7 resultados para Camp

em Helda - Digital Repository of University of Helsinki


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Nicotine, the addictive compound of tobacco products, exerts its effects in the brain by binding to neuronal acetylcholine nicotinic receptors (nAChRs). The aim of the present study was to increase the knowledge of nicotine s complex effects, the focus being on homomeric alpha7-nAChRs that are widely expressed in the brain. Nicotinic regulation of differential signalling molecules including transcriptional regulators was also studied. We found that the number of alpha7-nAChRs is increased in specific brain regions in mice, in a time-dependent manner after chronic oral nicotine administration. Our results suggest that in addition to alpha4beta2-nAChRs, the other major nAChR subtype expressed in the brain, the number of alpha7-nAChRs is affected by chronic presence of nicotine. We suggest that when studying the long-term effects of nicotine, the duration on administration is of great importance. Next, we observed that nicotine exposure induces accumulation of cAMP in cell cultures expressing nAChRs. Furthermore, nicotine-induced alpha7-nAChR upregulation was potentiated by treatments enhancing cAMP-signalling, suggesting a role for cAMP in the upregulation process. Protein kinase C (PKC) was found essential for the basal regulation of alpha7-nAChR number. The nicotine-evoked alpha7-nAChR upregulation could be further increased by PKC overexpression. Thirdly, the effects of nicotine on dopamine and cAMP regulated phosphoprotein (DARPP-32) were characterised in rat brain. The results show that DARPP-32 is regulated by both acute and long-term nicotine treatment in the striatal subdivisions. The effect of acute nicotine is dose-dependent and the three striatal regions display differential sensitivities to nicotine. Chronic nicotine is also able to regulate DARPP-32 signalling with prominent effect seen in the nucleus accumbens (NAc), suggesting a role for DARPP-32 in the mediation of long-term effects of nicotine. Finally, the regulation of transcription factors Elk-1 and FosB/deltaFosB by nicotine was investigated. We found that Elk-1 is activated by acute nicotine selectively in the NAc core and hippocampal area CA1, whereas acute nicotine does not affect FosB/deltaFosB. Long-term intermittent or continuous nicotine increases the level of total Elk-1 in the same brain regions as acute nicotine. FosB/deltaFosB is also affected by chronic nicotine. Thus, similarly to other drugs of abuse, nicotine regulates transcriptional regulators Elk-1 and FosB/deltaFosB. These results bring further support for a common mechanism underlying the development of addiction. Nicotine s positive effects on learning and memory might involve the transcription factor Elk-1 based on the changes seen in the hippocampus, the key area in cognitive functions.

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Russian Karelians were one of the small peasant nations of the Russian Empire that began to identify themselves as nations during the late imperial period. At that historical moment Russian Karelia fell between an economically undeveloped empire and the rapidly modernizing borderland of Finland. The economic and cultural lure of Finland drew Karelians into the Finnish camp. This attraction was seen as a challenge to Russia and influenced the straggle between Russia and Finland for the Karelians. This struggle was waged from 1905 to 1917. This work is focused on the beginning stage of the struggle, its various phases, and their results. The confrontation extended into different dimensions (economic, political, ideological, church and cultural politics) and occurred on two levels: central and regional. Countermeasures against local nationalisms developed much earlier both in Russia and in other empires for use were also used in the Russian Karelian case. Economic policies were deployed to try to make relations with Russia more alluring for Karelians and to improve their economic condition. However, these efforts produced only minimal results due to the economic weakness of the empire and a lack of finances. Fear of the economic integration of the Karelians and Finns, which would have stimulated the economy of the Karelia, also hindered these attempts. The further development of the Orthodox Church, the schools and the zemstvos in Karelia yielded fewer results than expected due to the economic underdevelopment of the region and the avoidance of the Finnish language. Policizing measures were the most successfull, as all activities in Russian Karelia by the Finns were entirely halted in practice. However, the aspiration of Russian Karelians to integrate their home districts with Finland remained a latent force that just waited for an opportunity to push to the surface again. Such a chance materialized with the Russian revolution. The Karelian question was also a part of Russian domestic political confrontation. At the and of the 1800s, the Russian nationalist right had grown strong and increasingly gained the favor of the autocracy. The right political forces exploited the Karelian question in its anti-Finnish ideology and in its general resistance to the national emancipation of the minority peoples of Russia. A separate ideology was developed, focusing on the closeness of Karelians to the "great Russian people." Simultaneously, this concept found a place in the ultramonarchist myth of the particularly close connection between the people and tsar that was prominent in the era of Nicholas II. This myth assigned the Karelians a place amongst the "simple people" faithful to the tsar.

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This study aims to examine the operations and significance of the Klemetti Institute (Klemetti-Opisto) as a developer of Finnish music culture from 1953 to 1968 during the term of office of the Institute s founder and first director, Arvo Vainio. The Klemetti Institute was originally established as a choir institute, but soon expanded to offer a wide range of music courses. In addition to providing courses for choir leaders and singers, the Institute began its orchestral activities as early as the mid-1950s. Other courses included ear training seminars as well as courses for young people s music instructors and in playing the kantele (a Finnish string instrument) and solo singing. More than 20 types of courses were offered over the 16-year period. The Klemetti Institute s courses were incorporated into the folk high school courses offered by the Orivesi Institute (Oriveden Opisto) and were organised during the summer months of June and July. In addition to funding based on the Folk High School Act, financial assistance was obtained from various foundations and funds, such as the Wihuri Foundation. This study is linked to the context of historical research. I examine the Klemetti Institute s operations chronologically, classifying instruction into different course types, and analyse concert activities primarily in the section on the Institute s student union. The source material includes the Klemetti Institute archives, which consist of Arvo Vainio s correspondence, student applications, register books and cards, journals and student lists, course albums and nearly all issues of the Klemettiläinen bulletin. In addition, I have used focused interviews and essays to obtain extensive data from students and teachers. I concentrate on primary school teachers, who accounted for the majority of course participants. A total of more than 2,300 people participated in the courses, nearly half of whom took courses during at least two summers. Primary school teachers accounted for 50% to 70% of the participants in most courses and constituted an even larger share of participants in some courses, such as the music instructor course. The Klemetti Institute contributed to the expansion throughout Finland of a new ideal for choral tone. This involved delicate singing which strives for tonal purity and expressiveness. Chamber choirs had been virtually unheard of in Finland, but the Klemetti Institute Chamber Choir popularised them. Chamber choirs are characterised by an extensive singing repertoire ranging from the Middle Ages to the present. As the name suggests, chamber choirs were originally rather small mixed choirs. Delicate singing meant the avoidance of extensive vibrato techniques and strong, heavy forte sounds, which had previously been typical of Finnish choirs. Those opposing and shunning this new manner of singing called it ghost singing . The Klemetti Institute s teachers included Finland s most prominent pedagogues and artists. As the focused essays, or reminiscences as I call them, show, their significance for the students was central. I examine extensively the Klemetti Institute s enthusiastic atmosphere, which during the early years was characterised by what some writers described as a hunger for music . In addition to distributing a new tonal ideal and choir repertoire, the Klemetti Institute also distributed new methods of music education, thus affecting the music teaching of Finnish primary schools, in particular. The Orff approach, which included various instruments, became well known, although some of Orff s ideas, such as improvisation and physical exercise, were initially unfamiliar. More important than the Orff approach was the in-depth teaching at the Klemetti Institute of the Hungarian ear training method known as the Kodály method. Many course participants were among those launching specialist music classes in schools, and the method became the foundation for music teaching in many such schools. The Klemetti Institute was also a pioneer in organising orchestra camps for young people. The Klemetti Institute promoted Finnish music culture and played an important role in the continuing music education of primary school teachers. Keywords: adult education, Grundtvigian philosophy, popular enlightenment, Klemetti Institute, Kodály method, choir singing, choir conducting, music history, music education, music culture, music camp, Orff approach, Orff-Schulwerk, Orivesi Institute, instrument teaching, free popular education, communality, solo singing, voice production

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From the Soviet point of view the actual substance of Soviet-Finnish relations in the second half of 1950s clearly differed from the contemporary and later public image, based on friendship and confidence rhetoric. As the polarization between the right and the left became more underlined in Finland in the latter half of the 1950s, the criticism towards the Soviet Union became stronger, and the USSR feared that this development would have influence on Finnish foreign policy. From the Soviet point of view, the security commitments of FCMA-treaty needed additional guarantees through control of Finnish domestic politics and economic relations, especially during international crises. In relation to Scandinavia, Finland was, from the Soviet point of view, the model country of friendship or neutrality policy. The influence of the Second Berlin Crisis or the Soviet-Finnish Night Frost Crisis in 1958-1959 to Soviet policy towards Scandinavia needs to be observed from this point of view. The Soviet Union used Finland as a tool, in agreement with Finnish highest political leadership, for weakening of the NATO membership of Norway and Denmark, and for maintaining Swedish non-alliance. The Finnish interest to EFTA membership in the summer of 1959, at the same time with the Scandinavian countries, seems to have caused a panic reaction in the USSR, as the Soviets feared that these economic arrangements would reverse the political advantages the country had received in Finland after the Night Frost Crisis. Together with history of events, this study observes the interaction of practical interests and ideologies, both in individuals and in decision-making organizations. The necessary social and ideological reforms in the Soviet Union after 1956 had influence both on the legitimacy of the regime, and led to contradictions in the argumentation of Soviet foreign policy. This was observed both in the own camp as well as in the West. Also, in Finland a breakthrough took place in the late 1950's: as the so-called counter reaction lost to the K-line, "a special relationship" developed with the Soviet Union. As a consequence of the Night Frost Crisis the Soviet relationship became a factor decisively defining the limits of domestic politics in Finland, a part of Finnish domestic political argumentation. Understood from this basis, finlandization is not, even from the viewpoint of international relations, a special case, but a domestic political culture formed by the relationship between a dominant state, a superpower, and a subordinate state, Finland.

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As the resistance of bacteria to conventional antibiotics has become an increasing problem, new antimicrobial drugs are urgently needed. One possible source of new antibacterial agents is a group of cationic antimicrobial peptides (CAMPs) produced by practically all living organisms. These peptides are typically small, amphipathic and positively charged and contain well defined a-helical or b-sheet secondary structures. The main antibacterial action mechanism of CAMPs is considered to be disruption of the cell membrane, but other targets of CAMPs also exist. Some bacterial species have evolved defence mechanisms against the harmful effects of CAMPs. One of the most effective defence mechanisms is reduction of the net negative charge of bacterial cell surfaces. Global analysis of gene expression of two Gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus, was used to further study the stress responses induced by different types of CAMPs. B. subtilis cells were treated with sublethal concentrations of a-helical peptide LL-37, b-sheet peptide protegrin 1 or synthetic analogue poly-L-lysine, and the changes in gene expression were studied using DNA macroarrays. In the case of S. aureus, three different a-helical peptides were selected for the transcriptome analyses: temporin L, ovispirin-1 and dermaseptin K4-S4(1-16). Transcriptional changes caused by peptide stress were examined using oligo DNA microarrays. The transcriptome analysis revealed two main cell signalling mechanisms mediating CAMP stress responses in Gram-positive bacteria: extracytoplasmic function (ECF)sigma factors and two-component systems (TCSs). In B. subtilis, ECF sigma factors sigW and sigM as well as TCS LiaRS responded to the cell membrane disruption caused by CAMPs. In S. aureus, CAMPs caused a similar stress response to antibiotics interfering in cell wall synthesis, and TCS VraSR was strongly activated. All of these transcriptional regulators are known to respond to several compounds other than CAMPs interfering with cell envelope integrity, suggesting that they sense cell envelope stress in general. Among the most strongly induced genes were yxdLM (in B. subtilis) and vraDE (in S. aureus) encoding homologous ABC transporters. Transcription of yxdLM and vraDE operons is controlled by TCSs YxdJK and ApsRS, respectively. These TCSs seemed to be responsible for the direct recognition of CAMPs. The yxdLM operon was specifically induced by LL-37, but its role in CAMP resistance remained unclear. VraDE was proven to be a bacitracin transporter. We also showed that the net positive charge of the cell wall affects the signalrecognition of different TCSs responding to cell envelope stress. Inactivation of the Dlt system responsible for the D-alanylation of teichoic acids had a strong and differential effect on the activity of the studied TCSs, depending on their functional role in cells and the stimuli they sense.

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Bone is a mineralized tissue that enables multiple mechanical and metabolic functions to be carried out in the skeleton. Bone contains distinct cell types: osteoblasts (bone-forming cells), osteocytes (mature osteoblast that embedded in mineralized bone matrix) and the osteoclasts (bone-resorbing cells). Remodelling of bone begins early in foetal life, and once the skeleton is fully formed in young adults, almost all of the metabolic activity is in this form. Bone is constantly destroyed or resorbed by osteoclasts and then replaced by osteoblasts. Many bone diseases, i.e. osteoporosis, also known as bone loss, typically reflect an imbalance in skeletal turnover. The cyclic adenosine monophosphate (cAMP) and the cyclic guanosine monophosphate (cGMP) are second messengers involved in a variety of cellular responses to such extracellular agents as hormones and neurotransmitters. In the hormonal regulation of bone metabolism, i.e. via parathyroid hormone (PTH), parathyroid hormone-related peptide (PTHrp) and prostaglandin E2 signal via cAMP. cAMP and cGMP are formed by adenylate and guanylate cyclases and are degraded by phosphodiesterases (PDEs). PDEs determine the amplitudes of cyclic nucleotide-mediated hormonal responses and modulate the duration of the signal. The activities of the PDEs are regulated by multiple inputs from other signalling systems and are crucial points of cross-talk between the pathways. Food-derived bioactive peptides are reported to express a variety of functions in vivo. The angiotensin-converting enzymes (ACEs) are involved in the regulation of the specific maturation or degradation of a number of mammalian bioactive peptides. The bioactive peptides offer also a nutriceutical and a nutrigenomic aspect to bone cell biology. The aim of this study was to investigate the influence of PDEs and bioactive peptides on the activation and the differentiation of human osteoblast cells. The profile of PDEs in human osteoblast-like cells and the effect of glucocorticoids on the function of cAMP PDEs, were investigated at the mRNA and enzyme levels. The effects of PDEs on bone formation and osteoblast gene expression were determined with chemical inhibitors and siRNAs (short interfering RNAs). The influence of bioactive peptides on osteoblast gene expression and proliferation was studied at the mRNA and cellular levels. This work provides information on how PDEs are involved in the function and the differentiation of osteoblasts. The findings illustrate that gene-specific silencing with an RNA interference (RNAi) method is useful in inhibiting, the gene expression of specific PDEs and further, PDE7 inhibition upregulates several osteogenic genes and increases bALP activity and mineralization in human mesenchymal stem cells-derived osteoblasts. PDEs appear to be involved in a mechanism by which glucocorticoids affect cAMP signaling. This may provide a potential route in the formation of glucocorticoid-induced bone loss, involving the down-regulation of cAMP-PDE. PDEs may play an important role in the regulation of osteoblastic differentiation. Isoleucine-proline-proline (IPP), a bioactive peptide, possesses the potential to increase osteoblast proliferation, differentiation and signalling.

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The RASCALS expedition spent over three weeks at the Summit camp research station near the top of the Greenland Ice Sheet during polar summer 2010. During this time, detailed measurements of the physical and optical properties of Arctic perennial snow were carried out concurrently with snow albedo and reflectance measurements. Favorable weather conditions during the campaign enabled the collection of a large dataset on Arctic snow albedo and associated quantities for use in developing and validating remote sensing algorithms for snow albedo using satellites. This report provides a description of the measurements and conditions during the campaign. RASCALS-retkikunnan tehtävä oli tutkia Grönlannin mannerjäätikön lumen fysikaalisia ja optisia ominaisuuksia sekä Auringon valon vuorovaikutusta lumen kanssa. Retikunta vietti hieman yli kolme viikkoa mannerjäätikön keskellä sijaitsevalla Summit Camp-tutkimusasemalla tehden mittauksia. Sääolot suosivat kampanjaa, jonka seurauksena onnistuttiin keräämään laaja ja monipuolinen tietoaineisto mannerjäätikön lumen pintakerroksesta ja eritoten lumen heijastavuuden (albedon)käyttäytymisestä. Aineisto on hyödyllinen kehitettäessä ja varmennettaessa lumen albedon kaukokartoitusmenetelmiä satelliiteilla.