11 resultados para computer assisted tomography

em Helda - Digital Repository of University of Helsinki


Relevância:

80.00% 80.00%

Publicador:

Resumo:

Tutkimuksen tavoitteena oli tutkia tietokoneavusteisen opetuksen opetusmenetelmänä ja tietokoneavusteisten opetusohjelmien oppimateriaalina soveltuvuutta erilaisiin sähköalan ammatillisiin opetus- ja oppimistilanteisiin. Tietokoneavusteisilla opetusohjelmilla tarkoitetaan tässä tutkimuksessa erilaisia digitaaliseen muotoon tallennettuja oppimateriaaleja ja tietokoneavusteisella opetuksella näiden digitaalisten oppimateriaalien hyödyntämistä erilaisissa oppimistilanteissa. Opetusteknologian kehittymisen myötä myöskin opettajin valittavissa olevat opetusmenetelmät lisääntyvät ja monipuolistuvat. Vastaavalla tavalla myöskin oppimateriaalit kehittyvät ja mahdollistavat oppijan näkökulmasta entistä yksilöllisemmät opiskelumahdollisuudet. Tutkimuksen viitekehyksen liittyvinä keskeisinä elementteinä olivat tietokoneavusteinen opetus opetusmenetelmänä ja sen valintaan liittyvät tekijät: oppisisällöt ja oppimiselle asetetut tavoitteet, opettajan opetusmenetelmällinen osaaminen, erilaiset oppijat yksilöllisine oppimistavoitteineen sekä käytettävissä olevat erilaiset oppimateriaalit. Tutkimus toteutettiin toimintatutkimuksena ja siihen osallistui tutkijan lisäksi 15 sähköalan opettajaa kahdesta erikokoisesta ammattioppilaitoksesta. Varsinainen toimintatutkimus aloitettiin keväällä 1994 ja se jatkui kevääseen 1996. Lisäksi suoritettiin vertaileva tutkimus, johon osallistui 9 opettajaa kolmesta erillisestä ammattioppilaitoksesta syksyllä 1996 jatkuen kevääseen 1997. Keskeisimmistä tutkimustuloksista mainitsen opettajien heikon tuntemuksen tietokoneavusteisesta opetuksesta ja sen hyödyntämiseen liittyvistä elementeistä. Opettajilta puuttuu taito suunnitella tietokoneavusteisia opetusohjelmia oppimateriaaleina hyödyntäviä opetus- ja oppimistilanteita. Tutkimuksen mukaan opettajilla ei kuitenkaan ole negatiivista ennakkoasennetta opetusmenetelmää kohtaan ja opiskelijat suhtautuvat erittäin myönteisesti erilaisiin tietokoneavusteisiin opetusohjelmiin oppimateriaaleina. Avainsanat: Tietokoneavusteinen opetus, tietokoneavusteinen oppiminen, tietokoneavusteinen oppimateriaali

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The aim of the study was to explore why the MuPSiNet project - a computer and network supported learning environment for the field of health care and social work - did not develop as expected. To grasp the problem some hypotheses were formulated. The hypotheses regarded the teachers' skills in and attitudes towards computing and their attitudes towards constructivist study methods. An online survey containing 48 items was performed. The survey targeted all the teachers within the field of health care and social work in the country, and it produced 461 responses that were analysed against the hypotheses. The reliability of the variables was tested using the Cronbach alpha coefficient and t-tests. Poor basic computing skills among the teachers combined with a vulnerable technical solution, and inadequate project management combined with lack of administrative models for transforming economic resources into manpower were the factors that turned out to play a decisive role in the project. Other important findings were that the teachers had rather poor skills and knowledge in computing, computer safety and computer supported instruction, and that these skills were significantly poorer among female teachers who were in majority in the sample. The fraction of teachers who were familiar with software for electronic patient records (EPR) was low. The attitudes towards constructivist teaching methods were positive, and further education seemed to utterly increase the teachers' readiness to use alternative teaching methods. The most important conclusions were the following: In order to integrate EPR software as a natural tool in teaching planning and documenting health care, it is crucial that the teachers have sufficient basic skills in computing and that more teachers have personal experience of using EPR software. In order for computer supported teaching to become accepted it is necessary to arrange with extensive further education for the teachers presently working, and for that further education to succeed it should be backed up locally among other things by sufficient support in matters concerning computer supported teaching. The attitudes towards computing showed significant gender differences. Based on the findings it is suggested that basic skills in computing should also include an awareness of data safety in relation to work in different kinds of computer networks, and that projects of this kind should be built up around a proper project organisation with sufficient resources. Suggestions concerning curricular development and further education are also presented. Conclusions concerning the research method were that reminders have a better effect, and that respondents tend to answer open-ended questions more verbosely in electronically distributed online surveys compared to traditional surveys. A method of utilising randomized passwords to guarantee respondent anonymity while maintaining sample control is presented. Keywords: computer-assisted learning, computer-assisted instruction, health care, social work, vocational education, computerized patient record, online survey

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The aim of the thesis was to compare the correspondence of the outcome a computer assisted program appearance compared to the original image. The aspect of the study was directed to embroidery with household machines. The study was made from the usability point of view with Brother's PE-design 6.0 embroidery design programs two automatic techniques; multicoloured fragment design and multicoloured stitch surface design. The study's subject is very current because of the fast development of machine embroidery. The theory is based on history of household sewing machines, embroidery sewing machines, stitch types in household sewing machines, embroidery design programs as well as PE-design 6.0 embroidery design program's six automatic techniques. Additionally designing of embroidery designs were included: original image, digitizing, punching, applicable sewing threads as well as the connection between embroidery designs and materials used on embroidery. Correspondences of sewn appearances were examined with sewing experimental methods. 18 research samples of five original image were sewn with both techniques. Experiments were divided into four testing stages in design program. Every testing stage was followed by experimental sewing with Brother Super Galaxie 3100D embroidery machine. Experiments were reported into process files and forms made for the techniques. Research samples were analysed on images syntactic bases with sensory perception assessment. Original images and correspondence of the embroidery appearances were analysed with a form made of it. The form was divided into colour and shape assessment in five stage-similarity-scale. Based on this correspondence analysis it can be said that with both automatic techniques the best correspondence of colour and shape was achieved by changing the standard settings and using the makers own thread chart and edited original image. According to the testing made it is impossible to inform where the image editing possibilities of the images are sufficient or does the optimum correspondence need a separate program. When aiming at correspondence between appearances of two images the computer is unable to trace by itself the appearance of the original image. Processing a computer program assisted embroidery image human perception and personal decision making are unavoidable.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

In this study the researcher wanted to show the observed connection of mathematics and textile work. To carry this out the researcher designed a textbook by herself for the upper secondary school in Tietoteollisuuden Naiset TiNA project at Helsinki University of Technology (URL:http://tina.tkk.fi/). The assignments were designed as additional teaching material to enhance and reinforce female students confidence in mathematics and in the management of their textile work. The research strategy applied action research, out of which two cycles two have been carried out. The first cycle consists of establishing the textbook and in the second cycle its usability is investigated. The third cycle is not included in this report. In the second cycle of the action research the data was collected from 15 teachers, five textile teachers, four mathematics teachers and six teachers of both subjects. They all got familiar with the textbook assignments and answered a questionnaire on the basis of their own teaching experience. The questionnaire was established by applying the theories of usability and teaching material assessment study. The data consisted of qualitative and quantitative information, which was analysed by content analysis with computer assisted table program to either qualitative or statistical description. According to the research results, the textbook assignments seamed to be applied better to mathematics lessons than textile work. The assignments pointed out, however, the clear interconnectedness of textile work and mathematics. Most of the assignments could be applied as such or as applications in the upper secondary school textile work and mathematics lessons. The textbook assignments were also applicable in different stages of the teaching process, e.g. as introduction, repetition or to support individual work or as group projects. In principle the textbook assignments were in well placed and designed in the correct level of difficulty. Negative findings concerned some too difficult assignments, lack of pupil motivation and unfamiliar form of task for the teacher. More clarity for some assignments was wished for and there was especially expressed a need for easy tasks and assignments in geometry. Assignments leading to the independent thinking of the pupil were additionally asked for. Two important improvements concerning the textbook attainability would be to get the assignments in html format over the Internet and to add a handicraft reference book.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Taking the appropriation of objects as a theoretical starting point, this study makes a distinction between a conceptual and practical level of adopting new objects and products in everyday life. The study applies the concept of appropriation in social food research and examines consumers appropriation of functional foods, i.e., foods developed to improve health and well-being or reduce the risk of disease beyond the usual nutritional effects of foods. The study uses the concept of appropriation to understand the adoption and the process of making functional foods our own . First, the study focuses on the conceptual appropriation by analysing consumers interpretations and opinions on functional foods. Second, it analyses the use of functional foods and examines the role of sociodemographic and food- and health-related background factors in the use of functional foods. Both quantitative and qualitative data were used in the study. Altogether 1210 Finns representative of the population took part in a survey carried out in 2002 as computer-assisted telephone interviews (CATI). The survey examined the acceptability and use of functional foods in Finland. In 2004, eight focus group discussions were organised for 45 users and non-users of cholesterol-lowering spreads. The qualitative study focused on consumers interpretative perspectives on healthy eating and functional foods. The findings are reported in four original articles and a summary article. The results show that the appropriation of functional foods is a multifaceted phenomenon. The conceptual appropriation is related to consumers interpretations of functional foods in the context of healthy foods and healthy eating; their trust in the products, their manufacturers, research and control; and the relationship of functional foods and the ideal of natural foods. The analysis of the practical appropriation of four different types of foods marketed as functional showed that there are sociodemographic differences between users and non-users of the products, but more importantly, the differences are related to consumers food- and health-related views and practices. Consumers ways of appropriating functional foods in the conceptual and practical sense take shape in a complex web of ideas and everyday practices concerning food, health and eating as a whole. The results also indicate that the conceptual and practical appropriation are not necessarily uniform or coherent processes. Consumers interpret healthy eating and functional foods from a variety of perspectives and there is a multiplicity of rationales of using functional foods. Appropriation embraces many opposing dimensions simultaneously: good experiences and doubts, approval and criticism, expectations and things taken for granted.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Breast cancer is the most common cancer in women in the western countries. Approximately two-thirds of breast cancer tumours are hormone dependent, requiring estrogens to grow. Estrogens are formed in the human body via a multistep route starting from cholesterol. The final steps in the biosynthesis include the CYP450 aromatase enzyme, converting the male hormones androgens (preferred substrate androstenedione ASD) into estrogens(estrone E1), and the 17beta-HSD1 enzyme, converting the biologically less active E1 into the active hormone 17beta-hydroxyestradiol E2. E2 is bound to the nuclear estrogen receptors causing a cascade of biochemical reactions leading to cell proliferation in normal tissue, and to tumour growth in cancer tissue. Aromatase and 17beta-HSD1 are expressed in or near the breast tumour, locally providing the tissue with estrogens. One approach in treating hormone dependent breast tumours is to block the local estrogen production by inhibiting these two enzymes. Aromatase inhibitors are already on the market in treating breast cancer, despite the lack of an experimentally solved structure. The structure of 17beta-HSD1, on the other hand, has been solved, but no commercial drugs have emerged from the drug discovery projects reported in the literature. Computer-assisted molecular modelling is an invaluable tool in modern drug design projects. Modelling techniques can be used to generate a model of the target protein and to design novel inhibitors for them even if the target protein structure is unknown. Molecular modelling has applications in predicting the activities of theoretical inhibitors and in finding possible active inhibitors from a compound database. Inhibitor binding at atomic level can also be studied with molecular modelling. To clarify the interactions between the aromatase enzyme and its substrate and inhibitors, we generated a homology model based on a mammalian CYP450 enzyme, rabbit progesterone 21-hydroxylase CYP2C5. The model was carefully validated using molecular dynamics simulations (MDS) with and without the natural substrate ASD. Binding orientation of the inhibitors was based on the hypothesis that the inhibitors coordinate to the heme iron, and were studied using MDS. The inhibitors were dietary phytoestrogens, which have been shown to reduce the risk for breast cancer. To further validate the model, the interactions of a commercial breast cancer drug were studied with MDS and ligand–protein docking. In the case of 17beta-HSD1, a 3D QSAR model was generated on the basis of MDS of an enzyme complex with active inhibitor and ligand–protein docking, employing a compound library synthesised in our laboratory. Furthermore, four pharmacophore hypotheses with and without a bound substrate or an inhibitor were developed and used in screening a commercial database of drug-like compounds. The homology model of aromatase showed stable behaviour in MDS and was capable of explaining most of the results from mutagenesis studies. We were able to identify the active site residues contributing to the inhibitor binding, and explain differences in coordination geometry corresponding to the inhibitory activity. Interactions between the inhibitors and aromatase were in agreement with the mutagenesis studies reported for aromatase. Simulations of 17beta-HSD1 with inhibitors revealed an inhibitor binding mode with hydrogen bond interactions previously not reported, and a hydrophobic pocket capable of accommodating a bulky side chain. Pharmacophore hypothesis generation, followed by virtual screening, was able to identify several compounds that can be used in lead compound generation. The visualisation of the interaction fields from the QSAR model and the pharmacophores provided us with novel ideas for inhibitor development in our drug discovery project.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The study examines various uses of computer technology in acquisition of information for visually impaired people. For this study 29 visually impaired persons took part in a survey about their experiences concerning acquisition of infomation and use of computers, especially with a screen magnification program, a speech synthesizer and a braille display. According to the responses, the evolution of computer technology offers an important possibility for visually impaired people to cope with everyday activities and interacting with the environment. Nevertheless, the functionality of assistive technology needs further development to become more usable and versatile. Since the challenges of independent observation of environment were emphasized in the survey, the study led into developing a portable text vision system called Tekstinäkö. Contrary to typical stand-alone applications, Tekstinäkö system was constructed by combining devices and programs that are readily available on consumer market. As the system operates, pictures are taken by a digital camera and instantly transmitted to a text recognition program in a laptop computer that talks out loud the text using a speech synthesizer. Visually impaired test users described that even unsure interpretations of the texts in the environment given by Tekstinäkö system are at least a welcome addition to complete perception of the environment. It became clear that even with a modest development work it is possible to bring new, useful and valuable methods to everyday life of disabled people. Unconventional production process of the system appeared to be efficient as well. Achieved results and the proposed working model offer one suggestion for giving enough attention to easily overlooked needs of the people with special abilities. ACM Computing Classification System (1998): K.4.2 Social Issues: Assistive technologies for persons with disabilities I.4.9 Image processing and computer vision: Applications Keywords: Visually impaired, computer-assisted, information, acquisition, assistive technology, computer, screen magnification program, speech synthesizer, braille display, survey, testing, text recognition, camera, text, perception, picture, environment, trasportation, guidance, independence, vision, disabled, blind, speech, synthesizer, braille, software engineering, programming, program, system, freeware, shareware, open source, Tekstinäkö, text vision, TopOCR, Autohotkey, computer engineering, computer science

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Parkinson´s Disease (PD) is a neurodegenerative movement disorder resulting from loss of dopaminergic (DA) neurons in substantia nigra (SN). Possible causative treatment strategies for PD include neurotrophic factors, which protect and in some cases restore the function of dopaminergic neurons. Glial cell line-derived neurotrophic factor (GDNF) family of neurotrophic factors have been to date the most promising candidates for treatment of PD, demonstrating both neuroprotective and neurorestorative properties. We have investigated the role of GDNF in the rodent dopaminergic system and its possible crosstalk with other growth factors. We characterized the GDNF-induced gene expression changes by DNA microarray analysis in different neuronal systems, including in vitro cultured Neuro2A cells treated with GDNF, as well as midbrains from GDNF heterozygous (Hz) knockout mice. These microarray experiments, resulted in the identification of GDNF-induced genes, which were also confirmed by other methods. Further analysis of the dopaminergic system of GDNF Hz mice demonstrated about 40% reduction in GDNF levels, revealed increased intracellular dopamine concentrations and FosB/DeltaFosB expression in striatal areas. These animals did not show any significant changes in behavioural analysis of acute and repeated cocaine administration on locomotor activity, nor did they exhibit any changes in dopamine output following treatment with acute cocaine. We further analysed the significance of GDNF receptor RET signalling in dopaminergic system of MEN2B knock-in animals with constitutively active Ret. The MEN2B animals showed a robust increase in extracellular dopamine and its metabolite levels in striatum, increased tyrosine hydroxylase (TH) and dopamine transporter (DAT) protein levels by immunohistochemical staining and Western blotting, as well as increased Th mRNA levels in SN. MEN2B mice had increased number of DA neurons in SN by about 25% and they also exhibited increased sensitivity to the stimulatory effects of cocaine. We also developed a semi-throughput in vitro micro-island assay for the quantification of neuronal survival and TH levels by computer-assisted methodology from limited amounts of tissue. This assay can be applied for the initial screening for dopaminotrophic molecules, as well as chemical drug library screening. It is applicable to any neuronal system for the screening of neurotrophic molecules. Since our microarray experiments revealed possible GDNF-VEGF-C crosstalk we further concentrated on studying the neurotrophic effects of VEGF-C. We showed that VEGF-C acts as a neurotrophic molecule for the DA neurons both in vitro and in vivo, however without additive effect when used together with GDNF. The neuroprotective effect for VEGF-C in vivo in rat 6-OHDA model of PD was demonstrated. The possible signalling mechanisms of VEGF-C in the nervous system were investigated - infusion of VEGF-C to rat brain induced ERK activation, however no direct activation of RET signalling in vitro was found. VEGF-C treatment of rat striatum lead to up-regulation of VEGFR-1-3, indicating that VEGF-C can regulate the expression level of its own receptor. VEGF-C dopaminotrophic activity in vivo was further supported by increased vascular tissue in the neuroprotection experiments.