Bioabsorbable materials for osteosynthesis and small joint arthroplasty in the hand

Fractures and arthritic joint destruction are common in the hand. A reliable and stable fracture fixation can be achieved by metal implants, which however, become unnecessary or even harmful after consolidation. The silicone implant arthroplasty is the current method of choice for reconstruction of metacarpophalangeal joints in rheumatoid patients. However, the outcome tends to worsen with long-term follow-up and implant-related complications become frequent. To address these problems, bioabsorbable implants were designed for the hand area. Aims of the studies were: 1) to evaluate the biomechanical stabilities provided by self- reinforced (SR) bioabsorbable implants in a transverse and an oblique osteotomy of small tubular bones and to compare them with those provided by metal implants; 2) to evaluate the SR poly-L/DL-lactide 70/30 plate for osteosynthesis in a proof-of-principle type of experiment in three cases of hand injuries; and 3) to evaluate the poly-L/D-lactide (PLA) 96/4 joint scaffold, a composite joint implant with a supplementary intramedullary Polyactive® stem and Swanson silicone implant in an experimental small joint arthroplasty model. Methods used were: 1) 112 fresh frozen human cadaver and 160 pig metacarpal bones osteotomised transversally or obliquely, respectively, and tested ex vivo in three point bending and in torsion; 2) three patient cases of complex hand injuries; and 3) the fifth metacarpophalangeal joints reconstructed in 18 skeletally-mature minipigs and studied radiologically and histologically. The initial fixation stabilities provided by bioabsorbable implants in the tubular bones of the hand were comparable with currently-employed metal fixation techniques, and were sufficient for fracture stabilisation in three preliminary cases in the hand. However, in torsion the stabilities provided by bioabsorbable implants were lower than that provided by metal counterparts. The bioabsorbable plate enhanced the bending stability for the bioabsorbable fixation construct. PLA 96/4 joint scaffolds demonstrated good biocompatibility and enabled fibrous tissue in-growth in situ. After scaffold degradation, a functional, stable pseudarthrosis with dense fibrous connective tissue was formed. However, the supplementary Polyactive® stem caused a deleterious tissue reaction and therefore the stem can not be applied to the composite joint implant. The bioabsorbable implants have potential for use in clinical hand surgery, but have to await validation in clinical patient series and controlled trials.

A Historical Approach to Children s Physics Education : Modelling of DC-circuit Phenomena in a Small Group

This three-phase design research describes the modelling processes for DC-circuit phenomena. The first phase presents an analysis of the development of the DC-circuit historical models in the context of constructing Volta s pile at the turn of the 18th century. The second phase involves the designing of a teaching experiment for comprehensive school third graders. Among other considerations, the design work utilises the results of the first phase and research literature of pupils mental models for DC-circuit phenomena. The third phase of the research was concerned with the realisation of the planned teaching experiment. The aim of this phase was to study the development of the external representations of DC-circuit phenomena in a small group of third graders. The aim of the study has been to search for new ways to guide pupils to learn DC-circuit phenomena while emphasing understanding at the qualitative level. Thus, electricity, which has been perceived as a difficult and abstract subject, could be learnt more comprehensively. Especially, the research of younger pupils learning of electricity concepts has not been of great interest at the international level, although DC-circuit phenomena are also taught in the lower classes of comprehensive schools. The results of this study are important, because there has tended to be more teaching of natural sciences in the lower classes of comprehensive schools, and attempts are being made to develop this trend in Finland. In the theoretical part of the research an Experimental-centred representation approach, which emphasises the role of experimentalism in the development of pupil s representations, is created. According to this approach learning at the qualitative level consists of empirical operations like experimenting, observations, perception, and prequantification of nature phenomena, and modelling operations like explaining and reasoning. Besides planning teaching, the new approach can be used as an analysis tool in describing both historical modelling and the development of pupils representations. In the first phase of the study, the research question was: How did the historical models of DC-circuit phenomena develop in Volta s time? The analysis uncovered three qualitative historical models associated with the historical concept formation process. The models include conceptions of the electric circuit as a scene in the DC-circuit phenomena, the comparative electric-current phenomenon as a cause of different observable effect phenomena, and the strength of the battery as a cause of the electric-current phenomenon. These models describe the concept formation process and its phases in Volta s time. The models are portrayed in the analysis using fragments of the models, where observation-based fragments and theoretical fragements are distinguished from each other. The results emphasise the significance of the qualitative concept formation and the meaning of language in the historical modelling of DC-circuit phenomena. For this reason these viewpoints are stressed in planning the teaching experiment in the second phase of the research. In addition, the design process utilised the experimentation behind the historical models of DC-circuit phenomena In the third phase of the study the research question is as follows: How will the small group s external representations of DC-circuit phenomena develop during the teaching experiment? The main question is divided into the following two sub questions: What kind of talk exists in the small group s learning? What kinds of external representations for DC-circuit phenomena exist in the small group discourse during the teaching experiment? The analysis revealed that the teaching experiment of the small group succeeded in its aim to activate talk in the small group. The designed connection cards proved especially successful in activating talk. The connection cards are cards that represent the components of the electric circuit. In the teaching experiment the pupils constructed different connections with the connection cards and discussed, what kinds of DC-circuit phenomena would take place in the corresponding real connections. The talk of the small group was analysed by comparing two situations, firstly, when the small group discussed using connections made with the connection cards and secondly with the same connections using real components. According to the results the talk of the small group included more higher-order thinking when using the connection cards than with similar real components. In order to answer the second sub question concerning the small group s external representations that appeared in the talk during the teaching experiment; student talk was visualised by the fragment maps which incorporate the electric circuit, the electric current and the source voltage. The fragment maps represent the gradual development of the external representations of DC-circuit phenomena in the small group during the teaching experiment. The results of the study challenge the results of previous research into the abstractness and difficulty of electricity concepts. According to this research, the external representations of DC-circuit phenomena clearly developed in the small group of third graders. Furthermore, the fragment maps uncover that although the theoretical explanations of DC-circuit phenomena, which have been obtained as results of typical mental model studies, remain undeveloped, learning at the qualitative level of understanding does take place.

Constructing Fair Tourism in Ecuador: The Case of Asoguabo

Tämän pro gradu-tutkielman tarkoitus on tutkia, miten reilun kaupan banaania tuottavan El Guabon pienten banaaninviljelijöiden järjestön Asoguabon reilun turismin projekti on rakennettu. Projektin muotoutumista tutkitaan tässä työssä kahdesta eri näkökulmasta: siitä, miksi ja miten Asoguabo on monipuolistanut viljelystä turismiin, sekä siitä, millainen kuva projektista on rakennettu markkinoinnin kautta ja miten reilun kaupan mainonnasta tuttuja ilmiöitä on hyödynnetty reilun turismin rakentamisessa. Tutkielman teoreettisena taustana on maaseudun muutoksia tarkasteleva uuden ruraliteetin käsite. Turismi on viime vuosikymmenten aikana muuttunut, ja matkailijat etsivät yhä enemmän aitoja ja autenttisia matkailukokemuksia. Samanaikaisesti turismia on tuotteistettu korostamalla sen tiettyjä, kestävän kehityksen mukaisia piirteitä, ja erityisesti kehittyvissä maissa turismia markkinoidaan usein vaihtoehtoisena, yhteisöpohjaisena tai ekoturismina. Reilu turismi on uutena käsitteenä tullut mukaan tähän laajaan kirjoon, ja tämä tutkielma käsitteleekin Asoguabon projektia nimenomaan reilun turismin näkökulmasta. Tämä tutkielma on tapaustutkimus Asoguabon turismiprojektista, ja pohjautuu kuukauden pituiseen kenttätyöhön Ecuadorissa tammikussa 2010 sekä kirjoittajan aiempiin kokemuksiin Asoguabosta. Aineisto koostuu 21 puoli-strukturoidusta laadullisesta haastattelusta kuudentoista informantin kanssa, joista suurin osa oli hyvin läheisesti tekemisissä projektin kanssa. Tämän lisäksi aineistonkeruussa on käytetty havainnointia sekä projektin markkinointimateriaalien sisällönanalyysia. Tutkielma osoittaa reilun turismin projektin sisältävän monia haasteita ennen kuin se voi saavuttaa tavoitteensa tuottaa lisätuloja Asoguabon toimintaan. Tutkimushetkellä projekti hyödytti suoraan pääasiassa muutamia järjestön viljelijöitä, lähinnä niitä, jotka toimivat projektissa oppaina. Nämä oppaat hyötyvät projektista saamalla pieniä lisätuloja, kasvattamalla sosiaalista pääomaansa, sekä saamalla mahdollisuuden oppia muun muassa osallistumalla kursseille. Tutkimuksen keskeiset tulokset osoittavat myös, kuinka vuorovaikutus-ongelmat projektin eri toimijoiden välillä vaikeuttavat tiedonkulkua ja täten reilun turismin toimintaa. Nämä ongelmat myös lisäävät epätietoisuutta Asoguabon muiden viljelijöiden parissa. Lisäksi tutkimus osoittaa, kuinka reilun turismin projektin mainonnassa käytetään osittain samoja keinoja kuin reilun kaupan tuotteiden mainonnassa, joskin tuottajia on kuvattu mainosmateriaaleissa yllättävän vähän ja pääosassa ovat usein eurooppalaiset turistit.

Key Factors Influencing Economic Relationships and Communication in Finnish Food Chains

The aim of this report is to discuss the role of the relationship type and communication in two Finnish food chains, namely the pig meat-to-sausage (pig meat chain) and the cereal-to-rye bread (rye chain) chains. Furthermore, the objective is to examine those factors influencing the choice of a relationship type and the sustainability of a business relationship. Altogether 1808 questionnaires were sent to producers, processors and retailers operating in these two chains of which 224 usable questionnaires were returned (the response rate being 12.4%). The great majority of the respondents (98.7%) were small businesses employing less than 50 people. Almost 70 per cent of the respondents were farmers. In both chains, formal contracts were stated to be the most important relationship type used with business partners. Although for many businesses written contracts are a common business practice, the essential role of the contracts was the security they provide regarding the demand/supply and quality issues. Relative to the choice of the relationship types, the main difference between the two chains emerged especially with the prevalence of spot markets and financial participation arrangements. The usage of spot markets was significantly more common in the rye chain when compared to the pig meat chain, while, on the other hand, financial participation arrangements were much more common among the businesses in the pig meat chain than in the rye chain. Furthermore, the analysis showed that most of the businesses in the pig meat chain claimed not to be free to choose the relationship type they use. Especially membership in a co-operative and practices of a business partner were mentioned as the reasons limiting this freedom of choice. The main business relations in both chains were described as having a long-term orientation and being based on formal written contracts. Typical for the main business relationships was also that they are not based on the existence of the key persons only; the relationship would remain even if the key people left the business. The quality of these relationships was satisfactory in both chains and across all the stakeholder groups, though the downstream processors and the retailers had a slightly more positive view on their main business partners than the farmers and the upstream processors. The businesses operating in the pig meat chain seemed also to be more dependent on their main business relations when compared to the businesses in the rye chain. Although the communication means were rather similar in both chains (the phone being the most important), there was some variation between the chains concerning the communication frequency necessary to maintain the relationship with the main business partner. In short, the businesses in the pig meat chain seemed to appreciate more frequent communication with their main business partners when compared to the businesses in the rye chain. Personal meetings with the main business partners were quite rare in both chains. All the respondent groups were, however, fairly satisfied with the communication frequency and information quality between them and the main business partner. The business cultures could be argued to be rather hegemonic among the businesses both in the pig meat and rye chains. Avoidance of uncertainty, appreciation of long-term orientation and independence were considered important factors in the business cultures. Furthermore, trust, commitment and satisfaction in business partners were thought to be essential elements of business operations in all the respondent groups. In order to investigate which factors have an effect on the choice of a relationship type, several hypotheses were tested by using binary and multinomial logit analyses. According to these analyses it could be argued that avoidance of uncertainty and risk has a certain effect on the relationship type chosen, i.e. the willingness to avoid uncertainty increases the probability to choose stable relationships, like repeated market transactions and formal written contracts, but not necessary those, which require high financial commitment (like financial participation arrangements). The probability of engaging in financial participation arrangements seemed to increase with long-term orientation. The hypotheses concerning the sustainability of the economic relations were tested by using structural equation model (SEM). In the model, five variables were found to have a positive and statistically significant impact on the sustainable economic relationship construct. Ordered relative to their importance, those factors are: (i) communication quality, (ii) personal bonds, (iii) equal power distribution, (iv) local embeddedness and (v) competition.

Use of Document Management Systems - a Case Study of the Finnish Construction Industry

Triggered by the very quick proliferation of Internet connectivity, electronic document management (EDM) systems are now rapidly being adopted for managing the documentation that is produced and exchanged in construction projects. Nevertheless there are still substantial barriers to the efficient use of such systems, mainly of a psychological nature and related to insufficient training. This paper presents the results of empirical studies carried out during 2002 concerning the current usage of EDM systems in the Finnish construction industry. The studies employed three different methods in order to provide a multifaceted view of the problem area, both on the industry and individual project level. In order to provide an accurate measurement of overall usage volume in the industry as a whole telephone interviews with key personnel from 100 randomly chosen construction projects were conducted. The interviews showed that while around 1/3 of big projects already have adopted the use of EDM, very few small projects have adopted this technology. The barriers to introduction were investigated through interviews with representatives for half a dozen of providers of systems and ASP-services. These interviews shed a lot of light on the dynamics of the market for this type of services and illustrated the diversity of business strategies adopted by vendors. In the final study log files from a project which had used an EDM system were analysed in order to determine usage patterns. The results illustrated that use is yet incomplete in coverage and that only a part of the individuals involved in the project used the system efficiently, either as information producers or consumers. The study also provided feedback on the usefulness of the log files.

Board Effectiveness in Small Firms

Purpose: This study investigates boards of directors in small firms and explores the link between board effectiveness and the composition, roles and working styles of the boards. Design/methodology/approach: The study analyses data from a telephone survey of boards in 45 small firms. The survey included both the CEO and the chairperson of the board. Findings: The study identifies three groups of small firms: ‘paperboards’, ‘professional boards’, and ‘management lead’ boards. Results show that board composition, board roles and board working style influence board effectiveness in small firms. Research limitations/implications: Although the present study has found a link between board effectiveness and the role, composition and working style of boards of small firms, other potentially influential factors are also worthy of investigation; for example, the personal characteristics of the individuals involved, generational factors in family firms, and the situational circumstances of various firms. Practical implications: The study reveals that, in practice, the management team and the board are substantially intertwined in small firms. Originality/value: The main contributions are that the study explores how boards in small firms actually function and gives a detailed account of their composition and roles.More insight into this issue is important given the overemphasis within the governance literature on input-output studies using samples of large publiclylisted firms.