245 resultados para Boxberg, Katja


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This study investigates whether there are differences in profitability of PPI companies based on the growth strategy they have chosen to follow. It is examined whether those companies following organic growth strategy are more profitable than those companies following acquisitive growth strategy. It is also investigated are ones larger than the others, or are ones growing faster than the others. Also, the factors affecting the profitability of acquisitive companies are further examined. The results showed that there actually are differences between the two groups. Organically grown companies were found to be more profitable, smaller and growing slower than acquisitive companies. When it comes to examining only acquisitive companies there could be found factors that better or worsen the profitability of companies. For example targets that the company has bought in developing markets were making them more profitable.

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Tämän työn tavoitteena oli selvittää TMP-massan lujuusominaisuuksien parantamismahdollisuuksia jauhatuksen keinoin. Tarkastelun kohteena olivat rejektijauhatuksen eriyttäminen päälinjasta, päälinjan ajotapojen vaikutukset massan laatuun sekä energiansäästöterien testaus. Erillisen rejektijauhatuksen pilot kokeiden myötä oli havaittavissa, että erillisjauhettu rejekti itsessään oli todella pitkäkuituista ja hyvät lujuusominaisuudet omaavaa massaa. Koeajo kuitenkin osoitti, että 9 % annostelu määrä päälinjan akseptimassaan ei riitä nostamaan valmiin massaseoksen lujuusominaisuuksia. Eriytetty rejektijauhatus voi kuitenkin parantaa prosessin hallittavuutta ja mahdollistaa tuotantotason noston. Päälinjan ajotavanmuutoskokeiden tulosten myötä voitiin havaita, että 300 t/d tuotantotaso tuotti kuidunpituuksiltaan, lujuuksiltaan ja tikkupitoisuuksiltaan parempaa massaa kuin 270 t/d tuotantotaso. Samaan aikaan tapahtunut bulkin lasku oli siedettävällä tasolla huomioitaessa vetolujuudessa tapahtuva parannus. Ajotavanmuutoskokeet osoittivat myös sen, että pienellä ensimmäisen ja toisen jauhatusvaiheen kuormitussuhteiden muutoksella on saavutettavissa parannusta sekä veto- että repäisylujuudessa, bulkissa tapahtuvien muutosten pysyessä siedettävällä tasolla. Tähän tulokseen päästiin löysäämällä ensimmäisen vaiheen jauhinten teräväliä kymmenyksellä ja vastaavasti tiukkaamalla toisen vaiheen jauhinten teräväliä niin, että jauhatuksen kokonaisenergianominaiskulutus pysyi vakiotasolla. Energiansäästöterien testauksessa havaittiin, että terien avulla on mahdollista säästää jauhatukseen kuluvassa energiassa noin 0,15 – 0,2 MWh/t. Saavutettavissa oleva energiansäästö ei kuitenkaan ole riittävä kompensoimaan massan laadun heikkenemistä, sillä energiansäästöterien myötä massan bulkki, kuidunpituus sekä veto- ja repäisylujuus laskivat verrattaessa niiden tasoon käytettäessä normaaliteriä.

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Keskustelua. Vastine Katja Huumon kirja-arvosteluun // Historiallinen aikakauskirja. 100 (2002) : 4

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Dreaming is a pure form of phenomenality, created by the brain untouched by external stimulation or behavioral activity, yet including a full range of phenomenal contents. Thus, it has been suggested that the dreaming brain could be used as a model system in a biological research program on consciousness (Revonsuo, 2006). In the present thesis, the philosophical view of biological realism is accepted, and thus, dreaming is considered as a natural biological phenomenon, explainable in naturalistic terms. The major theoretical contribution of the present thesis is that it explores dreaming from a multidisciplinary perspective, integrating information from various fields of science, such as dream research, consciousness research, evolutionary psychology, and cognitive neuroscience. Further, it places dreaming into a multilevel framework, and investigates the constitutive, etiological, and contextual explanations for dreaming. Currently, the only theory offering a full multilevel explanation for dreaming, that is, a theory including constitutive, etiological, and contextual level explanations, is the Threat Simulation Theory (TST) (Revonsuo, 2000a; 2000b). The empirical significance of the present thesis lies in the tests conducted to test this specific theory put forth to explain the form, content, and biological function of dreaming. The first step in the empirical testing of the TST was to define exact criteria for what is a ‘threatening event’ in dreams, and then to develop a detailed and reliable content analysis scale with which it is possible to empirically explore and quantify threatening events in dreams. The second step was to seek answers to the following questions derived from the TST: How frequent threatening events are in dreams? What kind of qualities these events have? How threatening events in dreams relate to the most recently encoded or the most salient memory traces of threatening events experienced in waking life? What are the effects of exposure to severe waking life threat on dreams? The results reveal that threatening events are relatively frequent in dreams, and that the simulated threats are realistic. The most common threats include aggression, are targeted mainly against the dream self, and include simulations of relevant and appropriate defensive actions. Further, real threat experiences activate the threat simulation system in a unique manner, and dream content is modulated by the activation of long term episodic memory traces with highest negative saliency. To sum up, most of the predictions of the TST tested in this thesis received considerable support. The TST presents a strong argument that explains the specific design of dreams as threat simulations. The TST also offers a plausible explanation for why dreaming would have been selected for: because dreaming interacted with the environment in such a way that enhanced fitness of ancestral humans. By referring to a single threat simulation mechanism it furthermore manages to explain a wide variety of dream content data that already exists in the literature, and to predict the overall statistical patterns of threat content in different samples of dreams. The TST and the empirical tests conducted to test the theory are a prime example of what a multidisciplinary approach to mental phenomena can accomplish. Thus far, dreaming seems to have always resided in the periphery of science, never regarded worth to be studied by the mainstream. Nevertheless, when brought to the spotlight, the study of dreaming can greatly benefit from ideas in diverse branches of science. Vice versa, knowledge learned from the study of dreaming can be applied in various disciplines. The main contribution of the present thesis lies in putting dreaming back where it belongs, that is, into the spotlight in the cross-road of various disciplines.

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Neuropeptide Y (NPY) is a widely expressed neurotransmitter in the central and peripheral nervous systems. Thymidine 1128 to cytocine substitution in the signal sequence of the preproNPY results in a single amino acid change where leucine is changed to proline. This L7P change leads to a conformational change of the signal sequence which can have an effect on the intracellular processing of NPY. The L7P polymorphism was originally associated with higher total and LDL cholesterol levels in obese subjects. It has also been associated with several other physiological and pathophysiological responses such as atherosclerosis and T2 diabetes. However, the changes on the cellular level due to the preproNPY signal sequence L7P polymorphism were not known. The aims of the current thesis were to study the effects of the [p.L7]+[p.L7] and the [p.L7]+[p.P7] genotypes in primary cultured and genotyped human umbilical vein endothelial cells (HUVEC), in neuroblastoma (SK-N-BE(2)) cells and in fibroblast (CHO-K1) cells. Also, the putative effects of the L7P polymorphism on proliferation, apoptosis and LDL and nitric oxide metabolism were investigated. In the course of the studies a fragment of NPY targeted to mitochondria was found. With the putative mitochondrial NPY fragment the aim was to study the translational preferences and the mobility of the protein. The intracellular distribution of NPY between the [p.L7]+[p.L7] and the [p.L7]+[p.P7] genotypes was found to be different. NPY immunoreactivity was prominent in the [p.L7]+[p.P7] cells while the proNPY immunoreactivity was prominent in the [p.L7]+[p.L7] genotype cells. In the proliferation experiments there was a difference in the [p.L7]+[p.L7] genotype cells between early and late passage (aged) cells; the proliferation was raised in the aged cells. NPY increased the growth of the cells with the [p.L7]+[p.P7] genotype. Apoptosis did not seem to differ between the genotypes, but in the aged cells with the [p.L7]+[p.L7] genotype, LDL uptake was found to be elevated. Furthermore, the genotype seemed to have a strong effect on the nitric oxide metabolism. The results indicated that the mobility of NPY protein inside the cells was increased within the P7 containing constructs. The existence of the mitochondria targeted NPY fragment was verified, and translational preferences were proved to be due to the origin of the cells. Cell of neuronal origin preferred the translation of mature NPY (NPY1-36) when compared to the non neuronal cells that translated both, NPY and the mitochondrial fragment of NPY. The mobility of the mitochondrial fragment was found to be minimal. The functionality of the mitochondrial NPY fragment remains to be investigated. L7P polymorphism in the preproNPY causes a series of intracellular changes. These changes may contribute to the state of cellular senescence, vascular tone and lead to endothelial dysfunction and even to increased susceptibility to diseases, like atherosclerosis and T2 diabetes.

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The skeleton undergoes continuous turnover throughout life. In women, an increase in bone turnover is pronounced during childhood and puberty and after menopause. Bone turnover can be monitored by measuring biochemical markers of bone resorption and bone formation. Tartrate-resistant acid phosphatase (TRACP) is an enzyme secreted by osteoclasts, macrophages and dendritic cells. The secreted enzyme can be detected from the blood circulation by recently developed immunoassays. In blood circulation, the enzyme exists as two isoforms, TRACP 5a with an intact polypeptide chain and TRACP 5b in which the polypeptide chain consists of two subunits. The 5b form is predominantly secreted by osteoclasts and is thus associated with bone turnover. The secretion of TRACP 5b is not directly related to bone resorption; instead, the levels are shown to be proportional to the number of osteoclasts. Therefore, the combination of TRACP 5b and a marker reflecting bone degradation, such as C-terminal cross-linked telopeptides of type I collagen (CTX), enables a more profound analysis of the changes in bone turnover. In this study, recombinant TRACP 5a-like protein was proteolytically processed into TRACP 5b-like two subunit form. The 5b-like form was more active both as an acid phosphatase and in producing reactive oxygen species, suggesting a possible function for TRACP 5b in osteoclastic bone resorption. Even though both TRACP 5a and 5b were detected in osteoclasts, serum TRACP 5a levels demonstrated no change in response to alendronate treatment of postmenopausal women. However, TRACP 5b levels decreased substantially, demonstrating that alendronate decreases the number of osteoclasts. This was confirmed in human osteoclast cultures, showing that alendronate decreased the number of osteoclats by inducing osteoclast apoptosis, and TRACP 5b was not secreted as an active enzyme from the apoptotic osteoclasts. In peripubertal girls, the highest levels of TRACP 5b and other bone turnover markers were observed at the time of menarche, whereas at the same time the ratio of CTX to TRACP 5b was lowest, indicating the presence of a high number of osteoclasts with decreased resorptive activity. These results support the earlier findings that TRACP 5b is the predominant form of TRACP secreted by osteoclasts. The major source of circulating TRACP 5a remains to be established, but is most likely other cells of the macrophage-monocyte system. The results also suggest that bone turnover can be differentially affected by both osteoclast number and their resorptive activity, and provide further support for the possible clinical use of TRACP 5b as a marker of osteoclast number.