165 resultados para Kekki, Saara
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In recent years, one important objective of cardiovascular research has been to find new markers that would improve the risk stratification and diagnosis of patients presenting with symptoms of acute coronary syndrome (ACS). Pregnancy-associated plasma protein A (PAPP-A) is a large metalloproteinase involved in insulin-like growth factor signalling. It is expressed in various tissues and seems to be involved in many physiological and pathological processes, such as folliculogenesis, bone formation, wound healing, pregnancy and atherosclerosis. The aim of this thesis was to investigate PAPP-A in ACS patients. Circulating concentrations of PAPP-A had been previously shown to be elevated in ACS. In this study it was revealed that the form of PAPP-A causing this elevation was the free noncomplexed PAPP-A. Thus, the form of PAPP-A in the circulation of ACS patients differed from the complexed PAPP-A form abundantly present in the circulation during pregnancy. A point-of-care method based on time-resolved immunofluorometric assays was developed, which enabled the rapid detection of free PAPP-A. The method was found to perform well with serum and heparin plasma samples as well as with heparinized whole blood samples. With this method the concentrations of free PAPP-A in healthy individuals were shown to be negligible. When the clinical performance of the method was evaluated with serum samples from ACS patients, it was shown that the free PAPP-A concentration in the admission sample was an independent predictor of myocardial infarction and death. Moreover, as a prognostic marker, free PAPP-A was revealed to be superior to total PAPPA, i.e. the combination of free and complexed PAPP-A, which has been measured by the other groups in this field. As heparin products are widely used as medication in ACS patients, the effect of heparin products on free PAPP-A molecule and circulating concentrations were also investigated in this study. It was shown that intravenous administration of low molecular weight or unfractionated heparin elicits a rapid release of free PAPP-A into the circulation in haemodialysis patients and patients undergoing angiography. Moreover, the interaction between PAPP-A and heparin was confirmed in gel filtration studies. Importantly, the patients included in the clinical evaluation of the free PAPP-A detection method developed had not received any heparin product medication before the admission sample and thus the results were not affected by the heparin effect. In conclusion, free PAPP-A was identified as a novel marker associated with ACS. The point-of-care methods developed enable rapid detection of this molecule which predicts adverse outcome when measured in the admission sample of ACS patients. However, the effect revealed of heparin products on circulating PAPP-A concentrations should be acknowledged when further studies are conducted related to free or total PAPP-A in ACS.
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Sahatavaran tuotannossa käytetään runsaasti lämpöä ja sähköä. Sähköä käytetään pääasiassa sahausvaiheessa ja lämpöä kuivausvaiheessa. Sahatavarakuutiosta haihdutetaan vettä kuivaamoissa noin 230-600 kiloa. Sahatavara kuivataan, koska kuivattu sahatavara säilyy paremmin ja on lisäksi kevyempää, kestävämpää ja sen muodonmuutokset ovat pienempiä. Työssä käsiteltävällä sahalla on erääseen kanavakuivaamoon tehty koerakennelma, jonka avulla kuivaamosta poistettavan ilman sisältämää lämpöä hyödynnetään sahatavaran lämmittämisessä kuivauslämpötilaan kuormanvaihdon jälkeen. Energiansäästön lisäksi rakennelman toivotaan ehkäisevän kuormanvaihdosta aiheutuvia olosuhdemuutoksia kuivausprosessin muissa vaiheissa. Poistoilman sisältämä höyry lauhtuu lämmittäessään kylmää sahatavaraa. Lauhtumisen yhteydessä vapautuu runsaasti energiaa. Tehtyjen kokeiden perusteella koerakennelma vähensi lämmönkulutusta selvästi. Lämmönkulutuksen alenema oli jopa teorialaskelmaa suurempi, mistä syystä kokeellisessa osassa tehtyihin mittaustuloksiin on syytä suhtautua varauksella. Perinteisessä kuivaamossa kosteus poistuu pääasiassa vesihöyrynä, mutta koerakennelman avulla saadaan noin puolet puusta haihdutetusta vedestä lauhtumaan takaisin vedeksi.
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Kirja-arvio
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Kirjallisuusarvostelu
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Kirjallisuusarvostelu
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Tutkielmassa on selvitetty, vastaavatko Suomessa käytetty hevosenlan-nan jätteeksi määrittely ja hevosenlannan polttamista koskevat vaatimuk-set EU:n lainsäädäntöä. Lisäksi haluttiin etsiä mahdollisuuksia keventää hevosenlannan polttamiselle asetettuja vaatimuksia. Tutkielma toteutettiin lainopillista ja de lege ferenda –menetelmiä käyttäen. Hevosenlanta on EU:n sivutuoteasetuksen mukaan eläimistä saatava si-vutuote, johon sovelletaan jätedirektiiviä silloin, kun se on tarkoitettu pol-tettavaksi tai muuhun direktiivissä määriteltyyn tarkoitukseen. Jätelain so-veltamisala on jätedirektiiviä laajempi, sillä jätelakia sovelletaan hevosen-lantaan riippumatta siitä, minkälaiseen käsittelyyn se on tarkoittu. Suo-messa meneillään olevan jätelain uudistamisen myötä jätelain sovelta-misala tulee vastaamaan jätedirektiivin soveltamisalaa. Hevosenlannan polttamiselle Suomen jätteenpolttoasetuksessa asetetut vaatimukset vastaavat EU:n jätteenpolttodirektiivin vaatimuksia. Hevosen-lannan polttamisen helpottamiseksi tulisi jatkotutkimuksissa selvittää ensi-sijaisesti sitä, voidaanko jätteenpolttodirektiivissä polttamisen seurannalle asetetuista teknisistä vaatimuksista myöntää poikkeuksia poltettaessa ta-salaatuista hevosenlanta-kuivikeseosta.
The relationship between a virtual leader’s communication practices and a virtual team’s performance
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A lot of research has been carried out into virtual teams and virtual leadership, yet there is hardly any research available on the communication behaviour of virtual leaders within a real business context. This research assessed the communication practices of virtual leaders and analysed the relationship between these practices and the performance of virtual teams. The objective of this research was to examine the distinctions of virtual teams, to study the leader’s role in a virtual team and its performance, and to examine the leader’s communication practices within virtual teams. The research involves a case study in which interviews have been carried out within an international technology company headquartered in Finland. Qualitative research methods were applied in the research. Based on the results of the study it can be said that there is a strong relationship between a virtual leader’s communication practices and a virtual team member’s job satisfaction. Through their communication practices, activities and message contents, leaders can affect the job satisfaction of virtual team members. In virtual leadership the focus is not in virtual but in leadership. It does not matter if the context is virtual or face-to-face; similar communication practices are good in both cases. As the global economic crisis strongly affected the sales results of the between a leader’s communication practices and a virtual team’s objective performance cannot be made.
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Artikel i konferensvolym 2009.
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Integrin transmembrane receptor functions are regulated by adaptor molecules binding to their alpha and beta subunit intracellular domains, or tails, thus affecting integrin traffic and adhesion during e.g. cell motility. Interestingly, many cellular proteins function in both cell motility and cell division, thus raising the possibility that integrins might be involved in regulating the cell cycle. A thorough understanding of cell division is essential in cell biology and in human malignancies. It is well established that failures to complete cell cycle can give rise to genetically unstable cells with tumorigenic properties. Transformed cells promote the disruption of intercellular adhesions such as tight junctions, and this correlates with the onset of cell motility, invasion and unfavorable prognosis in cancer. In this study, we analyzed integrin regulation, mediated by adaptor binding to the subunit tail, during cell motility and cell division. We revealed a novel molecular mechanism by which Rab21, through association with the integrin alpha subunits, drives integrin endosomal traffic during mitotic phases. In addition, we found indications for this finding in vivo, as RAB21 gene deletions were mapped in ovarian and prostate cancer samples. Importantly, the multinucleated phenotype of cultured ovarian cancer cells could be reverted by Rab21 overexpression. In this thesis work, we also show how the tight junction protein ZO-1 unexpectedly interacts with the 5 integrin cytoplasmic domain in the lamellipodia to promote cell motility and at the cleavage furrow to support separation of the daughter cells. The alpha5-ZO-1 complex formation was dependent on PKC which regulates ZO-1 phosphorylation and its subcellular localization. In addition, by an in situ detection method, we showed that a subset of metastatic human lung cancers expressed the alpha5beta-ZO-1 complex. Taken together, we were able to identify new molecular pathways that regulate integrin functions in an alpha tail-mediated fashion. These findings firmly suggest that genetic alterations in integrin traffic may lead to progression of tumorigenesis as a result of failed cell division. Also, the interplay of integrins and ZO-1 in forming spatially regulated adhesive structures broadens our view of crosstalk between pathways and distinct adhesive structures that can be involved in cancer cell biology.
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Tutkimuksen tavoitteena on tarkastella maksuehtojen ja niiden aiheuttamien kustannusten merkitystä käyttöpääoman ja asiakkuuksien hallinnassa. Tavoitteena on selvittää maksuehtojen kohdeyritykselle mahdollisesti aiheuttamia kustannuksia ja niiden vaikutusta käyttöpääomaan ja asiakaskannattavuuksiin. Tutkimuksen teoriaosuuden muodostaa käyttöpääoman ja asiakkuuksien hallinnan kirjallisuuskatsaus. Pääpaino on ostovelkojen ja myyntisaatavien hallinnassa sekä asiakaslaskentatoimen laskentamenetelmissä. Tutkimuksen empiriaosuus käsittelee kohdeyrityksen maksuehtojen kautta teoriaosassa esitettyjä aihealueita. Johtopäätöksenä voidaan todeta, että kohdeyrityksen tämän hetkisillä maksuehdoilla ei ole suurta negatiivista vaikutusta yrityksen käyttöpääomaan. Maksuehdoista aiheutuneiden kustannusten merkitys asiakaskannattavuuksissa korostuu enemmän pienten kuin suurten asiakkaiden kohdalla.
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Kirjallisuusarvostelu
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Kirjallisuusarvostelu