineering. Bone marrow is the most easily accessible source of mesenchymal stem cells (MSCs), and harbours two distinct populations of adult stem cells; namely hematopoietic stem cells (HSCs) and bone mesenchymal stem cells (BMSCs). Unlike HSCs, there are yet no rigorous criteria for characterizing BMSCs. Changing understanding about the pluripotency of BMSCs in recent studies has expanded their potential application; however, the underlying molecular pathways which impart the features distinctive to BMSCs remain elusive. Furthermore, the sparse in vivo distribution of these cells imposes a clear limitation to their in vitro study. Also, when BMSCs are cultured in vitro there is a loss of the in vivo microenvironment which results in a progressive decline in proliferation potential and multipotentiality. This is further exacerbated with increased passage number, characterized by the onset of senescence related changes. Accordingly, establishing protocols for generating large numbers of BMSCs without affecting their differentiation potential is necessary. The principal aims of this thesis were to identify potential molecular factors for characterizing BMSCs from osteoarthritic patients, and also to attempt to establish culture protocols favourable for generating large number of BMSCs, while at the same time retaining their proliferation and differentiation potential. Previously published studies concerning clonal cells have demonstrated that BMSCs are heterogeneous populations of cells at various stages of growth. Some cells are higher in the hierarchy and represent the progenitors, while other cells occupy a lower position in the hierarchy and are therefore more committed to a particular lineage. This feature of BMSCs was made evident by the work of Mareddy et al., which involved generating clonal populations of BMSCs from bone marrow of osteoarthritic patients, by a single cell clonal culture method. Proliferation potential and differentiation capabilities were used to group cells into fast growing and slow growing clones. The study presented here is a continuation of the work of Mareddy et al. and employed immunological and array based techniques to identify the primary molecular factors involved in regulating phenotypic characteristics exhibited by contrasting clonal populations. The subtractive immunization (SI) was used to generate novel antibodies against favourably expressed proteins in the fast growing clonal cell population. The difference between the clonal populations at the transcriptional level was determined using a Stem Cell RT2 Profiler TM PCR Array which focuses on stem cell pathway gene expression. Monoclonal antibodies (mAb) generated by SI were able to effectively highlight differentially expressed antigenic determinants, as was evident by Western blot analysis and confocal microscopy. Co-immunoprecipitation, followed by mass spectroscopy analysis, identified a favourably expressed protein as the cytoskeletal protein vimentin. The stem cell gene array highlighted genes that were highly upregulated in the fast growing clonal cell population. Based on their functions these genes were grouped into growth factors, cell fate determination and maintenance of embryonic and neural stem cell renewal. Furthermore, on a closer analysis it was established that the cytoskeletal protein vimentin and nine out of ten genes identified by gene array were associated with chondrogenesis or cartilage repair, consistent with the potential role played by BMSCs in defect repair and maintaining tissue homeostasis, by modulating the gene expression pattern to compensate for degenerated cartilage in osteoarthritic tissues. The gene array also presented transcripts for embryonic lineage markers such as FOXA2 and Sox2, both of which were significantly over expressed in fast growing clonal populations. A recent groundbreaking study by Yamanaka et al imparted embryonic stem cell (ESCs) -like characteristic to somatic cells in a process termed nuclear reprogramming, by the ectopic expression of the genes Sox2, cMyc and Oct4. The expression of embryonic lineage markers in adult stem cells may be a mechanism by which the favourable behaviour of fast growing clonal cells is determined and suggests a possible active phenomenon of spontaneous reprogramming in fast growing clonal cells. The expression pattern of these critical molecular markers could be indicative of the competence of BMSCs. For this reason, the expression pattern of Sox2, Oct4 and cMyc, at various passages in heterogeneous BMSCs population and tissue derived cells (osteoblasts and chondrocytes), was investigated by a real-time PCR and immunoflourescence staining. A strong nuclear staining was observed for Sox2, Oct4 and cMyc, which gradually weakened accompanied with cytoplasmic translocation after several passage. The mRNA and protein expression of Sox2, Oct4 and cMyc peaked at the third passage for osteoblasts, chondrocytes and third passage for BMSCs, and declined with each subsequent passage, indicating towards a possible mechanism of spontaneous reprogramming. This study proposes that the progressive decline in proliferation potential and multipotentiality associated with increased passaging of BMSCs in vitro might be a consequence of loss of these propluripotency factors. We therefore hypothesise that the expression of these master genes is not an intrinsic cell function, but rather an outcome of interaction of the cells with their microenvironment; this was evident by the fact that when removed from their in vivo microenvironment, BMSCs undergo a rapid loss of stemness after only a few passages. One of the most interesting aspects of this study was the integration of factors in the culture conditions, which to some extent, mimicked the in vivo microenvironmental niche of the BMSCs. A number of studies have successfully established that the cellular niche is not an inert tissue component but is of prime importance. The total sum of stimuli from the microenvironment underpins the complex interplay of regulatory mechanisms which control multiple functions in stem cells most importantly stem cell renewal. Therefore, well characterised factors which affect BMSCs characteristics, such as fibronectin (FN) coating, and morphogens such as FGF2 and BMP4, were incorporated into the cell culture conditions. The experimental set up was designed to provide insight into the expression pattern of the stem cell related transcription factors Sox2, cMyc and Oct4, in BMSCs with respect to passaging and changes in culture conditions. Induction of these pluripotency markers in somatic cells by retroviral transfection has been shown to confer pluripotency and an ESCs like state. Our study demonstrated that all treatments could transiently induce the expression of Sox2, cMyc and Oct4, and favourably affect the proliferation potential of BMSCs. The combined effect of these treatments was able to induce and retain the endogenous nuclear expression of stem cell transcription factors in BMSCs over an extended number of in vitro passages. Our results therefore suggest that the transient induction and manipulation of endogenous expression of transcription factors critical for stemness can be achieved by modulating the culture conditions; the benefit of which is to circumvent the need for genetic manipulations. In summary, this study has explored the role of BMSCs in the diseased state of osteoarthritis, by employing transcriptional profiling along with SI. In particular this study pioneered the use of primary cells for generating novel antibodies by SI. We established that somatic cells and BMSCs have a basal level of expression of pluripotency markers. Furthermore, our study indicates that intrinsic signalling mechanisms of BMSCs are intimately linked with extrinsic cues from the microenvironment and that these signals appear to be critical for retaining the expression of genes to maintain cell stemness in long term in vitro culture. This project provides a basis for developing an “artificial niche” required for reversion of commitment and maintenance of BMSC in their uncommitted homeostatic state.

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Over less than a decade, we have witnessed a seismic shift in the way knowledge is produced and exchanged. This is opening up new opportunities for civic and community engagement, entrepreneurial behaviour, sustainability initiatives and creative practices. It also has the potential to create fresh challenges in areas of privacy, cyber-security and misuse of data and personal information. The field of urban informatics focuses on the use and impacts of digital media technology in urban environments. Urban informatics is a dynamic and cross-disciplinary area of inquiry that encapsulates social media, ubiquitous computing, mobile applications and location-based services. Its insights suggest the emergence of a new economic force with the potential for driving innovation, wealth and prosperity through technological advances, digital media and online networks that affect patterns of both social and economic development. Urban informatics explores the intersections between people, place and technology, and their implications for creativity, innovation and engagement. This paper examines how the key learnings from this field can be used to position creative and cultural institutions such as galleries, libraries, archives and museums (GLAM) to take advantage of the opportunities presented by these changing social and technological developments. This paper introduces the underlying principles, concepts and research areas of urban informatics, against the backdrop of modern knowledge economies. Both theoretical ideas and empirical examples are covered in this paper. The first part discusses three challenges: a. People, and the challenge of creativity: The paper explores the opportunities and challenges of urban informatics that can lead to the design and development of new tools, methods and applications fostering participation, the democratisation of knowledge, and new creative practices. b. Technology, and the challenge of innovation: The paper examines how urban informatics can be applied to support user-led innovation with a view to promoting entrepreneurial ideas and creative industries. c. Place, and the challenge of engagement: The paper discusses the potential to establish place-based applications of urban informatics, using the example of library spaces designed to deliver community and civic engagement strategies. The discussion of these challenges is illustrated by a review of projects as examples drawn from diverse fields such as urban computing, locative media, community activism, and sustainability initiatives. The second part of the paper introduces an empirically grounded case study that responds to these three challenges: The Edge, the Queensland Government’s Digital Culture Centre which is an initiative of the State Library of Queensland to explore the nexus of technology and culture in an urban environment. The paper not only explores the new role of libraries in the knowledge economy, but also how the application of urban informatics in prototype engagement spaces such as The Edge can provide transferable insights that can inform the design and development of responsive and inclusive new library spaces elsewhere. To set the scene and background, the paper begins by drawing the bigger picture and outlining some key characteristics of the knowledge economy and the role that the creative and cultural industries play in it, grasping new opportunities that can contribute to the prosperity of Australia.

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This PhD study examines whether water allocation becomes more productive when it is re-allocated from 'low' to 'high' efficient alternative uses in village irrigation systems (VISs) in Sri Lanka. Reservoir-based agriculture is a collective farming economic activity, which inter-sectoral allocation of water is assumed to be inefficient due to market imperfections and weak user rights. Furthermore, the available literature shows that a „head-tail syndrome. is the most common issue for intra-sectoral water management in „irrigation. agriculture. This research analyses the issue of water allocation by using primary data collected from two surveys of 460 rice farmers and 325 fish farming groups in two administrative districts in Sri Lanka. Technical efficiency estimates are undertaken for both rice farming and culture-based fisheries (CBF) production. The equi-marginal principle is applied for inter and intra-sectoral allocation of water. Welfare benefits of water re-allocation are measured through consumer surplus estimation. Based on these analyses, the overall findings of the thesis can be summarised as follows. The estimated mean technical efficiency (MTE) for rice farming is 73%. For CBF production, the estimated MTE is 33%. The technical efficiency distribution is skewed to the left for rice farming, while it skewed to the right for CBF production. The results show that technical efficiency of rice farming can be improved by formalising transferability of land ownership and, therefore, water user rights by enhancing the institutional capacity of Farmer Organisations (FOs). Other effective tools for improving technical efficiency of CBF production are strengthening group stability of CBF farmers, improving the accessibility of official consultation, and attracting independent investments. Inter-sectoral optimal allocation shows that the estimated inefficient volume of water in rice farming, which can be re-allocated for CBF production, is 32%. With the application of successive policy instruments (e.g., a community transferable quota system and promoting CBF activities), there is potential for a threefold increase in marginal value product (MVP) of total reservoir water in VISs. The existing intra-sectoral inefficient volume of water use in tail-end fields and head-end fields can potentially be removed by reducing water use by 10% and 23% respectively and re-allocating this to middle fields. This re-allocation may enable a twofold increase in MVP of water used in rice farming without reducing the existing rice output, but will require developing irrigation practices to facilitate this re-allocation. Finally, the total productivity of reservoir water can be increased by responsible village level institutions and primary level stakeholders (i.e., co-management) sharing responsibility of water management, while allowing market forces to guide the efficient re-allocation decisions. This PhD has demonstrated that instead of farmers allocating water between uses haphazardly, they can now base their decisions on efficient water use with a view to increasing water productivity. Such an approach, no doubt will enhance farmer incomes and community welfare.