Repair of segmental bone defects with fiber-reinforced composite: a study of material development and an animal model on rabbits

The Repair of segmental defects in load-bearing long bones is a challenging task because of the diversity of the load affecting the area; axial, bending, shearing and torsional forces all come together to test the stability/integrity of the bone. The natural biomechanical requirements for bone restorative materials include strength to withstand heavy loads, and adaptivity to conform into a biological environment without disturbing or damaging it. Fiber-reinforced composite (FRC) materials have shown promise, as metals and ceramics have been too rigid, and polymers alone are lacking in strength which is needed for restoration. The versatility of the fiber-reinforced composites also allows tailoring of the composite to meet the multitude of bone properties in the skeleton. The attachment and incorporation of a bone substitute to bone has been advanced by different surface modification methods. Most often this is achieved by the creation of surface texture, which allows bone growth, onto the substitute, creating a mechanical interlocking. Another method is to alter the chemical properties of the surface to create bonding with the bone – for example with a hydroxyapatite (HA) or a bioactive glass (BG) coating. A novel fiber-reinforced composite implant material with a porous surface was developed for bone substitution purposes in load-bearing applications. The material’s biomechanical properties were tailored with unidirectional fiber reinforcement to match the strength of cortical bone. To advance bone growth onto the material, an optimal surface porosity was created by a dissolution process, and an addition of bioactive glass to the material was explored. The effects of dissolution and orientation of the fiber reinforcement were also evaluated for bone-bonding purposes. The Biological response to the implant material was evaluated in a cell culture study to assure the safety of the materials combined. To test the material’s properties in a clinical setting, an animal model was used. A critical-size bone defect in a rabbit’s tibia was used to test the material in a load-bearing application, with short- and long-term follow-up, and a histological evaluation of the incorporation to the host bone. The biomechanical results of the study showed that the material is durable and the tailoring of the properties can be reproduced reliably. The Biological response - ex vivo - to the created surface structure favours the attachment and growth of bone cells, with the additional benefit of bioactive glass appearing on the surface. No toxic reactions to possible agents leaching from the material could be detected in the cell culture study when compared to a nontoxic control material. The mechanical interlocking was enhanced - as expected - with the porosity, whereas the reinforcing fibers protruding from the surface of the implant gave additional strength when tested in a bone-bonding model. Animal experiments verified that the material is capable of withstanding load-bearing conditions in prolonged use without breaking of the material or creating stress shielding effects to the host bone. A Histological examination verified the enhanced incorporation to host bone with an abundance of bone growth onto and over the material. This was achieved with minimal tissue reactions to a foreign body. An FRC implant with surface porosity displays potential in the field of reconstructive surgery, especially regarding large bone defects with high demands on strength and shape retention in load-bearing areas or flat bones such as facial / cranial bones. The benefits of modifying the strength of the material and adjusting the surface properties with fiber reinforcement and bone-bonding additives to meet the requirements of different bone qualities are still to be fully discovered.

Extrauterine leiomyomata presenting with sepsis requiring hemicolectomy

Extrauterine leiomyomas are rare, benign, and may arise in any anatomic sites. Their unusual growth pattern may even mimic malignancy and can result in a clinical dilemma. Occasionally, uterine leiomyomas become adherent to surrounding structures. They also develop an auxiliary blood supply, and lose their original attachment to the uterus, thus becoming 'parasitic'. Parasitic myomas may also be iatrogenically created after uterine fibroid surgery, particularly if morcellation is used. This report presented two cases of parasitic myomas with sepsis, both requiring right hemicolectomy. It reviewed the pertinent literature.

Nikkelille selektiivisen kelatoivan adsorbenttimateriaalin valmistus ja tutkiminen

Metallien laajamittaisen ja runsaan käytön vuoksi nykyään on keskityttävä aikaisempaa tarkemmin metallipäästöjen estämiseen ja puhdistamiseen. Metallien puhdistamiseen jätevesistä voidaan käyttää erilaisia yksikköoperaatiomenetelmiä, mutta selektiivisempään erotukseen päästään ioninvaihto- ja adsorbenttimateriaaleilla. Työn tarkoitusena on valmistaa ja tutkia nikkeliselektiivisiä adsorbenttimateriaaleja. Lisäksi tutkimuskohteena on nikkelin ja 1,10-fenantroliinin välisen kompleksin muodostuminen eri pH-arvoilla. Selektiivisten adsorbenttimateriaalien valmistaminen onnistuu liittämällä kiinteään kantajaan ligandi. Tämän työn tapauksessa nikkelitemplaatin liittäminen kiinteään kantajaan funktionalisointivaiheessa muodostaa adsorbenttiin nikkelille spesifisen kohdan. Käytännössä spesifisyyden syntyminen ei ole itsestäänselvyys, vaan se riippuu paljon funktionalisointitavasta. Tässä työssä funktionalisointitapana olivat fysikaalinen adsorptio ja impregnointi. Nikkelin ja 1,10-fenantroliinin välisen kompleksin muodostumista tutkittiin eri pH-arvojen lisäksi neljällä eri happokonsentraatiolla. Tuloksia verrattiin sellaisen liuoksen spektriin, missä oli pelkkää nikkeliä. Tuloksista havaittiin, että komplekseja muodostuu käytännössä samalla tavalla pH:n ollessa 1–6. Vasta 5 M HNO3 alkoi heikentää kompleksien muodostumista, ja 10 M HNO3 esti kompleksien muodostumisen täysin. Adsorbenttimateriaaleja valmistettiin useita erilaisia, joihin osaan liitettiin nikkelitemplaatti ja osa jätettiin ilman templaattia. Työssä keskityttiin tutkimaan erityisesti kolmea silikasta valmistettua materiaalia, joissa vain kahdessa oli nikkelitemplaatti. Nikkelitemplaattien olemassaololla ei havaittu olevan juurikaan merkitystä nikkelin erottamiseen vesiliuoksista. Materiaaleille tehdyt regenerointikokeet osoittivat, että materiaalien toiminta ja kapasiteetti eivät olleet toivotulla tasolla.

Nuorten kokemien elämysten yksilölliset ja yhteisölliset merkitykset

Tutkimuksessa tarkastellaan nuorten antamia merkityksiä elämykseksi nimetylle kokemukselle ja tunteelle. Tavoitteena on ollut selvittää elämysten kokemista nuorten näkökulmasta ja suhteuttaa nuorten kokemuksilleen antamia merkityksiä laajemmin nuoruutta ja elämyksien kokemista käsittelevään yhteiskunnalliseen keskusteluun. Elämysten merkityksellistämistä analysoidaan suhteessa identiteetin muodostukseen. Yksilöllisesti koetut elämykset saavat merkityksensä diskursiivisesti rakentuneen todellisuuden ympäröimänä. Tutkimus paikantuu sosiologisen nuorisotutkimuksen ja tunteiden tutkimuksen alaan sekä metodologisesti fenomenologis-konstruktivistisen tutkimuksen alaan. Tutkimuksen taustalla on elämyshakuisuutta käsittelevä teoria. Elämyshakuisuuden tulkinta fenomenologisesta viitekehyksestä tuo käsitteen ymmärtämiseen uuden ulottuvuuden. Elämyshakuisuus kuvaa asennoitumistapaa eli sitä, miten yksilö orientoituu ympäröivään maailmaan. Tällöin ei edellytetä intentionaalisten tekojen tietoista luonnetta. Toiminnalliset prosessit muovautuvat vuorovaikutuksen myötä samaan tapaan kuin ihminen ruumiillisena subjektina muovautuu. Tutkimuksen aineisto koostuu lukion ensimmäisen luokan oppilaiden kirjoituksista (519 kpl), lastensuojeluinstituutioissa ja kuntoutuskeskuksissa asuvien nuorten yksilöteemahaastatteluista (16 nuorta) sekä seikkailualan asiantuntijoiden teemahaastatteluista (20 aikuista). Nuorten kirjoitukset on kerätty vuosina 1996–1997 ja 2002–2003. Aineiston analyysi on aineistolähtöinen. Erilaiset osa-aineistot työssäni avaavat erilaisia näkökulmia elämysten kokemiseen. Aineistojen analyysi ja tutkimukset teoreettiset lähtökohdat ovat rakentuneet analyysin edetessä ja vuorovaikutussuhteessa toisiinsa. Nuorten elämyksiä käsittelevä kerronta on moninaista ja elämyksiä koetaan erilaisissa tilanteissa. Elämykselle ei ole yhtä määritelmää, kokemisen paikkaan tai kokemisen syytä vaan kokemuksen merkitys rakentuu tilanteisesti. Elämys kuitenkin erottuu muista kokemuksista sen muistettavuuden, ainutlaatuisuuden, uutuuden ja intensiivisyyden perusteella. Nuorten elämyksellisissä hetkissä korostuvat harrastusten yhteydessä koetut uudet, erilaiset, yhteisöllisesti jaetut, mutta myös maailmaa nuorille avaavat itsenäisyyden tunnetta ja hallintaa tuottavat kokemukset. Yksi merkittävä uusia elämyksiä ja tietoa tuottava asia nuorten elämässä on seurustelu. Myös matkailu, erilaiset retket ja leirit olivat nuorille elämyksiä tuottavia tilanteita. Kaikilla nuorilla ei kuitenkaan ole sellaisia harrastuksia, joihin he olisivat sitoutuneita tai joissa he pääsisivät ilmaisemaan itseään ja kokemaan onnistumista. Nuorten elämyksiä käsittelevissä hetkissä nuorten vapaa-ajan toiminta, ympäristö ja sosiaaliset suhteet ovat keskeisessä asemassa. Nuoret eivät ensisijaisesti ajatelleet itse etsivänsä tai toisten nuorten etsivän elämyksiä viihdeteollisuuden tuottamista asioista. Elämyksissä arvostettiin aitoutta ja koettu tunne määritti sitä, oliko jokin koettu elämyksenä vai ei. Toisaalta erilaisten päihteiden todettiin mahdollisesti tuottavan elämyksiä, mutta niidenkin yhteydessä korostettiin usein muita asioita kokemusta rakentavina. Nuorten elämyskokemuksissa toisten nuorten merkitys, luottamus, läheisyyteen ja hyväksyntään liittyvät kokemukset korostuvat. Myös aikuisten asiantuntijoiden omaa nuoruutta käsittelevät elämykset olivat emotionaaliselta merkitykseltään hyvin samanlaisia kuin tämän päivän nuorten esittämät. Elämyksiksi miellettyjä kokemuksia pidettiin arvokkaina. Niiden uskottiin suuntaavan yksilön toimintaa.

Receptors and endocytosis of coxsackievirus A9

Coxsackievirus A9 (CV-A9) belongs to human enteroviruses within family Picornaviridae, which are the main cause of aseptic meningitis. In addition, CV-A9 causes a wide range of other clinical manifestations of acute disease including respiratory infections, myocarditis, encephalitis and severe generalized infections in newborns. In this study, the functions of integrins αVβ6 and αVβ3 in the attachment and cellular entry of CV-A9 were analyzed. Further, virus and cell surface interactions and endocytosis of CV-A9 were studied in specific cell lines. Also, a method for production of GFP-expressing CV-A9 particles by long PCR-mediated mutagenesis and in vivo transcription was developed. The results indicated that RGD-motif (arginine-glycine-asparagine) that resides in the viral capsid is important for CV-A9 infection particularly in cell lines expressing integrin αVβ6 and that this integrin serves as a high affinity attachment receptor for the virus. CV-A9 is also capable of infecting certain cell lines independently of αV-integrins by binding to the cell surface HSPA5 protein. Regardless of the attachment stage, the internalization of the virus occurs via the same entry pathway and is dependent on β2M, dynamin, and Arf6 but independent of clathrin and caveolin-1. Furthermore, the virus internalization occurs within Arf6-containing vesicles suggesting that Arf6 is central mediator of CV-A9 endocytosis. While in this study the results of CV-A9 endocytosis were based on microscopical visualization within individual fixed cells, a rapid method for generation of a virus for real-time imaging was also described.

Evaluation of a model for induction of periodontal disease in dogs

There are several methods for inducing periodontal disease in animal models, being the bone defect one of the most reported. This study aimed to evaluate this model, through clinical, radiographic, tomographic and histological analyzes, thus providing standardized data for future regenerative works. Twelve dogs were subjected to the induction protocol. In a first surgical procedure, a mucoperiosteal flap was made on the buccal aspect of the right third and fourth premolars and a defect was produced exposing the furcation and mesial and distal roots, with dimensions: 5mm coronoapical, 5mm mesiodistal, and 3mm buccolingual. Periodontal ligament and cementum were curetted and the defect was filled with molding polyester, which was removed after 21 days on new surgical procedure. Clinical and radiographic examinations were performed after the two surgeries and before the collection of parts for dental tomography and histological analysis. All animals showed grade II furcation exposure in both teeth. Clinical attachment level increased after induction. Defect size did not change for coronoapical and buccolingual measurements, while mesiodistal size was significantly higher than at the time of defect production. Radiographic analysis showed decreased radiopacity and discontinuity of lamina dura in every tooth in the furcation area. The horizontal progression of the disease was evident in micro-computed tomography and defect content in the histological analysis. Therefore, it is concluded that this method promotes the induction of periodontal disease in dogs in a standardized way, thus being a good model for future work.

Unidirectional fiber-reinforced composite as an oral implant abutment material: Experimental studies of E-glass fiber/BisGMA-TEGDMA polymer in vitro

Fiber-reinforced composites (FRCs) are a new group of non-metallic biomaterials showing a growing popularity in many dental and medical applications. As an oral implant material, FRC is biocompatible in bone tissue environment. Soft tissue integration to FRC polymer material is unclear. This series of in vitro studies aimed at evaluating unidirectional E-glass FRC polymer in terms of mechanical, chemical, and biological properties in an attempt to develop a new non-metallic oral implant abutment alternative. Two different types of substrates were investigated: (a) Plain polymer (BisGMA 50%–TEGDMA 50%) and (b) Unidirectional FRC. The mechanical behavior of high fiber-density FRCs was assessed using a three-point bending test. Surface characterization was performed using scanning electron and spinning disk confocal microscopes. The surface wettability/energy was determined using sessile drop method. The blood response, including blood-clotting ability and platelet morphology was evaluated. Human gingival fibroblast cell responses - adhesion kinetics, adhesion strength, and proliferation activity - were studied in cell culture environment using routine test conditions. A novel tissue culture method was developed and used to evaluate porcine gingival tissue graft attachment and growth on the experimental composite implants. The analysis of the mechanical properties showed that there is a direct proportionality in the relationship between E-glass fiber volume fraction and toughness, modulus of elasticity, and load bearing capacity; however, flexural strength did not show significant improvement when high fiber-density FRC is used. FRCs showed moderate hydrophilic properties owing to the presence of exposed glass fibers on the polymer surface. Blood-clotting time was shorter on FRC substrates than on plain polymer. The FRC substrates also showed higher platelet activation state than plain polymer substrates. Fibroblast cell adhesion strength and proliferation rate were highly pronounced on FRCs. A tissue culture study revealed that gingival epithelium and connective tissue established an immediate close contact with both plain polymer and FRC implants. However, FRC seemed to guide epithelial migration outwards from the tissue/implant interface. Due to the anisotropic and hydrophilic nature of FRC, it can be concluded that this material enhances biological events related with soft tissue integration on oral implant surface.

Turveperävaunun väsymiskestävyyden parantaminen

Työssä tutkittiin turveperävaunun renkaan kiinnitysrakenteen väsymiskestävyyttä. Väsymiskestävyyden parantamiseksi renkaiden kiinnityskohdan muotoilu ja mitoitus suunniteltiin uudelleen. Suunnittelussa keskityttiin ensisijaisesti nimellisten ja rakenteellisten jännitysheilahdusten pienentämiseen. Sekä vanhan, että uuden rakenneratkaisun väsymiskestoikiä tarkasteltiin käyttämällä hot spot – menetelmää.

Characterization of Leaf-Type Ferredoxin-NADP+ Oxidoreductase (FNR) Isoforms in Arabidopsis thaliana

Life on earth is based on sunlight, which is captured in chemical form by photosynthetic reactions. In the chloroplasts of plants, light reactions of photosynthesis take place at thylakoid membranes, whereas carbon assimilation reactions occur in the soluble stroma. The products of linear electron transfer (LET), highly-energetic ATP molecules, and reducing power in the form of NADPH molecules, are further used in the fixation of inorganic CO2 molecules into organic sugars. Ferredoxin-NADP+ oxidoreductase (FNR) catalyzes the last of the light reactions by transferring electrons from ferredoxin (FD) to NADP+. In addition to LET, FNR has been suggested to play a role in cyclic electron transfer (CET), which produces ATP without the accumulation of reducing equivalents. CET is proposed to occur via two putative routes, the PGR5- route and the NDH-route. In this thesis, the leaf-type FNR (LFNR) isoforms LFNR1 and LFNR2 of a model organism, Arabidopsis thaliana, were characterized. The physiological roles of LFNRs were investigated using single and double mutant plants. The viability of the single mutants indicates functionality of both isoforms, with neither appearing to play a specific role in CET. The more severe phenotype of low-temperature adapted fnr2 plants compared to both wild-type (WT) and fnr1 plants suggests a specific role for LFNR2 under unfavorable growth conditions. The more severe phenotype of the fnr1 x fnr2 (F1 generation) plants compared to single mutants reflects down-regulated photosynthetic capacity, whereas slightly higher excitation pressure indicates mild over-excitation of electron transfer chain (ETC). However, induction of CET and various photoprotective mechanisms enable adaptation of fnr1 x fnr2 plants to scarcity of LFNR. The fnr1 fnr2 plants (F2 generation), without detectable levels of LFNR, were viable only under heterotrophic conditions. Moreover, drought stress induced acceleration of the rate of P700 + re-reduction in darkness was accompanied by a concomitant up-regulation of the PGR5-route specific components, PGR5 and PGRL1, demonstrating the induction of CET via the PGR5-route. The up-regulation of relative transcriptional expression of the FD1 gene indicates that the FD1 isoform may have a specific function in CET, while no such role could be defined for either of the LFNR isoforms. Both the membrane-bound and soluble LFNR1 and LFNR2 each appear as two distinct spots after 2D-PAGE with different isoelectric points (pIs), indicating the existence of post-translational modifications (PTMs) which do not determine the membrane attachment of LFNR. The possibility of phosphorylation and glycosylation PTMs were excluded, but all four LFNR forms were shown to contain acetylated lysine residues as well as alternative N-termini. N-terminal acetylation was shown to shift the pI of both LFNRs to be more acidic. In addition, all four LFNR forms were demonstrated to interact both with FD1 and FD2 in vitro

Uuden tiedon hankinta ja hyödyntäminen organisaation innovaatioprosesseissa

Tämän tutkimuksen tavoitteena oli tutkia, miten uuden ja erityisesti tulevaisuuteen suuntautuvan tiedon hankintaa ja hyödyntämistä organisaatioiden innovaatioprosesseissa voidaan tarkastella ja jäsentää sekä kehittää avoimen innovaatioteorioiden pohjalta. Tulevaisuustiedon järjestelmällinen hyödyntäminen on yhä tärkeämmässä asemassa 2010-luvun organisaatioiden innovatiivisuuden ja kilpailukyvyn kannalta. Tämä on abstraktin luonteensa vuoksi erittäin haasteellista mutta teoriassa mahdollista, jos uuden tiedon liittämisestä organisaation käyttöön on tehty tärkeä ja selkeä osa koko organisaation strategiaa. Uuden tiedon tehokkaaseen käsittelemiseen ja siirtämiseen organisaatiossa tarvitaan suunnitelmallista ennakointitoimintaa, sosiaalisia sovittelumekanismeja ja rakentavaa yhteistyötä myös ulkopuolisten toimijoiden kanssa. Valitun teoriakehyksen pohjalta laadittiin yksinkertaistettu kyselytutkimus, johon oli liitetty absorptiiviseen kapasiteettiin, visionääriseen kyvykkyyteen, ennakointitoimintaan ja uuden tiedon käsittelyyn liittyviä käsitteitä. Kyselyn tarkoituksena oli myös tarjota organisaatiolle mahdollisuus tarkastella nykyistä tilaansa uuden tiedon monivaiheisen hyödyntämisen kannalta. Kyselytutkimus lähetettiin suomalaisille teollisuusyrityksille ja saatuja vastauksia käytettiin empiirisenä aineistona. Empiiristä aineistoa tarkasteltiin kvantitatiivisin menetelmän ja tuloksista saatiin hyödyllistä tietoa yritysten toiminnasta käytännöntasolta.

Comparing adult-youth and adult-adult online sexual solicitation: Manipulative behaviors, situational factors, and outcomes

Online sexual solicitation (solicitation) of youth has received widespread media and research attention during the last decade. The prevalence rates of youth who have experienced solicitation or solicitation attempts vary between studies depending on the methodology used (e.g., whether youth or adults are the target study group). In studies focusing on youth victims, the prevalence of solicitation attempts made by adults during the past year is typically reported to be between 5 and 9%. Adults who solicit youth online have been found to use deception and other manipulative behaviors to gain access to sexual activities with youth. However, previous studies have lacked a control group of adults who solicit other adults online. Without this comparison, one could argue that deceiving others online about one’s identity, and engaging in manipulative behaviors, is an inherent part of most online sexual interactions with strangers. Additionally, little is known about the associations between manipulative behaviors and the solicitation outcomes. In research concerning offline sexual behaviors, it has been noted that situational factors, such as sexual arousal, may alter both sexual interest and behavior. The effects of situational factors on online sexual behaviors have been less extensively studied (especially so with a quantitative approach); no studies have to date focused on adults’ solicitation of youth. Investigating the role of a lowered sexual age preference and the role of situational factors in the soliciting adults could be an important step in order to receive deeper knowledge of the role of traits and states in the context of solicitation. Additionally, there is a lack of knowledge of the effect of the age of the youth. Although previous studies on solicitation has found that older youth, compared with younger youth and children, are more often solicited, the possible reasons for this have not been investigated. Are adults who solicit youth affected by legal deterrence (through the legal age of consent), is it because older youth are more available online, or are the adults’ age preferences merely a product of a normally distributed age preference in the population? The purpose of the present thesis was fivefold: 1) to obtain an estimate of the frequency of adults’ solicitation of youth as self-reported and observed in actual behavior; 2) to explore whether the legal age of consent (LAC) affects solicitation frequency, or whether a normally distributed sexual age preference more accurately describe the proportion of solicited youth of different ages; 3) to investigate the associations of both traits (e.g., lower sexual age preference) and states (immediate situational factors, such as alcohol intoxication), and the solicitation target; 4) to explore whether adults who solicit youth and adults who solicit adults are equally deceitful and manipulative online, and whether the different solicitation outcomes are as common in both groups; and 5) to investigate whether the deceitful and manipulative behaviors engaged in had different associations with the solicitation outcomes depending on the age of the solicited. In the survey study, a convenience sample of 1393 adult participants (aged 18 years or older) self-reported any online communication with strangers during the past year. Of these, 56% (776 respondents) reported that they had solicited or attempted to solicit at least one stranger. Of the respondents, 453 (58.4%) were men, and 323 (41.6%) were women. Participants with only adult contacts (18 years or older) constituted the majority (640 respondents). In contrast, 136 individuals reported a youth contact (a 13 year old or younger, or a 14 to 17-year old). Approximately half of the participants were men in the adult contact group, while 75% of the participants were men in the youth contact group. Approximately 60% of the participants with youth contacts were recruited from two websites associated with a pedophilic sexual interest. In an online quasi-experimental study, with researchers impersonating youth of different ages (10–18 year olds) in chat rooms, 251 online conversations with chat room visitors made up the entire sample. All chat room visitors alleged to be men. The self-reported frequency of having solicited youth (0–17-year olds) during the past year was approximately 10% in our sample of adults who reported communicating with any strangers online. When we observed this behavior in chat rooms, we found that approximately 30% of the chat room visitors who believed they interacted with a 10 to 14 year old attempted to solicit the youth. We found that solicitation attempts increased equally much when increasing the age of the impersonated youth from 14 to 16, as from 16 to 18. Thus, we concluded that a normally distributed age preference in the population was a more plausible explanation to the effect of the age of the solicited, rather than the LAC (here; 15 and 16). If the chat room visitors would have been deterred only by the LAC, we would have expected that the change in amount of solicitation attempts from an illegal age group to a legal age group would have been significantly stronger than changes between age groups within illegal-illegal and legal-legal groups. Our subsample of survey participants from the pedophilia-related websites expectedly reported that they had solicited youth more often in comparison to the sample gathered through general (i.e., not associated with any particular sexual preference) websites. We also found that participants with a youth contact reported higher levels of sexual arousal and shame before the sexual interaction with their online contact, compared with participants with an adult contact. Additionally, the participants with youth contacts who reported consumption of child- and adolescent pornography also reported being more sexually aroused before the interaction, compared to the participants with youth contacts who did not report consumption of these kinds of pornography. We also found clear indications that the online sexual interaction had an alleviatory effect on reported levels of sadness, boredom and stress, independent of the age of the contact. Generally, the participants with youth and adult contacts reported deceiving their contacts as often and suggesting keeping the communication a secret from someone as often. Participants with a youth contact, however, reported using more persuasion techniques for online sexual purposes or for the purpose of an offline meeting, compared to those with an adult contact. In the chat rooms, we found that more indirect ways of future sexual communication (e.g., continuing chatting) was suggested by the chat room visitors that were under the assumption of interacting with youth aged 10 to 14, compared with more direct means (e.g., meeting offline). Survey participants with youth contacts who had used deception, suggested keeping the interactions a secret, and/or persuaded their contact by appealing to the contacts feelings of love and attachment for the participant had also more often engaged in cybersex with the contact. No other manipulative behaviors were associated with the other investigated solicitation outcomes (receiving a sexual picture, meeting offline, and engaging in sexual contact offline) within this group of participants. However, using deception, suggesting secrecy and using persuasion was also positively associated with certain solicitation outcomes within participants with an adult contact. In summary, adults’ solicitation of youth is much more frequent when observed in chat rooms than self-reported. Additionally, an underlying lowered sexual age preference seems to be a motivating factor on a group level in adults who solicit youth. We concluded that directed prevention efforts should be made on pedophiliarelated websites. Additionally, the role of situational factors, especially sexual arousal in persons with a pedo- or hebephilic sexual interest should be investigated further in the context of online sexual solicitation.

Learning information technology business in a changing industry landscape. Introducing Team Entrepreneurship in Renewing Bachelor Education in Renewing Bachelor Education in Information

Speed, uncertainty and complexity are increasing in the business world all the time. When knowledge and skills become quickly irrelevant, new challenges are set for information technology (IT) education. Meta-learning skills – learning how to learn rapidly - and innovation skills have become more essential than single technologies or other specific issues. The drastic changes in the information and communications technology (ICT) sector have caused a need to reconsider how IT Bachelor education in Universities of Applied Sciences should be organized and employed to cope with the change. The objective of the study was to evaluate how a new approach to IT Bachelor education, the ICT entrepreneurship study path (ICT-ESP) fits IT Bachelor education in a Finnish University of Applied Sciences. This kind of educational arrangement has not been employed elsewhere in the context of IT Bachelor education. The study presents the results of a four-year period during which IT Bachelor education was renewed in a Finnish University of Applied Sciences. The learning environment was organized into an ICT-ESP based on Nonaka’s knowledge theory and Kolb’s experiental learning. The IT students who studied in the ICT-ESP established a cooperative and learned ICT by running their cooperative at the University of Applied Sciences. The students (called team entrepreneurs) studied by reading theory in books and other sources of explicit information, doing projects for their customers, and reflecting in training sessions on what was learnt by doing and by studying the literature. Action research was used as the research strategy in this study. Empirical data was collected via theme-based interviews, direct observation, and participative observation. Grounded theory method was utilized in the data analysis and the theoretical sampling was used to guide the data collection. The context of the University of Applied Sciences provided a good basis for fostering team entrepreneurship. However, the results showed that the employment of the ICT-ESP did not fit into the IT Bachelor education well enough. The ICT-ESP was cognitively too tough for the team entrepreneurs because they had two different set of rules to follow in their studies. The conventional courses engaged lot of energy which should have been spent for professional development in the ICT-ESP. The amount of competencies needed in the ICT-ESP for professional development was greater than those needed for any other ways of studying. The team entrepreneurs needed to develop skills in ICT, leadership and self-leadership, team development and entrepreneurship skills. The entrepreneurship skills included skills on marketing and sales, brand development, productization, and business administration. Considering the three-year time the team entrepreneurs spent in the ICT-ESP, the challenges were remarkable. Changes to the organization of IT Bachelor education are also suggested in the study. At first, it should be admitted that the ICT-ESP produces IT Bachelors with a different set of competencies compared to the conventional way of educating IT Bachelors. Secondly, the number of courses on general topics in mathematics, physics, and languages for team entrepreneurs studying in the ICTESP should be reconsidered and the conventional course-based teaching of the topics should be reorganized to support the team coaching process of the team entrepreneurs with their practiceoriented projects. Third, the upcoming team entrepreneurs should be equipped with relevant information about the ICT-ESP and what it would require in practice to study as a team entrepreneur. Finally, the upcoming team entrepreneurs should be carefully selected before they start in the ICT-ESP to have a possibility to eliminate solo players and those who have a too romantic view of being a team entrepreneur. The results gained in the study provided answers to the original research questions and the objectives of the study were met. Even though the IT degree programme was terminated during the research process, the amount of qualitative data gathered made it possible to justify the interpretations done.

Further biochemical characterization of Mycobacterium leprae laminin-binding proteins

It has been demonstrated that the alpha2 chain of laminin-2 present on the surface of Schwann cells is involved in the process of attachment of Mycobacterium leprae to these cells. Searching for M. leprae laminin-binding molecules, in a previous study we isolated and characterized the cationic proteins histone-like protein (Hlp) and ribosomal proteins S4 and S5 as potential adhesins involved in M. leprae-Schwann cell interaction. Hlp was shown to bind alpha2-laminins and to greatly enhance the attachment of mycobacteria to ST88-14 Schwann cells. In the present study, we investigated the laminin-binding capacity of the ribosomal proteins S4 and S5. The genes coding for these proteins were PCR amplified and their recombinant products were shown to bind alpha2-laminins in overlay assays. However, when tested in ELISA-based assays and in adhesion assays with ST88-14 cells, in contrast to Hlp, S4 and S5 failed to bind laminin and act as adhesins. The laminin-binding property and adhesin capacity of two basic host-derived proteins were also tested, and only histones, but not cytochrome c, were able to increase bacterial attachment to ST88-14 cells. Our data suggest that the alanine/lysine-rich sequences shared by Hlp and eukaryotic H1 histones might be involved in the binding of these cationic proteins to laminin.

Teollinen öljyn erotus koalesenssisuodatuksella väliaineessa

Koalesenssi on ilmiö, jossa dispergoidun faasin pisarat pyrkivät muodostamaan suurempia pisaroita kunnes erotettava faasi muodostuu. Koalesenssi tapahtuu kolmessa päävaiheessa, jotka ovat lähestyminen, kiinnittyminen ja irrotus. Lähestymiseen vaikuttavat mekanismit ovat muuan muassa sieppaus, diffuusio, törmäysvaikutus, sedimentaatio, sähköiset repul-siovoimat ja van der Waalsin voimat. Kiinnittymisvaiheessa dispergoidun faasin pisarat syrjäyttävät väliaineen nestekalvon samalla kostuttaen väliaineen pinnan. Irrotusvaiheessa pisaran hydrodynaaminen voima voittaa pisaran ja väliaineen välisen adheesiovoiman. Koalesenssin tehokkuuteen vaikuttavat useat eri parametrit kuten virtausnopeus, pedin ominaisuudet, väliaineen ominaisuudet sekä emulsion ominaisuudet. Nämä kaikki asiat tulee ottaa huomioon koalesenssisuodatuksen suunnittelussa. Koalesenssisuodatus lukeutuu syväsuodatusmenetelmiin, jotka on ollut käytössä jo yli 100 vuotta. Koalesenssisuodatusmenetelmä on tehokas menetelmä pienten pisaroiden erottami-seen. Menetelmää käytetään esimerkiksi öljyisten jätevesien puhdistuksessa. Teollisen öljyn syväsuodatuksen etuihin kuuluu muun muassa sen kompakti koko, alhaisemmat käyt-tökustannukset, korkea erotusaste, kyky erotella pienetkin pisarat sekä helppo operointi, automatisointi ja huolto. Suurin haittapuoli on kuitenkin väliaineen tukkeutuminen, joten prosessi vaatii puhdistuksen tai väliaineen uusimisen. Tämän kandidaatintyön tarkoituksena oli koota kirjallisuustyö öljyn koalesenssisuodatuk-sesta. Työssä kartoitettiin koalesenssisuodatuksen lähtökohdat, teoria, tärkeimmät teolli-suuden sovellukset sekä väliaineet.

A fucan from the brown seaweed Spatoglossum schröederi inhibits Chinese hamster ovary cell adhesion to several extracellular matrix proteins

Fucans, a family of sulfated polysaccharides present in brown seaweed, have several biological activities. Their use as drugs would offer the advantage of no potential risk of contamination with viruses or particles such as prions. A fucan prepared from Spatoglossum schröederi was tested as a possible inhibitor of cell-matrix interactions using wild-type Chinese hamster ovary cells (CHO-K1) and the mutant type deficient in xylosyltransferase (CHO-745). The effect of this polymer on adhesion properties with specific extracellular matrix components was studied using several matrix proteins as substrates for cell attachment. Treatment with the polymer inhibited the adhesion of fibronectin to both CHO-K1 (2 x 10(5))()and CHO-745 (2 x 10(5) and 5 x 10(5)) cells. No effect was detected with laminin, using the two cell types. On the other hand, adhesion to vitronectin was inhibited in CHO-K1 cells and adhesion to type I collagen was inhibited in CHO-745 cells. In spite of this inhibition, the fucan did not affect either cell proliferation or cell cycle. These results demonstrate that this polymer is a new anti-adhesive compound with potential pharmacological applications.