935 resultados para Tissue Culture
Resumo:
National culture is deeply rooted in values, which are learned and acquired when we are young (2007, p. 6), and „embedded deeply in everyday life. (Newman & Nollen, 1996, p. 754). Values have helped to shape us into who we are today. In other words, as we grow older, the cultural values we have learned and adapted to will mould our daily practices. This is reflected in our actions, behaviours, and the ways in which we communicate. Based on the previous assertion, it can be suggested that national culture may also influence organisational culture, as our „behaviour at work is a continuation of behaviour learned earlier. (Hofstede, 1991, p. 4). Cultural influence in an organisation could be evidenced by looking at communication practices: how employees interact with one another as they communicate in their daily practices. Earlier studies in organisational communication see communication as the heart of an organisation in which it serves, and as „the essence of organised activity and the basic process out of which all other functions derive. (Bavelas and Barret, cited in Redding, 1985, p. 7). Hence, understanding how culture influences communication will help with understanding organisational behaviour. This study was conducted to look at how culture values, which are referred to as culture dimensions in this thesis, influenced communication practices in an organisation that was going through a change process. A single case study was held in a Malaysian organisation, to investigate how Malaysian culture dimensions of respect, collectivism, and harmony were evidenced in the communication practices. Data was collected from twelve semi-structured interviews and five observation sessions. Guided by six attributes identified in the literature, (1) acknowledging seniority, knowledge and experience, 2) saving face, 3) showing loyalty to organisation and leaders, 4) demonstrating cohesiveness among members, 5) prioritising group interests over personal interests, and 6) avoiding confrontations of Malaysian culture dimensions, this study found eighteen communication practices performed by employees of the organisation. This research contributes to the previous cultural work, especially in the Malaysian context, in which evidence of Malaysian culture dimensions of respect, collectivism, and harmony were displayed in communication practices: 1) acknowledging the status quo, 2) obeying orders and directions, 3) name dropping, 4) keeping silent, 5) avoiding questioning, 6) having separate conversations, 7) adding, not criticising, 8) sugar coating, 9) instilling a sense of belonging, 10) taking sides, 11) cooperating, 12) sacrificing personal interest, 13) protecting identity, 14) negotiating, 15) saying „yes. instead of „no., 16) giving politically correct answers, 17) apologising, and 18) tolerating errors. Insights from this finding will help us to understand the organisational challenges that rely on communication, such as during organisational change. Therefore, data findings will be relevant to practitioners to understand the impact of culture on communication practices across countries.
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The use of animal sera for the culture of therapeutically important cells impedes the clinical use of the cells. We sought to characterize the functional response of human mesenchymal stem cells (hMSCs) to specific proteins known to exist in bone tissue with a view to eliminating the requirement of animal sera. Insulin-like growth factor-I (IGF-I), via IGF binding protein-3 or -5 (IGFBP-3 or -5) and transforming growth factor-beta 1 (TGF-beta(1)) are known to associate with the extracellular matrix (ECM) protein vitronectin (VN) and elicit functional responses in a range of cell types in vitro. We found that specific combinations of VN, IGFBP-3 or -5, and IGF-I or TGF-beta(1) could stimulate initial functional responses in hMSCs and that IGF-I or TGF-beta(1) induced hMSC aggregation, but VN concentration modulated this effect. We speculated that the aggregation effect may be due to endogenous protease activity, although we found that neither IGF-I nor TGF-beta(1) affected the functional expression of matrix metalloprotease-2 or -9, two common proteases expressed by hMSCs. In summary, combinations of the ECM and growth factors described herein may form the basis of defined cell culture media supplements, although the effect of endogenous protease expression on the function of such proteins requires investigation.
Resumo:
Browse > Journals> Automation Science and Enginee ...> Volume: 5 Issue: 3 Microassembly Fabrication of Tissue Engineering Scaffolds With Customized Design 4468741 abstract Han Zhang; Burdet, E.; Poo, A.N.; Hutmacher, D.W.; GE Global Res. Center Ltd., Shanghai This paper appears in: Automation Science and Engineering, IEEE Transactions on Issue Date: July 2008 Volume: 5 Issue:3 On page(s): 446 - 456 ISSN: 1545-5955 Digital Object Identifier: 10.1109/TASE.2008.917011 Date of Current Version: 02 July 2008 Sponsored by: IEEE Robotics and Automation Society Abstract This paper presents a novel technique to fabricate scaffold/cell constructs for tissue engineering by robotic assembly of microscopic building blocks (of volume 0.5$,times,$0.5$,times,$0.2 ${hbox{mm}}^{3}$ and 60 $mu {hbox{m}}$ thickness). In this way, it becomes possible to build scaffolds with freedom in the design of architecture, surface morphology, and chemistry. Biocompatible microparts with complex 3-D shapes were first designed and mass produced using MEMS techniques. Semi-automatic assembly was then realized using a robotic workstation with four degrees of freedom integrating a dedicated microgripper and two optical microscopes. Coarse movement of the gripper is determined by pattern matching in the microscopes images, while the operator controls fine positioning and accurate insertion of the microparts. Successful microassembly was demonstrated using SU-8 and acrylic resin microparts. Taking advantage of parts distortion and adhesion forces, which dominate at micro-level, the parts cleave together after assembly. In contrast to many current scaffold fabrication techniques, no heat, pressure, electrical effect, or toxic chemical reaction is involved, a critical condition for creating scaffolds with biological agents.
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In this age of evidence-based practice, nurses are increasingly expected to use research evidence in a systematic and judicious way when making decisions about patient care practices. Clinicians recognise the role of research when it provides valid, realistic answers in practical situations. Nonetheless, research is still perceived by some nurses as external to practice and implementing research findings into practice is often difficult. Since its conceptual platform in the 1960s, the emergence and growth of Nursing Development Units, and later, Practice Development Units has been described in the literature as strategic, organisational vehicles for changing the way nurses think about nursing by promoting and supporting a culture of inquiry and research-based practice. Thus, some scholars argue that practice development is situated in the gap between research and practice. Since the 1990s, the discourse has shifted from the structure and outcomes of developing practice to the process of developing practice, using a Practice Development methodology; underpinned by critical social science theory, as a vehicle for changing the culture and context of care. The nursing and practice development literature is dominated by descriptive reports of local practice development activity, typically focusing on reflection on processes or outcomes of processes, and describing perceived benefits. However, despite the volume of published literature, there is little published empirical research in the Australian or international context on the effectiveness of Practice Development as a methodology for changing the culture and context of care - leaving a gap in the literature. The aim of this study was to develop, implement and evaluate the effectiveness of a Practice Development model for clinical practice review and change on changing the culture and context of care for nurses working in an acute care setting. A longitudinal, pre-test/post-test, non-equivalent control group design was used to answer the following research questions: 1. Is there a relationship between nurses' perceptions of the culture and context of care and nurses' perceptions of research and evidence-based practice? 2. Is there a relationship between engagement in a facilitated process of Practice Development and change in nurses' perceptions of the culture and context of care? 3. Is there a relationship between engagement in a facilitated process of Practice Development and change in nurses' perceptions of research and evidence-based practice? Through a critical analysis of the literature and synthesis of the findings of past evaluations of Nursing and Practice Development structures and processes, this research has identified key attributes consistent throughout the chronological and theoretical development of Nursing and Practice Development that exemplify a culture and context of care that is conducive to creating a culture of inquiry and evidence-based practice. The study findings were then used in the development, validation and testing of an instrument to measure change in the culture and context of care. Furthermore, this research has also provided empirical evidence of the relationship of the key attributes to each other and to barriers to research and evidence-based practice. The research also provides empirical evidence regarding the effectiveness of a Practice Development methodology in changing the culture and context of care. This research is noteworthy in its contribution to advancing the discipline of nursing by providing evidence of the degree to which attributes of the culture and context of care, namely autonomy and control, workplace empowerment and constructive team dynamics, can be connected to engagement with research and evidence-based practice.
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This workshop proposes to explore new approaches to cultivate and support sustainable food culture in urban environments via human computer interaction design and ubiquitous technologies. Food is a challenging issue in urban contexts: while food consumption decisions are made many times a day, most food interaction for urbanites occurs based on convenience and habitual practices. This situation is contrasting to the fact that food is at the centre of global environment, health, and social issues that are becoming increasingly immanent and imminent. As such, it is timely and crucial to ask: what are feasible, effective, and innovative ways to improve human-food-interaction through human-computer-interaction in order to contribute to environmental, health, and social sustainability in urban environments? This workshop brings together insights across disciplines to discuss this question, and plan and promote individual, local, and global change for sustainable food culture.
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This thesis examines the culture of contemporary writers’ festivals in an international context. In the last five decades writers’ festivals have emerged in cities across the world, and during this time they have expanded their literary discussions and debates to include numerous other topics of broad interest to society. To examine the expanded popularity and function of writers’ festivals, this thesis establishes a new vantage point for theorising the content now typically generated by these events using concepts in urban festivals and public culture research. Importantly, the new vantage point addresses the limitations of current commentary on writers’ festivals which routinely claim they trivialize literature, and more generally, contribute to the decline of public culture. The thesis presents two case studies: one on the Brisbane Writers Festival in Australia and the other on the International Festival of Authors in Toronto, Canada. The first case study, which focuses on the 2007 Brisbane Writers Festival, illustrates the many overlapping and often conflicting discourses as well as opinions productively discussed and debated at writers’ festivals. Key topic discussed and debated at the Festival include local topics about the host city—its history, literature and politics, as well as broader literary, political and celebrity culture topics. The diversity of topics discussed at the 2007 Brisbane Writers Festival is typical of the majority of writers’ festivals similarly located outside the largest geographic centres of global literary production and circulation, and designated as ‘peripheral’ festivals in this research. The second case study on Toronto’s International Festival of Authors examines the ways in which the 2006 Festival almost exclusively focussed on literary and celebrity culture discourses, and promoted itself on these terms. The 2006 International Festival of Authors’ discussion and debate of a narrow range of topics is typical of the few writers’ festivals located in global centres of literary production and circulation, and unlike ‘peripheral’ festivals they are not experiencing the same growth in number or popularity. The aim of these ‘international’ Festivals is not to democratise their elite literary beginnings, but rather to promote ‘literature’ as a niche brand for quality writing that is valid on a global scale. This thesis will assert that while all writers’ festivals are influenced by the marketing desires of publishing companies, the aim of international writers’ festivals in marketing to a virtually and globally connected elite literary audience makes them more susceptible to experiencing declines in audience and author participation.
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Osteophytes form through the process of chondroid metamorphosis of fibrous tissue followed by endochondral ossification. Osteophytes have been found to consist of three different mesenchymal tissue regions including endochondral bone formation within cartilage residues, intra-membranous bone formation within fibrous tissue and bone formation within bone marrow spaces. All these features provide evidence of mesenchymal stem cells (MSC) involvement in osteophyte formation; nevertheless, it remains to be characterised. MSC from numerous mesenchymal tissues have been isolated but bone marrow remains the “ideal” due to the ease of ex vivo expansion and multilineage potential. However, the bone marrow stroma has a relatively low number of MSC, something that necessitates the need for long-term culture and extensive population doublings in order to obtain a sufficient number of cells for therapeutic applications. MSC in vitro have limited proliferative capacity and extensive passaging compromises differentiation potential. To overcome this barrier, tissue derived MSC are of strong interest for extensive study and characterisation, with a focus on their potential application in therapeutic tissue regeneration. To date, no MSC type cell has been isolated from osteophyte tissue, despite this tissue exhibiting all the hallmark features of a regenerative tissue. Therefore, this study aimed to isolate and characterise cells from osteophyte tissues in relation to their phenotype, differentiation potential, immuno-modulatory properties, proliferation, cellular ageing, longevity and chondrogenesis in in vitro defect model in comparison to patient matched bone marrow stromal cells (bMSC). Osteophyte derived cells were isolated from osteophyte tissue samples collected during knee replacement surgery. These cells were characterised by the expression of cell surface antigens, differentiation potential into mesenchymal lineages, growth kinetics and modulation of allo-immune responses. Multipotential stem cells were identified from all osteophyte samples namely osteophyte derived mesenchymal stem cells (oMSC). Extensively expanded cell cultures (passage 4 and 9 respectively) were used to confirm cytogenetic stability and study signs of cellular aging, telomere length and telomerase activity. Cultured cells at passage 4 were used to determine 84 pathway focused stem cell related gene expression profile. Micro mass pellets were cultured in chondrogenic differentiation media for 21 days for phenotypic and chondrogenic related gene expression. Secondly, cell pellets differentiated overnight were placed into articular cartilage defects and cultured for further 21 days in control medium and chondrogenic medium to study chondrogenesis and cell behaviour. The surface antigen expression of oMSC was consistent with that of mesenchymal stem cells, such as lacking the haematopoietic and common leukocyte markers (CD34, CD45) while expressing those related to adhesion (CD29, CD166, CD44) and stem cells (CD90, CD105, CD73). The proliferation capacity of oMSC in culture was superior to that of bMSC, and they readily differentiated into tissues of the mesenchymal lineages. oMSC also demonstrated the ability to suppress allogeneic T-cell proliferation, which was associated with the expression of tryptophan degrading enzyme indoleamine 2,3 dioxygenase (IDO). Cellular aging was more prominent in late passage bMSC than in oMSC. oMSC had longer telomere length in late passages compared with bMSC, although there was no significant difference in telomere lengths in the early passages in either cell type. Telomerase activity was detectable only in early passage oMSC and not in bMSC. In osteophyte tissues telomerase positive cells were found to be located peri vascularly and were Stro-1 positive. Eighty-four pathway-focused genes were investigated and only five genes (APC, CCND2, GJB2, NCAM and BMP2) were differentially expressed between bMSC and oMSC. Chondrogenically induced micro mass pellets of oMSC showed higher staining intensity for proteoglycans, aggrecan and collagen II. Differential expression of chondrogenic related genes showed up regulation of Aggrecan and Sox 9 in oMSC and collagen II in bMSC. The in vitro defect models of oMSC in control medium showed rounded and aggregated cells staining positively for proteoglycan and presence of some extracellular matrix. In contrast, defects with bMSC showed fragmentation and loss of cells, fibroblast-like cell morphology staining positively for proteoglycans. For defects maintained in chondrogenic medium, rounded, aggregated and proteoglycan positive cells were found in both oMSC and bMSC cultures. Extracellular matrix and cellular integration into newly formed matrix was evident only in oMSC defects. For analysis of chondrocyte hypertrophy, strong expression of type X collagen could be noticed in the pellet cultures and transplanted bMSC. In summary, this study demonstrated that osteophyte derived cells had similar properties to mesenchymal stem cells in the expression of antigen phenotype, differential potential and suppression of allo-immune response. Furthermore, when compared to bMSC, oMSC maintained a higher proliferative capacity due to a retained level of telomerase activity in vitro, which may account for the relatively longer telomeres delaying growth arrest by replicative senescence compared with bMSC. oMSC behaviour in defects supported chondrogenesis which implies that cells derived from regenerative tissue can be an alternative source of stem cells and have a potential clinical application for therapeutic stem cell based tissue regeneration.
Resumo:
The periosteum plays an indispensable role in both bone formation and bone defect healing. In this study we constructed an artificial in vitro periosteum by incorporating osteogenic differentiated bone marrow stromal cells (BMSCs) and cobalt chloride (CoCl(2))-treated BMSCs. The engineered periostea were implanted both subcutaneously and into skull bone defects in SCID mice to investigate ectopic and orthotopic osteogenesis and vascularization. After two weeks in subcutaneous and four weeks in bone defect areas, the implanted constructs were assessed for ectopic and orthotopic osteogenesis and vascularization by micro-CT, histomorphometrical and immunohistochemical methods. The results showed that CoCl(2) pre-treated BMSCs induced higher degree of vascularization and enhanced osteogenesis within the implants in both ectopic and orthotopic areas. This study provided a novel approach using BMSCs sourced from the same patient for both osteogenic and pro-angiogenic purposes in constructing tissue engineered periosteum to enhance vascularized osteogenesis.
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The dream of a cosmopolitical utopia has been around for thousands of years. Yet the promise of being locally situated and at the same time globally connected and mobile has never seemed more possible than it is today. The question remains as to whether it is positive and realistic for us to have multiple loyalties. Can we sustain community and solidarity with our neighbours while we look beyond our nation? And if we can't - or won't – consider distant strangers as part of our own world, are there increasingly dire consequences? This book reconnects classical sociological theory and contemporary ideas on mobility, otherness, material assemblages, consumption and surveillance to render the idea of a global cosmopolitan utopia amenable to sociological investigation. The book takes a realistic approach to the development of cosmopolitical arrangements. It embraces the imaginative impulses the cosmopolitan dream provides, but takes into account the political, ethical and cultural dimensions of such cosmopolitan developments. In revisiting the relevance of classical sociological approaches in the context of contemporary theoretical challenges, the distinctive approach this book takes to understanding cosmopolitanism will be of use to scholars and students alike.
Resumo:
College students (N = 3,435) in 26 cultures reported their perceptions of age-related changes in physical, cognitive, and socioemotional areas of functioning and rated societal views of aging within their culture. There was widespread cross-cultural consensus regarding the expected direction of aging trajectories with (1) perceived declines in societal views of aging, physical attractiveness, the ability to perform everyday tasks, and new learning, (2) perceived increases in wisdom, knowledge, and received respect, and (3) perceived stability in family authority and life satisfaction. Cross-cultural variations in aging perceptions were associated with culture-level indicators of population aging, education levels, values, and national character stereotypes. These associations were stronger for societal views on aging and perceptions of socioemotional changes than for perceptions of physical and cognitive changes. A consideration of culture-level variables also suggested that previously reported differences in aging perceptions between Asian and Western countries may be related to differences in population structure.
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Since the early 1980s, researchers and practitioners in the organisational and management fields have presumed a link between organisational, or corporate, culture and organisational performance. Whilst many believe this exists, other authors have been critical of the validity of such studies. Part of this doubt stems from a reliance on measures of organisational performance that are based purely on financial measures of business growth. Using the construction industry as the subject of his research, Vaughan Coffey traces the development of the literature on organisational culture and business effectiveness and investigates the culture–performance link using a new and highly objective measure of company performance and an evaluation of organisational culture, which is largely behaviourally-based. Providing a theoretical contribution to the field, this work shows that various cultural traits appear to be closely linked to objectively measured organisational effectiveness. This book will be valuable to professionals and researchers in the fields of management and public policy. It indicates directions for construction companies to develop and change, and in doing so strengthen their chances of remaining strong when opportunities for work might deplete and only the most successful companies will be able to survive.---- Selected Contents: 1. An Introduction to Organizations, Culture, Performance and Construction 2. Organizations, Culture and Climate 3. Organizational Culture Studies 4. Measuring Organizational Performance and Effectiveness 5. Organizational Culture and Effectiveness – The Link Between Them 6. Research on the Relationship between Organizational Culture and Performance in Hong Kong Construction Companies 7. The Hong Kong Experiment – Presentation of Demographic Data, Overall Results and some Descriptive and Qualitative Analysis 8. Detailed Statistical Analysis of the Docs and Pass Data in Relation to the Major Research Questions 9. Four Hong Kong Construction Mini-Case Studies 10. Conclusions and Future Research Directions