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  • Jääskeläinen, Tarja-Leena (1992)
  • Pitkäjärvi, Mari-Anne (Helsingin yliopisto, 2012)
    The purpose of this study was to obtain information to support decision making in the development of successful teaching strategies and clinical placements among English-Language-Taught Degree Programmes (ELTDP) in faculties of healthcare in Finnish universities of applied sciences. This was achieved by descriptions and analysis of the experiences and conceptions of students and teachers. A methodological triangulation was used to conduct the study. In the first phase, descriptions of the students and the teachers experiences of teaching strategies and clinical placements were sought. Data were collected from general nursing and public health nursing teachers (n=18) and also from nursing students (n=27) through focus groups interview. The data were analyzed through thematic content analysis. In the second phase, a structured questionnaire based on the results of the first phase and relevant literature was developed to further investigate the students views. This instrument included items grouped as dimensions for teaching strategies (7 dimensions) and for clinical placements (5 dimensions). The quantitative data were collected from 283 general nursing, public health nursing and physiotherapy students. Statistical methods were used to analyze the data, which compared Finnish students experiences with Finnish students experiences. The findings of the first phase of the study suggest that both students and teachers alike perceived concreteness of instruction as important for ELTDP students learning. Similarly, both groups emphasized the value of the use of a variety of student centered methods to promote the learning of everyone in the culturally diverse student population. The clinical placements were perceived as challenging, due to international students lack of Finnish or Swedish speaking proficiency and also due to their negative experiences in the placements. The findings of the second phase revealed that all ELTDP students experiences of the dimensions of teaching strategies were mainly positive. The most positive experiences for all were with the cultural diversity in the learning community and with concreteness and practicality of theoretical instruction. The most negative experiences were about assessments. The international students felt less satisfied with their lives than did their Finnish peers. However, all students felt motivated to complete their studies. Despite the fact that the international students felt welcome on their placements, they were more likely than the Finnish students to have had the experience of an unsupportive clinical environment. Key words: cultural diversity, healthcare student, teaching strategies, clinical placements, ELTDP students, conceptions of students and teachers.
  • Pilkinton-Pihko, Diane (Helsingin yliopisto, 2013)
    In higher education, the desire to internationalize has created demands for an internationalized academia to use English increasingly in teaching outside the English native-speaking world. Given this situation, perhaps other criteria for measuring successful communication should be considered than that of the native-speaking minority. With lecturers whose native language is not English increasingly teaching their subjects through English, there is a growing need to develop adequate measures for this purpose and situation as the current normative standards are no longer tenable. Establishing adequate measures for this purpose and situation are relevant to institutions facing the challenge of providing EMI courses and programs while ensuring credible quality control. In order to determine what criteria might be adequate for assessing spoken professional English in an international context, this study investigates self-assessments of professional language in relation to language ideologies. The study involves English-medium instruction (EMI) in the field of engineering and takes place at a Finnish university. Using a mixed-methods approach, the study employed an explorative strategy that involved a concurrent design. The two methods were used in parallel and the results integrated at the interpretation phrase. This approach provides a general picture through micro- and macro-level analyses: the self-perceptions of EMI lecturers (i.e. qualitative) and their students perceptions of English in lectures (i.e. quantitative). The investigation employs a bottom-up approach, and is primarily qualitative. The findings are based on authentic data: video-recorded interviews and lectures, their transcriptions, and a questionnaire. The findings show that EMI lecturers have two basic representations of their English: A) when they compare their English to native-like targets, they find fault with their English, and B) when they think of themselves in their normal work environment, they see their English as working rather well. Certain language ideologies induced type A discourse, including standard language and NS language ideologies, and others induced type B discourse, such as English-as-a-global-language ideologies. The results from the student questionnaire also support interpretation B. Since meaningful testing should reflect the target situation, what my informants say in the type B discourse is relevant to developing assessment criteria. Their views to Common European Framework of Reference for Languages (CEFR) scales are also extremely useful in pointing the way towards the central elements upon which relevant assessments for professional English in an international environment should be based. The conclusions indicate a comprehensibility goal over native-likeness for assessing spoken professional English in an international context. The study outlines some criteria relevant for assessing spoken English for this purpose and situation.
  • Ryytty, Jussi-Pekka (2003)
    Syftet med avhandlingen var att i form av en fallstudie studera de service inom socialvården, som produceras av icke-offentliga aktörer och som stiger direkt på den offentliga serviceproduktionens ansvarsområde, utgående ur debatter kring den tredje sektorn och välfärdspluralism anknutet till samhällets strukturella förändringar. Jag ville granska vilken roll den tredje sektorn har i den kommunala serviceproduktionen och som mitt fönster till samhället valde jag de privata aktörerna inom socialvården i Ekenäs, till vilken den empiriska undersökningen var koncentrerad. Jag utgick ur en diskursiv insikt på orsaker och bakgrund via utländska debatter för att sedan vinkla in mig till Finland på 90-talet med de utländska rötterna som grund för debatt från 70-talet, med en inblick på det nya årtusendet. Den huvudsakliga datainsamlingsmetoden var fem temaintervjuer, med tre representanter för den offentliga sektorn och två för den privata. Analysen framskred i flere gallringar, kategorier bildades, vilket resulterade i rubriker med en offentlig- och privat synvinkel. Varje kapitel består av dessa bägge synvinklar och slutar med en kort sammanfattning. Implikationer som kunde dras var att de privata enheternas roll i Ekenäs inom socialvården var marginella och kompletterande, samt som en lokal företeelse steg åldringsvården starkt fram. Av arbetet framgick att en blandad ekonomi av välfärd är inte i en vidare utsträckning ett trovärdigt alternativ.
  • Liu, Shanna (Helsingin yliopisto, 2014)
    Bacteriocins are natural weapons of bacterial inter-species competition in food preservation arsenal. Bacteriocins produced by lactic acid bacteria have gained particular attention owing to their potential application as the substitute of artificial chemical preservatives. This research made use of genetic engineering technologies to clone the class IIa bacteriocin genes and construct bacteriocin structural gene expression systems, aiming at solving the problem of low bacteriocin production in wild type lactic acid bacteria strains and achieving efficient killing of Listeria monocytogenes. The total DNA of Pediococcus acidilactici PA003 was used as the template to amplify the structural gene pedA, which was inserted into pET32a(+) vector and transformed into Escherichia coli. The recombinant plasmid containing the pedA gene was verified by DNA sequencing. This recombinant strain was induced with IPTG and it efficiently expressed a 22 kDa Trx-PedA fusion protein as inclusion bodies. One protein band corresponding to the predicted molecular mass of pediocin was obtained after renaturation and enterokinase treatment. The agar diffusion assay revealed that 512 arbitrary unit (AU) antilisterial activities were obtained from 1 ml culture of recombinant E. coli. The same strategy was adopted using pET20b(+) as the expression vector. The PelB signal peptide in this vector resulted in soluble expression of fusion protein both in the intracellular and periplasmic space with totally 384 AU/ml production. Lactococcus lactis cells were engineered to bind to cellulose by fusing cellulose-binding domain of Cellvibrio japonicus with PrtP, NisP and AcmA anchors for surface display. The CBD-PrtP showed the most efficient immobilization. Expression of sortase with the CBD-PrtP fusion did not improve binding of the anchor to the cell wall. Next, the surface display technique was aimed to be combined with secretion of antilisterial bacteriocins in order to construct an E. coli strain with capacity to bind and kill L. monocytogenes cells. Such cells could be used to test the hypothesis that antilisterial bacteriocin secreting cells kill listerial cells more efficiently if they also have the capacity to bind to listerial cells. Therefore, the CBD500 and CBDP35 cell-wall binding domains from Listeria phage endolysins were used to engineer E. coli cells to bind to L. monocytogenes cells using different cell anchoring domains. First CBD500 was fused to the outer membrane anchor of Yersinia enterocolitica adhesin YadA for potential surface display. Whole-cell ELISA showed that CBD-YadA fusion was displayed on the cell surface. However, production of the fusion protein was detrimental to the growth of recombinant cells. Therefore, a fragment of the E. coli outer membrane protein OmpA was selected for fused expression of CBD500 in E. coli. Western blot revealed the OmpA-CBD was mainly localized on the external surface of recombinant cells. However, the accessibility of the CBD on the cell envelope to cells of Listeria could not be shown. For an improved surface display, CBD was expressed as FliC CBD chimeric protein in flagella. CBD500 and CBDP35 domain coding sequences were inserted into vector pBluescript/fliCH7. CBD insertion in flagella was confirmed by Western blot. The FliC CBDP35 flagella were isolated and shown to bind to L. monocytogenes WSLC 1019 cells. To test the hypothesis that bacteriocin-secreting cells kill target cells more efficiently by binding to the target cells, bacteriocin-secreting strains with binding ability to Listeria cells were constructed. Antilisterial E. coli was obtained either by transferring pediocin production from Lactobacillus plantarum WHE 92 or leucocin C production from Leuconostoc carnosum 4010. The Listeria-binding cells producing pediocin decreased approximately 40 per cent of the Listeria cells during three hours, whereas the cell-free medium with the corresponding amount of pediocin could only inhibit cell growth but did not decrease the number of viable Listeria cells after the three hours incubation. The cell-mediated leucocin C killing resulted in a two-log reduction of Listeria, whereas the corresponding amount of leucocin C in spent culture medium could only inhibit growth without bacteriocidal effect. These results indicate that close contact between Listeria and bacteriocin-producing cells is beneficial for the killing effect by preventing its dilution in the environment and adsorption onto particles before taking effect to the target cells.
  • Clark, Barnaby (Helsingin yliopisto, 2010)
    The Taita Hills in southeastern Kenya form the northernmost part of Africa’s Eastern Arc Mountains, which have been identified by Conservation International as one of the top ten biodiversity hotspots on Earth. As with many areas of the developing world, over recent decades the Taita Hills have experienced significant population growth leading to associated major changes in land use and land cover (LULC), as well as escalating land degradation, particularly soil erosion. Multi-temporal medium resolution multispectral optical satellite data, such as imagery from the SPOT HRV, HRVIR, and HRG sensors, provides a valuable source of information for environmental monitoring and modelling at a landscape level at local and regional scales. However, utilization of multi-temporal SPOT data in quantitative remote sensing studies requires the removal of atmospheric effects and the derivation of surface reflectance factor. Furthermore, for areas of rugged terrain, such as the Taita Hills, topographic correction is necessary to derive comparable reflectance throughout a SPOT scene. Reliable monitoring of LULC change over time and modelling of land degradation and human population distribution and abundance are of crucial importance to sustainable development, natural resource management, biodiversity conservation, and understanding and mitigating climate change and its impacts. The main purpose of this thesis was to develop and validate enhanced processing of SPOT satellite imagery for use in environmental monitoring and modelling at a landscape level, in regions of the developing world with limited ancillary data availability. The Taita Hills formed the application study site, whilst the Helsinki metropolitan region was used as a control site for validation and assessment of the applied atmospheric correction techniques, where multiangular reflectance field measurements were taken and where horizontal visibility meteorological data concurrent with image acquisition were available. The proposed historical empirical line method (HELM) for absolute atmospheric correction was found to be the only applied technique that could derive surface reflectance factor within an RMSE of < 0.02 ps in the SPOT visible and near-infrared bands; an accuracy level identified as a benchmark for successful atmospheric correction. A multi-scale segmentation/object relationship modelling (MSS/ORM) approach was applied to map LULC in the Taita Hills from the multi-temporal SPOT imagery. This object-based procedure was shown to derive significant improvements over a uni-scale maximum-likelihood technique. The derived LULC data was used in combination with low cost GIS geospatial layers describing elevation, rainfall and soil type, to model degradation in the Taita Hills in the form of potential soil loss, utilizing the simple universal soil loss equation (USLE). Furthermore, human population distribution and abundance were modelled with satisfactory results using only SPOT and GIS derived data and non-Gaussian predictive modelling techniques. The SPOT derived LULC data was found to be unnecessary as a predictor because the first and second order image texture measurements had greater power to explain variation in dwelling unit occurrence and abundance. The ability of the procedures to be implemented locally in the developing world using low-cost or freely available data and software was considered. The techniques discussed in this thesis are considered equally applicable to other medium- and high-resolution optical satellite imagery, as well the utilized SPOT data.
  • Rajala, Taneli (2014)
    Enhancement of polymer electrolyte fuel cell tolerance to CO impurities would allow the use of lower quality hydrogen, thus reducing the costs without compromising fuel cell performance. In this work, the effect of carbon monoxide is mitigated by combining different methods, including air bleed, varying the anode flow rate and using a state-of-the-art Pt-Ru catalyst at two operating temperatures. The tolerance was investigated by feeding a novel arrangement of segmented cells with hydrogen containing carbon monoxide less than 20 ppm. Anode exhaust gas was constantly analysed using a gas chromatograph. It was discovered that increasing the volumetric flow rate of hydrogen and especially utilising ruthenium in the catalyst enhance the carbon monoxide tolerance. When applying the air bleed, an oxygen/CO molar ratio of at least 117 was required to stop the poisoning with a platinum catalyst. Approximately a fifth of the air bleed needed with platinum was enough with Pt-Ru. The results also suggest that when applying air bleed at elevated temperatures, it is beneficial to lower the cell temperature for the duration of the air bleed.