7 resultados para Complex systems

em Helda - Digital Repository of University of Helsinki


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A Journey in the Landscape of Sustainable School Development “A Journey in the Landscape of Sustainable School Development” is a story of the Sorrila School development process. This research deals with a school development project as a process, and as a part of international projects on Education for Sustainable Development, with ENSI (Environment and School Initiatives) being the most important. The main purpose of the study was to analyze the change process as a general phenomenon as well as the learning connected to it. The research describes the development period 2001–2008 at the Sorrila Primary school. The research questions are as follows: 1. What did pupils learn during the research and development period? 2. How did the coordinating teacher develop personally? 3. How were the ENSI targets and other closely linked projects reached? 4. What was the feedback from the pupils, their parents and other teachers at the school? 5. How did the developing process proceed in 2001–2008? The method used was integrating action research, which also had ethnographical elements. Narrative was the form of the data as well as the manner of reporting. The method as a whole was integrating, ethnographical action research as a story. The research data consisted mostly of Knowledge Forum notes written by the teacher-researcher. Knowledge Forum is an Internetbased collaborative knowledge-building programme. Pupils’, parents’ and other teachers’ feedback, newspaper articles and students’ writings complied the data, which consists of material from seven years. Sustainable development was the basis of the school improvement. The targets of the United Nations Decade of Education for Sustainable Development (2005–2014) were part of the development projects. According to the research results the school was seen as part of complex systems where manifold and interactive learning took place. The learning of pupils, teachers and the school as a community can be characterised socioculturally. The school was able to reach a level of collaborative transformative learning. As well as several concrete projects, such as Comenius school project, school development consisted of networking at many levels. Along with the projects and networking, the school was able to apply the pedagogy of connection, by carrying out integrative and cross-disciplinary themes and using various learning and teaching methods. International cooperation was a natural part of the work. A figure of Aunt Green, the role model of the teacher researcher, was an innovation which resembled a change agent. The other role of the teacherresearcher as a coordinator, was important for her own professional development. According to the results the change process, which relied on sustainable school development, led the school along a road of positive renewals. It was not a series of projects but an ongoing process. The objectives of the international projects were accomplished to a great extent during the research period. According to the principles of action research, the main results were put forward in order to help others to develop their schools. Frictions and problems as well as positive experiences and rejecting dualities were seen as change forces. Keywords: education for sustainable development (ESD), sustainable school development, teacher professional development, integrating, pedagogy of connection, transformative learning

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Microbes in natural and artificial environments as well as in the human body are a key part of the functional properties of these complex systems. The presence or absence of certain microbial taxa is a correlate of functional status like risk of disease or course of metabolic processes of a microbial community. As microbes are highly diverse and mostly notcultivable, molecular markers like gene sequences are a potential basis for detection and identification of key types. The goal of this thesis was to study molecular methods for identification of microbial DNA in order to develop a tool for analysis of environmental and clinical DNA samples. Particular emphasis was placed on specificity of detection which is a major challenge when analyzing complex microbial communities. The approach taken in this study was the application and optimization of enzymatic ligation of DNA probes coupled with microarray read-out for high-throughput microbial profiling. The results show that fungal phylotypes and human papillomavirus genotypes could be accurately identified from pools of PCR amplicons generated from purified sample DNA. Approximately 1 ng/μl of sample DNA was needed for representative PCR amplification as measured by comparisons between clone sequencing and microarray. A minimum of 0,25 amol/μl of PCR amplicons was detectable from amongst 5 ng/μl of background DNA, suggesting that the detection limit of the test comprising of ligation reaction followed by microarray read-out was approximately 0,04%. Detection from sample DNA directly was shown to be feasible with probes forming a circular molecule upon ligation followed by PCR amplification of the probe. In this approach, the minimum detectable relative amount of target genome was found to be 1% of all genomes in the sample as estimated from 454 deep sequencing results. Signal-to-noise of contact printed microarrays could be improved by using an internal microarray hybridization control oligonucleotide probe together with a computational algorithm. The algorithm was based on identification of a bias in the microarray data and correction of the bias as shown by simulated and real data. The results further suggest semiquantitative detection to be possible by ligation detection, allowing estimation of target abundance in a sample. However, in practise, comprehensive sequence information of full length rRNA genes is needed to support probe design with complex samples. This study shows that DNA microarray has the potential for an accurate microbial diagnostic platform to take advantage of increasing sequence data and to replace traditional, less efficient methods that still dominate routine testing in laboratories. The data suggests that ligation reaction based microarray assay can be optimized to a degree that allows good signal-tonoise and semiquantitative detection.

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We consider a chain composed of $N$ coupled harmonic oscillators in contact with heat baths at temperature $T_\ell$ and $T_r$ at sites 1 and $N$ respectively. The oscillators are also subjected to non-momentum conserving bulk stochastic noises. These make the heat conductivity satisfy Fourier's law. Here we describe some new results about the hydrodynamical equations for typical macroscopic energy and displacement profiles, as well as their fluctuations and large deviations, in two simple models of this type.

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Failures in industrial organizations dealing with hazardous technologies can have widespread consequences for the safety of the workers and the general population. Psychology can have a major role in contributing to the safe and reliable operation of these technologies. Most current models of safety management in complex sociotechnical systems such as nuclear power plant maintenance are either non-contextual or based on an overly-rational image of an organization. Thus, they fail to grasp either the actual requirements of the work or the socially-constructed nature of the work in question. The general aim of the present study is to develop and test a methodology for contextual assessment of organizational culture in complex sociotechnical systems. This is done by demonstrating the findings that the application of the emerging methodology produces in the domain of maintenance of a nuclear power plant (NPP). The concepts of organizational culture and organizational core task (OCT) are operationalized and tested in the case studies. We argue that when the complexity of the work, technology and social environment is increased, the significance of the most implicit features of organizational culture as a means of coordinating the work and achieving safety and effectiveness of the activities also increases. For this reason a cultural perspective could provide additional insight into the problem of safety management. The present study aims to determine; (1) the elements of the organizational culture in complex sociotechnical systems; (2) the demands the maintenance task sets for the organizational culture; (3) how the current organizational culture at the case organizations supports the perception and fulfilment of the demands of the maintenance work; (4) the similarities and differences between the maintenance cultures at the case organizations, and (5) the necessary assessment of the organizational culture in complex sociotechnical systems. Three in-depth case studies were carried out at the maintenance units of three Nordic NPPs. The case studies employed an iterative and multimethod research strategy. The following methods were used: interviews, CULTURE-survey, seminars, document analysis and group work. Both cultural analysis and task modelling were carried out. The results indicate that organizational culture in complex sociotechnical systems can be characterised according to three qualitatively different elements: structure, internal integration and conceptions. All three of these elements of culture as well as their interrelations have to be considered in organizational assessments or important aspects of the organizational dynamics will be overlooked. On the basis of OCT modelling, the maintenance core task was defined as balancing between three critical demands: anticipating the condition of the plant and conducting preventive maintenance accordingly, reacting to unexpected technical faults and monitoring and reflecting on the effects of maintenance actions and the condition of the plant. The results indicate that safety was highly valued at all three plants, and in that sense they all had strong safety cultures. In other respects the cultural features were quite different, and thus the culturally-accepted means of maintaining high safety also differed. The handicraft nature of maintenance work was emphasised as a source of identity at the NPPs. Overall, the importance of safety was taken for granted, but the cultural norms concerning the appropriate means to guarantee it were little reflected. A sense of control, personal responsibility and organizational changes emerged as challenging issues at all the plants. The study shows that in complex sociotechnical systems it is both necessary and possible to analyse the safety and effectiveness of the organizational culture. Safety in complex sociotechnical systems cannot be understood or managed without understanding the demands of the organizational core task and managing the dynamics between the three elements of the organizational culture.

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Modern drug discovery gives rise to a great number of potential new therapeutic agents, but in some cases the efficient treatment of patient may not be achieved because the delivery of active compounds to the target site is insufficient. Thus, drug delivery is one of the major challenges in current pharmaceutical research. Numerous nanoparticle-based drug carriers, e.g. liposomes, have been developed for enhanced drug delivery and targeting. Drug targeting may enhance the efficiency of the treatment and, importantly, reduce unwanted side effects by decreasing drug distribution to non-target tissues. Liposomes are biocompatible lipid-based carriers that have been studied for drug delivery during the last 40 years. They can be functionalized with targeting ligands and sensing materials for triggered activation. In this study, various external signal-assisted liposomal delivery systems were developed. Signals can be used to modulate drug permeation or release from the liposome formulation, and they provide accurate control of time, place and rate of activation. The study involved three types of signals that were used to trigger drug permeation and release: electricity, heat and light. Electrical stimulus was utilized to enhance the permeation of liposomal DNA across the skin. Liposome/DNA complex-mediated transfections were performed in tight rat epidermal cell model. Various transfection media and current intensities were tested, and transfection efficiency was evaluated non-invasively by monitoring the concentration of secreted reporter protein in cell culture medium. Liposome/DNA complexes produced gene expression, but electrical stimulus did not enhance the transfection efficiency significantly. Heat-sensitive liposomal drug delivery system was developed by coating liposomes with biodegradable and thermosensitive poly(N-(2-hydroxypropyl) methacrylamide-mono/dilactate polymer. Temperature-triggered liposome aggregation and contents release from liposomes were evaluated. The cloud point temperature (CP) of the polymer was set to 42 °C. Polymer-coated liposome aggregation and contents release were observed above CP of the polymer, while non-coated liposomes remained intact. Polymer precipitates above its CP and interacts with liposomal bilayers. It is likely that this induces permeabilization of the liposomal membrane and contents release. Light-sensitivity was introduced to liposomes by incorporation of small (< 5 nm) gold nanoparticles. Hydrophobic and hydrophilic gold nanoparticles were embedded in thermosensitive liposomes, and contents release was investigated upon UV light exposure. UV light-induced lipid phase transitions were examined with small angle X-ray scattering, and light-triggered contents release was shown also in human retinal pigment epithelial cell line. Gold nanoparticles absorb light energy and transfer it into heat, which induces phase transitions in liposomes and triggers the contents release. In conclusion, external signal-activated liposomes offer an advanced platform for numerous applications in drug delivery, particularly in the localized drug delivery. Drug release may be localized to the target site with triggering stimulus that results in better therapeutic response and less adverse effects. Triggering signal and mechanism of activation can be selected according to a specific application.

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Since 1997 the Finnish Jabal Haroun Project (FJHP) has studied the ruins of the monastery and pilgrimage complex (Gr. oikos) of Aaron located on a plateau of the Mountain of Prophet Aaron, Jabal an-Nabi Harûn, ca. 5 km to the south-west of the UNESCO World Heritage site of Petra in Jordan. The state of conservation and the damaging processes affecting the stone structures of the site are studied in this M.A. thesis. The chapel was chosen as an example, as it represents the phasing and building materials of the entire site. The aim of this work is to act as a preliminary study with regards to the planning of long-term conservation at the site. The research is empirical in nature. The condition of the stones in the chapel walls was mapped using the Illustrated Glossary on Stone Deterioration, by the ICOMOS International Scientific Committee for Stone. This glossary combines several standards and systems of damage mapping used in the field. Climatic conditions (temperature and RH %) were monitored for one year (9/2005-8/2006) using a HOBO Microstation datalogger. The measurements were compared with contemporary measurements from the nearest weather station in Wadi Musa. Salts in the stones were studied by taking samples from the stone surfaces by scraping and with the “Paper Pulp”-method; with a poultice of wet cellulose fiber (Arbocel BC1000) and analyzing what main types of salts were to be found in the samples. The climatic conditions on the mountain were expected to be rapidly changing and to differ clearly from conditions in the neighboring areas. The rapid changes were confirmed, but the values did not differ as much as expected from those nearby: the 12 months monitored had average temperatures and were somewhat drier than average. Earlier research in the area has shown that the geological properties of the stone material influence its deterioration. The damage mapping showed clearly, that salts are also a major reason for stone weathering. The salt samples contained several salt combinations, whose behavior in the extremely unstable climatic conditions is difficult to predict. Detailed mapping and regular monitoring of especially the structures, that are going remain exposed, is recommended in this work.