434 resultados para Rational perspective
Resumo:
Crowdsourcing harnesses the potential of large and open networks of people. It is a relatively new phenomenon and attracted substantial interest in practice. Related research, however, lacks a theoretical foundation. We propose a system-theoretical perspective on crowdsourcing systems to address this gap and illustrate its applicability by using it to classify crowdsourcing systems. By deriving two principal dimensions from theory, we identify four fundamental types of crowdsourcing systems that help to distinguish important features of such systems. We analyse their respective characteristics and discuss implications and requirements for various aspects related to the design of such systems. Our results demonstrate that systems theory can inform the study of crowdsourcing systems. The identified system types and the implications on their design may prove useful for researchers to frame future studies and for practitioners to identify the right crowdsourcing systems for a particular purpose.
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This paper seeks to explore how organisations can effectively use performance management systems (PMS) to monitor collective identities. The monitoring of relationships between identity and an influential PMS—the balanced scorecard (BSC)—are explored. Drawing from identity and management accounting literature, this paper argues that identity products, patternings and processes are commonly positioned, monitored and interpreted through the multiple perspectives and levels of the BSC. Specifically, human, technical and organisational capital under the Learning and Growth perspective of the BSC can incorporate various identity measures that sustain the relative, distinctive and fluid nature of identities. The value of this research is to strengthen the theoretical grounds which position identity as an important dimension of organisational capital in PMS.
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Purpose - Since the beginning of human existence, humankind has sought, organized and used information as it evolved patterns and practices of human information behaviors. However, the field of human information behavior (HIB) has not heretofore pursued an evolutionary understanding of information behavior. The goal of this exploratory study is to provide insight about the information behavior of various individuals from the past to begin the development of an evolutionary perspective for our understanding of HIB. Design/methodology/approach - This paper presents findings from a qualitative analysis of the autobiographies and personal writings of several historical figures, including Napoleon Bonaparte, Charles Darwin, Giacomo Casanova and others. Findings - Analysis of their writings shows that these persons of the past articulated aspects of their HIB's, including information seeking, information organization and information use, providing tangible insights into their information-related thoughts and actions. Practical implications - This paper has implications for expanding the nature of our evolutionary understanding of information behavior and provides a broader context for the HIB research field. Originality/value - This the first paper in the information science field of HIB to study the information behavior of historical figures and begin to develop an evolutionary framework for HIB research. © Emerald Group Publishing Limited.
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While the role of executives’ cognition in organisations’ responses to change is a central topic in strategic cognition research, changes in firms’ environment are typically not measured directly but described either as an event (for example, new industry legislation) or represented by a time period (e.g. when a new technology impacted an industry). The Australian mining sector has witnessed a historically significant change in demand for its products and we begin by developing measures of changes in supply and demand for key commodities during the period 1992-2008. We identify sub-groups of firms based on their activities and commodity sector and examine the relation of these variables to executives’ cognition and to firms’ CapEx. We find industry, firm and cognitive variables are related to both strategic cognition and firms’ CapEx.
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Proteases regulate a spectrum of diverse physiological processes, and dysregulation of proteolytic activity drives a plethora of pathological conditions. Understanding protease function is essential to appreciating many aspects of normal physiology and progression of disease. Consequently, development of potent and specific inhibitors of proteolytic enzymes is vital to provide tools for the dissection of protease function in biological systems and for the treatment of diseases linked to aberrant proteolytic activity. The studies in this thesis describe the rational design of potent inhibitors of three proteases that are implicated in disease development. Additionally, key features of the interaction of proteases and their cognate inhibitors or substrates are analysed and a series of rational inhibitor design principles are expounded and tested. Rational design of protease inhibitors relies on a comprehensive understanding of protease structure and biochemistry. Analysis of known protease cleavage sites in proteins and peptides is a commonly used source of such information. However, model peptide substrate and protein sequences have widely differing levels of backbone constraint and hence can adopt highly divergent structures when binding to a protease’s active site. This may result in identical sequences in peptides and proteins having different conformations and diverse spatial distribution of amino acid functionalities. Regardless of this, protein and peptide cleavage sites are often regarded as being equivalent. One of the key findings in the following studies is a definitive demonstration of the lack of equivalence between these two classes of substrate and invalidation of the common practice of using the sequences of model peptide substrates to predict cleavage of proteins in vivo. Another important feature for protease substrate recognition is subsite cooperativity. This type of cooperativity is commonly referred to as protease or substrate binding subsite cooperativity and is distinct from allosteric cooperativity, where binding of a molecule distant from the protease active site affects the binding affinity of a substrate. Subsite cooperativity may be intramolecular where neighbouring residues in substrates are interacting, affecting the scissile bond’s susceptibility to protease cleavage. Subsite cooperativity can also be intermolecular where a particular residue’s contribution to binding affinity changes depending on the identity of neighbouring amino acids. Although numerous studies have identified subsite cooperativity effects, these findings are frequently ignored in investigations probing subsite selectivity by screening against diverse combinatorial libraries of peptides (positional scanning synthetic combinatorial library; PS-SCL). This strategy for determining cleavage specificity relies on the averaged rates of hydrolysis for an uncharacterised ensemble of peptide sequences, as opposed to the defined rate of hydrolysis of a known specific substrate. Further, since PS-SCL screens probe the preference of the various protease subsites independently, this method is inherently unable to detect subsite cooperativity. However, mean hydrolysis rates from PS-SCL screens are often interpreted as being comparable to those produced by single peptide cleavages. Before this study no large systematic evaluation had been made to determine the level of correlation between protease selectivity as predicted by screening against a library of combinatorial peptides and cleavage of individual peptides. This subject is specifically explored in the studies described here. In order to establish whether PS-SCL screens could accurately determine the substrate preferences of proteases, a systematic comparison of data from PS-SCLs with libraries containing individually synthesised peptides (sparse matrix library; SML) was carried out. These SML libraries were designed to include all possible sequence combinations of the residues that were suggested to be preferred by a protease using the PS-SCL method. SML screening against the three serine proteases kallikrein 4 (KLK4), kallikrein 14 (KLK14) and plasmin revealed highly preferred peptide substrates that could not have been deduced by PS-SCL screening alone. Comparing protease subsite preference profiles from screens of the two types of peptide libraries showed that the most preferred substrates were not detected by PS SCL screening as a consequence of intermolecular cooperativity being negated by the very nature of PS SCL screening. Sequences that are highly favoured as result of intermolecular cooperativity achieve optimal protease subsite occupancy, and thereby interact with very specific determinants of the protease. Identifying these substrate sequences is important since they may be used to produce potent and selective inhibitors of protolytic enzymes. This study found that highly favoured substrate sequences that relied on intermolecular cooperativity allowed for the production of potent inhibitors of KLK4, KLK14 and plasmin. Peptide aldehydes based on preferred plasmin sequences produced high affinity transition state analogue inhibitors for this protease. The most potent of these maintained specificity over plasma kallikrein (known to have a very similar substrate preference to plasmin). Furthermore, the efficiency of this inhibitor in blocking fibrinolysis in vitro was comparable to aprotinin, which previously saw clinical use to reduce perioperative bleeding. One substrate sequence particularly favoured by KLK4 was substituted into the 14 amino acid, circular sunflower trypsin inhibitor (SFTI). This resulted in a highly potent and selective inhibitor (SFTI-FCQR) which attenuated protease activated receptor signalling by KLK4 in vitro. Moreover, SFTI-FCQR and paclitaxel synergistically reduced growth of ovarian cancer cells in vitro, making this inhibitor a lead compound for further therapeutic development. Similar incorporation of a preferred KLK14 amino acid sequence into the SFTI scaffold produced a potent inhibitor for this protease. However, the conformationally constrained SFTI backbone enforced a different intramolecular cooperativity, which masked a KLK14 specific determinant. As a consequence, the level of selectivity achievable was lower than that found for the KLK4 inhibitor. Standard mechanism inhibitors such as SFTI rely on a stable acyl-enzyme intermediate for high affinity binding. This is achieved by a conformationally constrained canonical binding loop that allows for reformation of the scissile peptide bond after cleavage. Amino acid substitutions within the inhibitor to target a particular protease may compromise structural determinants that support the rigidity of the binding loop and thereby prevent the engineered inhibitor reaching its full potential. An in silico analysis was carried out to examine the potential for further improvements to the potency and selectivity of the SFTI-based KLK4 and KLK14 inhibitors. Molecular dynamics simulations suggested that the substitutions within SFTI required to target KLK4 and KLK14 had compromised the intramolecular hydrogen bond network of the inhibitor and caused a concomitant loss of binding loop stability. Furthermore in silico amino acid substitution revealed a consistent correlation between a higher frequency of formation and the number of internal hydrogen bonds of SFTI-variants and lower inhibition constants. These predictions allowed for the production of second generation inhibitors with enhanced binding affinity toward both targets and highlight the importance of considering intramolecular cooperativity effects when engineering proteins or circular peptides to target proteases. The findings from this study show that although PS-SCLs are a useful tool for high throughput screening of approximate protease preference, later refinement by SML screening is needed to reveal optimal subsite occupancy due to cooperativity in substrate recognition. This investigation has also demonstrated the importance of maintaining structural determinants of backbone constraint and conformation when engineering standard mechanism inhibitors for new targets. Combined these results show that backbone conformation and amino acid cooperativity have more prominent roles than previously appreciated in determining substrate/inhibitor specificity and binding affinity. The three key inhibitors designed during this investigation are now being developed as lead compounds for cancer chemotherapy, control of fibrinolysis and cosmeceutical applications. These compounds form the basis of a portfolio of intellectual property which will be further developed in the coming years.
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Two major difficulties facing widespread clinical implementation of existing Tissue Engineering (TE) strategies for the treatment of musculoskeletal disorders are (1) the cost, space and time required for ex vivo culture of a patient’s autologous cells prior to re-implantation as part of a TE construct, and (2) the potential risks and availability constraints associated with transplanting exogenous (foreign) cells. These hurdles have led to recent interest in endogenous TE strategies, in which the regenerative potential of a patient’s own cells is harnessed to promote tissue regrowth without ex vivo cell culture. This article provides a focused perspective on key issues in the development of endogenous TE strategies, progress to date, and suggested future research directions toward endogenous repair and regeneration of musculoskeletal tissues and organs.
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The issue of carbon sequestration rights has become topical following the United Nations Convention on Climate Change and the subsequent Kyoto Protocol which identified emissions trading as one of the mechanisms to reduce greenhouse gas emissions. The Australian Government has responded by initiating the Garnaut Climate Change Review which in its final report, proposed that an emissions trading scheme be introduced and set out some of the desirable features of such a trading scheme. This proposal has been the subject of much debate and at this stage there still seems to be little clarity surrounding the topic of emissions trading in Australia. The treatment of rights to carbon sequestered in vegetation is also an issue when reconciled with the system of land tenure and ownership in many jurisdictions. These carbon property rights are treated differently in different Australian and international jurisdictions ranging from recognition of their new and unique nature to fitting them within a more established common law framework, e.g.a profit a prendre. This paper identifies the treatment of these sequestered carbon rights within the wider property rights framework in Australia and considers issues that this treatment may inflict on land holders when there is a fracturing of ownership between the rights of the carbon in vegetation and the ownership of the land.
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A national Discipline-Based Initiative project for ICT, funded by the ALTC, has sought to identify the issues and challenges facing the sector. The crisis in ICT education spans high schools, universities and industry. The demand for skilled ICT graduates is increasing yet enrolments are declining. Several factors contribute to this decline including the perceived quality of teaching and a poor perception of the ICT profession amongst the general public. This paper reports on a consultation process with the academic community. Academic concerns include the capacity of the sector to survive the downturn, and improving relationships with industry which should benefit students, academics and industry. An outcome of the consultation process has been the formation of the Australian Council of Deans of ICT (ACDICT) which will have broad responsibility for addressing the issues affecting ICT higher education.
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A national Discipline-Based Initiative (DBI) project for Information and Communications Technology (ICT), funded by the Australian Learning and Teaching Council, has sought the opinions of recent graduates of ICT in the workplace to help inform the curriculum. An online survey was devised to question graduates on workplace requirements and university preparation for abilities categorized as: personal interpersonal; cognitive; business and technical. The graduates in employment have highlighted broad mismatches between the requirements of their professional work in these categories and the preparation for employment they received from university. A regression analysis was used to determine influences on graduates’ opinions of the preparation they received at university. The quantitative and qualitative results from this survey could have far reaching consequences for ICT education and this initiative will enable the development of curricula that ensures graduates are equipped with the skills required by the ICT industry.
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The underlying objective of this study was to develop a novel approach to evaluate the potential for commercialisation of a new technology. More specifically, this study examined the 'ex-ante'. evaluation of the technology transfer process. For this purpose, a technology originating from the high technology sector was used. The technology relates to the application of software for the detection of weak signals from space, which is an established method of signal processing in the field of radio astronomy. This technology has the potential to be used in commercial and industrial areas other than astronomy, such as detecting water leakages in pipes. Its applicability to detecting water leakage was chosen owing to several problems with detection in the industry as well as the impact it can have on saving water in the environment. This study, therefore, will demonstrate the importance of interdisciplinary technology transfer. The study employed both technical and business evaluation methods including laboratory experiments and the Delphi technique to address the research questions. There are several findings from this study. Firstly, scientific experiments were conducted and these resulted in a proof of concept stage of the chosen technology. Secondly, validation as well as refinement of criteria from literature that can be used for „ex-ante. evaluation of technology transfer has been undertaken. Additionally, after testing the chosen technology.s overall transfer potential using the modified set of criteria, it was found that the technology is still in its early stages and will require further development for it to be commercialised. Furthermore, a final evaluation framework was developed encompassing all the criteria found to be important. This framework can help in assessing the overall readiness of the technology for transfer as well as in recommending a viable mechanism for commercialisation. On the whole, the commercial potential of the chosen technology was tested through expert opinion, thereby focusing on the impact of a new technology and the feasibility of alternate applications and potential future applications.
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Purpose: The purpose of this study is to investigate Latin American online purchase behaviour with a specific focus on the influence of perceived risk and trust. While studies of this nature have been conducted quite extensively in developed countries, their application in developing countries, such as Latin America is limited. Our study addresses this gap in the literature with an empirical study conducted in Chile. Design/methodology/approach: The authors develop and test a proposed model of the influence of consumer’s perceptions of risk and trust on their attitudes and intentions to purchase on the Internet. An online survey method is used. The sample consists of 176 Chilean consumers who have made at least one purchase online. The data is analysed using structural equation modelling technique (SEM). Findings: The analysis revealed that of the perceived risk and trust factors examined, trust in third party assurances and a cultural environment of trust had the strongest positive influence on intentions to continuing purchasing online. Perceived risk had an inverse relationship with attitude and consumers’ attitude has a positive influence on intentions to purchase online. Trust in online vendors and a propensity to trust were both insignificant. Practical implications: Practically, these results identity which risk and trust beliefs towards purchasing online have the most effect thereby providing insights into how companies should seek to mitigate perceptions of risk to encourage new and return purchasers. Additionally, this research shows that consumers in a Latin American country, recognised as a collectivist, high risk avoidance culture, are willing to make purchases online despite the risks involved. Originality/value: The study and its results is one of few available that consider a Latin American context. The value of the findings provides insights into the specific risk and trust factors that influence Chilean consumers when considering purchasing online. The tested model adds value not only to the literature on Latin American consumer behaviour but also provides guidance for companies offering online retailing facilities in these less developed countries.
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Information Technology and its relationship to organisational performance has been a subject of continued interest to researchers and other stakeholders in developing countries. While there is concurrence that IT does contribute to performance, and we are efficiently expanding our knowledge on what factors cause better leveraging of IT resources in organisations, we have done little to understand how these factors interact with technology that results in improved performance. This paper suggests looking that the interaction between organisational resources and technology within the structurational lens, which recognises the recursive interaction between technology and people in the presence of social practices, and the norms that inform their ongoing practices. An ethnographic approach to understanding this interaction between technology and resources, as suggested by the structuration perspective, is suggested, aiming to provide richer insights on the nature of the environment that promotes better use of IT resources in developing countries. Such insights could provide the IT users in developing countries with at least an initial conception of the “IT usage platform” that they could promote in their organisations to leverage the most from their IT resources.
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This study explores the international entrepreneurial values influencing the intensity of Internet use in the internationalization process of small to medium sized enterprises (SMEs), within the Australian tourism industry. The findings point to a relationship between the values of international entrepreneurs and the inclination of the firm to develop and initiate international activity. And so, this study endeavors to offer insight into issues that remain unresolved in existing tourism and international entrepreneurship (IE) literature. Two effective but underutilized qualitative methods were used in this study to identify the values of international entrepreneurs. They are repertory test and laddering analysis.